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Neural precursor cells (NPCs) generate new neurons to supplement neuronal loss as well as to repair damaged neural circuits. Therefore, NPCs have potential applications in a variety of neurological diseases, such as spinal cord injury, traumatic brain injury, and glaucoma. Specifically, improving NPCs proliferation and manipulating their differentiated cell types can be a beneficial therapy for a variety of these diseases. ADT-OH is a slow-releasing organic H2 S donor that produces a slow and continuous release of H2 S to maintain normal brain functions. In this study, we aimed to explore the effect of ADT-OH on NPCs. Our results demonstrated that ADT-OH promotes self-renewal and antiapoptosis ability of cultured NPCs. Additionally, it facilitates more NPCs to differentiate into neurons and oligodendrocytes, while inhibiting their differentiation into astrocytes. Furthermore, it enhances axonal growth. Moreover, we discovered that the mRNA and protein expression of ß-catenin, TCF7L2, c-Myc, Ngn1, and Ngn2, which are key genes that regulate NPCs self-renewal and differentiation, were increased in the presence of ADT-OH. Altogether, these results indicate that ADT-OH may be a promising drug to regulate the neurogenesis of NPCs, and needs to be studied in the future for clinical application potential.
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Sulfeto de Hidrogênio , Células-Tronco Neurais , Animais , Diferenciação Celular , Células Cultivadas , Sulfeto de Hidrogênio/metabolismo , Sulfeto de Hidrogênio/farmacologia , Mamíferos , Células-Tronco Neurais/metabolismo , Neurônios , TionasRESUMO
Traumatic nerve injuries have become a common clinical problem, and axon regeneration is a critical process in the successful functional recovery of the injured nervous system. In this study, we found that peripheral axotomy reduces PTEN expression in adult sensory neurons; however, it did not alter the expression level of PTEN in IB4-positive sensory neurons. Additionally, our results indicate that the artificial inhibition of PTEN markedly promotes adult sensory axon regeneration, including IB4-positive neuronal axon growth. Thus, our results provide strong evidence that PTEN is a prominent repressor of adult sensory axon regeneration, especially in IB4-positive neurons.
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Regeneração Nervosa/fisiologia , Proteínas do Tecido Nervoso/antagonistas & inibidores , Crescimento Neuronal/fisiologia , PTEN Fosfo-Hidrolase/antagonistas & inibidores , Fenantrenos/farmacologia , Lectinas de Plantas/análise , Neuropatia Ciática/fisiopatologia , Células Receptoras Sensoriais/metabolismo , Animais , Células Cultivadas , Regulação para Baixo/efeitos dos fármacos , Gânglios Espinais/citologia , Regulação da Expressão Gênica/efeitos dos fármacos , Camundongos , Camundongos Knockout , Regeneração Nervosa/efeitos dos fármacos , Proteínas do Tecido Nervoso/biossíntese , Proteínas do Tecido Nervoso/deficiência , Proteínas do Tecido Nervoso/genética , Crescimento Neuronal/efeitos dos fármacos , PTEN Fosfo-Hidrolase/deficiência , PTEN Fosfo-Hidrolase/fisiologia , RNA Mensageiro/biossíntese , RNA Mensageiro/genética , Células Receptoras Sensoriais/química , Células Receptoras Sensoriais/classificação , Células Receptoras Sensoriais/efeitos dos fármacosRESUMO
The anatomical structure of the mammalian cerebral cortex is the essential foundation for its complex neural activity. This structure is developed by proliferation, differentiation, and migration of neural progenitor cells (NPCs), the fate of which is spatially and temporally regulated by the proper gene. This study was used in utero electroporation and found that the well-known oncogene c-Myc mainly promoted NPCs' proliferation and their transformation into intermediate precursor cells. Furthermore, the obtained results also showed that c-Myc blocked the differentiation of NPCs to postmitotic neurons, and the expression of telomere reverse transcriptase was controlled by c-Myc in the neocortex. These findings indicated c-Myc as a key regulator of the fate of NPCs during the development of the cerebral cortex.
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Córtex Cerebral/crescimento & desenvolvimento , Células-Tronco Neurais/citologia , Proteínas Proto-Oncogênicas c-myc/genética , Células-Tronco/citologia , Animais , Diferenciação Celular/genética , Proliferação de Células/genética , Córtex Cerebral/metabolismo , Desenvolvimento Embrionário/genética , Feminino , Regulação da Expressão Gênica no Desenvolvimento/genética , Camundongos , Células-Tronco Neurais/metabolismo , Neurogênese/genética , Neurônios/citologia , Neurônios/metabolismo , Gravidez , Células-Tronco/metabolismoRESUMO
The inflammatory response is a critical regulator for the regeneration of axon following nervous system injury. Nuclear factor-kappa B (NF-κB) is characteristically known for its ubiquitous role in the inflammatory response. However, its functional role in adult mammalian axon growth remains elusive. Here, we found that the NF-κB signaling pathway is activated in adult sensory neurons through peripheral axotomy. Furthermore, inhibition of NF-κB in peripheral sensory neurons attenuated their axon growth in vitro and in vivo. Our results also showed that NF-κB modulated axon growth by repressing the phosphorylation of STAT3. Furthermore, activation of STAT3 significantly promoted adult optic nerve regeneration. Taken together, the findings of our study indicated that NF-κB/STAT3 cascade is a critical regulator of intrinsic axon growth capability in the adult nervous system.
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Axônios/fisiologia , NF-kappa B/metabolismo , Proteínas Proto-Oncogênicas c-myc/metabolismo , Regeneração/fisiologia , Fator de Transcrição STAT3/metabolismo , Animais , Anticorpos , Células Cultivadas , Feminino , Regulação da Expressão Gênica/efeitos dos fármacos , Regulação da Expressão Gênica/fisiologia , Gliceraldeído 3-Fosfato/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular/farmacologia , Camundongos , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos ICR , NF-kappa B/antagonistas & inibidores , NF-kappa B/genética , Nervo Óptico , Prolina/análogos & derivados , Prolina/farmacologia , Proteínas Proto-Oncogênicas c-myc/genética , Fator de Transcrição STAT3/antagonistas & inibidores , Fator de Transcrição STAT3/genética , Nervo Isquiático , Tiocarbamatos/farmacologiaRESUMO
While axon regeneration is a key determinant of functional recovery of the nervous system after injury, it is often poor in the mature nervous system. Influx of extracellular calcium (Ca2+ ) is one of the first phenomena that occur following axonal injury, and calcium/calmodulin-dependent protein kinase II (CaMKII), a target substrate for calcium ions, regulates the status of cytoskeletal proteins such as F-actin. Herein, we found that peripheral axotomy activates CaMKII in dorsal root ganglion (DRG) sensory neurons, and inhibition of CaMKII impairs axon outgrowth in both the peripheral and central nervous systems (PNS and CNS, respectively). Most importantly, we also found that the activation of CaMKII promotes PNS and CNS axon growth, and regulatory effects of CaMKII on axon growth occur via affecting the length of the F-actin. Thus, we believe our findings provide clear evidence that CaMKII is a critical modulator of mammalian axon regeneration.
Assuntos
Actinas/genética , Proteína Quinase Tipo 2 Dependente de Cálcio-Calmodulina/genética , Regeneração Nervosa/genética , Crescimento Neuronal/genética , Animais , Axônios/metabolismo , Axônios/patologia , Cálcio/metabolismo , Sistema Nervoso Central/crescimento & desenvolvimento , Sistema Nervoso Central/metabolismo , Gânglios Espinais/crescimento & desenvolvimento , Gânglios Espinais/metabolismo , Cones de Crescimento/metabolismo , Humanos , Camundongos , Nervos Periféricos/crescimento & desenvolvimento , Nervos Periféricos/patologia , Células Receptoras Sensoriais/metabolismo , Células Receptoras Sensoriais/patologiaRESUMO
With high incidence and mortality, gastric cancer seriously threatened human's life. It is arduous and necessary to investigate its pathogenesis and dig effective drugs. In this study, we explored the role of 6-Gingerol (GI), a natural active ingredient, in treating gastric cancer cells. MTT assay and colony formation assay were utilized to confirmed that GI can control the proliferation of gastric cancer cells, which is time and concentration-dependent to some extent. The Annexin V-FITC/PI staining results by flow cytometry reveal that GI induces the apoptosis of gastric cancer cells. And a study on further pathways by western blot shows that GI brings about cell apoptosis by inhibiting the activation of STAT3. GI therefore may be a good candidate for treating gastric cancer.
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OBJECTIVE: To assess and compare the pharmacokinetic properties and bioavailability of a newly developed formulation of amisulpride with those of a conventional formulation in healthy Chinese volunteers under fasting state. MATERIALS AND METHODS: A single-dose, two-sequence crossover study was designed. 20 healthy subjects (14 males and 6 females) were randomized into two groups. A single oral dose of amisulpride (200 mg) was given after an overnight fast of 12 hours. Blood samples were taken at scheduled time spots and separated by a washout period of 14 days. Plasma concentration of amisulpride was measured by high-performance liquid chromatography-fluorescence detector (HPLC-FLD) method. RESULTS: The pharmacokinetic parameters of AUC0-tlast, AUC0-∞, and Cmax for the 20 subjects after a single oral dose of the trial preparation or the reference preparation were 4,767.2 and 4,856.3 ng×h×mL-1; 4,891.7 and 5,043.2 ng×h×mL-1; 584.7 and 586.3 ng×mL-1, respectively. The relative bioavailability was 98.9 ± 14.5%. No significant difference was found among the main pharmacokinetic parameters in the two preparations by ANOVA. The 90% confidence intervals for the geometric mean ratios (test/reference) of Cmax and AUC0-tlast were 90.7 - 109.1% and 92.5 - 103.6%, respectively, meeting the predetermined criteria (80 - 125%) for bioequivalence. No serious adverse events were reported. CONCLUSION: The study demonstrated that the two preparations met the regulatory criteria for bioequivalence and both formulations were well tolerated.â©.
Assuntos
Medicamentos Genéricos/farmacocinética , Sulpirida/análogos & derivados , Comprimidos/farmacocinética , Administração Oral , Adulto , Amissulprida , Área Sob a Curva , Povo Asiático , Disponibilidade Biológica , Química Farmacêutica/métodos , Estudos Cross-Over , Feminino , Meia-Vida , Voluntários Saudáveis , Humanos , Masculino , Sulpirida/farmacocinética , Equivalência Terapêutica , Adulto JovemRESUMO
Isoliquiritigenin, a flavonoid found in licorice, has been considered as an antioxidive and hepato-protective agent. Recent studies have shown that a possible mechanism for triptolide-induced hepatotoxicity is related to oxidative damage induced by reactive oxygen species. This study was done to investigate the protection effect of isoliquiritigenin against triptolide-induced hepatotoxicity and the mechanism involved. An acute liver injury model was established by intraperitoneal injection of triptolide (1.0 mg · kg-1) in mice. Different doses of isoliquiritigenin (12.5, 25 and 50 mg · kg-1) were employed as protection. The activities of AST, ALT, ALP and LDH in serum and levels of GSH, GPx, SOD, CAT and MDA in liver tissue were detected. The histopathological changes of liver tissues were observed after HE staining. The protein expression of Nrf2 was detected by western blot. Pretreatment with isoliquiritigenin significantly prevented the triptolide-induced hepatotoxicity indicated by reduced activities of AST, ALT, ALP and LDH. Moreover, isoliquiritigenin pretreatment also prevented from triptolide-induced hepatotoxicity by inhibiting MDA and restoring the levels of GSH, GPx, SOD and CAT. In addition, isoliquiritigenin could attenuate histopathological changes induced by triptolide. Furthermore, the results indicated that isoliquiritigenin pretreatment caused an increase in the protein expression of Nrf2. These results indicated that isoliquiritigenin could protect against triptolide-induced hepatotoxicity via activation of the Nrf2 pathway.
Assuntos
Chalconas/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Diterpenos/antagonistas & inibidores , Diterpenos/toxicidade , Fator 2 Relacionado a NF-E2/metabolismo , Fenantrenos/antagonistas & inibidores , Fenantrenos/toxicidade , Substâncias Protetoras/farmacologia , Animais , Doença Hepática Induzida por Substâncias e Drogas/patologia , Compostos de Epóxi/antagonistas & inibidores , Compostos de Epóxi/toxicidade , Fígado/efeitos dos fármacos , Fígado/metabolismo , Testes de Função Hepática , Masculino , Malondialdeído/antagonistas & inibidores , Camundongos , Camundongos Endogâmicos ICR , Fator 2 Relacionado a NF-E2/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Transdução de Sinais/efeitos dos fármacosRESUMO
G protein-coupled receptor 50 (GPR50), a risk factor for major depressive disorder and bipolar affective disorder, is expressed in both the developmental and adult brain. However, the function of GPR50 in the brain remains unknown. We here show GPR50 is expressed by neural progenitor cells (NPCs) in the ventricular zone of embryonic brain. Knockdown of GPR50 with a small interference RNA (siRNA) decreased self-renewal and neuronal differentiation, but not glial differentiation of NPCs. Moreover, overexpression of either full-length GPR50 or the intracellular domain of GPR50, rather than the truncated GPR50 in which the intracellular domain is deleted in, increased neuronal differentiation, indicating that GPR50 promotes neuronal differentiation of NPCs in an intracellular domain-dependent manner. We further described that the transcriptional activity of the intracellular domain of notch on Hes1 gene was repressed by overexpression of GPR50. In addition, decreased levels of transcription factor 7-like 2 (TCF7L2) mRNA was observed in GPR50 siRNA-transfected NPCs, suggesting that knockdown of GPR50 impairs wnt/ß-catenin signaling. Moreover, the mRNA levels of neurogenin (Ngn) 1, Ngn2 and cyclin D1, the target genes of notch and wnt/ß-catenin signalings, in NPCs were reduced by knockdown of GPR50. Therefore, GPR50 promotes self-renewal and neuronal differentiation of NPCs possibly through regulation of notch and wnt/ß-catenin signalings.
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Células-Tronco Embrionárias/citologia , Proteínas do Tecido Nervoso/metabolismo , Células-Tronco Neurais/citologia , Neurogênese , Receptores Acoplados a Proteínas G/metabolismo , Receptores Notch/metabolismo , Via de Sinalização Wnt , Animais , Células Cultivadas , Células-Tronco Embrionárias/metabolismo , Expressão Gênica , Técnicas de Silenciamento de Genes , Camundongos , Camundongos Endogâmicos C57BL , Proteínas do Tecido Nervoso/genética , Células-Tronco Neurais/metabolismo , Receptores Acoplados a Proteínas G/genética , beta Catenina/metabolismoRESUMO
Five new steroidal saponins, paripolins D-H (1-5), and 6 known compounds (6-11) were isolated from the aerial parts of Paris polyphylla var. yunnanensis. The structures of 1-5 were determined using spectroscopic analyses in conjunction with acid hydrolysis. It is for the first time to report the 12-hydroxysteroidal saponins from the genus Paris. The effect of all isolated compounds on blood coagulation was determined in vitro using the plasma recalcification time method. Compounds 1 and 2 showed potent procoagulant activity, and 5-11 exhibited significant anticoagulant activity.
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Liliaceae , Saponinas , Liliaceae/química , Rizoma/química , Estrutura Molecular , Saponinas/farmacologia , Saponinas/química , Coagulação SanguíneaRESUMO
This study aimed to explore the psychological mechanisms behind the relationship between kindergarten parental satisfaction and parental loyalty. This study used the parental satisfaction scale, parental trust scale, parental relationship commitment scale, and parental loyalty scale on 923 kindergarten parents. The test was conducted on 923 kindergarten parents. The results of this study showed that parental satisfaction significantly and positively affected parental loyalty. Parental trust was partially mediated between parental satisfaction and parental loyalty. Parental relationship commitment was also partially mediated between parental satisfaction and parental loyalty. Regarding to parental satisfaction and parental loyalty, parental trust and parental relationship commitment had chain mediation effect between parental satisfaction and parental loyalty. The findings of this study provided valuable insights into the effect of parental satisfaction on parental loyalty and offer concrete practical suggestions for kindergarten operators to improve the loyalty of kindergarten parents.
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Axonal regeneration plays an important role in functional recovery after nervous system damage. However, after axonal injury in mammals, regeneration is often poor. The deletion of Krüppel-like factor-4 (Klf4) has been shown to promote axonal regeneration in retinal ganglion cells. However, the effects of Klf4 deletion on the corticospinal tract and peripheral nervous system are unknown. In this study, using a mouse model of sciatic nerve injury, we show that the expression of Klf4 in dorsal root ganglion sensory neurons was significantly reduced after peripheral axotomy, suggesting that the regeneration of the sciatic nerve is associated with Klf4. In vitro, dorsal root ganglion sensory neurons with Klf4 knockout exhibited significantly enhanced axonal regeneration. Furthermore, the regeneration of the sciatic nerve was enhanced in vivo following Klf4 knockout. Finally, AAV-Cre virus was used to knockout the Klf4 gene in the cortex. The deletion of Klf4 enhanced regeneration of the corticospinal tract in mice with spinal cord injury. Together, our findings suggest that regulating KLF4 activity in neurons is a potential strategy for promoting axonal regeneration and functional recovery after nervous system injury. This study was approved by the Animal Ethics Committee at Soochow University, China (approval No. SUDA20200316A01).
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AIM: To investigate the anticancer property and possible mechanism of action of a novel sugar-substituted thalidomide derivative (STA-35) on HL-60 cells in vitro. METHODS: TNF-alpha-induced NF-kappaB activation was determined using a reporter gene assay. The MTT assay was used to measure cytotoxicity of the compound. The appearance of apoptotic Sub-G1 cells was detected by flow cytometry analysis. PARP cleavage and protein expression of NF-kappaB p65 and its inhibitor IkappaB were viewed by Western blotting. RESULTS: TA-35 (1-20 micromol/L) suppressed TNF-alpha-induced NF-kappaB activation in transfected cells (HEK293/pNiFty-SEAP) in a dose- (1-20 micromol/L) and time-dependent (0-48 h) manner. It was also shown that STA-35 exerted a dose-dependent inhibitory effect on HL-60 cell proliferation with an IC(50) value of 9.05 micromol/L. In addition, STA-35 induced apoptosis in HL-60 cells, as indicated by the appearance of a Sub-G1 peak in the cell cycle distribution, as well as poly ADP-ribose polymerase (PARP) cleavage. Subsequently, both NF-kappaB p65 and its inhibitor IkappaB gradually accumulated in cytoplasmic extracts in a dose- and time-dependent manner, indicating the blockage of NF-kappaB translocation induced by TNF-alpha from the cytoplasm to the nucleus. CONCLUSION: A novel sugar-substituted thalidomide derivative, STA-35, is potent toward HL-60 cells in vitro and induces apoptosis by the suppression of NF-kappaB activation.
Assuntos
Inibidores da Angiogênese/farmacologia , Antineoplásicos/farmacologia , Glucosídeos/farmacologia , Células HL-60 , NF-kappa B/metabolismo , Talidomida/análogos & derivados , Talidomida/farmacologia , Inibidores da Angiogênese/química , Inibidores da Angiogênese/uso terapêutico , Animais , Antineoplásicos/química , Antineoplásicos/uso terapêutico , Apoptose/efeitos dos fármacos , Linhagem Celular , Proliferação de Células/efeitos dos fármacos , Genes Reporter , Glucosídeos/química , Glucosídeos/toxicidade , Células HL-60/efeitos dos fármacos , Células HL-60/metabolismo , Humanos , Estrutura Molecular , Neoplasias/tratamento farmacológico , Neoplasias/metabolismo , Poli(ADP-Ribose) Polimerases/metabolismo , Talidomida/química , Talidomida/uso terapêutico , Talidomida/toxicidade , Fator de Necrose Tumoral alfa/metabolismoRESUMO
Quercetin (QCT) has been shown to have anticancer activities associated with apoptosis and autophagy induction. However, whether autophagy is functionally responsible for the inhibitory effect of QCT on hepatocellular carcinoma (HCC) remains elusive. This study aims to investigate if QCT inhibits HCC growth via autophagy induction. The in vitro experiments showed that QCT inhibited the growth of human HCC cells in dose- and time-dependent manners and had minimal cytotoxicity to normal hepatocytes. QCT increased both autophagosomes and autolysosomes in HCC cells, as determined by electron microscopy, GFP-RFP-LC3 fluorescence confocal microscopy and Western blot analysis of autophagy-related biomarkers. Functional assays using pathway-specific inhibitors, activators or siRNAs indicated that QCT stimulated autophagy in part via inhibiting the AKT/mTOR pathway and activating the MAPK pathways. Further functional experiments using autophagy inhibitors demonstrated that QCT induced apoptosis of HCC cells in part via stimulating autophagy. The in vivo studies showed that QCT significantly inhibited tumor growth associated with apoptosis induction and autophagy stimulation, and that inhibition of autophagy significantly alleviated the QCT effect on tumor growth inhibition and apoptosis induction. To the best of our knowledge, this is the first in vivo report to demonstrate that QCT inhibits HCC tumor growth and induces apoptosis in part via stimulation of autophagy. Our results provide strong experimental evidence to support that autophagy stimulation may be an important mechanism by which QCT induces cancer cell apoptosis, and pave the way for further clinical investigations by applying QCT or QCT-rich foods for HCC intervention.
Assuntos
Autofagia/efeitos dos fármacos , Carcinoma Hepatocelular/tratamento farmacológico , Neoplasias Hepáticas/tratamento farmacológico , Quercetina/farmacologia , Animais , Antineoplásicos Fitogênicos/farmacologia , Apoptose/efeitos dos fármacos , Autofagia/genética , Carcinoma Hepatocelular/patologia , Regulação Neoplásica da Expressão Gênica/efeitos dos fármacos , Células Hep G2 , Hepatócitos/efeitos dos fármacos , Humanos , Neoplasias Hepáticas/patologia , Masculino , Camundongos Endogâmicos BALB C , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Ensaios Antitumorais Modelo de XenoenxertoRESUMO
OBJECTIVE: To investigate the effect of substance P (SP) on expression of beta1-adrenergic receptor (beta1-AR) in cultured neonatal rat cardiomyocytes. METHODS: Cardiomyocytes were obtained from 1-3 days old Sprague-Dawley (SD) rats and cultured for 72 hours. Six wells of the cultured cells were divided into two groups (n=3 in each group): control group and SP group (incubated with 10(-7) mol/L of SP). Immunocytochemistry was used to detect the expression of beta1-AR in cultured rat cardiomyocytes. Fifteen wells of the cultured cells were divided into five groups (n=3 in each group): control group and four SP groups (incubated with 10(-9), 10 (-8), 10(-7), 10(-6) mol/L of SP respectively). Quantitative analysis of the expression of beta1-AR in cultured neonatal rat cardiomyocytes of all the groups was performed using flow cytometry. RESULTS: The results of immunocytochemistry showed that the expression of beta1-AR in cardiomyocytes in SP group was lower than that in control group (positive unit: 179.16+/-48.18 vs. 205.79+/-117.42, average light density: 128.26+/-22.72 vs. 157.35+/-33.11, both P<0.05). The results of flow cytometry showed that significantly lower levels of expression of beta1-AR were observed in the groups treated with SP in the concentrations ranging from 10 (-8) mol/L to 10 (-6) mol/L (151.85+/-4.63,135.00+/-6.84,121.41+/-5.22 vs. 161.35+/-3.09,all P<0.05). CONCLUSION: SP could down-regulate the expression of beta1-AR in cultured rat cardiomyocytes in vitro.
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Miócitos Cardíacos/metabolismo , Receptores Adrenérgicos beta 1/metabolismo , Substância P/farmacologia , Animais , Células Cultivadas , Regulação para Baixo/efeitos dos fármacos , Feminino , Masculino , Miócitos Cardíacos/efeitos dos fármacos , Ratos , Ratos Sprague-DawleyRESUMO
In the past few decades, the incidence of liver cancer has been rapidly rising across the world. Rosemary is known to possess antioxidant activity and is used as natural antioxidant food preservative. It is proposed to have anticancer activity in treating different tumor models. In this study, we try to explore the impact of rosemary extracts on upregulating the level of Nrf2 and Nrf2-regulatory proteins, Sestrin2 and MRP2 in HepG2 cells, and to speculate its potential mechanism. The anticancer activity of rosemary extract, including its polyphenolic diterpenes carnosic acid and carnosol, was evaluated to understand the potential effect on HepG2 cells. Rosemary extract, carnosic acid, and carnosol induced the expression of Sestrin2 and MRP2 associate with enhancement of Nrf2 protein level in HepG2 cells, in which carnosic acid showed most obvious effect. Although the activation pathway of Nrf2/ARE was not exactly assessed, it can be assumed that the enhancement of expression of Sestrin2 and MRP2 may result from upregulation of Nrf2.
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Glycogen synthase kinases 3 (GSK3) α and ß are expressed in the nervous system, and disruption of GSK3 signaling has been implicated in a wide range of neurodevelopmental and psychiatric disorders. Although several studies have established a role of GSK3 signaling in the nervous system, much less is known about isoform-specific functions. Here, we have examined the role of GSK3α and GSK3ß in the developing neocortex by performing in utero electroporation with specific small interfering RNAs targeting each isoform. We found that depletion of either GSK3α or GSK3ß commonly promoted the proliferation of neural progenitor cells in the ventricular zone, but at later stages, knocking down of each isoform resulted in distinct outcomes. In particular, the transformation of radial progenitors to intermediate progenitor cells was promoted in GSK3α-depleted cells, but markedly prevented in GSK3ß-depleted cells. Moreover, knocking down of GSK3ß but not GSK3α prevented the generation of upper-layer Cux1+ neurons. Consistent with the distinct outcomes, protein levels of c-Myc and ß-catenin, well-known substrates of GSK3, were differentially affected by depletion of GSK3α and GSK3ß. Together, these results suggest that GSK3α and GSK3ß might play distinct roles in the genesis and differentiation of neuronal lineage cells during neocortex development by differential regulation of downstream signaling pathways.
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To investigate the potential role of nuclear factor erythroid 2-related factor 2 (Nrf2) in licorice ethanol extract (LEE) against triptolide- (TP-) induced hepatotoxicity, HepG2 cells were exposed to LEE (30, 60, and 90 mg·L-1) for 12 h and then treated with TP (50 nM) for 24 h. Besides, an acute liver injury model was established in ICR mice by a single dose of TP (1.0 mg·kg-1, i.p.). Relevant oxidant and antioxidant mediators were analyzed. TP led to an obvious oxidative stress as evidenced by increasing levels of ROS and decreasing GSH contents in HepG2 cells. In vitro results were likely to hold true in in vivo experiments. LEE protected against TP-induced oxidative stress in both in vitro and in vivo conditions. Furthermore, the decreased level of Nrf2 in the TP-treated group was observed. The mRNA levels of downstream genes decreased as well in ICR mice liver, whereas they increased in HepG2 cells. In contrast, LEE pretreatment significantly increased the level of Nrf2 and its downstream genes. LEE protects against TP-induced oxidative stress partly via the activation of Nrf2 pathway.
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5-Hydroxymethylfurfural (5-HMF), a water-soluble compound extracted from wine-processed Fructus corni, is a novel hepatic protectant for treating acute liver injury. The present study was designed to investigate the protective effect of 5-HMF in human L02 hepatocytes injured by D-galactosamine (GalN) and tumor necrosis factor-α (TNF-α) in vitro and to explore the underlying mechanisms of action. Our results showed that 5-HMF caused significant increase in the viability of L02 cells injured by GalN/TNF-α, in accordance with a dose-dependent decrease in apoptotic cell death confirmed by morphological and flow cytometric analyses. Based on immunofluorescence and Western blot assays, we found that GalN/TNF-α induced ER stress in the cells, as indicated by the disturbance of intracellular Ca(2+) concentration, the activation of protein kinase RNA (PKR)-like ER kinase (PERK), phosphorylation of eukaryotic initiation factor 2 alpha (eIF2α), and expression of ATF4 and CHOP proteins, which was reversed by 5-HMF pre-treatment in a dose-dependent manner. The anti-apoptotic effect of 5-HMF was further evidenced by balancing the expression of Bcl-2 family members. In addition, the knockdown of PERK suppressed the expression of phospho-PERK, phospho-eIF2α, ATF4, and CHOP, resulting in a significant decrease in cell apoptosis after the treatment with GalN/TNF-α. 5-HMF could enhance the effects of PERK knockdown, protecting the cells against the GalN/TNF-α insult. In conclusion, these findings demonstrate that 5-HMF can effectively protect GalN/TNF-α-injured L02 hepatocytes against ER stress-induced apoptosis through the regulation of the PERK-eIF2α signaling pathway, suggesting that it is a possible candidate for liver disease therapy.
Assuntos
Cornus/química , Estresse do Retículo Endoplasmático/efeitos dos fármacos , Fator de Iniciação 2 em Eucariotos/metabolismo , Furaldeído/análogos & derivados , Hepatócitos/efeitos dos fármacos , Extratos Vegetais/farmacologia , Fator de Necrose Tumoral alfa/metabolismo , eIF-2 Quinase/metabolismo , Apoptose/efeitos dos fármacos , Fator de Iniciação 2 em Eucariotos/genética , Furaldeído/farmacologia , Galactosamina/metabolismo , Hepatócitos/citologia , Hepatócitos/metabolismo , Humanos , Fígado/citologia , Fígado/efeitos dos fármacos , Fígado/metabolismo , Substâncias Protetoras/farmacologia , Transdução de Sinais/efeitos dos fármacos , Fator de Necrose Tumoral alfa/genética , eIF-2 Quinase/genéticaRESUMO
Contactin-associated protein 4 (Caspr4), also known as contactin-associated protein-like protein (CNTNAP4), is expressed in various regions of the brain. Recent reports suggest that CNTNAP4 is a susceptibility gene of autism spectrum disorders (ASDs). However, the molecular function of Caspr4 in the brain has yet to be identified. In this study, we show an essential role of Caspr4 in neural progenitor cells (NPCs). Caspr4 is expressed in NPCs in the subventricular zone (SVZ), a neurogenic region in the developing cortex. Knocking down of Caspr4 enhances the proliferation of NPCs derived from the SVZ of embryonic day 14 mouse. Neuronal differentiation is increased by overexpression of Caspr4, but decreased by knocking down of Caspr4 in cultured mouse NPCs. Transfection of the intracellular domain of Caspr4 (C4ICD) rescues the abnormal decreased neuronal differentiation of Caspr4-knocking down NPCs. Ligand of Numb protein X2 (LNX2), a binding partner of Numb, interacts with Caspr4 in a PDZ domain-dependent manner and plays a similar role to Caspr4 in NPCs. Moreover, transfection of LNX2 rescues the decreased neuronal differentiation in Caspr4-knocking down NPCs. In contrast, transfection of C4ICD fails to do so in LNX2-knocking down NPCs. These results indicate that Caspr4 inhibits neuronal differentiation in a LNX-dependent manner. Therefore, this study reveals a novel role of Caspr4 through LNX2 in NPCs, which may link to the pathogenesis of ASDs.