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1.
Indian J Med Microbiol ; 50: 100658, 2024 Jun 28.
Artigo em Inglês | MEDLINE | ID: mdl-38925279

RESUMO

The Aeromonadaceae family, comprised of gram-negative bacilli, is ubiquitously distributed across the globe. Infections by Aeromonas species encompass gastroenteritis, septicaemia, skin and soft tissue infections (SSTIs), pneumonia, and peritonitis. This report delineates a case of Aeromonas hydrophila infection, manifesting as an array of pustules on the patient's lower extremities subsequent to the ingestion of marine crustaceans, specifically prawns. Prompt diagnosis and the initiation of an appropriate antibiotic regimen are imperative to mitigate the risk of further complications.

2.
Nat Metab ; 6(4): 639-650, 2024 Apr.
Artigo em Inglês | MEDLINE | ID: mdl-38671149

RESUMO

Thyroid hormones (THs) are key hormones that regulate development and metabolism in mammals. In man, the major target tissues for TH action are the brain, liver, muscle, heart, and adipose tissue. Defects in TH synthesis, transport, metabolism, and nuclear action have been associated with genetic and endocrine diseases in man. Over the past few years, there has been renewed interest in TH action and the therapeutic potential of THs and thyromimetics to treat several metabolic disorders such as hypercholesterolemia, dyslipidaemia, non-alcoholic fatty liver disease (NAFLD), and TH transporter defects. Recent advances in the development of tissue and TH receptor isoform-targeted thyromimetics have kindled new hope for translating our fundamental understanding of TH action into an effective therapy. This review provides a concise overview of the historical development of our understanding of TH action, its physiological and pathophysiological effects on metabolism, and future therapeutic applications to treat metabolic dysfunction.


Assuntos
Hormônios Tireóideos , Humanos , Hormônios Tireóideos/metabolismo , Animais , Doenças Metabólicas/metabolismo , Receptores dos Hormônios Tireóideos/metabolismo
3.
Liver Res ; 8(1): 34-45, 2024 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-38544909

RESUMO

The onset of metabolic dysfunction-associated steatohepatitis (MASH) or non-alcoholic steatohepatitis (NASH) represents a tipping point leading to liver injury and subsequent hepatic complications in the natural progression of what is now termed metabolic dysfunction-associated steatotic liver diseases (MASLD), formerly known as non-alcoholic fatty liver disease (NAFLD). With no pharmacological treatment currently available for MASH/NASH, the race is on to develop drugs targeting multiple facets of hepatic metabolism, inflammation, and pro-fibrotic events, which are major drivers of MASH. Nuclear receptors (NRs) regulate genomic transcription upon binding to lipophilic ligands and govern multiple aspects of liver metabolism and inflammation. Ligands of NRs may include hormones, lipids, bile acids, and synthetic ligands, which upon binding to NRs regulate the transcriptional activities of target genes. NR ligands are presently the most promising drug candidates expected to receive approval from the United States Food and Drug Administration as a pharmacological treatment for MASH. This review aims to cover the current understanding of NRs, including nuclear hormone receptors, non-steroid hormone receptors, circadian NRs, and orphan NRs, which are currently undergoing clinical trials for MASH treatment, along with NRs that have shown promising results in preclinical studies.

4.
Biochim Biophys Acta Mol Basis Dis ; 1870(3): 167025, 2024 03.
Artigo em Inglês | MEDLINE | ID: mdl-38237741

RESUMO

BACKGROUND: Bone marrow mesenchymal stem cells (BM-MSC) are an integral part of the BM niche that is essential to maintain hematopoietic homeostasis. In aplastic anemia (AA), a few studies have reported phenotypic defects in the BM-MSC, such as reduced proliferation, imbalanced differentiation, and apoptosis; however, the alterations at the molecular level need to be better characterized. Therefore, the current study aims to identify the causative factors underlying the compromised functions of AA BM-MSC that might eventually be contributing to the AA pathobiology. METHODS: We performed RNA sequencing (RNA-Seq) using the Illumina platform to comprehend the distinction between the transcriptional landscape of AA and control BM-MSC. Further, we validated the alterations observed in senescence by Senescence- associated beta-galactosidase (SA -ß-gal) assay, DNA damage by γH2AX staining, and telomere attrition by relative telomere length assessment and telomerase activity assay. We used qRT-PCR to analyze changes in some of the genes associated with these molecular mechanisms. RESULTS: The transcriptome profiling revealed enrichment of senescence-associated genes and pathways in AA BM-MSC. The senescent phenotype of AA BM-MSC was accompanied by enhanced SA -ß-gal activity and elevated expression of senescence associated genes TP53, PARP1, and CDKN1A. Further, we observed increased γH2AX foci indicating DNA damage, reduced telomere length, and diminished telomerase activity in the AA BM-MSC. CONCLUSION: Our results highlight that AA BM-MSC have a senescent phenotype accompanied by other cellular defects like DNA damage and telomere attrition, which are most likely driving the senescent phenotype of AA BM-MSC thus hampering their hematopoiesis supporting properties as observed in AA.


Assuntos
Anemia Aplástica , Células-Tronco Mesenquimais , Telomerase , Humanos , Anemia Aplástica/genética , Anemia Aplástica/metabolismo , Telomerase/genética , Telomerase/metabolismo , Células-Tronco Mesenquimais/metabolismo , Telômero/genética , Reparo do DNA
5.
Environ Toxicol ; 39(2): 840-856, 2024 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-37853854

RESUMO

INTRODUCTION: Hepatocellular carcinoma (HCC) is a common solid cancer and the leading cause of cancer deaths worldwide. Sorafenib is the first drug used to treat HCC but its effectiveness needs to be improved, and it is important to find ways to treat cancer that combine sorafenib with other drugs. Synergistic therapies lower effective drug doses and side effects while enhancing the anticancer effect. PURPOSE: In the present study, the therapeutic potential of sorafenib in combination with escin and its underlying mechanism in targeting liver cancer has been established. STUDY DESIGN/METHODS: The IC50 of sorafenib and escin against HepG2, PLC/PRF5 and Huh7 cell lines were determined using MTT assay. The combination index, dose reduction index, isobologram and concentrations producing synergy were evaluated using the Chou-Talaly algorithm. The sub-effective concentration of sorafenib and escin was selected to analyze cytotoxic synergistic potential. Cellular ROS, mitochondrial membrane potential, annexin V and cell cycle were evaluated using a flow-cytometer, and autophagy biomarkers were determined using western blotting. Moreover, autophagy was knocked down using ATG5 siRNA to confirm its role. A DEN-induced liver cancer rat model was developed to check the synergy of sorafenib and escin. RESULTS: Different concentrations of escin reduced the IC50 of sorafenib in HepG2, PLC/PRF5 and Huh7 cell lines. Chou-Talaly algorithm determined cytotoxic synergistic concentrations of sorafenib and escin in these cell lines. Mechanistically, this combination over-expressed p62 and LC-II, reflecting autophagy block and induced late apoptosis, further reconfirmed by ATG5 knockdown. Sorafenib and escin combination  reduced HCC serum biomarker α-feto protein (α-FP) by 1.5 folds. This combination restricted liver weight, tumor number and size, also, conserved morphological features of liver cells. The combination selectively targeted the G0 /G1 phase of cancer cells. CONCLUSION: Escin and sorafenib combination potentially up-regulates p62 to block autophagy to induce late apoptosis in liver cancer cells.


Assuntos
Antineoplásicos , Carcinoma Hepatocelular , Neoplasias Hepáticas , Animais , Ratos , Antineoplásicos/farmacologia , Apoptose , Carcinoma Hepatocelular/patologia , Linhagem Celular Tumoral , Proliferação de Células , Escina/farmacologia , Neoplasias Hepáticas/patologia , Proteínas Associadas aos Microtúbulos , Sorafenibe/farmacologia
6.
Int J Biol Macromol ; 252: 126328, 2023 Dec 01.
Artigo em Inglês | MEDLINE | ID: mdl-37579900

RESUMO

Lung cancer is the most common and lethal cancer worldwide, yet there are no adequate and novel medications to control this illness. Previous reports suggested the potential of protein kinases to target lung cancer by regulating autophagy. This study establishes the role of aescin, a triterpenoid saponin, in targeting protein kinases responsible for lung cancer proliferation and mobility. The experimental data revealed that aescin significantly impedes lung cancer cell proliferation by downregulating protein kinases such as AKT, mTOR, MEK, and ERK. Downregulation of AKT-mTOR may promote a string of events inducing cytotoxic autophagy-mediated apoptosis in the presence of aescin. Besides, aescin decreases mobility and invasion by downregulating HIF-1α and VEGF gene expressions. Moreover, it successfully monitors EGFR gene expression, improves lung histology, and regulates biochemical parameters in a pre-clinical DEN-induced lung cancer model. Aescin was observed to be safe and non-toxic in both in silico toxicity predictions and ex vivo erythrocyte fragility assays. Hence, this study elucidates the molecular mechanism of aescin in targeting protein kinases and suggests that it could be a safer and more viable therapeutic agent for lung cancer treatment.


Assuntos
Neoplasias Pulmonares , Saponinas , Triterpenos , Humanos , Escina/farmacologia , Escina/uso terapêutico , Neoplasias Pulmonares/tratamento farmacológico , Saponinas/farmacologia , Proteínas Proto-Oncogênicas c-akt/metabolismo , Triterpenos/farmacologia , Linhagem Celular Tumoral , Apoptose , Serina-Treonina Quinases TOR/metabolismo , Pulmão/metabolismo , Autofagia
7.
Toxicol In Vitro ; 93: 105666, 2023 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-37611852

RESUMO

Combination therapy has been proposed as a promising approach for lung cancer treatment, as it can enhance anticancer efficacy, and reduce dosages and adverse effects. This study aimed to explore the therapeutic potential of gossypol, a natural polyphenolic compound with sorafenib for treating lung cancer cells and elucidating its mechanism of action. The MTT assay was utilized to determine the IC50 of sorafenib and gossypol against A549 and NCI H460 cell lines. The Chou-Talaly algorithm was employed to determine the combination index (CI). A sub-effective concentration of sorafenib and gossypol was chosen to investigate the possibility of cytotoxic synergy. Autophagy biomarkers were identified using Western blotting, and the function of autophagy was determined using ATG5 siRNA. Results show that IC50 of sorafenib significantly reduced in A549 and NCI H460 cells when co-treated with gossypol. The combination treatment showed a synergistic cytotoxic effect against tested cell lines. The Chou-Talaly algorithm confirmed sorafenib's dose reduction index (DRI) up to 3.86. In A549 cells, combination treatment down-regulated p62 and up-regulated LC3-II, indicating the initiation of autophagy-dependent cytotoxicity. This was further confirmed by siRNA ATG5 knockdown. Additionally, the combination treatment exclusively targeted G0/G1 phase cancer cells. In conclusion, the combination of gossypol and sorafenib shows a synergistic increase in the cytotoxic effect by promoting autophagy and apoptosis.


Assuntos
Antineoplásicos , Gossipol , Neoplasias Pulmonares , Humanos , Sorafenibe/farmacologia , Gossipol/farmacologia , Linhagem Celular Tumoral , Neoplasias Pulmonares/tratamento farmacológico , Neoplasias Pulmonares/patologia , Antineoplásicos/farmacologia , Apoptose , Autofagia , RNA Interferente Pequeno/farmacologia , Proliferação de Células
8.
Cells ; 12(14): 1845, 2023 07 13.
Artigo em Inglês | MEDLINE | ID: mdl-37484201

RESUMO

Non-alcoholic steatohepatitis (NASH) is a clinically serious stage of non-alcoholic fatty liver disease (NAFLD). Histologically characterized by hepatocyte ballooning, immune cell infiltration, and fibrosis, NASH, at a molecular level, involves lipid-induced hepatocyte death and cytokine production. Currently, there are very few diagnostic biomarkers available to screen for NASH, and no pharmacological intervention is available for its treatment. In this study, we show that hepatocyte damage induced by lipotoxicity results in the release of extracellular RNAs (eRNAs), which serve as damage-associated molecular patterns (DAMPs) that stimulate the expression of pro-apoptotic and pro-inflammatory cytokines, aggravate inflammation, and lead to cell death in HepG2 cells. Furthermore, the inhibition of eRNA activity by RNase 1 significantly increases cellular viability and reduces NF-kB-mediated cytokine production. Similarly, RNase 1 administration significantly improves hepatic steatosis, inflammatory and injury markers in a murine NASH model. Therefore, this study, for the first time, underscores the therapeutic potential of inhibiting eRNA action as a novel strategy for NASH treatment.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Camundongos , Animais , Hepatopatia Gordurosa não Alcoólica/metabolismo , Hepatócitos/metabolismo , Inflamação/patologia , Citocinas
9.
Phytother Res ; 37(10): 4819-4837, 2023 Oct.
Artigo em Inglês | MEDLINE | ID: mdl-37468281

RESUMO

Combining anti-cancer drugs has been exploited as promising treatment strategy to target lung cancer. Synergistic chemotherapies increase anti-cancer effect and reduce effective drug doses and side effects. In this study, therapeutic potential of escin in combination with sorafenib has been explored. 3-(4,5-Dimethylthiazol-2-yl)-2 5-diphenyltetrazolium bromide assay was used to calculate IC50 values. The synergy was evaluated using Chou-Talaly algorithm. Cellular reactive oxygen species, mitochondrial membrane potential, annexin V, and cell-cycle studies were done by flow-cytometer, and autophagy biomarkers expression were determined using western blotting. Moreover, autophagy was knocked down using ATG5 siRNA to confirm its role, diethylnitrosamine-induced lung cancer model was used to check the synergy of sorafenib/escin. Escin significantly reduced the IC50 of sorafenib in A549 and NCIH460 cells. The combination of sorafenib/escin produced a 2.95 and 5.45 dose reduction index for sorafenib in A549 and NCI-H460 cells. The combination of over-expressed p62 and LC3-II reflects autophagy block-mediated late apoptosis. This phenomenon was reconfirmed by ATG5 knockdown. This combination also selectively targeted G0/G1 phase of cancer cells. In in vivo study, the combination reduced tumour load and lower elevated serum biochemical parameters. The combination of sorafenib/escin synergistically inhibits autophagy to induce late apoptosis in lung cancer cells' G0/G1 phase.

10.
Biochem Pharmacol ; 212: 115550, 2023 06.
Artigo em Inglês | MEDLINE | ID: mdl-37060962

RESUMO

Cancer stem cells (CSCs) are a subset of cancer cells with self-renewal ability and tumor initiating properties. Unlike the other non-stem cancer cells, CSCs resist traditional therapy and remain a major cause of disease relapse. With the recent advances in metabolomics, various studies have demonstrated that CSCs have distinct metabolic properties. Metabolic reprogramming in CSCs contributes to self-renewal and maintenance of stemness. Accumulating evidence suggests that rewiring of energy metabolism is a key player that enables to meet energy demands, maintains stemness, and sustains cancer growth and invasion. CSCs use various mechanisms such as increased glycolysis, redox signaling, and autophagy modulation to overcome nutritional deficiency and sustain cell survival. The alterations in lipid metabolism acquired by the CSCs support biomass production through increased dependence on fatty acid synthesis and ß-oxidation, and contribute to oncogenic signaling pathways. This review summarizes our current understanding of lipid metabolism in CSCs and how pharmacological regulation of autophagy and lipid metabolism influences CSC phenotype. Increased dependence on lipid metabolism appears as an attractive strategy to eliminate CSCs using therapeutic agents that specifically target CSCs based on their modulation of lipid metabolism.


Assuntos
Metabolismo dos Lipídeos , Neoplasias , Humanos , Metabolismo dos Lipídeos/fisiologia , Neoplasias/patologia , Metabolismo Energético , Células-Tronco Neoplásicas/patologia , Autofagia
11.
Genes (Basel) ; 14(3): 553, 2023 02 23.
Artigo em Inglês | MEDLINE | ID: mdl-36874473

RESUMO

Lipotoxicity is a phenomenon of lipid-induced cellular injury in nonadipose tissue. Excess of free saturated fatty acids (SFAs) contributes to hepatic injury in nonalcoholic fatty liver disease (NAFLD), which has been growing at an unprecedented rate in recent years. SFAs and their derivatives such as ceramides and membrane phospholipids have been shown to induce intrahepatic oxidative damage and ER stress. Autophagy represents a cellular housekeeping mechanism to counter the perturbation in organelle function and activation of stress signals within the cell. Several aspects of autophagy, including lipid droplet assembly, lipophagy, mitophagy, redox signaling and ER-phagy, play a critical role in mounting a strong defense against lipotoxic lipid species within the hepatic cells. This review provides a succinct overview of our current understanding of autophagy-lipotoxicity interaction and its pharmacological and nonpharmacological modulation in treating NAFLD.


Assuntos
Hepatopatia Gordurosa não Alcoólica , Humanos , Autofagia , Hepatócitos , Mitofagia , Ceramidas , Ácidos Graxos não Esterificados
12.
Biochim Biophys Acta Mol Basis Dis ; 1869(4): 166662, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36754244

RESUMO

Nonalcoholic steatohepatitis (NASH) is considered a pivotal stage in nonalcoholic fatty liver disease (NAFLD) progression and increases the risk of end-stage liver diseases such as fibrosis, cirrhosis, and hepatocellular carcinoma (HCC). The etiology of NASH is multifactorial and identifying reliable molecular players has proven difficult. Presently, there are no approved drugs for NASH treatment, which has become a leading cause of liver transplants worldwide. Here, using public human transcriptomic NAFLD dataset, we uncover Cystic fibrosis transmembrane conductance receptor (CFTR) as a differentially expressed gene in the livers of human NASH patients. Similarly, murine Cftr expression was also found to be upregulated in two mouse models of diet-induced NASH. Furthermore, the pharmacological inhibition of CFTR significantly reduced NASH progression in mice and its overexpression aggravated lipotoxicity in human hepatic cells. These results, thus, underscore the involvement of murine Cftr in the pathogenesis of NASH and raise the intriguing possibility of its pharmacological inhibition in human NASH.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Hepatopatia Gordurosa não Alcoólica , Animais , Humanos , Camundongos , Carcinoma Hepatocelular/genética , Regulador de Condutância Transmembrana em Fibrose Cística/genética , Fibrose , Neoplasias Hepáticas/patologia , Hepatopatia Gordurosa não Alcoólica/tratamento farmacológico , Hepatopatia Gordurosa não Alcoólica/genética , Hepatopatia Gordurosa não Alcoólica/metabolismo
13.
Adv Cancer Biol Metastasis ; 7: 100079, 2023 Jul.
Artigo em Inglês | MEDLINE | ID: mdl-36536947

RESUMO

Breast cancer (BC) is one of the most frequently diagnosed cancers in women worldwide. It has surpassed lung cancer as the leading cause of cancer-related death. Breast cancer brain metastasis (BCBM) is becoming a major clinical concern that is commonly associated with ER-ve and HER2+ve subtypes of BC patients. Metastatic lesions in the brain originate when the cancer cells detach from a primary breast tumor and establish metastatic lesions and infiltrate near and distant organs via systemic blood circulation by traversing the BBB. The colonization of BC cells in the brain involves a complex interplay in the tumor microenvironment (TME), metastatic cells, and brain cells like endothelial cells, microglia, and astrocytes. BCBM is a significant cause of morbidity and mortality and presents a challenge to developing successful cancer therapy. In this review, we discuss the molecular mechanism of BCBM and novel therapeutic strategies for patients with brain metastatic BC.

14.
World J Hepatol ; 15(12): 1272-1283, 2023 Dec 27.
Artigo em Inglês | MEDLINE | ID: mdl-38192406

RESUMO

Autophagy, a cellular degradative process, has emerged as a key regulator of cellular energy production and stress mitigation. Dysregulated autophagy is a common phenomenon observed in several human diseases, and its restoration offers curative advantage. Non-alcoholic fatty liver disease (NAFLD), more recently renamed metabolic dysfunction-associated steatotic liver disease, is a major metabolic liver disease affecting almost 30% of the world population. Unfortunately, NAFLD has no pharmacological therapies available to date. Autophagy regulates several hepatic processes including lipid metabolism, inflammation, cellular integrity and cellular plasticity in both parenchymal (hepatocytes) and non-parenchymal cells (Kupffer cells, hepatic stellate cells and sinusoidal endothelial cells) with a profound impact on NAFLD progression. Understanding cell type-specific autophagy in the liver is essential in order to develop targeted treatments for liver diseases such as NAFLD. Modulating autophagy in specific cell types can have varying effects on liver function and pathology, making it a promising area of research for liver-related disorders. This review aims to summarize our present understanding of cell-type specific effects of autophagy and their implications in developing autophagy centric therapies for NAFLD.

16.
Biochim Biophys Acta Mol Cell Res ; 1869(12): 119355, 2022 12.
Artigo em Inglês | MEDLINE | ID: mdl-36113664

RESUMO

Autophagy and telomere maintenance are two cellular survival processes that show a strong correlation during human ageing and cancer growth, however, their causal relationship remains unclear. In this study, using an unbiased transcriptomics approach, we uncover a novel role of autophagy genes in regulating telomere extension and maintenance pathways. Concomitantly, the pharmacological inhibition of ULK1 (Unc-51 like autophagy activating kinase 1) attenuated human telomerase reverse transcriptase (hTERT) gene expression and telomerase activity in HepG2 cells. Furthermore, the suppression of telomerase activity upon ULK1 inhibition was associated with telomere shortening and onset of cellular senescence in HepG2 cells. These results, thus, demonstrate a direct role of autophagy in maintaining cellular longevity via regulation of telomerase activity, which may have implications in the pathophysiology of ageing and cancers.


Assuntos
Neoplasias , Telomerase , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/genética , Proteína Homóloga à Proteína-1 Relacionada à Autofagia/metabolismo , Hepatócitos/metabolismo , Humanos , Peptídeos e Proteínas de Sinalização Intracelular/genética , Peptídeos e Proteínas de Sinalização Intracelular/metabolismo , Telomerase/genética , Telomerase/metabolismo , Telômero/genética , Telômero/metabolismo , Encurtamento do Telômero
17.
Life Sci ; 309: 120964, 2022 Nov 15.
Artigo em Inglês | MEDLINE | ID: mdl-36115584

RESUMO

INTRODUCTION AND AIM: Purpurin, a naturally occurring anthraquinone isolated from the roots of Rubia cordifolia, exhibits anti-cancer, anti-genotoxic, anti-microbial, neuromodulatory and photodynamic activity. However, purpurin's in vivo and in vitro antioxidant mechanism remains unexplored. The present study explores the anti-oxidative mechanism of purpurin under the influence of alcohol using in vivo and in vitro test systems. METHODS: Mice hepatocytes and alcohol-induced liver toxicity model were used to evaluate the effect of purpurin. The non-enzymatic and enzymatic oxidative stress markers were estimated by the colorimetric method. The reactive oxygen species (ROS) were quantified in mitochondria and cells using flow cytometer. Real-time PCR and western blotting were used to quantify cytochrome 450 subtype 2E1 (CYP2E1) and Nrf2 expression in the liver tissue of mice. In silico studies were performed through receptor-ligand binding interaction. KEY FINDINGS: Purpurin effectively reduced total cellular and mitochondrial ROS in primary hepatocytes and WRL-68 cells. It prevented alcohol-induced ROS-dependent biochemical and cellular insults observed by analysing the serum glutamic pyruvic transaminase (SGPT), glutamic-oxaloacetic transaminase (SGOT) levels and CYP2E1 expression in liver tissue of alcohol-administered mice. Moreover, it also restored the activity of antioxidant enzymes. Its antioxidant effect was established by glutathione and ROS-dependent mechanisms using buthionine sulfoximine and N-acetyl cysteine. Along with alcohol, purpurin up-regulated Nrf2 expression in hepatocytes. SIGNIFICANCE: This work confirmed the ameliorative effect of purpurin for alcohol-induced hepatotoxicity by drabbing free radicals and curbing oxidative stress via activation of antioxidant signalling pathways.


Assuntos
Antraquinonas , Doença Hepática Induzida por Substâncias e Drogas , Etanol , Fator 2 Relacionado a NF-E2 , Animais , Camundongos , Alanina Transaminase/metabolismo , Antraquinonas/farmacologia , Antioxidantes/farmacologia , Aspartato Aminotransferases/metabolismo , Butionina Sulfoximina/farmacologia , Doença Hepática Induzida por Substâncias e Drogas/tratamento farmacológico , Doença Hepática Induzida por Substâncias e Drogas/prevenção & controle , Cisteína/farmacologia , Citocromo P-450 CYP2E1/metabolismo , Etanol/toxicidade , Glutationa/metabolismo , Ligantes , Fator 2 Relacionado a NF-E2/metabolismo , Estresse Oxidativo , Espécies Reativas de Oxigênio/metabolismo
18.
J Hepatol ; 77(5): 1246-1255, 2022 11.
Artigo em Inglês | MEDLINE | ID: mdl-35820507

RESUMO

BACKGROUND & AIMS: Several recent clinical studies have shown that serum homocysteine (Hcy) levels are positively correlated, while vitamin B12 (B12) and folate levels are negative correlated, with non-alcoholic steatohepatitis (NASH) severity. However, it is not known whether hyperhomocysteinemia (HHcy) plays a pathogenic role in NASH. METHODS: We examined the effects of HHcy on NASH progression, metabolism, and autophagy in dietary and genetic mouse models, patients, and primates. We employed vitamin B12 (B12) and folate (Fol) to reverse NASH features in mice and cell culture. RESULTS: Serum Hcy correlated with hepatic inflammation and fibrosis in NASH. Elevated hepatic Hcy induced and exacerbated NASH. Gene expression of hepatic Hcy-metabolizing enzymes was downregulated in NASH. Surprisingly, we found increased homocysteinylation (Hcy-lation) and ubiquitination of multiple hepatic proteins in NASH including the key autophagosome/lysosome fusion protein, Syntaxin 17 (Stx17). This protein was Hcy-lated and ubiquitinated, and its degradation led to a block in autophagy. Genetic manipulation of Stx17 revealed its critical role in regulating autophagy, inflammation and fibrosis during HHcy. Remarkably, dietary B12/Fol, which promotes enzymatic conversion of Hcy to methionine, decreased HHcy and hepatic Hcy-lated protein levels, restored Stx17 expression and autophagy, stimulated ß -oxidation of fatty acids, and improved hepatic histology in mice with pre-established NASH. CONCLUSIONS: HHcy plays a key role in the pathogenesis of NASH via Stx17 homocysteinylation. B12/folate also may represent a novel first-line therapy for NASH. LAY SUMMARY: The incidence of non-alcoholic steatohepatitis, for which there are no approved pharmacological therapies, is increasing, posing a significant healthcare challenge. Herein, based on studies in mice, primates and humans, we found that dietary supplementation with vitamin B12 and folate could have therapeutic potential for the prevention or treatment of non-alcoholic steatohepatitis.


Assuntos
Hiper-Homocisteinemia , Hepatopatia Gordurosa não Alcoólica , Animais , Ácidos Graxos , Fibrose , Ácido Fólico , Homocisteína , Humanos , Inflamação , Metionina , Camundongos , Hepatopatia Gordurosa não Alcoólica/etiologia , Hepatopatia Gordurosa não Alcoólica/prevenção & controle , Proteínas Qa-SNARE , Vitamina B 12 , Vitaminas
19.
Biochim Biophys Acta Mol Basis Dis ; 1868(10): 166455, 2022 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-35680107

RESUMO

Autophagy inhibition is currently considered a novel therapeutic strategy for cancer treatment. Lipoic acid (LA), a naturally occurring compound found in all prokaryotic and eukaryotic cells, inhibits breast cancer cell growth; however, the effect of LA on autophagy-mediated breast cancer cell death remains unknown. Our study identified that LA blocks autophagic flux by inhibiting autophagosome-lysosome fusion and lysosome activity which increases the accumulation of autophagosomes in MCF-7 and MDA-MB231 cells, leading to cell death of breast cancer cells. Interestingly, autophagic flux blockade limits the recycling of cellular fuels, resulting in insufficient substrates for cellular bioenergetics. Therefore, LA impairs cellular bioenergetics by the inhibition of mitochondrial function and glycolysis. We show that LA-induced ROS generation is responsible for the blockade of autophagic flux and cellular bioenergetics in breast cancer cells. Moreover, LA-mediated blockade of autophagic flux and ROS generation may interfere with the regulation of the BCSCs/progenitor phenotype. Here, we demonstrate that LA inhibits mammosphere formation and subpopulation of BCSCs. Together, these results implicate that LA acts as a prooxidant, potent autophagic flux inhibitor, and causes energetic impairment, which may lead to cell death in breast cancer cells/BCSCs.


Assuntos
Neoplasias , Ácido Tióctico , Autofagossomos/metabolismo , Autofagia , Metabolismo Energético , Neoplasias/metabolismo , Espécies Reativas de Oxigênio/metabolismo , Ácido Tióctico/farmacologia , Ácido Tióctico/uso terapêutico
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