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:(1) normal glucose group (NG,5.5 mmol/L D-glucose),(2) high glucose group (HG,30 mmol/L D-glucose),and (3) 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 muscle 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.
ABSTRACT
Objective To investigate pathological changes of lens epithelium cells (LECs) and expressions of matrix metalloproteinase-3 (MMP-3),alpha-smooth muscle actin (α-SMA),and fibronectin (Fn) in lens epithelial cells of experimental diabetic cataract rats,and to evaluate the roles of MMP-3,α-SMA,and Fn in the pathogenesis of diabetic cataract.Methods A total of 105 healthy Sprague-Dawley (SD) rats without lens diseases was randomly divided into normal control (n =45) and diabetic model (n =60) groups.Diabetic model rats were subjected to intraperitoneal injection of streptozotocin (STZ) (60 mg/kg),and those in the normal control group received injection with 0.1 mmol/L citric acid buffer solution of the same volume.The diabetic models were affirmed upon a fasting blood ≥ 16.65 mmol/L at the 3rd days after the injection.Once a week,the changes of blood glucose and body weight were monitored and the progression of cataract formation in both lenses of all rats was recorded with slit lamp observation.At end of 4 weeks,8 weeks,and 12 weeks after STZ injection,lenses were isolated and embedded in paraffin.The LECs histopathology was examined with HE staining.Immunohistochemical method was used to detect expressions of MMP-3,α-SMA,and Fn in normal and diabetic LECs.The related comparisons and statistic analysis were carried out.Results The lenses of control group were always completely transparent throughout the period of experiment with 31.48％,77.78％,and 100％ of lenses in diabetic model group swelling at 4th,8th,and 12th week,respectively.Under the light microscopic level,it has been showed that lens epithelium cells,which was occurred aggregate plaque and arranged in many layers,presented some morphologic characteristics of fibroblasts by HE staining.In control group LECs regularly,MMP-3,α-SMA,and Fn did not express equally;MMP-3,α-SMA,and Fn expressions increased obviously highly,difference had statistical significance compared to diabetic cataract group LECs (P ＜ 0.01).With the development of course of disease,the differences in expression of MMP-3,α-SMA,and Fn were significant between the diabetic cataract LECs and the control group (P ＜ 0.01).During the progression of diabetic cataract,the expression of Fn was positively correlated with that of α-SMA and MMP-3 (r =0.994,P ＜ 0.01;r =0.993,P ＜ 0.01).Conclusions The diabetic cataract liyingbody animal model was established successfully,which has laid down necessary basis to expound the morbidity mechanism of diabetic cataract.In the lens of diabetic cataract group,the expressions of α-SMA,MMP-3,and Fn were significantly increased.They participated in the occurrence and development of diabetic cataract.The expression of Fn was positively correlated with α-SMA and MMP-3.The lens epithelium cells which took on elongated aspect like fibroblast cells appeared epithelial-mesenchymal transformation (EMT),which mediated the occurrence and development of LECs fibrosis.
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Objective To investigate the concentration change of indoxyl sulfate (IS) in blood and the renal expression of renal fibrosis-related factors (transforming growth factor-beta 1, TGF-β1;fibronectin, FN) after administration of mutagenic lactobacilli by oral.Methods A total of 60 male Sprague-Dawley (SD) rats aged 6 weeks was divided randomly into 3 groups.The normal control group (Sham group, n =20) received Sham operation of just incision of skin without kidney removed.The other two groups of rats were renal failure models selected from survivals of the other 40 rats who received real operation with 5/6 of kidney removed.Finally, 35 survived renal-failure rats were divided randomly into 2 groups : pathological control group(Model group, n =17) who were administrated of 2ml sterile saline solution once a day by gavage, and experimental group (lactobacillus bulgaricus (LB) group, n =18) who were administrated of 2 ml mutagenic lactobacilli (1.5 × 108 cfu/ml) once a day by gavage.Eight weeks later, blood specimens were taken to test the concentration of IS with high performance liquid chromatography-fluorescence detection (HPLC-FLU), and urea and creatinine by automatic biochemical analyzer;moreover, the rats were killed to get kidney tissues for pathological examination.Results The levels of serum IS, urea, and creatinine were statistically significantly different between two groups (P ＜ 0.05).Both the levels of renal tubular damage and renal interstitial fibrosis were both lessen in the experimental group compared to the model group (P ＜0.05).TGF-β1 and FN expressions in renal tissues were significantly decreased (P ＜0.05).Conclusions Mutagenic lactobacilli not only reduces serum concentration of IS, urea and creatinine in renal failure rats but lowers the expressions of TGF-β1 and FN in renal tissues.