RESUMO
This study aimed to investigate the protective effect of salvinorin A on the cerebral pial artery after forebrain ischemia and explore related mechanisms. Thirty Sprague-Dawley rats received forebrain ischemia for 10 min. The dilation responses of the cerebral pial artery to hypercapnia and hypotension were assessed in rats before and 1 h after ischemia. The ischemia reperfusion (IR) control group received DMSO (1 µL/kg) immediately after ischemia. Two different doses of salvinorin A (10 and 20 µg/kg) were administered following the onset of reperfusion. The 5th, 6th, and 7th groups received salvinorin A (20 µg/kg) and LY294002 (10 µM), L-NAME (10 μM), or norbinaltorphimine (norBIN, 1 μM) after ischemia. The levels of cGMP in the cerebrospinal fluid (CSF) were also measured. The phosphorylation of AKT (p-AKT) was measured in the cerebral cortex by western blot at 24 h post-ischemia. Cell necrosis and apoptosis were examined by hematoxylin-eosin staining (HE) and TUNEL staining, respectively. The motor function of the rats was evaluated at 1, 2, and 5 days post-ischemia. The dilation responses of the cerebral pial artery were significantly impaired after ischemia and were preserved by salvinorin A treatment. In addition, salvinorin A significantly increased the levels of cGMP and p-AKT, suppressed cell necrosis and apoptosis of the cerebral cortex and improved the motor function of the rats. These effects were abolished by LY294002, L-NAME, and norBIN. Salvinorin A preserved cerebral pial artery autoregulation in response to hypercapnia and hypotension via the PI3K/AKT/cGMP pathway.
Assuntos
Animais , Masculino , Ratos , Artérias Cerebrais/efeitos dos fármacos , Isquemia Encefálica/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Diterpenos Clerodânicos/farmacologia , Transdução de Sinais , Artérias Cerebrais/fisiopatologia , Isquemia Encefálica/tratamento farmacológico , Morfolinas/administração & dosagem , Cromonas/administração & dosagem , Ratos Sprague-Dawley , GMP Cíclico/líquido cefalorraquidiano , GMP Cíclico/metabolismo , NG-Nitroarginina Metil Éster , Diterpenos Clerodânicos/antagonistas & inibidores , Modelos Animais de Doenças , Naltrexona/administração & dosagem , Naltrexona/análogos & derivadosRESUMO
Development and selection of an ideal scaffold is of importance for tissue engineering. Poly(3-hydroxybutyrate-co-3-hydroxyhexanoate) (PHBHHx) is a biocompatible bioresorbable copolymer that belongs to the polyhydroxyalkanoate family. Because of its good biocompatibility, PHBHHx has been widely used as a cell scaffold for tissue engineering. This review focuses on the utilization of PHBHHx-based scaffolds in tissue engineering. Advances in the preparation, modification, and application of PHBHHx scaffolds are discussed.
Assuntos
Humanos , /química , Materiais Biocompatíveis/química , Caproatos/química , Engenharia Tecidual/métodos , Alicerces Teciduais/química , /uso terapêutico , Materiais Biocompatíveis/uso terapêutico , Osso e Ossos/fisiologia , Caproatos/uso terapêutico , Cartilagem/fisiologia , Liofilização , Músculo Liso/fisiologia , Regeneração , Propriedades de SuperfícieRESUMO
SRY-related high-mobility-group box 9 (Sox9) gene is a cartilage-specific transcription factor that plays essential roles in chondrocyte differentiation and cartilage formation. The aim of this study was to investigate the feasibility of genetic delivery of Sox9 to enhance chondrogenic differentiation of human umbilical cord blood-derived mesenchymal stem cells (hUC-MSCs). After they were isolated from human umbilical cord blood within 24 h after delivery of neonates, hUC-MSCs were untreated or transfected with a human Sox9-expressing plasmid or an empty vector. The cells were assessed for morphology and chondrogenic differentiation. The isolated cells with a fibroblast-like morphology in monolayer culture were positive for the MSC markers CD44, CD105, CD73, and CD90, but negative for the differentiation markers CD34, CD45, CD19, CD14, or major histocompatibility complex class II. Sox9 overexpression induced accumulation of sulfated proteoglycans, without altering the cellular morphology. Immunocytochemistry demonstrated that genetic delivery of Sox9 markedly enhanced the expression of aggrecan and type II collagen in hUC-MSCs compared with empty vector-transfected counterparts. Reverse transcription-polymerase chain reaction analysis further confirmed the elevation of aggrecan and type II collagen at the mRNA level in Sox9-transfected cells. Taken together, short-term Sox9 overexpression facilitates chondrogenesis of hUC-MSCs and may thus have potential implications in cartilage tissue engineering.
Assuntos
Humanos , Diferenciação Celular/genética , Condrogênese/genética , Sangue Fetal/citologia , Células-Tronco Mesenquimais/citologia , Fatores de Transcrição SOX9/genética , Agrecanas/biossíntese , Western Blotting , Cartilagem/metabolismo , Proliferação de Células/genética , Condrócitos/metabolismo , Colágeno Tipo II/biossíntese , Citometria de Fluxo , Proteínas de Fluorescência Verde , Regulação da Expressão Gênica/fisiologia , Células Endoteliais da Veia Umbilical Humana/citologia , Imuno-Histoquímica , Imunofenotipagem , Cultura Primária de Células , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Engenharia Tecidual , TransfecçãoRESUMO
Angiopoietin (Ang)-1 and Ang-2 interact in angiogenesis to activate the Tie-2 receptor, which may be involved in new vessel maturation and regression. Mast cells (MCs) are also involved in formation of new blood vessels and angiogenesis. The present study was designed to test whether MCs can mediate angiogenesis in myocardial microvascular endothelial cells (MMVECs). Using a rat MMVEC and MC co-culture system, we observed that Ang-1 protein levels were very low even though its mRNA levels were increased by MCs. Interestingly, MCs were able to enhance migration, proliferation, and capillary-like tube formation, which were associated with suppressed Ang-2 protein expression, but not Tie-2 expression levels. These MCs induced effects that could be reversed by either tryptase inhibitor [N-tosyl-L-lysine chloromethyl ketone (TLCK)] or chymase inhibitor (N-tosyl-L-phenylalanyl chloromethyl ketone), with TLCK showing greater effects. In conclusion, our data indicated that MCs can interrupt neovessel maturation via suppression of the Ang-2/Tie-2 signaling pathway.
RESUMO
Ischemic stroke (IS) is a multifactorial disorder, and genetic factors act as important contributors to its onset and progression. Inflammation is a key event that is closely associated with the pathophysiology of IS. The association of genetic polymorphisms of inflammatory cytokines with IS remains poorly understood. We investigated the relationship between the variable number of tandem repeats (VNTR) for IL-4, which is an important biomarker of inflammation, and the risk of IS. To assess the nature of the VNTR polymorphism in IL-4 and identify any links with IS, we recruited 200 subjects from a unique population that has 60% European and 40% East Asian ancestry. The subjects comprised 100 IS patients diagnosed using magnetic resonance imaging within 24 h of symptom onset and 100 age-, gender- and ethnicity-matched normal healthy controls. VNTR was identified using high-performance capillary electrophoresis with specially designed tailed primers. The IL-4 VNTR polymorphism was significantly associated with IS after adjustment for cardiovascular risk factors (OR = 0.571, 95%CI = 0.330-0.949, P < 0.05). Our data indicate that IL-4 VNTR polymorphism may affect susceptibility to IS in the Chinese Uyghur population. Moreover, total cholesterol, fasting blood glucose, waist-to-hip ratio, hypertension, history of heart diseases, and negative events may increase the risk of IS, with a trend for HDL to be a protective factor for IS in the Uyghur population.