1
|
Wang J, Lu X, Zhang W, Liu GH. Endogenous retroviruses in development and health. Trends Microbiol 2024; 32:342-354. [PMID: 37802660 DOI: 10.1016/j.tim.2023.09.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2023] [Revised: 09/12/2023] [Accepted: 09/13/2023] [Indexed: 10/08/2023]
Abstract
Endogenous retroviruses (ERVs) are evolutionary remnants of retroviral infections in which the viral genome became embedded as a dormant regulatory element within the host germline. When ERVs become activated, they comprehensively rewire genomic regulatory networks of the host and facilitate critical developmental events, such as preimplantation development and placentation, in a manner specific to species, developmental stage, and tissues. However, accumulating evidence suggests that aberrant ERV transcription compromises genome stability and has been implicated in cellular senescence and various pathogenic processes, underscoring the significance of host genomic surveillance mechanisms. Here, we revisit the prominent functions of ERVs in early development and highlight their emerging roles in mammalian post-implantation development and organogenesis. We also discuss their implications for aging and pathological processes such as microbial infection, immune response. Furthermore, we discuss recent advances in stem-cell-based models, single-cell omics, and genome editing technologies, which serve as beacons illuminating the versatile nature of ERVs in mammalian development and health.
Collapse
Affiliation(s)
- Jichang Wang
- Advanced Medical Technology Center, The First Affiliated Hospital, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou, 510080, China; Key Laboratory for Stem Cells and Tissue Engineering (Sun Yat-sen University), Ministry of Education, Guangzhou, 510080, China.
| | - Xinyi Lu
- State Key Laboratory of Medicinal Chemical Biology, Nankai University, Tianjin 300350, China.
| | - Weiqi Zhang
- CAS Key Laboratory of Genomic and Precision Medicine, Beijing Institute of Genomics and China National Center for Bioinformation, Chinese Academy of Sciences, Beijing 100101, China.
| | - Guang-Hui Liu
- State Key Laboratory of Membrane Biology, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China; Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, Beijing 100101, China; Beijing Institute for Stem Cell and Regenerative Medicine, Beijing 100101, China; University of Chinese Academy of Sciences, Beijing 100049, China; Advanced Innovation Center for Human Brain Protection, and National Clinical Research Center for Geriatric Disorders, Xuanwu Hospital Capital Medical University, Beijing 100053, China.
| |
Collapse
|
2
|
Pugacheva EM, Bhatt DN, Rivero-Hinojosa S, Tajmul M, Fedida L, Price E, Ji Y, Loukinov D, Strunnikov AV, Ren B, Lobanenkov VV. BORIS/CTCFL epigenetically reprograms clustered CTCF binding sites into alternative transcriptional start sites. Genome Biol 2024; 25:40. [PMID: 38297316 PMCID: PMC10832218 DOI: 10.1186/s13059-024-03175-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2023] [Accepted: 01/15/2024] [Indexed: 02/02/2024] Open
Abstract
BACKGROUND Pervasive usage of alternative promoters leads to the deregulation of gene expression in carcinogenesis and may drive the emergence of new genes in spermatogenesis. However, little is known regarding the mechanisms underpinning the activation of alternative promoters. RESULTS Here we describe how alternative cancer-testis-specific transcription is activated. We show that intergenic and intronic CTCF binding sites, which are transcriptionally inert in normal somatic cells, could be epigenetically reprogrammed into active de novo promoters in germ and cancer cells. BORIS/CTCFL, the testis-specific paralog of the ubiquitously expressed CTCF, triggers the epigenetic reprogramming of CTCF sites into units of active transcription. BORIS binding initiates the recruitment of the chromatin remodeling factor, SRCAP, followed by the replacement of H2A histone with H2A.Z, resulting in a more relaxed chromatin state in the nucleosomes flanking the CTCF binding sites. The relaxation of chromatin around CTCF binding sites facilitates the recruitment of multiple additional transcription factors, thereby activating transcription from a given binding site. We demonstrate that the epigenetically reprogrammed CTCF binding sites can drive the expression of cancer-testis genes, long noncoding RNAs, retro-pseudogenes, and dormant transposable elements. CONCLUSIONS Thus, BORIS functions as a transcription factor that epigenetically reprograms clustered CTCF binding sites into transcriptional start sites, promoting transcription from alternative promoters in both germ cells and cancer cells.
Collapse
Affiliation(s)
- Elena M Pugacheva
- Molecular Pathology Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA.
| | - Dharmendra Nath Bhatt
- Molecular Pathology Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Samuel Rivero-Hinojosa
- Center for Cancer and Immunology Research, Children's National Research Institute, Washington, DC, 20010, USA
| | - Md Tajmul
- Molecular Pathology Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Liron Fedida
- Molecular Pathology Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Emma Price
- Molecular Pathology Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Yon Ji
- Molecular Pathology Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Dmitri Loukinov
- Molecular Pathology Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA
| | - Alexander V Strunnikov
- Guangzhou Institutes of Biomedicine and Health, Molecular Epigenetics Laboratory, 190 Kai Yuan Avenue, Science Park, Guangzhou, 510530, China
| | - Bing Ren
- Ludwig Institute for Cancer Research, 9500 Gilman Drive, La Jolla, CA, 92093, USA
- Department of Cellular and Molecular Medicine, Center for Epigenomics, Moores Cancer Center and Institute of Genomic Medicine, University of California, San Diego School of Medicine, La Jolla, CA, 92093-0653, USA
| | - Victor V Lobanenkov
- Molecular Pathology Section, Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, National Institutes of Health, Bethesda, MD, 20892, USA.
| |
Collapse
|
3
|
Wu M, Li M, Liu W, Yan M, Li L, Ding W, Nian X, Dai W, Sun D, Zhu Y, Huang Q, Lu X, Cai Z, Hong F, Li X, Zhang L, Liu Z, Mo W, Zhang X, Zhang L. Nucleoporin Seh1 maintains Schwann cell homeostasis by regulating genome stability and necroptosis. Cell Rep 2023; 42:112802. [PMID: 37453065 DOI: 10.1016/j.celrep.2023.112802] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2023] [Revised: 06/06/2023] [Accepted: 06/26/2023] [Indexed: 07/18/2023] Open
Abstract
Schwann cells play critical roles in peripheral neuropathies; however, the regulatory mechanisms of their homeostasis remain largely unknown. Here, we show that nucleoporin Seh1, a component of nuclear pore complex, is important for Schwann cell homeostasis. Expression of Seh1 decreases as mice age. Loss of Seh1 leads to activated immune responses and cell necroptosis. Mice with depletion of Seh1 in Schwann cell lineage develop progressive reduction of Schwann cells in sciatic nerves, predominantly non-myelinating Schwann cells, followed by neural fiber degeneration and malfunction of the sensory and motor system. Mechanistically, Seh1 safeguards genome stability by mediating the interaction between SETDB1 and KAP1. The disrupted interaction after ablation of Seh1 derepresses endogenous retroviruses, which triggers ZBP1-dependent necroptosis in Schwann cells. Collectively, our results demonstrate that Seh1 is required for Schwann cell homeostasis by maintaining genome integrity and suggest that decrease of nucleoporins may participate in the pathogenesis of periphery neuropathies.
Collapse
Affiliation(s)
- Mei Wu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Gynaecology and Obstetrics, Women and Children's Hospital Affiliated to Xiamen University, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Man Li
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Gynaecology and Obstetrics, Women and Children's Hospital Affiliated to Xiamen University, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Wei Liu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Gynaecology and Obstetrics, Women and Children's Hospital Affiliated to Xiamen University, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Minbiao Yan
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Gynaecology and Obstetrics, Women and Children's Hospital Affiliated to Xiamen University, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Li Li
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Gynaecology and Obstetrics, Women and Children's Hospital Affiliated to Xiamen University, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Weichao Ding
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Gynaecology and Obstetrics, Women and Children's Hospital Affiliated to Xiamen University, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Ximing Nian
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Gynaecology and Obstetrics, Women and Children's Hospital Affiliated to Xiamen University, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Wenxiu Dai
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Gynaecology and Obstetrics, Women and Children's Hospital Affiliated to Xiamen University, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Di Sun
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Gynaecology and Obstetrics, Women and Children's Hospital Affiliated to Xiamen University, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Yanqin Zhu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Gynaecology and Obstetrics, Women and Children's Hospital Affiliated to Xiamen University, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Qiuying Huang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Gynaecology and Obstetrics, Women and Children's Hospital Affiliated to Xiamen University, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Xiaoyun Lu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Gynaecology and Obstetrics, Women and Children's Hospital Affiliated to Xiamen University, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Zhiyu Cai
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Gynaecology and Obstetrics, Women and Children's Hospital Affiliated to Xiamen University, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Fan Hong
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Gynaecology and Obstetrics, Women and Children's Hospital Affiliated to Xiamen University, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Xuewen Li
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Gynaecology and Obstetrics, Women and Children's Hospital Affiliated to Xiamen University, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Ling Zhang
- Department of Clinic Laboratory, the affiliated Chenggong Hospital, School of Medicine, Xiamen University, Xiamen, Fujian 361102, China
| | - Zhixiong Liu
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Gynaecology and Obstetrics, Women and Children's Hospital Affiliated to Xiamen University, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Wei Mo
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Gynaecology and Obstetrics, Women and Children's Hospital Affiliated to Xiamen University, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Xueqin Zhang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Gynaecology and Obstetrics, Women and Children's Hospital Affiliated to Xiamen University, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China
| | - Liang Zhang
- State Key Laboratory of Cellular Stress Biology, School of Life Sciences, Department of Gynaecology and Obstetrics, Women and Children's Hospital Affiliated to Xiamen University, Faculty of Medicine and Life Sciences, Xiamen University, Xiamen, Fujian 361102, China.
| |
Collapse
|
4
|
Jin Y, Lu Y, Lin L, Liu C, Ma X, Chen X, Zhou Z, Hu Z, Pu J, Chen G, Deng Q, Jiang L, Li Y, Zhao Y, Wang H, Fu J, Li W, Zhu S. Harnessing endogenous transcription factors directly by small molecules for chemically induced pluripotency inception. Proc Natl Acad Sci U S A 2023; 120:e2215155120. [PMID: 37192170 PMCID: PMC10214147 DOI: 10.1073/pnas.2215155120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2022] [Accepted: 03/27/2023] [Indexed: 05/18/2023] Open
Abstract
Chemistry-alone approach has recently been applied for incepting pluripotency in somatic cells, representing a breakthrough in biology. However, chemical reprogramming is hampered by low efficiency, and the underlying molecular mechanisms remain unclear. Particularly, chemical compounds do not have specific DNA-recognition domains or transcription regulatory domains, and then how do small molecules work as a driving force for reinstating pluripotency in somatic cells? Furthermore, how to efficiently clear materials and structures of an old cell to prepare the rebuilding of a new one? Here, we show that small molecule CD3254 activates endogenous existing transcription factor RXRα to significantly promote mouse chemical reprogramming. Mechanistically, CD3254-RXRα axis can directly activate all the 11 RNA exosome component genes (Exosc1-10 and Dis3) at transcriptional level. Unexpectedly, rather than degrading mRNAs as its substrates, RNA exosome mainly modulates the degradation of transposable element (TE)-associated RNAs, particularly MMVL30, which is identified as a new barrier for cell-fate determination. In turn, MMVL30-mediated inflammation (IFN-γ and TNF-α pathways) is reduced, contributing to the promotion of successful reprogramming. Collectively, our study provides conceptual advances for translating environmental cues into pluripotency inception, particularly, identifies that CD3254-RXRα-RNA exosome axis can promote chemical reprogramming, and suggests modulation of TE-mediated inflammation via CD3254-inducible RNA exosome as important opportunities for controlling cell fates and regenerative medicine.
Collapse
Affiliation(s)
- Yan Jin
- The Second Affiliated Hospital and Life Sciences Institute and School of Medicine, The Ministry of Education Key Laboratory of Biosystems Homeostasis and Protection and Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Zhejiang University, Hangzhou310058, China
| | - Yunkun Lu
- The Second Affiliated Hospital and Life Sciences Institute and School of Medicine, The Ministry of Education Key Laboratory of Biosystems Homeostasis and Protection and Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Zhejiang University, Hangzhou310058, China
| | - Lianyu Lin
- The Second Affiliated Hospital and Life Sciences Institute and School of Medicine, The Ministry of Education Key Laboratory of Biosystems Homeostasis and Protection and Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Zhejiang University, Hangzhou310058, China
| | - Chao Liu
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Beijing100101, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Beijing100101, China
| | - Xiaojie Ma
- The Second Affiliated Hospital and Life Sciences Institute and School of Medicine, The Ministry of Education Key Laboratory of Biosystems Homeostasis and Protection and Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Zhejiang University, Hangzhou310058, China
| | - Xi Chen
- The Second Affiliated Hospital and Life Sciences Institute and School of Medicine, The Ministry of Education Key Laboratory of Biosystems Homeostasis and Protection and Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Zhejiang University, Hangzhou310058, China
| | - Ziyu Zhou
- The Second Affiliated Hospital and Life Sciences Institute and School of Medicine, The Ministry of Education Key Laboratory of Biosystems Homeostasis and Protection and Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Zhejiang University, Hangzhou310058, China
| | - Zhensheng Hu
- The Second Affiliated Hospital and Life Sciences Institute and School of Medicine, The Ministry of Education Key Laboratory of Biosystems Homeostasis and Protection and Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Zhejiang University, Hangzhou310058, China
| | - Jiaqi Pu
- The Second Affiliated Hospital and Life Sciences Institute and School of Medicine, The Ministry of Education Key Laboratory of Biosystems Homeostasis and Protection and Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Zhejiang University, Hangzhou310058, China
- Department of Endocrinology, Children's Hospital of Zhejiang University School of Medicine, Hangzhou310052, China
| | - Guo Chen
- The Second Affiliated Hospital and Life Sciences Institute and School of Medicine, The Ministry of Education Key Laboratory of Biosystems Homeostasis and Protection and Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Zhejiang University, Hangzhou310058, China
| | - Qian Deng
- The Second Affiliated Hospital and Life Sciences Institute and School of Medicine, The Ministry of Education Key Laboratory of Biosystems Homeostasis and Protection and Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Zhejiang University, Hangzhou310058, China
| | - Liling Jiang
- The Second Affiliated Hospital and Life Sciences Institute and School of Medicine, The Ministry of Education Key Laboratory of Biosystems Homeostasis and Protection and Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Zhejiang University, Hangzhou310058, China
| | - Yuhan Li
- The Second Affiliated Hospital and Life Sciences Institute and School of Medicine, The Ministry of Education Key Laboratory of Biosystems Homeostasis and Protection and Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Zhejiang University, Hangzhou310058, China
| | - Yulong Zhao
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Beijing100101, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Beijing100101, China
| | - Hao Wang
- Hangzhou Women’s Hospital, Prenatal Diagnosis Center, Zhejiang University, Hangzhou310008, China
| | - Junfen Fu
- Department of Endocrinology, Children's Hospital of Zhejiang University School of Medicine, Hangzhou310052, China
| | - Wei Li
- State Key Laboratory of Stem Cell and Reproductive Biology, Institute of Zoology, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Beijing100101, China
- Institute for Stem Cell and Regeneration, Chinese Academy of Sciences, University of Chinese Academy of Sciences, Beijing100101, China
| | - Saiyong Zhu
- The Second Affiliated Hospital and Life Sciences Institute and School of Medicine, The Ministry of Education Key Laboratory of Biosystems Homeostasis and Protection and Zhejiang Provincial Key Laboratory for Cancer Molecular Cell Biology, Zhejiang University, Hangzhou310058, China
| |
Collapse
|
5
|
Amatori S, Persico G, Cantatore F, Rusin M, Formica M, Giorgi L, Macedi E, Casciaro F, Errico Provenzano A, Gambardella S, Noberini R, Bonaldi T, Fusi V, Giorgio M, Fanelli M. Small molecule-induced epigenomic reprogramming of APL blasts leading to antiviral-like response and c-MYC downregulation. Cancer Gene Ther 2022; 30:671-682. [PMID: 36536122 DOI: 10.1038/s41417-022-00576-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 11/23/2022] [Accepted: 11/30/2022] [Indexed: 12/23/2022]
Abstract
AbstractAcute promyelocytic leukemia (APL) is an aggressive subtype of acute myeloid leukemia (AML) in which the PML/RARα fusion protein exerts oncogenic activities by recruiting repressive complexes to the promoter of specific target genes. Other epigenetic perturbations, as alterations of histone H3 lysine 9 trimethylation (H3K9me3), have been frequently found in AMLs and are associated with leukemogenesis and leukemia progression. Here, we characterized the epigenomic effects of maltonis, a novel maltol-derived molecule, in APL cells. We demonstrate that maltonis treatments induce a profound remodulation of the histone code, reducing global H3K9me3 signal and modulating other histone post-translational modifications. Transcriptomic and epigenomic analyses revealed that maltonis exposure induces changes of genes expression associated with a genomic redistribution of histone H3 lysine 4 trimethylation (H3K4me3) and lysine 27 acetylation (H3K27ac). Upregulation of interferon alpha and gamma response and downregulation of c-MYC target genes, in function of c-MYC reduced expression (monitored in all the hematopoietic neoplasms tested), represent the most significant modulated pathways. These data demonstrate the ability of maltonis to epigenetically reprogram the gene expression profile of APL cells, inducing an intriguing antiviral-like response, concomitantly with the downregulation of c-MYC-related pathways, thus making it an attractive candidate for antileukemic therapy.
Collapse
|
6
|
Lyu Y, Ge Y. Toward Elucidating Epigenetic and Metabolic Regulation of Stem Cell Lineage Plasticity in Skin Aging. Front Cell Dev Biol 2022; 10:903904. [PMID: 35663405 PMCID: PMC9160930 DOI: 10.3389/fcell.2022.903904] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 04/21/2022] [Indexed: 11/13/2022] Open
Abstract
Skin is the largest organ in human body, harboring a plethora of cell types and serving as the organismal barrier. Skin aging such as wrinkling and hair graying is graphically pronounced, and the molecular mechanisms behind these phenotypic manifestations are beginning to unfold. As in many other organs and tissues, epigenetic and metabolic deregulations have emerged as key aging drivers. Particularly in the context of the skin epithelium, the epigenome and metabolome coordinately shape lineage plasticity and orchestrate stem cell function during aging. Our review discusses recent studies that proposed molecular mechanisms that drive the degeneration of hair follicles, a major appendage of the skin. By focusing on skin while comparing it to model organisms and adult stem cells of other tissues, we summarize literature on genotoxic stress, nutritional sensing, metabolic rewiring, mitochondrial activity, and epigenetic regulations of stem cell plasticity. Finally, we speculate about the rejuvenation potential of rate-limiting upstream signals during aging and the dominant role of the tissue microenvironment in dictating aged epithelial stem cell function.
Collapse
Affiliation(s)
| | - Yejing Ge
- Department of Cancer Biology, The University of Texas MD Anderson Cancer Center, Houston, TX, United States
| |
Collapse
|
7
|
Abstract
Purpose of Review Hematopoietic stem cells (HSCs) are formed embryonically during a dynamic developmental process and later reside in adult hematopoietic organs in a quiescent state. In response to their changing environment, HSCs have evolved diverse mechanisms to cope with intrinsic and extrinsic challenges. This review intends to discuss how HSCs and other stem cells co-opted DNA and RNA innate immune pathways to fine-tune developmental processes. Recent Findings Innate immune receptors for nucleic acids like the RIG-I-like family receptors and members of DNA sensing pathways are expressed in HSCs and other stem cells. Even though the “classic” role of these receptors is recognition of foreign DNA or RNA from pathogens, it was recently shown that cellular transposable element (TE) RNA or R-loops activate such receptors, serving as endogenous triggers of inflammatory signaling that can shape HSC formation during development and regeneration. Summary Endogenous TEs and R-loops activate RNA and DNA sensors, which trigger distinct inflammatory signals to fine-tune stem cell decisions. This phenomenon could have broad implications for diverse somatic stem cells, for a variety of diseases and during aging.
Collapse
|