Adiponectin C1q/Tumor Necrosis Factor-Related Protein 13 (CTRP13) Protects against Renal Inflammation and Fibrosis in Obstructive Nephropathy.

Renal inflammation and fibrosis are the important pathological phenomena associated with obstructive nephropathy. However, the underlying mechanism associated with this disease has yet to be fully elucidated. The present study, therefore, aimed to investigate the effects mediated by C1q/tumor necrosis factor-related protein 13 (CTRP13) on renal inflammation and fibrosis in addition to elucidating the underlying mechanism. To meet this aim, a mouse unilateral ureteral obstruction (UUO)-mediated renal dysfunction model was established. In addition, hematoxylin-eosin staining (H&E) staining and immunofluorescence experiments as well as Western blotting and reverse transcription quantitative (RT q) PCR analyses were performed. Recombinant CTRP13 was used to investigate the role of CTRP13 in chronic renal inflammation and fibrosis. A decreased expression level of CTRP13 was identified in the plasma of patients with renal fibrosis and in UUO-model mice. The renal histopathological and functional analyses revealed that CTRP13 could both reverse UUO mediated renal dysfunction and ameliorate the conditions of tubulointerstitial fibrosis and tubular injury. Additionally, CTRP13 was found to inhibit the expression levels of extracellular matrix proteins and proinflammatory mediators. In terms of the underlying mechanism, the protective effects on inflammation and fibrosis of the kidneys of CTRP13-treated mice undergoing UUO were found to be associated with the inactivation of the TGF ß/Smad and NF κB p65 signaling pathways. Taken together, these findings have suggested that CTRP13 fulfills a vital role in the progression of obstructive nephropathy, thereby uncovering brand new insights into possible leads for the therapeutic treatment of chronic kidney disease (CKD).

Cell Infiltrative Inner Connected Porous Hydrogel Improves Neural Stem Cell Migration and Differentiation for Functional Repair of Spinal Cord Injury.

The disadvantages of cell-adaptive microenvironments and cellular diffusion out of the lesion have limited hydrogel-based scaffold transplantation treatment for neural connectivity, leading to permanent neurological disability from spinal cord injury. Herein, porous GelMA scaffold was prepared, in which the inner porous structure was optimized. The average pore size was 168 ± 71 µm with a porosity of 77.1%. The modulus of porous hydrogel was 593 ± 4 Pa compared to 1535 ± 85 Pa of bulk GelMA. The inner connected porous structure provided a cell-infiltrative matrix for neural stem cell migration and differentiation in vitro and eventually enhanced neuron differentiation and hindlimb strength and movement of animals in in vivo experiments. Furthermore, inflammation response and apoptosis were also alleviated after implantation. This work demonstrated that the porous hydrogel with appropriately connected micropores exhibit favorable cellular responses compared with traditional non-porous GelMA hydrogel. Taken together, our findings suggest that porous hydrogel is a promising scaffold for future delivery of stem cells and has prospects in material design for the treatment of spinal cord injury.

Overexpression of ethylene response factor ERF96 gene enhances selenium tolerance in Arabidopsis.

Ethylene response factors (ERFs) are involved in the regulation of plant responses to biotic and abiotic stresses. Here we provide evidence for a role of ERF96, a member of the ERF transcription factor group IX, in selenite tolerance in Arabidopsis. ERF96 gene was rapidly up-regulated in response to selenite stress. Overexpression of ERF96 enhanced Arabidopsis resistance to selenite stress, while ERF96-silenced plants demonstrated wild-type (WT) resistance to selenite. In addition, the overexpression plants had significantly lower selenium (Se) content in shoots when subjected to selenite stress. Further investigation indicated that overexpression of ERF96 reduced transcript levels of selenite/phosphate transporters PHT1;1 and PHT2;1, which influenced Arabidopsis Se uptake and allocation in the presence of selenite. Moreover, our experiments showed that overexpression of ERF96 enhanced Arabidopsis antioxidant activity. Under selenite stress, ERF96-overexpressing lines exhibited the significant increases in catalase (CAT) and glutathione peroxidase (GPX) activities as well as the glutathione (GSH) content, while had a decrease in reactive oxygen species (ROS) accumulation compared to WT. Taken together, our results demonstrate that ERF96 plays a positive role in the regulation of selenite tolerance in Arabidopsis.

Predictive value of circulating coagulation related microRNAs expressions for major adverse cardiac and cerebral event risk in patients undergoing continuous ambulatory peritoneal dialysis: a cohort study.

BACKGROUND: We aimed to investigate the correlation of coagulation related microRNAs (miRNAs) expressions with major adverse cardiac and cerebral event (MACCE) risk in patients undergoing continuous ambulatory peritoneal dialysis (CAPD). METHODS: 198 end-stage renal disease (ESRD) patients underwent CAPD were consecutively recruited in this study. Clinical characteristics as well as physiological and biochemical indexes were recorded. Peripheral blood was collected after enrollment to separate plasma, and 13 blood coagulation related miRNAs were detected by the real-time quantitative polymerase chain reaction. All patents were followed up for 48 months, and the last follow-up date was 2018/12/31. MACCEs occurred during the follow up were documented, and MACCE-free survival was calculated. RESULTS: MACCE incidence at 1 year, 2 year, 3 year and 4 year was 2.5, 6.1, 9.1 and 13.1% respectively, and mean MACCE-free survival was 45.2 (95% CI 44.0-46.4) months. Kaplan-Meier curves showed that miR-30e-5p, miR-92a-3p, miR-106a-5p and miR-126-5p high expressions were associated with longer MACCE-survival, while miR-423-5p high expression correlated with shorter MACCE-free survival. Multivariate Cox's regression analysis disclosed that miR-92a-3p, miR-126-5p and miR-652-3p independently predicted longer MACCE-free survival, while miR-423-5p independently predicted reduced MACCE-free survival in CAPD patients. CONCLUSION: Circulating miR-92a-3p, miR-126-5p, miR-652-3p and miR-423-5p exhibit potential to serve as novel biomarkers for MACCE risk in patients undergoing CAPD.

Circular RNA ABCB10 promotes tumor progression and correlates with pejorative prognosis in clear cell renal cell carcinoma.

OBJECTIVE: Our study aimed to evaluate the effect of circular RNA ABCB10 (circ-ABCB10) on proliferation and apoptosis of clear cell renal cell carcinoma (ccRCC) cells, and its prognostic value in patients with ccRCC. METHODS: Circ-ABCB10 expression in five ccRCC cell lines and normal kidney epithelial cell line was measured by quantitative polymerase chain reaction (qPCR). Empty overexpression, circ-ABCB10 overexpression, empty shRNA, and circ-ABCB10 shRNA plasmids were transfected into A498 cells as negative control for circ-ABCB10 over expression {NC (+)}, Circ-ABCB10(+), negative control (-){NC(-)}, and Circ-ABCB10(-) groups, then cell proliferation and apoptosis were evaluated by Cell Counting Kit-8 and annexin V/propidium iodide. Meanwhile, apoptotic markers were measured by western blot. Subsequently, circ-ABCB10 expression in tumor tissues and paired adjacent tissues from 120 ccRCC patients was measured by qPCR. RESULTS: Circ-ABCB10 expression was elevated in all the ccRCC cell lines compared with the normal kidney cells line. A498 cell proliferation was enhanced in the Circ-ABCB10(+) group compared with the NC(+) group, while it was inhibited in the Circ-ABCB10(-) group compared with the NC (-) group; and A498 cell apoptosis was repressed in the Circ-ABCB10(+) group than the NC(+) group, but was promoted in the Circ-ABCB10(-) group compared with the NC(-) group. In addition, circ-ABCB10 was up-regulated in tumor tissues compared with paired adjacent tissues, and its high expression correlated with the advanced pathological grade and the tumor node metastasis stage as well as independently predicting worse overall survival in ccRCC patients. CONCLUSION: Circ-ABCB10 promotes tumor progression and correlates with pejorative prognosis in ccRCC.

The role of cytokinin in selenium stress response in Arabidopsis.

Cytokinins (CKs) regulate many developmental processes and environmental stress responses in plants. In this study, our data provide evidence that CK negatively regulates Arabidopsis selenium (Se) stress response. CK-deficient plant ipt1 3 5 7 exhibited enhanced Se tolerance which was abolished by exogenous benzylaminopurine (BA) application, while CK- receptor -deficient mutants ahk2 and ahk3 were sensitive to Se stress. Further investigation suggested that CK regulated Se tolerance of ipt1 3 5 7 through reduction of Se uptake and activation of metabolism detoxification, which had significantly lower transcriptions of high-affinity transporters PHT1;1, PHT1;8, PHT1;9 and the higher transcription of selenocysteine methyltransferase (SMT) respectively. Moreover, Se tolerance of ipt1 3 5 7 was associated with the enhanced antioxidant levels which had the higher catalase (CAT), ascorbate peroxidase (APX) and glutathione peroxidase (GPX) activities as well as the higher glutathione (GSH) content. On the other hand, loss-of-function mutations in single CK receptor genes could increase Se uptake and reactive oxygen species (ROS) accumulation, which caused Se sensitivity in ahk2 and ahk3 mutants. Taken together, these findings provide new insights to the role of CK in Se stress response in Arabidopsis.

The skewed frequency of B-cell subpopulation CD19+ CD24 hi CD38 hi cells in peripheral blood mononuclear cells is correlated with the elevated serum sCD40L in patients with active systemic lupus erythematosus.

CD19+ CD24hi CD38hi cells play an essential role in maintaining immune homeostasis. CD40 signaling is involved in regulating the induction and function of CD19+ CD24hi CD38hi cells. Changes in B-cell subpopulations and CD19+ CD24hi CD38hi cells have been observed in systemic lupus erythematosus (SLE) patients. Whether changes in the B-cell subpopulation are related to the aberrant CD40 signaling in SLE patients remains unclear. In this study, we examined changes in the levels of CD19+ CD24hi CD38hi cells and CD19+ CD24hi CD38low cells in peripheral blood mononuclear cells and the serum level of soluble CD40 ligand (sCD40L) in 30 patients with SLE. Through routine biochemical assays and flow cytometry assay, we found that (1) the CD19+ CD24hi CD38hi cell subset was upregulated in SLE patients compared to that in healthy controls (HCs) (P < 0.05); (2) the CD19+ CD24hi CD38low cell subset was downregulated in SLE patients compared with that in HCs; and (3) CD38 expression was positively correlated with SLE manifestations and the serum sCD40L level (P < 0.05). In conclusion, the relative level of Bregs is significantly higher in SLE patients than in HCs and is positively correlated with disease activity and sCD40L level.

Cytokinin is involved in TPS22-mediated selenium tolerance in Arabidopsis thaliana.

Background and Aims: Excess selenium (Se) is toxic to plants, but relatively little is known about the regulatory mechanism of plant Se tolerance. This study explored the role of the TPS22 gene in Se tolerance in Arabidopsis thaliana. Methods: Arabidopsis wild type and XVE mutant seeds were grown on half-strength MS media containing Na2SeO3 for screening of the Se-tolerant mutant tps22. The XVE T-DNA-tagged genomic sequence in tps22 was identified by TAIL-PCR. The TPS22 gene was transformed into the mutant tps22 and wild type plants using the flower infiltration method. Wild type, tps22 mutant and transgenic seedlings were cultivated on vertical plates for phenotype analysis, physiological index measurement and gene expression analysis. Key Results: We identified an Arabidopsis Se-tolerant mutant tps22 from the XVE pool lines, and cloned the gene which encodes the terpenoid synthase (TPS22). TPS22 was downregulated by Se stress, and loss-of-function of TPS22 resulted in decreased Se accumulation and enhanced Se tolerance; by contrast, overexpression of TPS22 showed similar traits to the wild type under Se stress. Further analysis revealed that TPS22 mediated Se tolerance through reduction of Se uptake and activation of metabolism detoxification, which decreased transcription of high-affinity transporters PHT1;1, PHT1;8 and PHT1;9 and significantly increased transcription of selenocysteine methyltransferase (SMT), respectively. Moreover, loss-of-function of TPS22 resulted in reduced cytokinin level and repression of cytokinin signalling components AHK3 and AHK4, and upregulation of ARR3, ARR15 and ARR16. Exogenous cytokinin increased transcription of PHT1;1, PHT2;1 and SMT and decreased Se tolerance of the tps22 mutant. In addition, enhanced Se resistance of the tps22 mutant was associated with glutathione (GSH). Conclusions: Se stress downregulated TPS22, which reduced endogenous cytokinin level, and then affected the key factors of Se uptake and metabolism detoxification. This cascade of events resulted in reduced Se accumulation and enhanced Se tolerance.

Ouabain-induced apoptosis and inhibition of viability of tubulointerstitial cells by regulating NKA/pSrc/pERK/pAkt/pS6k/caspase 3 may contribute to lupus nephritis development.

This study aimed to investigate the underlying molecular mechanism of ouabain-induced apoptosis and inhibited viability of tubulointerstitial cells in lupus nephritis (LN). Serum ouabain expression in 21 LN patients and 20 healthy controls (HCs) was detected by ELISA. Na-K-ATPase α1 (NKA) expression in kidney tissue from 21 LN patients and 6 controls who underwent nephrectomy was determined by immunohistochemistry assay. HK-2 cells were treated by ouabain with concentration 0 nM (control), 0.1 nM, 1 nM, 10 nM, 100 nM and 1000 nM for 72 h; MTT assay was performed at 24 h, 48 h and 72 h to detect cells viability, AV/PI assay was conducted at 24 h to detect the cell apoptosis. NKA expression was detected by immunofluorescence assay and western blot (WB) while pSrc, pERK, pAkt, pS6K and caspase 3 expression was detected by WB after 100 nM ouabain treatment. Serum ouabain was elevated in LN patients compared to HCs, while kidney NKA was reduced in LN patients compared with controls. HK-2 cell viability by MTT assay was decreased while cell apoptosis by AV/PI was increased at each time point after ouabain 0.1 nM, 1 nM, 10 nM, 100 nM and 1000 nM treatment compared to control group. Both immunofluorescence and WB disclosed that NKA expression was decreased at 12 h and 24 h compared to 0 h after 100 nM ouabain treatment. Moreover, pSrc, pERK, pAkt, pS6K and caspase 3 expressions were elevated after 100 nM ouabain treatment. In conclusion, ouabain may contribute to LN etiology by inhibiting human proximal tubular cell viability and promoting cells apoptosis through regulating NKA, pSrc, pERK, pAkt, pS6K and caspase 3.

Involvement of NOX in the regulation of renal tubular expression of Na/K-ATPase in acute unilateral ureteral obstruction rats.

BACKGROUND/AIMS: Renal tubular expression of Na/K-ATPase has been reported to be rapidly reduced in kidneys after unilateral ureteral obstruction (UUO), contributing to compromised sodium regulation. In this study, apocynin was utilized to test the hypothesis that the renal nicotinamide adenine dinucleotide phosphate (NADPH) oxidase (NOX) system is involved in the regulation of Na/K-ATPase expression in early UUO. METHODS: Eighty Wistar rats underwent UUO or sham surgery, and half of each group was administered 100 mg/kg apocynin by oral gavage after surgery. Renal tissue samples were collected on day 1 and day 3 after surgery and the distribution of NOX2, NOX4 and Na/K-ATPase was assessed by immunofluorescence and immunohistochemical staining. The Heme oxygenase-1 (HO-1), NOX2, NOX4, osteopontin, Na/K-ATPase and aquaporin-1 (AQP-1) content of renal homogenates was assessed by immunoblotting, and malondialdehyde (MDA), nitric oxide (NO) content was assessed by biochemical analyses. Activity of inducible NO synthase (iNOS) and antioxidant enzymes was assessed by enzymatic assay. RESULTS: Kidney Na/K-ATPase and AQP-1 content was decreased, and MDA and NOX4, NOX2 and HO-1 content were increased in the obstructed kidneys of UUO rats. Apocynin attenuated these changes and partially, but significantly, reversed the downregulation of Na/K-ATPase and AQP-1 in UUO rats. However, apocynin did not alter iNOS activity and NO production, osteopontin expression or the activity of antioxidant enzymes. CONCLUSION: Activation of the NOX system and subsequent production of ROS are likely responsible for the downregulation of renal tubular Na/K-ATPase expression in early UUO.

Superiority of laparoscopy in the peritoneal dialysis catheter reset surgery.

Peritoneal dialysis catheter surgery has been used in clinical treatment for nearly 40 years, and open surgery under local anesthesia is the conventional method. However, catheter displacement after open surgery is still the thorny issue during our clinical practice. Then the reset surgery is often required to be taken again. Nowadays, laparoscopic peritoneal dialysis catheter draws our attention due to its advantages of accurate positioning, smaller incision, and less pain, and its clinical application has been limited. While laparoscopic surgery is recognized, there are few relevant studies on whether there is difference during the catheter reset process between the two surgical approaches. In this study, we mainly discussed the rate of secondary catheter migration, the incidence of complications after catheter reset for two surgical approaches and the hospital stay as well as the total clinical cost for the two surgical approaches. In this study, we retrospectively analyzed 25 cases of end-stage renal disease, who received catheterization for peritoneal dialysis and regular peritoneal dialysis in our hospital from March 2010 to December 2013, and had a medical history of catheter migration. We collected the relevant clinical data for all patients. Fifteen patients selected laparoscopic catheter reset, and 10 patients selected the traditional surgical method for catheter reset by themselves. For all patients enrolled, we analyzed the incidence of secondary catheter migration and postoperative complications, hospitalization time, and total cost for different methods of reset. Through the studies above, we found that laparoscopic peritoneal dialysis catheter surgery offered accurate catheter location and a small incision that was easy to heal. Besides, the incidence of postoperative complications for the laparoscopic surgery was lower than that for traditional surgical approach for catheter reset. The average hospitalization time for laparoscopic surgery was shorter than that for the traditional surgical approach. The total cost of laparoscopic surgery was more than that of the traditional surgery. Therefore, the rational application of a laparoscopic peritoneal dialysis catheter and reset surgery can increase the success rate of peritoneal dialysis, reduce the complications, shorten hospitalization time of patients, and thus enhance patient's confidence to stick it out.

Involvement of Na/K-ATPase in hydrogen peroxide-induced activation of the Src/ERK pathway in LLC-PK1 cells.

We have shown that Na/K-ATPase interacts with Src. Here, we test the role of this interaction in H2O2-induced activation of Src and ERK. We found that exposure of LLC-PK1 cells to H2O2 generated by the addition of glucose oxidase into the culture medium activated Src and ERK1/2. It also caused a modest reduction in the number of surface Na/K-ATPases and in ouabain-sensitive Rb(+) uptake. These effects of H2O2 seem similar to those induced by ouabain, a specific ligand of Na/K-ATPase, in LLC-PK1 cells. In accordance, we found that the effects of H2O2 on Src and ERK1/2 were inhibited in α1 Na/K-ATPase-knockdown PY-17 cells. Whereas expression of wild-type α1 or the A420P mutant α1 defective in Src regulation rescued the pumping activity in PY-17 cells, only α1, and not the A420P mutant, was able to restore the H2O2-induced activation of protein kinases. Consistent with this, disrupting the formation of the Na/K-ATPase/Src complex with pNaKtide attenuated the effects of H2O2 on the kinases. Moreover, a direct effect of H2O2 on Na/K-ATPase-mediated regulation of Src was demonstrated. Finally, H2O2 reduced the expression of E-cadherin through the Na/K-ATPase/Src-mediated signaling pathway. Taken together, the data suggest that the Na/K-ATPase/Src complex may serve as one of the receptor mechanisms for H2O2 to regulate Src/ERK protein kinases and consequently the phenotype of renal epithelial cells.

Reduction of Na/K-ATPase potentiates marinobufagenin-induced cardiac dysfunction and myocyte apoptosis.

Decreases in cardiac Na/K-ATPase have been documented in patients with heart failure. Reduction of Na/K-ATPase α1 also contributes to the deficiency in cardiac contractility in animal models. Our previous studies demonstrate that reduction of cellular Na/K-ATPase causes cell growth inhibition and cell death in renal proximal tubule cells. To test whether reduction of Na/K-ATPase in combination with increased cardiotonic steroids causes cardiac myocyte death and cardiac dysfunction, we examined heart function in Na/K-ATPase α1 heterozygote knock-out mice (α1(+/-)) in comparison to wild type (WT) littermates after infusion of marinobufagenin (MBG). Adult cardiac myocytes were also isolated from both WT and α1(+/-) mice for in vitro experiments. The results demonstrated that MBG infusion increased myocyte apoptosis and induced significant left ventricle dilation in α1(+/-) mice but not in their WT littermates. Mechanistically, it was found that in WT myocytes MBG activated the Src/Akt/mTOR signaling pathway, which further increased phosphorylation of ribosome S6 kinase (S6K) and BAD (Bcl-2-associated death promoter) and protected cells from apoptosis. In α1(+/-) myocytes, the basal level of phospho-BAD is higher compared with WT myocytes, but MBG failed to induce further activation of the mTOR pathway. Reduction of Na/K-ATPase also caused the activation of caspase 9 but not caspase 8 in these cells. Using cultures of neonatal cardiac myocytes, we demonstrated that inhibition of the mTOR pathway by rapamycin also enabled MBG to activate caspase 9 and induce myocyte apoptosis.

The invasion of tobacco mosaic virus RNA induces endoplasmic reticulum stress-related autophagy in HeLa cells.

The ability of human cells to defend against viruses originating from distant species has long been ignored. Owing to the pressure of natural evolution and human exploration, some of these viruses may be able to invade human beings. If their 'fresh' host had no defences, the viruses could cause a serious pandemic, as seen with HIV, SARS (severe acute respiratory syndrome) and avian influenza virus that originated from chimpanzees, the common palm civet and birds, respectively. It is unknown whether the human immune system could tolerate invasion with a plant virus. To model such an alien virus invasion, we chose TMV (tobacco mosaic virus) and used human epithelial carcinoma cells (HeLa cells) as its 'fresh' host. We established a reliable system for transfecting TMV-RNA into HeLa cells and found that TMV-RNA triggered autophagy in HeLa cells as shown by the appearance of autophagic vacuoles, the conversion of LC3-I (light chain protein 3-I) to LC3-II, the up-regulated expression of Beclin1 and the accumulation of TMV protein on autophagosomal membranes. We observed suspected TMV virions in HeLa cells by TEM (transmission electron microscopy). Furthermore, we found that TMV-RNA was translated into CP (coat protein) in the ER (endoplasmic reticulum) and that TMV-positive RNA translocated from the cytoplasm to the nucleolus. Finally, we detected greatly increased expression of GRP78 (78 kDa glucose-regulated protein), a typical marker of ERS (ER stress) and found that the formation of autophagosomes was closely related to the expanded ER membrane. Taken together, our data indicate that HeLa cells used ERS and ERS-related autophagy to defend against TMV-RNA.