[Effect of LDL on human mesangial cell proliferation]

Hyperlipidemia is one of the main features of nephrotic syndrome (NS), which has been reported to be important in the pathogenesis of mesangial cell proliferation. In an attempt to understand if LDL of the NS patients is more nephrotoxic on the development of mesangial cell proliferation, serum lipoprotein composition of normal controls, patients of NS untreated and treated with steroid drugs were measured, moreover, the influence of LDL from each group of patients on the proliferation of human mesangial cell (HMC) were observed. Lipoprotein composition was measured by enzymic methods. LDL was prepared by ultracentrifugation and used within three weeks. HMC was cultured and identified by classical methods, mesangial cell proliferation was observed by 3H-TdR incorporation according to the dose of LDL from 20-1000 micrograms/ml and time from 24 hours to 72 hours. Our results indicated that: 1. Both the NS patients untreated and treated with steroid drugs showed hypercholesterolemia and hypertriglyceride, serum low-density lipoprotein cholesterol (LDL-ch) concentration were higher in these patients than in the normal control group but there was no significant difference between NS untreated and treated groups. 2. LDL from normal controls or NS patients had biphasic effect on HMC proliferation. Low concentration stimulated HMC proliferation in concentration dependent and time-dependent manner, where as high concentration inhibited HMC proliferation. There was no significant difference on the effect of HMC proliferation between NS untreated and treated groups.(ABSTRACT TRUNCATED AT 250 WORDS)