C-peptide exhibits a late induction effect on matrix metallopeptidase-9 in high glucose-stimulated rat mesangial cells

Abstract

Abstract. Insufficient matrix metalloproteinase (MMP)-9 and MMP-2 is considered to be a contributor of extracellular matrix (ECM) accumulation in diabetic nephropathy (DN). C-peptide can reverse fibrosis, thus exerting a beneficial effect on DN. Whether C-peptide induces MMP-9 and MMP-2 to reverse ECM accumulation is not clear. In the present study, in order to determine ECM metabolism, rat mesangial cells were treated with high glucose (HG) and C-peptide intervention, then the early and late effects of C-peptide on HG-affected MMP-9 and MMP-2 were evaluated. Firstly, it was confirmed that HG mainly suppressed MMP-9 expression levels. Furthermore, C-peptide treatment induced MMP-9 expression at 6 h and suppressed it at 24 h, revealing the early dual effects of C-peptide on MMP-9 expression. Subsequently, significant increase in MMP-9 expression at 72, 96 and 120 h C-peptide treatment was observed. These changes in MMP-9 protein content confirmed its expression changes following late C-peptide treatment. Furthermore, at 96 and 120 h C-peptide treatment reversed the HG-inhibited MMP-9 secretion, further indicating the late induction effect of C-peptide on MMP-9. The present results demonstrated that C-peptide exerted a late induction effect on MMP-9 in HG-stimulated rat mesangial cells, which may be associated with the underlying mechanism of C-peptide's reversal effects on DN. IntroductionDiabetic nephropathy (DN), the leading cause of end stage renal disease, is the major cause of mortality in type 1 diabetes mellitus (DM) and the second most severe complications in type 2 diabetes (1,2). Deposition of extracellular matrix (ECM) in mesangial areas is a feature of DN, and mesangial cells have been proposed to be the determinant of ECM accumulation (3,4). However, the mechanism underlying ECM accumulation in DN is not fully clarified.Matrix metalloproteinases (MMPs) are a family of zinc-dependent endopeptidases that can degrade numerous types of ECM components (5,6). Among others, MMP-2 basally expresses while MMP-9 is an inducible enzyme, both of which primarily degrade types-I and -IV collagen and laminin, major components of ECM (7-9). Generally, MMP-2 and MMP-9 are involved in tumor metastasis (6,10). Furthermore, it has been shown that insufficient MMP-2 and MMP-9 may be a contributor of ECM accumulation in DN (11). However, the expression levels of MMP-2 and MMP-9 in DN remain controversial, and even short-and long-term hyperglycemia may exert differential effects (8,(12)(13)(14). As an inducible enzyme, MMP-9 may be more easily affected in patients with DN (15). Therefore, the changes of MMP-2, and particularly MMP-9, for high glucose (HG) stimulation require clarification.C-peptide is the linker between the A-chain and B-chain of insulin. Lack of C-peptide along with insulin is the primary feature of type 1 DM and late stage of type 2 DM (16). C-peptide has been found to have unique beneficial effects on DN, attenuating glomerular and tubular injury (17)(18)(19). Physiological concentration of C-peptide ca...

The Impact of C-Peptide and Diabetes Mellitus on Coronary Ectasia and Effect of Coronary Ectasia and C-Peptide on Long-Term Outcomes: A Retrospective Cohort Study

“…Matrix metalloproteinases play an important role in the development of CAE [30]. Wang et al found that C-peptide induces matrix metalloproteinase 9 (MMP9) in mesangial cells in an experimental mouse model [31]. C-peptide-mediated stimulation of mitogen-activated protein kinases (MAPKs) has been demonstrated in previous studies and MAPK signal-mediated induction of MMP2, which plays a role in the pathogenesis of CAE, may contribute to the development of CAE [30,32,33].…”

Research Progress of C-Peptide and Its Physiological Function

“…The protective mechanism of C-peptide on DN is as follows: a) C-peptide stimulates eNOS gene transcription, inhibits iNOS expression, down-regulates RAGE and up-regulates PKA, and prevents and delays microangiopathy in the kidney [2] [6]. b) Matrix metalloproteinases (MMPs) are zinc-dependent endopeptidases, which can degrade many types of extracellular matrix components.C-peptides may reduce the accumulation of DN extracellular matrix by delaying MMP-9 expression, thus reversing DN [7]. c) C-peptide may be used as a natural antioxidant to protect the function of islet β cells and delay DN [8].…”