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Background Biomarkers that provide insight into drivers of aging are needed for people with human immunodeficiency virus (PWH). The study objective was to determine if epigenetic age acceleration (EAA) markers are associated with physiologic frailty measured by the Veterans Aging Cohort Study (VACS) Index and predict all-cause mortality for PWH. Methods Epigenome-wide DNA methylation was profiled in VACS total white blood cell samples collected during 2005–2007 from 531 PWH to generate 6 established markers of EAA. The association of each EAA marker was tested with VACS Index 2.0. All-cause mortality was assessed over 10 years. For each EAA marker, the hazard ratio per increased year was determined using Cox regression. To evaluate mortality discrimination, C-statistics were derived. Results Participants were mostly men (98.5%) and non-Hispanic Black (84.4%), with a mean age of 52.4 years (standard deviation [SD], 7.8 years). Mean VACS Index score was 59.3 (SD, 16.4) and 136 deaths occurred over a median follow-up of 8.7 years. Grim age acceleration (AA), PhenoAA, HannumAA, and extrinsic epigenetic AA were associated with the VACS Index and mortality. HorvathAA and intrinsic epigenetic AA were not associated with either outcome. GrimAA had the greatest mortality discrimination among EAA markers and predicted mortality independently of the VACS Index. One-year increase in GrimAA was associated with a 1-point increase in VACS Index and a 10% increased hazard for mortality. Conclusions The observed associations between EAA markers with physiologic frailty and mortality support future research to provide mechanistic insight into the accelerated aging process and inform interventions tailored to PWH for promoting increased healthspan.

Categorizing clinical risk amidst heterogeneous multimorbidity in older people living with HIV/AIDS (PLWH) may help prioritize and optimize health care engagements.PLWH and their prevalent conditions in 8 health domains diagnosed before January 1, 2015 were identified using 2014-2016 Medicare claims and the Chronic Conditions Data Warehouse. Latent profile analysis identified 4 distinct clinical subgroups based on the likelihood of conditions occurring together [G1: healthy, G2: substance use (SU), G3: pulmonary (PULM), G4: cardiovascular conditions (CV)]. Restricted mean survival time regression estimated the association of each subgroup with the 365 day mean event-free days until death, first hospitalization, and nursing home admission. Zero-inflated Poisson regression estimated hospitalization frequency in 2-year follow-up.Of 11,196 older PLWH, 71% were male, and the average age was 61 (SD 9.2) years. Compared with healthy group, SU group had a mean of 30 [95% confidence interval: (19.0 to 40.5)], PULM group had a mean of 28 (22.1 to 34.5), and CV group had a mean of 22 (15.0 to 22.0) fewer hospitalization-free days over 1 year. Compared with healthy group (2.8 deaths/100 person-years), CV group (8.4) had a mean of 4 (3.8 to 6.8) and PULM group (7.9) had a mean of 3 (0.7 to 5.5) fewer days alive; SU group (6.0) was not different. There was no difference in restricted mean survival time for nursing home admission. Compared with healthy group, SU group had 1.42-fold [95% confidence interval: (1.32 to 1.54)], PULM group had 1.71-fold (1.61 to 1.81), and CV group had 1.28-fold (1.20 to 1.37) higher rates of hospitalization.Identifying clinically distinct subgroups with latent profile analysis may be useful to identify targets for interventions and health care optimization in older PLWH.

Although people with HIV are living longer, as they age they remain disproportionately burdened with multimorbidity that is exacerbated in resource-poor settings. The geroscience hypothesis postulates that a discrete set of between five and ten hallmarks of biological ageing drive multimorbidity, but these processes have not been systematically examined in the context of people with HIV. We examine four major hallmarks of ageing (macromolecular damage, senescence, inflammation, and stem-cell dysfunction) as gerodrivers in the context of people with HIV. As a counterbalance, we introduce healthy ageing, physiological reserve, intrinsic capacity, and resilience as promoters of geroprotection that counteract gerodrivers. We discuss emerging geroscience-based diagnostic biomarkers and therapeutic strategies, and provide examples based on recent advances in cellular senescence, and other, non-pharmacological approaches. Finally, we present a conceptual model of biological ageing in the general population and in people with HIV that integrates gerodrivers and geroprotectors as modulators of homoeostatic reserves and organ function over the lifecourse.

Introduction The aim of this proof-of-concept study is to explore sleep health disparity and associations with frailty in middle-aged (i.e., age< 65 years) people living with HIV (PLWH) in an African setting. Methods Data were from 98 participants (age: 56.8±4.3 [mean±SD] years; female: 49 [50%]) enrolled in Botswana, Africa, between March-December 2021. Forty-eight participants were HIV seropositive (i.e., PLWH) and on suppressive antiretroviral therapy regimens; 50 participants were confirmed uninfected (i.e., controls). PLWH and controls were matched for age and sex. Sleep health was assessed subjectively based on answers to two questions related to sleep quality, and was scored 1 (i.e., better sleep quality) if the participant answered “very much” to question “I am sleeping well” and “not at all” to question “I need to sleep during the day” or 0 (i.e., worse sleep quality) if otherwise. To assess frailty, 29 health deficits related to weight loss, obesity, physical activity, emotion, and fatigue were examined to construct a composite frailty index ranged between 0 and 1 (i.e., 0=no deficit present and 1=all deficits present). Logistic regression and linear regression models were conducted respectively to compare sleep quality (dichotomous) and the frailty index (continuous) between PLWH and controls. In addition, linear regression models were used to examine the association between frailty index and sleep quality stratified by HIV serostatus. All models were adjusted for age and sex. Statistical significance was rendered at p< 0.05. Results PLWH displayed 2.5-fold higher odds of having worse sleep quality compared to controls (PLWH: 61.4%, controls: 38.6%; p=0.02). The frailty index did not differ significantly between PLWH (0.15±0.08 [mean±SD]; range: [0.02, 0.36]) and controls (0.14±0.10; range: [0.03, 0.56]; p=0.6). Within PLWH, having worse sleep quality was significantly associated with an increase in the frailty index (0.76 SD of the group) (p< 0.001). No significant association was observed in HIV-seronegative controls (p=0.4). Conclusion Treated PLWH had worse self-reported sleep than controls, and worse sleep quality in PLWH is linked to an increased burden of physical frailty in Africa. Future studies are warranted to elucidate the causal direction and underlying mechanisms. Support (if any) Developmental Award (CFAR; P30AI060354); Pilot Grant (HIV&Aging; R33AG067069-02).

Age-related changes in immune cell composition and functionality are associated with multimorbidity and mortality. However, many centenarians delay the onset of aging-related disease suggesting the presence of elite immunity that remains highly functional at extreme old age. To identify immune-specific patterns of aging and extreme human longevity, we analyzed novel single cell profiles from the peripheral blood mononuclear cells (PBMCs) of 7 centenarians (mean age 106) and publicly available single cell RNA-sequencing (scRNA-seq) datasets that included an additional 7 centenarians as well as 52 people at younger ages (20-89 years). The analysis confirmed known shifts in the ratio of lymphocytes to myeloid cells, and noncytotoxic to cytotoxic cell distributions with aging, but also identified significant shifts from CD4+ T cell to B cell populations in centenarians suggesting a history of exposure to natural and environmental immunogens. Our transcriptional analysis identified cell type signatures specific to exceptional longevity that included genes with age-related changes (e.g., increased expression of STK17A, a gene known to be involved in DNA damage response) as well as genes expressed uniquely in centenarians’ PBMCs (e.g., S100A4, part of the S100 protein family studied in age-related disease and connected to longevity and metabolic regulation). Collectively, these data suggest that centenarians harbor unique, highly functional immune systems that have successfully adapted to a history of insults allowing for the achievement of exceptional longevity.

People living with HIV (PLWH) are disproportionately burdened with multimorbidity and decline in physiologic function compared to their uninfected counterparts, but biological mechanisms that differentially contribute to the decline in muscle function in PLWH compared to uninfected people remains understudied. The study site was Brigham and Women’s Hospital, Harvard Medical School, Boston MA. We evaluated skeletal muscle tissue for levels of total NAD, NAD+ and NADH in middle-aged asymptomatic PLWH, coinfected with hepatitis C virus (HCV) and/or cytomegalovirus (CMV) and compared them to uninfected control participants. Of the 54 persons with muscle biopsy data, the mean age 57 years with 33% women. Total NAD levels declined in skeletal muscle in association with HIV infection, and was exacerbated by HCV and CMV coinfection, with lowest levels of total NAD, NAD+ and NADH among persons that were coinfected with all three viruses (P=0.015, P=0.014, P=0.076; respectively). Levels of total NAD, NAD+ and NADH in skeletal muscle were inversely associated with inflammation (P=0.014, P=0.013, P=0.055; respectively). Coinfections were also associated with measures of inflammation (CD4/CD8 ratio: P< 0.001 and sCD163: P< 0.001), immune activation (CD38 and HLA-DR expression on CD8 T cells: P< 0.001). Additionally, coinfection was associated with increased physiologic frailty, based on the VACS Index 1.0 assessment (P=0.001). Further research is warranted to determine the clinical relevance of preclinical deficits in NAD metabolites in skeletal muscle in association with viral coinfection and inflammation, as well as the observed association between viral coinfection and physiologic frailty.

BACKGROUND: Biomarkers that provide insight into drivers of aging are needed for people with human immunodeficiency virus (PWH). The study objective was to determine if epigenetic age acceleration (EAA) markers are associated with physiologic frailty measured by the Veterans Aging Cohort Study (VACS) Index and predict all-cause mortality for PWH. METHODS: Epigenome-wide DNA methylation was profiled in VACS total white blood cell samples collected during 2005–2007 from 531 PWH to generate 6 established markers of EAA. The association of each EAA marker was tested with VACS Index 2.0. All-cause mortality was assessed over 10 years. For each EAA marker, the hazard ratio per increased year was determined using Cox regression. To evaluate mortality discrimination, C-statistics were derived. RESULTS: Participants were mostly men (98.5%) and non-Hispanic Black (84.4%), with a mean age of 52.4 years (standard deviation [SD], 7.8 years). Mean VACS Index score was 59.3 (SD, 16.4) and 136 deaths occurred over a median follow-up of 8.7 years. Grim age acceleration (AA), PhenoAA, HannumAA, and extrinsic epigenetic AA were associated with the VACS Index and mortality. HorvathAA and intrinsic epigenetic AA were not associated with either outcome. GrimAA had the greatest mortality discrimination among EAA markers and predicted mortality independently of the VACS Index. One-year increase in GrimAA was associated with a 1-point increase in VACS Index and a 10% increased hazard for mortality. CONCLUSIONS: The observed associations between EAA markers with physiologic frailty and mortality support future research to provide mechanistic insight into the accelerated aging process and inform interventions tailored to PWH for promoting increased healthspan.

Testosterone supplementation during energy deficit promotes whole body lean mass accretion, but the mechanisms underlying that effect remain unclear. To elucidate those mechanisms, skeletal muscle molecular adaptations were assessed from muscle biopsies collected before, 1 h, and 6 h after exercise and a mixed meal (40 g protein, 1 h postexercise) following 14 days of weight maintenance (WM) and 28 days of an exercise- and diet-induced 55% energy deficit (ED) in 50 physically active nonobese men treated with 200 mg testosterone enanthate/wk (TEST) or placebo (PLA) during the ED. Participants ( n = 10/group) exhibiting substantial increases in leg lean mass and total testosterone (TEST) were compared with those exhibiting decreases in both of these measures (PLA). Resting androgen receptor (AR) protein content was higher and fibroblast growth factor-inducible 14 (Fn14), IL-6 receptor (IL-6R), and muscle ring-finger protein-1 gene expression was lower in TEST vs. PLA during ED relative to WM ( P < 0.05). Changes in inflammatory, myogenic, and proteolytic gene expression did not differ between groups after exercise and recovery feeding. Mechanistic target of rapamycin signaling (i.e., translational efficiency) was also similar between groups at rest and after exercise and the mixed meal. Muscle total RNA content (i.e., translational capacity) increased more during ED in TEST than PLA ( P < 0.05). These findings indicate that attenuated proteolysis at rest, possibly downstream of AR, Fn14, and IL-6R signaling, and increased translational capacity, not efficiency, may drive lean mass accretion with testosterone administration during energy deficit.

Background: People living with HIV (PLWH) are disproportionately burdened with multimorbidity and decline in physiologic function compared with their uninfected counterparts, but biological mechanisms that differentially contribute to the decline in muscle function in PLWH compared with uninfected people remain understudied. Setting: The study site was Brigham and Women's Hospital, Harvard Medical School, Boston, MA. Methods: We evaluated skeletal muscle tissue for levels of total nicotinamide adenine dinucleotide (NAD), NAD+, and nicotinamide adenine dinucleotide (NADH) in middle-aged asymptomatic PLWH, coinfected with hepatitis C virus and/or cytomegalovirus and compared them with uninfected control participants. Results: Of the 54 persons with muscle biopsy data, the mean age was 57 years with 33% women. Total NAD levels declined in skeletal muscle in association with HIV infection and was exacerbated by hepatitis C virus and cytomegalovirus coinfection, with lowest levels of total NAD, NAD+, and NADH among persons who were coinfected with all 3 viruses (P = 0.015, P = 0.014, and P = 0.076, respectively). Levels of total NAD, NAD+, and NADH in skeletal muscle were inversely associated with inflammation (P = 0.014, P = 0.013, and P = 0.055, respectively). Coinfections were also associated with measures of inflammation (CD4/CD8 ratio: P < 0.001 and sCD163: P < 0.001) and immune activation (CD38 and human leukocyte antigen-DR expression on CD8 T cells: P < 0.001). In addition, coinfection was associated with increased physiologic frailty based on the Veteran Aging Cohort Study 1.0 index assessment (P = 0.001). Conclusions: Further research is warranted to determine the clinical relevance of preclinical deficits in NAD metabolites in skeletal muscle in association with viral coinfection and inflammation, as well as the observed association between viral coinfection and physiologic frailty.

People aging with HIV (PAWH) infection experience greater impairments in physical and cognitive function, in addition to higher rates of peripheral comorbid conditions (e.g., renal failure, diabetes, bone fracture, hypertension, cardiovascular disease, polypharmacy, and multimorbidity). While multifactorial drivers, including HIV infection itself, antiretroviral therapy-related toxicities, disparities in care, and biobehavioral factors, likely contribute, there remains an overarching question as to what are the relevant age-related mechanisms and models that could inform interventions that promote health span and life span in PAWH? This workshop was convened to hear from experts on the biology of aging and HIV researchers studying PAWH to focus on advancing investigations at the interface of HIV and Aging. In this study, we summarize the discussions from the Harvard Center for AIDS Research and Boston Claude D. Pepper cosponsored workshop on HIV and Aging, which took place in October 2018.

Background: Severe energy deficits during military operations, produced by significant increases in exercise and limited dietary intake, result in conditions that degrade lean body mass and lower-body muscle function, which may be mediated by concomitant reductions in circulating testosterone. Methods: We conducted a three-phase, proof-of-concept, single centre, randomised, double-blind, placebo-controlled trial (CinicalTrials.gov, NCT02734238) of non-obese men: 14-d run-in, free-living, eucaloric diet phase; 28-d live-in, 55% exercise- and diet-induced energy deficit phase with (200 mg testosterone enanthate per week, Testosterone, n = 24) or without (Placebo, n = 26) exogenous testosterone; and 14-d recovery, free-living, ad libitum diet phase. Body composition was the primary end point; secondary endpoints included lower-body muscle function and health-related biomarkers. Findings: Following energy deficit, lean body mass increased in Testosterone and remained stable in Placebo, such that lean body mass significantly differed between groups [mean difference between groups (95% CI), 2.5 kg (3.3, 1.6); P

In Greek mythology, Tithonus was granted eternal life but not eternal youth. As time passes he withers, slowly losing his health and all that he knew, lamenting a cruel immortality.(1)

HIV-infected individuals are at an increased risk of osteoporosis despite effective viral suppression. Observations that myostatin null mice have increased bone mass led us to hypothesize that simian immunodeficiency virus (SIV)-associated bone loss may be attenuated by blocking myostatin/TGFβ signaling. In this proof-of-concept study, pair-housed juvenile male rhesus macaques were inoculated with SIVmac239. Four weeks later, animals were treated with vehicle or Fc-conjugated soluble activin receptor IIB (ActR2B·Fc, iv. 10 mg ∗ kg−1 ∗ week−1) – an antagonist of myostatin and related members of TGFβ superfamily. Limb and trunk bone mineral content (BMC) and density (BMD) using dual-energy X-Ray absorptiometry, circulating markers of bone growth and turnover, and serum testosterone levels were measured at baseline and during the 12-week intervention period. The increase in BMC was significantly greater in the ActRIIB.Fc-treated group (+8 g) than in the placebo group (−4 g) (p < 0.05). BMD also increased significantly more in the ActRIIB.Fc-treated macaques (+0.03 g/cm2) than in the placebo-treated animals (+0 g/cm2) (p < 0.005). Serum osteocalcin was about two-fold higher in the ActRIIB.Fc-treated group than in the placebo group (p < 0.05), but serum C-terminal telopeptide and testosterone levels did not differ significantly between groups. The expression levels of TNFalpha (p < 0.05), GADD45 (p

In the era of effective antiretroviral therapy, the number of older people with HIV (PWH) is increasing, and those aging with HIV are experiencing an increasing burden of age-associated comorbidities. Life expectancy among older PWH is approaching that of demographically comparable HIV-uninfected (HIV-) adults. With this changing demographic of PWH come new challenges for researchers and clinicians in how to identify, address, and manage the complex interplay of treated HIV infection and aging-associated factors. In response to these challenges, the annual International Workshop on HIV and Aging was initiated in 2009 as a multidisciplinary platform for scientific discourse on the research and clinical complications arising from the aging population of PWH. The multidisciplinary nature of the workshop has resulted in a wide range of topics addressed over the past 9 years, from basic mechanisms in aging and HIV pathogenesis, to epidemiology of aging within large cohorts, interventions, and implementation of clinical programs. Herein, we summarize the key topics discussed at the 9th Annual International Workshop on HIV and Aging 2018, including "inflammaging," mitochondrial dysfunction, exercise interventions, HIV-associated neurocognitive impairment, metabolic dysfunction, menopause, and polypharmacy. In addition to recent developments in research and clinical care, we discuss open questions and future research directions required to better understand the interaction of HIV and aging.

Sustained periods of severe energy deficit during military operations, produced by significant increases in aerobic-type physical work and limited dietary intake, result in conditions that degrade lean body mass (LBM) and lower-body muscle function, which may be mediated by concomitant reductions in circulating testosterone. Therefore, we studied the effects of restoring testosterone by supplementation (200 mg testosterone enanthate/wk, TEST), compared to placebo (1 mL sesame seed oil/wk, PLA), on body composition and lower-body muscular strength and endurance during 28 d of severe exercise- and diet-induced energy deficit in non-obese, young men. Following energy deficit, concentrations of free testosterone decreased, total testosterone remained unchanged, and sex-hormone binding globulin (SHBG) increased in PLA; whereas, total and free testosterone increased and SHBG was unchanged in TEST, such that, total and free testosterone were greater and SHBG concentrations were lower in TEST than PLA. During energy deficit, TEST attenuated weight loss and increased DXA-derived LBM compared to PLA, but both groups had a similar increase in type I slow twitch myosin heavy chain cross-sectional area (CSA) and decrease in type II fast twitch myosin heavy chain CSA. Lower-body muscle function declines and adverse event rates did not differ by group during energy deficit. Supplemental testosterone may be an effective pharmacological LBM enhancement strategy during short-term periods of exercise- and diet-induced energy deficit in non-obese, young men, but does not appear to mitigate lower-body functional decline. Funding:The research reported in this publication is supported by the Collaborative Research to Optimize Warfighter Nutrition II and III projects and the Joint Program Committee-5, funded by the US Department of Defense. Declaration of Interest: J.C.W., O.T.C., and K.M.G. reported that their institution received funding from the US Department of Defense for work associated with this publication. H.R.L. reported receiving personal fees from Pfizer, Inc., for work outside this publication. All remaining authors declare no competing interests. The opinions or assertions contained herein are the private views of the authors and are not to be construed as official or as reflecting the views of the Army or the Department of Defense. Any citations of commercial organizations and trade names in this report do not constitute an official Department of the Army endorsement of approval of the products or services of these organizations. Ethical Approval: This study was approved by the Pennington Biomedical Research Center (PBRC) Institutional Review Board and the Human Research Protection Office of the US Army Medical Research and Materiel Command.

BACKGROUND People aging with HIV are living with increased risk for functional decline compared with uninfected adults of the same age. Early preclinical changes in biomarkers in middle-aged individuals at risk for mobility and functional decline are needed. OBJECTIVE This pilot study aims to compare measures of free-living activity with lab-based measures. In addition, we aim to examine differences in the activity level and patterns by HIV status. METHODS Forty-six men (23 HIV+, 23 HIV−) currently in the MATCH (Muscle and Aging Treated Chronic HIV) cohort study wore a consumer-grade wristband accelerometer continuously for 3 weeks. We used free-living activity to calculate the gait speed and time spent at different activity intensities. Accelerometer data were compared with lab-based gait speed using the 6-minute walk test (6-MWT). Plasma biomarkers were measured and biobehavioral questionnaires were administered. RESULTS HIV+ men more often lived alone (P=.02), reported more pain (P=.02), and fatigue (P=.048). In addition, HIV+ men had lower blood CD4/CD8 ratios (P CONCLUSIONS Accelerometer-based assessment of gait speed and activity patterns are lower for asymptomatic men living with HIV compared with uninfected controls and may be useful as preclinical digital biomarkers that precede differences captured in lab-based measures.

Background The physiological consequences of severe energy deficit include hypogonadism and the loss of fat-free mass. Prolonged energy deficit also impacts physical performance, mood, attentiveness, and decision-making capabilities. This study will determine whether maintaining a eugonadal state during severe, sustained energy deficit attenuates physiological decrements and maintains mental performance. This study will also assess the effects of normalizing testosterone levels during severe energy deficit and recovery on gut health and appetite regulation. Methods Fifty physically active men will participate in a 3-phase, randomized, placebo-controlled study. After completing a 14-d, energy-adequate, diet acclimation phase (protein: 1.6 g ∙ kg− 1 ∙ d− 1; fat: 30% total energy intake), participants will be randomized to undergo a 28-d, 55% energy deficit phase with (DEF + TEST: 200 mg testosterone enanthate per week) or without (DEF) exogenous testosterone. Diet and physical activity will be rigorously controlled. Recovery from the energy deficit (ad libitum diet, no testosterone) will be assessed until body mass has been recovered within ± 2.5% of initial body mass. Body composition, stable isotope methodologies, proteomics, muscle biopsies, whole-room calorimetry, molecular biology, activity/sleep monitoring, personality and cognitive function assessments, functional MRI, and comprehensive biochemistries will be used to assess physiological and psychological responses to energy restriction and recovery feeding while volunteers are in an expected hypogonadal versus eugonadal state. Discussion The Optimizing Performance for Soldiers (OPS) study aims to determine whether preventing hypogonadism will mitigate declines in physical and mental function that typically occur during prolonged energy deficit, and the efficacy of testosterone replacement on recovery from severe underfeeding. Trial Registration: NCT02734238 .

HIV-infected individuals may be at increased risk of poor physical function. Chronic inflammation has been associated with decreased physical function in the elderly and may also influence physical function in HIV-infected individuals.This cross-sectional study assessed physical function in 65 HIV-infected women aged 40 and older on stable antiretroviral treatment using the Short Physical Performance Battery (SPPB): a standardized test of balance, walking speed, and lower- extremity strength developed for elderly populations. The relationship between low SPPB score, selected demographic and medical characteristics, and high inflammatory biomarker profile was analyzed using Fisher's exact test and Wilcoxon rank sum test.The median age of subjects was 49 years (interquartile range [IQR] 45-55), and the median CD4 T-cell count was 675 cells/mm(3) (IQR 436-828). Thirteen subjects (20%) had a low SPPB score. Subjects with a low SPPB score were more likely to be cigarette smokers (p=0.03), had more medical comorbidities (p=0.01), and had higher levels of interleukin-6 (IL-6) (p0.05). They also tended to be older (median age 55 vs. 48, p=0.06), more likely to have diabetes (p=0.07), and have higher levels of soluble tumor necrosis factor-1 (p=0.09).Twenty percent of women aged 40 and older with well-treated HIV had poor physical-function performance, which was associated with the high burden of comorbidities in this population and with increased IL-6. However, it is unclear from this cross-sectional study whether increased inflammation was related to poor physical function or to other factors, such as age and medical comorbidities.

Human immunodeficiency virus (HIV)-infected individuals are at increased risk of age-associated functional impairment, even with effective antiretroviral therapy (ART). Whether accelerated aging occurs in chronic HIV infection and the biological mechanisms that underlay aging with chronic HIV infection remains unclear. We undertook a prospective observational study of 170 middle-aged, HIV-infected ambulatory men and women with CD4+ T-cell counts of at least 350 per ml and undetectable plasma viremia while on effective antiretroviral therapy, and uninfected control participants. We measured biomarkers for inflammation and immune activation, fatigue, the Veterans Aging Cohort Study (VACS) mortality index, and conducted physical function assessment and accelerometer tracking. A subset of participants also received a skeletal muscle biopsy and computerized tomography scan. Compared to the uninfected, HIV+ participants displayed increased immune activation (P

Slower gait speed is a well-established indicator for increased risk of morbidity and mortality. However, gold standard measurement methods like the six-minute walk test (6MWT), are difficult to use in a clinical setting and may not capture important differences in free-living, volitional activity. We enrolled 46 men (23 HIV+, 23 HIV-) from a prospective observational study (MATCH) of men and women, 50–65 years old. Participants wore an activity tracker (i.e., Nokia Pulse Ox) for three weeks. Tracker data was used to create average gait speed and a measure of percent time at quartiles of maximum observed gait speed. Lab-based, 6MWT gait speed did not differ significantly by HIV status. Free-living, tracker assessed gait speed was significantly slower among HIV+ compared to uninfected participants. HIV+ participants also spent more time at lower activity levels. Free-living gait speed may provide an important digital biomarker of risks not detected by traditional lab-based measures.

Objectives To determine reference values for laboratory tests in individuals aged 85 and older. Design Cross-sectional cohort study. Setting International. Participants Long Life Family Study (LLFS) participants (N~5,000, age: range 25–110, median 67, 45% male). Measurements Serum biomarkers were selected based on association with aging-related diseases and included complete blood count, lipids (triglycerides, high-density lipoprotein cholesterol, low-density lipoprotein cholesterol, total cholesterol), 25-hydroxyvitamin D2 and D3, vitamin D epi-isomer, diabetes mellitus–related biomarkers (adiponectin, insulin, insulin-like growth factor 1, glucose, glycosylated hemoglobin, soluble receptor for advanced glycation endproduct), kidney disease–related biomarkers (albumin, creatinine, cystatin), endocrine biomarkers (dehydroepiandrosterone, sex-hormone binding globulin, testosterone), markers of inflammation (interleukin 6, high-sensitivity C-reactive protein, N-terminal pro b-type natriuretic peptide), ferritin, and transferrin. Results Of 38 measured biomarkers, 34 were significantly correlated with age. Summary statistics were generated for all biomarkers according to sex and 5-year age increments from 50 and up after excluding participants with diseases and treatments that were associated with biomarkers. A biomarker data set was also generated that will be useful for other investigators seeking to compare biomarker levels between studies. Conclusion Levels of several biomarkers change with older age in healthy individuals. The descriptive statistics identified herein will be useful in future studies and, if replicated in additional studies, might also become useful in clinical practice. The availability of the reference data set will facilitate appropriate calibration of biomarkers measured in different laboratories.

The review articles in this issue provide an improved appreciation for microRNA (miRNA) as an essential feature of lineage commitment and regulatory guidance during tissue development that, when absent or hampered, often lead to disease states. In the coming years, there is much to be learned about adaptive (and maladaptive) states by examining how the expression of miRNAs is influenced by the genetic architecture of miR genes, clusters, and mirtrons, as well as miRNA polymorphism and polymorphism in their mRNA targets. We are also introduced to several modes of miRNA regulation (negative feedback, positive feedback, and cross regulatory) that monitor, modulate, or resolve signaling pathways in a variety of biologic processes that include sepsis response, fibrosis, acute exercise, and steroid biology. Perhaps the homeostasis or micromanagement of these miRNA regulatory systems, when perturbed, arrive at new stable networked interactions that have an undesired effect of promoting or antagonizing disease severity and cancer progression. Clearly, a better understanding of these miRNA regulatory networks, as well as improved therapeutic tools for guiding miRNA expression and their targets toward desired outcomes, will be the subject of many advances in miRNA biology over the coming years.

Efficient muscle regeneration requires the clearance of dead and dying tissue via phagocytosis before remodeling. We have previously shown that mice lacking stem cell antigen-1 (Sca-1) display a defect in skeletal muscle regeneration characterized by increased fibrosis and decreased turnover of the extracellular matrix. In the present study we demonstrate that Sca-1−/− mice have a defect in their capacity to recruit soluble IgM, and subsequently C3 complement, to damaged muscle. We hypothesize that this defect in recruitment delays or decreases phagocytosis by macrophages, contributing to the previously observed fibrotic phenotype of these mice. As the primary source of soluble IgM is peritoneal B-1a cells, which are a subset of self-renewing B cells, we analyzed this cell population and observed a significant reduction in B-1a cells in Sca-1−/− animals. Interestingly, these mice are protected from ischemia-reperfusion injury, an acute inflammatory reaction also mediated by IgM and C3 complement that has been linked to a deficit in B-1a cells in previous studies. Collectively, these data reveal a novel role for Sca-1 in innate immunity during muscle regeneration and indicate that further elucidation of immuno-myogenic processes will help to better understand and promote muscle regeneration.

Sca-1 (stem cell antigen-1) is a member of the Ly-6 family of proteins and regulates cell proliferation, differentiation, and self-renewal in multiple tissues. In skeletal muscle, Sca-1 inhibits both proliferation and differentiation of myogenic cells. Sca-1 expression is dynamically regulated during muscle regeneration, and mice lacking Sca-1 display increased fibrosis following muscle injury. Here, we show that Sca-1 expression is negatively regulated by TGF-β1 and that this inhibition is dependent on Smad3. We demonstrate that levels of TGF-β1 in skeletal muscle rapidly increase on injury and that the majority of this TGFβ1 is produced by infiltrating macrophages. Sca-1 is expressed in multiple cell types, and we demonstrate that TGF-β1 represses Sca-1 expression in T cells and other immune cell populations derived from the spleen, indicating that regulation by TGF-β1 is a general feature of Sca-1 expression in multiple cell types. Elucidation of the mechanisms by which Sca-1 expression is regulated may aid in the understanding of muscle homeostasis, potentially identifying novel therapeutic targets for muscle diseases.—Long, K., Montano, M., Pavlath, G. K. Sca-1 is negatively regulated by TGF-β1 in myogenic cells.

Muscle atrophy remains a significant concern in multiple inflammatory conditions, including injury, sepsis, cachexia, and HIV‐associated wasting. Herein, we show that inflammatory stressors, including TNF‐α, IFN‐γ, or lipopolysaccharide, potently induced the novel expression of the RNA editor ADAR1, an observation not previously described in muscle cells. We also observed that cytokine stimulation suppressed muscle‐associated microRNAs, an observation also not previously demonstrated. To map potential effects of ADAR1 induction in the muscle program, we conducted knockdown and overexpression studies in the mouse C2C12 muscle precursor cell (MPC) line and in primary human MPCs. We show that knockdown of stress‐induced ADAR1 increased inflammation‐mediated declines in the muscle differentiation markers Myogenin and myosin heavy chain, and knockdown reduced levels of active phosphorylated Akt (phospho‐Akt), but had no effect on microRNA transcript levels, suggesting a role for ADAR1 in buffering inflammatory stress effects on myogenic transcription and protein synthesis pathways. In addition, overexpression of recombinant ADAR1 suppressed active phosphorylated double‐stranded RNA (dsRNA)‐dependent protein kinase (phospho‐PKR), consistent with a role for ADAR1 in limiting inflammation‐driven catabolic atrophy pathways. Collectively, these data identify a novel regulatory role for ADAR1 activation under inflammatory stress to both promote muscle protein synthesis pathways and limit atrophy pathways. Clin Trans Sci 2010; Volume 3: 73–80

BACKGROUND: Infants of human immunodeficiency virus (HIV)-infected women have high mortality, but the immunologic integrity and protection afforded by the breast milk of HIV-infected women is unknown. METHODS: We determined morbidity and mortality by 24 months among breast-fed infants of 588 HIV-infected and 137 HIV-uninfected women followed-up in a clinical trial in Botswana. A matched case-control study compared clinical, behavioral, and breast milk immunologic parameters among 120 HIV-infected women by infant outcome. Breast milk factors were also compared between HIV-infected and HIV-uninfected women. RESULTS: Twenty-four-month mortality was 29.5% among HIV-infected infants, 6.7% among HIV-exposed uninfected infants, and 1.6% among HIV-unexposed infants. No differences were detected in breast milk immunologic profiles of HIV-infected women whose infants were either ill or well. Discontinuation of breast-feeding was the strongest predictor of illness (P

Testosterone treatment induces erythrocytosis that could potentially affect blood viscosity and cardiovascular risk. We thus investigated the effects of testosterone administration on blood viscosity and erythrocyte deformability using mouse models. Blood viscosity, erythrocyte deformability, and hematocrits were measured in normal male and female mice, as well as in females and castrated males after short-term (2 wk) and long-term (5–7 mo) testosterone intervention (50 mg/kg, weekly). Castrated males for long-term intervention were studied in parallel with the normal males to assess the effect of long-term testosterone deprivation. An additional short-term intervention study was conducted in females with a lower testosterone dose (5 mg/kg). Our results indicate no rheological difference among normal males, females, and castrated males at steady-state. Short-term high-dose testosterone increased hematocrit and whole-blood viscosity in both females and castrated males. This effect diminished after long-term treatment, in association with increased erythrocyte deformability in the testosterone-treated mice, suggesting the presence of adaptive mechanism. Considering that cardiovascular events in human trials are seen early after intervention, rheological changes as potential mediator of vascular events warrant further investigation.

Neisseria gonorrhoeae is an obligate human pathogen that represents a significant health concern, particularly in the developing world. Although generally associated with an acute inflammatory infection of urogenital epithelia cells, infections have been noted in multiple tissues and many infected individuals can become asymptomatic carriers. Few studies of immune response to N. gonorrhoeae infection in peripheral blood have evaluated the production of T helper cytokines (TH1/TH2) induced early after infection. We developed a quantitative realtime PCR assay based on the gonococcal rmpIII gene to monitor dose-response effects of infection on cytokine release from peripheral blood mononuclear cells (PBMCs). We observed upregulation of CD69 transcription and surface CD25 expression on lymphocytes, consistent with early T-cell activation. We observed dosage-dependent transcription of the chemotactic factor IL-8 and previously unreported activation of the chemoattractant MCP-2. Multiplex analysis of broad cytokine protein production revealed a differential increase in the TH1 and TH2 associated cytokines: IL-2, IL-4, IL-8, IL-10, IL-12, IFN-gamma, TNF-alpha and MCP-1. Markov models of protein accumulation implicated a cross-regulated response to infection, notably for IL-8, IL-10 and IL-12. Taken together, the cytokine profile we observed early in response to whole gonococcal bacteria was broader than has been previously described and may have relevance for the contribution of antagonistic signaling events early in infection and in understanding peripheral immune mechanisms engaged to control infection.

Perinatal transmission of human immunodeficiency virus (HIV)-1 represents a major problem in many regions of the world, especially Southern Africa. With the exception of viral and proviral load, the role for maternal cofactors in perinatal transmission outcome is largely unknown. In this study, an assessment was made of peripheral blood mononuclear cells (PBMC) gene-expression profiles to better understand transcriptional changes associated with HIV-1 infection and perinatal transmission among young adult mothers with infants in Botswana. Peripheral blood mononuclear cells specimens were used from 25 HIV+ drug naive and 20 HIV− healthy mothers, similar in age and location, collected in 1999–2000 and 2003, and processed with the exact same methods, as previously described. Expression profiling of 22 277 microarray gene probes implicated a broad initiation of innate response gene-sets, including toll-like receptor, interferon-stimulated and antiviral RNA response pathways in association with maternal HIV-1 infection. Maternal transmission status was further associated with host genes that influence RNA processing and splicing patterns. In addition to real-time polymerase chain reaction validation of specific genes, enriched category validation of PBMC profiles was conducted using two independent data sets for either HIV-1 infection or an unrelated RNA virus, severe acute respiratory virus infection. HIV-1 pathogen-specific host profiles should prove a useful tool in infection and transmission intervention efforts worldwide. Supplementary information The online version of this article (doi:10.1038/sj.gene.6364297) contains supplementary material, which is available to authorized users.

The association between sexual activity and human herpes virus-8 (HHV-8) infection has been established, but the mode of acquisition is still unclear. Blood samples from 238 individuals from Northern Cameroon were tested to evaluate the incidence of herpes simplex virus-2 (HSV-2), human immunodeficiency virus (HIV), Treponema pallidum, and HHV-8 infections and to identify their possible association. The presence of HSV-2 antibodies was associated significantly with gender, age, and HIV, HHV-8 antilatent, and T. pallidum antibodies, but not with HHV-8 antilytic antibodies. In a multivariate model older age, female gender, seropositivity for HIV, for HHV-8 latent antigens and for T. pallidum were associated independently with seropositivity for HSV-2. HSV-2-seropositive individuals had significantly higher titers of antibodies to both lytic (P = 0.019) and latent (P = 0.021) HHV-8 antigens. These results suggest that HSV-2 infection can contribute to sexual transmission of HHV-8 infection. J. Med. Virol. 74:467–472, 2004. © 2004 Wiley-Liss, Inc.

The major group of human immunodeficiency viruses (HIV-1) that comprise the current global pandemic have diversified during their worldwide spread and may be divided into at least 10 distinct subtypes or clades, A through J. Subtype B predominates in North America and Europe, subtype E predominates in Southeast Asia, and subtype C predominates in sub-Saharan Africa. Functional distinctions in long terminal repeat (LTR) architecture among HIV subtypes have been identified, thus raising the possibility that regulatory divergence among the subtypes of HIV-1 has occurred. In addition to the transcriptional specificity of the HIV-1 LTR, productive HIV-1 replication is also dependent upon the viral Tat protein. Therefore, we sought to investigate whether interactions between host signaling pathways and the NF-kappaB regions of different HIV-1 subtypes, together with subtype-specific interactions between Tat, TAR, and cellular proteins, modulate the efficiency of HIV-1 clade-specific gene transcription. We demonstrate that the NF-kappaB sites of subtypes B and E both bind NF-kappaB-related complexes. However, the duplicated kappaB sites of the C subtype do not compete for NF-kappaB binding. Also, clade E Tat protein possesses the highest transactivation capacity, regardless of the LTR context. Furthermore, preliminary evidence suggests that the acetylation of subtype-specific Tat proteins may correlate with their transactivation efficiency.

In this chapter, we conclude with a discussion of personalized medicine, namely, the process and opportunity of matching individuals with an undesirable condition to treatments tailored to that individual, or tailored to a subgroup of individuals with a similar condition (this form of personalized medicine is known as ‘stratified’ medicine). We also discuss personalized medicine from the context of evidence-based model building of disease and the use of population-based data on variation in disease presentation and progression.

In this chapter we discuss translational models for studying infectious diseases, with a focus on HIV. We introduce acute infection and chronic infection, discuss how infections influence immune response, and discuss cells and target tissues of infection. We discuss aspects of innate immune response, such as cytokine production and TLR signaling. Adaptive immune response with production of antigen-specific effectors, including neutralizing antibody response and cytolytic T cell response (e.g. cytotoxic T lymphocyte (CTL)), is discussed. Host conditions arising from infection are discussed, including accelerated aging phenotypes, microbiome alterations and co-infection. Model systems used to study HIV, including cell lines and animal models, are described, along with their limitations. Recent efforts on eradication of the hidden reservoir of latent virus are discussed.

In this chapter we begin a discussion on the regulatory processes that need to be considered when embarking on a translational research initiative. These include the bioethics of the research, as well as the IRB considerations for research on human subjects and the animal welfare requirements for their use in translational research. Historic examples of bioethical compromise are discussed, such as Tuskegee, as well as measures designed to protect human subjects in research, such as the Belmont report. Discussion centers on the role of respect, beneficence and justice in considering translational research protocols. Institutional committees’ guidance in the use of animals for research studies is discussed. Existing challenges regarding privacy of health-related information are discussed, such as electronic health records and Big Data.

Translational biology in medicine is a scientific process of bridge building between observations in the basic biological sciences and their application in the medical sciences. This chapter introduces the concept of translational medicine and emphasizes a role for model biological systems used in translational medicine to explore molecular processes that underlie human health and disease. This book describes model systems and their application to specific areas of biomedical research. There are two themes that recur throughout the book: one theme is concerned with an emerging research trend of describing individuals and their conditions within a continuum of population phenotypic, genotypic and environmental diversity, and the other theme highlights the value added to research in the biomedical sciences using a multidisciplinary approach cutting across several disciplines to describe disease conditions and their health trajectories. The concept of personalized medicine is introduced as a diagnostic and therapeutic strategy that considers patient variability in disease presentation and severity. The role of evidence-based biomedicine, in contrast to ideal notions of disease and healthy states, as a tool to better describe human health and disease is introduced. A brief overview of chapter topics is outlined.

We have discussed model systems and analytical tools available to the translational researcher, including various cellular and organismal models ( Chapters 1– 2), as well as methods for monitoring outcomes in research using biomarkers, gene expression and genome association studies ( Chapters 3– 4). In this chapter, we provide examples of recent translational research occurring in the aging and longevity field. The examples chosen are intended to illustrate the breadth of ongoing research in aging biology. We also discuss efforts to understand what biological mechanisms contribute to the aging process, as well as what biomedical challenges posed by aging can potentially be influenced by translational research-driven intervention to optimize lifespan and healthspan.

The use of experimental model systems to study complex biomedical conditions is an essential feature of translational biology in medicine. In this chapter, we begin with a discussion of some of the basic features of model systems, their assumptions, strengths and limitations, as well as the role of accuracy and precision in characterizing models and forecasting outcomes. We then introduce various model systems including cell lines and primary cells, and animal models including nematodes, mice and non-human primates. We discuss the application of these experimental model systems to the analysis of cellular senescence and cell growth, infection and immune response, and drug discovery. We discuss animal and cellular models in biomedical research and how they have been used to test hypotheses about fundamental questions in modern biomedicine, such as molecular and physiologic processes in aging, mechanisms engaged in response to tissue injury and regeneration, and the pathobiology of infectious disease.

Biomarkers (i.e. biological markers) can be measured in blood or tissues, and are used to monitor biological outcomes. We discuss how biomarkers may (or may not) be specific to the disease, but can nevertheless be useful as a biomedical surveillance tool. We present a standard procedure for engaging in biomarker discovery, evaluation in human subject studies and clinical relevance, as well as limitations and challenges. We discuss biomarker measurements, including discrimination, positive predictive value and negative predictive value. We discuss receiver operating characteristic (ROC) analysis. We provide an example of the use of Bayesian approaches in biomarker analysis that highlights the use of prior conditions. We illustrate several examples of biomarkers for aging, cellular senescence, inflammation and obesity. We discuss use of microRNAs and the microbiome in biomarker analysis, and the use of biomarkers in monitoring athletes and their use of anabolic agents.

In this chapter, we discuss translational approaches to skeletal muscle injury, repair and regeneration. We introduce muscle stem cells, known as satellite cells, and discuss the muscle stem cell niche. We discuss muscle differentiation, myogenesis and how this process is affected in aging. We briefly describe various muscle regulatory pathways that influence muscle growth, including the androgen pathway and testosterone, the IGF pathway, amino acid pathways, Wnt and calcium signaling, and follistatin. We also discuss negative muscle regulators and atrophy-promoting pathways including myostatin, transforming growth factor (TGF) signaling, inflammation and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-kB) signaling. We discuss muscle loss phenotypes such as cachexia and age-associated decline in mass and function, that is, sarcopenia. We discuss approaches to improve muscle mass and function, such as exercise, SARMs and anabolic supplementation.

We address the problem of comparing interindividual genomic sequence diversity between two populations. Although the methods are general, for concreteness we focus on comparing two human immunodeficiency virus (HIV) infected populations. From a viral isolate(s) taken from each individual in a sample of persons from each population, suppose one or multiple measurements are made on the genetic sequence of a coding region of HIV. Given a definition of genetic distance between sequences, the goal is to test if the distribution of interindividual distances differs between populations. If distances between all pairs of sequences within each group are used, then data-dependencies arising from the use of multiple sequences from individuals invalidates the use of a standard two-sample test such as the t-test. Where this problem has been recognized, a typical solution has been to apply a standard test to a reduced dataset comprised of one sequence or a consensus sequence from each patient. Disadvantages of this procedure are that the conclusion of the test depends on the choice of utilized sequences, often an arbitrary decision, and exclusion of replicate sequences from the analysis may needlessly sacrifice statistical power. We present a new test free of these drawbacks, which is based on a statistic that linearly combines all possible standard test statistics calculated from independent sequence subsamples. We describe statistical power advantages of the test and illustrate its use by application to nucleotide sequence distances measured from HIV-1 infected populations in southern Africa (GenBank accession numbers AF110959--AF110981) and North America/Europe. The test makes minimal assumptions, is maximally efficient and objective, and is broadly applicable.

Zinc finger-containing GLI proteins are involved in the development of Caenorhabditis elegans, Xenopus, Drosophila , zebrafish, mice, and humans. In this study, we show that an isoform of human GLI-2 strongly synergizes with the Tat transactivating proteins of human immunodeficiency virus types 1 and 2 (HIV-1 and -2) and markedly stimulates viral replication. GLI-2 also synergizes with the previously described Tat cofactor cyclin T1 to stimulate Tat function. Surprisingly, GLI-2/Tat synergy is not dependent on either a typical GLI DNA binding site or an intact Tat activation response element but does require an intact TATA box. Thus, GLI-2/Tat synergy results from a mechanism of action which is novel both for a GLI protein and for a Tat cofactor. These findings link the GLI family of transcriptional and developmental regulatory proteins to Tat function and HIV replication.

The human immunodeficiency virus type 1 (HIV-1) epidemic within southern Africa is predominantly associated with the HIV-1C subtype. Functional analysis of the enhancer region within the long terminal repeat (LTR) indicates that HIV-1C isolates have >/=3 NF-kappaB binding sites, unlike other subtypes, which have only 1 or 2 sites. A correlation was shown between NF-kappaB enhancer configuration and responsiveness to the proinflammatory cytokine tumor necrosis factor (TNF)-alpha within the context of naturally occurring subtype LTRs, subtype-specific NF-kappaB enhancer regions cloned upstream of an isogenic HXB2 core promoter or a heterologous SV40 minimal promoter, and full-genome subtype clones. In all cases, TNF-alpha activation was correlated with the subtype configuration of the NF-kappaB enhancer. Whether the naturally occurring gain-of-function in the NF-kappaB enhancer of HIV-1C observed in this study can provide a selective advantage for the virus in vivo remains to be determined and warrants further study.

At least 10 different genetic human immunodeficiency virus type 1 (HIV-1) subtypes (A-J) are responsible for the AIDS pandemic. Much of the understanding of HIV-1 disease progression derives from studies in the developed world where HIV infection is almost exclusively subtype B. This has led many to question whether the properties and consequences of HIV-1 infection can be generalized across subtypes that afflict the majority of infected persons in the developing world. From 1985 to 1997, a prospective study of registered female sex workers in Senegal tracked the introduction and spread of HIV-1 subtypes A, C, D, and G. In clinical follow-up, the AIDS-free survival curves differed by HIV-1 subtype. Women infected with a non-A subtype were 8 times more likely to develop AIDS than were those infected with subtype A (hazard ratio=8.23; P=. 009), the predominant subtype in the study. These data suggest that HIV-1 subtypes may differ in rates of progression to AIDS.