JKAMP inhibits the osteogenic capacity of adipose-derived stem cells in diabetic osteoporosis by modulating the Wnt signaling pathway through intragenic DNA methylation

Abstract

Background Diabetic osteoporosis (DOP) is a systemic metabolic bone disease caused by diabetes mellitus (DM). Adipose-derived stem cells (ASCs) play an important role in bone regeneration. Our previous study confirmed that ASCs from DOP mice (DOP-ASCs) have a lower osteogenesis potential compared with control ASCs (CON-ASCs). However, the cause of this poor osteogenesis has not been elucidated. Therefore, this study investigated the underlying mechanism of the decline in the osteogenic potential of DOP-ASCs from the perspective of epigenetics and explored methods to enhance their osteogenic capacity. Methods The expression level of JNK1-associated membrane protein (JKAMP) and degree of DNA methylation in CON-ASCs and DOP-ASCs were measured by mRNA expression profiling and MeDIP sequencing, respectively. JKAMP small interfering RNA (siRNA) and a Jkamp overexpression plasmid were used to assess the role of JKAMP in osteogenic differentiation of CON-ASCs and DOP-ASCs. Immunofluorescence, qPCR, and western blotting were used to measure changes in expression of Wnt signaling pathway-related genes and osteogenesis-related molecules after osteogenesis induction. Alizarin red and ALP staining was used to confirm the osteogenic potential of stem cells. Bisulfite-specific PCR (BSP) was used to detect JKAMP methylation degree. Results Expression of JKAMP and osteogenesis-related molecules (RUNX2 and OPN) in DOP-ASCs was decreased significantly in comparison with CON-ASCs. JKAMP silencing inhibited the Wnt signaling pathway and reduced the osteogenic ability of CON-ASCs. Overexpression of JKAMP in DOP-ASCs rescued the impaired osteogenic capacity caused by DOP. Moreover, JKAMP in DOP-ASCs contained intragenic DNA hypermethylated regions related to the downregulation of JKAMP expression. Conclusions Intragenic DNA methylation inhibits the osteogenic ability of DOP-ASCs by suppressing expression of JKAMP and the Wnt signaling pathway. This study shows an epigenetic explanation for the reduced osteogenic ability of DOP-ASCs and provides a potential therapeutic target to prevent and treat osteoporosis.

Long non‑coding RNA RP11‑84C13.1 promotes osteogenic differentiation of bone mesenchymal stem cells and alleviates osteoporosis progression via the miR‑23b‑3p/RUNX2 axis

“…siRNAs have been used to study a variety of diseases, including osteoporosis. By Alizarin Red staining, it was revealed that osteogenic differentiation of hBMSCs was induced by transfection of si-STAT5a for 14 days ( 38 ); osteogenic differentiation of mBMSCs was inhibited by transfection of si-KLF5 for 14 days ( 39 ); the osteogenic ability of CON-ASCs was decreased by transfection of si-Jkamp for 14 days ( 40 ); osteogenic differentiation of hJBMMSCs was reduced by transfection of si-SEMA3A for 14 days ( 37 ). In general, siRNAs have a short role time in cells, which may be attributed to the gradual dilution of siRNAs after transfection in cell replication, so that the gene silencing effect gradually disappears.…”

Melatonin and the Programming of Stem Cells

“…However, these epigenetic differences in DNA methylation of osteogenic and adipogenic factors do not yet explain the difference in Wnt signaling. The solution of this problem may be sought in findings concerning a relationship between DNA hypermethylation and reduced Wnt signaling in ADMSCs [174][175][176]. Although these results have not been made in a melatoninrelated context, but rather in that of diabetes and advanced glycation end products, they may be taken as a proof of principle.…”

METTL3‐m6A methylase regulates the osteogenic potential of bone marrow mesenchymal stem cells in osteoporotic rats via the Wnt signalling pathway

“…The Wnt signalling pathway is a pivotal regulator of bone differentiation, development and homeostasis of BMSCs. [26][27][28] Todd et al…”

“…The Wnt signalling pathway is a pivotal regulator of bone differentiation, development and homeostasis of BMSCs 26–28 . Todd et al found that Wnt16 was significantly reduced in the BMSCs of ovariectomized (OVX) mice 29 .…”