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1.
J Cell Mol Med ; 23(8): 5771-5781, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31199069

RESUMO

Diabetic cardiomyopathy (DCM) is characterized by increased left ventricular mass and wall thickness, decreased systolic function, reduced ejection fraction (EF) and ultimately heart failure. The 4-O-methylhonokiol (MH) has been isolated mainly from the bark of the root and stem of Magnolia species. In this study, we aimed to elucidate whether MH can effectively prevent DCM in type 2 diabetic (T2D) mice and, if so, whether the protective response of MH is associated with its activation of AMPK-mediated inhibition of lipid accumulation and inflammation. A total number of 40 mice were divided into four groups: Ctrl, Ctrl + MH, T2D, T2D + MH. Five mice from each group were sacrificed after 3-month MH treatment. The remaining animals in each group were kept for additional 3 months without further MH treatment. In T2D mice, the typical DCM symptoms were induced as expected, reflected by decreased ejection fraction and lipotoxic effects inducing lipid accumulation, oxidative stress, inflammatory reactions, and final fibrosis. However, these typical DCM changes were significantly prevented by the MH treatment immediately or 3 months after the 3-month MH treatment, suggesting MH-induced cardiac protection from T2D had a memory effect. Mechanistically, MH cardiac protection from DCM may be associated with its lipid metabolism improvement by the activation of AMPK/CPT1-mediated fatty acid oxidation. In addition, the MH treatment of DCM mice significantly improved their insulin resistance levels by activation of GSK-3ß. These results indicate that the treatment of T2D with MH effectively prevents DCM probably via AMPK-dependent improvement of the lipid metabolism.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Compostos de Bifenilo/uso terapêutico , Diabetes Mellitus Experimental/tratamento farmacológico , Diabetes Mellitus Tipo 2/tratamento farmacológico , Cardiomiopatias Diabéticas/tratamento farmacológico , Cardiomiopatias Diabéticas/prevenção & controle , Lignanas/uso terapêutico , Metabolismo dos Lipídeos , Animais , Compostos de Bifenilo/farmacologia , Glicemia/metabolismo , Diabetes Mellitus Experimental/sangue , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/fisiopatologia , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/complicações , Diabetes Mellitus Tipo 2/fisiopatologia , Cardiomiopatias Diabéticas/complicações , Cardiomiopatias Diabéticas/fisiopatologia , Fibrose , Inflamação/sangue , Inflamação/patologia , Inflamação/fisiopatologia , Lignanas/farmacologia , Masculino , Camundongos Endogâmicos C57BL , Modelos Biológicos , Estresse Oxidativo/efeitos dos fármacos
2.
Toxicol Appl Pharmacol ; 370: 93-105, 2019 05 01.
Artigo em Inglês | MEDLINE | ID: mdl-30876865

RESUMO

Diabetic nephropathy (DN) is one of the most serious long-term complications of type 2 diabetes (T2D). 4-O-methylhonokiol (MH) is one of the biologically active ingredients extracted from the Magnolia stem bark. In this study, we aim to elucidate whether treatment with MH can ameliorate or slow-down progression of DN in a T2D murine model and, if so, whether the protective response of MH correlates with AMPK-associated anti-oxidant and anti-inflammatory effects. To induce T2D, mice were fed normal diet (ND) or high fat diet (HFD) for 3 months to induce insulin resistance, followed by an intraperitoneal injection of STZ to induce hyperglycemia. Both T2D and control mice received gavage containing vehicle or MH once diabetes onset for 3 months. Once completing 3-month MH treatment, five mice from each group were sacrificed as 3 month time-point. The rest mice in each group were sacrificed 3 months later as 6 month time-point. In T2D mice, the typical DN symptoms were induced as expected, reflected by increased proteinuria, renal lipid accumulation and lipotoxic effects inducing oxidative stress, and inflammatory reactions, and final fibrosis. However, these typical DN changes were significantly prevented by MH treatment for 3 months and even at 3 months post-MH withdrawal. Mechanistically, MH renal-protection from DN may be related to lipid metabolic improvement and oxidative stress attenuation along with increases in AMPK/PGC-1α/CPT1B-mediated fatty acid oxidation and Nrf2/SOD2-mediated anti-oxidative stress. Results showed the preventive effect of MH on the renal oxidative stress and inflammation in DN.


Assuntos
Proteínas Quinases Ativadas por AMP/metabolismo , Compostos de Bifenilo/administração & dosagem , Nefropatias Diabéticas/prevenção & controle , Ácidos Graxos/metabolismo , Lignanas/administração & dosagem , Fator 2 Relacionado a NF-E2/fisiologia , Estresse Oxidativo/efeitos dos fármacos , Animais , Anti-Inflamatórios/administração & dosagem , Antioxidantes/administração & dosagem , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Tipo 2/complicações , Nefropatias Diabéticas/patologia , Dieta Hiperlipídica , Ativação Enzimática/efeitos dos fármacos , Resistência à Insulina , Rim/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Oxirredução , Fitoterapia
3.
PLoS Genet ; 9(2): e1003206, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23437001

RESUMO

Danforth's short tail mutant (Sd) mouse, first described in 1930, is a classic spontaneous mutant exhibiting defects of the axial skeleton, hindgut, and urogenital system. We used meiotic mapping in 1,497 segregants to localize the mutation to a 42.8-kb intergenic segment on chromosome 2. Resequencing of this region identified an 8.5-kb early retrotransposon (ETn) insertion within the highly conserved regulatory sequences upstream of Pancreas Specific Transcription Factor, 1a (Ptf1a). This mutation resulted in up to tenfold increased expression of Ptf1a as compared to wild-type embryos at E9.5 but no detectable changes in the expression levels of other neighboring genes. At E9.5, Sd mutants exhibit ectopic Ptf1a expression in embryonic progenitors of every organ that will manifest a developmental defect: the notochord, the hindgut, and the mesonephric ducts. Moreover, at E 8.5, Sd mutant mice exhibit ectopic Ptf1a expression in the lateral plate mesoderm, tail bud mesenchyme, and in the notochord, preceding the onset of visible defects such as notochord degeneration. The Sd heterozygote phenotype was not ameliorated by Ptf1a haploinsufficiency, further suggesting that the developmental defects result from ectopic expression of Ptf1a. These data identify disruption of the spatio-temporal pattern of Ptf1a expression as the unifying mechanism underlying the multiple congenital defects in Danforth's short tail mouse. This striking example of an enhancer mutation resulting in profound developmental defects suggests that disruption of conserved regulatory elements may also contribute to human malformation syndromes.


Assuntos
Desenvolvimento Embrionário/genética , Mutagênese Insercional/genética , Retroelementos/genética , Fatores de Transcrição , Animais , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Regulação da Expressão Gênica no Desenvolvimento/genética , Humanos , Mesoderma/anormalidades , Mesoderma/crescimento & desenvolvimento , Camundongos , Pâncreas/anormalidades , Pâncreas/crescimento & desenvolvimento , Medula Espinal/anormalidades , Medula Espinal/crescimento & desenvolvimento , Cauda/anatomia & histologia , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
4.
Front Immunol ; 15: 1411771, 2024.
Artigo em Inglês | MEDLINE | ID: mdl-39211049

RESUMO

Background: Observational studies have suggested that herpes virus infections increase the risk of allograft dysfunction after tissue and organ transplantation, but it is still unclear whether this association is causal. The aim of this study was to assess the causal relationship between four herpes virus infections and allograft dysfunction. Methods: We used two-sample bidirectional Mendelian randomization (MR) to investigate the causality between four herpes virus infections - cytomegalovirus (CMV), Epstein-Barr virus (EBV), herpes simplex virus (HSV) and varicella zoster virus (VZV) - and allograft dysfunction after tissue and organ transplantation. Based on summary data extracted from genome-wide association studies (GWAS), we chose eligible single nucleotide polymorphisms (SNPs) as instrumental variables. The Inverse variance weighted (IVW) method was used as the main analysis method, supplemented by Weighted median and MR-Egger analyses. The MR-PRESSO test, MR-Egger intercept test, heterogeneity test, leave-one-out analysis and funnel plot were used to analyze the sensitivity of MR results. Results: We found EBV early antigen-D (EA-D) antibody levels and shingles were the only two variables associated with an increased risk of allograft dysfunction. No evidence of allograft dysfunction increasing the risk of the four herpes virus infections was observed. Sensitivity analyses confirmed the robustness of our results. Conclusions: Our results suggest that EBV and VZV are involved in graft rejection or dysfunction. However, the relationship between CMV and HSV infections and allograft dysfunction remains unclear and requires further clarification.


Assuntos
Estudo de Associação Genômica Ampla , Análise da Randomização Mendeliana , Transplante de Órgãos , Polimorfismo de Nucleotídeo Único , Humanos , Transplante de Órgãos/efeitos adversos , Infecções por Herpesviridae/imunologia , Infecções por Herpesviridae/virologia , Aloenxertos , Rejeição de Enxerto/imunologia
5.
Proc Natl Acad Sci U S A ; 106(2): 534-9, 2009 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-19118203

RESUMO

It was recently shown that perceiving the avidity of T cell activation can be translated into peripheral T cell regulation to control autoimmune disease. This regulation is achieved by CD8(+) T cells that recognize a common surrogate target structure, Qa-1/Hsp60sp, preferentially expressed by activated T cells of intermediate but not high avidity. A truncated self-reactive repertoire, devoid of high-avidity T cells, generated by thymic negative selection, allows selective down-regulation of intermediate-avidity T cells to accomplish self-nonself discrimination in the periphery. Identification of the common surrogate target structure expressed on intermediate-avidity T cells opens up a conceptual theme to understand the relationship between the specificity of peripheral immune regulation and self-nonself discrimination. Here, we investigated peptide vaccination induced cross-protection mediated by CD8(+) T cells in two autoimmune disease models, experimental allergic encephalomyelitis (EAE) and type 1 diabetes (T1D). We show that Qa-1 restricted CD8(+) T cells cross-protect animals from either EAE or T1D without abrogating the immune response to foreign antigens. Cross-protection occurs because potentially pathogenic self-reactive T cells included in the pool of intermediate-avidity T cells are capable of preferentially expressing common surrogate target structures on their surface to render themselves subject to the down-regulation, independent of the specificity of the antigens that they are triggered by. Thus, like in the thymus, the immune system discriminates self from nonself, during adaptive immunity in the periphery, not by recognizing the structural differences between self and foreign antigens, but rather by perceiving the avidity of T cell activation.


Assuntos
Doenças Autoimunes/imunologia , Ativação Linfocitária/imunologia , Tolerância a Antígenos Próprios/imunologia , Especificidade do Receptor de Antígeno de Linfócitos T/imunologia , Linfócitos T/imunologia , Animais , Linfócitos T CD8-Positivos/imunologia , Reações Cruzadas/imunologia , Diabetes Mellitus Experimental/imunologia , Modelos Animais de Doenças , Encefalomielite Autoimune Experimental/imunologia , Antígenos de Histocompatibilidade Classe I , Camundongos
6.
J Am Soc Nephrol ; 22(8): 1497-504, 2011 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-21784893

RESUMO

HIVAN1, HIVAN2, and HIVAN3 are nephropathy-susceptibility loci previously identified in the HIV-1 transgenic mouse, a model of collapsing glomerulopathy. The HIVAN1 and HIVAN2 loci modulate expression of Nphs2, which encodes podocin and several other podocyte-expressed genes. To identify additional loci predisposing to nephropathy, we performed a genome-wide scan in 165 backcross mice generated between the nephropathy-sensitive HIV-1-transgenic FVB/NJ (TgFVB) strain and the resistant Balb/cJ (BALB) strain. We identified a major susceptibility locus (HIVAN4) on chromosome 6 G3-F3, with BALB alleles conferring a twofold reduction in severity (peak LOD score = 4.0). Similar to HIVAN1 and HIVAN2, HIVAN4 modulated expression of Nphs2, indicating a common pathway underlying these loci. We independently confirmed the HIVAN4 locus in a sister TgFVB colony that experienced a dramatic loss of nephropathy subsequent to a breeding bottleneck. In this low-penetrance line, 3% of the genome was admixed with BALB alleles, suggesting a remote contamination event. The admixture localized to discrete segments on chromosome 2 and at the HIVAN4 locus. HIVAN4 candidate genes include killer lectin-like receptor genes as well as A2m and Ptpro, whose gene products are enriched in the glomerulus and interact with HIV-1 proteins. In summary, these data identify HIVAN4 as a major quantitative trait locus for nephropathy and a transregulator of Nphs2. Furthermore, similar selective breeding strategies may help identify further susceptibility loci.


Assuntos
Predisposição Genética para Doença , Nefropatias/genética , Alelos , Animais , Mapeamento Cromossômico , Cruzamentos Genéticos , Feminino , HIV-1/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Nefropatias/diagnóstico , Escore Lod , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Modelos Genéticos
7.
World J Diabetes ; 13(8): 600-612, 2022 Aug 15.
Artigo em Inglês | MEDLINE | ID: mdl-36159226

RESUMO

BACKGROUND: Diabetic nephropathy (DN) is the principal cause of end-stage renal disease. Previous studies have shown that clopidogrel can prevent the early progression of renal injury. AIM: To elucidate whether clopidogrel is beneficial against DN by using a db/db mouse model. METHODS: db/db mice with a higher urinary albumin/creatinine ratio (ACR) relative to age- and sex-matched wild-type control mice were randomly allocated to clopidogrel and vehicle treatment groups. Clopidogrel was administered at doses of 5, 10, and 20 mg/kg by gavage for 12 wk. Body mass, blood glucose level, and urinary creatinine and albumin concentrations in each group were measured before and after the intervention. Renal fibrosis was evaluated using periodic acid-Schiff and Masson's trichrome staining. The renal protein expression of tumor necrosis factor-α (TNF-α), interleukin-1ß (IL-1ß), and F4/80 was assessed using immunohistochemistry. Urinary TNF-α, monocyte chemoattractant protein-1 (MCP-1), and IL-6 levels were analyzed using enzyme-linked immunosorbent assay; TNF-α and IL-1ß mRNA expression was measured using real-time quantitative polymerase chain reaction. The protein expression of fibronectin (FN) and collagen I was assessed using immunohistochemistry. RESULTS: Clopidogrel treatment did not affect the body mass or blood glucose level of the db/db mice; however, it increased bleeding time and reduced urinary ACR in a dose-dependent manner. Immunohistochemical staining revealed an amelioration of renal fibrosis, significantly lower deposition of FN and collagen I, and significantly lower expression of the proinflammatory cytokines TNF-α and IL-1ß and lower levels of urinary TNF-α and MCP-1 in the clopidogrel-treated db/db mice (P < 0.05). Furthermore, clopidogrel significantly reduced macrophage infiltration into the glomeruli of the db/db mice. CONCLUSION: Clopidogrel significantly reduced renal collagen deposition and fibrosis and prevented renal dysfunction in db/db mice, most likely through inhibition of renal macrophage infiltration and the associated inflammation.

8.
Kidney Int ; 78(5): 453-62, 2010 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-20520596

RESUMO

Most mouse models of diabetes do not fully reproduce features of human diabetic nephropathy, limiting their utility in inferring mechanisms of human disease. Here we performed detailed phenotypic and genetic characterization of leptin-receptor (Lepr) deficient mice on the FVB/NJ background (FVB(db/db)), an obese model of type II diabetes, to determine their suitability to model human diabetic nephropathy. These mice have sustained hyperglycemia, significant albuminuria and characteristic diabetic renal findings including mesangial sclerosis and nodular glomerulosclerosis after 6 months of age. In contrast, equally obese, hyperglycemic Lepr/Sur1 deficient C57BL/6J (Sur1 has defective insulin secretion) mice have minimal evidence of nephropathy. A genome-wide scan in 165 Lepr deficient backcross progeny derived from FVB/NJ and C57BL/6J identified a major locus influencing nephropathy and albuminuria on chromosome 8B1-C5 (Dbnph1 locus, peak lod score 5.0). This locus was distinct from those contrasting susceptibility to beta cell hypertrophy and HIV-nephropathy between the same parental strains, indicating specificity to diabetic kidney disease. Genome-wide expression profiling showed that high and low risk Dbnph1 genotypes were associated with significant enrichment for oxidative phosphorylation and lipid clearance, respectively; molecular pathways shared with human diabetic nephropathy. Hence, we found that the FVB(db/db) mouse recapitulates many clinical, histopathological and molecular features of human diabetic nephropathy. Identifying underlying susceptibility gene(s) and downstream dysregulated pathways in these mice may provide insight into the disease pathogenesis in humans.


Assuntos
Mapeamento Cromossômico , Diabetes Mellitus Tipo 2/genética , Nefropatias Diabéticas/genética , Predisposição Genética para Doença , Animais , Diabetes Mellitus Tipo 2/complicações , Modelos Animais de Doenças , Perfilação da Expressão Gênica , Ligação Genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Obesos
9.
Urology ; 136: 241-244, 2020 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-31605682

RESUMO

Ewing sarcoma/primitive neuroectodermal tumor (ES/PNET) of the kidney in children younger than 10 years of age is extremely rare. We describe here the case of a 7-year-old female patient who was diagnosed with ES/PNET. The timeframe for this case spanned from 8 months prior to diagnosis until 8 months postsurgical removal of the tumor. In addition, we summarized the cases of PNET in children younger than 10 years of age in the last decade.


Assuntos
Neoplasias Renais/diagnóstico por imagem , Neoplasias Renais/patologia , Imageamento por Ressonância Magnética , Neoplasias Primárias Múltiplas/diagnóstico por imagem , Neoplasias Primárias Múltiplas/patologia , Tumores Neuroectodérmicos Primitivos Periféricos/diagnóstico por imagem , Tumores Neuroectodérmicos Primitivos Periféricos/patologia , Sarcoma de Ewing/diagnóstico por imagem , Sarcoma de Ewing/patologia , Tomografia Computadorizada por Raios X , Criança , Feminino , Humanos , Estadiamento de Neoplasias
10.
Diabetes Metab J ; 44(4): 566-580, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32431116

RESUMO

BACKGROUND: Fibroblast growth factor 21 (FGF21) has been only reported to prevent type 1 diabetic nephropathy (DN) in the streptozotocin-induced type 1 diabetes mellitus (T1DM) mouse model. However, the FVB (Cg)-Tg (Cryaa-Tag, Ins2-CALM1) 26OVE/PneJ (OVE26) transgenic mouse is a widely recommended mouse model to recapture the most important features of T1DM nephropathy that often occurs in diabetic patients. In addition, most previous studies focused on exploring the preventive effect of FGF21 on the development of DN. However, in clinic, development of therapeutic strategy has much more realistic value compared with preventive strategy since the onset time of DN is difficult to be accurately predicted. Therefore, in the present study OVE26 mice were used to investigate the potential therapeutic effects of FGF21 on DN. METHODS: Four-month-old female OVE26 mice were intraperitoneally treated with recombinant FGF21 at a dose of 100 µg/kg/day for 3 months. The diabetic and non-diabetic control mice were treated with phosphate-buffered saline at the same volume. Renal functions, pathological changes, inflammation, apoptosis, oxidative stress and fibrosis were examined in mice of all groups. RESULTS: The results showed that severe renal dysfunction, morphological changes, inflammation, apoptosis, and fibrosis were observed in OVE26 mice. However, all the renal abnormalities above in OVE26 mice were significantly attenuated by 3-month FGF21 treatment associated with improvement of renal adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) activity and sirtuin 1 (SIRT1) expression. CONCLUSION: Therefore, this study demonstrated that FGF21 might exert therapeutic effects on DN through AMPK-SIRT1 pathway.


Assuntos
Diabetes Mellitus Experimental , Diabetes Mellitus Tipo 1 , Nefropatias Diabéticas , Animais , Diabetes Mellitus Tipo 1/tratamento farmacológico , Nefropatias Diabéticas/tratamento farmacológico , Feminino , Fatores de Crescimento de Fibroblastos , Masculino , Camundongos
11.
Life Sci ; 254: 117783, 2020 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-32413404

RESUMO

AIMS: This study aimed to examine the anti-fibrotic role of Nuclear Factor-Erythroid derived 2 (NF-E2) in human renal tubule (HK-11) cells and in type 1 and type 2 diabetic (T1D, T2D) mouse kidneys. MAIN METHODS: Anti-fibrotic effects of NF-E2 were examined in transforming growth factor-ß (TGF-ß) treated HK-11 cells by over-expressing/silencing NF-E2 expression and determining its effects on profibrotic signaling. NF-E2 proteasomal degradation was confirmed by proteasome inhibition in HK-11 cells and diabetic mice. Clinical relevance of changes in NF-E2 expression to fibrotic changes in the kidney were assessed in T1D and T2D mouse kidneys. KEY FINDINGS: NF-E2 expression was significantly decreased in TGF-ß treated HK-11 cells and in kidneys of diabetic mice with concurrent increase in expression of fibrotic proteins. TGF-ß treatment of HK-11 cells did not inhibit NF-E2 mRNA expression, suggesting that the post-translational changes may contribute to NF-E2 protein degradation. The down-regulation of NF-E2 expression was attributed to its proteasomal degradation, as TGF-ß- and diabetes-induced NF-E2 down regulation was prevented by proteasome inhibitor treatment. In HK-11 cells TGF-ß treatment decreased E-cadherin expression and induced pSer82Hsp27/NF-E2 association, likely to promote NF-E2 degradation, as Hsp27 can target proteins to the proteasome. A critical role for NF-E2 in regulation of renal fibrosis was demonstrated as over-expression of NF-E2 or silencing NF-E2 expression, decreased or increased profibrotic proteins in TGF-ß-treated HK-11 cells, respectively. SIGNIFICANCE: NF-E2, a novel anti-fibrotic protein, is down-regulated in diabetic kidneys. Preserving/inducing NF-E2 expression in diabetic kidneys may provide a therapeutic potential to combat DN.


Assuntos
Diabetes Mellitus Experimental/metabolismo , Fibrose/fisiopatologia , Subunidade p45 do Fator de Transcrição NF-E2/fisiologia , Animais , Caderinas/biossíntese , Células Cultivadas , Inibidores de Cisteína Proteinase/farmacologia , Diabetes Mellitus Experimental/genética , Regulação para Baixo , Fibrose/metabolismo , Técnicas de Silenciamento de Genes , Proteínas de Choque Térmico HSP27/metabolismo , Humanos , Rim/metabolismo , Túbulos Renais/metabolismo , Leupeptinas/farmacologia , Masculino , Camundongos , Camundongos Transgênicos , Subunidade p45 do Fator de Transcrição NF-E2/biossíntese , Subunidade p45 do Fator de Transcrição NF-E2/genética , Ligação Proteica/efeitos dos fármacos , Transdução de Sinais/fisiologia , Fator de Crescimento Transformador beta/efeitos adversos , Fator de Crescimento Transformador beta/antagonistas & inibidores
12.
Oncogene ; 39(6): 1302-1317, 2020 02.
Artigo em Inglês | MEDLINE | ID: mdl-31636388

RESUMO

Intratumoral heterogeneity in bladder cancer is a barrier to accurate molecular sub-classification and treatment efficacy. However, individual cellular and mechanistic contributions to tumor heterogeneity are controversial. We examined potential mechanisms of FOXA1 and PTEN inactivation in bladder cancer and their contribution to tumor heterogeneity. These analyses were complemented with inactivation of FOXA1 and PTEN in intermediate and luminal mouse urothelium. We show inactivation and reduced expression of FOXA1 and PTEN is prevalent in human disease, where PTEN and FOXA1 are downregulated by allelic loss and site-specific DNA hypermethylation, respectively. Conditional inactivation of both Foxa1 and Pten in intermediate/luminal cells in mice results in development of bladder cancer exhibiting squamous features as well as enhanced sensitivity to a bladder-specific carcinogen. In addition, FOXA1 is hypermethylated in basal bladder cancer cell lines, and this is reversed by treatment with DNA methyltransferase inhibitors. By integrating human correlative and in vivo studies, we define a critical role for PTEN loss and epigenetic silencing of FOXA1 in heterogeneous human disease and show genetic targeting of luminal/intermediate cells in mice drives squamous differentiation.


Assuntos
Carcinoma de Células Escamosas/patologia , Diferenciação Celular , Metilação de DNA , Fator 3-alfa Nuclear de Hepatócito/genética , Perda de Heterozigosidade , PTEN Fosfo-Hidrolase/genética , Neoplasias da Bexiga Urinária/patologia , Animais , Apoptose , Biomarcadores Tumorais , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/metabolismo , Proliferação de Células , Feminino , Regulação Neoplásica da Expressão Gênica , Fator 3-alfa Nuclear de Hepatócito/metabolismo , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Neoplasias Musculares/genética , Neoplasias Musculares/metabolismo , Neoplasias Musculares/patologia , PTEN Fosfo-Hidrolase/metabolismo , Prognóstico , Células Tumorais Cultivadas , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/metabolismo
13.
Kidney Int ; 75(4): 366-72, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19092797

RESUMO

HIV-1 transgenic mice on the FVB/NJ background (TgFVB) are a well validated model of HIV-associated nephropathy (HIVAN). A mapping study between TgFVB and CAST/EiJ (CAST) strains showed this trait to be influenced by a major susceptibility locus on chromosome 3A1-A3 (HIVAN1), with CAST alleles associated with increased risk of disease. We introgressed a 50 Mb interval, encompassing this HIVAN1 locus, from CAST into the TgFVB genome (TgFVB-HIVAN1(CAST) congenic mice). Compared to the TgFVB strain, these congenic mice developed an earlier onset of proteinuria, a rapid progression to kidney failure, and increased mortality. A prospective study of these congenic mice also showed that they had a significantly greater histologic and biochemical evidence of glomerulopathy with one-third of mice developing global glomerulosclerosis by 6 weeks of age. An F2 cross between TgFVB and the congenic mice identified a significant linkage (LOD=3.7) to a 10 cM interval within the HIVAN1 region between D3Mit167 and D3Mit67 resulting in a 60% reduction of the original interval. These data independently confirm that a gene on chromosome 3A1-A3 increases susceptibility to HIVAN, resulting in early onset and rapid progression of kidney disease. These mice represent a new model to study the development and progression of collapsing glomerulopathy.


Assuntos
Nefropatia Associada a AIDS/genética , Predisposição Genética para Doença , Glomerulonefrite/genética , HIV-1/genética , Animais , Mapeamento Cromossômico , Cromossomos , Progressão da Doença , Glomerulonefrite/patologia , Camundongos , Camundongos Congênicos
14.
Sci Rep ; 9(1): 270, 2019 01 22.
Artigo em Inglês | MEDLINE | ID: mdl-30670749

RESUMO

Tumorigenesis requires accumulation of genetic and epigenetic alterations, some of which drive tumor initiation. "Oncogene addiction" describes the phenomenon that (1) well-established cancers are dependent on one mutated oncogene or pathway for the maintenance of a malignant phenotype and that (2) withdrawal of the single oncogenic event leads to growth arrest and/or cancer regression. While oncogene addiction has been experimentally validated in advanced tumor models, its role in tumor precursors has not been investigated. We utilized the requirement of Forkhead box A1 (Foxa1) for transcriptional activation of the Upk2-promoter to temporally control the expression of Upk2-HRAS* oncogene, an inducer of urothelial hyperplasia in transgenic mice. Inducible homozygous knockout of Foxa1 in Upk2-HRAS*/UBC-CreERT2/Foxa1loxp/loxp mice results in reduced HRAS* levels. This led to a marked reduction of urothelial proliferation as evidenced by urothelial thinning, degenerative changes such as intracellular vacuole formation, and reduced Ki67 expression. Reduced proliferation did not affect basal, Krt14-positive cells, supporting the fact that Foxa1-regulated Upk2-HRAS* expression occurs primarily in supra-basal cells. Our results indicate that maintenance of urothelial hyperplasia in Upk2-HRAS* mice depends on continuous expression of Foxa1 and activated HRAS, and that mutated receptor tyrosine kinases, FOXA1 and/or other downstream effectors may mediate oncogene addiction in urothelial hyperplasia.


Assuntos
Carcinoma de Células de Transição/genética , Carcinoma de Células de Transição/patologia , Fator 3-alfa Nuclear de Hepatócito/metabolismo , Lesões Pré-Cancerosas/patologia , Proteínas Proto-Oncogênicas p21(ras)/genética , Neoplasias da Bexiga Urinária/genética , Animais , Carcinogênese/genética , Proliferação de Células/genética , Modelos Animais de Doenças , Regulação Neoplásica da Expressão Gênica , Fator 3-alfa Nuclear de Hepatócito/genética , Humanos , Hiperplasia/genética , Hiperplasia/patologia , Camundongos , Camundongos Knockout , Camundongos Transgênicos , Lesões Pré-Cancerosas/genética , Ativação Transcricional , Bexiga Urinária/patologia , Neoplasias da Bexiga Urinária/patologia , Urotélio/patologia
15.
Int J Biol Sci ; 15(1): 239-252, 2019.
Artigo em Inglês | MEDLINE | ID: mdl-30662363

RESUMO

Hyperglycemia-induced renal fibrosis causes end-stage renal disease. Clopidogrel, a platelet inhibitor, is often administered to decrease cardiovascular events in diabetic patients. We investigated whether clopidogrel can reduce diabetes-induced renal fibrosis in a streptozotocin-induced type 1 diabetes murine model and fibronectin involvement in this protective response. Diabetic and age-matched controls were sacrificed three months after the onset of diabetes, and additional controls and diabetic animals were further treated with clopidogrel or vehicle for three months. Diabetes induced renal morphological changes and fibrosis after three months. Clopidogrel, administered during the last three months, significantly decreased blood glucose, collagen and fibronectin expression compared to vehicle-treated diabetic mice. Diabetes increased TGF-ß expression, inducing fibrosis via Smad-independent pathways, MAP kinases, and Akt activation at three months but returned to baseline at six months, whereas the expression of fibronectin and collagen remained elevated. Our results suggest that activation of TGF-ß, CTGF, and MAP kinases are early profibrotic signaling events, resulting in significant fibronectin accumulation at the early time point and returning to baseline at a later time point. Akt activation at the three-month time point may serve as an adaptive response in T1D. Mechanisms of clopidogrel therapeutic effect on the diabetic kidney remain to be investigated as this clinically approved compound could provide novel approaches to prevent diabetes-induced renal disease, therefore improving patients' survival.


Assuntos
Clopidogrel/uso terapêutico , Diabetes Mellitus Experimental/complicações , Diabetes Mellitus Experimental/tratamento farmacológico , Fibronectinas/metabolismo , Fibrose/tratamento farmacológico , Fibrose/etiologia , Nefropatias/tratamento farmacológico , Animais , Coagulação Sanguínea/efeitos dos fármacos , Western Blotting , Clopidogrel/farmacologia , Fibrose/metabolismo , Imuno-Histoquímica , Rim/efeitos dos fármacos , Rim/patologia , Nefropatias/etiologia , Nefropatias/metabolismo , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Antagonistas do Receptor Purinérgico P2Y/farmacologia , Antagonistas do Receptor Purinérgico P2Y/uso terapêutico
16.
Oncogenesis ; 8(12): 69, 2019 Nov 26.
Artigo em Inglês | MEDLINE | ID: mdl-31772149

RESUMO

The discovery of bladder cancer transcriptional subtypes provides an opportunity to identify high risk patients, and tailor disease management. Recent studies suggest tumor heterogeneity contributes to regional differences in molecular subtype within the tumor, as well as during progression and following treatment. Nonetheless, the transcriptional drivers of the aggressive basal-squamous subtype remain unidentified. As PPARÉ£ has been repeatedly implicated in the luminal subtype of bladder cancer, we hypothesized inactivation of this transcriptional master regulator during progression results in increased expression of basal-squamous specific transcription factors (TFs) which act to drive aggressive behavior. We initiated a pharmacologic and RNA-seq-based screen to identify PPARÉ£-repressed, basal-squamous specific TFs. Hierarchical clustering of RNA-seq data following treatment of three human bladder cancer cells with a PPARÉ£ agonist identified a number of TFs regulated by PPARÉ£ activation, several of which are implicated in urothelial and squamous differentiation. One PPARÉ£-repressed TF implicated in squamous differentiation identified is Transcription Factor Activating Protein 2 alpha (TFAP2A). We show TFAP2A and its paralog TFAP2C are overexpressed in basal-squamous bladder cancer and in squamous areas of cystectomy samples, and that overexpression is associated with increased lymph node metastasis and distant recurrence, respectively. Biochemical analysis confirmed the ability of PPARÉ£ activation to repress TFAP2A, while PPARÉ£ antagonist and PPARÉ£ siRNA knockdown studies indicate the requirement of a functional receptor. In vivo tissue recombination studies show TFAP2A and TFAP2C promote tumor growth in line with the aggressive nature of basal-squamous bladder cancer. Our findings suggest PPARÉ£ inactivation, as well as TFAP2A and TFAP2C overexpression cooperate with other TFs to promote the basal-squamous transition during tumor progression.

17.
J Clin Invest ; 115(2): 302-12, 2005 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-15668735

RESUMO

We show in these studies that Qa-1-dependent CD8+ T cells are involved in the establishment and maintenance of peripheral self tolerance as well as facilitating affinity maturation of CD4+ T cells responding to foreign antigen. We provide experimental evidence that the strategy used by the Qa-1-dependent CD8+ T cells to accomplish both these tasks in vivo is to selectively downregulate T cell clones that respond to both self and foreign antigens with intermediate, not high or low, affinity/avidity. Thus, the immune system evolved to regulate peripheral immunity using a unified mechanism that efficiently and effectively permits the system to safeguard peripheral self tolerance yet promote the capacity to deal with foreign invaders.


Assuntos
Linfócitos T CD4-Positivos/imunologia , Linfócitos T CD8-Positivos/imunologia , Tolerância a Antígenos Próprios/imunologia , Animais , Autoantígenos/genética , Autoantígenos/imunologia , Autoimunidade/genética , Autoimunidade/imunologia , Diferenciação Celular/genética , Diferenciação Celular/imunologia , Linhagem da Célula/genética , Linhagem da Célula/imunologia , Antígenos de Histocompatibilidade Classe I/imunologia , Ativação Linfocitária/genética , Ativação Linfocitária/imunologia , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Transgênicos , Tolerância a Antígenos Próprios/genética
18.
J Cancer ; 9(9): 1527-1537, 2018.
Artigo em Inglês | MEDLINE | ID: mdl-29760790

RESUMO

Cancer is a leading cause of death throughout the world, and cancer therapy remains a big medical challenge in terms of both its therapeutic efficacy and safety. Therefore, to find out a safe anticancer drug has been long goal for oncologist and medical scientists. Among clinically used medicines with no or little toxicity, fenofibrate is a drug of the fibrate class that plays an important role in lowering the levels of serum cholesterol and triglycerides while elevating the levels of high-density lipoproteins. Recently, several studies have implied that fenofibrate may exert anticancer effects via a variety of pathways involved in apoptosis, cell-cycle arrest, invasion, and migration. Given the great potential that fenofibrate may have anticancer effects, this review was to investigate all published works which directly or indirectly support the anticancer activity of fenofibrate. These studies provide evidence that fenofibrate exerted antitumor effects in several human cancer cell lines, such as breast, liver, glioma, prostate, pancreas, and lung cancer cell lines. Among these studies some have further confirmed the possibility and efficacy of fenofibrate anticancer in xenograft mouse models. In the last part of this review, we also discuss the potential mechanisms of action of fenofibrate based on the available information. Overall, we may repurpose fenofibrate as an anticancer drug in cancer treatment, which urgently need further and comprehensively investigated.

19.
Nat Rev Urol ; 14(2): 98-106, 2017 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-27898096

RESUMO

Genomic and transcriptional studies have identified discrete molecular subtypes of bladder cancer. These observations could be the starting point to identify new treatments. Several members of the forkhead box (FOX) superfamily of transcription factors have been found to be differentially expressed in the different bladder cancer subtypes. In addition, the FOXA protein family are key regulators of embryonic bladder development and patterning. Both experimental and clinical data support a role for FOXA1 and FOXA2 in urothelial carcinoma. FOXA1 is expressed in embryonic and adult urothelium and its expression is altered in urothelial carcinomas and across disparate molecular bladder cancer subtypes. FOXA2 is normally absent from the adult urothelium, but developmental studies identified FOXA2 as a marker of a transient urothelial progenitor cell population during bladder development. Studies also implicate FOXA2 in bladder cancer and several other FOX proteins might be involved in development and/or progression of this disease; for example, FOXA1 and FOXO3A have been associated with clinical patient outcomes. Future studies should investigate to what extent and by which mechanisms FOX proteins might be directly involved in bladder cancer pathogenesis and treatment responses.


Assuntos
Biomarcadores Tumorais/biossíntese , Regulação Neoplásica da Expressão Gênica , Fator 3-alfa Nuclear de Hepatócito/biossíntese , Neoplasias da Bexiga Urinária/genética , Neoplasias da Bexiga Urinária/metabolismo , Biomarcadores Tumorais/genética , Fatores de Transcrição Forkhead/biossíntese , Fatores de Transcrição Forkhead/genética , Fator 3-alfa Nuclear de Hepatócito/genética , Humanos , Neoplasias da Bexiga Urinária/diagnóstico
20.
Sci Rep ; 6: 38531, 2016 12 07.
Artigo em Inglês | MEDLINE | ID: mdl-27924948

RESUMO

Discrete bladder cancer molecular subtypes exhibit differential clinical aggressiveness and therapeutic response, which may have significant implications for identifying novel treatments for this common malignancy. However, research is hindered by the lack of suitable models to study each subtype. To address this limitation, we classified bladder cancer cell lines into molecular subtypes using publically available data in the Cancer Cell Line Encyclopedia (CCLE), guided by genomic characterization of bladder cancer by The Cancer Genome Atlas (TCGA). This identified a panel of bladder cancer cell lines which exhibit genetic alterations and gene expression patterns consistent with luminal and basal molecular subtypes of human disease. A subset of bladder cancer cell lines exhibit in vivo histomorphologic patterns consistent with luminal and basal subtypes, including papillary architecture and squamous differentiation. Using the molecular subtype assignments, and our own RNA-seq analysis, we found overexpression of GATA3 and FOXA1 cooperate with PPARÉ£ activation to drive transdifferentiation of a basal bladder cancer cells to a luminial phenotype. In summary, our analysis identified a set of human cell lines suitable for the study of molecular subtypes in bladder cancer, and furthermore indicates a cooperative regulatory network consisting of GATA3, FOXA1, and PPARÉ£ drive luminal cell fate.


Assuntos
Fator de Transcrição GATA3/metabolismo , Fator 3-alfa Nuclear de Hepatócito/metabolismo , PPAR gama/metabolismo , Neoplasias da Bexiga Urinária/classificação , Neoplasias da Bexiga Urinária/genética , Animais , Sequência de Bases , Biomarcadores Tumorais/metabolismo , Linhagem Celular Tumoral , Regulação Neoplásica da Expressão Gênica , Redes Reguladoras de Genes , Estudos de Associação Genética , Humanos , Ratos , Sequências Reguladoras de Ácido Nucleico/genética , Análise de Sequência de RNA , Neoplasias da Bexiga Urinária/patologia , Urotélio/patologia
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