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1.
Stroke ; 54(10): 2698-2707, 2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37694403

RESUMO

The Stroke Treatment Academic Industry Roundtable (STAIR) convened a session and workshop regarding enrollment in acute stroke trials during the STAIR XII meeting on March 22, 2023. This forum brought together stroke physicians and researchers, members of the National Institute of Neurological Disorders and Stroke, industry representatives, and members of the US Food and Drug Administration to discuss the current status and opportunities for improving enrollment in acute stroke trials. The workshop identified the most relevant issues impacting enrollment in acute stroke trials and addressed potential action items for each. Focus areas included emergency consent in the United States and other countries; careful consideration of eligibility criteria to maximize enrollment and representativeness; investigator, study coordinator, and pharmacist availability outside of business hours; trial enthusiasm/equipoise; site start-up including contractual issues; site champions; incorporation of study procedures into standard workflow as much as possible; centralized enrollment at remote sites by study teams using telemedicine; global trials; and coenrollment in trials when feasible. In conclusion, enrollment of participants is the lifeblood of acute stroke trials and is the rate-limiting step for testing an exciting array of new approaches to improve patient outcomes. In particular, efforts should be undertaken to broaden the medical community's understanding and implementation of emergency consent procedures and to adopt designs and processes that are easily incorporated into standard workflow and that improve trials' efficiencies and execution. Research and actions to improve enrollment in ongoing and future trials will improve stroke outcomes more broadly than any single therapy under consideration.


Assuntos
Médicos , Acidente Vascular Cerebral , Estados Unidos , Humanos , Consenso , Definição da Elegibilidade , National Institute of Neurological Disorders and Stroke (USA) , Acidente Vascular Cerebral/terapia
2.
Rev Med Chil ; 150(5): 597-602, 2022 May.
Artigo em Espanhol | MEDLINE | ID: mdl-37906759

RESUMO

BACKGROUND: A secondary cause can be found in up to one third of women with osteoporosis, potentially modifying their therapeutic approach. AIM: To determine the prevalence of secondary causes and risk factors for decreased bone mineral density (BMD) and osteoporosis. MATERIAL AND METHODS: We included postmenopausal women with a diagnosis of osteoporosis or low BMD who consulted for the first time in an endocrinology clinic between October 2018 and March 2020. A complete medical history, physical examination and a standardized laboratory assessment to identify secondary causes were performed. RESULTS: During the study period, 114 women were evaluated, 30 of them with low BMD and 84 with osteoporosis. After obtaining a medical history and a structured laboratory screening, at least one secondary cause was found in 50% of patients with osteoporosis and in 67% of those with low BMD. Most patients with no identified secondary cause had at least one risk factor for fragility fractures. CONCLUSIONS: A structured evaluation that includes medical history and standardized laboratory study in postmenopausal women with osteoporosis or low BMD, is a valuable tool to identify secondary causes of osteoporosis.


Assuntos
Fraturas Ósseas , Osteoporose , Humanos , Feminino , Densidade Óssea , Pós-Menopausa , Osteoporose/epidemiologia , Osteoporose/etiologia , Fraturas Ósseas/complicações , Fraturas Ósseas/epidemiologia , Minerais
3.
Stroke ; 52(2): 505-510, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-33423513

RESUMO

BACKGROUND AND PURPOSE: We aim to identify the subgroup of acute ischemic stroke patients with higher probabilities of benefiting from a potential neuroprotective drug using baseline outcome predictors and test whether different selection criteria strategies can improve detected treatment effect. METHODS: We analyzed the association between final infarct volume (FIV), measured on 24- to 72-hour computed tomography, and National Institutes of Health Stroke Scale at discharge/day 5 of acute stroke patients who underwent endovascular treatment. Models were adjusted for age, sex, and affected hemisphere. We analyzed the impact of absolute (5-15 mL) and relative (33%) FIV reductions in the National Institutes of Health Stroke Scale in the whole population and in different subsets of patients selected according to baseline imaging criteria using computed tomography perfusion. RESULTS: We analyzed 627 patients; association between FIV and 5-day National Institutes of Health Stroke Scale was best described with a quadratic function, with a regression coefficient ß=1.56 ([95% CI, 1.45-1.67] P<0.001) in the adjusted analysis. In the models considering a fixed absolute (5/15 mL) FIV reduction, treatment effect was highest when patients with predicted larger FIV were excluded, whereas in a 33% FIV reduction model, treatment effect increased with the exclusion of patients with expected excellent outcomes. CONCLUSIONS: Patients either with excellent outcomes after endovascular thrombectomy or with large infarcts may dilute the treatment effect in stroke neuroprotective drug trials. Computed tomography perfusion on admission may help selecting adequate patients according to expected drug effect profile.


Assuntos
AVC Isquêmico/tratamento farmacológico , Modelos Teóricos , Fármacos Neuroprotetores/uso terapêutico , Seleção de Pacientes , Idoso , Idoso de 80 Anos ou mais , Procedimentos Endovasculares , Feminino , Humanos , AVC Isquêmico/patologia , AVC Isquêmico/cirurgia , Masculino , Pessoa de Meia-Idade , Trombectomia
4.
Calcif Tissue Int ; 109(2): 132-138, 2021 08.
Artigo em Inglês | MEDLINE | ID: mdl-33839802

RESUMO

X-Linked Hypophosphatemia (XLH) is the most common cause of inherited hypophosphatemic rickets. Dental involvement, including spontaneous abscesses and/or fistulae, is an important part of the disease and has not been completely defined, especially in cohorts from developing countries. To describe oral health status in a cohort of Chilean patients with XLH and explore its correlation with biochemical presentation and treatment, we conducted a cross-sectional observational study of patients with PHEX mutation-confirmed XLH. All patients had an oral clinical exam, radiographic evaluation; clinical and biochemical data were obtained to determine their association with oral features. Twenty-six patients were included, 77% adults and 23% children. Most adults (89%) had past or current dental pulp pathology (abscesses and/or fistulae). Pulpal chamber enlargement and radiolucent apical lesions were common radiological features (94 and 74%, respectively). In children, abscess and/or fistulae were also common (33%). Caries index, which was determined by dmft/DMFT, was higher than the Chilean national average. Early and long-term therapy with phosphate and activated vitamin D was associated with lower carious index and attachment loss. XLH patients frequently present with high pulpal involvement and carious index. Conventional therapy was associated with lower carious index and attachment loss. These data highlight the importance of early and periodical dental care in order to prevent dental damage and assure a good quality of oral health for XLH patients.


Assuntos
Raquitismo Hipofosfatêmico Familiar , Hipofosfatemia , Adulto , Criança , Estudos Transversais , Raquitismo Hipofosfatêmico Familiar/complicações , Raquitismo Hipofosfatêmico Familiar/epidemiologia , Raquitismo Hipofosfatêmico Familiar/genética , Fator de Crescimento de Fibroblastos 23 , Humanos , Mutação , Saúde Bucal , Endopeptidase Neutra Reguladora de Fosfato PHEX/genética , Fosfatos
5.
Calcif Tissue Int ; 108(1): 128-142, 2021 01.
Artigo em Inglês | MEDLINE | ID: mdl-32504138

RESUMO

Tumor-induced osteomalacia (TIO) is a rare paraneoplastic syndrome caused by tumoral production of fibroblast growth factor 23 (FGF23). The hallmark biochemical features include hypophosphatemia due to renal phosphate wasting, inappropriately normal or frankly low 1,25-dihydroxy-vitamin D, and inappropriately normal or elevated FGF23. TIO is caused by typically small, slow growing, benign phosphaturic mesenchymal tumors (PMTs) that are located almost anywhere in the body from the skull to the feet, in soft tissue or bone. The recent identification of fusion genes in a significant subset of PMTs has provided important insights into PMT tumorigenesis. Although management of this disease may seem straightforward, considering that complete resection of the tumor leads to its cure, locating these often-tiny tumors is frequently a challenge. For this purpose, a stepwise, systematic approach is required. It starts with thorough medical history and physical examination, followed by functional imaging, and confirmation of identified lesions by anatomical imaging. If the tumor resection is not possible, medical therapy with phosphate and active vitamin D is indicated. Novel therapeutic approaches include image-guided tumor ablation and medical treatment with the anti-FGF23 antibody burosumab or the pan-FGFR tyrosine kinase inhibitor, BGJ398/infigratinib. Great progress has been made in the diagnosis and treatment of TIO, and more is likely to come, turning this challenging, debilitating disease into a gratifying cure for patients and their providers.


Assuntos
Hipofosfatemia , Neoplasias de Tecido Conjuntivo , Osteomalacia , Síndromes Paraneoplásicas , Anticorpos Monoclonais Humanizados/uso terapêutico , Fator de Crescimento de Fibroblastos 23 , Fatores de Crescimento de Fibroblastos/genética , Humanos , Neoplasias de Tecido Conjuntivo/complicações , Osteomalacia/etiologia , Síndromes Paraneoplásicas/etiologia , Compostos de Fenilureia/uso terapêutico , Fosfatos , Pirimidinas/uso terapêutico
6.
J Am Soc Nephrol ; 31(9): 2184-2192, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32631973

RESUMO

BACKGROUND: The rare lysosomal storage disease nephropathic cystinosis presents with renal Fanconi syndrome that evolves in time to CKD. Although biochemical abnormalities in common causes of CKD-mineral and bone disorder have been defined, it is unknown if persistent phosphate wasting in nephropathic cystinosis is associated with a biochemical mineral pattern distinct from that typically observed in CKD-mineral and bone disorder. METHODS: We assessed and compared determinants of mineral homeostasis in patients with nephropathic cystinosis across the predialysis CKD spectrum to these determinants in age- and CKD stage-matched patients, with causes of CKD other than nephropathic cystinosis. RESULTS: The study included 50 patients with nephropathic cystinosis-related CDK and 97 with CKD from other causes. All major aspects of mineral homeostasis were differentially effected in patients with CKD stemming from nephropathic cystinosis versus other causes. Patients with nephropathic cystinosis had significantly lower percent tubular reabsorption of phosphate and fibroblast growth factor-23 (FGF23) at all CKD stages, and lower blood phosphate in CKD stages 3-5. Linear regression analyses demonstrated lower FGF23 levels in nephropathic cystinosis participants at all CKD stages when corrected for eGFR and age, but not when adjusted for serum phosphate. CONCLUSIONS: Nephropathic cystinosis CKD patients have mineral abnormalities that are distinct from those in CKD stemming from other causes. Persistently increased urinary phosphate excretion maintains serum phosphate levels within the normal range, thus protecting patients with nephropathic cystinosis from elevations of FGF23 during early CKD stages. These findings support the notion that phosphate is a significant driver of increased FGF23 levels in CKD and that mineral abnormalities associated with CKD are likely to vary depending on the underlying renal disease.


Assuntos
Distúrbio Mineral e Ósseo na Doença Renal Crônica/metabolismo , Cistinose/metabolismo , Fatores de Crescimento de Fibroblastos/sangue , Adolescente , Adulto , Criança , Pré-Escolar , Feminino , Fator de Crescimento de Fibroblastos 23 , Homeostase , Humanos , Masculino , Fosfatos/metabolismo , Vitamina D/sangue , Adulto Jovem
7.
Rev Med Chil ; 148(3): 404-408, 2020 Mar.
Artigo em Espanhol | MEDLINE | ID: mdl-32730387

RESUMO

Hypophosphatemia is a relatively frequent and a potentially serious adverse drug effect. Clinically it is characterized by bone pain and muscle weakness. There are several mechanisms by which a drug can induce hypophosphatemia and they can be classified according to whether or not they are mediated by an excess of Fibroblast Growth Factor 23 (FGF23). We report two patients with the condition: (i) A 49-year-old woman with Chronic Myeloid Leukemia (CML) and gastric sleeve surgery at 46 years of age. After receiving intravenous carboxymaltose iron in one occasion due to refractory anemia, she developed symptomatic hypophosphatemia. Urinary phosphate losses associated with high FGF23 levels were confirmed. Plasma phosphate returned to normal values 90 days after the iron administration. (ii) A 40-year-old man with a history of CML in whom imatinib was started. He developed symptomatic hypophosphatemia due to non FGF23-mediated hyperphosphaturia. As treatment with imatinib could not be interrupted, hypophosphatemia and its symptoms resolved with oral phosphate intake. These cases illustrate the importance of recognizing and treating drug-induced hypophosphatemia in a timely manner, and thus avoid the morbidity associated with this entity.


Assuntos
Hipofosfatemia , Administração Intravenosa , Adulto , Feminino , Fator de Crescimento de Fibroblastos 23 , Humanos , Mesilato de Imatinib , Ferro , Masculino , Pessoa de Meia-Idade , Fosfatos
8.
Stroke ; 50(11): 3228-3237, 2019 11.
Artigo em Inglês | MEDLINE | ID: mdl-31526124

RESUMO

Background and Purpose- Recanalization of the occluded artery is a primary goal in stroke treatment. Unfortunately, endovascular treatment is not always available, and tPA (tissue-type plasminogen activator) therapy is limited by its narrow therapeutic window; importantly, the rate of early arterial recanalization after tPA administration is low, especially for platelet-rich thrombi. The mechanisms for this tPA resistance are not well known. Since neutrophil extracellular traps (NETs) have been implicated in this setting, our aim was to study whether NET pharmacological modulation can reverse tPA resistance and the role of TLR4 (Toll-like receptor 4), previously related to NET formation, in thrombosis. Methods- To this goal, we have used a mouse photothrombotic stroke model, which produces a fibrin-free thrombus composed primarily of aggregated platelets and thrombi obtained from human stroke patients. Results- Our results demonstrate that (1) administration of DNase-I, which promotes NETs lysis, but not of tPA, recanalizes the occluded vessel improving photothrombotic stroke outcome; (2) a preventive treatment with Cl-amidine, impeding NET formation, completely precludes thrombotic occlusion; (3) platelet TLR4 mediates NET formation after photothrombotic stroke; and (4) ex vivo fresh platelet-rich thrombi from ischemic stroke patients are effectively lysed by DNase-I. Conclusions- Hence, our data open new avenues for recanalization of platelet-rich thrombi after stroke, especially to overcome tPA resistance.


Assuntos
Desoxirribonuclease I/farmacologia , Resistência a Medicamentos/efeitos dos fármacos , Armadilhas Extracelulares/metabolismo , Acidente Vascular Cerebral , Trombose , Ativador de Plasminogênio Tecidual/farmacologia , Animais , Modelos Animais de Doenças , Masculino , Camundongos , Camundongos Transgênicos , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/metabolismo , Acidente Vascular Cerebral/patologia , Trombose/tratamento farmacológico , Trombose/metabolismo , Trombose/patologia , Receptor 4 Toll-Like/metabolismo
9.
Mol Ther ; 26(8): 2047-2059, 2018 08 01.
Artigo em Inglês | MEDLINE | ID: mdl-29910175

RESUMO

Since Toll-like receptor 4 (TLR4) mediates brain damage after stroke, development of TLR4 antagonists is a promising therapeutic strategy for this disease. Our aim was to generate TLR4-blocking DNA aptamers to be used for stroke treatment. From a random oligonucleotide pool, we identified two aptamers (ApTLR#1R, ApTLR#4F) with high affinity for human TLR4 by systematic evolution of ligands by exponential enrichment (SELEX). Optimized truncated forms (ApTLR#1RT, ApTLR#4FT) were obtained. Our data demonstrate specific binding of both aptamers to human TLR4 as well as a TLR4 antagonistic effect. ApTLR#4F and ApTLR#4FT showed a long-lasting protective effect against brain injury induced by middle cerebral artery occlusion (MCAO), an effect that was absent in TLR4-deficient mice. Similar effects were obtained in other MCAO models, including in rat. Additionally, efficacy of ApTLR#4FT in a model of brain ischemia-reperfusion in rat supports the use of this aptamer in patients undergoing artery recanalization induced by pharmacological or mechanical interventions. The absence of major toxicology aspects and the good safety profile of the aptamers further encourage their future clinical positioning for stroke therapy and possibly other diseases in which TLR4 plays a deleterious role.


Assuntos
Aptâmeros de Nucleotídeos/administração & dosagem , Infarto da Artéria Cerebral Média/tratamento farmacológico , Acidente Vascular Cerebral/prevenção & controle , Receptor 4 Toll-Like/metabolismo , Animais , Aptâmeros de Nucleotídeos/farmacologia , Modelos Animais de Doenças , Humanos , Infarto da Artéria Cerebral Média/complicações , Infarto da Artéria Cerebral Média/etiologia , Camundongos , Ratos , Técnica de Seleção de Aptâmeros , Transdução de Sinais , Acidente Vascular Cerebral/genética , Acidente Vascular Cerebral/metabolismo
10.
Stroke ; 47(1): 206-13, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26628388

RESUMO

BACKGROUND AND PURPOSE: 3ß-Hydroxysteroid-Δ24 reductase (DHCR24) or selective alzheimer disease indicator 1 (seladin-1), an enzyme of cholesterol biosynthetic pathway, has been implicated in neuroprotection, oxidative stress, and inflammation. However, its role in ischemic stroke remains unexplored. The aim of this study was to characterize the effect of seladin-1/DHCR24 using an experimental stroke model in mice. METHODS: Dhcr24(+/-) and wild-type (WT) mice were subjected to permanent middle cerebral artery occlusion. In another set of experiments, WT mice were treated intraperitoneally either with vehicle or U18666A (seladin-1/DHCR24 inhibitor, 10 mg/kg) 30 minutes after middle cerebral artery occlusion. Brains were removed 48 h after middle cerebral artery occlusion for infarct volume determination. For protein expression determination, peri-infarct region was obtained 24 h after ischemia, and Western blot or cytometric bead array was performed. RESULTS: Dhcr24(+/-) mice displayed larger infarct volumes after middle cerebral artery occlusion than their WT littermates. Treatment of WT mice with the seladin-1/DHCR24 inhibitor U18666A also increased ischemic lesion. Inflammation-related mediators were increased after ischemia in Dhcr24(+/-) mice compared with WT counterparts. Consistent with a role of cholesterol in proper function of glutamate transporter EAAT2 in membrane lipid rafts, we found a decreased association of EAAT2 with lipid rafts after ischemia when DHCR24 is genetically deleted or pharmacologically inhibited. Accordingly, treatment with U18666A decreases [(3)H]-glutamate uptake in cultured astrocytes. CONCLUSIONS: These results support the idea that lipid raft integrity, ensured by seladin-1/DHCR24, plays a crucial protective role in the ischemic brain by guaranteeing EAAT2-mediated uptake of glutamate excess.


Assuntos
Transportador 2 de Aminoácido Excitatório/metabolismo , Microdomínios da Membrana/metabolismo , Proteínas do Tecido Nervoso/antagonistas & inibidores , Proteínas do Tecido Nervoso/deficiência , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/antagonistas & inibidores , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/deficiência , Acidente Vascular Cerebral/metabolismo , Acidente Vascular Cerebral/prevenção & controle , Androstenos/farmacologia , Animais , Animais Recém-Nascidos , Células Cultivadas , Transportador 2 de Aminoácido Excitatório/genética , Ácido Glutâmico/metabolismo , Masculino , Microdomínios da Membrana/efeitos dos fármacos , Microdomínios da Membrana/genética , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Knockout , Proteínas do Tecido Nervoso/genética , Oxirredutases atuantes sobre Doadores de Grupo CH-CH/genética , Acidente Vascular Cerebral/genética
12.
J Neuroinflammation ; 12: 87, 2015 May 10.
Artigo em Inglês | MEDLINE | ID: mdl-25958332

RESUMO

BACKGROUND: Aging is not just a risk factor of stroke, but it has also been associated with poor recovery. It is known that stroke-induced neurogenesis is reduced but maintained in the aged brain. However, there is no consensus on how neurogenesis is affected after stroke in aged animals. Our objective is to determine the role of aging on the process of neurogenesis after stroke. METHODS: We have studied neurogenesis by analyzing proliferation, migration, and formation of new neurons, as well as inflammatory parameters, in a model of cerebral ischemia induced by permanent occlusion of the middle cerebral artery in young- (2 to 3 months) and middle-aged mice (13 to 14 months). RESULTS: Aging increased both microglial proliferation, as shown by a higher number of BrdU(+) cells and BrdU/Iba1(+) cells in the ischemic boundary and neutrophil infiltration. Interestingly, aging increased the number of M1 monocytes and N1 neutrophils, consistent with pro-inflammatory phenotypes when compared with the alternative M2 and N2 phenotypes. Aging also inhibited (subventricular zone) SVZ cell proliferation by decreasing both the number of astrocyte-like type-B (prominin-1(+)/epidermal growth factor receptor (EGFR)(+)/nestin(+)/glial fibrillary acidic protein (GFAP)(+) cells) and type-C cells (prominin-1(+)/EGFR(+)/nestin(-)/Mash1(+) cells), and not affecting apoptosis, 1 day after stroke. Aging also inhibited migration of neuroblasts (DCX(+) cells), as indicated by an accumulation of neuroblasts at migratory zones 14 days after injury; consistently, aged mice presented a smaller number of differentiated interneurons (NeuN(+)/BrdU(+) and GAD67(+) cells) in the peri-infarct cortical area 14 days after stroke. CONCLUSIONS: Our data confirm that stroke-induced neurogenesis is maintained but reduced in aged animals. Importantly, we now demonstrate that aging not only inhibits proliferation of specific SVZ cell subtypes but also blocks migration of neuroblasts to the damaged area and decreases the number of new interneurons in the cortical peri-infarct area. Thus, our results highlight the importance of using aged animals for translation to clinical studies.


Assuntos
Movimento Celular/fisiologia , Proliferação de Células/fisiologia , Córtex Cerebral/patologia , Infarto da Artéria Cerebral Média/patologia , Microglia/fisiologia , Neurogênese/fisiologia , Neurônios/fisiologia , Envelhecimento , Animais , Células Sanguíneas/patologia , Células Sanguíneas/fisiologia , Infarto Encefálico/etiologia , Infarto Encefálico/patologia , Bromodesoxiuridina/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Córtex Cerebral/fisiopatologia , Modelos Animais de Doenças , Proteína Duplacortina , Proteína Glial Fibrilar Ácida/metabolismo , Infarto da Artéria Cerebral Média/complicações , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Proteínas dos Microfilamentos/metabolismo , Microglia/patologia , Neurônios/patologia , Infiltração de Neutrófilos/fisiologia , Fosfopiruvato Hidratase/metabolismo
13.
FASEB J ; 28(11): 4710-8, 2014 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-25063846

RESUMO

Toll-like receptor 4 (TLR4) mediates brain damage after stroke. Now our objective is to determine TLR4 involvement in stroke-induced neurogenesis. Stroke was induced by permanent middle cerebral artery occlusion in wild-type and TLR4-deficient mice. Stereological and densitometric analysis of immunofluorescence-labeled brain sections and FACS analysis of cell suspensions were performed. Our results show that subventricular zone (SVZ) cell proliferation after stroke depends on infarct size. Second, when comparing brains with similar lesions, TLR4 attenuated SVZ proliferation, as shown by a decrease in prominin-1(+)/EGFR(+)/nestin(-) cells (type-C cells) at 1-2 d, and in BrdU(+) cells at 7 d, in TLR4(+/+) vs. TLR4(-/-) mice. Interestingly, 7 d after the infarct, neuroblasts in TLR4(+/+) mice migrated farther distances, reaching areas closer to the lesion than those in TLR4-deficient mice. However, at 14 d, TLR4-deficient mice presented a higher number of neuroblasts in all migratory zones than the TLR4(+/+) counterparts, which suggests that TLR4 deficiency delays neuroblast migration. Consistently, TLR4(+/+) mice showed an increased number of interneurons (NeuN(+)/BrdU(+)/GAD67(+) cells) in peri-infarct cortex 14-28 d after stroke. Our data indicate that, despite a negative effect on SVZ cell proliferation, TLR4 plays an important role in stroke-induced neurogenesis by promoting neuroblasts migration and increasing the number of new cortical neurons after stroke.


Assuntos
Isquemia Encefálica/metabolismo , Movimento Celular/fisiologia , Neurogênese/fisiologia , Neurônios/metabolismo , Receptor 4 Toll-Like/metabolismo , Animais , Isquemia Encefálica/imunologia , Proliferação de Células/fisiologia , Imunidade Inata/fisiologia , Masculino , Camundongos Endogâmicos C57BL , Receptor 4 Toll-Like/imunologia
14.
Pharmaceutics ; 16(6)2024 May 30.
Artigo em Inglês | MEDLINE | ID: mdl-38931862

RESUMO

ApTOLL, a TLR4 modulator aptamer, has demonstrated cerebroprotective effects in a permanent ischemic stroke mouse model, as well as safety and efficacy in early phase clinical trials. We carried out reverse translation research according to STAIR recommendations to further characterize the effects and mechanisms of ApTOLL after transient ischemic stroke in rats and to better inform the design of pivotal clinical trials. Adult male rats subjected to transient middle cerebral artery occlusion were treated either with ApTOLL or the vehicle intravenously at different doses and time-points. ApTOLL was compared with TAK-242 (a TLR4 inhibitor). Female rats were also studied. After neurofunctional evaluation, brains were removed for infarct/edema volume, hemorrhagic transformation, and histologic determinations. Peripheral leukocyte populations were assessed via flow cytometry. ApTOLL showed U-shaped dose-dependent cerebroprotective effects. The maximum effective dose (0.45 mg/kg) was cerebroprotective when given both before reperfusion and up to 12 h after reperfusion and reduced the hemorrhagic risk. Similar effects occurred in female rats. Both research and clinical ApTOLL batches induced slightly superior cerebroprotection when compared with TAK-242. Finally, ApTOLL modulated circulating leukocyte levels, reached the brain ischemic tissue to bind resident and infiltrated cell types, and reduced the neutrophil density. These results show the cerebroprotective effects of ApTOLL in ischemic stroke by reducing the infarct/edema volume, neurofunctional impairment, and hemorrhagic risk, as well as the peripheral and local immune response. They provide information about ApTOLL dose effects and its therapeutic time window and target population, as well as its mode of action, which should be considered in the design of pivotal clinical trials.

15.
Br J Pharmacol ; 181(17): 3263-3281, 2024 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-38742374

RESUMO

BACKGROUND AND PURPOSE: ApTOLL is an aptamer selected to antagonize toll-like receptor 4 (TLR4), a relevant actor for innate immunity involved in inflammatory responses in multiple sclerosis (MS) and other diseases. The currently available therapeutic arsenal to treat MS is composed of immunomodulators but, to date, there are no (re)myelinating drugs available in clinics. In our present study, we studied the effect of ApTOLL on different animal models of MS. EXPERIMENTAL APPROACH: The experimental autoimmune encephalomyelitis (EAE) model was used to evaluate the effect of ApTOLL on reducing the inflammatory component. A more direct effect on oligodendroglia was studied with the cuprizone model and purified primary cultures of murine and human oligodendrocyte precursor cells (OPCs) isolated through magnetic-activated cell sorting (MACS) from samples of brain cortex. Also, we tested these effects in an ex vivo model of organotypic cultures demyelinated with lysolecithin (LPC). KEY RESULTS: ApTOLL treatment positively impacted the clinical symptomatology of mice in the EAE and cuprizone models, which was associated with better preservation plus restoration of myelin and oligodendrocytes in the demyelinated lesions of animals. Restoration was corroborated on purified cultures of rodent and human OPCs. CONCLUSION AND IMPLICATIONS: Our findings reveal a new therapeutic approach for the treatment of inflammatory and demyelinating diseases such as MS. The molecular nature of the aptamer exerts not only an anti-inflammatory effect but also neuroprotective and remyelinating effects. The excellent safety profile demonstrated by ApTOLL in animals and humans opens the door to future clinical trials in MS patients.


Assuntos
Aptâmeros de Nucleotídeos , Encefalomielite Autoimune Experimental , Camundongos Endogâmicos C57BL , Esclerose Múltipla , Animais , Humanos , Esclerose Múltipla/tratamento farmacológico , Encefalomielite Autoimune Experimental/tratamento farmacológico , Encefalomielite Autoimune Experimental/patologia , Encefalomielite Autoimune Experimental/imunologia , Camundongos , Aptâmeros de Nucleotídeos/farmacologia , Feminino , Cuprizona , Oligodendroglia/efeitos dos fármacos , Células Cultivadas , Receptor 4 Toll-Like/metabolismo , Receptor 4 Toll-Like/antagonistas & inibidores , Bainha de Mielina/efeitos dos fármacos , Bainha de Mielina/metabolismo
16.
Biochim Biophys Acta ; 1823(2): 430-8, 2012 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-22178387

RESUMO

Poor oxygenation (hypoxia) influences important physiological and pathological situations, including development, ischemia, stroke and cancer. Hypoxia induces protein synthesis inhibition that is primarily regulated at the level of initiation step. This regulation generally takes place at two stages, the phosphorylation of the subunit α of the eukaryotic initiation factor (eIF) 2 and the inhibition of the eIF4F complex availability by dephosphorylation of the inhibitory protein 4E-BP1 (eukaryotic initiation factor 4E-binding protein 1). The contribution of each of them is mainly dependent of the extent of the oxygen deprivation. We have evaluated the regulation of hypoxia-induced translation inhibition in nerve growth factor (NGF)-differentiated PC12 cells subjected to a low oxygen concentration (0.1%) at several times. Our findings indicate that protein synthesis inhibition occurs primarily by the disruption of eIF4F complex through 4E-BP1 dephosphorylation, which is produced by the inhibition of the mammalian target of rapamycin (mTOR) activity via the activation of REDD1 (regulated in development and DNA damage 1) protein in a hypoxia-inducible factor 1 (HIF1)-dependent manner, as well as the translocation of eIF4E to the nucleus. In addition, this mechanism is reinforced by the increase in 4E-BP1 levels, mainly at prolonged times of hypoxia.


Assuntos
Hipóxia Celular , Fator de Iniciação 4F em Eucariotos/metabolismo , Fator de Crescimento Neural/farmacologia , Neurônios/metabolismo , Biossíntese de Proteínas , Trifosfato de Adenosina/metabolismo , Animais , Proteínas de Transporte/metabolismo , Diferenciação Celular , Fator de Iniciação 4F em Eucariotos/genética , Peptídeos e Proteínas de Sinalização Intracelular , Neurônios/citologia , Células PC12 , Fosfoproteínas/metabolismo , Ratos
17.
Stroke ; 44(8): 2333-7, 2013 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-23723308

RESUMO

BACKGROUND AND PURPOSE: Sirtuin 1 (SIRT1) is a member of NAD+-dependent protein deacetylases implicated in a wide range of cellular functions and has beneficial properties in pathologies including ischemia/reperfusion processes and neurodegeneration. However, no direct evidence has been reported on the direct implication of SIRT1 in ischemic stroke. The aim of this study was to establish the role of SIRT1 in stroke using an experimental model in mice. METHODS: Wild-type and Sirt1-/- mice were subjected to permanent focal ischemia by permanent ligature. In another set of experiments, wild-type mice were treated intraperitoneally with vehicle, activator 3 (SIRT1 activator, 10 mg/kg), or sirtinol (SIRT1 inhibitor, 10 mg/kg) for 10 minutes, 24 hours, and 40 hours after ischemia. Brains were removed 48 hours after ischemia for determining the infarct volume. Neurological outcome was evaluated using the modified neurological severity score. RESULTS: Exposure to middle cerebral artery occlusion increased SIRT1 expression in neurons of the ipsilesional mouse brain cortex. Treatment of mice with activator 3 reduced infarct volume, whereas sirtinol increased ischemic injury. Sirt1-/- mice displayed larger infarct volumes after ischemia than their wild-type counterparts. In addition, SIRT1 inhibition/deletion was concomitant with increased acetylation of p53 and nuclear factor κB (p65). CONCLUSIONS: These results support the idea that SIRT1 plays an important role in neuroprotection against brain ischemia by deacetylation and subsequent inhibition of p53-induced and nuclear factor κB-induced inflammatory and apoptotic pathways.


Assuntos
Isquemia Encefálica/metabolismo , Encéfalo/metabolismo , Sirtuína 1/fisiologia , Sirtuínas/fisiologia , Acetilação , Alelos , Animais , Proteínas Reguladoras de Apoptose/fisiologia , Encéfalo/patologia , Isquemia Encefálica/patologia , Isquemia Encefálica/prevenção & controle , Infarto da Artéria Cerebral Média/complicações , Mediadores da Inflamação/antagonistas & inibidores , Mediadores da Inflamação/fisiologia , Camundongos , Camundongos Knockout , NF-kappa B/antagonistas & inibidores , NF-kappa B/fisiologia , Distribuição Aleatória , Transdução de Sinais/genética , Método Simples-Cego , Sirtuína 1/deficiência , Sirtuína 1/genética , Sirtuínas/administração & dosagem , Sirtuínas/antagonistas & inibidores , Proteína Supressora de Tumor p53/antagonistas & inibidores , Proteína Supressora de Tumor p53/biossíntese , Regulação para Cima/fisiologia
18.
J Neurochem ; 126(6): 819-26, 2013 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-23600725

RESUMO

CDP-choline has shown neuroprotective effects in cerebral ischemia. In humans, although a recent trial International Citicoline Trial on Acute Stroke (ICTUS) has shown that global recovery is similar in CDP-choline and placebo groups, CDP-choline was shown to be more beneficial in some patients, such as those with moderate stroke severity and not treated with t-PA. Several mechanisms have been proposed to explain the beneficial actions of CDP-choline. We have now studied the participation of Sirtuin1 (SIRT1) in the neuroprotective actions of CDP-choline. Fischer rats and Sirt1⁻/⁻ mice were subjected to permanent focal ischemia. CDP-choline (0.2 or 2 g/kg), sirtinol (a SIRT1 inhibitor; 10 mg/kg), and resveratrol (a SIRT1 activator; 2.5 mg/kg) were administered intraperitoneally. Brains were removed 24 and 48 h after ischemia for western blot analysis and infarct volume determination. Treatment with CDP-choline increased SIRT1 protein levels in brain concomitantly to neuroprotection. Treatment with sirtinol blocked the reduction in infarct volume caused by CDP-choline, whereas resveratrol elicited a strong synergistic neuroprotective effect with CDP-choline. CDP-choline failed to reduce infarct volume in Sirt1⁻/⁻ mice. Our present results demonstrate a robust effect of CDP-choline like SIRT1 activator by up-regulating its expression. Our findings suggest that therapeutic strategies to activate SIRT1 may be useful in the treatment of stroke. Sirtuin 1 (SIRT1) is implicated in a wide range of cellular functions. Regarding stroke, there is no direct evidence. We have demonstrated that citicoline increases SIRT1 protein levels in brain concomitantly to neuroprotection. Citicoline fails to reduce infarct volume in Sirt1⁻/⁻ mice. Our findings suggest that therapeutic strategies acting on SIRT1 may be useful in the treatment of stroke.


Assuntos
Citidina Difosfato Colina/farmacologia , Fármacos Neuroprotetores , Nootrópicos/farmacologia , Sirtuína 1/biossíntese , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/metabolismo , Animais , Anti-Inflamatórios não Esteroides/farmacologia , Benzamidas/farmacologia , Western Blotting , Isquemia Encefálica/tratamento farmacológico , Isquemia Encefálica/metabolismo , Células Cultivadas , Sinergismo Farmacológico , Infarto da Artéria Cerebral Média/patologia , Masculino , Camundongos , Camundongos Knockout , Monócitos/metabolismo , Naftóis/farmacologia , Neurônios/efeitos dos fármacos , Ratos , Ratos Endogâmicos F344 , Resveratrol , Sirtuína 1/antagonistas & inibidores , Estilbenos/farmacologia
19.
Foods ; 12(12)2023 Jun 08.
Artigo em Inglês | MEDLINE | ID: mdl-37372524

RESUMO

This pilot study explored the effectiveness of tailored informational interventions to reduce the surplus and waste of fruits and vegetables at the distribution level in Chile. Stalls from a fresh food market were randomized to intervention (n = 5 selling fruits, n = 5 selling vegetables) or control (n = 4 selling fruits, n = 4 selling vegetables) groups. The causes of surplus and waste were estimated by questionnaires. Surplus, avoidable waste, and unavoidable waste were measured using direct quantification before and after the intervention, and were expressed relative to the initial stock. Before the intervention, the surplus was (median [25th-75th percentile]) 46.2% [33.3-51.2] for fruits and 51.5% [41.3-55.0] for vegetables; avoidable waste was 0.1% [0.0-0.8] for fruits and 1.8% [0.7-5.3] for vegetables; and unavoidable waste was 0.0% [0.0-1.0] for fruits and 0.0% [0.0-1.3] for vegetables. Planning and storage represented the main causes explaining surplus and waste. After the intervention, the intervention group decreased the surplus of fruits compared to the control group (-17.8% [-29.0--11.0] vs. 5.8% [-0.6-7.8], respectively; p = 0.016), without other differences. In conclusion, tailored informational interventions based on the causes of surplus and waste may reduce the surplus of fruits in a fresh food market. Interventions might also include management strategies for the surplus to improve grocers' business operations.

20.
Front Cell Neurosci ; 17: 1219847, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37636586

RESUMO

Chronic cerebral hypoperfusion due to carotid artery stenosis is a major cause of vascular cognitive impairment and dementia (VCID). Bilateral carotid artery stenosis (BCAS) in rodents is a well-established model of VCID where most studies have focused on white matter pathology and subsequent cognitive deficit. Therefore, our aim was to study the implication of adult hippocampal neurogenesis in hypoperfusion-induced VCID in mice, and its relationship with cognitive hippocampal deficits. Mice were subjected to BCAS; 1 and 3 months later, hippocampal memory and neurogenesis/cell death were assessed, respectively, by the novel object location (NOL) and spontaneous alternation performance (SAP) tests and by immunohistology. Hypoperfusion was assessed by arterial spin labeling-magnetic resonance imaging (ASL-MRI). Hypoperfused mice displayed spatial memory deficits with decreased NOL recognition index. Along with the cognitive deficit, a reduced number of newborn neurons and their aberrant morphology indicated a remarkable impairment of the hippocampal neurogenesis. Both increased cell death in the subgranular zone (SGZ) and reduced neuroblast proliferation rate may account for newborn neurons number reduction. Our data demonstrate quantitative and qualitative impairment of adult hippocampal neurogenesis disturbances associated with cerebral hypoperfusion-cognitive deficits in mice. These findings pave the way for novel diagnostic and therapeutic targets for VCID.

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