Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 7.141
Filtrar
1.
N Engl J Med ; 384(25): 2406-2417, 2021 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-34161705

RESUMO

BACKGROUND: Autophagy is the major intracellular degradation route in mammalian cells. Systemic ablation of core autophagy-related (ATG) genes in mice leads to embryonic or perinatal lethality, and conditional models show neurodegeneration. Impaired autophagy has been associated with a range of complex human diseases, yet congenital autophagy disorders are rare. METHODS: We performed a genetic, clinical, and neuroimaging analysis involving five families. Mechanistic investigations were conducted with the use of patient-derived fibroblasts, skeletal muscle-biopsy specimens, mouse embryonic fibroblasts, and yeast. RESULTS: We found deleterious, recessive variants in human ATG7, a core autophagy-related gene encoding a protein that is indispensable to classical degradative autophagy. Twelve patients from five families with distinct ATG7 variants had complex neurodevelopmental disorders with brain, muscle, and endocrine involvement. Patients had abnormalities of the cerebellum and corpus callosum and various degrees of facial dysmorphism. These patients have survived with impaired autophagic flux arising from a diminishment or absence of ATG7 protein. Although autophagic sequestration was markedly reduced, evidence of basal autophagy was readily identified in fibroblasts and skeletal muscle with loss of ATG7. Complementation of different model systems by deleterious ATG7 variants resulted in poor or absent autophagic function as compared with the reintroduction of wild-type ATG7. CONCLUSIONS: We identified several patients with a neurodevelopmental disorder who have survived with a severe loss or complete absence of ATG7, an essential effector enzyme for autophagy without a known functional paralogue. (Funded by the Wellcome Centre for Mitochondrial Research and others.).


Assuntos
Anormalidades Múltiplas/genética , Ataxia/genética , Proteína 7 Relacionada à Autofagia/genética , Autofagia/genética , Deficiências do Desenvolvimento/genética , Mutação de Sentido Incorreto , Adolescente , Adulto , Autofagia/fisiologia , Proteína 7 Relacionada à Autofagia/fisiologia , Células Cultivadas , Cerebelo/anormalidades , Simulação por Computador , Face/anormalidades , Feminino , Fibroblastos , Genes Recessivos , Humanos , Lactente , Masculino , Músculo Esquelético/metabolismo , Músculo Esquelético/patologia , Malformações do Sistema Nervoso/genética , Linhagem , Fenótipo
2.
Nat Commun ; 12(1): 3651, 2021 06 15.
Artigo em Inglês | MEDLINE | ID: mdl-34131122

RESUMO

Extracellular cytokines are enriched in the tumor microenvironment and regulate various important properties of cancers, including autophagy. However, the precise molecular mechanisms underlying the link between autophagy and extracellular cytokines remain to be elucidated. In the present study, we demonstrate that IL-6 activates autophagy through the IL-6/JAK2/BECN1 pathway and promotes chemotherapy resistance in colorectal cancer (CRC). Mechanistically, IL-6 triggers the interaction between JAK2 and BECN1, where JAK2 phosphorylates BECN1 at Y333. We demonstrate that BECN1 Y333 phosphorylation is crucial for BECN1 activation and IL-6-induced autophagy by regulating PI3KC3 complex formation. Furthermore, we investigate BECN1 Y333 phosphorylation as a predictive marker for poor CRC prognosis and chemotherapy resistance. Combination treatment with autophagy inhibitors or pharmacological agents targeting the IL-6/JAK2/BECN1 signaling pathway may represent a potential strategy for CRC cancer therapy.


Assuntos
Autofagia/fisiologia , Proteína Beclina-1/metabolismo , Tratamento Farmacológico , Interleucina-6/metabolismo , Autofagia/efeitos dos fármacos , Proteínas Relacionadas à Autofagia/metabolismo , Proteína Beclina-1/química , Proteína Beclina-1/genética , Linhagem Celular Tumoral , Neoplasias Colorretais/tratamento farmacológico , Neoplasias Colorretais/metabolismo , Resistencia a Medicamentos Antineoplásicos/genética , Regulação Neoplásica da Expressão Gênica , Humanos , Interleucina-6/farmacologia , Janus Quinase 2/química , Janus Quinase 2/metabolismo , Fosforilação , Domínios e Motivos de Interação entre Proteínas , Fator de Transcrição STAT3/metabolismo , Transdução de Sinais/efeitos dos fármacos
3.
Nat Commun ; 12(1): 3928, 2021 06 24.
Artigo em Inglês | MEDLINE | ID: mdl-34168130

RESUMO

The thrombospondin (Thbs) family of secreted matricellular proteins are stress- and injury-induced mediators of cellular attachment dynamics and extracellular matrix protein production. Here we show that Thbs1, but not Thbs2, Thbs3 or Thbs4, induces lethal cardiac atrophy when overexpressed. Mechanistically, Thbs1 binds and activates the endoplasmic reticulum stress effector PERK, inducing its downstream transcription factor ATF4 and causing lethal autophagy-mediated cardiac atrophy. Antithetically, Thbs1-/- mice develop greater cardiac hypertrophy with pressure overload stimulation and show reduced fasting-induced atrophy. Deletion of Thbs1 effectors/receptors, including ATF6α, CD36 or CD47 does not diminish Thbs1-dependent cardiac atrophy. However, deletion of the gene encoding PERK in Thbs1 transgenic mice blunts the induction of ATF4 and autophagy, and largely corrects the lethal cardiac atrophy. Finally, overexpression of PERK or ATF4 using AAV9 gene-transfer similarly promotes cardiac atrophy and lethality. Hence, we identified Thbs1-mediated PERK-eIF2α-ATF4-induced autophagy as a critical regulator of cardiomyocyte size in the stressed heart.


Assuntos
Fator 4 Ativador da Transcrição/metabolismo , Miocárdio/patologia , Trombospondinas/metabolismo , eIF-2 Quinase/metabolismo , Fator 4 Ativador da Transcrição/genética , Animais , Atrofia , Autofagia/fisiologia , Cardiomegalia/genética , Cardiomegalia/patologia , Estresse do Retículo Endoplasmático/genética , Fator de Iniciação 2 em Eucariotos/metabolismo , Expressão Gênica , Lisossomos/metabolismo , Masculino , Camundongos Transgênicos , Miócitos Cardíacos/patologia , Proteólise , Trombospondinas/genética , eIF-2 Quinase/genética
4.
Int J Mol Sci ; 22(10)2021 May 18.
Artigo em Inglês | MEDLINE | ID: mdl-34070207

RESUMO

In domestic ruminants, endometrial receptivity is related to successful pregnancy and economic efficiency. Despite several molecules having been reported in the past regarding endometrial receptivity regulation, much regarding the mechanism of endometrial receptivity regulation remains unknown due to the complex nature of the trait. In this work, we demonstrated that the cysteine-rich transmembrane bone morphogenetic protein (BMP) regulator 1 (CRIM1) served as a novel regulator in the regulation of goat endometrial receptivity in vitro. Our results showed that hormones and IFN-τ increased the expression of CRIM1 in goat endometrial epithelial cells (EECs). Knockdown of CRIM1 via specific shRNA hindered cell proliferation, cell adhesion and prostaglandins (PGs) secretion and thus derailed normal endometrial receptivity. We further confirmed that receptivity defect phenotypes due to CRIM1 interference were restored by ATG7 overexpression in EECs while a loss of ATG7 further impaired receptivity phenotypes. Moreover, our results showed that changing the expression of ATG7 affected the reactive oxygen species (ROS) production. Moreover, mR-143-5p was shown to be a potential upstream factor of CRIM1-regulated endometrial receptivity in EECs. Overall, these results suggest that CRIM1, as the downstream target of miR-143-5p, has effects on ATG7-dependent autophagy, regulating cell proliferation, cell adhesion and PG secretion, and provides a new target for the diagnosis and treatment of early pregnancy failure and for improving the success rates of artificial reproduction.


Assuntos
Receptores de Proteínas Morfogenéticas Ósseas/fisiologia , Implantação do Embrião/genética , Endométrio/fisiologia , Cabras/fisiologia , Animais , Autofagia/efeitos dos fármacos , Autofagia/genética , Autofagia/fisiologia , Proteína 7 Relacionada à Autofagia/deficiência , Proteína 7 Relacionada à Autofagia/genética , Proteína 7 Relacionada à Autofagia/fisiologia , Receptores de Proteínas Morfogenéticas Ósseas/antagonistas & inibidores , Receptores de Proteínas Morfogenéticas Ósseas/genética , Adesão Celular , Proliferação de Células , Células Cultivadas , Implantação do Embrião/fisiologia , Endométrio/citologia , Endométrio/efeitos dos fármacos , Células Epiteliais/citologia , Células Epiteliais/efeitos dos fármacos , Células Epiteliais/fisiologia , Estradiol/farmacologia , Feminino , Técnicas de Silenciamento de Genes , Cabras/genética , Interferon Tipo I/farmacologia , MicroRNAs/genética , MicroRNAs/metabolismo , Modelos Biológicos , Gravidez , Proteínas da Gravidez/farmacologia , Progesterona/farmacologia , Prostaglandinas/metabolismo , RNA Interferente Pequeno/genética , Espécies Reativas de Oxigênio/metabolismo , Regulação para Cima
5.
Int J Mol Sci ; 22(9)2021 Apr 29.
Artigo em Inglês | MEDLINE | ID: mdl-33946854

RESUMO

Hexokinases are a family of ubiquitous exose-phosphorylating enzymes that prime glucose for intracellular utilization. Hexokinase 2 (HK2) is the most active isozyme of the family, mainly expressed in insulin-sensitive tissues. HK2 induction in most neoplastic cells contributes to their metabolic rewiring towards aerobic glycolysis, and its genetic ablation inhibits malignant growth in mouse models. HK2 can dock to mitochondria, where it performs additional functions in autophagy regulation and cell death inhibition that are independent of its enzymatic activity. The recent definition of HK2 localization to contact points between mitochondria and endoplasmic reticulum called Mitochondria Associated Membranes (MAMs) has unveiled a novel HK2 role in regulating intracellular Ca2+ fluxes. Here, we propose that HK2 localization in MAMs of tumor cells is key in sustaining neoplastic progression, as it acts as an intersection node between metabolic and survival pathways. Disrupting these functions by targeting HK2 subcellular localization can constitute a promising anti-tumor strategy.


Assuntos
Hexoquinase/fisiologia , Proteínas de Neoplasias/fisiologia , Neoplasias/enzimologia , Animais , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Apoptose/fisiologia , Autofagia/fisiologia , Sinalização do Cálcio/fisiologia , Hipóxia Celular , Peptídeos Penetradores de Células/uso terapêutico , Indução Enzimática , Regulação Neoplásica da Expressão Gênica , Glicólise/fisiologia , Hexoquinase/antagonistas & inibidores , Humanos , Membranas Intracelulares/enzimologia , Camundongos , MicroRNAs/genética , Mitocôndrias/metabolismo , Terapia de Alvo Molecular , Proteínas de Neoplasias/antagonistas & inibidores , Neoplasias/terapia , Neoplasias Experimentais/enzimologia , Fosforilação , Inibidores de Proteínas Quinases/farmacologia , Inibidores de Proteínas Quinases/uso terapêutico , Processamento de Proteína Pós-Traducional , Ratos , Ubiquitinação
6.
Nat Commun ; 12(1): 2849, 2021 05 14.
Artigo em Inglês | MEDLINE | ID: mdl-33990590

RESUMO

Long-term depression (LTD) of synaptic strength can take multiple forms and contribute to circuit remodeling, memory encoding or erasure. The generic term LTD encompasses various induction pathways, including activation of NMDA, mGlu or P2X receptors. However, the associated specific molecular mechanisms and effects on synaptic physiology are still unclear. We here compare how NMDAR- or P2XR-dependent LTD affect synaptic nanoscale organization and function in rodents. While both LTDs are associated with a loss and reorganization of synaptic AMPARs, only NMDAR-dependent LTD induction triggers a profound reorganization of PSD-95. This modification, which requires the autophagy machinery to remove the T19-phosphorylated form of PSD-95 from synapses, leads to an increase in AMPAR surface mobility. We demonstrate that these post-synaptic changes that occur specifically during NMDAR-dependent LTD result in an increased short-term plasticity improving neuronal responsiveness of depressed synapses. Our results establish that P2XR- and NMDAR-mediated LTD are associated to functionally distinct forms of LTD.


Assuntos
Proteína 4 Homóloga a Disks-Large/fisiologia , Depressão Sináptica de Longo Prazo/fisiologia , Receptores de N-Metil-D-Aspartato/fisiologia , Trifosfato de Adenosina/administração & dosagem , Animais , Autofagia/fisiologia , Células Cultivadas , Proteína 4 Homóloga a Disks-Large/deficiência , Feminino , Hipocampo/citologia , Hipocampo/fisiologia , Técnicas In Vitro , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Potenciais Pós-Sinápticos em Miniatura/fisiologia , Modelos Neurológicos , N-Metilaspartato/administração & dosagem , Plasticidade Neuronal/fisiologia , Neurônios/citologia , Neurônios/efeitos dos fármacos , Neurônios/fisiologia , Ratos , Ratos Sprague-Dawley , Receptores de AMPA/fisiologia , Receptores Purinérgicos P2X/fisiologia
7.
Nat Commun ; 12(1): 3014, 2021 05 21.
Artigo em Inglês | MEDLINE | ID: mdl-34021162

RESUMO

Members of the chromodomain-helicase-DNA binding (CHD) protein family are chromatin remodelers implicated in human pathologies, with CHD6 being one of its least studied members. We discovered a de novo CHD6 missense mutation in a patient clinically presenting the rare Hallermann-Streiff syndrome (HSS). We used genome editing to generate isogenic iPSC lines and model HSS in relevant cell types. By combining genomics with functional in vivo and in vitro assays, we show that CHD6 binds a cohort of autophagy and stress response genes across cell types. The HSS mutation affects CHD6 protein folding and impairs its ability to recruit co-remodelers in response to DNA damage or autophagy stimulation. This leads to accumulation of DNA damage burden and senescence-like phenotypes. We therefore uncovered a molecular mechanism explaining HSS onset via chromatin control of autophagic flux and genotoxic stress surveillance.


Assuntos
Autofagia/fisiologia , Dano ao DNA , DNA Helicases/genética , DNA Helicases/metabolismo , Proteínas do Tecido Nervoso/genética , Proteínas do Tecido Nervoso/metabolismo , Autofagia/genética , Cromatina , Montagem e Desmontagem da Cromatina/genética , Proteínas de Ligação a DNA/metabolismo , Epigenômica , Edição de Genes , Expressão Gênica , Síndrome de Hallermann/genética , Humanos , Mutação , Fenótipo
8.
Med Sci Monit ; 27: e928480, 2021 May 01.
Artigo em Inglês | MEDLINE | ID: mdl-33931577

RESUMO

BACKGROUND Acute myocardial infarction is the leading cause of mortality among adults worldwide. The present study aimed to investigate the role and mechanism of thrombin and SIRT1 in hypoxia/reoxygenation (H/R) injury. MATERIAL AND METHODS H9c2 cardiomyocytes were used to create an H/R model to simulate in vivo ischemia/reperfusion injury. The MTT assay was used to measure cell viability, qRT-PCR was used to detect the level of SIRT1, thrombin, and PAR-1, and western blot analysis was conducted for evaluation of thrombin, PAR-1, SIRT1, LC3I, LC3II, and Beclin1. ELISA was applied for determination of IL-1ß, IL-6, TNF-alpha, MMP-9, and ICAM-1. After the establishment of the H/R model, superoxide dismutase (SOD) activity was evaluated by the xanthine oxidase method, malondialdehyde content was detected by thiobarbituric acid assay, and reactive oxygen species generation was measured by CM-H2DCFDA. RESULTS The findings showed that thrombin enhanced inflammatory factor secretion and oxidative stress but inhibited cell viability in H/R-injured cardiomyocytes. We also observed that thrombin promoted autophagy in H/R-injured cardiomyocytes. In addition, thrombin enhanced the upregulation of SIRT1 expression by H/R. However, it was found that inhibition of SIRT1 could suppress the effect of thrombin on inflammatory factor secretion, oxidative stress, and cell viability. Moreover, downregulation of SIRT1 suppressed the inhibitory effect of thrombin on autophagy in H/R injury. CONCLUSIONS Thrombin aggravates H/R injury of cardiomyocytes by activating an autophagy pathway mediated by SIRT1. These findings might provide a potential target therapy for the treatment of ischemia/reperfusion injury in future clinical work.


Assuntos
Autofagia/fisiologia , Hipóxia/metabolismo , Traumatismo por Reperfusão Miocárdica/metabolismo , Miócitos Cardíacos/metabolismo , Transdução de Sinais/fisiologia , Sirtuína 1/metabolismo , Trombina/metabolismo , Animais , Apoptose/fisiologia , Sobrevivência Celular/fisiologia , Regulação para Baixo/fisiologia , Inflamação/metabolismo , Malondialdeído/metabolismo , Estresse Oxidativo/fisiologia , Ratos , Regulação para Cima/fisiologia
9.
Life Sci ; 277: 119585, 2021 Jul 15.
Artigo em Inglês | MEDLINE | ID: mdl-33957169

RESUMO

AIMS: Oxidative damage and altered metabolic reactions are suspected to initiate the autophagy. The exercise training significantly impacts testicular antioxidant and metabolic potentials. However, the underlying mechanism(s) that the exercise-induced alterations can affect the autophagy markers remained unknown. This study explored the effect of exercise training on antioxidant and metabolic statuses of testicular tissue and uncovered the possible cross-link between these statuses and autophagy-inducers expression. MAIN METHODS: Wistar rats were divided into sedentary control, low (LICT), moderate (MICT), and high (HICT) intensity continuous training groups. Following 8 weeks of training, the testicular total antioxidant capacity (TAC), total oxidant status (TOS), glutathione (GSH), and NADP+/NADPH as oxidative biomarkers along with intracytoplasmic carbohydrate and lipid droplet patterns, lactate dehydrogenase (LDH) activity, and lactate as metabolic elements were assessed. Finally, the autophagy-inducers expression and sperm count were examined. KEY FINDINGS: With no significant impact on the oxidative biomarkers and metabolic elements, the LICT and MICT groups exhibited statistically unremarkable (p < 0.05) impacts on spermatogenesis differentiation, spermiogenesis ratio, and sperm count while increased the autophagy-inducers expression. Reversely, the HICT group, simultaneous with suppressing the antioxidant biomarkers (TAC↓, GSH↓, TOS↑, NADP+/NADPH↑), significantly (p < 0.05) reduced the testicular LDH activity and lactate level, changed the intracytoplasmic carbohydrate and lipid droplet's pattern, and amplified the classical autophagy-inducers p62, Beclin-1, autophagy-related gene (ATG)-7, and light chain 3 (LC3)-II/I expression. SIGNIFICANCE: The autophagy-inducers overexpression has occurred after HICT induction, most probably to eliminate the oxidative damage cargoes, while increased to maintain the metabolic homeostasis in the LICT and MICT groups.


Assuntos
Estresse Oxidativo/fisiologia , Esforço Físico/fisiologia , Testículo/metabolismo , Animais , Antioxidantes/metabolismo , Autofagia/fisiologia , Biomarcadores , Glutationa/análise , Treinamento Intervalado de Alta Intensidade/métodos , Masculino , Metabolômica/métodos , NADP/análise , Oxidantes/metabolismo , Condicionamento Físico Animal/métodos , Ratos , Ratos Wistar , Espécies Reativas de Oxigênio/metabolismo , Espermatogênese/fisiologia , Espermatozoides/metabolismo , Testículo/fisiologia
10.
Nat Commun ; 12(1): 2550, 2021 05 05.
Artigo em Inglês | MEDLINE | ID: mdl-33953176

RESUMO

Melanoma is the deadliest skin cancer. Despite improvements in the understanding of the molecular mechanisms underlying melanoma biology and in defining new curative strategies, the therapeutic needs for this disease have not yet been fulfilled. Herein, we provide evidence that the Activating Molecule in Beclin-1-Regulated Autophagy (Ambra1) contributes to melanoma development. Indeed, we show that Ambra1 deficiency confers accelerated tumor growth and decreased overall survival in Braf/Pten-mutated mouse models of melanoma. Also, we demonstrate that Ambra1 deletion promotes melanoma aggressiveness and metastasis by increasing cell motility/invasion and activating an EMT-like process. Moreover, we show that Ambra1 deficiency in melanoma impacts extracellular matrix remodeling and induces hyperactivation of the focal adhesion kinase 1 (FAK1) signaling, whose inhibition is able to reduce cell invasion and melanoma growth. Overall, our findings identify a function for AMBRA1 as tumor suppressor in melanoma, proposing FAK1 inhibition as a therapeutic strategy for AMBRA1 low-expressing melanoma.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Melanoma/genética , Melanoma/metabolismo , Animais , Autofagia/fisiologia , Proteína Beclina-1/metabolismo , Linhagem Celular Tumoral , Movimento Celular , Proliferação de Células , Modelos Animais de Doenças , Feminino , Quinase 1 de Adesão Focal/metabolismo , Regulação Neoplásica da Expressão Gênica , Humanos , Masculino , Melanoma/patologia , Camundongos , PTEN Fosfo-Hidrolase/genética , PTEN Fosfo-Hidrolase/metabolismo , Fenótipo , Proteínas Proto-Oncogênicas B-raf/genética , Proteínas Proto-Oncogênicas B-raf/metabolismo , Transdução de Sinais , Transcriptoma
11.
Phytomedicine ; 87: 153578, 2021 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-34038839

RESUMO

BACKGROUND: Parkinson's disease (PD) is one of the most common neurodegenerative motor disorders, and is characterized by the presence of Lewy bodies containing misfolded α-synuclein (α-syn) and by selective degeneration of midbrain dopamine neurons. Studies have shown that upregulation of ubiquitin-proteasome system (UPS) activity promotes the clearance of aggregation-prone proteins such as α-syn and Tau, so as to alleviate the neuropathology of neurodegenerative diseases. PURPOSE: To identify and investigate lycorine as a UPS enhancer able to decrease α-syn in transgenic PD models. METHODS: Dot blot was used to screen α-syn-lowering compounds in an inducible α-syn overexpression cell model. Inducible wild-type (WT) and mutant α-syn-overexpressing PC12 cells, WT α-syn-overexpressing N2a cells and primary cultured neurons from A53T transgenic mice were used to evaluate the effects of lycorine on α-syn degradation in vitro. Heterozygous A53T transgenic mice were used to evaluate the effects of lycorine on α-syn degradation in vivo. mCherry-GFP-LC3 reporter was used to detect autophagy-dependent degradation. Ub-R-GFP and Ub-G76V-GFP reporters were used to detect UPS-dependent degradation. Proteasome activity was detected by fluorogenic substrate Suc-Leu-Leu-Val-Tyr-AMC (Suc-LLVY-AMC). RESULTS: Lycorine significantly promoted clearance of over-expressed WT and mutant α-syn in neuronal cell lines and primary cultured neurons. More importantly, 15 days' intraperitoneal administration of lycorine effectively promoted the degradation of α-syn in the brains of A53T transgenic mice. Mechanistically, lycorine accelerated α-syn degradation by activating cAMP-dependent protein kinase (PKA) to promote proteasome activity. CONCLUSION: Lycorine is a novel α-syn-lowering compound that works through PKA-mediated UPS activation. This ability to lower α-syn implies that lycorine has the potential to be developed as a pharmaceutical for the treatment of neurodegenerative diseases, such as PD, associated with UPS impairment and protein aggregations.


Assuntos
Alcaloides de Amaryllidaceae/farmacologia , Proteínas Quinases Dependentes de AMP Cíclico/metabolismo , Doença de Parkinson/tratamento farmacológico , Fenantridinas/farmacologia , alfa-Sinucleína/metabolismo , Animais , Autofagia/efeitos dos fármacos , Autofagia/fisiologia , AMP Cíclico/metabolismo , Modelos Animais de Doenças , Humanos , Masculino , Camundongos Transgênicos , Fármacos Neuroprotetores/farmacologia , Células PC12 , Doença de Parkinson/metabolismo , Doença de Parkinson/patologia , Complexo de Endopeptidases do Proteassoma/metabolismo , Ratos , Ubiquitina/metabolismo , Regulação para Cima/efeitos dos fármacos , alfa-Sinucleína/genética
12.
Nat Commun ; 12(1): 2099, 2021 04 08.
Artigo em Inglês | MEDLINE | ID: mdl-33833239

RESUMO

In Duchenne muscular dystrophy (DMD), sarcolemma fragility and myofiber necrosis produce cellular debris that attract inflammatory cells. Macrophages and T-lymphocytes infiltrate muscles in response to damage-associated molecular pattern signalling and the release of TNF-α, TGF-ß and interleukins prevent skeletal muscle improvement from the inflammation. This immunological scenario was extended by the discovery of a specific response to muscle antigens and a role for regulatory T cells (Tregs) in muscle regeneration. Normally, autoimmunity is avoided by autoreactive T-lymphocyte deletion within thymus, while in the periphery Tregs monitor effector T-cells escaping from central regulatory control. Here, we report impairment of thymus architecture of mdx mice together with decreased expression of ghrelin, autophagy dysfunction and AIRE down-regulation. Transplantation of dystrophic thymus in recipient nude mice determine the up-regulation of inflammatory/fibrotic markers, marked metabolic breakdown that leads to muscle atrophy and loss of force. These results indicate that involution of dystrophic thymus exacerbates muscular dystrophy by altering central immune tolerance.


Assuntos
Tolerância Imunológica/imunologia , Músculo Esquelético/patologia , Atrofia Muscular/patologia , Distrofia Muscular Animal/patologia , Timo/patologia , Animais , Autofagia/fisiologia , Grelina/biossíntese , Macrófagos/imunologia , Masculino , Camundongos , Camundongos Endogâmicos BALB C , Camundongos Endogâmicos C57BL , Camundongos Endogâmicos mdx , Camundongos Nus , Distrofia Muscular de Duchenne/patologia , Linfócitos T/transplante , Linfócitos T Reguladores/imunologia , Timo/transplante , Fatores de Transcrição/biossíntese
13.
Biochem Biophys Res Commun ; 555: 182-189, 2021 05 28.
Artigo em Inglês | MEDLINE | ID: mdl-33823364

RESUMO

Autophagy and apoptosis, as major modes of cell death, play critical roles in cellular homeostasis. Our previous study demonstrated that the cross-talk between autophagy and apoptosis regulated cadmium-induced testicular injury and self-recovery, influencing male fertility. However, the underlying mechanism remains blurry. Herein, our subfertility rat model indicated that cadmium-induced autophagy and apoptosis were ameliorated by the activation of SIRT3 and blunted by the inhibition of SIRT3 in rat testis. Further, generating SIRT3 overexpression and knockdown models in TM3 mouse Leydig cells, we found that melatonin (SIRT3 activator) and overexpression of SIRT3 rescued cadmium-induced autophagy and apoptosis in TM3 cells. Knockdown of SIRT3 induced autophagy and apoptosis, which failed to be reversed by melatonin in TM3 cells. Taken together, SIRT3 functions as a pivotal protective factor in testicular Leydig cells injury, and melatonin regulates the cross-talk between autophagy and apoptosis by SIRT3, ameliorating cadmium-induced testicular injury.


Assuntos
Apoptose/fisiologia , Autofagia/fisiologia , Células Intersticiais do Testículo/metabolismo , Melatonina/metabolismo , Sirtuína 3/metabolismo , Adenina/análogos & derivados , Adenina/farmacologia , Animais , Apoptose/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Cádmio/toxicidade , Células Cultivadas , Técnicas de Silenciamento de Genes , Células Intersticiais do Testículo/efeitos dos fármacos , Masculino , Melatonina/farmacologia , Camundongos , Ratos Sprague-Dawley , Sirtuína 3/genética , Sirtuínas/metabolismo , Testículo/citologia , Testículo/efeitos dos fármacos , Testículo/metabolismo
14.
Nat Cell Biol ; 23(5): 450-456, 2021 05.
Artigo em Inglês | MEDLINE | ID: mdl-33903736

RESUMO

Macroautophagic clearance of cytosolic materials entails the initiation, growth and closure of autophagosomes. Cargo triggers the assembly of a web of cargo receptors and core machinery. Autophagy-related protein 9 (ATG9) vesicles seed the growing autophagosomal membrane, which is supplied by de novo phospholipid synthesis, phospholipid transport via ATG2 proteins and lipid flipping by ATG9. Autophagosomes close via ESCRT complexes. Here, we review recent discoveries that illuminate the molecular mechanisms of autophagosome formation and discuss emerging questions in this rapidly developing field.


Assuntos
Autofagossomos/metabolismo , Proteínas Relacionadas à Autofagia/metabolismo , Autofagia/fisiologia , Retículo Endoplasmático/metabolismo , Proteínas de Membrana/metabolismo , Proteínas de Saccharomyces cerevisiae/metabolismo
15.
Oxid Med Cell Longev ; 2021: 2353504, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33854691

RESUMO

We investigated whether there was activation of NLRP1 inflammasomes and excessive autophagy in oxidative stress damage. And we further demonstrate whether there is a cascade relationship between the activation of NLRP1 inflammasomes and the phenomenon of excessive autophagy. To observe the expression level of the NLRP1 inflammasome group in the pathological process of trophoblast cell oxidative stress, western blot, immunofluorescence, and qRT-PCR were performed. Autophagy in trophoblast cells after the action of H2O2 was detected by using normal trophoblast cells' NLRP1-specific activator (MDP) as a positive control. The presence of excessive autophagy was determined by comparing it with the autophagy-related proteins in normal trophoblast cells. Through siRNA-NLRP1, we investigated the role of oxidative stress and the NLRP1 inflammasome in autophagy in cells. 100 µmol MDP for 24 hours can be used as the optimal concentration of the NLRP1 activator. In human placental trophoblast oxidative stress, the model group significantly increased the expression level of inflammasome IL-1ß, CASP1, and NLRP1, compared with the control group NLRP3, and LC3-II, Beclin-1, ATG5, ATG7, and p62 overactivated the autophagy ability of cells. After the activation of NLRP1, the expression of these inflammasomes increased, accompanied by the decrease in autophagy. After the expression of NLRP1 was silenced by RNAi, the expression of inflammasome IL-1ß, CASP1, and NLRP3 was also decreased. Still, the autophagy level was increased, which was manifested by the high expression of LC3-II, Beclin-1, ATG5, and ATG7 and the decrease in p62. Trophoblast cells showed the expression of NLRP1 protein and excessive autophagy under oxidative stress. Simultaneously, the NLRP1 inflammasome of trophoblast cells in the state of oxidative stress was correlated with autophagy. Inflammasome activation and autophagy were shown to be linked and to influence each other mutually. These may also provide new therapeutic targets in a pathological pregnancy.


Assuntos
Inflamassomos/metabolismo , Proteínas NLR/metabolismo , Estresse Oxidativo/fisiologia , Placenta/metabolismo , Trofoblastos/metabolismo , Autofagia/fisiologia , Linhagem Celular , Feminino , Humanos , Proteínas NLR/genética , Placenta/patologia , Gravidez , RNA Mensageiro/genética , RNA Mensageiro/metabolismo , RNA Interferente Pequeno/genética , RNA Interferente Pequeno/metabolismo , Trofoblastos/patologia
16.
Int J Mol Sci ; 22(5)2021 Mar 07.
Artigo em Inglês | MEDLINE | ID: mdl-33800062

RESUMO

Autophagy is involved in different degenerative diseases and it may control epigenetic modifications, metabolic processes, stem cells differentiation as well as apoptosis. Autophagy plays a key role in maintaining the homeostasis of cartilage, the tissue produced by chondrocytes; its impairment has been associated to cartilage dysfunctions such as osteoarthritis (OA). Due to their location in a reduced oxygen context, both differentiating and mature chondrocytes are at risk of premature apoptosis, which can be prevented by autophagy. AutophagomiRNAs, which regulate the autophagic process, have been found differentially expressed in OA. AutophagomiRNAs, as well as other regulatory molecules, may also be useful as therapeutic targets. In this review, we describe and discuss the role of autophagy in OA, focusing mainly on the control of autophagomiRNAs in OA pathogenesis and their potential therapeutic applications.


Assuntos
Autofagia/fisiologia , Osteoartrite/tratamento farmacológico , Osteoartrite/patologia , Animais , Autofagia/efeitos dos fármacos , Diferenciação Celular , Senescência Celular/efeitos dos fármacos , Condrócitos/citologia , Condrócitos/fisiologia , Modelos Animais de Doenças , Humanos , MicroRNAs , Fatores de Transcrição/genética , Fatores de Transcrição/metabolismo
17.
Ecotoxicol Environ Saf ; 217: 112256, 2021 Jul 01.
Artigo em Inglês | MEDLINE | ID: mdl-33901779

RESUMO

Non-alcoholic fatty liver disease (NAFLD) has been the most common chronic liver disease in the world, including the developing countries. NAFLD is metabolic disease with significant lipid deposition in the hepatocytes of the liver, which is usually associated with oxidative stress, inflammation and fibrogenesis, and insulin resistance. Progressive NAFLD can develop into non-alcoholic steatohepatitis (NASH) or hepatocellular carcinoma. The current evidence proposes that environmental pollutants promote development and progression of NAFLD, and autophagy plays a vital role but is multifactorial affected in NAFLD. In this review, we analyzed on the regulations of common environmental pollutants on autophagy in NAFLD. To clarify the involved roles of autophagy, we discussed the dysregulation of autophagy by environmental pollutants in adipose tissue and gut, and their interactions with liver, as well as epigenetic regulation on autophagy by environmental pollutants. Furthermore, protective roles of potential therapeutic treatments on the multiple-hits of autophagy in NAFLD were descripted.


Assuntos
Autofagia/fisiologia , Poluentes Ambientais/toxicidade , Hepatopatia Gordurosa não Alcoólica/fisiopatologia , Tecido Adiposo/metabolismo , Carcinoma Hepatocelular/metabolismo , Poluentes Ambientais/metabolismo , Epigênese Genética , Hepatócitos/metabolismo , Humanos , Inflamação/metabolismo , Resistência à Insulina/fisiologia , Fígado/metabolismo , Neoplasias Hepáticas/patologia , Hepatopatia Gordurosa não Alcoólica/induzido quimicamente , Estresse Oxidativo
18.
Int J Mol Sci ; 22(7)2021 Mar 31.
Artigo em Inglês | MEDLINE | ID: mdl-33807278

RESUMO

Pompe disease is an autosomal recessive disorder caused by a deficiency in the enzyme acid alpha-glucosidase. The late-onset form of Pompe disease (LOPD) is characterized by a slowly progressing proximal muscle weakness, often involving respiratory muscles. In LOPD, the levels of GAA enzyme activity and the severity of the clinical pictures may be highly variable among individuals, even in those who harbour the same combination of GAA mutations. The result is an unpredictable genotype-phenotype correlation. The purpose of this study was to identify the genetic factors responsible for the progression, severity and drug response in LOPD. We report here on a detailed clinical, morphological and genetic study, including a whole exome sequencing (WES) analysis of 11 adult LOPD siblings belonging to two Italian families carrying compound heterozygous GAA mutations. We disclosed a heterogeneous pattern of myopathic impairment, associated, among others, with cardiac defects, intracranial vessels abnormality, osteoporosis, vitamin D deficiency, obesity and adverse response to enzyme replacement therapy (ERT). We identified deleterious variants in the genes involved in autophagy, immunity and bone metabolism, which contributed to the severity of the clinical symptoms observed in the LOPD patients. This study emphasizes the multisystem nature of LOPD and highlights the polygenic nature of the complex phenotype disclosed in these patients.


Assuntos
Autofagia/genética , Doença de Depósito de Glicogênio Tipo II/genética , alfa-Glucosidases/genética , Adulto , Idoso , Autofagia/fisiologia , Terapia de Reposição de Enzimas/métodos , Família , Feminino , Variação Genética/genética , Humanos , Itália , Masculino , Pessoa de Meia-Idade , Músculo Esquelético/metabolismo , Mutação , Linhagem , Músculos Respiratórios , Irmãos , alfa-Glucosidases/metabolismo
19.
Toxicology ; 456: 152770, 2021 05 30.
Artigo em Inglês | MEDLINE | ID: mdl-33823232

RESUMO

Extensive health studies had declared that exposure to particulate matter (PM) was closely associated with neurodegenerative diseases, i.e. Parkinson's disease (PD). Our aim was to clarify the potential molecular mechanism by which PM2.5 aggravated PD symptoms using in vitro and in vivo PD models. In this study, PC12 cells treated with rotenone (1 µM) and/or PM2.5 (50 µg/mL) for 4 days was used as the in vitro model. C57BL/6 J mice expored to PM2.5 (inhalation, 2.5 mg/kg) and rotenone (intraperitoneal injection, 30 mg/kg) for 28 days was used as the in vivo model. Rapamycin was used to promote the level of autophagy. The results showed that after exposure to PM2.5, the apoptosis of rotenone-treated PC12 cells were increased by increasing the ROS levels and decreasing the levels of mitochondrial membrane potential. In rotenone-treated PC12 cells, exposure to PM2.5 could decrease the expression levels of LC3II and Atg5, and increase the expression level of mTOR, suggesting that PM2.5 exposure inhibited autophagy. Furthermore, the mitophagy related genes, including PINK1 and Parkin, were decreased. At the same time, inhalation of PM2.5 could relieve the behavioral abnormalities of PD mouse induced by rotenone. The levels of inflammatory factors (TNF-α, IL-1ß, and IL-6) were significantly increased. Inhalation of PM2.5 could induce the oxidative stress and apoptosis in the substantia nigra of PD mouse, as well as the key markers of autophagy and mitophagy were also changed, which was consistent with the cell model. Besides, rapamycin would relieve the damaging effect of PM2.5 by triggering autophagy and mitophagy in rotenone-induced PD models. These results indicated that exposure to PM2.5 aggravated the behavioral abnormalities of PD symptoms through increasing oxidative stress, decreasing autophagy and mitophagy, and inducing mitochondria-mediated neuronal apoptosis. These findings not only revealed the effects and mechanism of PM2.5 exposure on PD, but also provided fundamental data that can be exploited to develop environmental safety policies.


Assuntos
Autofagia/efeitos dos fármacos , Exposição por Inalação/efeitos adversos , Mitofagia/efeitos dos fármacos , Transtornos Parkinsonianos/induzido quimicamente , Transtornos Parkinsonianos/metabolismo , Material Particulado/toxicidade , Animais , Autofagia/fisiologia , Inseticidas/toxicidade , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Mitofagia/fisiologia , Células PC12 , Transtornos Parkinsonianos/patologia , Material Particulado/administração & dosagem , Ratos , Rotenona/toxicidade , Transdução de Sinais/efeitos dos fármacos , Transdução de Sinais/fisiologia
20.
Nutrients ; 13(3)2021 Mar 18.
Artigo em Inglês | MEDLINE | ID: mdl-33803798

RESUMO

Caloric restriction (CR) slows the aging process, extends lifespan, and exerts neuroprotective effects. It is widely accepted that CR attenuates ß-amyloid (Aß) neuropathology in models of Alzheimer's disease (AD) by so-far unknown mechanisms. One promising process induced by CR is autophagy, which is known to degrade aggregated proteins such as amyloids. In addition, autophagy positively regulates glucose uptake and may improve cerebral hypometabolism-a hallmark of AD-and, consequently, neural activity. To evaluate this hypothesis, APPswe/PS1delta9 (tg) mice and their littermates (wild-type, wt) underwent CR for either 16 or 68 weeks. Whereas short-term CR for 16 weeks revealed no noteworthy changes of AD phenotype in tg mice, long-term CR for 68 weeks showed beneficial effects. Thus, cerebral glucose metabolism and neuronal integrity were markedly increased upon 68 weeks CR in tg mice, indicated by an elevated hippocampal fluorodeoxyglucose [18F] ([18F]FDG) uptake and increased N-acetylaspartate-to-creatine ratio using positron emission tomography/computer tomography (PET/CT) imaging and magnet resonance spectroscopy (MRS). Improved neuronal activity and integrity resulted in a better cognitive performance within the Morris Water Maze. Moreover, CR for 68 weeks caused a significant increase of LC3BII and p62 protein expression, showing enhanced autophagy. Additionally, a significant decrease of Aß plaques in tg mice in the hippocampus was observed, accompanied by reduced microgliosis as indicated by significantly decreased numbers of iba1-positive cells. In summary, long-term CR revealed an overall neuroprotective effect in tg mice. Further, this study shows, for the first time, that CR-induced autophagy in tg mice accompanies the observed attenuation of Aß pathology.


Assuntos
Doença de Alzheimer/dietoterapia , Peptídeos beta-Amiloides/metabolismo , Fenômenos Fisiológicos da Nutrição Animal , Autofagia/fisiologia , Restrição Calórica/métodos , Doença de Alzheimer/patologia , Animais , Ácido Aspártico/análogos & derivados , Ácido Aspártico/metabolismo , Proteínas de Ligação ao Cálcio/metabolismo , Córtex Cerebral/metabolismo , Creatina/metabolismo , Modelos Animais de Doenças , Fluordesoxiglucose F18 , Glucose/metabolismo , Hipocampo/diagnóstico por imagem , Hipocampo/metabolismo , Espectroscopia de Ressonância Magnética , Aprendizagem em Labirinto , Camundongos , Camundongos Endogâmicos C3H , Camundongos Endogâmicos C57BL , Camundongos Transgênicos , Proteínas dos Microfilamentos/metabolismo , Neurônios/fisiologia , Placa Amiloide/dietoterapia , Placa Amiloide/patologia , Tomografia por Emissão de Pósitrons combinada à Tomografia Computadorizada , Compostos Radiofarmacêuticos
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...