#2161 Phosphodiesterase V inhibitor attenuates the fibrotic gene expression of human renal fibroblast derived from IgA nephropathy: an in-vitro study

Abstract

Abstract Background and Aims Renal fibrosis (RF) is the final common pathway that determines the progression of many glomerular disease including IgA nephropathy (IgAN). Till date there is no definite therapy available to retard RF. Being the key mediator of fibrosis, TGF-β is being targeted in many studies. Phosphodiesterase V inhibitor (PDE5i) is known to inhibit TGF-β but its role in RF is yet to be established. Hence, in the current in-vitro study we wish to establish the role of PDE5 inhibitor as an inhibitor of TGF-β and hence the RF. Method This is a pilot study to evaluate the efficacy of ‘Phosphodiesterase V inhibitor’ on TGFβ1 induced fibrosis on fibroblasts derived from biopsy specimen of IgA nephropathy patients. Renal fibroblasts were cultured from six IgA patients. The fibroblasts cells were treated with PDE5i inhibitor (tadalafil) (at different doses of 1 µm, 5 µm, 10 µm and 15 µm), both before and after stimulation with transforming growth factor beta-1 (TGF-b1) (at doses of 5 ng/ml, 10 ng/ml, 15 ng/ml and 20 ng/ml). Gene expression was studied by real-time polymerase chain reaction (RT-PCR) for messenger ribonucleic acid (mRNA) of pro-fibrotic genes Col1a1, Col1a2, FN1, CTGF, ASMA, TIMP1, and anti-fibrotic MMP2. Objectives Results Our results shows that TGFβ significantly increased the expression of profibrotic gene (Col1a1, Col1a2, ASMA, CTGF, FN and TIMP1) at concentration of 10 ng/ml in the fibroblast cells derived from IgAN patients. Treatment of fibroblast cells with Tadalafil (PDE5 inhibitor) significantly decreased the pro-fibrotic gene mRNA expression (Col1a1, Col1a2, ASMA, CTGF, FN and TIMP1) with increased anti-fibrotic gene expression (MMP2) at the dose of 5 µm and 10 µm concentration in the fibroblast cells (Fig. 1). Conclusion This study may provide potential therapeutic target for prevention of renal fibrosis in IgAN patients. Till date PDE5 inhibitors were not used for IgAN. We found that, PDE5 inhibitor reduces the fibrosis in this in vitro study, this drug may be proposed as a potential therapy for IgAN.