Hepatocyte growth factor inhibits tubular epithelial­myofibroblast transdifferentiation by suppression of angiotensin II via the JAK2/STAT3 signaling pathway.

Tubular epithelial­myofibroblast transdifferentiation (TEMT) is important in the development of chronic renal failure. The present study investigated whether hepatocyte growth factor (HGF) inhibits TEMT, and whether this function may be associated with the inhibition of angiotensin II (AngII) and the Janus kinase 2/signal transducer and activator of transcription 3 (JAK2/STAT3) signaling pathway. Human HK­2 kidney proximal tubular cells were divided into 4 groups and treated with AngII (1x10­6 M), HGF (8x10­3 M), AngII plus HGF or control conditions, followed by an assessment of apoptosis induction and the expression levels of α­smooth muscle actin (α­SMA), which is a marker of TEMT. as well as the activation level of JAK2, phosphorylated (p)­JAK2, STAT3 and p­STAT3 signaling pathways. In HK­2 cells, α­SMA mRNA and protein expression levels increased following treatment with AngII, however, decreased expression was observed following exposure to HGF. HGF counteracted the AngII­induced increase in the expression of α­SMA in HK­2 cells. Similar expression profiles were observed for the phosphorylated forms of JAK2 and STAT3, indicating the possible involvement of this signaling pathway. The results demonstrated that treatment of cells with AngII was associated with the induction of apoptosis when compared with the control. By contrast, treatment with HGF attenuated AngII­induced apoptosis. The results suggested that HGF may inhibit TEMT by inhibiting AngII through the JAK2/STAT3 signaling pathway in HK­2 cells and HGF may prevent apoptosis induced by AngII. The present study provides a basis for understanding the mechanisms involved in the inhibition of TEMT by HGF, which requires further investigation.

Pathological changes, TGF-ß1 expression, and the effects of hepatocyte growth factor in 5/6 nephrectomized rats.

Several studies have shown that hepatocyte growth factor (HGF) ameliorates chronic renal failure, but its mechanism of action is unclear. This study was designed to test the delivery of HGF in the PCI-neo vector, using the 5/6 nephrectomized rat as a model for chronic renal failure, and to confirm that this protective function is associated with decreased protein expression of transforming growth factor-beta1 (TGF-ß1). Rats were randomly divided into the following groups: Control (untreated), PCI-neo (vector control), 5/6 nephrectomy, and PCI-neo-HGF. Rats were sacrificed at both the fifth and ninth week after 5/6 nephrectomy. Kidney specimens were used for pathological examination (hematoxylin-eosin staining), and detection of TGF-ß1 protein (Western blot and immunohistochemistry) expression. Blood urea nitrogen, serum creatinine, and 24-h urinary protein excretion (UPE) were increased, renal interstitium was seriously injured, and TGF-ß1 protein expression was elevated in 5/6 nephrectomized rats compared to control rats at either time point. Red blood cell and hemoglobin levels decreased in the ninth week after 5/6 nephrectomy. PCI-neo-HGF expression ameliorated the aforementioned changes and decreased TGF-ß1 expression, not only in the fifth week, but also in the ninth week after surgery. The process of renal injury in the 5/6 nephrectomized rat was consistent with that of chronic renal failure. The increase in TGF-ß1 expression was maintained after 5/6 nephrectomy. HGF relieved chronic renal failure, this protection was associated with down-regulation of TGF-ß1 protein expression, and the protective effects were long-term and stable after 5/6 nephrectomy.

Hepatocyte growth factor-induced amelioration in chronic renal failure is associated with reduced expression of α-smooth muscle actin.

This study aimed to examine whether hepatocyte growth factor (HGF) can improve renal function in 5/6 nephrectomized rats and investigate whether this function is associated with a decrease in α-smooth muscle actin (α-SMA) expression in rat glomerulus mesangial cells and renal interstitium. Rats were randomly divided into the following groups: control, PCI-neo, sham-operation, 5/6 nephrectomy, and low-dose and high-dose PCI-neo-HGF. Rats were killed in the ninth week after 5/6 nephrectomy, and the kidney specimens were subjected to pathological examination by Hematoxylin-Eosin staining and detection of α-SMA expression by reverse transcriptase-polymerase chain reaction (RT-PCR), Western blot, and immunohistochemistry. The results showed that blood urea nitrogen and serum creatinine levels were increased, renal interstitium was injured, and α-SMA expression was elevated in 5/6 nephrectomized rats compared with that in control. The above changes were ameliorated in the rats injected with PCI-neo-HGF vector. At the molecular level we found that PCI-neo-HGF repressed α-SMA expression in mesangial cells stimulated by lipopolysaccharide. In conclusion, our data suggest that HGF can relieve chronic renal failure, and this protection is associated with the down-regulation of α-SMA expression in mesangial cells and renal interstitium.

Hepatocyte growth factor-induced amelioration in renal interstitial fibrosis is associated with reduced expression of alpha-smooth muscle actin and transforming growth factor-beta1.

Several studies have shown that hepatocyte growth factor (HGF) ameliorates renal interstitial fibrosis, but the mechanism is not fully clear. This study was designed to examine whether HGF can relieve renal interstitial injury in 5/6 nephrectomized rats, and to confirm whether this function was associated with decrease in alpha-smooth muscle actin (alpha-SMA) and transforming growth factor-betal (TGF-beta1) expression. The animals were randomized into 8 groups comprising 6 animals (n = 6) each: control (group I), PCI-neo (group II, 900 microg), sham-operation (group III, not nephrectomy), model or 5/6 nephrectomy group (group IV), lotensin group (an angiotensin converting enzyme inhibitor, group V, 0.6 mg/100 g/day for 5 weeks), low-dose PCI-neo-HGF group (group VI, 690 microg), high-dose PCI-neo-HGF group (group VII, 1380 microg) and lotensin + high-dose PCI-neo-HGF group (group VIII, 0.6 mg/100 g/day for 5 weeks, 1380 microg). The animals were sacrificed in the 5th week after 5/6 nephrectomy. The specimens of kidneys were used for pathological examination (hematoxylin-eosin staining), detection of alpha-SMA and TGF-beta1 mRNA (Reverse transcriptase-polymerase chain reaction) and protein (Western blot and immunohistochemistry) expression. The results showed that in 5/6 nephrectomized rats blood urea nitrogen (BUN), serum creatinine (CRE) and 24 h urinary albumin excretion (UAE) were increased, renal interstitium was injured seriously and alpha-SMA, TGF-beta1 mRNA and protein expression were elevated compared with those of control. The above changes were ameliorated and alpha-SMA and TGF-beta 1 expression was reduced by both PCI-neo-HGF and lotensin. The lotensin + high-dose PCI-neo-HGF group rats exhibited the most significant therapeutic effect both in decreasing the BUN, CRE and 24 h UAE and in relieving renal interstitial injury. In conclusion, the study demonstrated that HGF can relieve renal interstitial injury and this protection was associated with down-regulation of a-SMA and TGF-beta 1 expressions.

[The relationship between hyperuricaemia and clinic pathology of IgA nephropathy].

OBJECTIVE: To analyze the correlation between the level of serum uric acid and the clinical and pathological features of IgA nephropathy. METHODS: Totally 148 patients diagnosed as IgA nephropathy by renal biopsy in our hospital from January 2007 to December 2010 were divided into hyperuricaemic group (41 cases) and non-hyperuricaemic group (107 cases) according to the level of serum uric acid. The clinical parameters and renal pathology grade were compared. RESULTS: There were significant differences between hyperuricaemic group and non-hyperuricaemic group in the incidences of hypertension (63.4% vs 38.3%), disease duration [(18.90 ± 10.12) months vs (9.46 ± 3.91) months] and body mass index [(22.81 ± 3.60) kg/m(2) vs (15.32 ± 2.54) kg/m(2)] (all P < 0.05), while no differences in age and sex (both P > 0.05). The blood urea nitrogen (BUN) [(8.93 ± 4.28) mmol/L vs (5.21 ± 2.18) mmol/L], creatinine (Cr) [(155.96 ± 107.72) µmol/L vs (79.52 ± 40.01) µmol/L], serum triglycerides [(2.11 ± 1.06) mmol/L vs (1.86 ± 1.20) mmol/L] and 24-hour urine protein amount [(4328.16 ± 1434.25) mg/24 h vs (2885.10 ± 1388.15) mg/24 h] were significantly different between the two groups (all P < 0.05). The percentage of Lee's grade I + II in hyperuricaemic group was 12.2%, and IV + V grade was 39.0%, while percentage of Lee's grade I + II in non-hyperuricaemic group was 25.2%, and IV + V grade was 16.9% (P < 0.05). Tubulointerstitial lesions (TIL) grade III + IV was more in hyperuricaemic group, which was 68.3%, while TIL grade II was more in non-hyperuricaemic group, which was 76.6%. Renal artery damage grade II + III was more in hyperuricaemic group, which was 73.2%, while renal artery damage grade 0 + I was more in non-hyperuricaemic group, which was 69.2%. CONCLUSIONS: The level of serum uric acid was related with 24-hour urine protein amount, blood pressure and kidney function in IgA nephropathy, and Lee's grade, TIL grade and renal artery damage grade were severe in hyperuricaemic group.