Mitochondrial Functions Are Compromised in CD4 T Cells From ART-Controlled PLHIV

The hallmark of HIV/AIDS is a gradual depletion of CD4 T cells. Despite effective control by antiretroviral therapy (ART), a significant subgroup of people living with HIV (PLHIV) fails to achieve complete immune reconstitution, deemed as immune non-responders (INRs). The mechanisms underlying incomplete CD4 T cell recovery in PLHIV remain unclear. In this study, CD4 T cells from PLHIV were phenotyped and functionally characterized, focusing on their mitochondrial functions. The results show that while total CD4 T cells are diminished, cycling cells are expanded in PLHIV, especially in INRs. HIV-INR CD4 T cells are more activated, displaying exhausted and senescent phenotypes with compromised mitochondrial functions. Transcriptional profiling and flow cytometry analysis showed remarkable repression of mitochondrial transcription factor A (mtTFA) in CD4 T cells from PLHIV, leading to abnormal mitochondrial and T cell homeostasis. These results demonstrate a sequential cellular paradigm of T cell over-activation, proliferation, exhaustion, senescence, apoptosis, and depletion, which correlates with compromised mitochondrial functions. Therefore, reconstituting the mtTFA pathway may provide an adjunctive immunological approach to revitalizing CD4 T cells in ART-treated PLHIV, especially in INRs

ATM Deficiency Accelerates DNA Damage, Telomere Erosion, and Premature T Cell Aging in HIV-Infected Individuals on Antiretroviral Therapy

HIV infection leads to a phenomenon of inflammaging, in which chronic inflammation induces an immune aged phenotype, even in individuals on combined antiretroviral therapy (cART) with undetectable viremia. In this study, we investigated T cell homeostasis and telomeric DNA damage and repair machineries in cART-controlled HIV patients at risk for inflammaging. We found a significant depletion of CD4 T cells, which was inversely correlated with the cell apoptosis in virus-suppressed HIV subjects compared to age-matched healthy subjects (HS). In addition, HIV CD4 T cells were prone to DNA damage that extended to chromosome ends—telomeres, leading to accelerated telomere erosion—a hallmark of cell senescence. Mechanistically, the DNA double-strand break (DSB) sensors MRE11, RAD50, and NBS1 (MRN complex) remained intact, but both expression and activity of the DNA damage checkpoint kinase ataxia-telangiectasia mutated (ATM) and its downstream checkpoint kinase 2 (CHK2) were significantly suppressed in HIV CD4 T cells. Consistently, ATM/CHK2 activation, DNA repair, and cellular functions were also impaired in healthy CD4 T cells following ATM knockdown or exposure to the ATM inhibitor KU60019 in vitro, recapitulating the biological effects observed in HIV-derived CD4 T cells in vivo. Importantly, ectopic expression of ATM was essential and sufficient to reduce the DNA damage, apoptosis, and cellular dysfunction in HIV-derived CD4 T cells. These results demonstrate that failure of DSB repair due to ATM deficiency leads to increased DNA damage and renders CD4 T cells prone to senescence and apoptotic death, contributing to CD4 T cell depletion or dysfunction in cART-controlled, latent HIV infection

Telomeric Injury by KML001 in Human T Cells Induces Mitochondrial Dysfunction Through p53-PGC-1α Pathway

Telomere erosion and mitochondrial dysfunction are prominent features of aging cells with progressive declines of cellular functions. Whether telomere injury induces mitochondrial dysfunction in human T lymphocytes, the major component of adaptive host immunity against infection and malignancy, remains unclear. We have recently shown that disruption of telomere integrity by KML001, a telomere-targeting drug, induces T cell senescence and apoptosis via the telomeric DNA damage response (DDR). In this study, we used KML001 to further investigate the role and mechanism of telomere injury in mitochondrial dysregulation in aging T cells. We demonstrate that targeting telomeres by KML001 induces mitochondrial dysfunction, as evidenced by increased mitochondrial swelling and decreased mitochondrial membrane potential, oxidative phosphorylation, mitochondrial DNA content, mitochondrial respiration, oxygen consumption, glycolysis, and ATP energy production. Mechanistically, we found that the KML001-induced telomeric DDR activated p53 signaling, which in turn repressed the expression of peroxisome proliferator-activated receptor-gamma coactivator 1 alpha (PGC-1α) and nuclear respiratory factor 1 (NRF-1), leading to T cell mitochondrial dysfunction. These results, forging a direct link between telomeric and mitochondrial biology, shed new light on the human T cell aging network, and demonstrate that the p53-PGC-1α-NRF-1 axis contributes to mitochondrial dysfunction in the setting of telomeric DDR. This study suggests that targeting this axis may offer an alternative, novel approach to prevent telomere damage-mediated mitochondrial and T cell dysfunctions to combat a wide range of immune aging-associated human diseases

Inhibition of Topoisomerase IIA (Top2α) Induces Telomeric DNA Damage and T Cell Dysfunction During Chronic Viral Infection

T cells play a critical role in controlling viral infection; however, the mechanisms regulating their responses remain incompletely understood. Here, we investigated the role of topoisomerase IIA (Top2α, an enzyme that is essential in resolving entangled DNA strands during replication) in telomeric DNA damage and T cell dysfunction during viral infection. We demonstrated that T cells derived from patients with chronic viral (HBV, HCV, and HIV) infection had lower Top2α protein levels and enzymatic activity, along with an accumulation of the Top2α cleavage complex (Top2cc) in genomic DNA. In addition, T cells from virally infected subjects with lower Top2α levels were vulnerable to Top2α inhibitor-induced cell apoptosis, indicating an important role for Top2α in preventing DNA topological disruption and cell death. Using Top2α inhibitor (ICRF193 or Etoposide)-treated primary T cells as a model, we demonstrated that disrupting the DNA topology promoted DNA damage and T cell apoptosis via Top2cc accumulation that is associated with protein-DNA breaks (PDB) at genomic DNA. Disruption of the DNA topology was likely due to diminished expression of tyrosyl-DNA phosphodiesterase 2 (TDP2), which was inhibited in T cells in vitro by Top2α inhibitor and in vivo by chronic viral infection. These results suggest that immune-evasive viruses (HBV, HCV, and HIV) can disrupt T cell DNA topology as a mechanism of dysregulating host immunity and establishing chronic infection. Thus, restoring the DNA topologic machinery may serve as a novel strategy to protect T cells from unwanted DNA damage and to maintain immune competence

Childhood Asthma and Smoking: Moderating Effect of Preterm Status and Birth Weight

Introduction Although studies have examined the association between childhood asthma and parental smoking and secondhand smoke, little research has explored the moderating role of birth weight and prematurity (BWP) status on this association. We examined the association between secondhand smoke exposure, asthma, and asthma severity in children aged six to 17 as well as the modifying effect of BWP on parental smoking and asthma. Methods We used data from 36,954 children from the National Survey of Children\u27s Health 2017-2018. In addition to univariate analysis, adjusted and unadjusted logistic regression models were used to estimate the effect of secondhand smoke on asthma. The interaction term between parental smoking and BWP was tested. Multinomial regression was used to evaluate the association between secondhand smoke on asthma severity. Results About 15.1 % of children had asthma and 15.4% of parents reported smoking. Odds of asthma were higher in children living with an outdoor (AOR, 1.27; 95% CI, 1.06-1.52) and indoor (AOR, 1.46; 95% CI, 1.01-2.11) smoker in the adjusted model. The association of parental smoking with asthma differed by birth weight and premature status. Normal weight children who are premature had the highest odds ratio (AOR, 2.15; 95% CI, 1.2-3.86). In the multinomial model, low birth weight and premature children had higher odds of mild (AOR, 1.90; 95% CI, 1.40-2.56) and moderate/severe (AOR, 1.81; 95% CI, 1.16-2.84) asthma compared to the no asthma group. Conclusion The Association of parental smoking on asthma was modified by BWP. Focused asthma interventions in children should inquire about BWP status as well as parental smoking and household smoke exposure to reduce asthma morbidity and mortality

Infant Feeding Practices and Asthma in Children Aged 6 Months to 5 Years Using a Propensity Score Approach

OBJECTIVES: We examined the association between exclusive breastfeeding, early introduction of feeding formula, early weaning, and asthma in children aged six months to five years in a sample of non-institutionalized US children using a propensity score approach. METHODS: Our study used data from the National Survey of Children\u27s Health (2012-2018) of 3,820 children with physician-diagnosed asthma aged 6 months to 5 years. Propensity score matching (PSM) was applied to control selection bias with age, sex, race, birth weight, Federal Poverty Level, parent\u27s education, and parent smoking history used as covariates in PSM. The total number in the matched sample was 6,904 (3,452 non-asthmatics; 3,452 asthmatics). Matched and unmatched samples were analysed using the χ test and multiple logistic regression. RESULTS: Exclusive breastfeeding was protective against asthma in the pre-matching (AOR 0.72; 95% CI: 0.54-0.97; p = 0.03) and post-matching (AOR 0.66; 95% CI: 0.55-0.81; p \u3c 0.001) samples. Formula feeding before 6 months was associated with asthma in unmatched (AOR 1.38; 95% CI: 1.15-1.66; p \u3c 0.001) and matched (AOR 1.31; 95% CI: 1.16-1.47; p \u3c 0.001) sample. Early weaning before 6 months was associated with asthma in unmatched (AOR 1.62; 95% CI: 1.35-1.54; p \u3c 0.001) and matched sample (AOR 1.37; 95% CI: 1.23-1.54; p \u3c 0.001). CONCLUSION: Public health systems should continue to recommend the implementation of the World Health Organization exclusive breastfeeding guideline in developed countries. Asthma interventions in children under two years should continue to emphasize exclusive breastfeeding to reduce the incidence of infant asthma

Caregivers’ Self-Rated General Health, Physical and Mental Health Status, Disease Morbidity and Association with Uncontrolled Asthma in Children

This study examined the association between caregivers’ self-rated general health, poor physical/mental health days, disease morbidity and asthma control in children from the United States with current asthma. The data analyzed for this study were obtained from 7522 children aged 0–17 years who participated in the 2012–2014, 2015–2017, 2018, and 2019 cycles of the Behavioral Risk Factor Surveillance System Asthma Call-back Survey (ACBS). We employed univariate analysis to describe the study population and weighted binary logistic regression to examine the association of predictors with asthma control. Approximately 50% of the children had uncontrolled asthma. The results show that caregivers who reported fair general health had a 61% higher likelihood of reporting uncontrolled asthma in their children compared to those who reported good/very good/excellent health (adjusted odds ratio [aOR] = 1.61; 95% confidence interval [CI], 1.14–2.26). Poor caregiver general health did not reach statistical significance in predicting uncontrolled asthma (aOR = 1.05, 95% CI, 0.62–1.75). Furthermore, having 1 to 14 poor physical/mental health days ([aOR] = 1.70; 95% CI, 1.28–2.227) and ≥15 poor physical/mental health days (aOR = 1.82, 95% CI, 1.31–2.53) was predictive of uncontrolled asthma in children. Additionally, endorsing one reported disease (aOR = 1.49, 95% CI, 1.15–1.93) and ≥2 diseases (aOR = 1.38, 95% CI, 1.08–1.78) was associated with uncontrolled child asthma. These findings underscore the association between caregivers’ self-reported general health, poor mental/physical health days, disease morbidity and uncontrolled asthma among children from the U.S. with asthma. Pediatricians and child health practitioners should recall the importance of this relationship. To facilitate the identification of caregivers at risk and provide more comprehensive and effective care for children with asthma, healthcare practitioners should utilize every child asthma care encounter to inquire about the overall health of caregivers

The Role of Disabled-2 (Dab2) in Diseases

Disabled-2 (Dab2/DOC-2) is a mitogen-responsive adaptor protein required for multiple cellular functions. It is involved in many signaling pathways and plays an integral role in vesicular uptake and trafficking, modulating immune function, protein–protein interactions, cellular homeostasis and differentiation, oncogenesis, and inflammatory processes in organ systems. It contains domains for binding to NPXY motif-containing and SH3 domain-containing adapter proteins, phosphoinositides, glycoprotein 100 (gp100, or megalin), integrins, clathrin, and myosin VI. However, the molecular mechanism(s) of Dab2′s biological function still remain to be elucidated. In this review, we provide an extensive up-to-date understanding of the function of Dab2 and its regulation in cardiovascular diseases, immune disorders, tumorigenesis, and central nervous system disorders

DSTYK Enhances Chemoresistance in Triple-Negative Breast Cancer Cells

Breast cancer, as the most prevalent cancer in women, is responsible for more than 15% of new cancer cases and about 6.9% of all cancer-related death in the US. A major cause of therapeutic failure in breast cancer is the development of resistance to chemotherapy, especially for triple-negative breast cancer (TNBC). Therefore, how to overcome chemoresistance is the major challenge to improve the life expectancy of breast cancer patients. Our studies demonstrate that TNBC cells surviving the chronic treatment of chemotherapeutic drugs show significantly higher expression of the dual serine/threonine and tyrosine protein kinase (DSTYK) than non-treated parental cells. In our in vitro cellular models, DSTYK knockout via the CRISPR/Cas9-mediated technique results in apoptotic cell death of chemoresistant cells upon drug treatment. Moreover, DSTYK knockout promotes chemotherapeutic drug-induced tumor cell death in an orthotopic mouse model. These findings suggest that DSTYK exerts an important and previously unknown role in promoting chemoresistance. Our studies provide fundamental insight into the role of DSTYK in chemoresistance in TNBC cells and lay the foundation for the development of new strategies targeting DSTYK for improving TNBC therapy