Nephridial Tissue Research Articles

Mitochondrial reactive oxygen species initiate gasdermin D-mediated pyroptosis and contribute to paraquat-induced nephrotoxicity

Paraquat (PQ)-induced acute kidney injury (AKI) progresses rapidly and is associated with high mortality rates; however, no specific antidote for PQ has been identified. Poor understanding of toxicological mechanisms underlying PQ has hindered the development of suitable treatments to combat PQ exposure. Gasdermin D (GSDMD), a key executor of pyroptosis, has recently been shown to enhance nephrotoxicity in drug-induced AKI. To explore the role of pyroptosis in PQ-induced AKI, the plasma membrane damage of the cells was detected by LDH release assay. Western blot was performed to detect the cleavage of GSDMD. RNA sequencing analysis was performed to explore the mechanism of PQ induced nephrotoxicity. Herein, we demonstrated that PQ could induce pyroptosis in HK-2 cells and nephridial tissues. Mechanistically, PQ initiated GSDMD cleavage, and GSDMD knockout attenuated PQ-induced nephrotoxicity in vivo. Further analysis revealed that the accumulation of mitochondrial reactive oxygen species (ROS) induced p38 activation, contributing to PQ-induced pyroptosis. Furthermore, mitoquinone, a mitochondria-targeted antioxidant, reduced mitochondrial ROS levels and inhibited pyroptosis. Collectively, these findings provide insights into the role of GSDMD-dependent pyroptosis as a novel mechanism of PQ-induced AKI.

Transcriptome, antioxidant enzymes and histological analysis reveal molecular mechanisms responsive to low salinity stress in Phascolosoma esculenta

Phascolosoma esculenta is an economically species inhabiting the intertidal zone and is farmed with high output. During artificial propagation, P. esculenta underwent mass death after torrential rain due to low salinity. In this paper, the effect of salinity on P. esculenta was studied for the first time. The results showed that P. esculenta died when exposed to water of 10‰ salinity, and their body lengths were about two times larger than when exposed to salinity of 25‰. The groups exposed to 10‰ salinity underwent severe necrosis. The activity of T-SOD and T-AOC in nephridial tissues increased between 3 and 12 h, but not at 9 h, T-SOD was highest in the control group and lowest in the death group, and T-AOC was highest in the death group and lowest in the survivor group. The concentration of MDA increased from 3 to 9 h and then decreased, and was highest in the death group and lowest in the control group. 35,053 unique genes, including 15,445 new genes, were acquired based on the 61.63 Gb Clean RNA-Seq Data. 27773 average alternative splicing (AS) events were found in the death group, which was 83.74% and 83.54% of that in the control and survivor group, respectively. Additionally, 1596 significantly differentially expressed genes (DEGs) were observed, which were classified into several functional categories, including genes involved in ion transporters, cation transport, RNA processing, immune response etc. The study had also found a significant number of genes involved in the pathways, including Mineral absorption, AMPK signaling pathway, Oxidative phosphorylation, and Phagosome pathways, such as Hsp70, Hsp20, Gst, solute carrier family genes, calcium channel regulatory activity genes, and pre-rRNA processing proteins. Overall, these results provide numerous candidate genes for future investigations and valuable insights into the mechanisms underlying the culture of P. esculenta in lower salinity.

Effect of granules made by new-medicinal parts of Crocus sativus on hyperuricemia in rats and its mechanism

To explore the effect of the granules made by new-medicinal parts of Crocus sativus(NMPCS) on hyperuricemia(HUA) in rats, the rat model of HUA was established by intramuscular injection of 3% potassium oxonate and intraperitoneal injection of 4% pyrazinamide. The content of serum uric acid was monitored every week for 3 consecutive weeks. After the experiment, the levels of serum uric acid, urine uric acid, serum creatinine, blood urea nitrogen(BUN), and xanthine oxidase(XOD) were determined. The protein and gene expressions of XOD were determined by Western blot method and fluorescence quantitative polymerase chain reaction(qPCR), and the morphological changes in the liver tissue were performed by hematoxylin-eosin(HE) staining. The results showed that as compared with the model group, the levels of serum uric acid in the positive drug group and the low, medium, and high-dose NMPCS groups were lower(P<0.05), the levels of urine uric acid in the high-dose NMPCS group were decreased(P<0.01), and there was no statistical difference in the medium and low-dose NMPCS groups. The levels of BUN in the high and low-dose NMPCS groups were decreased(P<0.05), and the levels of serum creatinine did not change in the administration groups. The positive drug group and the low, medium, and high-dose NMPCS groups significantly reduced the liver damage, with only a few hepatocytes vacuolization and a small number of red blood cells in the central venous area. The nephridial tissue structure was slightly abnormal, with a small number of red blood cell infiltration, and no obvious inflammatory cell infiltration was found in the glomerulus in these groups. No degeneration was found in renal tubular epithelial cells, with mild glomerular and tubular lesions and a small amount of sodium urate deposition and crystallization in the positive drug group and the low, medium, and high-dose NMPCS groups. The relative protein expressions of XOD in the positive drug group and the high dose NMPCS group were decreased(P<0.05), and the relative mRNA expressions of XOD in the positive drug group and the high and low-dose NMPCS groups were decreased as well(P<0.05). The above results show that NMPCS reduces uric acid in rats with HUA by regulating XOD, which provides a certain experimental basis for the development of NMPCS as a new medicine for the treatment of HUA.

Clinical study on the use of advanced magnetic resonance imaging in lupus nephritis

ObjectivesTo investigate the correlation between the histopathology of the kidney and clinical indicators in patients with lupus nephritis (LN) using magnetic resonance imaging (MRI).MethodsA total 50 female participants were enrolled in the study. Thirty patients with LN were divided into types 2, 3, 4, and 5, according to their pathological features. The control group consisted of 20 healthy female volunteers. Serum creatinine, C3, C1q, and anti-ds-DNA were measured. Conventional MRI, DTI, DWI, and BOLD scanning was performed to obtain the FA, ADC, and R2* values for the kidney.ResultsCompared with the control group, FA and the ADC were decreased in patients with LN, while the R2* value was increased (P < 0.05). The overall comparison of the SLEDAI (Activity index of systemic lupus erythematosus) score, total pathological score, AI, and serum creatinine C3 showed that these were significantly different between the two groups (P < 0.05). FA and the ADC were negatively correlated with urinary, blood ds-DNA, and serum creatinine and positively correlated with C1q (P < 0.05). The R2* value was positively correlated with urinary NGAL, blood ds-DNA, and serum creatinine (P < 0.05). FA and the ADC were negatively correlated with the SLEDAI score, total pathological score, AI, CI, nephridial tissue C3, and C1q. The R2* value was positively correlated with the SLEDAI score, total pathological score, AI, CI, nephridial tissue C3, and C1q (P < 0.05).ConclusionsMRI examination in female patients with LN was correlated with pathologic test results, which may have clinical significance in determining the disease’s severity, treatment, and outcome.

LncRNA ANRIL-mediated miR-181b-5p/S1PR1 axis is involved in the progression of uremic cardiomyopathy through activating T cells

This study aimed to explore the regulatory role of lncRNA ANRIL/miR-181b-5p/S1PR1 in UC. UC mouse model was established by 5/6th nephrectomy. We detected body weight, serum levels of renal function and inflammatory factors (biochemical analyzer/ELISA), and cardiac parameters (echocardiography). HE and Masson staining showed the pathological changes and fibrosis in myocardial and nephridial tissues. The expression of ANRIL, miR-181b-5p, and S1PR1 were detected by qRT-PCR or Western blot/immunofluorescence. T cells activation was analyzed by Flow cytometry. ANRIL/S1PR1 were up-regulated and miR-181b-5p was down-regulated in UC mice. ANRIL silencing up-regulated miR-181b-5p and down-regulated S1PR1 (a target of miR-181b-5p). ANRIL silencing increased the body weight, recovered renal function [decreased blood urea nitrogen (BUN) and serum creatinine (Scr)] and cardiac function [decreased left ventricular end-diastolic diameter (LVEDD), LV end-systolic diameter (LVESD), LV systolic anterior wall thickness (LVAWS), LV end-diastolic anterior wall thickness (LVAWD), myocardial performance index (MPI), and isovolumic relaxation time (IVRT); increased LV ejection fraction (LVEF), LVEF/MPI, fractional shortening (FS), and E- and A-waves (E/A)], inhibited the inflammation [decreased interferon (IFN)-γ, interleukin (IL)-2, IL-10, and tumor necrosis factor (TNF)-α], and relieved pathological injuries and fibrosis. ANRIL silencing also recovered the viability and inhibited the inflammation of activated T cells in vitro, and inhibited T cell activation in UC mice in vivo. In addition, miR-181b-5p overexpression exhibited same effects with ANRIL silencing in UC. ANRIL silencing inhibited T cell activation through regulating miR-181b-5p/S1PR1, contributing to the remission of UC.

Xiaoyu Xiezhuo Drink Protects against Ischemia-Reperfusion Acute Kidney Injury in Aged Mice through Inhibiting the TGF-β1/Smad3 and HIF1 Signaling Pathways.

Acute kidney injury (AKI) is responsible for significant mortality among hospitalized patients that is especially troubling aged people. An effective self-made Chinese medicine formula, Xiaoyu Xiezhuo Drink (XXD), displayed therapeutic effects on AKI. However, the compositions and underlying mechanisms of XXD remain to be elucidated. In this study, we used the ultra-high-performance liquid chromatography method coupled with hybrid triple quadrupole time-of-flight mass spectrometry (UHPLC-Q-TOF-MS) to investigate the chemical components in XXD. Then, the absorbable components of XXD were identified based on the five principles and inputted into the SwissTargetPrediction and STITCH databases to identify the drug targets. AKI-related targets were collected from the GenCLiP 3, GeneCards, and DisGeNET databases. The crossover genes of XXD and AKI were identified for functional enrichment analysis. The protein-protein interaction (PPI) network of crossover genes was constructed, followed by the identification of hub genes. Subsequently, the effects and potential mechanisms of XXD on AKI predicted by the network pharmacology and bioinformatics analyses were experimentally validated in ischemia-reperfusion (I/R) injury-induced AKI aged mouse models. A total of 122 components in XXD were obtained; among them, 58 components were found that could be absorbed in the blood. There were 800 potential drug targets predicted from the 58 absorbable components in AKI which shared 36 crossover genes with AKI-related targets. The results of functional enrichment analysis indicated that crossover genes mostly associated with the response to oxidative stress and the HIF1 signaling pathway. In the PPI network analysis, 12 hub genes were identified, including ALB, IL-6, TNF, TP53, VEGFA, PTGS2, TLR4, NOS3, EGFR, PPARG, HIF1A, and HMOX1. In AKI aged mice, XXD prominently alleviated I/R injury-induced renal dysfunction, abnormal renal pathological changes, and cellular senescence, inflammation, and oxidative damage with a reduction in the expression level of the inflammatory mediator, α-SMA, collagen-1, F4/80, TP53, VEGFA, PTGS2, TLR4, NOS3, EGFR, PPARG, HIF1A, ICAM-1, TGF-β1, Smad3, and p-Smad3 and an increase of nephridial tissue p-H3, Ki67, HMOX1, MMP-9, and Smad7 levels. In summary, our findings suggest that XXD has renoprotective effects against AKI in aged mice via inhibiting the TGF-β1/Smad3 and HIF1 signaling pathways.

Research on mechanism of MAPK signal pathway induced by BMSCs for the proteinuria of rat's kidney, glomerulosclerosis and activity of RAS.

The aim of the article was to explore the mechanism of MAPK (Mitogen-activated protein kinase) signal pathway induced by BMSCs (Bone marrow mesenchymal stem cells) for the proteinuria of rat's kidney, glomerulosclerosis and activity of RAS (Renin angiotensin) system. Thirty rats were divided into sham group, FSGS (Focal Segmental Glomerular Sclerosis) group and BMSCs group. The variation of biochemical criterion and protein of rats in the three groups was compared. The variation condition of rats' kidney and GSI (Glomerular sclerosis index), ECM/GA (Extracellular matrix/glomerular area) was compared. The activity of RAS was analyzed. Finally, the p38 MAPK and p-p38 MAPK protein was compared. Compared with sham group rats, the SCr, BUN and proteinuria after twenty-four hours in FSGS group was improved. The blood albumin was notably reduced. At the same time, there was evident deterioration in the pathology of nephridial tissue (p<0.05). The biochemical criterion in transplanted BMSCs group was significantly reduced. At the same time, the blood albumin and pathology of nephridial tissue was also improved (p<0.05). The glomerulus in sham group was normal. There was abundant induration for the glomerulus in FSGS group compared with sham group. The relative value of GSI and ECM/GA was higher than in sham group (p<0.05). The relative value of GSI and ECM/GA in BMSCs group was reduced notably compared with FSGS group (p<0.05). The activity of RAS in FSGS group was enhanced. But activity of RAS in BMSCs group was remarkably restrained. The p38 MAPK and p-p38 MAPK protein in FSGS group was significantly increased compared with the other groups (p<0.05). The protein expression in BMSCs group and inhibitor group was restrained (p<0.05). The BMSCs could restrain the proteinuria of rat's kidney and activity of RAS and they were related with the expression of MAPK signal pathway closely.

Phospholipase A2 Receptor Autoantibodies as a Novel Serological Biomarker for Autoimmune Thyroid Disease Associated Nephropathy.

Aims: To develop a highly sensitive immunoassay for PLA2R autoantibodies and study the relationship between PLA2R autoantibodies and autoimmune thyroid disease-associated nephropathy.Methods: We applied a highly sensitive time-resolved fluoroimmunoassay to quantitatively detect the concentration of phospholipase A2 receptor (PLA2R) antibodies in the serum of patients with Graves' disease, Hashimoto's thyroiditis (HT), nephrotic patients with idiopathic membranous nephropathy (IMN), and normal controls. We immunohistochemically analyzed the existing PLA2R target antigen in the thyroid tissue of patients with Graves' disease and HT, as well as the nephridial tissue of nephrotic patients with IMN.Results: PLA2R antibody concentrations in the serum of normal controls, patients with nodular goiter, Graves' disease, and HT, as well as patients with IMN were 1.13 ± 0.43, 1.07 ± 0.22, 2.12 ± 2.11, 8.07 ± 4.74, and 15.91 ± 19.50 mg/L, respectively. PLA2R antibody concentration in the serum and the area under the receiver operating characteristic curve in patients with HT and IMN were increased significantly. Immunohistochemistry revealed obvious staining of PLA2R in tissues from patients with HT, with a positive rate of 66.67%.Conclusions: PLA2R is a potential pathogenic target antigen for HT, and the production of PLA2R antibodies may cause autoimmune thyroid disease-associated nephropathy.

PLA2R: The Same Target Antigen of Idiopathic Membranous Nephropathy and Hashimoto's Thyroiditis?

Background: Autoimmune thyroid disease associated nephropathy was identified 40 years ago; however, the cause of the disease remains unknown. Methods: Phospholipase A2 receptor (PLA2R) antibodies was assayed quantitatively in the serum of patients with Graves' disease, Hashimoto's thyroiditis (HT), idiopathic membranous nephropathy (IMN) and normal controls by time-resolved fluoroimmunoassay. PLA2R antigens were immunohistochemically analyzed in the thyroid tissue with Graves' disease and HT, as well as the nephridial tissue with IMN. Findings: The concentration of phospholipase A2 receptor (PLA2R) antibodies in the serum of normal controls, patients with Nodular goiter, Graves' disease and HT, as well as patients with IMN was 1.13 ± 0.43 mg/L, 1.07 ± 0.22mg/L, 2.12 ± 2.11mg/L, 8.07 ± 4.74mg/L, and 15.91 ± 19.50mg/L, respectively. The concentration of PLA2R antibodies in the serum and its areas under the curve of ROC in HT and IMN cases increased significantly. The immunohistochemistry revealed that the tissues of the patients with HT were obviously stained, with a positive rate of 66.67%. Interpretation: PLA2R may be a pathogenic target antigen for HT, and the production of anti-PLA2R antibodies may cause autoimmune thyroid disease associated nephropathy. Funding Statement: Clinical Medical Science fund of Jiangsu Province (No. BL2014022), Jiangsu Maternal and Child Health Research Project (FRC201741), and Wuxi City Science and Education Project (ZDRC006) supported the study. Declaration of Interests: All Authors declare no competing financial interests. Ethics Approval Statement: Patients from Jiangsu Jiangyuan Hospital and the Wuxi People’s Hospital affiliated to Nanjing Medical University, were enrolled. The study protocol was approved by the medical ethics committee of Jiangsu Jiangyuan Hospital and Affiliated Wuxi People's Hospital of Nanjing Medical University.

Administration of Curcumin Protects Kidney Tubules Against Renal Ischemia-Reperfusion Injury (RIRI) by Modulating Nitric Oxide (NO) Signaling Pathway

Background/Aims: To explore the protective effect of curcumin on renal ischemia-reperfusion injury (RIRI) in rats, and its influence on nephridial tissue’s NO and cGMP levels as well as downstream signaling pathway, to elucidate the possible mechanism of curcumin on RIRI. Methods: 36 Sprague Dawley rats (SD rats) were randomly divided into Sham group, Model group, curcumin (CUR +) Model group, 12 rats per group. They were all given RIRI model preparation by unilateral artery occlusion method. All groups’ β2-MG in urine in 24h, serum Cr and BUN were compared, and UAER were calculated. Nitric oxide synthase (NOS), cGMP-dependent protein kinase (PKG), Caspase-3 expression were all determined by western blot. Nitric oxide (NO), NOS and cGMP levels were also examined by using ELISA. All groups’ nephridial histomorphology and kidney tubules score were evaluated and compared. Results: β2-MG and UAER in urine, serum Cr and BUN, in renal tissue were all elevated in Model of RIRI, indicating the success of animal model of RIRI establishment, and above index in CUR + Model group were all lower than those in Model group. Furthermore, iNOS, NO, cGMP, PKG and Caspase-3 in renal tissue were all increased in Model of RIRI, indicating the NO signaling pathway was activated, which is one of the pathogenesis of RIRI, and above index in CUR + Model group were all lower than those in Model group, suggesting that inactivation of iNOS/NO/cGMP/PKG signaling pathway is one of the reasons that explain the protective effect of curcumin in RIRI. Conclusion: The activation of iNOS/NO/cGMP/PKG signaling pathway and the consequent promoted apoptosis of renal tubules are significantly involved in the pathogenesis of development of RIRI, and curcumin treatment could protect renal tubules against RIRI, at least partially, by suppressing the activated iNOS/NO/cGMP/PKG signaling pathway.

The influence of mutant lactobacilli on serum creatinine and urea nitrogen concentrations and renal pathology in 5/6 nephrectomized rats

Objectives: To explore the capacity of mutant lactobacilli to remove creatinine (Cr) and urea nitrogen (UN) via the gastrointestinal tract and its effects on renal pathology in the 5/6 nephrectomized rat model of chronic renal failure.Methods: Sixty Sprague–Dawley rats were randomly divided into a Sham group, a Model group, a wide-type Lactobacilli group (L.B group), and a Mutant Lactobacilli group (Mut-L.B group). The rats in the Model, LB and Mut-L.B groups underwent 5/6 nephrectomy. Eight weeks after administration, 24-h urine, orbital blood and digestive secretions were collected to analyze Cr and UN levels. Pathological changes in nephridial tissues were observed by hematoxylin and eosin and Masson trichrome staining, and the expression of TGF-β1 and FN was detected by immunohistochemistry.Results: There were no significant differences in urinary Cr and UN levels among the Sham, L.B and Mut-L.B groups (p > .05), while serum and digestive Cr and UN levels were significantly decreased in the Mut-L.B group (p < .01). Furthermore, renal tubular injury and interstitial fibrosis were significantly reduced and TGF-β1 and FN expression was decreased (p < .05) in the Mut-L.B group.Conclusion: Mutant lactobacilli decreased serum Cr and UN levels, reduced the expression of TGF-β1 and FN in renal tissues and alleviated renal interstitial injury and fibrosis in a rat model of chronic renal failure in a mechanism that may involve decomposition and not just excretion of small molecule toxins in the gastrointestinal tract.

Protective Effects of Dimedone Pyrone on Podocytes in Rats with Diabetic Nephropathy

Purpose: To investigate the effect of dimedone pyrone (DP) on podocytes in rats with diabetic nephropathy (DN).Methods: The rats were randomly assigned into 5 experimental groups (n = 10), viz, non-diabetic control with no treatment (ND/NT), diabetic with no treatment (DG/NT), diabetic treated with 5 mg/kg dimedone pyrone (DG/DP 5), diabetic treated with 10 mg/kg dimedone pyrone (DG/DP 10) and diabetic treated with 20 mg/kk dimedone pyrone (DG/DP 20) group. Clinical parameters, including 24 h urinary protein, blood urea nitrogen (BUN), serum creatinine (SCR), blood glucose (GLU), and kidney weight (KW)/body weight (BW) were determined after 12 weeks of treatment. Hematoxylin and eosin staining was used to examine renal pathological changes while transmission electron microscopy (TEM) was employed for evaluation of structural changes in the podocytes. The expression levels of nephrin and podocin were evaluated using immunofluorescence staining.Results: Dimedone pyrone caused a significant decrease in SCR, BUN, GLU, KW/BW and 24 h urine protein in DG/DP 20 group compared to DG/NT group. Furthermore, incidences of glomerular disorders, chronic tubulo-interstitial damage and glomerular podocyte lesions decreased significantly following dimedone pyrone treatment. Glomeruli, tubules and podocytes exhibited pathomorphological improvements while nephrin and podocin protein expression levels were significantly higher in the nephridial tissue. Decrease in relative kidney weight (KW/BW) and 24 h urinary protein level were improved significantly on treatment with dimedone pyrone. Moreover, glomerular disorder, chronic tubulo-interstitial damage and glomerular podocyte lesions were also suppressed. The improvement was more significant in DG/DP 20 compared to DG/DP 5 and DG/DP 10 groups.Conclusion: Dimedone pyrone exhibits a protective effect on the podocytes of rats and may be of therapeutic importance in the treatment of diabetic nephropathy.Keywords: Dimedone pyrone, Podocin, Diabetic neuropathy, Nephrin, Glomerular disorders

Renal Expression and Clinical Significance of High Mobility Group Box 1 in Lupus Nephritis

Objective: To evaluate the clinical significance of high mobility group box 1 (HMGB1) expression in nephridial tissues of lupus nephritis (LN). Methods: Sixty-three patients with active LN and 15 systemic lupus erythematosus (SLE) (combined without LN) were included. Renal biopsies were performed in the two groups. The biopsies were evaluated according to the World Health Organization (WHO) classification and renal disease activity was estimated using the British Isles lupus assessment group (BILAG) index. Serum levels of HMGB1 were analyzed by western blot. HMGB1 expression in renal tissue was assessed by immunohistochemistry in the two groups. The correlation between HMGB1 and renal active index (AI), chronicity index (CI), pathological type of LN was analyzed. Results: LN biopsies showed WHO class III, IV or V and all patients had high renal disease activity (BILAG A/B). The HMGB1 expression was higher in the LN groups than the control groups (t = 9.263, P P P P P HMGB1 increased only slightly in the patients only with SLE; however, in patients with LN WHO class IV a significant decrease was observed (P = 0.02). Immunostaining revealed a pronounced extranuclear HMGB1 expression predominantly outlining the glomerular endothelium and in the mesangium. There were significant differences in HMGB1 expression between LN and control biopsies and it existed with apparent association to histopathological classification and clinical outcome. Conclusions: Renal tissue expression and serum levels of HMGB1 were elevated in LN. The unusual elevation of HMGB1 in serum and tissue in LN may reflect persistent inflammatory activity, which clearly indicates a role for HMGB1 in pathogenesis of LN.

Carboxymethylation of an exopolysaccharide from Lachnum and effect of its derivatives on experimental chronic renal failure

Carboxymethylated polysaccharide CLEP-1b was prepared from a single component (LEP-1b) of Lachnum YM281 exopolysaccharides by molecular modification with a degree of substitution (DS) of 0.286. Infrared result proved that the carboxymethylation of LEP-1b succeeded and 13C NMR result showed that the carboxymethyl group (CH2COOH) was chemically linked to an oxygen (O) atom of the hydroxyl on C-3 of LEP-1b. LEP-1b could improve the histopathological status of kidney and significantly reduce the contents of serum creatinine (Scr) and blood urea nitrogen (BUN), and increase the contents of total protein and albumin. It could also enhance the activity of SOD, GSH-PX, CAT, GSH and decrease MDA contents in the nephridial and hepatic tissues. What's more, CLEP-1b showed more significant effects than LEP-1b at the same dosage. The research indicated that LEP-1b and CLEP-1b could mitigate the chronic renal failure of mice and the effects were closely associated with antioxidant activity.

Effect of Cordyceps sinensis and Tripterygium wilfordii polyglycosidium on podocytes in rats with diabetic nephropathy.

The aim of the present study was to investigate the effects of Cordyceps sinensis (CS) and Tripterygium wilfordii polyglycosidium (TWP) on podocytes in rats with diabetic nephropathy (DN). DN rat models were established and divided randomly into normal control (group A), DN (group B), CS (group C), TWP (group D) and CS and TWP groups (group E). After 12 weeks, levels of 24-h urinary protein, blood urea nitrogen (BUN), serum creatinine (SCR), white blood cells, blood glucose (GLU), aspartate aminotransferase, alanine aminotransferase and kidney weight (KW)/body weight (BW) were determined. Renal pathological changes were evaluated using hematoxylin and eosin staining, whereas the structural changes in the podocytes were observed under a transmission electron microscope. The expression levels of nephrin and podocin were evaluated using immunofluorescence staining. Compared with group A, the SCR and BUN levels in group B were higher (P<0.05) and the GLU, KW/BW and the 24-h urine protein were markedly higher (P<0.01). Moreover, incidences of glomerular disorders, chronic tubulointerstitial damage and glomerular podocyte lesions in groups B, C, D and E were observed, compared with group A. The high cortical expression of nephrin and podocin protein decreased. Compared with group B, the KW/BW and 24-h urinary protein level in groups C, D and E were lower (P<0.01). The glomeruli, tubules and podocytes exhibited pathomorphological improvements and the nephrin and podocin protein expression levels were higher in the nephridial tissue. A decrease in KW/BW and the 24-h urinary protein level, as well as improvements in glomerular disorder, chronic tubulointerstitial damage and glomerular podocyte lesions, were observed in groups C, D and E. Therefore, the results demonstrated that CS and TWP exhibited a protective effect on the podocytes of rats with DN. Moreover, CS combined with TWP increased this protective effect.

Lidocaine protects against renal and hepatic dysfunction in septic rats via downregulation of Toll-like receptor 4

The present study was designed to determine the renoprotective and hepatoprotective effect of lidocaine in septic rats through the Toll‑like receptor 4 (TLR4) signaling pathway. Adult male Sprague‑Dawley rats were randomly divided into the following three groups: control, sepsis model and 10% lidocaine. A model of sepsis was established by injection of lipopolysaccharide (LPS; 5mg/kg) into the intraperitoneal cavity of rats. The same volume of saline was injected intraperitoneally into rats of the control group instead of LPS. Light microscopy was used to observe structural changes of the hepatic and nephridial tissues. qPCR was used to measure TLR4 mRNA expression levels and the protein expression was detected by flow cytometry. Western blotting was used to measure myocardial nuclear factor κB (NF‑κB) protein levels and ELISA was used to measure the levels of interleukin‑6 (IL‑6) in hepatic and nephridial tissues. The results demonstrated that 10%lidocaine treatment markedly decreased hepatic and nephridial injury in septic rats and inhibited the expression levels of TLR4, NF‑κB and IL‑6, which were upregulated in the sepsis model. In addition, the results indicated that lidocaine protects against renal and hepatic dysfunction in septic rats, which may be mediated by the downregulation of TLR4 and associated signaling molecules and inhibition of the inflammatory response.

Erythropoietin promotes the repair effect of acute kidney injury by bone-marrow mesenchymal stem cells transplantation

Bone-marrow mesenchymal stem cells (BMSCs) transplantation is effective for acute kidney injury (AKI) repair but with limited efficiency. In the present study, BMSCs marked by bromodeoxyuridine (BrdU) were transplanted to the AKI mouse model with erythropoietin (EPO) being subcutaneously injected. The blood urea nitrogen (BUN) and serum creatinine (Scr) levels, pathological changes, distribution of BMSCs, expressions of the cytokeratin 18 (CK18) and the stromal cell-derived factor 1 (SDF-1) in the nephridial tissues were measured. The directional migration of BMSCs to the AKI microenvironment invitro was also tested. The results showed that BMSCs transplantation or EPO injection alone decreased the BUN and Scr levels and the acute tubular necrosis (ATN) scoring in varied degrees. The combination of these decreased the above indicators' levels significantly. BrdU(+) cells (BMSCs) were observed in the AKI nephridial tissues, and CK18 expressed in the cytoplasm of these cells. EPO injection increased the proportion of BrdU(+) cells with the enhanced expression of SDF-1 in the AKI nephridial tissues. EPO increased the migrating number of BMSCs to the AKI microenvironment invitro, and additional anti-SDF-1 treatment with SDF-1 antibody neutralized this effect. Our results showed that EPO increased the number of the transplanted BMSCs in the injured nephridial tissues and enhanced the AKI repair effect of BMSCs transplantation. The enhanced kidney-homing efficiency for BMSCs mediated by the SDF-1/CXCR4 pathway is one of the possible mechanisms for EPO performance.

Hepatitis B virus X protein modulates apoptosis in human renal proximal tubular epithelial cells by activating the JAK2/STAT3 signaling pathway

Hepatitis B virus X protein (HBx) is a multifunctional protein, and it activates multiple signal transduction pathways in multiple types of cells and regulates the process of cell apoptosis. In the present study, we mainly investigated the correlation between HBx and renal tubular epithelial cell apoptosis in hepatitis B virus-associated glomerulonephritis (HBVGN) and the possible signaling mechanism. Cell apoptosis in nephridial tissues of patients with HBVGN were determined by the TUNEL method. HBx, p-STAT3 and STAT3 levels in nephridial tissues were determined by immunohistochemical assay, and a correlation analysis between HBx expression levels and apoptosis index in nephridial tissues was conducted. The activation of the JAK2/STAT3 signaling pathway in HK-2 cells and the expression of the apoptosis-related proteins Bax and Bcl-2 were determined by western blot analysis following transfection with the HBx eukaryotic expression vector. Cellular proliferation activity was determined by the CCK-8 method, and cell apoptosis was determined with HO33342 staining using transmission electron microscopy and Annexin V/PI double staining flow cytometry. The results revealed that the apoptosis index in nephridial tissues of patients with HBVGN was significantly higher when compared to that of the control group, and p-STAT3 expression levels in HBVGN nephridial tissues were significantly increased. In the control group, no HBx expression was observed in the nephridial tissues, whereas HBx expression was found in the nephridial tissues of 86% of the patients with HBVGN. The HBx expression levels had a linear correlation with the apoptosis index in the nephridial tissues. After target gene HBx infection, expression levels of both p-JAK2 and p-STAT3 in human proximal HK-2 cells were significantly increased, and the Bax/Bcl-2 ratio was also significantly increased. At the same time, cellular proliferation of HK-2 cells was significantly inhibited, and the rate of apoptosis was increased. After incubation with AG490, the JAK2/STAT3 signaling pathway was partially blocked, which caused a decrease in the Bax/Bcl-2 ratio and reduced cell apoptosis caused by HBx. In conclusion, HBx upregulates the Bax/Bcl-2 ratio by activating the JAK2/STAT3 signaling pathway to cause renal tubular epithelial cell apoptosis, and it is possibly involved in the pathogenic mechanism of nephridial tissue damage caused by HBV.

Iron chelator alleviates tubulointerstitial fibrosis in diabetic nephropathy rats by inhibiting the expression of tenascinC and other correlation factors

Tubulointerstitial fibrosis is the final common pathway to diabetic nephropathy. However, only a few drugs are responsible for this pathologic process. We investigated the possible effect of deferiprone (iron chelator) treatment on experimental diabetic nephropathy (DN) rats, as well as the mechanisms involved in this process. Diabetic nephropathy was induced in rats by feeding on high-carbohydrate-fat food and injecting streptozotocin. After 20 weeks of deferiprone treatment, tubulointerstitial morphology was detected by staining with hematoxylin-eosin and Masson's trichrome. Tubulointerstitial fibrosis was measured using the point-counting technique. Biochemical parameters including fasting glucose, insulin resistance (IR), serum iron, ferritin, transferrin saturation (TS), and urinary albumin/creatinine ratio (UA/C) were detected in diabetic nephropathy models. Semiquantitative RT-PCR, western blot, and immunohistochemistry were utilized for evaluating mRNA and protein levels of tenascin C, fibronectin 1 (Fn1), TGF-β1, and collagen IV in nephridial tissue, respectively. Malonialdehyde (MDA) and superoxide dismutase (SOD) were determined by pyrogallol and thiobarbituric acid method. Tubulointerstitial fibrosis was significantly ameliorated after deferiprone treatment, and both mRNA and protein expressions of profibrotic factors were inhibited in treatment groups. Meanwhile, high levels of serum iron, ferritin, TS, and UA/C were observed in DN rats. These factors were down-regulated by deferiprone treatment. Furthermore, deferiprone effectively relieved serum IR and regulated oxidative stress process. Our results demonstrated the anti-fibrosis potential and renoprotective effects of deferiprone for diabetic nephropathy, and this process was partially mediated by tenascin C blocking.

Effect of stachydrine on endoplasmic reticulum stress-induced apoptosis in rat kidney after unilateral ureteral obstruction

Our study aimed at determining the effect of stachydrine on the PERK, CHOP, and caspase-3 in rat kidney with RIF. Rats were randomly divided into control group, model group, enalapril group, high stachydrine group, medium stachydrine group, and low stachydrine group. RIF models of five groups were developed by unilateral ureteral obstruction except the control group. The rats were sacrificed 12 days after surgery and blood samples were collected. Serum creatinine (Scr) and blood urea nitrogen (BUN) levels were detected. Renal tubular damage index was determined by HE staining. The area percentage of RIF was determined by the Masson method. Expressions of PERK, CHOP, and caspase-3 in kidney were determined by immunohistochemistry. Tubulointerstitial injury index, RIF, serum Scr, BUN level, and expressions of PERK, CHOP, and caspase-3 were different between the model and treatment groups (P < 0.05; P < 0.01). The expressions of PERK, CHOP, and caspase-3 in nephridial tissue were reduced (P < 0.05), tubulointerstitial injury and RIF were reduced (P < 0.05), and Scr and BUN were lower (P < 0.05) in the high stachydrine group than those in the enalapril group. The expressions of PERK, CHOP, and caspase-3 were reduced in the endoplasmic reticulum stress-related apoptosis pathway after stachydrine treatment. Consequently, apoptosis was prevented, and RIF was inhibited.