Deficiency of geranylgeranyl biphosphate synthase in kidney tubules causes cystic kidney disease.

Polycystic kidney disease (PKD) is a common hereditary kidney disease. Although PKD occurrence is associated with certain gene mutations, its onset regulatory mechanisms are still not well understood. Here, we first report that the key enzyme geranylgeranyl diphosphate synthase (GGPPS) is specifically expressed in renal tubular epithelial cells of mouse kidneys. We aimed to explore the role of GGPPS in PKD. In this study, we established a Ggppsfl/fl:Cdh16cre mouse model and compared its phenotype with that of wild-type mice. A Ggpps-downregulation HK2 cell model was also used to further determine the role of GGPPS. We found that GGPPS was specifically expressed in renal tubular epithelial cells of mouse kidneys. Its expression also increased with age. Low GGPPS expression was observed in human ADPKD tissues. In the Ggppsfl/fl:Cdh16cre mouse model, Ggpps deletion in renal tubular epithelial cells induced the occurrence and development of renal tubule cystic dilation and caused the death of mice after birth due to abnormal renal function. Enhanced proliferation of cyst-lining epithelial cells was also observed after the knockout of Ggpps. These processes were related to the increased rate of Rheb on membrane/cytoplasm and hyperactivation of mTORC1 signaling. In conclusion, the deficiency of GGPPS in kidney tubules induced the formation of renal cysts. It may play a critical role in PKD pathophysiology. A novel therapeutic strategy could be designed according to this work.

Recurrence of Henoch Schoenlein Purpura Nephritis in Children: A Retrospective Study.

The aim of the study was to identify predictive patient characteristics for Henoch Schoenlein Purpura (HSPN) relapse in childhood HSPN. One hundred and thirty-five Chinese children with HSPN were enrolled in this study, mean age 10.25 ± 3.39 years. The pathology of HSPN was according to the International Study of Kidney Disease in Children criteria.(ISKDC); ISKDC II(mesangial proliferation (MP)) AND ISKDC III (MP with <50 % crescents).Recurrence of HSPN was observed in 66.3 % patients; male to female ratio (2:1)Statistically significant correlation existed between biopsy grade(p < 0.001), gender(p < 0.001),age ranges(p = 0.002) and treatment regimen (p < 0.001)in the frequency of recurrent HSPN episodes. We identified some significant predictors for HSPN relapse such as the severity of HSPN, adjunctive therapies administered to these patients,and close attention should be paid in patients between the ages 7 and 12 years old. In addition, the use of mycophenolate mofetil as an adjunctive therapy in the treatment of HSPN may reduce the frequency of HSPN relapse episodes in children.

Lectin-induced renal local complement activation is involved in tubular interstitial injury in diabetic nephropathy.

BACKGROUND: Complement has been suggested to be involved in diabetic nephropathy (DN), but the exact significance and underlying mechanisms remain unclear. Data about renal local complement activation in DN patients is scarce. The purpose of the study was to clarify the significance and mechanism of renal local complement activation in DN. METHODS: Sixty-two biopsy-proven DN patients were recruited. Renal expression of C1Q, factor B, C5b-9, MBL and MBL-associated serine protease 1 (MASP1) were detected and associated with the kidney damage. RESULTS: C5b-9, MBL and MASP1 was found to increase with the progression of DN. Especially, the level of C5b-9, MBL and MASP1 in tubular interstitium was closely associated with the damage degree of tubular interstitium. In addition, MBL and MASP1 co-localized and their levels in tubular interstitium correlated with the levels of C5b-9 in tubules and tubular interstitium. CONCLUSION: Increased renal local complement activation was present in DN patients and might contribute to the kidney damage, especially tubular interstitial damage. MBL pathway might play an important role in renal tubular interstitial complement activation. Methods against complement activation or MBL pathway might be effective in reducing renal tubular interstitial damage in DN patients.

The emerging role of fibroblast growth factor 21 in diabetic nephropathy.

Diabetic nephropathy (DN), an important cause of end-stage renal diseases, brings about great social and economic burden. Due to the variable pathological changes and clinical course, the prognosis of DN is very difficult to predict. DN is also usually associated with enhanced genomic damage and cellular injury. Fibroblast growth factor 21 (FGF21), a nutritionally regulated hormone secreted mainly by the liver, plays a critical role in metabolism. Administration of FGF21 decreases blood glucose, triglyceride, and cholesterol levels, and improves insulin sensitivity, which is closely associated with the development and progression of glomerular diseases. In addition, FGF21 level was associated with renal function. However, the precise role of FGF21 in DN remains unclear. This review will give a comprehensive understanding of the underlying role of FGF21 and its possible interaction with other molecules in DN.

Dalbergioidin Ameliorates Doxorubicin-Induced Renal Fibrosis by Suppressing the TGF-ß Signal Pathway.

We investigated the effect of Dalbergioidin (DAL), a well-known natural product extracted from Uraria crinita, on doxorubicin- (DXR-) induced renal fibrosis in mice. The mice were pretreated for 7 days with DAL followed by a single injection of DXR (10 mg/kg) via the tail vein. Renal function was analyzed 5 weeks after DXR treatment. DXR caused nephrotoxicity. The symptoms of nephrotic syndrome were greatly improved after DAL treatment. The indices of renal fibrosis, the phosphorylation of Smad3, and the expression of alpha-smooth muscle actin (α-SMA), fibronectin, collagen III (Col III), E-cadherin, TGF-ß, and Smad7 in response to DXR were all similarly modified by DAL. The present findings suggest that DAL improved the markers for kidney damage investigated in this model of DXR-induced experimental nephrotoxicity.

Investigation of Pathogenic Genes in Chinese sporadic Hypertrophic Cardiomyopathy Patients by Whole Exome Sequencing.

Hypertrophic cardiomyopathy (HCM) is a cardiovascular disease with high heterogeneity. Limited knowledge concerning the genetic background of nearly 40% HCM cases indicates there is a clear need for further investigation to explore the genetic pathogenesis of the disease. In this study, we undertook a whole exome sequencing (WES) approach to identify novel candidate genes and mutations associated with HCM. The cohort consisted of 74 unrelated patients with sporadic HCM (sHCM) previously determined to be negative for mutations in eight sarcomere genes. The results showed that 7 of 74 patients (9.5%) had damaging mutations in 43 known HCM disease genes. Furthermore, after analysis combining the Transmission and De novo Association (TADA) program and the ToppGene program, 10 putative genes gained priority. A thorough review of public databases and related literature revealed that there is strong supporting evidence for most of the genes playing roles in various aspects of heart development. Findings from recent studies suggest that the putative and known disease genes converge on three functional pathways: sarcomere function, calcium signaling and metabolism pathway. This study illustrates the benefit of WES, in combination with rare variant analysis tools, in providing valuable insight into the genetic etiology of a heterogeneous sporadic disease.

miR-27a promotes cell proliferation and metastasis in renal cell carcinoma.

miR-27a has been reported to exhibit abnormal expression in renal cell carcinoma (RCC), but the role of miR-27a in RCC remains unknown. In our study, up-regulation of miR-27a was validated by Real-time PCR analysis in 133 RCC samples. Overexpression of miR-27a promoted cell migration, invasion and proliferation in vitro, while its low expression exerted opposite effects. Kaplan-Meier analysis demonstrated that the patients with high expression of miR-27a had a worse overall and relapse-free survivals compared with those with low expression of miR-27a. Cox proportional hazards analyses showed that miR-27a expression was an independent prognostic factor for RCC patients. Collectively, our findings illustrate the promoting-cancer effect of miR-27a in RCC, suggesting that miR-27a could be a potential therapeutic target for RCC. Additionally, Kaplan-Meier analyses and Cox proportional regression analysis suggest that miR-27a may be a potential biomarker for predicting the survival of RCC patients.

Longikaurin E induces apoptosis of pancreatic cancer cells via modulation of the p38 and PI3K/AKT pathways by ROS.

Pancreatic cancer is a devastating disease with a poor prognosis. It ranks as the fourth or fifth most common cancer in men and women and has the lowest 5-year survival rate. Therefore, there is an urgent need to develop novel therapeutic agents for pancreatic cancer. Longikaurin E (LE), which is derived from the traditional herbal medicine Rabdosia longituba, had been reported to have anti-proliferative and pro-apoptotic properties in several types of cancers. In this study, we investigated the cytotoxic properties of LE against pancreatic cancer cells and explored the mechanism behind the observed apoptosis. Pancreatic cancer cell lines cultured in the presence of LE exhibited dose- and time-dependent growth suppression by clone formation, methylthiazoltetrazolium assay, lactate dehydrogenase cytotoxicity assay, and fluorescence-activated cell sorting analysis, respectively. In addition, these culture conditions also induced the generation of cellular reactive oxygen species (ROS). In order to determine the mechanisms underlying LE-induced cytotoxicity, we used reverse transcription polymerase chain reaction and Western blot analysis in the pancreatic cancer cell line PANC1. The results showed that the expression of Bax was noticeably upregulated and the expression levels of Bcl-2, Bcl-XL, survivin, and c-Myc were significantly downregulated. We also observed increased p38 phosphorylation and decreased phosphorylation of the PI3K/AKT pathway. Interestingly, we also found that LE activated caspase-3. However, N-acetyl-L-cysteine, a kind of antioxidant, reversed all of these cellular activities. In conclusion, this study suggested that LE induced apoptosis of pancreatic cancer cells via ROS generation to modulate the p38 and PI3K/AKT pathways and could be a promising anti-pancreatic agent.

Leonurine ameliorates LPS-induced acute kidney injury via suppressing ROS-mediated NF-κB signaling pathway.

Acute kidney injury (AKI) is an abrupt loss of kidney function. Severe AKI requires renal replacement therapy and has high mortality. Leonurine (LEO), an alkaloid isolated from Leonurus cardiaca, has shown biological effects such as antioxidant, anticoagulant, and anti-apoptosis. We have examined the effect of LEO on lipopolysaccharide (LPS)-induced AKI in mice and further studied the mechanism involved. Blood urea nitrogen (BUN), creatinine and cytokine were estimated in the serum or tissue. Kidney tissue specimens were used for biochemical estimations of lipid peroxides (LPO), reduced glutathione (GSH), and reactive oxygen species (ROS). The effects of LEO on LPS-induced renal tissue damage were detected by hematoxylin and eosin (HE) stain and electron microscopy. The production of cytokines in the tissue and blood was measured by ELISA. Protein phosphorylation and protein subcellular localization were tested by Western blot. LEO is protected against LPS-induced AKI, improved animal survival and maintained the redox balance. The beneficial effects of LEO were accompanied by the down-regulation of TNF-α, IL-1, IL-6, IL-8, KIM-1 expression and by the inhibition of the phosphorylation of IκBα and p65 translocalization. These results suggest that LEO may suppress NF-κB activation and inhibit pro-inflammatory cytokine production via decreasing cellular ROS production. Accumulating studies have demonstrated that LEO reduces kidney injury and protects renal functions from LPS-induced kidney injury.

Association of megsin 2093C/T, 2180C/T and C25663G gene polymorphism with the risk of IgA nephropathy.

The association between megsin 2093C/T, 2180C/T and C25663G gene polymorphisms and IgA nephropathy (IgAN) risk remains unclear. We aimed to evaluate the association between megsin 2093C/T, 2180C/T and C25663G gene polymorphisms and IgAN risk by performing a meta-analysis. Eligible studies were searched according to predefined criteria by using electronic databases. Six articles were identified for the analysis of the association between megsin 2093C/T, 2180C/T and C25663G gene polymorphisms and IgAN risk. 2093C/T C allele was associated with IgAN risk in overall populations and Asians (overall populations: p = 0.014, Asians: p = 0.037). 2093C/T CC/TT genotype was not associated with IgAN risk in overall populations, Caucasians and Asians. 2180C/T C allele was correlated with IgAN risk in Caucasians (p = 0.024). 2180C/T CC/TT genotype was not associated with IgAN risk in overall populations, Caucasians and Asians. C25663G gene polymorphism was not associated with IgAN onset in Asians. In conclusion, megsin 2093C/T C allele may be genetic marker for IgAN susceptibility in overall populations and Asians. 2180C/T C allele may be risk factor for IgAN onset in Caucasians. However, more studies should be performed in the future.

Protective effects of sinomenine against doxorubicin-induced nephrosis in rats.

Sinomenine (SN, 1) is a pure compound extracted from the Sinomenium acutum plant. We investigated the protective effects and mechanism of action of SN in a rat model of doxorubicin (DOX)-induced nephrosis. Nephrosis was induced by a single dose of 5 mg/kg DOX, and DOX-treated rats received a daily i.p. injection of 10 or 30 mg/kg SN, or saline (n = 6). Urine and serum biochemical parameters, serum TNF-α and IL-1ß levels, nephrin, podocin, α-actinin-4, and peroxisome proliferator-activated receptor-α (PPAR-α) protein expression, and renal ultrastructure were examined at day 28. Compound 1 significantly attenuated the effect of DOX on urine and serum biochemical parameters. Electron microscopy demonstrated that 1 suppressed DOX-induced increases in foot process width. Compared with those in control rats, nephrin, podocin, and PPAR-α protein expressions decreased in the glomeruli of DOX-treated rats, and this effect was significantly attenuated by 1. However, no appreciable alterations were observed in the expression level of α-actinin-4. DOX significantly increased serum TNF-α and IL-1ß compared with those in control rats, and 1 significantly reduced the serum levels of TNF-α and IL-1ß. SN ameliorates DOX-induced nephrotic syndrome in rats, resulting in a modulation of renal nephrin, podocin expression, and thereby protecting podocytes from injury.

[Nephrotic syndrome complicated with intracranial venous thrombosis treated with urokinase: report of 5 cases].

OBJECTIVE: To explore the effect of urokinase and low molecular weight heparin in children with nephrotic syndrome complicated with intracranial venous thrombosis. METHODS: Urokinase and low molecular weight heparin were administered to the 5 patients intravenously. The initial dose of urokinase was 2000 - 4000 U/(kg.d), the initial pulse dose was 20 000 - 40 000 U given within 15 - 30 minutes, and the left was infused by using a pump, from the second day 2000 U/(kg.d) urokinase was infused daily for 3 to 7 days. During the treatment thrombin time (TT), activated partial thromboplastin time (APTT) were tested 3 times every week, with particular attention to bleeding. Low molecular weight heparin 100 - 120 AXaIU/kg, 1 or 2 times per day was hypodermally injected for a course of two weeks. Anti-platelet drugs: long-term oral administration of dipyridamole 3 - 5 mg/(kg.d) was applied 2 - 3 times every day for 3 months. RESULTS: The clinical symptoms disappeared after one month of the combined therapy of urokinase, low molecular weight heparin and dipyridamole in 5 cases of nephrotic syndrome complicated with intracranial venous thrombosis in children, the plasma viscosity returned to normal in 1 month, activated partial thromboplastin time, prothrombin time, fibrinogen degradation products returned to normal in 1 to 2 months, venous thrombosis disappeared after 1 to 3 months in head CT or MRI examination, showing the cerebral venous sinus thrombosis complete recanalization without relapse cases in follow-up. CONCLUSION: The early application of urokinase and low molecular heparin and anti-platelet coagulation drugs was effective. The early diagnosis, treatment and prevention of intracranial vein thrombosis in patients with nephrotic syndrome is important.

[Clinical and pathological study of 47 cases with Alport syndrome].

OBJECTIVE: To analyze the clinical and pathological features of children with Alport syndrome (AS). METHODS: A series of 47 patients with AS from unrelated families hospitalized from Jan. 1990 to Jan. 2007 were involved in this study. The clinical and histopathological data were collected and analyzed. RESULTS: Of the 47 cases, 32 were male and 15 female, M/F: 2.1:1. The patient's age ranged from 15 months to 13 years, mean 9 years. Thirty-nine of the 47 cases had positive family history, X-linked dominant inheritance AS was diagnosed in 37 cases, autosomal recessive inheritance AS in 2 cases. Gross hematuria or microscopic hematuria were found in 59.3% of the cases as the first manifestations, while 29.8% showed edema or proteinuria. The major clinical manifestations were isolated hematuria (23.4%), hematuria and proteinuria (36.2%), nephrotic syndrome (29.8%), and renal failure (10.6%). Hematuria and proteinuria existed in all the cases, while only 7 to 13 years children had nephrotic syndrome and renal failure. Of the 47 patients, 33 (70.2%) showed mesangial proliferative glomerulonephritis (MsPGN) under the light microscope, 13 (27.6%) focal segmental glomerulosclerosis (FSGS), 1 (2.1%) membrane proliferative glomerulonephritis (MPGN). For immunofluorescence, there was IgM (40.4%) as the dominant deposition in 19 patients, IgA in 9 (19.1%), IgG in 9 (19.1%), and 10 (21.4%) were negative. Thirty-nine cases showed typical glomerular basement membrane (GBM) pathological changes under electron microscope, while thin basement membrane in 8 cases; 46 showed abnormal skin and/or renal alpha-chain distribution. CONCLUSION: For Alport syndrome, number of male patients was higher than that of female patients. There was a significant difference among different age groups. Hematuria might be present throughout the course, while urine protein increases gradually. MsPGN was the dominant pathological change. The GBM pathological changes in younger children is not typical, so the immunofluorescence test of alpha-chain in collagen IV should be used as an important diagnostic method.