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Tang L, Zhang J, Han J, Zhang D, Zhang H, Liu J, Li X. Molecular mechanism of circHIPK3 in mitochondrial function in septic acute kidney injury. ENVIRONMENTAL TOXICOLOGY 2024; 39:2596-2609. [PMID: 38205898 DOI: 10.1002/tox.24127] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 11/20/2023] [Accepted: 12/25/2023] [Indexed: 01/12/2024]
Abstract
Cell senescence, glycolysis, and mitochondrial deficit jointly regulate the development of septic acute kidney injury (SAKI). This study aimed to explore the role of circular RNA HIPK3 (circHIPK3) in mitochondrial function in SAKI. The SAKI mouse model was established by Candida albicans infection, followed by Western blot assay, measurements of serum lactate, and adenosine triphosphate (ATP), 5,5',6,6'-tetrachloro-1,1',3,3'-tetraethylbenzimi-dazolylcarbocyanine iodide (JC-1) staining and flow cytometry. Human renal tubular epithelial cells were treated with lipopolysaccharide to establish the SAKI cell model, followed by cell counting kit-8 assay, tests of hexokinase activity, lactate production, oxygen consumption rate, extracellular acidification rate, ATP, and JC-1 staining, and Western blot assay. The roles of mitochondrial pyruvate carrier 1 (MPC1) were validated by kidney function tests, hematoxylin and eosin staining, periodic acid-Schiff staining, and SA-β-gal staining. circHIPK3 downregulation reduced glycolysis and mitochondrial dysfunction both in vivo and in vitro through the microRNA (miR)-148b-3p/DNMT1/3a/Klotho axis. Inhibition of miR-148b-3p or Klotho increased glycolysis and mitochondrial dysfunction. Knockdown of MPC1 increased lactate content and decreased ATP levels and MMP both in vivo and in vitro. Collectively, circHIPK3, in concert with the miR-148b-3p/DNMT1/3a/Klotho axis, increased glycolysis, and inhibited the negative regulation of lactate production by MPC1, and aggravated mitochondrial dysfunction and cell senescence in SAKI.
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Affiliation(s)
- Lili Tang
- Department of Critical Care Medicine, The Fifth Affiliated Hospital (Zhuhai) of Zunyi Medical University, Zhuhai, People's Republic of China
- Department of Emergency, The Fifth Affiliated Hospital (Zhuhai) of Zunyi Medical University, Zhuhai, People's Republic of China
| | - Jie Zhang
- Department of Critical Care Medicine, The Fifth Affiliated Hospital (Zhuhai) of Zunyi Medical University, Zhuhai, People's Republic of China
- Department of Emergency, The Fifth Affiliated Hospital (Zhuhai) of Zunyi Medical University, Zhuhai, People's Republic of China
| | - Jing Han
- Department of Critical Care Medicine, The Fifth Affiliated Hospital (Zhuhai) of Zunyi Medical University, Zhuhai, People's Republic of China
- Department of Emergency, The Fifth Affiliated Hospital (Zhuhai) of Zunyi Medical University, Zhuhai, People's Republic of China
| | - Danhong Zhang
- Department of Critical Care Medicine, The Fifth Affiliated Hospital (Zhuhai) of Zunyi Medical University, Zhuhai, People's Republic of China
- Department of Emergency, The Fifth Affiliated Hospital (Zhuhai) of Zunyi Medical University, Zhuhai, People's Republic of China
| | - Hongtao Zhang
- Department of Critical Care Medicine, The Fifth Affiliated Hospital (Zhuhai) of Zunyi Medical University, Zhuhai, People's Republic of China
- Department of Emergency, The Fifth Affiliated Hospital (Zhuhai) of Zunyi Medical University, Zhuhai, People's Republic of China
| | - Jun Liu
- Department of Critical Care Medicine, The Fifth Affiliated Hospital (Zhuhai) of Zunyi Medical University, Zhuhai, People's Republic of China
- Department of Emergency, The Fifth Affiliated Hospital (Zhuhai) of Zunyi Medical University, Zhuhai, People's Republic of China
| | - Xiaoyue Li
- Department of Critical Care Medicine, The Fifth Affiliated Hospital (Zhuhai) of Zunyi Medical University, Zhuhai, People's Republic of China
- Department of Emergency, The Fifth Affiliated Hospital (Zhuhai) of Zunyi Medical University, Zhuhai, People's Republic of China
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Saraiva IE, Hamahata N, Huang DT, Kane-Gill SL, Rivosecchi RM, Shiva S, Nolin TD, Chen X, Minturn J, Chang CCH, Li X, Kellum J, Gómez H. Metformin for sepsis-associated AKI: a protocol for the Randomized Clinical Trial of the Safety and FeasibiLity of Metformin as a Treatment for sepsis-associated AKI (LiMiT AKI). BMJ Open 2024; 14:e081120. [PMID: 38688665 PMCID: PMC11086423 DOI: 10.1136/bmjopen-2023-081120] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/18/2023] [Accepted: 04/15/2024] [Indexed: 05/02/2024] Open
Abstract
INTRODUCTION Acute kidney injury (AKI) is a common complication of sepsis associated with increased risk of death. Preclinical data and observational human studies suggest that activation of AMP-activated protein kinase, an ubiquitous master regulator of energy that can limit mitochondrial injury, with metformin may protect against sepsis-associated AKI (SA-AKI) and mortality. The Randomized Clinical Trial of the Safety and FeasibiLity of Metformin as a Treatment for sepsis-associated AKI (LiMiT AKI) aims to evaluate the safety and feasibility of enteral metformin in patients with sepsis at risk of developing SA-AKI. METHODS AND ANALYSIS Blind, randomised, placebo-controlled clinical trial in a single-centre, quaternary teaching hospital in the USA. We will enrol adult patients (18 years of age or older) within 48 hours of meeting Sepsis-3 criteria, admitted to intensive care unit, with oral or enteral access. Patients will be randomised 1:1:1 to low-dose metformin (500 mg two times per day), high-dose metformin (1000 mg two times per day) or placebo for 5 days. Primary safety outcome will be the proportion of metformin-associated serious adverse events. Feasibility assessment will be based on acceptability by patients and clinicians, and by enrolment rate. ETHICS AND DISSEMINATION This study has been approved by the Institutional Review Board. All patients or surrogates will provide written consent prior to enrolment and any study intervention. Metformin is a widely available, inexpensive medication with a long track record for safety, which if effective would be accessible and easy to deploy. We describe the study methods using the Standard Protocol Items for Randomized Trials framework and discuss key design features and methodological decisions. LiMiT AKI will investigate the feasibility and safety of metformin in critically ill patients with sepsis at risk of SA-AKI, in preparation for a future large-scale efficacy study. Main results will be published as soon as available after final analysis. TRIAL REGISTRATION NUMBER NCT05900284.
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Affiliation(s)
- Ivan E Saraiva
- CRISMA Center, Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Program for Critical Care Nephrology, Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Natsumi Hamahata
- Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - David T Huang
- CRISMA Center, Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Sandra L Kane-Gill
- CRISMA Center, Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Program for Critical Care Nephrology, Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Pharmacy & Therapeutics, University of Pittsburgh School of Pharmacy, Pittsburgh, Pennsylvania, USA
- Department of Pharmacy, University of Pittsburgh Medical Center Health System, Pittsburgh, Pennsylvania, USA
| | - Ryan M Rivosecchi
- Department of Pharmacy, University of Pittsburgh Medical Center Health System, Pittsburgh, Pennsylvania, USA
| | - Sruti Shiva
- Department of Pharmacology & Chemical Biology, Vascular Medical Institute, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Thomas D Nolin
- Department of Pharmacy & Therapeutics, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Renal-Electrolyte Division, Department of Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Xinlei Chen
- Department of Biostatistics, School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - John Minturn
- CRISMA Center, Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
| | - Chung-Chou H Chang
- Department of Biostatistics, School of Public Health, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Department of Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Xiaotong Li
- Department of Pharmacy & Therapeutics, University of Pittsburgh School of Pharmacy, Pittsburgh, Pennsylvania, USA
| | - John Kellum
- Program for Critical Care Nephrology, Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
| | - Hernando Gómez
- CRISMA Center, Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
- Program for Critical Care Nephrology, Department of Critical Care Medicine, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
- Department of Critical Care Medicine, University of Pittsburgh, Pittsburgh, Pennsylvania, USA
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Li ZL, Huang MM, Yu MY, Nie DF, Fu SL, Di JJ, Lan T, Liu BC, Wu QL. Mitochondrial fumarate promotes ischemia/reperfusion-induced tubular injury. Acta Physiol (Oxf) 2024; 240:e14121. [PMID: 38409944 DOI: 10.1111/apha.14121] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Revised: 01/20/2024] [Accepted: 01/23/2024] [Indexed: 02/28/2024]
Abstract
AIM Mitochondrial dysfunction, a characteristic pathological feature of renal Ischemic/reperfusion injury (I/RI), predisposes tubular epithelial cells to maintain an inflammatory microenvironment, however, the exact mechanisms through which mitochondrial dysfunction modulates the induction of tubular injury remains incompletely understood. METHODS ESI-QTRAP-MS/MS approach was used to characterize the targeted metabolic profiling of kidney with I/RI. Tubule injury, mitochondrial dysfunction, and fumarate level were evaluated using qPCR, transmission electron microscopy, ELISA, and immunohistochemistry. RESULTS We demonstrated that tubule injury occurred at the phase of reperfusion in murine model of I/RI. Meanwhile, enhanced glycolysis and mitochondrial dysfunction were found to be associated with tubule injury. Further, we found that tubular fumarate, which resulted from fumarate hydratase deficiency and released from dysfunctional mitochondria, promoted tubular injury. Mechanistically, fumarate induced tubular injury by causing disturbance of glutathione (GSH) hemostasis. Suppression of GSH with buthionine sulphoximine administration could deteriorate the fumarate inhibition-mediated tubule injury recovery. Reactive oxygen species/NF-κB signaling activation played a vital role in fumarate-mediated tubule injury. CONCLUSION Our studies demonstrated that the mitochondrial-derived fumarate promotes tubular epithelial cell injury in renal I/RI. Blockade of fumarate-mediated ROS/NF-κB signaling activation may serve as a novel therapeutic approach to ameliorate hypoxic tubule injury.
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Affiliation(s)
- Zuo-Lin Li
- Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, Jiangsu, China
| | - Ming-Min Huang
- Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, Jiangsu, China
| | - Meng-Yao Yu
- Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, Jiangsu, China
| | - Di-Fei Nie
- Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, Jiangsu, China
| | - Sha-Li Fu
- Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, Jiangsu, China
| | - Jing-Jing Di
- Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, Jiangsu, China
| | - Ting Lan
- Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, Jiangsu, China
| | - Bi-Cheng Liu
- Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, Jiangsu, China
| | - Qiu-Li Wu
- Institute of Nephrology, Zhong Da Hospital, Southeast University School of Medicine, Nanjing, Jiangsu, China
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Yu X, Xin Q, Hao Y, Zhang J, Ma T. An early warning model for predicting major adverse kidney events within 30 days in sepsis patients. Front Med (Lausanne) 2024; 10:1327036. [PMID: 38469459 PMCID: PMC10925638 DOI: 10.3389/fmed.2023.1327036] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2023] [Accepted: 12/18/2023] [Indexed: 03/13/2024] Open
Abstract
Background In sepsis patients, kidney damage is among the most dangerous complications, with a high mortality rate. In addition, major adverse kidney events within 30 days (MAKE30) served as a comprehensive and unbiased clinical outcome measure for sepsis patients due to the recent shift toward targeting patient-centered renal outcomes in clinical research. However, the underlying predictive model for the prediction of MAKE30 in sepsis patients has not been reported in any study. Methods A cohort of 2,849 sepsis patients from the Medical Information Mart for Intensive Care (MIMIC)-IV database was selected and subsequently allocated into a training set (n = 2,137, 75%) and a validation set (n = 712, 25%) through randomization. In addition, 142 sepsis patients from the Xi'An No. 3 Hospital as an external validation group. Univariate and multivariate logistic regression analyses were conducted to ascertain the independent predictors of MAKE30. Subsequently, a nomogram was developed utilizing these predictors, with an area under curve (AUC) above 0.6. The performance of nomogram was assessed through calibration curve, receiver operating characteristics (ROC) curve, and decision curve analysis (DCA). The secondary outcome was 30-day mortality, persistent renal dysfunction (PRD), and new renal replacement therapy (RRT). MAKE30 were a composite of death, PRD, new RRT. Results The construction of the nomogram was based on several independent predictors (AUC above 0.6), including age, respiratory rate (RR), PaO2, lactate, and blood urea nitrogen (BUN). The predictive model demonstrated satisfactory discrimination for MAKE30, with an AUC of 0.740, 0.753, and 0.821 in the training, internal validation, and external validation cohorts, respectively. Furthermore, the simple prediction model exhibited superior predictive value compared to the SOFA model in both the training (AUC = 0.710) and validation (AUC = 0.692) cohorts. The nomogram demonstrated satisfactory calibration and clinical utility as evidenced by the calibration curve and DCA. Additionally, the predictive model exhibited excellent accuracy in forecasting 30-day mortality (AUC = 0.737), PRD (AUC = 0.639), and new RRT (AUC = 0.846) within the training dataset. Additionally, the model displayed predictive power for 30-day mortality (AUC = 0.765), PRD (AUC = 0.667), and new RRT (AUC = 0.783) in the validation set. Conclusion The proposed nomogram holds the potential to estimate the risk of MAKE30 promptly and efficiently in sepsis patients within the initial 24 h of admission, thereby equipping healthcare professionals with valuable insights to facilitate personalized interventions.
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Affiliation(s)
- Xiaoyuan Yu
- Department of Hematology, The Affiliated Hospital of Northwest University, Xi’an No. 3 Hospital, Shaanxi, Xi’an, China
| | - Qi Xin
- Department of Hepatobiliary Surgery, The First Affiliated Hospital of Xi’an Jiaotong University, Xi’an, Shaanxi, China
| | - Yun Hao
- Department of Nephrology, Yuequn Yuan District, The First Hospital of Jilin University, Changchun, Jilin, China
| | - Jin Zhang
- Department of Hematology, The Affiliated Hospital of Northwest University, Xi’an No. 3 Hospital, Shaanxi, Xi’an, China
| | - Tiantian Ma
- Department of Hematology, The Affiliated Hospital of Northwest University, Xi’an No. 3 Hospital, Shaanxi, Xi’an, China
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Chrysopoulou M, Rinschen MM. Metabolic Rewiring and Communication: An Integrative View of Kidney Proximal Tubule Function. Annu Rev Physiol 2024; 86:405-427. [PMID: 38012048 DOI: 10.1146/annurev-physiol-042222-024724] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2023]
Abstract
The kidney proximal tubule is a key organ for human metabolism. The kidney responds to stress with altered metabolite transformation and perturbed metabolic pathways, an ultimate cause for kidney disease. Here, we review the proximal tubule's metabolic function through an integrative view of transport, metabolism, and function, and embed it in the context of metabolome-wide data-driven research. Function (filtration, transport, secretion, and reabsorption), metabolite transformation, and metabolite signaling determine kidney metabolic rewiring in disease. Energy metabolism and substrates for key metabolic pathways are orchestrated by metabolite sensors. Given the importance of renal function for the inner milieu, we also review metabolic communication routes with other organs. Exciting research opportunities exist to understand metabolic perturbation of kidney and proximal tubule function, for example, in hypertension-associated kidney disease. We argue that, based on the integrative view outlined here, kidney diseases without genetic cause should be approached scientifically as metabolic diseases.
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Affiliation(s)
| | - Markus M Rinschen
- Department of Biomedicine, Aarhus University, Aarhus, Denmark;
- III. Department of Medicine and Hamburg Center for Kidney Health, University Medical Center Hamburg-Eppendorf, Hamburg, Germany
- Aarhus Institute of Advanced Studies, Aarhus University, Aarhus, Denmark
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Wang T, Huang Y, Zhang X, Zhang Y, Zhang X. Advances in metabolic reprogramming of renal tubular epithelial cells in sepsis-associated acute kidney injury. Front Physiol 2024; 15:1329644. [PMID: 38312312 PMCID: PMC10834781 DOI: 10.3389/fphys.2024.1329644] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2023] [Accepted: 01/09/2024] [Indexed: 02/06/2024] Open
Abstract
Sepsis-associated acute kidney injury presents as a critical condition characterized by prolonged hospital stays, elevated mortality rates, and an increased likelihood of transition to chronic kidney disease. Sepsis-associated acute kidney injury suppresses fatty acid oxidation and oxidative phosphorylation in the mitochondria of renal tubular epithelial cells, thus favoring a metabolic shift towards glycolysis for energy production. This shift acts as a protective mechanism for the kidneys. However, an extended reliance on glycolysis may contribute to tubular atrophy, fibrosis, and subsequent chronic kidney disease progression. Metabolic reprogramming interventions have emerged as prospective strategies to counteract sepsis-associated acute kidney injury by restoring normal metabolic function, offering potential therapeutic and preventive modalities. This review delves into the metabolic alterations of tubular epithelial cells associated with sepsis-associated acute kidney injury, stressing the importance of metabolic reprogramming for the immune response and the urgency of metabolic normalization. We present various intervention targets that could facilitate the recovery of oxidative phosphorylation-centric metabolism. These novel insights and strategies aim to transform the clinical prevention and treatment landscape of sepsis-associated acute kidney injury, with a focus on metabolic mechanisms. This investigation could provide valuable insights for clinicians aiming to enhance patient outcomes in the context of sepsis-associated acute kidney injury.
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Affiliation(s)
- Tiantian Wang
- Department of Critical Care Medicine, The Affiliated Huaian No 1 People's Hospital of Nanjing Medical University, Huaian, Jiangsu, China
| | - Ying Huang
- Department of Critical Care Medicine, The Affiliated Huaian No 1 People's Hospital of Nanjing Medical University, Huaian, Jiangsu, China
| | - Xiaobei Zhang
- Department of Critical Care Medicine, The Affiliated Huaian No 1 People's Hospital of Nanjing Medical University, Huaian, Jiangsu, China
| | - Yi Zhang
- Department of Critical Care Medicine, The Affiliated Huaian No 1 People's Hospital of Nanjing Medical University, Huaian, Jiangsu, China
| | - Xiangcheng Zhang
- Department of Critical Care Medicine, The Affiliated Huaian No 1 People's Hospital of Nanjing Medical University, Huaian, Jiangsu, China
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Zhao L, Hao Y, Tang S, Han X, Li R, Zhou X. Energy metabolic reprogramming regulates programmed cell death of renal tubular epithelial cells and might serve as a new therapeutic target for acute kidney injury. Front Cell Dev Biol 2023; 11:1276217. [PMID: 38054182 PMCID: PMC10694365 DOI: 10.3389/fcell.2023.1276217] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Accepted: 11/08/2023] [Indexed: 12/07/2023] Open
Abstract
Acute kidney injury (AKI) induces significant energy metabolic reprogramming in renal tubular epithelial cells (TECs), thereby altering lipid, glucose, and amino acid metabolism. The changes in lipid metabolism encompass not only the downregulation of fatty acid oxidation (FAO) but also changes in cell membrane lipids and triglycerides metabolism. Regarding glucose metabolism, AKI leads to increased glycolysis, activation of the pentose phosphate pathway (PPP), inhibition of gluconeogenesis, and upregulation of the polyol pathway. Research indicates that inhibiting glycolysis, promoting the PPP, and blocking the polyol pathway exhibit a protective effect on AKI-affected kidneys. Additionally, changes in amino acid metabolism, including branched-chain amino acids, glutamine, arginine, and tryptophan, play an important role in AKI progression. These metabolic changes are closely related to the programmed cell death of renal TECs, involving autophagy, apoptosis, necroptosis, pyroptosis, and ferroptosis. Notably, abnormal intracellular lipid accumulation can impede autophagic clearance, further exacerbating lipid accumulation and compromising autophagic function, forming a vicious cycle. Recent studies have demonstrated the potential of ameliorating AKI-induced kidney damage through calorie and dietary restriction. Consequently, modifying the energy metabolism of renal TECs and dietary patterns may be an effective strategy for AKI treatment.
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Affiliation(s)
- Limei Zhao
- The Fifth Clinical Medical College of Shanxi Medical University, Taiyuan, Shanxi, China
| | - Yajie Hao
- The Fifth Clinical Medical College of Shanxi Medical University, Taiyuan, Shanxi, China
| | - Shuqin Tang
- The Fifth Clinical Medical College of Shanxi Medical University, Taiyuan, Shanxi, China
| | - Xiutao Han
- The Third Clinical College, Shanxi University of Chinese Medicine, Jinzhong, Shanxi, China
| | - Rongshan Li
- Department of Nephrology, Shanxi Provincial People’s Hospital, The Fifth Clinical Medical College of Shanxi Medical University, Taiyuan, Shanxi, China
| | - Xiaoshuang Zhou
- Department of Nephrology, Shanxi Provincial People’s Hospital, The Fifth Clinical Medical College of Shanxi Medical University, Taiyuan, Shanxi, China
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Zhang H, Deng Z, Wang Y, Zheng X, Zhou L, Yan S, Wang Y, Dai Y, Kanwar Y, Deng F. CHIP protects against septic acute kidney injury by inhibiting NLRP3-mediated pyroptosis. iScience 2023; 26:107762. [PMID: 37692286 PMCID: PMC10492219 DOI: 10.1016/j.isci.2023.107762] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2023] [Revised: 07/16/2023] [Accepted: 08/25/2023] [Indexed: 09/12/2023] Open
Abstract
Septic acute kidney injury (S-AKI), the most common type of acute kidney injury (AKI), is intimately related to pyroptosis and oxidative stress in its pathogenesis. Carboxy-terminus of Hsc70-interacting protein (CHIP), a U-box E3 ligase, modulates oxidative stress by degrading its targeted proteins. The role of CHIP in S-AKI and its relevance with pyroptosis have not been investigated. In this study, we showed that CHIP was downregulated in renal proximal tubular cells in lipopolysaccharide (LPS)-induced S-AKI. Besides, the extent of redox injuries in S-AKI was attenuated by CHIP overexpression or activation but accentuated by CHIP gene disruption. Mechanistically, our work demonstrated that CHIP interacted with and ubiquitinated NLRP3 to promote its proteasomal degradation, leading to the inhibition of NLRP3/ACS inflammasome-mediated pyroptosis. In summary, this study revealed that CHIP ubiquitinated NLRP3 to alleviate pyroptosis in septic renal injuries, suggesting that CHIP might be a potential therapeutic target for S-AKI.
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Affiliation(s)
- Hao Zhang
- Department of Urology, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
| | - Zebin Deng
- Department of Urology, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
| | - Yilong Wang
- Department of Cardiology, The First Affiliated Hospital of Sun Yat-sen University, Guangzhou, China
| | - Xiaoping Zheng
- Department of Urology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong, China
| | - Lizhi Zhou
- Department of Urology, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
| | - Shu Yan
- Guangzhou Institute of Pediatrics, Guangzhou Women and Children’s Medical Center, Guangzhou Medical University, Guangzhou, Guangdong, China
| | - Yinhuai Wang
- Department of Urology, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
| | - Yingbo Dai
- Department of Urology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, Guangdong, China
| | - Yashpal.S. Kanwar
- Departments of Pathology & Medicine, Northwestern University, Chicago, IL, USA
| | - Fei Deng
- Department of Urology, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
- Department of Nephrology, The Second Xiangya Hospital, Central South University, Changsha, Hunan 410011, China
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Zhang L, Miao M, Xu X, Bai M, Wu M, Zhang A. From Physiology to Pathology: The Role of Mitochondria in Acute Kidney Injuries and Chronic Kidney Diseases. KIDNEY DISEASES (BASEL, SWITZERLAND) 2023; 9:342-357. [PMID: 37901706 PMCID: PMC10601966 DOI: 10.1159/000530485] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/09/2022] [Accepted: 03/18/2023] [Indexed: 10/31/2023]
Abstract
Background Renal diseases remain an increasing public health issue affecting millions of people. The kidney is a highly energetic organ that is rich in mitochondria. Numerous studies have demonstrated the important role of mitochondria in maintaining normal kidney function and in the pathogenesis of various renal diseases, including acute kidney injuries (AKIs) and chronic kidney diseases (CKDs). Summary Under physiological conditions, fine-tuning mitochondrial energy balance, mitochondrial dynamics (fission and fusion processes), mitophagy, and biogenesis maintain mitochondrial fitness. While under AKI and CKD conditions, disruption of mitochondrial energy metabolism leads to increased oxidative stress. In addition, mitochondrial dynamics shift to excessive mitochondrial fission, mitochondrial autophagy is impaired, and mitochondrial biogenesis is also compromised. These mitochondrial injuries regulate renal cellular functions either directly or indirectly. Mitochondria-targeted approaches, containing genetic (microRNAs) and pharmaceutical methods (mitochondria-targeting antioxidants, mitochondrial permeability pore inhibitors, mitochondrial fission inhibitors, and biogenesis activators), are emerging as important therapeutic strategies for AKIs and CKDs. Key Messages Mitochondria play a critical role in the pathogenesis of AKIs and CKDs. This review provides an updated overview of mitochondrial homeostasis under physiological conditions and the involvement of mitochondrial dysfunction in renal diseases. Finally, we summarize the current status of mitochondria-targeted strategies in attenuating renal diseases.
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Affiliation(s)
- Lingge Zhang
- Department of Nephrology, Children’s Hospital of Nanjing Medical University, Nanjing, China
- Nanjing Key Laboratory of Pediatrics, Children’s Hospital of Nanjing Medical University, Nanjing, China
| | - Mengqiu Miao
- Department of Nephrology, Children’s Hospital of Nanjing Medical University, Nanjing, China
- Nanjing Key Laboratory of Pediatrics, Children’s Hospital of Nanjing Medical University, Nanjing, China
| | - Xinyue Xu
- School of Medicine, Southeast University, Nanjing, China
| | - Mi Bai
- Department of Nephrology, Children’s Hospital of Nanjing Medical University, Nanjing, China
- Nanjing Key Laboratory of Pediatrics, Children’s Hospital of Nanjing Medical University, Nanjing, China
| | - Mengqiu Wu
- Department of Nephrology, Children’s Hospital of Nanjing Medical University, Nanjing, China
- Nanjing Key Laboratory of Pediatrics, Children’s Hospital of Nanjing Medical University, Nanjing, China
| | - Aihua Zhang
- Department of Nephrology, Children’s Hospital of Nanjing Medical University, Nanjing, China
- Nanjing Key Laboratory of Pediatrics, Children’s Hospital of Nanjing Medical University, Nanjing, China
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Packer M. Fetal Reprogramming of Nutrient Surplus Signaling, O-GlcNAcylation, and the Evolution of CKD. J Am Soc Nephrol 2023; 34:1480-1491. [PMID: 37340541 PMCID: PMC10482065 DOI: 10.1681/asn.0000000000000177] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2023] [Accepted: 06/07/2023] [Indexed: 06/22/2023] Open
Abstract
ABSTRACT Fetal kidney development is characterized by increased uptake of glucose, ATP production by glycolysis, and upregulation of mammalian target of rapamycin (mTOR) and hypoxia-inducible factor-1 alpha (HIF-1 α ), which (acting in concert) promote nephrogenesis in a hypoxic low-tubular-workload environment. By contrast, the healthy adult kidney is characterized by upregulation of sirtuin-1 and adenosine monophosphate-activated protein kinase, which enhances ATP production through fatty acid oxidation to fulfill the needs of a normoxic high-tubular-workload environment. During stress or injury, the kidney reverts to a fetal signaling program, which is adaptive in the short term, but is deleterious if sustained for prolonged periods when both oxygen tension and tubular workload are heightened. Prolonged increases in glucose uptake in glomerular and proximal tubular cells lead to enhanced flux through the hexosamine biosynthesis pathway; its end product-uridine diphosphate N -acetylglucosamine-drives the rapid and reversible O-GlcNAcylation of thousands of intracellular proteins, typically those that are not membrane-bound or secreted. Both O-GlcNAcylation and phosphorylation act at serine/threonine residues, but whereas phosphorylation is regulated by hundreds of specific kinases and phosphatases, O-GlcNAcylation is regulated only by O-GlcNAc transferase and O-GlcNAcase, which adds or removes N-acetylglucosamine, respectively, from target proteins. Diabetic and nondiabetic CKD is characterized by fetal reprogramming (with upregulation of mTOR and HIF-1 α ) and increased O-GlcNAcylation, both experimentally and clinically. Augmentation of O-GlcNAcylation in the adult kidney enhances oxidative stress, cell cycle entry, apoptosis, and activation of proinflammatory and profibrotic pathways, and it inhibits megalin-mediated albumin endocytosis in glomerular mesangial and proximal tubular cells-effects that can be aggravated and attenuated by augmentation and muting of O-GlcNAcylation, respectively. In addition, drugs with known nephroprotective effects-angiotensin receptor blockers, mineralocorticoid receptor antagonists, and sodium-glucose cotransporter 2 inhibitors-are accompanied by diminished O-GlcNAcylation in the kidney, although the role of such suppression in mediating their benefits has not been explored. The available evidence supports further work on the role of uridine diphosphate N -acetylglucosamine as a critical nutrient surplus sensor (acting in concert with upregulated mTOR and HIF-1 α signaling) in the development of diabetic and nondiabetic CKD.
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Affiliation(s)
- Milton Packer
- Baylor Heart and Vascular Institute , Dallas , Texas and Imperial College , London , United Kingdom
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11
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Li Y, Gu W, Hepokoski M, Pham H, Tham R, Kim YC, Simonson TS, Singh P. Energy Metabolism Dysregulation in Chronic Kidney Disease. KIDNEY360 2023; 4:1080-1094. [PMID: 37222594 PMCID: PMC10476685 DOI: 10.34067/kid.0000000000000153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 05/08/2023] [Indexed: 05/25/2023]
Abstract
Key Points There is significant enrichment in metabolic pathways in early stages in the subtotal nephrectomy model of CKD. Proximal tubular mitochondrial respiration is suppressed likely from mitochondrial dysfunction in substrate utilization and ATP synthesis. There is significant suppression of pyruvate dehydrogenase and increased glycolysis in proximal tubules. Background CKD is a significant contributor to morbidity and mortality. A better understanding of mechanisms underlying CKD progression is indispensable for developing effective therapies. Toward this goal, we addressed specific gaps in knowledge regarding tubular metabolism in the pathogenesis of CKD using the subtotal nephrectomy (STN) model in mice. Methods Weight- and age‐matched male 129X1/SvJ mice underwent sham or STN surgeries. We conducted serial GFR and hemodynamic measurements up to 16 weeks after sham and STN surgery and established the 4-week time point for subsequent studies. Results For a comprehensive assessment of renal metabolism, we conducted transcriptomic analyses, which showed significant enrichment of pathways involved in fatty acid metabolism, gluconeogenesis, glycolysis, and mitochondrial metabolism in STN kidneys. Expression of rate-limiting fatty acid oxidation and glycolytic enzymes was increased in STN kidneys, and proximal tubules in STN kidneys exhibited increased functional glycolysis but decreased mitochondrial respiration, despite an increase in mitochondrial biogenesis. Assessment of the pyruvate dehydrogenase complex pathway showed significant suppression of pyruvate dehydrogenase, suggesting decreased provision of acetyl CoA from pyruvate for the citric acid cycle to fuel mitochondrial respiration. Conclusion Metabolic pathways are significantly altered in response to kidney injury and may play an important role in the disease progression.
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Affiliation(s)
- Ying Li
- Division of Nephrology and Hypertension, University of California San Diego, San Diego, California
- VA San Diego Healthcare System, San Diego, California
| | - Wanjun Gu
- Division of Pulmonary, Critical Care and Sleep Medicine, University of California San Diego, San Diego, California
| | - Mark Hepokoski
- VA San Diego Healthcare System, San Diego, California
- Division of Pulmonary, Critical Care and Sleep Medicine, University of California San Diego, San Diego, California
| | - Hai Pham
- Division of Nephrology and Hypertension, University of California San Diego, San Diego, California
- VA San Diego Healthcare System, San Diego, California
| | - Rick Tham
- Division of Nephrology and Hypertension, University of California San Diego, San Diego, California
- VA San Diego Healthcare System, San Diego, California
| | - Young Chul Kim
- Division of Nephrology and Hypertension, University of California San Diego, San Diego, California
- VA San Diego Healthcare System, San Diego, California
| | - Tatum S. Simonson
- Division of Pulmonary, Critical Care and Sleep Medicine, University of California San Diego, San Diego, California
| | - Prabhleen Singh
- Division of Nephrology and Hypertension, University of California San Diego, San Diego, California
- VA San Diego Healthcare System, San Diego, California
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12
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An S, Yao Y, Hu H, Wu J, Li J, Li L, Wu J, Sun M, Deng Z, Zhang Y, Gong S, Huang Q, Chen Z, Zeng Z. PDHA1 hyperacetylation-mediated lactate overproduction promotes sepsis-induced acute kidney injury via Fis1 lactylation. Cell Death Dis 2023; 14:457. [PMID: 37479690 PMCID: PMC10362039 DOI: 10.1038/s41419-023-05952-4] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2023] [Revised: 06/24/2023] [Accepted: 07/05/2023] [Indexed: 07/23/2023]
Abstract
The increase of lactate is an independent risk factor for patients with sepsis-induced acute kidney injury (SAKI). However, whether elevated lactate directly promotes SAKI and its mechanism remain unclear. Here we revealed that downregulation of the deacetylase Sirtuin 3 (SIRT3) mediated the hyperacetylation and inactivation of pyruvate dehydrogenase E1 component subunit alpha (PDHA1), resulting in lactate overproduction in renal tubular epithelial cells. We then found that the incidence of SAKI and renal replacement therapy (RRT) in septic patients with blood lactate ≥ 4 mmol/L was increased significantly, compared with those in septic patients with blood lactate < 2 mmol/L. Further in vitro and in vivo experiments showed that additional lactate administration could directly promote SAKI. Mechanistically, lactate mediated the lactylation of mitochondrial fission 1 protein (Fis1) lysine 20 (Fis1 K20la). The increase in Fis1 K20la promoted excessive mitochondrial fission and subsequently induced ATP depletion, mitochondrial reactive oxygen species (mtROS) overproduction, and mitochondrial apoptosis. In contrast, PDHA1 activation with sodium dichloroacetate (DCA) or SIRT3 overexpression decreased lactate levels and Fis1 K20la, thereby alleviating SAKI. In conclusion, our results show that PDHA1 hyperacetylation and inactivation enhance lactate overproduction, which mediates Fis1 lactylation and exacerbates SAKI. Reducing lactate levels and Fis1 lactylation attenuate SAKI.
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Affiliation(s)
- Sheng An
- Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
- Guangdong Provincial Key Laboratory of Cardiac Function and Microcirculation, Department of Pathophysiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Yi Yao
- Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
- Guangdong Provincial Key Laboratory of Cardiac Function and Microcirculation, Department of Pathophysiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Hongbin Hu
- Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Junjie Wu
- Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
- Guangdong Provincial Key Laboratory of Cardiac Function and Microcirculation, Department of Pathophysiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Jiaxin Li
- Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Lulan Li
- Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Jie Wu
- Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Maomao Sun
- Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
- Guangdong Provincial Key Laboratory of Cardiac Function and Microcirculation, Department of Pathophysiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Zhiya Deng
- Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
- Guangdong Provincial Key Laboratory of Cardiac Function and Microcirculation, Department of Pathophysiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Yaoyuan Zhang
- Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
| | - Shenhai Gong
- School of Traditional Chinese Medicine, Southern Medical University, Guangzhou, 510515, China
| | - Qiaobing Huang
- Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China
- Guangdong Provincial Key Laboratory of Cardiac Function and Microcirculation, Department of Pathophysiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China
| | - Zhongqing Chen
- Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China.
- Guangdong Provincial Key Laboratory of Cardiac Function and Microcirculation, Department of Pathophysiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China.
| | - Zhenhua Zeng
- Department of Critical Care Medicine, Nanfang Hospital, Southern Medical University, Guangzhou, 510515, China.
- Guangdong Provincial Key Laboratory of Cardiac Function and Microcirculation, Department of Pathophysiology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, 510515, China.
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13
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Piret SE, Mallipattu SK. Transcriptional regulation of proximal tubular metabolism in acute kidney injury. Pediatr Nephrol 2023; 38:975-986. [PMID: 36181578 DOI: 10.1007/s00467-022-05748-2] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2022] [Revised: 08/07/2022] [Accepted: 08/26/2022] [Indexed: 11/30/2022]
Abstract
The kidney, and in particular the proximal tubule (PT), has a high demand for ATP, due to its function in bulk reabsorption of solutes. In normal PT, ATP levels are predominantly maintained by fatty acid β-oxidation (FAO), the tricarboxylic acid (TCA) cycle, and oxidative phosphorylation. The normal PT also undertakes gluconeogenesis and metabolism of amino acids. Acute kidney injury (AKI) results in profound PT metabolic alterations, including suppression of FAO, gluconeogenesis, and metabolism of some amino acids, and upregulation of glycolytic enzymes. Recent studies have elucidated new transcriptional mechanisms regulating metabolic pathways in normal PT, as well as the metabolic switch in AKI. A number of transcription factors have been shown to play important roles in FAO, which are themselves downregulated in AKI, while hypoxia-inducible factor 1α, which is upregulated in ischemia-reperfusion injury, is a likely driver of the upregulation of glycolytic enzymes. Transcriptional regulation of amino acid metabolic pathways is less well understood, except for catabolism of branched-chain amino acids, which is likely suppressed in AKI by upregulation of Krüppel-like factor 6. This review will focus on the transcriptional regulation of specific metabolic pathways in normal PT and in AKI, as well as highlighting some of the gaps in knowledge and challenges that remain to be addressed.
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Affiliation(s)
- Sian E Piret
- Division of Nephrology and Hypertension, Department of Medicine, Stony Brook University, 101 Nicolls Road, Stony Brook, NY, 11794, USA.
| | - Sandeep K Mallipattu
- Division of Nephrology and Hypertension, Department of Medicine, Stony Brook University, 101 Nicolls Road, Stony Brook, NY, 11794, USA
- Renal Division, Northport VA Medical Center, Northport, NY, USA
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14
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Stasi A, Franzin R, Caggiano G, Losapio R, Fiorentino M, Alfieri C, Gesualdo L, Stallone G, Castellano G. New Frontiers in Sepsis-Induced Acute Kidney Injury and Blood Purification Therapies: The Role of Polymethylmethacrylate Membrane Hemofilter. Blood Purif 2023; 52:1-14. [PMID: 36693337 PMCID: PMC10210082 DOI: 10.1159/000528685] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Accepted: 11/17/2022] [Indexed: 01/25/2023]
Abstract
Acute kidney injury (AKI) is a common consequence of sepsis with a mortality rate of up to 40%. The pathogenesis of septic AKI is complex and involves several mechanisms leading to exacerbated inflammatory response associated with renal injury. A large body of evidence suggests that inflammation is tightly linked to AKI through bidirectional interaction between renal and immune cells. Preclinical data from our and other laboratories have identified in complement system activation a crucial mediator of AKI. Partial recovery following AKI could lead to long-term consequences that predispose to chronic dysfunction and may also accelerate the progression of preexisting chronic kidney disease. Recent findings have revealed striking morphological and functional changes in renal parenchymal cells induced by mitochondrial dysfunction, cell cycle arrest via the activation of signaling pathways involved in aging process, microvascular rarefaction, and early fibrosis. Although major advances have been made in our understanding of the pathophysiology of AKI, there are no available preventive and therapeutic strategies in this field. The identification of ideal clinical biomarkers for AKI enables prompt and effective therapeutic strategy that could prevent the progression of renal injury and promote repair process. Therefore, the use of novel biomarkers associated with clinical and functional criteria could provide early interventions and better outcome. Several new drugs for AKI are currently being investigated; however, the complexity of this disease might explain the failure of pharmacological intervention targeting just one of the many systems involved. The hypothesis that blood purification could improve the outcome of septic AKI has attracted much attention. New relevant findings on the role of polymethylmethacrylate-based continuous veno-venous hemofiltration in septic AKI have been reported. Herein, we provide a comprehensive literature review on advances in the pathophysiology of septic AKI and potential therapeutic approaches in this field.
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Affiliation(s)
- Alessandra Stasi
- Renal, Dialysis and Transplantation Unit, Department of Precision and Regenerative Medicine and Ionian Area (DIMEPRE-J), University of Bari, Bari, Italy
| | - Rossana Franzin
- Renal, Dialysis and Transplantation Unit, Department of Precision and Regenerative Medicine and Ionian Area (DIMEPRE-J), University of Bari, Bari, Italy
| | - Gianvito Caggiano
- Renal, Dialysis and Transplantation Unit, Department of Precision and Regenerative Medicine and Ionian Area (DIMEPRE-J), University of Bari, Bari, Italy
| | - Rosa Losapio
- Renal, Dialysis and Transplantation Unit, Department of Precision and Regenerative Medicine and Ionian Area (DIMEPRE-J), University of Bari, Bari, Italy
| | - Marco Fiorentino
- Renal, Dialysis and Transplantation Unit, Department of Precision and Regenerative Medicine and Ionian Area (DIMEPRE-J), University of Bari, Bari, Italy
| | - Carlo Alfieri
- Nephrology, Dialysis and Renal Transplant Unit, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
| | - Loreto Gesualdo
- Renal, Dialysis and Transplantation Unit, Department of Precision and Regenerative Medicine and Ionian Area (DIMEPRE-J), University of Bari, Bari, Italy
| | - Giovanni Stallone
- Nephrology Dialysis and Transplantation Unit, Department of Medical and Surgical Sciences, Advanced Research Center on Kidney Aging (A.R.K.A.), University of Foggia, Foggia, Italy
| | - Giuseppe Castellano
- Nephrology, Dialysis and Renal Transplant Unit, Department of Clinical Sciences and Community Health, University of Milan, Milan, Italy
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15
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Dai Q, Zhang H, Tang S, Wu X, Wang J, Yi B, Liu J, Li Z, Liao Q, Li A, Liu Y, Zhang W. Vitamin D- VDR (vitamin D receptor) alleviates glucose metabolism reprogramming in lipopolysaccharide-induced acute kidney injury. Front Physiol 2023; 14:1083643. [PMID: 36909229 PMCID: PMC9998528 DOI: 10.3389/fphys.2023.1083643] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2022] [Accepted: 02/13/2023] [Indexed: 03/14/2023] Open
Abstract
Background: Our previous study showed that vitamin D (VD)-vitamin D receptor (VDR) plays a nephroprotective role in lipopolysaccharide (LPS)-induced acute kidney injury (AKI). Recently, glucose metabolism reprogramming was reported to be involved in the pathogenesis of AKI. Objective: To investigate the role of VD-VDR in glucose metabolism reprogramming in LPS-induced AKI. Methods: We established a model of LPS-induced AKI in VDR knockout (VDR-KO) mice, renal proximal tubular-specific VDR-overexpressing (VDR-OE) mice and wild-type C57BL/6 mice. In vitro, human proximal tubular epithelial cells (HK-2 cells), VDR knockout and VDR overexpression HK-2 cell lines were used. Results: Paricalcitol (an active vitamin D analog) or VDR-OE reduced lactate concentration, hexokinase activity and PDHA1 phosphorylation (a key step in inhibiting aerobic oxidation) and simultaneously ameliorated renal inflammation, apoptosis and kidney injury in LPS-induced AKI mice, which were more severe in VDR-KO mice. In in vitro experiments, glucose metabolism reprogramming, inflammation and apoptosis induced by LPS were alleviated by treatment with paricalcitol or dichloroacetate (DCA, an inhibitor of p-PDHA1). Moreover, paricalcitol activated the phosphorylation of AMP-activated protein kinase (AMPK), and an AMPK inhibitor partially abolished the protective effect of paricalcitol in LPS-treated HK-2 cells. Conclusion: VD-VDR alleviated LPS-induced metabolic reprogramming in the kidneys of AKI mice, which may be attributed to the inactivation of PDHA1 phosphorylation via the AMPK pathway.
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Affiliation(s)
- Qing Dai
- Department of Nephrology, Third Xiangya Hospital, Central South University, Changsha, China
| | - Hao Zhang
- Department of Nephrology, Third Xiangya Hospital, Central South University, Changsha, China
| | - Shiqi Tang
- Department of Nephrology, Third Xiangya Hospital, Central South University, Changsha, China
| | - Xueqin Wu
- Department of Nephrology, Third Xiangya Hospital, Central South University, Changsha, China
| | - Jianwen Wang
- Department of Nephrology, Third Xiangya Hospital, Central South University, Changsha, China
| | - Bin Yi
- Department of Nephrology, Third Xiangya Hospital, Central South University, Changsha, China
| | - Jishi Liu
- Department of Nephrology, Third Xiangya Hospital, Central South University, Changsha, China
| | - Zhi Li
- Department of Nephrology, Third Xiangya Hospital, Central South University, Changsha, China
| | - Qin Liao
- Department of Anesthesiology, Third Xiangya Hospital, Central South University, Changsha, China
| | - Aimei Li
- Department of Nephrology, Third Xiangya Hospital, Central South University, Changsha, China
| | - Yan Liu
- Department of Nephrology, Third Xiangya Hospital, Central South University, Changsha, China
| | - Wei Zhang
- Department of Nephrology, Third Xiangya Hospital, Central South University, Changsha, China
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16
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Gómez H. Reprogramming Metabolism to Enhance Kidney Tolerance during Sepsis: The Role of Fatty Acid Oxidation, Aerobic Glycolysis, and Epithelial De-Differentiation. Nephron Clin Pract 2022; 147:31-34. [PMID: 36349802 PMCID: PMC9928807 DOI: 10.1159/000527392] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 09/30/2022] [Indexed: 11/06/2022] Open
Abstract
BACKGROUND The recognition that sepsis induces acute kidney injury (AKI) in the absence of overt necrosis or apoptosis and even in the presence of increased renal blood flow has led to the consideration that kidney tubular epithelial cells (TECs) may deploy defense mechanisms to survive the insult. SUMMARY This concept dovetails well with the notion that the defense against infection not only depends on the capacity of the immune system to limit the microbial burden or resistance capacity but also on the capacity of the host to limit tissue injury, collectively known as tolerance. To sustain the high energy requirement that ion transport mandates, kidney TECs use fatty acid oxidation (FAO) as one of the preferred sources of energy. Inflammatory processes like endotoxemia and sepsis decrease mitochondrial FAO and hinder mitochondrial respiration. Impaired FAO is associated with TEC de-differentiation, loss of kidney function, and TEC injury through lipotoxicity and oxidative stress in the acute setting, and with maladaptive repair and fibrosis after AKI in the latter stages. AMP-activated protein kinase (AMPK) is a master regulator of energy and promoter of FAO that can be activated pharmacologically to protect against AKI and death during experimental sepsis, operating through a tolerance mechanism. KEY MESSAGES Organ dysfunction during sepsis is the expression of tissue injury and adaptive defense mechanisms operating through resistance or tolerance that prioritize cell survival over organ function. Metabolic reprogramming away from FAO/oxidative phosphorylation seems to be a common pathological denominator throughout the AKI continuum that may be targeted through the activation of AMPK.
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Affiliation(s)
- Hernando Gómez
- Department of Critical Care Medicine, Program for Critical Care Nephrology, The CRISMA Center, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, USA
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17
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Singh P. Reprogramming of Energy Metabolism in Kidney Disease. Nephron Clin Pract 2022; 147:61-64. [PMID: 36063803 PMCID: PMC9928604 DOI: 10.1159/000526308] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2022] [Accepted: 07/26/2022] [Indexed: 11/19/2022] Open
Abstract
Kidney tubules have high metabolic activity to support solute transport and other cellular functions. Energy generation in the kidney is largely dependent on mitochondrial oxidative phosphorylation, particularly in the proximal tubules. Important alterations in the pathways of energy generation and cellular metabolism have been identified in early and late stages of kidney disease. This review provides a succinct summary of the current literature on the central role of energy metabolism in the pathophysiology of acute and chronic kidney disease.
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Affiliation(s)
- Prabhleen Singh
- Division of Nephrology and Hypertension, University of California San Diego, San Diego, California, USA
- VA San Diego Healthcare System, San Diego, California, USA
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18
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Hotait ZS, Lo Cascio JN, Choos END, Shepard BD. The sugar daddy: the role of the renal proximal tubule in glucose homeostasis. Am J Physiol Cell Physiol 2022; 323:C791-C803. [PMID: 35912988 PMCID: PMC9448277 DOI: 10.1152/ajpcell.00225.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2022] [Revised: 07/26/2022] [Accepted: 07/26/2022] [Indexed: 11/22/2022]
Abstract
Renal blood flow represents >20% of total cardiac output and with this comes the great responsibility of maintaining homeostasis through the intricate regulation of solute handling. Through the processes of filtration, reabsorption, and secretion, the kidneys ensure that solutes and other small molecules are either returned to circulation, catabolized within renal epithelial cells, or excreted through the process of urination. Although this occurs throughout the renal nephron, one segment is tasked with the bulk of solute reabsorption-the proximal tubule. Among others, the renal proximal tubule is entirely responsible for the reabsorption of glucose, a critical source of energy that fuels the body. In addition, it is the only other site of gluconeogenesis outside of the liver. When these processes go awry, pathophysiological conditions such as diabetes and acidosis result. In this review, we highlight the recent advances made in understanding these processes that occur within the renal proximal tubule. We focus on the physiological mechanisms at play regarding glucose reabsorption and glucose metabolism, emphasize the conditions that occur under diseased states, and explore the emerging class of therapeutics that are responsible for restoring homeostasis.
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Affiliation(s)
- Zahraa S Hotait
- Department of Human Science, Georgetown University, Washington, District of Columbia
| | - Julia N Lo Cascio
- Department of Human Science, Georgetown University, Washington, District of Columbia
| | - Elijah N D Choos
- Department of Human Science, Georgetown University, Washington, District of Columbia
| | - Blythe D Shepard
- Department of Human Science, Georgetown University, Washington, District of Columbia
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19
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Wang CH, Lu WL, Chiang SL, Tsai TH, Liu SC, Hsieh CH, Su PH, Huang CY, Tsai FJ, Lin YJ, Huang YN. T Cells Mediate Kidney Tubular Injury via Impaired PDHA1 and Autophagy in Type 1 Diabetes. J Clin Endocrinol Metab 2022; 107:2556-2570. [PMID: 35731579 DOI: 10.1210/clinem/dgac378] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/17/2021] [Indexed: 11/19/2022]
Abstract
CONTEXT Nephropathy is a severe complication of type 1 diabetes (T1DM). However, the interaction between the PDHA1-regulated mechanism and CD4+ T cells in the early stage of kidney tubular injury remains unknown. OBJECTIVE To evaluate the role of PDHA1 in the regulation of tubular cells and CD4+ T cells and further to study its interaction in tubular cell injury in T1DM. METHODS Plasma and total RNA were collected from T cells of T1DM patients (n = 35) and healthy donors (n = 33) and evaluated for neutrophil gelatinase-associated lipocalin (NGAL), kidney injury molecule-1, PDHA1, and biomarkers of CD4+ T cells including T helper 1 cells (Th1) and regulatory T cells (Treg) markers. HK-2 cells cocultured with CD4+ T cells from T1DM patients or healthy donors (HDs) to evaluate the interaction with CD4+ T cells. RESULTS Increased PDHA1 gene expression levels in CD4+ T cells were positively associated with the plasma level of NGAL in T1DM patients and HDs. Our data demonstrated that the Th1/Treg subsets skewed Th1 in T1DM. Knockdown of PDHA1 in kidney tubular cells decreased ATP/ROS production, NAD/NADH ratio, mitochondrial respiration, and cell apoptosis. Furthermore, PDHA1 depletion induced impaired autophagic flux. Coculture of tubular cells and T1DM T cells showed impaired CPT1A, upregulated FASN, and induced kidney injury. CONCLUSION Our findings indicate that Th1 cells induced tubular cell injury through dysregulated metabolic reprogramming and autophagy, thereby indicating a new therapeutic approach for kidney tubular injury in T1DM.
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Affiliation(s)
- Chung-Hsing Wang
- Division of Genetics and Metabolism, Children's Hospital of China Medical University, Taichung 40402, Taiwan
- School of Medicine, China Medical University, Taichung 40402, Taiwan
| | - Wen-Li Lu
- Division of Genetics and Metabolism, Children's Hospital of China Medical University, Taichung 40402, Taiwan
| | - Shang-Lun Chiang
- Department of Medical Laboratory Science, College of Medical Science and Technology, I-Shou University, Kaohsiung 82445, Taiwan
| | - Tsung-Hsun Tsai
- Division of Urology, Department of Surgery, Taichung Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Taichung 42743, Taiwan
| | - Su-Ching Liu
- Department of Medical Research, Children's Hospital of China Medical University, Taichung 40402, Taiwan
| | - Chia-Hung Hsieh
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung 40402
- Department of Medical Research, China Medical University Hospital, Taichung 40402, Taiwan
| | - Pen-Hua Su
- Department of Pediatrics, Chung Shan Medical University Hospital, Taichung 40242, Taiwan
- School of Medicine, Chung Shan Medical University; Taichung 40242, Taiwan
| | - Chih-Yang Huang
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung 40402
- Department of Medical Research, China Medical University Hospital, Taichung 40402, Taiwan
- Cardiovascular and Mitochondrial Related Disease Research Center, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien 97002, Taiwan
- Center of General Education, Buddhist Tzu Chi Medical Foundation, Tzu Chi University of Science and Technology, Hualien 97002, Taiwan
- Department of Medical Laboratory Science and Biotechnology, Asia University, Taichung 41354, Taiwan
| | - Fuu-Jen Tsai
- Genetic Center, Department of Medical Research, China Medical University Hospital, Taichung 40402, Taiwan
| | - Yu-Jung Lin
- Cardiovascular and Mitochondrial Related Disease Research Center, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Hualien 97002, Taiwan
| | - Yu-Nan Huang
- Division of Genetics and Metabolism, Children's Hospital of China Medical University, Taichung 40402, Taiwan
- Department of Life Sciences, National Chung Hsing University, Taichung 40227, Taiwan
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20
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Immunometabolic rewiring of tubular epithelial cells in kidney disease. Nat Rev Nephrol 2022; 18:588-603. [PMID: 35798902 DOI: 10.1038/s41581-022-00592-x] [Citation(s) in RCA: 26] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/25/2022] [Indexed: 12/20/2022]
Abstract
Kidney tubular epithelial cells (TECs) have a crucial role in the damage and repair response to acute and chronic injury. To adequately respond to constant changes in the environment, TECs have considerable bioenergetic needs, which are supported by metabolic pathways. Although little is known about TEC metabolism, a number of ground-breaking studies have shown that defective glucose metabolism or fatty acid oxidation in the kidney has a key role in the response to kidney injury. Imbalanced use of these metabolic pathways can predispose TECs to apoptosis and dedifferentiation, and contribute to lipotoxicity and kidney injury. The accumulation of lipids and aberrant metabolic adaptations of TECs during kidney disease can also be driven by receptors of the innate immune system. Similar to their actions in innate immune cells, pattern recognition receptors regulate the metabolic rewiring of TECs, causing cellular dysfunction and lipid accumulation. TECs should therefore be considered a specialized cell type - like cells of the innate immune system - that is subject to regulation by immunometabolism. Targeting energy metabolism in TECs could represent a strategy for metabolically reprogramming the kidney and promoting kidney repair.
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21
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Abstract
Sepsis-associated AKI is a life-threatening complication that is associated with high morbidity and mortality in patients who are critically ill. Although it is clear early supportive interventions in sepsis reduce mortality, it is less clear that they prevent or ameliorate sepsis-associated AKI. This is likely because specific mechanisms underlying AKI attributable to sepsis are not fully understood. Understanding these mechanisms will form the foundation for the development of strategies for early diagnosis and treatment of sepsis-associated AKI. Here, we summarize recent laboratory and clinical studies, focusing on critical factors in the pathophysiology of sepsis-associated AKI: microcirculatory dysfunction, inflammation, NOD-like receptor protein 3 inflammasome, microRNAs, extracellular vesicles, autophagy and efferocytosis, inflammatory reflex pathway, vitamin D, and metabolic reprogramming. Lastly, identifying these molecular targets and defining clinical subphenotypes will permit precision approaches in the prevention and treatment of sepsis-associated AKI.
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Affiliation(s)
- Shuhei Kuwabara
- Division of Nephrology and Center for Immunity, Inflammation, and Regenerative Medicine, University of Virginia, Charlottesville, Virginia
| | - Eibhlin Goggins
- Division of Nephrology and Center for Immunity, Inflammation, and Regenerative Medicine, University of Virginia, Charlottesville, Virginia
| | - Mark D Okusa
- Division of Nephrology and Center for Immunity, Inflammation, and Regenerative Medicine, University of Virginia, Charlottesville, Virginia
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22
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Chen Z, Wang H, Hu B, Chen X, Zheng M, Liang L, Lyu J, Zeng Q. Transcription factor nuclear factor erythroid 2 p45-related factor 2 (NRF2) ameliorates sepsis-associated acute kidney injury by maintaining mitochondrial homeostasis and improving the mitochondrial function. Eur J Histochem 2022; 66:3412. [PMID: 35726572 PMCID: PMC9251609 DOI: 10.4081/ejh.2022.3412] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2022] [Accepted: 05/19/2022] [Indexed: 12/12/2022] Open
Abstract
Mitochondrial dysfunction has a role in sepsis-associated acute kidney injury (S-AKI), so the restoration of normal mitochondrial homeostasis may be an effective treatment strategy. Transcription factor nuclear factor erythroid 2 p45-related factor 2 (NRF2) is a main regulator of cell-redox homeostasis, and recent studies reported that NRF2 activation helped to preserve mitochondrial morphology and function under conditions of stress. However, the role of NRF2 in the process of S-AKI is still not well understood. The present study investigated whether NRF2 regulates mitochondrial homeostasis and influences mitochondrial function in S-AKI. We demonstrated activation of NRF2 in an in vitro model: lipopolysaccharide (LPS) challenge of ductal epithelial cells of rat renal tubules (NRK-52e cells), and an in vivo model: cecal ligation and puncture (CLP) of rats. Over-expression of NRF2 attenuated oxidative stress, apoptosis, and the inflammatory response; enhanced mitophagy and mitochondrial biogenesis; and mitigated mitochondrial damage in the in vitro model. In vivo experiments showed that rats treated with an NRF2 agonist had higher adenosine triphosphate (ATP) levels, lower blood urea nitrogen and creatinine levels, fewer renal histopathological changes, and higher expression of mitophagy-related proteins [PTEN-induced putative kinase 1 (PINK1), parkin RBR E3 ubiquitin protein ligase (PRKN), microtubule-associated protein 1 light chain 3 II (LC3 II)] and mitochondrial biogenesis-related proteins [peroxisome proliferator-activated receptor γ coactivator-1 (PGC-1α) and mitochondrial transcription factor A (TFAM)]. Electron microscopy of kidney tissues showed that mitochondrial damage was alleviated by treatment with an NRF2 agonist, and the opposite response occurred upon treatment with an NRF2 antagonist. Overall, our findings suggest that mitochondria have an important role in the pathogenesis of S-AKI, and that NRF2 activation restored mitochondrial homeostasis and function in the presence of this disease. This mitochondrial pathway has the potential to be a novel therapeutic target for the treatment of S-AKI.
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Affiliation(s)
- Zhijiang Chen
- Department of Pediatrics, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong.
| | - Huili Wang
- Department of Laboratory, Guangdong Women and Children Hospital, Guangzhou, Guangdong.
| | - Bin Hu
- Department of Pediatrics, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong.
| | - Xinxin Chen
- Department of Pediatrics, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong.
| | - Meiyu Zheng
- Department of Pediatrics, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong.
| | - Lili Liang
- Department of Pediatrics, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong.
| | - Juanjuan Lyu
- Department of Pediatrics, West China Second University Hospital, Sichuan University, Chengdu, Sichuan.
| | - Qiyi Zeng
- Department of Pediatrics, Zhujiang Hospital, Southern Medical University, Guangzhou, Guangdong.
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23
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Hepokoski M, Singh P. Mitochondria as mediators of systemic inflammation and organ cross talk in acute kidney injury. Am J Physiol Renal Physiol 2022; 322:F589-F596. [PMID: 35379000 PMCID: PMC9054254 DOI: 10.1152/ajprenal.00372.2021] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Acute kidney injury (AKI) is a systemic inflammatory disease that contributes to remote organ failures. Multiple organ failure is the leading cause of death due to AKI, and lack of understanding of the mechanisms involved has precluded the development of novel therapies. Mitochondrial injury in AKI leads to mitochondrial fragmentation and release of damage-associated molecular patterns, which are known to active innate immune pathways and systemic inflammation. This review presents current evidence suggesting that extracellular mitochondrial damage-associated molecular patterns are mediators of remote organ failures during AKI that have the potential to be modifiable.
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Affiliation(s)
- Mark Hepokoski
- 1Veterans Affairs San Diego Healthcare System, San Diego, California,2Division of Pulmonary and Critical Care Medicine, University of California, San Diego, California
| | - Prabhleen Singh
- 1Veterans Affairs San Diego Healthcare System, San Diego, California,3Division of Nephrology and Hypertension, University of California, San Diego, California
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24
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Ho KM, Morgan DJR. The Proximal Tubule as the Pathogenic and Therapeutic Target in Acute Kidney Injury. Nephron Clin Pract 2022; 146:494-502. [PMID: 35272287 DOI: 10.1159/000522341] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 01/27/2022] [Indexed: 12/29/2022] Open
Abstract
BACKGROUND In 2004, the term acute kidney injury (AKI) was introduced with the intention of broadening our understanding of rapid declines in renal function and to replace the historical terms of acute renal failure and acute tubular necrosis (ATN). Despite this evolution in terminology, the mechanisms of AKI have stayed largely elusive with the pathophysiological concepts of ATN remaining the mainstay in our understanding of AKI. SUMMARY The proximal tubule (PT), having the highest mitochondrial content in the kidney and relying heavily on oxidative phosphorylation to generate ATP, is vulnerable to ischaemic insults and mitochondrial dysfunction. Histologically, pathological changes in the PT are more consistent than changes to the glomeruli or the loop of Henle in AKI. Physiologically, activation of tubuloglomerular feedback due to PT dysfunction leads to an increase in preglomerular afferent arteriole resistance and a reduction in glomerular filtration. Pharmacologically, frusemide - a drug commonly used in the setting of oliguric AKI - is actively secreted by the PT and its diuretic effect is compromised by its failure to be secreted into the urine and thus be delivered to its site of action at the loop of Henle in AKI. Increases in the urinary, but not plasma biomarkers, of PT injury within 1 h of shock suggest that the PT as the initiation pathogenic target of AKI. KEY MESSAGE Therapeutic agents targeting specifically the PT epithelial cells, in particular its mitochondria - including amino acid ergothioneine and superoxide scavenger MitoTEMPO - show great promises in ameliorating AKI.
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Affiliation(s)
- Kwok M Ho
- Department of Intensive Care Medicine, Royal Perth Hospital, Perth, Washington, Australia.,Medical School, University of Western Australia, Perth, Washington, Australia.,School of Veterinary & Life Sciences, Murdoch University, Perth, Washington, Australia
| | - David J R Morgan
- Department of Intensive Care Medicine, Fiona Stanley Hospital, Perth, Washington, Australia
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25
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Huen SC. Metabolism as Disease Tolerance: Implications for Sepsis-Associated Acute Kidney Injury. Nephron Clin Pract 2022; 146:291-294. [PMID: 34161955 PMCID: PMC8695642 DOI: 10.1159/000516877] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2021] [Accepted: 04/24/2021] [Indexed: 01/03/2023] Open
Abstract
Sepsis is a significant cause for mortality among critically ill patients. Metabolic derangements that develop in sepsis are often considered to be pathologic, contributing to sepsis morbidity and mortality. However, alterations in metabolism during sepsis are multifaceted and are incompletely understood. Acute anorexia during infection is an evolutionarily conserved response, suggesting a potential protective role of anorexia in the host response to infection. In animal models of bacterial inflammation, fasting metabolic programs associated with acute anorexia such as those regulated by fibroblast growth factor 21 and ketogenesis are associated with improved survival. Other fasting metabolic pathways such as fatty acid oxidation and autophagy are also implicated in preventing acute kidney injury (AKI). Global metabolic changes during sepsis and current clinical interventions can potentially affect disease tolerance mechanisms and modify the risk of AKI.
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Affiliation(s)
- Sarah C Huen
- Departments of Internal Medicine-Nephrology and Pharmacology, The University of Texas Southwestern Medical Center, Dallas, Texas, USA
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26
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Li Y, Hepokoski M, Gu W, Simonson T, Singh P. Targeting Mitochondria and Metabolism in Acute Kidney Injury. J Clin Med 2021; 10:3991. [PMID: 34501442 PMCID: PMC8432487 DOI: 10.3390/jcm10173991] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2021] [Revised: 08/20/2021] [Accepted: 08/25/2021] [Indexed: 12/21/2022] Open
Abstract
Acute kidney injury (AKI) significantly contributes to morbidity and mortality in critically ill patients. AKI is also an independent risk factor for the development and progression of chronic kidney disease. Effective therapeutic strategies for AKI are limited, but emerging evidence indicates a prominent role of mitochondrial dysfunction and altered tubular metabolism in the pathogenesis of AKI. Therefore, a comprehensive, mechanistic understanding of mitochondrial function and renal metabolism in AKI may lead to the development of novel therapies in AKI. In this review, we provide an overview of current state of research on the role of mitochondria and tubular metabolism in AKI from both pre-clinical and clinical studies. We also highlight current therapeutic strategies which target mitochondrial function and metabolic pathways for the treatment of AKI.
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Affiliation(s)
- Ying Li
- Division of Nephrology and Hypertension, University of California San Diego, San Diego, CA 92093, USA;
- VA San Diego Healthcare System, San Diego, CA 92161, USA;
| | - Mark Hepokoski
- VA San Diego Healthcare System, San Diego, CA 92161, USA;
- Division of Pulmonary, Critical Care and Sleep Medicine, University of California San Diego, San Diego, CA 92093, USA; (W.G.); (T.S.)
| | - Wanjun Gu
- Division of Pulmonary, Critical Care and Sleep Medicine, University of California San Diego, San Diego, CA 92093, USA; (W.G.); (T.S.)
| | - Tatum Simonson
- Division of Pulmonary, Critical Care and Sleep Medicine, University of California San Diego, San Diego, CA 92093, USA; (W.G.); (T.S.)
| | - Prabhleen Singh
- Division of Nephrology and Hypertension, University of California San Diego, San Diego, CA 92093, USA;
- VA San Diego Healthcare System, San Diego, CA 92161, USA;
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27
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Krüppel-like factor 6-mediated loss of BCAA catabolism contributes to kidney injury in mice and humans. Proc Natl Acad Sci U S A 2021; 118:2024414118. [PMID: 34074766 DOI: 10.1073/pnas.2024414118] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Altered cellular metabolism in kidney proximal tubule (PT) cells plays a critical role in acute kidney injury (AKI). The transcription factor Krüppel-like factor 6 (KLF6) is rapidly and robustly induced early in the PT after AKI. We found that PT-specific Klf6 knockdown (Klf6 PTKD) is protective against AKI and kidney fibrosis in mice. Combined RNA and chromatin immunoprecipitation sequencing analysis demonstrated that expression of genes encoding branched-chain amino acid (BCAA) catabolic enzymes was preserved in Klf6 PTKD mice, with KLF6 occupying the promoter region of these genes. Conversely, inducible KLF6 overexpression suppressed expression of BCAA genes and exacerbated kidney injury and fibrosis in mice. In vitro, injured cells overexpressing KLF6 had similar decreases in BCAA catabolic gene expression and were less able to utilize BCAA. Furthermore, knockdown of BCKDHB, which encodes one subunit of the rate-limiting enzyme in BCAA catabolism, resulted in reduced ATP production, while treatment with BCAA catabolism enhancer BT2 increased metabolism. Analysis of kidney function, KLF6, and BCAA gene expression in human chronic kidney disease patients showed significant inverse correlations between KLF6 and both kidney function and BCAA expression. Thus, targeting KLF6-mediated suppression of BCAA catabolism may serve as a key therapeutic target in AKI and kidney fibrosis.
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28
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Curtis LM, George J, Vallon V, Barnes S, Darley-Usmar V, Vaingankar S, Cutter GR, Gutierrez OM, Seifert M, Ix JH, Mehta RL, Sanders PW, Agarwal A. UAB-UCSD O'Brien Center for Acute Kidney Injury Research. Am J Physiol Renal Physiol 2021; 320:F870-F882. [PMID: 33779316 DOI: 10.1152/ajprenal.00661.2020] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Acute kidney injury (AKI) remains a significant clinical problem through its diverse etiologies, the challenges of robust measurements of injury and recovery, and its progression to chronic kidney disease (CKD). Bridging the gap in our knowledge of this disorder requires bringing together not only the technical resources for research but also the investigators currently endeavoring to expand our knowledge and those who might bring novel ideas and expertise to this important challenge. The University of Alabama at Birmingham-University of California-San Diego O'Brien Center for Acute Kidney Injury Research brings together technical expertise and programmatic and educational efforts to advance our knowledge in these diverse issues and the required infrastructure to develop areas of novel exploration. Since its inception in 2008, this O'Brien Center has grown its impact by providing state-of-the-art resources in clinical and preclinical modeling of AKI, a bioanalytical core that facilitates measurement of critical biomarkers, including serum creatinine via LC-MS/MS among others, and a biostatistical resource that assists from design to analysis. Through these core resources and with additional educational efforts, our center has grown its investigator base to include >200 members from 51 institutions. Importantly, this center has translated its pilot and catalyst funding program with a $37 return per dollar invested. Over 500 publications have resulted from the support provided with a relative citation ratio of 2.18 ± 0.12 (iCite). Through its efforts, this disease-centric O'Brien Center is providing the infrastructure and focus to help the development of the next generation of researchers in the basic and clinical science of AKI. This center creates the promise of the application at the bedside of the advances in AKI made by current and future investigators.
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Affiliation(s)
- Lisa M Curtis
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - James George
- Department of Surgery, University of Alabama at Birmingham, Birmingham, Alabama
| | - Volker Vallon
- Division of Nephrology, Department of Medicine, University of California-San Diego, San Diego, California
| | - Stephen Barnes
- Department of Pharmacology and Toxicology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Victor Darley-Usmar
- Department of Pathology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Sucheta Vaingankar
- Division of Pediatric Nephrology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Gary R Cutter
- School of Public Health, University of Alabama at Birmingham, Birmingham, Alabama
| | - Orlando M Gutierrez
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama
| | - Michael Seifert
- Division of Pediatric Nephrology, University of Alabama at Birmingham, Birmingham, Alabama
| | - Joachim H Ix
- Division of Nephrology, Department of Medicine, University of California-San Diego, San Diego, California
| | - Ravindra L Mehta
- Division of Nephrology, Department of Medicine, University of California-San Diego, San Diego, California
| | - Paul W Sanders
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama.,Department of Veterans Affairs, Birmingham, Alabama
| | - Anupam Agarwal
- Division of Nephrology, Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama.,Department of Veterans Affairs, Birmingham, Alabama
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29
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Schaub JA, Venkatachalam MA, Weinberg JM. Proximal Tubular Oxidative Metabolism in Acute Kidney Injury and the Transition to CKD. KIDNEY360 2020; 2:355-364. [PMID: 35373028 PMCID: PMC8740982 DOI: 10.34067/kid.0004772020] [Citation(s) in RCA: 27] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/06/2020] [Accepted: 12/22/2020] [Indexed: 02/04/2023]
Abstract
The proximal tubule relies on oxidative mitochondrial metabolism to meet its energy needs and has limited capacity for glycolysis, which makes it uniquely susceptible to damage during AKI, especially after ischemia and anoxia. Under these conditions, mitochondrial ATP production is initially decreased by several mechanisms, including fatty acid-induced uncoupling and inhibition of respiration related to changes in the shape and volume of mitochondria. Glycolysis is initially insufficient as a source of ATP to protect the cells and mitochondrial function, but supplementation of tricarboxylic acid cycle intermediates augments anaerobic ATP production, and improves recovery of mitochondrial oxidative metabolism. Incomplete recovery is characterized by defects of respiratory enzymes and lipid metabolism. During the transition to CKD, tubular cells atrophy but maintain high expression of glycolytic enzymes, and there is decreased fatty acid oxidation. These metabolic changes may be amenable to a number of therapeutic interventions.
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Affiliation(s)
- Jennifer A. Schaub
- Nephrology Division, Department of Medicine, University of Michigan, Ann Arbor, Michigan
| | | | - Joel M. Weinberg
- Nephrology Division, Department of Medicine, University of Michigan, Ann Arbor, Michigan
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30
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Liu Z, Tang C, He L, Yang D, Cai J, Zhu J, Shu S, Liu Y, Yin L, Chen G, Liu Y, Zhang D, Dong Z. The negative feedback loop of NF-κB/miR-376b/NFKBIZ in septic acute kidney injury. JCI Insight 2020; 5:142272. [PMID: 33328388 PMCID: PMC7819752 DOI: 10.1172/jci.insight.142272] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 11/04/2020] [Indexed: 12/29/2022] Open
Abstract
Sepsis is the leading cause of acute kidney injury (AKI). However, the pathogenesis of septic AKI remains largely unclear. Here, we demonstrate a significant decrease of microRNA-376b (miR-376b) in renal tubular cells in mice with septic AKI. Urinary miR-376b in these mice was also dramatically decreased. Patients with sepsis with AKI also had significantly lower urinary miR-376b than patients with sepsis without AKI, supporting its diagnostic value for septic AKI. LPS treatment of renal tubular cells led to the activation of NF-κB, and inhibition of NF-κB prevented a decrease of miR-376b. ChIP assay further verified NF-κB binding to the miR-376b gene promoter upon LPS treatment. Functionally, miR-376b mimics exaggerated tubular cell death, kidney injury, and intrarenal production of inflammatory cytokines, while inhibiting miR-376b afforded protective effects in septic mice. Interestingly, miR-376b suppressed the expression of NF-κB inhibitor ζ (NFKBIZ) in both in vitro and in vivo models of septic AKI. Luciferase microRNA target reporter assay further verified NFKBIZ as a direct target of miR-376b. Collectively, these results illustrate the NF-κB/miR-376b/NFKBIZ negative feedback loop that regulates intrarenal inflammation and tubular damage in septic AKI. Moreover, urinary miR-376b is a potential biomarker for the diagnosis of AKI in patients with sepsis.
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Affiliation(s)
| | | | - Liyu He
- Department of Nephrology and
| | | | | | | | | | | | | | | | - Yu Liu
- Department of Nephrology and
| | - Dongshan Zhang
- Department of Nephrology and.,Department of Emergency Medicine, The Second Xiangya Hospital at Central South University, Changsha, Hunan, China
| | - Zheng Dong
- Department of Nephrology and.,Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University and Charlie Norwood VA Medical Center, Augusta, Georgia, USA
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