Effects of Inflammation and Depression on Telomere Length in Young Adults in the United States

Sex-specific modulating role of social support in the associations between oxidative stress, inflammation, and telomere length in older adults

Telomere length, a biomarker of human aging, is related to adverse health outcomes. Growing evidence indicates that oxidative stress and inflammation contributes to telomere shortening, whereas social support may protect from telomere shortening. Despite sex differences in telomere length and social support, little is known about whether there are sex differences in the relationship between oxidative stress/inflammation and telomere length, and sex-specific moderating roles of social support in older adults. Using data from the National Health and Nutrition Examination Survey (NHANES) 1999-2002, this study assessed whether the associations between oxidative stress/inflammation and telomere length vary with sex and explored social support as a moderator in these associations among 2289 older adults. Oxidative stress was measured based on serum Gamma-glutamyl transferase (GGT), and inflammation was measured based on C-reactive protein (CRP). After adjusting for the covariates, GGT was significantly associated with telomere length in females only (β =  - 0.037, 95% CI =  - 0.070, - 0.005), while CRP was associated with telomere length in males only (β =  - 0.019, 95% CI =  - 0.035, - 0.002). Moreover, high social support mitigated the negative association between GGT and telomere length, which was more evident in females. Furthermore, social support moderated the association between CRP and telomere length in males aged 70 and above. Our findings indicated that biological mechanisms related to telomere length may vary with sex, while social support plays a sex-specific moderating role.

CRL4DCAF4 E3 ligase-mediated degradation of MEN1 transcriptionally reactivates hTERT to sustain immortalization in colorectal cancer cells

Telomerase reactivation is implicated in approximately 85% of human cancers, yet its underlying mechanism remains elusive. In this study, we elucidate that the cullin-RING ubiquitin ligase 4 (CRL4) complex drives the reactivation of human telomerase reverse transcriptase (hTERT) in colorectal cancer (CRC) by degrading the tumor suppressor, menin 1 (MEN1). Our data show that, in noncancerous intestinal epithelial cells, the transcription factor specificity protein 1 (Sp1) recruits both the histone acetyltransferase p300 and MEN1 to suppress hTERT expression, thus maintaining telomere shortness post-cell division. Inflammation-induced microenvironments trigger an activation of the CRL4DCAF4 E3 ligase, leading to MEN1 ubiquitination and degradation in CRC cells. This process nullifies MEN1's inhibitory action, reactivates hTERT expression at the transcriptional level, interrupts telomere shortening and spurs uncontrolled cellular proliferation. Notably, MEN1 overexpression in CRC cells partially counteracts these oncogenic phenotypes. NSC1517, an inhibitor of the CRL4DCAF4 complex identified through high-throughput screening from a plant-derived chemical pool, hinders MEN1 degradation, attenuates hTERT expression and suppresses tumor growth in mouse xenograft models. Collectively, our research elucidates the transcriptional mechanism driving hTERT reactivation in CRC. Targeting the CRL4DCAF4 E3 ligase emerges as a promising strategy to counteract cancer cell immortalization and curb tumor progression.

Differential effects of long- and short-term exposure to PM2.5 on accelerating telomere shortening: from in vitro to epidemiological studies

Exposure to air pollutants has been associated with DNA damage and increases the risks of respiratory diseases, such as asthma and COPD; however short- and long-term effects of air pollutants on telomere dysfunction remain unclear. We investigated the impact of short- and long-term exposure to fine particulate matter with an aerodynamic diameter below 2.5 μm (PM2.5) on telomere length in human bronchial epithelial BEAS-2B cells, and assessed the potential correlation between PM2.5 exposure and telomere length in the LIGHTS childhood cohort study. We observed that long-term, but not short-term, PM2.5 exposure was significantly associated with telomere shortening, along with the downregulation of human telomerase reverse transcriptase (hTERT) mRNA and protein levels. Moreover, long-term exposure to PM2.5 induced proinflammatory cytokine secretion, notably interleukin 6 (IL-6) and IL-8, triggered subG1 cell cycle arrest, and ultimately caused cell death. Long-term exposure to PM2.5 upregulated the LC3-II/ LC3-I ratio but led to p62 protein accumulation in BEAS-2B cells, suggesting a blockade of autophagic flux. Moreover, consistent with our in vitro findings, our epidemiological study found significant association between annual average exposure to higher PM2.5 and shortening of leukocyte telomere length in children. However, no significant association between 7-day short-term exposure to PM2.5 and leukocyte telomere length was observed in children. By combining in vitro experimental and epidemiological studies, our findings provide supportive evidence linking potential regulatory mechanisms to population level with respect to long-term PM2.5 exposure to telomere shortening in humans.

Chronic Astrocytic TNFα Production in the Preoptic-Basal Forebrain Causes Aging-like Sleep-Wake Disturbances in Young Mice

Sleep disruption is a frequent problem of advancing age, often accompanied by low-grade chronic central and peripheral inflammation. We examined whether chronic neuroinflammation in the preoptic and basal forebrain area (POA-BF), a critical sleep-wake regulatory structure, contributes to this disruption. We developed a targeted viral vector designed to overexpress tumor necrosis factor-alpha (TNFα), specifically in astrocytes (AAV5-GFAP-TNFα-mCherry), and injected it into the POA of young mice to induce heightened neuroinflammation within the POA-BF. Compared to the control (treated with AAV5-GFAP-mCherry), mice with astrocytic TNFα overproduction within the POA-BF exhibited signs of increased microglia activation, indicating a heightened local inflammatory milieu. These mice also exhibited aging-like changes in sleep-wake organization and physical performance, including (a) impaired sleep-wake functions characterized by disruptions in sleep and waking during light and dark phases, respectively, and a reduced ability to compensate for sleep loss; (b) dysfunctional VLPO sleep-active neurons, indicated by fewer neurons expressing c-fos after suvorexant-induced sleep; and (c) compromised physical performance as demonstrated by a decline in grip strength. These findings suggest that inflammation-induced dysfunction of sleep- and wake-regulatory mechanisms within the POA-BF may be a critical component of sleep-wake disturbances in aging.

Genetic polymorphisms affecting telomere length and their association with cardiovascular disease in the Heinz-Nixdorf-Recall study

Short telomeres are associated with cardiovascular disease (CVD). We aimed to investigate, if genetically determined telomere-length effects CVD-risk in the Heinz-Nixdorf-Recall study (HNRS) population. We selected 14 single-nucleotide polymorphisms (SNPs) associated with telomere-length (p<10-8) from the literature and after exclusion 9 SNPs were included in the analyses. Additionally, a genetic risk score (GRS) using these 9 SNPs was calculated. Incident CVD was defined as fatal and non-fatal myocardial infarction, stroke, and coronary death. We included 3874 HNRS participants with available genetic data and had no known history of CVD at baseline. Cox proportional-hazards regression was used to test the association between the SNPs/GRS and incident CVD-risk adjusting for common CVD risk-factors. The analyses were further stratified by CVD risk-factors. During follow-up (12.1±4.31 years), 466 participants experienced CVD-events. No association between SNPs/GRS and CVD was observed in the adjusted analyses. However, the GRS, rs10936599, rs2487999 and rs8105767 increase the CVD-risk in current smoker. Few SNPs (rs10936599, rs2487999, and rs7675998) showed an increased CVD-risk, whereas rs10936599, rs677228 and rs4387287 a decreased CVD-risk, in further strata. The results of our study suggest different effects of SNPs/GRS on CVD-risk depending on the CVD risk-factor strata, highlighting the importance of stratified analyses in CVD risk-factors.

Strong associations of telomere length and mitochondrial copy number with suicidality and abuse history in adolescent depressed individuals

Major depressive disorder (MDD) is highly prevalent in adolescents and is a major risk factor for suicidality. Recent evidence shows that accelerated cellular senescence/aging is associated with psychiatric illness, including depression, in adults. The present study examined if the relationships of telomere length (TL) and mitochondrial DNA copy number (mtDNAcn), two critical indicators of cellular senescence/aging, are altered in depressed adolescents and whether these alterations are associated with suicidality, early-life adversities, and other co-occuring factors. In genomic DNA isolated from 53 adolescents (ages 16-19, 19 MDD with suicide attempt/suicidal ideation [MDD + SI/SA], 14 MDD without SA/SI [MDD-SI/SA], and 20 healthy controls [HC]), TL and mtDNAcn were measured as the ratio between the number of telomere repeats and that of a single-copy nuclear-hemoglobin [HBG] gene or the amount of mtDNA (NADH dehydrogenase, subunit 1) relative to HBG. Our data show that TL was significantly lower, and mtDNAcn was significantly higher in the total MDD group than HC. TL was significantly lower and mtDNAcn was significantly higher in the MDD + SA/SI group than in the HC, whereas there were no differences in the MDD-SI/SA group. TL was positively correlated with mtDNAcn in both HC and MDD-SA/SI groups; however, TL was negatively correlated with mtDNAcn in MDD + SA/SI. Furthermore, TL was negatively correlated with the severity of both depression and anxiety, while mtDNAcn was positively correlated with the severity of prior emotional abuse. Our study indicates that cellular senescence is more advanced in depressed adolescents with suicidal ideation and that childhood emotional abuse may participate in such a process.

Shorter telomere length predicts poor antidepressant response and poorer cardiometabolic indices in major depression

Telomere length (TL) is a marker of biological aging, and shorter telomeres have been associated with several medical and psychiatric disorders, including cardiometabolic dysregulation and Major Depressive Disorder (MDD). In addition, studies have shown shorter TL to be associated with poorer response to certain psychotropic medications, and our previous work suggested shorter TL and higher telomerase activity (TA) predicts poorer response to Selective Serotonin Reuptake Inhibitor (SSRI) treatment. Using a new group of unmedicated medically healthy individuals with MDD (n = 48), we sought to replicate our prior findings demonstrating that peripheral blood mononuclear cell (PBMC) TL and TA predict response to SSRI treatment and to identify associations between TL and TA with biological stress mediators and cardiometabolic risk indices. Our results demonstrate that longer pre-treatment TL was associated with better response to SSRI treatment (β = .407 p = .007). Additionally, we observed that TL had a negative relationship with allostatic load (β = - .320 p = .017) and a cardiometabolic risk score (β = - .300 p = .025). Our results suggest that PBMC TL reflects, in part, the cumulative effects of physiological stress and cardiovascular risk in MDD and may be a biomarker for predicting SSRI response.

The Relationship Between Telomeres, Cognition, Mood, and Physical Function: A Systematic Review

Background and Purpose: Cognitive, affective, and physical symptoms and alterations in their function are seen across chronic illnesses. Data suggest that environmental, psychological, and physiological factors contribute to symptom experience, potentially through loss of telomeres (telomere attrition), structures at the ends of chromosomes. Telomere length is affected by many factors including environmental (e.g., exercise, diet, smoking) and physiological (e.g., response to stress), as well as from oxidative damage and inflammation that occurs in many disease processes. Moreover, telomere attrition is associated with chronic disease (cancer, cardiovascular disease, Alzheimer's disease) and predicts higher morbidity and mortality rates. However, findings are inconsistent among telomere roles and relationships with health outcomes. This article aims to synthesize the current state-of-the-science of telomeres and their relationship with cognitive, affective, and physical function and symptoms. Method: A comprehensive literature search was performed in two databases: CINAHL and PUBMED. A total of 33 articles published between 2000 and 2022 were included in the final analysis. Results: Telomere attrition is associated with various changes in cognitive, affective, and physical function and symptoms. However, findings are inconsistent. Interventional studies (e.g., meditation and exercise) may affect telomere attrition, potentially impacting health outcomes. Conclusion: Nursing research and practice are at the forefront of furthering the understanding of telomeres and their relationships with cognitive, affective, and physical function and symptoms. Future interventions targeting modifiable risk factors may be developed to improve health outcomes across populations.

By what molecular mechanisms do social determinants impact cardiometabolic risk?

While it is well known from numerous epidemiologic investigations that social determinants (socioeconomic, environmental, and psychosocial factors exposed to over the life-course) can dramatically impact cardiovascular health, the molecular mechanisms by which social determinants lead to poor cardiometabolic outcomes are not well understood. This review comprehensively summarizes a variety of current topics surrounding the biological effects of adverse social determinants (i.e., the biology of adversity), linking translational and laboratory studies with epidemiologic findings. With a strong focus on the biological effects of chronic stress, we highlight an array of studies on molecular and immunological signaling in the context of social determinants of health (SDoH). The main topics covered include biomarkers of sympathetic nervous system and hypothalamic-pituitary-adrenal axis activation, and the role of inflammation in the biology of adversity focusing on glucocorticoid resistance and key inflammatory cytokines linked to psychosocial and environmental stressors (PSES). We then further discuss the effect of SDoH on immune cell distribution and characterization by subset, receptor expression, and function. Lastly, we describe epigenetic regulation of the chronic stress response and effects of SDoH on telomere length and aging. Ultimately, we highlight critical knowledge gaps for future research as we strive to develop more targeted interventions that account for SDoH to improve cardiometabolic health for at-risk, vulnerable populations.

Higher Daily Air Temperature Is Associated with Shorter Leukocyte Telomere Length: KORA F3 and KORA F4

Higher air temperature is associated with increased age-related morbidity and mortality. To date, short-term effects of air temperature on leukocyte telomere length have not been investigated in an adult population. We aimed to examine the short-term associations between air temperature and leukocyte telomere length in an adult population-based setting, including two independent cohorts. This population-based study involved 5864 participants from the KORA F3 (2004-2005) and F4 (2006-2008) cohort studies conducted in Augsburg, Germany. Leukocyte telomere length was assessed by a quantitative PCR-based method. We estimated air temperature at each participant's residential address through a highly resolved spatiotemporal model. We conducted cohort-specific generalized additive models to explore the short-term effects of air temperature on leukocyte telomere length at lags 0-1, 2-6, 0-6, and 0-13 days separately and pooled the estimates by fixed-effects meta-analysis. Our study found that between individuals, an interquartile range (IQR) increase in daily air temperature was associated with shorter leukocyte telomere length at lags 0-1, 2-6, 0-6, and 0-13 days (%change: -2.96 [-4.46; -1.43], -2.79 [-4.49; -1.07], -4.18 [-6.08; -2.25], and -6.69 [-9.04; -4.27], respectively). This meta-analysis of two cohort studies showed that between individuals, higher daily air temperature was associated with shorter leukocyte telomere length.

Updated Understanding of the Causes of Cancer, and a New Theoretical Perspective of Combinational Cancer Therapies, a Hypothesis

We present an integrative understanding of cancer as a metabolic multifactorial, multistage disease. We focus on underlying genetics-environmental interactions, evidenced by telomere changes. A range of genetic and epigenetic factors, including physical agents and predisposing factors such as diet and lifestyle are included. We present a structured model of the causes of cancer, methods of investigations, approaches to cancer prevention, and polypharmaceutical multidisciplinary complex treatment within a framework of personalized medicine. We searched PubMed, National Cancer Institute online, and other databases for publications regarding causes of cancer, reports of novel mitochondrial reprogramming, epigenetic, and telomerase therapies and state-of-the-art investigations. We focused on multistep treatment protocols to enhance early detection of cancer, and elimination or neutralization of the causes and factors associated with cancer formation and progression.Our aim is to suggest a model therapeutic protocol that incorporates the patient's genome, metabolism, and immune system status; stage of tumor development; and comorbidity(ies), if any. Investigation and treatment of cancer is a challenge that requires further holistic studies that improve the quality of life and survival rates, but are most likely to aid prevention.

Born to Age: When Adult Congenital Heart Disease Converges With Geroscience

Advances in imaging, catheter-based interventions, congenital heart disease surgery, and clinical management of congenital heart disease (CHD) have yielded a dramatic change in age distribution of the CHD population. This implores clinicians and researchers to gain a better understanding of aging, as this will be the cornerstone to how we plan and manage this rapidly evolving group of patients. In this article, we first review the demographic changes in the CHD population and then describe the systemic complications of disease observed in young patients with CHD, following which we discuss general concepts in aging that may be transferable to the CHD population. Finally, we review inflammation and its potential impact on aging. We provide a new lens on aging in CHD and its functional consequences in CHD, with the goal of stimulating an exchange of knowledge between geroscientists and CHD.

Intermediate Effects of Body Mass Index and C-Reactive Protein on the Serum Cotinine- Leukocyte Telomere Length Association

We aimed to examine the association between serum cotinine and leukocyte telomere length (LTL) and the intermediate effects of body mass index (BMI) and C-reactive protein (CRP) on modulating the association. This study included 4,047 adults from the 1999 to 2002 National Health and Nutrition Examination Survey. In the combined sample, after adjusting for age, race, sex, physical activity, and alcohol use, the total effect of serum cotinine on LTL was significant (standardized regression coefficient, β = −0.049, p = 0.001) without BMI and CRP included in the model. With inclusion of BMI but without CRP in the model, the direct effect of cotinine on LTL in its absolute value increased to β = −0.053 (p < 0.001), and the suppression effect of BMI was estimated at 8.8%. With inclusion of CRP but without BMI in the model, the direct effect of cotinine on LTL in its absolute value decreased to β = −0.040 (p = 0.008), and the mediation effect of CRP was estimated at 16.9%. With inclusion of both BMI and CRP in the model, BMI and CRP still had significant suppression and mediation effects, respectively, on the cotinine-LTL association. These findings suggest that weight and inflammation have different roles in the inverse association between serum cotinine and LTL.

Stress and telomere shortening: Insights from cellular mechanisms

Short telomeres confer risk of degenerative diseases. Chronic psychological stress can lead to disease through many pathways, and research from in vitro studies to human longitudinal studies has pointed to stress-induced telomere damage as an important pathway. However, there has not been a comprehensive model to describe how changes in stress physiology and neuroendocrine pathways can lead to changes in telomere biology. Critically short telomeres or the collapse of the telomere structure caused by displacement of telomere binding protein complex shelterin elicit a DNA damage response and lead to senescence or apoptosis. In this narrative review, we summarize the key roles glucocorticoids, reactive oxygen species (ROS) and mitochondria, and inflammation play in mediating the relationship between psychological stress and telomere maintenance. We emphasis that these mediators are interconnected and reinforce each other in positive feedback loops. Telomere length has not been studied across the lifespan yet, but the initial setting point at birth appears to be the most influential point, as it sets the lifetime trajectory, and is influenced by stress. We describe two types of intergenerational stress effects on telomeres - prenatal stress effects on telomeres during fetal development, and 'telotype transmission" -the directly inherited transmission of short telomeres from parental germline. It is clear that the initial simplistic view of telomere length as a mitotic clock has evolved into a far more complex picture of both transgenerational telomere influences, and of interconnected molecular and cellular pathways and networks, as hallmarks of aging where telomere maintenance is a key player interacting with mitochondria. Further mechanistic investigations testing this comprehensive model of stress mediators shaping telomere biology and the telomere-mitochondrial nexus will lead to better understanding from cell to human lifespan aging, and could lead to anti-aging interventions.

Association Between Body Weight and Telomere Length Is Predominantly Mediated Through C-Reactive Protein

CONTEXT

Both obesity and inflammation are related to accelerated aging. It is not yet known whether inflammation mediates the effects of obesity on aging.

OBJECTIVE

This work aims to dissect the direct effect of body mass index (BMI) and its indirect effect through C-reactive protein (CRP) on leukocyte telomere length (LTL) to determine the mediation effect of CRP on the BMI-LTL association.

METHODS

The study cohort included 5451 adults (1404 Mexican American, 3114 White, and 933 Black individuals; 53.5% male; mean age = 49.2 years) from the 1999 to 2002 National Health and Nutrition Examination Survey. General mediation models were used to examine the mediation effect of CRP on the BMI-LTL association.

RESULTS

After adjusting for age, race, sex, physical activity, alcohol use, and serum cotinine, the total effect of BMI on LTL was significant (standardized regression coefficient, β = -.054, P < .001) without CRP included in the model. With inclusion of CRP in the model, the indirect effect of BMI on LTL through CRP was estimated at β equal to -.023 (P < .001), and the direct effect of BMI on LTL in its absolute value decreased to β equal to -.031 (P = .025). The mediation effect of CRP was estimated at 42.6%. The mediation model parameters did not differ significantly between race and sex groups.

CONCLUSION

These results suggest that the inverse BMI-LTL association is partly mediated by obesity-induced inflammation. The significant direct effect of BMI on LTL with removal of the mediation effect through CRP indicates that obesity is associated with LTL attrition also through other noninflammatory mechanisms.

Linking the Triad of Telomere Length, Inflammation, and Gut Dysbiosis in the Manifestation of Depression

Telomere length is an indispensable marker for cellular and biological aging, and it also represents an individual's physical and mental health status. Telomere shortening has been observed in chronic inflammatory conditions, which in turn accelerates aging and risk for psychiatric disorders, including depression. Considering the influence of inflammation and telomere shortening on the gut-brain axis, herein we describe a plausible interplay between telomere attrition, inflammation, and gut dysbiosis in the neurobiology of depression. Telomere shortening and hyperinflammation are well reported in depression. A negative impact of augmented inflammation has been noted on the intestinal permeability and microbial consortia and their byproducts in depressive patients. Moreover, gut dysbiosis provokes host-immune responses. As the gut microbiome is gaining importance in the manifestation and management of depression, herein we discuss whether telomere attrition is connected with the perturbation of commensal microflora. We also describe a pathological connection of cortisol with hyperinflammation, telomere shortening, and gut dysbiosis occurring in depression. This review summarizes how the triad of telomere attrition, inflammation, and gut dysbiosis is interconnected and modulates the risk for depression by regulating the systemic cortisol levels.

Sleep duration, Health Promotion Index (HPI), sRAGE and ApoE-ε4 genotype are associated with telomere length (TL) in healthy elderly Australians

Significant alterations in sleep duration and/or quality of sleep become more pronounced as people get older. Poor sleep in elderly people is associated with adverse health outcomes and cellular ageing. We examined the relationship between TL and sleep duration, Health Promotion Index (HPI), and tested whether the presence of ApoE-ε4 allele impacts both sleep and TL. The present study was carried out in 174 healthy elderly subjects (21% male; mean age 53.79 years) from South Australia. Lymphocyte telomere length (TL) was measured by real-time qPCR and ApoE genotype was determined by TaqMan assay. HPI was calculated from a questionnaire regarding 8 lifestyle habits, including sleeping hours. Multivariate regression analysis was used to establish these associations adjusted for specified confounders. TL was found to be inversely associated with age (r = - 0.199; p = 0.008) and BMI (r = - 0.121; p = 0.11), and was significantly shorter in participants who slept for <7 hours (p = 0.001) relative to those sleeping ≥7 hours. TL was positively correlated with HPI (r = 0.195; p = 0.009). ApoE-ε4 allele carriers who slept for less than 7 hours had shortest TL (p = 0.01) compared to non-carriers. Plasma sRAGE level was significantly (p = 0.001) lower in individuals who sleep <7 hours and ApoE-ϵ4 carriers. Our results suggest that inadequate sleep duration or poor HPI is associated with shorter TL in cognitively normal elderly people and that carriage of APOE-ε4 genotype may influence the extent of these effects.

Telomeres: the role of shortening and senescence in major depressive disorder and its therapeutic implications

Major depressive disorder (MDD) is one of the most prevalent and debilitating psychiatric disorders, with a large number of patients not showing an effective therapeutic response to available treatments. Several biopsychosocial factors, such as stress in childhood and throughout life, and factors related to biological aging, may increase the susceptibility to MDD development. Included in critical biological processes related to aging and underlying biological mechanisms associated with MDD is the shortening of telomeres and changes in telomerase activity. This comprehensive review discusses studies that assessed the length of telomeres or telomerase activity and function in peripheral blood cells and brain tissues of MDD individuals. Also, results from in vitro protocols and animal models of stress and depressive-like behaviors were included. We also expand our discussion to include the role of telomere biology as it relates to other relevant biological mechanisms, such as the hypothalamic-pituitary-adrenal (HPA) axis, oxidative stress, inflammation, genetics, and epigenetic changes. In the text and the discussion, conflicting results in the literature were observed, especially considering the size of telomeres in the central nervous system, on which there are different protocols with divergent results in the literature. Finally, the context of this review is considering cell signaling, transcription factors, and neurotransmission, which are involved in MDD and can be underlying to senescence, telomere shortening, and telomerase functions.

Regulation of PINX1 expression ameliorates lipopolysaccharide-induced lung injury and alleviates cell senescence during the convalescent phase through affecting the telomerase activity

PIN2/TERF1-interacting telomerase inhibitor 1 (PINX1) is necessary for telomerase reverse transcriptase (TERT) elements to bind at telomeres and non-telomere sites. We aimed to investigate the role of PINX1 and TERT in lipopolysaccharide (LPS)-induced lung injury during acute stage and convalescent phase. Lung injury rat model was induced, and the expression of PINX1 and TERT in serum and lung tissues was examined using RT-qPCR on day 0 (D0), D3, and D14, respectively. The pathologic changes of lung tissues on D3 and D14 were detected using hematoxylin and eosin staining after TERT overexpression, PINX1 overexpression, or PINX1 silencing in lung injury rats. Results revealed that TERT was persistently reduced on D3 and D14, while PINX1 was decreased on D3 but increased on D14. TERT overexpression and PINX1 silencing led to the most serious lung damage, the highest levels of inflammatory factors and apoptosis on D3, while the best recovery was observed on D14. Simultaneously, PINX1 overexpression presented the opposite effects at acute stage and convalescent phase. Co-immunoprecipitation (co-IP) assay verified the connection between PINX1 and TERT. Taken together, these findings demonstrated that regulation of PINX1 expression ameliorates lung injury and alleviates cell senescence during the convalescent phase through affecting the telomerase activity.

Shorter Telomere Length in Peripheral Blood Leukocytes Is Associated with Post-Traumatic Chronic Osteomyelitis

Background: This study investigated the association between post-traumatic chronic osteomyelitis (COM) and peripheral leukocyte telomere length (PLTL) and explored factors associated with PLTL in COM. Methods: A total of 56 patients with post-traumatic COM of the extremity and 62 healthy control subjects were recruited. The PLTL was measured by real-time PCR. Binary logistic regression analysis was used to identify factors in correlation with telomere length. Sex, age, white blood cell (WBC) count, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), and infection duration were included as independent variables in the logistic regression model. Results: Post-traumatic COM patients had significantly shorter PLTLs (5.39 ± 0.40) than healthy control subjects (5.69 ± 0.46; p < 0.001). Binary logistic regression analysis showed that PLTL had a statistically significant association with age (B = -0.072; p = 0.013) and CRP (B = -0.061; p = 0.033). The logistic regression model was statistically significant and explained 31.4% (Nagelkerke R2) of the change in telomere length and correctly classified 69.6% of the cases. Conclusions: Patients with post-traumatic COM have shorter PLTLs than healthy subjects. The PLTL erosion of post-traumatic COM was partially explained by age and CRP.

Updated Understanding of Cancer as a Metabolic and Telomere-Driven Disease, and Proposal for Complex Personalized Treatment, a Hypothesis

In this review, we propose a holistic approach to understanding cancer as a metabolic disease. Our search for relevant studies in medical databases concludes that cancer cells do not evolve directly from normal healthy cells. We hypothesize that aberrant DNA damage accumulates over time-avoiding the natural DNA controls that otherwise repair or replace the rapidly replicating cells. DNA damage starts to accumulate in non-replicating cells, leading to senescence and aging. DNA damage is linked with genetic and epigenetic factors, but the development of cancer is favored by telomerase activity. Evidence indicates that telomere length is affected by chronic inflammations, alterations of mitochondrial DNA, and various environmental factors. Emotional stress also influences telomere length. Chronic inflammation can cause oxidative DNA damage. Oxidative stress, in turn, can trigger mitochondrial changes, which ultimately alter nuclear gene expression. This vicious cycle has led several scientists to view cancer as a metabolic disease. We have proposed complex personalized treatments that seek to correct multiple changes simultaneously using a psychological approach to reduce chronic stress, immune checkpoint therapy with reduced doses of chemo and radiotherapy, minimal surgical intervention, if any, and mitochondrial metabolic reprogramming protocols supplemented by intermittent fasting and personalized dietary plans without interfering with the other therapies.

Effects of fermented rice bran on DEN-induced oxidative stress in mice: GSTP1, LINE-1 methylation, and telomere length ratio

N-diethylnitrosamine (DEN), a well-known carcinogen, not only induces excessive reactive oxygen species but also suppresses DNA methylation. This study investigated the effect of fermented rice bran (FRB) treatment on DEN-induced oxidative stress through DNA methylation and telomere length analysis. To evaluate the potential protective role of FRB in oxidative stress, two different doses of FRB, DEN, and their combination were administered to mice that were preadapted or not to FRB. Glutathione-S-transferase P1 (GSTP1) methylation levels significantly decreased at 2 and 24 hr after FRB and DEN co-administration in mice with and without pre-adaptation. Moreover, GSTP1 mRNA was upregulated under DEN-induced oxidative stress. Furthermore, changes in long interspersed nuclear element-1 methylation were observed from the viewpoint of genomic instability. In addition, FRB preadapted mice displayed a lower telomere length ratio than the non-adapted mice, suggesting that FRB adaptation offers advantages over the non-adapted conditions in terms of inflammation suppression. PRACTICAL APPLICATIONS: DEN induces excessive ROS, which is associated with oxidative stress on DNA and other cellular components, resulting in inflammation. This study shows that FRB may alleviate DEN-triggered oxidative stress, based on changes in GSTP1, LINE-1 methylation, and telomere length ratios, thereby, revealing the potential of dietary intervention during inflammation. Furthermore, this study furthers the current understanding of DNA methylation mechanisms underlying the antioxidant and anti-inflammatory effects of functional food components. These results indicate that dietary inclusion of FRB may help decrease oxidative DNA damage and its associated inflammation at early stages of a disease.