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1.
BMC Immunol ; 23(1): 43, 2022 09 14.
Artigo em Inglês | MEDLINE | ID: mdl-36104771

RESUMO

BACKGROUND: Autophagy is an important mechanism for promoting Mycobacterium clearance from macrophages. Pathogenic and non-pathogenic mycobacterium can activate the mTOR pathway while simultaneously inducing autophagy. M. tuberculosis and M. bovis BCG inhibit autophagy and favor intracellular bacteria survival. RESULTS: We observed that pre-infection of live or heat-killed BCG could prevent autophagy induced by pharmacological activators or M. smegmatis, a strong autophagy-inducing mycobacterium. BCG-derived lipids are responsible for autophagy inhibition. However, post-infection with BCG could not stop the autophagy initiated by M. smegmatis, which increases further autophagy induction and mycobacteria clearance. Coinfection with BCG and heat killed M. smegmatis enhanced antigen specific CD4+ T cell responses and reduced mycobacterial survival. CONCLUSION: These results suggest that autophagy-inducing M. smegmatis could be used to promote better innate and consequential adaptive immune responses, improving BCG vaccine efficacy.


Assuntos
Mycobacterium tuberculosis , Eficácia de Vacinas , Autofagia/fisiologia , Vacina BCG , Macrófagos
2.
PLoS Biol ; 20(9): e3001737, 2022 Sep.
Artigo em Inglês | MEDLINE | ID: mdl-36099296

RESUMO

The nutrient-activated mTORC1 (mechanistic target of rapamycin kinase complex 1) signaling pathway determines cell size by controlling mRNA translation, ribosome biogenesis, protein synthesis, and autophagy. Here, we show that vimentin, a cytoskeletal intermediate filament protein that we have known to be important for wound healing and cancer progression, determines cell size through mTORC1 signaling, an effect that is also manifested at the organism level in mice. This vimentin-mediated regulation is manifested at all levels of mTOR downstream target activation and protein synthesis. We found that vimentin maintains normal cell size by supporting mTORC1 translocation and activation by regulating the activity of amino acid sensing Rag GTPase. We also show that vimentin inhibits the autophagic flux in the absence of growth factors and/or critical nutrients, demonstrating growth factor-independent inhibition of autophagy at the level of mTORC1. Our findings establish that vimentin couples cell size and autophagy through modulating Rag GTPase activity of the mTORC1 signaling pathway.


Assuntos
Filamentos Intermediários , Complexos Multiproteicos , Animais , Autofagia/fisiologia , Tamanho Celular , GTP Fosfo-Hidrolases/metabolismo , Filamentos Intermediários/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Camundongos , Complexos Multiproteicos/metabolismo , Transdução de Sinais , Vimentina/metabolismo
3.
Cells ; 11(17)2022 Aug 23.
Artigo em Inglês | MEDLINE | ID: mdl-36078029

RESUMO

Autophagy is an evolutionally conserved degradation mechanism for maintaining cell homeostasis whereby cytoplasmic components are wrapped in autophagosomes and subsequently delivered to lysosomes for degradation. This process requires the concerted actions of multiple autophagy-related proteins and accessory regulators. In neurons, autophagy is dynamically regulated in different compartments including soma, axons, and dendrites. It determines the turnover of selected materials in a spatiotemporal control manner, which facilitates the formation of specialized neuronal functions. It is not surprising, therefore, that dysfunctional autophagy occurs in epilepsy, mainly caused by an imbalance between excitation and inhibition in the brain. In recent years, much attention has been focused on how autophagy may cause the development of epilepsy. In this article, we overview the historical landmarks and distinct types of autophagy, recent progress in the core machinery and regulation of autophagy, and biological roles of autophagy in homeostatic maintenance of neuronal structures and functions, with a particular focus on synaptic plasticity. We also discuss the relevance of autophagy mechanisms to the pathophysiology of epileptogenesis.


Assuntos
Autofagia , Epilepsia , Autofagossomos/metabolismo , Autofagia/fisiologia , Axônios/metabolismo , Epilepsia/metabolismo , Humanos , Neurônios/metabolismo
4.
Cells ; 11(17)2022 Sep 02.
Artigo em Inglês | MEDLINE | ID: mdl-36078149

RESUMO

Environmental noise is a common hazard in military operations. Military service members during long operations are often exposed to around-the-clock noise and suffer massive emotional and cognitive dysfunction related to an Alzheimer's disease (AD)-like neuropathology. It is essential to clarify the mechanisms underlying the effects of around-the-clock noise exposure on the central nervous system. Here, Wistar rats were continuously exposed to white noise (95 dB during the on-duty phase [8:00-16:00] and 75 dB during the off-duty phase (16:00-8:00 the next day)) for 40 days. The levels of phosphorylated tau, amyloid-ß (Aß), and neuroinflammation in the cortex and hippocampus were assessed and autophagosome (AP) aggregation was observed by transmission electron microscopy. Dyshomeostasis of autophagic flux resulting from around-the-clock noise exposure was assessed at different stages to investigate the potential pathological mechanisms. Around-the-clock noise significantly increased Aß peptide, tau phosphorylation at Ser396 and Ser404, and neuroinflammation. Moreover, the AMPK-mTOR signaling pathway was depressed in the cortex and the hippocampus of rats exposed to around-the-clock noise. Consequently, autophagosome-lysosome fusion was deterred and resulted in AP accumulation. Our results indicate that around-the-clock noise exposure has detrimental influences on autophagic flux homeostasis and may be associated with AD-like neuropathology in the cortex and the hippocampus.


Assuntos
Doença de Alzheimer , Doenças do Sistema Nervoso , Doença de Alzheimer/metabolismo , Peptídeos beta-Amiloides/metabolismo , Animais , Autofagia/fisiologia , Homeostase , Ratos , Ratos Wistar
5.
STAR Protoc ; 3(3): 101662, 2022 Sep 16.
Artigo em Inglês | MEDLINE | ID: mdl-36097383

RESUMO

Aggrephagy is a major way to clear protein aggregates. Here, we describe a pipeline of experiments to find autophagy receptors for aggrephagy. Steps include an in vitro reconstitution to recapitulate autophagosome recognizing aggregates and receptor identification steps based on flow cytometry and mass spectrometry. We also describe functional validation steps based on immunofluorescence and immunoblot. The protocol provides a practical way to identify aggrephagy receptors. For complete details on the use and execution of this protocol, please refer to Ma et al. (2022).


Assuntos
Macroautofagia , Agregados Proteicos , Animais , Autofagossomos/metabolismo , Autofagia/fisiologia , Proteínas de Transporte/metabolismo , Mamíferos/metabolismo
6.
Front Cell Infect Microbiol ; 12: 834895, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36061866

RESUMO

Macroautophagy is a ubiquitous homeostasis and health-promoting recycling process of eukaryotic cells, targeting misfolded proteins, damaged organelles and intracellular infectious agents. Some intracellular pathogens such as Salmonella enterica serovar Typhimurium hijack this process during pathogenesis. Here we investigate potential protein-protein interactions between host transcription factors and secreted effector proteins of Salmonella and their effect on host gene transcription. A systems-level analysis identified Salmonella effector proteins that had the potential to affect core autophagy gene regulation. The effect of a SPI-1 effector protein, SopE, that was predicted to interact with regulatory proteins of the autophagy process, was investigated to validate our approach. We then confirmed experimentally that SopE can directly bind to SP1, a host transcription factor, which modulates the expression of the autophagy gene MAP1LC3B. We also revealed that SopE might have a double role in the modulation of autophagy: Following initial increase of MAP1LC3B transcription triggered by Salmonella infection, subsequent decrease in MAP1LC3B transcription at 6h post-infection was SopE-dependent. SopE also played a role in modulation of the autophagy flux machinery, in particular MAP1LC3B and p62 autophagy proteins, depending on the level of autophagy already taking place. Upon typical infection of epithelial cells, the autophagic flux is increased. However, when autophagy was chemically induced prior to infection, SopE dampened the autophagic flux. The same was also observed when most of the intracellular Salmonella cells were not associated with the SCV (strain lacking sifA) regardless of the autophagy induction status before infection. We demonstrated how regulatory network analysis can be used to better characterise the impact of pathogenic effector proteins, in this case, Salmonella. This study complements previous work in which we had demonstrated that specific pathogen effectors can affect the autophagy process through direct interaction with autophagy proteins. Here we show that effector proteins can also influence the upstream regulation of the process. Such interdisciplinary studies can increase our understanding of the infection process and point out targets important in intestinal epithelial cell defense.


Assuntos
Infecções por Salmonella , Salmonella typhimurium , Autofagia/fisiologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Células Epiteliais/metabolismo , Humanos , Salmonella typhimurium/genética
7.
Sci Rep ; 12(1): 13983, 2022 Aug 17.
Artigo em Inglês | MEDLINE | ID: mdl-35977966

RESUMO

There is still an unmet need for development of safer antimelanogenic or melanin-degrading agents for skin hyperpigmentation, induced by intrinsic or extrinsic factors including aging or ultraviolet irradiation. Owing to the relatively low cytotoxicity compared with other chemical materials, several studies have explored the role of 2'-fucosyllactose (2'-FL), the most dominant component of human milk oligosaccharides. Here, we showed that 2'-FL reduced melanin levels in both melanocytic cells and a human skin equivalent three-dimensional in vitro model. Regarding the cellular and molecular mechanism, 2'-FL induced LC3I conversion into LC3II, an autophagy activation marker, followed by the formation of LC3II+/PMEL+ autophagosomes. Comparative transcriptome analysis provided a comprehensive understanding for the up- and downstream cellular processes and signaling pathways of the AMPK-ULK1 signaling axis triggered by 2'-FL treatment. Moreover, 2'-FL activated the phosphorylation of AMPK at Thr172 and of ULK1 at Ser555, which were readily reversed in the presence of dorsomorphin, a specific AMPK inhibitor, with consequent reduction of the 2'-FL-mediated hypopigmentation. Taken together, these findings demonstrate that 2'-FL promotes melanin degradation by inducing autophagy through the AMPK-ULK1 axis. Hence, 2'-FL may represent a new natural melanin-degrading agent for hyperpigmentation.


Assuntos
Proteínas Quinases Ativadas por AMP , Hiperpigmentação , Proteínas Quinases Ativadas por AMP/metabolismo , Autofagia/fisiologia , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular , Melaninas , Leite Humano/metabolismo , Trissacarídeos
8.
Cell Mol Life Sci ; 79(9): 488, 2022 Aug 19.
Artigo em Inglês | MEDLINE | ID: mdl-35984564

RESUMO

An imbalance of human mesenchymal stem cells (hMSCs) adipogenic and osteogenic differentiation is crucial in the pathogenesis of osteoporosis, and elucidation of the underlying mechanism is urgently needed. APPL1, an adaptor protein of the adiponectin receptor, was recently shown to be closely related to bone mass. However, the role of APPL1 in the imbalance of hMSC differentiation in osteoporosis is unclear. Therefore, we aimed to explore the mechanisms by which APPL1 alters hMSCs adipogenic differentiation in osteoporosis. Here, we found that APPL1 expression was downregulated in elderly patients with osteoporosis and in mouse osteoporosis model. APPL1 negatively regulated hMSC adipogenic differentiation in vivo and in vitro. Mechanistically, by enhancing ubiquitination-mediated Myoferlin degradation, downregulated APPL1 expression increased the risk of lysosome dysfunction during hMSCs adipogenic differentiation. Lysosomal dysfunction inhibited autophagy flux by suppressing autophagosome degradation and promoted hMSC differentiation towards the adipocyte lineage. Our findings suggest that APPL1/Myoferlin downregulation promoted hMSCs adipogenic differentiation by inhibiting autophagy flux, further impairing the balance of hMSCs adipogenic and osteogenic differentiation in osteoporosis; the APPL1/ Myoferlin axis may be a promising diagnostic and therapeutic target for osteoporosis.


Assuntos
Proteínas Adaptadoras de Transdução de Sinal , Proteínas de Membrana , Células-Tronco Mesenquimais , Proteínas Musculares , Osteoporose , Proteínas Adaptadoras de Transdução de Sinal/genética , Proteínas Adaptadoras de Transdução de Sinal/metabolismo , Adipogenia/genética , Idoso , Animais , Autofagia/fisiologia , Proteínas de Ligação ao Cálcio , Diferenciação Celular/fisiologia , Células Cultivadas , Humanos , Proteínas de Membrana/genética , Proteínas de Membrana/metabolismo , Células-Tronco Mesenquimais/metabolismo , Camundongos , Proteínas Musculares/metabolismo , Osteogênese/genética , Osteoporose/genética , Osteoporose/metabolismo
9.
Mech Ageing Dev ; 207: 111714, 2022 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-35931242

RESUMO

Myocardial infarction (MI) is the most common cause of heart failure (HF) worldwide. The aim of this study was to investigate the role of Klotho in cardiac function and remodeling as well as its underlying mechanism in mice with MI-induced HF. For in vivo analyses, MI or sham MI were established in C57BL/6 mice. For in vitro analyses, the H9C2 cells were used to establish a model of oxygen glucose deprivation (OGD). The In vivo and in vitro models were treated with or without Klotho. 3-methyladenine (3-MA) was used to inhibit autophagy in MI mice and H9C2 cells. Cardiac function, cardiac fibrosis, cardiomyocyte autophagy, inflammatory cytokines and myocardial apoptosis were measured. Our results revealed that Klotho significantly improved cardiac function and remodeling, reduced cardiac fibrosis, and suppressed the levels of myocardial inflammatory factors and apoptosis in MI-induced HF model. Klotho enhanced autophagy in cardiomyocytes and inhibited PI3K/AKT/mTOR signaling pathway in the mouse model of MI. Similar observations were made in the OGD model after treatment with Klotho. However, the cardioprotective effects of Klotho was significantly suppressed by 3-MA. Our data indicate that Klotho exerts its cardioprotective effects against MI-induced HF by inducing autophagy through the inhibition of PI3k/AKT/mTOR signaling pathway.


Assuntos
Insuficiência Cardíaca , Infarto do Miocárdio , Animais , Apoptose , Autofagia/fisiologia , Citocinas/metabolismo , Fibrose , Glucose/metabolismo , Insuficiência Cardíaca/metabolismo , Camundongos , Camundongos Endogâmicos C57BL , Infarto do Miocárdio/complicações , Infarto do Miocárdio/patologia , Miócitos Cardíacos/metabolismo , Oxigênio/metabolismo , Fosfatidilinositol 3-Quinases/metabolismo , Proteínas Proto-Oncogênicas c-akt/metabolismo , Serina-Treonina Quinases TOR/metabolismo
10.
EMBO J ; 41(17): e112180, 2022 09 01.
Artigo em Inglês | MEDLINE | ID: mdl-35920021

RESUMO

Refeeding after a period of starvation is known to suppress autophagy in the liver. Surprising new work by Seok et al (2022) shows that refeeding activates lipophagy in the intestine, which may help fats in our diet to be efficiently processed after a meal.


Assuntos
Metabolismo dos Lipídeos , Inanição , Autofagia/fisiologia , Humanos , Fígado/metabolismo , Inanição/metabolismo
11.
Int J Mol Sci ; 23(16)2022 Aug 10.
Artigo em Inglês | MEDLINE | ID: mdl-36012149

RESUMO

Glioblastoma (GB) cells physically interact with peritumoral pericytes (PCs) present in the brain microvasculature. These interactions facilitate tumor cells to aberrantly increase and benefit from chaperone-mediated autophagy (CMA) in the PC. GB-induced CMA leads to major changes in PC immunomodulatory phenotypes, which, in turn, support cancer progression. In this review, we focus on the consequences of the GB-induced up-regulation of CMA activity in PCs and evaluate how manipulation of this process could offer new strategies to fight glioblastoma, increasing the availability of treatments for this cancer that escapes conventional therapies. We finally discuss the use of modified PCs unable to increase CMA in response to GB as a cell therapy alternative to minimize undesired off-target effects associated with a generalized CMA inhibition.


Assuntos
Autofagia Mediada por Chaperonas , Glioblastoma , Autofagia/fisiologia , Glioblastoma/patologia , Glioblastoma/terapia , Humanos , Lisossomos/patologia , Chaperonas Moleculares/genética , Pericitos/patologia
12.
Biochem Biophys Res Commun ; 623: 140-147, 2022 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-35914352

RESUMO

In the setting of virus infection, autophagy regulates the synthesis of type I interferon (IFN) via multiple mechanisms to prevent adverse overreaction. Interferon regulatory factor (IRF) 3, the dominant transcriptional factor of type I IFN, can be degraded via autophagy-lysosomal pathway. However, the exact regulatory mechanism is not yet well elucidated. IRF3 was targeted into autophagosome by interacting with cargo receptors including p62, NDP52 and NBR1. The recent studies have reported the mechanism of p62 and NDP52 sequestrating IRF3. This work aims to investigate the role of NBR1 in the process of IRF3 degradation. We found that blocking autophagy via ATG3/ATG7 knockout and chemical inhibitors both resulted in the accumulation of IRF3 protein and increased synthesis of type I IFN, while enhancing autophagy activity led to more obvious clearance of IRF3 in HEK293T cells infected with Sendai virus (SeV). Our data suggested that NBR1 bound both unphosphorylated and phosphorylated IRF3 through its ubiquitin-associated domain. Meanwhile, viral infection elevated the expression of NBR1, which sequentially formed a negative feedback loop to promote IRF3 degradation and hence optimized the type I IFN signaling. This study expands the knowledge of molecular mechanisms regulating the IRF3 stability and function during viral infection.


Assuntos
Fator Regulador 3 de Interferon/metabolismo , Interferon Tipo I , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Viroses , Autofagia/fisiologia , Células HEK293 , Humanos , Interferon Tipo I/metabolismo , Proteínas/metabolismo
13.
Molecules ; 27(15)2022 Jul 27.
Artigo em Inglês | MEDLINE | ID: mdl-35956750

RESUMO

7α,25-dihydroxycholesterol (7α,25-DHC) is an oxysterol synthesized from 25-hydroxycholesterol by cytochrome P450 family 7 subfamily B member 1 (CYP7B1) and is a monooxygenase (oxysterol-7α-hydroxylase) expressed under inflammatory conditions in various cell types. In this study, we verified that 7α,25-DHC-induced oxiapoptophagy is mediated by apoptosis, oxidative stress, and autophagy in L929 mouse fibroblasts. MTT assays and live/dead cell staining revealed that cytotoxicity was increased by 7α,25-DHC in L929 cells. Consequentially, cells with condensed chromatin and altered morphology were enhanced in L929 cells incubated with 7α,25-DHC for 48 h. Furthermore, apoptotic population was increased by 7α,25-DHC exposure through the cascade activation of caspase-9, caspase-3, and poly (ADP-ribose) polymerase in the intrinsic pathway of apoptosis in these cells. 7α,25-DHC upregulated reactive oxygen species (ROS) in L929 cells. Expression of autophagy biomarkers, including beclin-1 and LC3, was significantly increased by 7α,25-DHC treatment in L929 cells. 7α,25-DHC inhibits the phosphorylation of Akt associated with autophagy and increases p53 expression in L929 cells. In addition, inhibition of G-protein-coupled receptor 183 (GPR183), a receptor of 7α,25-DHC, using GPR183 specific antagonist NIBR189 suppressed 7α,25-DHC-induced apoptosis, ROS production, and autophagy in L929 cells. Collectively, GPR183 regulates 7α,25-DHC-induced oxiapoptophagy in L929 cells.


Assuntos
Oxisteróis , Receptores Acoplados a Proteínas G , Animais , Apoptose/genética , Apoptose/fisiologia , Autofagia/genética , Autofagia/fisiologia , Fibroblastos/metabolismo , Hidroxicolesteróis/metabolismo , Camundongos , Oxisteróis/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Receptores Acoplados a Proteínas G/metabolismo
14.
Front Endocrinol (Lausanne) ; 13: 937367, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35966083

RESUMO

Adrenal masses are one of the most common tumors in humans. The majority are benign and non-functioning and therefore do not require immediate treatment. In contrast, the rare adrenal malignant tumors are often highly aggressive and with poor prognosis. Besides usually being detected in advanced stages, often already with metastases, one of the reasons of the unfavorable outcome of the patients with adrenal cancer is the absence of effective treatments. Autophagy is one of the intracellular pathways targeted by several classes of chemotherapeutics. Mitotane, the most commonly used drug for the treatment of adrenocortical carcinoma, was recently shown to also modulate autophagy. Autophagy is a continuous programmed cellular process which culminates with the degradation of cellular organelles and proteins. However, being a dynamic mechanism, understanding the autophagic flux can be highly complex. The role of autophagy in cancer has been described paradoxically: initially described as a tumor pro-survival mechanism, different studies have been showing that it may result in other outcomes, namely in tumor cell death. In adrenal tumors, this dual role of autophagy has also been addressed in recent years. Studies reported both induction and inhibition of autophagy as a treatment strategy of adrenal malignancies. Importantly, most of these studies were performed using cell lines. Consequently clinical studies are still required. In this review, we describe what is known about the role of autophagy modulation in treatment of adrenal tumors. We will also highlight the aspects that need further evaluation to understand the paradoxical role of autophagy in adrenal tumors.


Assuntos
Neoplasias do Córtex Suprarrenal , Neoplasias das Glândulas Suprarrenais , Carcinoma Adrenocortical , Neoplasias do Córtex Suprarrenal/tratamento farmacológico , Neoplasias das Glândulas Suprarrenais/tratamento farmacológico , Neoplasias das Glândulas Suprarrenais/patologia , Carcinoma Adrenocortical/tratamento farmacológico , Autofagia/fisiologia , Morte Celular , Humanos
15.
Medicina (Kaunas) ; 58(8)2022 Aug 20.
Artigo em Inglês | MEDLINE | ID: mdl-36013596

RESUMO

Background and Objectives: Age-related macular degeneration is a slow-progressing disease in which lipofuscin accumulates in the retina, causing inflammation and apoptosis of retinal pigment epithelial (RPE) cells. This study aimed to identify N-methyl-D-aspartate (NMDA) signaling as a novel mechanism for scavenging N-retinylidene-N-retinylethanolamine (A2E), a component of ocular lipofuscin, in human RPE cells. Materials and Methods: A2E degradation assays were performed in ARPE-19 cells using fluorescently labeled A2E. The autophagic activity in ARPE-19 cells was measured upon blue light (BL) exposure, after A2E treatment. Autophagy flux was determined by measuring LC3-II formation using immunoblotting and confocal microscopy. To determine whether autophagy via the NMDA receptor is involved in A2E clearance, ATG5-deficient cells were used. Results: Ro 25-6981, an NR2B-selective NMDA receptor antagonist, effectively cleared A2E. Ro 25-6981 reduced A2E accumulation in the lysosomes of ARPE-19 cells at sub-cytotoxic concentrations, while increasing the formation of LC3-II and decreasing p62 protein levels in a concentration-dependent manner. The autophagic flux monitored by RFP-GFP-LC3 and bafilomycin A1 assays was significantly increased by Ro 25-6981. A2E clearance by Ro 25-6981 was abolished in ATG5-depleted ARPE-19 cells, suggesting that A2E degradation by Ro 25-6981 was mediated by autophagy. Furthermore, treatment with other NMDA receptor antagonists, CP-101,606 and AZD6765, showed similar effects on autophagy activation and A2E degradation in ARPE-19 cells. In contrast, glutamate, an NMDA receptor agonist, exhibited a contrasting effect, suggesting that both the activation of autophagy and the degradation of A2E by Ro 25-6981 in ARPE-19 cells occur through inhibition of the NMDA receptor pathway. Conclusions: This study demonstrates that NMDA receptor antagonists degrade lipofuscin via autophagy in human RPE cells and suggests that NMDA receptor antagonists could be promising new therapeutics for retinal degenerative diseases.


Assuntos
Lipofuscina , Epitélio Pigmentado da Retina , Autofagia/fisiologia , Células Epiteliais , Humanos , Lipofuscina/metabolismo , Lipofuscina/farmacologia , Receptores de N-Metil-D-Aspartato/metabolismo , Epitélio Pigmentado da Retina/metabolismo , Pigmentos da Retina/metabolismo , Pigmentos da Retina/farmacologia , Retinoides/metabolismo , Retinoides/toxicidade
16.
FASEB J ; 36(9): e22491, 2022 09.
Artigo em Inglês | MEDLINE | ID: mdl-35947089

RESUMO

Accumulation of lipid substances decreased the activity of osteoblasts. Trehalose is a typical stress metabolite to form a protective membrane on cell surface which has been demonstrated to regulate lipid metabolism. This activity of Trehalose indicates the potential effect of osteoporosis treatment. Our study aimed to determine the therapeutic effect of Trehalose in high fat-induced osteoporosis. We used palmitic acid (PA) to mimic the state of high fat and observed the apoptosis ratio of osteoblasts increased. After adding Trehalose, the apoptosis ratio decreased obviously. Autophagy is a regulatory means involved in the process of apoptosis. We detected the autophagy protein and found that the expression of Beclin-1, Atg5, and LC3 II increased, and p62 decreased after Trehalose treatment. When adding an autophagy inhibitor (3-MA), the expression of Beclin-1, Atg5, and LC3 II decreased, and p62 increased. These results indicated autophagy was an important factor involved in the preventive effect of Trehalose in PA-induced apoptosis. SIRT3 is a mitochondrial gene that can inhibit apoptosis, which has been reported to promote autophagy. We used SIRT3-siRNA to silence the expression of SIRT3 and found the effect of Trehalose was counteracted. The apoptosis ratio increased and the expression of Beclin-1, Atg5, and LC3 II decreased, p62 increased. Additionally, we also fed the mice with a high-fat diet (HFD) and intragastrical Trehalose. The results showed that Trehalose could inhibit the bone mass loss with HFD. Our study revealed the effect and mechanism of Trehalose in the treatment of osteoporosis.


Assuntos
Osteoporose , Sirtuína 3 , Proteínas Quinases Ativadas por AMP/metabolismo , Animais , Apoptose , Autofagia/fisiologia , Proteína Beclina-1/metabolismo , Camundongos , Osteoblastos/metabolismo , Osteoporose/tratamento farmacológico , Ácido Palmítico/toxicidade , Serina-Treonina Quinases TOR/metabolismo , Trealose/farmacologia
17.
Contrast Media Mol Imaging ; 2022: 3357694, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35965629

RESUMO

Mycoplasma pneumoniae (M. pneumoniae) is the most common cause of community-acquired pneumonia. Toll-like receptors (TLRs) play an essential role in pneumonia. The purpose of this study was to investigate the roles of TLR4 in M. pneumoniae. Mice were administrated with 100 µl (1 × 107 ccu/ml) of M. pneumoniae. HE staining was applied for histological analysis. The protein expression was determined by western blot. The cytokine level was detected by ELISA. The results showed that TLR4-deficient mice were protected from M. pneumoniae. However, downregulation of TLR4 inhibited inflammatory response and autophagy. Moreover, transcription factor EB (TFEB) participated in M. pneumoniae-induced inflammatory response and autophagy, while knockdown of TLR4 downregulated TFEB and its nuclear translocation.


Assuntos
Mycoplasma pneumoniae , Receptor 4 Toll-Like/metabolismo , Animais , Autofagia/fisiologia , Camundongos , Mycoplasma pneumoniae/metabolismo , Receptor 4 Toll-Like/genética
18.
Contrast Media Mol Imaging ; 2022: 7614497, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35992546

RESUMO

Osteoarthritis (OA) is a rheumatic disease and its pathogenesis involves the dysregulation of noncoding RNAs. Therefore, the regulatory mechanism of circular RNA MELK (circMELK) was specified in this work. OA human cartilage tissue was collected, and circMELK, miR-497-5p, and myeloid differentiation factor 88 (MYD88) expression were examined. Human chondrocytes were stimulated with interleukin- (IL-) 1ß and interfered with vectors altering circMELK, miR-497-5p, and MyD88 expression to observe their effects on cell viability, cell cycle and apoptosis, autophagy, and inflammation. The binding relationship between RNAs was verified. The data presented that OA cartilage tissues presented raised circMELK and MYD88 and inhibited miR-497-5p expression. IL-1ß suppressed cell viability, prevented cell cycle, and induced apoptosis, autophagy, and inflammation of chondrocytes. Functionally, IL-1ß-induced changes of chondrocytes could be attenuated by suppressing circMELK or overexpressing miR-497-5p. circMELK acted as a sponge of miR-497-5p while miR-497-5p was a regulator of MYD88. MYD88 restricted the effect of overexpressing miR-497-5p on IL-1ß-stimulated chondrocytes. MYD88 triggered nuclear factor-kappaB (NF-κB) pathway activation. Shortly, CircMELK promotes chondrocyte apoptosis and inhibits autophagy in OA by regulating MYD88/NF-κB signaling axis through miR-497-5p. Our study proposes a new molecular mechanism for the development of OA.


Assuntos
MicroRNAs , Fator 88 de Diferenciação Mieloide , NF-kappa B , Osteoartrite , Proteínas Serina-Treonina Quinases , RNA Circular , Apoptose/genética , Apoptose/fisiologia , Autofagia/genética , Autofagia/fisiologia , Condrócitos/metabolismo , Humanos , Inflamação/genética , Inflamação/metabolismo , MicroRNAs/genética , MicroRNAs/metabolismo , Fator 88 de Diferenciação Mieloide/genética , Fator 88 de Diferenciação Mieloide/metabolismo , NF-kappa B/genética , NF-kappa B/metabolismo , Osteoartrite/genética , Osteoartrite/metabolismo , Osteoartrite/patologia , Proteínas Serina-Treonina Quinases/genética , Proteínas Serina-Treonina Quinases/metabolismo , RNA Circular/genética , RNA Circular/metabolismo
19.
Sheng Li Xue Bao ; 74(4): 633-638, 2022 Aug 25.
Artigo em Chinês | MEDLINE | ID: mdl-35993214

RESUMO

Fibroblast growth factor 21 (FGF21) is a growth factor with endocrine function in the fibroblast growth factor family. Previous reports have shown that FGF21 is involved in the regulation of energy metabolism and plays a protective role in cardiovascular diseases such as coronary heart disease, diabetes, non-alcoholic fatty liver disease and so on. Recent studies have found that FGF21 can induce autophagy in a variety of tissues and organs, and autophagy is involved in many pathological processes of cardiovascular diseases, including vascular calcification, atherosclerosis, and myocardial ischemia-reperfusion injury. Therefore, FGF21 may play a protective role in a variety of cardiovascular diseases by regulating autophagy. This article reviews the research progress on the protective role of FGF21 in cardiovascular diseases by inducing autophagy.


Assuntos
Autofagia , Doenças Cardiovasculares , Fatores de Crescimento de Fibroblastos , Autofagia/genética , Autofagia/fisiologia , Doenças Cardiovasculares/genética , Doenças Cardiovasculares/metabolismo , Fatores de Crescimento de Fibroblastos/genética , Fatores de Crescimento de Fibroblastos/metabolismo , Humanos , Traumatismo por Reperfusão Miocárdica/genética , Traumatismo por Reperfusão Miocárdica/metabolismo
20.
J Inorg Biochem ; 236: 111974, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36027844

RESUMO

Excessive molybdenum (Mo) and cadmium (Cd) are toxic environmental pollutants. Our previous research confirmed excessive Mo and Cd co-induced calcium homeostasis disorder and autophagy in duck kidneys, but how calcium ion (Ca2+) regulates autophagy is unclear. The results revealed that the Mo- and/or Cd-induced cytosolic Ca2+ concentration ([Ca2+]c) increase mainly came from intracellular calcium stores. Mo and/or Cd caused mitochondrial Ca2+ content ([Ca2+]mit) and [Ca2+]c increase with endoplasmic reticulum (ER) Ca2+ content ([Ca2+]ER) decrease and upregulated calcium homeostasis-related factor expression levels, but 2-Aminoethoxydiphenyl borate (2-APB) reversed subcellular Ca2+ redistribution. Increased Phospholipase C (PLC) and inositol 1,4,5-trisphosphate (IP3) activities and inositol 1,4,5-trisphosphate receptor (IP3R) expression level were observed in Mo- and/or Cd-treated cells, which was reversed by the PLC inhibitor U-73122. 2-APB and 1,2-Bis (2-aminophenoxy) ethane-N,N,N',N'-tetraacetic acid acetoxymethyl ester (BAPTA-AM) addition mitigated [Ca2+]c and autophagy (variations in microtubule-associated protein light chain 3 (LC3), LC3B-II/LC3B-I, autophagy related 5 (ATG5), sequestosome-1(P62), programmed cell death-1 (Beclin-1) and Dynein expression levels, LC3 puncta, autophagosomes and acid vesicle organelles) under Mo and/or Cd treatment, respectively, while thapsigargin (TG) had the opposite impacts. Additionally, the calmodulin-dependent protein kinase kinase ß (CaMKKß) inhibitor STO-609 reversed the increased CaMKKß, adenosine 5'-monophosphate-activated protein kinase (AMPK), Beclin-1, and LC3B-II/LC3B-I protein expression levels and reduced mammalian target of rapamycin (mTOR) and P62 protein expression levels in Mo- and/or Cd-exposed cells. Collectively, the results confirmed that [Ca2+]c overload resulted from PLC/IP3/IP3R pathway-mediated ER Ca2+ release, and then activated autophagy by the CaMKKß/AMPK/mTOR pathway in Mo- and/or Cd-treated duck renal tubular epithelial cells.


Assuntos
Quinase da Proteína Quinase Dependente de Cálcio-Calmodulina , Poluentes Ambientais , Proteínas Quinases Ativadas por AMP/metabolismo , Adenosina , Animais , Autofagia/fisiologia , Proteína Beclina-1/metabolismo , Cádmio/metabolismo , Cádmio/toxicidade , Cálcio/metabolismo , Quinase da Proteína Quinase Dependente de Cálcio-Calmodulina/metabolismo , Patos/metabolismo , Dineínas/metabolismo , Células Epiteliais/metabolismo , Ésteres , Etano , Inositol 1,4,5-Trifosfato , Receptores de Inositol 1,4,5-Trifosfato , Mamíferos/metabolismo , Proteínas Associadas aos Microtúbulos/metabolismo , Molibdênio/metabolismo , Serina-Treonina Quinases TOR/metabolismo , Tapsigargina , Fosfolipases Tipo C/metabolismo
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