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1.
Am J Physiol Cell Physiol ; 326(3): C935-C947, 2024 Mar 01.
Artigo em Inglês | MEDLINE | ID: mdl-38284121

RESUMO

The molecular basis of renal interstitial fibrosis, a major pathological feature of progressive kidney diseases, remains poorly understood. Autophagy has been implicated in renal fibrosis, but whether it promotes or inhibits fibrosis remains controversial. Moreover, it is unclear how autophagy is activated and sustained in renal fibrosis. The present study was designed to address these questions using the in vivo mouse model of unilateral ureteral obstruction and the in vitro model of hypoxia in renal tubular cells. Both models showed the activation of hypoxia-inducible factor-1 (HIF-1) and autophagy along with fibrotic changes. Inhibition of autophagy with chloroquine reduced renal fibrosis in unilateral ureteral obstruction model, whereas chloroquine and autophagy-related gene 7 knockdown decreased fibrotic changes in cultured renal proximal tubular cells, supporting a profibrotic role of autophagy. Notably, pharmacological and genetic inhibition of HIF-1 led to the suppression of autophagy and renal fibrosis in these models. Mechanistically, knock down of BCL2 and adenovirus E1B 19-kDa-interacting protein 3 (BNIP3), a downstream target gene of HIF, decreased autophagy and fibrotic changes during hypoxia in BUMPT cells. Together, these results suggest that HIF-1 may activate autophagy via BNIP3 in renal tubular cells to facilitate the development of renal interstitial fibrosis.NEW & NOTEWORTHY Autophagy has been reported to participate in renal fibrosis, but its role and underlying activation mechanism is unclear. In this study, we report the role of HIF-1 in autophagy activation in models of renal fibrosis and further investigate the underlying mechanism.


Assuntos
Nefropatias , Obstrução Ureteral , Camundongos , Animais , Obstrução Ureteral/complicações , Obstrução Ureteral/genética , Obstrução Ureteral/metabolismo , Fator 1 Induzível por Hipóxia , Nefropatias/patologia , Hipóxia , Autofagia/genética , Fibrose , Cloroquina/farmacologia
2.
J Transl Med ; 22(1): 9, 2024 01 02.
Artigo em Inglês | MEDLINE | ID: mdl-38169402

RESUMO

Epigenetic regulation is reported to play a significant role in the pathogenesis of various kidney diseases, including renal cell carcinoma, acute kidney injury, renal fibrosis, diabetic nephropathy, and lupus nephritis. However, the role of epigenetic regulation in calcium oxalate (CaOx) crystal deposition-induced kidney injury remains unclear. Our study demonstrated that the upregulation of enhancer of zeste homolog 2 (EZH2)-mediated ferroptosis facilitates CaOx-induced kidney injury. CaOx crystal deposition promoted ferroptosis in vivo and in vitro. Usage of liproxstatin-1 (Lip-1), a ferroptosis inhibitor, mitigated CaOx-induced kidney damage. Single-nucleus RNA-sequencing, RNA-sequencing, immunohistochemical and western blotting analyses revealed that EZH2 was upregulated in kidney stone patients, kidney stone mice, and oxalate-stimulated HK-2 cells. Experiments involving in vivo EZH2 knockout, in vitro EZH2 knockdown, and in vivo GSK-126 (an EZH2 inhibitor) treatment confirmed the protective effects of EZH2 inhibition on kidney injury and ferroptosis. Mechanistically, the results of RNA-sequencing and chromatin immunoprecipitation assays demonstrated that EZH2 regulates ferroptosis by suppressing solute carrier family 7, member 11 (SLC7A11) expression through trimethylation of histone H3 lysine 27 (H3K27me3) modification. Additionally, SOX4 regulated ferroptosis by directly modulating EZH2 expression. Thus, this study demonstrated that SOX4 facilitates ferroptosis in CaOx-induced kidney injury through EZH2/H3K27me3-mediated suppression of SLC7A11.


Assuntos
Nefropatias Diabéticas , Ferroptose , Cálculos Renais , Humanos , Camundongos , Animais , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Oxalato de Cálcio , Histonas/metabolismo , Epigênese Genética , Rim/patologia , Nefropatias Diabéticas/metabolismo , Cálculos Renais/patologia , RNA/metabolismo , Fatores de Transcrição SOXC/metabolismo , Sistema y+ de Transporte de Aminoácidos
4.
Theranostics ; 13(6): 1860-1875, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37064878

RESUMO

Rationale: The role of histone methylation modifications in renal disease, particularly in sepsis-induced acute kidney injury (AKI), remains unclear. This study aims to investigate the potential involvement of the histone methyltransferase zeste homolog 2 (EZH2) in sepsis-induced AKI and its impact on apoptosis and inflammation. Methods: We first examined the expression of EZH2 in the kidney of sepsis-induced AKI (LPS injection) mice and LPS-stimulated tubular epithelial cells. We next constructed the EZH2 knockout mice to further confirm the effects of EZH2 on apoptosis and inflammatory response in AKI. And the inflammatory level of epithelial cells can be reflected by detecting chemokines and the chemotaxis of macrophages. Subsequently, we constructed the EZH2 knocked-down cells again and performed Chromatin Immunoprecipitation sequencing to screen out the target genes regulated by EZH2 and the enrichment pathway. Then we confirmed the EZH2 target gene and its regulatory pathway in vivo and in vitro experiments. Experimental results were finally confirmed using another in vivo model of sepsis-induced AKI (cecal perforation ligation). Results: The study found that EZH2 was upregulated in sepsis-induced AKI and that silencing EZH2 could reduce renal tubular injury by decreasing apoptosis and inflammatory response of tubular epithelial cells. EZH2 knockout mice showed significantly reduced renal inflammation and macrophage infiltration. Chromatin immunoprecipitation sequencing and polymerase chain reaction identified Sox9 as a target of EZH2. EZH2 was found to be enriched on the promoter of Sox9. Silencing EZH2 resulted in a significant increase in the transcriptional level of Sox9 and activation of the Wnt/ß-catenin signaling pathway. The study further reversed the effects of EZH2 silencing by silencing Sox9 or administering the Wnt/ß-catenin inhibitor icg001. It was also found that Sox9 positively regulated the expression of ß-catenin and its downstream pathway-related genes. Finally, the study showed that the EZH2 inhibitor 3-deazaneplanocin A significantly alleviated sepsis-induced AKI. Conclusion: Our results indicate that silencing EZH2 can protect renal function by relieving transcriptional inhibition of Sox9, activating the Wnt/ß-catenin pathway, and attenuating tubular epithelial apoptosis and inflammatory response of the renal interstitium. These results highlight the potential therapeutic value of targeting EZH2 in sepsis-induced AKI.


Assuntos
Injúria Renal Aguda , Proteína Potenciadora do Homólogo 2 de Zeste , Sepse , Animais , Camundongos , Injúria Renal Aguda/genética , Apoptose , beta Catenina/metabolismo , Proteína Potenciadora do Homólogo 2 de Zeste/metabolismo , Histona Metiltransferases/metabolismo , Histonas/metabolismo , Inflamação , Lipopolissacarídeos , Camundongos Knockout , Sepse/complicações
5.
BMC Nephrol ; 23(1): 400, 2022 12 13.
Artigo em Inglês | MEDLINE | ID: mdl-36513992

RESUMO

BACKGROUND: Thrombotic thrombocytopenic purpura (TTP) is a rare and life-threatening thrombotic microangiopathy characterized by microangiopathic hemolytic anemia, severe thrombocytopenia, and organ ischemia. It is related to severe deficiency in ADAMTS13, which is usually acquired via ADAMTS13 autoantibodies or inherited via mutations of the ADAMTS13 gene. The etiology of acquired TTP including HIV infection, pregnancy, autoimmune disease, organ transplantation, drugs, malignancy and so on. Here, we firstly reported a patient diagnosed as acquired TTP after pegylated interferon therapy for hepatitis B and COVID-19 vaccination. CASE PRESENTATION: A 36-year-old male attended to our unit with a five-day history of intermittent hematuria and progressive fatigue on January 5th, 2022. He had a 13 years history of hepatitis B infection and undergone pegylated interferon treatment (which was paused for two months because of COVID-19 vaccination) for nearly 3 years. Laboratory evaluation revealed a haemoglobin level of 61 g/L, platelet count of 11 × 109/L, lactate dehydrogenase 2133 U/L. The direct and indirect Coombs test were both negative. On a peripheral blood smear, there were about 18.8% schistocytes. Meanwhile, the results of ADAMTS 13 activity and antibody were < 5% and 181.34 ng/ml (131.25-646.5), respectively CONCLUSION: This case firstly reported the rare complication of TTP after pegylated interferon treatment for hepatitis B and COVID-19 vaccine injection. This unique sign warrants more attention as an early cue of diagnosis of TTP and be aware of the rarity adverse effect of interferon therapy and COVID-19 vaccination.


Assuntos
Vacinas contra COVID-19 , COVID-19 , Infecções por HIV , Hepatite B , Púrpura Trombocitopênica Trombótica , Adulto , Feminino , Humanos , Masculino , Gravidez , Vacinas contra COVID-19/efeitos adversos , Hepatite B/complicações , Hepatite B/diagnóstico , Hepatite B/tratamento farmacológico , Interferons , Polietilenoglicóis/efeitos adversos , Púrpura Trombocitopênica Trombótica/induzido quimicamente , Púrpura Trombocitopênica Trombótica/diagnóstico , Púrpura Trombocitopênica Trombótica/terapia
6.
FASEB J ; 36(8): e22477, 2022 08.
Artigo em Inglês | MEDLINE | ID: mdl-35881071

RESUMO

Diabetes may prevent kidney repair and sensitize the kidney to fibrosis or scar formation. To test this possibility, we examined renal fibrosis induced by unilateral ureteral obstruction (UUO) in diabetic mouse models. Indeed, UUO induced significantly more renal fibrosis in both Akita and STZ-induced diabetic mice than in nondiabetic mice. The diabetic mice also had more apoptosis and interstitial macrophage infiltration during UUO. In vitro, hypoxia induced higher expression of the fibrosis marker protein fibronectin in high glucose-conditioned renal tubular cells than in normal glucose cells. Mechanistically, hypoxia induced significantly more hypoxia-inducible factor-1 α (HIF-1 α) in high glucose cells than in normal glucose cells. Inhibition of HIF-1 attenuated the expression of fibronectin induced by hypoxia in high-glucose cells. Consistently, UUO induced significantly higher HIF-1α expression along with fibrosis in diabetic mice kidneys than in nondiabetic kidneys. The increased expression of fibrosis induced by UUO in diabetic mice was diminished in proximal tubule-HIF-1α-knockout mice. Together, these results indicate that diabetes sensitizes kidney tissues and cells to fibrogenesis probably by enhancing HIF-1 activation.


Assuntos
Diabetes Mellitus Experimental , Nefropatias , Obstrução Ureteral , Animais , Diabetes Mellitus Experimental/metabolismo , Fibronectinas/metabolismo , Fibrose , Glucose/metabolismo , Hipóxia/metabolismo , Fator 1 Induzível por Hipóxia/metabolismo , Rim/metabolismo , Nefropatias/patologia , Camundongos , Obstrução Ureteral/metabolismo
7.
BMC Nephrol ; 21(1): 140, 2020 04 17.
Artigo em Inglês | MEDLINE | ID: mdl-32303194

RESUMO

BACKGROUND: Raccoon eyes or periorbital ecchymosis is caused by blood tracking into periorbital tissues, which is mostly recognized in injuries of head and neck, basal skull fractures, convexity fractures and facial fractures. It was also reported in systematic disorders, such as multiple myeloma, amyloidosis, Kaposi's sarcoma, migraine and neuroblastoma. However, it is unusual to see a patient showing periorbital purpura after kidney biopsy with no other ecchymosis. Here, we firstly reported this rare symptom after kidney biopsy in a patient who was finally diagnosed as immunoglobulin light chain (AL) amyloidosis. CASE PRESENTATION: A 64-year old woman was admitted to our clinic with 1.5 years history of sub-nephrotic proteinuria and slowly progressive deterioration of renal function. Laboratory -investigations revealed an M-peak in the λ fraction of IgA and concentrations of serum free-light-chain (FLC) were 44.95 mg/L for κ isotype and 173 mg/L for λ isotype. Unexpectedly the patient showed periorbital purpura 24 h later after kidney biopsy with no more other ecchymosis. Renal biopsy showed massively glomerulosclerosis, interstitial fibrosis with positively Congo red staining in mesangial areas. For fluorescent staining, the kidney tissue showed strongly λ light-chain deposition. The fibrils (8-12 nm in diameter) were confirmed by electron micrograph. CONCLUSIONS: This case firstly reported this rare symptom after the kidney biopsy in a patient who was finally diagnosed as AL amyloidosis. And this unique sign of periorbital ecchymosis warrants more attention as an early cue of amyloidosis.


Assuntos
Biópsia/efeitos adversos , Equimose , Oftalmopatias , Amiloidose de Cadeia Leve de Imunoglobulina , Rim/patologia , Insuficiência Renal , Biópsia/métodos , Diagnóstico Diferencial , Progressão da Doença , Equimose/diagnóstico , Equimose/etiologia , Oftalmopatias/diagnóstico , Oftalmopatias/etiologia , Feminino , Humanos , Amiloidose de Cadeia Leve de Imunoglobulina/complicações , Amiloidose de Cadeia Leve de Imunoglobulina/patologia , Amiloidose de Cadeia Leve de Imunoglobulina/fisiopatologia , Cadeias lambda de Imunoglobulina/sangue , Microscopia de Fluorescência/métodos , Pessoa de Meia-Idade , Insuficiência Renal/sangue , Insuficiência Renal/etiologia , Insuficiência Renal/fisiopatologia , Insuficiência Renal/urina
8.
Am J Physiol Renal Physiol ; 315(3): F479-F486, 2018 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-29513074

RESUMO

The aim of our current study was to investigate the long-term effect and the mechanism of triptolide in an adult nonorthologous rat model of polycystic kidney disease (PKD). Male wild-type (+/+) and Cy/+ cystic Han:SPRD rats were treated with vehicle or triptolide from 4 to 16 wk of age. Rats were killed at 16 wk of age for blood, urine, and organ collection. Human-derived WT9-12 PKD cells were treated with triptolide with or without IL-6 pretreatment. Cell proliferation, apoptosis, and cytotoxicity were determined. Western blotting and immunohistochemistry analysis were performed to evaluate the activation of IL-6-JAK2-STAT3 pathway. Renal function was protected by 12 wk of triptolide treatment in cystic Han:SPRD rats as shown by reduced blood urea nitrogen, serum creatinine, and proteinuria levels. Cyst and kidney growth were also retarded by triptolide treatment in Cy/+ rats. We further found that the proliferation index was reduced by triptolide in cystic rats, which was correlated with the reduced expression of IL-6/IL-6 receptor, decreased phosphorylation of JAK2-STAT3, and increased expression of suppressor of cytokine signaling 3 (SOCS3). The inhibitory effect of triptolide was further studied in WT9-12 cells. Triptolide inhibited cell proliferation and the activation of JAK2-STAT3 pathway in PKD cells, but it increased the expression of SOCS3. Pretreatment with IL-6 attenuated the inhibitory effect of triptolide on STAT3 phosphorylation. Our study revealed a long-term beneficial effect of triptolide in PKD that was probably through inhibition of the JAK2-STAT3 pathway.


Assuntos
Diterpenos/farmacologia , Janus Quinase 2/metabolismo , Rim/efeitos dos fármacos , Fenantrenos/farmacologia , Doenças Renais Policísticas/prevenção & controle , Fator de Transcrição STAT3/metabolismo , Animais , Apoptose/efeitos dos fármacos , Nitrogênio da Ureia Sanguínea , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Creatinina/sangue , Modelos Animais de Doenças , Progressão da Doença , Compostos de Epóxi/farmacologia , Humanos , Interleucina-6/metabolismo , Rim/enzimologia , Rim/patologia , Rim/fisiopatologia , Masculino , Fosforilação , Doenças Renais Policísticas/enzimologia , Doenças Renais Policísticas/genética , Doenças Renais Policísticas/patologia , Proteinúria/enzimologia , Proteinúria/genética , Proteinúria/prevenção & controle , Ratos Transgênicos , Receptores de Interleucina-6/metabolismo , Transdução de Sinais/efeitos dos fármacos , Proteína 3 Supressora da Sinalização de Citocinas/metabolismo
9.
Br J Nutr ; 119(1): 22-29, 2018 01.
Artigo em Inglês | MEDLINE | ID: mdl-29208058

RESUMO

Diabetic nephropathy (DN) is a major cause of chronic kidney disease. We aimed to investigate the effect of the low-protein diets (LPD) supplemented with ketoacids (LPD+KA) in KKAy mice, an early type 2 DN model. KKAy mice were treated with normal protein diet (NPD), LPD or LPD+KA from 12 to 24 weeks of age. A period of 12-week treatment with LPD significantly reduced albuminuria as compared with that observed after NPD treatment. Treatment with LPD+KA further reduced albuminuria as compared with that observed with LPD treatment alone. Moreover, LPD treatment reduced mesangial expansion, thickness of glomerular basement membrane and the severity of the podocyte foot process effacement in KKAy mice; these effects were more pronounced in KKAy mice treated with LPD+KA. Both LPD and LPD+KA treatments slightly reduced total body weight, but had no significant effect on kidney weight and blood glucose concentrations when compared with NPD-treated KKAy mice. LPD treatment slightly attenuated oxidative stress in kidneys as compared with that observed in NPD-treated KKAy mice; however, LPD+KA treatment remarkably ameliorated oxidative stress in diabetic kidneys as shown by decreased malondialdehyde concentrations, protein carbonylation, nitrotyrosine expression and increased superoxide dismutase expression. Nutritional therapy using LPD+KA confers additional renal benefits as compared with those of LPD treatment alone in early type 2 DN through inhibition of oxidative stress.


Assuntos
Nefropatias Diabéticas/dietoterapia , Dieta com Restrição de Proteínas , Cetoácidos/química , Estresse Oxidativo , Insuficiência Renal Crônica/dietoterapia , Albuminúria/terapia , Animais , Diabetes Mellitus Experimental/dietoterapia , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 2/dietoterapia , Diabetes Mellitus Tipo 2/metabolismo , Nefropatias Diabéticas/metabolismo , Suplementos Nutricionais , Modelos Animais de Doenças , Membrana Basal Glomerular/metabolismo , Rim/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Tamanho do Órgão , Insuficiência Renal Crônica/metabolismo
10.
Sci Rep ; 7: 44892, 2017 03 20.
Artigo em Inglês | MEDLINE | ID: mdl-28317867

RESUMO

Interstitial fibrosis, a common pathological feature of chronic kidney diseases, is often associated with apoptosis in renal tissues. To determine the associated apoptotic pathway and its role in renal interstitial fibrosis, we established a mouse model in which Bax and Bak, two critical genes in the intrinsic pathway of apoptosis, were deleted specifically from kidney proximal tubules and used this model to examine renal apoptosis and interstitial fibrosis following unilateral urethral obstruction (UUO). It was shown that double knockout of Bax and Bak from proximal tubules attenuated renal tubular cell apoptosis and suppressed renal interstitial fibrosis in UUO. The results indicate that the intrinsic pathway of apoptosis contributes significantly to the tubular apoptosis and renal interstitial fibrosis in kidney diseases.


Assuntos
Apoptose/genética , Túbulos Renais Proximais/metabolismo , Obstrução Uretral/genética , Obstrução Uretral/patologia , Proteína Killer-Antagonista Homóloga a bcl-2/deficiência , Proteína X Associada a bcl-2/deficiência , Animais , Colágeno/metabolismo , Modelos Animais de Doenças , Células Epiteliais/metabolismo , Fibrose , Camundongos , Camundongos Knockout
11.
J Biol Chem ; 292(11): 4571-4582, 2017 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-28119452

RESUMO

Nephrotoxicity is a major adverse effect of cisplatin-mediated chemotherapy in cancer patients. The pathogenesis of cisplatin-induced nephrotoxicity remains largely unclear, making it difficult to design effective renoprotective approaches. Here, we have examined the role of microRNAs (miRNAs) in cisplatin-induced nephrotoxicity. We show that cisplatin nephrotoxicity was not affected by overall depletion of both beneficial and detrimental miRNAs from kidney proximal tubular cells in mice in which the miRNA-generating enzyme Dicer had been conditionally knocked out. To identify miRNAs involved in cisplatin nephrotoxicity, we used microarray analysis to profile miRNA expression and identified 47 up-regulated microRNAs and 20 down-regulated microRNAs in kidney cortical tissues. One up-regulated miRNA was miR-375, whose expression was also induced in cisplatin-treated renal tubular cells. Interestingly, inhibition of miR-375 decreased cisplatin-induced apoptosis, suggesting that miR-375 is a cell-damaging or pro-apoptotic agent. Blockade of P53 or NF-κB attenuated cisplatin-induced miR-375 expression, supporting a role of P53 and NF-κB in miR-375 induction. We also identified hepatocyte nuclear factor 1 homeobox B (HNF-1ß) as a key downstream target of miR-375. Of note, we further demonstrated that HNF-1ß protected renal cells against cisplatin-induced apoptosis. Together, these results suggest that upon cisplatin exposure, P53 and NF-κB collaboratively induce miR-375 expression, which, in turn, represses HNF-1ß activity, resulting in renal tubular cell apoptosis and nephrotoxicity.


Assuntos
Antineoplásicos/toxicidade , Cisplatino/toxicidade , Regulação da Expressão Gênica/efeitos dos fármacos , Fator 1-beta Nuclear de Hepatócito/genética , Rim/efeitos dos fármacos , MicroRNAs/genética , Animais , Apoptose/efeitos dos fármacos , Rim/metabolismo , Camundongos , Camundongos Knockout , Ribonuclease III/genética
12.
Kidney Int ; 91(1): 106-118, 2017 01.
Artigo em Inglês | MEDLINE | ID: mdl-27622990

RESUMO

Renal ischemia-reperfusion injury is a leading cause of acute kidney injury; the pathogenesis of which remains poorly understood and effective therapies are still lacking. Here we tested whether microRNAs, identified as critical regulators of cell health and disease, are involved in this process. We found that miR-17-5p was significantly up-regulated during renal ischemia-reperfusion injury in mice and during hypoxia in cultured renal tubular cells. In cultured cells, miR-17-5p directly inhibited the expression of death receptor 6 (DR6) and attenuated apoptosis during hypoxia. Blockade of miR-17-5p abolished the suppression of DR6 and facilitated caspase activation and apoptosis. In vivo, an miR-17-5p mimic suppressed DR6 expression and protected against renal ischemia-reperfusion injury. We further verified that miR-17-5p induction during renal ischemia-reperfusion injury was dependent on p53. Inhibition of p53 with pifithrin-α or a dominant-negative mutant led to the repression of miR-17-5p expression under hypoxia in vitro. Moreover, miR-17-5p induction during renal ischemia-reperfusion injury was attenuated in proximal tubule p53 knockout mice, supporting the role of p53 in miR-17-5p induction in vivo. Thus, p53/miR-17-5p/DR6 is a new protective pathway in renal ischemia-reperfusion injury and may be targeted for the prevention and treatment of ischemic acute kidney injury.


Assuntos
Injúria Renal Aguda/metabolismo , MicroRNAs/metabolismo , Receptores do Fator de Necrose Tumoral/metabolismo , Traumatismo por Reperfusão/metabolismo , Proteína Supressora de Tumor p53/metabolismo , Injúria Renal Aguda/etiologia , Animais , Apoptose , Benzotiazóis/farmacologia , Caspases/metabolismo , Linhagem Celular , Modelos Animais de Doenças , Hipóxia/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Túbulos Renais/citologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Mutação , Traumatismo por Reperfusão/complicações , Transdução de Sinais , Tolueno/análogos & derivados , Tolueno/farmacologia , Proteína Supressora de Tumor p53/antagonistas & inibidores , Proteína Supressora de Tumor p53/genética , Regulação para Cima
13.
Kidney Blood Press Res ; 41(6): 848-864, 2016.
Artigo em Inglês | MEDLINE | ID: mdl-27871084

RESUMO

BACKGROUND/AIMS: Blockage of the renin-angiotensin II system (RAS) prevents or delays albuminuria in diabetic patients. The aim of this study was to investigate the inhibitory mechanism of the angiotensin receptor blocker olmesartan on albuminuria in a murine model of diabetic nephropathy. METHODS: Male db/db diabetic mice were fed with placebo or 20 mg/kg olmesartan by daily gavage for 12 weeks. Conditionally immortalized mouse podocytes were treated with glucose, angiotensin II, olmesartan or p38 inhibitor s8307 in different experimental conditions after differentiation. RESULTS: Olmesartan reduced albuminuria in db/db mice without change in body weight and glycemia. The increase of apoptotic cells and decrease of podocytes in the diabetic glomerulus were prevented by olmesartan. Moreover, olmesartan restored silent mating type information regulation 1 (SIRT1) expression in diabetic glomeruli. Furthermore, olmesartan treatment suppressed p38 phosphorylation but did not restore adenosine 5'-monophosphate-activated protein kinase (AMPK) phosphorylation in the diabetic glomerulus. In vitro study revealed that olmesartan prevented angiotensin II/p38/SIRT1 induced podocyte apoptosis, but it only slightly prevented high glucose/AMPK/SIRT1 induced podocyte apoptosis. In addition, the p38 inhibitor s8307 reversed SIRT1 expression and angiotensin II induced podocyte apoptosis. CONCLUSIONS: Olmesartan reduced albuminuria in diabetic nephropathy through inhibiting angiotensin II/p38/SIRT1 triggered podocyte apoptosis.


Assuntos
Albuminúria/prevenção & controle , Apoptose/efeitos dos fármacos , Nefropatias Diabéticas/tratamento farmacológico , Imidazóis/farmacologia , Podócitos/patologia , Tetrazóis/farmacologia , Albuminúria/tratamento farmacológico , Angiotensina II/efeitos dos fármacos , Animais , Linhagem Celular , Modelos Animais de Doenças , Masculino , Camundongos , Camundongos Endogâmicos , Sirtuína 1/efeitos dos fármacos , Proteínas Quinases p38 Ativadas por Mitógeno/efeitos dos fármacos
14.
Nephrol Dial Transplant ; 31(11): 1826-1834, 2016 11.
Artigo em Inglês | MEDLINE | ID: mdl-27190325

RESUMO

BACKGROUND: Inflammation plays an important role in polycystic kidney disease (PKD). The current study aimed to examine the efficacy of the anti-inflammatory compound resveratrol in PKD and to investigate its underlying mechanism of action. METHODS: Male Han:SPRD (Cy/+) rats with PKD were treated with 200 mg/kg/day resveratrol or vehicle by gavage for 5 weeks. Human autosomal dominant (AD) PKD cells, three-dimensional (3D) Madin-Darby canine kidney cells and zebrafish were treated with various concentrations of resveratrol or the nuclear factor κB (NF-κB) inhibitor QNZ. RESULTS: Resveratrol treatment reduced blood urea nitrogen levels and creatinine levels by 20 and 24%, respectively, and decreased two-kidney/total body weight ratio by 15% and cyst volume density by 24% in Cy/+ rats. The proliferation index and the macrophage infiltration index were reduced by 40 and 43%, respectively, in resveratrol-treated cystic kidneys. Resveratrol reduced the levels of the pro-inflammatory factors monocyte chemoattractant protein-1 (MCP-1), tumor necrosis factor-α (TNF-α) and complement factor B (CFB) in Cy/+ rat kidneys in parallel with the decreased activity of NF-κB (p50/p65). The activation of NF-κB and its correlation with pro-inflammatory factor expression were confirmed in human ADPKD cells and kidney tissues. Resveratrol and QNZ inhibited the expression of MCP-1, TNF-α and CFB and reduced NF-κB activity in ADPKD cells. Moreover, NF-κB blockage minimized the inhibition of inflammatory factor production by resveratrol treatment. Furthermore, resveratrol or QNZ inhibited cyst formation in the 3D cyst and zebrafish models. CONCLUSIONS: The NF-κB signaling pathway is activated and partly responsible for inflammation in polycystic kidney tissues. Targeting inflammation through resveratrol could be a new strategy for PKD treatment in the future.


Assuntos
Anti-Inflamatórios não Esteroides/farmacologia , Inflamação/prevenção & controle , NF-kappa B/antagonistas & inibidores , Doenças Renais Policísticas/prevenção & controle , Rim Policístico Autossômico Dominante/prevenção & controle , Estilbenos/farmacologia , Animais , Estudos de Casos e Controles , Quimiocina CCL2/metabolismo , Progressão da Doença , Cães , Humanos , Inflamação/metabolismo , Inflamação/patologia , Células Madin Darby de Rim Canino , Masculino , NF-kappa B/metabolismo , Doenças Renais Policísticas/metabolismo , Doenças Renais Policísticas/patologia , Rim Policístico Autossômico Dominante/metabolismo , Rim Policístico Autossômico Dominante/patologia , Ratos , Ratos Sprague-Dawley , Resveratrol , Transdução de Sinais , Fator de Necrose Tumoral alfa/metabolismo , Peixe-Zebra
15.
Am J Physiol Renal Physiol ; 310(11): F1284-94, 2016 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-26984954

RESUMO

Inhibition of the overactivated alternative complement pathway in autosomal dominant polycystic kidney disease (ADPKD) retards disease progression in animal models; however, it remains unknown how complement factor B (CFB) is upregulated in ADPKD. Here, we showed that the overexpression of CFB in cystic kidneys is associated with increased JAK2/STAT1 activity and enhanced expression of the polycystin-1 C-terminal tail (PC1-CTT). Overexpression or blockage of STAT1 increased or decreased CFB expression and CFB promoter activity. Moreover, overexpression of PC1-CTT induced JAK2/STAT1 activation and CFB upregulation in renal tubular epithelial cells. Furthermore, PC1-CTT overexpression increased human CFB promoter activity, whereas dominant negative STAT1 plasmids or mutation of putative STAT1 responsive elements decreased PC1-CTT-induced CFB promoter activity. The effect of CFB on macrophage differentiation was tested on a mouse macrophage cell line. Bioactive CFB dose dependently promoted macrophage M2 phenotype conversion. In addition, conditioned media from renal epithelial cells promoted macrophage M2 phenotype conversion which was blocked by STAT1 inhibition in a dose-dependent manner. Conditioned media from PC1-CTT-transfected renal epithelial cells further promoted macrophage M2 phenotype conversion, which was suppressed by fludarabine or a CFB antibody. In addition, we show that NF-κB acts downstream of PC1-CTT and may partly mediate PC1-CTT-induced CFB expression. In conclusion, our study reveals possible mechanisms of CFB upregulation in ADPKD and a novel role of PC1-CTT in ADPKD-associated inflammation. Furthermore, our study suggests that targeting STAT1 may be a new strategy to prevent inflammation in the kidney of patients with ADPKD.


Assuntos
Fator B do Complemento/metabolismo , Rim/metabolismo , Rim Policístico Autossômico Dominante/metabolismo , Fator de Transcrição STAT1/metabolismo , Canais de Cátion TRPP/metabolismo , Animais , Linhagem Celular , Células Cultivadas , Fator B do Complemento/genética , Células Epiteliais/metabolismo , Regulação da Expressão Gênica , Humanos , Janus Quinase 2/metabolismo , Rim Policístico Autossômico Dominante/genética , Ratos , Fator de Transcrição STAT1/genética , Canais de Cátion TRPP/genética
16.
Sci Rep ; 6: 22171, 2016 Feb 26.
Artigo em Inglês | MEDLINE | ID: mdl-26916346

RESUMO

Endotoxemia in sepsis, characterized by systemic inflammation, is a major cause of acute kidney injury (AKI) in hospitalized patients, especially in intensive care unit; however the underlying pathogenesis is poorly understood. Autophagy is a conserved, cellular catabolic pathway that plays crucial roles in cellular homeostasis including the maintenance of cellular function and viability. The regulation and role of autophagy in septic or endotoxic AKI remains unclear. Here we show that autophagy was induced in kidney tubular cells in mice by the endotoxin lipopolysaccharide (LPS). Pharmacological inhibition of autophagy with chloroquine enhanced LPS-induced AKI. Moreover, specific ablation of autophagy gene 7 (Atg7) from kidney proximal tubules worsened LPS-induced AKI. Together, the results demonstrate convincing evidence of autophagy activation in endotoxic kidney injury and support a renoprotective role of autophagy in kidney tubules.


Assuntos
Injúria Renal Aguda/patologia , Proteína 7 Relacionada à Autofagia/genética , Autofagia/fisiologia , Cloroquina/uso terapêutico , Endotoxemia/patologia , Túbulos Renais Proximais/patologia , Lipopolissacarídeos/toxicidade , Injúria Renal Aguda/prevenção & controle , Animais , Autofagia/efeitos dos fármacos , Cisplatino/toxicidade , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Traumatismo por Reperfusão
17.
Clin Nutr ; 33(5): 850-8, 2014 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-24200200

RESUMO

BACKGROUND & AIMS: Mesenteric adipose tissue hypertrophy is a hallmark of Crohn's disease and can express various adipokines. Exclusive enteral nutrition could effectively induce remission in Crohn's disease with mechanisms largely unknown. We investigated whether exclusive enteral nutrition could modify mesenteric fat in patients with active Crohn's disease. METHODS: Sixteen patients who underwent resection for ileum Crohn's disease were studied. As a control group, eight patients without inflammatory bowel disease were enrolled. Before operation, eight Crohn's disease patients received exclusive enteral nutrition for four weeks, and the other patients had no nutritional therapy. The mesenteric fat samples were obtained during operation. Adipocyte size, adipokine production and topical C-reactive protein level were assessed. RESULTS: The adipocyte size from patients treated with exclusive enteral nutrition was much larger than that from Crohn's disease patients without nutritional therapy. Furthermore, protein levels of proinflammatory adipokines such as TNF-alpha and leptin were lower while protein level of adiponectin was higher in these patients. As to mRNA level, the expression of adiponctin was up-regulated and leptin was down-regulated in the patients received enteral nutrition. CONCLUSIONS: Exclusive enteral nutrition could ameliorate mesenteric fat alterations which are associated with intestinal injury in patients with Crohn's disease by restoring adipocyte morphology and diminishing the inflammatory environment of mesenteric fat.


Assuntos
Tecido Adiposo/fisiopatologia , Doença de Crohn/terapia , Nutrição Enteral , Adiponectina/sangue , Adolescente , Adulto , Índice de Massa Corporal , Proteína C-Reativa/metabolismo , Regulação para Baixo , Feminino , Humanos , Interleucina-6/sangue , Interleucina-6/genética , Leptina/sangue , Masculino , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Manejo de Espécimes , Fator de Necrose Tumoral alfa/sangue , Regulação para Cima , Adulto Jovem
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