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1.
Biosci Rep ; 44(6)2024 Jun 26.
Artigo em Inglês | MEDLINE | ID: mdl-38808772

RESUMO

Liver fibrosis is the excessive accumulation of extracellular matrix proteins that occurs in most types of chronic liver disease. At the cellular level, liver fibrosis is associated with the activation of hepatic stellate cells (HSCs) which transdifferentiate into a myofibroblast-like phenotype that is contractile, proliferative and profibrogenic. HSC transdifferentiation induces genome-wide changes in gene expression that enable the cell to adopt its profibrogenic functions. We have previously identified that the deubiquitinase ubiquitin C-terminal hydrolase 1 (UCHL1) is highly induced following HSC activation; however, the cellular targets of its deubiquitinating activity are poorly defined. Here, we describe a role for UCHL1 in regulating the levels and activity of hypoxia-inducible factor 1 (HIF1), an oxygen-sensitive transcription factor, during HSC activation and liver fibrosis. HIF1 is elevated during HSC activation and promotes the expression of profibrotic mediator HIF target genes. Increased HIF1α expression correlated with induction of UCHL1 mRNA and protein with HSC activation. Genetic deletion or chemical inhibition of UCHL1 impaired HIF activity through reduction of HIF1α levels. Furthermore, our mechanistic studies have shown that UCHL1 elevates HIF activity through specific cleavage of degradative ubiquitin chains, elevates levels of pro-fibrotic gene expression and increases proliferation rates. As we also show that UCHL1 inhibition blunts fibrogenesis in a pre-clinical 3D human liver slice model of fibrosis, these results demonstrate how small molecule inhibitors of DUBs can exert therapeutic effects through modulation of HIF transcription factors in liver disease. Furthermore, inhibition of HIF activity using UCHL1 inhibitors may represent a therapeutic opportunity with other HIF-related pathologies.


Assuntos
Células Estreladas do Fígado , Subunidade alfa do Fator 1 Induzível por Hipóxia , Cirrose Hepática , Ubiquitina Tiolesterase , Ubiquitina Tiolesterase/genética , Ubiquitina Tiolesterase/metabolismo , Cirrose Hepática/genética , Cirrose Hepática/patologia , Cirrose Hepática/metabolismo , Animais , Células Estreladas do Fígado/metabolismo , Células Estreladas do Fígado/patologia , Subunidade alfa do Fator 1 Induzível por Hipóxia/metabolismo , Subunidade alfa do Fator 1 Induzível por Hipóxia/genética , Camundongos , Humanos , Regulação da Expressão Gênica , Transdiferenciação Celular/genética
2.
JAMA Intern Med ; 2024 May 13.
Artigo em Inglês | MEDLINE | ID: mdl-38739404

RESUMO

Importance: Before 2021, the US Food and Drug Administration required mifepristone to be dispensed in person, limiting access to medication abortion. Objective: To estimate the effectiveness, acceptability, and feasibility of dispensing mifepristone for medication abortion using a mail-order pharmacy. Design, Setting, and Participants: This prospective cohort study was conducted from January 2020 to May 2022 and included 11 clinics in 7 states (5 abortion clinics and 6 primary care sites, 4 of which were new to abortion provision). Eligible participants were seeking medication abortion at 63 or fewer days' gestation, spoke English or Spanish, were age 15 years or older, and were willing to take misoprostol buccally. After assessing eligibility for medication abortion through an in-person screening, mifepristone and misoprostol were prescribed using a mail-order pharmacy. Patients had standard follow-up care with the clinic. Clinical information was collected from medical records. Consenting participants completed online surveys about their experiences 3 and 14 days after enrolling. A total of 540 participants were enrolled; 10 withdrew or did not take medication. Data were analyzed from August 2022 to December 2023. Intervention: Mifepristone, 200 mg, and misoprostol, 800 µg, prescribed to a mail-order pharmacy and mailed to participants instead of dispensed in person. Main Outcomes and Measures: Proportion of patients with a complete abortion with medications only, reporting satisfaction with the medication abortion, and reporting timely delivery of medications. Results: Clinical outcome information was obtained and analyzed for 510 abortions (96.2%) among 506 participants (median [IQR] age, 27 [23-31] years; 506 [100%] female; 194 [38.3%] Black, 88 [17.4%] Hispanic, 141 [27.9%] White, and 45 [8.9%] multiracial/other individuals). Of these, 436 participants (85.5%; 95% CI, 82.2%-88.4%) received medications within 3 days. Complete abortion occurred after medication use in 499 cases (97.8%; 95% CI, 96.2%-98.9%). There were 24 adverse events (4.7%) for which care was sought for medication abortion symptoms; 3 patients (0.6%; 95% CI, 0.1%-1.7%) experienced serious adverse events requiring hospitalization (1 with blood transfusion); however, no adverse events were associated with mail-order dispensing. Of 477 participants, 431 (90.4%; 95% CI, 87.3%-92.9%) indicated that they would use mail-order dispensing again for abortion care, and 435 participants (91.2%; 95% CI, 88.3%-93.6%) reported satisfaction with the medication abortion. Findings were similar to those of other published studies of medication abortion with in-person dispensing. Conclusions and Relevance: The findings of this cohort study indicate that mail-order pharmacy dispensing of mifepristone for medication abortion was effective, acceptable to patients, and feasible, with a low prevalence of serious adverse events. This care model should be expanded to improve access to medication abortion services.

3.
Glob Health Res Policy ; 9(1): 1, 2024 Jan 02.
Artigo em Inglês | MEDLINE | ID: mdl-38163917

RESUMO

Despite a proliferation of the United Nations General Assembly high-level meetings on a range of health issues and developmental challenges, global funding continues to flow disproportionately to HIV and maternal, newborn and child health (MNCH). Using the experience of MNCH, this short article argues that successful human rights framing and the development of robust and regular reporting mechanisms in the international development architecture has contributed to these areas receiving attention. Taking non-communicable diseases (NCDs) as an example of a relatively neglected health area, we propose mechanisms that would improve integrated reporting of health issues in a way that aligns with the move toward cross-cutting themes and matching political and financial commitments with impact. As new frameworks are being developed to support multi-agency approaches to achieving SDG 3-including reporting and accountability-there are opportunities to ensure MNCH and NCDs jointly seek data collection measures that can support specific targets and indicators that link NCDs with early childhood development.


Assuntos
Saúde da Criança , Doenças não Transmissíveis , Criança , Recém-Nascido , Humanos , Pré-Escolar , Nações Unidas , Desenvolvimento Infantil , Saúde Global , Coleta de Dados
4.
Nat Commun ; 14(1): 7446, 2023 Dec 04.
Artigo em Inglês | MEDLINE | ID: mdl-38049435

RESUMO

As billions of nocturnal avian migrants traverse North America, twice a year they must contend with landscape changes driven by natural and anthropogenic forces, including the rapid growth of the artificial glow of the night sky. While airspaces facilitate migrant passage, terrestrial landscapes serve as essential areas to restore energy reserves and often act as refugia-making it critical to holistically identify stopover locations and understand drivers of use. Here, we leverage over 10 million remote sensing observations to develop seasonal contiguous United States layers of bird migrant stopover density. In over 70% of our models, we identify skyglow as a highly influential and consistently positive predictor of bird migration stopover density across the United States. This finding points to the potential of an expanding threat to avian migrants: peri-urban illuminated areas may act as ecological traps at macroscales that increase the mortality of birds during migration.


Assuntos
Migração Animal , Poluição Luminosa , Animais , Estados Unidos , Aves , América do Norte , Telemetria , Estações do Ano
5.
BMJ Glob Health ; 8(10)2023 10.
Artigo em Inglês | MEDLINE | ID: mdl-37907235

RESUMO

Since the original UN General Assembly 'special session' for HIV/AIDS, there has been a proliferation of health-related high-level meetings (HLMs), including three for non-communicable diseases (NCDs) and a 2019 HLM on universal health coverage that was closely aligned to the NCD framework. This paper attempts to assess the impact of these meetings in terms of funding allocations, domestic NCD policy implementation, as well as the level of international engagement with the HLMs by reviewing attendance data and records of statements ('interventions') made by country delegations. In contrast to HIV/AIDS, whilst NCDs have enjoyed a marked rise in international political exposure and high-level political commitments, these have not always translated into national policy implementation or greater funding allocations. This is true even for countries that have engaged most deeply with HLMs. These findings should give pause to NCD advocacy groups that expend substantial energy in calling for further high-level political commitments and highlight the need to focus support on the translation of commitments into sustainably funded action.


Assuntos
Síndrome da Imunodeficiência Adquirida , Doenças não Transmissíveis , Humanos , Doenças não Transmissíveis/epidemiologia , Doenças não Transmissíveis/prevenção & controle , Política de Saúde , Nível de Saúde , Nações Unidas
6.
Biomolecules ; 13(10)2023 09 27.
Artigo em Inglês | MEDLINE | ID: mdl-37892137

RESUMO

Dysregulation of metabolic functions in the liver impacts the development of diabetes and metabolic disorders. Normal liver function can be compromised by increased inflammation via the activation of signaling such as nuclear factor (NF)-κB signaling. Notably, we have previously identified lysine demethylase 2A (KDM2A)-as a critical negative regulator of NF-κB. However, there are no studies demonstrating the effect of KDM2A on liver function. Here, we established a novel liver-specific Kdm2a knockout mouse model to evaluate KDM2A's role in liver functions. An inducible hepatic deletion of Kdm2a, Alb-Cre-Kdm2afl/fl (Kdm2a KO), was generated by crossing the Kdm2a floxed mice (Kdm2afl/fl) we established with commercial albumin-Cre transgenic mice (B6.Cg-Tg(Alb-cre)21Mgn/J). We show that under a normal diet, Kdm2a KO mice exhibited increased serum alanine aminotransferase (ALT) activity, L-type triglycerides (TG) levels, and liver glycogen levels vs. WT (Kdm2afl/fl) animals. These changes were further enhanced in Kdm2a liver KO mice in high-fat diet (HFD) conditions. We also observed a significant increase in NF-κB target gene expression in Kdm2a liver KO mice under HFD conditions. Similarly, the KO mice exhibited increased immune cell infiltration. Collectively, these data suggest liver-specific KDM2A deficiency may enhance inflammation in the liver, potentially through NF-κB activation, and lead to liver dysfunction. Our study also suggests that the established Kdm2afl/fl mouse model may serve as a powerful tool for studying liver-related metabolic diseases.


Assuntos
Hepatopatias , NF-kappa B , Camundongos , Animais , NF-kappa B/genética , NF-kappa B/metabolismo , Fígado/metabolismo , Inflamação/genética , Inflamação/metabolismo , Transdução de Sinais , Hepatopatias/metabolismo
7.
Pract Radiat Oncol ; 13(6): e471-e474, 2023.
Artigo em Inglês | MEDLINE | ID: mdl-37414248

RESUMO

Sulfur hexafluoride (SF6) is a widely used insulating gas in medical linear accelerators (LINACs) due to its high dielectric strength, heat transfer capabilities, and chemical stability. However, its long lifespan and high Global Warming Potential (GWP) make it a significant contributor to the environmental impact of radiation oncology. SF6 has an atmospheric lifespan of 3200 years and a GWP 23,000 times that of carbon dioxide. The amount of SF6 that can be emitted through leakage from machines is also concerning. It is estimated that the approximate 15,042 LINACs globally may leak up to 64,884,185.9 carbon dioxide equivalent per year, which is the equivalent greenhouse gas emissions of 13,981 gasoline-powered passenger vehicles driven for 1 year. Despite being regulated as a greenhouse gas under the United Nations Framework Convention on Climate Change, SF6 use within health care is often exempt from regulation, and only a few states in the United States have specific SF6 management regulations. This article highlights the need for radiation oncology centers and LINAC manufacturers to take responsibility for minimizing SF6 emissions. Programs that track usage and disposal, conduct life-cycle assessments, and implement leakage detection can help identify SF6 sources and promote recovery and recycling. Manufacturers are investing in research and development to identify alternative gases, improve leak detection, and minimize SF6 gas leakage during operation and maintenance. Alternative gases with lower GWP, such as nitrogen, compressed air, and perfluoropropane, may be considered as replacements for SF6; however, more research is needed to evaluate their feasibility and performance in radiation oncology. The article emphasizes the need for all sectors, including health care, to reduce their emissions to meet the goals of the Paris Agreement and ensure the sustainability of health care and our patients. Although SF6 is practical in radiation oncology, its environmental impact and contribution to the climate crisis cannot be ignored. Radiation oncology centers and manufacturers must take responsibility for reducing SF6 emissions by implementing best practices and promoting research and development around alternatives. To meet global emissions reduction goals and protect both planetary and patient health, the reduction of SF6 emissions will be essential.


Assuntos
Gases de Efeito Estufa , Radioterapia (Especialidade) , Humanos , Estados Unidos , Dióxido de Carbono/análise , Gases/análise , Hexafluoreto de Enxofre/análise
8.
Immunity ; 56(7): 1578-1595.e8, 2023 07 11.
Artigo em Inglês | MEDLINE | ID: mdl-37329888

RESUMO

It is currently not well known how necroptosis and necroptosis responses manifest in vivo. Here, we uncovered a molecular switch facilitating reprogramming between two alternative modes of necroptosis signaling in hepatocytes, fundamentally affecting immune responses and hepatocarcinogenesis. Concomitant necrosome and NF-κB activation in hepatocytes, which physiologically express low concentrations of receptor-interacting kinase 3 (RIPK3), did not lead to immediate cell death but forced them into a prolonged "sublethal" state with leaky membranes, functioning as secretory cells that released specific chemokines including CCL20 and MCP-1. This triggered hepatic cell proliferation as well as activation of procarcinogenic monocyte-derived macrophage cell clusters, contributing to hepatocarcinogenesis. In contrast, necrosome activation in hepatocytes with inactive NF-κB-signaling caused an accelerated execution of necroptosis, limiting alarmin release, and thereby preventing inflammation and hepatocarcinogenesis. Consistently, intratumoral NF-κB-necroptosis signatures were associated with poor prognosis in human hepatocarcinogenesis. Therefore, pharmacological reprogramming between these distinct forms of necroptosis may represent a promising strategy against hepatocellular carcinoma.


Assuntos
Neoplasias Hepáticas , NF-kappa B , Humanos , NF-kappa B/metabolismo , Proteínas Quinases/metabolismo , Necroptose , Inflamação/patologia , Proteína Serina-Treonina Quinases de Interação com Receptores/genética , Proteína Serina-Treonina Quinases de Interação com Receptores/metabolismo , Apoptose
9.
Am J Pathol ; 193(4): 417-429, 2023 04.
Artigo em Inglês | MEDLINE | ID: mdl-36690076

RESUMO

miRNAs are 22 nucleotides long and belong to a class of noncoding RNAs that plays an important role in regulating gene expression at a post-transcriptional level. Studies show aberrant levels of miRNAs to be associated with profibrotic processes in idiopathic pulmonary fibrosis (IPF). However, most of these studies used whole IPF tissue or in vitro monocultures in which fibrosis was artificially induced. The current study used laser microdissection to collect fibroblastic foci (FF), the key pathologic lesion in IPF, isolated miRNAs, and compared their expression levels with those found in whole IPF lung tissue and/or in vitro cultured fibroblast from IPF or normal lungs. Sequencing libraries were generated, and data generated were bioinformatically analyzed. A total of 18 miRNAs were significantly overexpressed in FF tissue when compared with whole IPF tissue. Of those, 15 were unique to FF. Comparison of FF with cultured IPF fibroblasts also revealed differences in miRNA composition that impacted several signaling pathways. The miRNA composition of FF is both overlapping and distinct from that of whole IPF tissue or cultured IPF fibroblasts and highlights the importance of characterizing FF biology as a phenotypically and functionally discrete tissue microenvironment.


Assuntos
Fibrose Pulmonar Idiopática , MicroRNAs , Humanos , MicroRNAs/genética , MicroRNAs/metabolismo , Pulmão/patologia , Fibrose Pulmonar Idiopática/metabolismo , Fibroblastos/metabolismo
10.
Hepatology ; 78(4): 1050-1063, 2023 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-36089330

RESUMO

BACKGROUND AND AIMS: Hepatocellular carcinoma (HCC) is a leading cause of cancer-related death. The NF-κB transcription factor family subunit c-Rel is typically protumorigenic; however, it has recently been reported as a tumor suppressor. Here, we investigated the role of c-Rel in HCC. APPROACH AND RESULTS: Histological and transcriptional studies confirmed expression of c-Rel in human patients with HCC, but low c-Rel expression correlated with increased tumor cell proliferation and mutational burden and was associated with advanced disease. In vivo , global ( Rel-/- ) and epithelial specific ( RelAlb ) c-Rel knockout mice develop more tumors, with a higher proliferative rate and increased DNA damage, than wild-type (WT) controls 30 weeks after N-diethylnitrosamine injury. However, tumor burden was comparable when c-Rel was deleted in hepatocytes once tumors were established, suggesting c-Rel signaling is important for preventing HCC initiation after genotoxic injury, rather than for HCC progression. In vitro , Rel-/- hepatocytes were more susceptible to genotoxic injury than WT controls. ATM-CHK2 DNA damage response pathway proteins were suppressed in Rel-/- hepatocytes following genotoxic injury, suggesting that c-Rel is required for effective DNA repair. To determine if c-Rel inhibition sensitizes cancer cells to chemotherapy, by preventing repair of chemotherapy-induced DNA damage, thus increasing tumor cell death, we administered single or combination doxorubicin and IT-603 (c-Rel inhibitor) therapy in an orthotopic HCC model. Indeed, combination therapy was more efficacious than doxorubicin alone. CONCLUSION: Hepatocyte c-Rel signaling limits genotoxic injury and subsequent HCC burden. Inhibiting c-Rel as an adjuvant therapy increased the effectiveness of DNA damaging agents and reduced HCC growth.


Assuntos
Carcinoma Hepatocelular , Neoplasias Hepáticas , Animais , Humanos , Camundongos , Carcinogênese/genética , Carcinoma Hepatocelular/patologia , Dano ao DNA , Doxorrubicina/farmacologia , Hepatócitos/metabolismo , Neoplasias Hepáticas/metabolismo , Camundongos Knockout , NF-kappa B/metabolismo , Proteínas Proto-Oncogênicas c-rel/metabolismo
11.
AMA J Ethics ; 24(10): E1004-1012, 2022 10 01.
Artigo em Inglês | MEDLINE | ID: mdl-36215193

RESUMO

Clinicians and organizations in the health sector have healing missions, and physicians, specifically, take oaths to "do no harm." Yet, paradoxically, health care operations contribute to pollution and exacerbate environmental disease burden. This article offers a view of how health sector actions exacerbate climate warming and iatrogenically harm global public health and argues that clinicians and organizations have ethical responsibilities to respond.


Assuntos
Atenção à Saúde , Organizações , Mudança Climática , Saúde Global , Instalações de Saúde , Humanos
13.
Am J Nurs ; 122(6): 7, 2022 06 01.
Artigo em Inglês | MEDLINE | ID: mdl-35617542

RESUMO

Bringing awareness to this major public health issue.


Assuntos
Doença de Alzheimer , Demência , Humanos , Saúde Pública
14.
Gut ; 2022 Apr 27.
Artigo em Inglês | MEDLINE | ID: mdl-35477863

RESUMO

OBJECTIVE: Hepatocellular carcinoma (HCC) is increasingly associated with non-alcoholic steatohepatitis (NASH). HCC immunotherapy offers great promise; however, recent data suggests NASH-HCC may be less sensitive to conventional immune checkpoint inhibition (ICI). We hypothesised that targeting neutrophils using a CXCR2 small molecule inhibitor may sensitise NASH-HCC to ICI therapy. DESIGN: Neutrophil infiltration was characterised in human HCC and mouse models of HCC. Late-stage intervention with anti-PD1 and/or a CXCR2 inhibitor was performed in murine models of NASH-HCC. The tumour immune microenvironment was characterised by imaging mass cytometry, RNA-seq and flow cytometry. RESULTS: Neutrophils expressing CXCR2, a receptor crucial to neutrophil recruitment in acute-injury, are highly represented in human NASH-HCC. In models of NASH-HCC lacking response to ICI, the combination of a CXCR2 antagonist with anti-PD1 suppressed tumour burden and extended survival. Combination therapy increased intratumoural XCR1+ dendritic cell activation and CD8+ T cell numbers which are associated with anti-tumoural immunity, this was confirmed by loss of therapeutic effect on genetic impairment of myeloid cell recruitment, neutralisation of the XCR1-ligand XCL1 or depletion of CD8+ T cells. Therapeutic benefit was accompanied by an unexpected increase in tumour-associated neutrophils (TANs) which switched from a protumour to anti-tumour progenitor-like neutrophil phenotype. Reprogrammed TANs were found in direct contact with CD8+ T cells in clusters that were enriched for the cytotoxic anti-tumoural protease granzyme B. Neutrophil reprogramming was not observed in the circulation indicative of the combination therapy selectively influencing TANs. CONCLUSION: CXCR2-inhibition induces reprogramming of the tumour immune microenvironment that promotes ICI in NASH-HCC.

15.
Front Neurol ; 13: 823202, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-35280288

RESUMO

The International Classification of Functioning, Disability and Health framework recognizes that an individual's functioning post-stroke reflects an interaction between their health condition and contextual factors encompassing personal and environmental factors. Personal factors significantly impact rehabilitation outcomes as they determine how an individual evaluates their situation and copes with their condition in daily life. A key personal factor is self-efficacy-an individual's belief in their capacity to achieve certain outcomes. Self-efficacy influences an individual's motivational state to execute behaviors necessary for achieving desired rehabilitation outcomes. Stroke rehabilitation practice and research now acknowledge self-efficacy and motivation as critical elements in post-stroke recovery, and increasing evidence highlights their contributions to motor (re)learning. Given the informative value of neuroimaging-based biomarkers in stroke, elucidating the neurological underpinnings of self-efficacy and motivation may optimize post-stroke recovery. In this review, we examine the role of self-efficacy and motivation in stroke rehabilitation and recovery, identify potential neural substrates underlying these factors from current neuroimaging literature, and discuss how leveraging these factors and their associated neural substrates has the potential to advance the field of stroke rehabilitation.

16.
Res Aging ; 44(5-6): 369-381, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-34344251

RESUMO

Building on theory suggesting that loneliness is distinct from living arrangements, social isolation, and perceived social support, we examined change in loneliness for older people at the onset of the COVID-19 pandemic. Analyzing 14-years of data with multilevel mixed-effects models, we found higher levels of loneliness among people living alone, people more socially isolated, and people with less perceived support. Gender affected changes in loneliness, controlling for social isolation, perceived support, living arrangements, age, education, income, health, and marital status. Women, whether living alone or with others, experienced increases in loneliness; women living alone reported the greatest increase in loneliness. Men living alone reported high levels of loneliness prior to the pandemic, but only a slight increase over time. These analyses, which demonstrate that loneliness changed at the onset of the pandemic as a function of gender and living arrangement identify older people most likely to benefit from intervention.


Assuntos
COVID-19 , Solidão , Idoso , Feminino , Ambiente Domiciliar , Humanos , Masculino , Pandemias , Isolamento Social
17.
J Child Neurol ; 37(1): 56-63, 2022 01.
Artigo em Inglês | MEDLINE | ID: mdl-34657501

RESUMO

OBJECTIVE: To explore perspectives of pediatric neurologists regarding sexual and reproductive health care for adolescent women with epilepsy (WWE) and intellectual disability. METHODS: We interviewed pediatric neurologists regarding sexual and reproductive health for WWE with intellectual disability. We audio-recorded and transcribed interviews and conducted qualitative analysis. RESULTS: 16 pediatric neurologists participated. Themes included the following: (1) Pediatric neurologists have differing perspectives about how intellectual disability affects WWE's sexual and reproductive health needs, (2) pediatric neurologists provide sexual and reproductive health counseling variable in content and frequency to this population, (3) pediatric neurologists tend to recommend longer-term methods of contraception for this population, and (4) pediatric neurologists are asked to be involved in decision-making around sterilization, yet express ethico-legal reservations. CONCLUSION: Our findings suggest pediatric neurologists provide variable, often suboptimal, sexual and reproductive health care for WWE and intellectual disability. Themes reveal ethical concerns among neurologists about sexual and reproductive health practices including sterilization. More tailored clinical guidelines and provider training on sexual and reproductive health for this population may be beneficial.


Assuntos
Atitude do Pessoal de Saúde , Educação de Pessoa com Deficiência Intelectual/métodos , Neurologistas/estatística & dados numéricos , Pediatras/estatística & dados numéricos , Padrões de Prática Médica/estatística & dados numéricos , Saúde Reprodutiva/educação , Saúde Sexual/educação , Adolescente , Adulto , Feminino , Humanos , Deficiência Intelectual , Masculino , Estados Unidos , Adulto Jovem
18.
Hepatology ; 74(6): 3441-3459, 2021 12.
Artigo em Inglês | MEDLINE | ID: mdl-34233024

RESUMO

BACKGROUND AND AIMS: NAFLD is the most common hepatic pathology in western countries and no treatment is currently available. NAFLD is characterized by the aberrant hepatocellular accumulation of fatty acids in the form of lipid droplets (LDs). Recently, it was shown that liver LD degradation occurs through a process termed lipophagy, a form of autophagy. However, the molecular mechanisms governing liver lipophagy are elusive. Here, we aimed to ascertain the key molecular players that regulate hepatic lipophagy and their importance in NAFLD. APPROACH AND RESULTS: We analyzed the formation and degradation of LD in vitro (fibroblasts and primary mouse hepatocytes), in vivo and ex vivo (mouse and human liver slices) and focused on the role of the autophagy master regulator mammalian target of rapamycin complex (mTORC) 1 and the LD coating protein perilipin (Plin) 3 in these processes. We show that the autophagy machinery is recruited to the LD on hepatic overload of oleic acid in all experimental settings. This led to activation of lipophagy, a process that was abolished by Plin3 knockdown using RNA interference. Furthermore, Plin3 directly interacted with the autophagy proteins focal adhesion interaction protein 200 KDa and autophagy-related 16L, suggesting that Plin3 functions as a docking protein or is involved in autophagosome formation to activate lipophagy. Finally, we show that mTORC1 phosphorylated Plin3 to promote LD degradation. CONCLUSIONS: These results reveal that mTORC1 regulates liver lipophagy through a mechanism dependent on Plin3 phosphorylation. We propose that stimulating this pathway can enhance lipophagy in hepatocytes to help protect the liver from lipid-mediated toxicity, thus offering a therapeutic strategy in NAFLD.


Assuntos
Autofagia , Fígado Gorduroso/metabolismo , Hepatócitos/metabolismo , Alvo Mecanístico do Complexo 1 de Rapamicina/metabolismo , Perilipina-3/metabolismo , Transdução de Sinais , Animais , Humanos , Masculino , Camundongos , Camundongos Endogâmicos C57BL
20.
EMBO J ; 40(9): e106048, 2021 05 03.
Artigo em Inglês | MEDLINE | ID: mdl-33764576

RESUMO

Cellular senescence is characterized by an irreversible cell cycle arrest as well as a pro-inflammatory phenotype, thought to contribute to aging and age-related diseases. Neutrophils have essential roles in inflammatory responses; however, in certain contexts their abundance is associated with a number of age-related diseases, including liver disease. The relationship between neutrophils and cellular senescence is not well understood. Here, we show that telomeres in non-immune cells are highly susceptible to oxidative damage caused by neighboring neutrophils. Neutrophils cause telomere dysfunction both in vitro and ex vivo in a ROS-dependent manner. In a mouse model of acute liver injury, depletion of neutrophils reduces telomere dysfunction and senescence. Finally, we show that senescent cells mediate the recruitment of neutrophils to the aged liver and propose that this may be a mechanism by which senescence spreads to surrounding cells. Our results suggest that interventions that counteract neutrophil-induced senescence may be beneficial during aging and age-related disease.


Assuntos
Lesão Pulmonar Aguda/imunologia , Tetracloreto de Carbono/efeitos adversos , Neutrófilos/citologia , Espécies Reativas de Oxigênio/metabolismo , Encurtamento do Telômero , Lesão Pulmonar Aguda/induzido quimicamente , Lesão Pulmonar Aguda/metabolismo , Animais , Linhagem Celular , Senescência Celular , Técnicas de Cocultura , Modelos Animais de Doenças , Feminino , Fibroblastos/citologia , Fibroblastos/metabolismo , Humanos , Masculino , Camundongos , Neutrófilos/metabolismo , Estresse Oxidativo , Comunicação Parácrina
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