Analysis of the Contribution of 6-mer Seed Toxicity to HIV-1-Induced Cytopathicity.

HIV-1 (HIV) infects CD4+ T cells, the gradual depletion of which can lead to AIDS in the absence of antiretroviral therapy (ART). Some cells, however, survive HIV infection and persist as part of the latently infected reservoir that causes recurrent viremia after ART cessation. Improved understanding of the mechanisms of HIV-mediated cell death could lead to a way to clear the latent reservoir. Death induced by survival gene elimination (DISE), an RNA interference (RNAi)-based mechanism, kills cells through short RNAs (sRNAs) with toxic 6-mer seeds (positions 2 to 7 of sRNA). These toxic seeds target the 3' untranslated region (UTR) of mRNAs, decreasing the expression of hundreds of genes critical for cell survival. In most cells under normal conditions, highly expressed cell-encoded nontoxic microRNAs (miRNAs) block access of toxic sRNAs to the RNA-induced silencing complex (RISC) that mediates RNAi, promoting cell survival. HIV has been shown to inhibit the biogenesis of host miRNAs in multiple ways. We now report that HIV infection of cells deficient in miRNA expression or function results in enhanced RISC loading of an HIV-encoded miRNA HIV-miR-TAR-3p, which can kill cells by DISE through a noncanonical (positions 3 to 8) 6-mer seed. In addition, cellular RISC-bound sRNAs shift to lower seed viability. This also occurs after latent HIV provirus reactivation in J-Lat cells, suggesting independence of permissiveness of cells to viral infection. More precise targeting of the balance between protective and cytotoxic sRNAs could provide new avenues to explore novel cell death mechanisms that could be used to kill latent HIV. IMPORTANCE Several mechanisms by which initial HIV infection is cytotoxic to infected cells have been reported and involve various forms of cell death. Characterizing the mechanisms underlying the long-term survival of certain T cells that become persistent provirus reservoirs is critical to developing a cure. We recently discovered death induced by survival gene elimination (DISE), an RNAi-based mechanism of cell death whereby toxic short RNAs (sRNAs) containing 6-mer seed sequences (exerting 6-mer seed toxicity) targeting essential survival genes are loaded into RNA-induced silencing complex (RISC) complexes, resulting in inescapable cell death. We now report that HIV infection in cells with low miRNA expression causes a shift of mostly cellular RISC-bound sRNAs to more toxic seeds. This could prime cells to DISE and is further enhanced by the viral microRNA (miRNA) HIV-miR-TAR-3p, which carries a toxic noncanonical 6-mer seed. Our data provide multiple new avenues to explore novel cell death mechanisms that could be used to kill latent HIV.

Quality of ethnicity data within Scottish health records and implications of misclassification for ethnic inequalities in severe COVID-19: a national linked data study.

BACKGROUND: We compared the quality of ethnicity coding within the Public Health Scotland Ethnicity Look-up (PHS-EL) dataset, and other National Health Service datasets, with the 2011 Scottish Census. METHODS: Measures of quality included the level of missingness and misclassification. We examined the impact of misclassification using Cox proportional hazards to compare the risk of severe coronavirus disease (COVID-19) (hospitalization & death) by ethnic group. RESULTS: Misclassification within PHS-EL was higher for all minority ethnic groups [12.5 to 69.1%] compared with the White Scottish majority [5.1%] and highest in the White Gypsy/Traveller group [69.1%]. Missingness in PHS-EL was highest among the White Other British group [39%] and lowest among the Pakistani group [17%]. PHS-EL data often underestimated severe COVID-19 risk compared with Census data. e.g. in the White Gypsy/Traveller group the Hazard Ratio (HR) was 1.68 [95% Confidence Intervals (CI): 1.03, 2.74] compared with the White Scottish majority using Census ethnicity data and 0.73 [95% CI: 0.10, 5.15] using PHS-EL data; and HR was 2.03 [95% CI: 1.20, 3.44] in the Census for the Bangladeshi group versus 1.45 [95% CI: 0.75, 2.78] in PHS-EL. CONCLUSIONS: Poor quality ethnicity coding in health records can bias estimates, thereby threatening monitoring and understanding ethnic inequalities in health.

The role of subjective, interpersonal, and structural social isolation in 12-month and lifetime anxiety disorders.

BACKGROUND: Anxiety disorders are among the most prevalent psychiatric conditions worldwide, and the incidence of anxiety disorders among adults in the U.S. have increased over the last decade. Anxiety disorders can have debilitating effects on multiple areas of functioning and quality of life. Recently, social isolation has emerged as an important public health problem associated with worse health and well-being outcomes. Research on the connection between social isolation and mental health has found that multiple dimensions of social isolation may negatively impact mental health, but few inquiries have focused on the association between social isolation and anxiety. This study examined the relationships between multiple dimensions of social isolation and anxiety disorders in a nationally representative sample of adults aged 18 and older. METHODS: The sample includes 6082 individuals from the National Survey of American Life. This study examined whether three different dimensions of social isolation-subjective, interpersonal, and structural-were associated with 12-month and lifetime anxiety disorders (any anxiety disorder, posttraumatic stress disorder (PTSD), generalized anxiety disorder (GAD), panic disorder (PD), social anxiety disorder (SAD), and agoraphobia (AG). Logistic regressions were used to test the associations between the three social isolation variables and the anxiety outcomes. RESULTS: This study found that of the three dimensions of social isolation, subjective isolation was most consistently related to both lifetime and 12-month anxiety disorders. Those who were subjectively isolated had increased odds of meeting criteria for any anxiety disorder, PTSD, GAD, PD, and AG over the past 12 months and throughout their lifetimes. Structural isolation was negatively associated with lifetime and 12-month AG. CONCLUSIONS: Public health approaches should include mental health and primary care providers and need to target social isolation, especially subjective isolation, which may be key in preventing anxiety disorders and the worsening of anxiety disorders. Future public health research is needed on how and in what ways the differing dimensions of social isolation impact mental health.

The state of loneliness and social isolation research: current knowledge and future directions.

In this editorial, we consider the current state of loneliness and social isolation research around the world, including knowledge gaps in the empirical literature.

Later-life depressive symptoms during the Covid-19 pandemic: Investigations of individual, cumulative, and synergistic effects of social isolation.

OBJECTIVES: This study examines associations between social isolation and depressive symptoms among Hong Kong Chinese adults aged 65 and older by investigating the distinct effects of individual indicators, cumulative index, and typologies of social isolation during the Covid-19 pandemic. METHODS: We used a sample of 260 older adults from a cross-sectional, city-wide online survey targeting 1,109 aged 45+ adults through purposive sampling. Seven indicators of social isolation (not married; living alone; not engaging in social/organizational activities; no social contact with friends or families; lack of family and friends networks; loneliness) using Cornwell & Waite's framework were selected to construct three unique types of social isolation measures. We used latent class analysis (LCA) and regression models to examine the effects of varied typologies of social isolation on depressive symptoms. RESULTS: Individual model of social isolation showed that lack of social contact and feeling lonely were significant predictors of depressive symptoms. A strong linear-trend gradient effect of cumulative social isolation on depressive symptoms was also observed. The LCA model identified four typologies of social isolation (socially isolated; living alone but socially engaged; married but lacking social ties, and not socially isolated); those in the 'socially isolated' and 'married but lacking social ties' groups had the most depressive symptoms. CONCLUSION: Three operationalizations of social isolation demonstrated different utilities and implications in assessing the impacts of social isolation on depressive symptoms. Social contacts and loneliness, rather than living status or other characteristics of isolation, were the factors most strongly associated with depressive symptoms. Support programs should target lonely older adults who lack social engagement opportunities, as they are at increased risk of depression.

Investigating ethnic inequalities in hearing aid use in England and Wales: a cross-sectional study.

OBJECTIVE: To establish whether ethnic inequalities exist in levels of self-reported hearing difficulty and hearing aid use among middle-aged adults. DESIGN: Cross-sectional data from the UK Biobank resource. STUDY SAMPLE: 164,460 participants aged 40-69 who answered hearing questions at an assessment centre in England or Wales. RESULTS: After taking into account objectively assessed hearing performance and a corresponding correction for bias in non-native English speakers, as well as a range of correlates including demographic, socioeconomic, and health factors, there were lower levels of hearing aid use for people from Black African (OR 0.36, 95% CI 0.17-0.77), Black Caribbean (OR 0.38, 95% CI 0.22-0.65) and Indian (OR 0.60, 95% CI 0.41-0.86) ethnic groups, compared to the White British or Irish group. Men from most ethnic minority groups and women from Black African, Black Caribbean and Indian groups were less likely to report hearing difficulty than their White British or Irish counterparts. CONCLUSIONS: For equivalent levels of hearing loss, the use of hearing aids is lower among ethnic minority groups. Inequalities are partly due to lower levels of self-reported hearing difficulty among minority groups. However, even when self-reported hearing difficulty is considered, hearing aid use remains lower among many ethnic minority groups.

Patterns of energy availability of free-living athletes display day-to-day variability that is not reflected in laboratory-based protocols: Insights from elite male road cyclists.

The physiological effects of low energy availability (EA) have been studied using a homogenous daily EA pattern in laboratory settings. However, whether this daily EA pattern represents those of free-living athletes and is therefore ecologically valid is unknown. To investigate this, we assessed daily exercise energy expenditure, energy intake and EA in 10 free-living elite male road cyclists (20 min Mean Maximal Power: 5.27 ± 0.25 W · kg-1) during 7 consecutive days of late pre-season training. Energy intake was measured using the remote-food photography method and exercise energy expenditure estimated from cycling crank-based power-metres. Seven-day mean ± SD energy intake and exercise energy expenditure was 57.9 ± 10.4 and 38.4 ± 8.6 kcal · kg FFM-1 · day-1, respectively. EA was 19.5 ± 9.1 kcal · kg FFM-1 · day-1. Within-participants correlation between daily energy intake and exercise energy expenditure was .62 (95% CI: .43 - .75; P < .001), and .60 (95% CI: .41 - .74; P < .001) between carbohydrate intake and exercise energy expenditure. However, energy intake only partially compensated for exercise energy expenditure, increasing 210 kcal · day-1 per 1000 kcal · day-1 increase in expenditure. EA patterns displayed marked day-to-day fluctuation (range: -22 to 76 kcal · kg FFM-1 · day-1). The validity of research using homogenous low EA patterns therefore requires further investigation.

Discrimination and social isolation among African Americans: The moderating role of skin tone.

OBJECTIVES: Discrimination is an urgent public health problem. A number of major cities and counties across the United States has declared racism a public health crisis. While there is a growing body of research on the discrimination-health connection, less is known regarding the social relational consequences of discrimination. The present study addresses this knowledge gap by investigating the relationship between discrimination, skin tone, and objective and subjective social isolation using a nationally representative sample of African Americans. METHOD: This analysis was based upon the African American subsample (N = 3,570) of the National Survey of American Life. Discrimination was assessed with the Everyday Discrimination Scale. Objective and subjective isolation differentiated between respondents who were (a) socially isolated from both family and friends, (b) socially isolated from friends only, (c) socially isolated from family only, and (d) not socially isolated. Skin tone was self-reported. Multinomial logistic regression analyses were used to test the study hypotheses. RESULTS: The analyses indicated that more frequent discriminatory experiences were associated with increased risk for subjective and objective social isolation. Skin tone moderated the association between discrimination and subjective isolation; the discrimination-isolation relationship was stronger among participants with darker skin tones. CONCLUSIONS: These findings shed light on African Americans' nuanced experiences with discrimination and colorism. Further, the data demonstrate heterogeneity in the vulnerability to the adverse effects of discrimination within the African American population; the relationship between discrimination and subjective isolation was stratified by skin tone. This underscores the well-documented and persistent racialized social stratification system in the United States (PsycInfo Database Record (c) 2022 APA, all rights reserved).

Low energy availability: history, definition and evidence of its endocrine, metabolic and physiological effects in prospective studies in females and males.

Energy availability (EA) is defined as the amount of dietary energy available to sustain physiological function after subtracting the energetic cost of exercise. Insufficient EA due to increased exercise, reduced energy intake, or a combination of both, is a potent disruptor of the endocrine milieu. As such, EA is conceived as a key etiological factor underlying a plethora of physiological dysregulations described in the female athlete triad, its male counterpart and the Relative Energy Deficiency in Sport models. Originally developed upon female-specific physiological responses, this concept has recently been extended to males, where experimental evidence is limited. The majority of data for all these models are from cross-sectional or observational studies where hypothesized chronic low energy availability (LEA) is linked to physiological maladaptation. However, the body of evidence determining causal effects of LEA on endocrine, and physiological function through prospective studies manipulating EA is comparatively small, with interventions typically lasting ≤ 5 days. Extending laboratory-based findings to the field requires recognition of the strengths and limitations of current knowledge. To aid this, this review will: (1) provide a brief historical overview of the origin of the concept in mammalian ecology through its evolution of algebraic calculations used in humans today, (2) Outline key differences from the 'energy balance' concept, (3) summarise and critically evaluate the effects of LEA on tissues/systems for which we now have evidence, namely: hormonal milieu, reproductive system endocrinology, bone metabolism and skeletal muscle; and finally (4) provide perspectives and suggestions for research upon identified knowledge gaps.

Professional service use among older African Americans, Black Caribbeans, and Non-Hispanic Whites for serious health and emotional problems.

This study examined racial and ethnic differences in professional service use by older African Americans, Black Caribbeans, and Non-Hispanic Whites in response to a serious personal problem. The analytic sample (N = 862) was drawn from the National Survey of American Life. Findings indicated that African Americans and Black Caribbeans were less likely to use services than Whites. Type and race of providers seen varied by respondents' race and ethnicity. Among respondents who did not seek professional help, reasons for not seeking help varied by ethnicity. Study findings are discussed in relation to practice implications.

Loneliness in senior housing communities.

There are many studies on loneliness among community-dwelling older adults; however, there is limited research examining the extent and correlates of loneliness among older adults who reside in senior housing communities. This study examines the extent and correlates of loneliness in three public senior housing communities in the St. Louis area. Data for this project was collected with survey questionnaires with a total sample size of 148 respondents. Loneliness was measured using the Hughes 3-item loneliness scale. Additionally, the questionnaire contained measures on socio-demographics, health/mental health, social engagement, and social support. Missing data for the hierarchical multivariate regression models were imputed using multiple imputation methods. Results showed approximately 30.8% of the sample was not lonely, 42.7% was moderately lonely, and 26.6% was severely lonely. In the multivariate analyses, loneliness was primarily associated with depressive symptoms. Contrary to popular opinion, our study found the prevalence of loneliness was high in senior housing communities. Nevertheless, senior housing communities could be ideal locations for reducing loneliness among older adults. Interventions should focus on concomitantly addressing both an individual's loneliness and mental health.

Phospholipase D1 Couples CD4+ T Cell Activation to c-Myc-Dependent Deoxyribonucleotide Pool Expansion and HIV-1 Replication.

Quiescent CD4+ T cells restrict human immunodeficiency virus type 1 (HIV-1) infection at early steps of virus replication. Low levels of both deoxyribonucleotide triphosphates (dNTPs) and the biosynthetic enzymes required for their de novo synthesis provide one barrier to infection. CD4+ T cell activation induces metabolic reprogramming that reverses this block and facilitates HIV-1 replication. Here, we show that phospholipase D1 (PLD1) links T cell activation signals to increased HIV-1 permissivity by triggering a c-Myc-dependent transcriptional program that coordinates glucose uptake and nucleotide biosynthesis. Decreasing PLD1 activity pharmacologically or by RNA interference diminished c-Myc-dependent expression during T cell activation at the RNA and protein levels. PLD1 inhibition of HIV-1 infection was partially rescued by adding exogenous deoxyribonucleosides that bypass the need for de novo dNTP synthesis. Moreover, the data indicate that low dNTP levels that impact HIV-1 restriction involve decreased synthesis, and not only increased catabolism of these nucleotides. These findings uncover a unique mechanism of action for PLD1 inhibitors and support their further development as part of a therapeutic combination for HIV-1 and other viral infections dependent on host nucleotide biosynthesis.

Extended family and friendship support and suicidality among African Americans.

PURPOSE: This study examined the relationship between informal social support from extended family and friends and suicidality among African Americans. METHODS: Logistic regression analysis was based on a nationally representative sample of African Americans from the National Survey of American Life (N = 3263). Subjective closeness and frequency of contact with extended family and friends and negative family interaction were examined in relation to lifetime suicide ideation and attempts. RESULTS: Subjective closeness to family and frequency of contact with friends were negatively associated with suicide ideation and attempts. Subjective closeness to friends and negative family interaction were positively associated with suicide ideation and attempts. Significant interactions between social support and negative interaction showed that social support buffers against the harmful effects of negative interaction on suicidality. CONCLUSIONS: Findings are discussed in relation to the functions of positive and negative social ties in suicidality.

Genetic analysis of the localization of APOBEC3F to human immunodeficiency virus type 1 virion cores.

UNLABELLED: Members of the APOBEC3 family of cytidine deaminases vary in their proportions of a virion-incorporated enzyme that is localized to mature retrovirus cores. We reported previously that APOBEC3F (A3F) was highly localized into mature human immunodeficiency virus type 1 (HIV-1) cores and identified that L306 in the C-terminal cytidine deaminase (CD) domain contributed to its core localization (C. Song, L. Sutton, M. Johnson, R. D'Aquila, J. Donahue, J Biol Chem 287:16965-16974, 2012, http://dx.doi.org/10.1074/jbc.M111.310839). We have now determined an additional genetic determinant(s) for A3F localization to HIV-1 cores. We found that one pair of leucines in each of A3F's C-terminal and N-terminal CD domains jointly determined the degree of localization of A3F into HIV-1 virion cores. These are A3F L306/L368 (C-terminal domain) and A3F L122/L184 (N-terminal domain). Alterations to one of these specific leucine residues in either of the two A3F CD domains (A3F L368A, L122A, and L184A) decreased core localization and diminished HIV restriction without changing virion packaging. Furthermore, double mutants in these leucine residues in each of A3F's two CD domains (A3F L368A plus L184A or A3F L368A plus L122A) still were packaged into virions but completely lost core localization and anti-HIV activity. HIV virion core localization of A3F is genetically separable from its virion packaging, and anti-HIV activity requires some core localization. IMPORTANCE: Specific leucine-leucine interactions are identified as necessary for A3F's core localization and anti-HIV activity but not for its packaging into virions. Understanding these signals may lead to novel strategies to enhance core localization that may augment effects of A3F against HIV and perhaps of other A3s against retroviruses, parvoviruses, and hepatitis B virus.

Assessing Social Isolation: Pilot Testing Different Methods.

Social isolation is a significant public health problem among many older adults; however, most of the empirical knowledge about isolation derives from community-based samples. There has been less attention given to isolation in senior housing communities. The objectives of this pilot study were to test two methods to identify socially isolated residents in low-income senior housing and compare findings about the extent of isolation from these two methods. The first method, self-report by residents, included 47 out of 135 residents who completed in-person interviews. To determine self-report isolation, residents completed the Lubben Social Network Scale 6 (LSNS-6). The second method involved a staff member who reported the extent of isolation on all 135 residents via an online survey. Results indicated that 26% of residents who were interviewed were deemed socially isolated by the LSNS-6. Staff members rated 12% of residents as having some or a lot of isolation. In comparing the two methods, staff members rated 2% of interviewed residents as having a lot of isolation. The combination of self-report and staff report could be more informative than just self-report alone, particularly when participation rates are low. However, researchers should be aware of the potential discrepancy between these two methods.

Phospholipase D2 mediates survival signaling through direct regulation of Akt in glioblastoma cells.

The lack of innovative drug targets for glioblastoma multiforme (GBM) limits patient survival to approximately 1 year following diagnosis. The pro-survival kinase Akt provides an ideal target for the treatment of GBM as Akt signaling is frequently activated in this cancer type. However, the central role of Akt in physiological processes limits its potential as a therapeutic target. In this report, we show that the lipid-metabolizing enzyme phospholipaseD(PLD) is a novel regulator of Akt inGBM.Studies using a combination of small molecule PLD inhibitors and siRNA knockdowns establish phosphatidic acid, the product of the PLD reaction, as an essential component for the membrane recruitment and activation of Akt. Inhibition of PLD enzymatic activity and subsequent Akt activation decreases GBM cell viability by specifically inhibiting autophagic flux. We propose a mechanism whereby phosphorylation of beclin1 by Akt prevents binding of Rubicon (RUN domain cysteine-rich domain containing beclin1-interacting protein), an interaction known to inhibit autophagic flux. These findings provide a novel framework through which Akt inhibition can be achieved without directly targeting the kinase.

The innate immune factor apolipoprotein L1 restricts HIV-1 infection.

Apolipoprotein L1 (APOL1) is a major component of the human innate immune response against African trypanosomes. Although the mechanism of the trypanolytic activity of circulating APOL1 has been recently clarified, the intracellular function(s) of APOL1 in human cells remains poorly defined. Like that of many genes linked to host immunity, APOL1 expression is induced by proinflammatory cytokines gamma interferon (IFN-γ) and tumor necrosis factor alpha (TNF-α). Additionally, IFN-γ-polarized macrophages that potently restrict HIV-1 replication express APOL1, which suggests that APOL1 may contribute to HIV-1 suppression. Here, we report that APOL1 inhibits HIV-1 replication by multiple mechanisms. We found that APOL1 protein targeted HIV-1 Gag for degradation by the endolysosomal pathway. Interestingly, we found that APOL1 stimulated both endocytosis and lysosomal biogenesis by promoting nuclear localization of transcription factor EB (TFEB) and expression of TFEB target genes. Moreover, we demonstrated that APOL1 depletes cellular viral accessory protein Vif, which counteracts the host restriction factor APOBEC3G, via a pathway involving degradation of Vif in lysosomes and by secretion of Vif in microvesicles. As a result of Vif depletion by APOL1, APOBEC3G was not degraded and reduced infectivity of progeny virions. In support of this model, we also showed that endogenous expression of APOL1 in differentiated U937 monocytic cells stimulated with IFN-γ resulted in a reduced production of virus particles. This finding supports the hypothesis that induction of APOL1 contributes to HIV-1 suppression in differentiated monocytes. Deciphering the precise mechanism of APOL1-mediated HIV-1 restriction may facilitate the design of unique therapeutics to target HIV-1 replication.

Loneliness and Psychological Distress Among Older Californians: The Moderating Roles of Citizenship Status and English Proficiency.

OBJECTIVES: Guided by the theory of stress proliferation, our study examined whether loneliness, citizenship status, and English proficiency were associated with psychological distress among older adults, and if citizenship status and English proficiency moderated these relationships. METHODS: Using the older adult subsample (65+ years) of the 2019-2020 California Health Interview Survey (N = 15,210), we assessed cross-sectional associations between loneliness, citizenship status, and English proficiency on psychological distress by conducting multivariable linear regression models. Interaction terms were included in subsequent models to determine if citizenship status and English proficiency moderated the relationship between loneliness and psychological distress. RESULTS: In unadjusted models, greater loneliness was associated with higher distress. Both naturalized citizens and noncitizens, and those with limited English proficiency (LEP) exhibited greater distress than US born citizens and those who speak English only (EO). After adjusting for sociodemographic and health covariables, loneliness remained significant for distress although the relationships between citizenship status and English proficiency became attenuated. With the inclusion of interactions, the magnitude of the relationship between loneliness and distress was stronger for naturalized citizens and those with LEP than native-born citizens and those who speak EO, respectively. DISCUSSION: Loneliness was the most consistent stressor affecting multiple life domains. However, our findings demonstrate that stress proliferation is occurring among older immigrant adults and the interplay between loneliness, citizenship status, and English proficiency is contributing to heightened distress. Further attention is needed in understanding the role of multiple stressors influencing mental health among immigrant older adults.