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Fu Y, Xiang Y, Li H, Chen A, Dong Z. Inflammation in kidney repair: Mechanism and therapeutic potential. Pharmacol Ther 2022; 237:108240. [PMID: 35803367 DOI: 10.1016/j.pharmthera.2022.108240] [Citation(s) in RCA: 28] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 06/29/2022] [Accepted: 06/30/2022] [Indexed: 02/07/2023]
Abstract
The kidney has a remarkable ability of repair after acute kidney injury (AKI). However, when injury is severe or persistent, the repair is incomplete or maladaptive and may lead to chronic kidney disease (CKD). Maladaptive kidney repair involves multiple cell types and multifactorial processes, of which inflammation is a key component. In the process of inflammation, there is a bidirectional interplay between kidney parenchymal cells and the immune system. The extensive and complex crosstalk between renal tubular epithelial cells and interstitial cells, including immune cells, fibroblasts, and endothelial cells, governs the repair and recovery of the injured kidney. Further research in this field is imperative for the discovery of biomarkers and promising therapeutic targets for kidney repair. In this review, we summarize the latest progress in the immune response and inflammation during maladaptive kidney repair, analyzing the interaction between immune cells and intrinsic kidney cells, pointing out the potentialities of inflammation-related pathways as therapeutic targets, and discussing the challenges and future research prospects in this field.
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Affiliation(s)
- Ying Fu
- Department of Nephrology, Hunan Key Laboratory of Kidney Disease and Blood Purification, The Second Xiangya Hospital at Central South University, Changsha 410011, China
| | - Yu Xiang
- Department of Nephrology, Hunan Key Laboratory of Kidney Disease and Blood Purification, The Second Xiangya Hospital at Central South University, Changsha 410011, China
| | - Honglin Li
- Department of Nephrology, Hunan Key Laboratory of Kidney Disease and Blood Purification, The Second Xiangya Hospital at Central South University, Changsha 410011, China
| | - Anqun Chen
- Department of Nephrology, Hunan Key Laboratory of Kidney Disease and Blood Purification, The Second Xiangya Hospital at Central South University, Changsha 410011, China
| | - Zheng Dong
- Department of Nephrology, Hunan Key Laboratory of Kidney Disease and Blood Purification, The Second Xiangya Hospital at Central South University, Changsha 410011, China; Department of Cellular Biology and Anatomy, Medical College of Georgia at Augusta University and Charlie Norwood VA Medical Center, Augusta, GA, USA.
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Liu D, Shu G, Jin F, Qi J, Xu X, Du Y, Yu H, Wang J, Sun M, You Y, Zhu M, Chen M, Zhu L, Shen Q, Ying X, Lou X, Jiang S, Du Y. ROS-responsive chitosan-SS31 prodrug for AKI therapy via rapid distribution in the kidney and long-term retention in the renal tubule. SCIENCE ADVANCES 2020; 6:6/41/eabb7422. [PMID: 33036968 PMCID: PMC7546709 DOI: 10.1126/sciadv.abb7422] [Citation(s) in RCA: 105] [Impact Index Per Article: 26.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/15/2020] [Accepted: 08/21/2020] [Indexed: 05/06/2023]
Abstract
The development of drugs with rapid distribution in the kidney and long-term retention in the renal tubule is a breakthrough for enhanced treatment of acute kidney injury (AKI). Here, l-serine-modified chitosan (SC) was synthesized as a potential AKI kidney-targeting agent due to the native cationic property of chitosan and specific interaction between kidney injury molecule-1 (Kim-1) and serine. Results indicated that SC was rapidly accumulated and long-term retained in ischemia-reperfusion-induced AKI kidneys, especially in renal tubules, which was possibly due to the specific interactions between SC and Kim-1. SC-TK-SS31 was then prepared by conjugating SS31, a mitochondria-targeted antioxidant, to SC via reactive oxygen species (ROS)-sensitive thioketal linker. Because of the effective renal distribution combined with ROS-responsive drug release behavior, the administration of SC-TK-SS31 led to an enhanced therapeutic effect of SS31 by protecting mitochondria from damage and reducing the oxidative stress, inflammation, and cell apoptosis.
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Affiliation(s)
- Di Liu
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, 866 Yu-Hang-Tang Road, Hangzhou 310058, China
| | - Gaofeng Shu
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, 866 Yu-Hang-Tang Road, Hangzhou 310058, China
| | - Feiyang Jin
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, 866 Yu-Hang-Tang Road, Hangzhou 310058, China
| | - Jing Qi
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, 866 Yu-Hang-Tang Road, Hangzhou 310058, China
| | - Xiaoling Xu
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, 866 Yu-Hang-Tang Road, Hangzhou 310058, China
| | - Yan Du
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, 866 Yu-Hang-Tang Road, Hangzhou 310058, China
| | - Hui Yu
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, 866 Yu-Hang-Tang Road, Hangzhou 310058, China
| | - Jun Wang
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, 866 Yu-Hang-Tang Road, Hangzhou 310058, China
| | - Mingchen Sun
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, 866 Yu-Hang-Tang Road, Hangzhou 310058, China
| | - Yuchan You
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, 866 Yu-Hang-Tang Road, Hangzhou 310058, China
| | - Minxia Zhu
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, 866 Yu-Hang-Tang Road, Hangzhou 310058, China
| | - Meixuan Chen
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, 866 Yu-Hang-Tang Road, Hangzhou 310058, China
| | - Luwen Zhu
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, 866 Yu-Hang-Tang Road, Hangzhou 310058, China
| | - Qiying Shen
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, 866 Yu-Hang-Tang Road, Hangzhou 310058, China
| | - Xiaoying Ying
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, 866 Yu-Hang-Tang Road, Hangzhou 310058, China
| | - Xuefang Lou
- School of Medicine, Zhejiang University City College, Hangzhou 310015, China.
| | - Saiping Jiang
- Department of Pharmacy, The First Affiliated Hospital, College of Medicine, Zhejiang University, 79 Qingchun Road, Hangzhou 310003, China.
| | - Yongzhong Du
- Institute of Pharmaceutics, College of Pharmaceutical Sciences, Zhejiang University, 866 Yu-Hang-Tang Road, Hangzhou 310058, China.
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Hu JB, Li SJ, Kang XQ, Qi J, Wu JH, Wang XJ, Xu XL, Ying XY, Jiang SP, You J, Du YZ. CD44-targeted hyaluronic acid-curcumin prodrug protects renal tubular epithelial cell survival from oxidative stress damage. Carbohydr Polym 2018; 193:268-280. [DOI: 10.1016/j.carbpol.2018.04.011] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2018] [Revised: 03/31/2018] [Accepted: 04/02/2018] [Indexed: 11/15/2022]
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Kannan N, Tang VW. Myosin-1c promotes E-cadherin tension and force-dependent recruitment of α-actinin to the epithelial cell junction. J Cell Sci 2018; 131:jcs.211334. [PMID: 29748378 DOI: 10.1242/jcs.211334] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/21/2017] [Accepted: 05/02/2018] [Indexed: 12/26/2022] Open
Abstract
Actomyosin II contractility in epithelial cell plays an essential role in tension-dependent adhesion strengthening. One key unsettling question is how cellular contraction transmits force to the nascent cell-cell adhesion when there is no stable attachment between the nascent adhesion complex and actin filament. Here, we show that myosin-1c is localized to the lateral membrane of polarized epithelial cells and facilitates the coupling between actin and cell-cell adhesion. Knockdown of myosin-1c compromised the integrity of the lateral membrane, reduced the generation of tension at E-cadherin, decreased the strength of cell-cell cohesion in an epithelial cell monolayer and prevented force-dependent recruitment of junctional α-actinin. Application of exogenous force to cell-cell adhesions in a myosin-1c-knockdown cell monolayer fully rescued the localization defect of α-actinin, indicating that junction mechanoregulation remains intact in myosin-1c-depleted cells. Our study identifies a role of myosin-1c in force transmission at the lateral cell-cell interface and underscores a non-junctional contribution to tension-dependent junction regulation.
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Affiliation(s)
- Nivetha Kannan
- Department of Cell and Developmental Biology, University of Illinois, Urbana-Champaign, IL 61801 USA
| | - Vivian W Tang
- Department of Cell and Developmental Biology, University of Illinois, Urbana-Champaign, IL 61801 USA
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Tsurkan MV, Hauser PV, Zieris A, Carvalhosa R, Bussolati B, Freudenberg U, Camussi G, Werner C. Growth factor delivery from hydrogel particle aggregates to promote tubular regeneration after acute kidney injury. J Control Release 2013; 167:248-55. [DOI: 10.1016/j.jconrel.2013.01.030] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2012] [Revised: 01/24/2013] [Accepted: 01/28/2013] [Indexed: 10/27/2022]
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Neuwirt H, Eder IE, Puhr M, Rudnicki M. SOCS-3 is downregulated in progressive CKD patients and regulates proliferation in human renal proximal tubule cells in a STAT1/3 independent manner. J Transl Med 2013; 93:123-34. [PMID: 23108375 DOI: 10.1038/labinvest.2012.154] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Proliferation and the sequence of epithelial to mesenchymal transition (EMT) and mesenchymal to epithelial transition (MET), called epithelial-mesenchymal-epithelial (EME) cycling are pivotal mechanisms of kidney repair and fibrosis. Furthermore, data suggest that dedifferentiation (EMT) is a prerequisite for proliferation of tubule cells. These processes have been shown to be regulated by STAT1/3 signaling. Suppressor of cytokine signaling-3 (SOCS-3) is a negative regulator of STAT1/3 signaling. Using a transcriptomics data set of patients with proteinuric kidney diseases we found that low levels of SOCS-3 RNA were associated with high-serum creatinine values in the long-term follow-up, which suggested a role of SOCS-3, regulated signaling in progression of chronic kidney disease. This result was validated in an independent cohort of patients with proteinuric nephropathies on protein level. In addition ∼60% of STAT target genes were differentially expressed in relation to stable kidney disease patients. Using two renal cellular models and SOCS-3 knockdown by short interfering RNA we investigated SOCS-3 effects on oncostatin M-induced STAT activation, differentiation and proliferation. SOCS-3 knockdown resulted in enhanced pSTAT1/3 phosphorylation and epithelial differentiation. The latter effect was only slightly enhanced by OSM treatment. Cellular proliferation was inhibited after SOCS-3 knockdown. This effect could not be further stimulated by OSM. Effects of SOCS-3 knockdown were not enhanced by downregulation of STAT1/3, suggesting a STAT independent effect on cell cycle regulators. Indeed, knockdown and overexpression of SOCS-3 were associated with decrease and increase of cyclin D1, -E and proliferation, respectively. In summary, SOCS-3 inhibits phosphorylation of pSTAT1/3 in renal tubule cells. Additionally, we show for the first time that-in vivo-loss of SOCS-3 is associated with unfavorable prognosis. In vitro, downregulation of SOCS-3 inhibits dedifferentiation (EMT) and cellular proliferation in kidney proximal tubule cells.
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Affiliation(s)
- Hannes Neuwirt
- Department of Internal Medicine IV, Nephrology and Hypertension, Medical University Innsbruck, Innsbruck, Austria.
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Fujikura T, Togawa A, Sun Y, Iwakura T, Yasuda H, Fujigaki Y. Dephosphorylated Ser985 of c-Met is associated with acquired resistance to rechallenge injury in rats that had recovered from uranyl acetate-induced subclinical renal damage. Clin Exp Nephrol 2012; 17:504-14. [PMID: 23250664 DOI: 10.1007/s10157-012-0757-5] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2012] [Accepted: 12/10/2012] [Indexed: 10/27/2022]
Abstract
BACKGROUND We previously reported that rats that had recovered from mild proximal tubule (PT) injury induced by a sub-toxic dose of uranyl acetate (UA) showed partial resistance to a subsequent nephrotoxic dose of UA in association with reduced renal dysfunction and accelerated PT proliferation. We demonstrated that this resistance may involve hepatocyte growth factor (HGF)/c-Met signaling. Here, we examined whether primary cultured tubular cells derived from this model had acquired sensitivity to HGF. METHODS Tubular cells were isolated by collagenase digestion from rat kidneys after recovery from UA-induced mild PT injury and were cultured for 48 h. Their survival and proliferation were examined using the MTS assay/5-bromo-2'-deoxyuridine labeling or MTS assay, respectively, and their migration was assayed using wound-healing and cell scattering assays, with/without HGF. HGF/c-Met signaling was assayed using phospho-specific antibodies. RESULTS HGF-stimulated cultured tubular cells from UA-treated rats showed better survival after UA exposure and higher proliferation and migration than cells from vehicle-treated rats. Furthermore, HGF induced higher phosphorylation of c-Met (Tyr1234/1235) and of its major downstream signals (AKT and extracellular signal-regulated kinase 1/2) with maintained dephosphorylation of Ser985 as a negative regulator of HGF/c-Met signaling in the tubular cells of UA-treated rats compared to those of vehicle-treated rats. Immunohistochemically, dephosphorylated Ser985 was confirmed in PT cells in vivo. CONCLUSIONS These results suggest that elevated sensitivity to HGF, via dephosphorylated Ser985 of c-Met of tubular cells that had recovered from mild tubular injury, may be associated with cytoprotection, accelerated proliferation and migration.
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Affiliation(s)
- Tomoyuki Fujikura
- Internal Medicine 1, Hamamatsu University School of Medicine, 1-20-1 Handayama, Higashiku, Hamamatsu, Shizuoka, 431-3192, Japan
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Zhang H, Bai H, Yi Z, He X, Mo S. Effect of Stem Cell Factor and Granulocyte-Macrophage Colony-Stimulating Factor-Induced Bone Marrow Stem Cell Mobilization on Recovery from Acute Tubular Necrosis in Rats. Ren Fail 2012; 34:350-7. [DOI: 10.3109/0886022x.2011.647340] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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Singbartl K, Kellum JA. AKI in the ICU: definition, epidemiology, risk stratification, and outcomes. Kidney Int 2011; 81:819-25. [PMID: 21975865 DOI: 10.1038/ki.2011.339] [Citation(s) in RCA: 313] [Impact Index Per Article: 24.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Acute kidney injury (AKI) has emerged as a major public health problem that affects millions of patients worldwide and leads to decreased survival and increased progression of underlying chronic kidney disease (CKD). Recent consensus criteria for definition and classification of AKI have provided more consistent estimates of AKI epidemiology. Patients, in particular those in the ICU, are dying of AKI and not just simply with AKI. Even small changes in serum creatinine concentrations are associated with a substantial increase in the risk of death. AKI is not a single disease but rather a syndrome comprising multiple clinical conditions. Outcomes from AKI depend on the underlying disease, the severity and duration of renal impairment, and the patient's renal baseline condition. The development of AKI is the consequence of complex interactions between the actual insult and subsequent activation of inflammation and coagulation. Contrary to the conventional view, recent experimental and clinical data argue against renal ischemia-reperfusion as a sine qua non condition for the development of AKI. Loss of renal function can occur without histological signs of tubular damage or even necrosis. The detrimental effects of AKI are not limited to classical well-known symptoms such as fluid overload and electrolyte abnormalities. AKI can also lead to problems that are not readily appreciated at the bedside and can extend well beyond the ICU stay, including progression of CKD and impaired innate immunity. Experimental and small observational studies provide evidence that AKI impairs (innate) immunity and is associated with higher infection rates.
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Affiliation(s)
- Kai Singbartl
- Department of Critical Care Medicine, Clinical Research, Investigation, and Systems Modeling of Acute Illness Center, University of Pittsburgh, Pittsburgh, Pennsylvania 15261, USA
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Acquired resistance to rechallenge injury in rats that recovered from mild renal damage induced by uranyl acetate: accelerated proliferation and hepatocyte growth factor/c-Met axis. Clin Exp Nephrol 2011; 15:666-675. [DOI: 10.1007/s10157-011-0453-x] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2011] [Accepted: 04/07/2011] [Indexed: 11/27/2022]
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Ding Z, Chen Z, Chen X, Cai M, Guo H, Chen X, Gong N. Adenovirus-mediated anti-sense ERK2 gene therapy inhibits tubular epithelial-mesenchymal transition and ameliorates renal allograft fibrosis. Transpl Immunol 2011; 25:34-41. [PMID: 21530658 DOI: 10.1016/j.trim.2011.04.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Revised: 03/30/2011] [Accepted: 04/05/2011] [Indexed: 02/01/2023]
Abstract
PURPOSE Epithelial-mesenchymal transition (EMT) plays an important role in progress of renal allograft fibrosis. The adenovirus-mediated anti-sense extracellular signal-regulated kinase 2 (Adanti-ERK2) gene therapy was used to block ERK signaling pathway, and its effect on EMT and renal allograft fibrosis both in vivo and in vitro was explored. METHODS We first generated an in vitro EMT model by connective tissue growth factor (CTGF) stimulation in a HK-2 cell culture system, and then applied Adanti-ERK2 gene therapy on it. The transition of epithelial marker (E-cadherin) to mesenchymal markers (α-SMA, Vimentin) and the cell mobility function alteration were monitored for the observation of EMT progress. In vivo, a rat renal transplant model with Fisher-Lewis combination was employed and the Adanti-ERK2 gene therapy was given. The tubular EMT changes and pathology of allograft fibrosis were examined. RESULTS In vitro, Adanti-ERK2 gene therapy inhibited CTGF-induced tubular EMT and attenuated the cell motility function induced by CTGF. In vivo, Adanti-ERK2 gene therapy attenuated tubular EMT, modulated the infiltration of macrophages and CD8(+), CD4(+)T lymphocytes, and ameliorated fibrosis effectively in the renal allografts 24weeks after transplantation. CONCLUSIONS Adanti-ERK2 gene therapy inhibits tubular EMT and attenuates renal allograft fibrosis. It is possible to develop promising molecular drug(s) in the future based on ERK signaling pathway.
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Affiliation(s)
- Zhao Ding
- Institute of Organ Transplantation, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, China
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Sekine M, Monkawa T, Morizane R, Matsuoka K, Taya C, Akita Y, Joh K, Itoh H, Hayashi M, Kikkawa Y, Kohno K, Suzuki A, Yonekawa H. Selective depletion of mouse kidney proximal straight tubule cells causes acute kidney injury. Transgenic Res 2011; 21:51-62. [PMID: 21431867 PMCID: PMC3264875 DOI: 10.1007/s11248-011-9504-z] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2010] [Accepted: 03/08/2011] [Indexed: 12/27/2022]
Abstract
The proximal straight tubule (S3 segment) of the kidney is highly susceptible to ischemia and toxic insults but has a remarkable capacity to repair its structure and function. In response to such injuries, complex processes take place to regenerate the epithelial cells of the S3 segment; however, the precise molecular mechanisms of this regeneration are still being investigated. By applying the “toxin receptor mediated cell knockout” method under the control of the S3 segment-specific promoter/enhancer, Gsl5, which drives core 2 β-1,6-N-acetylglucosaminyltransferase gene expression, we established a transgenic mouse line expressing the human diphtheria toxin (DT) receptor only in the S3 segment. The administration of DT to these transgenic mice caused the selective ablation of S3 segment cells in a dose-dependent manner, and transgenic mice exhibited polyuria containing serum albumin and subsequently developed oliguria. An increase in the concentration of blood urea nitrogen was also observed, and the peak BUN levels occurred 3–7 days after DT administration. Histological analysis revealed that the most severe injury occurred in the S3 segments of the proximal tubule, in which tubular cells were exfoliated into the tubular lumen. In addition, aquaporin 7, which is localized exclusively to the S3 segment, was diminished. These results indicate that this transgenic mouse can suffer acute kidney injury (AKI) caused by S3 segment-specific damage after DT administration. This transgenic line offers an excellent model to uncover the mechanisms of AKI and its rapid recovery.
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Affiliation(s)
- Michiko Sekine
- Department of Laboratory Animal Science, Tokyo Metropolitan Institute of Medical Science, 2-1-6 Kami-kitazawa, Setagaya-ku, Tokyo, 156-8506, Japan
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Acquired resistance to rechallenge injury in rats recovered from subclinical renal damage with uranyl acetate--Importance of proliferative activity of tubular cells. Toxicol Appl Pharmacol 2009; 243:104-10. [PMID: 19931553 DOI: 10.1016/j.taap.2009.11.018] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2009] [Revised: 10/25/2009] [Accepted: 11/10/2009] [Indexed: 02/07/2023]
Abstract
Animals recovered from acute renal failure are resistant to subsequent insult. We investigated whether rats recovered from mild proximal tubule (PT) injury without renal dysfunction (subclinical renal damage) acquire the same resistance. Rats 14 days after recovering from subclinical renal damage, which was induced by 0.2 mg/kg of uranyl acetate (UA) (sub-toxic dose), were rechallenged with 4 mg/kg of UA (nephrotoxic dose). Fate of PT cells and renal function were examined in response to nephrotoxic dose of UA. All divided cells after sub-toxic dose of UA insult were labeled with bromodeoxyuridine (BrdU) for 14 days then the number of PT cells with or without BrdU-labeling was counted following nephrotoxic dose of UA insult. Rats recovered from subclinical renal damage gained resistance to nephrotoxic dose of UA with reduced renal dysfunction, less severity of peak damage (necrotic and TUNEL+ apoptotic cells) and accelerated PT cell proliferation, but with earlier peak of PT damage. The decrease in number of PT cells in the early phase of rechallenge injury with nephrotoxic UA was more in rats pretreated with sub-toxic dose of UA than vehicle pretreated rats. The exaggerated loss of PT cells was mainly caused by the exaggerated loss of BrdU+ divided cells. In contrast, accelerated cell proliferation in rats recovered from sub-toxic dose of UA was observed mainly in BrdU- non-divided cells. The findings suggest that rats recovered from subclinical renal damage showed partial acquired resistance to nephrotoxic insult. Accelerated recovery with increased proliferative activity of non-divided PT cells after subclinical renal damage may mainly contribute to acquired resistance.
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Physiological basis for the use of erythropoietin in critically ill patients at risk for acute kidney injury. Curr Opin Crit Care 2009; 14:621-6. [PMID: 19005302 DOI: 10.1097/mcc.0b013e328317ee82] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
PURPOSE OF REVIEW Acute kidney injury (AKI) frequently occurs in critically ill patients and is an independent risk factor for poor outcome. The prevention of kidney injury in intensive care remains a great challenge as specific nephroprotective therapies are still lacking. The present review summarizes recent evidence for the use of erythropoietin as a promising candidate to provide protection from AKI. RECENT FINDINGS Beyond the known hematopoietic actions of erythropoietin, a number of preclinical studies demonstrated that erythropoietin possesses pleiotropic, organ-protecting properties. Preconditional and postconditional erythropoietin treatment was shown to protect from ischemic, toxic and septic AKI. Despite heterogeneities in study design and dose, erythropoietin consistently ameliorated renal injury. The mechanisms of protection remain largely unclear but may involve reduction of apoptosis, induction of cellular proliferation and tissue repair as well as mobilization of stem cells. SUMMARY Animal studies revealed a physiological basis for the use of erythropoietin in AKI, which may be clinically applicable to prevent AKI in critically ill patients, but clinical studies are still lacking.
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