RESUMO
Diabetic peripheral neuropathy (DPN) is a chronic complication associated with nerve dysfunction and uncontrolled hyperglycemia. Unfortunately, due to its complicated etiology, there has been no successful therapy for DPN. Our research recently revealed that jatrorrhizine (JAT), one of the active constituents of Rhizoma Coptidis, remarkably ameliorated DPN. This work highlighted the potential mechanism through which JAT relieves DPN using db/db mice. The results indicated that JAT treatment significantly decreased the threshold for thermal and mechanical stimuli and increased nerve conduction velocity. Histopathological analysis revealed that JAT significantly increased the number of sciatic nerve fibers and axons, myelin thickness, and axonal diameters. Additionally, JAT markedly elevated the expression of myelination-associated proteins (MBP, MPZ, and Pmp22). The screening of histone deacetylases (HDAC) determined that histone deacetylase 3 (HDAC3) is an excellent target for JAT-induced myelination enhancement. Liquid chromatography-mass spectrometry-(MS)/MS and coimmunoprecipitation analyses further confirmed that HDAC3 antagonizes the NRG1-ErbB2-PI3K-AKT signaling axis by interacting with Atxn2l to augment SCs myelination. Thus, JAT ameliorates SCs myelination in DPN mice via inhibiting the recruitment of Atxn2l by HDAC3 to regulate the NRG1-ErbB2-PI3K-AKT pathway.
Assuntos
Diabetes Mellitus , Neuropatias Diabéticas , Camundongos , Animais , Proteínas Proto-Oncogênicas c-akt/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Neuropatias Diabéticas/tratamento farmacológico , Células de Schwann , Histona Desacetilases/metabolismo , Nervo Isquiático , Diabetes Mellitus/patologia , Neuregulina-1/metabolismoRESUMO
Shi-Zhen-An-Shen decoction (SZASD), a Chinese herbal medicine that is a liquor extracted from plants by boiling, has been reported to be effective in treating schizophrenia. However, the mechanism is unclear. Abnormal demyelination has been implicated in schizophrenia. The aim of this study was to investigate the effect of SZASD on myelin in demyelinated mice exhibiting schizophrenia-like behaviors. Sixty male C57BL/6 mice were randomly divided into six groups (n = 10 per group): (1) control group, (2) cuprizone (CPZ, a copper chelator that induced demyelination, 0.2% w/w)+saline, (3) CPZ+low-dose SZASD (8.65 g·kg-1·d-1), (4) CPZ+medium-dose SZASD (17.29 g·kg-1·d-1), (5) CPZ+high-dose SZASD (25.94 g·kg-1·d-1), and (6) CPZ+quetiapine (QTP, an atypical antipsychotic that served as a positive treatment control, 10 mg·kg-1·d-1). Mice in groups 2-6 were treated with CPZ added to rodent chow for six weeks to induce demyelination. During the last two weeks, these mice were given an oral gavage of sterile saline, SZASD, or quetiapine. Behavioral tests and brain analyses were conducted after the last treatment. The brain expression of myelin basic protein (MBP) and neuregulin-1 (NRG-1) was assessed using immunohistochemistry and Western blots. CPZ induced significant schizophrenia-like behaviors in the mice, including reduced nest-building activity and sensory gating deficits. Hyperlocomotor activity was accompanied by significant reductions in MBP expression in the corpus callosum, hippocampus, and cerebral cortex. However, both QTP and SZASD significantly reversed the schizophrenia-like behaviors and demyelination in CPZ-fed mice. The QTP and medium-dose SZASD resulted in better therapeutic effects compared to the low and high SZASD doses. Reduced NRG-1 expression was observed in CPZ-fed mice compared with controls, but neither QTP nor SZASD showed significant influence on NRG-1 expression in the hippocampus. Together, SZASD showed a therapeutic effect on demyelinated mice, and the improvement of demyelination might not be through the NRG-1 pathway.
Assuntos
Antipsicóticos/farmacologia , Encéfalo/efeitos dos fármacos , Cuprizona/farmacologia , Medicina Herbária , Neuregulina-1/metabolismo , Animais , Astrócitos/efeitos dos fármacos , Comportamento Animal/efeitos dos fármacos , Doenças Desmielinizantes/induzido quimicamente , Doenças Desmielinizantes/tratamento farmacológico , Modelos Animais de Doenças , Masculino , Camundongos , Microglia/efeitos dos fármacos , Neuregulina-1/efeitos dos fármacosRESUMO
BACKGROUND: Patients suffering from schizophrenic psychosis show reduced synaptic connectivity compared to healthy individuals. Furthermore, the use of cannabis often precedes the onset of schizophrenic psychosis. Therefore, we investigated whether consumption of cannabis has an impact on the methylation pattern of schizophrenia candidate genes concerned with the development and preservation of synapses and synaptic function. METHODS: Fifty blood samples of outpatients affected by treatment-resistant schizophrenic psychosis were collected in the outpatient department of Ch Ste Anne/INSERM (Paris, France). Extracted DNA was sent to the LMN/MHH (Hanover, Germany) where DNA samples were bisulfite converted. The methylation patterns of the promoter region of neuregulin 1 (NRG1), neurexin (NRXN1), disrupted in schizophrenia 1 (DISC1), and microtubule-associated-protein tau (MAPT) were then analysed by sequencing according to Sanger. RESULTS: In NRXN1 the group of non-consumer patients showed a methylation rate slightly lower than controls. In patients with preliminary use of tetrahydrocannabinol (THC) the NRXN1 promoter turned out to be methylated almost two times higher than in non-consumer patients. In MAPT, non-consumer patients showed a significant lower mean methylation rate in comparison to controls. In THC-consuming patients the difference compared with controls became less. NRG1 and DISC1 showed no significant differences between groups, whereas DISC1 appeared to be not methylated at all. CONCLUSION: In MAPT and NRXN1 mean methylation rates were lower in non-consumer patients compared with controls, which seems to be a compensatory mechanism. With consumption of THC, mean methylation rates were increased: in the case of MAPT compared with controls, and in NRXN1 even significantly beyond that. Methylation of NRG1 and DISC1 seems not to be affected by the psychiatric disorder or by consumption of THC.
Assuntos
Agonistas de Receptores de Canabinoides/farmacologia , Metilação de DNA/efeitos dos fármacos , Dronabinol/farmacologia , Regiões Promotoras Genéticas/efeitos dos fármacos , Esquizofrenia/sangue , Adulto , Proteínas de Ligação ao Cálcio/metabolismo , Feminino , Humanos , Masculino , Proteínas do Tecido Nervoso/metabolismo , Moléculas de Adesão de Célula Nervosa/metabolismo , Neuregulina-1/metabolismo , Proteínas tau/metabolismoRESUMO
Jinmaitong (JMT), a compound prescription of traditional Chinese medicine, has long been used as a therapy for diabetic peripheral neuropathy (DPN). However, the neuroprotective mechanisms of JMT and its effect on gut microbiota remained unknown. Here, we examined the effects of JMT on behavior, pathomorphology and gut microbiota in streptozotocin (STZ)-induced DPN rats. Compared to distilled water administration, JMT reversed decreases in mechanical withdraw threshold and intraepidermal nerve fiber density, improved neurological morphology of sciatic nerves, increased serum neuregulin 1 (NRG1) level and contactin-associated protein (Caspr)-positive paranodes, and decreased amyloid precursor protein (APP) accumulation in DPN rats. More importantly, JMT enriched nine species of the gut microbiota of DPN rats, helping to prevent dysbiosis. Among these species, p_Actinobacteria, p_Proteobacteria and c_Actinobacteria were negatively correlated with DPN phenotypes and positively correlated with serum NRG1 level. These results indicate that JMT may exert a neuroprotective effect by modulating phenotype-associated gut microbiota and increasing serum NRG1 level in STZ-induced DPN rats. JMT may therefore be an effective complementary and alternative anti-DPN therapy.
Assuntos
Neuropatias Diabéticas , Medicamentos de Ervas Chinesas/farmacologia , Microbioma Gastrointestinal/efeitos dos fármacos , Neuregulina-1/metabolismo , Animais , Diabetes Mellitus Experimental , Neuropatias Diabéticas/metabolismo , Neuropatias Diabéticas/patologia , Ratos , Nervo Isquiático/efeitos dos fármacos , Nervo Isquiático/patologia , EstreptozocinaRESUMO
Cerebral hypoperfusion is a common feature of cerebral small vascular disease (CSVD), which has been considered as one of the causes of cognitive decline in recent years. Epimedium flavonoids (EF) are the main ingredients extracted from Epimedium. The purpose of this study was to investigate the effects of EF on cognitive impairment, and the underlying mechanisms in rats with permanent occlusion of the bilateral common carotid artery (2VO). EF (50, 100, and 200 mg/kg) was intragastrically administered for 12 weeks starting 2 weeks after 2VO surgery. The results showed that EF treatment improved learning and memory impairment in 2VO rats evaluated by novel object recognition and Y-maze tests. NeuN immunohistochemical staining indicated that EF alleviated neuronal loss in the hippocampus and cerebral cortex of 2VO rats. MAP-2 immunofluorescence staining and western blotting showed that EF protected neuronal dendrites and increased the expression of cytoskeleton proteins MAP-2 and NF200 in the hippocampus of 2VO rats. Moreover, EF protected the synapse ultrastructure detected by transmission electron microscopy, and increased the expression of synaptic plasticity-related proteins, including synaptophysin, synaptotagmin-I, synapsin I, PSD-95, p-NMDA2B, and p-CaMKII-α in the hippocampus of 2VO rats. In addition, EF increased the expression of neuregulin-1 (NRG-1), p-ErbB4, brain-derived neurotrophic factor (BDNF), p-Fyn, PI3K, p-Akt, and p-CREB in the hippocampus of 2VO rats. These results suggest that EF may protect neurons and synapses by activating the NRG1/ErbB4, BDNF/Fyn, and P13 K/Akt/CREB pathways in the hippocampus and cerebral cortex, thus improving cognitive impairment induced by chronic cerebral hypoperfusion. EF may be a potential candidate drug for chronic cerebral hypoperfusion and CSVD therapy.
Assuntos
Fator Neurotrófico Derivado do Encéfalo/metabolismo , Doenças de Pequenos Vasos Cerebrais/metabolismo , Epimedium , Flavonoides/uso terapêutico , Neuregulina-1/metabolismo , Proteínas Proto-Oncogênicas c-fyn/metabolismo , Receptor ErbB-4/metabolismo , Animais , Encéfalo/efeitos dos fármacos , Encéfalo/metabolismo , Doenças de Pequenos Vasos Cerebrais/tratamento farmacológico , Circulação Cerebrovascular/efeitos dos fármacos , Circulação Cerebrovascular/fisiologia , Relação Dose-Resposta a Droga , Flavonoides/farmacologia , Masculino , Neurônios/efeitos dos fármacos , Neurônios/metabolismo , Fármacos Neuroprotetores/farmacologia , Fármacos Neuroprotetores/uso terapêutico , Extratos Vegetais/farmacologia , Extratos Vegetais/uso terapêutico , Ratos , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia , Sinapses/efeitos dos fármacos , Sinapses/metabolismoRESUMO
Chronic cerebral hypoperfusion is a common cause of cerebral small vascular disease (CSVD). White matter (WM) lesions are the typical pathological manifestation of CSVD and contribute to cognitive decline. Epimedium flavonoids (EF) are the main component in Epimedium brevicornu Maxim., which is commonly used in traditional Chinese medicine. The purpose of this study was to investigate the effects of EF on cognitive impairment and the underlying mechanisms in a CSVD rat model induced with chronic cerebral hypoperfusion. The model was established by permanent bilateral common carotid artery occlusion (2VO) in rats. EF (50, 100, and 200 mg/kg) was intragastrically administered once a day for 12 weeks starting 2 weeks after 2VO surgery. The learning and memory capacity of the rats were measured using the Morris water maze and step-through tests. WM lesions were observed by MRI-diffusion tensor imaging, transmission electron microscopy, and LFB staining. Oligodendrocytes were detected by immunohistochemistry. Western blotting assay was used to determine the level of protein expression. The results showed that EF significantly improved learning and memory impairment, alleviated WM nerve fiber injuries and demyelination, and increased the number of mature oligodendrocytes in the corpus callosum, subcortical WM, and periventricular WM in 2VO rats. Mechanistically, EF reduced the expression of Lingo-1 and ROCK2 and increased the levels of phosphorylated (p-) Fyn, brain-derived neurotrophic factor (BDNF), TrkB, neuregulin-1 (NRG-1), p-ErbB4, PI3K p85 and p110α, p-Akt, and p-CREB in the corpus callosum of 2VO rats. These results suggest that EF may improve cognitive impairment and WM lesions induced by chronic cerebral hypoperfusion through inhibiting the Lingo-1/Fyn/ROCK pathway and activating the BDNF/TrkB, NRG-1/ErbB4, and the downstream PI3K/Akt/CREB pathways in WM. Thus, EF can be used as a potential neuroprotective agent in CSVD therapy.
Assuntos
Encéfalo/efeitos dos fármacos , Doenças de Pequenos Vasos Cerebrais/patologia , Disfunção Cognitiva/etiologia , Medicamentos de Ervas Chinesas/farmacologia , Transdução de Sinais/efeitos dos fármacos , Substância Branca/efeitos dos fármacos , Animais , Encéfalo/metabolismo , Encéfalo/patologia , Fator Neurotrófico Derivado do Encéfalo/metabolismo , Doenças de Pequenos Vasos Cerebrais/complicações , Doenças de Pequenos Vasos Cerebrais/metabolismo , Disfunção Cognitiva/metabolismo , Disfunção Cognitiva/patologia , Epimedium , Flavonoides/farmacologia , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Proteínas de Membrana/metabolismo , Proteínas do Tecido Nervoso/metabolismo , Neuregulina-1/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-fyn/metabolismo , Ratos , Ratos Sprague-Dawley , Substância Branca/patologia , Quinases Associadas a rho/metabolismoRESUMO
Resistance to cancer therapy is a challenge because of innate tumor heterogeneity and constant tumor evolution. Since the pathway of resistance cannot be predicted, combination therapies may address this progression. We discovered that in addition to IGF1 and IGF2, IGFBP-3 binds bFGF, HGF, neuregulin, and PDGF AB with nanomolar affinity. Because growth factors drive resistance, simultaneous inhibition of multiple growth factor pathways may improve the efficacy of precision therapy. Growth factor sequestration by IGFBP-3-Fc enhances the activity of EGFR inhibitors by decreasing cell survival and inhibiting bFGF, HGF, and IGF1 growth factor rescue and also potentiates the activity of other cancer drugs. Inhibition of tumor growth in vivo with adjuvant IGFBP-3-Fc with erlotinib versus erlotinib after treatment cessation supports that the combination reduces cell survival. Inhibition of multiple growth factor pathways may postpone resistance and extend progression-free survival in many cancer indications.
Assuntos
Receptores ErbB/genética , Cloridrato de Erlotinib/farmacologia , Regulação Neoplásica da Expressão Gênica , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/genética , Neoplasias Pulmonares/tratamento farmacológico , Inibidores de Proteínas Quinases/farmacologia , Carga Tumoral/efeitos dos fármacos , Animais , Antineoplásicos/farmacologia , Linhagem Celular Tumoral , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Resistencia a Medicamentos Antineoplásicos/genética , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/metabolismo , Fatores de Crescimento de Fibroblastos/genética , Fatores de Crescimento de Fibroblastos/metabolismo , Células HEK293 , Células HT29 , Fator de Crescimento de Hepatócito/genética , Fator de Crescimento de Hepatócito/metabolismo , Humanos , Fragmentos Fc das Imunoglobulinas/farmacologia , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/antagonistas & inibidores , Proteína 3 de Ligação a Fator de Crescimento Semelhante à Insulina/metabolismo , Fator de Crescimento Insulin-Like I/genética , Fator de Crescimento Insulin-Like I/metabolismo , Fator de Crescimento Insulin-Like II/genética , Fator de Crescimento Insulin-Like II/metabolismo , Neoplasias Pulmonares/genética , Neoplasias Pulmonares/metabolismo , Neoplasias Pulmonares/patologia , Células MCF-7 , Masculino , Camundongos , Camundongos Endogâmicos NOD , Neuregulina-1/genética , Neuregulina-1/metabolismo , Fator de Crescimento Derivado de Plaquetas/genética , Fator de Crescimento Derivado de Plaquetas/metabolismo , Transdução de Sinais , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
HER2 overexpression is frequently associated with tumor metastasis and poor prognosis of breast cancer. More evidence indicates that HER3 is involved in HER2-resistant therapies. Combination treatments with two or more different monoclonal antibodies are a promising strategy to overcome resistance to HER2 therapies. We presented a novel fully human HER2-targeted monoclonal antibody, GB235, screened from a phage-display library against the HER2 antigen. GB235 in combination with Trastuzumab overcomes resistance in HER2-positive tumors and results in more sustained inhibition of tumor growth over time. The competition binding assay showed that the epitopes of GB235 do not overlap with those of Pertuzumab and Trastuzumab on HER2. Further HER2 mutagenesis results revealed that the binding epitopes of GB235 were located in the domain III of HER2. The mechanism of action of GB235 in blocking HER2-driven tumors is different from the mechanisms of Trastuzumab or Pertuzumab. GB235 does not affect the heterodimerization of HER2 and HER3, whereas the GB235 combined treatment with Trastuzumab significantly inhibited heregulin-induced HER3 phosphorylation and downstream signaling. Moreover, GB235 in combination with Trastuzumab reversed the resistance to heregulin-induced proliferation in HER2-overexpressing cancer cell lines. GB235 combined with Trastuzumab treatment in xenograft models resulted in improved antitumor activity. Complete tumor suppression was observed in the HER2-positive NCI-N87 xenograft model treated with the combination treatment with GB235 and Trastuzumab. In a Trastuzumab-resistant patient-derived tumor xenograft model GA0060, GB235 plus Trastuzumab reversed the resistance to Trastuzumab monotherapy. Because GB235 showed a different working mechanism with Pertuzumab and Trastuzumab, these agents can be considered complementary therapy against HER2 overexpression tumors.
Assuntos
Anticorpos Monoclonais/farmacologia , Protocolos de Quimioterapia Combinada Antineoplásica/farmacologia , Resistencia a Medicamentos Antineoplásicos/efeitos dos fármacos , Neoplasias/tratamento farmacológico , Receptor ErbB-2/antagonistas & inibidores , Animais , Anticorpos Monoclonais/uso terapêutico , Protocolos de Quimioterapia Combinada Antineoplásica/uso terapêutico , Linhagem Celular Tumoral , Feminino , Humanos , Camundongos , Neoplasias/patologia , Neuregulina-1/metabolismo , Fosforilação/efeitos dos fármacos , Receptor ErbB-2/metabolismo , Receptor ErbB-3/metabolismo , Transdução de Sinais/efeitos dos fármacos , Trastuzumab/farmacologia , Trastuzumab/uso terapêutico , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
With an estimated 38 million current patients, heart failure (HF) is a leading cause of morbidity and mortality worldwide. Although the aetiology differs, HF is largely a disease of cardiomyocyte (CM) death or dysfunction. Due to the famously limited amount of regenerative capacity of the myocardium, the only viable option for advanced HF patients is cardiac transplantation; however, donor's hearts are in very short supply. Thus, novel regenerative strategies are urgently needed to reconstitute the injured hearts. Emerging data from our lab and others have elucidated that CM-specific deletion of glycogen synthase kinase (GSK)-3 family of kinases induces CM proliferation, and the degree of proliferation is amplified in the setting of cardiac stress. If this proliferation is sufficiently robust, one could induce meaningful regeneration without the need for delivering exogenous cells to the injured myocardium (i.e. cardiac regeneration in situ). Herein, we will discuss the emerging role of the GSK-3s in CM proliferation and differentiation, including their potential implications in cardiac regeneration. The underlying molecular interactions and cross-talk among signalling pathways will be discussed. We will also review the specificity and limitations of the available small molecule inhibitors targeting GSK-3 and their potential applications to stimulate the endogenous cardiac regenerative responses to repair the injured heart.
Assuntos
Proliferação de Células/efeitos dos fármacos , Quinase 3 da Glicogênio Sintase/antagonistas & inibidores , Insuficiência Cardíaca/tratamento farmacológico , Miócitos Cardíacos/efeitos dos fármacos , Inibidores de Proteínas Quinases/uso terapêutico , Regeneração/efeitos dos fármacos , Animais , Diferenciação Celular/efeitos dos fármacos , Receptores ErbB/metabolismo , Quinase 3 da Glicogênio Sintase/metabolismo , Insuficiência Cardíaca/enzimologia , Insuficiência Cardíaca/patologia , Insuficiência Cardíaca/fisiopatologia , Via de Sinalização Hippo , Humanos , Miócitos Cardíacos/enzimologia , Miócitos Cardíacos/patologia , Neuregulina-1/metabolismo , Proteínas Serina-Treonina Quinases/metabolismo , Transdução de SinaisRESUMO
Diabetic cardiomyopathy (DCM) is one of the main cardiac complications among diabetic patients. According to previous studies, the pathogenesis of DCM is associated with oxidative stress, apoptosis and proliferation of local cardiac cells. It showed, NRG1 can improve the function of mitochondria, and thereby, increasing proliferation and decreasing apoptosis of cardiac muscle cell via ErbB/AKT signaling, also, exert antioxidative function. Besides, NRG1/ErbB pathway was impaired in the DCM model which suggested this signaling played key role in DCM. Astraglaus polysaccharide (APS), one of the active components of Astragalus mongholicus, showed striking antioxidative effect. Here, in this study, our data showed that APS can promote proliferation and decrease apoptosis in AGE-induced DCM cell model, besides, APS can decrease intracellular ROS level, increase activity of SOD, GSH-Px and lower level of MDA and NO in DCM cell model, indicating APS exerted antioxidative function in DCM model cells. Besides, western blot results revealed APS induced NRG1 expressing and the phosphorylation level of ErbB2/4. In addition, the elevated NRG1 promoted AKT and PI3k phosphorylation which indicated APS may exert its function by NRG1/ErbB and the downstream AKT/PI3K signaling. Canertinib is ErbB inhibitor. The effect of APS on proliferation, apoptosis, antioxidation and NRG1/ErbB pathway was partly abolished after the cells were co-treated with APS and canertinib. Taken together, these results suggested APS may display its protective function in DCM cells by activating NGR1/ErbB signaling pathway. And our study increased potential for prevention and therapy to DCM.
Assuntos
Antioxidantes/farmacologia , Astrágalo/química , Cardiomiopatias Diabéticas/tratamento farmacológico , Extratos Vegetais/farmacologia , Transdução de Sinais/efeitos dos fármacos , Animais , Antioxidantes/uso terapêutico , Apoptose/efeitos dos fármacos , Cardiomiopatias Diabéticas/patologia , Morfolinas/farmacologia , Miócitos Cardíacos/efeitos dos fármacos , Miócitos Cardíacos/patologia , Neuregulina-1/metabolismo , Proteínas Oncogênicas v-erbB/metabolismo , Estresse Oxidativo/efeitos dos fármacos , Fosfatidilinositol 3-Quinases/metabolismo , Fosforilação/efeitos dos fármacos , Extratos Vegetais/uso terapêutico , Polissacarídeos/farmacologia , Polissacarídeos/uso terapêutico , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Espécies Reativas de Oxigênio/metabolismoRESUMO
Spinal cord injury (SCI) results in glial activation and neuroinflammation, which play pivotal roles in the secondary injury mechanisms with both pro- and antiregeneration effects. Presently, little is known about the endogenous molecular mechanisms that regulate glial functions in the injured spinal cord. We previously reported that the expression of neuregulin-1 (Nrg-1) is acutely and chronically declined following traumatic SCI. Here, we investigated the potential ramifications of Nrg-1 dysregulation on glial and immune cell reactivity following SCI. Using complementary in vitro approaches and a clinically-relevant model of severe compressive SCI in rats, we demonstrate that immediate delivery of Nrg-1 (500 ng/day) after injury enhances a neuroprotective phenotype in inflammatory cells associated with increased interleukin-10 and arginase-1 expression. We also found a decrease in proinflammatory factors including IL-1ß, TNF-α, matrix metalloproteinases (MMP-2 and 9) and nitric oxide after injury. In addition, Nrg-1 modulates astrogliosis and scar formation by reducing inhibitory chondroitin sulfate proteoglycans after SCI. Mechanistically, Nrg-1 effects on activated glia are mediated through ErbB2 tyrosine phosphorylation in an ErbB2/3 heterodimer complex. Furthermore, Nrg-1 exerts its effects through downregulation of MyD88, a downstream adaptor of Toll-like receptors, and increased phosphorylation of Erk1/2 and STAT3. Nrg-1 treatment with the therapeutic dosage of 1.5 µg/day significantly improves tissue preservation and functional recovery following SCI. Our findings for the first time provide novel insights into the role and mechanisms of Nrg-1 in acute SCI and suggest a positive immunomodulatory role for Nrg-1 that can harness the beneficial properties of activated glia and inflammatory cells in recovery following SCI.
Assuntos
Doenças do Sistema Nervoso/tratamento farmacológico , Doenças do Sistema Nervoso/etiologia , Neuregulina-1/uso terapêutico , Neuroglia/fisiologia , Recuperação de Função Fisiológica/fisiologia , Traumatismos da Medula Espinal/complicações , Animais , Animais Recém-Nascidos , Arginase/metabolismo , Células Cultivadas , Meios de Cultivo Condicionados/farmacologia , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Proteína Glial Fibrilar Ácida/metabolismo , Interleucina-10/metabolismo , Lipopolissacarídeos/toxicidade , Locomoção/efeitos dos fármacos , Camundongos , Camundongos Endogâmicos C57BL , Neuregulina-1/metabolismo , Neuregulina-1/farmacologia , Neuroglia/efeitos dos fármacos , Ratos , Recuperação de Função Fisiológica/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacos , Traumatismos da Medula Espinal/patologia , Fatores de TempoRESUMO
Cardiac microvascular endothelial cells (CMECs) are important angiogenic components and are injured rapidly after cardiac ischaemia and anoxia. Cardioprotective effects of Qiliqiangxin (QL), a traditional Chinese medicine, have been displayed recently. This study aims to investigate whether QL could protect CMECs against anoxic injury and to explore related signalling mechanisms. CMECs were successfully cultured from Sprague-Dawley rats and exposed to anoxia for 12 hrs in the absence and presence of QL. Cell migration assay and capillary-like tube formation assay on Matrigel were performed, and cell apoptosis was determined by TUNEL assay and caspase-3 activity. Neuregulin-1 (NRG-1) siRNA and LY294002 were administrated to block NRG-1/ErbB and PI3K/Akt signalling, respectively. As a result, anoxia inhibited cell migration, capillary-like tube formation and angiogenesis, and increased cell apoptosis. QL significantly reversed these anoxia-induced injuries and up-regulated expressions of NRG-1, phospho-ErbB2, phospho-ErbB4, phospho-Akt, phospho-mammalian target of rapamycin (mTOR), hypoxia-inducible factor-1α (HIF-1α) and vascular endothelial growth factor (VEGF) in CMECs, while NRG-1 knockdown abolished the protective effects of QL with suppressed NRG-1, phospho-ErbB2, phospho-ErbB4, phospho-Akt, phospho-mTOR, HIF-1α and VEGF expressions. Similarly, LY294002 interrupted the beneficial effects of QL with down-regulated phospho-Akt, phospho-mTOR, HIF-1α and VEGF expressions. However, it had no impact on NRG-1/ErbB signalling. Our data indicated that QL could attenuate anoxia-induced injuries in CMECs via NRG-1/ErbB signalling which was most probably dependent on PI3K/Akt/mTOR pathway.
Assuntos
Cardiotônicos/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Células Endoteliais/metabolismo , Microvasos/patologia , Miocárdio/patologia , Transdução de Sinais/efeitos dos fármacos , Animais , Caspase 3/metabolismo , Hipóxia Celular/efeitos dos fármacos , Movimento Celular/efeitos dos fármacos , Separação Celular , Células Cultivadas , Cromonas/farmacologia , Células Endoteliais/efeitos dos fármacos , Técnicas de Silenciamento de Genes , Masculino , Morfolinas/farmacologia , Neovascularização Fisiológica/efeitos dos fármacos , Neuregulina-1/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , RNA Interferente Pequeno/metabolismo , Ratos Sprague-Dawley , Receptor ErbB-2/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Regulação para Cima/efeitos dos fármacosRESUMO
Deficits in neuronal migration during development in the central nervous system may contribute to psychiatric diseases. The ligand neuregulin1 (NRG1) and its receptor ErbB4 are genes conferring susceptibility to schizophrenia, playing a key role in the control of neuronal migration both during development and adulthood. Several NRG1 and ErbB4 isoforms were identified, which deeply differ in their characteristics. Here we focused on the four ErbB4 isoforms and the two NRG1 isoforms differing in their EGF-like domain, namely α and ß. We hypothesized that these isoforms, which are differently regulated in schizophrenic patients, could play different roles in neuronal migration. Our hypothesis was strengthened by the observation that both NRG1α and NRG1ß and the four ErbB4 isoforms are expressed in the medial and lateral ganglionic eminences and in the cortex during development in rat. We analysed in vitro the signal transduction pathways activated by the different ErbB4 isoforms following the treatment with soluble recombinant NRG1α or NRG1ß and the ability to stimulate migration. Our data show that two ErbB4 isoforms, namely JMa-cyt2 and JMb-cyt1, following NRG1α and NRG1ß treatment, strongly activate AKT phosphorylation, conferring high migratory activity to neuronal progenitors, thus demonstrating that both NRG1α and NRG1ß can play a role in neuronal migration.
Assuntos
Movimento Celular , Células-Tronco Neurais/metabolismo , Neuregulina-1/metabolismo , Receptor ErbB-4/metabolismo , Animais , Linhagem Celular , Córtex Cerebral/citologia , Córtex Cerebral/embriologia , Córtex Cerebral/metabolismo , Hipotálamo/citologia , Hipotálamo/embriologia , Hipotálamo/metabolismo , Células-Tronco Neurais/fisiologia , Neuregulina-1/genética , Neurogênese , Fosforilação , Isoformas de Proteínas/genética , Isoformas de Proteínas/metabolismo , Processamento de Proteína Pós-Traducional , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos , Ratos Wistar , Receptor ErbB-4/genéticaRESUMO
INTRODUCTION: Increasing evidence implicates the role of the cell types surrounding motor neurons, such as interneurons and glial cells, in non-cell autonomous neurodegeneration of amyotrophic lateral sclerosis (ALS). C-boutons, the large cholinergic synapses that innervate spinal α-motor neurons to control their excitability, are progressively lost from motor neurons in both human ALS and mutant Cu/Zn superoxide dismutase 1 (SOD1)-ALS mice. Neuregulin-1 (NRG1), a trophic factor implicated in neural development, transmission, and synaptic plasticity, has been reported to localize in the synapse of C-boutons. However, the roles of NRG1 in maintenance of motor neuron health and activity, as well as the functional consequences of its alteration in motor neuron disease, are not fully understood. RESULTS: NRG1 was localized to the post-synaptic face of C-boutons and its expression was significantly lost in SOD1-ALS mice and human ALS patients. Losses of NRG1 expression and C-boutons occurred almost contemporaneously in SOD1-ALS mice. In addition, expressions of ErbB3 and ErbB4, receptors for NRG1, were reduced in the motor neurons of SOD1-ALS mice. Furthermore, viral-mediated delivery of type III-NRG1 to the spinal cord restored the number of C-boutons and extended the survival time of SOD1-ALS mice. CONCLUSIONS: These results suggest that maintenance of NRG1-ErbB4/3 axis by supplementation of NRG1 confers neuroprotection in motor neuron disease, partly through the maintenance of C-boutons of spinal motor neurons.
Assuntos
Esclerose Lateral Amiotrófica , Neurônios Motores/patologia , Neuregulina-1/metabolismo , Neuroproteção/fisiologia , Terminações Pré-Sinápticas/metabolismo , Medula Espinal/patologia , Adulto , Fatores Etários , Idoso , Idoso de 80 Anos ou mais , Esclerose Lateral Amiotrófica/tratamento farmacológico , Esclerose Lateral Amiotrófica/genética , Esclerose Lateral Amiotrófica/patologia , Animais , Modelos Animais de Doenças , Feminino , Regulação da Expressão Gênica/genética , Humanos , Masculino , Proteínas de Membrana/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Pessoa de Meia-Idade , Neurônios Motores/metabolismo , Mutação/genética , Proteínas do Tecido Nervoso/metabolismo , Mudanças Depois da Morte , Receptor ErbB-3/metabolismo , Canais de Potássio Shab/metabolismo , Superóxido Dismutase/genética , Superóxido Dismutase-1 , Proteínas Vesiculares de Transporte de Acetilcolina/metabolismoRESUMO
Neuregulin 1 (Nrg1) is one of the most active members of the epidermal growth factor (EGF)-like family, which bind to the ErbB tyrosine kinase receptor and play many roles in modulation of synaptic activity, synaptogenesis, GABAergic neurotransmission, neurotransmitter receptor expression and the hormonal control of neuroendocrine reproductive development. In this study, we cloned and characterized the cDNA of goose Nrg1 originating from hypothalamus tissues of Huoyan goose using RACE method, investigated the mRNA expression profiles during different stages of the egg-laying cycle by real-time PCR. Multiple alignments and phylogenetic analyses of the deduced amino acid sequence were conducted using bioinformatics tools. We also determined the profiles of blood serum progesterone, estradiol, FSH and LH content during different egg-laying stages using radioimmunoassay. The cDNA of Nrg1 is consisted of 2061bp open reading frame encoding 686 amino acids. The deduced amino acid sequence of goose Nrg1 contains one EGF domain from amino acid residues 224 to 265 and shows a closer genetic relationship to the avian species than to other mammal species. The expression level of Nrg1 mRNA increased from the pre-laying period to the peak-laying period, reached its peak in the peak-laying period, and then decreased in the ceased period. The concentrations of FSH and estradiol in blood serum have the similar changing trend. These results might suggest a potential correlation between Nrg1/ErbB signaling network with the reproductive neuroendocrine of Huoyan goose.
Assuntos
Clonagem Molecular/métodos , Gansos/fisiologia , Perfilação da Expressão Gênica/métodos , Neuregulina-1/genética , Oviposição , Animais , Biologia Computacional/métodos , Estradiol/sangue , Hormônio Foliculoestimulante/sangue , Gansos/genética , Regulação da Expressão Gênica , Hipotálamo/metabolismo , Hormônio Luteinizante/sangue , Neuregulina-1/metabolismo , Filogenia , Progesterona/sangueRESUMO
OBJECTIVE: It has been reported that Qiliqiangxin (QL), a traditional Chinese medicine compound, could inhibit cardiac hypertrophy and remodeling, and improve cardiac function. However, whether and how it reverses cardiac remodeling in rats post myocardial infarction (MI) remains unknown. This study aims to explore related mechanisms linked with cardiac function improvement and attenuation of cardiac remodeling by QL in rats with experimental MI. METHODS: MI was induced by ligation of left anterior descending coronary artery (LAD) in male Sprague-Dawley rats. Rats with LVEF < 50% at four weeks after procedure were treated for another 6 weeks with placebo, QL and captopril. Echocardiography and plasma NT-proBNP were measured at the end of study, and histological studies were performed. Protein expressions of Neuregulin-1 (NRG-1), total-Akt, phospho-Akt (Ser473), hydroxy-HIF-1α (Pro564), VEGF, Bax, Bcl-2 and Caspase 3 were examined by Western blot. mRNA expression of NRG-1 and p53 was detected by real-time PCR. RESULTS: Compared with the placebo group, QL improved cardiac function, reduced left ventricular dimension, inhibited interstitial inflammation and fibrosis, increased neovascularization, and attenuated cardiomyocyte apoptosis. Meanwhile QL significantly upregulated the expression of HIF-1α, VEGF, enhanced phosphorylation of Akt, decreased the ratio of Bax/Bcl-2 and Caspase 3 expression. Furthermore, we observed upregulation of NRG-1 and downregulation of p53 after QL treatment. CONCLUSION: Our data suggest that the beneficial effects of QL on improving cardiac function and attenuating cardiac remodeling post MI are associated with angiogenesis enhancement and apoptosis inhibition, which may be mediated via activation of NRG-1/Akt signaling and suppression of p53 pathway.
Assuntos
Cardiotônicos/farmacologia , Medicamentos de Ervas Chinesas/farmacologia , Infarto do Miocárdio/tratamento farmacológico , Volume Sistólico/efeitos dos fármacos , Função Ventricular Esquerda/efeitos dos fármacos , Remodelação Ventricular/efeitos dos fármacos , Animais , Apoptose/efeitos dos fármacos , Proteínas Reguladoras de Apoptose/metabolismo , Modelos Animais de Doenças , Fibrose , Masculino , Infarto do Miocárdio/metabolismo , Infarto do Miocárdio/patologia , Infarto do Miocárdio/fisiopatologia , Miocárdio/metabolismo , Miocárdio/patologia , Peptídeo Natriurético Encefálico/sangue , Neovascularização Fisiológica/efeitos dos fármacos , Neuregulina-1/metabolismo , Fragmentos de Peptídeos/sangue , Proteínas Proto-Oncogênicas c-akt/metabolismo , Ratos Sprague-Dawley , Transdução de Sinais/efeitos dos fármacos , Proteína Supressora de Tumor p53/metabolismo , Fator A de Crescimento do Endotélio Vascular/metabolismoRESUMO
Laminarin, found in marine brown algae, is used as a carbohydrate reserve for phytoplankton; however, it is also used in traditional Chinese medicine, and has been shown to have several biological activities, including anticancer activities. In this study, we examined the mechanisms through which laminarin from Laminaria digitata induces apoptosis in HT-29 colon cancer cells, as well as the involvement of the ErbB signaling pathway. Cell viability assay revealed that laminarin induced cell death in a dose-dependent manner. Cell cycle analysis revealed that laminarin increased the percentage of cells in the sub-G1 and G2-M phase. Western blot analysis demonstrated that laminarin inhibited the heregulin-stimulated phosphorylation of ErbB2. A decrease in cellular proliferation was also observed; this was found to be dependent on ErbB, which activates c-Jun N-terminal kinase. These findings demonstrate the important role of the epidermal growth factor receptor in colon cancer tumorigenesis, and suggest the potential of laminarin as a bio-functional food with anticancer effects on human colon cancer.
Assuntos
Antineoplásicos/farmacologia , Apoptose/efeitos dos fármacos , Neoplasias do Colo/metabolismo , Receptores ErbB/metabolismo , Polissacarídeos/farmacologia , Transdução de Sinais/efeitos dos fármacos , Ciclo Celular/efeitos dos fármacos , Proteínas de Ciclo Celular/genética , Proteínas de Ciclo Celular/metabolismo , Linhagem Celular Tumoral , Neoplasias do Colo/genética , Receptores ErbB/genética , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Glucanos , Células HT29 , Humanos , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Neuregulina-1/genética , Neuregulina-1/metabolismo , Fosforilação/efeitos dos fármacos , Proteínas Proto-Oncogênicas c-akt/metabolismoRESUMO
Establishing stable coculture systems with neuronal and Schwann cell lines has been considered difficult, presumably because of their high proliferative activity and phenotypic differences from primary cultured cells. The present study is aimed at developing methods for myelin formation under coculture of the neural crest-derived pheochromocytoma cell line PC12 and the immortalized adult rat Schwann cell line IFRS1. Prior to coculture, PC12 cells were seeded at low density (3 × 10(2)/cm(2)) and maintained in serum-free medium with N2 supplement, ascorbic acid (50 µg/ml), and nerve growth factor (NGF) (50 ng/ml) for a week. Exposure to such a NGF-rich environment with minimum nutrients accelerated differentiation and neurite extension, but not proliferation, of PC12 cells. When IFRS1 cells were added to NGF-primed PC12 cells, the cell density ratio of PC12 cells to IFRS1 cells was adjusted from 1:50 to 1:100. The cocultured cells were then maintained in serum-free medium with B27 supplement, ascorbic acid (50 µg/ml), NGF (10 ng/ml), and recombinant soluble neuregulin-1 type III (25 ng/ml). Myelin formation was illustrated by light and electron microscopy performed at day 28 of coculture. The stable PC12-IFRS1 coculture system is free of technical and ethical problems arising from the primary culture and can be a valuable tool to study peripheral nerve degeneration and regeneration.
Assuntos
Bainha de Mielina/metabolismo , Neurônios/citologia , Células de Schwann/citologia , Animais , Diferenciação Celular , Técnicas de Cocultura , Fatores de Crescimento Neural/farmacologia , Neuregulina-1/metabolismo , Neuritos/fisiologia , Neurônios/metabolismo , Células PC12 , Ratos , Células de Schwann/metabolismoRESUMO
Gonadotropin-releasing hormone (GnRH) is secreted from hypothalamic neurons (GnRH neurons). GnRH neurons have a GnRH receptor belonging to the G-protein-coupled receptors. The stimulation of this receptor activates extracellular signal-regulated kinase (ERK). In the present study, we found that epidermal growth factor receptor (EGFR) and ErbB4 were expressed in immortalized GnRH neurons (GT1-7 cells). AG1478, a relatively specific inhibitor of the ErbB family, and small interfering RNA (siRNA) for ErbB4 inhibited the GnRH-induced activation of ERK in GT1-7 cells, suggesting that EGFR and ErbB4 were necessary for the activation. In addition, GnRH induced the cleavage of ErbB4 and accumulation of an 80-kDa fragment. After treatment of the cells with 50 nM GnRH for 5 min, about 80% of ErbB4 was cleaved. Biotinylation of cell surface proteins revealed that more than 70% of the cell surface ErbB4 was cleaved by GnRH treatment. A higher concentration and longer treatment were necessary for GnRH to induce ErbB4 cleavage than ERK activation. TAPI-2, an inhibitor of tumor necrosis factor-α-converting enzyme (TACE), and siRNA for TACE inhibited the cleavage of ErbB4, suggesting that TACE was involved. After ErbB4 cleavage, the activation of ERK by neuregulin 1 was almost completely inhibited. These results suggest that the down-regulation of ErbB4 expression is induced by G-protein-coupled receptor stimulation.
Assuntos
Receptores ErbB/metabolismo , Hormônio Liberador de Gonadotropina/metabolismo , Hipotálamo/metabolismo , Neurônios/metabolismo , Processamento de Proteína Pós-Traducional , Receptores LHRH/metabolismo , Proteínas ADAM/antagonistas & inibidores , Proteínas ADAM/genética , Proteínas ADAM/metabolismo , Proteína ADAM17 , Animais , Linhagem Celular , Regulação para Baixo , Ativação Enzimática , Inibidores Enzimáticos/farmacologia , Receptores ErbB/antagonistas & inibidores , Receptores ErbB/genética , MAP Quinases Reguladas por Sinal Extracelular/metabolismo , Hipotálamo/efeitos dos fármacos , Camundongos , Neuregulina-1/metabolismo , Neurônios/efeitos dos fármacos , Fosforilação , Interferência de RNA , Receptor ErbB-4 , Fatores de Tempo , TransfecçãoRESUMO
Cytostatic drugs were developed to target specific molecular pathways shown to drive tumor growth. Although this approach has been very successful in treating cancers, its use is often hindered by off-target toxic effects. An example of this is trastuzumab, which targets the erbB2 kinase receptor. This drug successfully decreases tumor growth but adversely affects cardiac function. This observation led to important studies elucidating the importance of the erbB pathway in cardioprotection and angiogenesis. This review addresses the problem of off-target effects of cytostatic drugs (specifically trastuzumab) and their effect on cardiac function, summarizes the neuregulin-1 (NRG)/erbB signaling pathway, and discusses its importance in cardiac myocytes. It also highlights important findings showing the role of NRG/erbB signaling in microvascular preservation and angiogenesis, with a brief discussion of preclinical and clinical data regarding treatment of cardiovascular disease with NRG.