YC-SCAN2 July 2025 Webinar

Transcript

• 00:07People are
• 00:09screaming, and so we'll give
• 00:11them a few,
• 00:12minutes. But
• 00:13in the meanwhile,
• 00:15I just wanna take the
• 00:16opportunity
• 00:16to,
• 00:18to welcome,
• 00:19doctor Emma Johnson.
• 00:21Emma,
• 00:23is a PhD,
• 00:25and she's an assistant professor
• 00:27at WashU and has a
• 00:28joint appointment,
• 00:30in psychological and brain sciences.
• 00:34Emma's research,
• 00:36centers
• 00:37on unraveling,
• 00:38the genetic
• 00:39architecture
• 00:41of substance use and addiction
• 00:43and how these intersect with,
• 00:46psychiatric conditions,
• 00:48including schizophrenia,
• 00:50suicidal behaviors,
• 00:53and also chronic pain.
• 00:55She applies statistical population and
• 00:58evolutionary genetic methods
• 01:00to large scale,
• 01:02genome wide association studies.
• 01:04Her work has included cross
• 01:06ancestry
• 01:07genetics,
• 01:08genetic analysis of schizophrenia,
• 01:11cannabis use disorder, and, tobacco,
• 01:15and smoking and addiction.
• 01:18She's done meta analysis of
• 01:19GWAS data on cannabis use
• 01:21disorder, which is published in
• 01:23Lancet Psychiatry.
• 01:25She's a key analyst,
• 01:27within the psychiatric genomics consortium
• 01:30substance use
• 01:31disorders working group,
• 01:34and she also collaborates
• 01:36in the collaborative
• 01:37study on the genetics of
• 01:39alcoholism.
• 01:41Emma has received a number
• 01:42of awards, which I'm not
• 01:43going to,
• 01:45to to talk about, but
• 01:46she's really well funded from,
• 01:49NIDA, from NIAAA,
• 01:51from the, Brain and Behavior
• 01:53Foundation,
• 01:54and also the American Foundation
• 01:56of Suicide Prevention. So,
• 01:59without further ado, I I'm
• 02:01gonna let Emma
• 02:04begin our presentation.
• 02:05Based on feedback from the
• 02:07previous webinars that we've had
• 02:09in the recent past,
• 02:11a number of folks have
• 02:12asked whether we could make
• 02:14it more interactive. And and
• 02:16so I asked Emma whether
• 02:18she'd be willing to
• 02:20kind of stop at the
• 02:21fifteen minute mark to take
• 02:23questions
• 02:24and to allow people to,
• 02:25you know, comment or ask
• 02:27questions. So Emma has graciously
• 02:29agreed to do that. So,
• 02:30Emma, thanks.
• 02:32And it's great having you.
• 02:34So take it away.
• 02:37Thank you so much.
• 02:40Let's see. It looks like
• 02:42I'm not able to share
• 02:43yet. Okay. There we go.
• 02:53K. Sorry. Suddenly, my mouse
• 02:55doesn't seem to be working.
• 02:59Alright. There we go.
• 03:02Okay.
• 03:12I think you all can
• 03:13see my slides. Does that
• 03:14look good? Yes. Okay.
• 03:17Awesome. Thank you.
• 03:19Thank you so much for
• 03:20that very kind introduction.
• 03:22I
• 03:23am going to try to
• 03:24keep an eye on time
• 03:25and stop every fifteen minutes
• 03:28or so,
• 03:29for questions.
• 03:30I will,
• 03:32be shrinking
• 03:34the videos, like, the the
• 03:36thumbnails,
• 03:36just so I can see
• 03:37my slides, but please feel
• 03:39free to speak up and
• 03:40interrupt me, if you do
• 03:41have a question at any
• 03:42point, but I will try
• 03:44to
• 03:44to pause.
• 03:47Thank you so much again
• 03:48for having me today. I'm
• 03:49really excited to talk about
• 03:51some,
• 03:52preliminary
• 03:52findings
• 03:53related to epigenetic differences in
• 03:55placental tissue
• 03:57associated with cannabis use during
• 03:59pregnancy.
• 04:01And I, don't have any,
• 04:03disclosures to report.
• 04:08So as that kind introduction
• 04:10mentioned, my work has primarily
• 04:11focused on trying to understand
• 04:13the genetics
• 04:14of substance use behaviors and
• 04:16substance use disorders. And that's
• 04:18not really,
• 04:20the work that I'm gonna
• 04:21be presenting today, but I
• 04:22think it's a a helpful
• 04:23place to start.
• 04:26So when I'm talking about
• 04:27substance use behaviors, I'm talking
• 04:29about studying
• 04:30behaviors that are complex and
• 04:32polygenic.
• 04:33And what I mean by
• 04:34complex is that,
• 04:36their behavior is influenced by
• 04:37both our genes and our
• 04:39environment.
• 04:42And by polygenic, I just
• 04:43mean that there's no one
• 04:44gene that causes the development
• 04:46of cannabis use disorder, but
• 04:48rather there are many genes
• 04:49and genetic variants all across
• 04:51our genome
• 04:52that influence,
• 04:54someone's risk for developing cannabis
• 04:56use disorder, for example.
• 05:00One way that we can
• 05:02study the genetics of substance
• 05:03use behaviors and a, a
• 05:05method that I've used in
• 05:07my work, is something called
• 05:08a genome wide association study.
• 05:12At its most basic, in
• 05:13a GWAS,
• 05:14we are simply recruiting cases
• 05:16with,
• 05:17whichever, you know, trait or
• 05:19phenotype that we're interested in
• 05:20studying, for example, a substance
• 05:22use disorder,
• 05:23and then we're recruiting controls.
• 05:27And we're comparing,
• 05:29small
• 05:30differences in our in the
• 05:32DNA of these cases and
• 05:33controls, so at the level
• 05:34of single base pair changes
• 05:37or single nucleotide
• 05:38polymorphisms.
• 05:42And if we compare these
• 05:44small differences in DNA across
• 05:46the genome, we can then
• 05:47visualize
• 05:48the results of this comparison
• 05:51in something called a Manhattan
• 05:52plot, an example of which
• 05:54I'm showing here.
• 05:56This was
• 05:57one of the first really
• 05:58large scale
• 06:00GWAS of alcohol dependence.
• 06:02However you might notice,
• 06:03this didn't really look like
• 06:05the skyline of Manhattan at
• 06:06this point. It maybe looked
• 06:07a little bit more like
• 06:08the skyline of St. Louis.
• 06:11But in this Manhattan plot
• 06:12you can see that the,
• 06:14associations between genetic variants or
• 06:17these single nucleotide polymorphisms,
• 06:20those are distributed
• 06:22based on physical position across
• 06:24the genome along the x
• 06:25axis
• 06:26and then
• 06:28their position on the, oops,
• 06:29on the y axis indicates
• 06:31how strongly that particular variant
• 06:33is associated with,
• 06:35the trait being studied, in
• 06:36this case, alcohol dependence.
• 06:38So we can see, in
• 06:40this example that there's a
• 06:41region on chromosome four
• 06:43that was very strongly associated
• 06:45with,
• 06:46risk for alcohol dependence. In
• 06:48this case, this is a
• 06:49gene related to the metabolization
• 06:51of alcohol.
• 06:55So we have performed, GWAS
• 06:57of cannabis use disorder.
• 06:59This was a a GWAS
• 07:01published in twenty twenty in
• 07:02Lancet Psychiatry,
• 07:04and we identified,
• 07:05two genomic loci here that
• 07:07were associated with risk of
• 07:08cannabis use disorder.
• 07:10Since then, an even larger
• 07:12study has been published. This
• 07:13was a study led by,
• 07:15Dan Levy and Joel Galerter,
• 07:18which,
• 07:19included many more cases than
• 07:20our twenty twenty GWAS, and
• 07:22we were able to identify
• 07:23many more
• 07:24genomic loci that were associated
• 07:26with cannabis use disorder.
• 07:31So we know that genetic
• 07:32factors can influence our likelihood
• 07:34to engage in substance use
• 07:36behaviors,
• 07:36our risk for developing substance
• 07:39use disorders.
• 07:42But the work I'm gonna
• 07:43talk about today is really
• 07:44more concerned with how substance
• 07:46use may affect our genome
• 07:48or more accurately,
• 07:50our epigenome and transcriptome.
• 07:54While our DNA sequence remains
• 07:56static from birth, our epigenome
• 07:59is dynamic so it can
• 08:00change,
• 08:01throughout our lifetime,
• 08:03and these epigenetic changes can
• 08:05actually influence the
• 08:08expression
• 08:08of of different genes.
• 08:10And there are different ways
• 08:11that this can happen. So,
• 08:13for example, histone modifications
• 08:15can increase or decrease gene
• 08:17expression
• 08:18by changing how tightly wound
• 08:20the DNA is around nucleosomes
• 08:23and how,
• 08:24easily accessible that DNA is
• 08:26for transcription factors
• 08:28related to gene expression.
• 08:30The addition
• 08:31of methyl groups to, certain
• 08:33spots in the DNA can
• 08:35also repress gene expression,
• 08:38again, by preventing transcription factors
• 08:40from from accessing the promoter
• 08:43region of genes.
• 08:46And environmental
• 08:47exposures like cannabis use can
• 08:50induce some of these changes
• 08:51in DNA methylation.
• 08:53And so the work that
• 08:54I'll present today really focuses
• 08:56on, this mechanism of,
• 08:59DNA methylation changes and how
• 09:01that, may be related to
• 09:03prenatal cannabis exposure.
• 09:08So I introduced a genome
• 09:10wide association earlier and that,
• 09:12you know, many of you
• 09:13may already be familiar with
• 09:14that. I think that's kind
• 09:15of helpful background for thinking
• 09:17about an epigenome wide association
• 09:19study or an EWAS,
• 09:20where here the question is
• 09:22slightly different. Instead of asking
• 09:24what genetic variants, what genes
• 09:27are associated with,
• 09:29cannabis use, for example,
• 09:30here we're asking,
• 09:32are there,
• 09:34regions of our genome where
• 09:36cannabis use has changed
• 09:38or is associated with changes
• 09:40in DNA methylation?
• 09:42So I'm showing here an
• 09:44example of an EWAS,
• 09:46from Fong and colleagues that
• 09:47was published in twenty twenty
• 09:49four where they identified,
• 09:52four spots in the genome
• 09:53that were associated with differential
• 09:55DNA methylation
• 09:56according to lifetime cannabis use.
• 10:02Actually, this is probably a
• 10:03good place to stop maybe.
• 10:05Are there any questions so
• 10:06far?
• 10:10I maybe see something in
• 10:12the chat.
• 10:15Oh, no. Thank you, Wendy.
• 10:17Okay. Well, hearing no questions,
• 10:19feel free to interrupt me,
• 10:21but I will keep going
• 10:22for now.
• 10:25So I wanted to take
• 10:26a step back first and
• 10:27talk a little bit about
• 10:28the changes that we're seeing
• 10:30in cannabis use, at least
• 10:31in the US.
• 10:34Many of you may know
• 10:34this already, but as legalization
• 10:36has expanded,
• 10:37cannabis use, has continued to
• 10:40rise in the United States.
• 10:42So in this figure on
• 10:43the left here, we can
• 10:44see increases in both, twelve
• 10:46months
• 10:47use and daily use,
• 10:49from two thousand eight to
• 10:50twenty twenty three.
• 10:52And this is, across both
• 10:55early or younger adults as
• 10:57well as, older adults.
• 11:00People generally report using cannabis
• 11:02to,
• 11:03help with their anxiety,
• 11:05to help with, pain as
• 11:07well as other issues,
• 11:08And many people who use
• 11:09cannabis won't experience any adverse
• 11:12effects,
• 11:13but some people may. And
• 11:15these potential issues can include
• 11:16symptoms of cannabis use disorder,
• 11:19even acute psychosis
• 11:20or cannabinoid hyperemesis syndrome. So
• 11:23there can be serious
• 11:25adverse side effects,
• 11:26for some folks who use
• 11:27cannabis.
• 11:31We're not only seeing increases
• 11:33in cannabis use in the
• 11:34general population, but we're also
• 11:35seeing increases
• 11:37in pregnant individuals.
• 11:39So in this,
• 11:41figure shown here,
• 11:43we're seeing from two thousand
• 11:44two to twenty sixteen
• 11:46decreases
• 11:47in, prenatal use of alcohol
• 11:49and cigarettes,
• 11:50but a slight increase
• 11:52in prenatal use of marijuana.
• 11:56Many people who, have used
• 11:58marijuana in their lifetime
• 11:59continue to use it during
• 12:00pregnancy,
• 12:01and this is because many
• 12:02of these individuals report believing
• 12:04that cannabis use is relatively
• 12:06safe to use while pregnant.
• 12:10However, we also know that
• 12:11the potency of cannabis, so
• 12:13the proportion of THC
• 12:15in cannabis samples, has also
• 12:17steadily increased over the years.
• 12:21So if we look, the
• 12:23proportion of THC and cannabis
• 12:25samples,
• 12:26it's essentially quadrupled,
• 12:28from nineteen ninety five to
• 12:30twenty twenty two.
• 12:32So the cannabis that people
• 12:33were using in the past
• 12:34is not the same cannabis
• 12:35that people are using today.
• 12:37It's has,
• 12:39a much higher level of
• 12:40THC
• 12:41in many cannabis samples.
• 12:47I'm showing here, another a
• 12:49figure from another study
• 12:51published in twenty nineteen that,
• 12:53compared
• 12:55cannabis use, from two thousand
• 12:57two, two thousand three with
• 12:58cannabis use from twenty sixteen
• 13:00to twenty seventeen.
• 13:02And, again, we're seeing increases
• 13:03in cannabis use not only
• 13:05in,
• 13:07nonpregnant women, but also in
• 13:08pregnant women and especially during
• 13:10that first trimester.
• 13:14On the right, I'm showing,
• 13:16an excerpt from an article
• 13:17from The New York Times,
• 13:18back in twenty seventeen,
• 13:21which just includes some kind
• 13:22of interesting,
• 13:24anecdotal
• 13:25quotes from someone who was
• 13:26interviewed.
• 13:27And this person says that
• 13:28her OB GYN was concerned
• 13:30about whether she was using
• 13:31alcohol or tobacco
• 13:33while she was pregnant,
• 13:34but they weren't really concerned
• 13:36with her marijuana use
• 13:38and said that since it
• 13:39hadn't been studied that much,
• 13:41they couldn't advise her really
• 13:43one way or the other
• 13:44whether it was safe or
• 13:45unsafe.
• 13:46She also says that,
• 13:48because marijuana is natural and
• 13:50everyone's using it, she felt
• 13:52like it was probably okay
• 13:53to use.
• 13:55So this seems to be
• 13:56kind of the general attitude
• 13:58around cannabis use during pregnancy
• 13:59right now.
• 14:02But in part because of
• 14:03these increases in potency,
• 14:05it's really important for us
• 14:06to study prenatal cannabis use
• 14:08and whether it might be
• 14:09affecting
• 14:10birth outcomes as well as
• 14:12both short and long term
• 14:13child behaviors.
• 14:18In terms of birth outcomes,
• 14:20there's relatively
• 14:22solid evidence that,
• 14:23low birth weight is associated
• 14:25with prenatal cannabis use. So
• 14:27as an example, I'm showing
• 14:28a figure here from a
• 14:29a meta analysis
• 14:31that did find
• 14:32higher risk of low birth
• 14:34weight in people who use
• 14:35cannabis prenatally.
• 14:38In terms of effects on
• 14:40child behavior,
• 14:41the literature is a little
• 14:42bit more mixed. So findings
• 14:43tend to be inconsistent.
• 14:45They've tended to come from
• 14:47smaller samples,
• 14:48and there are different confounders
• 14:50that can be really hard
• 14:51to,
• 14:52to tease apart.
• 14:57I wanted to highlight a
• 14:58couple of studies.
• 14:59The first one, this was
• 15:01a a study done using
• 15:03the adolescent brain cognitive development
• 15:04sample, which is a very
• 15:06large
• 15:07longitudinal study of children across
• 15:09the United States.
• 15:11And this is a paper
• 15:12led by Sarah Paul, here
• 15:14in the psychological and brain
• 15:16sciences department at WashU, mentored
• 15:18by Ryan Bogdan.
• 15:20And Sarah found that prenatal
• 15:22cannabis exposure was associated with
• 15:25a number of different,
• 15:27outcomes, including,
• 15:29higher BMI, lower cognitive function,
• 15:32as well as some behavioral
• 15:34outcomes,
• 15:35including externalizing
• 15:37problems
• 15:38and greater likelihood of attention
• 15:40problems.
• 15:41And importantly, she found this,
• 15:43these differences both in women
• 15:46who,
• 15:48use cannabis,
• 15:50both
• 15:51prior to when they they
• 15:52knew that they were pregnant
• 15:53as well as after they
• 15:54knew that they were pregnant.
• 15:58A paper led by David
• 16:00Behringer,
• 16:01looked at,
• 16:02a later follow-up, a later
• 16:04time point in the same
• 16:06ABCD study,
• 16:07and he found very similar,
• 16:10associations
• 16:11as Sarah did. So he
• 16:12saw that prenatal cannabis use
• 16:14was associated with,
• 16:16for example, conduct problems, ADHD
• 16:18problems,
• 16:19stress, and obsessive compulsive problems
• 16:21in these children.
• 16:27That might be another good
• 16:28place to pause.
• 16:31It looked like there might
• 16:32be a couple of
• 16:34questions. Yeah. I think,
• 16:36and Nikola had a question.
• 16:38Nikola, do you wanna ask
• 16:39a question, and then Joel
• 16:41has a question too?
• 16:45Hi, Emma.
• 16:46Yeah. I was wondering what
• 16:48issue I mean, was these
• 16:49questions referred to the to
• 16:51the first part of this
• 16:52talk. So what issue was
• 16:53used for the EWOS?
• 16:56That's a great for the
• 16:57g also for the GWOS?
• 17:00Yeah. That's a great question.
• 17:02For that EWAS, I was
• 17:03not a coauthor on that
• 17:04paper, so I would have
• 17:05to double check that.
• 17:08I thought that was done
• 17:09in blood,
• 17:12but I will I will
• 17:13have to double check that.
• 17:19Let's see. I see a
• 17:20question from Joel as well.
• 17:22But for the EWAS? Oh,
• 17:24yeah. For the EWAS, I
• 17:25believe it was in blood,
• 17:26but I will have to
• 17:27double check that for you.
• 17:28I for the GWAS, you
• 17:29you are not sure, but
• 17:30for the GWAS. But do
• 17:32you figure
• 17:33that the the
• 17:34the change in methylation is
• 17:35a consequence
• 17:37of the
• 17:38cannabis use?
• 17:40Is that a consequence?
• 17:41Sorry. Could you repeat that?
• 17:43Is it is Is that
• 17:45the is the the change
• 17:46in the methylation is a
• 17:48consequence of a of a
• 17:49cannabis use?
• 17:51So, yeah, that's another great
• 17:53question. I think that's something
• 17:54that,
• 17:56you know, that EWAS had
• 17:57to kind of tease apart.
• 17:58Was that actually a consequence
• 17:59of the cannabis use?
• 18:01And one way you can
• 18:02do that is look at
• 18:03whether these,
• 18:05these methylation sites overlap with
• 18:08the sites from the GWAS.
• 18:10If I remember correctly, in
• 18:12that EWAS, I don't think
• 18:13they overlap with,
• 18:15GWAS loci. And so it
• 18:17does seem like, you know,
• 18:18that would be evidence that
• 18:19this is potentially,
• 18:21a consequence of cannabis use,
• 18:24but that is a little
• 18:25bit hard to tease apart
• 18:26from,
• 18:28you know, for example, other
• 18:29substance use, other substance exposures,
• 18:31things like that. So so
• 18:33my point is that it
• 18:34doesn't mark the the
• 18:37the,
• 18:38how to say, it doesn't
• 18:39say that,
• 18:41that those those logos are
• 18:43risk factor for cannabis use
• 18:44disorder.
• 18:47In,
• 18:48if I'm understanding If I
• 18:49mean, if you if you
• 18:50are not if you do
• 18:51the GWAS for for a
• 18:52neuropsychiatric disorders and you see,
• 18:53you know, over sixty thousand
• 18:55people that there is a
• 18:56a a logo or a
• 18:57gene, which is basically Mhmm.
• 18:59As a variant, you can,
• 19:00you know, with some, you
• 19:02know, statistical analysis, you can
• 19:04say that, that that that
• 19:05variant is associated to the
• 19:06disease. So that to the,
• 19:08for example, to to autism
• 19:09or schizophrenia.
• 19:10In this case, the the
• 19:11increase in the methylation specific
• 19:13locus is a consequence of
• 19:15of the of of the
• 19:17fact that people smoke marijuana
• 19:18or it's be or or
• 19:19it's a it's a it's
• 19:22it's a it's a can
• 19:23can be,
• 19:24taught as a risk factor
• 19:26for for a for a
• 19:26cannabis use disorder. That's my
• 19:28question. Yeah.
• 19:31Yeah. I mean I mean,
• 19:32I think I think it's
• 19:33hard to That doesn't mean
• 19:34to be that's hard to
• 19:35tease apart. I think one
• 19:37way to look at that
• 19:37is just whether it's overlapping
• 19:39with those GWAS
• 19:40loci.
• 19:41You know, if it does,
• 19:42then,
• 19:43that would be evidence that
• 19:44it might be reflecting more
• 19:45of a a risk factor
• 19:46rather than a consequence. But,
• 19:49but I think if you
• 19:49don't see that overlap, I
• 19:51would interpret that as as
• 19:52evidence for it being more
• 19:53of a consequence
• 19:55driven locus.
• 19:58Does that make sense? Yeah.
• 20:01I think clarified
• 20:03that the EVAS was done
• 20:04in blood.
• 20:05Yeah. Thank you for looking
• 20:07that up. And then Joel
• 20:08has a question.
• 20:11Yeah. You pointed out that
• 20:13the THC content of cannabis
• 20:15has roughly quadrupled
• 20:17over
• 20:18relatively short period of time.
• 20:21My question is to what
• 20:22extent does that translate to
• 20:24increased THC exposure in a
• 20:26user?
• 20:27So for example, if someone
• 20:29switches from drinking beer to
• 20:31drinking
• 20:32whiskey or something with a
• 20:33higher alcohol content,
• 20:35they may always drink to
• 20:36about the same level of
• 20:37intoxication.
• 20:39Is that the case also
• 20:41with cannabis use, or are
• 20:43people really
• 20:44becoming exposed to much higher
• 20:46levels of THC now?
• 20:49That's a really good question.
• 20:50I don't actually know if
• 20:51I know the answer to
• 20:52that. Cyril, do you have
• 20:53an idea?
• 20:55It's a great question, Joel.
• 20:57Many people have argued that
• 20:59people are just titrating the
• 21:01amount of THC
• 21:03they need to get to
• 21:04the desired level of high.
• 21:06But if you look at
• 21:07other outcomes and not just
• 21:09acute intoxication,
• 21:10it looks like
• 21:12if you're using higher
• 21:16products that contain higher THC
• 21:18levels,
• 21:19you're also more likely to
• 21:20be to become addicted to,
• 21:23to develop cannabis use disorder,
• 21:26because
• 21:26of the higher potency
• 21:28THC. So it it's a
• 21:30great question. I don't think
• 21:31anyone has actually looked at
• 21:33whether
• 21:34the,
• 21:35the the levels of THC
• 21:37that someone's exposed to when
• 21:38they're using these high potency
• 21:40products is any different
• 21:42from
• 21:44people who are using lower,
• 21:45potency products
• 21:47back in the seventies, eighties,
• 21:49and nineties. It's a great
• 21:50question.
• 21:56And then I see one
• 21:57more question in the chat
• 21:58about, is that low birth
• 22:00weight for gestational
• 22:01age?
• 22:03Yes. I believe so.
• 22:09Yeah. Wanna continue?
• 22:11Yeah. If there are no
• 22:12other questions for now, I'll
• 22:14keep going, but,
• 22:15thank you.
• 22:17Alright.
• 22:21Where were we?
• 22:23Right. So,
• 22:25you know, we see some
• 22:26evidence
• 22:27of prenatal cannabis use having
• 22:28an effect on these birth
• 22:30outcomes and potentially child
• 22:32behaviors later in life,
• 22:34but more research is really
• 22:36needed on the mechanisms behind
• 22:38these relationships
• 22:40and whether the in utero
• 22:41environment, the epigenome, the transcriptome
• 22:43might potentially be a mediating
• 22:45factor of these relationships.
• 22:49So what I mean by
• 22:50this is we can think
• 22:51about a direct path where
• 22:53if the mother is, you
• 22:54know, using cannabis while she's
• 22:56pregnant, the THC can pass
• 22:58directly from the mother's blood
• 22:59through the placenta to the
• 23:00fetus,
• 23:01and it can be exposed
• 23:02to THC
• 23:04that way. But we can
• 23:05also think about how the
• 23:07placenta might be kind of
• 23:08a a mediating factor and
• 23:10sort of an indirect pathway
• 23:12because the THC can bind
• 23:13to endocannabinoid
• 23:14receptors
• 23:16in the placenta.
• 23:18And,
• 23:20this endocannabinoid
• 23:21system is really important,
• 23:23in early pregnancy. It's important
• 23:24for embryo implantation
• 23:26as well as the formation
• 23:27and development of the placenta.
• 23:31Cannabinoid receptors are expressed in
• 23:33the placenta, and endocannabinoid levels
• 23:35vary with gestational
• 23:37age.
• 23:38And it's been shown that
• 23:39prenatal cannabis use, is associated
• 23:42with altered placental circulation
• 23:44as well as other potentially,
• 23:47harmful effects on the placenta
• 23:49during fetus development. And so
• 23:51it may be that,
• 23:53there's also this kind of
• 23:54indirect pathway where prenatal cannabis
• 23:57use affects the formation and
• 23:58the structure and function of
• 24:00the placenta,
• 24:01and that can then in
• 24:02turn,
• 24:03affect the the fetal development.
• 24:09There hasn't been,
• 24:11a ton of studies yet
• 24:12on how prenatal cannabis use
• 24:14might affect,
• 24:15the epigenome or transcriptome in
• 24:17placental tissue
• 24:19and then linking that with
• 24:20offspring behavior.
• 24:22But I did wanna point
• 24:23out a neat study from
• 24:24Rompaul and colleagues that was
• 24:26published in twenty twenty
• 24:28one. They studied,
• 24:30thirty maternal cannabis users. This
• 24:32was self report of cannabis
• 24:34use either prenatal or postnatal,
• 24:36so kind of,
• 24:38just around pregnancy,
• 24:39and compared them to,
• 24:41just over a hundred controls.
• 24:44And what they found was
• 24:45this maternal cannabis use,
• 24:47was associated with anxiety, aggression,
• 24:50hyperactivity
• 24:51in the children at three
• 24:52to six years of age.
• 24:55In the placental tissue, they
• 24:57found reduced gene expression specifically
• 24:59in immune
• 25:00related gene networks.
• 25:03And,
• 25:04these gene networks were then
• 25:05correlated with that increase in
• 25:07anxiety,
• 25:08in the children.
• 25:10So these are really, intriguing
• 25:12findings,
• 25:15but we really need more
• 25:16research in this area.
• 25:20And so the work that
• 25:21I'll present today is based
• 25:22on the cannabis use during
• 25:23early life and development study
• 25:25or the cuddle study.
• 25:27This is a a study
• 25:28that was designed to assess
• 25:30the effects of prenatal cannabis
• 25:31use on baby's brain and
• 25:33behavior.
• 25:34And so the study recruited
• 25:35pregnant people with a lifetime
• 25:37history of cannabis use. So
• 25:40everyone in this study has
• 25:41used cannabis
• 25:42during their lifetime.
• 25:45Cases and controls simply differ
• 25:47on whether they continue to
• 25:48use cannabis
• 25:49during pregnancy.
• 25:55I won't spend too much
• 25:56time on this table because
• 25:57I think it's a little
• 25:58bit hard to read, but
• 25:59this should give you kind
• 26:00of a sense of what
• 26:02this sample looks like. These
• 26:03were all people recruited,
• 26:05in St. Louis here at
• 26:06WashU.
• 26:08I'm highlighting,
• 26:09some
• 26:11some numbers that I think
• 26:12might be of particular interest.
• 26:14As I mentioned earlier, everyone
• 26:16in the sample has used
• 26:17cannabis in their lifetime,
• 26:20and most of, the cases
• 26:21and controls
• 26:22had used cannabis in the
• 26:24two years prior to their
• 26:26pregnancy.
• 26:29In the cases,
• 26:32those individuals use marijuana at
• 26:34least four times or more
• 26:35a week.
• 26:36After awareness of pregnancy, eleven
• 26:38percent of them did. So
• 26:39we have some people who
• 26:40are still,
• 26:41using marijuana quite regularly during
• 26:43their pregnancy.
• 26:46In terms of what cannabis
• 26:48use looks like in this
• 26:49sample,
• 26:50about fifteen percent of these
• 26:52participants report, using cannabis by
• 26:55smoking it as a joint,
• 26:57whereas most of the sample
• 26:58reports using it,
• 27:00through smoking blunts.
• 27:03There's a little bit of
• 27:04vaping.
• 27:06About ten percent use cannabis,
• 27:08via edibles,
• 27:09and then four percent use
• 27:11cannabis through other forms.
• 27:14They also reported on, why
• 27:16they're using cannabis during pregnancy,
• 27:18and around fifty percent of
• 27:19them use it for, nausea
• 27:21and vomiting.
• 27:22Forty percent use it to
• 27:24manage their anxiety or stress
• 27:25levels.
• 27:26Around fifty percent are using
• 27:28it for appetite regulation.
• 27:30And then, the rest are
• 27:32using it for sleep difficulties,
• 27:34pain,
• 27:35and other motives.
• 27:40Some preliminary data from this
• 27:42Cuddl study
• 27:44suggests that we are seeing
• 27:45effects of prenatal cannabis exposure
• 27:47on birth weight.
• 27:49So this is very consistent
• 27:50with the the literature that
• 27:52I showed earlier in this
• 27:53talk. So we are seeing
• 27:54an effect of prenatal cannabis
• 27:56exposure on,
• 27:57lower birth weight
• 27:59relative to gestational age.
• 28:01And then we're also seeing
• 28:03some evidence for higher,
• 28:05externalizing
• 28:06behaviors in the children
• 28:08who were exposed,
• 28:09to prenatal cannabis.
• 28:14So we're seeing some, interesting
• 28:16preliminary findings from this study.
• 28:19And,
• 28:20the the data that I'll
• 28:21present now is from a
• 28:22twenty twenty, BDRF grant
• 28:25that we received to collect
• 28:27placental tissue from the CAUTL
• 28:28study and analyze DNA methylation
• 28:31signatures in this tissue.
• 28:33So we collected, DNA methylation
• 28:35data on one hundred and
• 28:36ninety two of these samples,
• 28:39one hundred and twenty one,
• 28:40with prenatal cannabis use and
• 28:42seventy one without prenatal cannabis
• 28:44use. And, I wanted to
• 28:46highlight my two co mentors
• 28:47on this grant, Ryan Bogdan
• 28:49and Danny Fallon.
• 28:52And so the main questions,
• 28:54that we were seeking to
• 28:55answer with this grant or
• 28:56this project
• 28:57was, is prenatal cannabis use
• 28:59associated with
• 29:01differences in DNA methylation in
• 29:02the placental tissue?
• 29:04And do these epigenetic variations
• 29:06mediate
• 29:07any associations that we're seeing
• 29:09between prenatal cannabis use and
• 29:11these child outcomes?
• 29:16I see that there might
• 29:17be a question in the
• 29:18chat.
• 29:21Is this controlling for other
• 29:23drug use? Is that relating
• 29:24to the Rompalla et al
• 29:26study?
• 29:28Yeah. That was for me,
• 29:29Emma. That was
• 29:31the
• 29:32the the low birth weight
• 29:34Mhmm. In your Puddl sample,
• 29:36was that controlling for other
• 29:37drug use and other,
• 29:39you know,
• 29:40confounding
• 29:41potential confounders like
• 29:43lifestyle and socioeconomic
• 29:45status, etcetera?
• 29:47Yes. Yes.
• 29:49That was. So I'll talk
• 29:50a little bit more. Right.
• 29:52Actually, this is a good
• 29:53time to talk about it.
• 29:54So in this study, we
• 29:55tried to exclude
• 29:58individuals who reported using tobacco,
• 30:00to try to, you know,
• 30:01kind of separate these associations
• 30:03as much as possible. But,
• 30:06we did perform urine drug
• 30:08screening tests on participants, and
• 30:10we were seeing that,
• 30:12you know, some who had
• 30:13reported not using tobacco were
• 30:15testing positive for cotinine exposure.
• 30:18We think some of that
• 30:19is related to,
• 30:21the the mode of cannabis
• 30:23use. So, again, a lot
• 30:24of these folks are using
• 30:26cannabis via blunts.
• 30:28So it's being wrapped in
• 30:30tobacco paper, and so we
• 30:31think that might be
• 30:33contributing to some of these
• 30:34positive cotinine,
• 30:36tests. So, anyway, all that
• 30:38to say, yes. That was
• 30:39controlling for,
• 30:41exposure to cotinine or tobacco.
• 30:44And I believe we're also
• 30:47accounting for,
• 30:48for SES.
• 30:51I can't remember the exact
• 30:52measure we used, but, yeah,
• 30:54that was accounting for,
• 30:56potential confounders.
• 31:01Any other questions at this
• 31:02point?
• 31:03I I think that's,
• 31:05that finding seems to be
• 31:06consistent with some studies done
• 31:08in the UK,
• 31:10looking at birth weight in
• 31:12in children born to Rastafarian
• 31:14mothers. Oh, interesting.
• 31:17That's an old fairly old
• 31:18study. That was one of
• 31:20the, findings.
• 31:23Yeah. It seems like this
• 31:24association between,
• 31:27let's see if I can
• 31:28go back, between
• 31:29prenatal cannabis use and low
• 31:30birth weight seems to be
• 31:32fairly consistent
• 31:33in the literature.
• 31:36So I think that's one
• 31:37that we're feeling, you know,
• 31:39we're feeling pretty good about
• 31:40that one.
• 31:44Let's see. Okay.
• 31:45There's no questions.
• 31:47I'll keep going for now,
• 31:49but we can pause again
• 31:50in a minute.
• 31:53So in our study for
• 31:54these epigenetic,
• 31:55analyses,
• 31:56the DNA methylation data was
• 31:58collected using the Illumina EPIC
• 32:00array,
• 32:01and we perform pretty standard
• 32:03quality control procedures.
• 32:06For the actual EWAS, we're
• 32:07testing the association
• 32:09of methylation
• 32:10at each site with prenatal
• 32:12cannabis years.
• 32:13And then the analysis I'll
• 32:15present today, we're controlling for
• 32:16cotinine exposure,
• 32:18from the urine drug screening
• 32:20test,
• 32:21as well as age and
• 32:22sample plate.
• 32:24And then I'm also gonna
• 32:25present some follow-up analysis to
• 32:26this EWAS, looking at differentially
• 32:28methylated regions of the genome
• 32:31as well as gene enrichment
• 32:32analysis.
• 32:37So, again, I just wanted
• 32:38to present what the the
• 32:40motivations for using marijuana look
• 32:42like,
• 32:44in our subsample
• 32:45of individuals,
• 32:47who were included in this,
• 32:50EWAS.
• 32:51So the patterns within the
• 32:52subset are largely reflecting what
• 32:54we're seeing in the full
• 32:55cuddle sample. Most of these
• 32:57participants are reporting using to
• 32:58help with, nausea or to
• 33:00help with their appetite,
• 33:03but we're also seeing many
• 33:04report using marijuana to help
• 33:06with anxiety or stress levels,
• 33:09sleep, and managing pain.
• 33:15Here is the Manhattan plot
• 33:17from our EWAS of prenatal
• 33:18cannabis use.
• 33:20Again, this was in a
• 33:21sample of a hundred and
• 33:22ninety two participants.
• 33:24A hundred and twenty one
• 33:25of those participants had prenatal
• 33:26cannabis use and seventy one,
• 33:29did not have prenatal cannabis
• 33:30use.
• 33:31So as we might expect,
• 33:33with a sample size like
• 33:35this, we didn't find any,
• 33:38CpG sites that were significantly
• 33:41associated at the epigenome
• 33:43wide
• 33:43level correcting for all these
• 33:45different tests.
• 33:46And, again, this was controlling
• 33:47for codenine exposure.
• 33:52I wanted to zoom in
• 33:53and highlight just a couple
• 33:54of these. I'm not picking
• 33:55these two for any particular
• 33:56reason,
• 33:58but I just think it's
• 33:59kind of interesting to, actually
• 34:01look at the data a
• 34:02little bit more closely.
• 34:03So you can see at
• 34:04these two individual sites,
• 34:06again, these didn't quite reach
• 34:08the,
• 34:09significance threshold when we correct,
• 34:11across the genome,
• 34:13but we are seeing some
• 34:15differences here in terms of
• 34:16prenatal cannabis use.
• 34:19So that's being shown on,
• 34:21the right side of these
• 34:22two panels,
• 34:23comparing that to people with
• 34:25no prenatal cannabis use. And
• 34:27at both of these sites,
• 34:28we are tending to see
• 34:30higher levels of methylation on
• 34:32average
• 34:33compared to,
• 34:35the group of people with
• 34:36with no pre prenatal cannabis
• 34:38use.
• 34:39One other thing you'll know
• 34:40is that the the range
• 34:42of
• 34:43methylation
• 34:44differs across these different sites.
• 34:46So for example, we're seeing
• 34:47a much tighter,
• 34:49range, much less variation in
• 34:51terms of the proportion of
• 34:53methylation
• 34:54at this site on the
• 34:55left compared to that site
• 34:57on the right.
• 35:01We then looked at differentially
• 35:03methylated regions across the genome.
• 35:06So this is, if you're
• 35:08familiar with GWAS,
• 35:09this seems kind of somewhat
• 35:10similar to gene based analyses.
• 35:13We're here. We're combining
• 35:15we're basically aggregating the signals
• 35:17across these individual CPG sites,
• 35:21and sort of combining these
• 35:23signals,
• 35:23when the CpG sites are
• 35:25close together
• 35:26to look, more at specific
• 35:28genomic regions rather than individual
• 35:31site variation.
• 35:32And we did find some
• 35:34significant
• 35:35different differentially methylated regions across
• 35:37the genome.
• 35:39I then took these, the
• 35:41sites within these regions,
• 35:43into something called the EWAS
• 35:45Atlas.
• 35:46And,
• 35:47in the EWAS Atlas, you
• 35:48can see,
• 35:50you know, based on, prior
• 35:51published EWAS, what these different
• 35:53sites have been,
• 35:55associated with.
• 35:56And so we saw that
• 35:57these differentially methylated regions have
• 35:59been previously implicated in studies
• 36:01of,
• 36:02rheumatoid arthritis as well as
• 36:04maternal alcohol consumption,
• 36:06airway inflammation,
• 36:08asthma, preterm birth,
• 36:10cancer and autism spectrum disorder,
• 36:12BMI,
• 36:14smoking, cognitive function, air pollution,
• 36:16and childhood stress.
• 36:18So this was really interesting
• 36:20to see.
• 36:21First of all, it's interesting
• 36:22to see some of these
• 36:23inflammation
• 36:24related phenotypes pop up.
• 36:26It was also interesting to
• 36:27see things like cognitive function
• 36:29and BMI,
• 36:30which I mentioned earlier,
• 36:32that Sarah Paul found
• 36:34related to prenatal cannabis use
• 36:35in her study in the
• 36:37ABCD study.
• 36:39So we're seeing a lot
• 36:40of these,
• 36:43child outcomes that have been
• 36:45implicated across multiple different studies,
• 36:48these inflammation related phenotypes
• 36:50as well as,
• 36:52different substance use related phenotypes
• 36:53like alcohol consumption and smoking.
• 36:59This might be another good
• 37:00place to stop. I see
• 37:01a
• 37:02oh, nope. Not a question.
• 37:04Okay.
• 37:05Alright.
• 37:07I will keep going.
• 37:09So next, I,
• 37:12sorted
• 37:13the effects from our EWAS
• 37:15according to their effect size,
• 37:18as well as how strongly
• 37:19they were associated with prenatal
• 37:21cannabis years.
• 37:23And so if we just
• 37:24take,
• 37:25these top nominally significant
• 37:28sites,
• 37:29again, this isn't,
• 37:30significant when we correct for
• 37:32the epigenome wide level significance,
• 37:34but,
• 37:35these are nominally significant.
• 37:38And I tested whether these
• 37:40specific sites were or genes
• 37:42at these sites were enriched
• 37:44for any specific
• 37:45cell types or biological pathways.
• 37:49And we see enrichment in,
• 37:51the amygdala nucleus, the b
• 37:53cells, the placenta,
• 37:54and excitatory
• 37:55neurons,
• 37:56some different biological pathways,
• 37:59including the regulation of cell
• 38:00cycles
• 38:01and neuroblast
• 38:02proliferation,
• 38:04as well as an association
• 38:05with respiratory system diseases.
• 38:08So again, this is preliminary
• 38:10data. We didn't find any,
• 38:12epigenome wide significant
• 38:14sites, but we are seeing
• 38:15some potentially interesting
• 38:17differentially methylated regions of the
• 38:19epigenome
• 38:21as well as enrichment in,
• 38:23potentially interesting cell types, tissues,
• 38:25and biological pathways.
• 38:29As I mentioned earlier,
• 38:31the regions that we found
• 38:32have been previously
• 38:33implicated in phenotypes like cognition,
• 38:36preterm birth, and inflammation.
• 38:41And,
• 38:42we did find that some
• 38:43of these genes were enriched
• 38:44for signaling pathways, respiratory disease,
• 38:47And so these may potentially
• 38:49be, different mechanisms by which
• 38:51prenatal cannabis use is influencing
• 38:53child behavioral outcomes.
• 38:57So in terms of what's
• 38:58next,
• 38:59for this study as well
• 39:00as future studies,
• 39:02the first thing I want
• 39:03to look at is whether
• 39:05these differentially methylated,
• 39:07sites or regions are overlapping
• 39:09with the GWAS loci. So
• 39:11this came up earlier when
• 39:12we were talking about how
• 39:14can we differentiate whether this
• 39:15is really,
• 39:16representing a consequence
• 39:18of cannabis use or cannabis
• 39:20exposure,
• 39:21or is this maybe just
• 39:22overlapping with,
• 39:24preexisting genetic liability for cannabis
• 39:26use? And so that's something
• 39:27that we wanna look at
• 39:29by testing whether these sites
• 39:30are overlapping with,
• 39:33sites that pop up in
• 39:34genetic studies of cannabis use.
• 39:38We're also interested in testing
• 39:40whether these epigenetic signals
• 39:42are potentially mediating associations
• 39:44between prenatal cannabis use
• 39:47and child behavioral outcomes in
• 39:48the Cuddl study. For example,
• 39:50those,
• 39:51associations that we're seeing with
• 39:52externalizing
• 39:54behaviors.
• 39:57And then,
• 39:59you know, as I mentioned
• 39:59earlier, this is really preliminary
• 40:01data.
• 40:02So,
• 40:04you know, this isn't a
• 40:05huge sample, and it would
• 40:06be really nice if we
• 40:07could potentially replicate this, in
• 40:09another study or meta analyze,
• 40:12with other studies out there.
• 40:13So
• 40:14the healthy brain and child
• 40:16development or the HPCD
• 40:17study,
• 40:18is collecting placental tissue.
• 40:21This is a study of,
• 40:22I believe, over seven thousand,
• 40:25mothers and children.
• 40:27Around twenty five percent of
• 40:29the sample will have substance
• 40:30use.
• 40:31So, you know, it's not
• 40:33an exact match for the
• 40:34Cuddl study,
• 40:35in terms of recruitment, but
• 40:37it could be a potentially
• 40:38useful replication sample and maybe
• 40:40useful for meta analysis.
• 40:42We're also looking at the,
• 40:44PACE consortium, the Pregnancy and
• 40:46Childhood Epigenetics
• 40:48consortium as another potential opportunity
• 40:50for some sort of meta
• 40:52analysis here.
• 40:57And, with that, I would
• 40:59like to thank,
• 41:00support from BBRF for this
• 41:02project as well as all
• 41:03of my collaborators
• 41:04and, especially the CUDL PIs,
• 41:06Arbana Agarwal and Cynthia Rogers,
• 41:09the Cuddl participants and staff,
• 41:11and,
• 41:12support from NIDA.
• 41:18Thanks. I guess I'll take
• 41:19any other questions now.
• 41:23Great. Thank
• 41:24you. Questions? It's open to
• 41:26the floor.
• 41:32So if while we're waiting
• 41:34for others to drum up
• 41:35questions,
• 41:39can you comment on dose
• 41:41response?
• 41:43Did you have enough fine
• 41:45grain data on
• 41:47on Yeah. Cannabis exposure?
• 41:50That's a good question.
• 41:53That is something I would
• 41:54really like to look at.
• 41:55We we do have that
• 41:57data,
• 41:58to some extent.
• 42:01You know, so we did
• 42:02have participants self report,
• 42:05how much how frequently they
• 42:06were using cannabis at each
• 42:08trimester of pregnancy.
• 42:10And so that would that's
• 42:12something that would be really
• 42:13interesting to look at, I
• 42:14think, especially if we could
• 42:15kind of separate out these
• 42:17effects
• 42:18by trimester. I don't know
• 42:20if our sample size,
• 42:22you know, is really going
• 42:24to allow some of that,
• 42:25but,
• 42:28but that would be really
• 42:29interesting to to look at
• 42:30a measure of
• 42:32heaviness of
• 42:33use instead of this this
• 42:35dichotomous
• 42:35cannabis use versus no cannabis
• 42:37use during pregnancy.
• 42:40And related to that,
• 42:43you know, given that cannabis
• 42:45has so many
• 42:47distinct compounds,
• 42:49can you comment on
• 42:51do you have any thoughts
• 42:52about CBD versus THC?
• 42:57I
• 42:58yeah.
• 42:59That's another good question.
• 43:01I don't know that I
• 43:02have any thoughts on that
• 43:03right now.
• 43:07Yeah. I mean, I wish
• 43:08we I wish we had
• 43:10more data on, you know,
• 43:11potency and the makeup of
• 43:14the cannabis that that our
• 43:16participants are using.
• 43:20Yeah. I think it's kind
• 43:20of tough to get at
• 43:21some of that. But,
• 43:25yeah, but if you have
• 43:26any thoughts, I would love
• 43:27to hear them.
• 43:28Sure. Sure.
• 43:30I I should let you
• 43:31know that someone on the,
• 43:32who's attending this, your your
• 43:34webinar is actually doing some
• 43:36experimental work in nonhuman primates,
• 43:40and it'd be interesting for
• 43:41the two of you to
• 43:42to Yeah.
• 43:44To connect.
• 43:45I don't know if you
• 43:46want to say anything,
• 43:47about that, Nicola.
• 43:52Yeah. No. I I think
• 43:53it's,
• 43:56for the great talk. And,
• 43:58you know, I I have
• 43:59many ideas. For example, you
• 44:01know, I'm I was wondering
• 44:02if if you had considered
• 44:03to
• 44:04I mean, for sure, we
• 44:05will connect, actually. So so
• 44:08so I'm sure that that
• 44:09we will have, many points
• 44:11in common.
• 44:13Just just a last question
• 44:15for this talk. I was
• 44:16wondering if you consider to
• 44:17use the the,
• 44:20to to put in culture
• 44:21IPS cells from people,
• 44:23from children,
• 44:24predatally as opposed to,
• 44:26cannabis,
• 44:27to cannabinoids
• 44:28and maybe, you know, generate
• 44:30organoids and see if there
• 44:31is a you can see
• 44:32still, you can see those
• 44:34epigenetic
• 44:35modification in a in a
• 44:36in a in the in
• 44:38in a
• 44:39in this derived cells. Yeah.
• 44:41I mean, I think that
• 44:42would be very cool. That
• 44:43would be cool. Right? Yeah.
• 44:45That's the dream.
• 44:48Yeah. I I think that
• 44:48would be really cool. But
• 44:50but dream dream I mean,
• 44:51it's not like I mean,
• 44:52it can be it's doable.
• 44:53Why it's a dream, you
• 44:54think?
• 44:56I mean, it's a dream
• 44:56to find something probably, but
• 44:58it's a doable from from
• 44:59from the
• 45:00from the technical doable. Right?
• 45:02I mean, it's Yeah. Definitely.
• 45:04Much I mean, logistically, you
• 45:05need to recruit the the
• 45:07the children. So and they
• 45:08were all all I mean
• 45:09but but Yeah. Taking care
• 45:11of a
• 45:13a funding perspective.
• 45:15But,
• 45:16yeah.
• 45:17But, no. I think that
• 45:18would be that would be
• 45:20really,
• 45:21really interesting, I think. Because
• 45:23if if you find it
• 45:23is a you know, alteration
• 45:25of methylation in a in
• 45:27a specific loci,
• 45:28once in organoids, I mean,
• 45:29that would be actually I
• 45:31mean, you can do a
• 45:32functional analysis. Right? You know?
• 45:34I think. Yeah.
• 45:37Yeah. We should talk more.
• 45:39Okay. Thank you. Absolutely. For
• 45:41sure. Thanks.
• 45:42I see a a raised
• 45:44hand. There's a question in
• 45:45the chat, and there's, I
• 45:47suppose,
• 45:47someone
• 45:48who's raised their hand. Is
• 45:50that
• 45:53I'll go ahead and start.
• 45:54Emma, thank you very much.
• 45:55This is Kent Vrana from
• 45:57Penn State.
• 45:58I wonder if you could
• 45:59comment on the rationale
• 46:01for using
• 46:02peripheral blood
• 46:04for EWAS studies as a
• 46:06surrogate marker for anything that
• 46:08might be going on in
• 46:09circuitry in the brain,
• 46:10especially if you're going to
• 46:12correlate it
• 46:13later with behavior in the
• 46:15offspring?
• 46:18Yeah.
• 46:19That's a great question. So
• 46:20I think you're referring to
• 46:21that, the earlier
• 46:22EWAS that I presented,
• 46:25at the beginning where they
• 46:26were using that peripheral blood.
• 46:28That that's correct.
• 46:30Yeah.
• 46:31You know, I,
• 46:34actually don't know off the
• 46:35top of my head how
• 46:36well,
• 46:37those markers in peripheral blood
• 46:39overlap with with what has
• 46:41maybe been found in other
• 46:42tissues.
• 46:45You know, I don't know
• 46:45that they overlap
• 46:47very well, but I think
• 46:48it's,
• 46:49to some extent
• 46:50kind of logistics and and
• 46:52what they could collect,
• 46:54for those different studies that
• 46:55went into that meta analysis.
• 46:58So I don't think, you
• 46:59know, peripheral blood is ideal.
• 47:02And that's why, you know,
• 47:03we are really excited to
• 47:04look at placental tissue in
• 47:05particular,
• 47:07you know, as it is
• 47:08potentially so
• 47:10important for fetal development and,
• 47:12you know, can maybe have
• 47:14effects on on later child
• 47:15behavior.
• 47:16We don't quite know that
• 47:17yet. But,
• 47:19but I think based on
• 47:20that Rompalla study, it does
• 47:22seem like there's potential
• 47:23that placental tissue could be
• 47:25mediating this. So
• 47:27I don't know if that
• 47:28fully answers your question,
• 47:30but
• 47:31but I am glad that
• 47:32we could look specifically at
• 47:33placental tissue.
• 47:36Yeah. It's I've learned a
• 47:37lot, and I just wrestle
• 47:38with it because
• 47:40and even in your placental
• 47:41study,
• 47:43what what outcome and how
• 47:44would you correlate a change
• 47:46in in the behavior of
• 47:47the placenta or or its
• 47:49physiology with later outcomes?
• 47:53Yeah.
• 47:54I mean,
• 47:55it is just a correlation
• 47:57at the end of the
• 47:57day. You know, and I
• 47:58think we can try to
• 47:59control for as many confounding
• 48:01factors as possible, but it
• 48:03is kind of hard to
• 48:05to tie
• 48:06whatever we're finding specifically to,
• 48:10you know, changes in placental,
• 48:14gene expression and function and
• 48:15development with with these later
• 48:17child behaviors. But
• 48:20yeah. Yeah. It's a good
• 48:21question.
• 48:23There's a question from Angie
• 48:25Fritz.
• 48:27Do you I'll let you
• 48:28read it, or do you
• 48:28want me to read it
• 48:29out to the group? Oh,
• 48:31sure.
• 48:33Or, Angie, I see you've
• 48:34unmuted. I don't know if
• 48:35you wanna read your question
• 48:36maybe.
• 48:40I think this is related
• 48:41to talking about mediation between
• 48:43prenatal cannabis use and child
• 48:44behavioral outcomes. Would we also
• 48:47include the development of neurodevelopmental
• 48:49disorders
• 48:50in that relationship?
• 48:53Yes. Yeah. I think, we're
• 48:55certainly interested in whether prenatal
• 48:56cannabis use,
• 48:58also affects
• 49:00neurodevelopmental
• 49:01disorders in children.
• 49:03There's a question from
• 49:05Elizabeth Halvorsen.
• 49:11Oh, just a comment. Oh,
• 49:13thank you. And then there's
• 49:14a question from,
• 49:16from Mohini Ranganathan.
• 49:20Yeah. So this question is
• 49:22asking about sex dimorphic effects
• 49:24and in utero exposure.
• 49:27That's a really interesting question.
• 49:28That's something I haven't explored.
• 49:31So I don't really have
• 49:32a good answer for you
• 49:33now. But,
• 49:35yeah, that's potentially really interesting
• 49:37and and something we should
• 49:38look at.
• 49:41I I have a question
• 49:42that that may be a
• 49:43public health relevance. So
• 49:45do you have can you
• 49:46comment on whether,
• 49:48the timing of exposure
• 49:52matters in order to be
• 49:53able to advise women who
• 49:55are
• 49:56using cannabis. So that is
• 49:57to say, if,
• 50:00if we believe that if
• 50:01you stop
• 50:03using cannabis, say,
• 50:05soon as you're informed and
• 50:06it's only restricted to
• 50:08the early part of the
• 50:09first trimester, is that
• 50:11going to have
• 50:13fewer consequences
• 50:15relative to if you continue
• 50:16smoking throughout pregnancy?
• 50:20That's a great question. That's
• 50:21really important. I mean, I,
• 50:24you know, I don't know.
• 50:25I'm not a clinician. I
• 50:26should say that. But, you
• 50:28know, I think based on
• 50:29what
• 50:30Sarah Paul found, at least,
• 50:32in the ABCD study,
• 50:34you know, it seems like,
• 50:37you know, the effects on,
• 50:40BMI, cognitive function,
• 50:42these different child behaviors like
• 50:44attention problems.
• 50:46The associations between prenatal cannabis
• 50:48use and these different problems
• 50:49were attenuated,
• 50:51but they they were still
• 50:52there in the women who
• 50:54use cannabis,
• 50:56only before they knew that
• 50:58they were pregnant. So only
• 50:59in that you know, those
• 51:01really early stages of pregnancy.
• 51:04We're still seeing these associations
• 51:06with increased
• 51:08child attention problems,
• 51:10greater BMI, lower cognitive function.
• 51:12And so
• 51:14it does seem like there's
• 51:16there's not any period of
• 51:17pregnancy that is without risk.
• 51:21You know, and so those
• 51:22problems might be less if
• 51:23you stop using cannabis after
• 51:26after you realize that you're
• 51:27pregnant, but,
• 51:28it does seem like there's
• 51:29still a risk at those
• 51:30early stages of pregnancy.
• 51:35K. Great.
• 51:41You know, there there's also,
• 51:44their recommendations
• 51:45often from dispensaries where bud
• 51:47tenders are advising,
• 51:50pregnant women to,
• 51:53to use certain kinds of
• 51:55cannabis.
• 51:56Mhmm. Have you had any
• 51:58success in in educating,
• 52:02you know, bartenders and dispensaries
• 52:04in your community?
• 52:08No.
• 52:09I have heard of that.
• 52:13You know, we
• 52:14yeah. That's a great question.
• 52:16We haven't,
• 52:19you know, really tried to
• 52:20take this into that realm
• 52:22of actually talking to,
• 52:24dispensaries in the community, but
• 52:27but I think that's a
• 52:27really interesting idea and could
• 52:29potentially have
• 52:30major public health impact. So
• 52:33yeah.
• 52:34I see another question in
• 52:36the chat and then also
• 52:37a raised hand.
• 52:39This question in the chat
• 52:40is asking about, is there
• 52:41a description of cannabis withdrawal
• 52:43and neonates similar to opioid
• 52:45withdrawal?
• 52:47I
• 52:48I feel bad. I don't
• 52:49actually know the answer to
• 52:49this.
• 52:51Someone else might.
• 52:53But
• 52:54I I don't I don't
• 52:55know. I don't think it's
• 52:56been studied. Mhmm. But
• 53:00it'll be interesting. Yeah. That
• 53:02withdrawal
• 53:03in general is highly variable
• 53:05in its expression. You know?
• 53:07Some people experience
• 53:09significant withdrawal and others don't
• 53:11experience
• 53:12much.
• 53:13So I and I don't
• 53:14know if anyone's studying that.
• 53:16So Yeah. Interesting question.
• 53:20Someone else to see a
• 53:21hand raised.
• 53:22Yeah.
• 53:24Yes. Thanks so much for
• 53:26your presentation, Emma.
• 53:28I had a question concerning
• 53:30the study where you,
• 53:33processed the placenta samples,
• 53:36for the EWAS.
• 53:38Did you
• 53:39like, what part of the
• 53:41tissue
• 53:42was used? Because I'm assuming
• 53:43we you know, there's a
• 53:45decidua, the villi, and, you
• 53:47know, if we're making inferences,
• 53:48did you guys,
• 53:51were you guys specific about
• 53:52the tissue
• 53:55sample that you used?
• 53:57Yeah. We are using the
• 53:59villus tissue
• 54:00for for this for these
• 54:02EWAS samples.
• 54:04We took more tissue samples,
• 54:06from different regions of the
• 54:07placenta, but for this EWAS,
• 54:09we're using the villus tissue.
• 54:12Okay.
• 54:13And I had
• 54:15a a second question
• 54:16whether for the
• 54:19EWAS
• 54:20analysis,
• 54:21were was there any comparison
• 54:23between I'm just curious. Moms
• 54:25that,
• 54:27this is, like, their first
• 54:28pregnancy versus this is their
• 54:30second or third pregnancies.
• 54:32Are there any, you know,
• 54:34variations with that,
• 54:36if they were to be
• 54:37grouped into,
• 54:39the number of pregnancies?
• 54:44Another great question. I don't
• 54:45know that we've really looked
• 54:47at that yet.
• 54:49You know, I know we
• 54:50have that data,
• 54:51but I don't know that
• 54:52anyone in Cuddl has looked
• 54:53at whether,
• 54:56you know, whether it is
• 54:57the first or a later
• 54:58pregnancy, whether that's associated with
• 55:00cannabis use or,
• 55:02any of these outcomes that
• 55:03we're looking at. But,
• 55:05yeah, that that would be
• 55:07interesting to look at. Do
• 55:08you have any
• 55:10hypotheses? I'm curious.
• 55:14I'm not
• 55:15I'm not you know, like,
• 55:17I think,
• 55:18not having that clinical background,
• 55:20obviously,
• 55:21not much.
• 55:22But I think the reason
• 55:23why I asked the question
• 55:25was,
• 55:26I'm under the assumption that,
• 55:29you know, probably during the
• 55:30first pregnancy, there's not as
• 55:32much, you know, consumption and
• 55:34then they become more addicted.
• 55:36Is this,
• 55:38phenotype that we see more
• 55:39pronounced,
• 55:41for example, and are the
• 55:43effects on the babies,
• 55:45you know,
• 55:46reflecting that as well?
• 55:48Yeah. Yeah. And sorry to
• 55:50put you on the spot
• 55:51there.
• 55:52No worries. That was not
• 55:53nice. But,
• 55:54no. I think that's a
• 55:55really interesting question and just
• 55:57something that we haven't looked
• 55:58at yet. But,
• 56:01yeah, yeah, we might take
• 56:02a look at that.
• 56:04Okay.
• 56:05I I have a question,
• 56:07Emma. Thank you.
• 56:09To,
• 56:10could could your findings be
• 56:12explained by
• 56:14just the effects of,
• 56:17the burning by byproducts of
• 56:20plant material
• 56:21and not specifically to THC
• 56:24or which I'm which I'm
• 56:26assuming you're suggesting that this
• 56:28is related to
• 56:29the cannabinoids present in
• 56:32in cannabis. So could this
• 56:33be from,
• 56:34you know, nonspecific,
• 56:36chemicals that are released when
• 56:38you combust
• 56:39plant material?
• 56:43I
• 56:43yeah. I mean, I
• 56:45guess I guess it could.
• 56:50Yeah.
• 56:52That's an interesting question. I'm
• 56:53not sure how we would
• 56:54get at that except maybe
• 56:55looking across the different modes
• 56:57of use.
• 56:58We don't have many people,
• 57:01you know, that were using,
• 57:02like, edibles or,
• 57:05nonsmoking
• 57:06modes of use. But,
• 57:11yeah, you know, potentially, maybe
• 57:13we could look within those
• 57:14samples and see. It's just
• 57:16kind of a sensitivity analysis.
• 57:18I noticed that you had
• 57:19only about eight percent who
• 57:21were using edibles. And
• 57:23is it those is it
• 57:24that those eight percent were
• 57:26exclusively using edibles, or they
• 57:28were using edibles and
• 57:30other,
• 57:32products?
• 57:33Or nine percent. Yeah.
• 57:35So I think,
• 57:38I added these numbers up
• 57:39right before this talk because
• 57:40I wanna make sure. So
• 57:41I think this adds up
• 57:42to a hundred percent. And
• 57:44so,
• 57:45I believe this question asked
• 57:46about the most common mode
• 57:48of use, and so I
• 57:49think they could only select
• 57:50one for this Okay. Which
• 57:52kind of gets at your
• 57:53question.
• 57:55So I think those ten
• 57:56percent are are primarily using
• 57:58edible forms of cannabis.
• 58:02So that could be something,
• 58:03or maybe we can look
• 58:04specifically at those samples.
• 58:07And I suppose you if
• 58:08you compare,
• 58:10two samples of women who
• 58:12smoked tobacco
• 58:13and you find similar kinds
• 58:14of findings that might indicate
• 58:16that it's
• 58:16related to just the combustion
• 58:18of
• 58:19Yeah.
• 58:20Mhmm.
• 58:24Other questions?
• 58:25We have a minute two
• 58:28two messages. Let's see. And
• 58:30I see a hand up
• 58:31as well.
• 58:32Yes.
• 58:33Talida, do you have another
• 58:35question?
• 58:38Yes.
• 58:39I was curious to see,
• 58:40did you find any,
• 58:43differentially expressed,
• 58:45T cell signatures in the
• 58:47EOS? Because I know you'd
• 58:48mentioned the b cell, but
• 58:49I'm curious to see if,
• 58:51there's anything that came up
• 58:53for the t cells.
• 58:54I don't think we found
• 58:56anything related to t cells
• 58:57at this point, but,
• 59:01yeah, I don't think so.
• 59:02But
• 59:03but I can double check
• 59:04that.
• 59:05Okay. Okay. Yeah. Thanks.
• 59:07Yeah. I I asked because
• 59:09there is,
• 59:11studies have shown that at
• 59:12the second trimester,
• 59:14there is
• 59:16an increase in T cell
• 59:17population
• 59:18when they did the single
• 59:19cell analysis.
• 59:21B cell, not as much.
• 59:23That's why I was wondering
• 59:25what that can imply.
• 59:28Yeah. Yeah. That's interesting. We'll
• 59:30have to think about that.
• 59:32Oh, yeah. Thank you.
• 59:34So we are we are
• 59:35out of time, but, Emma,
• 59:36thank you very much. This
• 59:37is really great. I'm so
• 59:39glad that we were able
• 59:40to ask you questions on
• 59:42the fly during the presentation.
• 59:43It certainly made for a
• 59:45much more interactive experience, and
• 59:47this is really exciting work,
• 59:49and I hope that you
• 59:49and,
• 59:51Nicola can, you know, continue
• 59:53our discussions about your common
• 59:55interests. So thanks very much.
• 59:57Really appreciate
• 59:58it. Thank you so much.
• 59:59And I if it's okay,
• 01:00:00I was gonna pop my
• 01:00:02email on the chat, or
• 01:00:03maybe people already have it
• 01:00:04if there were questions that
• 01:00:06I didn't get to answer.
• 01:00:07Oh, that's fabulous. Thank you.
• 01:00:09Yeah. Let me do that
• 01:00:10now.
• 01:00:12Thank you so much for
• 01:00:13having me. This was really
• 01:00:14nice. You.
• 01:00:16Thank you. Thanks. Bye. Bye.