Study of the effect and mechanism of relaxin on the ECM excretion of Human renal mesangial cells cultured in high ambient glucose

Abstract

Objective To explore the effect and mechanism of relaxin on the production of extracellular matrix (ECM) excreted by high glucose stimulated human renal mesangial cells. Methods Cultured human mesangial cells (HMCs) were divided into three groups: ⑴ normal glucose group (NG, 5.5 mmol/L D-glucose), ⑵ high glucose group (HG, 30 mmol/L D-glucose), and ⑶ high glucose+ relaxin group. Cell count kit (CCK8) was used to examine the cell proliferation. The levels of fibronectin and collagen type Ⅳ in the culture supernatants were examined with a solid-phase enzyme-linked immunoadsorbent assay (ELISA); Western blot method was used to detect the expression of α-smooth muscle actin (α-SMA) protein. The transforming growth factor -β1 (TGF-β1) mRNA expression was detected with quantitative polymerase chain reaction (qPCR) method. Results No proliferation and inhibition effects were observed in both normal and high glucose group. Compared to the normal glucose group, the levels of fibronectin, and collagen type Ⅳ increased significantly(57.28±0.59 vs 41.85±0.03, 56.52±0.88 vs 33.80±0.24, P<0.01)after cultured 48 h in high concentration of glucose. Compared to the high glucose group, a significantly decreases of fibronectin and collagen type Ⅳ (47.08±0.03 vs 57.28±0.59, 36.16±0.52 vs 56.52±0.88, P<0.01) were observed in the relaxin treated group. The expressions of α-smooth mus-cle actin and TGF-β1 were decreased (P<0.01). Conclusions Relaxin can suppress the overproduction of ECM excreted by HMC cultured in high ambient glucose, and its mechanism is partly due to the inhibition of TGF-β1. Key words: Relaxin/PD; Glucose/AD; Mesangial cells/ME/DE; Extracellular matrix/DE; Transforming growth factor beta1/ME; Actins/ME; Collagen type IV/ME; Fibronectins/ME