51
|
Park SY, Shrestha S, Youn YJ, Kim JK, Kim SY, Kim HJ, Park SH, Ahn WG, Kim S, Lee MG, Jung KS, Park YB, Mo EK, Ko Y, Lee SY, Koh Y, Park MJ, Song DK, Hong CW. Autophagy Primes Neutrophils for Neutrophil Extracellular Trap Formation during Sepsis. Am J Respir Crit Care Med 2017; 196:577-589. [PMID: 28358992 DOI: 10.1164/rccm.201603-0596oc] [Citation(s) in RCA: 102] [Impact Index Per Article: 14.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
RATIONALE Neutrophils are key effectors in the host's immune response to sepsis. Excessive stimulation or dysregulated neutrophil functions are believed to be responsible for sepsis pathogenesis. However, the mechanisms regulating functional plasticity of neutrophils during sepsis have not been fully determined. OBJECTIVES We investigated the role of autophagy in neutrophil functions during sepsis in patients with community-acquired pneumonia. METHODS Neutrophils were isolated from patients with sepsis and stimulated with phorbol 12-myristate 13-acetate (PMA). The levels of reactive oxygen species generation, neutrophil extracellular trap (NET) formation, and granule release, and the autophagic status were evaluated. The effect of neutrophil autophagy augmentation was further evaluated in a mouse model of sepsis. MEASUREMENTS AND MAIN RESULTS Neutrophils isolated from patients who survived sepsis showed an increase in autophagy induction, and were primed for NET formation in response to subsequent PMA stimulation. In contrast, neutrophils isolated from patients who did not survive sepsis showed dysregulated autophagy and a decreased response to PMA stimulation. The induction of autophagy primed healthy neutrophils for NET formation and vice versa. In a mouse model of sepsis, the augmentation of autophagy improved survival via a NET-dependent mechanism. CONCLUSIONS These results indicate that neutrophil autophagy primes neutrophils for increased NET formation, which is important for proper neutrophil effector functions during sepsis. Our study provides important insights into the role of autophagy in neutrophils during sepsis.
Collapse
Affiliation(s)
- So Young Park
- 1 Department of Pulmonary and Critical Care Medicine, KyungHee University Medical Center, Seoul, Republic of Korea
| | | | | | - Jun-Kyu Kim
- 3 Department of Physiology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| | | | - Hyun Jung Kim
- 4 Department of Internal Medicine, Kyungpook National University Hospital, Daegu, Republic of Korea
| | - So-Hee Park
- 5 Department of Pulmonary and Critical Care Medicine, KyungHee University Hospital at Gangdong, Seoul, Republic of Korea
| | | | - Shin Kim
- 6 Department of Immunology, Keimyung University School of Medicine, Daegu, Republic of Korea
| | - Myung Goo Lee
- 7 Lung Research Institute of Hallym University, College of Medicine, Hallym University, Chuncheon, Republic of Korea.,8 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Chuncheon Sacred Heart Hospital, Chuncheon, Republic of Korea
| | - Ki-Suck Jung
- 7 Lung Research Institute of Hallym University, College of Medicine, Hallym University, Chuncheon, Republic of Korea.,9 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Hallym University Sacred Heart Hospital, Anyang, Republic of Korea
| | - Yong Bum Park
- 7 Lung Research Institute of Hallym University, College of Medicine, Hallym University, Chuncheon, Republic of Korea.,10 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Kangdong Sacred Heart Hospital, Seoul, Republic of Korea; and
| | - Eun-Kyung Mo
- 7 Lung Research Institute of Hallym University, College of Medicine, Hallym University, Chuncheon, Republic of Korea.,10 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Kangdong Sacred Heart Hospital, Seoul, Republic of Korea; and
| | - Yousang Ko
- 7 Lung Research Institute of Hallym University, College of Medicine, Hallym University, Chuncheon, Republic of Korea.,10 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Kangdong Sacred Heart Hospital, Seoul, Republic of Korea; and
| | - Suh-Young Lee
- 7 Lung Research Institute of Hallym University, College of Medicine, Hallym University, Chuncheon, Republic of Korea.,8 Division of Pulmonary, Allergy and Critical Care Medicine, Department of Internal Medicine, Chuncheon Sacred Heart Hospital, Chuncheon, Republic of Korea
| | - Younsuck Koh
- 11 Department of Pulmonary and Critical Care Medicine, Asan Medical Center, University of Ulsan College of Medicine, Seoul, Republic of Korea
| | - Myung Jae Park
- 1 Department of Pulmonary and Critical Care Medicine, KyungHee University Medical Center, Seoul, Republic of Korea
| | | | - Chang-Won Hong
- 3 Department of Physiology, School of Medicine, Kyungpook National University, Daegu, Republic of Korea
| |
Collapse
|
52
|
Lewis A, Zuckerbraun B, Griepentrog J, Zhang X, Rosengart M. Reducing Animal Use with a Biotelemetry-Enhanced Murine Model of Sepsis. Sci Rep 2017; 7:6622. [PMID: 28747734 PMCID: PMC5529427 DOI: 10.1038/s41598-017-05497-5] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2017] [Accepted: 05/30/2017] [Indexed: 01/20/2023] Open
Abstract
Animal models of sepsis exhibit considerable variability in the temporal development of the physiologic response, which reduces the power of studies, particularly if interventions are tested at arbitrary time points. We developed a biotelemetry-based model of cecal ligation and puncture (CLP) that standardizes the testing of time-sensitive therapies to specific criteria of physiologic deterioration. In this study we seek to further define the variability in physiologic response to CLP sepsis and conduct a cost analysis detailing the potential for reducing animal usage. We have further characterized the variability in physiologic response after CLP in mice and determined peaks in the temporal distribution of points of physiologic decline. Testing therapies at physiologic thresholds reduces the variability found in historical fixed time-based models. Though initial cost is higher with biotelemetry, this is eventually offset by the significantly reduced number of mice needed to conduct physiologically relevant sepsis experiments.
Collapse
Affiliation(s)
- Anthony Lewis
- Department of Surgery, University of Pittsburgh, Pittsburgh, USA
| | | | - John Griepentrog
- Department of Surgery, University of Pittsburgh, Pittsburgh, USA
| | - Xianghong Zhang
- Department of Surgery, University of Pittsburgh, Pittsburgh, USA
| | | |
Collapse
|
53
|
Zhang X, Yuan D, Sun Q, Xu L, Lee E, Lewis AJ, Zuckerbraun BS, Rosengart MR. Calcium/calmodulin-dependent protein kinase regulates the PINK1/Parkin and DJ-1 pathways of mitophagy during sepsis. FASEB J 2017; 31:4382-4395. [PMID: 28615325 DOI: 10.1096/fj.201601096rrr] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2016] [Accepted: 06/06/2017] [Indexed: 11/11/2022]
Abstract
During sepsis and shock states, mitochondrial dysfunction occurs. Consequently, adaptive mechanisms, such as fission, fusion, and mitophagy, are induced to eliminate damaged portions or entire dysfunctional mitochondria. The regulatory PINK1/Parkin and DJ-1 pathways are strongly induced by mitochondrial depolarization, although a direct link between loss of mitochondrial membrane potential (ΔΨ) and mitophagy has not been identified. Mitochondria also buffer Ca2+, and their buffering capacity is dependent on ΔΨ Here, we characterize a role for calcium/calmodulin-dependent protein kinase (CaMK) I in the regulation of these mechanisms. Loss of ΔΨ with either pharmacologic depolarization or LPS leads to Ca2+-dependent mitochondrial recruitment and activation of CaMKI that precedes the colocalization of PINK1/Parkin and DJ-1. CaMKI is required and serves as both a PINK1 and Parkin kinase. The mechanisms operate in both immune and nonimmune cells and are induced in in vivo models of endotoxemia, sepsis, and hemorrhagic shock. These data support the idea that CaMKI links mitochondrial stress with the PINK1/Parkin and DJ-1 mechanisms of mitophagy.-Zhang, X., Yuan, D., Sun, Q., Xu, L., Lee, E., Lewis, A. J., Zuckerbraun, B. S., Rosengart, M. R. Calcium/calmodulin-dependent protein kinase regulates the PINK1/Parkin and DJ-1 pathways of mitophagy during sepsis.
Collapse
Affiliation(s)
- Xianghong Zhang
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Du Yuan
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.,Department of Medicine, The Third Xiangya Hospital, Central South University, Changsha, China
| | - Qian Sun
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Li Xu
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA.,Department of Emergency Surgery, Union Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Emma Lee
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Anthony J Lewis
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Brian S Zuckerbraun
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Matthew R Rosengart
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania, USA;
| |
Collapse
|
54
|
Use of Biotelemetry to Define Physiology-Based Deterioration Thresholds in a Murine Cecal Ligation and Puncture Model of Sepsis. Crit Care Med 2017; 44:e420-31. [PMID: 26862708 DOI: 10.1097/ccm.0000000000001615] [Citation(s) in RCA: 31] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
OBJECTIVES Murine models of critical illness are commonly used to test new therapeutic interventions. However, these interventions are often administered at fixed time intervals after the insult, perhaps ignoring the inherent variability in magnitude and temporality of the host response. We propose to use wireless biotelemetry monitoring to define and validate criteria for acute deterioration and generate a physiology-based murine cecal ligation and puncture model that is more similar to the conduct of human trials of sepsis. DESIGN Laboratory and animal research. SETTING University basic science laboratory. SUBJECTS Male C57BL/6 mice. INTERVENTIONS Mice underwent cecal ligation and puncture, and an HD-X11 wireless telemetry monitor (Data Sciences International) was implanted that enabled continuous, real-time measurement of heart rate, core temperature, and mobility. We performed a population-based analysis to determine threshold criteria that met face validity for acute physiologic deterioration. We assessed construct validity by temporally matching mice that met these acute physiologic deterioration thresholds with mice that had not yet met deterioration threshold. We analyzed matched blood samples for blood gas, inflammatory cytokine concentration, cystatin C, and alanine aminotransferase. MEASUREMENTS AND MAIN RESULTS We observed that a 10% reduction in both heart rate and temperature sustained for greater than or equal to 10 minutes defined acute physiologic deterioration. There was significant variability in the time to reach acute deterioration threshold across mice, ranging from 339 to 529 minutes after cecal ligation and puncture. We found adequate construct validity, as mice that met criteria for acute deterioration had significantly worse shock, systemic inflammation (elevated tumor necrosis factor-α, p = 0.003; interleukin-6, p = 0.01; interleukin-10, p = 0.005), and acute kidney injury when compared with mice that had not yet met acute deterioration criteria. CONCLUSIONS We defined a murine threshold for acute physiologic deterioration after cecal ligation and puncture that has adequate face and construct validity. This model may enable a more physiology-based model for evaluation of novel therapeutics in critical illness.
Collapse
|
55
|
Suppression of T Cell Autophagy Results in Decreased Viability and Function of T Cells Through Accelerated Apoptosis in a Murine Sepsis Model. Crit Care Med 2017; 45:e77-e85. [PMID: 27618275 PMCID: PMC5364514 DOI: 10.1097/ccm.0000000000002016] [Citation(s) in RCA: 56] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Supplemental Digital Content is available in the text. Objective: While type 1 programmed cell death (apoptosis) of T cells leads to immunosuppression in sepsis, a crosstalk between apoptosis and autophagy (type 2 programmed cell death) has not been shown. The aim of this study is to elucidate the details of the interaction between autophagy and immunosuppression. Design: Laboratory investigation in the murine sepsis model. Setting: University laboratory. Subjects: Six- to 8-week-old male mice. Interventions: We investigated the kinetics of autophagy in T cells from spleen in a cecal ligation and puncture model with green fluorescent protein-microtubule-associated protein light chain 3 transgenic mice. We analyzed apoptosis, mitochondrial homeostasis and cytokine production in T cells, and survival rate after cecal ligation and puncture using T cell–specific autophagy-deficient mice. Measurements and Main Results: We observed an increase of autophagosomes, which was assessed by flow cytometry. However, an autophagy process in CD4+ T cells during sepsis was insufficient including the accumulation of p62. On the other hand, a blockade of autophagy accelerated T cell apoptosis compared with the control mice, augmenting the gene expression of Bcl-2-like 11 and programmed cell death 1. Furthermore, mitochondrial accumulation in T cells occurred via a blockade of autophagy during sepsis. In addition, interleukin-10 production in CD4+ T cells from the cecal ligation and puncture–operated knockout mice was markedly increased. Consequently, deficiency of autophagy in T cells significantly decreased the survival rate in the murine sepsis model. Conclusions: We demonstrated that blocking autophagy accelerated apoptosis and increased mortality in concordance with the insufficient autophagy process in CD4+ T cells in the murine sepsis model, suggesting that T cell autophagy plays a protective role against apoptosis and immunosuppression in sepsis.
Collapse
|
56
|
Abstract
The host defence against infection is an adaptive response in which several mechanisms are deployed to decrease the pathogen load, limit tissue injury and restore homeostasis. In the past few years new evidence has suggested that the ability of the immune system to limit the microbial burden - termed resistance - might not be the only defence mechanism. In fact, the capacity of the host to decrease its own susceptibility to inflammation- induced tissue damage - termed tolerance - might be as important as resistance in determining the outcome of the infection. Metabolic adaptations are central to the function of the cellular immune response. Coordinated reprogramming of metabolic signalling enables cells to execute resistance and tolerance pathways, withstand injury, steer tissue repair and promote organ recovery. During sepsis-induced acute kidney injury, early reprogramming of metabolism can determine the extent of organ dysfunction, progression to fibrosis, and the development of chronic kidney disease. Here we discuss the mechanisms of tolerance that act in the kidney during sepsis, with particular attention to the role of metabolic responses in coordinating these adaptive strategies. We suggest a novel conceptual model of the cellular and organic response to sepsis that might lead to new avenues for targeted, organ-protective therapies.
Collapse
|
57
|
Chen G, Dong Z, Liu H, Liu Y, Duan S, Liu Y, Liu F, Chen H. mTOR Signaling Regulates Protective Activity of Transferred CD4+Foxp3+ T Cells in Repair of Acute Kidney Injury. THE JOURNAL OF IMMUNOLOGY 2016; 197:3917-3926. [DOI: 10.4049/jimmunol.1601251] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/20/2016] [Accepted: 09/21/2016] [Indexed: 12/16/2022]
|
58
|
Affiliation(s)
- Anthony J. Lewis
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Christopher W. Seymour
- The Clinical Research, Investigation, and Systems Modeling of Acute illness (CRISMA) Center, Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - Matthew R. Rosengart
- Department of Surgery, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
- The Clinical Research, Investigation, and Systems Modeling of Acute illness (CRISMA) Center, Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| |
Collapse
|
59
|
Kim TW, Kim YJ, Kim HT, Park SR, Lee MY, Park YD, Lee CH, Jung JY. NQO1 Deficiency Leads Enhanced Autophagy in Cisplatin-Induced Acute Kidney Injury Through the AMPK/TSC2/mTOR Signaling Pathway. Antioxid Redox Signal 2016; 24:867-83. [PMID: 26935540 DOI: 10.1089/ars.2015.6386] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
AIMS Recent studies have revealed that autophagy is induced under various disease conditions; however, the role of autophagy in pathological states is controversial. NAD(P)H quinone oxidoreductase 1 (NQO1) is a highly inducible cytoprotective gene that regulates reactive oxygen species (ROS) generation. In this study, we examined whether NQO1 deficiency affects the autophagy process in response to cisplatin-induced nephrotoxicity. RESULTS In vitro, NQO1 and autophagy-associated proteins were induced after cisplatin treatment and the autophagosomes markedly increased in the cisplatin-treated NQO1-knockdown ACHN cells together with increased ROS production. In vivo, NQO1-KO mice displayed a significant increase in cisplatin-induced acute kidney injury (AKI), as indicated by elevated tubular damage and apoptosis as well as by suppressed cytoprotective signals. In agreement with the in vitro findings, NQO1-KO cisplatin-treated mice displayed a notable increase in autophagy-associated protein expression compared with their wild-type counterparts. Meanwhile, the expression of Ras-related protein 7, which participates in autophagosome maturation and lysosome fusion, markedly decreased in NQO1-KO mice, indicating hampered progress in late autophagy, and was accompanied by increased p62 protein expression. Moreover, NQO1 deletion enhanced the effect of the mammalian target of the rapamycin inhibitor, rapamycin, and led to enhanced tuberous sclerosis complex 2 phosphorylation through AMP-activated protein kinase activation. INNOVATION AND CONCLUSION These results indicate that autophagy may be enhanced to counter the increased stress due to NQO1 deficiency, an oxidative stress barrier. The present results demonstrate the significant influence of NQO1 on the autophagy process and support the hypothesis that autophagy plays a protective role under oxidative stress conditions. Antioxid. Redox Signal. 24, 867-883.
Collapse
Affiliation(s)
- Tae-Won Kim
- 1 Department of Veterinary Medicine, Institute of Veterinary Science, Chungnam National University , Daejeon, Republic of Korea
| | - Young-Jung Kim
- 1 Department of Veterinary Medicine, Institute of Veterinary Science, Chungnam National University , Daejeon, Republic of Korea
| | - Hyun-Tae Kim
- 1 Department of Veterinary Medicine, Institute of Veterinary Science, Chungnam National University , Daejeon, Republic of Korea
| | - Se-Ra Park
- 1 Department of Veterinary Medicine, Institute of Veterinary Science, Chungnam National University , Daejeon, Republic of Korea
| | - Mee-Young Lee
- 2 Herbal Medicine Formulation Research Group, Korea Institute of Oriental Medicine , Daejeon, Republic of Korea
| | - Yong-Deok Park
- 3 Department of Biomedical Science, Youngdong University , Yeongdong, Republic of Korea
| | - Chul-Ho Lee
- 4 Laboratory Animal Center, Korea Research Institute of Bioscience and Biotechnology , Daejeon, Republic of Korea
| | - Ju-Young Jung
- 1 Department of Veterinary Medicine, Institute of Veterinary Science, Chungnam National University , Daejeon, Republic of Korea
| |
Collapse
|
60
|
Tan X, Chen Y, Liang X, Yu C, Lai Y, Zhang L, Zhao X, Zhang H, Lin T, Li R, Shi W. Lipopolysaccharide-induced podocyte injury is mediated by suppression of autophagy. Mol Med Rep 2016; 14:811-8. [PMID: 27221629 DOI: 10.3892/mmr.2016.5301] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2015] [Accepted: 03/11/2016] [Indexed: 11/06/2022] Open
Abstract
High-level autophagy has an important role in maintaining the stable state of podocytes. The present study explored the influence of lipopolysaccharide (LPS) on autophagic activity in podocytes and demonstrated its mechanistic involvement in LPS-induced injury. Conditionally immortalized podocytes were cultured in vitro and were treated with chloroquine (CQ), LPS, LPS+rapamycin or LPS+3‑methyladenine (3‑MA). The autophagic vesicles and endoplasmic reticulum were observed using transmission electron microscopy. The tandem mRFP‑GFP‑LC3 adenovirus was used to detect autophagosomes and autolysosomes. The expression levels of light chain 3‑II (LC3 II), beclin‑1, P62, CCAAT‑enhancer‑binding protein homologous protein (CHOP) and podocin were determined by western blot analysis. Autophagic vesicles were detected in podocytes under basic conditions. CQ was found to increase the protein levels of LC3 II in a time‑dependent manner (2, 4 or 6 h), confirming the high activity of autophagy in podocytes. Compared with the control group, LPS induced the expansion of the endoplasmic reticulum and high expression levels of CHOP, while decreasing the protein expression of podocin. Notably, podocytes treated with LPS showed decreases in LC3 II and beclin‑1 levels and autophagosome/autolysosome numbers, which was accompanied by high P62 levels. Furthermore, the autophagy enhancer rapamycin reversed the downregulation of LC3 II and podocin, and the upregulation of CHOP induced by LPS, while the autophagy inhibitor 3‑MA aggravated the effects of LPS. In conclusion, the present study demonstrated that LPS inhibited podocyte autophagy, which contributed to LPS-induced injury of podocytes.
Collapse
Affiliation(s)
- Xiaofan Tan
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Yuanhan Chen
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Xinling Liang
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Chunping Yu
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Yuxiong Lai
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Li Zhang
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Xingchen Zhao
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Hong Zhang
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Ting Lin
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Ruizhao Li
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| | - Wei Shi
- Division of Nephrology, Guangdong General Hospital, Guangdong Academy of Medical Sciences, Guangzhou, Guangdong 510080, P.R. China
| |
Collapse
|
61
|
Ho J, Yu J, Wong SH, Zhang L, Liu X, Wong WT, Leung CCH, Choi G, Wang MHT, Gin T, Chan MTV, Wu WKK. Autophagy in sepsis: Degradation into exhaustion? Autophagy 2016; 12:1073-82. [PMID: 27172163 DOI: 10.1080/15548627.2016.1179410] [Citation(s) in RCA: 105] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Autophagy is one of the innate immune defense mechanisms against microbial challenges. Previous in vitro and in vivo models of sepsis demonstrated that autophagy was activated initially in sepsis, followed by a subsequent phase of impairment. Autophagy modulation appears to be protective against multiple organ injuries in these murine sepsis models. This is achieved in part by preventing apoptosis, maintaining a balance between the productions of pro- and anti-inflammatory cytokines, and preserving mitochondrial functions. This article aims to discuss the role of autophagy in sepsis and the therapeutic potential of autophagy enhancers.
Collapse
Affiliation(s)
- Jeffery Ho
- a Department of Anesthesia and Intensive Care , The Chinese University of Hong Kong, Hong Kong Special Administrative Region , China
| | - Jun Yu
- b State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences and Department of Medicine and Therapeutics , The Chinese University of Hong Kong, Hong Kong Special Administrative Region , China
| | - Sunny H Wong
- b State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences and Department of Medicine and Therapeutics , The Chinese University of Hong Kong, Hong Kong Special Administrative Region , China
| | - Lin Zhang
- c School of Biomedical Sciences, The Chinese University of Hong Kong, Hong Kong Special Administrative Region , China
| | - Xiaodong Liu
- a Department of Anesthesia and Intensive Care , The Chinese University of Hong Kong, Hong Kong Special Administrative Region , China
| | - Wai T Wong
- a Department of Anesthesia and Intensive Care , The Chinese University of Hong Kong, Hong Kong Special Administrative Region , China
| | - Czarina C H Leung
- a Department of Anesthesia and Intensive Care , The Chinese University of Hong Kong, Hong Kong Special Administrative Region , China
| | - Gordon Choi
- a Department of Anesthesia and Intensive Care , The Chinese University of Hong Kong, Hong Kong Special Administrative Region , China
| | - Maggie H T Wang
- d The Jockey Club School of Public Health and Primary Care, The Chinese University of Hong Kong, Hong Kong Special Administrative Region , China
| | - Tony Gin
- a Department of Anesthesia and Intensive Care , The Chinese University of Hong Kong, Hong Kong Special Administrative Region , China
| | - Matthew T V Chan
- a Department of Anesthesia and Intensive Care , The Chinese University of Hong Kong, Hong Kong Special Administrative Region , China
| | - William K K Wu
- a Department of Anesthesia and Intensive Care , The Chinese University of Hong Kong, Hong Kong Special Administrative Region , China.,b State Key Laboratory of Digestive Disease, Li Ka Shing Institute of Health Sciences and Department of Medicine and Therapeutics , The Chinese University of Hong Kong, Hong Kong Special Administrative Region , China
| |
Collapse
|
62
|
Autophagy, Innate Immunity and Tissue Repair in Acute Kidney Injury. Int J Mol Sci 2016; 17:ijms17050662. [PMID: 27153058 PMCID: PMC4881488 DOI: 10.3390/ijms17050662] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2016] [Revised: 04/14/2016] [Accepted: 04/20/2016] [Indexed: 01/09/2023] Open
Abstract
Kidney is a vital organ with high energy demands to actively maintain plasma hemodynamics, electrolytes and water homeostasis. Among the nephron segments, the renal tubular epithelium is endowed with high mitochondria density for their function in active transport. Acute kidney injury (AKI) is an important clinical syndrome and a global public health issue with high mortality rate and socioeconomic burden due to lack of effective therapy. AKI results in acute cell death and necrosis of renal tubule epithelial cells accompanied with leakage of tubular fluid and inflammation. The inflammatory immune response triggered by the tubular cell death, mitochondrial damage, associative oxidative stress, and the release of many tissue damage factors have been identified as key elements driving the pathophysiology of AKI. Autophagy, the cellular mechanism that removes damaged organelles via lysosome-mediated degradation, had been proposed to be renoprotective. An in-depth understanding of the intricate interplay between autophagy and innate immune response, and their roles in AKI pathology could lead to novel therapies in AKI. This review addresses the current pathophysiology of AKI in aspects of mitochondrial dysfunction, innate immunity, and molecular mechanisms of autophagy. Recent advances in renal tissue regeneration and potential therapeutic interventions are also discussed.
Collapse
|
63
|
Yang Y, Song M, Liu Y, Liu H, Sun L, Peng Y, Liu F, Venkatachalam MA, Dong Z. Renoprotective approaches and strategies in acute kidney injury. Pharmacol Ther 2016; 163:58-73. [PMID: 27108948 DOI: 10.1016/j.pharmthera.2016.03.015] [Citation(s) in RCA: 73] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2016] [Accepted: 03/18/2016] [Indexed: 12/17/2022]
Abstract
Acute kidney injury (AKI) is a major renal disease associated with high mortality rate and increasing prevalence. Decades of research have suggested numerous chemical and biological agents with beneficial effects in AKI. In addition, cell therapy and molecular targeting have been explored for reducing kidney tissue damage and promoting kidney repair or recovery from AKI. Mechanistically, these approaches may mitigate oxidative stress, inflammation, cell death, and mitochondrial and other organellar damage, or activate cytoprotective mechanisms such as autophagy and pro-survival factors. However, none of these findings has been successfully translated into clinical treatment of AKI. In this review, we analyze these findings and propose experimental strategies for the identification of renoprotective agents or methods with clinical potential. Moreover, we propose the consideration of combination therapy by targeting multiple targets in AKI.
Collapse
Affiliation(s)
- Yuan Yang
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Meifang Song
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Yu Liu
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Hong Liu
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Lin Sun
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Youming Peng
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China
| | - Fuyou Liu
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China.
| | | | - Zheng Dong
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan, China; Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University and Charlie Norwood VA Medical Center, Augusta, GA, USA.
| |
Collapse
|
64
|
Lewis AJ, Billiar TR, Rosengart MR. Biology and Metabolism of Sepsis: Innate Immunity, Bioenergetics, and Autophagy. Surg Infect (Larchmt) 2016; 17:286-93. [PMID: 27093228 DOI: 10.1089/sur.2015.262] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Sepsis is a complex, heterogeneous physiologic condition that represents a significant public health concern. While many insights into the pathophysiology of sepsis have been elucidated over the past decades of research, important questions remain. This article serves as a review of several important areas in sepsis research. Understanding the innate immune response has been at the forefront as of late, especially in the context of cytokine-directed therapeutic trials. Cellular bioenergetic changes provide insight into the development of organ dysfunction in sepsis. Autophagy and mitophagy perform crucial cell housekeeping and stress response functions. Finally, age-related changes and their potential impact on the septic response are reviewed.
Collapse
Affiliation(s)
- Anthony J Lewis
- Department of Surgery, University of Pittsburgh , Pittsburgh, Pennsylvania
| | - Timothy R Billiar
- Department of Surgery, University of Pittsburgh , Pittsburgh, Pennsylvania
| | | |
Collapse
|
65
|
Leventhal JS, Ni J, Osmond M, Lee K, Gusella GL, Salem F, Ross MJ. Autophagy Limits Endotoxemic Acute Kidney Injury and Alters Renal Tubular Epithelial Cell Cytokine Expression. PLoS One 2016; 11:e0150001. [PMID: 26990086 PMCID: PMC4798771 DOI: 10.1371/journal.pone.0150001] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2015] [Accepted: 02/08/2016] [Indexed: 01/20/2023] Open
Abstract
Sepsis related acute kidney injury (AKI) is a common in-hospital complication with a dismal prognosis. Our incomplete understanding of disease pathogenesis has prevented the identification of hypothesis-driven preventive or therapeutic interventions. Increasing evidence in ischemia-reperfusion and nephrotoxic mouse models of AKI support the theory that autophagy protects renal tubular epithelial cells (RTEC) from injury. However, the role of RTEC autophagy in septic AKI remains unclear. We observed that lipopolysaccharide (LPS), a mediator of gram-negative bacterial sepsis, induces RTEC autophagy in vivo and in vitro through TLR4-initiated signaling. We modeled septic AKI through intraperitoneal LPS injection in mice in which autophagy-related protein 7 was specifically knocked out in the renal proximal tubules (ATG7KO). Compared to control littermates, ATG7KO mice developed more severe renal dysfunction (24hr BUN 100.1mg/dl +/- 14.8 vs 54.6mg/dl +/- 11.3) and parenchymal injury. After injection with LPS, analysis of kidney lysates identified higher IL-6 expression and increased STAT3 activation in kidney lysates from ATG7KO mice compared to controls. In vitro experiments confirmed an altered response to LPS in RTEC with genetic or pharmacological impairment of autophagy. In conclusion, RTEC autophagy protects against endotoxin induced injury and regulates downstream effects of RTEC TLR4 signaling.
Collapse
Affiliation(s)
- Jeremy S. Leventhal
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Renal Division, James J Peters Bronx VA Medical Center, Bronx, New York, United States of America
- * E-mail:
| | - Jie Ni
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Morgan Osmond
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Kyung Lee
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - G. Luca Gusella
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Fadi Salem
- Department of Pathology, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
| | - Michael J. Ross
- Division of Nephrology, Department of Medicine, Icahn School of Medicine at Mount Sinai, New York, New York, United States of America
- Renal Division, James J Peters Bronx VA Medical Center, Bronx, New York, United States of America
| |
Collapse
|
66
|
Arulkumaran N, Deutschman CS, Pinsky MR, Zuckerbraun B, Schumacker PT, Gomez H, Gomez A, Murray P, Kellum JA. MITOCHONDRIAL FUNCTION IN SEPSIS. Shock 2016; 45:271-81. [PMID: 26871665 PMCID: PMC4755359 DOI: 10.1097/shk.0000000000000463] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Mitochondria are an essential part of the cellular infrastructure, being the primary site for high-energy adenosine triphosphate production through oxidative phosphorylation. Clearly, in severe systemic inflammatory states, like sepsis, cellular metabolism is usually altered, and end organ dysfunction is not only common, but also predictive of long-term morbidity and mortality. Clearly, interest is mitochondrial function both as a target for intracellular injury and response to extrinsic stress have been a major focus of basic science and clinical research into the pathophysiology of acute illness. However, mitochondria have multiple metabolic and signaling functions that may be central in both the expression of sepsis and its ultimate outcome. In this review, the authors address five primary questions centered on the role of mitochondria in sepsis. This review should be used both as a summary source in placing mitochondrial physiology within the context of acute illness and as a focal point for addressing new research into diagnostic and treatment opportunities these insights provide.
Collapse
Affiliation(s)
| | - Clifford S. Deutschman
- Department of Pediatrics and Molecular Medicine, Hofstra-North Shore-Long Island Jewish School of Medicine
| | - Michael R. Pinsky
- Department of Critical Care Medicine, University of Pittsburgh School of Medicine
| | | | - Paul T. Schumacker
- Departments of Pediatrics-Neonatology, Cell and Molecular Biology and Medicine, Northwestern University Feinberg School of Medicine
| | - Hernando Gomez
- Department of Critical Care Medicine, University of Pittsburgh School of Medicine
- Center for Critical Care Nephrology, University of Pittsburgh, Pittsburgh PA
| | - Alonso Gomez
- Academia Colombiana de Medicina Critica (ACOMEC)
- Division of Critical Care Medicine, Clínica Palermo, Bogotá, Colombia
| | | | - John A. Kellum
- Department of Critical Care Medicine, University of Pittsburgh School of Medicine
- Center for Critical Care Nephrology, University of Pittsburgh, Pittsburgh PA
| |
Collapse
|
67
|
Autophagy is activated to protect against endotoxic acute kidney injury. Sci Rep 2016; 6:22171. [PMID: 26916346 PMCID: PMC4768171 DOI: 10.1038/srep22171] [Citation(s) in RCA: 63] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Accepted: 02/09/2016] [Indexed: 01/19/2023] Open
Abstract
Endotoxemia in sepsis, characterized by systemic inflammation, is a major cause of acute kidney injury (AKI) in hospitalized patients, especially in intensive care unit; however the underlying pathogenesis is poorly understood. Autophagy is a conserved, cellular catabolic pathway that plays crucial roles in cellular homeostasis including the maintenance of cellular function and viability. The regulation and role of autophagy in septic or endotoxic AKI remains unclear. Here we show that autophagy was induced in kidney tubular cells in mice by the endotoxin lipopolysaccharide (LPS). Pharmacological inhibition of autophagy with chloroquine enhanced LPS-induced AKI. Moreover, specific ablation of autophagy gene 7 (Atg7) from kidney proximal tubules worsened LPS-induced AKI. Together, the results demonstrate convincing evidence of autophagy activation in endotoxic kidney injury and support a renoprotective role of autophagy in kidney tubules.
Collapse
|
68
|
Zhang L, Ai Y, Tsung A. Clinical application: Restoration of immune homeostasis by autophagy as a potential therapeutic target in sepsis. Exp Ther Med 2016; 11:1159-1167. [PMID: 27073416 DOI: 10.3892/etm.2016.3071] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2015] [Accepted: 12/04/2015] [Indexed: 02/07/2023] Open
Abstract
Sepsis-induced lymphocyte and dendritic cell apoptosis contributes to immunosuppression, resulting in an inability to eradicate the primary infection and a propensity to acquire secondary infections. However, the inhibition of apoptosis may produce unexpected and undesirable consequences. Another cellular process, autophagy, is also activated in immune cells. There is increasing evidence to suggest that autophagy confers a protective effect in sepsis. The protective mechanisms underlying this effect include limiting apoptotic cell death and maintaining cellular homeostasis. Therefore, understanding the regulation of immune cell autophagy and apoptosis may provide insight into novel therapeutic strategies. The present review examined potential novel therapeutic strategies aimed at restoring immune homeostasis by inducing autophagy. The restoration of balance between apoptosis and autophagy may be a novel approach for improving sepsis-induced immunosuppression and decreasing susceptibility to sepsis.
Collapse
Affiliation(s)
- Lemeng Zhang
- Department of Intensive Care Unit, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Yuhang Ai
- Department of Intensive Care Unit, Xiangya Hospital, Central South University, Changsha, Hunan 410008, P.R. China
| | - Allan Tsung
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213, USA
| |
Collapse
|
69
|
Cho HI, Kim SJ, Choi JW, Lee SM. Genipin alleviates sepsis-induced liver injury by restoring autophagy. Br J Pharmacol 2016; 173:980-91. [PMID: 26660048 DOI: 10.1111/bph.13397] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2015] [Revised: 11/18/2015] [Accepted: 11/30/2015] [Indexed: 12/22/2022] Open
Abstract
BACKGROUND AND PURPOSE Autophagy is an essential cytoprotective system that is rapidly activated in response to various stimuli including inflammation and microbial infection. Genipin, an aglycon of geniposide found in gardenia fruit, is well known to have anti-inflammatory, antibacterial and antioxidative properties. This study examined the protective mechanisms of genipin against sepsis, with particular focus on the autophagic signalling pathway. EXPERIMENTAL APPROACH Mice were subjected to sepsis by caecal ligation and puncture (CLP). Genipin (1, 2.5 and 5 mg·kg(-1) ) or vehicle (saline) was injected i.v. immediately (0 h) after CLP, and chloroquine (60 mg·kg(-1) ), an autophagy inhibitor, was injected i.p. 1 h before CLP. Blood and liver tissues were isolated 6 h after CLP. KEY RESULTS Genipin improved survival rate and decreased serum levels of aminotransferases and pro-inflammatory cytokines after CLP; effects abolished by chloroquine. The liver expression of autophagy-related protein (Atg)12-Atg5 conjugate increased after CLP, and this increase was enhanced by genipin. CLP decreased Atg3 protein liver expression, and genipin attenuated this decrease. CLP impaired autophagic flux, as indicated by increased liver expression of microtubule-associated protein-1 light chain 3-II and sequestosome-1/p62 protein; this impaired autophagic flux was restored by genipin, and chloroquine abolished this effect. Genipin also attenuated the decreased expression of lysosome-associated membrane protein-2 and Rab7 protein and increased expression of calpain 1 protein induced by CLP in the liver. CONCLUSIONS AND IMPLICATIONS Our findings suggest that genipin protects against septic injury by restoring impaired autophagic flux. Therefore, genipin might be a potential therapeutic agent for the treatment of sepsis.
Collapse
Affiliation(s)
- Hong-Ik Cho
- School of Pharmacy, Sungkyunkwan University, Suwon, 440-746, South Korea
| | - So-Jin Kim
- School of Pharmacy, Sungkyunkwan University, Suwon, 440-746, South Korea
| | - Joo-Wan Choi
- School of Pharmacy, Sungkyunkwan University, Suwon, 440-746, South Korea
| | - Sun-Mee Lee
- School of Pharmacy, Sungkyunkwan University, Suwon, 440-746, South Korea
| |
Collapse
|
70
|
Kaushal GP, Shah SV. Autophagy in acute kidney injury. Kidney Int 2016; 89:779-91. [PMID: 26924060 DOI: 10.1016/j.kint.2015.11.021] [Citation(s) in RCA: 273] [Impact Index Per Article: 34.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 11/12/2015] [Accepted: 11/19/2015] [Indexed: 02/09/2023]
Abstract
Autophagy is a conserved multistep pathway that degrades and recycles damaged organelles and macromolecules to maintain intracellular homeostasis. The autophagy pathway is upregulated under stress conditions including cell starvation, hypoxia, nutrient and growth-factor deprivation, endoplasmic reticulum stress, and oxidant injury, most of which are involved in the pathogenesis of acute kidney injury (AKI). Recent studies demonstrate that basal autophagy in the kidney is vital for the normal homeostasis of the proximal tubules. Deletion of key autophagy proteins impaired renal function and increased p62 levels and oxidative stress. In models of AKI, autophagy deletion in proximal tubules worsened tubular injury and renal function, highlighting that autophagy is renoprotective in models of AKI. In addition to nonselective sequestration of autophagic cargo, autophagy can facilitate selective degradation of damaged organelles, particularly mitochondrial degradation through the process of mitophagy. Damaged mitochondria accumulate in autophagy-deficient kidneys of mice subjected to ischemia-reperfusion injury, but the precise mechanisms of regulation of mitophagy in AKI are not yet elucidated. Recent progress in identifying the interplay of autophagy, apoptosis, and regulated necrosis has revived interest in examining shared pathways/molecules in this crosstalk during the pathogenesis of AKI. Autophagy and its associated pathways pose potentially unique targets for therapeutic interventions in AKI.
Collapse
Affiliation(s)
- Gur P Kaushal
- Renal Section, Medicine Service, Central Arkansas Veterans Healthcare System, Little Rock, Arkansas, USA; Division of Nephrology, Department of Internal Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA.
| | - Sudhir V Shah
- Renal Section, Medicine Service, Central Arkansas Veterans Healthcare System, Little Rock, Arkansas, USA; Division of Nephrology, Department of Internal Medicine, University of Arkansas for Medical Sciences, Little Rock, Arkansas, USA
| |
Collapse
|
71
|
Abstract
Acute kidney injury (AKI) continues to be a significant contributor to morbidity, mortality, and health care expenditure. In the United States alone, it is estimated that more than $10 billion is spent on AKI every year. Currently, there are no available therapies to treat established AKI. The mitochondrion is positioned to be a critical player in AKI with its dual role as the primary source of energy for each cell and as a key regulator of cell death. This review aims to cover the current state of research on the role of mitochondria in AKI, while also proposing potential therapeutic targets and future therapies.
Collapse
Affiliation(s)
- Kenneth M Ralto
- Division of Nephrology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA
| | - Samir M Parikh
- Division of Nephrology, Beth Israel Deaconess Medical Center and Harvard Medical School, Boston, MA.
| |
Collapse
|
72
|
Swaminathan S, Rosner MH, Okusa MD. Emerging therapeutic targets of sepsis-associated acute kidney injury. Semin Nephrol 2015; 35:38-54. [PMID: 25795498 DOI: 10.1016/j.semnephrol.2015.01.005] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Sepsis-associated acute kidney injury (SA-AKI) is linked to high morbidity and mortality. To date, singular approaches to target specific pathways known to contribute to the pathogenesis of SA-AKI have failed. Because of the complexity of the pathogenesis of SA-AKI, a reassessment necessitates integrative approaches to therapeutics of SA-AKI that include general supportive therapies such as the use of vasopressors, fluids, antimicrobials, and target-specific and time-dependent therapeutics. There has been recent progress in our understanding of the pathogenesis and treatment of SA-AKI including the temporal nature of proinflammatory and anti-inflammatory processes. In this review, we discuss the clinical and experimental basis of emerging therapeutic approaches that focus on targeting early proinflammatory and late anti-inflammatory processes, as well as therapeutics that may enhance cellular survival and recovery. Finally, we include ongoing clinical trials in sepsis.
Collapse
Affiliation(s)
- Sundararaman Swaminathan
- Division of Nephrology, Center for Immunity, Inflammation and Regenerative Medicine, University of Virginia Health System, Charlottesville, VA
| | - Mitchell H Rosner
- Division of Nephrology, Center for Immunity, Inflammation and Regenerative Medicine, University of Virginia Health System, Charlottesville, VA
| | - Mark D Okusa
- Division of Nephrology, Center for Immunity, Inflammation and Regenerative Medicine, University of Virginia Health System, Charlottesville, VA.
| |
Collapse
|
73
|
Abstract
Per milligram of tissue, only the heart exceeds the kidney's abundance of mitochondria. Not surprisingly, renal mitochondria are most densely concentrated in the epithelium of the nephron, at sites where the chemical work of moving solutes against electrochemical gradients places large and constant demands for adenosine triphosphate. Derangements of renal epithelial mitochondria appear to be a hallmark for diverse forms of acute kidney injury (AKI). The pathogenesis of multiple-organ dysfunction syndrome in sepsis is complex, but a substantial body of experimental and observational human data supports the twin concepts that mitochondrial dysfunction contributes to impaired filtration and that recovery of mitochondrial structure and function is essential for recovery from sepsis-associated AKI. These insights have suggested novel methods to diagnose, stratify, prevent, or even treat this common and deadly complication of critical illness. This review will do the following: (1) describe the structure and functions of healthy mitochondria and how renal energy metabolism relates to solute transport; (2) provide an overview of the evidence linking mitochondrial pathology to renal disease; (3) summarize the mitochondrial lesions observed in septic AKI; (4) analyze the role of mitochondrial processes including fission/fusion, mitophagy, and biogenesis in the development of septic AKI and recovery from this disease; and (5) explore the potential for therapeutically targeting mitochondria to prevent or treat septic AKI.
Collapse
|
74
|
Gómez H, Jin K, Kellum JA. The Role of Energy Regulation in the Tubular Epithelial Cell Response to Sepsis. Nephron Clin Pract 2015; 131:255-8. [PMID: 26619116 DOI: 10.1159/000437278] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Accepted: 06/28/2015] [Indexed: 11/19/2022] Open
Abstract
Sepsis is considered today a major public health problem. Despite that mortality has been consistently associated with organ compromise, the mechanisms by which sepsis causes multiple organ dysfunction are not well understood, and hence, therapy remains reactive and non-specific. Recent studies have challenged previous paradigms by demonstrating that acute kidney injury can occur in the setting of a normal or an even increased renal blood flow, and that it is characterized by tubular injury and not by necrosis or apoptosis. This finding suggests that mechanisms other than hypoperfusion may be at play, and that adaptive responses of the tubular epithelial cell may be key to understanding the origin of organ dysfunction in the setting of sepsis. In this review, we discuss evidence suggesting that the activation of energy regulatory processes and mitochondrial quality control processes may not only be drivers of this response, but also be factors that may alter the course of organ dysfunction during sepsis in clinically relevant ways.
Collapse
Affiliation(s)
- Hernando Gómez
- Center for Critical Care Nephrology, The CRISMA Center, Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pa., USA
| | | | | |
Collapse
|
75
|
Gatticchi L, Bellezza I, Del Sordo R, Peirce MJ, Sidoni A, Roberti R, Minelli A. The Tm7sf2 Gene Deficiency Protects Mice against Endotoxin-Induced Acute Kidney Injury. PLoS One 2015; 10:e0141885. [PMID: 26540160 PMCID: PMC4635018 DOI: 10.1371/journal.pone.0141885] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2015] [Accepted: 10/14/2015] [Indexed: 12/18/2022] Open
Abstract
Cholesterol is essential for diverse cellular functions and cellular and whole-body cholesterol homeostasis is highly controlled. Cholesterol can also influence cellular susceptibility to injury. The connection between cholesterol metabolism and inflammation is exemplified by the Tm7sf2 gene, the absence of which reveals an essential role in cholesterol biosynthesis under stress conditions but also results in an inflammatory phenotype, i.e. NF-κB activation and TNFα up-regulation. Here, by using Tm7sf2+/+and Tm7sf2−/− mice, we investigated whether the Tm7sf2 gene, through its role in cholesterol biosynthesis under stress conditions, is involved in the renal failure induced by the administration of LPS. We found that the loss of Tm7sf2 gene results in significantly reduced blood urea nitrogen levels accompanied by decreased renal inflammatory response and neutral lipid accumulation. The increased expression of fatty acids catabolic enzymes reduces the need of the renal autophagy, a known crucial nutrient-sensing pathway in lipid metabolism. Moreover, we observed that the Tm7sf2 insufficiency is responsible for the inhibition of the NF-κB signalling thus dampening the inflammatory response and leading to a reduced renal damage. These results suggest a pivotal role for Tm7sf2 in renal inflammatory and lipotoxic response under endotoxemic conditions.
Collapse
Affiliation(s)
- Leonardo Gatticchi
- Department of Experimental Medicine, University of Perugia, Piazzale Gambuli, 06124 Perugia, Italy
| | - Ilaria Bellezza
- Department of Experimental Medicine, University of Perugia, Piazzale Gambuli, 06124 Perugia, Italy
| | - Rachele Del Sordo
- Department of Experimental Medicine, University of Perugia, Piazzale Gambuli, 06124 Perugia, Italy
| | - Matthew J. Peirce
- Department of Experimental Medicine, University of Perugia, Piazzale Gambuli, 06124 Perugia, Italy
| | - Angelo Sidoni
- Department of Experimental Medicine, University of Perugia, Piazzale Gambuli, 06124 Perugia, Italy
| | - Rita Roberti
- Department of Experimental Medicine, University of Perugia, Piazzale Gambuli, 06124 Perugia, Italy
| | - Alba Minelli
- Department of Experimental Medicine, University of Perugia, Piazzale Gambuli, 06124 Perugia, Italy
- * E-mail:
| |
Collapse
|
76
|
MOF maintains transcriptional programs regulating cellular stress response. Oncogene 2015; 35:2698-710. [PMID: 26387537 PMCID: PMC4893634 DOI: 10.1038/onc.2015.335] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2014] [Revised: 07/09/2015] [Accepted: 08/04/2015] [Indexed: 12/14/2022]
Abstract
MOF (MYST1, KAT8) is the major H4K16 lysine acetyltransferase (KAT) in Drosophila and mammals and is essential for embryonic development. However, little is known regarding the role of MOF in specific cell lineages. Here we analyze the differential role of MOF in proliferating and terminally differentiated tissues at steady state and under stress conditions. In proliferating cells, MOF directly binds and maintains the expression of genes required for cell cycle progression. In contrast, MOF is dispensable for terminally differentiated, postmitotic glomerular podocytes under physiological conditions. However, in response to injury, MOF is absolutely critical for podocyte maintenance in vivo. Consistently, we detect defective nuclear, endoplasmic reticulum and Golgi structures, as well as presence of multivesicular bodies in vivo in podocytes lacking Mof following injury. Undertaking genome-wide expression analysis of podocytes, we uncover several MOF-regulated pathways required for stress response. We find that MOF, along with the members of the non-specific lethal but not the male-specific lethal complex, directly binds to genes encoding the lysosome, endocytosis and vacuole pathways, which are known regulators of podocyte maintenance. Thus, our work identifies MOF as a key regulator of cellular stress response in glomerular podocytes.
Collapse
|
77
|
Sancho-Martínez SM, López-Novoa JM, López-Hernández FJ. Pathophysiological role of different tubular epithelial cell death modes in acute kidney injury. Clin Kidney J 2015; 8:548-59. [PMID: 26413280 PMCID: PMC4581387 DOI: 10.1093/ckj/sfv069] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2015] [Accepted: 06/30/2015] [Indexed: 12/14/2022] Open
Abstract
The histological substrate of many forms of intrinsic acute kidney injury (AKI) has been classically attributed to tubular necrosis. However, more recent studies indicate that necrosis is not the main form of cell death in AKI and that other forms such as apoptosis, regulated necrosis (i.e. necroptosis and parthanatos), autophagic cell death and mitotic catastrophe, also participate in AKI and that their contribution depends on the cause and stage of AKI. Herein, we briefly summarize the main characteristics of the major types of cell death and we also critically review the existing evidence on the occurrence of different types of cell death reported in the most common experimental models of AKI and human specimens. We also discuss the pathophysiological mechanisms linking tubule epithelial cell death with reduced glomerular filtration, azotaemia and hydroelectrolytic imbalance. For instance, special relevance is given to the analysis of the inflammatory component of some forms of cell death over that of others, as an important and differential pathophysiological determinant. Finally, known molecular mechanisms and signalling pathways involved in each cell death type pose appropriate targets to specifically prevent or reverse AKI, provided that further knowledge of their participation and repercussion in each AKI syndrome is progressively increased in the near future.
Collapse
Affiliation(s)
- Sandra M Sancho-Martínez
- Departamento de Fisiología y Farmacología , Universidad de Salamanca , Salamanca , Spain ; Instituto de Investigación Biomédica de Salamanca (IBSAL) , Salamanca , Spain ; Instituto Reina Sofía de Investigación Nefrológica, Fundación Iñigo Álvarez de Toledo , Madrid , Spain
| | - José M López-Novoa
- Departamento de Fisiología y Farmacología , Universidad de Salamanca , Salamanca , Spain ; Instituto de Investigación Biomédica de Salamanca (IBSAL) , Salamanca , Spain ; Instituto Reina Sofía de Investigación Nefrológica, Fundación Iñigo Álvarez de Toledo , Madrid , Spain ; Critical Care Biomedical Research Group (BioCritic) , Valladolid , Spain
| | - Francisco J López-Hernández
- Departamento de Fisiología y Farmacología , Universidad de Salamanca , Salamanca , Spain ; Instituto de Investigación Biomédica de Salamanca (IBSAL) , Salamanca , Spain ; Instituto Reina Sofía de Investigación Nefrológica, Fundación Iñigo Álvarez de Toledo , Madrid , Spain ; Critical Care Biomedical Research Group (BioCritic) , Valladolid , Spain ; Instituto de Estudios de Ciencias de la Salud de Castilla y León (IESCYL) , Salamanca , Spain
| |
Collapse
|
78
|
Patschan D, Schwarze K, Henze E, Patschan S, Müller GA. Endothelial autophagy and Endothelial-to-Mesenchymal Transition (EndoMT) in eEPC treatment of ischemic AKI. J Nephrol 2015; 29:637-44. [PMID: 26289253 PMCID: PMC5016542 DOI: 10.1007/s40620-015-0222-0] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2015] [Accepted: 07/24/2015] [Indexed: 01/08/2023]
Abstract
BACKGROUND Autophagy enables cells to digest endogenous/exogenous waste products, thus potentially prolonging the cellular lifespan. Early endothelial progenitor cells (eEPCs) protect mice from ischemic acute kidney injury (AKI). The mid-term prognosis in AKI critically depends on vascular rarefication and interstitial fibrosis with the latter partly being induced by mesenchymal transdifferentiation of endothelial cells (EndoMT). This study aimed to determine the impact of eEPC preconditioning with different autophagy inducing agents [suberoylanilide hydroxamic acid (SAHA)/temsirolimus] in ischemic AKI. METHODS Male C57/Bl6 N mice were subjected to bilateral renal ischemia (40 min). Animals were injected with either untreated, or SAHA- or temsirolimus-pretreated syngeneic murine eEPCs at the time of reperfusion. Mice were analyzed 48 h and 4 weeks later. In addition, cultured eEPCs were treated with transforming growth factor (TGF)-β ± SAHA, autophagy (perinuclear LC3-II), and stress-induced premature senescence (SIPS-senescence-associated β-galactosidase, SA-β-Gal), and were evaluated 96 h later. RESULTS Cultured eEPCs showed reduced perinuclear density of LC3-II + vesicles and elevated levels of SA-β-Gal after treatment with TGF-β alone, indicating impaired autophagy and aggravated SIPS. These effects were completely abrogated by SAHA. Systemic administration of either SAHA or tems pretreated eEPCs resulted in elevated intrarenal endothelial p62 at 48 h and 4 weeks, indicating stimulated endothelial autophagy. This effect was most pronounced after injection of SAHA-treated eEPCs. At 4 weeks endothelial expression of mesenchymal alpha-smooth muscle actin (αSMA) was reduced in animals receiving untreated and SAHA-pretreated cells. In addition, SAHA-treated cells reduced fibrosis at week 4. Tems in contrast aggravated EndoMT. Postischemic renal function declined after renal ischemia and remained unaffected in all experimental cell treatment groups. CONCLUSION In ischemic AKI, intrarenal endothelial autophagy may be stabilized by systemic administration of pharmacologically preconditioned eEPCs. Early EPCs can reduce postischemic EndoMT and fibrosis in the mid-term. Autophagy induction in eEPCs either increases or decreases the mesenchymal properties of intrarenal endothelial cells, depending on the substance being used. Thus, endothelial autophagy induction in ischemic AKI, mediated by eEPCs is not a renoprotective event per se.
Collapse
Affiliation(s)
- Daniel Patschan
- Clinic of Nephrology and Rheumatology, University Medical Center of Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Germany.
| | - Katrin Schwarze
- Clinic of Nephrology and Rheumatology, University Medical Center of Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Germany
| | - Elvira Henze
- Clinic of Nephrology and Rheumatology, University Medical Center of Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Germany
| | - Susann Patschan
- Clinic of Nephrology and Rheumatology, University Medical Center of Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Germany
| | - Gerhard Anton Müller
- Clinic of Nephrology and Rheumatology, University Medical Center of Göttingen, Robert-Koch-Straße 40, 37075, Göttingen, Germany
| |
Collapse
|
79
|
Liu WJ, Shen TT, Chen RH, Wu HL, Wang YJ, Deng JK, Chen QH, Pan Q, Huang Fu CM, Tao JL, Liang D, Liu HF. Autophagy-Lysosome Pathway in Renal Tubular Epithelial Cells Is Disrupted by Advanced Glycation End Products in Diabetic Nephropathy. J Biol Chem 2015; 290:20499-510. [PMID: 26100632 DOI: 10.1074/jbc.m115.666354] [Citation(s) in RCA: 89] [Impact Index Per Article: 9.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2015] [Indexed: 12/16/2022] Open
Abstract
It has been suggested that autophagy protects renal tubular epithelial cells (TECs) from injury in diabetic nephropathy (DN). However, the manner in which the autophagy-lysosome pathway is changed in this state remains unclear. In this study of DN, we investigated the autophagic activity and lysosomal alterations in vivo and in vitro. We found that autophagic vacuoles and SQSTM1-positive proteins accumulated in TECs from patients with DN and in human renal tubular epithelial cell line (HK-2 cells) treated with advanced glycation end products (AGEs), the important factors that involved in the pathogenesis of DN. In HK-2 cells, exposure to AGEs caused a significant increase in autophagosomes but a marked decrease in autolysosomes, and the lysosomal turnover of LC3-II was not observed, although LC3-II puncta were co-localized with the irregular lysosomal-associated membrane protein1 granules after AGEs treatment. Furthermore, lysosomal membrane permeabilization was triggered by AGEs, which likely resulted in a decrease in the enzymatic activities of cathepsin B and cathepsin L, the defective acidification of lysosomes, and suppression of the lysosomal degradation of DQ-ovalbumin. Oxidative stress evoked by AGEs-receptor for AGE interaction likely played an important role in the lysosomal dysfunction. Additionally, ubiquitinated proteins were co-localized with SQSTM1-positive puncta and accumulated in HK-2 cells after exposure to AGEs, indicating blocked degradation of SQSTM1-positive and ubiquitinated aggregates. Taken together, the results show that lysosomal membrane permeabilization and lysosomal dysfunction are triggered by AGEs, which induce autophagic inactivation in TECs from patients with DN. Disruption of the autophagy-lysosome pathway should be focused when studying the mechanisms underlying DN.
Collapse
Affiliation(s)
- Wei Jing Liu
- From the Institute of Nephrology, Guangdong Medical College, Zhanjiang, Guangdong 524001, China
| | - Ting Ting Shen
- From the Institute of Nephrology, Guangdong Medical College, Zhanjiang, Guangdong 524001, China
| | - Rui Hong Chen
- From the Institute of Nephrology, Guangdong Medical College, Zhanjiang, Guangdong 524001, China
| | - Hong-Luan Wu
- From the Institute of Nephrology, Guangdong Medical College, Zhanjiang, Guangdong 524001, China
| | - Yan Jin Wang
- From the Institute of Nephrology, Guangdong Medical College, Zhanjiang, Guangdong 524001, China
| | - Jian Kun Deng
- From the Institute of Nephrology, Guangdong Medical College, Zhanjiang, Guangdong 524001, China
| | - Qiu Hua Chen
- From the Institute of Nephrology, Guangdong Medical College, Zhanjiang, Guangdong 524001, China
| | - Qingjun Pan
- From the Institute of Nephrology, Guangdong Medical College, Zhanjiang, Guangdong 524001, China
| | - Chang-mei Huang Fu
- From the Institute of Nephrology, Guangdong Medical College, Zhanjiang, Guangdong 524001, China
| | - Jing-li Tao
- From the Institute of Nephrology, Guangdong Medical College, Zhanjiang, Guangdong 524001, China
| | - Dong Liang
- From the Institute of Nephrology, Guangdong Medical College, Zhanjiang, Guangdong 524001, China
| | - Hua-feng Liu
- From the Institute of Nephrology, Guangdong Medical College, Zhanjiang, Guangdong 524001, China
| |
Collapse
|
80
|
Lu XM, Ma L, Jin YN, Yu YQ. Lumican overexpression exacerbates lipopolysaccharide-induced renal injury in mice. Mol Med Rep 2015; 12:4089-4094. [PMID: 26081832 PMCID: PMC4526055 DOI: 10.3892/mmr.2015.3940] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2014] [Accepted: 04/14/2015] [Indexed: 12/29/2022] Open
Abstract
The present study aimed to investigate the role of lumican in mice with endotoxin-induced acute renal failure (ARF). Lumican transgenic mice and wild-type mice were injected with lipopolysaccharide (LPS; 10 mg/kg) to establish a model of ARF. The mice were sacrificed at 24 h and the blood and renal tissue samples were collected. The value of serum creatinine (SCr) and blood urea nitrogen (BUN) were measured to determine renal function. An ELISA was used to determined the concentrations of renal cytokines, including tumor necrosis factor (TNF)α, interleukin (IL)-6, IL-4 and IL-10. The protein expression levels of Toll-like receptor (TLR4) and nuclear factor (NF)κB in renal tissues were assessed using western blot analysis. Terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling was performed to monitor apoptosis of renal tissue. Light microscopy and electron microscopy were used to observe structural changes in the renal tissues. Following the administration of LPS, the SCr and BUN values of mice in the lumican transgenic group were higher compared with those in the control group. The expression levels of renal TLR4, NFκB, TNFα, IL-6, IL-4 and IL-10 were upregulated in the lumican transgenic mice compared with those in the wild-type control group. Apoptosis was detected predominantly on the renal tubule. There was a significant difference in the optical density of apoptotic bodies between the control mice and the lumican transgenic mice. Light and electron microscopy demonstrated more severe renal tissue injury in the lumican transgenic mice compared with that in the control mice. In conclusion, LPS may cause excessive apoptosis in the renal tubular cells via the TLR4 signal transduction pathway, a decrease in the number of renal tubular cells and ARF. Lumican may be important in mice with LPS-induced ARF.
Collapse
Affiliation(s)
- Xiao-Mei Lu
- Department of Pathophysiology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Ling Ma
- Department of Pathophysiology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Yu-Nan Jin
- Department of Pathophysiology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning 110001, P.R. China
| | - Yan-Qiu Yu
- Department of Pathophysiology, College of Basic Medical Sciences, China Medical University, Shenyang, Liaoning 110001, P.R. China
| |
Collapse
|
81
|
Su Y, Qu Y, Zhao F, Li H, Mu D, Li X. Regulation of autophagy by the nuclear factor κB signaling pathway in the hippocampus of rats with sepsis. J Neuroinflammation 2015; 12:116. [PMID: 26067996 PMCID: PMC4472259 DOI: 10.1186/s12974-015-0336-2] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 06/03/2015] [Indexed: 11/18/2022] Open
Abstract
BACKGROUND Sepsis with brain dysfunction has contributed to an increase risk of morbidity and mortality. In its pathophysiology, both autophagy and nuclear factor κB (NF-κB) have been suggested to play important roles. Based on the fact that crosstalk between autophagy and NF-κB, two stress-response signaling pathways, has been detected in other pathophysiological processes, this study was undertaken to explore the process of autophagy in the hippocampus of septic rats and the role NF-κB plays in the regulation of autophagy during the process. METHODS Cecal ligation and puncture (CLP) or a sham operation was conducted on male Wistar rats. Pyrrolidine dithiocarbamate (PDTC), an inhibitor of the NF-κB signaling pathway, or a vehicle control, was used to treat with the rats 2 h before the CLP operation. Hematoxylin-eosin staining and biological signal recording was used to measure the morphological and physiological signs of hippocampal dysfunction. An electron microscope was used to observe autophagosome formation and lysosome activation in the hippocampus after CLP. Western blotting and immune histochemistry were used to detect the hippocampus levels of NF-κB and essential proteins involved in formation of the autophagosome (microtubule-associated protein light chain 3 (LC3), Beclin1, Lamp-1, and Rab7). RESULTS Compared with sham-operated rats, the CLP rats showed decreasing mean arterial pressure (MAP), increasing heart rate (HR), and pathological histological changes. CLP rats exhibited not only increased vacuolization through electron micrographs but also increased LC3-II, decreased Beclin1, LAMP-1, and Rab7 through the immunofluorescence and Western blot. However, PDTC + CLP rats revealed that inhibition of the NF-κB signal axis by PDTC increased the levels of LC3-II, Beclin1, LAMP-1, and Rab7 and improved physiological function including blood pressure and heart rate. CONCLUSIONS The autophagy process during the hippocampus of CLP rats might be blocked by the activation of NF-κB signaling pathway. Inhibition of NF-κB signaling pathway could enhance the completion of autophagy with a neuroprotective function in septic brains.
Collapse
Affiliation(s)
- YunJie Su
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, 610041, China.
| | - Yi Qu
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, 610041, China. .,Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University, Chengdu, 610041, China.
| | - FengYan Zhao
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, 610041, China. .,Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University, Chengdu, 610041, China.
| | - HuaFeng Li
- Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University, Chengdu, 610041, China. .,Department of Anesthesiology, West China Second University Hospital, Sichuan University, Chengdu, 610041, China.
| | - DeZhi Mu
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, 610041, China. .,Key Laboratory of Obstetric and Gynecologic and Pediatric Diseases and Birth Defects of Ministry of Education, Sichuan University, Chengdu, 610041, China. .,Department of Pediatrics and Neurology, University of California, San Francisco, CA, 94143, USA.
| | - XiHong Li
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, 610041, China.
| |
Collapse
|
82
|
Tilija Pun N, Subedi A, Kim MJ, Park PH. Globular Adiponectin Causes Tolerance to LPS-Induced TNF-α Expression via Autophagy Induction in RAW 264.7 Macrophages: Involvement of SIRT1/FoxO3A Axis. PLoS One 2015; 10:e0124636. [PMID: 25961287 PMCID: PMC4427353 DOI: 10.1371/journal.pone.0124636] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2014] [Accepted: 03/17/2015] [Indexed: 02/07/2023] Open
Abstract
Adiponectin, an adipokine predominantly produced from adipose tissue, exhibited potent anti-inflammatory properties. In particular, it inhibits production of pro-inflammatory cytokines, including tumor necrosis factor-α (TNF-α), in macrophages. Autophagy, an intracellular self-digestion process, has been recently shown to regulate inflammatory responses. In the present study, we investigated the role of autophagy induction in the suppression of Lipopolysaccharide (LPS) -induced TNF-α expression by globular adiponectin (gAcrp) and its potential mechanisms. Herein, we found that gAcrp treatment increased expression of genes related with autophagy, including Atg5 and microtubule-associated protein light chain (LC3B), induced autophagosome formation and autophagy flux in RAW 264.7 macrophages. Similar results were observed in primary macrophages isolated peritoneum of mice. Interestingly, inhibition of autophagy by pretreatment with Bafilomycin A1 or knocking down of LC3B gene restored suppression of TNF-α expression, tumor necrosis factor receptor- associated factor 6 (TRAF6) expression and p38MAPK phosphorylation by gAcrp, implying a critical role of autophagy induction in the development of tolerance to LPS-induced TNF-α expression by gAcrp. We also found that knocking-down of FoxO3A, a forkhead box O member of transcription factor, blocked gAcrp-induced expression of LC3II and Atg5. Moreover, gene silencing of Silent information regulator 1 (SIRT1) blocked both gAcrp-induced nuclear translocation of FoxO3A and LC3II expression. Finally, pretreatment with ROS inhibitors, prevented gAcrp-induced SIRT1 expression and further generated inhibitory effects on gAcrp-induced autophagy, indicating a role of ROS production in gAcrp-induced SIRT1 expression and subsequent autophagy induction. Taken together, these findings indicate that globular adiponectin suppresses LPS-induced TNF-α expression, at least in part, via autophagy activation. Furthermore, SIRT1-FoxO3A axis plays a crucial role in gAcrp-induced autophagy in macrophages.
Collapse
Affiliation(s)
- Nirmala Tilija Pun
- College of Pharmacy, Yeungnam University, Gyeongsan, Gyeongsangbuk-do 712–749, Republic of Korea
| | - Amit Subedi
- College of Pharmacy, Yeungnam University, Gyeongsan, Gyeongsangbuk-do 712–749, Republic of Korea
| | - Mi Jin Kim
- College of Pharmacy, Yeungnam University, Gyeongsan, Gyeongsangbuk-do 712–749, Republic of Korea
| | - Pil-Hoon Park
- College of Pharmacy, Yeungnam University, Gyeongsan, Gyeongsangbuk-do 712–749, Republic of Korea
- * E-mail:
| |
Collapse
|
83
|
Nakano D, Doi K, Kitamura H, Kuwabara T, Mori K, Mukoyama M, Nishiyama A. Reduction of Tubular Flow Rate as a Mechanism of Oliguria in the Early Phase of Endotoxemia Revealed by Intravital Imaging. J Am Soc Nephrol 2015; 26:3035-44. [PMID: 25855781 DOI: 10.1681/asn.2014060577] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2014] [Accepted: 02/08/2015] [Indexed: 12/13/2022] Open
Abstract
Urine output is widely used as a criterion for the diagnosis of AKI. Although several potential mechanisms of septic AKI have been identified, regulation of urine flow after glomerular filtration has not been evaluated. This study evaluated changes in urine flow in mice with septic AKI. The intratubular urine flow rate was monitored in real time by intravital imaging using two-photon laser microscopy. The tubular flow rate, as measured by freely filtered dye (FITC-inulin or Lucifer yellow), time-dependently declined after LPS injection. At 2 hours, the tubular flow rate was slower in mice injected with LPS than in mice injected with saline, whereas BP and GFR were similar in the two groups. Importantly, fluorophore-conjugated LPS selectively accumulated in the proximal tubules that showed reduced tubular flow at 2 hours and luminal obstruction with cell swelling at 24 hours. Delipidation of LPS or deletion of Toll-like receptor 4 in mice abolished these effects, whereas neutralization of TNF-α had little effect on LPS-induced tubular flow retention. Rapid intravenous fluid resuscitation within 6 hours improved the tubular flow rate only when accompanied by the dilation of obstructed proximal tubules with accumulated LPS. These findings suggest that LPS reduces the intratubular urine flow rate during early phases of endotoxemia through a Toll-like receptor 4-dependent mechanism, and that the efficacy of fluid resuscitation may depend on the response of tubules with LPS accumulation.
Collapse
Affiliation(s)
| | - Kent Doi
- Department of Emergency and Critical Care Medicine, University Hospital, University of Tokyo, Tokyo; and
| | | | | | - Kiyoshi Mori
- Medical Innovation Center, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | | | | |
Collapse
|
84
|
Sureshbabu A, Ryter SW, Choi ME. Oxidative stress and autophagy: crucial modulators of kidney injury. Redox Biol 2015; 4:208-14. [PMID: 25613291 PMCID: PMC4803795 DOI: 10.1016/j.redox.2015.01.001] [Citation(s) in RCA: 242] [Impact Index Per Article: 26.9] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 12/31/2014] [Accepted: 01/01/2015] [Indexed: 12/21/2022] Open
Abstract
Both acute kidney injury (AKI) and chronic kidney disease (CKD) that lead to diminished kidney function are interdependent risk factors for increased mortality. If untreated over time, end stage renal disease (ESRD) is an inevitable outcome. Acute and chronic kidney diseases occur partly due to imbalance between the molecular mechanisms that govern oxidative stress, inflammation, autophagy and cell death. Oxidative stress refers to the cumulative effects of highly reactive oxidizing molecules that cause cellular damage. Autophagy removes damaged organelles, protein aggregates and pathogens by recruiting these substrates into double membrane vesicles called autophagosomes which subsequently fuse with lysosomes. Mounting evidence suggests that both oxidative stress and autophagy are significantly involved in kidney health and disease. However, very little is known about the signaling processes that link them. This review is focused on understanding the role of oxidative stress and autophagy in kidney diseases. In this review, we also discuss the potential relationships between oxidative stress and autophagy that may enable the development of better therapeutic intervention to halt the progression of kidney disease and promote its repair and resolution. The molecular mechanisms underlying the regulation of oxidative stress responses and autophagy may exhibit considerable cross-talk. The autophagy pathway may be regulated in the context of kidney diseases. Failure or disruption of the autophagy pathway may contribute to the pathogenesis of kidney diseases. Targeting the autophagy pathway may show considerable therapeutic potential in the treatment and management of kidney disorders.
Collapse
Affiliation(s)
- Angara Sureshbabu
- Joan and Sanford I. Weill Department of Medicine, New York-Presbyterian Hospital, Weill Cornell Medical College, New York, NY, USA
| | - Stefan W Ryter
- Joan and Sanford I. Weill Department of Medicine, New York-Presbyterian Hospital, Weill Cornell Medical College, New York, NY, USA
| | - Mary E Choi
- Joan and Sanford I. Weill Department of Medicine, New York-Presbyterian Hospital, Weill Cornell Medical College, New York, NY, USA.
| |
Collapse
|
85
|
Wu Y, Zhang Y, Wang L, Diao Z, Liu W. The Role of Autophagy in Kidney Inflammatory Injury via the NF-κB Route Induced by LPS. Int J Med Sci 2015; 12:655-67. [PMID: 26283886 PMCID: PMC4532974 DOI: 10.7150/ijms.12460] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Accepted: 07/14/2015] [Indexed: 01/13/2023] Open
Abstract
Acute kidney injury (AKI) is a systemic inflammatory response syndrome associated with poor clinical outcomes. No treatments effective for AKI are currently available. Thus, there is an urgent need of development of treatments effective for AKI. Autophagy, an intracellular proteolytic system, is induced in renal cells during AKI. However, whether autophagy is protective or injurious for AKI needs to be clearly clarified. We addressed this question by pharmacological inhibition of autophagy using a mouse model of lipopolysaccharide (LPS) induced-AKI. We found that autophagy was induced in renal cortex of mice during LPS-induced AKI as reflected by a dose-and time-dependent increased accumulation of light chain 3-II (LC3-II), the common marker of autophagy, compared to that of control group; 2) the occurrence of intensive, punctate and increased immunohistochemical staining image of LC3-II in renal cortex; 3) the significant increase in the expression levels of Beclin-1, another key marker of autophagy; 4) the significantly increased levels of plasma urea and serum creatinine and 5) the significant increase in autophagagosome area ratio. We observed that 3-methyladenine (3-MA), a pharmacological inhibitor of autophagy, blocked autophagy flux, alleviated AKI and protected against LPS-induced AKI. LPS triggered kidney inflammation by activation of the canonical NF-κB pathway. This route can be modulated by autophagy. Activation of the canonical NF-κB pathway was reduced in 3-MA+LPS as compared to that in LPS-treated group of mice. Mice pretreated with 3-MA before exposure to LPS showed a reduction in p65 phosphorylation, resulting in the accumulation of ubiquitinated IκB. In conclusion, impairment of autophagy ameliorates LPS-induced inflammation and decreases kidney injury. The accumulation of ubiquitinated IκB may be responsible for this effect.
Collapse
Affiliation(s)
- Yu Wu
- 1. Department of Nephrology, Beijing Friendship Hospital, Capital Medical University, No. 95 Yong An Road, Xi Cheng District, Beijing 100050, China ; 2. Department of Nephrology, The First People's Hospital of Xuzhou, No. 19 Zhongshan North Road, Xuzhou 221002, Jiangsu, China
| | - Yang Zhang
- 3. Department of Anesthesiology, Xuzhou Medical College, Xuzhou 221004, Jiangsu, China
| | - Ling Wang
- 2. Department of Nephrology, The First People's Hospital of Xuzhou, No. 19 Zhongshan North Road, Xuzhou 221002, Jiangsu, China
| | - Zongli Diao
- 1. Department of Nephrology, Beijing Friendship Hospital, Capital Medical University, No. 95 Yong An Road, Xi Cheng District, Beijing 100050, China
| | - Wenhu Liu
- 1. Department of Nephrology, Beijing Friendship Hospital, Capital Medical University, No. 95 Yong An Road, Xi Cheng District, Beijing 100050, China
| |
Collapse
|
86
|
Fougeray S, Pallet N. Mechanisms and biological functions of autophagy in diseased and ageing kidneys. Nat Rev Nephrol 2014; 11:34-45. [PMID: 25385287 DOI: 10.1038/nrneph.2014.201] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Autophagy degrades pathogens, altered organelles and protein aggregates, and is characterized by the sequestration of cytoplasmic cargos within double-membrane-limited vesicles called autophagosomes. The process is regulated by inputs from the cellular microenvironment, and is activated in response to nutrient scarcity and immune triggers, which signal through a complex molecular network. Activation of autophagy leads to the formation of an isolation membrane, recognition of cytoplasmic cargos, expansion of the autophagosomal membrane, fusion with lysosomes and degradation of the autophagosome and its contents. Autophagy maintains cellular homeostasis during stressful conditions, dampens inflammation and shapes adaptive immunity. A growing body of evidence has implicated autophagy in kidney health, ageing and disease; it modulates tissue responses during acute kidney injuries, regulates podocyte homeostasis and protects against age-related renal disorders. The renoprotective functions of autophagy in epithelial renal cells and podocytes are mostly mediated by the clearance of altered mitochondria, which can activate inflammasomes and apoptosis, and the removal of protein aggregates, which might trigger inflammation and cell death. In translational terms, autophagy is undoubtedly an attractive target for developing new renoprotective treatments and identifying markers of kidney injury.
Collapse
Affiliation(s)
- Sophie Fougeray
- Departments of Medicine, Microbiology and Immunology, The Research Institute of the McGill University Health Center, 2155 Guy Street, Montreal, QC H3H 2R9, Canada
| | - Nicolas Pallet
- Service de Biochimie, Hôpital Européen Georges Pompidou, Assistance Publique-Hôpitaux de Paris, 20 Rue Leblanc, 75015 Paris, France
| |
Collapse
|
87
|
Escobar DA, Botero-Quintero AM, Kautza BC, Luciano J, Loughran P, Darwiche S, Rosengart MR, Zuckerbraun BS, Gomez H. Adenosine monophosphate-activated protein kinase activation protects against sepsis-induced organ injury and inflammation. J Surg Res 2014; 194:262-72. [PMID: 25456115 DOI: 10.1016/j.jss.2014.10.009] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2014] [Revised: 09/18/2014] [Accepted: 10/03/2014] [Indexed: 01/20/2023]
Abstract
BACKGROUND Mortality in sepsis is most often attributed to the development of multiple organ failure. In sepsis, inflammation-mediated endothelial activation, defined as a proinflammatory and procoagulant state of the endothelial cells, has been associated with severity of disease. Thus, the objective of this study was to test the hypothesis that adenosine monophosphate-activated protein kinase (AMPK) activation limits inflammation and endothelium activation to protect against organ injury in sepsis. 5-aminoimidazole-4-carboxamide ribonucleotide (AICAR), which is an adenosine monophosphate analog, has been used to upregulate activity of AMPK. Compound C is a cell-permeable pyrrazolopyrimidine compound that inhibits AMPK activity. METHODS Wild-type mice underwent cecal ligation and puncture (CLP) or sham surgery. Mice were randomized to vehicle, AICAR, or compound C. Mouse kidney endothelial cells were used for in vitro experiments. Renal and liver function were determined by serum cystatin C, blood urea nitrogen (BUN), creatinine, and alanine aminotransferase. Serum cytokines were measured by enzyme-linked immunosorbent assay. Microvascular injury was determined using Evans blue dye and electron microscopy. Immunohistochemistry was used to measure protein levels of phospho-AMPK (p-AMPK), microtubule-associated protein 1A/1B-light chain 3 (LC3), and intracellular adhesion molecule. LC3 levels were used as a measure of autophagosome formation. RESULTS AICAR decreased liver and kidney injury induced by CLP and minimized cytokine elevation in vivo and in vitro. CLP increased renal and hepatic phosphorylation of AMPK and autophagic signaling as determined by LC3. Inhibition of AMPK with compound C prevented CLP-induced autophagy and exacerbated tissue injury. Additionally, CLP led to endothelial injury as determined by electron microscopy and Evans blue dye extravasation, and AICAR limited this injury. Furthermore, AICAR limited CLP and lipopolysaccharide (LPS)-induced upregulation of intracellular adhesion molecule in vivo and in vitro and decreased LPS-induced neutrophil adhesion in vitro. CONCLUSIONS In this model, activation of AMPK was protective, and AICAR minimized organ injury by decreasing inflammatory cytokines and endothelial activation. These data suggest that AMPK signaling influences sepsis or LPS-induced endothelial activation and organ injury.
Collapse
Affiliation(s)
- Daniel A Escobar
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
| | | | - Benjamin C Kautza
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Jason Luciano
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Patricia Loughran
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Sophie Darwiche
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Matthew R Rosengart
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania; Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Brian S Zuckerbraun
- Department of Surgery, University of Pittsburgh, Pittsburgh, Pennsylvania; Department of Surgery, VA Pittsburgh Healthcare System, University of Pittsburgh, Pittsburgh, Pennsylvania; Center for Critical Care Nephrology, Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania
| | - Hernando Gomez
- Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania; Center for Critical Care Nephrology, Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania.
| |
Collapse
|
88
|
The aging kidney: increased susceptibility to nephrotoxicity. Int J Mol Sci 2014; 15:15358-76. [PMID: 25257519 PMCID: PMC4200815 DOI: 10.3390/ijms150915358] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Revised: 08/12/2014] [Accepted: 08/18/2014] [Indexed: 12/13/2022] Open
Abstract
Three decades have passed since a series of studies indicated that the aging kidney was characterized by increased susceptibility to nephrotoxic injury. Data from these experimental models is strengthened by clinical data demonstrating that the aging population has an increased incidence and severity of acute kidney injury (AKI). Since then a number of studies have focused on age-dependent alterations in pathways that predispose the kidney to acute insult. This review will focus on the mechanisms that are altered by aging in the kidney that may increase susceptibility to injury, including hemodynamics, oxidative stress, apoptosis, autophagy, inflammation and decreased repair.
Collapse
|
89
|
A unified theory of sepsis-induced acute kidney injury: inflammation, microcirculatory dysfunction, bioenergetics, and the tubular cell adaptation to injury. Shock 2014; 41:3-11. [PMID: 24346647 DOI: 10.1097/shk.0000000000000052] [Citation(s) in RCA: 516] [Impact Index Per Article: 51.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Given that the leading clinical conditions associated with acute kidney injury (AKI), namely, sepsis, major surgery, heart failure, and hypovolemia, are all associated with shock, it is tempting to attribute all AKI to ischemia on the basis of macrohemodynamic changes. However, an increasing body of evidence has suggested that in many patients, AKI can occur in the absence of overt signs of global renal hypoperfusion. Indeed, sepsis-induced AKI can occur in the setting of normal or even increased renal blood flow. Accordingly, renal injury may not be entirely explained solely on the basis of the classic paradigm of hypoperfusion, and thus other mechanisms must come into play. Herein, we put forward a "unifying theory" to explain the interplay between inflammation and oxidative stress, microvascular dysfunction, and the adaptive response of the tubular epithelial cell to the septic insult. We propose that this response is mostly adaptive in origin, that it is driven by mitochondria, and that it ultimately results in and explains the clinical phenotype of sepsis-induced AKI.
Collapse
|
90
|
Zhang X, Howell GM, Guo L, Collage RD, Loughran PA, Zuckerbraun BS, Rosengart MR. CaMKIV-dependent preservation of mTOR expression is required for autophagy during lipopolysaccharide-induced inflammation and acute kidney injury. THE JOURNAL OF IMMUNOLOGY 2014; 193:2405-15. [PMID: 25070845 DOI: 10.4049/jimmunol.1302798] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Autophagy, an evolutionarily conserved homeostasis process regulating biomass quantity and quality, plays a critical role in the host response to sepsis. Recent studies show its calcium dependence, but the calcium-sensitive regulatory cascades have not been defined. In this study, we describe a novel mechanism in which calcium/calmodulin-dependent protein kinase IV (CaMKIV), through inhibitory serine phosphorylation of GSK-3β and inhibition of FBXW7 recruitment, prevents ubiquitin proteosomal degradation of mammalian target of rapamycin (mTOR) and thereby augments autophagy in both the macrophage and the kidney. Under the conditions of sepsis studied, mTOR expression and activity were requisite for autophagy, a paradigm countering the current perspective that prototypically, mTOR inhibition induces autophagy. CaMKIV-mTOR-dependent autophagy was fundamentally important for IL-6 production in vitro and in vivo. Similar mechanisms were operant in the kidney during endotoxemia and served a cytoprotective role in mitigating acute kidney injury. Thus, CaMKIV-mTOR-dependent autophagy is conserved in both immune and nonimmune/parenchymal cells and is fundamental for the respective functional and adaptive responses to septic insult.
Collapse
Affiliation(s)
- Xianghong Zhang
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213
| | - Gina M Howell
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213
| | - Lanping Guo
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213
| | - Richard D Collage
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213
| | - Patricia A Loughran
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213; Department of Cell Biology, University of Pittsburgh, Pittsburgh, PA 15213; and
| | | | - Matthew R Rosengart
- Department of Surgery, University of Pittsburgh, Pittsburgh, PA 15213; Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, PA 15213
| |
Collapse
|
91
|
Yang CC, Yao CA, Yang JC, Chien CT. Sialic acid rescues repurified lipopolysaccharide-induced acute renal failure via inhibiting TLR4/PKC/gp91-mediated endoplasmic reticulum stress, apoptosis, autophagy, and pyroptosis signaling. Toxicol Sci 2014; 141:155-65. [PMID: 24973090 DOI: 10.1093/toxsci/kfu121] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Lipopolysaccharides (LPS) through Toll-like receptor 2 (TLR2) and Toll-like receptor 4 (TLR4) activation induce systemic inflammation where oxidative damage plays a key role in multiple organ failure. Because of the neutralization of LPS toxicity by sialic acid (SA), we determined its effect and mechanisms on repurified LPS (rLPS)-evoked acute renal failure. We assessed the effect of intravenous SA (10 mg/kg body weight) on rLPS-induced renal injury in female Wistar rats by evaluating blood and kidney reactive oxygen species (ROS) responses, renal and systemic hemodynamics, renal function, histopathology, and molecular mechanisms. SA can interact with rLPS through a high binding affinity. rLPS dose- and time-dependently reduced arterial blood pressure, renal microcirculation and blood flow, and increased vascular resistance in the rats. rLPS enhanced monocyte/macrophage (ED-1) infiltration and ROS production and impaired kidneys by triggering p-IRE1α/p-JNK/CHOP/GRP78/ATF4-mediated endoplasmic reticulum (ER) stress, Bax/PARP-mediated apoptosis, Beclin-1/Atg5-Atg12/LC3-II-mediated autophagy, and caspase 1/IL-1β-mediated pyroptosis in the kidneys. SA treatment at 30 min, but not 60 min after rLPS stimulation, gp91 siRNA and protein kinase C-α (PKC) inhibitor efficiently rescued rLPS-induced acute renal failure via inhibition of TLR4/PKC/NADPH oxidase gp91-mediated ER stress, apoptosis, autophagy and pyroptosis in renal proximal tubular cells, and rat kidneys. In response to rLPS or IFNγ, the enhanced Atg5, FADD, LC3-II, and PARP expression can be inhibited by Atg5 siRNA. Albumin (10 mg/kg body weight) did not rescue rLPS-induced injury. In conclusion, early treatment (within 30 min) of SA attenuates rLPS-induced renal failure via the reduction in LPS toxicity and subsequently inhibiting rLPS-activated TLR4/PKC/gp91/ER stress/apoptosis/autophagy/pyroptosis signaling.
Collapse
Affiliation(s)
- Chih-Ching Yang
- Department of Internal Medicine, National Yang-Ming University, Taipei 11221, Taiwan Department of Family Medicine, National Taiwan University Hospital and College of Medicine, Taipei, Taiwan
| | - Chien-An Yao
- National Taiwan University Hospital and College of Medicine, Taipei 10016, Taiwan
| | - Jyh-Chin Yang
- Department of Life Science, National Taiwan Normal University, Taipei 11677, Taiwan
| | - Chiang-Ting Chien
- Department of Planning, Ministry of Health and Welfare, Executive Yuan, Taipei 11558, Taiwan
| |
Collapse
|