March5-mediated Trim28 degradation preserves islet β-cell function in mice
Ontology highlight
ABSTRACT: Insulin deficiency from β-cell dysfunction underpins both type 1 and type 2 diabetes. However, the regulatory pathways underlying β-cell function remain incompletely understood. Here, we identify that March5 and Trim28 as key modulators of β-cell function. March5 is downregulated and Trim28 upregulated in islets from human or mouse with impaired glucose tolerance. Loss of March5 in β-cells impairs insulin production and glucose tolerance, while its overexpression improves both. Mechanistically, March5 inhibits Trim28 by targeting it for ubiquitination, thereby preventing Trim28-mediated Kindlin-2 degradation, which elevates MafA and insulin expression in male mice. Trim28 deletion in β-cells rescues glucose intolerance in March5-deficient male mice, highlighting their joint regulatory pathway. Furthermore, March5 and Kindlin-2 double haploinsufficiency significantly impair insulin production and glucose tolerance, underscoring their shared pathway. Importantly, islet transplantation with March5-overexpressing or Trim28-deficient β-cells effectively ameliorates glucose intolerance in streptozotocin-induced diabetic male mice. In conclusion, our results suggest that targeting the March5/Trim28/Kindlin-2/MafA pathway may offer a promising therapeutic strategy to restore β-cell function in diabetes.
INSTRUMENT(S): LTQ Orbitrap Elite
ORGANISM(S): Homo Sapiens (human)
TISSUE(S): Permanent Cell Line Cell, Cell Culture
DISEASE(S): Type 2 Diabetes Mellitus
SUBMITTER:
Yangshan Chen
LAB HEAD: Huiling Cao
PROVIDER: PXD066332 | Pride | 2025-07-24
REPOSITORIES: Pride
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