Short telomeres in alveolar type II cells associate with lung fibrosis in post COVID-19 patients with cancer.

The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the coronavirus disease 2019 (COVID-19) pandemic. The severity of COVID-19 increases with each decade of life, a phenomenon that suggest that organismal aging contributes to the fatality of the disease. In this regard, we and others have previously shown that COVID-19 severity correlates with shorter telomeres, a molecular determinant of aging, in patient's leukocytes. Lung injury is a predominant feature of acute SARS-CoV-2 infection that can further progress to lung fibrosis in post-COVID-19 patients. Short or dysfunctional telomeres in Alveolar type II (ATII) cells are sufficient to induce pulmonary fibrosis in mouse and humans. Here, we analyze telomere length and the histopathology of lung biopsies from a cohort of alive post-COVID-19 patients and a cohort of age-matched controls with lung cancer. We found loss of ATII cellularity and shorter telomeres in ATII cells concomitant with a marked increase in fibrotic lung parenchyma remodeling in post- COVID-19 patients compared to controls. These findings reveal a link between presence of short telomeres in ATII cells and long-term lung fibrosis sequel in Post-COVID-19 patients.

'Legs feed the wolf': An evolutionary perspective on psychosocial stress, physical activity, and their associations with telomere length in NCAA student-athletes and non-athletes

Psychosocial stress negatively impacts our mental and physical health, predisposing us to illness, worsened mental health, and accelerated aging. Conversely, regular physical activity, such as exercise and sports training, positively impacts our health. These opposing effects are intriguing because psychosocial stress and physical activity were inextricably linked throughout human evolution. Large populations of humans have only recently begun transitioning into more sedentary lifestyles, uncoupling psychosocial stress from physical activity. Improving our understanding of these two factors and their interactions will, in turn, improve our understanding of the mechanisms through which psychosocial stress impacts health in both modern and ancestral human populations.My dissertation examines whether physical activity moderates the association between psychosocial stress and capillary blood telomere length in NCAA student-athletes and their non- athlete counterparts in the general student population. My first paper develops an in-depth comparison of psychosocial stress in these two groups using a suite of psychosocial stress surveys and an adapted cognitive interview protocol. Student-athletes (N=65) reported lower levels of current perceived stress and anxiety symptoms (p<0.05) but similar levels of childhood psychosocial stress, recent exposure to external stressors, and depressive symptoms compared to non-athletes (N=57). My second paper utilized self-report and objective measures of physical activity (i.e., accelerometry) to compare physical activity patterns in these groups. Student- athletes (N=60) both self-reported higher levels of physical activity and recorded higher levels of activity via accelerometry (p>0.001) compared to non-athletes (N=50). Interestingly, categorical measures of activity levels (i.e., time spent in moderate-to-vigorous physical activity) identified Rowers as the most active among student-athletes, but continuous measures of activity levels (e.g., total physical activity level) identified Track and Field athletes as the most active (p>0.05 for both comparisons).My third and final paper tested whether higher physical activity weakened the association between childhood psychosocial stress and telomere length estimated from capillary blood collected on Hemaspot HF devices (N=111). Telomeres are DNA sequences that protect the ends of chromosomes. They shorten with cell replication, age, and oxidative stress, leading to functional decline with age and worsened health outcomes. Importantly, psychosocial stress is thought to accelerate TL shortening. My a priori analyses did not support a direct association between psychosocial stress, physical activity, or the interaction of these variables and telomere length. However, a post hoc analysis found that individuals who recorded higher total physical activity demonstrated a positive association between childhood psychosocial stress and telomere length (i.e., higher childhood stress predicted longer telomeres) while individuals who recorded lower total physical activity had a negative association (i.e., higher childhood psychosocial stress predicted shorter telomeres).My results do not offer explicit support for the hypothesis that physical activity moderates the effects of psychosocial stress on telomere length. However, my project adds to the literature in at least several ways. It produced a novel and much-needed comparison of psychosocial stress between NCAA student-athletes and non-athletes. It illustrated and validated several data collection techniques for psychosocial stress and physical activity. Further, my telomere findings offer an exciting direction for the future exploration of psychosocial stress- physical activity interactions. Lastly, this work improves our overall understanding of NCAA student-athletes' mental and physical health and how their unique circumstances intersect with the ongoing effects of the COVID-19 pandemic. (PsycInfo Database Record (c) 2023 APA, all rights reserved)

Zebrafish models of COVID-19.

Although COVID-19 has only recently appeared, research studies have already developed and implemented many animal models for deciphering the secrets of the disease and provided insights into the biology of SARS-CoV-2. However, there are several major factors that complicate the study of this virus in model organisms, such as the poor infectivity of clinical isolates of SARS-CoV-2 in some model species, and the absence of a persistent infection, immunopathology, severe acute respiratory distress syndrome, and none of the systemic complications which characterize COVID-19 clinically. Another important limitation is that SARS-CoV-2 mainly causes severe COVID-19 in older people with comorbidities, which represents a serious problem when attempting to use young and immunologically naïve laboratory animals in COVID-19 testing. We review here the main animal models developed so far to study COVID-19 and the unique advantages of the zebrafish model that may help to contribute to understand this disease, in particular to the identification and repurposing of drugs to treat COVID-19, to reveal the mechanism of action and side-effects of Spike-based vaccines, and to decipher the high susceptibility of aged people to COVID-19.

Analysis of Relative Average Length of Telomeres in Leukocytes of Women with COVID-19.

Coronavirus disease (COVID-19) is an acute infectious disease of the respiratory tract caused by a new SARS-CoV-2 coronavirus. A global vaccination program against SARS-CoV-2 continues, and the incidence of COVID-19 worldwide is significantly decreasing. However, among millions of those who survived COVID-19, numerous groups will need assistance due to increased clinical consequences after COVID-19. Currently, there is a need to search for molecular biomarkers for monitoring the onset and progression of post-COVID syndrome. For this purpose, the relative average length of chromosome regions was studied in the groups of women of reproductive age: in the group of patients (n = 64) recovered from COVID-19 and in the control group (n = 42) of women of the same age. The analysis was carried out using a method of multiplex monochrome quantitative real-time PCR on DNA samples isolated from the peripheral blood leukocytes. According to the results of the study, it was established that the relative average length of chromosomes in the peripheral blood leukocytes was statistically significantly lower in the group of patients with COVID-19 than in the control group (p < 0.05). The results obtained allow one to state that the observed shortening of the relative average length of telomeres in the group of patients that recovered from COVID-19 can indicate that SARS-CoV-2 infection can directly cause the erosion of telomeres in the blood cells, particularly, in leukocytes. Thus, the determination of the relative average length of telomeres can be an informative prognostic marker for estimating the risk of the severity of COVID-19 disease and the development of post-COVID syndrome.

An exploratory analysis of leukocyte telomere length among pregnant and non-pregnant people.

Background: Leukocyte telomere length (LTL) is a biomarker that is affected by older age, psychosocial stress, and medical comorbidities. Despite the relevance of these factors to obstetric practice, little is known about LTL in pregnancy. Our study explored longitudinal LTL dynamics in pregnant and non-pregnant people. Objective: This pilot study compares changes in LTL between pregnant and non-pregnant people over time, explores potential correlations between LTL and mental health measures, and investigates associations between short first-trimester LTL and adverse pregnancy outcomes. Study design: This was a prospective pilot cohort study of nulliparous pregnant and non-pregnant people between ages 18 and 50 who presented for care at a single institution from January to November 2020. Pregnant people were enrolled between 10 and 14 weeks gestation. Participants had two blood samples drawn for LTL; the first on the day of enrollment and the second on postpartum day 1 (pregnant cohort) or 7 months later (non-pregnant cohort). LTL was measured using quantitative PCR. The primary outcome was the difference between pregnant and non-pregnant people in LTL change between the two timepoints (basepair difference per 30-day period). Secondary outcomes included differences in responses to the Patient Health Questionnaire-9 (PHQ-9) and a survey about stress related to COVID-19. Differences in LTL were tested using t-tests and linear regression models, both crude and adjusted for age. A subgroup analysis was conducted within the pregnant cohort to examine whether shorter first-trimester LTL was associated with adverse pregnancy outcomes. We conducted t-tests to compare LTL between people with and without each categorical outcome and computed Pearson correlation coefficients between LTL and continuous outcomes such as gestational age at delivery. Results: 46 pregnant and 30 non-pregnant people were enrolled; 44 pregnant and 18 non-pregnant people completed all LTL assessments. There were no between-group differences in LTL change (-4.2 ± 22.2 bp per 30 days pregnant versus -6.4 ± 11.2 bp per 30 days non-pregnant, adjusted beta 2.1, 95% CI -9.0-13.2, p = 0.60). The prevalence of depression and pandemic-related stress were both low overall. The two groups did not differ in PHQ-9 scores, and no correlations were significant between LTL and PHQ-9 scores. Among the 44 pregnant people, shorter first-trimester LTL was significantly correlated with earlier gestational age at delivery (r = 0.35, p = 0.02). Conclusion: In this exploratory pilot cohort of reproductive-aged people with low levels of psychological stress, we described baseline changes in LTL over time in pregnant and non-pregnant participants. We found a correlation between shorter first-trimester LTL and earlier gestational age at delivery, which warrants further investigation in a larger cohort.

Telomere-length dependent T-cell clonal expansion: A model linking ageing to COVID-19 T-cell lymphopenia and mortality.

BACKGROUND: Severe COVID-19 T-cell lymphopenia is more common among older adults and entails poor prognosis. Offsetting the decline in T-cell count during COVID-19 demands fast and massive T-cell clonal expansion, which is telomere length (TL)-dependent. METHODS: We developed a model of TL-dependent T-cell clonal expansion capacity with age and virtually examined the relation of T-cell clonal expansion with COVID-19 mortality in the general population. FINDINGS: The model shows that an individual with average hematopoietic cell TL (HCTL) at age twenty years maintains maximal T-cell clonal expansion capacity until the 6th decade of life when this capacity rapidly declines by more than 90% over the next ten years. The collapse in the T-cell clonal expansion capacity coincides with the steep increase in COVID-19 mortality with age. INTERPRETATION: Short HCTL might increase vulnerability of many older adults, and some younger individuals with inherently short HCTL, to COVID-19 T-cell lymphopenia and severe disease. FUNDING: A full list of funding bodies that contributed to this study can be found in the Acknowledgements section.

Molecular Mechanisms of Alveolar Epithelial Stem Cell Senescence and Senescence-Associated Differentiation Disorders in Pulmonary Fibrosis.

Pulmonary senescence is accelerated by unresolved DNA damage response, underpinning susceptibility to pulmonary fibrosis. Recently it was reported that the SARS-Cov-2 viral infection induces acute pulmonary epithelial senescence followed by fibrosis, although the mechanism remains unclear. Here, we examine roles of alveolar epithelial stem cell senescence and senescence-associated differentiation disorders in pulmonary fibrosis, exploring the mechanisms mediating and preventing pulmonary fibrogenic crisis. Notably, the TGF-ß signalling pathway mediates alveolar epithelial stem cell senescence by mechanisms involving suppression of the telomerase reverse transcriptase gene in pulmonary fibrosis. Alternatively, telomere uncapping caused by stress-induced telomeric shelterin protein TPP1 degradation mediates DNA damage response, pulmonary senescence and fibrosis. However, targeted intervention of cellular senescence disrupts pulmonary remodelling and fibrosis by clearing senescent cells using senolytics or preventing senescence using telomere dysfunction inhibitor (TELODIN). Studies indicate that the development of senescence-associated differentiation disorders is reprogrammable and reversible by inhibiting stem cell replicative senescence in pulmonary fibrosis, providing a framework for targeted intervention of the molecular mechanisms of alveolar stem cell senescence and pulmonary fibrosis. Abbreviations: DPS, developmental programmed senescence; IPF, idiopathic pulmonary fibrosis; OIS, oncogene-induced replicative senescence; SADD, senescence-associated differentiation disorder; SALI, senescence-associated low-grade inflammation; SIPS, stress-induced premature senescence; TERC, telomerase RNA component; TERT, telomerase reverse transcriptase; TIFs, telomere dysfunction-induced foci; TIS, therapy-induced senescence; VIS, virus-induced senescence.

SARS-CoV-2 triggers DNA damage response in Vero E6 cells.

The novel severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) virus responsible for the current COVID-19 pandemic and has now infected more than 200 million people with more than 4 million deaths globally. Recent data suggest that symptoms and general malaise may continue long after the infection has ended in recovered patients, suggesting that SARS-CoV-2 infection has profound consequences in the host cells. Here we report that SARS-CoV-2 infection can trigger a DNA damage response (DDR) in African green monkey kidney cells (Vero E6). We observed a transcriptional upregulation of the Ataxia telangiectasia and Rad3 related protein (ATR) in infected cells. In addition, we observed enhanced phosphorylation of CHK1, a downstream effector of the ATR DNA damage response, as well as H2AX. Strikingly, SARS-CoV-2 infection lowered the expression of TRF2 shelterin-protein complex, and reduced telomere lengths in infected Vero E6 cells. Thus, our observations suggest SARS-CoV-2 may have pathological consequences to host cells beyond evoking an immunopathogenic immune response.

Evidence for Biological Age Acceleration and Telomere Shortening in COVID-19 Survivors.

The SARS-CoV-2 infection determines the COVID-19 syndrome characterized, in the worst cases, by severe respiratory distress, pulmonary and cardiac fibrosis, inflammatory cytokine release, and immunosuppression. This condition has led to the death of about 2.15% of the total infected world population so far. Among survivors, the presence of the so-called persistent post-COVID-19 syndrome (PPCS) is a common finding. In COVID-19 survivors, PPCS presents one or more symptoms: fatigue, dyspnea, memory loss, sleep disorders, and difficulty concentrating. In this study, a cohort of 117 COVID-19 survivors (post-COVID-19) and 144 non-infected volunteers (COVID-19-free) was analyzed using pyrosequencing of defined CpG islands previously identified as suitable for biological age determination. The results show a consistent biological age increase in the post-COVID-19 population, determining a DeltaAge acceleration of 10.45 ± 7.29 years (+5.25 years above the range of normality) compared with 3.68 ± 8.17 years for the COVID-19-free population (p < 0.0001). A significant telomere shortening parallels this finding in the post-COVID-19 cohort compared with COVID-19-free subjects (p < 0.0001). Additionally, ACE2 expression was decreased in post-COVID-19 patients, compared with the COVID-19-free population, while DPP-4 did not change. In light of these observations, we hypothesize that some epigenetic alterations are associated with the post-COVID-19 condition, particularly in younger patients (< 60 years).

Shorter telomere lengths in patients with severe COVID-19 disease.

The incidence of severe manifestations of COVID-19 increases with age with older patients showing the highest mortality, suggesting that molecular pathways underlying aging contribute to the severity of COVID-19. One mechanism of aging is the progressive shortening of telomeres, which are protective structures at chromosome ends. Critically short telomeres impair the regenerative capacity of tissues and trigger loss of tissue homeostasis and disease. The SARS-CoV-2 virus infects many different cell types, forcing cell turn-over and regeneration to maintain tissue homeostasis. We hypothesize that presence of short telomeres in older patients limits the tissue response to SARS-CoV-2 infection. We measure telomere length in peripheral blood lymphocytes COVID-19 patients with ages between 29 and 85 years-old. We find that shorter telomeres are associated to increased severity of the disease. Individuals within the lower percentiles of telomere length and higher percentiles of short telomeres have higher risk of developing severe COVID-19 pathologies.

The Nexus Between Telomere Length and Lymphocyte Count in Seniors Hospitalized With COVID-19.

Profound T-cell lymphopenia is the hallmark of severe coronavirus disease 2019 (COVID-19). T-cell proliferation is telomere length (TL) dependent and telomeres shorten with age. Older COVID-19 patients, we hypothesize, are, therefore, at a higher risk of having TL-dependent lymphopenia. We measured TL by the novel Telomere Shortest Length Assay (TeSLA), and by Southern blotting (SB) of the terminal restriction fragments in peripheral blood mononuclear cells of 17 COVID-19 and 21 non-COVID-19 patients, aged 87 ± 8 (mean ± SD) and 87 ± 9 years, respectively. TeSLA tallies and measures single telomeres, including short telomeres undetected by SB. Such telomeres are relevant to TL-mediated biological processes, including cell viability and senescence. TeSLA yields 2 key metrics: the proportions of telomeres with different lengths (expressed in %) and their mean (TeSLA mTL), (expressed in kb). Lymphocyte count (109/L) was 0.91 ± 0.42 in COVID-19 patients and 1.50 ± 0.50 in non-COVID-19 patients (p < .001). In COVID-19 patients, but not in non-COVID-19 patients, lymphocyte count was inversely correlated with the proportion of telomeres shorter than 2 kb (p = .005) and positively correlated with TeSLA mTL (p = .03). Lymphocyte count was not significantly correlated with SB mTL in either COVID-19 or non-COVID-19 patients. We propose that compromised TL-dependent T-cell proliferative response, driven by short telomere in the TL distribution, contributes to COVID-19 lymphopenia among old adults. We infer that infection with SARS-CoV-2 uncovers the limits of the TL reserves of older persons. Clinical Trials Registration Number: NCT04325646.

Influence of NAD+ as an ageing-related immunomodulator on COVID 19 infection: A hypothesis.

The aging-associated decline of biological functions represents an important contributor to the increase in morbidity and mortality of human beings. Of these biological functions deterioration; there is a significant decline in the heart function, impairments in the lungs gas exchange, and impairments in the immune function. Many alterations in the body humeral and cellular immune response were observed with ageing process: The circulating pro-inflammatory cytokines are increased, the naive lymphocytes are decreased, the numbers of the antigen-presenting cells areelevated and the overall response is impaired. In addition, ageing is associated with a progressive restriction in the telomere length. Telomeres are located at chromosomes ends and play an essential role in preserving chromosome stability. Also, telomere length is very important to the immune system, because of the high sensitivity of the immune cells to the shortening of telomeres. Telomeres shortening adversely affect the immune cells' function and developments. These adverse changes increased the susceptibility for severe infection, risk of hospitalization, and even death. Elderly COVID-19 patients are at a real risk of complications due to impaired immune function, cytokine storm and defective respiratory function. Administration of anti-ageing immunomodulation factors like Nicotinamide Adenine Dinucleotide NAD+ can minimize these changes through its potent immunomodulation and longevity effects. NAD+ has a direct inhibitory effect on PARP-1 and can prevent pro-inflammatory cytokines over-activation. Increasing the NAD+ level will also result in stabilizing telomeres and this has a positive impact on immune cells function.