Acid Suspends the Circadian Clock in Hypoxia through Inhibition of mTOR.

Recent reports indicate that hypoxia influences the circadian clock through the transcriptional activities of hypoxia-inducible factors (HIFs) at clock genes. Unexpectedly, we uncover a profound disruption of the circadian clock and diurnal transcriptome when hypoxic cells are permitted to acidify to recapitulate the tumor microenvironment. Buffering against acidification or inhibiting lactic acid production fully rescues circadian oscillation. Acidification of several human and murine cell lines, as well as primary murine T cells, suppresses mechanistic target of rapamycin complex 1 (mTORC1) signaling, a key regulator of translation in response to metabolic status. We find that acid drives peripheral redistribution of normally perinuclear lysosomes away from perinuclear RHEB, thereby inhibiting the activity of lysosome-bound mTOR. Restoring mTORC1 signaling and the translation it governs rescues clock oscillation. Our findings thus reveal a model in which acid produced during the cellular metabolic response to hypoxia suppresses the circadian clock through diminished translation of clock constituents.

The Impact of Childhood Adversity on Life Course Alcohol Use Patterns and Health Status Among People Living with HIV.

Adverse childhood experiences (ACEs) and financial hardship are associated with increased likelihood of heavier alcohol use and health challenges in adulthood among persons living with HIV (PWH). We examined whether retrospectively captured lifetime drinking trajectories are a pathway through which childhood hardships affect current health in a sample of 365 adult PWH. Childhood economic hardship and ACEs were used as main predictors. Measures of alcohol use included age at first drink and lifetime drinking trajectories. Health indicators included health-related quality of life, frailty, number of comorbidities, and symptoms of anxiety, depression, and post-traumatic stress disorder (PTSD). Structural equation modeling (SEM) was applied to estimate both direct and indirect pathways between childhood hardship and physical and mental health. Participants were mostly male; Black (84%); and averaged 48 years of age. SEM results supported both direct and indirect pathways between childhood experiences and adult health. ACEs were connected to physical health directly and mental health both directly and indirectly through age at first drink and drinking heaviness during ages 10-20. Childhood economic hardship related to mental health indirectly through higher drinking levels during ages 10-20. Childhood adverse experiences, economic hardship, and early drinking patterns appear to accumulate, resulting in later life physical and mental health concerns for PWH. Findings support taking a life course approach to health. This includes considering individual trauma histories in HIV care engagement and taking preventative approaches which support the economic and social well-being of vulnerable children to improve health in subsequent decades.

Vulnerability to helpless behavior is regulated by the circadian clock component CRYPTOCHROME in the mouse nucleus accumbens.

The nucleus accumbens (NAc), a central component of the midbrain dopamine reward circuit, exhibits disturbed circadian rhythms in the postmortem brains of depressed patients. We hypothesized that normal mood regulation requires proper circadian timing in the NAc, and that mood disorders are associated with dysfunctions of the NAc cellular circadian clock. In mice exhibiting stress-induced depression-like behavior (helplessness), we found altered circadian clock function and high nighttime expression of the core circadian clock component CRYPTOCHROME (CRY) in the NAc. In the NAc of helpless mice, we found that higher expression of CRY is associated with decreased activation of dopamine 1 receptor-expressing medium spiny neurons (D1R-MSNs). Furthermore, D1R-MSN-specific CRY-knockdown in the NAc reduced susceptibility to stress-induced helplessness and increased NAc neuronal activation at night. Finally, we show that CRY inhibits D1R-induced G protein activation, likely by interacting with the Gs protein. Altered circadian rhythms and CRY expression were also observed in human fibroblasts from major depressive disorder patients. Our data reveal a causal role for CRY in regulating the midbrain dopamine reward system, and provide a mechanistic link between the NAc circadian clock and vulnerability to depression.

Circadian rhythms in bipolar disorder patient-derived neurons predict lithium response: preliminary studies.

Bipolar disorder (BD) is a neuropsychiatric illness defined by recurrent episodes of mania/hypomania, depression and circadian rhythm abnormalities. Lithium is an effective drug for BD, but 30-40% of patients fail to respond adequately to treatment. Previous work has demonstrated that lithium affects the expression of "clock genes" and that lithium responders (Li-R) can be distinguished from non-responders (Li-NR) by differences in circadian rhythms. However, circadian rhythms have not been evaluated in BD patient neurons from Li-R and Li-NR. We used induced pluripotent stem cells (iPSCs) to culture neuronal precursor cells (NPC) and glutamatergic neurons from BD patients characterized for lithium responsiveness and matched controls. We identified strong circadian rhythms in Per2-luc expression in NPCs and neurons from controls and Li-R, but NPC rhythms in Li-R had a shorter circadian period. Li-NR rhythms were low amplitude and profoundly weakened. In NPCs and neurons, expression of PER2 was higher in both BD groups compared to controls. In neurons, PER2 protein levels were higher in BD than controls, especially in Li-NR samples. In single cells, NPC and neuron rhythms in both BD groups were desynchronized compared to controls. Lithium lengthened period in Li-R and control neurons but failed to alter rhythms in Li-NR. In contrast, temperature entrainment increased amplitude across all groups, and partly restored rhythms in Li-NR neurons. We conclude that neuronal circadian rhythm abnormalities are present in BD and most pronounced in Li-NR. Rhythm deficits in BD may be partly reversible through stimulation of entrainment pathways.

Alcohol use, physical activity, and muscle strength moderate the relationship between body composition and frailty risk among people living with HIV.

BACKGROUND: Antiretroviral therapy has improved life expectancy among people living with HIV (PLWH). Despite increased longevity, PLWH are at increased risk of age-related comorbidities, including frailty. We examined the relationship between body composition and frailty among PLWH, and moderation of this relationship by substance use, physical activity (PA), and physical function. METHODS: Participants (n = 341; 71% male, 48 ± 10 years, body mass index (BMI) = 27.3 ± 7.0 kg/m2 ) enrolled in the New Orleans Alcohol Use in HIV (NOAH) study underwent measures of body composition, muscle strength, and gait speed. Whole blood phosphatidylethanol (PEth) was measured, and substance use and PA were self-reported. Frailty risk measures included the 58-Item Deficit Index (DI58) and the Veterans Aging Cohort Study (VACS) Index 1.0, where higher scores indicate greater frailty risk. RESULTS: Multivariable linear regression adjusted for age, sex, and race showed that higher fat-free mass index (FFMI), body fat (%), waist-to-hip ratio, and body mass index (BMI) ≥ 25.0 kg/m2 vs. < 25.0 kg/m2 were significantly (p < 0.05) associated with decreased frailty risk measured by the VACS Index, whereas adjusted analyses showed no association between body composition variables and the DI58 score. Recent alcohol use, muscle strength, and PA, but not lifetime alcohol use or gait speed, significantly moderated associations between body composition variables and frailty risk with medium-to-large effect sizes. Subgroup analyses revealed a negative relationship between DI58 and FFMI among people with PEth > 8 ng/ml and negative relationships of VACS Index with FFMI and WHR in people with lower muscle strength. Overweight or obese BMI categories were positively associated with DI58 in people with lower muscle strength or higher PA level but negatively associated in those with higher muscle strength. CONCLUSIONS: Our findings indicate that body composition has significant modulatory effects on frailty risk in PLWH, where obesity increases the risk of frailty and greater muscle mass may be protective, even in individuals who use alcohol. These results highlight the importance of considering body composition, physical activity, and physical function in assessing frailty risk in PLWH, particularly among individuals who use alcohol. Moreover, they support the implementation of physical activity interventions to ameliorate the risk of frailty in aging PLWH.

Host innate and adaptive immunity shapes the gut microbiota biogeography.

The gut microbiota has a fundamental role in the development and the maturation of the host immune system. Both innate and adaptive immune cells have critical functions in microbial pathogen containment and clearance, but the regulation of the commensal microbiome ecosystem in the gastrointestinal tract by these major immune cell populations is incompletely defined. The role of specific innate and adaptive immune cell in the regulation of the microbiota in the intestinal tract biogeographically was investigated. Dendritic cells, macrophages, CD4+ T-cells, CD8+ T-cells, and B-cells were depleted using monoclonal antibodies and clodronate liposomes, and the microbial communities were determined by 16S rRNA gene sequencing. With specific immune cell depletion, distinct microbiota changes were observed. In general, immune cell depleted mice had higher microbiota richness and evenness at all gut anatomical sites. At each gut segment, samples from immune cell-depleted animals clustered away from the isotype/liposome control mice. This was especially dramatic for the small intestinal microbiota. Specifically, Enterobacteriaceae, Bacteroides acidifaciens, and Mucispirillum schaedleri were highly enriched in the mucosa and lumen of the small intestine in immune cell-deficient animals. Further, the mucosal microbiota had higher microbiota evenness compared with luminal microbiota at all gut segments, and the UniFrac distance between B cell depleted and isotype control mice was the largest in the duodenum followed by the ileum and colon. Taken together, the data suggest that innate and adaptive immune cells specifically contribute to the regulation of the gut microbiota's biogeographical distribution along the gastrointestinal tract, and microbiota in the duodenum mucosa are more responsive to host immune changes compared with other anatomical sites.

Associations of Binge Drinking and Heavy Alcohol Use on Sugar and Fat Intake in a Cohort of Southern People Living with HIV.

AIMS: To assess whether binge drinking and heavy alcohol use are associated with increased sugar and fat consumption among a Southern cohort of people living with HIV (PWH). METHODS: This was a cross-sectional analysis of PWH enrolled in the New Orleans Alcohol use in HIV (NOAH) Study (n = 215). Binge and heavy drinking were identified through a 30-day Alcohol Timeline-Followback and dietary intake was assessed through a 24-hour dietary recall. RESULTS: Participants were 65.4% male, 83.3% Black, with a mean age of 49.2 ± 9.9. Heavy drinkers consumed more total calories than abstainers (P = 0.035) and low-to-moderate drinkers (P = 0.024), and binge drinkers consumed more calories than non-binge drinkers (P = 0.025). Binge and heavy drinkers had significantly higher intake of total and saturated fat in grams. However, substantially increased caloric intake among these participants led to non-significant associations for alcohol use with high total and saturated fat intake as a percent of total energy intake (%TEI). Binge drinkers had lower odds of consuming high sugar as a %TEI (odds ratio: 0.31 [0.14, 0.68]). Additionally, sugar intake predicted total and saturated fat intake, and this association was slightly higher among binge drinkers (total fat P-value: 0.12). CONCLUSIONS: In this population of PWH, while binge and heavy drinking predicted higher caloric and fat intake in grams, binge drinkers were less likely to consume a high-sugar diet. This analysis suggests that interventions focused on reduced alcohol use may be especially beneficial in reducing metabolic disease burden in PWH if supplemented with information on incorporating lower energy-dense foods with reduced fat.

Alcohol Use Is Associated With Intestinal Dysbiosis and Dysfunctional CD8+ T-Cell Phenotypes in Persons With Human Immunodeficiency Virus.

BACKGROUND: Inflammation persists among persons with human immunodeficiency virus (PWH) despite effective antiretroviral therapy and may contribute to T-cell dysfunction. Alcohol use is prevalent among PWH and promotes intestinal leak, dysbiosis, and a proinflammatory milieu. Whether alcohol use is associated with T-cell late differentiation remains to be investigated. METHODS: Data and samples from PWH (N = 359 of 365) enrolled in the New Orleans Alcohol Use in HIV Study were used. Alcohol use was assessed by self-report (Alcohol Use Disorders Identification Test; lifetime alcohol exposure; 30-day Alcohol Timeline Followback) and phosphatidylethanol (PEth) quantitation. In a subset of participants, fecal bacterial content was assessed by ribosomal 16S marker gene deep sequencing and quantitative polymerase chain reaction. Intestinal leak was assessed by fecal-to-plasma α-1-antitrypsin (A1AT) enzyme-linked immunosorbent assay ratio. Peripheral T-cell populations were quantified by flow cytometry. RESULTS: Alcohol Use Disorder Identification Test scores were positively associated with activated-senescent, exhausted, and terminal effector memory CD45RA+CD8+ but not CD4+ T cells (cells/µL) after confounder adjustment (P < .050). Phosphatidylethanol was positively associated with A1AT (P < .050). The PEth and activated-senescent CD8+ were associated with bacterial ß-diversity (P < .050) and positively associated with the relative abundance of coabundant Prevotellaceae members (q < .100). CONCLUSIONS: Alcohol use among PWH is associated with CD8+ T-cell late differentiation, intestinal leak, and dysbiosis. Alcohol-associated dysbiosis is implicated in CD8+ T-cell senescence.

The transcription factors SIX3 and VAX1 are required for suprachiasmatic nucleus circadian output and fertility in female mice.

The homeodomain transcription factors sine oculis homeobox 3 (Six3) and ventral anterior homeobox 1 (Vax1) are required for brain development. Their expression in specific brain areas is maintained in adulthood, where their functions are poorly understood. To identify the roles of Six3 and Vax1 in neurons, we conditionally deleted each gene using Synapsincre , a promoter targeting maturing neurons, and generated Six3syn and Vax1syn mice. Six3syn and Vax1syn females, but not males, had reduced fertility, due to impairment of the luteinizing hormone (LH) surge driving ovulation. In nocturnal rodents, the LH surge requires a precise timing signal from the brain's circadian pacemaker, the suprachiasmatic nucleus (SCN), near the time of activity onset. Indeed, both Six3syn and Vax1syn females had impaired rhythmic SCN output, which was associated with weakened Period 2 molecular clock function in both Six3syn and Vax1syn mice. These impairments were associated with a reduction of the SCN neuropeptide vasoactive intestinal peptide in Vax1syn mice and a modest weakening of SCN timekeeping function in both Six3syn and Vax1syn mice. Changes in SCN function were associated with mistimed peak PER2::LUC expression in the SCN and pituitary in both Six3syn and Vax1syn females. Interestingly, Six3syn ovaries presented reduced sensitivity to LH, causing reduced ovulation during superovulation. In conclusion, we have identified novel roles of the homeodomain transcription factors SIX3 and VAX1 in neurons, where they are required for proper molecular circadian clock function, SCN rhythmic output, and female fertility.

Alcohol-associated intestinal dysbiosis alters mucosal-associated invariant T-cell phenotype and function.

BACKGROUND: Chronic alcohol consumption is associated with a compromised innate and adaptive immune responses to infectious disease. Mucosa-associated invariant T (MAIT) cells play a critical role in antibacterial host defense. However, whether alcohol-associated deficits in innate and adaptive immune responses are mediated by alterations in MAIT cells remains unclear. METHODS: To investigate the impact of alcohol on MAIT cells, mice were treated with binge-on-chronic alcohol for 10 days and sacrificed at day 11. MAIT cells in the barrier organs (lung, liver, and intestine) were characterized by flow cytometry. Two additional sets of animals were used to examine the involvement of gut microbiota on alcohol-induced MAIT cell changes: (1) Cecal microbiota from alcohol-fed (AF) mice were adoptive transferred into antibiotic-pretreated mice and (2) AF mice were treated with antibiotics during the experiment. MAIT cells in the barrier organs were measured via flow cytometry. RESULTS: Binge-on-chronic alcohol feeding led to a significant reduction in the abundance of MAIT cells in the barrier tissues. However, CD69 expression on tissue-associated MAIT cells was increased in AF mice compared with pair-fed (PF) mice. The expression of Th1 cytokines and the corresponding transcriptional factor was tissue specific, showing downregulation in the intestine and increases in the lung and liver in AF animals. Transplantation of fecal microbiota from AF mice resulted in a MAIT cell profile aligned to that of AF mouse donor. Antibiotic treatment abolished the MAIT cell differences between AF and PF animals. CONCLUSION: MAIT cells in the intestine, liver, and lung are perturbed by alcohol use and these changes are partially attributable to alcohol-associated dysbiosis. MAIT cell dysfunction may contribute to alcohol-induced innate and adaptive immunity and consequently end-organ pathophysiology.

Factors associated with phosphatidylethanol (PEth) sensitivity for detecting unhealthy alcohol use: An individual patient data meta-analysis.

BACKGROUND: Objective measurement of alcohol consumption is important for clinical care and research. Adjusting for self-reported alcohol use, we conducted an individual participant data (IPD) meta-analysis to examine factors associated with the sensitivity of phosphatidylethanol (PEth), an alcohol metabolite, among persons self-reporting unhealthy alcohol consumption. METHODS: We identified 21 eligible studies and obtained 4073 observations from 3085 participants with Alcohol Use Disorders Identification Test-Consumption (AUDIT-C) positive scores (≥3 for women and ≥4 for men) and PEth measurements. We conducted 1-step IPD meta-analysis using mixed effects models with random intercepts for study site. We examined the associations between demographic (sex, race/ethnicity, and age) and biologic (body mass index-BMI, hemoglobin, HIV status, liver fibrosis, and venous versus finger-prick blood collection) variables with PEth sensitivity (PEth≥8 ng/ml), adjusting for the level of self-reported alcohol use using the AUDIT-C score. RESULTS: One third (31%) of participants were women, 32% were African, 28% African American, 28% White, and 12% other race/ethnicity. PEth sensitivity (i.e., ≥8 ng/ml) was 81.8%. After adjusting for AUDIT-C, we found no associations of sex, age, race/ethnicity, or method of blood collection with PEth sensitivity. In models that additionally included biologic variables, those with higher hemoglobin and indeterminate and advanced liver fibrosis had significantly higher odds of PEth sensitivity; those with higher BMI and those living with HIV had significantly lower odds of PEth sensitivity. African Americans and Africans had higher odds of PEth sensitivity than whites in models that included biologic variables. CONCLUSIONS: Among people reporting unhealthy alcohol use, several biological factors (hemoglobin, BMI, liver fibrosis, and HIV status) were associated with PEth sensitivity. Race/ethnicity was associated with PEth sensitivity in some models but age, sex, and method of blood collection were not. Clinicians should be aware of these factors, and researchers should consider adjusting analyses for these characteristics where possible.

Long-term in vivo recording of circadian rhythms in brains of freely moving mice.

Endogenous circadian clocks control 24-h physiological and behavioral rhythms in mammals. Here, we report a real-time in vivo fluorescence recording system that enables long-term monitoring of circadian rhythms in the brains of freely moving mice. With a designed reporter of circadian clock gene expression, we tracked robust Cry1 transcription reporter rhythms in the suprachiasmatic nucleus (SCN) of WT, Cry1-/- , and Cry2-/- mice in LD (12 h light, 12 h dark) and DD (constant darkness) conditions and verified that signals remained stable for over 6 mo. Further, we recorded Cry1 transcriptional rhythms in the subparaventricular zone (SPZ) and hippocampal CA1/2 regions of WT mice housed under LD and DD conditions. By using a Cre-loxP system, we recorded Per2 and Cry1 transcription rhythms specifically in vasoactive intestinal peptide (VIP) neurons of the SCN. Finally, we demonstrated the dynamics of Per2 and Cry1 transcriptional rhythms in SCN VIP neurons following an 8-h phase advance in the light/dark cycle.

Circadian rhythm bifurcation induces flexible phase resetting by reducing circadian amplitude.

Shift-work and jet-lag-related disorders are caused by the limited flexibility of the suprachiasmatic nucleus (SCN), a master circadian clock in the hypothalamus, to adjust to new light-dark (LD) cycles. Recent findings confirmed here establish that behavioral jet lag after simulated time-zone travel is virtually eliminated following bifurcated circadian entrainment under a novel and atypical 24-h light:dark:light:dark (LDLD) cycle. To investigate the mechanisms of this fast resetting, we examined the oscillatory stability of the SCN and peripheral tissues in LDLD-bifurcated mice employing the dissection procedure as a perturbing resetting stimulus. SCN, lung, liver, and adrenal tissue were extracted at times throughout the day from female and male PER2::Luciferase knock-in mice entrained to either LDLD or a normal LD cycle. Except for adrenals, the phase of the cultured explants was more strongly set by dissection under LDLD than under normal LD. Acute bioluminescence levels of SCN explants indicate that the rhythm amplitude of PER2 is reduced and phase is altered in LDLD. Real-time quantitative PCR suggests that amplitude and rhythmicity of canonical clock genes in the lung, liver, and kidney are also significantly reduced in LDLD in vivo. Furthermore, spatiotemporal patterns of PER2 peak time in cultured SCN were altered in LDLD. These results suggest that altered gene expression patterns in the SCN caused by bifurcation likely result in fast resetting of behavior and cultured explants, consistent with previously reported mathematical models. Thus, non-invasive, simple light manipulations can make circadian rhythms more adaptable to abrupt shifts in the environmental LD cycle.

Comprehensive Assessment of Alcohol Consumption in People Living with HIV (PLWH): The New Orleans Alcohol Use in HIV Study.

BACKGROUND: High frequency of alcohol use among people living with HIV (PLWH) warrants careful assessment and screening to better understand its impact on HIV disease progression and development of comorbidities. Due to the limitations of the tools used to measure alcohol use, the links to health consequences are not fully understood. METHODS: We completed a cross-sectional analysis to examine the prevalence of alcohol consumption using multiple alcohol assessment tools and their correlation and consistency in a cohort of PLWH (N = 365) enrolled in the New Orleans Alcohol Use in HIV (NOAH) Study. Alcohol use was assessed with the Alcohol Use Disorders Identification Test (AUDIT), timeline followback (TLFB) Calendar, lifetime drinking history, Alcohol and Drug Addiction Severity Index, and blood levels of phosphatidylethanol (PEth). Spearman's correlations were estimated for continuous measures of alcohol consumption; Wilcoxon rank-sum tests were used to compare means; and logistic regression was used to estimate odds of alcohol use by demographic characteristics. RESULTS: Self-report of current alcohol use varied from 58.9 to 73.7% depending on the assessment. All the self-reported alcohol measures showed statistically significant correlations with the biological marker PEth. The highest correlation was with TLFB grams (r = 0.67, p < 0.001). Using TLFB, 73.7% of the cohort reported using alcohol in the last 30 days, and 61.6% had a positive PEth value. The prevalence of risky drinkers, meeting the TLFB > 3 (women) or >4 (men) drinks/day or>7 (women) or>14 (men) drinks/week, was 49.0%. Medium-risk drinking defined as an AUDIT score ≥ 8 was reported in 40.3%, and high-risk drinkers/probable AUD (AUDIT score ≥ 16) was met by 17.0% of the cohort. CONCLUSIONS: Our results demonstrate the importance of comprehensive assessments for alcohol use, including self-report via multiple assessment tools administered by trained staff, as well as the addition of biomarkers for improved classification of subjects into different drinking categories.

Adverse Childhood Experiences, Smoking and Alcohol Use, and Allostatic Load Among People Living with HIV.

Allostatic load is an indicator of multisystem physiologic dysregulation that may arise from prolonged or accumulated exposure to stress, including adverse childhood experiences (ACEs) and chronic stressors persisting into adulthood. People living with HIV (PLWH) may be particularly vulnerable given their high burdens of adversity across the life course. Using data from a cohort of middle aged PLWH, we examined associations between ACEs and two measures of allostatic load. In order to determine whether the negative impact of ACEs on allostatic load operates through increasing the adoption of adverse coping behaviors, we tested for mediation by smoking and alcohol use. PLWH who had experienced 4 or more ACEs had on average higher allostatic load in adulthood compared to those who experienced fewer. Neither smoking nor alcohol use mediated this relationship, however, suggesting alternative mechanisms may be at play.

CD44 mediates stem cell mobilization to damaged lung via its novel transcriptional targets, Cortactin and Survivin.

Beyond their role in bone and lung homeostasis, mesenchymal stem cells (MSCs) are becoming popular in cell therapy. Various insults may disrupt the repair mechanisms involving MSCs. One such insult is smoking, which is a major risk factor for osteoporosis and respiratory diseases. Upon cigarette smoke-induced damage, a series of reparatory mechanisms ensue; one such mechanism involves Glycosaminoglycans (GAG). One of these GAGs, namely hyaluronic acid (HA), serves as a potential therapeutic target in lung injury. However, much of its mechanisms of action through its major receptor CD44 remains unexplored. Our previous studies have identified and functionally validated that both cortactin (CTTN: marker of motility) and Survivin (BIRC5: required for cell survival) act as novel HA/CD44-downstream transcriptional targets underpinning cell motility. Here, human MSCs were treated with "Water-pipe" smoke to investigate the effects of cigarette smoke condensate (CSC) on these HA-CD44 novel signaling pathways. Our results show that CSC decreased the expression of both CD44 and its downstream targets CTTN and BIRC5 in MSCs, and that HA reversed these effects. Interestingly, CSC inhibited migration and invasion of MSCs upon CD44-targeted RNAi treatment. This shows the importance of CD44-HA/CTTN and CD44-HA/BIRC5 signaling pathways in MSC motility, and further suggests that these signaling pathways may provide a novel mechanism implicated in migration of MSCs during repair of lung tissue injury. These findings suggest that one should use caution before utilizing MSC from donors with history of smoking, and further pave the way towards the development of targeted therapeutic approaches against CD44-associated diseases.

Associations of Liver Disease with Alcohol Use among People Living with HIV and the Role of Hepatitis C: The New Orleans Alcohol Use in HIV Study.

AIM: This cross-sectional analysis of the New Orleans Alcohol Use in HIV (NOAH) study assesses whether current and lifetime alcohol use in people living with HIV (PLWH) are associated with greater liver disease and how hepatitis C-viral (HCV) co-infection (HIV/HCV+) modifies the association. METHODS: Alcohol use was measured by Lifetime Drinking History (LDH), a 30-day Timeline Followback calendar, the Alcohol Use Disorder Identification Test, and phosphatidylethanol. Liver disease was estimated by alanine aminotransferase (ALT), aspartate aminotransferase (AST), AST platelet ratio-index (APRI), fibrosis-4 index (FIB-4) and nonalcoholic fatty liver disease-fibrosis score. Associations between alcohol consumption and liver disease were estimated with multivariable logistic regression. Models were adjusted for age, sex, body-mass index, hepatitis B and HIV viral load. RESULTS: Participants (N = 353) were majority male (69%) and black (84%) with a mean age of 48.3 ± 10 years. LDH was significantly associated with advanced liver fibrosis (FIB-4 aOR = 22.22 [1.22-403.72]) only among HIV/HCV+ participants with an LDH of 100-600 kg. HIV/HCV+ participants had a higher prevalence of intermediate and advanced liver disease markers than HIV/HCV- (P < 0.0001). Advanced markers of liver disease were most strongly associated with hazardous drinking (≥40(women)/60(men) grams/day) (APRI aOR = 15.87 (3.22-78.12); FIB-4 aOR = 6.76 (1.81-7.16)) and PEth ≥400 ng/ml (APRI aOR = 17.52 (2.55-120.54); FIB-4 aOR = 17.75 (3.30-95.630). CONCLUSION: Results indicate a greater association of current alcohol use with liver disease than lifetime alcohol use, which varied by HCV status. These findings stress the importance of reducing alcohol use in PLWH to decrease risk of liver disease and fibrosis.

Alcohol-associated intestinal dysbiosis impairs pulmonary host defense against Klebsiella pneumoniae.

Chronic alcohol consumption perturbs the normal intestinal microbial communities (dysbiosis). To investigate the relationship between alcohol-mediated dysbiosis and pulmonary host defense we developed a fecal adoptive transfer model, which allows us to investigate the impact of alcohol-induced gut dysbiosis on host immune response to an infectious challenge at a distal organ, independent of prevailing alcohol use. Male C57BL/6 mice were treated with a cocktail of antibiotics (ampicillin, gentamicin, neomycin, vancomycin, and metronidazole) via daily gavage for two weeks. A separate group of animals was fed a chronic alcohol (or isocaloric dextrose pair-fed controls) liquid diet for 10 days. Microbiota-depleted mice were recolonized with intestinal microbiota from alcohol-fed or pair-fed (control) animals. Following recolonization groups of mice were sacrificed prior to and 48 hrs. post respiratory infection with Klebsiella pneumoniae. Klebsiella lung burden, lung immunology and inflammation, as well as intestinal immunology, inflammation, and barrier damage were examined. Results showed that alcohol-associated susceptibility to K. pneumoniae is, in part, mediated by gut dysbiosis, as alcohol-naïve animals recolonized with a microbiota isolated from alcohol-fed mice had an increased respiratory burden of K. pneumoniae compared to mice recolonized with a control microbiota. The increased susceptibility in alcohol-dysbiosis recolonized animals was associated with an increase in pulmonary inflammatory cytokines, and a decrease in the number of CD4+ and CD8+ T-cells in the lung following Klebsiella infection but an increase in T-cell counts in the intestinal tract following Klebsiella infection, suggesting intestinal T-cell sequestration as a factor in impaired lung host defense. Mice recolonized with an alcohol-dysbiotic microbiota also had increased intestinal damage as measured by increased levels of serum intestinal fatty acid binding protein. Collectively, these results suggest that alterations in the intestinal immune response as a consequence of alcohol-induced dysbiosis contribute to increased host susceptibility to Klebsiella pneumonia.

Reduced Serum Osteocalcin in High-Risk Alcohol Using People Living With HIV Does Not Correlate With Systemic Oxidative Stress or Inflammation: Data From the New Orleans Alcohol Use in HIV Study.

BACKGROUND: HIV infection is now largely a chronic condition as a result of the success of antiretroviral therapy. However, several comorbidities have emerged in people living with HIV (PLWH), including alcohol use disorders and musculoskeletal disorders. Alcohol use has been associated with lower bone mineral density, alterations to circulating bone turnover markers, and hypocalcemia. The pathophysiological basis of bone loss in the PLWH population is unclear but has been suggested to be linked to oxidative stress and inflammation. To test the hypothesis that PLWH consuming excessive alcohol have altered markers of bone turnover and/or calcium homeostasis in association with oxidative stress, we correlated measurements of alcohol consumption with markers of oxidative stress and inflammation, serum calcium concentrations, and measurements of bone turnover, including c-terminal telopeptide cross-links (CTX-1) and osteocalcin. METHODS: Data were drawn from cross-sectional baseline data from the ongoing New Orleans Alcohol Use in HIV (NOAH) study, comprised of 365 in care PLWH. Alcohol consumption measures (Alcohol Use Disorders Test, 30-day timeline follow-back calendar, and phosphatidylethanol [PEth]) were measured in a subcohort of 40 subjects selected based on highest and lowest PEth measurements. Multivariate linear regression was performed to test the relationships between alcohol consumption and systemic oxidative stress (4-hydroxynonenal; 4-HNE) and inflammation (c-reactive protein; CRP). RESULTS: Serum calcium and CTX-1 did not differ significantly between the high and low-PEth groups. Individuals in the high-PEth group had significantly lower serum osteocalcin (median low-PEth group: 13.42 ng/ml, inter-quartile range [IQR] 9.26 to 14.99 ng/ml; median high-PEth group 7.39 ng/ml, IQR 5.02 to 11.25 ng/ml; p = 0.0005, Wilcoxon rank-sum test). Osteocalcin negatively correlated with PEth (Spearman r = -0.45, p = 0.05) and self-reported measures after adjusting for covariates. Alcohol consumption showed mild, but significant, positive associations with serum 4-HNE, but not with CRP. Osteocalcin did not correlate with either 4-HNE or CRP. CONCLUSIONS: In this subcohort of PLWH, we detected significant associations between at-risk alcohol use and osteocalcin, and at-risk alcohol use and serum 4-HNE, suggesting suppression of bone formation independent of increased systemic oxidative stress with increasing alcohol consumption.

Intestinal Microbial Products From Alcohol-Fed Mice Contribute to Intestinal Permeability and Peripheral Immune Activation.

BACKGROUND: Alcohol use causes significant disruption of intestinal microbial communities, yet exactly how these dysbiotic communities interact with the host is unclear. We sought to understand the role of microbial products associated with alcohol dysbiosis in mice on intestinal permeability and immune activation in an in vitro model system. METHODS: Microbiota samples from binge-on-chronic alcohol-fed and pair-fed male and female mice were cultured in Gifu Anaerobic Broth for 24 hours under anaerobic conditions. Live/whole organisms were removed, and microbial products were collected and added to human peripheral blood mononuclear cells (PBMCs) or polarized C2BBe1 intestinal epithelial monolayers. Following stimulation, transepithelial electrical resistance (TEER) was measured using a volt/ohm meter and immune activation of PBMC was assessed via flow cytometry. RESULTS: Microbial products from male and female alcohol-fed mice significantly decreased TEER (mean percentage change from baseline alcohol-fed 0.86 Ω/cm2 vs. pair-fed 1.10 Ω/cm2 ) compared to microbial products from control mice. Following ex vivo stimulation, immune activation of PBMC was assessed via flow cytometry. We found that microbial products from alcohol-fed mice significantly increased the percentage of CD38+ CD4+ (mean alcohol-fed 17.32% ± 0.683% standard deviation (SD) vs. mean pair-fed 14.2% ± 1.21% SD, p < 0.05) and CD8+ (mean alcohol-fed 20.28% ± 0.88% SD vs. mean pair-fed 12.58% ± 3.59% SD, p < 0.05) T cells. CONCLUSIONS: Collectively, these data suggest that microbial products contribute to immune activation and intestinal permeability associated with alcohol dysbiosis. Further, utilization of these ex vivo microbial product assays will allow us to rapidly assess the impact of microbial products on intestinal permeability and immune activation and to identify probiotic therapies to ameliorate these defects.