Haikunshenxi 5/6 Nephrectomy Rat Glomerular Sclerosis Platelet-derived Growth Factor-bb Regulation Mechanism

Glomerular sclerosis(GS) is often the fundamental pathologicalcharacter of chronic renal failure(CRF). How to postpone GS has been animportant topic in the prevention and cure of CRF. The mechanisms of GSinclude the change of hemodynamics in glomcrulus, the injury of inherentcells in glomcrulus, the infiltration of macrophage, the abnormalexternalization of cell factors and the accumulation of extra cellularmatrix(ECM). The effects of the platelet-derived growthfactor-BB(PDGF-BB), one of the most important growth factors, ispenetrating all the while of GS. So to study its mechanisms and the wayto interrupt have considerable practical importance.PDGF-BB is an polypeptide growth factor excreted by blood disc,mononuclear macrophage, glomerular mesangial cells(GMCs) and renaltubular epithelial cell and so on. Its family consists of PDGF-AA, BB,CC and DD. The major physiological function of PDGF-BB is to promote thesynthesis of DNA. It can be over excreted by mononuclear macrophage andinherent cells of nephridial tissue in pathologic state, and then promotesthe proliferation and externalization of GMCs, the excess accumulationof ECM, and the synergistic effect with transforming growthfactor-β₁(TGF-β₁), and then leads to the occurrence and development ofGS.Fucoidan is a new second national grade traditional Chinese medicineused to cure CRF. The early stage clinical and animal experiments haveproved that this drug can postpone the procedure of CRF, but the mechanismsare still unknown to some extent. We established the 5/6 nephrectomy ratsmodel in order toinvestigate that weather fucoidan could prevent and cureCRF through the way of PDGF-BB, so as to provide the experimental basis for using it in clinic.ObjectiveTo provide the theoretical base to prevent and cure GS on clinic usingfucoidan, we used the 5/6 nephrectomy rats, and studied the effects offucoidan in the pharmacodynamics experiment and on the level of organism,organ, cell and gene.Methods1 72 male SD rats, weighting 200±20g, adopted for a week. Afterestablished by 5/6 nephrectomy, the rats were divided into 6 groups:normal group, sham operation group, model group, benazepril group,Niaoduqing group and fucoidan group. Benazepril group and Niaoduqinggroup are positive medicine control groups. The weight and the amount ofurine protein in 24 hours were measured every four weeks during theexperiment period. The remanent renal tissues were taken for pathologicalhistological observation including HE stain, PASM-HE stain, Mallory stainand Musson stain in 15th month after 5/6 nephrectomy. Blood ureanitrogen(BUN), serum creatinine(Scr), cholesterin(Cho), triglyceride(TG)and low density lipoprotein(LDL) were measured before the rats werekilled.2 The expression of PDGF-BB protein in rat's renal tissue was detectedby mean of immuno-histochemistry, and the expression of PDGF-BB mRNA wasdetected by mean of hybridization in situ.3 The GMCs cultured in vitro were induced by lipopolysaccharide(LPS),and corresponding drugs were given to interfere this proceed. Theproliferation of GMCs at times of 12 hours, 24 hours, 48 hours and 60 hourswere investigated by MTT colorimetry; The protein expression of PDGF-BBwas detected by the method of cell immune histochemistry and western blot;The expression of PDGF-BB mRNA was detected by reversetranscriptase-polymerase chain reaction(RT-PCR).Results 1 Fucoidan can control the over evacuation of urine protein of 5/6nephrectomy rats, and cut down Scr and BUN, what's more, this drug canimprove the pathological damnification of rats' renal tissue2 Fucoidan can reduce the expression of PDGF-BB protein and mRNA inrats' renal tissue.3 Fucoidan has the effect of leveling down the proliferation of GMCsstimulated by LPS.4 Fucoidan can decrease the content of PDGF-BB protein and mRNA thatwere over secreted by GMCs.ConclusionsThrough the investigation mentioned above, we can draw conclusionsas follows:Fucoidan can amendment the pathological damnification of 5/6nephrectomy rats' renal tissue. What's more, this drug can decrease theexpression of PDGF-BB protein and mRNA in renal tissue of model rats.Meanwhile it can also down regulate the proliferation of GMCs stimulatedby LPS and adjust the content of PDGF-BB protein and mRNA secreted by GMCs.All these conclusions tell us that one of the mechanisms of preventionand cure of GS using fucoidan may be that it can control the over expressionof PDGF-BB.