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1.
Cells ; 13(17)2024 Aug 25.
Artigo em Inglês | MEDLINE | ID: mdl-39272991

RESUMO

This study explores the impact of royal jelly (RJ) on small intestinal epigenomic changes. RJ, produced by honeybees, is known for its effects on metabolic diseases. The hypothesis is that RJ induces epigenomic modifications in small intestinal epithelial cells, affecting gene expression and contributing to metabolic health. Male db/m and db/db mice were used to examine RJ's effects through mRNA sequencing and CUT&Tag methods. This study focused on histone modifications and gene expression changes, with statistical significance set at p < 0.05. RJ administration improved insulin sensitivity and lipid metabolism without affecting body weight. GO and KEGG pathway analyses showed significant enrichment in metabolic processes, cellular components, and molecular functions. RJ altered histone modifications, increasing H3K27me3 and decreasing H3K23Ac in genes associated with the G2M checkpoint. These genes, including Smc2, Mcm3, Ccnd1, Rasal2, Mcm6, and Mad2l1, are linked to cancer progression and metabolic regulation. RJ induces beneficial epigenomic changes in small intestinal epithelial cells, improving metabolic health and reducing cancer-associated gene expression. These findings highlight RJ's potential as a therapeutic agent for metabolic disorders. Further research is needed to fully understand the mechanisms behind these effects and their implications for human health.


Assuntos
Epigenômica , Ácidos Graxos , Intestino Delgado , Animais , Ácidos Graxos/metabolismo , Intestino Delgado/efeitos dos fármacos , Intestino Delgado/metabolismo , Intestino Delgado/patologia , Camundongos , Masculino , Epigenômica/métodos , Histonas/metabolismo , Epigênese Genética/efeitos dos fármacos , Metabolismo dos Lipídeos/efeitos dos fármacos , Metabolismo dos Lipídeos/genética , Regulação da Expressão Gênica/efeitos dos fármacos
2.
Sci Rep ; 14(1): 14207, 2024 06 20.
Artigo em Inglês | MEDLINE | ID: mdl-38902359

RESUMO

This study aimed to confirm urinary protein fragments in relation to the presence of pancreatic ductal adenocarcinoma (PDAC) via a C-terminal proteomics strategy using exploratory and validation cohorts. Urinary fragments were examined by iTRAQ-labelling of tryptic peptides and concentrations of C-terminal fragments were evaluated. Only the urinary CD276 fragment showed a fold change (FC) of > 1.5 with a significant difference of P < 0.01 between healthy (H) and PDAC participants in both the exploratory (H, n = 42; PDAC, n = 39) and validation cohorts (H, n = 36; resectable PDAC, n = 28). The sensitivity and specificity of the CD276 fragment for diagnosing resectable PDAC were 75% and 89%, respectively, in the validation cohort. Postoperative urinary levels of the CD276 fragment were low as compared to those before surgery (n = 18, P < 0.01). Comprehensive C-terminus proteomics identified an increase in the urinary CD276 fragment level as a feature of patients with PDAC. The urinary CD276 fragment is a potential biomarker for detecting resectable PDAC.


Assuntos
Antígenos B7 , Biomarcadores Tumorais , Carcinoma Ductal Pancreático , Neoplasias Pancreáticas , Proteômica , Humanos , Neoplasias Pancreáticas/urina , Neoplasias Pancreáticas/cirurgia , Neoplasias Pancreáticas/diagnóstico , Proteômica/métodos , Feminino , Masculino , Biomarcadores Tumorais/urina , Idoso , Antígenos B7/urina , Antígenos B7/metabolismo , Pessoa de Meia-Idade , Carcinoma Ductal Pancreático/urina , Carcinoma Ductal Pancreático/cirurgia , Carcinoma Ductal Pancreático/diagnóstico
3.
Molecules ; 29(7)2024 Mar 24.
Artigo em Inglês | MEDLINE | ID: mdl-38611729

RESUMO

Royal jelly (RJ) is recognized as beneficial to mammalian health. Multilineage differentiation potential is an important property of mesenchymal stem cells (MSCs). C2C12 cells have an innate ability to differentiate into myogenic cells. Like MSCs, C2C12 cells can also differentiate into osteoblast- and adipocyte-lineage cells. We recently reported that RJ enhances the myogenic differentiation of C2C12 cells. However, the effect of RJ on osteoblast or adipocyte differentiation is still unknown. Here in this study, we have examined the effect of RJ on the osteoblast and adipocyte differentiation of C2C12 cells. Protease-treated RJ was used to reduce the adverse effects caused by RJ supplementation. To induce osteoblast or adipocyte differentiation, cells were treated with bone morphogenetic proteins (BMP) or peroxisome proliferator-activated receptor γ (PPARγ) agonist, respectively. RNA-seq was used to analyze the effect of RJ on gene expression. We found that RJ stimulates osteoblast and adipocyte differentiation. RJ regulated 279 genes. RJ treatment upregulated glutathione-related genes. Glutathione, the most abundant antioxidative factor in cells, has been shown to promote osteoblast differentiation in MSC and MSC-like cells. Therefore, RJ may promote osteogenesis, at least in part, through the antioxidant effects of glutathione. RJ enhances the differentiation ability of C2C12 cells into multiple lineages, including myoblasts, osteoblasts, and adipocytes.


Assuntos
Antioxidantes , Ácidos Graxos , Animais , Diferenciação Celular , Glutationa , Mioblastos , Mamíferos
4.
Artigo em Inglês | MEDLINE | ID: mdl-36686976

RESUMO

Objectives: Royal jelly (RJ), produced by honeybees, influences stem cell functions, such as pluripotency maintenance of mouse embryonic stem cells and prevention of aging-related muscle stem cell functional deterioration. Thus, we hypothesized that RJ administration has various health-promoting effects based on stem cells. However, its effects are unknown in humans. In this study, we have attempted for the first time to clarify whether the administration of RJ in humans affects stem cells. Materials and Methods: This randomized, double-blind, placebo-controlled study was performed on healthy subjects (n = 90) who received protease-treated RJ at a dose of 1200 mg/day or placebo daily for four weeks. Also, the participants with a low number of hematopoietic stem cells (HSCs) in peripheral blood were preferentially selected. HSC counts, endothelial progenitor cell (EPC) counts, blood cell counts in peripheral blood, cytokines in serum, and physical conditions were evaluated. Results and Conclusion. Eligible data from 86 subjects (placebo: 42, RJ: 44) who completed the study were analyzed. There were no significant differences between the two groups regarding the changes in peripheral HSC count (p=0.103), while diastolic blood pressure showed a significant improvement in the RJ group compared to that in the placebo group (p=0.032). The subgroup analysis excluded 14 subjects who complained of cold symptoms at baseline or within five days of the four-week study. The changes in the HSC populations were significantly higher in the RJ group than those in the placebo group (p=0.042). No adverse effects were observed in any of the groups. These results suggest that RJ administration affected the peripheral HSC count and may influence stem cell functions. Further research is needed to reveal the various health-promoting benefits of RJ based on stem cells.

5.
J Pept Sci ; 29(5): e3464, 2023 May.
Artigo em Inglês | MEDLINE | ID: mdl-36459408

RESUMO

Human seleno-epidermal growth factor (seleno-EGF), a 53-residue peptide where all six cysteine residues of the parent human EGF sequence were replaced by selenocysteines, was synthesized and the oxidative folding of a polypeptide containing three diselenide bonds was compared to that of the parent cysteine peptide. The crude high performance liquid chromatography (HPLC) profiles clearly showed that both the native EGF and its selenocysteine-analogue fold smoothly, yielding a single sharp peak, proving that even in the case of three disulfide-bonded polypeptides the disulfide-to-diselenide bond substitution is highly isomorphous, as confirmed by conformational circular dichroism measurements and particularly by the biological assays.


Assuntos
Cisteína , Selenocisteína , Humanos , Selenocisteína/química , Cisteína/química , Fator de Crescimento Epidérmico/química , Peptídeos/química , Dissulfetos/química , Dobramento de Proteína
6.
J Cachexia Sarcopenia Muscle ; 13(6): 3028-3047, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36162824

RESUMO

INTRODUCTION: Brazilian green propolis is an important honeybee product that is considered beneficial for health. Here, we examined the therapeutic potential of dietary supplementation with propolis against sarcopenic obesity using Db/Db mice. METHODS: Db/m mice fed a normal diet alone and Db/Db mice fed normal diet alone, or supplemented with different amounts of propolis (0.08, 0.4 and 2%), were examined for effects on sarcopenic obesity. RESULTS: Propolis improved the glucose tolerance (P < 0.001), increased the grip strength (P < 0.001) and the weight of soleus (P = 0.006) and plantaris muscles (P = 0.008). Moreover, propolis improved the non-alcoholic fatty liver disease activity score (P < 0.001) and decreased the expression of genes related to inflammation, liver fibrosis and fatty acid metabolism. Propolis decreased the accumulation of saturated fatty acids in the liver and increased their excretion in faeces. With regard to the innate immunity, propolis decreased the ratio of M1 macrophages (P = 0.008) and Type 1 and 3 innate lymphoid cells to CD45-positive cells (P < 0.001) and increased the ratio of M2 macrophages (P = 0.002) and ILC2s (P = 0.007) in the liver. Additionally, propolis decreased the expression of genes related to muscle atrophy and inflammation and the concentration of saturated fatty acids in the soleus muscle. 16S rRNA phylogenetic sequencing revealed that propolis increased the Bacteroidetes/Firmicutes ratio, and the abundance of Butyricicoccus and Acetivibrio genera. Gut microbiota related to the pentose phosphatase pathway and glycerolipid metabolism was more prevalent after the administration of propolis. CONCLUSIONS: This is the first study to demonstrate that propolis can improve sarcopenic obesity by improving dysbiosis due to overeating and provides new insights into diet-microbiota interactions during sarcopenic obesity.


Assuntos
Imunidade Inata , Própole , Camundongos , Abelhas , Animais , Própole/farmacologia , Própole/uso terapêutico , Dieta Hiperlipídica , RNA Ribossômico 16S , Filogenia , Linfócitos/metabolismo , Disbiose/tratamento farmacológico , Obesidade/tratamento farmacológico , Ácidos Graxos
7.
Free Radic Biol Med ; 174: 12-27, 2021 10.
Artigo em Inglês | MEDLINE | ID: mdl-34324979

RESUMO

The knockout (KO) of the cystine transporter xCT causes ferroptosis, a type of iron-dependent necrotic cell death, in mouse embryonic fibroblasts, but this does not occur in macrophages. In this study, we explored the gene that supports cell survival under a xCT deficiency using a proteomics approach. Analysis of macrophage-derived peptides that were tagged with iTRAQ by liquid chromatography-mass spectrometry revealed a robust elevation in the levels of carnosine dipeptidase II (CNDP2) in xCT KO macrophages. The elevation in the CNDP2 protein levels was confirmed by immunoblot analyses and this elevation was accompanied by an increase in hydrolytic activity towards cysteinylglycine, the intermediate degradation product of glutathione after the removal of the γ-glutamyl group, in xCT KO macrophages. Supplementation of the cystine-free media of Hepa1-6 cells with glutathione or cysteinylglycine extended their survival, whereas the inclusion of bestatin, an inhibitor of CNDP2, counteracted the effects of these compounds. We established CNDP2 KO mice by means of the CRISPR/Cas9 system and found a decrease in dipeptidase activity in the liver, kidney, and brain. An acetaminophen overdose (350 mg/kg) showed not only aggravated hepatic damage but also renal injury in the CNDP2 KO mice, which was not evident in the wild-type mice that were receiving the same dose. The aggravated renal damage in the CNDP2 KO mice was consistent with the presence of abundant levels of CNDP2 in the kidney, the organ prone to developing ferroptosis. These collective data imply that cytosolic CNDP2, in conjugation with the removal of the γ-glutamyl group, recruits Cys from extracellular GSH and supports redox homeostasis of cells, particularly in epithelial cells of proximal tubules that are continuously exposed to oxidative insult from metabolic wastes that are produced in the body.


Assuntos
Carnosina , Dipeptidases , Animais , Cisteína , Dipeptidases/genética , Fibroblastos , Glutationa , Camundongos
8.
Angew Chem Int Ed Engl ; 60(25): 13900-13905, 2021 06 14.
Artigo em Inglês | MEDLINE | ID: mdl-33825275

RESUMO

Caveolin-1, which is an essential protein for caveola formation, was chemically synthesized. It is composed of 177 amino acid residues, is triply palmitoylated at the C-terminal region, and is inserted into the lipid bilayer to form a V-shaped structure in the middle of the polypeptide chain. The entire sequence was divided into five peptide segments, each of which was synthesized by the solid-phase method. To improve the solubility of the C-terminal region, O-acyl isopeptide structures were incorporated. After ligation by the thioester method and the introduction of the palmitoyl groups, all the protecting groups were removed and the isopeptide structures were converted into the native peptide bond. Finally, the obtained polypeptide was successfully inserted into bicelles, thus showing the success of the synthesis.


Assuntos
Caveolina 1/síntese química , Caveolina 1/química , Estrutura Molecular
9.
Nutrients ; 10(9)2018 Sep 01.
Artigo em Inglês | MEDLINE | ID: mdl-30200401

RESUMO

Aging is associated with motor disorders that decrease the quality of life (QOL). Royal jelly (RJ), used as a dietary supplement, has shown various health benefits and, therefore, it has the potential to improve the QOL during aging. We have previously developed protease enzyme-treated RJ to avoid the anaphylactic response induced by RJ supplementation. However, the effects of a lifelong treatment with RJ on normal aging have not been fully clarified. In this study, we investigated the effects of enzyme-untreated RJ (NRJ) and enzyme-treated RJ (ERJ) on the aging process focusing on motor functions, by using a genetically heterogeneous (HET) mouse model experimentally endowed with genetic diversity. We performed four different physical performance tests (grip strength, wire hang, horizontal bar, and rotarod). We showed that the age-related impairment of the motor functions was significantly delayed in RJ-treated mice. Both NRJ and ERJ were similarly effective against these types of aging-associated declines. Histological analyses revealed that the RJ treatment affected the muscle fiber size at an advanced age. We also demonstrated that age-related changes in muscle satellite cell markers and catabolic genes were affected in RJ-treated mice. These results suggest that non-protein components of RJ improved the motor function in aging mice. These findings indicate that RJ has the potential to change the QOL during aging by regulating the motor function.


Assuntos
Envelhecimento/efeitos dos fármacos , Suplementos Nutricionais , Ácidos Graxos/farmacologia , Heterogeneidade Genética , Atividade Motora/efeitos dos fármacos , Destreza Motora/efeitos dos fármacos , Músculo Esquelético/efeitos dos fármacos , Fatores Etários , Envelhecimento/genética , Envelhecimento/metabolismo , Envelhecimento/patologia , Animais , Regulação da Expressão Gênica/efeitos dos fármacos , Longevidade/efeitos dos fármacos , Masculino , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Atividade Motora/genética , Força Muscular/efeitos dos fármacos , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Músculo Esquelético/fisiopatologia , Atrofia Muscular/tratamento farmacológico , Atrofia Muscular/metabolismo , Atrofia Muscular/patologia , Atrofia Muscular/fisiopatologia , Fatores Sexuais
10.
FEBS J ; 283(1): 144-56, 2016 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-26471009

RESUMO

During viral replication, the innate immune response is induced through the recognition of viral replication intermediates by host factor(s). One of these host factors, cyclic GMP-AMP synthetase (cGAS), was recently reported to be involved in the recognition of viral DNA derived from DNA viruses. However, it is uncertain whether cGAS is involved in the recognition of hepatitis B virus (HBV), which is a hepatotropic DNA virus. In the present study, we demonstrated that HBV genome-derived double-stranded DNA induced the innate immune response through cGAS and its adaptor protein, stimulator of interferon genes (STING), in human hepatoma Li23 cells expressing high levels of cGAS. In addition, we demonstrated that HBV infection induced ISG56 through the cGAS-STING signaling pathway. This signaling pathway also showed an antiviral response towards HBV through the suppression of viral assembly. From these results, we conclude that the cGAS-STING signaling pathway is required for not only the innate immune response against HBV but also the suppression of HBV assembly. The cGAS-STING signaling pathway may thus be a novel target for anti-HBV strategies.


Assuntos
Adenilil Ciclases/metabolismo , GMP Cíclico/metabolismo , Vírus da Hepatite B/imunologia , Imunidade Inata/imunologia , Proteínas de Membrana/metabolismo , Transdução de Sinais/imunologia , Montagem de Vírus , Hepatite B/imunologia , Hepatite B/metabolismo , Vírus da Hepatite B/metabolismo , Humanos , Células Tumorais Cultivadas
11.
FEBS Lett ; 589(10): 1112-8, 2015 Apr 28.
Artigo em Inglês | MEDLINE | ID: mdl-25836733

RESUMO

Hepatitis B virus (HBV) replication is controlled by liver-enriched transcriptional factors, including forkhead box protein A (FOXA) members. Here, we found that FOXA members are directly and indirectly involved in HBV replication in human hepatic cells. HBV replication was elevated in HuH-7 treated with individual FOXA members-specific siRNA. Reciprocally, the downregulation of HBV replication was observed in FOXA-induced HuH-7. However, the mechanism of downregulation is different among FOXA members at the level of HBV RNA transcription, such as precore/pg RNA and 2.1 kb RNA. In addition, FOXA1 and FOXA2 suppressed nuclear hormone receptors, such as HNF4α, that are related to HBV replication.


Assuntos
Carcinoma Hepatocelular/virologia , Replicação do DNA/fisiologia , DNA Viral/biossíntese , Vírus da Hepatite B/fisiologia , Fator 3-alfa Nuclear de Hepatócito/metabolismo , Fator 3-beta Nuclear de Hepatócito/metabolismo , Neoplasias Hepáticas/virologia , Proteínas de Neoplasias/metabolismo , Replicação Viral/fisiologia , Carcinoma Hepatocelular/genética , Carcinoma Hepatocelular/metabolismo , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , DNA Viral/genética , Fator 3-alfa Nuclear de Hepatócito/genética , Fator 3-beta Nuclear de Hepatócito/genética , Fator 4 Nuclear de Hepatócito/genética , Fator 4 Nuclear de Hepatócito/metabolismo , Humanos , Neoplasias Hepáticas/genética , Neoplasias Hepáticas/metabolismo , Neoplasias Hepáticas/patologia , Proteínas de Neoplasias/genética
12.
J Surg Res ; 175(1): 138-48, 2012 Jun 01.
Artigo em Inglês | MEDLINE | ID: mdl-21550066

RESUMO

BACKGROUND: Allograft dysfunction after liver transplantation requires histopathologic examination for confirmation of the diagnosis, however, the procedure is invasive and its interpretation is not always accurate. The aim of this study was to find novel protein markers in bile for the diagnosis of acute cellular rejection (ACR) after liver transplantation. MATERIALS AND METHODS: Quantitative proteomic analysis using the (18)O labeling method was used to search for bile proteins of interest. Nine recipients were selected who had liver dysfunction, diagnosed by liver biopsy, either with ACR (ACR group, n = 5) or without (LD group, n = 4). Donor bile samples were obtained from nine independent live liver donors. Enzyme activity in bile samples was assayed and liver biopsy specimens were immunostained for candidate protein of ACR. RESULTS: The analysis identified 78 proteins, among which alanine aminopeptidase N (APN/CD13) was considered a candidate marker of ACR. Comparative analysis of the ACR and LD groups showed high APN enzyme activity in three (60%) of five cases of the ACR group, while it was as low as donor level in all patients of the LD group. APN enzyme activity in bile samples of liver dysfunction liver transplantation (LDLT) recipients of the ACR group collected within 3 d before biopsy-confirmed ACR (n = 10) was significantly higher (584 ± 434 U/g protein) than in those of recipients free of ACR (n = 96, 301 ± 271 U/g protein) (P = 0.004). APN overexpression along bile canaliculi was observed during ACR in all five cases of the ACR group. CONCLUSION: APN in bile seems to be a useful and noninvasive biomarker of ACR after liver transplantation.


Assuntos
Bile/química , Antígenos CD13/análise , Rejeição de Enxerto/metabolismo , Hepatopatias/metabolismo , Transplante de Fígado/efeitos adversos , Transplantes/efeitos adversos , Doença Aguda , Adulto , Biomarcadores/análise , Antígenos CD13/metabolismo , Feminino , Rejeição de Enxerto/diagnóstico , Humanos , Fígado , Hepatopatias/diagnóstico , Doadores Vivos , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Adulto Jovem
14.
PLoS One ; 5(2): e9286, 2010 Feb 18.
Artigo em Inglês | MEDLINE | ID: mdl-20174586

RESUMO

BACKGROUND: The photopigment melanopsin has been suggested to act as a dominant photoreceptor in nonvisual photoreception including resetting of the circadian clock (entrainment), direct tuning or masking of vital status (activity, sleep/wake cycles, etc.), and the pupillary light reflex (PLR). Pituitary adenylate cyclase-activating polypeptide (PACAP) is exclusively coexpressed with melanopsin in a small subset of retinal ganglion cells and is predicted to be involved extensively in these responses; however, there were inconsistencies in the previous reports, and its functional role has not been well understood. METHODOLOGY/PRINCIPAL FINDINGS: Here we show that PACAP-deficient mice exhibited severe dysfunctions of entrainment in a time-dependent manner. The abnormalities in the mutant mice were intensity-dependent in phase delay and duration-dependent in phase advance. The knockout mice also displayed blunted masking, which was dependent on lighting conditions, but not completely lost. The dysfunctions of masking in the mutant mice were recovered by infusion of PACAP-38. By contrast, these mutant mice show a normal PLR. We examined the retinal morphology and innervations in the mutant mice, and no apparent changes were observed in melanopsin-immunoreactive cells. These data suggest that the dysfunctions of entrainment and masking were caused by the loss of PACAP, not by the loss of light input itself. Moreover, PACAP-deficient mice express an unusually early onset of activities, from approximately four hours before the dark period, without influencing the phase of the endogenous circadian clock. CONCLUSIONS/SIGNIFICANCE: Although some groups including us reported the abnormalities in photic entrainments in PACAP- and PAC(1)-knockout mice, there were inconsistencies in their results. The time-dependent dysfunctions of photic entrainment in the PACAP-knockout mice described in this paper can integrate the incompatible data in previous reports. The recovery of impaired masking by infusion of PACAP-38 in the mutant mice is the first direct evidence of the relationship between PACAP and masking. These results indicate that PACAP regulates particular nonvisual light responses by conveying parametric light information--that is, intensity and duration. The "early-bird" phenotype in the mutant mice originally reported in this paper supposed that PACAP also has a critical role in daily behavioral patterns, especially during the light-to-dark transition period.


Assuntos
Transdução de Sinal Luminoso/efeitos da radiação , Luz , Atividade Motora/efeitos da radiação , Células Fotorreceptoras/fisiologia , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/deficiência , Animais , Relógios Biológicos/genética , Relógios Biológicos/fisiologia , Encéfalo/metabolismo , Feminino , Expressão Gênica , Hibridização In Situ , Masculino , Camundongos , Camundongos Endogâmicos ICR , Camundongos Knockout , Atividade Motora/fisiologia , Proteínas Circadianas Period/genética , Fotoperíodo , Células Fotorreceptoras/metabolismo , Polipeptídeo Hipofisário Ativador de Adenilato Ciclase/genética , Pupila/fisiologia , Pupila/efeitos da radiação , Retina/fisiologia , Retina/efeitos da radiação , Reação em Cadeia da Polimerase Via Transcriptase Reversa , Opsinas de Bastonetes/genética , Fatores de Tempo
15.
Neurosci Res ; 66(1): 14-21, 2010 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-19766678

RESUMO

The glucose analog 2-deoxy-d-glucose (2DG) depletes cells of glucose. Inhibition of glycosylation caused by glucose depletion induces endoplasmic reticulum (ER) stress with subsequent apoptosis. Glucose-regulated protein 78 (GRP78) is a molecular chaperone that acts within the ER. During ER stress, GRP78 expression is induced as part of the unfolded protein response (UPR). We found that nerve growth factor (NGF) prevented 2DG-triggered ER stress-mediated apoptosis, but not the induction of GRP78 expression, in PC12 cells. Surprisingly, GRP78 expression was further up-regulated when NGF was added to 2DG-treated PC12 cells. When a specific inhibitor of phosphatidylinositol 3-kinase (PI3-K), LY294002, was added to 2DG plus NGF-treated cells, both the effects of NGF on 2DG-induced apoptosis and GRP78 expression were significantly diminished. In addition, versipelostatin (VST), a specific inhibitor of GRP78 expression, and small interfering RNA (siRNA) against GRP78 mRNA also decreased both the effects of NGF on 2DG-induced apoptosis and GRP78 expression. RT-PCR and Western blot analyses revealed that enhanced production of nuclear p50 ATF6, but not spliced XBP1, mainly contributed to the NGF-induced enhancement of GRP78 expression in 2DG-treated cells. These results suggest that the NGF-activated PI3-K/Akt signaling pathway plays a protective role against ER stress-mediated apoptosis via enhanced expression of GRP78 in PC12 cells.


Assuntos
Antimetabólitos/farmacologia , Apoptose/efeitos dos fármacos , Desoxiglucose/farmacologia , Retículo Endoplasmático/efeitos dos fármacos , Proteínas de Choque Térmico/metabolismo , Fator de Crescimento Neural/farmacologia , Análise de Variância , Animais , Proteínas de Ligação a DNA/genética , Proteínas de Ligação a DNA/metabolismo , Relação Dose-Resposta a Droga , Interações Medicamentosas , Chaperona BiP do Retículo Endoplasmático , Inibidores Enzimáticos/farmacologia , Proteínas de Choque Térmico/genética , Marcação In Situ das Extremidades Cortadas/métodos , Células PC12/ultraestrutura , RNA Mensageiro/metabolismo , Ratos , Fatores de Transcrição de Fator Regulador X , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo , Transfecção/métodos , Regulação para Cima/efeitos dos fármacos , Proteína 1 de Ligação a X-Box
16.
Brain Res ; 1228: 97-106, 2008 Sep 04.
Artigo em Inglês | MEDLINE | ID: mdl-18634768

RESUMO

beta-Adducin is a cytoskeletal protein that interacts with the actin filaments to suppress actin polymerization and facilitate actin-spectrin binding. We have previously shown that beta-adducin is phosphorylated by Fyn at tyrosine489 in the rat brain and bound to its Src-homology 2 domain. In the present study, we examined the immunohistochemical localization of the tyrosine489-phosphorylated form of beta-adducin (pY489-beta-adducin) in the rat brain. Among brain regions, highest immunoreactivity was located in the hypothalamic tanycytes that are of glial origin lining around the third cerebral ventricle. Their immunoreactive processes extended into the arcuate nucleus, ventromedial hypothalamus and the median eminence. In addition, the pY489-beta-adducin immunoreactivity in the tanycytes was enhanced after fasting for 36-48 h, being associated with a morphological change of the DARPP-32-immunoreactivity. Intraperitoneal injection of 2-deoxy-d-glucose also enhances pY489-beta-adducin immunoreactivity in the tanycytes, along with increased food intake. These results suggest that tyrosine phosphorylation of beta-adducin in the tanycytes is involved in hypothalamic regulation of food intake and energy homeostasis.


Assuntos
Proteínas de Ligação a Calmodulina/fisiologia , Proteínas do Citoesqueleto/fisiologia , Metabolismo Energético/fisiologia , Hipotálamo/metabolismo , Animais , Núcleo Arqueado do Hipotálamo/metabolismo , Proteínas de Ligação a Calmodulina/metabolismo , Ventrículos Cerebrais/metabolismo , Proteínas do Citoesqueleto/metabolismo , Desoxiglucose/administração & dosagem , Desoxiglucose/farmacologia , Fosfoproteína 32 Regulada por cAMP e Dopamina/metabolismo , Ingestão de Alimentos/efeitos dos fármacos , Ingestão de Alimentos/fisiologia , Jejum , Homeostase/efeitos dos fármacos , Hipotálamo/citologia , Hipotálamo/efeitos dos fármacos , Immunoblotting , Imuno-Histoquímica , Injeções Intraperitoneais , Injeções Intraventriculares , Masculino , Eminência Mediana/metabolismo , Fosfoproteínas/metabolismo , Fosfoproteínas/fisiologia , Fosforilação , Ratos , Ratos Wistar , Tirosina/metabolismo
17.
Biochem Biophys Res Commun ; 346(2): 600-5, 2006 Jul 28.
Artigo em Inglês | MEDLINE | ID: mdl-16765915

RESUMO

Fyn is a Src-family tyrosine kinase involved in neuronal development, transmission, and plasticity in mammalian central nervous system. We have previously reported that Fyn binds to a cytoskeletal protein, beta-adducin, in a phosphorylation-dependent manner. In the present report, we show that Fyn phosphorylates beta-adducin at tyrosine 489 located in its C-terminal tail domain. Phosphorylation of beta-adducin at Y489 was required for its association with the Fyn-SH2 domain. An antibody specific to the phosphorylated form of beta-adducin was raised in rabbits and showed that Y489 of beta-adducin was phosphorylated in wild type, but not in Fyn(-/-) mice, suggesting that Y489 of beta-adducin is phosphorylated downstream of Fyn in vivo. After phosphorylation at Y489, beta-adducin was translocated to the cell periphery, and colocalized with Fyn. These results suggest that Fyn phosphorylates and binds to beta-adducin at Y489, resulting in translocation of beta-adducin to the Fyn-enriched regions in the plasma membrane.


Assuntos
Proteínas de Ligação a Calmodulina/metabolismo , Proteínas Proto-Oncogênicas c-fyn/metabolismo , Tirosina/metabolismo , Animais , Células COS , Membrana Celular/metabolismo , Chlorocebus aethiops , Imuno-Histoquímica , Camundongos , Camundongos Knockout , Fosforilação , Ligação Proteica , Transporte Proteico , Proteínas Proto-Oncogênicas c-fyn/genética , Coelhos , Transdução de Sinais
18.
Biochem Biophys Res Commun ; 319(1): 178-84, 2004 Jun 18.
Artigo em Inglês | MEDLINE | ID: mdl-15158458

RESUMO

The hypothalamus has a central role in maintaining homeostases of physiological conditions including body temperature and energy balance. To examine molecular responses to cold exposure in the hypothalamus, we examined changes in protein tyrosine phosphorylation in the suprachiasmatic nucleus of the hypothalamus after acute cold exposure in rats. It was found that brain immunoglobulin-like molecule with tyrosine-based inhibitory motifs (BIT, also called SHPS-1, SIRPalpha or p84), a transmembrane glycoprotein with two ITIM motifs, showed enhanced tyrosine phosphorylation after cold exposure. Its tyrosine phosphorylation induced by cold exposure was also found in other hypothalamic nuclei including the paraventricular nucleus, lateral hypothalamic area, ventromedial hypothalamus, and arcuate nucleus. This phosphorylation was blocked by AP-5, an NMDA receptor antagonist, indicating that it was mediated by NMDA receptors. These results suggest that BIT is involved in the mechanism of neuronal responses to cold exposure in the hypothalamus.


Assuntos
Antígenos de Diferenciação/metabolismo , Hipotálamo/metabolismo , Glicoproteínas de Membrana/metabolismo , Molécula L1 de Adesão de Célula Nervosa/metabolismo , Receptores Imunológicos/metabolismo , Receptores de N-Metil-D-Aspartato/metabolismo , Tirosina/química , Motivos de Aminoácidos , Animais , Núcleo Celular/metabolismo , Temperatura Baixa , Concanavalina A/farmacologia , Immunoblotting , Masculino , Fosforilação , Testes de Precipitina , Ratos , Ratos Wistar , Sefarose/química , Núcleo Supraquiasmático/metabolismo , Temperatura , Fatores de Tempo
19.
FEBS Lett ; 557(1-3): 204-8, 2004 Jan 16.
Artigo em Inglês | MEDLINE | ID: mdl-14741368

RESUMO

BIT is a transmembrane glycoprotein with three immunoglobulin-like domains in its extracellular region and tyrosine phosphorylation sites in its cytosolic region. We have previously shown that BIT was tyrosine phosphorylated in the hypothalamic suprachiasmatic nucleus in response to light exposure during the dark period, and suggested that it was involved in the light entrainment of the circadian clock. To further investigate the function of BIT in the nervous system, we examined the effect of photic stimulation on its tyrosine phosphorylation in the rat retina. It was found that the tyrosine phosphorylation level of BIT in the retina was higher in the light period than in the dark period. In addition, a light stimulation during the dark period resulted in a rapid phosphorylation of BIT and a subsequent association of BIT with SHP-2. The phosphorylation state was quickly reverted when the light was turned off. The light-dependent phosphorylation of BIT was also observed in isolated cultured retinas, and this was blocked by a specific Src-family inhibitor, PP-2. Immunohistochemical study showed that BIT was highly enriched in the inner and outer plexiform layers in the retina, where the immunoreactivity to anti-SHP-2 antibody was also detected. These results suggest that tyrosine phosphorylation of BIT is involved in neuronal transmission in the retina.


Assuntos
Antígenos de Diferenciação , Glicoproteínas de Membrana/metabolismo , Molécula L1 de Adesão de Célula Nervosa/metabolismo , Receptores Imunológicos/metabolismo , Retina/fisiologia , Tirosina/metabolismo , Animais , Concanavalina A , Escuridão , Imuno-Histoquímica , Luz , Fosforilação , Fosfotirosina/metabolismo , Estimulação Luminosa , Ratos , Retina/citologia , Retina/metabolismo , Retina/efeitos da radiação , Domínios de Homologia de src
20.
Brain Res ; 976(2): 194-201, 2003 Jun 27.
Artigo em Inglês | MEDLINE | ID: mdl-12763253

RESUMO

Circadian rhythms of mammals are generated by a circadian oscillation of master pacemaker genes in the suprachiasmatic nucleus of the hypothalamus (SCN), and entrained by environmental factors such as 24-h light-dark cycles. We have previously shown that light exposure during the dark period enhanced tyrosine phosphorylation of brain immunoglobulin-like molecule with tyrosine-based activation motifs (BIT) in the rat SCN. To elucidate the functional roles of BIT in the circadian clock, we stimulated BIT using an anti-BIT monoclonal antibody (mAb) 1D4, which reacts with its extracellular region and induces phosphorylation of its intracellular tyrosine residues. Administration of mAb 1D4 into the third cerebral ventricle induced tyrosine phosphorylation of BIT in the SCN. Behavioral analyses showed that the SCN-injection of the antibody at CT15 induced a phase delay of the circadian rhythm of locomotor activity, and that at CT20 induced a phase advance. Pretreatment with MK801, a non-competitive antagonist of NMDARs, diminished the 1D4-induced phase shift at CT20, but not at CT15. These results suggest that BIT is involved in the entrainment of circadian rhythms through the function of NMDARs and non-NMDARs.


Assuntos
Antígenos de Diferenciação , Ritmo Circadiano/fisiologia , Glicoproteínas de Membrana/metabolismo , Molécula L1 de Adesão de Célula Nervosa/metabolismo , Receptores Imunológicos , Animais , Anticorpos Monoclonais/farmacologia , Células Cultivadas , Masculino , Glicoproteínas de Membrana/imunologia , Proteínas Quinases Ativadas por Mitógeno/metabolismo , Atividade Motora/fisiologia , Molécula L1 de Adesão de Célula Nervosa/imunologia , Neurônios/citologia , Neurônios/metabolismo , Fosforilação , Ratos , Ratos Wistar , Receptores de N-Metil-D-Aspartato/metabolismo , Núcleo Supraquiasmático/fisiologia , Tirosina/metabolismo
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