RESUMO
BACKGROUND: Angiogenesis is essential for the repair process after intracerebral hemorrhage (ICH). METHODS: Given the importance of the extracellular matrix (ECM) in angiogenesis, we analysed the temporal profile of angiogenesis in rat brains on days 4, 7, and 21 after ICH. To this end, we compared the expression of ECM-related genes between ICH-induced and sham-operated groups using a complementary DNA (cDNA) array. We further measured protein expression using western blot and immunohistochemistry assays. Fluorescein isothiocyanate (FITC)-dextran was injected into the tail vein to examine the angioarchitecture in the perihematomal region. RESULTS: Among the 88 ECM-related genes, we identified 42, 50, and 38 genes that were significantly upregulated on days 4, 7, and 21 after ICH, respectively (P < 0.05). Particularly, collagens, integrins, and matrix metalloproteinases (MMPs) were significantly increased on day 4 post-ICH and continued to increase at the other time points. Western blot and immunohistochemistry analyses showed a comparable trend in the upregulation of MMPs. Compared to the sham group, FITC-dextran labelling demonstrated decreased perfusion and increased vascular permeability in the perihematomal region in the ICH group. Doxycycline, an MMP inhibitor, significantly reduced angiogenesis (P < 0.05). CONCLUSIONS: The results of this study indicate that MMPs are involved in modulating angiogenesis following ICH.
Assuntos
Hemorragia Cerebral , Metaloproteinases da Matriz , Animais , Encéfalo/irrigação sanguínea , Encéfalo/metabolismo , Hemorragia Cerebral/genética , Matriz Extracelular/metabolismo , Imuno-Histoquímica , Metaloproteinases da Matriz/genética , Metaloproteinases da Matriz/metabolismo , RatosRESUMO
Acute intermittent porphyria (AIP) is an autosomal, dominant, hereditary metabolic disease caused by an inherited deï¬ciency of hydroxymethylbilane synthase (HMBS), a crucial enzyme in the heme biosynthetic pathway. It can affect the central, peripheral, and autonomic nervous systems. We report a 23-year Chinese woman who presented with severe abdominal pain, convulsions, constipation, tachycardia, quadriparesis, and hyponatremia, accompanied by posterior reversible encephalopathy syndrome (PRES). The clinical diagnosis of AIP was made after positive urine Watson-Schwartz test for porphobilinogen (PBG). Genetic testing is important for AIP patients in confirming the diagnosis. We identiï¬ed a new insertion mutation in intron 14 [c.1005dupC (p.I336Hfs*23)] of the HMBS in her genomic DNA. Timely and accurate treatment of AIP may improve disease prognosis. Key Words: Acute intermittent porphyria, Mutation, Posterior reversible encephalopathy syndrome.
Assuntos
Porfiria Aguda Intermitente , Síndrome da Leucoencefalopatia Posterior , Humanos , Feminino , Porfiria Aguda Intermitente/complicações , Porfiria Aguda Intermitente/diagnóstico , Porfiria Aguda Intermitente/genética , Hidroximetilbilano Sintase/genética , Síndrome da Leucoencefalopatia Posterior/diagnóstico , Convulsões/diagnóstico , MutaçãoRESUMO
Many hypotheses exist regarding the mechanism underlying delayed encephalopathy after acute carbon monoxide poisoning (DEACMP), including the inflammation and immune-mediated damage hypothesis and the cellular apoptosis and direct neuronal toxicity hypothesis; however, no existing hypothesis provides a satisfactory explanation for the complex clinical processes observed in DEACMP. Leucine-rich repeat and immunoglobulin-like domain-containing protein-1 (LINGO-1) activates the Ras homolog gene family member A (RhoA)/Rho-associated coiled-coil containing protein kinase 2 (ROCK2) signaling pathway, which negatively regulates oligodendrocyte myelination, axonal growth, and neuronal survival, causing myelin damage and participating in the pathophysiological processes associated with many central nervous system diseases. However, whether LINGO-1 is involved in DEACMP remains unclear. A DEACMP model was established in rats by allowing them to inhale 1000 ppm carbon monoxide gas for 40 minutes, followed by 3000 ppm carbon monoxide gas for an additional 20 minutes. The results showed that compared with control rats, DEACMP rats showed significantly increased water maze latency and increased protein and mRNA expression levels of LINGO-1, RhoA, and ROCK2 in the brain. Compared with normal rats, significant increases in injured neurons in the hippocampus and myelin sheath damage in the lateral geniculate body were observed in DEACMP rats. From days 1 to 21 after DEACMP, the intraperitoneal injection of retinoic acid (10 mg/kg), which can inhibit LINGO-1 expression, was able to improve the above changes observed in the DEACMP model. Therefore, the overexpression of LINGO-1 appeared to increase following carbon monoxide poisoning, activating the RhoA/ROCK2 signaling pathway, which may be an important pathophysiological mechanism underlying DEACMP. This study was reviewed and approved by the Medical Ethics Committee of Xiangya Hospital of Central South Hospital (approval No. 201612684) on December 26, 2016.
RESUMO
Coronary heart disease (CHD) remains a major public health burden. Endothelial-dependent coronary artery vasoreactivity is a significant indicator of vascular function. Endothelial dysfunction is characterized by decreased nitric oxide (NO) bioavailability and predicts late cardiovascular events. Astragaloside IV (AGIV) is the main active component of the herb Astragalus membranaceus. Although it shows a significant protective effect against vascular endothelial dysfunction, the mechanisms of AGIV promoting the vascular dilation have not been elucidated. This study investigated the vasodilator effect of AGIV on rat aortic rings and the underlying effect of AGIV via the PI3K/Akt/eNOS signaling pathway. We measured the relaxation of isolated RARs after different concentrations of AGIV treatment. Rat aorta endothelial cells were cultured with different doses of AGIV, dimethylsulfoxide, and NG-nitro L-arginine methyl ester. The expression of phosphorylated (p)-Akt and -endothelial nitric oxide synthase (p-eNOS) were tested by Western blot analysis. The messenger (m)RNA expression of eNOS was quantified by real-time polymerase chain reaction. AGIV exerted a vasodilator effect on the aortic rings and increased the NO content in a concentration-dependent manner. The vasorelaxation was suppressed by an eNOS inhibitor. AGIV regulated the PI3K/Akt/eNOS signaling pathway via phosphorylation of Akt at Ser473 and dephosphorylation of eNOS at Thr495. The mRNA expression of eNOS was remarkably upregulated by AGIV. AGIV significantly induced the dilation of the aortic rings, leading to the vasodilator response by enhancing the eNOS release via the PI3K/Akt/eNOS signaling pathway.
Assuntos
Aorta/efeitos dos fármacos , Células Endoteliais/efeitos dos fármacos , Óxido Nítrico Sintase Tipo III/metabolismo , Fosfatidilinositol 3-Quinase/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Saponinas/farmacologia , Triterpenos/farmacologia , Vasodilatação/efeitos dos fármacos , Vasodilatadores/farmacologia , Animais , Aorta/enzimologia , Células Cultivadas , Relação Dose-Resposta a Droga , Células Endoteliais/enzimologia , Técnicas In Vitro , Masculino , Óxido Nítrico/metabolismo , Óxido Nítrico Sintase Tipo III/genética , Fosforilação , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacosRESUMO
OBJECTIVE Reactive astrogliosis, a key feature that is characterized by glial proliferation, has been observed in rat brains after intracerebral hemorrhage (ICH). However, the mechanisms that control reactive astrogliosis formation remain unknown. Notch-1 signaling plays a critical role in modulating reactive astrogliosis. The purpose of this paper was to establish whether Notch-1 signaling is involved in reactive astrogliosis after ICH. METHODS ICH was induced in adult male Sprague-Dawley rats via stereotactic injection of autologous blood into the right globus pallidus. N-[ N-(3,5-difluorophenacetyl)-l-alanyl]- S-phenylglycine t-butyl ester (DAPT) was injected into the lateral ventricle to block Notch-1 signaling. The rats' brains were perfused to identify proliferating cell nuclear antigen (PCNA)-positive/GFAP-positive nuclei. The expression of GFAP, Notch-1, and the activated form of Notch-1 (Notch intracellular domain [NICD]) and its ligand Jagged-1 was assessed using immunohistochemical and Western blot analyses, respectively. RESULTS Notch-1 signaling was upregulated and activated after ICH as confirmed by an increase in the expression of Notch-1 and NICD and its ligand Jagged-1. Remarkably, blockade of Notch-1 signaling with the specific inhibitor DAPT suppressed astrocytic proliferation and GFAP levels caused by ICH. In addition, DAPT improved neurological outcome after ICH. CONCLUSIONS Notch-1 signaling is a critical regulator of ICH-induced reactive astrogliosis, and its blockage may be a potential therapeutic strategy for hemorrhagic injury.
Assuntos
Astrócitos/fisiologia , Hemorragia Cerebral/fisiopatologia , Modelos Animais de Doenças , Gliose/fisiopatologia , Receptor Notch1/fisiologia , Transdução de Sinais/fisiologia , Animais , Astrócitos/efeitos dos fármacos , Astrócitos/patologia , Encéfalo/efeitos dos fármacos , Encéfalo/fisiopatologia , Proliferação de Células/efeitos dos fármacos , Proliferação de Células/fisiologia , Hemorragia Cerebral/patologia , Dipeptídeos/farmacologia , Proteína Glial Fibrilar Ácida/metabolismo , Gliose/patologia , Proteína Jagged-1/metabolismo , Masculino , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Regulação para Cima/efeitos dos fármacosRESUMO
OBJECTIVE: Hyperbaric oxygen (HBO) is widely used in treating various neurological diseases. However, HBO for treatment of intracerebral haemorrhage (ICH) remains controversial, in either animal or clinical studies. Therefore, we conducted this systematic review and meta-analysis on studies describing the efficacy of HBO in animal models of ICH. METHODS: Studies were identified by searching mainstream databases through November 2015. The efficacy of HBO in animal models of ICH was assessed by changes in the brain water content (BWC), neurobehavioural outcome (NO) or both. Subgroup analyses were performed according to different design characteristics. RESULTS: In total 15 studies met our inclusion criteria. HBO can reduce the BWC (-0.982, 95% CI, -1.148 to -0.817; P < 0.01; 57 comparisons), and improve NO (-0.767, 95% CI, -1.376 to -0.159; P < 0.01; eight comparisons). HBO was most effective in reducing BWC when given 72 h after ICH for a 4- to 5-day consecutive treatment at the chamber pressure of 3.0 atmosphere absolute. Efficacy was higher with phenobarbital anaesthesia, the blood infusion model and in rabbits. CONCLUSION: Although HBO was found to be effective in experimental ICH, additional confirmation is needed due to possible publication bias, poor study quality and the limited number of studies conducting clinical trials.
Assuntos
Hemorragia Cerebral/metabolismo , Hemorragia Cerebral/terapia , Modelos Animais de Doenças , Oxigenoterapia Hiperbárica/métodos , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Hemorragia Cerebral/patologia , HumanosRESUMO
Reactive astrogliosis has occurred after intracerebral hemorrhage (ICH). Leukemia inhibitory factor (LIF) can act as a modulator for glial gene expression. Signal transducer and activator of transcription 3 (STAT3) is a critical regulator of reactive astrogliosis. The present study tested whether endogenous LIF acted on ICH-induced reactive astrogliosis via the STAT3 signaling pathway. Rats were divided into three experimental groups: 1) Rats received either an ICH or a needle insertion (sham), 2) Rats received 100 ng LIF or an equal volume of phosphate-buffered saline (PBS) by direct infusion into the lateral ventricle (LV) after ICH, and 3) AG490 (0.25 mg/kg) was injected into the LV to block STAT3 signaling. Brains were perfused to identify proliferating cell nuclear antigen (PCNA)+/glial fibrillary acidic protein (GFAP)+nuclei. The expression of GFAP, LIF, LIF receptor (LIFR), glycoprotein 130 (gp130), and phospho-STAT3 (p-STAT3) was evaluated by immunohistochemistry and Western blot, respectively. After ICH, the number of the PCNA+/GFAP+ nuclei and the expression of GFAP, LIF, LIFR, gp130, and p-STAT3 were increased. Moreover, LIF increased the number of PCNA+/GFAP+ nuclei and the expression of GFAP, LIFR, gp130, and p-STAT3. The number of PCNA+/ GFAP+ nuclei and GFAP protein levels were attenuated markedly after inhibition of p-STAT3. Together, these data suggest that LIF contributes to ICH-related reactive astrogliosis via activation of STAT3 signaling.
Assuntos
Hemorragia Cerebral/metabolismo , Gliose/metabolismo , Fator Inibidor de Leucemia/metabolismo , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais , Animais , Modelos Animais de Doenças , Inibidores Enzimáticos/administração & dosagem , Inibidores Enzimáticos/farmacologia , Proteína Glial Fibrilar Ácida/metabolismo , Antígeno Nuclear de Célula em Proliferação/metabolismo , Ratos , Ratos Sprague-Dawley , Fator de Transcrição STAT3/antagonistas & inibidores , Transdução de Sinais/efeitos dos fármacos , Tirfostinas/administração & dosagem , Tirfostinas/farmacologiaRESUMO
OBJECTIVES: To evaluate the effectiveness and safety of Guipi Decoction (, GPD) as an adjunctive in the treatment of depression. METHODS: A review of all relevant studies retrieved from a search of the following databases were conducted without any language restriction: Excerpt Medica Database (EMBASE), PubMed, Cochrane Central Register of Controlled Trials, China National Knowledge Infrastructure (CNKI), VIP Information, Wanfang Data, and the Chinese Biomedical Literature Database. Papers published until February 2013 were taken into consideration. The analysis was performed using the Cochrane software Revman 5.1. RESULTS: Nine randomized controlled trials involving 620 patients with depression were included in this review. The meta-analysis revealed that compared with antidepressant therapy alone, treatment with a combination of GPD and an antidepressant drug signifificantly improved the symptoms of depression [weighted mean difference (WMD):-3.09; 95% confifidence interval (CI):-4.11 to-2.07] and increased the rates of effectiveness (OR: 4.75; 95% CI: 2.66-8.51) as well as recovery (OR: 1.73; 95% CI: 1.17-2.56). The adverse effects of GPD were not found to be signifificant in these studies. CONCLUSIONS: The fifindings of this meta-analysis were in keeping with the notion that GPD formulations were effective in the treatment of depression without causing any serious adverse effects. However, currently available evidence was of low quality and therefore inadequate to justify a strong recommendation of using GPD formulations in the management of depression.
Assuntos
Depressão/tratamento farmacológico , Medicamentos de Ervas Chinesas/uso terapêutico , Medicina Tradicional Chinesa , Ensaios Clínicos Controlados Aleatórios como Assunto , Antidepressivos/administração & dosagem , Antidepressivos/efeitos adversos , Antidepressivos/uso terapêutico , Medicamentos de Ervas Chinesas/administração & dosagem , Medicamentos de Ervas Chinesas/efeitos adversos , Humanos , Medicina Tradicional Chinesa/efeitos adversos , Viés de Publicação , Resultado do TratamentoRESUMO
Intracerebral hemorrhage (ICH) is a subtype of stroke associated with high morbidity and mortality rates. No proven treatments are available for this condition. Iron-mediated free radical injury is associated with secondary damage following ICH. Deferoxamine (DFX), a ferric-iron chelator, is a candidate drug for the treatment of ICH. We performed a systematic review of studies involving the administration of DFX following ICH. In total, 20 studies were identified that described the efficacy of DFX in animal models of ICH and assessed changes in the brain water content, neurobehavioral score, or both. DFX reduced the brain water content by 85.7% in animal models of ICH (-0.86, 95% CI: -.48- -0.23; P < 0.01; 23 comparisons), and improved the neurobehavioral score by -1.08 (95% CI: -1.23- -0.92; P < 0.01; 62 comparisons). DFX was most efficacious when administered 2-4 h after ICH at a dose of 10-50 mg/kg depending on species, and this beneficial effect remained for up to 24 h postinjury. The efficacy was higher with phenobarbital anesthesia, intramuscular injection, and lysed erythrocyte infusion, and in Fischer 344 rats or aged animals. Overall, although DFX was found to be effective in experimental ICH, additional confirmation is needed due to possible publication bias, poor study quality, and the limited number of studies conducting clinical trials.
Assuntos
Hemorragia Cerebral/tratamento farmacológico , Desferroxamina/uso terapêutico , Sideróforos/uso terapêutico , Animais , Modelos Animais de Doenças , Camundongos , Ratos , Suínos , Resultado do TratamentoRESUMO
BACKGROUND: Intracerebral hemorrhage (ICH) is a fatal subtype of stroke that lacks effective treatments. Angiogenesis following ICH is an important response mediating brain recovery and repair. Phosphorylation of vascular endothelial growth factor receptor 2 (pVEGFR2) via PI3K/Akt signaling plays a key role in mediating cellular processes involved in repair, such as mitogenesis, angiogenesis, and vascular permeability. This study aimed to investigate the potential effects of Buyang Huanwu Decoction (BYHWD), a traditional Chinese medicine formula, on angiogenesis by VEGFR2 activation through the phosphatidylinositol 3 kinase (PI3K)/Akt signaling pathway in a mouse model of ICH. METHODS: Adult male Kunming mice (n = 50) were randomly assigned into sham and ICH-operated groups and treated with one of the followings SU5416 (VEGFR2 inhibitor), BYHWT and BYHWT + SU5416. ICH was induced in mice by injecting collagenase (type VII) into the right globus pallidus of the mouse brain. BYHWD (4.36 g/kg) was administrated in mice by intragastric infusion. Neurological function was evaluated in mice by a modified Neurological Severity Scores (mNSS) as well as corner turn and foot-fault tests. Angiogenesis was examined by intraperitoneal injection of 5-bromodeoxyuridine (BrdU) in mice to quantify new brain vessel growth. SU5416 treatment and assessment of VEGFR2 phosphorylation as well as alterations in PI3K/Akt signaling were performed to determine whether the effect of BYHWD on angiogenesis was partly mediated by phosphorylation of VEGFR2 via the PI3K/Akt signaling pathway. RESULTS: We show that BYHWD treated mice exhibited (i) significantly better recovery from neurological dysfunction, (ii) increased BrdU(+) nuclei in vWF(+) dilated brain vessels and (iii) higher VEGFR2 phosphorylation immunoreactivity in brain microvessels (P <0.05), (iv) higher expression of PI3K and pAkt at the protein level (P <0.05) when compared to untreated ICH mice. These beneficial effects were reversed by SU5416 (P <0.05). CONCLUSIONS: BYHWD promoted neurological recovery and angiogenesis after ICH in mice by enhancing VEGFR2 phosphorylation through the PI3K/Akt signaling pathway.
Assuntos
Encéfalo/efeitos dos fármacos , Hemorragia Cerebral/tratamento farmacológico , Medicamentos de Ervas Chinesas/uso terapêutico , Neovascularização Fisiológica/efeitos dos fármacos , Fosfatidilinositol 3-Quinase/metabolismo , Fitoterapia , Receptor 2 de Fatores de Crescimento do Endotélio Vascular/metabolismo , Animais , Astrágalo , Encéfalo/irrigação sanguínea , Proliferação de Células , Hemorragia Cerebral/metabolismo , Modelos Animais de Doenças , Medicamentos de Ervas Chinesas/farmacologia , Masculino , Camundongos , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação , Transdução de Sinais/efeitos dos fármacos , Acidente Vascular Cerebral/tratamento farmacológico , Acidente Vascular Cerebral/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
The aim of this study was to examine the central neurophysiological mechanisms during fatigue induced by submaximal isometric contractions. A total of 23 individuals participated in the study and were assigned to fatigue and nonfatigue groups. Handgrip force, root mean square (RMS) of surface electromyography (sEMG) signal and movement-related cortical potentials during self-paced submaximal handgrip isometric contractions were assessed for each participant. The experimental data showed significant decreases in both maximal voluntary contraction [-24.3%; F(3, 42)=19.62, P<0.001, ηp=0.48] and RMS [-30.1%; F(3, 42)=19.01, P<0.001, ηp=0.57] during maximal voluntary contractions and a significant increase [F(3, 42)=14.27, P<0.001, ηp=0.50] in the average RMS of sEMG over four blocks in the fatigue group. There was no significant difference in the readiness potential between the fatigue and the nonfatigue groups at early stages, and at late stages, significant differences were observed only at the Fp1 and FC1 sites. Motor potential amplitudes were significantly higher in the fatigue group than in the nonfatigue group irrespective of block or electrode positions. Positive waveforms were observed in the prefrontal cortex in states without muscle fatigue, whereas a negative waveform pattern was observed with muscle fatigue. Significant within-subject correlations were observed between motor potential at the C1 site and RMS of sEMG (r=-0.439, P=0.02, ηp=0.11). Neurophysiological evidence indicates that cortical activity increases in the prefrontal cortex, primary motor cortex and supplementary motor cortex with muscle fatigue. Muscle fatigue appears to have considerable effects on the components of movement-related cortical potentials during movement execution, whereas the readiness potential before movement is sensitive to cognitive demands during prolonged exercise. Our results provide additional evidence for a link between central motor command during movement execution and motor unit recruitment.
Assuntos
Braço/fisiologia , Encéfalo/fisiologia , Contração Isométrica/fisiologia , Movimento/fisiologia , Fadiga Muscular/fisiologia , Eletromiografia , Potencial Evocado Motor , Força da Mão/fisiologia , Humanos , Músculo Esquelético/fisiologia , Adulto JovemRESUMO
Healthy SD rats were randomly divided into 3 groups as sham operation (group A), ICH (group B), and HBO2 (group C). The behavioral change and angiogenesis in brain tissue of rats in each group were observed. The protein expression of PCNA, vWF, HIF1-α, and VEGF in rat brain was measured by immunohistochemistry, while the mRNA expression level of HIF1-α and VEGF was determined using quantitative real-time PCR. This study has investigated the effect of HBO2 on intracephalic angiogenesis in rats with intracerebral hemorrhage (ICH). There were significant differences in behavior score between HBO2 and ICH groups at 14, 21, and 28 days. A large number of vessel-like structures and microvessels were observed in perihematomal brain tissues in HBO2 group. There were significant differences in HIF1-α and VEGF protein and HIF1-α mRNA level between HBO2 and ICH groups at 14, 21, and 28 days; at 7, 14, 21, and 28 days, the differences in PCNA and vWF protein expression between the 2 groups were statistically significant. At 21 and 28 days, the expression levels of VEGF mRNA in the 2 groups differed significantly from each other. Our results indicate that HBO2 can significantly promote the expression of HIF1-α and VEGF at both mRNA and protein levels in rats with ICH, increase the protein expression of both PCNA and vWF, promote the formation of new blood vessels, and promote the recovery of behavioral ability, hence resulting in a rapid rehabilitation.
Assuntos
Hemorragia Cerebral/fisiopatologia , Hemorragia Cerebral/terapia , Oxigenoterapia Hiperbárica , Neovascularização Fisiológica/fisiologia , Animais , Encéfalo/irrigação sanguínea , Encéfalo/metabolismo , Encéfalo/fisiologia , Expressão Gênica/fisiologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/biossíntese , Antígeno Nuclear de Célula em Proliferação/biossíntese , Ratos , Recuperação de Função Fisiológica/fisiologia , Fatores de Tempo , Fator A de Crescimento do Endotélio Vascular/biossíntese , Fator de von Willebrand/biossínteseRESUMO
Based on the pathophysiology of the brain, advance in angiogenesis induced by stroke, and evidences of Chinese-medicine-mediated angiogenesis, the possibility to study the stroke-treating mechanism of Chinese medicine in angiogenesis was discussed. And regarding our previous work on angiogenesis modulated by qi-tonifying and stasis-eliminating therapy following intracerebral hemorrhage, we proposed some questions, which should be taken into account in the further work.
Assuntos
Medicina Tradicional Chinesa , Neovascularização Fisiológica , Acidente Vascular Cerebral/terapia , Encéfalo/irrigação sanguínea , Encéfalo/patologia , Humanos , Microvasos/patologia , CicatrizaçãoRESUMO
Spontaneous intracerebral hemorrhage (ICH) is one of the most severe types of stroke. Thrombin has been reported to participate in brain repair following ICH and play an important role in angiogenesis. Our previous studies have shown that ICH induces angiogenesis in damaged rat brain, accompanied by upregulation of expression of thrombospondin (TSP)-1 and TSP-2. The aim of the present study was to investigate whether the expression of TSP-1 and TSP-2 was regulated by thrombin in rat brain following ICH. A rat model of ICH was induced by injection of autologous blood into the right globus pallidus (GP). Hirudin, a thrombin specific inhibitor, or thrombin was injected into the GP. Immunohistochemistry, quantitative real-time reverse-transcription polymerase chain reaction (RT-PCR) and western blot assays were applied. Results showed that ICH induced an increase in the expression of TSP-1 mRNA and TSP-2 mRNA after ICH, whereas hirudin significantly inhibited the expression of TSPs mRNA after ICH (P<0.05). In contrast, sole thrombin treatment in normal rats induced strong expression of TSP-1 or TSP-2 in the blood vessels around the damaged brain region when compared with those without thrombin treatment. Western blot analysis data confirmed that the protein levels of TSPs were significantly increased when compared with those in the sham control group (P<0.01). These findings support that thrombin positively regulates the expression of TSP-1 and TSP-2 after ICH, which may be involved in modulating angiogenesis in injured brains following ICH.
Assuntos
Hemorragia Cerebral/genética , Regulação da Expressão Gênica/efeitos dos fármacos , RNA Mensageiro/biossíntese , Trombina/fisiologia , Trombospondina 1/biossíntese , Trombospondinas/biossíntese , Regulação para Cima/efeitos dos fármacos , Animais , Antitrombinas/farmacologia , Vasos Sanguíneos/metabolismo , Hemorragia Cerebral/tratamento farmacológico , Hemorragia Cerebral/metabolismo , Hirudinas/farmacologia , Masculino , Neovascularização Fisiológica , RNA Mensageiro/genética , Distribuição Aleatória , Ratos , Ratos Sprague-Dawley , Reação em Cadeia da Polimerase em Tempo Real , Trombina/farmacologia , Trombina/uso terapêutico , Trombospondina 1/genética , Trombospondinas/genéticaRESUMO
OBJECT: Angiogenesis occurs after intracerebral hemorrhage (ICH). Thrombin mediates mitogenesis and survival in endothelial cells and induces angiogenesis. The present study aimed to clarify whether thrombin is involved in triggering ICH-related angiogenesis. METHODS: In the first part of the experiment, autologous blood (with or without hirudin) was injected to induce ICH. In the second part, rats received either 1 U (50 µl) thrombin or 50 µl 0.9% sterile saline. In both parts, 5-bromo-2-deoxyuridine (BrdU) was administered intraperitoneally. Brains were perfused to identify BrdU-positive/von Willebrand factor (vWF)-positive nuclei. The expression of hypoxia-inducible factor-1α (HIF-1α), vascular endothelial growth factor (VEGF), angiopoietin-1 (Ang-1) and Ang-2 was evaluated by immunohistochemistry and quantitative real-time reverse transcription polymerase chain reaction. RESULTS: After ICH, the number of BrdU-/vWF-positive nuclei increased until Day 14, and vessels positive for HIF-1α, VEGF, Ang-1, and Ang-2 were observed around the clot. Quantitative analysis showed that ICH upregulated expression of HIF-1α, VEGF, Ang-1, and Ang-2 notably compared with that in sham controls (p < 0.05). However, hirudin significantly inhibited these effects. After thrombin treatment, many BrdU-positive/vWF-positive nuclei and HIF-1α-, VEGF-, Ang-1- and Ang-2-positive vessels could be detected around the affected region. CONCLUSIONS: Thrombin can induce angiogenesis in rat brains and may be an important trigger for ICH-related angiogenesis.