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Packaging of the genome into a protein capsid and its subsequent delivery into a host cell are two fundamental processes in the life cycle of a virus. Unlike double-stranded DNA viruses, which pump their genome into a preformed capsid, single-stranded RNA (ssRNA) viruses, such as bacteriophage MS2, co-assemble their capsid with the genome; however, the structural basis of this co-assembly is poorly understood. MS2 infects Escherichia coli via the host 'sex pilus' (F-pilus); it was the first fully sequenced organism and is a model system for studies of translational gene regulation, RNA-protein interactions, and RNA virus assembly. Its positive-sense ssRNA genome of 3,569 bases is enclosed in a capsid with one maturation protein monomer and 89 coat protein dimers arranged in a T = 3 icosahedral lattice. The maturation protein is responsible for attaching the virus to an F-pilus and delivering the viral genome into the host during infection, but how the genome is organized and delivered is not known. Here we describe the MS2 structure at 3.6 Å resolution, determined by electron-counting cryo-electron microscopy (cryoEM) and asymmetric reconstruction. We traced approximately 80% of the backbone of the viral genome, built atomic models for 16 RNA stem-loops, and identified three conserved motifs of RNA-coat protein interactions among 15 of these stem-loops with diverse sequences. The stem-loop at the 3' end of the genome interacts extensively with the maturation protein, which, with just a six-helix bundle and a six-stranded ß-sheet, forms a genome-delivery apparatus and joins 89 coat protein dimers to form a capsid. This atomic description of genome-capsid interactions in a spherical ssRNA virus provides insight into genome delivery via the host sex pilus and mechanisms underlying ssRNA-capsid co-assembly, and inspires speculation about the links between nucleoprotein complexes and the origins of viruses.
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Capsídeo/ultraestrutura , Microscopia Crioeletrônica , Genoma Viral/fisiologia , Levivirus/metabolismo , Levivirus/ultraestrutura , RNA Viral/ultraestrutura , Montagem de Vírus , Capsídeo/química , Capsídeo/metabolismo , Proteínas do Capsídeo/química , Proteínas do Capsídeo/metabolismo , Proteínas do Capsídeo/ultraestrutura , Fímbrias Bacterianas/química , Fímbrias Bacterianas/metabolismo , Fímbrias Bacterianas/ultraestrutura , Levivirus/química , Levivirus/genética , Modelos Moleculares , Conformação Molecular , Multimerização Proteica , RNA Viral/química , RNA Viral/metabolismoRESUMO
BACKGROUND: Inflammation is involved in the pathophysiology of depression, and circulating inflammatory cytokines have been associated with depressive symptoms. However, measuring circulating cytokines have inherent methodological limitations. In vitro lipopolysaccharide (LPS)-stimulated intracellular cytokines (ICCs) overcome these limitations. Furthermore, because psychosocial and physiological stressors activate inflammatory responses and LPS-stimulated ICCs reflect the inflammatory responsivity of monocytes to such stressors, ICCs may reflect individual stress responsivity. METHODS: This cross-sectional study examined whether LPS-stimulated expression of ICCs in peripheral blood mononuclear cells (PBMCs) is a sensitive inflammation measure correlated with depressive symptoms in 180 community-dwelling older adults. We tested correlations of not only intracellular but also circulating inflammatory markers with depressive symptoms assessed using the 10-item Center for Epidemiological Studies Depression Scale (CES-D). Intracellular markers included expression of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and both in PBMCs. Circulating markers included IL-6, TNF-α, and C-reactive protein (CRP) in plasma. RESULTS: None of the correlations were statistically significant. However, in contrast to circulating markers, the correlations of ICCs were consistently in the expected direction, i.e., higher ICC expression correlating with higher depression severity. DISCUSSION: Despite the non-significant findings, further research is required for the evaluation of LPS-stimulated ICC expression as biomarkers of depressive symptoms.
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Low back pain is the most common musculoskeletal complaint accounting for over 30 million visits to primary care physicians annually. Serious pathology is found in less than 1% of these visits. Therefore it is often a challenge to distinguish worrisome findings requiring further workup and treatment from common complaints of pain. Gout is an inflammatory arthritis that most commonly affects the appendicular skeleton. It is characterized by the saturation of uric acid and deposition of monosodium urate crystals in joints and tissues. Spinal involvement is rare and is not typically considered on the differential diagnosis for a patient presenting with acute low back pain. We present such a case of a 35-year-old male who presented with intractable back pain, highlighting the need to recognize signs and symptoms that raise suspicion for spinal gout.
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Gota , Dor Lombar , Humanos , Masculino , Dor Lombar/etiologia , Adulto , Gota/complicações , Doenças da Coluna Vertebral/diagnóstico , Doenças da Coluna Vertebral/complicações , Diagnóstico Diferencial , Supressores da Gota/uso terapêuticoRESUMO
Amid a worldwide pandemic in the setting of an era of rapidly developing technologies, we turn now to the novel and exciting endeavor of pioneering the metaverse. Described as the conglomeration of augmented reality, virtual reality, and artificial intelligence, the metaverse has widespread applications in multiple settings, including revolutionizing health care. It also holds the potential to transform geriatric medicine, introducing new dimensions through which we can prevent social isolation, encourage health and well-being, and offer a new dimension through which we manage chronic disease. Although it is still a futuristic and novel technology, the metaverse's realization may indeed be closer than we think.
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As the population across the globe continues to dramatically increase, the prevalence of cognitive impairment and dementia will inevitably increase as well, placing increasing burden on families and health care systems. Technological advancements over the past decade provide potential benefit in not only relieving caregiver burden of caring for a loved one with dementia, but also enables individuals with dementia to age in place. Technological devices have served to improve functioning, tracking and mobility. Similarly, smartphones, tablets and the ubiquitous world wide web have facilitated the dissemination of health information to previously hard to reach populations largely through use of various social media platforms. In this review, we discuss the current and future uses of technology via devices and social media to promote healthy aging in individuals with dementia, and also limitations and challenges to consider in the future.
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BACKGROUND: Dementia remains a stigmatized topic in the Chinese community. OBJECTIVE: This study aims to analyze and compare the usage of dementia educational YouTube videos and the modalities of video sharing over a 6-year period. METHODS: Dementia educational videos were uploaded to YouTube. Data was collected over a 6-year period. Results from the first 3 years were compared to those from the second 3 years using descriptive statistics and chi-square analysis. RESULTS: Over 6 years, the dementia educational videos generated a total watch time of 269,388 minutes, 37,690 views, and an average view duration of 7.1 minutes. Comparing the first and second 3-year periods of video performance data, there was a longer watch time (59,262 vs 210,126 minutes), more total views (9387 vs 28,303 views), and a longer average view duration (6.3 vs 7.4 minutes). Furthermore, WhatsApp has become a leading external traffic source and top sharing service, accounting for 43.5% (929/2137) and 67.0% (677/1011), respectively. CONCLUSIONS: Over 6 years, YouTube has become an increasingly popular tool to deliver culturally sensitive dementia education to Chinese Americans. WhatsApp continues to be the preferred method of sharing dementia education and has become a top external traffic source to dementia educational videos. Taken together, these social media platforms are promising means of reducing the disparity in dementia knowledge in linguistically and culturally isolated populations.
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BACKGROUND: Ensuring health literacy among underserved populations is essential amid an aging population. Accessible and appropriate (both culturally and linguistically) information is important when considering digital media education for older Chinese Americans. OBJECTIVE: This study aims to investigate how social media fare over time in disseminating health information and how we may most effectively educate this population. METHODS: For this study, 5 geriatric-themed educational videos about Parkinson disease, fall prevention, gastrointestinal health, oral health, and pulmonary disease were uploaded to YouTube. Data were collected over a 40-month period. Descriptive statistics and chi-square analysis were used to compare results from the first and second 20-month periods. RESULTS: In 40 months, the 5 videos in aggregate accrued 1171.1 hours of watch time, 7299 views, and an average view duration of 9.6 minutes. Comparing the first and second 20-month periods, there was a significant increase in mobile device usage, from 79.4% (3541/4458) to 83.3% (2367/2841). There was no significant difference in the usage of various external traffic sources and methods of sharing, with WhatsApp accounting for the majority of sharing in both 20-month periods. CONCLUSIONS: Our study provides insight into where to focus future strategies to optimize digital media content, and how to best recruit, direct, and disseminate health education to an older adult Chinese American population. Combining the success of YouTube, social media, and messaging platforms such as WhatsApp can help to transcend cultural and linguistic barriers to promote healthy aging.
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Holistic care means addressing the patient as a person; providing high-quality care by focusing on individual needs. Our goal is to implement a survey that quantifies the patients' physical, mental, and spiritual health to enable improvements in client-centered therapy in lower-limb amputees. For this, we worked with a 43-year-old Hispanic male with a medical history of insulin-dependent diabetes complicated by sequential lower limb amputations. The second amputation cost him his job and left him homeless. The patient was hospitalized after developing severe depression, to the point that he had command auditory hallucinations to kill himself. He was discharged back into the community after a three-week hospitalization. However, he was readmitted to the hospital a week later due to a resurgence of suicidal ideation. Our team engaged the patient using the "Holistic Health and Wellness Survey" of Raymond W. Smith, which we used to assess and address various domains of his mental, spiritual, and physical health. We were able to create obtainable goals for the patient for each category on which he scored low in the health and wellness survey. The patient's overall health and attitude improved substantially through his client-centered therapy, which addressed his quantified health needs; and he began to take an active role in developing short- and long-term goals that he found attainable as he adjusted to life as a double-amputee. This case illustrates the potential for improving client-centered therapy in lower-limb amputees. We believe that providers may benefit from implementing this health and wellness survey to better assess how to provide client-centered care for their patients.
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In conventional attenuated viral vaccines, immunogenicity is often suboptimal. Here we present a systematic approach for vaccine development that eliminates interferon (IFN)-modulating functions genome-wide while maintaining virus replication fitness. We applied a quantitative high-throughput genomics system to influenza A virus that simultaneously measured the replication fitness and IFN sensitivity of mutations across the entire genome. By incorporating eight IFN-sensitive mutations, we generated a hyper-interferon-sensitive (HIS) virus as a vaccine candidate. HIS virus is highly attenuated in IFN-competent hosts but able to induce transient IFN responses, elicits robust humoral and cellular immune responses, and provides protection against homologous and heterologous viral challenges. Our approach, which attenuates the virus and promotes immune responses concurrently, is broadly applicable for vaccine development against other pathogens.
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Imunogenicidade da Vacina/genética , Vírus da Influenza A/genética , Vírus da Influenza A/imunologia , Vacinas contra Influenza/genética , Vacinas contra Influenza/imunologia , Influenza Humana/prevenção & controle , Interferons/imunologia , Animais , Furões , Aptidão Genética , Genoma Viral , Estudo de Associação Genômica Ampla , Humanos , Imunidade Celular , Vírus da Influenza A/efeitos dos fármacos , Interferons/farmacologia , Camundongos , Mutação , Infecções por Orthomyxoviridae/prevenção & controle , Replicação Viral/genéticaRESUMO
Despite full immunoprophylaxis, mother-to-child transmission (MTCT) of Hepatitis B Virus still occurs in approximately 2-5% of HBsAg positive mothers. Little is known about the bottleneck of HBV transmission and the evolution of viral quasispecies in the context of MTCT. Here we adopted a newly developed tag linkage deep sequencing method and analyzed the quasispecies of four MTCT pairs that broke through immunoprophylaxis. By assigning unique tags to individual viral sequences, we accurately reconstructed HBV haplotypes in a region of 836 bp, which contains the major immune epitopes and drug resistance mutations. The detection limit of minor viral haplotypes reached 0.1% for individual patient sample. Dominance of "a determinant" polymorphisms were observed in two children, which pre-existed as minor quasispecies in maternal samples. In all four pairs of MTCT samples, we consistently observed a significant overlap of viral haplotypes shared between mother and child. We also demonstrate that the data can be potentially useful to estimate the bottleneck effect during HBV MTCT, which provides information to optimize treatment for reducing the frequency of MTCT.
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Vírus da Hepatite B/genética , Hepatite B/transmissão , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Complicações Infecciosas na Gravidez/virologia , Análise de Sequência de DNA/métodos , Criança , DNA Viral/genética , Evolução Molecular , Feminino , Haplótipos , Hepatite B/prevenção & controle , Hepatite B/virologia , Humanos , Transmissão Vertical de Doenças Infecciosas/prevenção & controle , Filogenia , Gravidez , Complicações Infecciosas na Gravidez/prevenção & controle , Quase-EspéciesRESUMO
Identification and annotation of functional residues are fundamental questions in protein sequence analysis. Sequence and structure conservation provides valuable information to tackle these questions. It is, however, limited by the incomplete sampling of sequence space in natural evolution. Moreover, proteins often have multiple functions, with overlapping sequences that present challenges to accurate annotation of the exact functions of individual residues by conservation-based methods. Using the influenza A virus PB1 protein as an example, we developed a method to systematically identify and annotate functional residues. We used saturation mutagenesis and high-throughput sequencing to measure the replication capacity of single nucleotide mutations across the entire PB1 protein. After predicting protein stability upon mutations, we identified functional PB1 residues that are essential for viral replication. To further annotate the functional residues important to the canonical or noncanonical functions of viral RNA-dependent RNA polymerase (vRdRp), we performed a homologous-structure analysis with 16 different vRdRp structures. We achieved high sensitivity in annotating the known canonical polymerase functional residues. Moreover, we identified a cluster of noncanonical functional residues located in the loop region of the PB1 ß-ribbon. We further demonstrated that these residues were important for PB1 protein nuclear import through the interaction with Ran-binding protein 5. In summary, we developed a systematic and sensitive method to identify and annotate functional residues that are not restrained by sequence conservation. Importantly, this method is generally applicable to other proteins about which homologous-structure information is available. IMPORTANCE: To fully comprehend the diverse functions of a protein, it is essential to understand the functionality of individual residues. Current methods are highly dependent on evolutionary sequence conservation, which is usually limited by sampling size. Sequence conservation-based methods are further confounded by structural constraints and multifunctionality of proteins. Here we present a method that can systematically identify and annotate functional residues of a given protein. We used a high-throughput functional profiling platform to identify essential residues. Coupling it with homologous-structure comparison, we were able to annotate multiple functions of proteins. We demonstrated the method with the PB1 protein of influenza A virus and identified novel functional residues in addition to its canonical function as an RNA-dependent RNA polymerase. Not limited to virology, this method is generally applicable to other proteins that can be functionally selected and about which homologous-structure information is available.
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Aminoácidos/genética , Aminoácidos/metabolismo , Vírus da Influenza A/enzimologia , Vírus da Influenza A/fisiologia , Proteínas Virais/genética , Proteínas Virais/metabolismo , Replicação Viral , Análise Mutacional de DNA , Curadoria de Dados , Sequenciamento de Nucleotídeos em Larga Escala , Modelos Moleculares , Conformação Proteica , Sinais Direcionadores de Proteínas , Transporte Proteico , Proteínas Virais/químicaRESUMO
Nuclear mRNA export is highly regulated to ensure accurate cellular gene expression. Viral inhibition of cellular mRNA export can enhance viral access to the cellular translation machinery and prevent anti-viral protein production but is generally thought to be nonselective. We report that ORF10 of Kaposi's sarcoma-associated herpesvirus (KSHV), a nuclear DNA virus, inhibits mRNA export in a transcript-selective manner to control cellular gene expression. Nuclear export inhibition by ORF10 requires an interaction with an RNA export factor, Rae1. Genome-wide analysis reveals a subset of cellular mRNAs whose nuclear export is blocked by ORF10 with the 3' UTRs of ORF10-targeted transcripts conferring sensitivity to export inhibition. The ORF10-Rae1 interaction is important for the virus to express viral genes and produce infectious virions. These results suggest that a nuclear DNA virus can selectively interfere with RNA export to restrict host gene expression for optimal replication.
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Transporte Ativo do Núcleo Celular , Herpesvirus Humano 8/fisiologia , Interações Hospedeiro-Patógeno , Proteínas Associadas à Matriz Nuclear/metabolismo , Proteínas de Transporte Nucleocitoplasmático/metabolismo , RNA Mensageiro/metabolismo , Proteínas Virais/metabolismo , Replicação Viral , Animais , Linhagem Celular , Regulação da Expressão Gênica , Humanos , Modelos Biológicos , Ligação ProteicaRESUMO
Abstract Background Inflammation is involved in the pathophysiology of depression, and circulating inflammatory cytokines have been associated with depressive symptoms. However, measuring circulating cytokines have inherent methodological limitations. In vitro lipopolysaccharide (LPS)-stimulated intracellular cytokines (ICCs) overcome these limitations. Furthermore, because psychosocial and physiological stressors activate inflammatory responses and LPS-stimulated ICCs reflect the inflammatory responsivity of monocytes to such stressors, ICCs may reflect individual stress responsivity. Methods This cross-sectional study examined whether LPS-stimulated expression of ICCs in peripheral blood mononuclear cells (PBMCs) is a sensitive inflammation measure correlated with depressive symptoms in 180 community-dwelling older adults. We tested correlations of not only intracellular but also circulating inflammatory markers with depressive symptoms assessed using the 10-item Center for Epidemiological Studies Depression Scale (CES-D). Intracellular markers included expression of interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and both in PBMCs. Circulating markers included IL-6, TNF-α, and C-reactive protein (CRP) in plasma. Results None of the correlations were statistically significant. However, in contrast to circulating markers, the correlations of ICCs were consistently in the expected direction, i.e., higher ICC expression correlating with higher depression severity. Discussion Despite the non-significant findings, further research is required for the evaluation of LPS-stimulated ICC expression as biomarkers of depressive symptoms.