Platelet-Endothelial Cell Interactions Modulate Smooth Muscle Cell Phenotype in an vitro Model of Type 2 Diabetes Mellitus.

Platelets (PLTs) - endothelial cells (ECs) interaction appears to contribute to phenotypic transition of VSMCs that play an important role in the physiological and pathological process of vascular complications in Type 2 diabetes (DM2). However, the precise mechanisms by which interactions between PLTs and ECs affect VSMCs phenotype, have largely remained unclear. We determined the effect of diabetic PLTs-ECs interaction to influence VSMCs migration, proliferation and phenotypic transformation in triple cell co-culture models using the qRT-PCR, western blot, fluorescence microscopy, wound scratch assays, CCK-8 assays, and gelatine zymography assays. Our results revealed that DM2 PLTs-ECs interaction to be associated with a significant down-regulation of VSMCs specific contractile phenotypic genes and proteins, including SM22α, SMA, Smoothelin-B and SM-MHC. Inversely, VSMCs specific proliferative phenotype genes and proteins levels including CCND1/and 2, SMemb, and PCNA were in up-regulation. Further, the DM2 originated PLTs-ECs interaction promoted the expression level of transforming growth factor (TGF)-β1, and the PI3K/Akt and MMP9 signaling pathway was activated subsequently. Finally, these reactions contributed to a synthetic phenotype of VSMCs, including the proliferation, migration and gelatinolytic activities. These findings suggest that PLTs-ECs interaction modulates the phenotypic transition of VSMCs between a contractile and proliferative/synthetic phenotype under diabetic conditions, conceivably providing important implications regarding the mechanisms controlling the VSMC phenotypic transition and the development of cardiovascular complications.