Active Motif's Podcast

In this episode of the Epigenetics Podcast, we caught up with Yael David from Memorial Sloan Kettering Cancer Center in New York to talk about her work on Effects of Non-Enzymatic Covalent Histone Modifications on Chromatin.  The David lab studies on non-enzymatic covalent modifications of Histones, including Histone glycation and citrullination. These modifications recognize metabolites that are produced in the cell and aid as a sensor for chromatin to quickly adapt to cellular changes. These unique modifications do not have a so-called erasing enzyme, which makes them terminal, rendering these sites inaccessible for further modifications such as methylation or acetylation.   A second area of research in the David lab is Histone H1. The lab has developed a new method to purify Histone H1, superior to the commonly used method of acid extraction which leads to degradation of Histone H1. This purification method enabled the lab to purify and characterize the functional properties of all Histone H1 variants.

In this episode of the Epigenetics Podcast, we caught up with Jason Buenrostro from Harvard University to talk about his work on developing biological tools to measure chromatin dynamics in single-cells. He explains how his lab uses these tools to study chromatin alterations in different cell types and disease states to uncover new mechanisms of gene regulation and their contribution to those diseases. In his first years of his research career Jason Buenrostro took a risk and just added an enzyme called Transposase to cells in a cell culture. What he saw on a subsequent agarose gel astonished him. He was able to recreate a nucleosomal ladder that he knew from experiments using MNase or DNase-Seq, however, without the tedious steps of optimization. In the following years he optimized that method and data analyzation into a method known today as ATAC-Seq. In recent years he was also able to bring ATAC-Seq to the next level and developed single cell ATAC-Seq (scATAC-Seq), and combining it with RNA-Seq in a mul

In this episode of the Epigenetics Podcast, we caught up with Karmella Haynes from Emory University to talk about her work on synthetic chromatin epigenetics. The Haynes lab focuses on the design of synthetic chromatin sensor proteins. The first one of this kind, the Polycomb Transcription Factor (PcTF), was published in 2011. It senses H3K27me3 and recruits effector proteins to the sites of this modification. This sensor can be brought into cancer cells to activate hundreds of silenced genes. The lab now focuses on characterizing the effects of these sensor proteins genome wide, and seeks to find a way to deliver those sensor into cancer cells, without affecting healthy cells. In this Episode we discuss how Karmella Haynes got into the field of Epigenetics, how she designed the PcTF sensor proteins, and the way she came to learn how important the right control experiments are. In the end we also discuss her activities to promote diversity and inclusion in science.   References Haynes, K. A., & S

In this episode of the Epigenetics Podcast, we caught up with Enrico Glaab from the University of Luxemburg to talk about his work on the development of integrative machine learning tools for neurodegenerative diseases. The work of Dr. Enrico Glaab focuses on neurodegenerative disorders like Parkinson’s and Alzheimer’s disease. In his group his team works on the development of software tools to analyze molecular, clinical and neuroimaging data for those diseases that can be used and applied easily by scientists and deliver publication ready figures. More recently, Enrico Glaab's group got interested in the influence of Epigenetics in Parkinson's and Alzheimer's disease. In this Episode we discuss how Enrico Glaab made the switch from wet-lab to becoming a bioinformatician and how he uses integrative machine learning tools to find approaches to not only cure but also be able to detect neurodegenerative diseases like Alzheimer's or Parkinson's early on.   References Enrico Glaab, Reinhard Schneider (2015)

In this episode of the Epigenetics Podcast, we caught up with Diane Dickel from Lawrence Berkeley National Laboratory to talk about her work on ultraconserved enhancers and enhancer redundancy. Diane Dickel and her co-workers study non-coding regions of the genome that harbor distant-acting transcriptional regulatory regions, called enhancers. Enhancers have been shown to be critical for normal embryonic development, implying evolutional conservation. Diane Dickel and her team try to identify and characterize enhancers at a genomic scale. Their efforts include the use of CRISPR/CAS9 to mutate enhancer sequences in order to understand sequence dependent functional relevance. In this episode we discuss the function of ultraconserved enhancers, what ultraconservation actually means, how enhancer redundancy works and how Diane Dickel dealt with a failed PhD project.   References Dickel, D. E., Ypsilanti, A. R., Pla, R., Zhu, Y., Barozzi, I., Mannion, B. J., Khin, Y. S., Fukuda-Yuzawa, Y., Plajzer-Frick, I.,

In this episode of the Epigenetics Podcast, we caught up with Sandra Hake from the Justus Liebig University in Giessen to talk about her work on variants of core histones and their role as modulators of chromatin structure and function. The overarching goal of Sandra Hake's research group is to understand how changes in chromatin structure and composition can influence various DNA-based processes, such as gene expression, repair of DNA damage, cell cycle progression, and genome stability. Their work deals with the study of histone variants which, together with DNA, represent the building blocks of the smallest chromatin components, the nucleosomes. They also investigate whether mutations and/or post-translational histone modifications and the deregulation of histone variant networks influence the emergence of diseases, especially the emergence of tumors. In this episode we discuss how Sandra Hake approaches the characterization and identification of novel histone variants like H3.3, H3.X and H3.Y, what it's

In this episode of the Epigenetics Podcast, we caught up with Déborah Bourc'his from L'Institut Curie in Paris to talk about her work on the role of DNA methylation in mammalian development. During her postdoc years Déborah Bourc'his was able to characterize DNMT3L, a protein with unknown function at that time. It turned out that this protein is the cofactor responsible for stimulating DNA methylation activity in both the male and the female germline. Later on she discovered a novel DNA methylation enzyme called DNMT3C, which was unknown because it was not properly annotated, there was no sign of expression, and it was only expressed in male fetal germ cells. Furthermore, this enzyme only evolved in rodents, as a defense against young transposons. In this episode we discuss the story behind how Déborah Bourc'his was able to discover and characterize the DNA methylation enzymes DNMT3L and DNMT3C and their role in mammalian development.   References R. Duffie, S. Ajjan, … D. Bourc’his (2014) The Gpr1/Zd

In this episode of the Epigenetics Podcast, we caught up with Axel Imhof from the Ludwig Maximilian University of Munich in Germany to talk about his work on the identification of chromatin associated proteins using mass spectrometry. As the head of the Proteomics Core Facility Axel Imhof collaborates with research groups around the world. In addition, in his own lab, he focuses on the assembly and composition of chromatin, how environmental metabolites influence epigenetic marks, and how chromatin factors can be used as markers for pathological states. In this episode we discuss what has changed in the field of mass spectrometry over the years, how Axel Imhof takes advantage of collaborations, how metabolites influence chromatin, and how he is helping to bring epigenetic profiling via mass spectrometry to the clinic.   References Bonaldi, T., Regula, J. T., & Imhof, A. (2003). The Use of Mass Spectrometry for the Analysis of Histone Modifications. In Methods in Enzymology (Vol. 377, pp. 111–130).

In this episode of the Epigenetics Podcast, we caught up with Steven Henikoff from the Fred Hutchinson Cancer Research Center in Seattle to talk about his work on Chromatin Profiling: From ChIP to CUT&RUN, CUT&Tag and CUTAC. In the last few years Steven Henikoff has been developing methods which profile the chromatin landscape by using enzyme tethering. The quest first started with ChEC-Seq, which improved on Uli Laemmli's method of Chromatin endogenous cleavage (ChEC) but used sequencing as a read-out rather than southern blotting. Next, Cleavage Under Targets & Release Using Nuclease (CUT&RUN) was developed by making a fusion protein of Protein A and micrococcal nuclease (MNase), making it possible to achieve antibody-targeted cleavage of chromatin fragments. And finally, Cleavage Under Targets & Tagmenation (CUT&Tag) was developed by using Transposase Tn5 instead of MNase, which adds sequencing adapters and fragments chromatin at the same time, streamlining the protocol even furthe

In this episode of the Epigenetics Podcast, we caught up with Charlotte Ling from Lund University in Sweden, to talk about her work on the role of DNA methylation in diabetes. Dr. Charlotte Ling investigates how epigenetics influences diabetes, a major age-related disease that affects millions of people around the world. She and her team identified CpG-SNPs and differentially methylated DNA in human pancreatic islets, associated with Type 2 Diabetes. In addition, she explored the impact of a six-month exercise intervention plan on DNA methylation and health in middle-aged diabetic men. Later-on, looking for useful applications for this knowledge, she determined blood-based biomarkers for diabetes and for successful treatment with Metformin, a common drug used for diabetes patients. In this episode we discuss how Charlotte Ling ended up in the field of diabetes, how the success of her work impacted her ability to go on vacations, and how the results of her work are now used to develop blood-based biomarkers

In this episode of the Epigenetics Podcast, we caught up with Monica Dus from the University of Michigan to talk about her work on nutriepigenetics and the effects of diet on behavior. The focus of Monica Dus and her team is to study the effect of sugar on the brain and how diet has an effect on behavior. The Dus lab takes a multidisciplinary approach to answer questions like "What causes animals to overeat if they consume foods rich in sugar, salt, and fat?" and "How does such a diet alter the basic physiology and biochemistry of the brain to promote food intake and weight gain?" By doing this, they showed recently that the Polycomb Repressive Complex 2 (PRC2) plays a role in reprogramming the sensory neurons of Drosophila Melanogaster, reducing sweet sensation and hence promoting obesity when flies are fed a high sugar diet. In response to that diet the binding of PRC2 to chromatin in sweet gustatory neurons is altered and reshapes the developmental transcriptional network. In this episode we discuss how

In this episode of the Epigenetics Podcast, we caught up with Céline Vallot from L'Institut Curie in Paris to discuss her work on investigating the dynamics of epigenetic plasticity in cancer with single cell technologies. During her Post-Doc years Céline Vallot worked on the inactive X chromosome. Using RNA-Seq she discovered a novel long noncoding RNA (lncRNA) called XACT. This lncRNA is expressed from and coats the active X chromosome in human pluripotent cells. Céline Vallot also showed that XACT is specific to humans and cannot be found in mice. After starting her own lab, Céline Vallot began to focus on Single Cell Epigenomics in Cancer. She and her team developed a high-throughput single-cell ChIP-seq approach which relies on a droplet microfluidics platform to profile the chromatin landscape of thousands of cells. By doing so they could show that a subset of cells within untreated drug-sensitive tumors share a common chromatin signature. This would have been impossible with common bulk approaches.

In this episode of the Epigenetics Podcast, we caught up with Margaret (“Peggy”) Goodell from Baylor College of Medicine in Houston, Texas to talk about her work on the epigenetic regulation of stem cell self-renewal and differentiation. Dr. Margret Goodell's laboratory focuses on how differentiation and self-renewal is regulated in hematopoietic stem cells (HSC). In the early stages of her research career, however, Dr. Goodell was able to develop a new method to purify stem cells. This method was based on the characteristic of stem cells to pump out the Hoechst dye that was used for the purification. In recent years, the focus of the lab has been to identify how HSCs decide whether to self-renew or differentiate. To get an answer to this question, the lab has performed genome-wide screens to find differentially expressed genes during the decision process. By doing that, they recently found that the DNA methyltransferase 3A (DNMT3A) was highly and specifically expressed in HSCs and that it is required for d

In this episode of the Epigenetics Podcast, we caught up with Dr. Keji Zhao from the National Heart, Lung, and Blood Institute at the National Institutes of Health in Bethesda, MD, to talk about his work on the genome-wide investigation of epigenetic marks and nucleosome positioning. Dr. Keji Zhao pioneered in the development of cutting-edge techniques in the field of epigenetics. Current methods at that time relied on DNA microarrays, however, Dr. Zhao wanted a more comprehensive and unbiased approach that would avoid the shortfalls of these array-based methods. Hence, he set out to develop new sequencing-based methods like ChIP-Seq and MNase-Seq with accompanying computational methods to analyze the huge amount of sequencing data that would be generated. Using the above-mentioned techniques, Dr. Zhao was able to show that histone deacetylases (HDACs) and histone acetyltransferases (HATs) were found at inactive and active genes, respectively, as previously thought. Surprisingly, he was also able to show th

In this episode of the Epigenetics Podcast, we caught up with Dr. Sarah Diermeier from the University of Otago in New Zealand to talk about her work on the role of long non-coding RNAs in tumor growth and treatment. Although only 1-2% of the human genome is transcribed into mRNAs that code for proteins, 75% of the genome is transcribed into non-coding RNAs. The function of these non-coding RNAs lie in the regulation of cellular processes and hence, offer the possibility of therapeutic intervention. Dr. Diermeier and her laboratory focus on a subset of these non-coding RNAs: the long non-coding RNAs (lncRNAs) that have been shown to play a role in breast and colorectal cancers. This interview discusses how the Diermeier lab uses state-of-the-art techniques to both answer fundamental questions about biological mechanisms and also for translational research approaches. We also touch upon Dr. Diermeier becoming mother during her first years being a PI and the challenges and opportunities faced while raising a c

In this episode of the Epigenetics Podcast, we caught up with Job Dekker from the University of Massachusetts Medical School to talk about his work on unraveling mechanisms of chromosome formation. In 2002, during graduate school, Job Dekker was the first author on the paper describing the chromosome conformation capture (3C) method, which revolutionized the field of nuclear architecture. In the 3C protocol, chromatin is crosslinked using formaldehyde and then digested using a restriction enzyme. After ligating the digested blunt ends of crosslinked DNA fragments together they can be analyzed using qPCR. In the next couple of years 3C was further developed and methods like 4C, 5C, and Hi-C were published. This led to the generation of genome-wide contact maps which helped understand the 3-D organization of the nucleus. Job Dekker’s research group is also part of the 4D Nucleome initiative, which is dedicated to understanding the structure of the human genome. More recent work of the lab includes analyzing i

In this episode of the Epigenetics Podcast, we caught up with Dr. Danny Reinberg from the New York University School of Medicine to talk about his work on transcription and polycomb in inheritance and disease. Dr. Danny Reinberg is a pioneer in the characterization of transcription factors for human RNA polymerase II. In his groundbreaking work in the 1990s, he purified the essential transcription factors and reconstituted the polymerase in vitro on both naked DNA and chromatin.  Dr. Reinberg next started focusing on the polycomb repressive complex 2 (PRC2), which is the only known methyltransferase for lysine 27 on histone H3. He biochemically characterized the PRC2 subunits EZH1 and EZH2. More recently, Dr. Reinberg has been investigating the role of PRC2 in neurons.  This interview discusses the story behind how Dr. Danny Reinberg started his research career by identifying the essential RNA polymerase transcription factors, how he discovered and characterized the polycomb repressive complex 2 (PRC2), and

In this episode of the Epigenetics Podcast, we caught up with Dr. Sandra Atlante and Dr. Carlo Gaetano from the Instituti Clinici Scientifici Maugeri in Pavia, Italy, to talk about the roles epigenetic mechanisms play in COVID-19. In early 2020 a novel coronavirus, SARS-CoV-2, emerged in Wuhan, China. This coronavirus causes the coronavirus disease 2019 (COVID-19) and rapidly spread all over the globe. In a worldwide effort, scientists and doctors tried to find drugs and looked for vaccines to help contain the spreading of the virus. It seems that an overreaction of the immune system, the so called "cytokine storm," could be one of the major complications of this disease. This reaction is not directly linked to the viral infection but is an overreaction of the body's own immune system. Therefore, small molecules that regulate gene expression via chromatin modifying enzymes might help keep the immune system in check. In this episode we discuss how Dr. Gaetano and Dr. Atlante set up studies to investigate the

In this episode of the Epigenetics Podcast, we caught up with Dr. Wolf Reik, Director at the Babraham Institute in Cambridge, UK, to talk about his work on the role of epigenetic factors in cellular reprogramming. In the beginning of his research career, Dr. Wolf Reik worked on cellular reprogramming during embryogenesis. Epigenetic marks like DNA methylation or post-translational modifications of histone tails are removed and reprogrammed during embryogenesis, which can limit the amount of epigenetic information that can be passed on to future generations. However, this process is sometimes defective, which can lead to transgenerational epigenetic inheritance. More recently, the laboratory of Dr. Wolf Reik has done pioneering work in the emerging field of single-cell experimental methods. The Reik lab developed a single-cell reduced representation bisulfite sequencing (scRRBS) approach to investigate DNA methylation at single-cell resolution. They also developed an integrated multi-omics approach called si

In this episode of the Epigenetics Podcast, we caught up with Dr. Srinivas Ramachandran, Assistant Professor at the University of Colorado, Anschutz Medical Campus, to talk about his work on ​in vivo nucleosome structure and dynamics. Dr. Srinivas Ramachandran studies the structure and dynamics of nucleosomes during cellular processes like transcription and DNA replication. During transcription, as the RNA polymerase transcribes along the DNA, it needs to pass nucleosomes. Dr. Ramachandran investigated the effect of nucleosomes on transcription and also studied how different histone variants affect this process. He found that the first nucleosome within a gene body is a barrier for the progression of RNA polymerase, and that presence of the histone variant H2A.Z in this first nucleosome lowers this barrier. Furthermore, Dr. Ramachandran developed a method called mapping in vivo nascent chromatin using EdU and sequencing (MINCE-Seq), enabling the study of chromatin landscapes right after DNA replication. In