scholarly journals TRPV4-mediated Ca2+ influx is essential to glomerular endothelial inflammation in sepsis associated acute kidney injury

Author(s):  
Xia Wang ◽  
Yinhua Wang ◽  
Guo Zhou ◽  
Yi Li ◽  
Huanhuan Huo ◽  
...  

Abstract Background Sepsis-associated acute kidney injury (S-AKI) is a frequent complication of critical patients and is associated with high morbidity and mortality. The glomerular endothelial cell injury is the main characteristics during S-AKI. Ca2+ influx is a key step in the establishment of endothelial injury. Transient receptor vanilloid subtype 4 (TRPV4) ion channels are permeable to Ca2+ and are widely expressed in endothelial cells. However, the role of TRPV4 on glomerular endothelial inflammation in S-AKI has remained elusive. Methods Mouse glomerular endothelial cells (MRGEC) were used to test the molecular mechanism of TRPV4 on LPS-induced glomerular endothelial inflammation. The cecal-ligation-and-puncture (CLP) model was established by ligation of cecum with 4-0 suture and punctured with a 21-gauge needle. Then 0.2mL faeces was extruded from the puncture site to trigger peritoneal inflammation. Results In the present study, we found that blocking TRPV4 diminishes LPS-induced cytosolic Ca2+-elevations, which are essential for glomerular endothelial inflammation and barrier function. Furthermore, TRPV4 regulated LPS-induced phosphorylation and translocation of NF-κB and IRF-3 in mouse glomerular endothelial cells (MRGEC). Clamping intracellular Ca2+ mimics the LPS-induce response seen in the absence of TRPV4. In vivo, pharmacological blockade or knock down of TRPV4 reduced the inflammatory response of glomerular endothelial cells, inhibited translocation of NF-κB and IRF-3, increased survival rate and improved renal function in CLP-induced sepsis but without altering renal cortical blood perfusion. Conclusions Taken together, these results suggested that inhibition of TRPV4 ameliorates glomerular endothelial inflammation, kidney dysfunction, and increased mortality via mediating Ca2+ overload and NF-κB/IRF-3 activation. These discoveries may provide novel pharmacological strategies for the treatment of glomerular endothelial dysfunction and kidney injury during endotoxemia, sepsis, and other inflammatory diseases.

2012 ◽  
Vol 303 (10) ◽  
pp. F1443-F1453 ◽  
Author(s):  
Chung-Hsi Hsing ◽  
Chiou-Feng Lin ◽  
Edmund So ◽  
Ding-Ping Sun ◽  
Tai-Chi Chen ◽  
...  

Bone morphogenetic protein (BMP)-7 protects sepsis-induced acute kidney injury (AKI). Dexmedetomidine (DEX), an α2-adrenoceptor (α2-AR) agonist, has anti-inflammatory effects. We investigated the protective effects of DEX on sepsis-induced AKI and the expression of BMP-7 and histone deacetylases (HDACs). In vitro , the effects of DEX or trichostatin A (TSA, an HDAC inhibitor) on TNF-α, monocyte chemotactic protein (MCP-1), BMP-7, and HDAC mRNA expression in LPS-stimulated rat renal tubular epithelial NRK52E cells, was determined using real-time PCR. In vivo, mice were intraperitoneally injected with DEX (25 μg/kg) or saline immediately and 12 h after cecal ligation and puncture (CLP) surgery. Twenty-four hours after CLP, we examined kidney injury and renal TNF-α, MCP-1, BMP-7, and HDAC expression. Survival was monitored for 120 h. LPS increased HDAC2, HDAC5, TNF-α, and MCP-1 expression, but decreased BMP-7 expression in NRK52E cells. DEX treatment decreased the HDAC2, HDAC5, TNF-α, and MCP-1 expression, but increased BMP-7 and acetyl histone H3 expression, whose effects were blocked by yohimbine, an α2-AR antagonist. With DEX treatment, the LPS-induced TNF-α expression and cell death were attenuated in scRNAi-NRK52E but not BMP-7 RNAi-NRK52E cells. In CLP mice, DEX treatment increased survival and attenuated AKI. The expression of HDAC2, HDAC5, TNF-α, and MCP-1 mRNA in the kidneys of CLP mice was increased, but BMP-7 was decreased. However, DEX treatment reduced those changes. DEX reduces sepsis-induced AKI by decreasing TNF-α and MCP-1 and increasing BMP-7, which is associated with decreasing HDAC2 and HDAC5, as well as increasing acetyl histone H3.


2011 ◽  
Vol 300 (3) ◽  
pp. F721-F733 ◽  
Author(s):  
David P. Basile ◽  
Jessica L. Friedrich ◽  
Jasmina Spahic ◽  
Nicole Knipe ◽  
Henry Mang ◽  
...  

Acute kidney injury induces the loss of renal microvessels, but the fate of endothelial cells and the mechanism of potential vascular endothelial growth factor (VEGF)-mediated protection is unknown. Cumulative cell proliferation was analyzed in the kidney of Sprague-Dawley rats following ischemia-reperfusion (I/R) injury by repetitive administration of BrdU (twice daily) and colocalization in endothelial cells with CD31 or cablin. Proliferating endothelial cells were undetectable for up to 2 days following I/R and accounted for only ∼1% of BrdU-positive cells after 7 days. VEGF-121 preserved vascular loss following I/R but did not affect proliferation of endothelial, perivascular cells or tubular cells. Endothelial mesenchymal transition states were identified by localizing endothelial markers (CD31, cablin, or infused tomato lectin) with the fibroblast marker S100A4. Such structures were prominent within 6 h and sustained for at least 7 days following I/R. A Tie-2-cre transgenic crossed with a yellow fluorescent protein (YFP) reporter mouse was used to trace the fate of endothelial cells and demonstrated interstititial expansion of YFP-positive cells colocalizing with S100A4 and smooth muscle actin following I/R. The interstitial expansion of YFP cells was attenuated by VEGF-121. Multiphoton imaging of transgenic mice revealed the alteration of YFP-positive vascular cells associated with blood vessels characterized by limited perfusion in vivo. Taken together, these data indicate that vascular dropout post-AKI results from endothelial phenotypic transition combined with an impaired regenerative capacity, which may contribute to progressive chronic kidney disease.


2020 ◽  
Vol 21 (11) ◽  
pp. 4095
Author(s):  
Samiksha Wasnik ◽  
Xiaolei Tang ◽  
Hongzheng Bi ◽  
Amir Abdipour ◽  
Edmundo E. Carreon ◽  
...  

This study was undertaken to test two therapies for acute kidney injury (AKI) prevention, IGF-1, which is renal protective, and BTP-2, which is a calcium entry (SOCE) inhibitor. We utilized lipopolysaccharide (LPS) IP, as a systemic model of AKI and studied in five groups of animals. Three experiments showed that at 7 days: (1) LPS significantly reduced serum IGF-1 and intramuscular IGF-I in vivo gene therapy rescued this deficiency. (2) Next, at the 7-day time point, our combination therapy, compared to the untreated group, caused a significant increase in survival, which was noteworthy because all of the untreated animals died in 72 h. (3) The four pathways associated with inflammation, including (A) increase in cytosolic calcium, (B) elaboration of proinflammatory cytokines, (C) impairment of vascular integrity, and (D) cell injury, were adversely affected in renal tissue by LPS, using a sublethal dose of LPS. The expression of several genes was measured in each of the above pathways. The combined therapy of IGF-1 and BTP-2 caused a favorable gene expression response in all four pathways. Our current study was an AKI study, but these pathways are also involved in other types of severe inflammation, including sepsis, acute respiratory distress syndrome, and probably severe coronavirus infection.


2011 ◽  
Vol 301 (1) ◽  
pp. F162-F170 ◽  
Author(s):  
Qingqing Wei ◽  
William D. Hill ◽  
Yunchao Su ◽  
Shuang Huang ◽  
Zheng Dong

Granulocyte colony-stimulating factor (G-CSF) is renoprotective during acute kidney injury (AKI) induced by ischemia and cisplatin nephrotoxicity; however, the underlying mechanism is not entirely clear. Rhabdomyolysis is another important clinical cause of AKI, due to the release of nephrotoxins (e.g., heme) from disrupted muscles. The current study has determined the effects of G-CSF on rhabdomyolysis-associated AKI using in vivo and in vitro models. In C57BL/6 mice, intramuscular injection of glycerol induced AKI, which was partially prevented by G-CSF pretreatment. Consistently, glycerol-induced renal tissue damage was ameliorated by G-CSF. In addition, animal survival following the glycerol injection was improved from ∼30 to ∼70% by G-CSF. In cultured renal tubular cells, hemin-induced apoptosis was also suppressed by G-CSF. Interestingly, G-CSF induced heme oxygenase-1 (HO-1, a critical enzyme for heme/hemin degradation and detoxification) in both cultured tubular cells and mouse kidneys. Blockade of HO-1 with protoporphyrin IX zinc(II) (ZnPP) could largely diminish the protective effects of G-CSF. Together, these results demonstrated the renoprotective effects of G-CSF in rhabdomyolysis-associated AKI. Notably, G-CSF may directly protect against tubular cell injury under the disease condition by inducing HO-1.


2021 ◽  
Vol 27 (1) ◽  
Author(s):  
Manna Li ◽  
Le Deng ◽  
Gaosi Xu

Abstract Background N6-Methyladenosine (m6A) modification has been implicated in many bioprocesses. However, its functions in diabetic nephropathy (DN) have not been determined. Here, we investigated the role of METTL14, a key component of the m6A methyltransferase complex, in DN. Methods The expression of METTL14 was detected in DN patients and human renal glomerular endothelial cells (HRGECs). In vitro and in vivo experiments were performed to explore the functions of METTL14 on high glocse-induced HRGECs and renal injury of DN mice. We also investigated whether METTL14 works by regulating α-klotho expression through m6A modification. Results METTL14 were highly expressed in kidneys of DN patients and high glocse-induced HRGECs both at the mRNA and protein level. Overexpression of METTL14 increased ROS, TNF-α and IL-6 levels and apoptosis in HRGECs. Conversely, METTL14 silence decreased the levels of ROS, TNF-α and IL-6 and cell apoptosis. We confirmed that METTL14 down-regulated α-klotho expression in an m6A-dependent manner. In addition, we also found that METTL14 aggravated renal injury and inflammation of db/db mice, which could partially rescued by α-klotho. Conclusion Our data revealed that METTL14 plays a vital role in high glucose-induced glomerular endothelial cells and diabetic nephropathy through m6A modification of α-klotho.


Author(s):  
Yanyan Yu ◽  
Xiangqian Li ◽  
Wenpeng Hu ◽  
Shichao Cui ◽  
Jiajia Dai ◽  
...  

Background and Purpose: Sepsis-induced acute kidney injury (AKI) and acute lung injury (ALI) have high morbidity and mortality, with no effective clinically available drugs. Anti-inflammation is effective strategy in the therapy of AKI and ALI. NF-κB is a target for the development of anti‑inflammatory agents. The purpose of the study is to evaluate the effect of 270, self-developed NF-κB inhibitor, in LPS-induced AKI and ALI. Experimental Approach: LPS-induced macrophages were used to examine the anti-inflammation activity of 270. Sepsis-induced AKI and ALI mice models were established by intraperitoneal injection of LPS (10 mg/kg) for 24 h. Oral administration 270 for 14 days before LPS stimulation. Plasma, kidney and lung tissues were collected and used for histopathology, biochemical assay, ELISA, RT-PCR, and western blot analyses. Key Results: In vitro, we showed that 270 suppressed the inflammation response in LPS-induced RAW 264.7 macrophages and bone marrow derived macrophages. In vivo, we found that 270 ameliorated LPS-induced AKI and ALI, as evidenced by improving various pathological changes, reducing the expression of pro-inflammation genes, blocking the activation of NF-κB and JNK pathways, attenuating the elevated myeloperoxidase (MPO) activity and malondialdehyde (MDA) content, ameliorating the activated ER stress, reversing the inhibition effect on autophagy in kidney and lung tissues, and alleviating the enhanced plasma level of creatinine (Crea), blood urea nitrogen (BUN) and pro-inflammation cytokines. Conclusions and Implications: Our investigations provides evidence that NF-κB inhibitor 270 is a potential drug against LPS-induced AKI and ALI in the future.


2021 ◽  
Vol 12 (4) ◽  
Author(s):  
Yue Zhang ◽  
Hongdong Huang ◽  
Wenhu Liu ◽  
Sha Liu ◽  
Xue Yan Wang ◽  
...  

AbstractThe role of microRNA-21-5p (miR-21-5p) in sepsis-induced acute kidney injury (AKI) has been seldom discussed. Therefore, the objective of this present study was to investigate the mechanism of endothelial progenitor cells-derived exosomes (EPCs-exos) in sepsis-induced AKI via miR-21-5p/runt-related transcription factor 1 (RUNX1) axis. miR-21-5p was downregulated and RUNX1 was upregulated in the kidney of cecal ligation and puncture (CLP) rats, and miR-21-5p targeted RUNX1. Elevation of miR-21-5p improved renal function and renal tissue pathological damage, attenuated serum inflammatory response, as well as reduced apoptosis and oxidative stress response in renal tissues, and regulated endothelial glycocalyx damage marker proteins syndecan-1 and heparanase-1 in CLP rats. Overexpression of RUNX1 abolished the impacts of elevated miR-21-5p in CLP rats. Also, EPCs-exos upregulated miR-21-5p expression, and functioned similar to elevation of miR-21-5p for CLP rats. Downregulating miR-21-5p partially reversed the effects of EPCs-exos on sepsis-induced AKI. Collectively, our study suggests that EPCs release miR-21-5p-containing exosomes to alleviate sepsis-induced AKI through RUNX1 silencing.


Toxins ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 521
Author(s):  
Janeyuth Chaisakul ◽  
Orawan Khow ◽  
Kulachet Wiwatwarayos ◽  
Muhamad Rusdi Ahmad Rusmili ◽  
Watcharamon Prasert ◽  
...  

Acute kidney injury (AKI) following Eastern Russell’s viper (Daboia siamensis) envenoming is a significant symptom in systemically envenomed victims. A number of venom components have been identified as causing the nephrotoxicity which leads to AKI. However, the precise mechanism of nephrotoxicity caused by these toxins is still unclear. In the present study, we purified two proteins from D. siamensis venom, namely RvPLA2 and RvMP. Protein identification using LCMS/MS confirmed the identity of RvPLA2 to be snake venom phospholipase A2 (SVPLA2) from Thai D. siamensis venom, whereas RvMP exhibited the presence of a factor X activator with two subunits. In vitro and in vivo pharmacological studies demonstrated myotoxicity and histopathological changes of kidney, heart, and spleen. RvPLA2 (3–10 µg/mL) caused inhibition of direct twitches of the chick biventer cervicis muscle preparation. After administration of RvPLA2 or RvMP (300 µg/kg, i.p.) for 24 h, diffuse glomerular congestion and tubular injury with minor loss of brush border were detected in envenomed mice. RvPLA2 and RvMP (300 µg/kg; i.p.) also induced congestion and tissue inflammation of heart muscle as well as diffuse congestion of mouse spleen. This study showed the significant roles of PLA2 and SVMP in snake bite envenoming caused by Thai D. siamensis and their similarities with observed clinical manifestations in envenomed victims. This study also indicated that there is a need to reevaluate the current treatment strategies for Thai D. siamensis envenoming, given the potential for irreversible nephrotoxicity.


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