Proximal Tubular Lats2 Ablation Exacerbates Ischemia/Reperfusion Injury (IRI)-Induced Renal Maladaptive Repair through the Upregulation of P53.

The Hippo pathway mediates renal maladaptive repair after acute kidney injury (AKI), which has been considered a driving force in the progression to chronic kidney disease (CKD). LATS2, a core kinase of the Hippo pathway, exerts non-Hippo-dependent functions in the regulation of the cell cycle and cell fate, providing new insights into AKI and further repair. However, its role remains unknown. Here, we utilized a proximal tubular Lats2 conditional knockout mouse strain (Lats2-CKO) to evaluate the effect of LATS2 deficiency on ischemia/reperfusion-induced AKI-to-CKD transition. Lats2-CKO mice presented with more severe tubular maladaptive repair, inflammatory infiltration, interstitial fibrosis, and apoptosis following AKI. Importantly, we discovered that Lats2 ablation caused the activation of p53, with increased levels of cellular apoptotic molecules (p21, Bax, and cleaved caspase-3), and decreased levels of anti-apoptotic molecules (Bcl-2 and Bcl-xL). Pifithirin-α (p53 inhibitor) effectively attenuated renal fibrosis, inflammation, and apoptosis in Lats2-CKO mice after AKI. Consistently, in vitro Lats2 overexpression decreased p53, p21, Bax and cleaved caspase 3 expression after hypoxia/reoxygenation (H/R) treatment. Of note, the phosphorylation of MDM2, which promotes the ubiquitination degradation of p53, at site Ser186 was decreased in Lats2-CKO kidneys, but increased by Lats2 overexpression in vitro. Therefore, LATS2 deficiency aggravated ischemia/reperfusion injury (IRI)-induced maladaptive repair via regulating the tubular MDM2-p53 axis in AKI-to-CKD transition.

The Hippo pathway and its correlation with acute kidney injury.

Acute kidney injury (AKI) is a significant clinical complication with a substantial impact on morbidity and mortality, for which therapeutic options remain limited. The Hippo signaling pathway is an evolutionarily conserved pathway implicated in cell proliferation, dedifferentiation, and apoptosis via phosphorylation and inactivation of its downstream effectors Yes-associated protein (YAP)/transcriptional co-activator with PDZ-binding motif (TAZ). Recent studies have revealed that the Hippo pathway plays a pivotal role in the pathogenesis and repair of AKI. The Hippo pathway can mediate renal dysfunction through modulation of mitochondrial apoptosis under AKI conditions. Transient activation of YAP/TAZ in the acute phase of AKI may benefit renal recovery and regeneration, whereas persistent activation of YAP/TAZ in severe AKI may lead to maladaptive repair and transition to chronic kidney disease. This review aims to summarize recent findings on the associations between the Hippo pathway and AKI and to identify new therapeutic targets and strategies for AKI.

In Vivo Inhibition of TRPC6 by SH045 Attenuates Renal Fibrosis in a New Zealand Obese (NZO) Mouse Model of Metabolic Syndrome.

Metabolic syndrome is a significant worldwide public health challenge and is inextricably linked to adverse renal and cardiovascular outcomes. The inhibition of the transient receptor potential cation channel subfamily C member 6 (TRPC6) has been found to ameliorate renal outcomes in the unilateral ureteral obstruction (UUO) of accelerated renal fibrosis. Therefore, the pharmacological inhibition of TPRC6 could be a promising therapeutic intervention in the progressive tubulo-interstitial fibrosis in hypertension and metabolic syndrome. In the present study, we hypothesized that the novel selective TRPC6 inhibitor SH045 (larixyl N-methylcarbamate) ameliorates UUO-accelerated renal fibrosis in a New Zealand obese (NZO) mouse model, which is a polygenic model of metabolic syndrome. The in vivo inhibition of TRPC6 by SH045 markedly decreased the mRNA expression of pro-fibrotic markers (Col1α1, Col3α1, Col4α1, Acta2, Ccn2, Fn1) and chemokines (Cxcl1, Ccl5, Ccr2) in UUO kidneys of NZO mice compared to kidneys of vehicle-treated animals. Renal expressions of intercellular adhesion molecule 1 (ICAM-1) and α-smooth muscle actin (α-SMA) were diminished in SH045- versus vehicle-treated UUO mice. Furthermore, renal inflammatory cell infiltration (F4/80+ and CD4+) and tubulointerstitial fibrosis (Sirius red and fibronectin staining) were ameliorated in SH045-treated NZO mice. We conclude that the pharmacological inhibition of TRPC6 might be a promising antifibrotic therapeutic method to treat progressive tubulo-interstitial fibrosis in hypertension and metabolic syndrome.

Identification of diagnostic markers and immune cell infiltration characteristics in antineutrophil cytoplasmic antibody-associated vasculitis by weighted gene co-expression network analysis.

BACKGROUND: Antineutrophil cytoplasmic antibody-associated vasculitis (AAV) is a group of life-threatening systemic autoimmune diseases. The aim of this study was to determine the relationship between the AAV hub gene and immune cell infiltration, and its value for clinical disease treatment. METHODS: We downloaded the microarray information of 37 AAV patients and 27 controls from Gene Expression Omnibus (GEO). Genes were classified into totally different modules exploitation weighted gene co-expression network analysis (WGCNA). AAV diagnostic indicators were screened and then assessed immune cell infiltration by the least absolute shrinkage and selection operator (LASSO) and CIBERSORT. Finally, Connectivity Map analysis was applied to predict possible AAV glomerulus injury improvement therapies. RESULTS: WGCNA was developed and differentially expressed genes were classified into 6 modules, the black module was most tightly correlated to AAV. Among them, TIMP1 and FCER1G were most closely related to clinical features. Resting mast cells and monocytes emerged as having the foremost distinguished variations in AAV. C3AR1 and FCER1G were involved in AAV development by immune regulation. Connectivity Map analysis indicated the most significant compound was fisetin. CONCLUSIONS: The present study is that the initial to spot immune cell infiltration with microarray data of glomeruli in AAV, which provides novel proof and clues for additional analysis of the molecular mechanisms.

Role of TRPC6 in kidney damage after acute ischemic kidney injury.

Transient receptor potential channel subfamily C, member 6 (TRPC6), a non-selective cation channel that controls influx of Ca2+ and other monovalent cations into cells, is widely expressed in the kidney. TRPC6 gene variations have been linked to chronic kidney disease but its role in acute kidney injury (AKI) is unknown. Here we aimed to investigate the putative role of TRPC6 channels in AKI. We used Trpc6-/- mice and pharmacological blockade (SH045 and BI-749327), to evaluate short-term AKI outcomes. Here, we demonstrate that neither Trpc6 deficiency nor pharmacological inhibition of TRPC6 influences the short-term outcomes of AKI. Serum markers, renal expression of epithelial damage markers, tubular injury, and renal inflammatory response assessed by the histological analysis were similar in wild-type mice compared to Trpc6-/- mice as well as in vehicle-treated versus SH045- or BI-749327-treated mice. In addition, we also found no effect of TRPC6 modulation on renal arterial myogenic tone by using blockers to perfuse isolated kidneys. Therefore, we conclude that TRPC6 does not play a role in the acute phase of AKI. Our results may have clinical implications for safety and health of humans with TRPC6 gene variations, with respect to mutated TRPC6 channels in the response of the kidney to acute ischemic stimuli.

Risk factors for left atrial thrombus or spontaneous echo contrast in non-valvular atrial fibrillation patients with low CHA2DS2-VASc score.

OBJECTIVE: Risk factors of left atrial thrombus (LAT) or spontaneous echo contrast (LASEC) in non-valvular atrial fibrillation (NVAF) had been reported. However, information in the subgroup of NVAF patients with low CHA2DS2-VASc scores was limited. Here, we evaluated the risk factors of LAT/LASEC in NVAF patients with low CHA2DS2-VASc scores. METHODS: Transesophageal echocardiography (TEE) file of NVAF patients with low CHA2DS2-VASc scores was reviewed (between June 2009 and Feb 2019) in this retrospective observational study. Binary logistic regression analysis was performed to identify risk factors other than the CHA2DS2-VASc score. Propensity score matching (PSM) was used to further evaluate independent risk markers for LAT/LASEC. The newly discovered factors were added to the CHA2DS2-VASc score, and receiver operating characteristic analysis was used to evaluate the ability of the model to predict LAT/LASEC. RESULTS: TEE files of 3056 NVAF patients with low CHA2DS2-VASc scores were reviewed. Regression analysis revealed elevated fibrinogen and enlarged left atrium (LA) were risk factors for LAT/LASEC. Further PSM analysis confirmed that elevated fibrinogen and enlarged LA were independent risk factors for LAT/LASEC. After including fibrinogen and left atrial diameter (LAD), the CHA2DS2-VASc score was more accurate for LAT/LASEC prediction in NVAF patients with low CHA2DS2-VASc scores (area under the curve difference is 0.241, 95% confidence interval (CI) 0.188-0.294, Z = 8.890, P < 0.0001). CONCLUSIONS: Elevated fibrinogen and enlarged LA were independent risk factors for LAT/LASEC in NVAF patients with low CHA2DS2-VASc scores. Taking fibrinogen and LAD into consideration may help improve LAT/LASEC risk evaluation, which warrants further validation studies.

Alzheimer disease effects of different stages on intestinal flora: A protocol for systematic review and meta-analysis.

BACKGROUND: Alzheimer disease (AD) is a common degenerative disease of the central nervous system that can be divided into 3 stages, according to the degree of cognitive impairment. The clinical manifestations are cognitive dysfunction and memory loss, impacting the daily activities of the affected individuals. In recent years, studies have demonstrated a relationship between intestinal flora and AD. However, no meta-analysis has documented the correlation between AD and intestinal flora, to the best of our knowledge. Herein, we sought to assess the correlation between different stages of AD and intestinal flora. A systematic and comprehensive understanding of this relationship is of great significance for developing prevention and treatment strategies against AD. METHODS: A comprehensive search of the medical literature in Chinese and English language was performed in databases, such as PubMed, EBSCO, CNKI, web of science, WanFang, Cochrane Library, and CBM databases. Pre-defined search strategies were used to retrieve clinical studies of Alzheimer disease and gut microbiota. The included studies were independently analyzed by the 2 researchers who extracted the data. The quality of the data was evaluated according to the "Cochrane system evaluator manual." Finally, Endnote and RevMan software were used for systematic regression and meta-analysis of evidence. RESULTS: We documented the intestinal flora changes in the 3 stages of Alzheimer disease, according to currently available clinical evidence, and revealed the correlation between the abundance and diversity of flora and treatment efficacy. These findings are essential for developing new strategies for the prevention and treatment of Alzheimer disease. INPLASY REGISTRATION NUMBER: INPLASY2021100093. ETHICS AND DISSEMINATION: Since all data utilized in this systematic review and meta-analysis are published, ethical approval was not needed.

NLRP3 associated with chronic kidney disease progression after ischemia/reperfusion-induced acute kidney injury.

Nod-like receptor protein 3 (NLRP3), as an inflammatory regulator, has been implicated in acute kidney injury (AKI). Failed recovery after AKI can lead to chronic kidney disease (CKD). However, the role of NLRP3 in the AKI-CKD transition is still unknown. A mild or severe AKI mouse model was performed by using ischemia-reperfusion injury (IRI). We evaluated the renal NLRP3 expression in acute and chronic phases of ischemic AKI, respectively. Although serum creatinine (Cr) and blood urea nitrogen (BUN) levels in AKI chronic phase were equivalent to normal baseline, histological analysis and fibrotic markers revealed that severe AKI-induced maladaptive tubular repair with immune cell infiltration and fibrosis. Tubular damage was restored completely in mild AKI rather than in severe AKI. Of note, persistent overexpression of NLRP3 was also found in severe AKI but not in mild AKI. In the severe AKI-induced chronic phase, there was a long-term high level of NLRP3 in serum or urine. Overt NLRP3 was mainly distributed in the abnormal tubules surrounded by inflammatory infiltrates and fibrosis, which indicated the maladaptive repair. Renal Nlrp3 overexpression was correlated with infiltrating macrophages and fibrosis. Renal NLRP3 signaling-associated genes were upregulated after severe AKI by RNA-sequencing. Furthermore, NLRP3 was found increased in renal tubular epitheliums from CKD biopsies. Together, persistent NLRP3 overexpression was associated with chronic pathological changes following AKI, which might be a new biomarker for evaluating the possibility of AKI-CKD transition.

[Effect of Jiedu Limai decoction in septic patients with syndrome of heat-toxin exuberance].

OBJECTIVE: To investigate the clinical effect of Jiedu Limai decoction in septic patients with syndrome of heat-toxin exuberance. METHODS: A prospective randomized controlled trial was conducted. From March 2019 to April 2020, septic patients with syndrome of heat-toxin exuberance admitted to intensive care unit (ICU) of Shanghai General Hospital and Songjiang Branch of Shanghai General Hospital were enrolled as the research objects, and they were divided into routine treatment group and Jiedu Limai decoction group by the random number table method. Patients in both groups were given standard treatment in accordance with the guidelines, and patients in the Jiedu Limai decoction group were given Jiedu Limai decoction in addition to the standard treatment, once a day for 14 days. The 28-day survival of patients of the two groups were recorded, the acute physiology and chronic health evaluation II (APACHE II) score, sequential organ failure assessment (SOFA) score, coagulation indexes, infection indexes, inflammatory cytokines and organ function indicators before treatment and 7 days after treatment in both groups were recorded, and the prognosis of the two groups were recorded. RESULTS: A total of 259 patients with infection or clinical diagnosis of infection admitted during the experimental observation period were included, and those who did not meet the Sepsis-3 diagnostic criteria, more than 80 years old or less than 18 years old, with multiple tumor metastases, autoimmune system diseases, with length of ICU stay less than 24 hours, with acute active gastrointestinal bleeding and with incomplete data were excluded. One hundred patients were finally enrolled, with 50 patients in the routine treatment group and 50 patients in the Jiedu Limai decoction group. There were no statistically significant differences in coagulation indexes, infection indicators, inflammatory cytokines and organ function indicators before treatment between the two groups. After 7 days of treatment, the coagulation indexes, infection biomarkers and inflammatory cytokines in the Jiedu Limai decoction group were significantly lower than those in the routine treatment group [D-dimer (mg/L): 2.2 (1.8, 8.5) vs. 4.0 (1.5, 8.7), fibrinogen (Fib, g/L): 3.7 (3.4, 4.3) vs. 4.2 (3.7, 4.3), fibrinogen degradation product (FDP, mg/L): 7.2 (5.4, 10.2) vs. 13.2 (9.2, 15.2), procalcitonin (PCT, µg/L): 0.4 (0.2, 2.9) vs. 0.5 (0.2, 0.9), C-reactive protein (CRP, mg/L): 50.1 (9.5, 116.0) vs. 75.1 (23.5, 115.2), interleukin-6 (IL-6, ng/L): 31.6 (21.6, 81.0) vs. 44.1 (14.0, 71.3), all P < 0.05], and the levels of B-type brain natriuretic peptide (BNP) and kidney injury molecule-1 (KIM-1) were significantly lowered [BNP (ng/L): 261.1 (87.5, 360.3) vs. 347.3 (128.8, 439.4), KIM-1 (µg/L): 0.86 (0.01, 1.40) vs. 1.24 (1.05, 1.57), both P < 0.05]. Compared with the routine treatment group, the number of new organ failure in the Jiedu Limai decoction group was decreased (30.0% vs. 50.0%, P < 0.05). Although there was no significant difference in 28-day mortality between the two groups (P > 0.05), the 28-day mortality in the Jiedu Limai decoction group was lower than that in the routine treatment group (18.0% vs. 24.0%). CONCLUSIONS: Combining Jiedu Limai decoction to the sepsis guideline in treating syndrome of heat-toxin exuberance can effectively improve patients' coagulation function, the situation of heart and renal injury, reduce the level of inflammatory cytokines, and fewer people develop new organ failure after treatment.

Hippo-YAP/MCP-1 mediated tubular maladaptive repair promote inflammation in renal failed recovery after ischemic AKI.

Acute kidney injury (AKI) is associated with significant morbidity and its chronic inflammation contributes to subsequent chronic kidney disease (CKD) development. Yes-associated protein (YAP), the major transcriptional coactivator of the Hippo pathway, has been shown associated with chronic inflammation, but its role and mechanism in AKI-CKD transition remain unclear. Here we aimed to investigate the role of YAP in AKI-induced chronic inflammation. Renal ischemia/reperfusion (I/R) was used to induce a mouse model of AKI-CKD transition. We used verteporfin (VP), a pharmacological inhibitor of YAP, to treat post-IRI mice for a period, and evaluated the influence of YAP inhibition on long-term outcomes of AKI. In our results, severe IRI led to maladaptive tubular repair, macrophages infiltration, and progressive fibrosis. Following AKI, the Hippo pathway was found significantly altered with YAP persistent activation. Besides, tubular YAP activation was associated with the maladaptive repair, also correlated with interstitial macrophage infiltration. Monocyte chemoattractant protein 1 (MCP-1) was found notably upregulated with YAP activation. Of note, pharmacological inhibition of YAP in vivo attenuated renal inflammation, including macrophage infiltration and MCP-1 overexpression. Consistently, in vitro oxygen-glucose deprivation and reoxygenation (OGD/R) induced YAP activation and MCP-1 overproduction whereas these could be inhibited by VP. In addition, we modulated YAP activity by RNA interference, which further confirmed YAP activation enhances MCP-1 expression. Together, we concluded tubular YAP activation with maladaptive repair exacerbates renal inflammation probably via promoting MCP-1 production, which contributes to AKI-CKD transition.

Protective effect of taraxasterol on ischemia/reperfusion-induced acute kidney injury via inhibition of oxidative stress, inflammation, and apoptosis.

Ischemia/reperfusion injury (IRI), the most common cause of acute kidney injury (AKI), is correlated with oxidative stress and subsequent inflammation. Taraxasterol, a natural product, has been shown to exert anti-oxidative and anti-inflammatory effects. However, the role of taraxasterol in renal IRI remains unknown. In this study, mice were subjected to 30 min of bilateral renal ischemia-reperfusion to induce AKI. Cellular hypoxia/reoxygenation (H/R) was used to mimic IRI in vitro. Western blotting, immunochemistry, immunofluorescence, TUNEL staining, ELISA, and flow cytometry were performed to evaluate kidney damage, oxidative stress, inflammation, and apoptosis in vivo and in vitro. Treatment with taraxasterol attenuated the following in a dose-dependent manner: tubular damage; infiltration of F4/80-positive macrophages; renal interstitial fibrosis; myeloperoxidase (MPO) activity; and expression of the inflammatory cytokines tumour necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and monocyte chemoattractant protein-1 (MCP-1). Moreover, taraxasterol treatment remarkably ameliorated apoptosis in the kidney by decreasing Bax expression and conserving Bcl2. Notably, MitoSOX assay revealed that treatment with taraxasterol suppressed the production of mitochondrial reactive oxygen species. Furthermore, taraxasterol suppressed phosphorylation of extracellular signal-regulated kinase (ERK) and c-Jun NH2-terminal kinase (JNK) of the mitogen-activated protein kinase (MAPK) signaling pathways in vivo and in vitro. In conclusion, these findings indicate that taraxasterol has a protective effect on IRI-induced AKI via inhibition of oxidative stress, inflammation, and apoptosis.

Porous Se@SiO2 nanospheres attenuate ischemia/reperfusion (I/R)-induced acute kidney injury (AKI) and inflammation by antioxidative stress.

OBJECTIVES: Acute kidney injury (AKI) is a growing global health concern, and is associated with high rates of mortality and morbidity in intensive care units. Se is a trace element with antioxidant properties. This study aimed to determine whether porous Se@SiO2 nanospheres could relieve oxidative stress and inflammation in ischemia/reperfusion (I/R)-induced AKI. METHODS: Male 6- to 8-week-old C57bl/6 mice were divided into four groups: sham + saline, sham + Se@SiO2, I/R + saline, and I/R + Se@SiO2. Mice in the I/R groups experienced 30 minutes of bilateral renal I/R to induce an AKI. Porous Se@SiO2 nanospheres (1 mg/kg) were intraperitoneally injected into mice in the I/R + Se@SiO2 group 2 hours before I/R, and the same dose was injected every 12 hours thereafter. Hypoxia/reoxygenation (H/R) was used to mimic I/R in vitro. PBS was used as a control treatment. Human kidney 2 cells were seeded into 12-well plates (5×105 cells/well) and divided into four groups: control + PBS group, control + Se@SiO2 group, H/R + PBS group, and H/R + Se@SiO2 group (n=3 wells). We then determined the expression levels of ROS, glutathione, inflammatory cytokines and proteins, fibrosis proteins, and carried out histological analysis upon kidney tissues. RESULTS: In vitro, intervention with porous Se@SiO2 nanospheres significantly reduced levels of ROS (P<0.05), inflammatory cytokines (P<0.05), and inflammation-associated proteins (P<0.05). In vivo, tubular damage, cell apoptosis, and interstitial inflammation during AKI were reduced significantly following treatment with porous Se@SiO2 nanospheres. Moreover, the occurrence of fibrosis and tubular atrophy after AKI was attenuated by porous Se@SiO2 nanospheres. CONCLUSION: Porous Se@SiO2 nanospheres exhibited a protective effect in I/R-induced AKI by resisting oxidative stress and inflammation. This suggests that porous Se@SiO2 nanospheres may represent a new therapeutic method for AKI.

Proinflammatory Effect of High Glucose Concentrations on HMrSV5 Cells via the Autocrine Effect of HMGB1.

Background: Peritoneal fibrosis, in which inflammation and apoptosis play crucial pathogenic roles, is a severe complication associated with the treatment of kidney failure with peritoneal dialysis (PD) using a glucose-based dialysate. Mesothelial cells (MCs) take part in the inflammatory processes by producing various cytokines and chemokines, such as monocyte chemoattractant protein 1 (MCP-1) and interleukin 8 (IL-8). The apoptosis of MCs induced by high glucose levels also contributes to complications of PD. High mobility group protein B1 (HMGB1) is an inflammatory factor that has repeatedly been proven to be related to the occurrence of peritoneal dysfunction. Aim: In this study, we aimed to explore the effect and underlying mechanism of endogenous HMGB1 in high-glucose-induced MC injury. Methods: The human peritoneal MC line, HMrSV5 was cultured in high-glucose medium and incubated with recombinant HMGB1. Cellular expression of HMGB1 was blocked using HMGB1 small interfering RNA (siRNA). Apoptosis and production of inflammatory factors as well as the potential intermediary signaling pathways were examined. Results: The major findings of these analyses were: (1) MCs secreted HMGB1 from the nucleus during exposure to high glucose levels; HMGB1 acted in an autocrine fashion on the MCs to promote the production of MCP-1 and IL-8; (2) HMGB1 had little effect on high-glucose-induced apoptosis of the MCs; and (3) HMGB1-mediated MCP-1 and IL-8 production depended on the activation of MAPK signaling pathways. In conclusion, endogenous HMGB1 plays an important role in the inflammatory reaction induced by high glucose on MCs via mitogen-activated protein kinase (MAPK) signaling pathways, but it seems to have little effect on high-glucose-induced apoptosis.