scholarly journals SIRT1-mediated HMGB1 deacetylation suppresses sepsis-associated acute kidney injury

2019 ◽  
Vol 316 (1) ◽  
pp. F20-F31 ◽  
Author(s):  
Siwei Wei ◽  
Youguang Gao ◽  
Xingui Dai ◽  
Weijun Fu ◽  
Shumin Cai ◽  
...  

Sepsis is the leading cause of death in the intensive care unit and continues to lack effective treatment. It is widely accepted that high-mobility group box 1 (HMGB1) is a key inflammatory mediator in the pathogenesis of sepsis. Moreover, some studies indicate that the functions of HMGB1 depend on its molecular localization and posttranslational modifications. Our previous study confirms that sirtuin 1, silent information regulator 2-related enzyme 1 (SIRT1), a type III deacetylase, can ameliorate sepsis-associated acute kidney injury (SA-AKI). We explored the effect and mechanism of SIRT1 on HMGB1 using a mouse model of cecal ligation and puncture-induced sepsis and LPS-treated human kidney (HK-2) cell line. We found that HMGB1 is elevated in the serum but is gradually reduced in kidney cells in the later stages of septic mice. The acetylation modification of HMGB1 is a key process before its nucleus-to-cytoplasm translocation and extracellular secretion in kidney cells, accelerating the development of SA-AKI. Moreover, SIRT1 can physically interact with HMGB1 at the deacetylated lysine sites K28, K29, and K30, subsequently suppressing downstream inflammatory signaling. Thus the SIRT1-HMGB1 signaling pathway is a crucial mechanism in the development of SA-AKI and presents a novel experimental perspective for future SA-AKI research.

2021 ◽  
Vol 8 ◽  
Author(s):  
Weitao Zhang ◽  
Ruochen Qi ◽  
Tingting Li ◽  
Xuepeng Zhang ◽  
Yi Shi ◽  
...  

Sepsis-associated acute kidney injury (SA-AKI) is a life-threatening syndrome. Lipopolysaccharide (LPS) is a widely used inducer for modeling SA-AKI both in vivo and in vitro. However, due to the innate complexity of the kidney architecture, the mechanisms underlying the pathogenesis of SA-AKI, as well as those involved in LPS-induced kidney injury remain to be clarified. Kidney organoids derived from human pluripotent stem cells (hPSCs) act as a model of multiple types of kidney cells in vitro and eliminate potential confounders in vivo. In the current study, we established LPS-induced kidney injury models both in vivo and in human kidney organoids. Kidney function, pathological changes, and markers of oxidative stress were evaluated with/without the presence of methylprednisolone (MP) treatment both in vivo and in vitro. The extent of LPS-induced oxidative stress and apoptosis in kidney organoids was further investigated in vitro. LPS-induced acute kidney injury in mice, together with pathological changes and increased oxidative stress, as well as enhanced apoptosis in kidney cells were evaluated. These phenomena were ameliorated by MP treatment. Experiments in kidney organoids showed that the LPS-induced apoptotic effects occurred mainly in podocytes and proximal tubular cells. Our experiments demonstrated the efficacy of using kidney organoids as a solid platform to study LPS-induced kidney injury. LPS induced oxidative stress as well as apoptosis in kidney cells independently of changes in perfusion or immune cell infiltration. MP treatment partially alleviated LPS-induced injury by reducing kidney cell oxidative stress and apoptosis.


2021 ◽  
Vol 12 ◽  
Author(s):  
Maomao Sun ◽  
Jiaxin Li ◽  
Liangfeng Mao ◽  
Jie Wu ◽  
Zhiya Deng ◽  
...  

Recent studies have shown that autophagy upregulation can attenuate sepsis-induced acute kidney injury (SAKI). The tumor suppressor p53 has emerged as an autophagy regulator in various forms of acute kidney injury (AKI). Our previous studies showed that p53 acetylation exacerbated hemorrhagic shock-induced AKI and lipopolysaccharide (LPS)-induced endothelial barrier dysfunction. However, the role of p53-regulated autophagy in SAKI has not been examined and requires clarification. In this study, we observed the dynamic changes of autophagy in renal tubular epithelial cells (RTECs) and verified the protective effects of autophagy activation on SAKI. We also examined the changes in the protein expression, intracellular distribution (nuclear and cytoplasmic), and acetylation/deacetylation levels of p53 during SAKI following cecal ligation and puncture (CLP) or LPS treatment in mice and in a LPS-challenged human RTEC cell line (HK-2 cells). After sepsis stimulation, the autophagy levels of RTECs increased temporarily, followed by a sharp decrease. Autophagy inhibition was accompanied by an increased renal tubular injury score. By contrast, autophagy agonists could reduce renal tubular damage following sepsis. Surprisingly, the expression of p53 protein in both the renal cortex and HK-2 cells did not significantly change following sepsis stimulation. However, the translocation of p53 from the nucleus to the cytoplasm increased, and the acetylation of p53 was enhanced. In the mechanistic study, we found that the induction of p53 deacetylation, due to either the resveratrol/quercetin -induced activation of the deacetylase Sirtuin 1 (Sirt1) or the mutation of the acetylated lysine site in p53, promoted RTEC autophagy and alleviated SAKI. In addition, we found that acetylated p53 was easier to bind with Beclin1 and accelerated its ubiquitination-mediated degradation. Our study underscores the importance of deacetylated p53-mediated RTEC autophagy in future SAKI treatments.


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.


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.


2017 ◽  
Vol 312 (2) ◽  
pp. F284-F296 ◽  
Author(s):  
David R. Emlet ◽  
Nuria Pastor-Soler ◽  
Allison Marciszyn ◽  
Xiaoyan Wen ◽  
Hernando Gomez ◽  
...  

We have characterized the expression and secretion of the acute kidney injury (AKI) biomarkers insulin-like growth factor binding protein 7 (IGFBP7) and tissue inhibitor of metalloproteinases-2 (TIMP-2) in human kidney epithelial cells in primary cell culture and tissue. We established cell culture model systems of primary kidney cells of proximal and distal tubule origin and observed that both proteins are indeed expressed and secreted in both tubule cell types in vitro. However, TIMP-2 is both expressed and secreted preferentially by cells of distal tubule origin, while IGFBP7 is equally expressed across tubule cell types yet preferentially secreted by cells of proximal tubule origin. In human kidney tissue, strong staining of IGFBP7 was seen in the luminal brush-border region of a subset of proximal tubule cells, and TIMP-2 stained intracellularly in distal tubules. Additionally, while some tubular colocalization of both biomarkers was identified with the injury markers kidney injury molecule-1 and neutrophil gelatinase-associated lipocalin, both biomarkers could also be seen alone, suggesting the possibility for differential mechanistic and/or temporal profiles of regulation of these early AKI biomarkers from known markers of injury. Last, an in vitro model of ischemia-reperfusion demonstrated enhancement of secretion of both markers early after reperfusion. This work provides a rationale for further investigation of these markers for their potential role in the pathogenesis of acute kidney injury.


2021 ◽  
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.


Antioxidants ◽  
2018 ◽  
Vol 7 (8) ◽  
pp. 105 ◽  
Author(s):  
Egor Plotnikov ◽  
Anna Brezgunova ◽  
Irina Pevzner ◽  
Ljubava Zorova ◽  
Vasily Manskikh ◽  
...  

Neonatal sepsis is one of the major causes of mortality and morbidity in newborns, greatly associated with severe acute kidney injury (AKI) and failure. Handling of newborns with kidney damage can be significantly different compared to adults, and it is necessary to consider the individuality of an organism’s response to systemic inflammation. In this study, we used lipopolysaccharide (LPS)-mediated acute kidney injury model to study mechanisms of kidney cells damage in neonatal and adult rats. We found LPS-associated oxidative stress was more severe in adults compared to neonates, as judged by levels of carbonylated proteins and products of lipids peroxidation. In both models, LPS-mediated septic simulation caused apoptosis of kidney cells, albeit to a different degree. Elevated levels of proliferating cell nuclear antigen (PCNA) in the kidney dropped after LPS administration in neonates but increased in adults. Renal fibrosis, as estimated by smooth muscle actin levels, was significantly higher in adult kidneys, whereas these changes were less profound in LPS-treated neonatal kidneys. We concluded that in LPS-mediated AKI model, renal cells of neonatal rats were more tolerant to oxidative stress and suffered less from long-term pathological consequences, such as fibrosis. In addition, we assume that by some features LPS administration simulates the conditions of accelerated aging.


2020 ◽  
Vol 19 (3) ◽  
pp. 270-276
Author(s):  
Jianying Wang ◽  
Xiaoting Yu

Acute kidney injury is a severe complication of sepsis. We have shown a protective effect of Platycodin D on sepsis induced acute kidney injury in an animal model that employs cecal ligation and puncture. Cecal ligation and puncture induced a series of degenerative changes in kidney, such as edema, hyperemia, and expansion in glomerular capillary, and inflammatory cells infiltration that were attenuated by Platycodin D. Also, rise in proinflammatory cytokine levels in septic rats was blunted by Platycodin D. Furthermore, Platycodin D administration reduced rise in serum levels of kidney injury markers-blood urea nitrogen and serum creatinine-in septic rats. Moreover, Platycodin D administration also suppressed the cell apoptosis in kidney that was associated with enhanced B-cell lymphoma 2 protein and reduced cleaved cysteine-aspartic protease-3 and BCL2-associated X protein. Lastly, Platycodin D administration attenuated sepsis-induced increase of phospho (p)-extracellular signal-regulated kinase, p-c-Jun NH2-terminal kinase, and p-p38. In conclusion, Platycodin D demonstrated protective effect against sepsis induced acute kidney injury through inactivation of mitogen activated protein kinase pathways, thus providing promising therapeutic strategy for the treatment of sepsis.


2018 ◽  
Vol 55 (4) ◽  
pp. 338-342 ◽  
Author(s):  
Eduardo Garcia VILELA ◽  
Camilla dos Santos PINHEIRO ◽  
Saulo Fernandes SATURNINO ◽  
Célio Geraldo de Oliveira GOMES ◽  
Vanuza Chagas do NASCIMENTO ◽  
...  

ABSTRACT BACKGROUND: Gastroesophageal varices and associated bleeding are a major cause of morbidity and mortality in cirrhotic patients. OBJECTIVE: To evaluate the potential role of the biomarkers HMGB1 (High Mobility Group Box 1) and IL-6 (Interleukin-6) as predictors of infection, acute kidney injury and mortality in these patients. METHODS: It is a prospective, observational study that included 32 cirrhotic patients with variceal bleeding. RESULTS: The subjects’mean age was 52±5 years and 20 (62.5%) were male. The average MELD was 17.53±5 and the average MELD-Na was 20.63±6.06. Thirty patients (93.3%) patients were Child-Pugh class B or C. Infection was present in 9 subjects (28.1%), acute kidney injury was present in 6 (18.1%) and 4 (12.5%) patients died. The median serum levels of HMGB1 were 1487 pg/mL (0.1 to 8593.1) and the median serum level of IL-6 was 62.1 pg/mL (0.1 to 1102.4). The serum levels of HMGB1 and IL-6 were significantly higher in patients who developed infection, acute kidney injury and death (P<0.05). The Spearman’s correlations for HMGB1 and IL-6 were 0.794 and 0.374 for infection, 0.53 and 0.374 for acute kidney injury and 0.467 and 0.404 for death, respectively. CONCLUSION: Serum levels of HMGB1 and IL-6 were higher in patients with the three studied outcomes. HMGB1 serum levels showed a high correlation with infection and a moderate correlation with acute kidney injury and death, while IL-6 showed a moderate correlation with infection and death and a low correlation with acute kidney injury.


2019 ◽  
Vol 131 (1) ◽  
pp. 105-118 ◽  
Author(s):  
Wenling Jian ◽  
Lili Gu ◽  
Brittney Williams ◽  
Yan Feng ◽  
Wei Chao ◽  
...  

Abstract Editor’s Perspective What We Already Know about This Topic What This Article Tells Us That Is New Background Sepsis remains a critical illness with high mortality. The authors have recently reported that mouse plasma RNA concentrations are markedly increased during sepsis and closely associated with its severity. Toll-like receptor 7, originally identified as the sensor for single-stranded RNA virus, also mediates host extracellular RNA-induced innate immune responses in vitro and in vivo. Here, the authors hypothesize that innate immune signaling via Toll-like receptor 7 contributes to inflammatory response, organ injury, and mortality during polymicrobial sepsis. Methods Sepsis was created by (1) cecal ligation and puncture or (2) stool slurry peritoneal injection. Wild-type and Toll-like receptor 7 knockout mice, both in C57BL/6J background, were used. The following endpoints were measured: mortality, acute kidney injury biomarkers, plasma and peritoneal cytokines, blood bacterial loading, peritoneal leukocyte counts, and neutrophil phagocytic function. Results The 11-day overall mortality was 81% in wild-type mice and 48% in Toll-like receptor 7 knockout mice after cecal ligation and puncture (N = 27 per group, P = 0.0031). Compared with wild-type septic mice, Toll-like receptor 7 knockout septic mice also had lower sepsis severity, attenuated plasma cytokine storm (wild-type vs. Toll-like receptor 7 knockout, interleukin-6: 43.2 [24.5, 162.7] vs. 4.4 [3.1, 12.0] ng/ml, P = 0.003) and peritoneal inflammation, alleviated acute kidney injury (wild-type vs. Toll-like receptor 7 knockout, neutrophil gelatinase-associated lipocalin: 307 ± 184 vs.139 ± 41-fold, P = 0.0364; kidney injury molecule-1: 40 [16, 49] vs.13 [4, 223]-fold, P = 0.0704), lower bacterial loading, and enhanced leukocyte peritoneal recruitment and phagocytic activities at 24 h. Moreover, stool slurry from wild-type and Toll-like receptor 7 knockout mice resulted in similar level of sepsis severity, peritoneal cytokines, and leukocyte recruitment in wild-type animals after peritoneal injection. Conclusions Toll-like receptor 7 plays an important role in the pathogenesis of polymicrobial sepsis by mediating host innate immune responses and contributes to acute kidney injury and mortality.


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