P-787 Gestational diabetes in mice induces embryonic fibro-adipogenic progenitors memory that impedes the recovery of injured skeletal muscle in adult offspring
Authors: Yan Y  S , Jin M , Huang H  F 
Published: July 2024

Abstract

Study question
Whether and how intrauterine hyperglycemia induced by Gestational diabetes steadily influences the function and fate of mesenchymal stem cells, specifically fibro-adipogenic progenitors.

Summary answer
Gestational diabetes in mice caused declines in self-renewal and paracrine in fibro-adipogenic progenitors, prompted adipogenesis and fibrosis, destroyed recovery after muscular injury in adult offspring.

What is known already
Gestational diabetes contributed to the increased susceptibility to metabolic disorders, cardiovascular diseases and atherosclerosis. Intrauterine hyperglycemia promoted placental inflammation and endowed the hematopoietic stem and progenitor cells. As an important mesenchymal stem cell, fibro-adipogenic progenitors (FAPs) play a key role in the process of “replace, repair, regeneration, restore and regress”. When acute injury happens to skeletal muscle, the fibro-adipogenic progenitors cluster start to renew itself and differentiate into functional cells like fibroblasts or adipocytes, secrete cytokines to nearby myoblasts, inducing myotube formation and muscle regeneration by cell-cell communication.

Study design, size, duration
Pregnant mice were randomly divided into control (CTR) and gestational diabetes (GDM) groups, GDM group was intraperitoneally injected with 100 mg/kg streptozotocin on gestational days (GDs) 6.5 and 12.5, while CTR group was treated with vehicle buffer. Only when random blood glucose level was higher than 16.8 mmol/L beginning on GD13.5 were regarded as the GDM group. At 8 weeks of offspring, we intramuscular injected cardiotoxin (CTX) to induce acute tibialis anterior muscle injury.

Participants/materials, setting, methods
7 days after CTX intramuscular injection (CTX-D7) in offspring, mice were sacrificed and tiabialis anterior muscle was selected. Perilipin immunochemical and immunofluorescent staining, MASSON and Sirius Red staining were used to evaluate the recovery extent between CTR and GDM groups. Then we used fluorescence-activated cell sorting to evaluate the self proliferation of fibro-adipogenic cells at CTX-D3. We also collected FAPs to perform induced differentiation in vitro, co-culture with myoblast and SMART-sequence to explore underlying mechanism.

Main results and the role of chance
7 days after cardiotoxin injection (CTX-D7), we used WGA to mark injured myofibers, eMHC to mark regenerated myofibers. Immunofluorescence and hematoxylin-eosin staining showed the muscle fibers in GDM male were still severe damaged and inadequate recovered when compared to CTR group. Perilipin immunochemical staining demonstrated more lipids deposition in GDM male muscle. MASSON and Sirius Red staining also revealed increased accumulation of collagen fibers in GDM group. Fluorescence-activated cell sorting firstly displayed depletion in numbers of Lineage-VCAM-Sca-1+ fibro-adipogeneic progenitors (FAPs) compartment in GDM group at CTX-D3 compared to CTR group. Using α-SMA to mark collagen fibers, perilipin to mark adiposity cells, we also observed activation of the FAPs into fibrosis or adipogenesis by in vitro induced differentiation. Myotubes formation experiment showed that myotubes were thinner and fusion extent was worse in myoblasts co-cultured with GDM FAPs rather than CTR FAPs. Finally, we performed SMART-sequence of FAPs between groups. Regarding p &lt; 0.05 and the absolute of log2 foldchange &gt;1 as significance, we totally found 1572 down-regulated genes, 1527 up-regulated genes in GDM FAPs. And the GO term analysis showed us that WNT signaling pathway, cell surface receptor signaling pathway were most highly affected.

Limitations, reasons for caution
We haven’t found out the key molecule in WNT signaling pathway, and how intrauterine hyperglycemia steadily affected FAP’s function remains to be explored. Also, whether other mesenchymal stem cells are influenced by short-term intrauterine hyperglycemia needs to be clarified.

Wider implications of the findings
Fibro-adipogenic progenitors is an important part of mesenchymal stem cells. These results demonstrated GDM in mice might induce mesenchymal memory that affects the long-term health of the offspring, which reminds us the stemness of GDM progenitors or stem cells might be destroyed and its cell-cell function may be also damaged.

Trial registration number
ZJU20210047