Cell Prolif: LncRNA-AK137033 regulates the Wnt signaling pathway through DNA methylation and inhibits the osteogenic potential of adipose-derived stem cells in diabetic osteoporosis

Background: Diabetes mellitus is a systemic metabolic disease characterized by hyperglycemia
.
This systemic disorder of glucose metabolism has a severe negative impact on the skeletal system, leading to a serious complication of the skeletal and joint system, namely diabetic osteoporosis (DOP)
.
In addition to the microenvironment of hyperglycemia, DOP patients also have the characteristics of bone microstructure damage, decreased bone strength, fracture susceptibility, and poor healing of bone defects
.
For bone defects in DOP patients, current treatments are suboptimal
.
With the rapid development of tissue engineering, bone tissue engineering includes scaffold materials and stem cells
.
Adipose-derived stem cells (ASCs) are one of the most widely used seed cells in bone tissue engineering
.
However, our previous study showed that diabetic osteoporotic adipose-derived stem cells (DOP-ASCs) had lower osteogenic potential compared with control adipose-derived stem cells (CON-ASCs), limiting their use in fractures and bone defects in DOP patients application in therapy
.
Therefore, the molecular mechanism of the decreased osteogenic ability of DOP-ASCs needs to be further explored to find potential targets for the treatment of bone defects in DOP patients
.

Objective: Bone tissue engineering based on adipose stem cells (ASCs) is expected to become a new method for the treatment of diabetic osteoporosis (DOP) with bone defects
.
However, compared with control ASCs, the osteogenic capacity of DOP-ASCs was reduced, increasing the difficulty of bone remodeling in patients with DOP
.
Furthermore, the reason for the poor osteogenesis of ASCs in a hyperglycemic microenvironment has not been elucidated
.
Therefore, this study explored the molecular mechanism of the decreased osteogenic potential of DOP-ASCs from the perspective of epigenetics, and provided possible therapeutic targets for bone repair in patients with DOP and bone defects
.

METHODS: A mouse model of DOP was established
.
CON-ASCs and DOP-ASCs were isolated from CON and DOP mice, respectively
.
The expression of AK137033 in CON-ASCs and DOP-ASCs was regulated in vitro by AK137033 small interfering RNA (siRNA) and AK137033 overexpression plasmid
.
AK137033 was knocked down or overexpressed in CON-ASCs and DOP-ASCs, respectively, using lentiviruses carrying shRNA-AK137033 or AK137033 cDNA
.
Hematoxylin and eosin (H&E), Masson's, Alizarin red, alkaline phosphatase (ALP) staining, micro-computed tomography (micro-CT), flow cytometry, qPCR, western blotting, The functional changes of ASCs were analyzed by immunofluorescence and bisulfite-specific PCR (bisulfite-specific PCR, BSP)
.

Results: The DOP mouse model was successfully established
.
Compared with CON-ASCs, the expression of AK137033, sFrp2 promoter DNA methylation level, Wnt signaling pathway markers, and osteogenic differentiation potential were all decreased in DOP-ASCs
.
In vitro experiments showed that silencing AK137033 inhibited the Wnt signaling pathway and the osteogenic ability of CON-ASCs by reducing the DNA methylation level in the sFrp2 promoter region
.
Furthermore, overexpression of AK137033 in DOP-ASCs abrogated these DOP-induced changes
.
The same results were obtained in vivo
.

Conclusion: LncRNA-AK137033 inhibits the osteogenic potential of DOP-ASCs by regulating the level of DNA methylation in the sFrp2 promoter region and regulating the Wnt signaling pathway
.
This study provides an important reference for finding new targets for the treatment of bone defects in DOP patients
.

Original source: Peng S, Gao Y, Shi S, et al.
LncRNA-AK137033 inhibits the osteogenic potential of adipose-derived stem cells in diabetic osteoporosis by regulating Wnt signaling pathway via DNA methylation.
  Cell Prolif 2021 Dec 24.