TY - JOUR
T1 - Distinct myofibre domains of the human myotendinous junction revealed by single-nucleus RNA sequencing
AU - Karlsen, Anders
AU - Yeung, Ching-Yan Chloé
AU - Schjerling, Peter
AU - Denz, Linda
AU - Hoegsbjerg, Christian
AU - Jakobsen, Jens R
AU - Krogsgaard, Michael R
AU - Koch, Manuel
AU - Schiaffino, Stefano
AU - Kjaer, Michael
AU - Mackey, Abigail L
N1 - © 2023. Published by The Company of Biologists Ltd.
PY - 2023/4/15
Y1 - 2023/4/15
N2 - The myotendinous junction (MTJ) is a specialized domain of the multinucleated myofibre that is faced with the challenge of maintaining robust cell-matrix contact with the tendon under high mechanical stress and strain. Here, we profiled 24,124 nuclei in semitendinosus muscle-tendon samples from three healthy males by using single-nucleus RNA sequencing (snRNA-seq), alongside spatial transcriptomics, to gain insight into the genes characterizing this specialization in humans. We identified a cluster of MTJ myonuclei represented by 47 enriched transcripts, of which the presence of ABI3BP, ABLIM1, ADAMTSL1, BICD1, CPM, FHOD3, FRAS1 and FREM2 was confirmed at the MTJ at the protein level in immunofluorescence assays. Four distinct subclusters of MTJ myonuclei were apparent, comprising two COL22A1-expressing subclusters and two subclusters lacking COL22A1 expression but with differing fibre type profiles characterized by expression of either MYH7 or MYH1 and/or MYH2. Our findings reveal distinct myonuclei profiles of the human MTJ, which represents a weak link in the musculoskeletal system that is selectively affected in pathological conditions ranging from muscle strains to muscular dystrophies.
AB - The myotendinous junction (MTJ) is a specialized domain of the multinucleated myofibre that is faced with the challenge of maintaining robust cell-matrix contact with the tendon under high mechanical stress and strain. Here, we profiled 24,124 nuclei in semitendinosus muscle-tendon samples from three healthy males by using single-nucleus RNA sequencing (snRNA-seq), alongside spatial transcriptomics, to gain insight into the genes characterizing this specialization in humans. We identified a cluster of MTJ myonuclei represented by 47 enriched transcripts, of which the presence of ABI3BP, ABLIM1, ADAMTSL1, BICD1, CPM, FHOD3, FRAS1 and FREM2 was confirmed at the MTJ at the protein level in immunofluorescence assays. Four distinct subclusters of MTJ myonuclei were apparent, comprising two COL22A1-expressing subclusters and two subclusters lacking COL22A1 expression but with differing fibre type profiles characterized by expression of either MYH7 or MYH1 and/or MYH2. Our findings reveal distinct myonuclei profiles of the human MTJ, which represents a weak link in the musculoskeletal system that is selectively affected in pathological conditions ranging from muscle strains to muscular dystrophies.
KW - Male
KW - Humans
KW - Myotendinous Junction
KW - Tendons/physiology
KW - Cell Nucleus/metabolism
KW - Muscle, Skeletal/metabolism
KW - Microfilament Proteins/metabolism
KW - LIM Domain Proteins/metabolism
KW - Cytoskeletal Proteins/metabolism
KW - Adaptor Proteins, Signal Transducing/metabolism
KW - Formins/metabolism
UR - http://www.scopus.com/inward/record.url?scp=85159179615&partnerID=8YFLogxK
U2 - 10.1242/jcs.260913
DO - 10.1242/jcs.260913
M3 - Journal article
C2 - 36924352
SN - 0021-9533
VL - 136
JO - Journal of Cell Science
JF - Journal of Cell Science
IS - 8
M1 - jcs260913
ER -