Urinary exosomes from patients with diabetic kidney disease induced podocyte apoptosis via microRNA-145-5p/Srgap2 and the RhoA/ROCK pathway

This study aimed to explore whether urinary exosomes from type 2 diabetes patients with DKD could induce podocyte apoptosis and the underlying pathological mechanisms. The exosomes were isolated from the urine samples of patients with DKD (DKD-Exo). Later, they were taken up and internalized by MPC5 cells. MPC5 cells were co-cultured with DKD-Exo (45 μg/ml) for 24 h in the presence or absence of microRNA-145-5p (miR-145-5p) inhibitor, fasudil and pcDNA-Srgap2 transfection. MiR-145-5p and Srgap2 expression was evaluated using real-time quantitative PCR. The protein levels of Srgap2, Bcl-2, Bax, and cleaved caspase-3, as well as ROCK activity were determined using Western blotting. Cell apoptosis was measured using flow cytometry and the TUNEL assay. miR-145-5p expression in MPC5 cells exposed to DKD-Exo was markedly upregulated. miR-145-5p negatively regulated Srgap2 levels. Exposure of MPC5 cells to DKD-Exo reduced Srgap2 expression and activated ROCK, which was partly reversed by the presence of the miR-145-5p inhibitor or Srgap2 overexpression. The apoptosis of MPC5 cells exposed to DKD-Exo increased significantly, which was counteracted by the addition of the miR-145-5p inhibitor and fasudil. The results showed that urinary exosomal miR-145-5p from patients with DKD induced podocyte apoptosis by inhibiting Srgap2 and activating the RhoA/ROCK pathway, suggesting that urinary exosomal miR-145-5p is involved in the pathological process of DKD and could become a noninvasive d...
Source: Experimental and Molecular Pathology - Category: Pathology Authors: Source Type: research