Long-term type 1 diabetes alters the deposition of collagens and proteoglycans in the early pregnant myometrium of mice

Abstract

troduction: We have previously shown that long-term type 1 diabetes affects the structural organization, contractile apparatus and extracellular matrix (ECM) of the myometrium during early pregnancy in mice. Objective: This study aimed to identify which myometrial ECM components are affected by diabetes, including fibril-forming collagen types I, III and V, as well as proteoglycans, decorin, lumican, fibromodulin and biglycan. Methods: Alloxaninduced type 1 diabetic female mice were divided into subgroups D1 and D2, formed by females that bred 90- 100 and 100-110 days after diabetes induction, respectively. The deposition of ECM components in the myometrium was evaluated by immunohistochemistry/immunofluorescence. Results: The subgroup D1 showed decreased deposition of collagen types I and III in the external muscle layer (EML) and decreased collagen types III and V in the internal muscle layer (IML). Collagen types I and III were decreased in both muscle layers of the subgroup D2. In addition, increased deposition of collagen types I and III and lumican as well as decreased collagen type V were observed in the connective tissue between muscle layers of D2. Lumican was decreased in the EML of the subgroups D1 and D2. Fibromodulin was repressed in the IML and EML of both D1 and D2. In contrast, decorin deposition diminished only in muscle layers of D2. No changes were noticed for biglycan. Conclusions: Subgroups D1 and D2 showed distinct stages of progression of diabetic complications in the myometrium, characterized by both common and specific sets of changes in the ECM composition.