TY - JOUR
T1 - Autophagy Is Involved in Mesenchymal Stem Cell Death in Coculture with Chondrocytes
AU - Paggi, Carlo Alberto
AU - Dudakovic, Amel
AU - Fu, Yao
AU - Garces, Catalina Galeano
AU - Hevesi, Mario
AU - Galeano Garces, Daniela
AU - Dietz, Allan B.
AU - van Wijnen, Andre J.
AU - Karperien, Marcel
N1 - Funding Information:
The authors are indebted to the generous support of William and Karen Eby and the philanthropic foundation in their names. We also acknowledge intramural funding from the Center of Regenerative Medicine at Mayo Clinic and NIH grant AR049069 (to AJVW), the Dutch Arthritis Association (to CAP) and the China Scholarship Council (to YF).
Publisher Copyright:
© The Author(s) 2020.
PY - 2021/12
Y1 - 2021/12
N2 - Objective: Cartilage formation is stimulated in mixtures of chondrocytes and human adipose–derived mesenchymal stromal cells (MSCs) both in vitro and in vivo. During coculture, human MSCs perish. The goal of this study is to elucidate the mechanism by which adipose tissue–derived MSC cell death occurs in the presence of chondrocytes. Methods: Human primary chondrocytes were cocultured with human MSCs derived from 3 donors. The cells were cultured in monoculture or coculture (20% chondrocytes and 80% MSCs) in pellets (200,000 cells/pellet) for 7 days in chondrocyte proliferation media in hypoxia (2% O2). RNA sequencing was performed to assess for differences in gene expression between monocultures or coculture. Immune fluorescence assays were performed to determine the presence of caspase-3, LC3B, and P62. Results: RNA sequencing revealed significant upregulation of >90 genes in the 3 cocultures when compared with monocultures. STRING analysis showed interconnections between >50 of these genes. Remarkably, 75% of these genes play a role in cell death pathways such as apoptosis and autophagy. Immunofluorescence shows a clear upregulation of the autophagic machinery with no substantial activation of the apoptotic pathway. Conclusion: In cocultures of human MSCs with primary chondrocytes, autophagy is involved in the disappearance of MSCs. We propose that this sacrificial cell death may contribute to the trophic effects of MSCs on cartilage formation.
AB - Objective: Cartilage formation is stimulated in mixtures of chondrocytes and human adipose–derived mesenchymal stromal cells (MSCs) both in vitro and in vivo. During coculture, human MSCs perish. The goal of this study is to elucidate the mechanism by which adipose tissue–derived MSC cell death occurs in the presence of chondrocytes. Methods: Human primary chondrocytes were cocultured with human MSCs derived from 3 donors. The cells were cultured in monoculture or coculture (20% chondrocytes and 80% MSCs) in pellets (200,000 cells/pellet) for 7 days in chondrocyte proliferation media in hypoxia (2% O2). RNA sequencing was performed to assess for differences in gene expression between monocultures or coculture. Immune fluorescence assays were performed to determine the presence of caspase-3, LC3B, and P62. Results: RNA sequencing revealed significant upregulation of >90 genes in the 3 cocultures when compared with monocultures. STRING analysis showed interconnections between >50 of these genes. Remarkably, 75% of these genes play a role in cell death pathways such as apoptosis and autophagy. Immunofluorescence shows a clear upregulation of the autophagic machinery with no substantial activation of the apoptotic pathway. Conclusion: In cocultures of human MSCs with primary chondrocytes, autophagy is involved in the disappearance of MSCs. We propose that this sacrificial cell death may contribute to the trophic effects of MSCs on cartilage formation.
KW - autophagy
KW - chondrocytes
KW - coculture
KW - mesenchymal stem cells
KW - pellet
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U2 - 10.1177/1947603520941227
DO - 10.1177/1947603520941227
M3 - Article
C2 - 32693629
AN - SCOPUS:85088377767
SN - 1947-6035
VL - 13
SP - 969S-979S
JO - Cartilage
JF - Cartilage
IS - 2_suppl
ER -