Serum BAFF levels are associated with the prognosis of idiopathic membranous nephropathy.

OBJECTIVE: High serum levels of B-cell activation factor (BAFF) and a proliferation-inducing ligand (APRIL) have been observed in patients with idiopathic membranous nephropathy (iMN); however, their relationships with disease severity and progression remain unclear. METHODS: Patients with iMN diagnosed via renal biopsy were enrolled in this study. The concentrations of BAFF and APRIL were determined using ELISA kits. Proteinuria remission, including complete remission (CR) and partial remission (PR), and renal function deterioration were defined as clinical events. The Cox proportional hazards method was used to analyze the relationship between cytokine levels and disease progression. RESULTS: Seventy iMN patients were enrolled in this study, with a median follow-up time of 24 months (range 6-72 months). The serum levels of BAFF and APRIL were higher in iMN patients than in healthy controls but lower than those in minimal change disease (MCD) patients. The serum BAFF level was positively correlated with the serum APRIL level, serum anti-phospholipase A2 receptor (anti-PLA2R) antibody level, and 24-h proteinuria and negatively correlated with the serum albumin (ALB) level. However, no significant correlation was observed between the serum APRIL level and clinical parameters. According to the multivariate Cox proportional hazards regression model adjusted for sex, age, systolic blood pressure (SBP), estimated glomerular filtration rate (eGFR), immunosuppressive agent use, 24-h proteinuria, APRIL level, and anti-PLA2R antibody, only the serum BAFF level was identified as an independent predictor of PR (HR, 0.613; 95% CI, 0.405-0.927; p = 0.021) and CR of proteinuria (HR, 0.362; 95% CI, 0.202-0.648; p < 0.001). CONCLUSIONS: A high serum BAFF level is associated with severe clinical manifestations and poor disease progression in patients with iMN.

LncRNA ATP1A1-AS1 inhibits cell proliferation and promotes cell apoptosis in thyroid carcinoma by regulating the miR-620/IRF2BP2 axis.

BACKGROUND: Thyroid carcinoma (THCA) is a common malignancy of the endocrine system. Further understanding of the molecular mechanism underlying THCA is crucial to develop effective diagnostic therapy and improve its treatments. In this study, we intended to provide novel direction for THCA targeted therapy from the aspect of lncRNA-miRNA-mRNA interaction. We aimed to investigate the function and molecular mechanism of lncRNA ATP1A1-AS1 in THCA. METHODS: Gene expression was assessed by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Cell growth was detected by CCK-8 and EdU assays. Flow cytometry was applied for analyzing cell apoptosis. The binding of ATP1A1-AS1 or IRF2BP2 to miR-620 was validated by RNA pulldown and luciferase reporter assays. The protein levels were examined by western blotting. RESULTS: ATP1A1-AS1 was decreased in THCA cells and tissues. ATP1A1-AS1 overexpression attenuated cell growth and promoted apoptosis. MiR-620, which was upregulated in THCA, was identified as a direct target of ATP1A1-AS1. Furthermore, IRF2BP2 was discovered to be a target of miR-620, which displayed low expression in THCA cells and tissues. Importantly, IRF2BP2 knockdown reversed the influence of ATP1A1-AS1 overexpression on THCA cell proliferation and apoptosis. CONCLUSIONS: LncRNA ATP1A1-AS1 inhibited cell growth and promotes apoptosis in THCA via the miR-620/IRF2BP2 axis.

IncRNA TYMSOS Promotes Epithelial-Mesenchymal Transition and Metastasis in Thyroid Carcinoma through Regulating MARCKSL1 and Activating the PI3K/Akt Signaling Pathway.

Thyroid carcinoma (THCA) has been increasing in incidence greater than other cancers. Long noncoding RNAs (lncRNAs) were reported to play crucial roles in THCA development. Our study aimed to explore the underlying mechanism of lncRNA thymidylate synthetase opposite strand RNA (TYMSOS) in THCA. TYMSOS and myristoylated alanine rich protein kinase C substrate like 1 (MARCKSL1) were upregulated whereas miR-130a-5p was downregulated in THCA cells and tissues. The results of loss-of-function assays showed that TYMSOS knockdown inhibited cell metastasis and epithelial-mesenchymal transition (EMT) in THCA. TYMSOS was primarily distributed in the cytoplasm of THCA cells, as shown by FISH assay. RNA pulldown and luciferase reporter assay further showed that TYMSOS binds with miR-130a-5p. Luciferase reporter assay also revealed that MARCKSL1 is targeted by miR-130a-5p. Rescue assay showed that the suppression of TYMSOS downregulation on THCA cell malignant behaviors was reversed by MARCKSL1 overexpression. Additionally, overexpressing MARCKSL1 offset the inhibition of TYMSOS downregu-lation on the PI3K/Akt signaling pathway. TYMSOS knockdown inhibits the growth of THCA tumors, as in vivo assays showed. Collectively, TYMSOS facilitates THCA progression by sponging miR-130a-5p and upregulating MARCKSL1 to activate the PI3K/Akt signaling pathway, providing new avenues for THCA treatment.

Optimal Value for Serum Anti-PLA2R Antibody in Primary Membranous Nephropathy: A Multicenter Observational Study.

INTRODUCTION: Anti-phospholipase A2 receptor antibody (PLA2R-Ab) is highly specific for primary membranous nephropathy (PMN). Here, we compare the diagnostic value of different circulating PLA2R-Ab cutoff titers in multicenter cohorts, with particular focus on determining the optimal cutoff value for Chinese patients. METHODS: In total, 288 patients with PMN and 301 with other nephropathies were recruited retrospectively from five hospitals in China between September 2011 and October 2018. PLA2R-Ab in serum obtained at renal biopsy was determined by enzyme-linked immunosorbent assay. The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), and receiver operating characteristic (ROC) curve of PLA2R-Ab in diagnosing PMN were assessed. Diagnostic efficiency was evaluated by internal validation. RESULTS: The sensitivity, specificity, PPV, NPV, and Youden index for PMN diagnosis were 71%, 90%, 88%, 75%, and 0.61 at the cutoff of 3.8 RU/mL; 74%, 86%, 84%, 76%, and 0.60 at 2.7 RU/mL; 68%, 92%, 90%, 73%, and 0.60 at 5.2 RU/mL; 64%, 95%, 93%, 72%, and 0.59 at 9.0 RU/mL; 57%, 96%, 94%, 68%, and 0.54 at 14.0 RU/mL; 51%, 97%, 95%, 66%, and 0.49 at 20.0 RU/mL; 47%, 98%, 96%, 64%, and 0.45 at 40.0 RU/mL, respectively. The area under the ROC curve was 0.83. CONCLUSION: By comprehensively considering specificity and sensitivity, we show that 3.8 RU/mL is the optimal cutoff of PLA2R-Ab in Chinese PMN patients, with a sensitivity of 71% and a specificity of 90%. The cutoff values were 5.2 RU/mL and 9.0 RU/mL when the diagnostic specificity was increased to 92% and 95%, respectively.

Detection of Microcystin-LR in the Cells and Natural Lake Water Samples by A Unique Fluorescence-Based Method.

Microcystin-LR (MC-LR) is widely distributed in natural lakes and could strongly inhibit protein phosphatase activity; it is also a potent liver tumor promoter. Over the last two decades, tremendous efforts have been devoted to enhance the detection of MC-LR in water samples. However, the traditional method is complex and costly, and achieving the fast, sensitive, and accurate determination of MC-LR in the cells and natural lakes by using fluorescence signal changes is fairly difficult. Our work explores novel fluorescent probes that are capable of concurrently analyzing and detecting MC-LR in the cells and water. In this study, we introduce, for the first time, 5-AF and 6-AF as small-molecule fluorescent probes suitable for MC-LR detection in the cells and water samples based on fluorescence signal changes. We titrated 5-AF and 6-AF with MC-LR in pure water, scanned the fluorescence of the sample, and then obtained the equation the fluorescence intensity versus MC-LR concentration curve. MC-LR in lake water samples was crudely purified, and then 5-AF was added to measure its fluorescence peak. The fluorescence intensity of 5-AF is significantly enhanced with increasing MC-LR concentration. This enhancement trend is stable and could be mathematically modeled. We also comprehensively analyzed the mechanism and recognition principle of the probe response to MC-LR in natural lake water. Moreover, we believe that 5-AF may be capable of detecting exogenous MC-LR in cells. The results of this study reveal that these unique fluorescent probes may be applied to construct near-infrared fluorescent probes that could detect MC-LR levels in vivo.

Bee Venom Melittin Disintegrates the Respiration of Mitochondria in Healthy Cells and Lymphoblasts, and Induces the Formation of Non-Bilayer Structures in Model Inner Mitochondrial Membranes.

In this paper, we examined the effects of melittin, a bee venom membrane-active peptide, on mitochondrial respiration and cell viability of healthy human lymphocytes (HHL) and Jurkat cells, as well as on lymphoblasts from acute human T cell leukemia. The viability of melittin-treated cells was related to changes in O2 consumption and in the respiratory control index (RCI) of mitochondria isolated from melittin-pretreated cells as well as of mitochondria first isolated from cells and then directly treated with melittin. It was shown that melittin is three times more cytotoxic to Jurkat cells than to HHL, but O2 consumption and RCI values of mitochondria from both cell types were equally affected by melittin when melittin was directly added to mitochondria. To elucidate the molecular mechanism of melittin's cytotoxicity to healthy and cancer cells, the effects of melittin on lipid-packing and on the dynamics in model plasma membranes of healthy and cancer cells, as well as of the inner mitochondrial membrane, were studied by EPR spin probes. The affinity of melittin binding to phosphatidylcholine, phosphatidylserine, phosphatidic acid and cardiolipin, and binding sites of phospholipids on the surface of melittin were studied by 31P-NMR, native PAGE and AutoDock modeling. It is suggested that the melittin-induced decline of mitochondrial bioenergetics contributes primarily to cell death; the higher cytotoxicity of melittin to cancer cells is attributed to its increased permeability through the plasma membrane.

Association of plasma neutrophil gelatinase-associated lipocalin with parameters of CKD-MBD in maintenance hemodialysis patients.

INTRODUCTION: Neutrophil gelatinase-associated lipocalin (NGAL) is not only a biomarker of kidney injury but also a bone-derived factor involved in metabolism. We aimed to explore relationships between plasma NGAL and chronic kidney disease-mineral bone disorder (CKD-MBD) parameters in maintenance hemodialysis (MHD) patients. MATERIALS AND METHODS: First, a cross sectional observational study, including 105 MHD patients, was conducted to explore relationships between plasma NGAL levels and CKD-MBD parameters. Second, impact of parathyroidectomy and auto-transplantation (PTX + AT) on plasma NGAL was investigated in 12 MHD patients with severe secondary hyperparathyroidism (SHPT). RESULTS: According to Spearman correlation analysis, plasma NGAL levels were positively correlated with female (r = 0.243, P = 0.012), vintage (r = 0.290, P = 0.003), Klotho (r = 0.234, P = 0.016), calcium(Ca) (r = 0.332, P = 0.001), alkaline phosphatase (ALP) (r = 0.401, P < 0.001) and intact parathyroid hormone (iPTH) (r = 0.256, P = 0.008); while inversely correlated with albumin(Alb) (r = - 0.201, P = 0.039). After adjusting for age, sex, vintage, Alb and all parameters of CKD-MBD(Ca, P, lg(ALP), lg(iPTH), Klotho and fibroblast growth factor 23(FGF23)), lg(NGAL) were positively correlated with Ca (r = 0.481, P < 0.001), P (r = 0.336, P = 0.037), lg(ALP) (r = 0.646, P < 0.001) in Partial correlation analysis; further multiple linear regression analysis showed same positive associations between lg(NGAL) and Ca (ß = 0.330, P = 0.002), P (ß = 0.218, P = 0.037), lg(ALP) (ß = 0.671, P < 0.001). During the 4-7 days after PTX + AT, plasma NGAL decreased from 715.84 (578.73, 988.14) to 688.42 (660.00, 760.26) ng/mL (P = 0.071), Klotho increased from 496.45 (341.73, 848.30) to 1138.25 (593.87, 2009.27) pg/mL (P = 0.099). CONCLUSION: Plasma NGAL levels were positively associated with ALP in MHD patients; and downtrends were shown after PTX + AT in patients with severe SHPT. These findings suggest that NGAL is a participant in CKD-MBD under MHD condition.

Effect of Glomerular Mannose-Binding Lectin Deposition on the Prognosis of Idiopathic Membranous Nephropathy.

OBJECTIVE: Co-deposition of mannose-binding lectin (MBL) and IgG4 anti-phospholipase A2 receptor (anti-PLA2R) autoantibodies under subepithelial cells has been observed in patients with idiopathic membranous nephropathy (iMN), but the relationships of MBL deposition to iMN severity and progression remain unclear. METHODS: Patients diagnosed with iMN who underwent renal puncture were enrolled and followed up for a median of 17 months (interquartile range [IQR], 9-25 months). Serum anti-PLA2R and anti-thrombospondin type-1 domain-containing 7A antibodies and MBL were detected by ELISA. Glomerular MBL and anti-PLA2R antibodies were detected by immunofluorescence. Proteinuria remission, including complete remission (CR), was defined as a clinical event. Clinicopathological characteristics and kidney outcomes were compared between patients with and without MBL deposition. RESULTS: In 67 prevalent patients with biopsy-proven iMN, serum anti-PLA2R antibodies and anti-THSD7A antibodies were present in 37 (55.3%) and 1 (1.4%) patient with iMN. The positivity of glomerular MBL deposition and tissue anti-PLA2R antibody was 53 (79.1%) and 49 (73.1%), respectively. No significant difference was found between the MBL-positive and negative groups in the albumin level (26.5 ± 6.6 and 28.6 ± 6.1 g/L), eGFR (104.8 ± 17.4 and 114.6 ± 16.1 mL/min/1.73 m2), 24-h proteinuria (5.35 and 4.25 g/day), or serum MBL level corrected by serum Cr 4.92 (IQR, 0.86, 8.90) and 2.28 (IQR, 0.4, 5.62). In a Cox proportional hazards regression model adjusted for sex, age, systolic blood pressure, eGFR, immunosuppressive agent use, 24-h proteinuria, and anti-PLA2R antibody concentration, glomerular MBL deposition was independently associated with ICR of proteinuria (HR, 6.31; 95% CI, 1.1-36.1; p = 0.039). CONCLUSIONS: The MBL pathway of complement activation is commonly initiated in patients with iMN, and patients with MBL deposition reach ICR faster than patients without MBL deposition.

Lipopolysaccharide Mediates the Destruction of Intercellular Tight Junction among Renal Tubular Epithelial Cells via RhoT1/SMAD-4/JAM-3 Pathway.

Background: The morbidity of sepsis induced acute kidney injury remains unacceptable high and the mechanisms of that disease remains unclear. For urine backleak and intercellular tight junction among tubular epithelial cells (TECs) destruction often occur during sepsis induced acute kidney injury, we examined whether lipopolysaccharide could damage intercellular tight junction among TECs and associated mechanisms in our present study. Methods: HK-2 cells were cultured, transfected with different SiRNAs and stimulated with LPS and PYR-41. Transepithelial Permeability Assay and Transepithelial Electrical Resistance Assay were used to evaluate intercellular tight junction destruction and Western Blot and Immunofluorescence were used to evaluate proteins expression. Results: Transepithelial Permeability increased significantly (P<0.05) and Transepithelial Electrical Resistance reduced remarkably (P<0.05) of the monolayer TECs stimulated with LPS. The expression of JAM-3 and RhoT1 decreased significantly (P<0.05) in TECs stimulated with LPS, while the level of SMAD-4 increased significantly (P<0.05). Downregulation of the expression of SMAD-4 with RNA interference could increase the expression of JAM-3 in LPS treated TECs. Moreover, upregulation of RhoT1 level by decreased the degradation of RhoT1 could decrease the expression of SMAD-4 and increase the JAM-3 level in TECs treated with LPS, while downregulation of RhoT1 level with RNA interference had the opposite effects. Conclusion: LPS mediates intercellular tight junction destruction among TECs and RhoT1/SMAD-4/JAM-3 is a pivotal pathway to mediate the phenomenon.

Serum anti-PLA2R antibody as a diagnostic biomarker of idiopathic membranous nephropathy: The optimal cut-off value for Chinese patients.

BACKGROUND: The M-type phospholipase A2 receptor (PLA2R) is a specific target autoantigen identified in idiopathic membranous nephropathy (IMN). The autoantibody against PLA2R (anti-PLA2R) may be used to diagnose IMN. However, the appropriate diagnosis cut-off value for Chinese patients with IMN has not been established. METHODS: In total, 119 patients who underwent renal biopsy (57 patients with IMN and 62 patients with non-IMN glomerulonephritis) and 22 healthy individuals were recruited for our observation study from Qianfoshan Hospital between September 2011 and March 2016. The serum concentration of anti-PLA2R was measured using a quantitative enzyme-linked immunosorbent assay (ELISA). The sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and receiver operating characteristic (ROC) curve of anti-PLA2R in diagnosing IMN were analysed based on the ELISA detection. RESULTS: The sensitivity, specificity, PPV, and NPV of anti-PLA2R in the diagnosis of IMN in the Chinese patients were 82.5, 75, 69.1, and 86.3% for the 2RU/ml cut-off value; 78.9, 91.7, 86.5, and 86.5% for the 2.6RU/ml cut-off value; 59.6, 95.2, 89.5, and 77.7% for the 14RU/ml cut-off value; 50.9, 96.4, 90.6, and 74.3% for the 20RU/ml cut-off value; and 47.4, 97.6, 93.1, and 73.2% for the 40RU/ml cut-off value, respectively. The area under the ROC curve was 0.879. CONCLUSIONS: The cut-off value of 2.6RU/ml is recommended for the use of anti-PLA2R for the diagnosis of IMN in Chinese patients based on the ELISA.

The spectrum of biopsy-proven secondary glomerular diseases: A cross-sectional study in China
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AIMS: The distribution of the spectrum of chronic kidney disease (CKD) has been found to vary with time. Limited information is available regarding the changing spectrum of secondary glomerular diseases (SGDs). To further investigate changes in the spectrum of SGDs, we performed a cross-sectional study. METHODS: From June 2010 to May 2015, 5,935 patients from 37 hospitals in Shandong Province were involved in this study. The study was divided into five periods according to 1-year intervals. The patients were divided into four age groups. RESULTS: Of the 5,935 patients with qualified specimens, 1,038 (17.5%) were diagnosed with a SGD. Lupus nephritis (LN) (27.6%) was the most frequently identified SGD, followed by Henoch-Schönlein purpura glomerulonephritis (HSPN) (21.7%) and diabetic nephropathy (DN) (21.6%). The prevalence rate of DN demonstrated an increasing trend, and this condition became the leading cause of renal biopsy in period 3 (29.3%). The proportion of patients with hepatitis B virus-associated nephritis (HBVAN) decreased from 14.7% in period 2 to 5.1% in period 5 (p < 0.001). The proportion of patients with amyloidosis nephropathy (AN) increased from 2.2% in period 1 to 7.0% in period 5 (p = 0.088). The prevalence rate of DN was 0.6% in pediatric patients and 40.7% in elderly patients (p < 0.001). CONCLUSIONS: In our study, SGD was the second leading cause of renal biopsy. The distribution of the spectrum of SGD varied with time and age. Given the possibility of a detection bias, larger prospective cohort studies are needed in the future.
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Increasing prevalence of membranous nephropathy in patients with primary glomerular diseases: A cross-sectional study in China.

AIM: Primary glomerular disease (PGD) remains the most common renal disease in China. A limited number of single centre studies show that the frequency of membranous nephropathy (MN) has increased; however, IgA nephropathy (IgAN) is still the most common PGD. To the best of our knowledge, there has been no multi-centre study in China that has explored the changes in PGD spectrum. To further investigate the changes in renal histopathological spectrum, we performed the cross-sectional study. METHOD: From June 2010 to May 2015, 5935 patients from 37 hospitals in Shandong Province were involved in this retrospective study. The study was divided into five periods according to 1-year intervals. The patients were divided into four age groups (≤18 years, 19-44 years, 45-59 years and ≥60 years). RESULT: Among the 5935 qualified specimens, 4855 (81.8%) were diagnosed with PGD. MN (43.3%) became the most common PGD instead of IgA (34.1%) (P < 0.001). The frequency of MN was increased from 30.7% in period 1 to 53.5% in period 5 (P < 0.001). The prevalence of MN tended to increase in every age section. IgA was the main cause of PGD in periods 1 and 2; however, its proportion decreased significantly from 41.8% in period 2 to 25.2% in period 5 (P < 0.001). CONCLUSION: Primary glomerular disease remains the most common renal disease in our study. For the first time, this cross-sectional study suggests that MN, in place of IgAN, has grown to be the first leading pathological type of PGD.

Angiotensin II down-regulates nephrin-Akt signaling and induces podocyte injury: roleof c-Abl.

Recent studies have shown that nephrin plays a vital role in angiotensin II (Ang II)-induced podocyte injury and thus contributes to the onset of proteinuria and the progression of renal diseases, but its specific mechanism remains unclear. c-Abl is an SH2/SH3 domain-containing nonreceptor tyrosine kinase that is involved in cell survival and regulation of the cytoskeleton. Phosphorylated nephrin is able to interact with molecules containing SH2/SH3 domains, suggesting that c-Abl may be a downstream molecule of nephrin signaling. Here we report that Ang II-infused rats developed proteinuria and podocyte damage accompanied by nephrin dephosphorylation and minimal interaction between nephrin and c-Abl. In vitro, Ang II induced podocyte injury and nephrin and Akt dephosphorylation, which occurred in tandem with minimal interaction between nephrin and c-Abl. Moreover, Ang II promoted c-Abl phosphorylation and interaction between c-Abl and SH2 domain-containing 5'-inositol phosphatase 2 (SHIP2). c-Abl small interfering RNA (siRNA) and STI571 (c-Abl inhibitor) provided protection against Ang II-induced podocyte injury, suppressed the Ang II-induced c-Abl-SHIP2 interaction and SHIP2 phosphorylation, and maintained a stable level of nephrin phosphorylation. These results indicate that c-Abl is a molecular chaperone of nephrin signaling and the SHIP2-Akt pathway and that the released c-Abl contributes to Ang II-induced podocyte injury.

HMGB1 Turns Renal Tubular Epithelial Cells into Inflammatory Promoters by Interacting with TLR4 During Sepsis.

Our study was undertaken to investigate whether the inflammatory mediator high-mobility group box 1 (HMGB1) can enter the renal tissue and urine and what is the functional change of renal tubular epithelial cells (TECs) interacting with HMGB1 during sepsis. We found that the transcription levels of interleukin 1 (IL-1) and interleukin 6 (IL-6) mRNA in TECs increased significantly during sepsis and these processes can be blocked by splenectomy. We also found out HMGB1 accumulated in the renal tissue and entered urine during sepsis and toll-like receptor 4 (TLR4) was expressed by TECs. In vitro, we demonstrated that HMGB1 induced MAPK and NF-κB activation and G1 cell cycle arrest in TECs. We also found that the mRNA transcription levels of IL-1, IL-6, and tissue inhibitor of metalloproteinases 2 (TIMP2) increased significantly and the IL-1, IL-6, and TIMP2 can be secreted by TECs stimulated by HMGB1. In contrast, LPS RS can block all of the processes above in vitro. In vivo, the increase of the mRNA transcription level of TIMP2 was also observed. These data indicate that HMGB1 accumulates in renal tissue and enters the urine and the interaction between HMGB1 and TLR4 turns TECs into inflammatory promoters during sepsis.

sPLA2 IB induces human podocyte apoptosis via the M-type phospholipase A2 receptor.

The M-type phospholipase A2 receptor (PLA2R) is expressed in podocytes in human glomeruli. Group IB secretory phospholipase A2 (sPLA2 IB), which is one of the ligands of the PLA2R, is more highly expressed in chronic renal failure patients than in controls. However, the roles of the PLA2R and sPLA2 IB in the pathogenesis of glomerular diseases are unknown. In the present study, we found that more podocyte apoptosis occurs in the kidneys of patients with higher PLA2R and serum sPLA2 IB levels. In vitro, we demonstrated that human podocyte cells expressed the PLA2R in the cell membrane. After binding with the PLA2R, sPLA2 IB induced podocyte apoptosis in a time- and concentration-dependent manner. sPLA2 IB-induced podocyte PLA2R upregulation was not only associated with increased ERK1/2 and cPLA2α phosphorylation but also displayed enhanced apoptosis. In contrast, PLA2R-silenced human podocytes displayed attenuated apoptosis. sPLA2 IB enhanced podocyte arachidonic acid (AA) content in a dose-dependent manner. These data indicate that sPLA2 IB has the potential to induce human podocyte apoptosis via binding to the PLA2R. The sPLA2 IB-PLA2R interaction stimulated podocyte apoptosis through activating ERK1/2 and cPLA2α and through increasing the podocyte AA content.

c-Abl mediates angiotensin II-induced apoptosis in podocytes.

Angiotensin II (Ang II) has been reported to cause podocyte apoptosis in rats both in vivo and in vitro studies. However, the underlying mechanisms are poorly understood. In the present study, we investigated the role of the nonreceptor tyrosine kinase c-Abl in Ang II-induced podocyte apoptosis. Male Sprague-Dawley rats in groups of 12 were administered either Ang II (400 kg/kg/min) or Ang II + STI-571 (50 mg/kg/day) by osmotic minipumps. In addition, 12 rats-receiving normal saline served as the control. Glomeruli c-Abl expression was carried out by real time PCR, Western blotting and immunolabeled, and occurrence of apoptosis was carried out by TUNEL staining and transmission electron microscopic analysis. In vitro studies, conditionally immortalized mouse podocytes were treated with Ang II (10(-9)-10(-6) M) in the presence or absence of either c-Abl inhibitor, Src-I1, specific c-Abl siRNA, or c-Abl plasmid alone. Quantification of podocyte c-Abl expression and c-Abl phosphorylation at Y245 and Y412 was carried out by real time PCR, Western blotting and immunofluorescence imaging. The nuclear c-Abl and p53 were quantified by co-immunoprecipitation and Western blotting studies. Podocyte apoptosis was analysed by flow cytometry and Hoechst-33342 staining. c-Abl expression was demonstrated in rat kidney podocytes in vivo and cultured mouse podocytes in vitro. Ang II-receiving rats displayed enhanced podocyte c-Abl expression. And Ang II significantly stimulated c-Abl expression in cultured podocytes. Furthermore Ang II upregulated podocyte c-Abl phosphorylation at Y245 and Y412. Ang II also induced an increase of nuclear p53 protein and nuclear c-Abl-p53 complexes in podocytes and podocyte apoptosis. Down-regulation of c-Abl expression by c-Abl inhibitor (Src-I1) as well as specific siRNA inhibited Ang II-induced podocyte apoptosis; conversely, podoctyes transfected with c-Abl plasmid displayed enhanced apoptosis. These findings indicate that c-Abl may mediates Ang II-induced podocyte apoptosis, and inhibition of c-Abl expression can protect podocytes from Ang II-induced injury.

Unsupervised nosologic imaging for glioma diagnosis.

In this letter a novel approach to create nosologic images of the brain using magnetic resonance spectroscopic imaging (MRSI) data in an unsupervised way is presented. Different tissue patterns are identified from the MRSI data using nonnegative matrix factorization and are then coded as different primary colors (i.e. red, green, and blue) in an RGB image, so that mixed tissue regions are automatically visualized as mixtures of primary colors. The approach is useful in assisting glioma diagnosis, where several tissue patterns such as normal, tumor, and necrotic tissue can be present in the same voxel/spectrum. Error-maps based on linear least squares estimation are computed for each nosologic image to provide additional reliability information, which may help clinicians in decision making. Tests on in vivo MRSI data show the potential of this new approach.