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Autophagy is an evolutionarily conserved process in which intracellular macromolecules are degraded in a lysosomal-dependent manner. It is central to cellular energy homeostasis and to quality control of intracellular components. A decline in autophagic activity is associated with aging, and contributes to the development of various age-associated pathologies, including cancer. There is an ongoing need to develop chemotherapeutic agents to improve morbidity and mortality for those diagnosed with cancer, as well as to decrease the cost of cancer care. Autophagic programs are altered in cancer cells to support survival in genetically and metabolically unstable environments, making autophagy an attractive target for new chemotherapy. Antiretroviral drugs, which have dramatically increased the life- and health spans of people with human immunodeficiency virus (HIV) (PWH), have offered promise in the treatment of cancer. One mechanism underlying the antineoplastic effects of antiretroviral drugs is the alteration of cancer cell autophagy that can potentiate cell death. Antiretroviral drugs could be repurposed into the cancer chemotherapy arsenal. A more complete understanding of the impact of antiretroviral drugs on autophagy is essential for effective repurposing. This review summarizes our knowledge of the effects of antiretroviral drugs on autophagy as potential adjunctive chemotherapeutic agents, and highlights gaps to be addressed to reposition antiretroviral drugs into the antineoplastic arsenal successfully.
Assuntos
Autofagia , Reposicionamento de Medicamentos , Neoplasias , Humanos , Autofagia/efeitos dos fármacos , Reposicionamento de Medicamentos/métodos , Neoplasias/tratamento farmacológico , Antineoplásicos/farmacologia , Antineoplásicos/uso terapêutico , Antirretrovirais/uso terapêutico , Antirretrovirais/farmacologia , Infecções por HIV/tratamento farmacológico , AnimaisRESUMO
Laura Cheney works at the crossroads of HIV and autophagy, a critical biological process for cellular homeostasis, to understand more completely the pathogenesis of HIV-associated neurocognitive impairment. In this mSphere of Influence article, she reflects on how "A pulse-chasable reporter processing assay for mammalian autophagic flux with HaloTag" by Willa Wen-You Yim, Hayashi Yamamoto, and Noboru Mizushima (eLife 11:e78923, 2022, https://doi.org/10.7554/eLife.78923) expands the tools for studying autophagy and inspired her to use this technology to develop a reporter to study autophagy of mitochondria, termed mitophagy, to further her own research goals.
Assuntos
Autofagia , Infecções por HIV , Animais , Mitocôndrias , Mitofagia , Infecções por HIV/patologia , MamíferosRESUMO
Human immunodeficiency virus (HIV) infection is associated with insulin resistance. HIV type 1 Nef downregulates cell surface protein expression, alters signal transduction, and interacts with the cytoskeleton and proteins involved in actin polymerization. These functions are required for glucose uptake by insulin-stimulated adipocytes. We sought to determine whether Nef alters adipocyte glucose homeostasis. Using radiolabeled glucose, we found that adipocytes exposed to recombinant Nef took in 42% less glucose after insulin stimulation than did control cells. This reduction resulted from a Nef-dependent inhibition of glucose transporter 4 (GLUT4) trafficking, as assessed by means of immunofluorescence microscopy. Immunoblot analysis revealed a decrease in phosphorylation of signal transducing proteins after Nef treatment, and fluorescence microscopy showed a dramatic alteration in cortical actin organization. We conclude that Nef interferes with insulin-stimulated processes in adipocytes. We have identified HIV Nef, which is detectable and antigenic in serum samples from HIV-infected people, as a novel contributor to the development of insulin resistance.
Assuntos
Adipócitos/metabolismo , Glucose/metabolismo , Infecções por HIV/complicações , HIV-1 , Resistência à Insulina/fisiologia , Produtos do Gene nef do Vírus da Imunodeficiência Humana/metabolismo , Células 3T3-L1 , Actinas/metabolismo , Adipócitos/efeitos dos fármacos , Adipócitos/virologia , Animais , Western Blotting , Membrana Celular/metabolismo , Relação Dose-Resposta a Droga , Regulação para Baixo , Proteínas Ativadoras de GTPase/metabolismo , Transportador de Glucose Tipo 4/metabolismo , Humanos , Insulina/farmacologia , Camundongos , Fosforilação , Proteínas Proto-Oncogênicas c-akt/metabolismo , Transdução de Sinais/fisiologia , Produtos do Gene nef do Vírus da Imunodeficiência Humana/sangue , Produtos do Gene nef do Vírus da Imunodeficiência Humana/farmacologiaRESUMO
A 61-year-old woman with severe gout, chronic kidney disease, type II diabetes, and heart failure with reduced ejection fraction was admitted with acute onset bilateral hand swelling and pain following a trauma. She was managed for a severe gout flare, but her symptoms, leukocytosis, and inflammatory markers did not improve. Six days into the hospital course, she developed fevers. Blood cultures grew Streptococcus pneumoniae. Intravenous antibiotics were started, and the patient underwent multiple incision and debridements of the bilateral hands with improvement in symptoms and clinical status. Septic arthritis secondary to S. pneumoniae is uncommon. We highlight this case to recognize that septic arthritis should always be considered when a patient presents with a painful, erythematous joint. Pneumococcal vaccination reduces the incidence of invasive pneumococcal disease, and should be prioritized for those at high risk for invasive disease and who are immunocompromised.
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HIV-associated neurocognitive impairment (HIV-NCI) persists in 15-40% of people with HIV (PWH) despite effective antiretroviral therapy. HIV-NCI significantly impacts quality of life, and there is currently no effective treatment for it. The development of HIV-NCI is complex and is mediated, in part, by the entry of HIV-infected mature monocytes into the central nervous system (CNS). Once in the CNS, these cells release inflammatory mediators that lead to neuroinflammation, and subsequent neuronal damage. Infected monocytes may infect other CNS cells as well as differentiate into macrophages, thus contributing to viral reservoirs and chronic neuroinflammation. Substance use disorders in PWH, including the use of methamphetamine (meth), can exacerbate HIV neuropathogenesis. We characterized the effects of meth on the transcriptional profile of HIV-infected mature monocytes using RNA-sequencing. We found that meth mediated an upregulation of gene transcripts related to viral infection, cell adhesion, cytoskeletal arrangement, and extracellular matrix remodeling. We also identified downregulation of several gene transcripts involved in pathogen recognition, antigen presentation, and oxidative phosphorylation pathways. These transcriptomic changes suggest that meth increases the infiltration of mature monocytes that have a migratory phenotype into the CNS, contributing to dysregulated inflammatory responses and viral reservoir establishment and persistence, both of which contribute to neuronal damage. Overall, our results highlight potential molecules that may be targeted for therapy to limit the effects of meth on HIV neuropathogenesis.
Assuntos
Infecções por HIV , Metanfetamina , Humanos , Macrófagos/metabolismo , Metanfetamina/farmacologia , Monócitos , Qualidade de VidaRESUMO
The blacklegged tick (Ixodes scapularis) is an important vector of emerging human pathogens. It has three blood-feeding stages, as follows: larva, nymph, and adult. Owing to inefficient transovarial transmission, at least for the Lyme disease agent (Borrelia burgdorferi), larval ticks rarely hatch infected, but they can acquire infection during their larval blood meal. Nymphal ticks are primarily responsible for transmitting pathogens to hosts, including humans. The transition from uninfected host-seeking larva to infectious host-seeking nymph is therefore a key aspect of human risk of infection. It can be divided into a series of steps, as follows: finding a host, taking a blood meal, becoming infected, molting, and overwintering. The chance of succeeding in each of these steps may depend on the species identity of the blood meal host. We used a Bayesian method to estimate the molting success of larval I. scapularis collected from four commonly parasitized species of birds and eight commonly parasitized small and mid-sized mammals found in the forests of Dutchess County, New York. We show that molting success varies substantially among host species; white-footed mice, veeries, and gray catbirds support particularly high molting success, whereas ticks feeding on short-tailed shrews, robins, and wood thrushes were less successful. We also show that larval molting success varies substantially between individual blood meal hosts, and that this intraspecific variability is much higher in some species than in others. The causes of both inter- and intraspecific variation in molting success remain to be determined.
Assuntos
Vetores Aracnídeos/crescimento & desenvolvimento , Ixodes/crescimento & desenvolvimento , Mamíferos/parasitologia , Muda , Aves Canoras/parasitologia , Infestações por Carrapato/veterinária , Animais , Vetores Aracnídeos/microbiologia , Teorema de Bayes , Borrelia burgdorferi , Feminino , Interações Hospedeiro-Parasita , Ixodes/microbiologia , Ixodes/fisiologia , Larva/fisiologia , Doença de Lyme/microbiologia , Doença de Lyme/transmissão , Doença de Lyme/veterinária , Masculino , New York , Ninfa/microbiologia , Ninfa/fisiologia , Dinâmica Populacional , Especificidade da EspécieRESUMO
Antiretroviral drugs have dramatically improved the morbidity and mortality of people living with HIV (PLWH). While current antiretroviral therapy (ART) regimens are generally well-tolerated, risks for side effects and toxicity remain as PLWH must take life-long medications. Antiretroviral drugs impact autophagy, an intracellular proteolytic process that eliminates debris and foreign material, provides nutrients for metabolism, and performs quality control to maintain cell homeostasis. Toxicity and adverse events associated with antiretrovirals may be due, in part, to their impacts on autophagy. A more complete understanding of the effects on autophagy is essential for developing antiretroviral drugs with decreased off target effects, meaning those unrelated to viral suppression, to minimize toxicity for PLWH. This review summarizes the findings and highlights the gaps in our knowledge of the impacts of antiretroviral drugs on autophagy.
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Antirretrovirais/toxicidade , Autofagia/efeitos dos fármacos , Animais , Quimioterapia Combinada , HIV/efeitos dos fármacos , Humanos , Inibidores de Proteases/farmacologia , Inibidores da Transcriptase Reversa/farmacologiaRESUMO
The COVID-19 pandemic has caused more than three million deaths globally. The severity of the disease is characterized, in part, by a dysregulated immune response. CD16+ monocytes are innate immune cells involved in inflammatory responses to viral infections, and tissue repair, among other functions. We characterized the transcriptional changes in CD16+ monocytes from PBMC of people with COVID-19, and from healthy individuals using publicly available single cell RNA sequencing data. CD16+ monocytes from people with COVID-19 compared to those from healthy individuals expressed transcriptional changes indicative of increased cell activation, and induction of a migratory phenotype. We also analyzed COVID-19 cases based on severity of the disease and found that mild cases were characterized by upregulation of interferon response and MHC class II related genes, whereas the severe cases had dysregulated expression of mitochondrial and antigen presentation genes, and upregulated inflammatory, cell movement, and apoptotic gene signatures. These results suggest that CD16+ monocytes in people with COVID-19 contribute to a dysregulated host response characterized by decreased antigen presentation, and an elevated inflammatory response with increased monocytic infiltration into tissues. Our results show that there are transcriptomic changes in CD16+ monocytes that may impact the functions of these cells, contributing to the pathogenesis and severity of COVID-19.
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COVID-19/virologia , Monócitos/virologia , Receptores de IgG/metabolismo , SARS-CoV-2/patogenicidade , Transcrição Gênica , Transcriptoma , Adulto , Idoso , Proteínas Reguladoras de Apoptose/genética , Proteínas Reguladoras de Apoptose/metabolismo , COVID-19/genética , COVID-19/imunologia , COVID-19/metabolismo , Estudos de Casos e Controles , Citocinas/genética , Citocinas/metabolismo , Feminino , Proteínas Ligadas por GPI/metabolismo , Perfilação da Expressão Gênica , Interações Hospedeiro-Patógeno , Humanos , Mediadores da Inflamação/metabolismo , Fatores Reguladores de Interferon/genética , Fatores Reguladores de Interferon/metabolismo , Masculino , Pessoa de Meia-Idade , Proteínas Mitocondriais/genética , Proteínas Mitocondriais/metabolismo , Monócitos/imunologia , Monócitos/metabolismo , RNA-Seq , SARS-CoV-2/imunologia , Índice de Gravidade de Doença , Análise de Célula Única , Adulto JovemRESUMO
A significant number of people living with HIV (PLWH) develop HIV-associated neurocognitive disorders (HAND) despite highly effective antiretroviral therapy (ART). Dysregulated macroautophagy (autophagy) is implicated in HAND pathogenesis. The viral protein Nef, expressed even with suppressive ART, and certain antiretrovirals affect autophagy in non-CNS cells. Astrocytes, vital for CNS microenvironment homeostasis and neuronal health, require autophagy for their own homeostasis. We hypothesized that extracellular Nef and/or ART impact astrocyte autophagy, thus contributing to HAND. We studied in-bulk and selective autophagic flux in primary human astrocytes treated with extracellular Nef and/or a combination of tenofovir+emtricitabine+raltegravir (ART) using Western blotting, a tandem fluorescent LC3 reporter, and transmission electron microscopy/morphometry. We show that after 24 h treatment, Nef and ART decrease autophagosomes through different mechanisms. While Nef accelerates autophagosome degradation without inducing autophagosome formation, ART inhibits autophagosome formation. Combination Nef+ART further depletes autophagosomes by inducing both abnormalities. Additionally, extracellular Nef and/or ART inhibit lysosomal degradation of p62, indicating Nef and/or ART affect in-bulk and selective autophagy differently. Dysregulation of both autophagic processes is maintained after 7 days of Nef and/or ART treatment. Persistent autophagy dysregulation due to chronic Nef and/or ART exposure may ultimately result in astrocyte and neuronal dysfunction, contributing to HAND.
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Antirretrovirais/uso terapêutico , Astrócitos/efeitos dos fármacos , Autofagia/efeitos dos fármacos , Infecções por HIV/tratamento farmacológico , Transtornos Neurocognitivos/induzido quimicamente , Produtos do Gene nef do Vírus da Imunodeficiência Humana/uso terapêutico , Antirretrovirais/farmacologia , Infecções por HIV/genética , Humanos , Produtos do Gene nef do Vírus da Imunodeficiência Humana/farmacologiaRESUMO
In human immunodeficiency virus-1 (HIV) infected individuals, substance abuse may accelerate the development and/or increase the severity of HIV associated neurocognitive disorders (HAND). It is proposed that CD14+CD16+ monocytes mediate HIV entry into the central nervous system (CNS) and that uninfected and infected CD14+CD16+ monocyte transmigration across the blood brain barrier (BBB) contributes to the establishment and propagation of CNS HIV viral reservoirs and chronic neuroinflammation, important factors in the development of HAND. The effects of substance abuse on the frequency of CD14+CD16+ monocytes in the peripheral circulation and on the entry of these cells into the CNS during HIV neuropathogenesis are not known. PBMC from HIV infected individuals were analyzed by flow cytometry and we demonstrate that the frequency of peripheral blood CD14+CD16+ monocytes in HIV infected substance abusers is increased when compared to those without active substance use. Since drug use elevates extracellular dopamine concentrations in the CNS, we examined the effects of dopamine on CD14+CD16+ monocyte transmigration across our in vitro model of the human BBB. The transmigration of this monocyte subpopulation is increased by dopamine and the dopamine receptor agonist, SKF 38393, implicating D1-like dopamine receptors in the increase in transmigration elicited by this neurotransmitter. Thus, elevated extracellular CNS dopamine may be a novel common mechanism by which active substance use increases uninfected and HIV infected CD14+CD16+ monocyte transmigration across the BBB. The influx of these cells into the CNS may increase viral seeding and neuroinflammation, contributing to the development of HIV associated neurocognitive impairments.
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Barreira Hematoencefálica/metabolismo , Dopamina/metabolismo , Infecções por HIV/metabolismo , Receptores de Lipopolissacarídeos/metabolismo , Receptores de IgG/metabolismo , Transtornos Relacionados ao Uso de Substâncias/metabolismo , Adulto , Barreira Hematoencefálica/efeitos dos fármacos , Barreira Hematoencefálica/patologia , Células Cultivadas , Estudos de Coortes , Dopamina/farmacologia , Feminino , Infecções por HIV/patologia , Humanos , Masculino , Pessoa de Meia-Idade , Monócitos/efeitos dos fármacos , Monócitos/metabolismo , Transtornos Relacionados ao Uso de Substâncias/patologia , Migração Transendotelial e Transepitelial/efeitos dos fármacos , Migração Transendotelial e Transepitelial/fisiologiaRESUMO
This study evaluated reliability, validity, and responsiveness of a new test of stereognosis (Byl-Cheney-Boczai Sensory Discriminator Test [BCBI]). Participants included 38 controls, 29 subjects with hand problems, and 3 raters. With eyes closed, after sweeping the digit over a design (10 mm x 10 mm) embedded in a plastic cube (13 mm x 13 mm), subjects matched the design palpated with a design on an answer sheet (10 trials/digits 2 and 4). The intra-class correlation coefficients were 0.997 and 0.994 for intra-rater and inter-rater reliability. No significant performance differences were found by gender or side. Accuracy was significantly higher for digit 2 versus digit 4, younger subjects versus older subjects, and controls versus subjects with pathology. There were significant (1) positive correlations (+0.41 to +0.53) between the BCBI and tests of stereognosis and graphesthesia; (2) negative correlations (-0.44 to -0.51) between the BCBI and the Purdue and digital reaction time; and (3) gains on the BCBI and function with therapy. The BCBI seems to be a reliable, valid, and responsive test of stereognosis that can be administered in 15 minutes in the cinic.