The association between telomere length and ischemic stroke risk and phenotype

Analysis of the Association between Telomere Length and Neurological Disability in Stroke Types

Background and Objectives: The association between neurological disability, prognosis, and telomere length (TL) in patients with stroke has been investigated in various ways. However, analysis of the type of stroke and ischemic stroke subgroups is limited. In this study, we aimed to determine the association between TL and neurological disability according to stroke type. Materials and Methods: This prospective study included patients with stroke who visited a single-center emergency department (ED) between January 2022 and December 2023. The association between TL and neurological disabilities, using the Modified Rankin Scale (mRS) and National Institutes of Health Stroke Scale (NIHSS), was evaluated according to the patient's stroke type and subgroup of ischemic stroke. Multivariate analysis was performed to determine the association between neurological disabilities in patients with ischemic stroke and the subgroups. Results: A total of 271 patients with stroke were enrolled. The NIHSS score was found to be higher at the time of ED visit (adjusted odds ratio [OR], 5.23; 95% confidence interval [CI], 1.59-17.2, p < 0.01) and 1 day later (adjusted OR, 7.78; 95% CI, 1.97-30.70, p < 0.01) in the ischemic stroke group with a short TL. In the other determined etiology (OD) or undetermined etiology (UD) group, the NIHSS was higher in the short TL group at the ED visit (adjusted OR, 7.89; 95% CI, 1.32-47.25, p = 0.02) and 1 day after (adjusted OR, 7.02; 95% CI, 1.14-43.47, p = 0.04). Conclusions: TL is associated with neurological disability in early ischemic stroke and is prominent in the UD and OD subgroups.

Electroacupuncture Ameliorates Neuronal Damage and Neurological Deficits after Cerebral Ischemia-Reperfusion Injury via Restoring Telomerase Reverse Transcriptase

The purpose of this study is to identify the therapeutic effect of electroacupuncture (EA) on cerebral ischemia-reperfusion (I/R) injury, and to clarify the regulatory mechanism related to telomerase reverse transcriptase (TERT)-mediated telomerase activity. A Middle cerebral artery occlusion/reperfusion (MCAO/R) animal model was constructed and rats were treated by EA invention at the Baihui (GV20) and Fengchi (GB20) acupoints. Neurological deficits were assessed via rotarod test and Morris water maze test. 2,3,5-Triphenyltertrazolium chloride (TTC) staining was performed to evaluate infarct volume. Histological changes were observed under H&E staining and Nissl staining. TERT expression was examined using qRT-PCR and western blot. Telomerase activity was assessed with TRAP method. Neuron apoptosis and senescence were assessed by TUNEL and immunofluorescence assays. Inflammatory cytokines and oxidative stress-indicators were examined using commercial kits. EA intervention at both GV20 and GB20 acupoints reduced infarct volumes (2.48 ± 1.89 vs. 29.56 ± 2.55), elevated the telomerase activity (0.84 ± 0.08 vs. 0.34 ± 0.09), and upregulated the levels of total TERT protein (0.61 ± 0.09 vs. 0.21 ± 0.05) and mitochondrial TERT (Mito-TERT; 0.54 ± 0.03 vs. 0.27 ± 0.03) in hippocampus tissues of MCAO/R rats. EA intervention attenuated motor dysfunction (112.00 ± 6.69 vs. 30.02 ± 2.60) and improved spatial learning (23.87 ± 1.90 vs. 16.23 ± 1.45) and memory ability (8.38 ± 1.06 vs. 4.13 ± 1.13) of rats with cerebral I/R injury. In addition, EA intervention significantly attenuated histopathological changes of injured neurons, mitigated neuron apoptosis (32.27 ± 5.52 vs. 65.83 ± 4.31) and senescence in MCAO/R rats, as well as inhibited excessive production of inflammatory cytokines and attenuated oxidative stress. However, the above therapeutic efficiency of EA intervention in MCAO/R rats was partly eliminated by TERT knockdown. EA intervention at GB20 and GV20 acupoints exerted a protective role in cerebral I/R injury partly through restoring TERT function, implying the clinical potential of EA treatment in the treatment of ischemic stroke.

Prediagnosis recognition of acute ischemic stroke by artificial intelligence from facial images

Stroke is a major threat to life and health in modern society, especially in the aging population. Stroke may cause sudden death or severe sequela-like hemiplegia. Although computed tomography (CT) and magnetic resonance imaging (MRI) are standard diagnosis methods, and artificial intelligence models have been built based on these images, shortage in medical resources and the time and cost of CT/MRI imaging hamper fast detection, thus increasing the severity of stroke. Here, we developed a convolutional neural network model by integrating four networks, Xception, ResNet50, VGG19, and EfficientNetb1, to recognize stroke based on 2D facial images with a cross-validation area under curve (AUC) of 0.91 within the training set of 185 acute ischemic stroke patients and 551 age- and sex-matched controls, and AUC of 0.82 in an independent data set regardless of age and sex. The model computed stroke probability was quantitatively associated with facial features, various clinical parameters of blood clotting indicators and leukocyte counts, and, more importantly, stroke incidence in the near future. Our real-time facial image artificial intelligence model can be used to rapidly screen and prediagnose stroke before CT scanning, thus meeting the urgent need in emergency clinics, potentially translatable to routine monitoring.

Cognitive and emotional impairment in stroke survivors: insights from a multi-center study on inpatient rehabilitation therapy

BACKGROUND

Individuals recovering from stroke often experience cognitive and emotional impairments, but rehab programs tend to focus on motor skills. The aim of this investigation is to systematically assess the change of magnitude of cognitive and emotional function subsequent to a conventional rehabilitative protocol administered to stroke survivors within a defined locale in China.

METHODS

This is a multicenter study; a total of 1884 stroke survivors who received in-hospital rehabilitation therapy were assessed on admission (T0) and discharge (T1). The tool of InterRAI was used to assess cognitive, emotional, and behavioral abnormality.

RESULTS

The patients aged >60 years, with a history of hypertension, and long stroke onset duration were more exposed to functional impairment (all p < 0.05). Both cognitive and emotional sections were significantly improved at T1 compared to T0 (p < 0.001). Initially, 64.97% and 46.55% of patients had cognitive or emotional impairment at T0, respectively; this percentage was 58.55% and 37.15% at T1.

CONCLUSION

Many stroke survivors have ongoing cognitive and emotional problems that require attention. It is essential to focus on rehabilitating these areas during the hospital stay, especially for older patients, those with a longer recovery, and those with hypertension history.

Age-Related Alterations in Immune Function and Inflammation: Focus on Ischemic Stroke

The aging of the global population poses significant scientific challenges. Moreover, the biological process of aging is the most significant risk factor for most chronic illnesses; therefore, understanding the molecular and cellular mechanisms underlying these aging-related challenges is crucial for extending the healthy lifespan of older individuals. Preventing brain aging remains a priority public health goal, and integrative and comprehensive aging analyses have revealed that immunosenescence is a potential cause of age-related brain damage and disease (e.g., stroke). Importantly, the neuroinflammatory and immune systems present two-way contact and thus can affect each other. Emerging evidence supports the numerous effects of immunosenescence- and inflammation-mediated immunity in neurologically injured brains. In this study, we briefly outline how aging alters the pathophysiology and transcriptional amplitude in patients who experienced stroke and then discuss how the immune system and its cellular components and molecular mechanisms are affected by age after stroke. Finally, we highlight emerging interventions with the potential to slow down or reduce aging and prevent stroke onset.

A Unified Model of Age-Related Cardiovascular Disease

Despite progress in biomedical technologies, cardiovascular disease remains the main cause of mortality. This is at least in part because current clinical interventions do not adequately take into account aging as a driver and are hence aimed at suboptimal targets. To achieve progress, consideration needs to be given to the role of cell aging in disease pathogenesis. We propose a model unifying the fundamental processes underlying most age-associated cardiovascular pathologies. According to this model, cell aging, leading to cell senescence, is responsible for tissue changes leading to age-related cardiovascular disease. This process, occurring due to telomerase inactivation and telomere attrition, affects all components of the cardiovascular system, including cardiomyocytes, vascular endothelial cells, smooth muscle cells, cardiac fibroblasts, and immune cells. The unified model offers insights into the relationship between upstream risk factors and downstream clinical outcomes and explains why interventions aimed at either of these components have limited success. Potential therapeutic approaches are considered based on this model. Because telomerase activity can prevent and reverse cell senescence, telomerase gene therapy is discussed as a promising intervention. Telomerase gene therapy and similar systems interventions based on the unified model are expected to be transformational in cardiovascular medicine.

Multi-omics research strategies in ischemic stroke: A multidimensional perspective

Ischemic stroke (IS) is a multifactorial and heterogeneous neurological disorder with high rate of death and long-term impairment. Despite years of studies, there are still no stroke biomarkers for clinical practice, and the molecular mechanisms of stroke remain largely unclear. The high-throughput omics approach provides new avenues for discovering biomarkers of IS and explaining its pathological mechanisms. However, single-omics approaches only provide a limited understanding of the biological pathways of diseases. The integration of multiple omics data means the simultaneous analysis of thousands of genes, RNAs, proteins and metabolites, revealing networks of interactions between multiple molecular levels. Integrated analysis of multi-omics approaches will provide helpful insights into stroke pathogenesis, therapeutic target identification and biomarker discovery. Here, we consider advances in genomics, transcriptomics, proteomics and metabolomics and outline their use in discovering the biomarkers and pathological mechanisms of IS. We then delineate strategies for achieving integration at the multi-omics level and discuss how integrative omics and systems biology can contribute to our understanding and management of IS.

Telomere Length as a marker of biological aging: A critical review of recent literature

INTRODUCTION

Aging is characterized as a syndrome of deleterious, progressive, universal, and irreversible function changes affecting every structural and functional aspect of the organism and accompanied by a generalized increase in mortality. Although a substantial number of candidates for biomarkers of aging have been proposed, none has been validated or universally accepted. Human telomeres constitute hexameric repetitive DNA sequence nucleoprotein complexes that cap chromosome ends, regulating gene expression and modulating stress-related pathways. Telomere length (TL) shortening is observed both in cellular senescence and advanced age, leading to the investigation of TL as a biomarker for aging and a risk factor indicator for the development and progression of the most common age-related diseases.

OBJECTIVE

The present review underlines the connection between TL and the pathophysiology of the diseases associated with telomere attrition.

METHODS

We performed a structured search of the PubMed database for peer-reviewed research of the literature regarding leukocyte TL and cardiovascular diseases (CVD), more specifically stroke and heart disease, and focused on the relevant articles published during the last 5 years. We also applied Hill's criteria of causation to strengthen this association.

RESULTS

We analyzed the recent literature regarding TL length, stroke, and CVD. Although approximately one-third of the available studies support the connection, the results of different studies seem to be rather conflicting as a result of different study designs, divergent methods of TL determination, small study samples, and patient population heterogeneity. After applying Hill's criteria, we can observe that the literature conforms to them weakly, with chronology being the only Hill criterion of causality that probably cannot be contested.

CONCLUSION

The present review attempted to examine the purported relation between leukocyte TL and age-related diseases such as CVD and more specific stroke and heart disease in view of the best established, comprehensive, medical and epidemiological criteria that have characterized the focused recent relevant research. Although several recommendations have been made that may contribute significantly to the field, a call for novel technical approaches and studies is mandatory to further elucidate the possible association.

Leukocyte Telomere Length as a Molecular Biomarker of Coronary Heart Disease

Background. This work is a review of preclinical and clinical studies of the role of telomeres and telomerase in the development and progression of coronary heart disease (CHD). Materials and methods. A search for full-text publications (articles, reviews, meta-analyses, Cochrane reviews, and clinical cases) in English and Russian was carried out in the databases PubMed, Oxford University Press, Scopus, Web of Science, Springer, and E-library electronic library using keywords and their combinations. The search depth is 11 years (2010–2021). Results. The review suggests that the relative leukocyte telomere length (LTL) is associated with the development of socially significant and widespread cardiovascular diseases such as CHD and essential hypertension. At the same time, the interests of researchers are mainly focused on the study of the relative LTL in CHD. Conclusions. Despite the scientific and clinical significance of the analyzed studies of the relative length of human LTL as a biological marker of cardiovascular diseases, their implementation in real clinical practice is difficult due to differences in the design and methodology of the analyzed studies, as well as differences in the samples by gender, age, race, and ethnicity. The authors believe that clinical studies of the role of the relative length of leukocyte telomeres in adult patients with coronary heart disease are the most promising and require large multicenter studies with a unified design and methodology.