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1.
Am J Physiol Renal Physiol ; 317(5): F1132-F1141, 2019 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-31432708

RESUMO

Voltage-dependent L-type Ca2+ channels (L-VDCCs) and the RhoA/Rho kinase pathway are two predominant intracellular signaling pathways that regulate renal microvascular reactivity. Traditionally, these two pathways have been thought to act independently; however, recent evidence suggests that these pathways could be convergent. We hypothesized that Rho kinase inhibitors can influence L-VDCC signaling. The effects of Rho kinase inhibitors Y-27632 or RKI-1447 on KCl-induced depolarization or the L-VDCC agonist Bay K8644 were assessed in afferent arterioles using an in vitro blood-perfused rat juxtamedullary nephron preparation. Superfusion of KCl (30-90 mM) led to concentration-dependent vasoconstriction of afferent arterioles. Administration of Y-27632 (1, 5, and 10 µM) or RKI-1447 (0.1, 1, and 10 µM) significantly increased the starting diameter by 16-65%. KCl-induced vasoconstriction was markedly attenuated with 5 and 10 µM Y-27632 and with 10 µM RKI-1447 (P < 0.05 vs. KCl alone). Y-27632 (5 µM) also significantly attenuated Bay K8644-induced vasoconstriction (P < 0.05). Changes in intracellular Ca2+ concentration ([Ca2+]i) were estimated by fura-2 fluorescence during KCl-induced depolarization in cultured A7r5 cells and in freshly isolated preglomerular microvascular smooth muscle cells. Administration of 90 mM KCl significantly increased fura-2 fluorescence in both cell types. KCl-mediated elevation of [Ca2+]i in A7r5 cells was suppressed by 1-10 µM Y-27632 (P < 0.05), but 10 µM Y-27632 was required to suppress Ca2+ responses in preglomerular microvascular smooth muscle cells. RKI-1447, however, significantly attenuated KCl-mediated elevation of [Ca2+]i. Y-27632 markedly inhibited Bay K8644-induced elevation of [Ca2+]i in both cell types. The results of the present study indicate that the Rho kinase inhibitors Y-27632 and RKI-1447 can partially inhibit L-VDCC function and participate in L-VDCC signaling.


Assuntos
Aorta/citologia , Canais de Cálcio/metabolismo , Rim/irrigação sanguínea , Miócitos de Músculo Liso/efeitos dos fármacos , Transdução de Sinais/fisiologia , Quinases Associadas a rho/antagonistas & inibidores , Éster Metílico do Ácido 3-Piridinacarboxílico, 1,4-Di-Hidro-2,6-Dimetil-5-Nitro-4-(2-(Trifluormetil)fenil)/farmacologia , Amidas/farmacologia , Animais , Arteríolas/efeitos dos fármacos , Proteínas de Bactérias , Linhagem Celular , Masculino , Miócitos de Músculo Liso/metabolismo , Cloreto de Potássio/farmacologia , Piridinas/farmacologia , Ratos , Proteínas Repressoras , Tiazóis/farmacologia , Ureia/análogos & derivados , Ureia/farmacologia , Vasoconstrição/efeitos dos fármacos
2.
Am J Physiol Renal Physiol ; 317(4): F957-F966, 2019 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-31432707

RESUMO

Toll-like receptor 4 (TLR4) activation contributes to vascular dysfunction in pathological conditions such as hypertension and diabetes, but the role of chronic TLR4 activation on renal autoregulatory behavior is unknown. We hypothesized that subclinical TLR4 stimulation with low-dose lipopolysaccharide (LPS) infusion increases TLR4 activation and blunts renal autoregulatory behavior. We assessed afferent arteriolar autoregulatory behavior in male Sprague-Dawley rats after prolonged LPS (0.1 mg·kg-1·day-1 sq) infusion via osmotic minipump for 8 or 14 days. Some rats also received daily cotreatment with either anti-TLR4 antibody (1 µg ip), competitive antagonist peptide (CAP; 3 mg/kg ip) or tempol (2 mmol/l, drinking water) throughout the 8-day LPS treatment period. Autoregulatory behavior was assessed using the in vitro blood-perfused juxtamedullary nephron preparation. Selected physiological measures, systolic blood pressure and baseline diameters were normal and similar across groups. Pressure-dependent vasoconstriction averaged 72 ± 2% of baseline in sham rats, indicating intact autoregulatory behavior. Eight-day LPS-treated rats exhibited significantly impaired pressure-mediated vasoconstriction (96 ± 1% of baseline), whereas it was preserved in rats that received anti-TLR4 antibody (75 ± 3%), CAP (84 ± 2%), or tempol (82 ± 2%). Using a 14-day LPS (0.1 mg·kg-1·day-1 sq) intervention protocol, CAP treatment started on day 7, where autoregulatory behavior is already impaired. Systolic blood pressures were normal across all treatment groups. Fourteen-day LPS treatment retained the autoregulatory impairment (95 ± 2% of baseline). CAP intervention starting on day 7 rescued pressure-mediated vasoconstriction with diameters decreasing to 85 ± 1% of baseline. These data demonstrate that chronic subclinical TLR4 activation impairs afferent arteriolar autoregulatory behavior through mechanisms involving reactive oxygen species and major histocompatibility complex class II activation.


Assuntos
Antígenos de Histocompatibilidade Classe II/efeitos dos fármacos , Homeostase/efeitos dos fármacos , Lipopolissacarídeos/toxicidade , Circulação Renal/efeitos dos fármacos , Animais , Pressão Sanguínea/efeitos dos fármacos , Óxidos N-Cíclicos/farmacologia , Masculino , Néfrons/efeitos dos fármacos , Néfrons/metabolismo , Ratos , Ratos Sprague-Dawley , Espécies Reativas de Oxigênio/metabolismo , Marcadores de Spin , Receptor 4 Toll-Like/antagonistas & inibidores , Vasoconstrição/efeitos dos fármacos
3.
J Am Acad Dermatol ; 80(3): 617-625, 2019 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-30287322

RESUMO

BACKGROUND: Infant death in keratitis-ichthyosis-deafness (KID) syndrome is recognized; its association with specific genotypes and pathophysiology is inadequately understood. OBJECTIVE: We sought to discover characteristics that account for poor outcomes in lethal KID syndrome. METHODS: We collected 4 new cases and 9 previously reported, genotyped cases of lethal KID syndrome. We performed new molecular modeling of the lethal mutants GJB2 p.A88V and GJB2 p.G45E. RESULTS: Infant death occurred in all patients with GJB2 p.G45E and p.A88V; it is unusual with other GJB2 mutations. Early death with those 2 "lethal" mutations is likely multifactorial: during life all had ≥1 serious infection; most had poor weight gain and severe respiratory difficulties; many had additional anatomic abnormalities. Structural modeling of GJB2 p.G45E identified no impact on the salt bridge previously predicted to account for abnormal central carbon dioxide sensing of GJB2 p.A88V. LIMITATIONS: This clinical review was retrospective. CONCLUSION: GJB2 p.G45E and p.A88V are the only KID syndrome mutations associated with uniform early lethality. Those electrophysiologically severe mutations in GJB2 reveal abnormalities in many organs in lethal KID syndrome. All patients with KID syndrome may have subtle abnormalities beyond the eyes, ears, and skin. Early genotyping of KID syndrome births will inform prognostic discussion.


Assuntos
Anormalidades Congênitas/genética , Conexinas/genética , Surdez/genética , Surdez/fisiopatologia , Insuficiência de Crescimento/genética , Ictiose/genética , Ictiose/fisiopatologia , Ceratite/genética , Ceratite/fisiopatologia , Fístula do Sistema Respiratório/genética , Peso Corporal/genética , Conexina 26 , Conexinas/química , Surdez/patologia , Feminino , Genótipo , Humanos , Ictiose/patologia , Lactente , Morte do Lactente , Recém-Nascido , Ceratite/patologia , Masculino , Modelos Moleculares , Estrutura Molecular , Mutação
4.
Dermatol Surg ; 44(3): 383-387, 2018 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28858920

RESUMO

BACKGROUND: Knowing the size of a cutaneous lesion can be important for tracking its progression over time, selecting the proper treatment modality, surgical planning, determining prognosis, and accurate billing. However, providers vary in their consistency, accuracy, and methods of measuring cutaneous lesions. OBJECTIVE: To investigate the clinical practices of US dermatologists and dermatologic surgeons regarding how they determine the size of cutaneous lesions. MATERIALS AND METHODS: A survey was electronically distributed to members of the American Society for Dermatologic Surgery. RESULTS: Four hundred twenty-six dermatologists completed the online survey. When a lesion is suspected to be malignant, 85% of respondents obtained exact measurements most, if not all, of the time; however, only 8% did for benign lesions. Most providers determined lesion sizes themselves rather than delegating to staff. When performing visual estimation, approximately three-quarters believed that they were accurate to within 1 to 2 mm. The top reasons for obtaining exact measurements were for tracking atypical pigmented lesions, determining treatment pathways, and accurate billing. CONCLUSION: The majority of respondents believed that lesion size affected management decisions; however, the need for exact measurement remains controversial, particularly for benign lesions. Future studies may investigate whether taking exact versus estimated measurements has an effect on outcomes.


Assuntos
Pesos e Medidas Corporais/normas , Dermatologia/normas , Dermatopatias/diagnóstico , Adulto , Idoso , Pesos e Medidas Corporais/tendências , Competência Clínica , Dermatologia/tendências , Feminino , Pesquisas sobre Atenção à Saúde , Humanos , Internet , Masculino , Pessoa de Meia-Idade , Padrões de Prática Médica/normas , Padrões de Prática Médica/tendências
5.
Am J Physiol Renal Physiol ; 308(6): F541-52, 2015 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-25587122

RESUMO

Collecting duct-derived endothelin (ET)-1 is an autocrine inhibitor of Na(+) and water reabsorption; its deficiency causes hypertension and water retention. Extracellular fluid volume expansion increases collecting duct ET-1, thereby promoting natriuresis and diuresis; however, how this coupling between volume expansion and collecting duct ET-1 occurs is incompletely understood. One possibility is that volume expansion increases tubular fluid flow. To investigate this, cultured IMCD3 cells were subjected to static or flow conditions. Exposure to a shear stress of 2 dyn/cm(2) for 2 h increased ET-1 mRNA content by ∼2.3-fold. Absence of perfusate Ca(2+), chelation of intracellular Ca(2+), or inhibition of Ca(2+) signaling (calmodulin, Ca(2+)/calmodulin-dependent kinase, calcineurin, PKC, or phospholipase C) prevented the flow response. Evaluation of possible flow-activated Ca(2+) entry pathways revealed no role for transient receptor potential (TRP)C3, TRPC6, and TRPV4; however, cells with TRPP2 (polycystin-2) knockdown had no ET-1 flow response. Flow increased intracellular Ca(2+) was blunted in TRPP2 knockdown cells. Nonspecific blockade of P2 receptors, as well as specific inhibition of P2X7 and P2Y2 receptors, prevented the ET-1 flow response. The ET-1 flow response was not affected by inhibition of either epithelial Na(+) channels or the mitochondrial Na(+)/Ca(2+) exchanger. Taken together, these findings provide evidence that in IMCD3 cells, flow, via polycystin-2 and P2 receptors, engages Ca(2+)-dependent signaling pathways that stimulate ET-1 synthesis.


Assuntos
Endotelina-1/metabolismo , Medula Renal/metabolismo , Túbulos Renais Coletores/metabolismo , Receptores Purinérgicos/metabolismo , Canais de Cátion TRPP/metabolismo , Animais , Cálcio/metabolismo , Sinalização do Cálcio , Linhagem Celular , Diurese , Canais Epiteliais de Sódio/metabolismo , Masculino , Camundongos , Natriurese , RNA Mensageiro/metabolismo , Ratos Sprague-Dawley , Sódio/metabolismo , Canais de Potencial de Receptor Transitório/metabolismo , Água/metabolismo
6.
Dermatol Surg ; 41(8): 903-12, 2015 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-26218724

RESUMO

BACKGROUND: Retention of academic Mohs surgeons is important for the growth of this specialty and teaching of residents and students. OBJECTIVE: To examine factors that influence retention of Mohs surgeons in academics and to better understand reasons for their departure. MATERIALS AND METHODS: A survey was electronically distributed to academic Mohs surgeons in the American College of Mohs Surgery, asking them to rate the importance of several variables on their decision to remain in academia. Private practice Mohs surgeons who had left academics were also surveyed. RESULTS: Two hundred thirty-six dermatologic surgeons completed the survey. Twenty-nine percent work full time in academics, and approximately 7% work part time. The top reasons for practicing in the academic setting are intellectual stimulation, teaching opportunities, and collaboration with other university physicians and researchers. Seventy-one percent of respondents reported they would stay in academics, 7% indicated they would not, and 22% were unsure. Unfair compensation, inadequate support staff, poor leadership, increased bureaucracy, and decreased autonomy were top reasons that may compel a Mohs surgeon to leave. CONCLUSION: Opportunities for intellectual stimulation, collaboration, and teaching remain the main draw for academic Mohs surgeons. A supportive environment, strong leadership, and establishing fair compensation are imperative in ensuring their stay.


Assuntos
Centros Médicos Acadêmicos , Escolha da Profissão , Dermatologia , Docentes de Medicina , Cirurgia de Mohs , Atitude do Pessoal de Saúde , Comportamento Cooperativo , Coleta de Dados , Feminino , Humanos , Liderança , Masculino , Pessoa de Meia-Idade , Admissão e Escalonamento de Pessoal , Reorganização de Recursos Humanos , Prática Privada , Autonomia Profissional , Pesquisadores , Salários e Benefícios , Recursos Humanos , Carga de Trabalho
7.
Am J Physiol Renal Physiol ; 306(6): F619-28, 2014 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-24477682

RESUMO

This study tested the hypothesis that P2Y12 receptor blockade with clopidogrel preserves renal autoregulatory ability during ANG II-induced hypertension. Clopidogrel was administered orally to male Sprague-Dawley rats chronically infused with ANG II. After 14 days of treatment, whole kidney autoregulation of renal blood flow was assessed in vivo in pentobarbital-anesthetized rats using an ultrasonic flow probe placed around the left renal artery. In ANG II-vehicle-treated rats, decreasing arterial pressure over a range from 160 to 100 mmHg resulted in a 25 ± 5% decrease in renal blood flow, demonstrating a significant loss of autoregulation with an autoregulatory index of 0.66 ± 0.15. However, clopidogrel treatment preserved autoregulatory behavior in ANG II-treated rats to levels indistinguishable from normotensive sham-operated (sham) rats (autoregulatory index: 0.04 ± 0.14). Compared with normotensive sham-vehicle-treated rats, ANG II infusion increased renal CD3-positive T cell infiltration by 66 ± 6%, induced significant thickening of the preglomerular vessels and glomerular basement membrane and increased glomerular collagen I deposition, tubulointerstitial fibrosis, damage to the proximal tubular brush border, and protein excretion. Clopidogrel significantly reduced renal infiltration of T cells by 39 ± 9% and prevented interstitial artery thickening, ANG II-induced damage to the glomerular basement membrane, deposition of collagen type I, and tubulointerstitial fibrosis, despite the maintenance of hypertension. These data demonstrate that systemic P2Y12 receptor blockade with clopidogrel protects against impairment of autoregulatory behavior and renal vascular injury in ANG II-induced hypertension, possibly by reducing renal T cell infiltration.


Assuntos
Angiotensina II/farmacologia , Hipertensão/induzido quimicamente , Rim/fisiopatologia , Receptores Purinérgicos P2Y12/fisiologia , Circulação Renal/fisiologia , Ticlopidina/análogos & derivados , Animais , Clopidogrel , Hipertensão/fisiopatologia , Rim/irrigação sanguínea , Masculino , Antagonistas do Receptor Purinérgico P2Y/farmacologia , Ratos , Ratos Sprague-Dawley , Tromboxano B2/sangue , Ticlopidina/farmacologia
8.
Am J Physiol Renal Physiol ; 307(1): F33-40, 2014 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-24872316

RESUMO

High dietary salt is common in Western countries and is an important contributor to increased cardiovascular disease. Autoregulation of renal blood flow (RBF) and glomerular filtration rate (GFR) is an essential function of the renal microcirculation that could be affected by excessive dietary salt. High salt (HS) increases renal ROS generation partly by the enzyme NADPH oxidase. We hypothesized that a HS diet would impair autoregulation via NADPH oxidase-dependent ROS generation. The role of NADPH-dependent ROS production on the blunted autoregulatory response with a HS diet was assessed in vitro and in vivo using the blood-perfused juxtamedullary nephron preparation and anesthetized rats, respectively. The increase in renal lipid peroxidation and p67(phox) expression induced by HS was prevented by apocynin treatment. Control afferent arterioles exhibited normal autoregulatory behavior in response to acute increases in renal perfusion pressure, whereas arterioles from HS rats exhibited a blunted response. Autoregulatory behavior in HS rats was restored in vitro by acute exposure to the NADPH oxidase inhibitor apocynin. At the whole kidney level, in vivo experiments showed that both RBF and GFR declined in HS rats when left kidney renal perfusion pressure was reduced from ambient to 95 mmHg, whereas control rats maintained stable GFR and RBF consistent with efficient autoregulatory behavior. Apocynin treatment improved in vivo autoregulatory behavior in HS rats and had no detectable effect in normal salt diet-fed rats. These data support the hypothesis that impaired renal autoregulatory behavior in rats fed a HS diet is mediated by NADPH oxidase-derived ROS.


Assuntos
Homeostase/efeitos dos fármacos , Rim/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Sódio na Dieta/farmacologia , Ração Animal , Animais , Pressão Sanguínea/efeitos dos fármacos , Taxa de Filtração Glomerular/efeitos dos fármacos , Homeostase/fisiologia , Hipertensão/fisiopatologia , Rim/metabolismo , Masculino , NADPH Oxidases/metabolismo , Ratos , Ratos Sprague-Dawley , Circulação Renal/efeitos dos fármacos , Circulação Renal/fisiologia
9.
Am J Physiol Renal Physiol ; 304(6): F801-7, 2013 Mar 15.
Artigo em Inglês | MEDLINE | ID: mdl-23269644

RESUMO

Autoregulation is critical for protecting the kidney against arterial pressure elevation and is compromised in some forms of hypertension. Evidence indicates that activated lymphocytes contribute importantly to cardiovascular injury in hypertension. We hypothesized that activated lymphocytes contribute to renal vascular dysfunction by impairing autoregulation and P2X(1) receptor signaling in ANG II-infused hypertensive rats. Male Sprague-Dawley rats receiving ANG II infusion were treated with a lymphocyte proliferation inhibitor, mycophenolate mofetil (MMF) for 2 wk. Autoregulation was assessed in vitro and in vivo using the blood-perfused juxtamedullary nephron preparation and anesthetized rats, respectively. ANG II-treated rats exhibited impaired autoregulation. At the single vessel level, pressure-mediated afferent arteriolar vasoconstriction was significantly blunted (P < 0.05 vs. control rats). At the whole kidney level, renal blood flow passively decreased as renal perfusion pressure was reduced. MMF treatment did not alter the ANG II-induced hypertensive state; however, MMF did preserve autoregulation. The autoregulatory profiles in both in vitro or in vivo settings were similar to the responses from control rats despite persistent hypertension. Autoregulatory responses are linked to P2X(1) receptor activation. Accordingly, afferent arteriolar responses to ATP and the P2X(1) receptor agonist ß,γ-methylene ATP were assessed. ATP- or ß,γ-methylene ATP-induced vasoconstriction was significantly attenuated in ANG II-infused hypertensive rats but was normalized by MMF treatment. Moreover, MMF prevented elevation of plasma transforming growth factor-ß1 concentration and lymphocyte and macrophage infiltration in ANG II-infused kidneys. These results suggest that anti-inflammatory treatment with MMF prevents lymphocyte infiltration and preserves autoregulation in ANG II-infused hypertensive rats, likely by normalizing P2X(1) receptor activation.


Assuntos
Hipertensão/imunologia , Imunossupressores/uso terapêutico , Linfócitos/efeitos dos fármacos , Ácido Micofenólico/análogos & derivados , Receptores Purinérgicos P2X1/metabolismo , Trifosfato de Adenosina/análogos & derivados , Albuminúria/tratamento farmacológico , Angiotensina II , Animais , Arteríolas/efeitos dos fármacos , Homeostase , Hipertensão/induzido quimicamente , Hipertensão/tratamento farmacológico , Hipertensão/metabolismo , Terapia de Imunossupressão , Imunossupressores/farmacologia , Ativação Linfocitária , Macrófagos/efeitos dos fármacos , Masculino , Ácido Micofenólico/farmacologia , Ácido Micofenólico/uso terapêutico , Ratos , Ratos Sprague-Dawley , Circulação Renal/efeitos dos fármacos , Fator de Crescimento Transformador beta1/sangue
10.
Ren Fail ; 35(10): 1455-64, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23992043

RESUMO

AIM: To assess the effect and safety of lanthanum carbonate (LC) for hypophosphatemia in patients with end-stage renal disease (ESRD). METHODS: According to the collaborative review group search strategy, we searched MEDLINE (1996 to 2012.12); EBCO (1996 to 2012.12), and CNKI. We searched Chinese journals by hand. We conducted quality assessment and data extraction by two independent investigators. Meta-analysis was conducted by RevMan 5.0. Results were expressed as OR with 95% confidence interval for dichotomous outcomes and WMD with 95% confidence interval for continuous outcomes. RESULT: We identified 16 reports which might meet the inclusion criteria for our review. The meta-analysis showed that LC was superior to placebo in treating hypophosphatemia of end-stage renal disease patients (OR = 5.46, 95% CI: 2.37 to 2.61, p < 0.005) and as efficient as conventional therapies (WMD = -0.06, 95% CI: -0.27 to 0.15, p = 0.57). The incidence of all adverse events was similar between LC- and placebo-treated patients (OR = 1.16, 95% CI: 0.79 to 1.68, p = 0.45). CONCLUSION: Lanthanum carbonate is well effective and tolerated in treating hyperphosphatemia of ESRD patients. Lanthanum carbonate is not likely to cause hypercalcemia compared to calcium-based phosphate binders.


Assuntos
Hiperfosfatemia/tratamento farmacológico , Falência Renal Crônica/complicações , Lantânio/uso terapêutico , Osso e Ossos/metabolismo , Cálcio/sangue , Humanos , Hiperfosfatemia/etiologia , Falência Renal Crônica/mortalidade , Lantânio/sangue , Hormônio Paratireóideo/sangue , Fosfatos/sangue , Calcificação Vascular/induzido quimicamente
11.
Environ Sci Pollut Res Int ; 30(3): 7207-7217, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36031677

RESUMO

Effectively facilitating Fe3+/Fe2+ cycles and expanding its operating pH range are keys to optimizing the traditional Fenton reaction. In this exploration, we used chitosan and ferrous sulfate as precursors to prepare a multicomponent magnetic Fe/C Fenton-like catalyst, which exhibited extraordinary catalytic properties and excellent stability performance in a pH range of 4~8. Besides, it could be easily separated from the solution by a magnet. The characterization showed that the supported Fe species include troilite-2H (FeS), lepidocrocite (FeOOH), and pyrrhotite-6T (Fe1 - xS) with a unique "core-shell structure." The presence of reductive iron sulfide core in the system can accelerate the reduction of Fe(III). Meanwhile, the graphite-like structure formed after calcination can adsorb and enrich priority pollutants near the active site through π-π coupling and strengthen electron transfer, which endows its high catalytic performance and enables it invulnerable to dissolved organic compounds.


Assuntos
Compostos Férricos , Nanopartículas , Compostos Férricos/química , Ferro/química , Carbono/química , Fenômenos Magnéticos , Nanopartículas/química , Peróxido de Hidrogênio/química , Catálise , Oxirredução
12.
J Biol Chem ; 284(42): 29230-9, 2009 Oct 16.
Artigo em Inglês | MEDLINE | ID: mdl-19700766

RESUMO

The tafazzin gene encodes a phospholipid-lysophospholipid transacylase involved in cardiolipin metabolism, but it is not known why it forms multiple transcripts as a result of alternative splicing. Here we studied the intracellular localization, enzymatic activity, and metabolic function of four isoforms of human tafazzin and three isoforms of Drosophila tafazzin upon expression in different mammalian and insect systems. When expressed in HeLa cells, all isoforms were localized in mitochondria except for the B-form of Drosophila tafazzin, which was associated with multiple intracellular membranes. Among the human isoforms, only full-length tafazzin (FL) and tafazzin lacking exon 5 (Delta5) had transacylase activity, and only these two isoforms were able to restore a normal cardiolipin pattern, normal respiratory activity of mitochondria, and male fertility in tafazzin-deficient flies. Both FL and Delta5 were associated with large protein complexes in 293T cell mitochondria, but treatment with alkali and proteinase K suggested that the Delta5 isoform was more integrated into the hydrophobic core of the membrane than the FL isoform. Although all Drosophila isoforms showed transacylase activity in vitro, only the A-form supported cardiolipin remodeling in flies. The data suggest that humans express two mitochondrial isoenzymes of tafazzin that have similar transacylase activities but different membrane topologies. Furthermore, the data show that the expression of human tafazzin in flies creates cardiolipin with a Drosophila pattern, suggesting that the characteristic fatty acid profile of cardiolipin is not determined by the substrate specificity of tafazzin.


Assuntos
Fatores de Transcrição/química , Fatores de Transcrição/genética , Aciltransferases , Processamento Alternativo , Animais , Animais Geneticamente Modificados , Cardiolipinas/química , Drosophila melanogaster , Éxons , Células HeLa , Humanos , Mitocôndrias/enzimologia , Fosfolipídeos/química , Isoformas de Proteínas , Estrutura Terciária de Proteína , Especificidade da Espécie , Especificidade por Substrato
13.
J Pharmacol Exp Ther ; 334(2): 430-8, 2010 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-20439437

RESUMO

Soluble epoxide hydrolase (sEH) is an enzyme involved in the metabolism of endogenous inflammatory and antiapoptotic mediators. However, the roles of sEH in diabetes and the pancreas are unknown. Our aims were to determine whether sEH is involved in the regulation of hyperglycemia in diabetic mice and to investigate the reasons for the regulation of insulin secretion by sEH deletion or inhibition in islets. We used two separate approaches, targeted disruption of Ephx2 gene [sEH knockout (KO)] and a selective inhibitor of sEH [trans-4-[4-(3-adamantan-1-ylureido)-cyclohexyloxy]-benzoic acid (t-AUCB)], to assess the role of sEH in glucose and insulin homeostasis in streptozotocin (STZ) mice. We also examined the effects of sEH KO or t-AUCB on glucose-stimulated insulin secretion (GSIS) and intracellular calcium levels in islets. Hyperglycemia in STZ mice was prevented by both sEH KO and t-AUCB. In addition, STZ mice with sEH KO had improved glucose tolerance. More important, when insulin levels were assessed by hyperglycemic clamp study, sEH KO was found to promote insulin secretion. In addition, sEH KO and t-AUCB treatment augmented islet GSIS. Islets with sEH KO had a greater intracellular calcium influx when challenged with high glucose or KCl in the presence of diazoxide. Moreover, sEH KO reduced islet cell apoptosis in STZ mice. These results show not only that sEH KO and its inhibition prevent hyperglycemia in diabetes, but also that sEH KO enhances islet GSIS through the amplifying pathway and decreases islet cell apoptosis in diabetes.


Assuntos
Apoptose , Benzoatos/farmacologia , Epóxido Hidrolases/antagonistas & inibidores , Epóxido Hidrolases/genética , Hiperglicemia/prevenção & controle , Insulina/metabolismo , Ilhotas Pancreáticas/efeitos dos fármacos , Ureia/análogos & derivados , Animais , Glicemia/metabolismo , Diabetes Mellitus Experimental/induzido quimicamente , Diabetes Mellitus Experimental/enzimologia , Diabetes Mellitus Experimental/fisiopatologia , Diazóxido/farmacologia , Teste de Tolerância a Glucose , Hiperglicemia/induzido quimicamente , Hiperglicemia/enzimologia , Secreção de Insulina , Espaço Intracelular/metabolismo , Ilhotas Pancreáticas/citologia , Ilhotas Pancreáticas/metabolismo , Camundongos , Camundongos Knockout , Estreptozocina , Ureia/farmacologia
14.
Clin Sci (Lond) ; 118(7): 463-71, 2010 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-19811450

RESUMO

The P2Y12 receptor antagonist clopidogrel blocks platelet aggregation, improves systemic endothelial nitric oxide bioavailability, and has anti-inflammatory effects. Since P2Y12 receptors have been identified in the vasculature, we hypothesized that clopidogrel ameliorates angiotensin II (Ang II) -induced vascular functional changes by blockade of P2Y12 receptors in the vasculature. Male Sprague Dawley rats were infused with Ang II (60 ng.min-1) or vehicle for 14 days. The animals were treated with clopidogrel (10mg*kg-1*day-1) or vehicle. Vascular reactivity was evaluated in second-order mesenteric arteries. Clopidogrel treatment did not change systolic blood pressure [(mmHg) control-vehicle, 117+/-7.1 vs. control- Clopidogrel, 125+/-4.2; AngII-vehicle, 197+/-10.7 vs. AngII-Clopidogrel, 198+/-5.2], but it normalized increased phenylephrine-induced vascular contractions [(%KCl) vehicle-treated, 182.2+/-18 vs. Clopidogrel, 133+/-14%), as well as impaired vasodilation to acetylcholine [(%) vehicle-treated, 71.7+/-2.2 vs. Clopidogrel, 85.3+/-2.8) in Ang II-treated animals. Vascular expression of P2Y12 receptor was determined by western blot. Pharmacological characterization of vascular P2Y12 was performed with the P2Y12 agonist 2-MeS-ADP. Although 2-MeSADP induced endothelium-dependent relaxation [(Emax %) = 71%+/-12), as well as contractile vascular responses (Emax %= 83+/-12) these actions are not mediated by P2Y12 receptor activation. 2-MeS-ADP produced similar vascular responses in control and Ang II rats. These results indicate potential effects of Clopidogrel, such as improvement of hypertension-related vascular functional changes that are not associated with direct actions of clopidogrel in the vasculature, supporting the concept that activated platelets contribute to endothelial dysfunction, possibly via impaired NO bioavailability.


Assuntos
Hipertensão/fisiopatologia , Artérias Mesentéricas/efeitos dos fármacos , Receptores Purinérgicos P2/metabolismo , Ticlopidina/análogos & derivados , Acetilcolina/farmacologia , Difosfato de Adenosina/análogos & derivados , Difosfato de Adenosina/farmacologia , Angiotensina II , Animais , Western Blotting , Clopidogrel , Relação Dose-Resposta a Droga , Endotélio Vascular/fisiopatologia , Inibidores Enzimáticos/farmacologia , Hipertensão/induzido quimicamente , Técnicas In Vitro , Masculino , Artérias Mesentéricas/metabolismo , Artérias Mesentéricas/fisiopatologia , NG-Nitroarginina Metil Éster/farmacologia , Antagonistas do Receptor Purinérgico P2Y/farmacologia , Ratos Sprague-Dawley , Receptores Purinérgicos P2Y12 , Tionucleotídeos/farmacologia , Ticlopidina/farmacologia , Vasodilatação/efeitos dos fármacos , Vasodilatadores/farmacologia
15.
Biol Sex Differ ; 11(1): 52, 2020 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-32928299

RESUMO

BACKGROUND: Premenopausal women have a lower risk of hypertension compared to age-matched men and postmenopausal women. P2Y2 and P2Y4 purinoceptor can be considered potential contributors to hypertension due to their emerging roles in regulating renal tubular Na+ transport. Activation of these receptors inhibits epithelial Na+ channel activity (ENaC) via a phospholipase C (PLC)-dependent pathway resulting in natriuresis. We recently reported that activation of P2Y2 and P2Y4 receptors in the renal medulla by UTP promotes natriuresis in male and ovariectomized (OVX) rats, but not in ovary-intact females. This led us to hypothesize that ovary-intact females have greater basal renal medullary activity of P2 (P2Y2 and P2Y4) receptors regulating Na+ excretion compared to male and OVX rats. METHODS: To test our hypothesis, we determined (i) the effect of inhibiting medullary P2 receptors by suramin (750 µg/kg/min) on urinary Na+ excretion in anesthetized male, ovary-intact female, and OVX Sprague Dawley rats, (ii) mRNA expression and protein abundance of P2Y2 and P2Y4 receptors, and (iii) mRNA expression of their downstream effectors (PLC-1δ and ENaCα) in renal inner medullary tissues obtained from these three groups. We also subjected cultured mouse inner medullary collecting duct cells (segment 3, mIMCD3) to different concentrations of 17ß-estradiol (E2, 0, 10, 100, and 1000 nM) to test whether E2 increases mRNA expression of P2Y2 and P2Y4 receptors. RESULTS: Acute P2 inhibition attenuated urinary Na+ excretion in ovary-intact females, but not in male or OVX rats. We found that P2Y2 and P2Y4 mRNA expression was higher in the inner medulla from females compared to males or OVX. Inner medullary lysates showed that ovary-intact females have higher P2Y2 receptor protein abundance, compared to males; however, OVX did not eliminate this sex difference. We also found that E2 dose-dependently upregulated P2Y2 and P2Y4 mRNA expression in mIMCD3. CONCLUSION: These data suggest that ovary-intact females have enhanced P2Y2 and P2Y4-dependent regulation of Na+ handling in the renal medulla, compared to male and OVX rats. We speculate that the P2 pathway contributes to facilitated renal Na+ handling in premenopausal females.


Assuntos
Canais Epiteliais de Sódio/metabolismo , Estradiol/metabolismo , Natriurese/fisiologia , Ovário/fisiologia , Receptores Purinérgicos P2Y2/metabolismo , Receptores Purinérgicos P2/metabolismo , Animais , Linhagem Celular , Relação Dose-Resposta a Droga , Canais Epiteliais de Sódio/genética , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Medula Renal/fisiologia , Masculino , Ovariectomia , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Ratos , Ratos Sprague-Dawley , Receptores Purinérgicos P2/genética , Receptores Purinérgicos P2Y2/genética , Fatores Sexuais , Suramina/farmacologia , Fosfolipases Tipo C/genética , Fosfolipases Tipo C/metabolismo
17.
Int J Womens Dermatol ; 3(1 Suppl): S58-S61, 2017 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28492041

RESUMO

Women are entering medicine at increasing rates, particularly in dermatology. In this study, we compared women's influence and status in academic dermatology with that of men by examining authorship roles in peer-reviewed dermatology literature. We examined the literature in 2009 and compared that to 10 years prior (1999). A total of 1399 articles were reviewed, 594 of which met study criteria and were included in statistical analysis. There was a marked increase in senior female authorship over a decade (22% vs. 38%, p < 0.001). Female first authorship increased as well (41% vs. 51%, p < 0.001). In contrast, changes in male senior and first authorship were not statistically significant. Federal funding for female senior authors increased over a decade (19% vs. 37%, p = 0.05), and female senior authors in the 2009 cohort were more likely to hold a dual MD/PhD degree (0% vs. 11%, p = 0.04) or pure PhD degree (11% vs. 27%, p = 0.04). Women are approaching parity with men in terms of authorship in the dermatology literature, and additional research training and attainment of federal funding have helped women publish as senior authors.

18.
Int J Womens Dermatol ; 2(1): 1-4, 2016 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-28491992

RESUMO

Women are entering medicine at increasing rates, particularly in dermatology. In this study, we compared women's influence and status in academic dermatology with that of men by examining authorship roles in peer-reviewed dermatology literature. We examined the literature in 2009 and compared that to 10 years prior (1999). A total of 1399 articles were reviewed, 594 of which met study criteria and were included in statistical analysis. There was a marked increase in senior female authorship over a decade (22% vs. 38%, p < 0.001). Female first authorship increased as well (41% vs. 51%, p < 0.001). In contrast, changes in male senior and first authorship were not statistically significant. Federal funding for female senior authors increased over a decade (19% vs. 37%, p = 0.05), and female senior authors in the 2009 cohort were more likely to hold a dual MD/PhD degree (0% vs. 11%, p = 0.04) or pure PhD degree (11% vs. 27%, p = 0.04). Women are approaching parity with men in terms of authorship in the dermatology literature, and additional research training and attainment of federal funding have helped women publish as senior authors.

19.
JAMA Dermatol ; 149(2): 178-86, 2013 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-23560298

RESUMO

OBJECTIVE: To characterize the presence of CD200 and CD200 receptor (CD200R) in the human cutaneous squamous cell carcinoma (SCC) microenvironment and to define a possible role for the CD200 axis in immune evasion by SCC. DESIGN: Gene expression in SCC vs normal skin was studied. Laser capture microdissection was used to determine differential expression of CD200 in normal skin vs actinic keratosis vs SCC in situ vs invasive SCC. Immunofluorescence microscopy was used to define expression of CD200R on macrophages, myeloid dendritic cells, natural killer cells, and T cells in SCC vs normal skin. The effects of SCC supernatant on induction of CD200 in human blood endothelial cells was also examined. SETTING: Academic Medical Center with an established Section of Mohs and Dermatologic Surgery and an active Cutaneous Biology Research Program. PARTICIPANTS: Surgical discard tissue from deidentified patients and samples of normal skin from healthy volunteers were used in this study. MAIN OUTCOME MEASURES: Expression of CD200 on SCC-associated blood vessels; expression of CD200 receptor on SCC-associated macrophages and T cells; and induction of CD200 on endothelial cells by SCC supernatants. RESULTS: CD200 gene and message were upregulated in SCC stroma. Immunostaining revealed a higher number of CD200(+) cells in SCC stroma than in normal dermis (180.8 cells/mm(2) vs 24.6 cells/mm(2)) (P<.01). CD200 was further identified mainly on blood vessel endothelium in SCC. Tumor supernatant was able to induce CD200 expression on human dermal blood endothelial cells in culture. CD200R was identified on macrophages and dendritic cells in SCC microenvironment. CONCLUSIONS: CD200 expression on local blood vessels may promote tumor progression by suppressing CD200R myeloid cells during diapedesis. These data highlight a previously unrecognized mechanism of immune evasion by SCC and may provide guidance for the development of targeted therapy.


Assuntos
Antígenos CD/genética , Antígenos de Superfície/genética , Carcinoma de Células Escamosas/patologia , Receptores de Superfície Celular/genética , Neoplasias Cutâneas/patologia , Regulação para Cima , Centros Médicos Acadêmicos , Carcinoma de Células Escamosas/genética , Carcinoma de Células Escamosas/imunologia , Células Dendríticas/metabolismo , Endotélio Vascular/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Células Matadoras Naturais/metabolismo , Microdissecção e Captura a Laser , Macrófagos/metabolismo , Microscopia de Fluorescência , Cirurgia de Mohs , Receptores de Orexina , Pele/metabolismo , Neoplasias Cutâneas/genética , Neoplasias Cutâneas/imunologia , Linfócitos T/metabolismo , Migração Transendotelial e Transepitelial , Microambiente Tumoral
20.
PLoS One ; 8(5): e62154, 2013.
Artigo em Inglês | MEDLINE | ID: mdl-23667456

RESUMO

Immune suppressed organ transplant recipients suffer increased morbidity and mortality from primary cutaneous SCC. We studied tumor microenvironment in transplant-associated SCC (TSCC), immune-competent SCC and normal skin by IHC, IF and RT-PCR on surgical discard. We determined T cell polarization in TSCC and SCC by intracellular cytokine staining of T cell crawl outs from human skin explants. We studied the effects of IL-22, an inducer of keratinocyte proliferation, on SCC proliferation in vitro. SCC and TSCC are both associated with significantly higher numbers of CD3(+) and CD8(+) T cells compared to normal skin. TSCC showed a higher proportion of Foxp3(+) T regs to CD8(+) T cells compared to SCC and a lower percentage of IFN-γ producing CD4(+) T cells. TSCC, however, had a higher percentage of IL-22 producing CD8(+) T cells compared to SCC. TSCC showed more diffuse Ki67 and IL-22 receptor (IL-22R) expression by IHC. IL-22 induced SCC proliferation in vitro despite serum starvation. Diminished cytotoxic T cell function in TSCC due to decreased CD8/T-reg ratio may permit tumor progression. Increased IL-22 and IL-22R expression could accelerate tumor growth in transplant patients. IL-22 may be an attractive candidate for targeted therapy of SCC without endangering allograft survival.


Assuntos
Linfócitos T CD8-Positivos/citologia , Carcinoma de Células Escamosas/imunologia , Carcinoma de Células Escamosas/patologia , Transplante de Órgãos/efeitos adversos , Subpopulações de Linfócitos T/citologia , Linfócitos T Reguladores/citologia , Complexo CD3/metabolismo , Linfócitos T CD8-Positivos/efeitos dos fármacos , Linfócitos T CD8-Positivos/imunologia , Carcinoma de Células Escamosas/etiologia , Carcinoma de Células Escamosas/metabolismo , Contagem de Células , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Fatores de Transcrição Forkhead/metabolismo , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Regulação Neoplásica da Expressão Gênica/imunologia , Humanos , Imunocompetência/imunologia , Interleucinas/farmacologia , Fosfoproteínas/metabolismo , Receptores de Interleucina/metabolismo , Fator de Transcrição STAT3/metabolismo , Pele/citologia , Pele/imunologia , Pele/patologia , Neoplasias Cutâneas/imunologia , Neoplasias Cutâneas/patologia , Subpopulações de Linfócitos T/efeitos dos fármacos , Subpopulações de Linfócitos T/imunologia , Linfócitos T Reguladores/efeitos dos fármacos , Linfócitos T Reguladores/imunologia , Células Th1/citologia , Células Th1/efeitos dos fármacos , Células Th1/imunologia , Microambiente Tumoral/efeitos dos fármacos , Microambiente Tumoral/imunologia , Regulação para Cima/efeitos dos fármacos , Regulação para Cima/imunologia , Interleucina 22
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