1
|
Korb A, Tajbakhsh S, Comai GE. Functional specialisation and coordination of myonuclei. Biol Rev Camb Philos Soc 2024. [PMID: 38477382 DOI: 10.1111/brv.13063] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2023] [Revised: 01/30/2024] [Accepted: 02/02/2024] [Indexed: 03/14/2024]
Abstract
Myofibres serve as the functional unit for locomotion, with the sarcomere as fundamental subunit. Running the entire length of this structure are hundreds of myonuclei, located at the periphery of the myofibre, juxtaposed to the plasma membrane. Myonuclear specialisation and clustering at the centre and ends of the fibre are known to be essential for muscle contraction, yet the molecular basis of this regionalisation has remained unclear. While the 'myonuclear domain hypothesis' helped explain how myonuclei can independently govern large cytoplasmic territories, novel technologies have provided granularity on the diverse transcriptional programs running simultaneously within the syncytia and added a new perspective on how myonuclei communicate. Building upon this, we explore the critical cellular and molecular sources of transcriptional and functional heterogeneity within myofibres, discussing the impact of intrinsic and extrinsic factors on myonuclear programs. This knowledge provides new insights for understanding muscle development, repair, and disease, but also opens avenues for the development of novel and precise therapeutic approaches.
Collapse
Affiliation(s)
- Amaury Korb
- Institut Pasteur, Université Paris Cité, CNRS UMR 3738, Stem Cells & Development Unit, 25 rue du Dr. Roux, Institut Pasteur, Paris, F-75015, France
| | - Shahragim Tajbakhsh
- Institut Pasteur, Université Paris Cité, CNRS UMR 3738, Stem Cells & Development Unit, 25 rue du Dr. Roux, Institut Pasteur, Paris, F-75015, France
| | - Glenda E Comai
- Institut Pasteur, Université Paris Cité, CNRS UMR 3738, Stem Cells & Development Unit, 25 rue du Dr. Roux, Institut Pasteur, Paris, F-75015, France
| |
Collapse
|
2
|
Sharma A, Zehra A, Mathew SJ. Myosin heavy chain-perinatal regulates skeletal muscle differentiation, oxidative phenotype and regeneration. FEBS J 2024. [PMID: 38358038 DOI: 10.1111/febs.17085] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2023] [Revised: 10/28/2023] [Accepted: 01/29/2024] [Indexed: 02/16/2024]
Abstract
Myosin heavy chain-perinatal (MyHC-perinatal) is one of two development-specific myosin heavy chains expressed exclusively during skeletal muscle development and regeneration. The specific functions of MyHC-perinatal are unclear, although mutations are known to lead to contracture syndromes such as Trismus-pseudocamptodactyly syndrome. Here, we characterize the functions of MyHC-perinatal during skeletal muscle differentiation and regeneration. Loss of MyHC-perinatal function leads to enhanced differentiation characterized by increased expression of myogenic regulatory factors and differentiation index as well as reduced reserve cell numbers in vitro. Proteomic analysis revealed that loss of MyHC-perinatal function results in a switch from oxidative to glycolytic metabolism in myofibers, suggesting a shift from slow type I to fast type IIb fiber type, also supported by reduced mitochondrial numbers. Paracrine signals mediate the effect of loss of MyHC-perinatal function on myogenic differentiation, possibly mediated by non-apoptotic caspase-3 signaling along with enhanced levels of the pro-survival apoptosis regulator Bcl2 and nuclear factor kappa-B (NF-κB). Knockdown of MyHC-perinatal during muscle regeneration in vivo results in increased expression of the differentiation marker myogenin (MyoG) and impaired differentiation, evidenced by smaller myofibers, elevated fibrosis and reduction in the number of satellite cells. Thus, we find that MyHC-perinatal is a crucial regulator of myogenic differentiation, myofiber oxidative phenotype and regeneration.
Collapse
Affiliation(s)
- Akashi Sharma
- Developmental Genetics Laboratory, Regional Centre for Biotechnology (RCB), NCR Biotech Science Cluster, Faridabad, India
- Affiliated to KIIT University, Bhubaneswar, India
| | - Aatifa Zehra
- Developmental Genetics Laboratory, Regional Centre for Biotechnology (RCB), NCR Biotech Science Cluster, Faridabad, India
| | - Sam J Mathew
- Developmental Genetics Laboratory, Regional Centre for Biotechnology (RCB), NCR Biotech Science Cluster, Faridabad, India
- Affiliated to KIIT University, Bhubaneswar, India
| |
Collapse
|
3
|
Kalita B, Sahu S, Bharadwaj A, Panneerselvam L, Martinez-Cebrian G, Agarwal M, Mathew SJ. The Wnt-pathway corepressor TLE3 interacts with the histone methyltransferase KMT1A to inhibit differentiation in Rhabdomyosarcoma. Oncogene 2024; 43:524-538. [PMID: 38177411 DOI: 10.1038/s41388-023-02911-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2022] [Revised: 11/25/2023] [Accepted: 11/29/2023] [Indexed: 01/06/2024]
Abstract
Rhabdomyosarcoma tumor cells resemble differentiating skeletal muscle cells, which unlike normal muscle cells, fail to undergo terminal differentiation, underlying their proliferative and metastatic properties. We identify the corepressor TLE3 as a key regulator of rhabdomyosarcoma tumorigenesis by inhibiting the Wnt-pathway. Loss of TLE3 function leads to Wnt-pathway activation, reduced proliferation, decreased migration, and enhanced differentiation in rhabdomyosarcoma cells. Muscle-specific TLE3-knockout results in enhanced expression of terminal myogenic differentiation markers during normal mouse development. TLE3-knockout rhabdomyosarcoma cell xenografts result in significantly smaller tumors characterized by reduced proliferation, increased apoptosis and enhanced differentiation. We demonstrate that TLE3 interacts with and recruits the histone methyltransferase KMT1A, leading to repression of target gene activation and inhibition of differentiation in rhabdomyosarcoma. A combination drug therapy regime to promote Wnt-pathway activation by the small molecule BIO and inhibit KMT1A by the drug chaetocin led to significantly reduced tumor volume, decreased proliferation, increased expression of differentiation markers and increased survival in rhabdomyosarcoma tumor-bearing mice. Thus, TLE3, the Wnt-pathway and KMT1A are excellent drug targets which can be exploited for treating rhabdomyosarcoma tumors.
Collapse
Affiliation(s)
- Bhargab Kalita
- Developmental Genetics Laboratory Regional Centre for Biotechnology (RCB) NCR Biotech Science Cluster 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad, 121001, Haryana, India
- Department of Pathology and Perlmutter Cancer Center, New York University School of Medicine, New York, NY, 10016, USA
| | - Subhashni Sahu
- Developmental Genetics Laboratory Regional Centre for Biotechnology (RCB) NCR Biotech Science Cluster 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad, 121001, Haryana, India
| | - Anushree Bharadwaj
- Developmental Genetics Laboratory Regional Centre for Biotechnology (RCB) NCR Biotech Science Cluster 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad, 121001, Haryana, India
| | - Lakshmikanthan Panneerselvam
- Developmental Genetics Laboratory Regional Centre for Biotechnology (RCB) NCR Biotech Science Cluster 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad, 121001, Haryana, India
| | | | - Megha Agarwal
- Developmental Genetics Laboratory Regional Centre for Biotechnology (RCB) NCR Biotech Science Cluster 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad, 121001, Haryana, India
- Affiliated to Manipal University, Manipal, Karnataka, 576104, India
- Department of Pediatrics, School of Medicine, Stanford University, Stanford, CA, USA
| | - Sam J Mathew
- Developmental Genetics Laboratory Regional Centre for Biotechnology (RCB) NCR Biotech Science Cluster 3rd Milestone, Faridabad-Gurgaon Expressway, Faridabad, 121001, Haryana, India.
- Affiliated to Manipal University, Manipal, Karnataka, 576104, India.
| |
Collapse
|