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3.
Transpl Int ; 36: 11589, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37680647

RESUMO

The Thrombotic Microangiopathy Banff Working Group (TMA-BWG) was formed in 2015 to survey current practices and develop minimum diagnostic criteria (MDC) for renal transplant TMA (Tx-TMA). To generate consensus among pathologists and nephrologists, the TMA BWG designed a 3-Phase study. Phase I of the study is presented here. Using the Delphi methodology, 23 panelists with >3 years of diagnostic experience with Tx-TMA pathology listed their MDC suggesting light, immunofluorescence, and electron microscopy lesions, clinical and laboratory information, and differential diagnoses. Nine rounds (R) of consensus resulted in MDC validated during two Rs using online evaluation of whole slide digital images of 37 biopsies (28 TMA, 9 non-TMA). Starting with 338 criteria the process resulted in 24 criteria and 8 differential diagnoses including 18 pathologic, 2 clinical, and 4 laboratory criteria. Results show that 3/4 of the panelists agreed on the diagnosis of 3/4 of cases. The process also allowed definition refinement for 4 light and 4 electron microscopy lesions. For the first time in Banff classification, the Delphi methodology was used to generate consensus. The study shows that Delphi is a democratic and cost-effective method allowing rapid consensus generation among numerous physicians dealing with large number of criteria in transplantation.


Assuntos
Transplante de Rim , Microangiopatias Trombóticas , Humanos , Consenso , Análise Custo-Benefício , Biópsia
4.
Transpl Int ; 36: 11590, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37680648

RESUMO

The Banff community summoned the TMA Banff Working Group to develop minimum diagnostic criteria (MDC) and recommendations for renal transplant TMA (Tx-TMA) diagnosis, which currently lacks standardized criteria. Using the Delphi method for consensus generation, 23 nephropathologists (panelists) with >3 years of diagnostic experience with Tx-TMA were asked to list light, immunofluorescence, and electron microscopic, clinical and laboratory criteria and differential diagnoses for Tx-TMA. Delphi was modified to include 2 validations rounds with histological evaluation of whole slide images of 37 transplant biopsies (28 TMA and 9 non-TMA). Starting with 338 criteria in R1, MDC were narrowed down to 24 in R8 generating 18 pathological, 2 clinical, 4 laboratory criteria, and 8 differential diagnoses. The panelists reached a good level of agreement (70%) on 76% of the validated cases. For the first time in Banff classification, Delphi was used to reach consensus on MDC for Tx-TMA. Phase I of the study (pathology phase) will be used as a model for Phase II (nephrology phase) for consensus regarding clinical and laboratory criteria. Eventually in Phase III (consensus of the consensus groups) and the final MDC for Tx-TMA will be reported to the transplantation community.


Assuntos
Transplante de Rim , Microangiopatias Trombóticas , Humanos , Transplante de Rim/efeitos adversos , Consenso , Rim , Microangiopatias Trombóticas/diagnóstico , Microangiopatias Trombóticas/etiologia , Aminas , Anticoagulantes , Aloenxertos
5.
Am J Pathol ; 188(11): 2508-2528, 2018 11.
Artigo em Inglês | MEDLINE | ID: mdl-30201495

RESUMO

Human parietal epithelial cells (PECs) are progenitor cells that sustain podocyte homeostasis. We hypothesized that the lack of apolipoprotein (APO) L1 ensures the PEC phenotype, but its induction initiates PEC transition (expression of podocyte markers). APOL1 expression and down-regulation of miR193a coincided with the expression of podocyte markers during the transition. The induction of APOL1 also stimulated transition markers in human embryonic kidney cells (cells with undetectable APOL1 protein expression). APOL1 silencing in PECs up-regulated miR193a expression, suggesting the possibility of a reciprocal feedback relationship between APOL1 and miR193a. HIV, interferon-γ, and vitamin D receptor agonist down-regulated miR193a expression and induced APOL1 expression along with transition markers in PECs. Luciferase assay suggested a putative interaction between miR193a and APOL1. Since silencing of APOL1 attenuated HIV-, vitamin D receptor agonist-, miR193a inhibitor-, and interferon-γ-induced expression of transition markers, APOL1 appears to be a critical functional constituent of the miR193a- APOL1 axis in PECs. This notion was confirmed by further enhanced expression of PEC markers in APOL1 mRNA-silenced PECs. In vivo studies, glomeruli in patients with HIV, and HIV/APOL1 transgenic mice had foci of PECs expressing synaptopodin, a transition marker. APOL1 likely regulates PEC molecular phenotype through modulation of miR193a expression, and APOL1 and miR193a share a reciprocal feedback relationship.


Assuntos
Nefropatia Associada a AIDS/patologia , Apolipoproteína L1/metabolismo , Células Epiteliais/patologia , Regulação da Expressão Gênica , Glomérulos Renais/patologia , MicroRNAs/genética , Nefropatia Associada a AIDS/metabolismo , Nefropatia Associada a AIDS/virologia , Animais , Apolipoproteína L1/genética , Estudos de Casos e Controles , Células Epiteliais/metabolismo , Células HEK293 , Células Hep G2 , Humanos , Glomérulos Renais/metabolismo , Camundongos , Camundongos Transgênicos
6.
Am J Pathol ; 186(2): 347-58, 2016 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-26683666

RESUMO

Dysregulated growth and loss of podocytes are important features of HIV-associated nephropathy. Recently, HIV was reported to induce a new type of programed cell death, pyroptosis, in T lymphocytes through induction of Nod-like receptor protein 3 (NLRP3) inflammasome complexes. We evaluated the role of HIV in podocyte NLRP3 inflammasome formation both in vivo and in vitro. Renal cortical sections of HIV-transgenic mice (Tg26) displayed increased expression of NLRP3, ASC (a CARD protein), caspase-1, and IL-1ß proteins, confirming NLRP3 inflammasome complex formation in podocytes of Tg26 mice. Renal tissues of Tg26 mice also displayed enhanced mRNA levels and protein expressions of inflammasome markers (NLRP3, ASC, and caspase-1, and IL-1ß). Serum of Tg26 mice also showed elevated concentrations of IL-1ß cytokine compared with FVBN mice. HIV induced pyroptosis in a dose- and time-dependent manner within podocytes, a phenotype of inflammasome activation. Caspase-1 inhibitor not only attenuated podocyte expression of caspase-1 and IL-1ß but also provided protection against pyroptosis, suggesting that HIV-induced podocyte injury was mediated by caspase-1 activation. Interestingly, HIV-induced podocyte pyroptosis could be partially inhibited by Tempol (a superoxide dismutase-mimetic agent) and by glyburide (an inhibitor of potassium efflux). These findings suggest that generation of reactive oxygen species and potassium efflux contribute to HIV-induced pyroptosis and NLRP3 inflammasome activation in podocytes.


Assuntos
Nefropatia Associada a AIDS/metabolismo , Proteínas Reguladoras de Apoptose/metabolismo , Proteínas de Transporte/metabolismo , Inflamassomos/metabolismo , Podócitos/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Animais , Apoptose/fisiologia , Camundongos , Proteína 3 que Contém Domínio de Pirina da Família NLR , Podócitos/virologia
7.
J Am Soc Nephrol ; 26(4): 817-29, 2015 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-25535303

RESUMO

Excessive TGF-ß signaling in epithelial cells, pericytes, or fibroblasts has been implicated in CKD. This list has recently been joined by endothelial cells (ECs) undergoing mesenchymal transition. Although several studies focused on the effects of ablating epithelial or fibroblast TGF-ß signaling on development of fibrosis, there is a lack of information on ablating TGF-ß signaling in the endothelium because this ablation causes embryonic lethality. We generated endothelium-specific heterozygous TGF-ß receptor knockout (TßRII(endo+/-)) mice to explore whether curtailed TGF-ß signaling significantly modifies nephrosclerosis. These mice developed normally, but showed enhanced angiogenic potential compared with TßRII(endo+/+) mice under basal conditions. After induction of folic acid nephropathy or unilateral ureteral obstruction, TßRII(endo+/-) mice exhibited less tubulointerstitial fibrosis, enhanced preservation of renal microvasculature, improvement in renal blood flow, and less tissue hypoxia than TßRII(endo+/+) counterparts. In addition, partial deletion of TßRII in the endothelium reduced endothelial-to-mesenchymal transition (EndoMT). TGF-ß-induced canonical Smad2 signaling was reduced in TßRII(+/-) ECs; however, activin receptor-like kinase 1 (ALK1)-mediated Smad1/5 phosphorylation in TßRII(+/-) ECs remained unaffected. Furthermore, the S-endoglin/L-endoglin mRNA expression ratio was significantly lower in TßRII(+/-) ECs compared with TßRII(+/+) ECs. These observations support the hypothesis that EndoMT contributes to renal fibrosis and curtailing endothelial TGF-ß signals favors Smad1/5 proangiogenic programs and dictates increased angiogenic responses. Our data implicate endothelial TGF-ß signaling and EndoMT in regulating angiogenic and fibrotic responses to injury.


Assuntos
Transdiferenciação Celular , Endotélio/metabolismo , Rim/patologia , Insuficiência Renal Crônica/metabolismo , Fator de Crescimento Transformador beta/metabolismo , Animais , Endoglina , Endotélio/patologia , Fibrose , Ácido Fólico , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Camundongos Transgênicos , Neovascularização Fisiológica , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , Receptor do Fator de Crescimento Transformador beta Tipo II , Receptores de Fatores de Crescimento Transformadores beta/genética , Receptores de Fatores de Crescimento Transformadores beta/metabolismo , Insuficiência Renal Crônica/patologia , Proteínas Smad/metabolismo , Obstrução Ureteral
8.
Am J Physiol Renal Physiol ; 309(3): F189-203, 2015 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-26084932

RESUMO

ANG II type 1 receptor blockade (AT1R-BLK) is used extensively to slow down the progression of proteinuric kidney diseases. We hypothesized that AT1R-BLK provides podocyte protection through regulation of silencing mediator of retinoic acid and thyroid hormone receptor (SMRT) and vitamin D receptor (VDR) expression under adverse milieus such as high glucose and human immunodeficiency virus infection. Both AT1R-BLK and VDR agonists (VDAs) stimulated VDR complex formation that differed not only in their composition but also in their functionality. AT1R-BLK-induced VDR complexes contained predominantly unliganded VDR, SMRT, and phosphorylated histone deacetylase 3, whereas VDA-VDR complexes were constituted by liganded VDR and CREB-binding protein/p300. AT1R-BLK-induced complexes attenuated podocyte acetyl-histone 3 levels as well as cytochrome P-450 family 24A1 expression, thus indicating their deacetylating and repressive properties. On the other hand, VDA-VDR complexes not only increased podocyte acetyl-histone 3 levels but also enhanced cytochrome P-450 family 24A1 expression, thus suggesting their acetylating and gene activation properties. AT1R-BLK- induced podocyte SMRT inhibited expression of the proapoptotic gene BAX through downregulation of Wip1 and phosphorylation of checkpoint kinase 2 in high-glucose milieu. Since SMRT-depleted podocytes lacked AT1R-BLK-mediated protection against DNA damage, it appears that SMRT is necessary for DNA repairs during AT1R-BLK. We conclude that AT1R-BLK provides podocyte protection in adverse milieus predominantly through SMRT expression and partly through unliganded VDR expression in 1,25(OH)2D-deficient states; on the other hand, AT1R-BLK contributes to liganded VDR expression in 1,25(OH)2D-sufficient states.


Assuntos
Bloqueadores do Receptor Tipo 1 de Angiotensina II/farmacologia , Correpressor 2 de Receptor Nuclear/fisiologia , Acetilação , Proteínas Reguladoras de Apoptose/biossíntese , Proteínas Correpressoras/efeitos dos fármacos , Dano ao DNA , Relação Dose-Resposta a Droga , Histonas/metabolismo , Humanos , Losartan/farmacologia , Podócitos/efeitos dos fármacos , Podócitos/enzimologia , Complexo de Endopeptidases do Proteassoma/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Receptores de Calcitriol/efeitos dos fármacos , Vitamina D3 24-Hidroxilase/biossíntese , Vitamina D3 24-Hidroxilase/metabolismo
10.
Am J Physiol Renal Physiol ; 305(3): F343-54, 2013 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-23678040

RESUMO

Oxidative stress has been implicated to contribute to HIV-induced kidney cell injury; however, the role of p53, a modulator of oxidative stress, has not been evaluated in the development of HIV-associated nephropathy (HIVAN). We hypothesized that mammalian target of rapamycin (mTOR) may be critical for the induction of p53-mediated oxidative kidney cell injury in HIVAN. To test our hypothesis, we evaluated the effect of an mTOR inhibitor, rapamycin, on kidney cell p53 expression, downstream signaling, and kidney cell injury in both in vivo and in vitro studies. Inhibition of the mTOR pathway resulted in downregulation of renal tissue p53 expression, associated downstream signaling, and decreased number of sclerosed glomeruli, tubular microcysts, and apoptosed and 8-hydroxy deoxyguanosine (8-OHdG)-positive (+ve) cells in Tg26 mice. mTOR inhibition not only attenuated kidney cell expression of p66ShcA and phospho-p66ShcA but also reactivated the redox-sensitive stress response program in the form of enhanced expression of manganese superoxide dismutase (MnSOD) and catalase. In in vitro studies, the mTOR inhibitor also provided protection against HIV-induced podocyte apoptosis. Moreover, mTOR inhibition downregulated HIV-induced podocyte (HP/HIV) p53 expression. Since HP/HIV silenced for mTOR displayed a lack of expression of p53 as well as attenuated podocyte apoptosis, this suggests that mTOR is critical for kidney cell p53 activation and associated oxidative kidney cell injury in the HIV milieu.


Assuntos
Nefropatia Associada a AIDS/patologia , Injúria Renal Aguda/etiologia , Injúria Renal Aguda/patologia , Infecções por HIV/complicações , Infecções por HIV/patologia , Estresse Oxidativo/fisiologia , Serina-Treonina Quinases TOR/fisiologia , Proteína Supressora de Tumor p53/fisiologia , 8-Hidroxi-2'-Desoxiguanosina , Animais , Apoptose/fisiologia , Catalase/metabolismo , Desoxiguanosina/análogos & derivados , Desoxiguanosina/metabolismo , Inativação Gênica , Humanos , Imuno-Histoquímica , Marcação In Situ das Extremidades Cortadas , Camundongos , Camundongos Transgênicos , Podócitos/patologia , Ratos , Reação em Cadeia da Polimerase em Tempo Real , Transdução de Sinais/fisiologia , Superóxido Dismutase/metabolismo
11.
Biomolecules ; 13(2)2023 01 31.
Artigo em Inglês | MEDLINE | ID: mdl-36830635

RESUMO

Glomerular parietal epithelial cells (PECs) have been increasingly recognized to have crucial functions. Lineage tracking in animal models showed the expression of a podocyte phenotype by PECs during normal glomerular growth and after acute podocyte injury, suggesting a reparative role of PECs. Conversely, activated PECs are speculated to be pathogenic and comprise extracapillary proliferation in focal segmental glomerulosclerosis (FSGS) and crescentic glomerulonephritis (CrescGN). The reparative and pathogenic roles of PECs seem to represent two sides of PEC behavior directed by the local milieu and mediators. Recent studies suggest microRNA-193a (miR193a) is involved in the pathogenesis of FSGS and CrescGN. In a mouse model of primary FSGS, the induction of miR193a caused the downregulation of Wilms' tumor protein, leading to the dedifferentiation of podocytes. On the other hand, the inhibition of miR193a resulted in reduced crescent lesions in a mouse model of CrescGN. Interestingly, in vitro studies report that the downregulation of miR193a induces trans-differentiation of PECs into a podocyte phenotype. This narrative review highlights the critical role of PEC behavior in health and during disease and its modulation by miR193a.


Assuntos
Glomerulosclerose Segmentar e Focal , MicroRNAs , Podócitos , Camundongos , Animais , Glomerulosclerose Segmentar e Focal/metabolismo , Glomerulosclerose Segmentar e Focal/patologia , Células Epiteliais/metabolismo , Glomérulos Renais/metabolismo , Glomérulos Renais/patologia , Podócitos/metabolismo , MicroRNAs/genética
12.
Am J Pathol ; 179(4): 1681-92, 2011 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-21871425

RESUMO

In the present study, we hypothesized that HIV-1-induced occult HIV-associated nephropathy (HIVAN) would become apparent in the presence of adverse host factors. To test our hypothesis, Vpr mice (which display doxycycline-dependent Vpr expression in podocytes) with two, three, and four copies of the angiotensinogen (Agt) gene (Vpr-Agt-2, Vpr-Agt-3, and Vpr-Agt-4) were administered doxycycline for 3 weeks (to develop clinically occult HIVAN) followed by doxycycline-free water during the next 3 weeks. Subsequently, renal biomarkers were measured, and kidneys were harvested for renal histology. Vpr-Agt-2 developed neither proteinuria nor elevated blood pressure, and displayed minimal glomerular and tubular lesions only, without any microcyst formation. Vpr-Agt-3 showed mild glomerular and tubular lesions and microcyst formation, whereas Vpr-Agt-4 showed moderate proteinuria, hypertension, glomerular sclerosis, tubular dilation, microcysts, and expression of epithelial mesenchymal transition markers. Vpr-Agt-4 not only displayed enhanced renal tissue expression of Agt, renin, and angiotensin-converting enzyme, but also had higher renal tissue concentrations of angiotensin II. Moreover, renal cells in Vpr-Agt-4 showed enhanced expression of transforming growth factor-ß, connective tissue growth factor, and vascular endothelial growth factor. These findings indicate that adverse host factors, such as the activation of the renin-angiotensin system, promote the progression of occult HIVAN to apparent HIVAN.


Assuntos
Nefropatia Associada a AIDS/patologia , Interações Hospedeiro-Patógeno , Nefropatia Associada a AIDS/complicações , Nefropatia Associada a AIDS/fisiopatologia , Angiotensina II/metabolismo , Angiotensinogênio/genética , Angiotensinogênio/metabolismo , Animais , Biomarcadores/metabolismo , Pressão Sanguínea/efeitos dos fármacos , Fator de Crescimento do Tecido Conjuntivo/metabolismo , Doxiciclina/farmacologia , Transição Epitelial-Mesenquimal/efeitos dos fármacos , Feminino , Dosagem de Genes/genética , Genes vpr , Interações Hospedeiro-Patógeno/efeitos dos fármacos , Rim/efeitos dos fármacos , Rim/enzimologia , Rim/patologia , Masculino , Camundongos , Camundongos Transgênicos , Peptidil Dipeptidase A/metabolismo , Fenótipo , Proteinúria/complicações , Proteinúria/patologia , Proteinúria/fisiopatologia , Renina/metabolismo , Sistema Renina-Angiotensina/efeitos dos fármacos , Fator de Crescimento Transformador beta/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismo
14.
Am J Pathol ; 177(2): 813-21, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20581056

RESUMO

Both glomerular and tubular lesions are characterized by a proliferative phenotype in HIV-associated nephropathy. We hypothesized that mammalian target of rapamycin (mTOR) contributes to the development of the HIVAN phenotype. Both glomerular and tubular epithelial cells showed enhanced expression of phospho (p)-mTOR in HIV-1 transgenic mice (Tgs). In addition, renal tissues of transgenic mice (RT-Tg) showed enhanced phosphorylation of p70S6 kinase and an associated diminished phosphorylation of eEF2. Moreover, RT-Tgs showed enhanced phosphorylation of 4EBP1 and eIF4B; these findings indicated activation of the mTOR pathway in RT-Tgs. To test our hypothesis, age- and sex-matched control mice and Tgs were administered either saline or rapamycin (an inhibitor of the mTOR pathway) for 4 weeks. Tgs receiving rapamycin not only showed inhibition of the mTOR-associated downstream signaling but also displayed attenuated renal lesions. RT-Tgs showed enhanced expression of hypoxia-inducible factor-alpha and also displayed increased expression of vascular endothelial growth factor; on the other hand, rapamycin inhibited RT-Tg expression of both hypoxia-inducible factor-alpha and vascular endothelial growth factor. We conclude that the mTOR pathway contributes to the HIVAN phenotype and that inhibition of the mTOR pathway can be used as a therapeutic strategy to alter the course of HIVAN.


Assuntos
Nefropatia Associada a AIDS/metabolismo , Transdução de Sinais/fisiologia , Serina-Treonina Quinases TOR/metabolismo , Nefropatia Associada a AIDS/patologia , Animais , Humanos , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Glomérulos Renais/citologia , Túbulos Renais/citologia , Masculino , Camundongos , Camundongos Transgênicos , Fenótipo , Proteínas Quinases S6 Ribossômicas 70-kDa/genética , Proteínas Quinases S6 Ribossômicas 70-kDa/metabolismo , Serina-Treonina Quinases TOR/genética , Fator A de Crescimento do Endotélio Vascular/genética , Fator A de Crescimento do Endotélio Vascular/metabolismo
15.
Am J Kidney Dis ; 57(5): 752-5, 2011 May.
Artigo em Inglês | MEDLINE | ID: mdl-21295898

RESUMO

Diffuse infiltrative lymphocytosis syndrome (DILS) is believed to be an immunologic syndrome, most likely in response to human immunodeficiency virus (HIV) antigens, and can be accompanied by decreased kidney function. The spectrum of kidney involvement includes acute or chronic kidney disease, primarily tubular proteinuria; enlarged kidneys on imaging studies; and dense lymphocytic tubulointerstitial infiltrates predominantly composed of CD8(+) T cells on kidney biopsy. We describe 3 newly diagnosed HIV-positive patients of African descent with the histologic and clinical diagnosis of DILS who presented with acute kidney injury associated with Gram-negative bacterial infections. Solely with specific antibiotic therapy without antiviral and/or corticosteroid therapy, all patients recovered from acute kidney injury and had partial to complete resolution of proteinuria and enlarged kidney size. These observations led us to hypothesize that an altered immunologic and/or inflammatory response to the endotoxin derived from Gram-negative bacteria, rather than an immunologic response directed to HIV-related antigens, may be a pathogenetic mechanism for the kidney disease associated with DILS in a subset of HIV-positive patients, especially those of immunogenetically susceptible African descent.


Assuntos
Injúria Renal Aguda/diagnóstico , Infecções por Bactérias Gram-Negativas/diagnóstico , Infecções por HIV/diagnóstico , Linfocitose/diagnóstico , Injúria Renal Aguda/complicações , Adulto , Diagnóstico Diferencial , Feminino , Infecções por Bactérias Gram-Negativas/complicações , Infecções por HIV/complicações , Humanos , Linfocitose/complicações , Masculino , Síndrome
16.
Am J Physiol Renal Physiol ; 298(3): F734-44, 2010 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-20015943

RESUMO

Human immunodeficiency virus (HIV)-1-associated nephropathy (HIVAN) is characterized by proliferation of glomerular and tubular epithelial cells. We studied the role of epithelial mesenchymal transdifferentiation (EMT) in the development of HIVAN phenotype. Renal cortical sections from six FVB/N (control) and six Tg26 (HIVAN) mice were immunolabeled for PCNA, alpha-smooth muscle actin (alpha-SMA), fibroblast-specific protein-1 (FSP1), CD3, and F4/80. Since periglomerular cells (PGCs) and peritubular cells (PTCs) did not show any labeling for CD3 and F4/80 but showed labeling for alpha-SMA or FSP1, it appears that these were myofibroblasts that migrated from either glomerular or tubular sites, respectively. Occurrence of EMT was also supported by diminished expression of E-cadherin by renal epithelial cells in Tg26 mice. Interestingly, Tg26 mice also showed enhanced renal tissue expression of ZEB2; henceforth, it appears that transcription of molecules required for maintenance of de novo renal epithelial cell phenotype was suppressed. To evaluate the role of ANG II, Tg26 mice in groups of three were administered either normal saline or telmisartan (an AT1 receptor blocker) for 2 wk, followed by evaluation for renal cell EMT. Renal cortical section of Tg26 mice showed a sevenfold increase (P < 0.001) in parietal epithelial cell (PEC)-PGC and a threefold increase (P < 0.01) in tubular cell (TC)-PTC proliferation (PCNA-positive cells). Similarly, both PECs-PGCs and TCs-PTCs in Tg26 mice showed enhanced expression of alpha-SMA and FSP1. Both PECs and podocytes contributed to the glomerular proliferative phenotype, but the contribution of PECs was much greater. Telmisartan-receiving Tg26 mice (TRM) showed attenuated number of proliferating PECs-PGCs and TCs-PTCs compared with saline-receiving Tg26 mice (SRM). Similarly, TRM showed diminished expression of alpha-SMA and FSP1 by both PECs-PGCs and TCs-PTCs compared with SRM. We conclude that EMT contributes to the manifestation of the proliferative phenotype in HIVAN mice.


Assuntos
Nefropatia Associada a AIDS/patologia , Proliferação de Células , Transdiferenciação Celular , Células Epiteliais/patologia , Fibroblastos/patologia , HIV-1/genética , Glomérulos Renais/patologia , Túbulos Renais/patologia , Nefropatia Associada a AIDS/metabolismo , Nefropatia Associada a AIDS/virologia , Actinas/metabolismo , Angiotensina II/metabolismo , Bloqueadores do Receptor Tipo 1 de Angiotensina II/administração & dosagem , Animais , Benzimidazóis/administração & dosagem , Benzoatos/administração & dosagem , Caderinas/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Proliferação de Células/efeitos dos fármacos , Transdiferenciação Celular/efeitos dos fármacos , Modelos Animais de Doenças , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/metabolismo , Células Epiteliais/virologia , Fibroblastos/efeitos dos fármacos , Fibroblastos/metabolismo , Fibroblastos/virologia , Infusões Subcutâneas , Glomérulos Renais/efeitos dos fármacos , Glomérulos Renais/metabolismo , Glomérulos Renais/virologia , Túbulos Renais/efeitos dos fármacos , Túbulos Renais/metabolismo , Túbulos Renais/virologia , Macrófagos/patologia , Camundongos , Camundongos Transgênicos , Fenótipo , Podócitos/patologia , Antígeno Nuclear de Célula em Proliferação/genética , Antígeno Nuclear de Célula em Proliferação/metabolismo , RNA Mensageiro/metabolismo , Receptor Tipo 1 de Angiotensina/metabolismo , Proteína A4 de Ligação a Cálcio da Família S100 , Proteínas S100 , Linfócitos T/patologia , Telmisartan
17.
Am J Pathol ; 174(2): 701-11, 2009 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-19147816

RESUMO

There are conflicting data regarding the effects of transplantation of bone marrow-derived cells (BMDCs) on the severity of diabetes. We therefore inquired whether the competence of BMDCs is preserved on adoptive transfer into diabetic (db/db) mice and how the adoptive transfer of BMDCs affects vascular and metabolic abnormalities in these mice. Recipient db/db mice received infusions of BMDCs prepared from either db/db or non-diabetic heterozygout mice (db/m) mice and effects on endothelium-dependent relaxation, insulin sensitivity, and renal function were evaluated. Recipients of BMDCs from db/m, but not db/db donors showed better glucose control, exhibited striking improvement in endothelium-dependent relaxation in response to acetylcholine, and had partially restored renal function. Improved glucose control was due to enhanced insulin sensitivity, most likely secondary to improved vascular function. Enhanced apoptosis of endothelial progenitor cells under oxidative stress, as well as decreased endothelial progenitor cell numbers were responsible for the apparent functional incompetence of BMDCs from db/db donors. Treatment of db/db mice with Ebselen restored the resistance of both BMDCs and endothelial progenitor cells to oxidative stress, improved acetylcholine-induced vasorelaxation, and reduced proteinuria in db/db recipients of BMDC transplantation. In conclusion, infusion of BMDCs obtained from db/m donors to db/db recipient mice benefited macrovascular function, insulin sensitivity, and nephropathy. BMDCs obtained from db/db mice were functionally incompetent secondary to the increased proportion of apoptotic cells on oxidative stress challenge; their competence was restored by Ebselen therapy.


Assuntos
Antioxidantes/farmacologia , Azóis/farmacologia , Transplante de Medula Óssea , Diabetes Mellitus Tipo 2/cirurgia , Compostos Organosselênicos/farmacologia , Células-Tronco/citologia , Transferência Adotiva , Amiloide/sangue , Animais , Células da Medula Óssea/citologia , Células da Medula Óssea/efeitos dos fármacos , Citocinas/sangue , Diabetes Mellitus Tipo 2/etiologia , Citometria de Fluxo , Imunofluorescência , Glucagon/sangue , Imuno-Histoquímica , Insulina/sangue , Polipeptídeo Amiloide das Ilhotas Pancreáticas , Isoindóis , Camundongos , Camundongos Mutantes , Obesidade/complicações , Células-Tronco/efeitos dos fármacos , Transplante Isogênico , Vasodilatação/fisiologia
18.
Am J Physiol Renal Physiol ; 297(3): F653-61, 2009 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-19553347

RESUMO

Apolipoprotein E (apoE) has been demonstrated to play an important role in providing protection against mesangial cell injury. In the present study, we evaluated the role of apoE and its associated downstream effects in human immunodeficiency virus (HIV)-associated nephropathy (HIVAN). Control (n = 6) and age- and sex-matched HIV-1 transgenic mice (Tg26, n = 6) were evaluated for their renal cortical expression of apoE. Renal tissue from Tg26 mice not only showed decreased apoE expression but also displayed downregulation of perlecan mRNA expression. In in vitro studies, conditionally immortalized human podocytes (CIHPs) were transduced with either NL4-3HIV (an HIV-1 construct lacking gag and pol, used for the development of Tg26 mouse model; NL4-3/CIHP) or empty vector (EV/CIHP); NL4-3/CIHPs and EV/CIHPs were studied for apoE mRNA expression. NL4-3/CIHPs showed reduction in apoE expression compared with EV/CIHPs. To evaluate the role of HIV-1 genes in the modulation of apoE expression, conditionally immortalized mouse podocytes (CIMPs) were transduced with individual HIV-1 gene constructs. Only nef-transduced CIMPs showed a decrease in apoE expression. To confirm this effect of nef in CIHPs, microarray analysis was performed in stable colonies of nef/CIHPs and EV/CIHPs. nef/CIHPs showed a 60% decrease in apoE and a 90% reduction in heparan sulfate mRNA expression. Moreover, nef transgenic mice showed a decrease in renal tissue expression of both apoE and perlecan. Both Tg26 and nef transgenic mice also showed areas of mesangial cell proliferation. These findings suggest that HIV-1-induced reduction in podocyte apoE expression and associated downregulation of podocyte perlecan might be contributing to mesangial cell (MC) phenotype in HIVAN.


Assuntos
Nefropatia Associada a AIDS/metabolismo , Apolipoproteínas E/metabolismo , HIV-1/genética , Células Mesangiais/metabolismo , Podócitos/metabolismo , Nefropatia Associada a AIDS/patologia , Nefropatia Associada a AIDS/virologia , Animais , Linhagem Celular Transformada , Proliferação de Células , Regulação para Baixo , Genótipo , HIV-1/metabolismo , Proteoglicanas de Heparan Sulfato/metabolismo , Humanos , Células Mesangiais/patologia , Células Mesangiais/virologia , Camundongos , Camundongos Transgênicos , Fenótipo , Podócitos/patologia , Podócitos/virologia , RNA Mensageiro/metabolismo , Transdução Genética , Produtos do Gene nef do Vírus da Imunodeficiência Humana/genética , Produtos do Gene nef do Vírus da Imunodeficiência Humana/metabolismo , Produtos do Gene vpr do Vírus da Imunodeficiência Humana/genética , Produtos do Gene vpr do Vírus da Imunodeficiência Humana/metabolismo
19.
Sci Rep ; 9(1): 3582, 2019 03 05.
Artigo em Inglês | MEDLINE | ID: mdl-30837512

RESUMO

APOL1-miR193a axis participates in the preservation of molecular phenotype of differentiated podocytes (DPDs). We examined the hypothesis that APOL1 (G0) preserves, but APOL1 risk alleles (G1 and G2) disrupt APOL1-miR193a axis in DPDs. DPDG0s displayed down-regulation of miR193a, but upregulation of nephrin expression. DPDG1s/G2s exhibited an increase in miR193a and down-regulation of the expression of adherens complex's constituents (CD2AP, nephrin, and dendrin). DPDG0s showed decreased Cathepsin L, enhanced dynamin expressions, and the intact actin cytoskeleton. On the contrary, DPDG1s/G2s displayed an increase in Cathepsin L, but down-regulation of dynamin expressions and disorganization of the actin cytoskeleton. APOL1 silencing enhanced miR193a and Cathepsin L, but down-regulated dynamin expressions. DPDG1s/G2s displayed nuclear import of dendrin, indicating an occurrence of destabilization of adherens complexes in APOL1 risk milieu. These findings suggest that DPDG1s and DPDG2s developed disorganized actin cytoskeleton as a consequence of disrupted APOL1-miR193a axis. Interestingly, docking and co-labeling studies suggested an interaction between APOL1 and CD2AP. APOL1G1/G1 and APOL1G1/G2 transgenic mice displayed nuclear import of dendrin indicating destabilization of adherens complexes in podocytes; moreover, these mice showed a four-fold increase in urinary albumin to creatinine ratio and development of focal segmental glomerular lesions.


Assuntos
Citoesqueleto de Actina/metabolismo , Apolipoproteína L1/metabolismo , Podócitos/citologia , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Alelos , Animais , Apolipoproteína L1/química , Apolipoproteína L1/genética , Diferenciação Celular , Proteínas do Citoesqueleto/metabolismo , Regulação da Expressão Gênica , Humanos , Camundongos , Modelos Moleculares , Podócitos/metabolismo , Conformação Proteica , Transdução de Sinais
20.
Front Biosci ; 13: 3480-7, 2008 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-18508449

RESUMO

In stroke-prone spontaneously hypertensive rats (SHRSP) end-organ damage is markedly accelerated by high-salt (HS) intake. Since epoxyeicosatrienoic acids (EETs) possess vasodepressor and natriuretic activities, we examined whether a soluble epoxide hydrolase (sEH) inhibitor, 12-(3-adamantan-1-yl-ureido)-dodecanoic acid (AUDA), to inhibit the metabolism of EETs, would protect against pathologic changes in SHRSP. Seven-week-old male SHRSP were treated as follows: normal salt (NS), NS + AUDA, HS and HS + AUDA. Systolic blood pressure (SBP) (205 +/- 4 v 187 +/- 7 mmHg) and proteinuria (3.7 +/- 0.2 v 2.6 +/- 0.2 mg/6 h), but not plasma EETs (11.0 +/- 0.9 v 9.7 +/- 1.1 ng/ml), were significantly increased at 9 weeks of age in HS v NS SHRSP. HS was associated with fibrinoid degeneration and hypertrophy of arterioles in the kidney and perivascular fibrosis and contraction band necrosis in the heart. AUDA ameliorated these early salt-dependent changes in saline-drinking SHRSP and increased plasma levels of EETs but did not affect water and electrolyte excretion. sEH inhibition may provide a therapeutic strategy for treating salt-sensitive hypertension and its sequelae.


Assuntos
Adamantano/análogos & derivados , Inibidores Enzimáticos/uso terapêutico , Epóxido Hidrolases/antagonistas & inibidores , Hipertensão/prevenção & controle , Ácidos Láuricos/uso terapêutico , Adamantano/uso terapêutico , Animais , Ácidos Eicosanoicos/metabolismo , Canais Epiteliais de Sódio/fisiologia , Masculino , Ratos , Ratos Endogâmicos SHR , Cloreto de Sódio/efeitos adversos , Acidente Vascular Cerebral/epidemiologia
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