[Progress of research on the role of CLCNKB gene in classical Bartter syndrome].

Bartter syndrome is an inherited metabolic disorder characterized by hypokalemic alkalosis and high rennin-angiotensin-aldosteronism which can occur at all ages but mainly in childhood. Classical Bartter syndrome is caused by loss-of-function variants in the gene encoding basolateral chloride channel ClC-Kb (CLCNKB), which is a common type of Bartter syndrome characterized with diverse clinical manifestations ranging from severe to very mild. This article reviews the function and mechanism of CLCNKB variants in Chinese population and the genotype-phenotype correlation of CLCNKB variants in classical Bartter syndrome.

Splicing Characterization of CLCNKB Variants in Four Patients With Type III Bartter Syndrome.

OBJECTIVE: Type III Bartter syndrome (BS) is caused by loss-of-function mutations in the gene encoding basolateral chloride channel ClC-Kb (CLCNKB), and is characterized by hypokalemic metabolic alkalosis and hyperreninemic hyperaldosteronism. Here, we investigated the molecular defects in four Chinese children with clinical manifestations of Bartter syndrome. METHODS: The genomic DNA of the four patients was screened for gene variations using whole-exome sequencing (WES). The candidate variants were validated by direct Sanger sequencing. Quantitative PCR (qPCR) was subsequently performed to confirm the whole CLCNK gene deletion mutation. A minigene assay and reverse transcription PCR (RT-PCR) were performed to analyze the effect of splice variants in vitro. RESULTS: Our patients showed early onset age with hyponatremia, hypokalemia, hypochloremia, repeated vomiting and growth retardation, suggesting Bartter syndrome. Genetic analysis revealed that all patients carried compound heterozygous or homozygous truncating variants in the CLCNKB gene. In particular, we identified a novel nonsense variant c.239G > A (p.(Trp80*)), two splice site variants (c.1053-1 G > A and c.1228-2A > G), a whole gene deletion, and a novel synonymous variant c.228A > C (p.(Arg76Arg)) which located -2 bp from the 5' splice donor site in exon 3. Furthermore, our in vitro minigene analysis revealed c.228A > C, c.1053-1G > A, and c.1228-2A > G cause the skipping of exon 3, exon 12, and exon 13, respectively. CONCLUSION: Our results support that the whole CLCNKB gene deletion is the most common mutation in Chinese patients with type III BS, and truncating and whole gene deletion variants may account for a more severe phenotype of patients. We verified the pathogenic effect of three splicing variants (c.228A > C, c.1053-1G > A, and c.1228-2A > G) which disturbed the normal mRNA splicing, suggesting that splice variants play an important role in the molecular basis of type III BS, and careful molecular profiling of these patients will be essential for future effective personalized treatment options.

Diagnosis of cobalamin C deficiency with renal abnormality from onset in a Chinese child by next generation sequencing: A case report.

The aim of the present study was to present the diagnosis and treatment course of a patient with cobalamin C deficiency (cblC) hospitalized with renal function abnormality from the onset. A female, 7-year-old patient who presented with a cough and progressive dyspnea for 1 day was admitted to the Children's Hospital of Nanjing Medical University (Nanjing, China). A routine clinical examination was performed, including physical examination, routine blood and urine tests, blood gas analysis, computed tomography scans of the head, chest and abdomen, electrocardiogram, echocardiography and abdominal ultrasonography. In addition, laboratory tests were performed, including tests for viral infection and markers of autoimmunity, humoral immunity, myocardial enzymes and tumors. Tandem mass analysis and renal biopsy were conducted. Next generation sequencing (NGS) was performed to identify mutated genes, and structural investigation was conducted to identify the key residue mutations in the patient. Routine clinical examination revealed that the patient had multiple organ failure, indicating the presence of metabolic disease. Tandem mass analysis and renal biopsy also indicated that the patient had methylmalonic acidemia (MMA) and thrombotic microangiopathy combined with focal renal cortical necrosis. Furthermore, next-generation sequencing identified the presence of two heterozygous mutations in the MMA cblC type with homocystinuria (MMACHC) gene. Structural analysis demonstrated that the two mutations were in key components of the MMACHC protein. The patient was finally diagnosed with cblC according to the results obtained. In conclusion, NGS may aid in the diagnosis and therapeutic management of cblC with renal abnormality from the onset in children.

Activation of ERK1/2 by NADPH oxidase-originated reactive oxygen species mediates uric acid-induced mesangial cell proliferation.

Hyperuricemia is associated with kidney complications including glomerulosclerosis and mesangial cell (MC) proliferation by poorly understood mechanisms. The present study investigated the underlying mechanisms that mediate uric acid (UA)-induced MC proliferation. A rat MC line, HBZY-1, was treated with various concentrations of UA in the presence or absence of a specific extracellular-regulated protein kinase 1/2 (ERK1/2) inhibitor (U0126), apocynin. UA dose dependently stimulated MC proliferation as shown by increased DNA synthesis and number of cells in the S and G2 phases in parallel with the upregulation of cyclin A2 and cyclin D1. In addition, UA time dependently promoted MC proliferation and significantly increased phosphorylation of ERK1/2 but not c-Jun NH2-terminal kinase and p38 MAPK in MCs as assessed by immunoblotting. Inhibition of ERK1/2 signaling via U0126 markedly blocked UA-induced MC proliferation. More importantly, UA induced intracellular reactive oxygen species (ROS) production of MCs dose dependently, which was completely blocked by apocynin, a specific NADPH oxidase inhibitor. Toll-like receptor (TLR)2 and TLR4 signaling had no effect on NADPH-derived ROS and UA-induced MC proliferation. Interestingly, pretreatment with apocynin inhibited ERK1/2 activation, the upregulation of cyclin A2 and cyclin D1, and MC proliferation. In conclusion, UA-induced MC proliferation was mediated by NADPH/ROS/ERK1/2 signaling pathway. This novel finding not only reveals the mechanism of UA-induced MC cell proliferation but also provides some potential targets for future treatment of UA-related glomerular injury.

[Clinical and immunological features of lupus nephritis in children: retrospective analysis of 40 cases].

OBJECTIVE: To analyze the clinical and immunological features of children with lupus nephritis (LN). METHODS: Chart records of 40 (4 male and 36 female) LN children who were admitted consecutively between January, 2005 and December, 2010 were reviewed. The baseline demographic, pathological and immunological data were analyzed. RESULTS: In the 40 LN patients analyzed, the mean age of the disease onset was 10.6 ± 2.6 (range from 2.6 to 14.3) years, and 35 cases (88%) were school-age children. Proteinuria was detected in all 40 cases, including nephrotic-range proteinuria in 12 (30%) cases, and isolated proteinuria in 9 (22%) cases. Twenty-six (65%) patients had varying degrees of hematuria. Acute nephritis was the most common sub-type, accounting for 47% of the total cases. Among the 39 cases undergoing renal biopsy, 3 were unclassified and the remaining 36 were classified, respectively, as type IV LN (50%, 18 cases), type II LN (22%, 8 cases). In the histopathologcally classified case, 100% were antinuclear antibody-positive, 61% were anti-dsDNA-positive, and 89% showed varying degrees of decrease in serum C3 and C4 concentrations. Following treatment for 6 months, a high LN remission rate (95%) was achieved; the acute renal activity index remained higher in IV, V+III and V+IV subtypes than in other subtypes, while the chronic index and the degree of tubulointerstitial damage were not different between histopathological subtypes. CONCLUSIONS: The clinical manifestations of LN children are diverse. Clinically, acute nephritis is the most common form of LN in children. Histopathologically, type IV is the most frequent subtype of LN. Early treatment may result in significant disease remission.

Correlation between PPAR Gene Polymorphisms and Primary Nephrotic Syndrome in Children.

Pediatric primary nephrotic syndrome (PNS) is a chronic disease promoted by metabolic and immune dysfunctions. Peroxisome proliferator-activated receptor (PPAR) polymorphisms have been associated with a variety of metabolic and kidney disorders. We therefore hypothesized that PPAR polymorphisms might be involved in the pathophysiology of PNS. We compared the distributions of the PPAR-γ Pro12Ala and Val290Met, PPAR-γ coactivator-α (PGC-1α) Gly482Ser, and PPAR-α Leu162Val single nucleotide polymorphisms (SNPs) between children with PNS and normal controls and analyzed their correlations with clinical and metabolic indicators and steroid responsiveness. There were no significant differences in distributions of any of the polymorphisms between PNS cases and controls. However, PNS patients with the PPAR-γ (Pro12Ala) PP genotype had significantly higher fasting serum insulin, IgA, and HOMA-IR levels and lower insulin sensitivity than did patients with PA and AA genotypes. Additionally, the PGC-1α (Gly482Ser) A allele was associated with lower CD8+ T-cell counts and higher triglyceride and complement C3 levels compared with the G allele. No polymorphisms were related to hormone sensitivity. These results suggest that the PPAR-γ (Pro12Ala) and PGC-1α (Gly482Ser) SNPs may influence insulin and triglyceride metabolism in children with PNS and may thus be relevant to the prognosis of this chronic condition.

Insulin resistance in children with primary nephrotic syndrome and normal renal function.

BACKGROUND: Insulin resistance (IR) is an independent risk factor for atherosclerosis or cardiovascular events and renal function impairment. The aim of this study was to investigate IR in children with primary nephrotic syndrome (NS). METHODS: One-hundred and nineteen primary NS patients with normal renal function and 125 normal controls were studied. Fasting blood glucose, fasting serum insulin, and fasting serum C-peptide were measured. The Homa index of insulin resistance (HOMA-IR), Islet B cell function, and insulin sensitivity index were calculated. Correlations were assessed between HOMA-IR, fasting serum C-peptide, blood pressure, blood lipids, renal function, coagulation, clinical disease type, pathology and the early therapeutic effectiveness of high-dose glucocorticoids. RESULTS: There was no evidence of IR in the primary NS group. Although levels of fasting blood glucose, fasting serum insulin and fasting serum C-peptide were all within the normal ranges, fasting serum C-peptide was significantly higher compared to the controls. There was no disorder of carbohydrate metabolism in different hormone therapy efficacy and pathological diagnosis. Although IR was not detected, a significant increase in blood pressure, uric acid, blood lipids and coagulability was observed in the primary NS group. CONCLUSION: A correlation observed between HOMA-IR, age, blood pressure, serum creatinine (Cr) and triglyceride may suggest that insulin sensitivity will emerge as renal disease progresses. Fasting serum C-peptide levels were increased in the primary NS group, suggesting that fasting serum C-peptide may be a protective factor.

The use of carbon black to catalyze the reduction of nitrobenzenes by sulfides.

Using carbon black (CB) as catalyst, the reduction of nitrobenzenes (NBs) to anilines by sulfides at room temperature was studied. In the reactions, CB serves as an intermedium to accelerate the reduction of NBs by sulfides. In the presence of 0.3g/L CB and 3.0 mM sulfides at pH 7.0 and 25°C, our results showed that CB-catalyzed reduction of NBs were pseudo-first order. The reduction rate constant of nitrobenzene was 0.0367 h(-1) in the presence of CB-1, which was 10 times more than the reduction rate constant in the absence of CB-1. Other experiments of different CB samples produced by different methods and different raw materials indicated that some active oxygenated functional groups on CB surface should be the reactive sites and play the dominant role in catalyzing the reduction of NBs. The catalytic reactions of different NBs by sulfides indicated that the reduction rate constants of chloronitrobenzenes to chloroanilines were greater than those of methylnitrobenzenes to methylanilines. And due to the effect of different substituent positions, the nitro group with meta substituent was reduced most easily while the nitro group with ortho substituent was reduced most difficulty.

[Mechanisms of decorin inhibiting epithelial-to-mesenchymal transition induced by transforming growth factor beta1 in renal tubular epithelial cells].

OBJECTIVE: To investigate the mechanisms of decorin inhibiting epithelial-to-mesenchymal transition (EMT) induced by transforming growth factor beta1 (TGF-beta1) in renal tubular epithelial cells. METHOD: HK-2 cells in vitro were divided into 4 groups: (1) negative control group; (2) decorin group, added with decorin 100 ng/ml ; (3) TGF-beta1 group, added with TGF-beta1 10 ng/ml; (4) decorin and TGF-beta1 group, added with decorin 100 ng/ml and TGF-beta1 10 ng/ml. The protein level of phosphor-ERK, phosphor-PI3K, phosphor-Smad(3) and beta-catenin was detected by Western blotting method. The snail mRNA level was tested by real time-PCR, while the lymphoid enhancer factor-1 (LEF-1) mRNA level was measured by RT-PCR. RESULTS: The snail (2.59 +/- 0.70:1.02 +/- 0.13) and LEF-1 mRNA (1.85 +/- 0.08:0.30 +/- 0.11) were significantly up-regulated, meanwhile the protein level of phosphor-ERK (1.11 +/- 0.09:0.47 +/- 0.07), phosphor-PI3K (14.79 +/- 1.02:2.48 +/- 0.06), phosphor-Smad(3) (0.95 +/- 0.02:0.08 +/- 0.01) and beta-catenin (1.46 +/- 0.20:0.49 +/- 0.05) were significantly increased in TGF-beta1 group compared to control group, while there were no statistically significant difference in all figures between control group and decorin group. The phosphor-ERK protein level (0.58 +/- 0.08) and the snail mRNA level (1.24 +/- 0.03) were significantly down-regulated in TGF-beta1 and decorin group compared to TGF-beta1 group, however there were no statistically significant differences in the level of phosphor-PI3K (15.84 +/- 1.64), phosphor-Smad(3) (0.90 +/- 0.04) and beta-catenin (1.42 +/- 0.09) between these two groups. CONCLUSION: Decorin inhibited EMT induced by TGF-beta1 which may be through blocking the ERK signal transduction pathway.

[Clinical and pathological features of Alport syndrome in children].

OBJECTIVE: To study the clinical and pathological features of Alport syndrome in children. METHODS: The clinical and histopathological data of 10 hospitalized children with Alport syndrome from February 2007 to February 2009 were retrospectively reviewed. RESULTS: There were 7 males and 3 females, with the age ranging from 2 years to 6 years and 7 months (mean 3 years and 2 months). Five of 10 cases had positive family history. X-linked dominant inheritance Alport syndrome was diagnosed in 8 cases, and autosomal recessive inheritance Alport syndrome in 2 cases. Recurrent gross hematuria was found in 5 cases, hematuria and proteinuria in 3 cases, massive proteinuria in 1 case, and nephritic syndrome in 1 case. Under the light microscope, 8 cases presented with mesangial proliferation glomerulonephritis, and 2 cases with focal segmental glomerulosclerosis. Immunofluorescence assay showed that all cases had IgM deposition in glomerulus. Only 1 case showed typical glomerular basement membrane (GBM) pathological changes. All cases showed abnormal alpha-chain distribution in renal collagen IV. CONCLUSIONS: The children with Alport syndrome have diverse clinical manifestations. Characteristic histopathological presentations could not be found under a light microscope, mesangial proliferation glomerulonephritis is the dominant pathological change, and IgM deposition in glomerulus is common. The GBM pathological change in children is not common. Immunofluorescence assay of alpha-chain in collagen IV is needed for the diagnosis of Alport syndrome.

[NADPH oxidase-derived reactive oxygen species involved in angiotensin II-induced monocyte chemoattractant protein-1 expression in mesangial cells].

OBJECTIVE: To investigate the origin of oxidative stress induced by angiotensin II (AngII) in human mesangial cells and the role of reactive oxygen species (ROS) in AngII-induced monocyte chemoattractant protein-1 (MCP-1) expression. METHODS: MCP-1 expression was determined by real time RT-PCR. ROS production was measured by DCFDA fluorescence. Nicotinamide adenine dinucleotide phosphate (NADPH) oxidase activity was examined by lucigenin chemiluminescence. p47phox and p67phox translocation was assayed by Western blot. Twenty-four male mice were randomly divided into three groups: the control, the AngIIinfusion [AngII 400 ng/(kg.min)], and the apocynin treatment. AngII was infused by subcutaneously osmotic minipump for 14 days. Urinary albumin and 8-isoprostane excretion were measured by ELISA. RESULTS: In cultured human mesangial cells, AngII induced the MCP-1 expression in a dose-dependent manner with 3.56 fold increase as compared with the control. AngII increased intracellular ROS production as early as 3 min with the peak at 60 min and was in a time and dose-dependent. Incubation with different dosages of AngII (1 nmol/L, 10 nmol/L, and 100 nmol/L AngII) for 60 min, ROS production increased at 1.82, 2.92, and 4.08 folds respectively. AngII-induced ROS generation was sensitive to diphenyleneiodonium sulfate (DPI, 10 micromol/L) and apocynin (500 micromol/L), two structurally distinct NADPH oxidase inhibitors. In contrast, inhibitors of other oxidant-producing enzymes, including the mitochondrial complex Iinhibitor rotenone, the xanthine oxidase inhibitor allopurinol, the cyclooxygenase inhibitor indomethacin, the lipoxygenase inhibitor nordihydroguiaretic acid, the cytochrome P450 oxygenase inhibitor ketoconazole and the nitric oxide synthase inhibitor G-nitro-L-arginine methyl ester were without an effect. AngII-induced ROS generation was inhibited by the AT1 antagonist losartan (10 micromol/L) but not the AT2 antagonist PD123319 (10 micromol/L). AngII treatment induced translocation of cytosolic of p47phox and p67phox to the membrane. The antioxidants almost abolished AngII-induced MCP-1 expression. AngII infusion increased urinary and p67 translocation by 2.69-, 2.97-, and 2.67-fold, respectively. CONCLUSIONS: NADPH oxidase-derived ROS is involved in AngII-induced MCP-1 expression. Inhibition of NADPH oxidase alleviates AngII-induced renal injury.

[Physical-chemical characteristics and phosphorus speciation of the sediments in the upper and middle reaches of the Yellow River].

The physical and chemical characteristics, various phosphorus forms from 10 sites in Yellow River's sediments were analyzed, and their relations were discussed. The results showed that, the values of total phosphorus, organic matter and active Fe, Al are 97.86-129.33 mg x kg(-1), 0.11%-1.96%, 2.02-7.40 mg x g(-1), 0.29-0.90 mg x g(-1), respectively. The main mineral compositions of the sediments are quartz and albite; the main clay minerals are montmorillonate, illite, chlorite and kaolinite. Inorganic-P is the main form of phosphorus speciation. Ca-P is 37.61-64.04 mg x kg(-1) and is the main form of IP. The cation exchange capacity was linearly correlated with the sum of clay and silt (R2 = 0.76). Also, the organic matter was linearly correlated with inorganic sedimentary phosphorus (R2 = 0.66). Moreover, the linear relationship between the sum of NaOH-P and BD-P and the sum of active Fe and active Al content was observed within the ten sediments investigated (R2 = 0.80).

[Characteristics of phosphorus sorption on Yellow River sediments from Inner Mongolia reach].

Sorption behavior of phosphorus on sediment samples taken from Inner Mongolia reach of the Yellow River in 6 different geographical sites was determined in laboratory, and the correlation between chemical-physical properties of the sediments and their phosphorus sorption characteristics was analyzed. The maximum sorption capacities were 43.64-85.46 mg/kg. The zero equilibrium P concentration (EPC0) of the sediments ranged from 0.0003 to 0.0198 mg/L, which was positively correlated to the contents of native adsorbed P (NAP). The sediments played a dual role of sink and source of P at different geographical sites. Sediments from Shizuishan, Wulateqianqi and Qingshuihe along the Yellow River were sources of phosphorus, while sediments from Wuhai, Linhe and Baotou cross sections were sinks of phosphorus, at the typical P concentrations of the river water. However, both the sorption and desorption capacities were low at the conditions tested here. The Langmuir sorption constant (k) was positively correlated to the cation exchange capacity (CEC), organic matter and clay mineral content, but negatively correlated to the particle size of the sediments. The maximum sorption capacity of phosphorus was remarkably correlated to the active Fe content. Active Fe played a key role in holding phosphorus on the sediments.

[The effects of core proteoglycan on the expressions of I and III collagen in human renal tubular epithelial cell induced by TGFbeta1 in vitro].

AIM: To explore the roles of core proteoglycan and TGFbeta1 on the expressions of I and III collagen in human renal tubular epithelial cell line(HK-2) in vitro. METHODS: Confluent HK-2 cells were exposed to TGFbeta1 and core proteoglycan for up to 48 h. The cells were divided into four groups. Group (1), negative control group; group(2), single 10 microg/L TGFbeta1 treated group; group (3), 10 microg/L TGFbeta1+10 microg/L core proteoglycan group; group (4), 10 microg/L TGFbeta1+100 microg/L core proteoglycan group. Morphologic characterization of HK-2 cells was shown by invertmicroscope; Precise amounts of I and III collagen mRNA were measured by RT-PCR. RESULTS: After 48 h, morphology of (1) group cells had no changes, most cells were normal shape; (2) group cells took great changes, most cells converted into spindle shape, like fibroblast, (3) and (4) groups, spindle shape cells reduced significantly. In contrast to (1) group, the expressions of I collagen in (2) group from mRNA significant increased by 27.86-fold. The expressions of III collagen increased by 21.83-fold. Comparing (3) and (4) groups to(2) group, the expressions of I collagen from mRNA effectively decreased 36.39% and 53.36%. III collagen expressions increased 26.35% and 47.96%èP<0.05érespectively. But, neither (3) group nor (4) group alone could regulate I and III collagen mRNA to normal levels. CONCLUSION: Core proteoglycan can inhibit the expressions of I and III collagen in HK-2 cells induced by TGFbeta1 in vitro. Possibly, suggest core proteoglycan contribute to the regulation of renal fibrosis.

[Phosphate sorption characteristics onto sediments in the middle and lower reaches of the Yellow River].

The equilibrium phosphate concentration (EPC0) of the Yellow River bed sediments has been measured, which was used to predict whether bed sediments are acting as a source or sink of soluble reactive phosphate (SRP). The modified Langmuir isotherm equation was used to describe phosphate (P) sorption on the Yellow River sediments. The maximum P sorption capacity (PAC) and P-binding energy constant (k) were obtained by the modified Langmuir isotherm model. Native adsorbed exchangeable phosphorus (NAP), the EPC0, and partitioning coefficients (Kp) were subsequently calculated by the corresponding formulae. The influence of pH values and ion strength were evaluated. All the EPC0 s are higher than the P concentration in the overlying water, indicating a potential source of phosphate from the sediments. PAC is linearly related to the contents of TOC of the sediment. The sorption capacity of P increased rapidly with pH below 6.0, and then reached a plateau between pH 6.0 to 9.7, and finally maintained at a slightly higher level from pH 9.7 to 12.0.The adsorption of P by the sediment decreased with the increase in Ca2+ ionic strength.

[Effects of core proteoglycan on the transdifferentiation of human renal tubular epithelial cell induced by transforming growth factor-beta1 in vitro].

OBJECTIVE: To study the effects of core proteoglycan on the transdifferentiation of human renal tubular epithelial cell induced by transforming growth factor beta1 (TGF-beta1) in vitro. METHOD: The cultured HK-2 cells were divided into six groups: A. negative control group; B. 10 ng/ml TGF-beta1 group; C. 10 ng/ml core proteoglycan treated group; D. 100 ng/ml core proteoglycan treated group; E. 10 ng/ml TGF-beta1 + 10 ng/ml core proteoglycan group; F. 10 ng/ml TGF-beta1 + 100 ng/ml core proteoglycan group. The changes in configuration of HK-2 cells were inspected 48 hours after adding the stimulating factor. At the same time, changes in mRNA of keratin, alpha-smooth muscle actin, vimentin were analyzed. RESULTS: Compared with group A, group B showed great changes in the morphology of cells, most cells converted into spindle shape, like fibroblast; groups E and F, especially group F showed significantly reduced spindle shape cells. Compared with group A, groups C and D had no significant changes in morphology of cells Compared with 10 ng/ml TGF-beta1 group and negative control, the mRNA expression of alpha-smooth muscle actin and vimentin had significant increase, but that of keratin reduced (P < 0.05). However, after combined treatment with TGF-beta1 and core proteoglycan, alpha-smooth muscle actin and vimentin expression were reduced significantly, while expression of keratin was up-regulated. Single core proteoglycan treated group and negative control group had no dramatic differences (P > 0.05). CONCLUSION: TGF-beta1 can induce the transdifferentiation of human renal tubular epithelial cell and core proteoglycan has some inhibitory effect on transdifferentiation of human renal tubular epithelial cell induced by TGF-beta1 in vitro.

2,2'-Bis(4-methoxy-phen-yl)-2,2'-bis-(tri-methyl-silan-yloxy)-2,2'-(ferrocene-1,1'-diyl)diacetonitrile.

In the title compound, [Fe(C(17)H(20)NO(2)Si)(2)], the Fe atom is situated on a crystallographic centre of inversion, leading to a perfectly staggered conformation of the Cp rings.

Characterization of a bioflocculant from a newly isolated Vagococcus sp. W31.

Screening of microorganisms producing flocculating substances was carried out. A strain secreting a large amount of bioflocculant was isolated from wastewater samples collected from the Little Moon River in Beijing. Based on the morphological properties and 16S rDNA sequence analysis, the isolate (designated W31) was classified as Vagococcus sp. A bioflocculant (named MBFW31) produced by W31 was extracted from the culture broth by ethanol precipitation and purified by gel chromatography. MBFW31 was heat-stable and had strong flocculating activity in a wide range of pH with relatively low dosage requirement. MBFW31 was identified as a polysaccharide with molecular weight over 2 x 10(6). It contained neutral sugar and uronic acid as its major and minor components, respectively. Infrared spectra showed the presence of hydroxyl, carboxyl and methoxyl group in its molecules. The present results suggested that MBFW31 had potential application in wastewater treatment.

[Effect of curcumin on extracellular matrix accumulation in the glomeruli in nephrotoxic sera nephritis rats].

OBJECTIVE: To observe whether curcumin could inhibit the accumulation of the collagen IV and fibronectin in the glomeruli in nephrotoxi sera nephritis rats. METHODS: Seventy-two healthy male Sprague-Dawley rats were divided into three groups, with 24 animals in each group. For normal control group, normal saline (0.5 ml/d) was injected through intra-caudal-vein for two days, and at the same time normal saline (0.5 ml/kg) was also daily administered intraperitoneally. For nephrotoxic sera nephritis group, nephrotoxic sera (0.5 ml/d) was injected through the tail vein for two days and dimethyl sulfoxide (0.5 ml/kg) was given intraperitoneally daily. For curcumin group, nephrotoxic sera was injected as above and meanwhile curcumin (50 mg.kg(-1).d(-1)) was administered intraperitoneally every day. Six rats in each group were killed on the 3rd, 7th, 14th and 28th day. Their renal tissue was fixed in 10% formalin for examining the expression of collagen IV and fibronectin. RESULTS: Minimal staining of collagen IV and fibronectin was detected in the basement membrane of normal control rats glomeruli. In the nephrotoxic sera nephritis rats and curcumin treated nephrotoxic sera nephritis rats, the accumulation of collagen IV and fibronectin was increased progressively, with significant difference in the accumulation of collagen IV (P<0.01) between these two groups at the same time points, while the significant difference in fibronectin accumulation (P<0.05) appeared only after the 7th days. CONCLUSION: Curcumin can reduce the accumulation of collagen IV and fibronectin in the glomeruli. Hence we postulated that curcumin might have beneficial effect for retarding glomerulosclerosis.

[Effects of colchicine on synthesis and excretion of cytokines and extracellular matrix by human renal fibroblasts].

OBJECTIVE: Renal interstitial fibrosis is the final common pathway leading to end-stage renal failure for progressive renal disease of various types. The present study was undertaken to add to the knowledge on colchicine's antiinflammatory and antifibrotic properties confirmed by both human and experimental studies. As the main effector cells, fibroblasts have a central role in the pathogenesis of renal fibrosis. This study aimed to investigate the effects of colchicine on the synthesis and excretion of cytokines transforming growth factor-beta1 (TGF-beta1), interleukin-1beta (IL-1beta) and extracellular matrix (collagen III, collagen IV) in human renal fibroblast. METHODS: Various concentrations of colchicine (5.0 micromol/L, 10.0 micromol/L, 20.0 micromol/L, 40.0 micromol/L) were used to pretreat human embryo renal fibroblasts for 1 hour which were cultured in vitro and then stimulated by 10.0 microg/ml of lipopolysaccharide (LPS). After 18 hours, these fibroblasts and their supernatant were collected. The expression of TGF-beta1 mRNA, IL-1beta mRNA in the cells was studied by using RT-PCR, and the excretion of TGF-beta1, IL-1beta, collagen III and collagen IV by the fibroblasts was assessed by ELISA respectively. RESULTS: (1) By pure stimulation with 10.0 micro g/ml LPS, the expression of TGF-beta1 mRNA and IL-1beta mRNA of fibroblasts was up-regulated 3 times (66.1 +/- 1.6 vs. 22.3 +/- 2.0, q = 590.5, P = 0.002) and 4.7 times (22.0 +/- 2.2 vs. 4.7 +/- 0.8, q = 106.8, P = 0.009), respectively. The protein excretion of TGF-beta1 and IL-1beta was remarkably increased as well compared with the control group [TGF-beta1: (516 +/- 14) pg/ml vs. (420 +/- 5) pg/ml (q = 80.3, P = 0.012), IL-1beta: (3.4 +/- 0.3) pg/ml vs. (0.3 +/- 0.1) pg/ml (q = 297.9, P = 0.003)]. (2) Colchicine could inhibit the expression of TGF-beta1 mRNA and protein in a dose-dependent manner. IL-1beta mRNA and protein were both up-regulated by colchicine. (3) LPS could not stimulate the excretion of extracellular matrix by fibroblasts, but the excretion of collagen III and collagen IV was down regulated by colchicine in a dose-dependent manner. CONCLUSION: (1) The expression of TGF-beta1 mRNA and the excretion of TGF-beta1 protein in the fibroblasts was significantly suppressed by colchicine, while the expression of IL-1beta mRNA and the excretion of IL-1beta protein were enhanced. (2) Colchicine has significant inhibitory effect on the excretion of extracellular matrix such as collagen III and collagen IV in fibroblasts.