Objective To explore the clinicopathological characteristics of acute kidney injury (AKI) of systemic sclerosis (SSc). Methods A retrospective study was performed on 11 SSc patients with AKI. The clinical data were analyzed and the patients were divided into antineutrophil cytoplasmic antibodies（ANCA） negative group (n=9) and ANCA positive (n=2) group. Results In the ANCA negative group, 2 cases were without malignant hypertension ,1 was acute tubular necrosis(ATN) caused by herbs, 6 were scleroderma renal crisis(SRC), including 4 with renal biopsy, indicating hypertrophic arterial media, edema, thickened intima, onion-skin lesion in interlobular arteries and afferent arterioles, as well as ischemic lesion in glomeruli. In the MPO-ANCA positive group, 1 was crescentic glomerulonephritis. Malignant hypertension was not noticed. All patients were given steroid, 8 of them received CTX in addition. Nine patients received dialysis, and 8 cases progressed to permanent hemodialysis. Six cases with SRC were given high dose ACEI and / or ARB. Six patients resulted in early death. Conclusions Scleroderma renal crisis and ANCA associated vasculitis may cause AKI in SSc patients. Patients with positive ANCA differ from those with negative ANCA in terms of clinical manifestation, pathology and treatment. Survival and prognosis of SSc patient were bad. High dose corticosteroids increases the risk of scleroderma renal crisis, so it is thereby recommended that dose above 15 mg/day should be avoided if possible.

Objective To evaluate the diuretic and natriuretic effect of aqueous extract of Astragali radix (ARE) and explore its possible mechanism. Methods Twelve healthy men were randomized to receive either placebo(n = 6) or a single oral dose of 0.3 g/kg body weight of ARE (n = 6) in a double-blind manner before oral administration of 10 ml/kg of 0.9% saline load. After two-week washout period, the subjects were crossed over. Results Compared with placebo, ARE produced significant increments in urinary sodium excretion(U_NaV) which reached a peak at 2 h [(0.30±0.05) vs (0.21±0.02) mmol/min, P < 0.05], as well as fractional sodium excretion, urinary excretion of chloride during 4 hours but none in urine volume, urinary potassium and creatinine excretion. No significant changes were observed in urine volume and urinary excretion of sodium, chloride and potassium during 12 hours and 24 hours. ARE also elevated plasma atrial natriuretic peptide level (pANP), urinary excretion of cGMP (U_cGMPV) and U_cGMPV/pANP ratio without affecting plasma renin--angiotensin-aldosterone system(RAAS), mean arterial blood pressure and creatinine clearance rate (Ccr). U_NaV was positively correlated with pANP, U_cGMPV and U_cGMPV/pANP ratio (r = 0.947,0.957,0.442, all P < 0.05), but not correlated with Ccr (r = 0.153, P > 0.05). Conclusions ARE induces obvious natriuresis in healthy men and the effect is at least partly attributed to an increase in ANP secretion and its renal responsiveness.

Objective To study the relationship between plasma advanced oxidation protein products (AOPP) and vascular calcification in uremic patients and to investigate the role of AOPP-HSA in osteoblast differentiation of human aortic smooth muscle cell (HASMC) in vitro. Methods Fifty patients with CKD stage Ⅴ were included in study and pieces of radial arteries were taken during the arteriovenous fistula operation. Ten patients with thymoma and normal renal function were chosen as controls. Pieces of internal thoracic artery were taken in the operation. The vessels were examined for calcification by alizarin red staining and for the presence of osteopontin(OPN) by immunohistochemistry. Measurements of intima-media thickness (IMT) and wall-to-lumen ratio of radial arteries were assessed with HE staining. Plasma AOPP and blood chemistry, including serum calcium, phosphate, iPTH were analyzed. AOPP-HSA was prepared in vitro with human serum albumin (HSA) and hypochloric acid. The effect of AOPP-HSA on the expression of OPN and core binding factor α1 (CBFα-1) were examined by real-time PCR in HASMC in vitro. Results Plasma AOPP levels in patients with CKD stage Ⅴwere significantly higher than those in controls [(90.22±55.88) vs (35.79±4.31) μmol/L, P < 0.01]. Vascular calcification was found in the media of the vessels of 24 uremic patients (48%), while not in controls. OPN was expressed in the media of the vessels of 44 uremic patients (88%), but there was little staining in control vessels. OPN was observed in all calcified vessels, and in 20 of the 26 non-calcified vessels (76.9%). Patients with calcified vessels showed remarkably higher levels of AOPP as compared with those without calcified vessels [(122.52±66.9) vs (61.29±31.23) μmol/L, P ＜ 0.01]. Pearson correlation analysis showed that plasma levels of AOPP were positively correlated with the extent of calcification (r ＝ 0.791, P ＜ 0.01), IMT (r ＝ 0.691, P ＜ 0.01) and wall-to-lumen ratio (r ＝ 0.354, P ＜ 0.05) of radial arteries. The extent of calcification was positively correlated with AOPP (r ＝ 0.791，P ＜ 0.01), serum phosphate (r ＝ 0.602, P ＜ 0.01) and serum iPTH (r ＝ 0.549, P ＜ 0.05). In vitro studies demonstrated that AOPP-HSA, compared to HSA and controls, directly increased the expression of CBFα-1 and OPN in HASMC. Conclusions Increased plasma AOPP and vascular calcification are found in patients with CKD stage Ⅴ. Plasma levels of AOPP are closely related to vascular calcification. In vitro AOPP may directly induce the osteoblast differentiation of HASMC.

Objective To observe the renal protection of rosiglitazone in diabetic rats and to investigate the mechanism. Methods Thirty-two SD rats (male, 200~250 g body weight) were divided into four groups as follows: normal rats, diabetic rats, diabetic rats treated with low dose of rosiglitazone and diabetic rats treated with high dose of rosiglitazone. After 4 weeks, blood glucose, blood lipid, blood creatinine, and 24 h urinary albumin were measured. Then, the rats were sacrificed. Lipid peroxidatin (MDA), the activities of NF-κB and antioxidant enzymes including Cu-Zn superoxide dismutase (Cu-Zn SOD), glutathione peroxidase (GSH-Px) and total antioxidative capacity(T-AOC) in kidney were examined too. In addition, the renal tissue was observed by light microscopy. The expression levels of mRNA and protein of monocyte chemoattractant protein 1(MCP-1) were semi-quantitatively determined with reverse transcription-polymerase chain reaction and immunohistochemical staining respectively. Results No significant differences of blood glucose and blood lipid were found between diabetic rats and rosiglitazone treatment groups. Compared with diabetic group, the levels of serum creatinine, urinary albumin excretory rate, MCP-1 mRNA and protein, renal MDA and the activity of NF-κB in high dose rosiglitazone treated group decreased significantly, but the activity of renal Cu-Zn SOD, GSH-Px and T-AOC increased significantly. Renal pathologic changes in high dose rosiglitazone treated group were also improved. Conclusion Rosiglitazone improves the biochemical parameters and renal pathologic changes in diabetic rats, which is closely related to the antioxidization and the decrease of NF-κB and MCP-1 activity in renal tissue.

Objective To study the effect of FK506 on renal hypertrophy and its mechanism in early diabetic rats. Methods Diabetes was induced with streptozotocin in rats, and FK506 (0.5 or 1.0 mg/kg) was orally administered once a day for 4 weeks. Relative kidney weight (RKW), 24-hour urinary albumin excretion rate (AER) and creatinine clearance rate (Ccr) were measured. Kidney pathology was observed by light microscopy. The expression of calcineurin (CaN), 1α type Ⅳ collagen, α-smooth muscle actin (α-SMA) and transforming growth factor β1 (TGFβ-1) were determined by Western blot or immunohistochemistry. Results Increased RKW was significantly reduced by FK506 treatment with 1.0 mg/kg (P < 0.05). Elevated AER was markedly attenuated by FK506 treatment with 0.5 and 1.0 mg/kg (P < 0.05, 0.01). Ccr in diabetic rat was not changed by FK506 treatment with 0.5 or 1.0 mg/kg. Elevated glomerular volume was significantly attenuated by FK506 treatment with 0.5 and 1.0 mg/kg (P < 0.05), and increased indices for tubulointerstitial injury were only ameliorated by FK506 treatment with 1.0 mg/kg (P <0.01). Western blot analysis demonstrated that the expression of CaN protein was increased by 2.4 folds in the kidney of diabetic rats as compared to control, and FK506 treatment with 0.5 and 1.0 mg/kg could reduce the increased expression of CaN protein by 38.0% and 73.2%. The expression levels of 1α type Ⅳ collagen, α-SMA and TGF-β1 protein in the kidney were significantly increased in diabetic rats and decreased by FK506 treatment (P < 0.05, 0.01). Conclusion FK506 can inhibit early renal hypertrophy in diabetic rats, whose mechanism may be at least partly associated with down-regulation on increased expression of CaN in the kidney of diabetic rats.

Objective To observe the protective effects of rosiglitazone (RSG) on nephrotoxicity induced by cyclosporine A (CsA) in rats and normal rat kidney cells (NRK). Methods Three groups of adult male Sprague-Dawley rats that received sodium-depletion diet (SD, 0.037% sodium) were studied. Controls (n = 12) were fed with SD and vehicle; CsA-treated rats (n = 15) were given SD and CsA (15 mg·kg^-1·d^-1, i.h.) to establish chronic CsA nephropathy(CCN); rosiglitazone-treated rats (n = 15) were given SD and CsA (15 mg·kg^-1·d^-1, i.h.) and RSG (5 mg·kg^-1·d^-1) by gavage. Six rats of each group were sacrificed at day 14 and others were sacrificed at the end of the study (day 35). Blood, urine and tissue sample were collected at the two time points. NRK cells were cultured and incubated with CsA and RSG at different concentrations. Kidneys underwent light microscopy by Masson staining to observe the renal interstitial fibrosis index and immunohistochemistry for α-SMA and TGF-β1. Renal cortex TGF-β1 mRNA expression was measured by RT-PCR. Phosphorylation-extracellular signal regulated kinase (p-ERK), fibronectin (FN) and type 1 receptor of angiotensin Ⅱ (AT1R) were measured by Western blot. Plasma and intrarenal Ang Ⅱ activity were measured by radioimmunology. Results Compared with control, CsA increased mononuclear cells infiltration in the interstitium at day 14, caused a significant decrease in the level of creatinine clearance rate, and induced tubulointerstitial fibrosis at day 35 (P < 0.01). These lesions of CCN were significantly ameliorated by RSG (P < 0.05). The overactiviated plasma and intrarenal angiotensin Ⅱ and the overexpression of fibronectin, α-SMA and TGF-β1 induced by CsA were alleviated by RSG (P < 0.05). Meanwhile, a significant increase of expression levels of TGF-β1, FN, p-ERK, AT1R protein in NRK cells by CsA was found (P < 0.01). Treatment with RSG for 24 h attenuated these upregulation (P< 0.01). Conclusions Rosiglitazone, possibly by activating PPARγ, delays the progression of CCN. These effects were linked to decreased expression of TGF-β1, α-SMA and ECM. PPARγ may be a new target for the prevention and treatment of CCN.

Objective To investigate the effects of high glucose and insulin on the expression of GLUT4 and the time course of GLUT4 translocation in glomerular mesangial cells (GMC) and to explore the role of GLUT4 in the genesis and development of diabetic nephropathy(DN). Methods Cultured 1097 rat GMC were divided into 8 groups: （1）control， （2）10^-9 mol/L insulin， （3）10^-8 mol/L insulin， （4）10^-6 mol/L insulin， （5）high glucose， （6）mannitol， （7）high glucose plus 10^-6 mol/L insulin， （8）high glucose plus 10^-9 mol/L insulin. GLUT4 mRNA expression was examined by reverse transcription-polymerase chain reaction (RT-PCR). Confocal microscopy was used to detect the presence of GLUT4 in each group and the time course of GLUT4 translocation in Group（2）, （3）and（4）. Results Insulin enhanced the expression of GLUT4. High glucose decreased the expression of GLUT4 obviously. Insulin induced the translocation of GLUT4 of GMC. The time course of GLUT4 translocation was similar in 10^-8 mol/L insulin and 10^-6 mol/L insulin. Maximal translocation of GLUT4 was reached at 15 min after insulin incubation. The fluorescent intensity of GLUT4 located in the cell membrane at all time points after 15 min was not significantly different（P > 0.05）. Conclusions Insulin can induce the translocation of GLUT4 in GMC and the time course is similar among different concentration groups. High glucose can inhibit the expression of GLUT4 in GMC. Insulin can partly reverse the effects caused by high glucose above. GLUT4 plays a significant role in the genesis and development of DN.

Objective To investigate short- and long-term outcome of the kidney after acute ischemia-reperfusion (IR) injury. Methods Rat model of renal IR was established with clamping both pedicles for 40 min followed by reperfusion. Blood sample and kidneys were collected at indicated times. Serum creatinine levels, mortality and histological change were observed throughout the study. Transmission electron microscopy (TEM) was used to observe tubular ultra-structure. Apoptosis was confirmed by terminal deoxynucleotidyl transferase (TdT)-mediated dUTP-biotin nick end labeling (TUNEL) assay. The extent of tubulointerstitial fibrosis was evaluated by Masson trichrome staining. The expression of α-smooth muscle actin (α-SMA) and transforming growth factor-β1(TGF-β1) was determined by Western blot and immunohistochemical analysis. Results Extensive proximal tubular necrosis, functional impairment and high mortality (32%, 8/25) were found in the early phase after renal IR injury, accompanied by a small number of apoptotic cells. Patchy tubulointerstitial fibrosis was obvious at 5th and 10th week postischemia, in correlation with renal hypertrophy and increased urinary output. Moreover, the expression of α-SMA and TGF-β1 increased significantly at first, 5th and 10th week in the kidneys of IR group compared to sham-operated group. Above expression was localized mainly in the injured tubulointerstitium, consistent with the distribution of renal fibrosis. Conclusions Severe renal IR injury may lead to acute tubular necrosis, functional disorder and high mortality in short term. The initial structural injury in the kidney is irreversible and tubulointerstitial fibrosis is the final outcome. Increased myofibrolasts (α-SMA positive) and overexpression of TGF-β1 maybe contribute to the process of tubulointerstitial fibrosis.

Objective To establish MCP-1 siRNA human renal tubular epithelial cells line and to investigate the inhibitory effect of plasma-mediated small interfering RNA (siRNA) on the expression of monocyte chemoattractant protein-1 (MCP-1) gene in human renal tubular epithelial cells (HKC). Methods Three pairs of siRNAs directed human’s MCP-1 mRNA 67, 116, 142 targets were designed and synthesized. Eukaryotic expression vector specific for MCP-1 was constructed and transiently transfected into HKC by lipofectamine. At 24 hour after transfection, the mRNA and protein expression of MCP-1 was detected by real time RT-PCR and Western blot, respectively. The most effective sequence and device lentivaris plasmids were chosen and lentivaris granule’s packaging as well as production were applied. Virus fluid was derived and its density was identified. HKC were transfected by virus fluid and MCP-1 siRNA human renal tubular epithelial cells line was established. The mRNA and protein expression of MCP-1 was detected by real time RT-PCR and Western blot, respectively. Results MCP-1 siRNA human renal tubular epithelial cells line were successfully established . Compared with the normal control group, the mRNA and protein expression of MCP-1 siRNA stable transfection group were markedly down-regulated [(68.49±6.38)%,（72.97±6.13）%, respectively] （P<0.01）. Conclusions MCP-1 siRNA can highly inhibit the expression level of MCP-1 gene. It suggests MCP-1 siRNA human renal tubular epithelial cells line be crucial for offering experimental data to detect gene function and prevent renal interstitial fibrosis.

Objective To study the effect of two TGF-β1 shRNA expression plasmids (pcDU6-A1-A2 and pcDU6-B1-B2) on proliferation, TGF-β1, CTGF and FN synthesis induced by human serum albumin(HSA) in HK2 cells and to explore the mechanism concerned. Methods A vector plasmid containing the shRNA of TGF-β1 was generated. An HK2 cell line was used in the study. Two TGF-β1 shRNA expression plasmids were transfected into cultured HK2 cells by lipofectamine 2000. Cellular proliferation was assessed by tetrazolium salt colorimetry (MTT). The semi-quantitative reverse transcriptive PCR was performed to detect the expression of TGF-β1, CTGF and FN mRNA. Levels of TGF-β1 and FN protein were measured with a sandwich enzyme-linked immunosorbent assay. Results After treating with 5 g/L HSA for 24 h in HK2 cells, cellular proliferating capacity significantly increased(P < 0.05). The expression levels of TGF-β1, CTGF and FN mRNA were up-regulated in HK2 cells stimulated by 5 g/L HSA, and levels of TGF-β1 and FN protein in the culture supernatant increased（P <0.05）. The introduction of pcDU6-A1-A2 and pcDU6-B1-B2 resulted in significant reduction of cell proliferation activity. The expression levels of TGF-β1, CTGF and FN mRNA were down-regulated (P < 0.05). Levels of TGF-β1 and FN protein in the culture supernatant decreased (P <0.05). There were no significant differences of the expression levels of TGF-β1, CTGF and FN mRNA between two pcDU6 vector plasmid mediated TGF-β1 shRNA groups(P >0.05). Conclusion pcDU6 vector plasmid-mediated TGF-β1 shRNA inhibits the mRNA expression of TGF-β1, CTGF, FN and cellular proliferation stimulated by HSA in HK2 cells, which may be related to the mediation of TGF-β1.