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1.
N Engl J Med ; 390(8): 701-711, 2024 Feb 22.
Artigo em Inglês | MEDLINE | ID: mdl-38329148

RESUMO

BACKGROUND: Thrombolytic agents, including tenecteplase, are generally used within 4.5 hours after the onset of stroke symptoms. Information on whether tenecteplase confers benefit beyond 4.5 hours is limited. METHODS: We conducted a multicenter, double-blind, randomized, placebo-controlled trial involving patients with ischemic stroke to compare tenecteplase (0.25 mg per kilogram of body weight, up to 25 mg) with placebo administered 4.5 to 24 hours after the time that the patient was last known to be well. Patients had to have evidence of occlusion of the middle cerebral artery or internal carotid artery and salvageable tissue as determined on perfusion imaging. The primary outcome was the ordinal score on the modified Rankin scale (range, 0 to 6, with higher scores indicating greater disability and a score of 6 indicating death) at day 90. Safety outcomes included death and symptomatic intracranial hemorrhage. RESULTS: The trial enrolled 458 patients, 77.3% of whom subsequently underwent thrombectomy; 228 patients were assigned to receive tenecteplase, and 230 to receive placebo. The median time between the time the patient was last known to be well and randomization was approximately 12 hours in the tenecteplase group and approximately 13 hours in the placebo group. The median score on the modified Rankin scale at 90 days was 3 in each group. The adjusted common odds ratio for the distribution of scores on the modified Rankin scale at 90 days for tenecteplase as compared with placebo was 1.13 (95% confidence interval, 0.82 to 1.57; P = 0.45). In the safety population, mortality at 90 days was 19.7% in the tenecteplase group and 18.2% in the placebo group, and the incidence of symptomatic intracranial hemorrhage was 3.2% and 2.3%, respectively. CONCLUSIONS: Tenecteplase therapy that was initiated 4.5 to 24 hours after stroke onset in patients with occlusions of the middle cerebral artery or internal carotid artery, most of whom had undergone endovascular thrombectomy, did not result in better clinical outcomes than those with placebo. The incidence of symptomatic intracerebral hemorrhage was similar in the two groups. (Funded by Genentech; TIMELESS ClinicalTrials.gov number, NCT03785678.).


Assuntos
Isquemia Encefálica , AVC Isquêmico , Imagem de Perfusão , Tenecteplase , Trombectomia , Ativador de Plasminogênio Tecidual , Humanos , Isquemia Encefálica/diagnóstico por imagem , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/mortalidade , Isquemia Encefálica/cirurgia , Fibrinolíticos/administração & dosagem , Fibrinolíticos/efeitos adversos , Fibrinolíticos/uso terapêutico , Hemorragias Intracranianas/induzido quimicamente , Hemorragias Intracranianas/diagnóstico por imagem , Perfusão , Imagem de Perfusão/métodos , Acidente Vascular Cerebral/diagnóstico por imagem , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/mortalidade , Acidente Vascular Cerebral/cirurgia , Tenecteplase/administração & dosagem , Tenecteplase/efeitos adversos , Tenecteplase/uso terapêutico , Trombectomia/efeitos adversos , Trombectomia/métodos , Ativador de Plasminogênio Tecidual/administração & dosagem , Ativador de Plasminogênio Tecidual/efeitos adversos , Ativador de Plasminogênio Tecidual/uso terapêutico , Resultado do Tratamento , Método Duplo-Cego , AVC Isquêmico/diagnóstico por imagem , AVC Isquêmico/tratamento farmacológico , AVC Isquêmico/mortalidade , AVC Isquêmico/cirurgia , Infarto da Artéria Cerebral Média/diagnóstico por imagem , Infarto da Artéria Cerebral Média/tratamento farmacológico , Infarto da Artéria Cerebral Média/cirurgia , Doenças das Artérias Carótidas/diagnóstico por imagem , Doenças das Artérias Carótidas/tratamento farmacológico , Doenças das Artérias Carótidas/cirurgia , Encéfalo/irrigação sanguínea , Encéfalo/diagnóstico por imagem , Tempo para o Tratamento
2.
Ophthalmology ; 2024 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-38852921

RESUMO

PURPOSE: Diabetic Retinopathy Clinical Research Network Protocol T suggests that the response to treatment among patients with diabetic macular edema (DME) may vary depending on baseline best-corrected visual acuity (BCVA). We evaluated the efficacy of faricimab 6 mg versus aflibercept 2 mg over 2 years in patients with DME and baseline BCVA of 20/50 or worse enrolled in faricimab phase III trials. DESIGN: YOSEMITE and RHINE were identically designed, multicenter, randomized, double-masked, active comparator-controlled, noninferiority trials. PARTICIPANTS: Adults ≥18 years of age with center-involving macular edema secondary to type 1 or 2 diabetes. METHODS: Patients were randomized to faricimab every 8 weeks (Q8W), faricimab personalized treat-and-extend (T&E) regimen, or aflibercept Q8W. Post hoc subgroup analyses were conducted using the intention-to-treat population with baseline BCVA of 20/50 or worse. MAIN OUTCOME MEASURES: Changes in ETDRS BCVA and central subfield thickness (CST) from baseline to years 1 and 2 were compared between treatment arms using mixed-model repeated measures analyses. RESULTS: In YOSEMITE and RHINE, respectively, 220 and 217 patients in the faricimab Q8W arm, 220 and 219 patients in the faricimab T&E arm, and 219 and 214 patients in the aflibercept Q8W arm showed baseline BCVA of 20/50 or worse. In both trials, mean change in ETDRS BCVA was comparable between treatments across trials at years 1 and 2. In YOSEMITE, adjusted mean change from baseline in CST (µm) at year 1 was greater with faricimab Q8W (-232.8; P < 0.0001) and faricimab T&E (-217.4; P = 0.0004) ) versus aflibercept Q8W (-190.4). In RHINE, this was faricimab Q8W (-214.2; P = 0.0006) and faricimab T&E (-206.6; P = 0.0116) versus aflibercept Q8W (-186.6). In both trials, change from baseline in CST at year 2 was greater with faricimab Q8W versus aflibercept. The median time to first CST of <325 µm and first absence of intraretinal fluid was shorter in the faricimab arms versus the aflibercept arm, with fewer injections on average. CONCLUSIONS: In patients with DME and baseline ETDRS BCVA of 20/50 or worse, faricimab treatment resulted in comparable visual acuity, greater reduction in retinal thickness, and fewer injections compared with aflibercept. FINANCIAL DISCLOSURE(S): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.

3.
Cell Commun Signal ; 22(1): 357, 2024 Jul 10.
Artigo em Inglês | MEDLINE | ID: mdl-38987851

RESUMO

BACKGROUND: Chronic kidney disease (CKD) is highly prevalent worldwide, and its global burden is substantial and growing. CKD displays a number of features of accelerated senescence. Tubular cell senescence is a common biological process that contributes to CKD progression. Tubulointerstitial inflammation is a driver of tubular cell senescence and a common characteristic of CKD. However, the mechanism by which the interstitial inflammation drives tubular cell senescence remains unclear. This paper aims to explore the role of exosomal miRNAs derived from macrophages in the development of tubular cell senescence. METHODS: Among the identified inflammation-related miRNAs, miR-155 is considered to be one of the most important miRNAs involved in the inflammatory response. Macrophages, the primary immune cells that mediate inflammatory processes, contain a high abundance of miR-155 in their released exosomes. We assessed the potential role of miR-155 in tubular cell senescence and renal fibrosis. We subjected miR-155-/- mice and wild-type controls, as well as tubular epithelial cells (TECs), to angiotensin II (AngII)-induced kidney injury. We assessed kidney function and injury using standard techniques. TECs were evaluated for cell senescence and telomere dysfunction in vivo and in vitro. Telomeres were measured by the fluorescence in situ hybridization. RESULTS: Compared with normal controls, miR-155 was up-regulated in proximal renal tubule cells in CKD patients and mouse models of CKD. Moreover, the expression of miR-155 was positively correlated with the extent of renal fibrosis, eGFR decline and p16INK4A expression. The overexpression of miR-155 exacerbated tubular senescence, evidenced by increased detection of p16INK4A/p21expression and senescence-associated ß-galactosidase activity. Notably, miR-155 knockout attenuates renal fibrosis and tubule cell senescence in vivo. Interestingly, once released, macrophages-derived exosomal miR-155 was internalized by TECs, leading to telomere shortening and dysfunction through targeting TRF1. A dual-luciferase reporter assay confirmed that TRF1 was the direct target of miR-155. Thus, our study clearly demonstrates that exosomal miR-155 may mediate communication between macrophages and TECs, subsequently inducing telomere dysfunction and senescence in TECs. CONCLUSIONS: Our work suggests a new mechanism by which macrophage exosomes are involved in the development of tubule senescence and renal fibrosis, in part by delivering miR-155 to target TRF1 to promote telomere dysfunction. Our study may provide novel strategies for the treatment of AngII-induced kidney injury.


Assuntos
Senescência Celular , Células Epiteliais , Exossomos , Túbulos Renais , Macrófagos , MicroRNAs , Telômero , MicroRNAs/genética , MicroRNAs/metabolismo , Senescência Celular/genética , Exossomos/metabolismo , Exossomos/genética , Animais , Células Epiteliais/metabolismo , Células Epiteliais/patologia , Macrófagos/metabolismo , Túbulos Renais/patologia , Túbulos Renais/metabolismo , Camundongos , Telômero/genética , Telômero/metabolismo , Humanos , Camundongos Endogâmicos C57BL , Masculino , Insuficiência Renal Crônica/genética , Insuficiência Renal Crônica/patologia , Fibrose/genética , Angiotensina II
4.
J Org Chem ; 89(9): 6494-6505, 2024 May 03.
Artigo em Inglês | MEDLINE | ID: mdl-38634729

RESUMO

Herein, a novel and practical methodology for the photoinduced decarboxylative difluoroalkylation and perfluoroalkylation of α-fluoroacrylic acids is reported. A wide range of α-fluoroacrylic acids can be used as applicable feedstocks, allowing for rapid access to structurally important difluoroalkylated and polyfluoroalkylated monofluoroalkenes with high Z-stereoselectivity under mild conditions. The protocol demonstrates excellent functional group compatibility and provides a platform for modifying complex biologically active molecules.

5.
Cereb Cortex ; 33(5): 1814-1825, 2023 02 20.
Artigo em Inglês | MEDLINE | ID: mdl-35511705

RESUMO

Exposure therapy is the most effective approach of behavioral therapy for anxiety and post-traumatic stress disorder (PTSD). But fear is easy to reappear even after successful extinction. So, identifying novel strategies for augmenting exposure therapy is rather important. It was reported that exercise had beneficial effects on cognitive and memory deficits. However, whether exercise could affect fear memory, especially for fear extinction remained elusive. Here, our results showed that exposure to acute mild exercise 1 or 2 h before extinction training can augment recent fear extinction retention and 2 h for the remote fear extinction retention. These beneficial effects could be attributed to increased YTHDF1 expression in medial prefrontal cortex (mPFC). Furthermore, by using an AAV-shRNA-based approach to silence YTHDF1 expression via stereotactic injection in prelimbic cortex (PL) or infralimbic cortex (IL), respectively, we demonstrated that silence YTHDF1 in IL, but not in PL, blunted augmentation of exposure therapy induced by acute mild exercise and accompanied with decreased NR2B and GluR1 expression. Moreover, YTHDF1 modulated dendritic spines remodeling of pyramidal neuron in IL. Collectively, our findings suggested that acute mild exercise acted as an effective strategy in augmenting exposure therapy with possible implications for understanding new treatment underlying PTSD.


Assuntos
Extinção Psicológica , Medo , Ratos , Animais , Extinção Psicológica/fisiologia , Medo/fisiologia , Ratos Sprague-Dawley , Córtex Pré-Frontal/metabolismo , Ansiedade
6.
J Org Chem ; 88(1): 513-524, 2023 01 06.
Artigo em Inglês | MEDLINE | ID: mdl-36545950

RESUMO

Herein, the efficient photoredox/nickel dual-catalyzed cyanoalkylation reaction of enamides is illustrated. A wide scope of enamides and cycloketone oxime esters was well-tolerated, affording the synthetically versatile and geometrically defined ß-cyanoalkylated enamide scaffolds. The synthetic practicality of this protocol was revealed by gram-scale reactions, further transformations of enamides, and late-stage modifications of biologically active molecules.


Assuntos
Amidas , Níquel , Estrutura Molecular , Catálise
7.
J Org Chem ; 87(7): 4654-4669, 2022 04 01.
Artigo em Inglês | MEDLINE | ID: mdl-35313107

RESUMO

Herein, a new strategy for the synthesis of monofluoroalkenes via employing α-fluoroacrylic acids and N-hydroxyphthalimide (NHPI) redox-active esters as coupling partners has been developed. This decarboxylative reaction enabled the formation of C(sp2)-C(sp3) bonds to provide a practical and efficient approach for the construction of a variety of monofluoroalkenes, which are key structural motifs in organic chemistry, under mild reaction conditions. The protocol exhibited excellent functional group compatibility and delivered monofluoroalkene products with excellent Z-stereoselectivity. This work also provides a platform for the modification of complex biologically active molecules containing carboxylic acids.


Assuntos
Ácidos Carboxílicos , Ésteres , Ácidos Carboxílicos/química , Descarboxilação , Ésteres/química , Oxirredução
8.
J Org Chem ; 86(13): 8829-8842, 2021 Jul 02.
Artigo em Inglês | MEDLINE | ID: mdl-34110828

RESUMO

Herein, a dual nickel/ruthenium strategy is developed for photoinduced decarboxylative cross-coupling between α,ß-unsaturated carboxylic acids and cycloketone oxime esters. The reaction mechanism is distinct from previous photoinduced decarboxylation of α,ß-unsaturated carboxylic acids. This reaction might proceed through a nickelacyclopropane intermediate. The C(sp2)-C(sp3) bond constructed by the aforementioned reaction provides an efficient approach to obtaining various cyanoalkyl alkenes, which are synthetically valuable organic skeletons in organic and medicinal chemistry, under mild reaction conditions. The protocol tolerates many critical functional groups and provides a route for the modification of complex organic molecules.

9.
Org Biomol Chem ; 18(19): 3674-3678, 2020 May 20.
Artigo em Inglês | MEDLINE | ID: mdl-32377647

RESUMO

A nickel-catalyzed defluorinative reductive cross-coupling of trifluoromethyl alkenes with epoxides has been developed. Various substituted trifluoromethyl alkenes and epoxides were found to be suitable reaction substrates. This reaction enabled C(sp3)-C(sp3) bond construction through allylic defluorinative cross-coupling of trifluoromethyl alkenes under mild reaction conditions. This methodology was highly compatible with various sensitive functional groups, providing access to a diverse array of functionalized gem-difluoroalkene-containing alcohol compounds.

10.
Am J Physiol Renal Physiol ; 317(6): F1605-F1611, 2019 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-31566428

RESUMO

The transient receptor potential canonical 6 (TRPC6) channel and podocin are colocalized in the glomerular slit diaphragm as an important complex to maintain podocyte function. Gain of TRPC6 function and loss of podocin function induce podocyte injury. We have previously shown that high glucose induces apoptosis of podocytes by activating TRPC6; however, whether the activated TRPC6 can alter podocin expression remains unknown. Western blot analysis and confocal microscopy were used to examine both expression levels of TRPC6, podocin, and nephrin and morphological changes of podocytes in response to high glucose. High glucose increased the expression of TRPC6 but reduced the expression of podocin and nephrin, in both cultured human podocytes and type 1 diabetic rat kidneys. The decreased podocin was diminished in TRPC6 knockdown podocytes. High glucose elevated intracellular Ca2+ in control podocytes but not in TRPC6 knockdown podocytes. High glucose also elevated the expression of a tight junction protein, zonula occludens-1, and induced the redistribution of zonula occludens-1 and loss of podocyte processes. These data together suggest that high glucose reduces protein levels of podocin by activating TRPC6 and induces morphological changes of cultured podocytes.


Assuntos
Glucose/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Peptídeos e Proteínas de Sinalização Intracelular/biossíntese , Proteínas de Membrana/antagonistas & inibidores , Proteínas de Membrana/biossíntese , Podócitos/metabolismo , Canal de Cátion TRPC6/biossíntese , Animais , Cálcio/metabolismo , Linhagem Celular , Células Cultivadas , Diabetes Mellitus Experimental/metabolismo , Diabetes Mellitus Tipo 1/metabolismo , Técnicas de Silenciamento de Genes , Humanos , Podócitos/efeitos dos fármacos , Ratos , Canal de Cátion TRPC6/efeitos dos fármacos , Proteína da Zônula de Oclusão-1/biossíntese
11.
J Org Chem ; 83(10): 5791-5800, 2018 05 18.
Artigo em Inglês | MEDLINE | ID: mdl-29664291

RESUMO

A survey of diversely substituted 2-arylbenzoic acids were synthesized and tested for use as proton shuttle in the direct arylation of indoles with bromobenzenes. It was found that 3-ethoxy-2-phenylbenzoic acid gives superior yield and selectivity for this class of substrates.

12.
Biochim Biophys Acta ; 1853(5): 965-74, 2015 May.
Artigo em Inglês | MEDLINE | ID: mdl-25601712

RESUMO

Our recent studies indicate that hydrogen peroxide (H2O2) only at high concentrations can cause oxidative stress in renal epithelial cells and induce apoptosis of podocytes. Consistently, the present study shows that H2O2, even at 1 mM, failed to induce intracellular oxidative stress and apoptosis of the podocytes due to efficient activity of catalase, an enzyme which degrades H2O2 to produce water and oxygen (O2). However, H2O2 acted as a source of O2 to allow acute ethanol to induce superoxide production and cause apoptosis of the podocytes. In contrast, acute ethanol alone did not elevate intracellular superoxide, even though it stimulates expression and translocation of p47phox to the plasma membrane. Inhibition of catalase abolished not only O2 production from H2O2 degradation, but also NOX2-dependent superoxide production in the podocytes challenged by both H2O2 and acute ethanol. In parallel, acute ethanol in the presence of H2O2, but neither ethanol nor H2O2 alone, stimulated transient receptor potential canonical 6 (TRPC6) channels and caused TRPC6-dependent elevation of intracellular Ca2+. These data suggest that exogenous H2O2 does not induce oxidative stress due to rapid degradation to produce O2 in the podocytes, but the oxygenated podocytes become sensitive to acute ethanol challenge and undergo apoptosis via a TRPC6-dependent elevation of intracellular Ca2+. Since cultured podocytes are considered in hypoxic conditions, H2O2 may be used as a source of O2 to establish an ischemia-reperfusion model in some type of cultured cells in which H2O2 does not directly induce intracellular oxidative stress.


Assuntos
Apoptose/efeitos dos fármacos , Etanol/farmacologia , Oxigênio/farmacologia , Podócitos/metabolismo , Superóxidos/metabolismo , Canais de Cátion TRPC/metabolismo , Catalase/metabolismo , Linhagem Celular , Membrana Celular/efeitos dos fármacos , Membrana Celular/metabolismo , Humanos , Peróxido de Hidrogênio/farmacologia , Espaço Intracelular/efeitos dos fármacos , Espaço Intracelular/metabolismo , Ativação do Canal Iônico/efeitos dos fármacos , Glicoproteínas de Membrana/metabolismo , NADPH Oxidase 2 , NADPH Oxidases/metabolismo , Naftoquinonas/farmacologia , Estresse Oxidativo/efeitos dos fármacos , Podócitos/efeitos dos fármacos , Transporte Proteico/efeitos dos fármacos , Canal de Cátion TRPC6
13.
J Am Soc Nephrol ; 26(7): 1576-87, 2015 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-25349201

RESUMO

We recently showed that lovastatin attenuates cyclosporin A (CsA)-induced damage of cortical collecting duct (CCD) principal cells by reducing intracellular cholesterol. Previous studies showed that, in cell expression models or artificial membranes, exogenous cholesterol directly inhibits inward rectifier potassium channels, including Kir1.1 (Kcnj1; the gene locus for renal outer medullary K(+) [ROMK1] channels). Therefore, we hypothesized that lovastatin might stimulate ROMK1 by reducing cholesterol in CCD cells. Western blots showed that mpkCCDc14 cells express ROMK1 channels with molecular masses that approximate the molecular masses of ROMK1 in renal tubules detected before and after treatment with DTT. Confocal microscopy showed that ROMK1 channels were not in the microvilli, where cholesterol-rich lipid rafts are located, but rather, the planar regions of the apical membrane of mpkCCDc14 cells. Furthermore, phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2], an activator of ROMK channels, was detected mainly in the microvilli under resting conditions along with the kinase responsible for PI(4,5)P2 synthesis, phosphatidylinositol-4-phosphate 5-kinase, type I γ [PI(4)P5K I γ], which may explain the low basal open probability and increased sensitivity to tetraethylammonium observed here for this channel. Notably, lovastatin induced PI(4)P5K I γ diffusion into planar regions and elevated PI(4,5)P2 and ROMK1 open probability in these regions through a cholesterol-associated mechanism. However, exogenous cholesterol alone did not induce these effects. These results suggest that lovastatin stimulates ROMK1 channels, at least in part, by inducing PI(4,5)P2 synthesis in planar regions of the renal CCD cell apical membrane, suggesting that lovastatin could reduce cyclosporin-induced nephropathy and associated hyperkalemia.


Assuntos
Colesterol/metabolismo , Túbulos Renais Coletores/metabolismo , Lovastatina/farmacologia , Microvilosidades/metabolismo , Canais de Potássio Corretores do Fluxo de Internalização/metabolismo , Análise de Variância , Animais , Western Blotting , Membrana Celular/metabolismo , Células Cultivadas , Ciclosporinas/metabolismo , Regulação da Expressão Gênica , Túbulos Renais Coletores/efeitos dos fármacos , Camundongos , Microscopia Confocal , Microvilosidades/efeitos dos fármacos , Microvilosidades/ultraestrutura , Modelos Animais , Canais de Potássio Corretores do Fluxo de Internalização/efeitos dos fármacos , Canais de Potássio Corretores do Fluxo de Internalização/genética , RNA Interferente Pequeno/metabolismo , Reação em Cadeia da Polimerase em Tempo Real/métodos , Valores de Referência , Sensibilidade e Especificidade , Transdução de Sinais
14.
Biochim Biophys Acta ; 1843(5): 894-901, 2014 May.
Artigo em Inglês | MEDLINE | ID: mdl-24518247

RESUMO

Clinical evidence suggests that statins reduce cancer incidence and mortality. However, there is lack of in vitro data to show the mechanism by which statins can reduce the malignancies of cancer cells. We used a human B lymphoma Daudi cells as a model and found that lovastatin inhibited, whereas exogenous cholesterol (Cho) stimulated, proliferation cell cycle progression in control Daudi cells, but not in the cells when transient receptor potential canonical 6 (TRPC6) channel was knocked down. Lovastatin decreased, whereas Cho increased, the levels of intracellular reactive oxygen species (ROS) respectively by decreasing or increasing the expression of p47-phox and gp91-phox (NOX2). Reducing intracellular ROS with either a mimetic superoxide dismutase (TEMPOL) or an NADPH oxidase inhibitor (apocynin) inhibited cell proliferation, particularly in Cho-treated cells. The effects of TEMPOL or apocynin were mimicked by inhibition of TRPC6 with SKF-96365. Lovastatin decreased TRPC6 expression and activity via a Cho-dependent mechanism, whereas Cho increased TRPC6 expression and activity via an ROS-dependent mechanism. Consistent with the fact that TRPC6 is a Ca(2+)-permeable channel, lovastatin decreased, but Cho increased, intracellular Ca(2+) also via ROS. These data suggest that lovastatin inhibits malignant B cell proliferation by reducing membrane Cho, intracellular ROS, TRPC6 expression and activity, and intracellular Ca(2+).


Assuntos
Proliferação de Células/efeitos dos fármacos , Inibidores de Hidroximetilglutaril-CoA Redutases/farmacologia , Lovastatina/farmacologia , Linfoma de Células B/patologia , Espécies Reativas de Oxigênio/metabolismo , Canais de Cátion TRPC/antagonistas & inibidores , Humanos , Técnicas de Patch-Clamp , Canal de Cátion TRPC6
15.
Biochim Biophys Acta ; 1833(6): 1434-42, 2013 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-23499875

RESUMO

Podocyte number is significantly reduced in diabetic patients and animal models, but the mechanism remains unclear. In the present study, we found that high glucose induced apoptosis in control podocytes which express transient receptor potential canonical 6 (TRPC6) channels, but not in TRPC6 knockdown podocytes in which TRPC6 was knocked down by TRPC6 silencing short hairpin RNA (shRNA). This effect was reproduced by treatment of podocytes with the reactive oxygen species (ROS), hydrogen peroxide (H2O2). Single-channel data from cell-attached, patch-clamp experiments showed that both high glucose and H2O2 activated the TRPC6 channel in control podocytes, but not in TRPC6 knockdown podocytes. Confocal microscopy showed that high glucose elevated ROS in podocytes and that H2O2 reduced the membrane potential of podocytes and elevated intracellular Ca(2+) via activation of TRPC6. Since intracellular Ca(2+) overload induces apoptosis, H2O2-induced apoptosis may result from TRPC6-mediated elevation of intracellular Ca(2+). These data together suggest that high glucose induces apoptosis in podocytes by stimulating TRPC6 via elevation of ROS.


Assuntos
Apoptose/efeitos dos fármacos , Cálcio/metabolismo , Glucose/farmacologia , Podócitos/patologia , Espécies Reativas de Oxigênio/metabolismo , Edulcorantes/farmacologia , Canais de Cátion TRPC/metabolismo , Western Blotting , Células Cultivadas , Humanos , Peróxido de Hidrogênio/farmacologia , Potenciais da Membrana/efeitos dos fármacos , Oxidantes/farmacologia , Técnicas de Patch-Clamp , Podócitos/efeitos dos fármacos , Podócitos/metabolismo , Canal de Cátion TRPC6
16.
Chemistry ; 20(47): 15334-8, 2014 Nov 17.
Artigo em Inglês | MEDLINE | ID: mdl-25308802

RESUMO

A copper-catalyzed reductive cross-coupling reaction of nonactivated alkyl tosylates and mesylates with alkyl and aryl bromides was developed. It provides a practical method for efficient and cost-effective construction of aryl-alkyl and alkyl-alkyl CC bonds with stereocontrol from readily available substrates. When used in an intramolecular fashion, the reaction enables convenient access to various substituted carbo- or heterocycles, such as 2,3-dihydrobenzofuran and benzochromene derivatives.

17.
Chem Commun (Camb) ; 60(51): 6556-6559, 2024 Jun 20.
Artigo em Inglês | MEDLINE | ID: mdl-38845407

RESUMO

Herein, a novel strategy is presented for the photoinduced decarboxylative and dehydrogenative cross-coupling of a wide range of α-fluoroacrylic acids with hydrogermanes. This methodology provides an efficient and robust approach for producing various germylated monofluoroalkenes with excellent stereoselectivity within a brief photoirradiation period. The feasibility of this reaction has been demonstrated through gram-scale reaction, conversion of germylated monofluoroalkenes, and modification of complex organic molecules.

18.
Neuropharmacology ; 258: 110089, 2024 Jul 20.
Artigo em Inglês | MEDLINE | ID: mdl-39033904

RESUMO

Autism spectrum disorder (ASD) is neurodevelopmental disorder with a high incidence rate, characterized by social deficits and repetitive behaviors. There is currently no effective management available to treat the core symptoms of ASD; however, oxidative stress has been implicated in its pathogenesis. Edaravone (EDA), a free-radical scavenger, is used to treat amyotrophic lateral sclerosis (ALS) and acute ischemic stroke (AIS). Here, we hypothesized that an oral formula of EDA may have therapeutic efficacy in the treatment of core ASD symptoms. A rat model of autism was established by prenatal exposure to valproic acid (VPA), and the offsprings were orally treated with EDA at low (3 mg/kg), medium (10 mg/kg), and high (30 mg/kg) doses once daily for 28 days starting from postnatal day 25 (PND25). Oral EDA administration alleviated the core symptoms in VPA rats in a dose-dependent manner, including repetitive stereotypical behaviors and impaired social interaction. Furthermore, oral administration of EDA significantly reduced oxidative stress in a dose-dependent manner, as evidenced by a reduction in oxidative stress markers and an increase in antioxidants in the blood and brain. In addition, oral EDA significantly attenuated downstream pathologies, including synaptic and mitochondrial damage in the brain. Proteomic analysis further revealed that EDA corrected the imbalance in brain oxidative reduction and mitochondrial proteins induced by prenatal VPA administration. Overall, these findings demonstrate that oral EDA has therapeutic potential for ASD by targeting the oxidative stress pathway of disease pathogenesis and paves the way towards clinical studies.

19.
Behav Brain Res ; 472: 115152, 2024 Jul 18.
Artigo em Inglês | MEDLINE | ID: mdl-39032868

RESUMO

The high rate of relapse to compulsive methamphetamine (MA)-taking and seeking behaviors after abstinence constitutes a major obstacle to the treatment of MA addiction. Perineuronal nets (PNNs), essential components of the extracellular matrix, play a critical role in synaptic function, learning, and memory. Abnormalities in PNNs have been closely linked to a series of neurological diseases, such as addiction. However, the exact role of PNNs in MA-induced related behaviors remains elusive. Here, we established a MA-induced conditioned place preference (CPP) paradigm in female mice and found that the number and average optical density of PNNs increased significantly in the medial prefrontal cortex (mPFC) of mice during the acquisition, extinction, and reinstatement stages of CPP. Notably, the removal of PNNs in the mPFC via chondroitinase ABC (ChABC) before extinction training not only facilitated the extinction of MA-induced CPP and attenuated the relapse of extinguished MA preference but also significantly reduced the activation of c-Fos in the mPFC. Similarly, the ablation of PNNs in the mPFC before reinstatement markedly lessened the reinstatement of MA-induced CPP, which was accompanied by the decreased expression of c-Fos in the mPFC. Collectively, our results provide more evidence for the implication of degradation of PNNs in facilitating extinction and preventing relapse of MA-induced CPP, which indicate that targeting PNNs may be an effective therapeutic option for MA-induced CPP memories.

20.
Biochim Biophys Acta ; 1823(2): 505-13, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22192444

RESUMO

Kv1.3 channels play an important role in modulating lymphocyte proliferation and apoptosis. We hypothesized that Kv1.3 channels in B lymphocytes might be regulated by rituximab, an antibody to CD20, a drug for treatments of B-cell lymphomas and autoimmune diseases. Using both whole-cell and cell-attached patch-clamp techniques, we found that rituximab inhibited Kv1.3 channels in Daudi human B lymphoma cells by promoting the channel inactivation at a concentration which was much greater than that required for activation of CD20. The effect of rituximab on Kv1.3 channels was abolished after selective blockade of FcγRIIB receptors with anti-FcγRIIB antibody. Western blot experiments showed that Daudi B cells expressed both Kv1.3 channel and the low affinity Fc receptor, FcγRIIB, which could be activated by the Fc region of rituximab. In contrast, normal lymphocytes expressed less Kv1.3 channels with faster inactivation. Confocal microscopy and flow cytometry data showed that rituximab induced apoptosis of Daudi B cells and that the effect was attenuated by blockade of FcγRIIB receptors and partially mimicked by inhibition of Kv1.3 channels. These results suggest that in addition to previously described complement-dependent cytotoxicity, rituximab also induces apoptosis of malignant B lymphocyte by stimulating FcγRIIB receptors and inhibiting Kv1.3 channels.


Assuntos
Anticorpos Monoclonais Murinos/metabolismo , Antineoplásicos/metabolismo , Canal de Potássio Kv1.3/metabolismo , Linfoma de Células B/metabolismo , Receptores de IgG/metabolismo , Adjuvantes Imunológicos/metabolismo , Animais , Linhagem Celular Tumoral , Toxina da Cólera , Humanos , Linfoma de Células B/patologia , Camundongos , Técnicas de Patch-Clamp , Bloqueadores dos Canais de Potássio/metabolismo , Quinina/metabolismo , Rituximab
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