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Abstract
Cells must tightly regulate their gene expression programs and yet rapidly respond to acute biochemical and biophysical cues within their environment. This information is transmitted to the nucleus through various signaling cascades, culminating in the activation or repression of target genes. Transcription factors (TFs) are key mediators of these signals, binding to specific regulatory elements within chromatin. While live-cell imaging has conclusively proven that TF-chromatin interactions are highly dynamic, how such transient interactions can have long-term impacts on developmental trajectories and disease progression is still largely unclear. In this review, we summarize our current understanding of the dynamic nature of TF functions, starting with a historical overview of early live-cell experiments. We highlight key factors that govern TF dynamics and how TF dynamics, in turn, affect downstream transcriptional bursting. Finally, we conclude with open challenges and emerging technologies that will further our understanding of transcriptional regulation.
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Affiliation(s)
- Kaustubh Wagh
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA; , ,
- Department of Physics, University of Maryland, College Park, Maryland, USA;
| | - Diana A Stavreva
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA; , ,
| | - Arpita Upadhyaya
- Department of Physics, University of Maryland, College Park, Maryland, USA;
- Institute for Physical Science and Technology, University of Maryland, College Park, Maryland, USA
| | - Gordon L Hager
- Laboratory of Receptor Biology and Gene Expression, National Cancer Institute, National Institutes of Health, Bethesda, Maryland, USA; , ,
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Nair SJ, Suter T, Wang S, Yang L, Yang F, Rosenfeld MG. Transcriptional enhancers at 40: evolution of a viral DNA element to nuclear architectural structures. Trends Genet 2022; 38:1019-1047. [PMID: 35811173 PMCID: PMC9474616 DOI: 10.1016/j.tig.2022.05.015] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2022] [Revised: 05/05/2022] [Accepted: 05/31/2022] [Indexed: 02/08/2023]
Abstract
Gene regulation by transcriptional enhancers is the dominant mechanism driving cell type- and signal-specific transcriptional diversity in metazoans. However, over four decades since the original discovery, how enhancers operate in the nuclear space remains largely enigmatic. Recent multidisciplinary efforts combining real-time imaging, genome sequencing, and biophysical strategies provide insightful but conflicting models of enhancer-mediated gene control. Here, we review the discovery and progress in enhancer biology, emphasizing the recent findings that acutely activated enhancers assemble regulatory machinery as mesoscale architectural structures with distinct physical properties. These findings help formulate novel models that explain several mysterious features of the assembly of transcriptional enhancers and the mechanisms of spatial control of gene expression.
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Affiliation(s)
- Sreejith J Nair
- Department of Oncology, Lombardi Comprehensive Cancer Center, Georgetown University, Washington, DC 20057, USA.
| | - Tom Suter
- Howard Hughes Medical Institute, Department and School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Susan Wang
- Howard Hughes Medical Institute, Department and School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA; Cellular and Molecular Medicine Graduate Program, University of California, San Diego, La Jolla, CA 92093, USA
| | - Lu Yang
- Howard Hughes Medical Institute, Department and School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Feng Yang
- Howard Hughes Medical Institute, Department and School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA
| | - Michael G Rosenfeld
- Howard Hughes Medical Institute, Department and School of Medicine, University of California, San Diego, La Jolla, CA 92093, USA.
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Hamledari H, Asghari P, Jayousi F, Aguirre A, Maaref Y, Barszczewski T, Ser T, Moore E, Wasserman W, Klein Geltink R, Teves S, Tibbits GF. Using human induced pluripotent stem cell-derived cardiomyocytes to understand the mechanisms driving cardiomyocyte maturation. Front Cardiovasc Med 2022; 9:967659. [PMID: 36061558 PMCID: PMC9429949 DOI: 10.3389/fcvm.2022.967659] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2022] [Accepted: 07/28/2022] [Indexed: 11/13/2022] Open
Abstract
Cardiovascular diseases are the leading cause of mortality and reduced quality of life globally. Human induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) provide a personalized platform to study inherited heart diseases, drug-induced cardiac toxicity, and cardiac regenerative therapy. However, the immaturity of CMs obtained by current strategies is a major hurdle in utilizing hiPSC-CMs at their fullest potential. Here, the major findings and limitations of current maturation methodologies to enhance the utility of hiPSC-CMs in the battle against a major source of morbidity and mortality are reviewed. The most recent knowledge of the potential signaling pathways involved in the transition of fetal to adult CMs are assimilated. In particular, we take a deeper look on role of nutrient sensing signaling pathways and the potential role of cap-independent translation mediated by the modulation of mTOR pathway in the regulation of cardiac gap junctions and other yet to be identified aspects of CM maturation. Moreover, a relatively unexplored perspective on how our knowledge on the effects of preterm birth on cardiovascular development can be actually utilized to enhance the current understanding of CM maturation is examined. Furthermore, the interaction between the evolving neonatal human heart and brown adipose tissue as the major source of neonatal thermogenesis and its endocrine function on CM development is another discussed topic which is worthy of future investigation. Finally, the current knowledge regarding transcriptional mediators of CM maturation is still limited. The recent studies have produced the groundwork to better understand CM maturation in terms of providing some of the key factors involved in maturation and development of metrics for assessment of maturation which proves essential for future studies on in vitro PSC-CMs maturation.
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Affiliation(s)
- Homa Hamledari
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
- Cellular and Regenerative Medicine Centre, BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Parisa Asghari
- Department of Cellular and Physiological Sciences, University of British Colombia, Vancouver, BC, Canada
| | - Farah Jayousi
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
- Cellular and Regenerative Medicine Centre, BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Alejandro Aguirre
- Department of Medical Genetics, University of British Colombia, Vancouver, BC, Canada
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Yasaman Maaref
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
- Cellular and Regenerative Medicine Centre, BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Tiffany Barszczewski
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
- Cellular and Regenerative Medicine Centre, BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Terri Ser
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
- Department of Pathology and Laboratory Medicine, University of British Colombia, Vancouver, BC, Canada
| | - Edwin Moore
- Department of Cellular and Physiological Sciences, University of British Colombia, Vancouver, BC, Canada
| | - Wyeth Wasserman
- Department of Medical Genetics, University of British Colombia, Vancouver, BC, Canada
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
| | - Ramon Klein Geltink
- BC Children’s Hospital Research Institute, Vancouver, BC, Canada
- Department of Pathology and Laboratory Medicine, University of British Colombia, Vancouver, BC, Canada
| | - Sheila Teves
- Department of Biochemistry and Molecular Biology, University of British Colombia, Vancouver, BC, Canada
| | - Glen F. Tibbits
- Department of Biomedical Physiology and Kinesiology, Simon Fraser University, Burnaby, BC, Canada
- Department of Molecular Biology and Biochemistry, Simon Fraser University, Burnaby, BC, Canada
- Cellular and Regenerative Medicine Centre, BC Children’s Hospital Research Institute, Vancouver, BC, Canada
- School of Biomedical Engineering, University of British Columbia, Vancouver, BC, Canada
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