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Background: Obesity is a major worldwide health problem and can be related to cellular senescence. Along with the rise in obesity, the comorbidity of renal ischemia-reperfusion (IR) injury is increasing. Whether obesity accelerates the severity of IR injury and whether senescence contributes to these conditions remain unclear. We studied the degree of injury and cellular senescence in the IR kidneys and perirenal adipose tissues of high-fat-diet-induced obese mice. Methods: C57BL/6 mice fed standard chow or a high-fat diet for 16 weeks were randomized to renal IR or sham group (n = 6-10 each). Renal IR was performed by unilateral clamping of the right renal pedicle for 30 minutes. Six weeks after surgery, renal function, perirenal fat/renal senescence, and histology were evaluated ex vivo. Results: Obese mice showed more renal tubular damage and fibrosis in IR injury than control mice, even though the degree of ischemic insult was comparable. Renal expression of senescence and its secretory phenotype was upregulated in either IR injury or with a high-fat diet and was further increased in the IR kidneys of obese mice. Fat senescence and the expression of tumor necrosis factor alpha were also increased, especially in the perirenal depot of the IR kidneys, with a high-fat diet. Conclusion: A high-fat diet aggravates IR injury in murine kidneys, which is associated, at least in part, with perirenal fat senescence and inflammation. These observations support the exploration of therapeutic targets of the adipo-renal axis in injured obese kidneys.
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A for-cause biopsy is performed to diagnose the cause of allograft dysfunction in kidney transplantation. We occasionally encounter ambiguous biopsy results in symptomatic kidney transplant recipients. Yet, the allograft survival outcome in symptomatic recipients with nonspecific allograft biopsy findings remains unclear. The purpose of this study was to analyze the impact of nonspecific for-cause biopsy findings in symptomatic kidney transplant recipients. We retrospectively collected records from 773 kidney transplant recipients between January 2008 and October 2021. The characteristics of transplant recipients with nonspecific findings in the first for-cause biopsy were analyzed. Nonspecific allograft biopsy findings were defined as other biopsy findings excluding rejection, borderline rejection, calcineurin inhibitor toxicity, infection, glomerulonephritis, and diabetic nephropathy. The graft outcome was compared between recipients who had never undergone a for-cause biopsy and those who had a first for-cause biopsy with nonspecific findings. The graft survival in recipients with nonspecific for-cause biopsy findings was comparable to that in recipients who did not require the for-cause biopsy before and after propensity score matching. Even in symptomatic kidney transplant recipients, nonspecific allograft biopsy findings might not be a poor prognostic factor for allograft survival compared to recipients who did not require the for-cause biopsy.
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Transplante de Rim , Humanos , Transplante de Rim/efeitos adversos , Estudos Retrospectivos , Transplantados , Rejeição de Enxerto/patologia , Sobrevivência de Enxerto , Aloenxertos , Biópsia , Rim/patologiaRESUMO
BACKGROUND: Sepsis is a major cause of acute kidney injury (AKI). Recent studies have demonstrated that ß-hydroxybutyrate (ß-HB) alleviates renal ischemia-reperfusion injury and cisplatin-induced renal injury in murine models. This study aimed to investigate whether ß-HB ameliorates sepsis-induced AKI (SIAKI) in a lipopolysaccharide (LPS)-induced mouse sepsis model. METHODS AND RESULTS: SIAKI was induced by intraperitoneally injecting LPS to C57BL/6 male mice. ß-HB was administrated intraperitoneally before LPS injection. The mice were divided into sham, ß-HB, LPS, and ß-HB + LPS groups. The histological damage score and serum creatinine level were significantly increased in the LPS group mice, but attenuated in the ß-HB + LPS group mice. The expression of phosphorylated nuclear factor-κB tumor necrosis factor-α/interleukin-6 and the number of F4/80-positive macrophages in the ß-HB + LPS group mice were lower than those in the LPS group mice. The number of TdT-mediated dUTP nick-end labeling (TUNEL)-positive tubular cells, cleaved caspase-3 expression, and Bax/Bcl-2 ratio in the ß-HB + LPS group mice were lower than those in the LPS group mice. CONCLUSION: ß-HB pre-treatment ameliorates SIAKI by reducing tubular apoptosis and inflammatory responses. Thus, ß-HB pre-treatment could be a potential prophylactic strategy against SIAKI.
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Injúria Renal Aguda , Sepse , Masculino , Camundongos , Animais , Ácido 3-Hidroxibutírico/farmacologia , Lipopolissacarídeos/farmacologia , Camundongos Endogâmicos C57BL , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/induzido quimicamente , Rim/metabolismo , Apoptose , Sepse/complicações , Sepse/tratamento farmacológico , Sepse/metabolismoRESUMO
The authors asked for an errata to correct the affiliation information. The corrected affiliations are as follows:Je Ho Ryu1,2, Jae Ryong Shim1, Tae Beom Lee1, Kwang Ho Yang1, Taeun Kim3, Seo Rin Kim4, Byung Hyun Choi1,21 Division of Hepato-Biliary-Pancreatic Surgery and Transplantation, Department of Surgery, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, South Korea2 Research Institute for Convergence of Biomedical Science and Technology, Pusan National University Yangsan Hospital, Yangsan, South Korea3 Department of Radiology, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Yangsan, South Korea4 Department of Internal medicine, Pusan National University Yangsan Hospital, Pusan National University School of Medicine, Yangsan, South KoreaThe change of affiliation does not affect the content or findings of the publication in any way. It is solely an update to the -authors' institutional affiliations.Reference:Je Ho Ryu, Jae Ryong Shim, Tae Beom Lee, Kwangho Yang, Taeun Kim, Seo Rin Kim, Byunghyun Choi. Modification of Venous Outflow to Avoid Thrombotic Graft Failure in Pancreas Transplantation. Ann Transplant. 2022; 27: e937514. DOI: 10.12659/AOT.937514.
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KAI1/CD82, a membrane tetraspanin protein, can prevent various cancers and retinal disorders through its anti-angiogenic and anti-metastatic capacity. However, little is known about its anti-inflammatory effect and molecular mechanism. Therefore, the present study aimed to inLPSvestigate effect of a recombinant protein of the large extracellular domain of human KAI1 (Gly 111-Leu 228, rhKAI1) on lipopolysaccharides (LPS)-stimulated RAW264.7 macrophage-like cells and mouse bone marrow-derived macrophages (BMDM) and to identify its underlying mechanism. Our data showed that rhKAI1 suppressed expression levels of classically macrophages (M1) phenotyperelated surface markers F4/80+CD86+ in LPS-stimulated BMDM and RAW264.7 cells. In addition, LPS markedly increased mRNA expression and release levels of pro-inflammatory cytokines and mediators such as interleukin (IL)-1ß, IL-6, tumor necrosis factor-α, cyclooxygenase-2, nitric oxide and prostaglandin E2, whereas these increases were substantially down-regulated by rhKAI1. Furthermore, LPS strongly increased expression of NF-κB p65 in the nuclei and phosphorylation of ERK, JNK, and p38 MAPK. However, nuclear translocation of NF-κB p65 and phosphorylation of JNK were greatly reversed in the presence of rhKAI1. Especially, rhKAI1 markedly suppressed expression of toll-like receptor (TLR4) and prevented binding of LPS with TLR4 through molecular docking predict analysis. Importantly, Glu 214 of rhKAI1 residue strongly interacted with Lys 360 of TLR4 residue, with a binding distance of 2.9 Å. Taken together, these findings suggest that rhKAI1 has an anti-inflammatory effect on LPS-polarized macrophages by interacting with TLR4 and down-regulating the JNK/NF-κB signaling pathway. [BMB Reports 2023; 56(6): 359-364].
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Lipopolissacarídeos , NF-kappa B , Animais , Camundongos , Humanos , NF-kappa B/metabolismo , Lipopolissacarídeos/farmacologia , Lipopolissacarídeos/metabolismo , Receptor 4 Toll-Like/metabolismo , Anti-Inflamatórios/farmacologia , Simulação de Acoplamento Molecular , Macrófagos/metabolismo , Células RAW 264.7 , Citocinas/metabolismo , Sistema de Sinalização das MAP Quinases , Proteína Kangai-1/metabolismo , Proteína Kangai-1/farmacologiaRESUMO
Procalcitonin (PCT) is a biomarker for diagnosing infections and guiding antibiotic therapy. In this study, we investigated whether PCT can predict survival and recovery at 28 days in critically ill patients with sepsis-induced acute kidney injury (SIAKI) receiving continuous renal replacement therapy (CRRT). We examined 649 patients with SIAKI who underwent CRRT in our intensive care unit. In a multivariable Cox regression analysis, a single PCT level at CRRT initiation was not associated with survival in all patients. However, the higher % PCT decrease over 72 hours after CRRT initiation was independently associated with the higher chance of 28-day survival (per 10% decrease, hazard ratio [HR] for mortality: 0.87, 95% confidence interval [CI]: 0.85-0.89; P < 0.001). Among the survivors, the % PCT decrease over 72 hours after CRRT initiation, not a single PCT level at CRRT initiation, was independently associated with recovery from dialysis (per 10% decrease, HR for renal recovery: 1.28, 95% CI:1.21-1.36; P < 0.001). This study demonstrated that the higher % PCT decrease was independently associated with the higher chance of survival and recovery from dialysis at 28 days in critically ill patients with SIAKI receiving CRRT. Thus, a decrease in the PCT level, not a single PCT level at CRRT initiation, could be a valuable tool for predicting prognosis in these patients.
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Injúria Renal Aguda , Terapia de Substituição Renal Contínua , Sepse , Humanos , Diálise Renal , Pró-Calcitonina , Terapia de Substituição Renal , Estado Terminal , Sepse/complicações , Sepse/terapia , Injúria Renal Aguda/terapia , Injúria Renal Aguda/complicações , Estudos RetrospectivosRESUMO
In retinal pigment epithelial (RPE) cells, transforming growth factor-beta (TGF-ß) plays a critical role in epithelial-mesenchymal transition (EMT), which contributes to various fibrotic retinal disorders. In the present study, we investigated the effect of recombinant human cluster of differentiation 82 (rhCD82), a tumor metastasis suppressor, on TGF-ß-induced EMT in the human RPE cell line APRE-19. The results show that TGF-ß1 significantly enhanced cell migration, invasion and the expression of EMT-mediate factors in ARPE-19 cells. However, rhCD82 markedly inhibited cell mobility and the expression of epithelial marker, zonula occludens-1, as well as increased the expression of mesenchymal markers, such as vimentin and α-smooth muscle actin in TGF-ß1-treated APRE-19 cells. In addition, TGF-ß1 upregulated the phosphorylation of Smad, extracellular signal regulated kinase (ERK) and glycogen synthase kinase-3ß (GSK-3ß), but only phosphorylation of Smad was suppressed by rhCD82. Noteworthy, rhCD82 greatly suppressed the expression of TGF-ß receptor I (TGFRI), TGFRII and integrins in TGF-ß1-treated APRE-19 cells. In particular, the result of molecular docking analysis and structural modeling show that rhCD82 partially interacts with the TGF-ß1 binding sites of TGFRI, TGFRII, integrin ß1 and integrin αv. Taken together, this finding suggested that rhCD82 suppressed TGF-ß1-induced EMT of RPE by blocking of Smad-dependent pathway, which is caused by rhCD82 interaction with TGFRs and integrins, suggesting new insight into CD82 as a potential therapeutic strategy in fibrotic retinal disorders.
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BACKGROUND: During the COVID-19 pandemic, maintenance of essential healthcare systems became very challenging. We describe the triage system of our institute, and assess the quality of care provided to critically ill non-COVID-19 patients requiring continuous renal replacement therapy (CRRT) during the pandemic. METHODS: We introduced an emergency triage pathway early in the pandemic. We retrospectively reviewed the medical records of patients who received CRRT in our hospital from January 2016 to March 2021. We excluded end-stage kidney disease patients on maintenance dialysis. Patients were stratified as medical and surgical patients. The time from hospital arrival to intensive care unit (ICU) admission, the time from hospital arrival to intervention/operation, and the in-hospital mortality rate were compared before (January 2016 to December 2019) and during (January 2021 to March 2021) the pandemic. RESULTS: The mean number of critically ill patients who received CRRT annually in the surgical department significantly decreased during the pandemic in (2016-2019: 76.5 ± 3.1; 2020: 56; p < 0.010). Age, sex, and the severity of disease at admission did not change, whereas the proportions of medical patients with diabetes (before: 44.4%; after: 56.5; p < 0.005) and cancer (before: 19.4%; after: 32.3%; p < 0.001) increased during the pandemic. The time from hospital arrival to ICU admission and the time from hospital arrival to intervention/operation did not change. During the pandemic, 59.6% of surgical patients received interventions/operations within 6 hours of hospital arrival. In Cox's proportional hazard modeling, the hazard ratio associated with the pandemic was 1.002 (0.778-1.292) for medical patients and 1.178 (0.783-1.772) for surgical patients. CONCLUSION: Our triage system maintained the care required by critically ill non-COVID-19 patients undergoing CRRT at our institution.
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Injúria Renal Aguda , COVID-19 , Terapia de Substituição Renal Contínua , Injúria Renal Aguda/epidemiologia , Injúria Renal Aguda/terapia , COVID-19/epidemiologia , COVID-19/terapia , Cuidados Críticos , Estado Terminal/terapia , Humanos , Unidades de Terapia Intensiva , Pandemias , Terapia de Substituição Renal , Estudos RetrospectivosRESUMO
BACKGROUND: Renal artery stenosis (RAS) is an important cause of chronic kidney disease and secondary hypertension. In animal models, renal ischemia leads to downregulation of growth factor expression and loss of intrarenal microcirculation. However, little is known about the sequelae of large-vessel occlusive disease on the microcirculation within human kidneys. METHOD: This study included five patients who underwent nephrectomy due to renovascular occlusion and seven nonstenotic discarded donor kidneys (four deceased donors). Micro-computed tomography was performed to assess microvascular spatial densities and tortuosity, an index of microvascular immaturity. Renal protein expression, gene expression and histology were studied in vitro using immunoblotting, polymerase chain reaction and staining. RESULTS: RAS demonstrated a loss of medium-sized vessels (0.2-0.3 mm) compared with donor kidneys (P = 0.037) and increased microvascular tortuosity. RAS kidneys had greater protein expression of angiopoietin-1, hypoxia-inducible factor-1α and thrombospondin-1 but lower protein expression of vascular endothelial growth factor (VEGF) than donor kidneys. Renal fibrosis, loss of peritubular capillaries (PTCs) and pericyte detachment were greater in RAS, yet they had more newly formed PTCs than donor kidneys. Therefore, our study quantified significant microvascular remodeling in the poststenotic human kidney. RAS induced renal microvascular loss, vascular remodeling and fibrosis. Despite downregulated VEGF, stenotic kidneys upregulated compensatory angiogenic pathways related to angiopoietin-1. CONCLUSIONS: These observations underscore the nature of human RAS as a microvascular disease distal to main vessel stenosis and support therapeutic strategies directly targeting the poststenotic kidney microcirculation in patients with RAS.
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Obstrução da Artéria Renal , Angiopoietina-1/metabolismo , Angiopoietina-1/uso terapêutico , Animais , Fibrose , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Rim/patologia , Obstrução da Artéria Renal/complicações , Circulação Renal/fisiologia , Trombospondinas/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo , Microtomografia por Raio-XRESUMO
Chronic ischemia triggers senescence in renal tubules and at least partly mediates kidney dysfunction and damage through a p16Ink4a -related mechanism. We previously showed that mesenchymal stromal/stem cells (MSCs) delivered systemically do not effectively decrease cellular senescence in stenotic murine kidneys. We hypothesized that selective MSC targeting to injured kidneys using an anti-KIM1 antibody (KIM-MSC) coating would enhance their ability to abrogate cellular senescence in murine renal artery stenosis (RAS). KIM-MSC were injected into transgenic INK-ATTAC mice, which are amenable for selective eradication of p16Ink4a+ cells, 4 weeks after induction of unilateral RAS. To determine whether KIM-MSC abolish p16Ink4a -dependent cellular senescence, selective clearance of p16Ink4a+ cells was induced in a subgroup of RAS mice using AP20187 over 3 weeks prior to KIM-MSC injection. Two weeks after KIM-MSC aortic injection, renal senescence, function, and tissue damage were assessed. KIM-MSC delivery decreased gene expression of senescence and senescence-associated secretory phenotype factors, and improved micro-MRI-derived stenotic-kidney glomerular filtration rate and perfusion. Renal fibrosis and tubular injury also improved after KIM-MSC treatment. Yet, their efficacy was slightly augmented by prior elimination of p16Ink4a+ senescent cells. Therefore, selective targeting of MSC to the injured kidney markedly improves their senolytic potency in murine RAS, despite incomplete eradication of p16+ cells. KIM-MSC may constitute a useful therapeutic strategy in chronic renal ischemic injury.
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Células-Tronco Mesenquimais , Obstrução da Artéria Renal , Animais , Senescência Celular , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Isquemia/metabolismo , Rim/metabolismo , Células-Tronco Mesenquimais/metabolismo , Camundongos , Camundongos Transgênicos , Obstrução da Artéria Renal/metabolismoRESUMO
RATIONALE: Neurofibromatosis type 1 (NF-1) is an autosomal-dominant neurocutaneous disorder that affects the skin, bones, and nervous system. The most common manifestation of kidney involvement is renal artery stenosis; glomerulonephritis is extremely rare. In this case report, we present a patient with NF-1 and immunoglobulin A nephropathy (IgAN). PATIENT CONCERNS: A 51-year-old Korean man previously diagnosed with NF-1 presented with persistent proteinuria and hematuria identified during a routine medical check-up. He had no history of hypertension or diabetes, and denied a history of alcohol use or smoking. DIAGNOSIS: The contrast-enhanced computed tomography scan revealed normal-sized kidneys and no evidence of renal artery stenosis. On the day of the kidney biopsy, laboratory tests showed a serum creatinine level of 1.1âmg/dL, urine protein/creatinine ratio of 1.3âg/g, and urine red blood cell count of >10 to 15/HPF. The kidney biopsy sample revealed IgAN grade III, according to Lee glomerular grading system. INTERVENTION: The patient was advised to take 4âmg of perindopril. OUTCOME: Three months after the treatment, the urine protein/creatinine ratio decreased to 0.6âg/g, with no change in the serum creatinine level (1.03âmg/dL). LESSONS: A genetic link between NF-1 and IgAN or other glomerular diseases is not established. However, activation of the mTOR pathway may explain this association.
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Glomerulonefrite por IGA/complicações , Neurofibromatose 1/complicações , Inibidores da Enzima Conversora de Angiotensina/uso terapêutico , Glomerulonefrite por IGA/tratamento farmacológico , Humanos , Masculino , Pessoa de Meia-Idade , Perindopril/uso terapêuticoRESUMO
BACKGROUND: Peripheral vascular diseases may induce chronic ischemia and cellular injury distal to the arterial obstruction. Cellular senescence involves proliferation arrest in response to stress, which can damage neighboring cells. Renal artery stenosis (RAS) induces stenotic-kidney dysfunction and injury, but whether these arise from cellular senescenceand their temporal pattern remain unknown. METHODS: Chronic renal ischemia was induced in transgenic INK-ATTAC and wild type C57BL/6 mice by unilateral RAS, and kidney function (in vivo micro-MRI) and tissue damage were assessed. Mouse healthy and stenotic kidneys were analyzed using unbiased single-cell RNA-sequencing. To demonstrate translational relevance, cellular senescence was studied in human stenotic kidneys. RESULTS: Using intraperitoneal AP20187 injections starting 1, 2, or 4 weeks after RAS, selective clearance of cells highly expressing p16Ink4a attenuated cellular senescence and improved stenotic-kidney function; however, starting treatment immediately after RAS induction was unsuccessful. Broader clearance of senescent cells, using the oral senolytic combination dasatinib and quercetin, in C57BL/6 RAS mice was more effective in clearing cells positive for p21 (Cdkn1a) and alleviating renal dysfunction and damage. Unbiased, single-cell RNA sequencing in freshly dissociated cells from healthy and stenotic mouse kidneys identified stenotic-kidney epithelial cells undergoing both mesenchymal transition and senescence. As in mice, injured human stenotic kidneys exhibited cellular senescence, suggesting this process is conserved. CONCLUSIONS: Maladaptive tubular cell senescence, involving upregulated p16 (Cdkn2a), p19 (Cdkn2d), and p21 (Cdkn1a) expression, is associated with renal dysfunction and injury in chronic ischemia. These findings support development of senolytic strategies to delay chronic ischemic renal injury.
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Senescência Celular/fisiologia , Inibidor p16 de Quinase Dependente de Ciclina/metabolismo , Isquemia/fisiopatologia , Rim/fisiopatologia , Insuficiência Renal Crônica/fisiopatologia , Quinases Ativadas por p21/metabolismo , Animais , Apoptose/efeitos dos fármacos , Caspase 8/metabolismo , Senescência Celular/efeitos dos fármacos , Senescência Celular/genética , Doença Crônica , Inibidor p16 de Quinase Dependente de Ciclina/genética , Inibidor de Quinase Dependente de Ciclina p19/metabolismo , Inibidor de Quinase Dependente de Ciclina p21/genética , Dasatinibe/farmacologia , Modelos Animais de Doenças , Ativação Enzimática/efeitos dos fármacos , Células Epiteliais/fisiologia , Transição Epitelial-Mesenquimal , Expressão Gênica , Fator de Crescimento Semelhante a EGF de Ligação à Heparina/genética , Humanos , Isquemia/etiologia , Rim/irrigação sanguínea , Rim/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Osteopontina/genética , Inibidores de Proteínas Quinases/farmacologia , Obstrução da Artéria Renal/complicações , Insuficiência Renal Crônica/etiologia , Insuficiência Renal Crônica/patologia , Análise de Sequência de RNA , Análise de Célula Única , Tacrolimo/análogos & derivados , Tacrolimo/farmacologia , Regulação para Cima , Quinases Ativadas por p21/genéticaRESUMO
Regenerative, cell-based therapy is a promising treatment option for diabetic kidney disease (DKD), which has no cure. To prepare for clinical translation, this systematic review and meta-analysis summarized the effect of cell-based interventions in DKD animal models and treatment-related factors modifying outcomes. Electronic databases were searched for original investigations applying cell-based therapy in diabetic animals with kidney endpoints (January 1998-May 2019). Weighted or standardized mean differences were estimated for kidney outcomes and pooled using random-effects models. Subgroup analyses tested treatment-related factor effects for outcomes (creatinine, urea, urine protein, fibrosis, and inflammation). In 40 studies (992 diabetic rodents), therapy included mesenchymal stem/stromal cells (MSC; 61%), umbilical cord/amniotic fluid cells (UC/AF; 15%), non-MSC (15%), and cell-derived products (13%). Tissue sources included bone marrow (BM; 65%), UC/AF (15%), adipose (9%), and others (11%). Cell-based therapy significantly improved kidney function while reducing injury markers (proteinuria, histology, fibrosis, inflammation, apoptosis, epithelial-mesenchymal-transition, oxidative stress). Preconditioning, xenotransplantation, and disease-source approaches were effective. MSC and UC/AF cells had greater effect on kidney function while cell products improved fibrosis. BM and UC/AF tissue sources more effectively improved kidney function and proteinuria vs adipose or other tissues. Cell dose, frequency, and administration route also imparted different benefits. In conclusion, cell-based interventions in diabetic animals improved kidney function and reduced injury with treatment-related factors modifying these effects. These findings may aid in development of optimal repair strategies through selective use of cells/products, tissue sources, and dose administrations to allow for successful adaptation of this novel therapeutic in human DKD.
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Diabetes Mellitus , Nefropatias Diabéticas , Transplante de Células-Tronco Mesenquimais , Células-Tronco Mesenquimais , Animais , Diabetes Mellitus/patologia , Nefropatias Diabéticas/metabolismo , Nefropatias Diabéticas/patologia , Nefropatias Diabéticas/terapia , Fibrose , Células-Tronco Mesenquimais/metabolismo , Cordão Umbilical/metabolismoRESUMO
Scattered tubular-like cells (STCs), dedifferentiated renal tubular epithelial cells, contribute to renal self-healing, but severe injury might blunt their effectiveness. We hypothesized that ischemic renovascular disease (RVD) induces senescence in STC and impairs their reparative potency. CD24+/CD133+ STCs were isolated from swine kidneys after 16 weeks of RVD or healthy controls. To test their reparative capabilities in injured kidneys, control or RVD-STC (5×105) were prelabeled and injected into the aorta of 2 kidneys, 1-clip (2k,1c) mice 2 weeks after surgery. Murine renal function and oxygenation were studied in vivo 2 weeks after injection using micro-magnetic resonance imaging, and fibrosis, tubulointerstitial injury, capillary density, and expression of profibrotic and inflammatory genes ex vivo. STC isolated from swine RVD kidneys showed increased gene expression of senescence and senescence-associated secretory phenotype markers and positive SA-ß-gal staining. Delivery of normal pig STCs in 2k,1c mice improved murine renal perfusion, blood flow, and glomerular filtration rate, and downregulated profibrotic and inflammatory gene expression. These renoprotective effects were blunted using STC harvested from RVD kidneys, which also failed to attenuate hypoxia, fibrosis, tubular injury, and capillary loss in injured mouse 2k,1c kidneys. Hence, RVD may induce senescence in endogenous STC and impair their reparative capacity. These observations implicate cellular senescence in the pathophysiology of ischemic kidney disease and support senolytic therapy to permit self-healing of senescent kidneys.
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Senescência Celular/fisiologia , Rim/patologia , Obstrução da Artéria Renal/patologia , Insuficiência Renal/patologia , Animais , Células Cultivadas , Feminino , Fibrose/metabolismo , Fibrose/patologia , Rim/metabolismo , Camundongos , Obstrução da Artéria Renal/metabolismo , Insuficiência Renal/metabolismo , SuínosRESUMO
Cell stress may give rise to insuperable growth arrest, which is defined as cellular senescence. Stenotic kidney (STK) ischemia and injury induced by renal artery stenosis (RAS) may be associated with cellular senescence. Mesenchymal stem cells (MSCs) decrease some forms of STK injury, but their ability to reverse senescence in RAS remains unknown. We hypothesized that RAS evokes STK senescence, which would be ameliorated by MSCs. Mice were studied after 4 weeks of RAS, RAS treated with adipose tissue-derived MSCs 2 weeks earlier, or sham. STK senescence-associated ß-galactosidase (SA-ß-Gal) activity was measured. Protein and gene expression was used to assess senescence and the senescence-associated secretory phenotype (SASP), and staining for renal fibrosis, inflammation, and capillary density. In addition, senescence was assessed as p16+ and p21+ urinary exosomes in patients with renovascular hypertension (RVH) without or 3 months after autologous adipose tissue-derived MSC delivery, and in healthy volunteers (HV). In RAS mice, STK SA-ß-Gal activity increased, and senescence and SASP marker expression was markedly elevated. MSCs improved renal function, fibrosis, inflammation, and capillary density, and attenuated SA-ß-Gal activity, but most senescence and SASP levels remained unchanged. Congruently, in human RVH, p21+ urinary exosomes were elevated compared to HV, and only slightly improved by MSC, whereas p16+ exosomes remained unchanged. Therefore, RAS triggers renal senescence in both mice and human subjects. MSCs decrease renal injury, but only partly mitigate renal senescence. These observations support exploration of targeted senolytic therapy in RAS.
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Senescência Celular/genética , Transplante de Células-Tronco Mesenquimais , Obstrução da Artéria Renal/terapia , beta-Galactosidase/genética , Tecido Adiposo/citologia , Animais , Modelos Animais de Doenças , Exossomos/genética , Humanos , Inflamação/genética , Inflamação/patologia , Inflamação/terapia , Rim/metabolismo , Rim/patologia , Células-Tronco Mesenquimais/citologia , Células-Tronco Mesenquimais/metabolismo , Camundongos , Obstrução da Artéria Renal/genética , Obstrução da Artéria Renal/patologiaRESUMO
Cellular senescence, a permanent arrest of cell proliferation, is characterized by a senescence-associated secretory phenotype (SASP), which reinforces senescence and exerts noxious effects on adjacent cells. Recent studies have suggested that transplanting small numbers of senescent cells suffices to provoke tissue inflammation. We hypothesized that senescent cells can directly augment renal injury. Primary scattered tubular-like cells (STCs) acquired from pig kidneys were irradiated by 10 Gy of cesium radiation, and 3 wk later cells were characterized for levels of senescence and SASP markers. Control or senescent STCs were then prelabeled and injected (5 × 105 cells) into the aorta of C57BL/6J mice. Four weeks later, renal oxygenation was studied in vivo using 16.4-T magnetic resonance imaging and function by plasma creatinine level. Renal markers of SASP, fibrosis, and microvascular density were evaluated ex vivo. Per flow cytometry, irradiation induced senescence in 80-99% of STCs, which showed increased gene expression of senescence and SASP markers, senescence-associated ß-galactosidase staining, and cytokine levels (especially IL-6) secreted in conditioned medium. Four weeks after injection, cells were detected engrafted in the mouse kidneys with no evidence for rejection. Plasma creatinine and renal tissue hypoxia increased in senescent compared with control cells. Senescent kidneys were more fibrotic, with fewer CD31+ endothelial cells, and showed upregulation of IL-6 gene expression. Therefore, exogenously delivered senescent renal STCs directly injure healthy mouse kidneys. Additional studies are needed to determine the role of endogenous cellular senescence in the pathogenesis of kidney injury and evaluate the utility of senolytic therapy.
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Proliferação de Células , Senescência Celular , Túbulos Renais/transplante , Rim/cirurgia , Animais , Proliferação de Células/efeitos da radiação , Células Cultivadas , Senescência Celular/efeitos da radiação , Feminino , Fibrose , Mediadores da Inflamação/metabolismo , Rim/metabolismo , Rim/patologia , Túbulos Renais/metabolismo , Túbulos Renais/patologia , Túbulos Renais/efeitos da radiação , Masculino , Camundongos Endogâmicos C57BL , Fenótipo , Sus scrofa , Transplante HeterólogoRESUMO
BACKGROUND/AIMS: Atherosclerotic renal artery stenosis (ARAS) may cause kidney injury and mitochondrial dysfunction, which is linked to cellular senescence. Elamipretide, a mitochondria-targeted peptide, improves renal function in ARAS, but whether it alleviates senescence is unknown. We hypothesized that elamipretide would reduce senescence stenotic kidney (STK) in ARAS. METHODS: Domestic pigs were randomized to control and unilateral ARAS untreated or treated with subcutaneous elamipretide (5d/wk) for 4 weeks starting after 6 weeks of ARAS or sham (n=6 each). After completion of treatment, STK renal blood flow (RBF) and glomerular filtration rate (GFR) were assessed in-vivo using multi-detector computed-tomography. Renal fibrosis and oxidative stress were analyzed in trichrome- and dihydroethidium-stained slides, respectively. Mitochondrial markers involved in the electrontransport chain (COX4, ATP/ADP ratio), biogenesis (PGC1α, PPARα), dynamics (MFN2, DRP1), and mitophagy (parkin, p62) were measured in the kidney using ELISA, western-blot, and immunohistochemistry. Cellular senescence (senescence-associated ß-galactosidase and heterochromatin foci, phosphorylated-H2AX, and p16/21/53) and senescence-associated secretory phenotype (SASP; PAI-1, MCP-1, TGFß, and TNFα) markers were studied by microscopy, quantitative reverse transcription-polymerase chain reaction, and western-blot. RESULTS: Blood pressure was elevated whereas STK-RBF and GFR were decreased in ARAS pigs, and tissue scarring was increased. ARAS induced STK cellular senescence and accumulated dysfunctional mitochondria, which were associated with cardiolipin loss, upregulated mitochondrial biogenesis, and defective mitophagy. Elamipretide normalized STK-RBF and GFR, alleviated fibrosis and oxidative stress, and restored mitochondrial cardiolipin, biogenesis, and mitophagy in ARAS, but did not change SASP markers, and attenuated only senescenceassociated ß-galactosidase activity and p53 gene expression. CONCLUSION: Mitochondrial protection improved renal function and fibrosis in the ARAS STK, but only partly mitigated cellular senescence. This finding suggests that mitochondrial dysfunction may not be a major determinant of cellular senescence in the early stage of ARAS.
Assuntos
Senescência Celular , Rim/fisiologia , Mitocôndrias/metabolismo , Obstrução da Artéria Renal/patologia , Animais , Cardiolipinas/metabolismo , Senescência Celular/efeitos dos fármacos , Creatinina/sangue , Dieta Hiperlipídica , Modelos Animais de Doenças , Feminino , Fibrose , Taxa de Filtração Glomerular , Rim/patologia , Mitocôndrias/efeitos dos fármacos , Mitofagia/efeitos dos fármacos , Oligopeptídeos/farmacologia , Oligopeptídeos/uso terapêutico , Estresse Oxidativo/efeitos dos fármacos , Coativador 1-alfa do Receptor gama Ativado por Proliferador de Peroxissomo/metabolismo , Obstrução da Artéria Renal/tratamento farmacológico , Obstrução da Artéria Renal/metabolismo , Circulação Renal/efeitos dos fármacos , Suínos , Proteína Supressora de Tumor p53/metabolismo , Ubiquitina-Proteína Ligases/metabolismoRESUMO
BACKGROUND: The collateral circulation is important in maintenance of blood supply to the ischemic kidney distal to renal artery stenosis (RAS). Obesity metabolic syndrome (MetS) preserves renal blood flow (RBF) in the stenotic kidney, but whether this is related to an increase of collateral vessel growth is unknown. We hypothesized that MetS increased collateral circulation around the renal artery. METHODS: Twenty-one domestic pigs were randomly divided into unilateral RAS fed an atherogenic (high-fat/high-fructose, MetS-RAS) or standard diet, or controls (n = 7 each). RBF, glomerular filtration rate (GFR), and the peristenotic collateral circulation were assessed after 10 weeks using multidetector computed tomography (CT) and the intrarenal microcirculation by micro-CT. Vascular endothelial growth factor (VEGF) expression was studied in the renal artery wall, kidney, and perirenal fat. Renal fibrosis and stiffness were examined by trichrome and magnetic resonance elastography. RESULTS: Compared with controls, RBF and GFR were decreased in RAS, but not in MetS-RAS. MetS-RAS formed peristenotic collaterals to the same extent as RAS pigs but induced greater intrarenal microvascular loss, fibrosis, stiffness, and inflammation. MetS-RAS also attenuated VEGF expression in the renal tissue compared with RAS, despite increased expression in the perirenal fat. CONCLUSIONS: MetS does not interfere with collateral vessel formation in the stenotic kidney, possibly because decreased renal arterial VEGF expression offsets its upregulation in perirenal fat, arguing against a major contribution of the collateral circulation to preserve renal function in MetS-RAS. Furthermore, preserved renal function does not protect the poststenotic kidney from parenchymal injury.
Assuntos
Circulação Colateral , Rim/irrigação sanguínea , Síndrome Metabólica/fisiopatologia , Microcirculação , Obstrução da Artéria Renal/fisiopatologia , Artéria Renal/fisiopatologia , Circulação Renal , Animais , Velocidade do Fluxo Sanguíneo , Modelos Animais de Doenças , Rim/patologia , Síndrome Metabólica/complicações , Síndrome Metabólica/metabolismo , Artéria Renal/metabolismo , Obstrução da Artéria Renal/complicações , Obstrução da Artéria Renal/metabolismo , Obstrução da Artéria Renal/patologia , Sus scrofa , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
Background: African American (AA) subjects with essential hypertension (EH) have greater inflammation and cardiovascular complications than Caucasian EH. An impaired endogenous cellular repair system may exacerbate vascular injury in hypertension, yet whether these differ between AA EH and Caucasian EH remains unknown. Vascular repair by circulating endothelial progenitor cells (EPCs) is controlled by regulators of EPC mobilization, homing, adhesion and new vessel formation, but can be hindered by various cytokines. We hypothesized that EPC levels and function would be impaired in AA EH compared with Caucasian EH, in association with increased levels of inflammatory mediators and EPC regulators. Methods: CD34+/KDR+ EPCs were isolated from inferior vena cava and renal vein blood samples of AA EH and Caucasian EH patients (n = 18 each) and from peripheral veins of 17 healthy volunteers (HVs) and enumerated using fluorescence-activated cell sorting. Angiogenic function of late-outgrowth endothelial cells expanded from these samples for 3 weeks was tested in vitro. Levels of inflammatory mediators, angiogenic factors and EPC regulators were measured by Luminex. Results: EPC levels were decreased in both AA and Caucasian EH compared with HVs, whereas their late-outgrowth endothelial cell angiogenic function was comparable. Levels of several inflammatory mediators were elevated in AA EH compared with Caucasian EH and HVs. Contrarily, vascular endothelial growth factor and its receptor-2 were lower. EPC levels inversely correlated with blood pressure in all hypertensive patients and estimated glomerular filtration rate with inflammatory mediators only in AA EH. Conclusions: Despite lower EPC numbers, decreased vascular endothelial growth factor signaling and inflammation, EPC function is preserved in AA EH compared with Caucasian EH and HVs, suggesting compensatory mechanisms for vascular repair.
Assuntos
Negro ou Afro-Americano/estatística & dados numéricos , Células Progenitoras Endoteliais/citologia , Hipertensão Essencial/fisiopatologia , Inflamação/patologia , Neovascularização Fisiológica , Fator A de Crescimento do Endotélio Vascular/metabolismo , População Branca/estatística & dados numéricos , Idoso , Pressão Sanguínea/fisiologia , Estudos de Casos e Controles , Células Cultivadas , Células Progenitoras Endoteliais/metabolismo , Hipertensão Essencial/metabolismo , Feminino , Taxa de Filtração Glomerular , Humanos , Inflamação/metabolismo , Masculino , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
Bladder rupture in patients undergoing renal transplant is rare. A 26-year-old man underwent a deceased-donor renal transplant. Postoperatively, he showed a good clinical course, but after removal of the urethral catheter, he complained of pain in the lower aspect of the abdomen and in the left flank. Findings of abdominal computed tomography and retrograde cystography revealed an extraperitoneal bladder rupture. We did not identify specific causes for this condition and believe that the bladder rupture was spontaneous. However, we could not rule out the possibility of traumatic rupture by the double-J ureteral stent. We decided to manage this case conservatively, with an indwelling urethral catheter and antibiotics, instead of by surgical repair. Results of repeated serial cystography during the treatment showed decreased contrast extravasation, and cystographic findings at 6 weeks showed no leakage of contrast medium. We confirmed complete healing of the ruptured bladder and removed the urethral catheter. Since then, the patient has maintained good renal function without any complications.