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1.
Arq Neuropsiquiatr ; 78(1): 21-27, 2020 01.
Artigo em Inglês | MEDLINE | ID: mdl-32074185

RESUMO

OBJECTIVE: The phytohormone abscisic acid (ABA) as a signaling molecule exists in various types of organisms from early multicellular to animal cells and tissues. It has been demonstrated that ABA has an antinociceptive effect in rodents. The present study was designed to assess the possible role of PKA and phosphorylated ERK (p-ERK) on the antinociceptive effects of intrathecal (i.t.) ABA in male Wistar rats. METHODS: The animals were cannulated intrathecally and divided into different experimental groups (n=6‒7): Control (no surgery), vehicle (received ABA vehicle), ABA-treated groups (received ABA in doses of 10 or 20 µg/rat), ABA plus H.89 (PKA inhibitor)-treated group which received the inhibitor 15 min prior to the ABA injection. Tail-flick and hot-plate tests were used as acute nociceptive stimulators to assess ABA analgesic effects. p-ERK was evaluated in the dorsal portion of the spinal cord using immunoblotting. RESULTS: Data showed that a microinjection of ABA (10 and 20 µg/rat, i.t.) significantly increased the nociceptive threshold in tail flick and hot plate tests. The application of PKA inhibitor (H.89, 100 nM/rat) significantly inhibited ABA-induced analgesic effects. Expression of p-ERK was significantly decreased in ABA-injected animals, which were not observed in the ABA+H.89-treated group. CONCLUSIONS: Overall, i.t. administration of ABA (10 µg/rat) induced analgesia and p-ERK down-expression likely by involving the PKA-dependent mechanism.


Assuntos
Ácido Abscísico/farmacologia , Analgésicos/farmacologia , Proteínas Quinases Dependentes de AMP Cíclico/efeitos dos fármacos , MAP Quinases Reguladas por Sinal Extracelular/efeitos dos fármacos , Reguladores de Crescimento de Planta/farmacologia , Medula Espinal/metabolismo , Animais , Western Blotting , Proteínas Quinases Dependentes de AMP Cíclico/análise , MAP Quinases Reguladas por Sinal Extracelular/análise , Peptídeos e Proteínas de Sinalização Intracelular/farmacologia , Masculino , Ratos Wistar , Valores de Referência , Reprodutibilidade dos Testes , Medula Espinal/efeitos dos fármacos , Fatores de Tempo
2.
Int J Mol Sci ; 20(18)2019 Sep 09.
Artigo em Inglês | MEDLINE | ID: mdl-31505887

RESUMO

The extensive usage of silver nanoparticles (AgNPs) as medical products such as antimicrobial and anticancer agents has raised concerns about their harmful effects on human beings. AgNPs can potentially induce oxidative stress and apoptosis in cells. However, humanin (HN) is a small secreted peptide that has cytoprotective and neuroprotective cellular effects. The aim of this study was to assess the harmful effects of AgNPs on human neuroblastoma SH-SY5Y cells and also to investigate the protective effect of HN from AgNPs-induced cell death, mitochondrial dysfunctions, DNA damage, and apoptosis. AgNPs were prepared with an average size of 18 nm diameter to study their interaction with SH-SY5Y cells. AgNPs caused a dose-dependent decrease of cell viability and proliferation, induced loss of plasma-membrane integrity, oxidative stress, loss of mitochondrial membrane potential (MMP), and loss of ATP content, amongst other effects. Pretreatment or co-treatment of HN with AgNPs protected cells from several of these AgNPs induced adverse effects. Thus, this study demonstrated for the first time that HN protected neuroblastoma cells against AgNPs-induced neurotoxicity. The mechanisms of the HN-mediated protective effect on neuroblastoma cells may provide further insights for the development of novel therapeutic agents against neurodegenerative diseases.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/farmacologia , Nanopartículas Metálicas/toxicidade , Mitocôndrias/metabolismo , Proteínas Mitocondriais/farmacologia , Prata/toxicidade , Morte Celular/efeitos dos fármacos , Linhagem Celular Tumoral , Membrana Celular/metabolismo , Membrana Celular/patologia , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Nanopartículas Metálicas/química , Mitocôndrias/patologia , Proteínas Mitocondriais/metabolismo , Neuroblastoma/metabolismo , Neuroblastoma/patologia , Doenças Neurodegenerativas/tratamento farmacológico , Doenças Neurodegenerativas/metabolismo , Doenças Neurodegenerativas/patologia , Síndromes Neurotóxicas/tratamento farmacológico , Síndromes Neurotóxicas/metabolismo , Síndromes Neurotóxicas/patologia , Estresse Oxidativo/efeitos dos fármacos , Prata/química
3.
Chemistry ; 25(66): 15198-15204, 2019 Nov 27.
Artigo em Inglês | MEDLINE | ID: mdl-31549755

RESUMO

Polytheonamide B (1) is a linear 48-mer natural peptide with alternating d- and l-amino acid residues. Compound 1 forms conducting channels for monovalent ions and exhibits potent cytotoxicity against MCF-7 cells. Previously, we reported that nanomolar concentrations of 1 induce plasma membrane depolarization and lysosomal pH disruption, which triggers apoptosis. Here, we report the cellular localization and biological action of a simplified synthetic analogue of 1, polytheonamide mimic 3. Compared with 1, the toxicity of 3 against MCF-7 cells is 16 times weaker. Although its plasma membrane depolarization effect is only 3.6 times lower, more 3 (20-fold) is required to neutralize lysosomal pH. Thus, the effective concentrations for lysosomal neutralization and cytotoxicity by 3 are comparable. These results strongly suggest that the activity of 3 against the lysosomal membrane is more important for apoptotic cell death than its effects on the plasma membrane, and provide valuable information regarding the unique behavior of polytheonamide-based molecules.


Assuntos
Membrana Celular/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/química , Lisossomos/metabolismo , Apoptose/efeitos dos fármacos , Corantes Fluorescentes/química , Humanos , Concentração de Íons de Hidrogênio , Interações Hidrofóbicas e Hidrofílicas , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/farmacologia , Células MCF-7 , Potenciais da Membrana/efeitos dos fármacos , Espectrometria de Fluorescência
4.
Int J Neurosci ; 129(11): 1053-1065, 2019 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-31215291

RESUMO

Aim: Alzheimer's disease (AD) is characterized by oxidative stress, neuroinflammation and progressive cognitive decline. Abscisic acid (ABA) is produced in a variety of mammalian tissues, including brain. It has anti-inflammatory and antioxidant effects and elicits a positive effect on spatial learning and memory performance. Here, the possible protective effect of ABA was evaluated in streptozotocin (STZ)-induced AD rat model which were injected intracerebroventriculary (i.c.v.) with STZ (3 mg/kg). Material and Methods: The STZ-treated animals received ABA (10 µg/rat, i.c.v.), ABA plus PPARß/δ receptor antagonist (GSK0660, 80 nM/rat) or ABA plus selective inhibitor of PKA (KT5720, 0.5 µg/rat) for 14 d. Learning and memory were determined using Morris water maze (MWM) and passive avoidance (PA) tests. Results: The data showed that STZ produced a significant learning and memory deficit in both MWM and PA tests. ABA significantly prevented the learning and memory impairment in STZ-treated rats. However, ABA effects were blocked by GSK0660 and KT5720. Conclusion: The data indicated that ABA attenuates STZ-induced learning and memory impairment and PPAR-ß/δ receptors and PKA signaling are involved, at least in part, in the ABA mechanism.


Assuntos
Ácido Abscísico/farmacologia , Doença de Alzheimer/tratamento farmacológico , Peptídeos e Proteínas de Sinalização Intracelular/farmacologia , Aprendizagem/efeitos dos fármacos , Fármacos Neuroprotetores/farmacologia , PPAR delta/antagonistas & inibidores , PPAR beta/antagonistas & inibidores , Reguladores de Crescimento de Planta/farmacologia , Ácido Abscísico/administração & dosagem , Doença de Alzheimer/induzido quimicamente , Animais , Antibióticos Antineoplásicos/farmacologia , Aprendizagem da Esquiva/efeitos dos fármacos , Carbazóis/farmacologia , Modelos Animais de Doenças , Masculino , Aprendizagem em Labirinto/efeitos dos fármacos , Fármacos Neuroprotetores/administração & dosagem , Pirróis/farmacologia , Ratos , Ratos Wistar , Estreptozocina/farmacologia , Sulfonas/farmacologia , Tiofenos/farmacologia
5.
J Biol Chem ; 294(26): 10236-10252, 2019 06 28.
Artigo em Inglês | MEDLINE | ID: mdl-31101654

RESUMO

Proper cell division relies on the coordinated regulation between a structural component, the mitotic spindle, and a regulatory component, anaphase-promoting complex/cyclosome (APC/C). Hematopoietic PBX-interacting protein (HPIP) is a microtubule-associated protein that plays a pivotal role in cell proliferation, cell migration, and tumor metastasis. Here, using HEK293T and HeLa cells, along with immunoprecipitation and immunoblotting, live-cell imaging, and protein-stability assays, we report that HPIP expression oscillates throughout the cell cycle and that its depletion delays cell division. We noted that by utilizing its D box and IR domain, HPIP plays a dual role both as a substrate and inhibitor, respectively, of the APC/C complex. We observed that HPIP enhances the G2/M transition of the cell cycle by transiently stabilizing cyclin B1 by preventing APC/C-Cdc20-mediated degradation, thereby ensuring timely mitotic entry. We also uncovered that HPIP associates with the mitotic spindle and that its depletion leads to the formation of multiple mitotic spindles and chromosomal abnormalities, results in defects in cytokinesis, and delays mitotic exit. Our findings uncover HPIP as both a substrate and an inhibitor of APC/C-Cdc20 that maintains the temporal stability of cyclin B1 during the G2/M transition and thereby controls mitosis and cell division.


Assuntos
Ciclossomo-Complexo Promotor de Anáfase/metabolismo , Proteínas Cdc20/metabolismo , Ciclo Celular , Ciclina B1/química , Regulação da Expressão Gênica/efeitos dos fármacos , Peptídeos e Proteínas de Sinalização Intracelular/farmacologia , Mitose , Ciclossomo-Complexo Promotor de Anáfase/antagonistas & inibidores , Ciclossomo-Complexo Promotor de Anáfase/genética , Proteínas Cdc20/antagonistas & inibidores , Proteínas Cdc20/genética , Células HEK293 , Células HeLa , Humanos , Fuso Acromático , Especificidade por Substrato
6.
Exp Mol Pathol ; 109: 42-50, 2019 08.
Artigo em Inglês | MEDLINE | ID: mdl-31085184

RESUMO

Subfertility is a major concern of long-term cancer survivors at the reproductive age. We have previously demonstrated that a potent humanin analogue, HNG, protected chemotherapy-induced apoptosis in germ cells but not cancer cells in a metastatic melanoma allograft model. In this study, we utilized severe combined immuno-deficiency (SCID) mice bearing human medulloblastoma to study the effect of HNG in Temozolomide (TMZ) induced male germ cell apoptosis and white blood cell (WBC) suppression. Human medulloblastoma DAOY cells were injected subcutaneously into the right flank of male SCID mice. Three weeks later, groups of tumor-bearing mice received one of the following treatments: vehicle, HNG, TMZ, or TMZ + HNG. 24 h after last injection, the tumors weights, complete blood counts, liver and spleen weights, male germ cell apoptosis was assessed. HNG did not affect TMZ's significant anti-tumor action. HNG significantly prevented TMZ-induced germ cell apoptosis and attenuated the suppressed total WBC and granulocyte counts in SCID mice with or without TMZ treatment. HNG also attenuated TMZ-induced body weight loss and decrease of spleen and liver weights. In conclusion, HNG ameliorated TMZ-induced germ cell apoptosis; WBC and granulocytes loss; and decreased body/organ weights without compromising the TMZ's anti-cancer action on medulloblastoma xenografts in SCID mice.


Assuntos
Apoptose/efeitos dos fármacos , Neoplasias Cerebelares/tratamento farmacológico , Peptídeos e Proteínas de Sinalização Intracelular/farmacologia , Meduloblastoma/tratamento farmacológico , Espermatozoides/efeitos dos fármacos , Temozolomida/farmacologia , Ensaios Antitumorais Modelo de Xenoenxerto/métodos , Animais , Antineoplásicos Alquilantes/farmacologia , Linhagem Celular Tumoral , Neoplasias Cerebelares/patologia , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/química , Fígado/efeitos dos fármacos , Fígado/patologia , Masculino , Meduloblastoma/patologia , Camundongos SCID , Tamanho do Órgão/efeitos dos fármacos , Espermatozoides/citologia , Baço/efeitos dos fármacos , Baço/patologia , Carga Tumoral/efeitos dos fármacos
7.
Cell Tissue Res ; 377(2): 161-165, 2019 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-31131430

RESUMO

Besides their well-known function in cellular bioenergetics, the role of mitochondria in signaling regulation of cells homeostasis and survival has been uncovered during the past few decades. Possessing an independent genome and a unique genetic code, mitochondria biosynthesize protective stress response factors, the "mitochondrial-derived peptides," import and deposit peptides within their matrix and are the target of peptides bound to bioactive agents, aiming at alleviation of pathology-related malfunction of the electron transport chain. As the rapidly evolving field of mitochondrial peptides is appropriate for therapeutic exploitation, a brief overview of the major recent findings is timely needed. Here, the focus is on the following issues: (i) the biological effects of mitochondrial-derived peptides (humanin, humanin-like peptides and MOTS-c) and their use in therapy, (ii) the abnormal accumulation of ß-amyloid peptide within the mitochondrial matrix and (iii) the effectiveness of "mitochondrial cell-penetrating/targeting peptides" as vehicles for delivery of bioactive agents into dysfunctional mitochondria.


Assuntos
Peptídeos beta-Amiloides/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/farmacologia , Mitocôndrias , Proteínas Mitocondriais/farmacologia , Animais , DNA Mitocondrial/efeitos dos fármacos , Humanos , Camundongos , Mitocôndrias/efeitos dos fármacos , Mitocôndrias/metabolismo , Mitocôndrias/patologia , Doenças Neurodegenerativas/tratamento farmacológico , Transdução de Sinais/efeitos dos fármacos
8.
Cryobiology ; 88: 47-53, 2019 06.
Artigo em Inglês | MEDLINE | ID: mdl-30959025

RESUMO

This study was aimed to investigate the protective effect of potent humanin analogue (HNG) supplementation to freezing media on freezing-thawing induced human sperm damage. We collected semen samples with normal sperm parameters from 15 healthy men. After the swim-up processing, the motile spermatozoa from each of the men were allocated to four equal groups: In the control group, the spermatozoa were frozen in media without HNG supplementation. In the other three groups, the spermatozoa were frozen in media supplemented with different concentrations of HNG (2 µM, 10 µM and 20 µM, respectively). We analyzed the sperm motility, viability, sperm mitochondrial membrane potential, apoptosis, sperm DNA fragmentation index (DFI), reactive oxygen species (ROS) and malondialdehyde (MDA) levels, and caspase-3 activity for the sperm in each group. As a result, supplementation of HNG with 2 µM, 10 µM and 20 µM to the freezing media all significantly improved sperm motility and viability (all p < 0.05) when compared with the control group. Similarly, we found that supplementation of HNG reduced the damage to the mitochondrial membrane and DNA integrity, and inhibited the reaction of oxidative stress and the activity of caspase-3 in sperm. Although these protective effects increased with the elevated concentration of HNG in the freezing media, a final HNG concentration of 20 µM failed to exert significant improvements when compared with the concentration of 10 µM (all p > 0.05). In conclusion, our results suggested that HNG supplementation to the freezing media could protect sperm cells from freezing-thawing induced sperm damage.


Assuntos
Criopreservação/métodos , Crioprotetores/farmacologia , Peptídeos e Proteínas de Sinalização Intracelular/farmacologia , Preservação do Sêmen/métodos , Espermatozoides/efeitos dos fármacos , Adulto , Animais , Apoptose/efeitos dos fármacos , Caspase 3/metabolismo , Fragmentação do DNA/efeitos dos fármacos , Congelamento , Humanos , Masculino , Malondialdeído/metabolismo , Potencial da Membrana Mitocondrial/efeitos dos fármacos , Estresse Oxidativo/efeitos dos fármacos , Espécies Reativas de Oxigênio/metabolismo , Motilidade Espermática/efeitos dos fármacos , Adulto Jovem
9.
Metabolism ; 94: 88-95, 2019 05.
Artigo em Inglês | MEDLINE | ID: mdl-30831144

RESUMO

OBJECTIVE: Low-density lipoprotein cholesterol (LDL-C) is the hallmark of atherosclerotic cardiovascular diseases. The hepatic LDL receptor (LDLR) plays an important role in clearance of circulating LDL-C. PCSK9 facilitates degradation of LDLR in the lysosome and antagonizing PCSK9 has been successfully used in the clinic to reduce blood LDL-C level. Here we identify a new player that modulates LDLR interaction with PCSK9, thus controlling LDLR degradation and cholesterol homeostasis. METHODS: The blood LDL-C and cholesterol levels were analyzed in mice with hepatic deletion of Paqr3 gene. The half-life of LDLR was analyzed in HepG2 cells. The interaction of PAQR3 with LDLR and PCSK9 was analyzed by co-immunoprecipitation and immunofluorescent staining. RESULTS: The blood LDL-C and total cholesterol levels in the mice with hepatic deletion of Paqr3 gene were significantly lower than the control mice after feeding with high-fat diet (p < 0.001 and p < 0.05 respectively). The steady-state level of LDLR protein is elevated by Paqr3 knockdown/deletion and reduced by PAQR3 overexpression. The half-life of LDLR protein is increased by Paqr3 knockdown and accelerated by PAQR3 overexpression. PAQR3 interacts with the ß-sheet domain of LDLR and the P-domain of PCSK9 respectively. In addition, PAQR3 can be localized in early endosomes and colocalized with LDLR, PCSK9 and LDL. Mechanistically, PAQR3 enhances the interaction between LDLR and PCSK9. CONCLUSION: Our study reveals that PAQR3 plays a pivotal role in controlling hepatic LDLR degradation and blood LDL-C level via modulating LDLR-PCSK9 interaction.


Assuntos
Colesterol/sangue , Peptídeos e Proteínas de Sinalização Intracelular/farmacologia , Pró-Proteína Convertase 9/metabolismo , Receptores de LDL/metabolismo , Animais , LDL-Colesterol/sangue , Células Hep G2 , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/deficiência , Peptídeos e Proteínas de Sinalização Intracelular/genética , Fígado/metabolismo , Camundongos , Ligação Proteica/efeitos dos fármacos
10.
Biochem Biophys Res Commun ; 509(4): 855-861, 2019 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-30638930

RESUMO

Worldwide, hepatocellular carcinoma (HCC) remains a top instigator of cancer mortality. Previous clinical studies have revealed that low serum cholesterol predicts a poor outcome in HCC patients, but the potential role of cholesterol in the progression of HCC remains controversial. In the present study,we tested the influence of cholesterol on the progression of DEN-induced HCC by feeding mice with a high cholesterol diet (HCD) and by depriving cholesterol with atorvastatin, a widely used inhibitor of the mevalonate pathway. We found that HCD induced more and larger liver tumors and an increased occurrence of lung metastasis in DEN-injected mice. These effects could be prevented by cholesterol deprivation with atorvastatin. In vitro, cholesterol loading repressed the proliferation, migration, and the invasion of SK hep1 cells, which was additionally prevented by cholesterol deprivation. Both in vivo and in vitro, cholesterol loading decreased the expression of Sterol regulatory element-binding protein cleavage-activating protein (SCAP), the translocation of sterol regulatory element-binding protein1 (SREBP1) to the nucleolus, and the genetic expression of FAS and ACC-1. Over-expression of SCAP in cholesterol-loaded SK hep1 cells promoted the nuclear translocation of SREBP1 and the expression of FAS and ACC-1, which promoted the proliferation, migration, and the invasion of SK hep1 cells. Knockdown of SCAP also restrained the cholesterol deletion-mediated up-regulation of fatty acid de novo synthesis in SK hep1 cells, inhibiting the atorvastatin-mediated proliferation, migration, and invasion of SK hep1 cells. In conclusion, cholesterol inhibited the progression of HCC through restraining SCAP-mediated fatty acid de novo synthesis.


Assuntos
Carcinoma Hepatocelular/patologia , Colesterol/farmacologia , Ácidos Graxos/biossíntese , Peptídeos e Proteínas de Sinalização Intracelular/antagonistas & inibidores , Neoplasias Hepáticas/patologia , Proteínas de Membrana/antagonistas & inibidores , Animais , Carcinoma Hepatocelular/induzido quimicamente , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Colesterol/administração & dosagem , Progressão da Doença , Peptídeos e Proteínas de Sinalização Intracelular/farmacologia , Neoplasias Hepáticas/induzido quimicamente , Proteínas de Membrana/farmacologia , Camundongos , Proteína de Ligação a Elemento Regulador de Esterol 1/metabolismo
11.
Biochem Biophys Res Commun ; 509(4): 911-917, 2019 02 19.
Artigo em Inglês | MEDLINE | ID: mdl-30638932

RESUMO

Dendritic cells (DCs) are professional antigen-presenting cells. The main function of DCs is to process antigen and present it to the T cells to induce T cell immunity. In addition to their function as potent stimulators of adaptive immunity, DCs are also crucial for maintaining immunological tolerance through the induction of peripheral regulatory T cells. Tumor necrosis factor-α-induced protein 8-2 (Tumor necrosis factor-α induced protein-8-like 2, TNFAIP8L2 or TIPE2) was expressed primarily by immune cells and maintains immune tolerance through the negative regulation of innate and adaptive immune responses. Previous studies indicate that TIPE2 in DCs may inhibit the innate immune response to RNA. However, the role of TIPE2 in DCs in the induction of peripheral tolerance remains unknown. Our current study showed that Tipe2-deficient DCs are more immature under homeostatic condition and consequently promote the induction of peripheral Tregs in the gut mucosa. Mechanistic studies revealed that TIPE2 promotes the expression of DC maturation markers CD80 and CD86 through the activation of PI3K-PKCδ-MAPK signaling pathway during the differentiation of DCs. Taken together, these results indicate that, in addition to acting as a negative regulator of pathogen-induced immune response, TIPE2 in DCs is also capable of promoting immune response under homeostatic condition through the suppression of peripheral tolerance.


Assuntos
Células Dendríticas/imunologia , Mucosa Intestinal/imunologia , Peptídeos e Proteínas de Sinalização Intracelular/farmacologia , Linfócitos T Reguladores/imunologia , Ativação Transcricional/imunologia , Animais , Diferenciação Celular/efeitos dos fármacos , Células Cultivadas , Homeostase , Humanos , Tolerância Imunológica/efeitos dos fármacos , Imunidade Inata/efeitos dos fármacos , Proteínas Quinases/efeitos dos fármacos , Proteínas Quinases/metabolismo , Transdução de Sinais , Ativação Transcricional/efeitos dos fármacos
12.
J Microbiol Biotechnol ; 28(12): 2121-2132, 2018 Dec 28.
Artigo em Inglês | MEDLINE | ID: mdl-30415530

RESUMO

Abnormal melanin synthesis results in several hyperpigmentary disorders such as freckles, melanoderma, age spots, and other related conditions. In this study, we investigated the antimelanogenic effects of an extract from the microalgae Chlamydomonas reinhardtii (CE) and potential mechanisms responsible for its inhibitory effect in B16F10, normal human epidermal melanocyte cells, and human skin-equivalent models. The CE extract showed significant dose-dependent inhibitory effects on α-melanocyte-stimulating, hormone-induced melanin synthesis in cells. Additionally, the CE extract exhibited suppressive effects on the mRNA and protein expression of microphthalmia-associated transcription factor, tyrosinase, tyrosinase-related protein-1, and tyrosinase-related protein-2. The CE extract also inhibited the phosphorylation of protein kinase A and extracellular signal-related kinase, which function as upstream regulators of melanogenesis. Using a three-dimensional, reconstructed pigmented epidermis model, the CE-mediated, anti-pigmentation effects were confirmed by Fontana-Masson staining and melanin content assays. Taken together, CE extract can be used as an anti-pigmentation agent.


Assuntos
Chlamydomonas reinhardtii/química , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Pigmentação/efeitos dos fármacos , Extratos Vegetais/farmacologia , Transdução de Sinais/efeitos dos fármacos , Animais , Linhagem Celular Tumoral/efeitos dos fármacos , Sobrevivência Celular/efeitos dos fármacos , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Relação Dose-Resposta a Droga , Regulação para Baixo/efeitos dos fármacos , Descoberta de Drogas , Células Epidérmicas/efeitos dos fármacos , Células Epidérmicas/patologia , Epiderme/efeitos dos fármacos , Epiderme/patologia , MAP Quinases Reguladas por Sinal Extracelular , Regulação da Expressão Gênica/efeitos dos fármacos , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/farmacologia , Oxirredutases Intramoleculares/metabolismo , Melaninas/metabolismo , Melanoma , Glicoproteínas de Membrana/metabolismo , Camundongos , Fator de Transcrição Associado à Microftalmia/metabolismo , Monofenol Mono-Oxigenase/metabolismo , Oxirredutases/metabolismo , Fosforilação , RNA Mensageiro/efeitos dos fármacos , Pele , alfa-MSH/metabolismo
13.
Int J Mol Sci ; 19(10)2018 Sep 29.
Artigo em Inglês | MEDLINE | ID: mdl-30274308

RESUMO

Humanin (HN) is a novel 24-amino acid peptide that protects neurons against N-methyl-d-aspartate (NMDA)-induced toxicity. However, the contribution of the different mitogen-activated protein kinases (MAPKs) signals to HN neuroprotection against NMDA neurotoxicity remains unclear. The present study was therefore aimed to investigate neuroprotective mechanisms of HN. We analyzed intracellular Ca2+ levels, reactive oxygen species (ROS) production, and the MAPKs signal transduction cascade using an in vitro NMDA-mediated excitotoxicity of cortical neurons model. Results showed that: (1) HN attenuated NMDA-induced neuronal insults by increasing cell viability, decreasing lactate dehydrogenase (LDH) release, and increasing cell survival; (2) HN reversed NMDA-induced increase in intracellular calcium; (3) pretreatment by HN or 1,2-bis(2-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (BAPTA-AM), an intracellular calcium chelator, decreased ROS generation after NMDA exposure; (4) administration of HN or N-Acetyl-l-cysteine (NAC), a ROS scavenger, inhibited NMDA-induced JNK and p38 MAPK activation. These results indicated that HN reduced intracellular elevation of Ca2+ levels, which, in turn, inhibited ROS generation and subsequent JNK and p38 MAPK activation that are involved in promoting cell survival in NMDA-induced excitotoxicity. Therefore, the present study suggests that inhibition of ROS-dependent JNK/p38 MAPK signaling pathway serves an effective strategy for HN neuroprotection against certain neurological diseases.


Assuntos
Peptídeos e Proteínas de Sinalização Intracelular/farmacologia , Sistema de Sinalização das MAP Quinases/efeitos dos fármacos , Proteínas Quinases Ativadas por Mitógeno/metabolismo , N-Metilaspartato/toxicidade , Proteínas Quinases p38 Ativadas por Mitógeno/metabolismo , Animais , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Transdução de Sinais/efeitos dos fármacos
14.
J Med Chem ; 61(19): 8707-8716, 2018 10 11.
Artigo em Inglês | MEDLINE | ID: mdl-30183282

RESUMO

Urotensin II (UII) and urotensin II-related peptide (URP) are functionally selective, suggesting that these two hormones might play distinct physiological role through different interactions with their cognate receptor UT. Hypothesizing that the Phe3 residue of URP, which is also present in UII, is a key-element of its specific UT activation, we evaluated the impact of its replacement by non-natural amino acids in URP. Each compound was evaluated for its ability to bind UT, induce rat aortic ring contraction, and activate Gq, G12, and ß-arrestin 1 signaling pathways. Such modifications impaired contractile efficacy, reflected by a reduced aptitude to activate G12 in URP but not in the truncated but equipotent UII4-11. Moreover, we have identified two structurally different UT modulators: [d-Phe(pI)3]URP and [Bip3]URP, which exert a probe-dependent action against UII and URP. These compounds should help us understand the specific roles of these hormones as well as guide further therapeutic development.


Assuntos
Aorta/fisiologia , Descoberta de Drogas , Peptídeos e Proteínas de Sinalização Intracelular/farmacologia , Hormônios Peptídicos/farmacologia , Fenilalanina/metabolismo , Urotensinas/farmacologia , Vasoconstrição/fisiologia , Regulação Alostérica , Animais , Aorta/efeitos dos fármacos , Arrestina/metabolismo , Células HEK293 , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/química , Hormônios Peptídicos/química , Fenilalanina/química , Ratos , Receptores Acoplados a Proteínas-G/metabolismo , Vasoconstrição/efeitos dos fármacos
15.
Cell Signal ; 52: 147-154, 2018 12.
Artigo em Inglês | MEDLINE | ID: mdl-30213686

RESUMO

Extracellular signal-regulated kinase (ERK), also known as classical mitogen-activated protein kinase, plays critical roles in cell regulation. ERK is activated through phosphorylation by a cascade of protein kinases including MEK. Various ligands activate the MEK/ERK pathway through receptor-dependent cell signaling. In cultured cells, many ligands such as growth factors, hormones, cytokines and vasoactive peptides elicit transient activation of MEK/ERK, often peaking at ~10 min after the cell treatment. Here, we describe a novel biological event, in which ligand-mediated cell signaling results in the dephosphorylation of MEK/ERK. Neuromedin N and neurotensin, peptides derived from the same precursor polypeptide, elicit cell signaling through the neurotensin receptors. In cultured human pulmonary artery smooth muscle cells (PASMCs), but not in human pulmonary artery endothelial cells (PAECs), we found that both neuromedin N and neurotensin promoted the dephosphorylation of ERK and MEK. Human PASMCs were found to express neurotensin receptor (NTR)-1, -2 and -3, while human PAECs only express NTR3. Neuromedin N-mediated dephosphorylation was suppressed by small chemical inhibitors of protein phosphatase 1/2A and peptidyl-prolyl isomerase. Transmission electron microscopy showed the formation of endocytic vesicles in response to neuromedin N treatment, and dephosphorylation did not occur when sorting nexin 9, a critical regulator of the endocytic vesicle formation, was knocked down. We conclude that neuromedin N and neurotensin elicit a unique dephosphorylation signaling in the MEK/ERK pathway that is regulated by endocytosis. Considering the pathophysiological importance of the MEK/ERK pathway, this discovery of the dephosphorylation mechanism should advance the field of cell signaling.


Assuntos
Células Endoteliais/metabolismo , Miócitos de Músculo Liso/metabolismo , Neurotensina/fisiologia , Fragmentos de Peptídeos/fisiologia , Artéria Pulmonar/metabolismo , Células Endoteliais/citologia , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/farmacologia , Sistema de Sinalização das MAP Quinases , Miócitos de Músculo Liso/citologia , Peptidilprolil Isomerase/antagonistas & inibidores , Nexinas de Proteases/metabolismo , Artéria Pulmonar/citologia , Proteínas de Ligação a RNA , Receptores de Neurotensina/metabolismo
16.
Life Sci ; 209: 466-471, 2018 Sep 15.
Artigo em Inglês | MEDLINE | ID: mdl-30144450

RESUMO

AIMS: Smooth muscle cells (SMCs) play a role in medial vascular calcification, which can be stimulated by high levels of serum phosphate and inflammatory mediators. The aim of this study was to investigate whether mitogen-activated protein kinases (MAPKs) (p38 MAPK, ERK1/2, and JNK) and protein kinase A (PKA) can participate in inorganic phosphate (Pi)- and inflammation response-stimulated SMC calcification. MAIN METHODS: We examined the change of Pi- and/or inflammation-stimulated human aortic smooth muscle cell (HASMC) calcification in the presence and absence of inhibitors or small interfering RNAs. KEY FINDINGS: Ca levels were increased in HASMCs incubated with 1.5-3.9 mM Pi, but not with 0.9 mM Pi or compared with non-Pi-treated HASMCs. Furthermore, the addition of interferon-γ (IFN-γ) increased pro-inflammatory cytokines [interleukin (IL)-1α, IL-6, and tumor necrosis factor-α (TNF-α)] in media containing Raw 264.7 cells. Ca levels were significantly increased in HASMCs cultured in IFN-γ-treated medium, compared with non-IFN-γ-treated medium in the presence of Pi (0.9-2.4 mM). The inhibition of p38 MAPK and PKA decreased HASMC calcification stimulated by Pi and IFN-γ-treated medium, though PKA inhibition produced a more significant reduction in calcification than p38 MAPK inhibition. SIGNIFICANCE: These results indicate that PKA inhibition can efficiently reduce Pi- and inflammation-stimulated SMC calcification.


Assuntos
Aorta/efeitos dos fármacos , Proteínas Quinases Dependentes de AMP Cíclico/antagonistas & inibidores , Inflamação/fisiopatologia , Interferon gama/farmacologia , Músculo Liso Vascular/efeitos dos fármacos , Fosfatos/farmacologia , Calcificação Vascular/tratamento farmacológico , Aorta/imunologia , Aorta/metabolismo , Aorta/patologia , Células Cultivadas , Humanos , Mediadores da Inflamação/metabolismo , Peptídeos e Proteínas de Sinalização Intracelular/farmacologia , Músculo Liso Vascular/imunologia , Músculo Liso Vascular/metabolismo , Músculo Liso Vascular/patologia , Fator de Necrose Tumoral alfa/metabolismo , Calcificação Vascular/imunologia , Calcificação Vascular/metabolismo , Calcificação Vascular/patologia
17.
Rejuvenation Res ; 21(4): 369-373, 2018 Aug.
Artigo em Inglês | MEDLINE | ID: mdl-30058454

RESUMO

Mitochondrial-derived peptides (MDPs), encoded by mitochondrial DNA, play a cytoprotective role by helping preserve mitochondrial function and cell viability under stressful conditions. Humanin and its homologs and MOTS-c are two of several MDPs hypothesized to have antiaging activity based on correlative studies. For example, humanin plasma levels are inversely correlated with growth hormone and insulin-like growth factor 1 expression, which may promote accelerated aging. Humanin has been shown to protect cells from beta amyloid toxicity and preserve endothelial cell function in a mouse model of atherosclerosis. Furthermore, both humanin and MOTS-c improve insulin sensitivity in mouse models of type 2 diabetes. Recently it was reported that a potent analogue of humanin blocks cardiac fibrosis in aging mice. Although it has been hypothesized that MDPs might have senolytic activity, in a recent report humanin and MOTS-c both exacerbate the senescence-associated-secretory-phenotype (SASP) in senescent cells by stimulating the secretion of IL-6, IL-1ß, IL-8, IL-10 and tumor necrosis factor α. It appears that the cytoprotective activity of the MDPs may be permissive for increased expression of a set of proinflammatory cytokines. Given the potential benefits of MDPs in many of the same diseases associated with the presence of senescent cells, a combination of senolytic and MDP-based treatments may be additive or synergistic. The MDPs would protect normal cells, whereas senescent cells would be eliminated by the senolytic therapy. It is even possible that MDPs by increasing the SASP phenotype would make the senescent cells more apt to be cleared by the immune system or more sensitive to senolytics. In contrast, if the MDPs actually cytoprotect the senescent cells, then the treatment can be performed serially with the senolytic used first.


Assuntos
Senescência Celular , Mitocôndrias/metabolismo , Peptídeos/farmacologia , Animais , Senescência Celular/efeitos dos fármacos , Fibroblastos/citologia , Fibroblastos/efeitos dos fármacos , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/farmacologia , Fenótipo
18.
Mol Immunol ; 101: 245-250, 2018 09.
Artigo em Inglês | MEDLINE | ID: mdl-30029058

RESUMO

Endothelial dysfunction and vascular complications induced by hyperglycemia play an important role in the pathological development of atherosclerosis in diabetes. Humanin, a 24-amino acid mitochondria-derived polypeptide, has displayed its cytoprotective effects in diverse cell types and tissues. In the current study, we aimed to characterize the effects of humanin on high glucose-induced endothelial dysfunction. Firstly, we found that humanin treatment induced the expression of Krüppel-like factor 2 (KLF2), an essential transcriptional regulator of endothelial function, at the transcriptional level in human umbilical vein endothelial cells (HUVECs). Additionally, our results indicate that humanin treatment regulated the expression of KLF2 target genes such as endothelial nitric oxide synthase (eNOS) and endothelin-1 (ET-1). Evidence demonstrated that the effects of humanin on KLF2 expression was mediated by the phosphorylation of extracellular signal regulated kinase 5 (ERK5). Furthermore, humanin restored high glucose-induced reduction of KLF2 expression. We also showed that humanin significantly reduced the expression of vascular cell adhesion molecule 1 (VCAM-1) and E-selectin. Notably, humanin treatment markedly prevented high glucose-induced attachment of the monocyte THP-1 cells to HUVECs. However, knockdown of KLF2 abolished these effects. Lastly, we report that humanin treatment inhibited high glucose-induced secretion of tumor necrosis factor-α (TNF-α) and interleukin-1ß (IL-1ß). These findings suggest that humanin may have therapeutic potential for the treatment of hyperglycemia-associated endothelial dysfunction.


Assuntos
Glucose/toxicidade , Células Endoteliais da Veia Umbilical Humana/patologia , Peptídeos e Proteínas de Sinalização Intracelular/farmacologia , Fatores de Transcrição Kruppel-Like/metabolismo , Monócitos/patologia , Adesão Celular/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/efeitos dos fármacos , Células Endoteliais da Veia Umbilical Humana/metabolismo , Humanos , Interleucina-1beta/metabolismo , Fatores de Transcrição Kruppel-Like/genética , Proteína Quinase 7 Ativada por Mitógeno/metabolismo , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , Células THP-1 , Fator de Necrose Tumoral alfa/metabolismo
19.
Am J Physiol Heart Circ Physiol ; 315(5): H1127-H1136, 2018 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-30004252

RESUMO

Cardiac fibrosis is a biological process that increases with age and contributes to myocardial dysfunction. Humanin (HN) is an endogenous mitochondria-derived peptide that has cytoprotective effects and reduces oxidative stress. The present study aimed to test the hypothesis that chronic supplementation of exogenous HN in middle-aged mice could prevent and reverse cardiac fibrosis and apoptosis in the aging heart. Female C57BL/6N mice at 18 mo of age received 14-mo intraperitoneal injections of vehicle (old group; n = 6) or HN analog (HNG; 4 mg/kg 2 times/wk, old + HNG group, n = 8) and were euthanized at 32 mo of age. C57BL/6N female mice (young group, n = 5) at 5 mo of age were used as young controls. HNG treatment significantly increased the ratio of cardiomyocytes to fibroblasts in aging hearts, as shown by the percentage of each cell type in randomly chosen fields after immunofluorescence staining. Furthermore, the increased collagen deposition in aged hearts was significantly reduced after HNG treatment, as indicated by picrosirius red staining. HNG treatment also reduced in aging mice cardiac fibroblast proliferation (5'-bromo-2-deoxyuridine staining) and attenuated transforming growth factor-ß1, fibroblast growth factor-2, and matrix metalloproteinase-2 expression (immunohistochemistry or real-time PCR). Myocardial apoptosis was inhibited in HNG-treated aged mice (TUNEL staining). To decipher the pathway involved in the attenuation of the myocardial fibrosis by HNG, Western blot analysis was done and showed that HNG upregulated the Akt/glycogen synthase kinase -3ß pathway in aged mice. Exogenous HNG treatment attenuated myocardial fibrosis and apoptosis in aged mice. The results of the present study suggest a role for the mitochondria-derived peptide HN in the cardioprotection associated with aging. NEW & NOTEWORTHY Cardiac fibrosis is a biological process that increases with age and contributes to myocardial dysfunction. Humanin is an endogenous mitochondria-derived peptide that has cytoprotective effects and reduces oxidative stress. Here, we demonstrate, for the first time, that exogenous humanin treatment attenuated myocardial fibrosis and apoptosis in aging mice. We also detected upregulated Akt/glycogen synthase kinase-3ß pathway in humanin analog-treated mice, which might be the mechanism involved in the cardioprotective effect of humanin analog in aging mice.


Assuntos
Envelhecimento , Cardiomiopatias/prevenção & controle , Fibroblastos/efeitos dos fármacos , Peptídeos e Proteínas de Sinalização Intracelular/farmacologia , Miócitos Cardíacos/efeitos dos fármacos , Substâncias Protetoras/farmacologia , Fatores Etários , Envelhecimento/metabolismo , Envelhecimento/patologia , Aldeídos/metabolismo , Animais , Apoptose/efeitos dos fármacos , Cardiomiopatias/metabolismo , Cardiomiopatias/patologia , Linhagem Celular Tumoral , Proliferação de Células/efeitos dos fármacos , Citocinas/metabolismo , Citoproteção , Feminino , Fibroblastos/metabolismo , Fibroblastos/patologia , Fibrose , Glicogênio Sintase Quinase 3 beta/metabolismo , Humanos , Metaloproteinase 2 da Matriz/metabolismo , Camundongos Endogâmicos C57BL , Miócitos Cardíacos/metabolismo , Miócitos Cardíacos/patologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Receptor Tipo 2 de Fator de Crescimento de Fibroblastos/metabolismo , Transdução de Sinais/efeitos dos fármacos , Fator de Crescimento Transformador beta1/metabolismo
20.
Plant Cell Environ ; 41(10): 2328-2341, 2018 10.
Artigo em Inglês | MEDLINE | ID: mdl-29852518

RESUMO

Environmental stresses are the major factors that limit productivity in plants. Here, we report on the function of an uncharacterized gene At1g07050, encoding a CCT domain-containing protein, from Arabidopsis thaliana. At1g07050 expression is highly repressed by oxidative stress. We used metabolomics, biochemical, and genomic approaches to analyse performance of transgenic lines with altered expression of At1g07050 under normal and oxidative stress conditions. At1g07050 overexpressing lines showed increased levels of reactive oxygen species (ROS), whereas knock-out mutants exhibited decreased levels of ROS and higher tolerance to oxidative stress generated in the chloroplast. Our results uncover a role for At1g07050 in cellular redox homeostasis controlling H2 O2 levels, due to changes in enzymes, metabolites, and transcripts related to ROS detoxification. Therefore, we call this gene FITNESS. Additionally, several genes such as ACD6, PCC1, and ICS1 related to salicylic acid signalling and defence were found differentially expressed among the lines. Notably, FITNESS absence significantly improved seed yield suggesting an effective fine-tuning trade-off between reproductive success and defence responses.


Assuntos
Proteínas de Arabidopsis/fisiologia , Arabidopsis/fisiologia , Peptídeos e Proteínas de Sinalização Intracelular/farmacologia , Proteínas Nucleares/farmacologia , Espécies Reativas de Oxigênio/metabolismo , Arabidopsis/genética , Arabidopsis/imunologia , Arabidopsis/metabolismo , Proteínas de Arabidopsis/genética , Proteínas de Arabidopsis/metabolismo , Proteínas de Arabidopsis/farmacologia , Clorofila/metabolismo , Cromatografia Gasosa-Espectrometria de Massas , Perfilação da Expressão Gênica , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Proteínas Nucleares/genética , Proteínas Nucleares/metabolismo , Filogenia , Imunidade Vegetal , Plantas Geneticamente Modificadas , Reação em Cadeia da Polimerase , Prolina/metabolismo , Reprodução , Transdução de Sinais
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