LncRNA AA465934 Improves Podocyte Injury by Promoting Tristetraprolin-Mediated HMGB1 DownRegulation in Diabetic Nephropathy.

Although LncRNA AA465934 expression is reduced in high glucose (HG)-treated podocytes, its role in HG-mediated podocyte injury and diabetic nephropathy (DN) remains unknown. Herein, we investigated the role of AA465934 in HG-mediated podocyte injury and DN using a spontaneous type II diabetic nephropathy (T2DN) model. The model was created by injecting AA465934 overexpressed adeno-associated virus (AAV) or control into mice. The levels of renal function, proteinuria, renal structural lesions, and podocyte apoptosis were then examined. Furthermore, AA465934 and autophagy levels, as well as tristetraprolin (TTP) and high mobility group box 1 (HMGB1) expression changes were detected. We also observed podocyte injury and the binding ability of TTP to E3 ligase proviral insertion in murine lymphomas 2 (PIM2), AA465934, or HMGB1. According to the results, AA465934 improved DN progression and podocyte damage in T2DN mice. In addition, AA465934 bound to TTP and inhibited its degradation by blocking TTP-PIM2 binding. Notably, TTP knock-down blocked the ameliorating effects of AA465934 and TTP bound HMGB1 mRNA, reducing its expression. Overexpression of HMGB1 inhibited the ability of AA465934 and TTP to improve podocyte injury. Furthermore, AA465934 bound TTP, inhibiting TTP-PIM2 binding, thereby suppressing TTP degradation, downregulating HMGB1, and reversing autophagy downregulation, ultimately alleviating HG-mediated podocyte injury and DN. Based on these findings, we deduced that the AA465934/TTP/HMGB1/autophagy axis could be a therapeutic avenue for managing podocyte injury and DN.

Uncovering the Mechanisms of Cinnamic Acid Treating Diabetic Nephropathy Based on Network Pharmacology, Molecular Docking, and Experimental Validation.

BACKGROUND: Cinnamic acid (Cinn) is a phenolic acid of Cinnamomum cassia (L.) J. Presl. that can ameliorate diabetic nephropathy (DN). However, comprehensive therapeutic targets and underlying mechanisms for Cinn against DN are limited. OBJECTIVE: In this study, a network pharmacology approach and in vivo experiments were adopted to predict the pharmacological effects and mechanisms of Cinn in DN therapy. METHODS: The nephroprotective effect of Cinn on DN was investigated by a streptozotocininduced diabetes mellitus (DM) mouse model. The protein-protein interaction network of Cinn against DN was established by a network pharmacology approach. The core targets were then identified and subjected to molecular docking with Cinn. RESULTS: Cinn treatment effectively restored body weight, ameliorated hyperglycemia, and reduced kidney dysfunction markers in DM mice, also demonstrating a reduction in tissue injury. Network pharmacology analysis identified 298 DN-Cinn co-target genes involved in various biological processes and pathways. Seventeen core targets were identified, eight of which showed significant differential expression in the DN and healthy control groups. Molecular docking analysis revealed a strong interaction between Cinn and PTEN. Cinn treatment downregulated the PTEN protein expression in DM mice. CONCLUSION: This study revealed the multi-target and multi-pathway characteristics of Cinn against DN. Cinn improved renal pathological damage of DN, which was related to the downregulation of PTEN.

Adipose-derived stem cell exosomes regulate Nrf2/Keap1 in diabetic nephropathy by targeting FAM129B.

BACKGROUND: Exosomes from adipose-derived stem cells (ADSCs-Exos) have exhibited a therapeutic role in diabetic nephropathy (DN). Further studies are needed to investigate how ADSCs-Exos regulate oxidative stress and inflammation in high glucose-induced podocyte injury. METHODS: An enzyme-linked immunosorbent assay (ELISA) was used to detect cellular inflammation. Reactive oxygen species (ROS) levels were assessed using flow cytometry in podocytes with different treatments. A malondialdehyde (MDA) kit was used to evaluate the lipid peroxidation levels in podocytes and kidney tissues of mice. Western blotting and co-immunoprecipitation were performed to detect protein expression and protein-protein interactions. RESULTS: ADSCs-Exos reversed oxidative stress and inflammation in podocytes and kidney tissues of DN mice induced by high glucose levels in vitro and in vivo. Interference with heme oxygenase-1 expression could reverse the improvement effect of ADSCs-Exos on oxidative stress induced by high glucose levels. Furthermore, high glucose inhibited nuclear factor erythroid 2-related factor 2 (Nrf2) protein expression and promoted Kelch-like ECH-associated protein 1 (Keap1) protein expression in podocytes, as well as their binding ability. As a potential target for Nrf2/Keap1 pathway regulation, FAM129B expression in podocytes is regulated by high glucose and ADSCs-Exos. Moreover, FAM129B siRNA blocked the inhibitory effect of ADSCs-Exos on intracellular ROS and MDA upregulation induced by high glucose in podocytes. CONCLUSION: ADSCs-Exos regulate the Nrf2/Keap1 pathway to alleviate inflammation and oxidative stress in DN by targeting FAM129B, which may provide a potential therapeutic strategy for DN.

Large vessel vasculitis with rare presentation of acute rhabdomyolysis: A case report and review of literature.

BACKGROUND: Musculoskeletal involvement in primary large vessel vasculitis (LVV), including giant cell arteritis and Takayasu's arteritis (TAK), tends to be subacute. With the progression of arterial disease, patients may develop polyarthralgia and myalgias, mainly involving muscle stiffness, limb/jaw claudication, cold/swelling extremities, etc. Acute development of rhabdomyolysis in addition to aortic aneurysm is uncommon in LVV. Herein, we report a rare case of LVV with the first presentation of acute rhabdomyolysis. CASE SUMMARY: A 70-year-old Asian woman suffering from long-term low back pain was hospitalized due to limb claudication, dark urine and an elevated creatine kinase (CK) level. After treatment with fluid resuscitation and antibiotics, the patient remained febrile. Her workup showed persistent elevated levels of inflammatory markers, and imaging studies revealed an aortic aneurysm. A decreasing CK was evidently combined with elevated inflammatory markers and negativity for anti-neutrophilic cytoplasmic antibodies. LVV was suspected and confirmed by magnetic resonance angiography and positron emission tomography with 18F-fluorodeoxyglucose/computed tomography. With a favourable response to immunosuppressive treatment, her symptoms resolved, and clinical remission was achieved one month later. However, after failing to follow the tapering schedule, the patient was readministered 25 mg/d prednisolone due to disease relapse. Follow-up examinations showed decreased inflammatory markers and substantial improvement in artery lesions after 6 mo of treatment. At the twelve-month follow-up, she was clinically stable and maintained on corticosteroid therapy. CONCLUSION: An exceptional presentation of LVV with acute rhabdomyolysis is described in this case, which exhibited a good response to immunosuppressive therapy, suggesting consideration for a differential diagnosis when evaluating febrile patients with myalgia and elevated CK. Timely use of high-dose steroids until a diagnosis is established may yield a favourable outcome.

A Case of a 49-Year-Old Man with Nonclassical Fabry Disease Diagnosed by Renal Biopsy.

Fabry disease (FD) is a rare X-linked lysosomal storage disorder caused by mutations in the galactosidase A (GLA) gene that result in deficiency of α-GLA activity, leading to major organ failure and premature mortality. According to different disease courses, FD can be divided into classical and nonclassical phenotypes. The nonclassical FD phenotype is always absent of characteristic symptoms, which makes identifying it challenging. This article presents a 49-year-old man with a 10-year history of proteinuria and decreased glomerular filtration rate. An electrocardiogram showed a complete right bundle branch block and abnormal Q waves in high lateral, accompanied by dramatically elevated ST segment. Consequently, a renal biopsy was performed. Vacuolation was found in many podocytes in light microscopic examinations. Similarly, a myelin-like structure was detected by electron microscopy. Pathological findings were most consistent with FD. Consequently, genetic analysis, p.R301Q (c.902G>A [p.Arg301Gln]), confirmed the FD diagnosis. Angiotensin receptor blocker and traditional Chinese medicine, but not enzyme replacement therapy, were prescribed due to financial constraints. The patient had stabilization of kidney disease 6 months later. The case showed that renal biopsy should be performed in patients with cardiac and renal symptoms, which could contribute toward the correct diagnosis for nonclassical FD type.

Xiaoyu Xiezhuo Drink Protects against Ischemia-Reperfusion Acute Kidney Injury in Aged Mice through Inhibiting the TGF-ß1/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-ß1, 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-ß1/Smad3 and HIF1 signaling pathways.

Leukemia inhibitory factor attenuates renal fibrosis through Stat3-miR-29c.

Leukemia inhibitory factory (LIF), as a member of the IL-6 family, has been reported to ameliorate myocardial fibrosis and myocardial cell death. The purpose of the present study was to investigate the effect of LIF on renal fibrosis and its underlying mechanism. Our results showed, first, that LIF inhibited collagen type 1 and collagen type 3 expression induced by ANG II in NRK-49F (rat kidney fibroblast) cells and in mice with unilateral ureteral obstruction. Second, LIF induced Stat3 Tyr(705) phosphorylation and inhibited Stat3 Tyr(705) and Ser(727) phosphorylation induced by ANG II in NRK-49F cells. Third, LIF exerted an antirenal fibrosis effect mainly through activation of Stat3 Tyr(705) phosphorylation in NRK-49F cells. These effects of LIF were not observed in Stat3(-/-) cells. Finally, LIF-Stat3 upregulated microRNA-29c expression, and the latter downregulated collagen type 1 and collagen type 3 expression in NRK-49F cells and in mice with unilateral ureteral obstruction. In conclusion, LIF played a role in antirenal fibrosis by competitively activating Stat3 Tyr(705) phosphorylation, which upregulated microRNA-29c to suppress collagen expression.

P300-dependent STAT3 acetylation is necessary for angiotensin II-induced pro-fibrotic responses in renal tubular epithelial cells.

AIM: To explore the signal transducer and activator of transcription 3 (STAT3) signaling pathway, especially STAT3 acetylation, in angiotensin II (Ang II)-induced pro-fibrotic responses in renal tubular epithelial cells. METHODS: Rat renal tubular epithelial cell line (NRK-52E) was used. STAT3 acetylation and phosphorylation, as well as the expression of fibronectin, collagen IV and transforming growth factor-ß1 (TGF-ß1) were examined using Western blotting. The level and localization of STAT3 phosphorylation on Tyr705 were detected with fluorescence immunocytochemistry. The cells were transfected with a plasmid vector carrying p300 gene or siRNA targeting p300 to regulate p300 expression. RESULTS: Overexpression of p300 significantly increased STAT3 acetylation on Lys685, STAT3 phosphorylation on Tyr705, and the expression of TGF-ß1, collagen IV and fibronectin in the cells. Treatment of the cells with Ang II (1 µmol/L) significantly increased STAT3 phosphorylation on Tyr705 through JAK2 activation, and dose-dependently increased the expression of fibronectin, collagen IV and TGF-ß1. Pretreatment with curcumin, an inhibitor of JAK2 and p300, blocked Ang II-induced effects. Knockdown of p300 significantly decreased STAT3 acetylation on Lys685, and abolished Ang II-stimulated STAT3 phosphorylation on Tyr705, whereas pretreatment of the cells with C646, a selective inhibitor of p300, inhibited Ang II-induced STAT3 nuclear translocation and the expression of TGF-ß1, collagen IV and fibronectin. Pretreatment of the cells with AG490, a JAK2 inhibitor, markedly inhibited Ang II-induced STAT3 phosphorylation on Tyr705 and fibronectin expression. CONCLUSION: p300-dependent STAT3 acetylation is necessary for Ang II-induced STAT3 phosphorylation and the consequent pro-fibrotic responses in renal tubular epithelial cells in vitro.

Inhibition of STAT3 acetylation is associated with angiotesin renal fibrosis in the obstructed kidney.

AIM: To explore the relationship between the signal transducer and activator of transcription 3 (STAT3) signaling and renal fibrosis. METHODS: Rat renal tubular epithelial NRK-52E cells were treated with angiotesin II (Ang II), nicotinamide (an inhibitor of NAD+-dependent class III protein deacetylases, SIRT1-7), or resveratrol (an activator of SIRT1). Mice underwent unilateral ureteral obstruction (UUO) were used for in vivo studies. Renal interstitial fibrosis was observed with HE and Masson's trichrome staining. STAT3 acetylation and phosphorylation, fibronectin, collagen I, collagen IV, and α-smooth muscle actin (α-SMA) levels were examined using Western blotting. RESULTS: Nicotinamide (0.625-10 mmol/L) dose-dependently increased STAT3 acetylation on Lys685 and phosphorylation on Tyr705 in NRK-52E cells, accompanied by accumulation of fibronectin and collagen IV. Ang II increased STAT3 phosphorylation on Tyr705 and the expression of fibronectin, collagen IV and α-SMA in the cells. Pretreatment with resveratrol (12.5 µmol/L) blocked Ang II-induced effects in the cells. UUO induced marked STAT3 phosphorylation, fibronectin, collagen IV and α-SMA accumulation, and renal interstitial fibrosis in the obstructed kidneys, which were significantly attenuated by daily administration of resveratrol (100 mg/kg). CONCLUSION: STAT3 acetylation plays an important role in activation of STAT3 signaling pathway and consequent renal fibrosis.

Candesartan inhibits LPS-induced expression increase of toll-like receptor 4 and downstream inflammatory factors likely via angiotensin II type 1 receptor independent pathway in human renal tubular epithelial cells.

The present study was to determine whether candesartan, an angiotensin II type 1 receptor blocker (ARB), exerts anti-inflammatory effects through inhibiting the toll-like receptor 4 (TLR4) pathway in human renal tubular epithelial cells (HKCs). The experiments were carried on cultured HKCs. By means of flow cytometry, Western blot, RT-PCR and ELISA techniques, the TLR4 protein, angiotensin II type 1 receptor (AT1R) and phosphorylated nuclear factor-kappa B (NF-κB) p65 protein level, mRNA levels of macrophage chemoattractant protein-1 (MCP-1) and regulated upon expression normal T cell expressed and secreted (RANTES), as well as MCP-1 and RANTES protein concentrations in conditioned media were measured. The results showed that lipopolysaccharide (LPS) upregulated the TLR4 protein level in cultured HKCs. Application of LPS increased NF-κB activation and induced release of its downstream inflammatory factors including MCP-1 and RANTES. Candesartan reversed LPS-induced upregulation of TLR4 expression, inhibited NF-κB activation, and reduced MCP-1 and RANTES release. However, knockdown on AT1R by siRNA did not change those previous effects of candesartan. These results suggest that candesartan-induced anti-inflammatory effect may be through a novel pathway, independent of AT1R.

[Effect of interleukin-10 level and human leukocyte antigen-DR expression as prognostic predictors in critically ill patients undergoing continuous renal replacement therapy].

OBJECTIVE: To inquire into interleukin-10 (IL--10) level and monocyte expression of human leukocyte antigen--DR (HLA--DR) are predictors of infection and prognosis in critically ill patients undergoing continuous renal replacement therapy (CRRT). METHODS: A total of 43 critically ill patients undergoing continuous veno-venous hemofiltration (CVVH) were recruited from the intensive care unit (ICU). Anti--coagulated blood was obtained at 1 day before and 4 days after undergoing CVVH, and plasma IL--10 level (enzyme linked immunosorbent assay) and HLA--DR expression (flow cytometry) were determined. Thirty healthy subjects were enrolled as controls. In addition, the correlation between IL--10 and acute physiology and chronic health evaluation II (APACHEII) score was assessed. RESULTS: (1)Altogether, 7 patients died among a total of 43 critically ill patients, the mortality was 16.3%. Eighteen patients had negative cultures during the study (group I), and 19 patients had positive cultures (group II), and in 6 patients positive bacterial culture appeared 72 hours after the beginning of the treatment (group III). (2) The IL--10 level (ng/L) was higher in patients than in healthy subjects [23.46 (46.71) vs. 0.32 (0.45), P < 0.01]. Compared with group I, the levels of IL--10 in group II and III were higher significantly [40.20 (46.44), 41.78 (49.63) vs. 7.33 (21.05), both P < 0.05]. Continuous observation revealed that IL--10 rapidly lowered in group I after treatment [4.50 (7.44) vs. 7.33 (21.05), P < 0.05], while there was no apparent change in patients of other two groups. It was found that IL--10 was significant positive correlation with the APACHEII score (r = 0.71, P < 0.01).(3) HLA--DR was lower in patients than in healthy individuals [21.65% (25.62%) vs. 90.39% (9.80%), P < 0.01]. After CVVH, HLA--DR expression was obviously increased in group I [64.95% (35.03%) vs. 32.45% (45.03%), P < 0.01]. However, there were no significant changes in the other two groups. The patients who died had persistent and extremely low HLA--DR expression. CONCLUSIONS: (1)A significant discriminative power of IL--10 levels in predicting disease severity was found among the patients receiving CRRT, and persistently high IL--10 level predicts poor prognosis. (2) Persistently low monocyte HLA--DR expression may indicate concomitant or impending infection in patients receiving CRRT.