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1.
Sci Rep ; 10(1): 7351, 2020 Apr 30.
Artigo em Inglês | MEDLINE | ID: mdl-32355258

RESUMO

The Japan Chronic Kidney Disease (CKD) Database (J-CKD-DB) is a large-scale, nation-wide registry based on electronic health record (EHR) data from participating university hospitals. Using a standardized exchangeable information storage, the J-CKD-DB succeeded to efficiently collect clinical data of CKD patients across hospitals despite their different EHR systems. CKD was defined as dipstick proteinuria ≥1+ and/or estimated glomerular filtration rate <60 mL/min/1.73 m2 base on both out- and inpatient laboratory data. As an initial analysis, we analyzed 39,121 CKD outpatients (median age was 71 years, 54.7% were men, median eGFR was 51.3 mL/min/1.73 m2) and observed that the number of patients with a CKD stage G1, G2, G3a, G3b, G4 and G5 were 1,001 (2.6%), 2,612 (6.7%), 23,333 (59.6%), 8,357 (21.4%), 2,710 (6.9%) and 1,108 (2.8%), respectively. According to the KDIGO risk classification, there were 30.1% and 25.5% of male and female patients with CKD at very high-risk, respectively. As the information from every clinical encounter from those participating hospitals will be continuously updated with an anonymized patient ID, the J-CKD-DB will be a dynamic registry of Japanese CKD patients by expanding and linking with other existing databases and a platform for a number of cross-sectional and prospective analyses to answer important clinical questions in CKD care.

2.
Nephrol Dial Transplant ; 35(5): 773-781, 2020 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-32221606

RESUMO

BACKGROUND: Long-term exposure to bioincompatible peritoneal dialysate causes the loss of mesothelial cells and accumulation of matrix proteins, leading to an increase in the thickness of the submesothelial layer, thereby limiting the long-term effectiveness of peritoneal dialysis (PD). However, the detailed molecular mechanisms underlying the process of peritoneal fibrosis have not been clearly elucidated. Wnt/ß-catenin signaling pathway activation has been suggested to play a pivotal role in the development of organ fibrosis. Moreover, Klotho protein can regulate Wnt/ß-catenin signaling. We examined the role of Klotho protein in reducing peritoneal fibrosis by inhibiting Wnt/ß-catenin signaling. METHODS: The ß-catenin-activated transgenic (BAT) driving expression of nuclear ß-galactosidase reporter transgenic (BAT-LacZ) mice, the alpha-Klotho gene under control of human elongation factor 1 alpha promoter [Klotho transgenic (KLTG) and C57BL/6 background] and C57BL/6 mice [wild-type (WT)] were used. The mice received daily intraperitoneal (i.p.) injections of 4.25% glucose with lactate (PD solution) or saline as a control for 4 weeks. Other mice received daily i.p. injections of the same volume of saline (normal control). RESULTS: After exposure to PD, Wnt signal activation was observed on the peritoneal mesothelial cells in WT-PD mice. The peritoneal fibrosis was also accelerated in WT-PD mice. The protein expression of ß-catenin and Wnt-inducible genes were also remarkably increased in WT-PD mice. On the other hand, KLTG-PD mice attenuated activation of Wnt/ß-catenin signaling after exposure to PD and ameliorated the progression of peritoneal fibrosis. CONCLUSIONS: Overexpression of Klotho protein protects the peritoneal membrane through attenuation of the Wnt/ß-catenin signaling pathway. The availability of recombinant Klotho protein would provide a novel potential therapeutic target in peritoneal fibrosis.

3.
FASEB J ; 33(11): 12253-12263, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31431054

RESUMO

Multiple clinical studies have shown that bardoxolone methyl, a potent activator of nuclear factor erythroid 2-related factor 2 (Nrf2), is effective in increasing glomerular filtration rate in patients with chronic kidney disease. However, whether an Nrf2 activator can protect tubules from proteinuria-induced tubular damage via anti-inflammatory and antioxidative stress mechanisms is unknown. Using an Institute of Cancer Research-derived glomerulonephritis (ICGN) mouse model of nephrosis, we examined the effects of dihydro-CDDO-trifluoroethyl amide (dh404), a rodent-tolerable bardoxolone methyl analog, in protecting the tubulointerstitium; dh404 markedly suppressed tubular epithelial cell damage in the renal interstitium of ICGN mice. The tubular epithelial cells of ICGN mice showed a decrease in the size and number of mitochondria, as well as the breakdown of the crista structure, whereas the number and ultrastructure of mitochondria were maintained by the dh404 treatment. To further determine the effect of dh404 on mitochondrial function, we used human proximal tubular cells in vitro. Stimulation with albumin and free fatty acid increased mitochondrial reactive oxygen species (ROS). However, dh404 administration diminished mitochondrial ROS. Our data show that dh404 significantly reduced proteinuria-induced tubular cell mitochondrial damage, suggesting that improved redox balance and mitochondrial function and suppression of inflammation underlie the cytoprotective mechanism of Nrf2 activators, including bardoxolone methyl, in diabetic kidney disease.-Nagasu, H., Sogawa, Y., Kidokoro, K., Itano, S., Yamamoto, T., Satoh, M., Sasaki, T., Suzuki, T., Yamamoto, M., Wigley, W. C., Proksch, J. W., Meyer, C. J., Kashihara, N. Bardoxolone methyl analog attenuates proteinuria-induced tubular damage by modulating mitochondrial function.

4.
Cells ; 8(5)2019 04 30.
Artigo em Inglês | MEDLINE | ID: mdl-31052273

RESUMO

SH3 domain-binding protein 2 (SH3BP2) is an adaptor protein that is predominantly expressed in immune cells, and it regulates intracellular signaling. We had previously reported that a gain-of-function mutation in SH3BP2 exacerbates inflammation and bone loss in murine arthritis models. Here, we explored the involvement of SH3BP2 in a lupus model. Sh3bp2 gain-of-function (P416R knock-in; Sh3bp2KI/+) mice and lupus-prone B6.MRL-Faslpr mice were crossed to yield double-mutant (Sh3bp2KI/+Faslpr/lpr) mice. We monitored survival rates and proteinuria up to 48 weeks of age and assessed renal damage and serum anti-double-stranded DNA antibody levels. Additionally, we analyzed B and T cell subsets in lymphoid tissues by flow cytometry and determined the expression of apoptosis-related molecules in lymph nodes. Sh3bp2 gain-of-function mutation alleviated the poor survival rate, proteinuria, and glomerulosclerosis and significantly reduced serum anti-dsDNA antibody levels in Sh3bp2KI/+Faslpr/lpr mice. Additionally, B220+CD4-CD8- T cell population in lymph nodes was decreased in Sh3bp2KI/+Faslpr/lpr mice, which is possibly associated with the observed increase in cleaved caspase-3 and tumor necrosis factor levels. Sh3bp2 gain-of-function mutation ameliorated clinical and immunological phenotypes in lupus-prone mice. Our findings offer better insight into the unique immunopathological roles of SH3BP2 in autoimmune diseases.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Mutação com Ganho de Função/genética , Lúpus Eritematoso Sistêmico/genética , Lúpus Eritematoso Sistêmico/patologia , Animais , Anticorpos Antinucleares/sangue , Apoptose , Linfócitos B/imunologia , Caspase 3/metabolismo , Diferenciação Celular , Células Dendríticas/metabolismo , Lúpus Eritematoso Sistêmico/sangue , Linfonodos/patologia , Macrófagos/metabolismo , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos MRL lpr , Fagocitose , Fenótipo , Análise de Sobrevida , Linfócitos T/imunologia , Fator de Necrose Tumoral alfa/metabolismo , Receptor fas/metabolismo
5.
Circulation ; 140(4): 303-315, 2019 Jul 23.
Artigo em Inglês | MEDLINE | ID: mdl-30773020

RESUMO

BACKGROUND: Sodium glucose cotransporter 2 inhibitors may reduce kidney hyperfiltration, thereby preventing diabetic kidney disease progression, which may in turn reduce cardiovascular risk, including heart failure. However, the mechanisms that regulate renal function responses to sodium glucose cotransporter 2 inhibition are not yet fully understood. We explored the renal protective effects of sodium glucose cotransporter 2 inhibition with empagliflozin, with a focus on glomerular hemodynamic effects and tubuloglomerular feedback using in vivo multiphoton microscopy imaging techniques. METHODS: C57BL/6 mice and spontaneously diabetic Ins2+/Akita mice were studied. The mice were treated with empagliflozin (20 mg·kg-1·d-1) and insulin for 4 weeks, and the single-nephron glomerular filtration rate was measured using multiphoton microscope. A neuronal nitric oxide synthase inhibitor (7-nitroindazole, 20 mg·kg-1·d-1) or a cyclooxygenase-2 inhibitor (SC58236, 6 mg/L), or an A1 adenosine receptor antagonist (8-cyclopentyl-1,3-dipropylxanthine, 1 mg·kg-1·d-1) was administered to elucidate the mechanisms of tubuloglomerular feedback signaling and single-nephron glomerular filtration rate regulation. RESULTS: The urinary excretion of adenosine, nitric oxide metabolites, and the prostanoid prostaglandin E2 was also quantified. The single-nephron glomerular filtration rate in the Ins2+/Akita group was higher than in controls (C57BL/6; 4.9±1.3 nL/min versus Ins2+/Akita; 15.8±6.8 nL/min) and lower in Ins2+/Akita /empagliflozin to 8.0±3.3 nL/min (P<0.01). In vivo imaging also revealed concomitant afferent arteriolar dilation (P<0.01) and increased glomerular permeability of albumin in the Ins2+/Akita group. Empagliflozin ameliorated these changes (P<0.01). Urinary adenosine excretion in the Ins2+/Akita/empagliflozin group was higher than in Ins2+/Akita (Ins2+/Akita; 3.4±1.4 nmol/d, Ins2+/Akita/empagliflozin; 11.2±3.0 nmol/d, P<0.05), whereas nitric oxide metabolites and prostaglandin E2 did not differ. A1 adenosine receptor antagonism, but not neuronal nitric oxide synthase or cyclooxygenase-2 inhibition, blocked the effect of empagliflozin on renal function. Empagliflozin increased urinary adenosine excretion and reduced hyperfiltration via afferent arteriolar constriction, effects that were abolished by A1 adenosine receptor blockade. CONCLUSIONS: Adenosine/A1 adenosine receptor pathways play a pivotal role in the regulation of the single-nephron glomerular filtration rate via tubuloglomerular feedback mechanisms in response to sodium glucose cotransporter 2 inhibition, which may contribute to renal and cardiovascular protective effects reported in clinical trials.

6.
Nephrology (Carlton) ; 24(1): 28-38, 2019 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-29068550

RESUMO

AIM: Acute kidney injury (AKI) is associated with chronic kidney disease, as well as high mortality, but effective treatments for AKI are still lacking. A recent study reported the prevention of renal injury, such as ischemia-reperfusion injury, by 5-aminolevulinic acid (ALA), which induces an antioxidant effect. The current study aimed to investigate the effect of ALA in a rhabdomyolysis-induced mouse model of AKI created by intramuscular injection of 50% glycerol. METHODS: Rhabdomyolysis-induced AKI was induced by an intramuscular injection of glycerol (5 mL/kg body weight) into mice. Administration of ALA (30 mg/kg, by gavage) was started from 48 h before or 24 h after glycerol injection. The mice were sacrificed at 72 h after glycerol injection. The roles of nuclear factor erythroid 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1), which is one of the Nrf2-related antioxidants, were further investigated through in vivo and in vitro methods. RESULTS: 5-aminolevulinic acid markedly reduced renal dysfunction and tubular damage in mice with rhabdomyolysis-induced AKI. ALA administration decreased oxidative stress, macrophage infiltration, and inflammatory cytokines and apoptosis. The expression of Nrf2 was upregulated by ALA administration. However, administration of Zinc protoporphyrin-9 (ZnPPIX) to inhibit HO-1 activity did not abolish these improvements by ALA. The expression of Nrf2-associated antioxidant factors other than HO-1 was also increased. CONCLUSION: These findings indicate that ALA exerts its antioxidant activity via Nrf2-associated antioxidant factors to provide a renoprotective effect against rhabdomyolysis-induced AKI.


Assuntos
Lesão Renal Aguda/prevenção & controle , Ácido Aminolevulínico/farmacologia , Antioxidantes/farmacologia , Túbulos Renais/efeitos dos fármacos , Fator 2 Relacionado a NF-E2/agonistas , Rabdomiólise/prevenção & controle , Lesão Renal Aguda/induzido quimicamente , Lesão Renal Aguda/metabolismo , Lesão Renal Aguda/patologia , Animais , Apoptose/efeitos dos fármacos , Células Cultivadas , Citocinas/metabolismo , Citoproteção , Modelos Animais de Doenças , Glicerol , Heme Oxigenase-1/metabolismo , Humanos , Mediadores da Inflamação/metabolismo , Túbulos Renais/metabolismo , Túbulos Renais/patologia , Macrófagos/efeitos dos fármacos , Macrófagos/metabolismo , Macrófagos/patologia , Masculino , Camundongos Endogâmicos C57BL , Fator 2 Relacionado a NF-E2/genética , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Rabdomiólise/induzido quimicamente , Rabdomiólise/metabolismo , Rabdomiólise/patologia , Transdução de Sinais/efeitos dos fármacos
7.
PLoS One ; 13(10): e0203823, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-30281670

RESUMO

Hypertension causes vascular complications, such as stroke, cardiovascular disease, and chronic kidney disease (CKD). The relationship between endothelial dysfunction and progression of kidney disease is well known. However, the relationship between the eNOS-NO pathway and chronic inflammation, which is a common pathway for the progression of kidney disease, remains unexplored. We performed in vivo experiments to determine the role of the eNOS-NO pathway by using eNOS-deficient mice in a hypertensive kidney disease model. All mice were unilateral nephrectomized (Nx). One week after Nx, the mice were randomly divided into two groups: the aldosterone infusion groups and the vehicle groups. All mice also received a 1% NaCl solution instead of drinking water. The aldosterone infusion groups were treated with hydralazine to correct blood pressure differences. After four weeks of drug administration, all mice were euthanized, and blood and kidney tissue samples were collected. In the results, NLRP3 inflammasome activation was elevated in the kidneys of the eNOS-deficient mice, and tubulointerstitial fibrosis was accelerated. Suppression of inflammasome activation by knocking out ASC prevented tubulointerstitial injury in the eNOS knockout mice, indicating that the eNOS-NO pathway is involved in the development of kidney dysfunction through acceleration of NLRP3 inflammasome in macrophages. We revealed that endothelial function, particularly the eNOS-NO pathway, attenuates the progression of renal tubulointerstitial injury via suppression of inflammasome activation. Clinically, patients who develop vascular endothelial dysfunction have lifestyle diseases, such as hypertension or diabetes, and are known to be at risk for CKD. Our study suggests that the eNOS-NO pathway could be a therapeutic target for the treatment of chronic kidney disease associated with endothelial dysfunction.


Assuntos
Hipertensão Renal/metabolismo , Hipertensão/metabolismo , Inflamassomos/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Óxido Nítrico/metabolismo , Insuficiência Renal Crônica/metabolismo , Aldosterona/farmacologia , Animais , Anti-Hipertensivos/administração & dosagem , Modelos Animais de Doenças , Endotélio/patologia , Endotélio/fisiopatologia , Fibrose , Humanos , Hidralazina/administração & dosagem , Hipertensão/complicações , Hipertensão Renal/tratamento farmacológico , Hipertensão Renal/patologia , Inflamassomos/efeitos dos fármacos , Rim/patologia , Macrófagos/efeitos dos fármacos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Terapia de Alvo Molecular , Proteína 3 que Contém Domínio de Pirina da Família NLR/genética , Óxido Nítrico Sintase Tipo III/genética , Cultura Primária de Células , Insuficiência Renal Crônica/induzido quimicamente , Insuficiência Renal Crônica/etiologia , Insuficiência Renal Crônica/patologia , Vasodilatadores/administração & dosagem
8.
Neuroscience ; 370: 170-180, 2018 02 01.
Artigo em Inglês | MEDLINE | ID: mdl-28571721

RESUMO

Potocki-Shaffer Syndrome is a rare neurodevelopmental syndrome associated with microdeletion of a region of Chromosome 11p11.2. Genetic evidence has implicated haploinsufficiency of PHF21A, a gene that encodes a histone-binding protein, as the likely cause of intellectual disability and craniofacial abnormalities in Potocki-Shaffer Syndrome. However, the molecular consequences of reduced PHF21A expression remain elusive. In this study, we analyzed by RNA-Sequencing (RNA-Seq) two patient-derived cell lines with heterozygous loss of PHF21A compared to unaffected individuals and identified 1,885 genes that were commonly misregulated. The patient cells displayed down-regulation of key pathways relevant to learning and memory, including Cyclic Adenosine Monophosphate (cAMP)-signaling pathway genes. We found that PHF21A is required for full induction of a luciferase reporter carrying cAMP-responsive elements (CRE) following stimulation by the cAMP analog, forskolin. Finally, PHF21A-deficient patient-derived cells exhibited a delayed induction of immediate early genes following forskolin stimulation. These results suggest that an impaired response to cAMP signaling might be involved in the pathology of PHF21A deficiency. This article is part of a Special Issue entitled: [SI: Molecules & Cognition].


Assuntos
AMP Cíclico/metabolismo , Histona Desacetilases/deficiência , Linhagem Celular , Deleção Cromossômica , Transtornos Cromossômicos/metabolismo , Cromossomos Humanos Par 11/metabolismo , Colforsina/farmacologia , AMP Cíclico/análogos & derivados , Exostose Múltipla Hereditária/metabolismo , Perfilação da Expressão Gênica , Regulação da Expressão Gênica/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Histona Desacetilases/genética , Humanos , Linfócitos/efeitos dos fármacos , Linfócitos/metabolismo , RNA Interferente Pequeno , Transcrição Genética
9.
Sci Rep ; 7(1): 8801, 2017 08 18.
Artigo em Inglês | MEDLINE | ID: mdl-28821730

RESUMO

Chronic inflammation can be a major driver of the failure of a variety of organs, including chronic kidney disease (CKD). The NLR family pyrin domain-containing 3 (NLRP3) inflammasome has been shown to play a pivotal role in inflammation in a mouse kidney disease model. Nuclear factor erythroid 2-related factor 2 (Nrf2), the master transcription factor for anti-oxidant responses, has also been implicated in inflammasome activation under physiological conditions. However, the mechanism underlying inflammasome activation in CKD remains elusive. Here, we show that the loss of Nrf2 suppresses fibrosis and inflammation in a unilateral ureter obstruction (UUO) model of CKD in mice. We consistently observed decreased expression of inflammation-related genes NLRP3 and IL-1ß in Nrf2-deficient kidneys after UUO. Increased infiltration of M1, but not M2, macrophages appears to mediate the suppression of UUO-induced CKD symptoms. Furthermore, we found that activation of the NLRP3 inflammasome is attenuated in Nrf2-deficient bone marrow-derived macrophages. These results demonstrate that Nrf2-related inflammasome activation can promote CKD symptoms via infiltration of M1 macrophages. Thus, we have identified the Nrf2 pathway as a promising therapeutic target for CKD.


Assuntos
Macrófagos/imunologia , Macrófagos/metabolismo , Fator 2 Relacionado a NF-E2/deficiência , Obstrução Ureteral/etiologia , Obstrução Ureteral/metabolismo , Animais , Modelos Animais de Doenças , Fibrose , Perfilação da Expressão Gênica , Inflamassomos/genética , Inflamassomos/metabolismo , Inflamação/etiologia , Inflamação/metabolismo , Inflamação/patologia , Rim/metabolismo , Rim/patologia , Ativação de Macrófagos/genética , Ativação de Macrófagos/imunologia , Camundongos , Camundongos Knockout , Obstrução Ureteral/patologia , Obstrução Ureteral/terapia
10.
Lab Invest ; 96(1): 25-36, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26552047

RESUMO

Increased generation of reactive oxygen species (ROS) is a common denominative pathogenic mechanism underlying vascular and renal complications in diabetes mellitus. Endothelial NAD(P)H oxidase is a major source of vascular ROS, and it has an important role in endothelial dysfunction. We hypothesized that activation of endothelial NAD(P)H oxidase initiates and worsens the progression of diabetic nephropathy, particularly in the development of albuminuria. We used transgenic mice with endothelial-targeted overexpression of the catalytic subunit of NAD(P)H oxidase, Nox2 (NOX2TG). NOX2TG mice were crossed with Akita insulin-dependent diabetic (Akita) mice that develop progressive hyperglycemia. We compared the progression of diabetic nephropathy in Akita versus NOX2TG-Akita mice. NOX2TG-Akita mice and Akita mice developed significant albuminuria above the baseline at 6 and 10 weeks of age, respectively. Compared with Akita mice, NOX2TG-Akita mice exhibited higher levels of NAD(P)H oxidase activity in glomeruli, developed glomerular endothelial perturbations, and attenuated expression of glomerular glycocalyx. Moreover, in contrast to Akita mice, the NOX2TG-Akita mice had numerous endothelial microparticles (blebs), as detected by scanning electron microscopy, and increased glomerular permeability. Furthermore, NOX2TG-Akita mice exhibited distinct phenotypic changes in glomerular mesangial cells expressing α-smooth muscle actin, and in podocytes expressing increased levels of desmin, whereas the glomeruli generated increased levels of ROS. In conclusion, activation of endothelial NAD(P)H oxidase in the presence of hyperglycemia initiated and exacerbated diabetic nephropathy characterized by the development of albuminuria. Moreover, ROS generated in the endothelium compounded glomerular dysfunctions by altering the phenotypes of mesangial cells and compromising the integrity of the podocytes.


Assuntos
Diabetes Mellitus Experimental/metabolismo , Nefropatias Diabéticas/metabolismo , NADPH Oxidases/metabolismo , Animais , Glicemia/análise , Diabetes Mellitus Experimental/enzimologia , Nefropatias Diabéticas/enzimologia , Feminino , Taxa de Filtração Glomerular/fisiologia , Glomérulos Renais/química , Glomérulos Renais/metabolismo , Glomérulos Renais/patologia , Masculino , Camundongos , Podócitos/química , Espécies Reativas de Oxigênio/metabolismo
11.
Clin Exp Nephrol ; 19(4): 567-75, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-25216785

RESUMO

BACKGROUND: Long-term peritoneal dialysis (PD) causes peritoneal dysfunction and structural alterations, eventually leading to peritoneal fibrosis. The endothelial nitric oxide synthase (eNOS)-NO signaling pathway contributes to the progression of organ fibrosis. However, it remains unknown whether NO signaling is involved in the process of peritoneal fibrosis. We evaluated the role of the eNOS-NO signaling pathway in the development of peritoneal fibrosis and whether stimulation of soluble guanylate cyclase (sGC), a downstream effector of NO, could attenuate peritoneal fibrosis. METHODS: We used wild-type (WT) and eNOS-deficient mice (eNOSKO). The mice underwent mechanical peritoneal stripping-induced peritoneal fibrosis at day 0. At 3, 7, 14, and 28 days after peritoneal stripping, the mice were killed. In some eNOSKO mice, the sGC stimulator Bay 41-2272 was administered by intraperitoneal injection. RESULTS: In WT mice, granulomatous tissue formation was observed in the submesothelial area at days 3 and 7. After day 7, the peritoneal membrane thickness gradually decreased and peritoneal tissue was repaired with leaving only slight fibrosis at day 28. However, eNOSKO mice demonstrated more progression of peritoneal fibrosis than WT mice at 28 days after peritoneal stripping. Expression of vimentin in the thickened peritoneum was prolonged after day 7 in eNOSKO mice. Treatment with Bay 41-2272 significantly attenuated peritoneal vimentin expression and fibrosis in the eNOSKO mice. CONCLUSIONS: Disruption of the eNOS-NO signaling pathway exacerbates peritoneal fibrosis by delaying wound healing. sGC stimulation may be a useful therapy for prevention of peritoneal fibrosis.


Assuntos
Guanilato Ciclase/metabolismo , Óxido Nítrico Sintase Tipo III/metabolismo , Óxido Nítrico/metabolismo , Fibrose Peritoneal/enzimologia , Receptores Citoplasmáticos e Nucleares/metabolismo , Animais , Fibrose , Isoenzimas/metabolismo , Queratinas/metabolismo , Masculino , Camundongos Endogâmicos C57BL , Camundongos Knockout , Diálise Peritoneal/efeitos adversos , Fibrose Peritoneal/etiologia , Fibrose Peritoneal/prevenção & controle , Peritônio/enzimologia , Peritônio/patologia , Transdução de Sinais , Guanilil Ciclase Solúvel , Vimentina/metabolismo
12.
Proc Natl Acad Sci U S A ; 111(43): 15514-9, 2014 Oct 28.
Artigo em Inglês | MEDLINE | ID: mdl-25313054

RESUMO

Inflammasomes are intracellular sensors that couple detection of pathogens and cellular stress to activation of Caspase-1, and consequent IL-1ß and IL-18 maturation and pyroptotic cell death. Here, we show that the absent in melanoma 2 (AIM2) and nucleotide-binding oligomerization domain-like receptor pyrin domain-containing protein 3 (NLRP3) inflammasomes trigger Caspase-1-dependent mitochondrial damage. Caspase-1 activates multiple pathways to precipitate mitochondrial disassembly, resulting in mitochondrial reactive oxygen species (ROS) production, dissipation of mitochondrial membrane potential, mitochondrial permeabilization, and fragmentation of the mitochondrial network. Moreover, Caspase-1 inhibits mitophagy to amplify mitochondrial damage, mediated in part by cleavage of the key mitophagy regulator Parkin. In the absence of Parkin activity, increased mitochondrial damage augments pyroptosis, as indicated by enhanced plasma membrane permeabilization and release of danger-associated molecular patterns (DAMPs). Therefore, like other initiator caspases, Caspase-1 activation by inflammasomes results in mitochondrial damage.


Assuntos
Caspase 1/metabolismo , Inflamassomos/metabolismo , Mitocôndrias/patologia , Animais , Apoptose , Proteínas de Transporte/metabolismo , Síndromes Periódicas Associadas à Criopirina/enzimologia , Síndromes Periódicas Associadas à Criopirina/patologia , Proteínas de Ligação a DNA/metabolismo , Humanos , Camundongos Endogâmicos C57BL , Mitocôndrias/metabolismo , Membranas Mitocondriais/metabolismo , Proteína 3 que Contém Domínio de Pirina da Família NLR , Permeabilidade , Transdução de Sinais , Ubiquitina-Proteína Ligases/metabolismo
13.
Clin Exp Hypertens ; 36(3): 159-64, 2014.
Artigo em Inglês | MEDLINE | ID: mdl-23786428

RESUMO

Abstract Hypertensive patients have a higher incidence of new-onset diabetic mellitus than normotensive subjects, and we hypothesized that hypertension induces morphological changes in islets via vascular injury. To test our hypothesis, we administrated hydralazine or irbesartan to spontaneously hypertensive stroke-prone (SHRsp) rats. A greater islet fibrosis was observed in SHRsp rats compared with controls, and irbesartan significantly ameliorated the fibrosis. High fat diet induced glucose intorelance in SHRsp rats and irbesartan but not hydralazine improved glucose torelance. We demonstrate islet morphological changes in hypertensive rats, and our data suggest that angiotensin receptor blockers have the potential to prevent islet injury.


Assuntos
Anti-Hipertensivos/farmacologia , Hipertensão/complicações , Ilhotas Pancreáticas/patologia , Estado Pré-Diabético/complicações , Lesões do Sistema Vascular , Animais , Compostos de Bifenilo/farmacologia , Pressão Sanguínea/fisiologia , Modelos Animais de Doenças , Hidralazina/farmacologia , Hipertensão/fisiopatologia , Irbesartana , Ilhotas Pancreáticas/efeitos dos fármacos , Masculino , Ratos Endogâmicos SHR , Tetrazóis/farmacologia , Lesões do Sistema Vascular/induzido quimicamente
14.
Lab Invest ; 93(3): 334-43, 2013 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-23295649

RESUMO

The development of interstitial fibrosis occurs with aging. Impaired angiogenesis, associated with progressive loss of the renal microvasculature, is thought to be a cause of age-related nephropathy. However, the mechanism of capillary loss in aging kidney has not been fully elucidated. Angiostatin is a kringle-containing fragment of plasminogen and is a potent inhibitor of angiogenesis in vivo. Whether angiostatin generation is increased in the aging kidney has not been investigated. We examined 4, 10, 16, and 24-month-old Sprague-Dawley rats for angiostatin production and found that angiostatin generation was increased in aged rats. The protein expression and the activity of cathepsin D-the enzyme for angiostatin production--were increased in aged rats. In the aging kidney, nitric oxide (NO) availability is decreased. To investigate the role of NO in angiostatin production, human umbilical vein endothelial cells were treated with L-NG-nitroarginine methyl ester (L-NAME). L-NAME-treated cells showed increased cathepsin D activity and angiostatin production. For in vivo experiments, 16- to 18-month-old rats were treated with L-NAME or molsidomine for 3 months. Angiostatin production was increased in L-NAME-treated kidney, accompanied by increased cathepsin D activity. In contrast, angiostatin production was decreased in molsidomine-treated kidney, accompanied by decreased cathepsin D activity. In conclusion, angiostatin generation by cathepsin D was increased in the aging rat kidney. Decreased NO production activated cathepsin D activity. Increased angiostatin production may be related to capillary loss and interstitial damage in the aging rat kidney.


Assuntos
Envelhecimento/metabolismo , Angiostatinas/biossíntese , Rim/metabolismo , Óxido Nítrico/metabolismo , Animais , Western Blotting , Catepsina D/metabolismo , Células Endoteliais da Veia Umbilical Humana , Humanos , Imuno-Histoquímica , Molsidomina , NG-Nitroarginina Metil Éster/farmacologia , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo Real , Estatísticas não Paramétricas
15.
Kidney Int ; 83(4): 662-73, 2013 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-23344476

RESUMO

Proteinuria is an independent risk factor for progressive renal diseases because it initiates or aggravates tubulointerstitial injury. Clinically, females are less susceptible to progression of chronic kidney disease; however, the mechanisms underlying the renoprotective effect of estrogen receptor stimulation have yet to be clarified. Recently, inflammasome-dependent inflammatory responses were shown to be triggered by free fatty acids, and mitochondria-derived reactive oxygen species were shown to be required for this response. Albumin-bound free fatty acids trigger inflammasome activation through mitochondrial reactive oxygen species production in human proximal tubule epithelial cells in vitro, an effect inhibited by raloxifene. Female ICR-derived glomerulonephritic mice (mice with hereditary nephritic syndrome) were ovariectomized and treated with raloxifene, a selective estrogen receptor modulator. Ovariectomized mice showed activation of tubular inflammasomes and elevated levels of inflammasome-dependent cytokines. Raloxifene attenuated these changes ameliorating tubulointerstitial damage, reduced production of reactive oxygen species, averted morphological changes, and improved respiratory function in mitochondria. The expression of genes that encode rate-limiting enzymes in the mitochondrial ß-oxidation pathway was reduced by ovariectomy but enhanced by raloxifene. Thus, inflammasomes may be a novel and promising therapeutic target for proteinuria-induced renal injury.


Assuntos
Apoptose/efeitos dos fármacos , Glomerulonefrite/tratamento farmacológico , Túbulos Renais Proximais/efeitos dos fármacos , Mitocôndrias/efeitos dos fármacos , Nefrite Hereditária/tratamento farmacológico , Estresse Oxidativo/efeitos dos fármacos , Proteinúria/tratamento farmacológico , Cloridrato de Raloxifeno/farmacologia , Moduladores Seletivos de Receptor Estrogênico/farmacologia , Animais , Atrofia , Células Cultivadas , Citocinas/metabolismo , Modelos Animais de Doenças , Feminino , Fibrose , Regulação da Expressão Gênica , Glomerulonefrite/genética , Glomerulonefrite/imunologia , Glomerulonefrite/metabolismo , Glomerulonefrite/patologia , Humanos , Inflamassomos/efeitos dos fármacos , Inflamassomos/imunologia , Mediadores da Inflamação/metabolismo , Túbulos Renais Proximais/imunologia , Túbulos Renais Proximais/metabolismo , Túbulos Renais Proximais/patologia , Peroxidação de Lipídeos/efeitos dos fármacos , Macrófagos/efeitos dos fármacos , Macrófagos/imunologia , Camundongos , Camundongos Endogâmicos ICR , Mitocôndrias/imunologia , Mitocôndrias/metabolismo , Mitocôndrias/patologia , NF-kappa B/metabolismo , Nefrite Hereditária/genética , Nefrite Hereditária/imunologia , Nefrite Hereditária/metabolismo , Nefrite Hereditária/patologia , Ovariectomia , Oxirredução , Proteinúria/genética , Proteinúria/imunologia , Proteinúria/metabolismo , Proteinúria/patologia
16.
Ther Apher Dial ; 16(6): 566-72, 2012 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-23190517

RESUMO

Hemodialysis techniques for small animals have not been established because no small dialysis apparatus has been available. We recently developed a small-size dialyzer and established an appropriate blood purification system for small animals. To confirm the appropriate dialysate flow rate, bovine blood was dialyzed for 60 min at a fixed blood flow rate of 1.0 mL/min and variable dialysate flow rates. Blood urea nitrogen and creatinine levels decreased significantly at a dialysate flow rate of 5 mL/min (from 13.7 ± 0.2 to 10.3 ± 1.2 mg/dL and 1.07 ± 0.15 to 0.61 ± 0.12 mg/dL, respectively, P < 0.05). To determine the appropriate in vivo conditions, extracorporeal circulation was performed in anesthetized male Sprague-Dawley rats at a dialysate flow rate of 0.0 mL/min, for 240 min, and at variable blood flow rates. Extracorporeal circulation was successful at a blood flow rate of 1.0 mL/min, but not 1.5 mL/min. To establish in vivo hemodialysis conditions, we used the animal model of end stage renal failure. Sprague-Dawley rats were fed a 0.75% adenine-containing diet for 3 weeks, after which they received hemodialysis for 120 min at a dialysate and blood flow rate of 5.0 and 1.0 mL/min, respectively. There were no significant changes in systolic blood pressure or heart rate during dialysis. Thus, this blood purification system can be safely used for small animals at a dialysate flow rate of 5.0 mL/min and a blood flow rate of 1.0 mL/min. This system provides a basis for further research on hemodialysis therapy.


Assuntos
Circulação Extracorpórea/métodos , Falência Renal Crônica/terapia , Membranas Artificiais , Diálise Renal/métodos , Animais , Velocidade do Fluxo Sanguíneo , Pressão Sanguínea , Nitrogênio da Ureia Sanguínea , Bovinos , Creatinina/sangue , Modelos Animais de Doenças , Frequência Cardíaca , Falência Renal Crônica/fisiopatologia , Masculino , Ratos , Ratos Sprague-Dawley , Diálise Renal/instrumentação
17.
Am J Physiol Renal Physiol ; 303(12): F1641-51, 2012 Dec 15.
Artigo em Inglês | MEDLINE | ID: mdl-23034937

RESUMO

Augmented Wnt signaling has been implicated in many fibrotic diseases including obstructive nephropathy. Soluble form Klotho has been reported to function as a secreted Wnt antagonist. In this study, we tested whether Klotho protein could reduce renal fibrosis by inhibition of Wnt signaling. Transgenic mice that overexpressed Klotho, wild-type mice, and Klotho hetero mutant mice underwent unilateral ureteral obstruction (UUO). In some Klotho hetero mutant mice, Klotho-encoding plasmid was transferred into the skeletal muscle by electroporation. UUO induced activation of Wnt signaling in wild-type but less in Klotho transgenic mice. Enhanced tubulointerstitial fibrosis in wild-type mice was also attenuated in Klotho transgenic mice. In contrast, Wnt signaling and concomitant tubulointerstitial fibrosis were further augmented in Klotho hetero mutant mice after UUO compared with wild-type mice. In Klotho-encoding plasmid-transfected Klotho hetero mutant mice, however, Wnt signaling was markedly reduced accompanied by a decrease in extracellular matrix deposition after UUO. In vitro studies showed that stimulation of Wnt3a induced prolonged cell cycle arrest at G(2)/M phase, with a resultant increase in production of fibrogenic cytokines. Cotreatment with Klotho bypassed the G(2)/M arrest and reduced fibrogenic cytokine production. In conclusion, Klotho is a critical negative regulator of Wnt signaling and a suppressor of renal fibrosis in the obstructed kidney model.


Assuntos
Glucuronidase/fisiologia , Nefropatias/prevenção & controle , Rim/patologia , Obstrução Ureteral/complicações , Via de Sinalização Wnt/fisiologia , Animais , Ciclo Celular/fisiologia , Células Cultivadas , Modelos Animais de Doenças , Feminino , Fibrose , Glucuronidase/genética , Técnicas In Vitro , Rim/fisiopatologia , Nefropatias/patologia , Nefropatias/fisiopatologia , Masculino , Camundongos , Camundongos Mutantes , Camundongos Transgênicos , Plasmídeos , Transfecção , Obstrução Ureteral/patologia , Obstrução Ureteral/fisiopatologia
18.
Kidney Blood Press Res ; 35(6): 549-57, 2012.
Artigo em Inglês | MEDLINE | ID: mdl-22890154

RESUMO

BACKGROUND/AIMS: The immunosuppressive drug tacrolimus (FK506) is used clinically to reduce the rejection rate in patients with kidney transplantation; however, the resultant nephrotoxicity remains a serious problem. In the present study we attempted to elucidate the mechanisms of glomerular injury induced by FK506 and the renoprotective effects of the angiotensin II receptor blocker telmisartan. METHODS: Seven-week-old male Wistar rats were divided into three groups: vehicle group, FK506 group, and FK506 + telmisartan group. After 8 weeks, we assessed kidney function and renal morphological changes including oxidative stress. We also assessed the effect of FK506 in human glomerular endothelial cells (hGECs) with regard to reactive oxygen species (ROS). RESULTS: FK506 induced ROS production via activation of NAD(P)H oxidase in the glomeruli. Expression of ICAM mRNA was increased in glomeruli from the FK506 group. These effects resulted in macrophage infiltration into the glomeruli. FK506 directly promoted NAD(P)H oxidase activity and accelerated production of ROS in hGECs. Conversely, cotreatment with telmisartan inhibited both NAD(P)H oxidase activity and production of ROS. CONCLUSION: These findings suggest that glomerular injury resulting from FK506 is caused by oxidative stress mediated by activation of NAD(P)H oxidase and that telmisartan exerts a renoprotective effect via antioxidative activity.


Assuntos
Endotélio Vascular/metabolismo , Imunossupressores/toxicidade , Glomérulos Renais/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Tacrolimo/toxicidade , Animais , Células Cultivadas , Endotélio Vascular/efeitos dos fármacos , Endotélio Vascular/patologia , Humanos , Inflamação/induzido quimicamente , Inflamação/metabolismo , Inflamação/patologia , Glomérulos Renais/efeitos dos fármacos , Glomérulos Renais/patologia , Masculino , Ratos , Ratos Wistar
20.
Am J Physiol Renal Physiol ; 302(11): F1402-8, 2012 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-22378818

RESUMO

Loss of functional nephrons associated with chronic kidney disease induces glomerular hyperfiltration and compensatory renal hypertrophy. We hypothesized that the endothelial nitric oxide synthase (eNOS) [soluble guanylate cyclase (sGC)] protein kinase G (PKG) pathway plays an important role in compensatory renal hypertrophy after unilateral nephrectomy. Analysis of mice subjected to unilateral nephrectomy showed increases in kidney weight-to-body weight and total protein-to-DNA ratios in wild-type but not eNOS knockout (eNOSKO) mice. Serum creatinine and blood urea nitrogen increased after nephrectomy in eNOSKO but not in wild-type mice. Furthermore, Bay 41-2272, an sGC stimulator, induced compensatory renal hypertrophy in eNOSKO mice and rescued renal function. The NO donor S-nitrosoglutathione (GSNO) and Bay 41-2272 stimulated PKG activity and induced phosphorylation of Akt protein in human proximal tubular cells. GSNO also induced phosphorylation of eukaryotic initiation factor 4E-binding protein and ribosomal protein S6. Our results highlight the importance of the eNOS-NO-PKG pathway in compensatory renal hypertrophy and suggest that reduced eNOS-NO bioavailability due to endothelial dysfunction is the underlying mechanism of failure of compensatory hypertrophy and acceleration of progressive renal dysfunction.


Assuntos
Lesão Renal Aguda/patologia , Endotélio/fisiologia , Rim/patologia , Óxido Nítrico Sintase Tipo III/metabolismo , Animais , Western Blotting , Contagem de Células , Proteínas Quinases Dependentes de GMP Cíclico/metabolismo , DNA/metabolismo , Endotélio/enzimologia , Hipertrofia , Rim/enzimologia , Túbulos Renais Proximais/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Nefrectomia , Óxido Nítrico/fisiologia , Doadores de Óxido Nítrico/farmacologia , Óxido Nítrico Sintase Tipo III/genética , Inclusão em Parafina , Biossíntese de Proteínas , RNA/biossíntese , RNA/isolamento & purificação , Circulação Renal , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Serina-Treonina Quinases TOR/metabolismo
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