1. Decipher pathogenic variants in monogenic cardiovascular diseases (monogenic CVDs).Read More
While monogenic CVDs are rare, these single causal variants can pose high risks to their recipient, often manifesting its disease phenotypes during childhood and leading to morbidity and sometimes premature death. The rapid progression and aid of next-generation sequencing has led to the conclusion that the genetics of monogenic CVDs, such as cardiomyopathies or channelopathies,are more heterogeneous and complex than previously thought, with an increasing number of genes and variants associated with each condition. For example, DNA testing in a cohort of hypertrophic cardiomyopathy (HCM) probands found that nearly half (45%) of the rare variants identified in one study were novel variants of uncertain significance (VUS). This knowledge gap significantly obstructs the potential widespread clinical application of genetic information and causes anxiety and stress to genetic variant carriers. To bridge this gap, we establish CRISPR-based screening strategies for the rapid insertion of more than 100 genetic variants in ion channels or TNNT2 genes into induced pluripotent stem cells (iPSCs) to decipher their pathogenicity in iPSC-derived cardiomyocytes (iPSC-CMs).
Representative publications:
❖Guo HC*, Liu LC, Nishiga M, Wu JC. Deciphering pathogenicity of variants of uncertain significance with CRISPR-edited iPSCs. Trends in Genetics. 2021; 37, 1109-1123. PMID: 34509299; PMCID: PMC8578372.
❖Belbachir N*, Portero V, Al Sayed ZR, Gourraud JB, Dilasser F, Jesel L, Guo HC, Wu H, Gaborit N, Guilluy C, Girardeau A, Bonnaud S, Simonet F, Karakachoff M, Pattier S, Scott C, Burel S, Marionneau C, Chariau C, Gaignerie A, David L, Genin E, Deleuze JF, Dina C, Sauzeau V, Loirand G, Baró I, Schott JJ, Probst V, Wu JC, Redon R, Charpentier F, Le Scouarnec S. RRAD mutation causes electrical and cytoskeletal defects in cardiomyocytes derived from a familial case of Brugada syndrome. Eur Heart J. 2019; 40(37):3081-3094. PMID: 31114854; PMCID: 6769825.
2. Decipher pathogenic variants in polygenic cardiovascular diseases (polygenic CVDs).Read More
Polygenic CVDs such as hypertension, coronary artery disease, atrial fibrillation, and hypercholesterolemia are common CVDs that result from the additive inheritance of multiple genetic variants at different loci alongside interactions with environmental factors, culminating in an affected disease phenotype. While each variant contributes a small phenotypic effect and is deemed of lower risk, the polygenic variants have much higher frequencies in human populations than monogenic and oligogenic variants. Moreover, the majority of polygenic variants are located in intronic and intergenic regions that affect gene regulation. These characteristics make it challenging to study genetic variants in polygenic CVDs. Although polygenic risk scores have been devised to estimate the risk of developing CVDs based on the total number of risky variants related to CVDs, it is still not feasible to identify the individual risks for pathogenic variants and the molecular basis of polygenic CVDs based on polygenic risk scores. To better address these issues, we develop an experimental design for multiplexing multiple iPSC lines from individuals to assess genetic variants-related line-to-line variation (e.g., eQTL) in a controlled condition (iPSC-pheWAS).
Representative publications:
❖Guo HC*, Yu X, Liu Y, Paik DT, David T Paik, Justesen JM, Chandy MJ, Jahng JW, Zhang TJ, Wu WJ, Rwere F, Pokhrel S, Simon DJ, Manhas A, Zhang A, Chen CH, Rivas MA, Gross ER, Mochly-Rosen D, Wu JC. SGLT2i ameliorates endothelial dysfunction associated with the common ALDH2 alcohol flushing variant. Science Translational Medicine. 2023 Jan 25;15(680):eabp9952. doi: 10.1126/scitranslmed.abp9952. PMID: 36696485
3. Define the genetic mechanism underlying congenital heart disease (CHD).Read More
CHDs represent the most common of human birth defects. CHDs are diagnosed during late stages of heart development by examining heart function and structure integrity, with heart surgeries being the primary therapeutic strategy for CHDs. Understanding the genetic mechanisms underlying heart development is essential to the early stages of diagnosis and precise treatments of CHDs. My research methodology combines the advancement in iPSC-derived cardiac organoids with single-cell RNA sequencing to understand the mechanisms of heart development, with the goal of developing early diagnosis and novel non-invasive therapies for CHDs.
Representative publications:
❖ Wang YJ, Zhang XC, Lam CK, Guo HC, Wang C, Zhang S, Wu JC, Snyder M, Li JJ. Systems analysis of de novo mutations in congenital heart diseases identified a protein network in the hypoplastic left heart syndrome. Cell Systems. 2022;13, 1–16. PMID: 36167075.
❖ Guo HC*, Tian L*, Zhang JZ, Kitani T, Paik DT, Lee WH, Wu JC. Single-cell RNA-sequencing of human embryonic stem cell differentiation delineates effects of nicotine on embryonic development. Stem Cell Reports. 2019; 12(4):772-786. PMID: 30827876. PMCID: 6449785.
❖ Lee J, Shao NY, Paik DT, Wu H, Guo HC, Termglinchan V, Churko JM, Kim Y, Kitani T, Zhao MT, Zhang Y, Wilson KD, Karakikes I, Snyder MP, Wu JC. SETD7 drives cardiac lineage commitment through stage-specific transcriptional activation. Cell Stem Cell. 2018; 22(3):428-444.e5 PMID: 29499155; PMCID: 5929163.
4. Investigate the role of Endogenous retroviruses (ERVs) in heart development and disease. Read More
ERVs are the descendants of germline invasions by exogenous retroviruses, which account for 8% of the human genome. Although most of the ERVs in the human genome are inactive, some have regulatory roles in human development and disease by acting as enhancers and promoters. Some ERVs can be transcribed into RNAs (ERV-RNAs) in a tissue-specific manner and play important roles in embryogenesis, cancers, nervous system disease, and autoimmune disease. Thus, treating human disease by targeting tissue-specific ERV RNAs holds immense therapeutic potential. For example, our previous work identified BANCR, a heart-specific and ERV-derived long non-coding RNA, promotes ventricular enlargement during heart development and induces dilated cardiomyopathy (DCM) under pathological conditions (Wilson*, Ameen*, Guo* et al., Development Cell 2020). With these observations, the Guo Lab is particularly interested in investigating the role of endogenous ERV-RNAs in heart development and cardiovascular diseases.
Representative publications:
❖Yang BX*, El Farran CA*, Guo HC * (co-first), Yu T*, Fang HT, Wang HF, Schlesinger S, Seah YF, Goh GY, Neo SP, Li Y, Lorincz MC, Tergaonkar V, Lim TM, Chen L, Gunaratne J, Collins JJ, Goff SP, Daley GQ, Bard FA, Loh YH. Systematic identification of factors for provirus silencing in embryonic stem cells. Cell. 2015; 163(1):230-45. PMID: 26365490; PMCID: 4686136.
❖Wilson KD*, Ameen M*, Guo HC* (co-first), Abilez OJ, Tian L, Mumbach MR, Diecke S, Qin X, Liu Y, Yang H, Ma N, Gaddam S, Cunningham NJ, Gu M, Neofytou E, Prado M, Hildebrandt TB, Karakikes I, Chang HY, Wu JC. Endogenous retrovirus-derived lncRNA BANCR promotes cardiomyocyte migration in humans and non-human primates. Dev Cell. 2020 July 28: S1534-5807(20)30580-3. PMID: 32763147; PMCID: PMC7529962
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