Telomeres and Telomerase in the Control of Stem Cells

Leukocyte telomere length and telomerase activity in Long COVID patients from Rio de Janeiro, Brazil

BACKGROUND

Coronavirus disease 2019 (COVID-19) is caused by the new coronavirus 2 (severe acute respiratory syndrome coronavirus 2 - SARS-CoV-2). Long COVID is a new condition associated with persistent COVID-19 symptoms and/or new emerging symptoms. Telomeres are specialised structures for genome protection at the end of chromosomes and telomerase is the enzyme that synthesises telomere DNA.

OBJECTIVES

Patients with Long COVID symptoms were recruited at the Pedro Ernesto University Hospital (HUPE) in Rio de Janeiro, Brazil, with the main purpose of investigating the association between telomere length and Long COVID.

METHODS

Leukocyte telomere length (LTL) was determined by quantitative real-time polymerase chain reaction (qPCR) in 34 Long COVID patients compared to a control group (n = 122). Telomerase activity was determined by qPCR assays using the commercial kit from ScienCell. A questionnaire on symptoms, vaccine doses and blood count was completed.

FINDINGS

The Long COVID patients were found to have an increase in LTL. Telomerase activity was also examined in a smaller number of patients and found to be reactivated in the blood.

MAIN CONCLUSIONS

It will be necessary to conduct further studies and monitor Long COVID patients to determine if future health issues could be linked to telomerase activity and elongated telomeres.

The relationship between physical activity and telomere length in women: A systematic review

Telomere length (TL) is a biomarker of cellular aging with variations observed by sex, age, race, and ethnicity. Prior studies have suggested that physical activity (PA) may positively impact TL by potentially elongating telomeres and slowing cellular aging. However, research examining the optimal type and intensity of PA needed to elicit these changes specific to women remains limited. This systematic review aimed to investigate variations in TL in response to PA among women, exploring how these effects differ by age, race, or ethnicity. Following PRISMA guidelines, searches across five databases identified 17 relevant studies published from 2008 to 2022. A narrative synthesis of study findings indicated PA did not have a significant relationship with TL in women. However, a possible positive relationship was noted between specific types of PA and TL, specific to combined aerobic and strength-training PA and high intensity interval training interventions. The impact of PA on TL appeared to be age-dependent as well, showing significant positive relationships between PA and TL in early and later adulthood but not in middle adulthood. Findings related to race or ethnicity were inconclusive due to limited analyses from the included studies. The studies varied greatly by PA type, intensity, duration, and frequency, which, along with the reliance on self-reported PA measures in the observational studies, impacted the ability to draw firm conclusions. This review underscores the necessity for future research in large cohort studies using objectively measured PA interventions to further clarify the complex associations between PA and TL in women.

Beyond Telomeres: Unveiling the Extratelomeric Functions of TERT in B-Cell Malignancies

The reactivation of telomerase enables cancer cells to maintain the telomere length, bypassing replicative senescence and achieving cellular immortality. In addition to its canonical role in telomere maintenance, accumulating evidence highlights telomere-length-independent functions of TERT, the catalytic subunit of telomerase. These extratelomeric functions involve the regulation of signaling pathways and transcriptional networks, creating feed-forward loops that promote cancer cell proliferation, resistance to apoptosis, and disease progression. This review explores the complex mechanisms by which TERT modulates key signaling pathways, such as NF-κB, AKT, and MYC, highlighting its role in driving autonomous cancer cell growth and resistance to therapy in B-cell malignancies. Furthermore, we discuss the therapeutic potential of targeting TERT's extratelomeric functions. Unlike telomere-directed approaches, which may require prolonged treatment to achieve effective telomere erosion, inhibiting TERT's extratelomeric functions offers the prospect of rapid tumor-specific effects. This strategy could complement existing chemotherapeutic regimens, providing an innovative and effective approach to managing B-cell malignancies.

From infection to immortality: The role of HPV and telomerase in head and neck cancer

Head and neck squamous cell carcinomas (HNSCCs) represent a heterogeneous group of malignancies with multifactorial aetiologies. High-risk human papillomavirus (hrHPV) infections, particularly HPV16, and the dysregulation of telomerase activity, specifically through its catalytic subunit, telomerase reverse transcriptase (TERT) are among the key contributors to HNSCC development and progression. HPV promotes oncogenesis via the E6 and E7 oncoproteins, which inactivate tumour suppressors TP53 and RB1, leading to unchecked cellular proliferation. Concurrently, telomerase activation plays a critical role in HNSCC by maintaining telomere length, thus enabling cellular immortality, and facilitating tumour development and progression. The interplay between HPV and telomerase is significant; HPV oncoprotein E6 enhances telomerase activity through multiple regulatory mechanisms, including upregulating TERT expression. Beyond telomere maintenance, TERT influences signalling pathways, cellular metabolism, and the tumour microenvironment, contributing to aggressive tumour behaviour and poor prognosis. This review integrates the roles of HPV and telomerase in HNSCC, focusing on their molecular mechanisms and interactions that drive carcinogenesis and influence disease progression. Understanding the synergistic effects of HPV and TERT in HNSCC may be crucial for risk stratification, prognostic assessment, and the development of novel therapeutic strategies targeting these specific molecular pathways.

The telomere connection between aging and cancer: The burden of replication stress and dysfunction

Aging is a complex process that affects individuals at the molecular, cellular, tissue, and systemic levels, arising from the cumulative effects of damage and reduced repair mechanisms. This process leads to the onset of age-related diseases, including cancer, which exhibits increased incidence with age. Telomeres, the protective caps at chromosome ends, play a crucial role in genome stability and are closely connected with aging and age-related disorders. Both excessively short and long telomere lengths may contribute to cancer development when their balance is disrupted. Fragile telomeres, characterized by abnormalities and replication stress, may provide novel insights into the connection between aging and cancer. The accumulation of fragile telomeres, possibly due to intense replicative stress, may represent a key factor. Given the dynamic nature of telomeres, large longitudinal studies are essential for understanding their role in aging and cancer susceptibility, which is crucial for developing effective strategies to promote healthy aging and mitigate cancer risk.

In Vitro models of leukemia development: the role of very small leukemic stem-like cells in the cellular transformation cascade

Recent experimental findings indicate that cancer stem cells originate from transformed very small embryonic-like stem cells. This finding represents an essential advancement in uncovering the processes that drive the onset and progression of cancer. In continuously growing cell lines, for the first time, our team's follow-up research on leukemia, lung cancer, and healthy embryonic kidney cells revealed stages that resembles very small precursor stem cells. This review explores the origin of leukemic stem-like cells from very small leukemic stem-like cells establish from transformed very small embryonic-like stem cells. We explore theoretical model of acute myeloid leukemia initiation and progresses through various stages, as well basing the HL60 cell line, present its hierarchical stage development in vitro, highlighting the role of these very small precursor primitive stages. We also discuss the potential implications of further research into these unique cellular stages for advancing leukemia and cancer treatment and prevention.

The Role of SARS-CoV-2 Spike Protein in Long-term Damage of Tissues and Organs, the Underestimated Role of Retrotransposons and Stem Cells, a Working Hypothesis

Coronavirus disease-2019 (COVID-19) is a respiratory disease in which Spike protein from SARS-CoV-2 plays a key role in transferring virus genomic code into target cells. Spike protein, which is found on the surface of the SARS-CoV-2 virus, latches onto angiotensin-converting enzyme 2 receptors (ACE2r) on target cells. The RNA genome of coronaviruses, with an average length of 29 kb, is the longest among all RNA viruses and comprises six to ten open reading frames (ORFs) responsible for encoding replicase and structural proteins for the virus. Each component of the viral genome is inserted into a helical nucleocapsid surrounded by a lipid bilayer. The Spike protein is responsible for damage to several organs and tissues, even leading to severe impairments and long-term disabilities. Spike protein could also be the cause of the long-term post-infectious conditions known as Long COVID-19, characterized by a group of unresponsive idiopathic severe neuro- and cardiovascular disorders, including strokes, cardiopathies, neuralgias, fibromyalgia, and Guillaume- Barret's like-disease. In this paper, we suggest a pervasive mechanism whereby the Spike proteins either from SARS-CoV-2 mRNA or mRNA vaccines, tend to enter the mature cells, and progenitor, multipotent, and pluripotent stem cells (SCs), altering the genome integrity. This will eventually lead to the production of newly affected clones and mature cells. The hypothesis presented in this paper proposes that the mRNA integration into DNA occurs through several components of the evolutionarily genetic mechanism such as retrotransposons and retrotransposition, LINE-1 or L1 (long interspersed element-1), and ORF-1 and 2 responsible for the generation of retrogenes. Once the integration phase is concluded, somatic cells, progenitor cells, and SCs employ different silencing mechanisms. DNA methylation, followed by histone modification, begins to generate unlimited lines of affected cells and clones that form affected tissues characterized by abnormal patterns that become targets of systemic immune cells, generating uncontrolled inflammatory conditions, as observed in both Long COVID-19 syndrome and the mRNA vaccine.

Telomerase-based vaccines: a promising frontier in cancer immunotherapy

Telomerase, an enzyme crucial for maintaining telomere length, plays a critical role in cellular immortality and is overexpressed in most cancers. This ubiquitous presence makes telomerase, and specifically its catalytic subunit, human telomerase reverse transcriptase (hTERT), an attractive target for cancer immunotherapy. This review explores the development and application of telomerase-based vaccines, focusing on DNA and peptide-based approaches. While DNA vaccines demonstrate promising immunogenicity, peptide vaccines, such as UV1, UCPVax, and Vx-001, have shown clinical efficacy in certain cancer types. Recent advancements in vaccine design, including multiple peptides and adjuvants, have enhanced immune responses. However, challenges remain in achieving consistent and durable anti-tumor immunity. Accordingly, we discuss the mechanisms of action, preclinical and clinical data, and the potential of these vaccines to elicit robust and durable anti-tumor immune responses. This review highlights the potential of telomerase-based vaccines as a promising strategy for cancer treatment and identifies areas for future research.

New insights into methods to measure biological age: a literature review

Biological age is a concept that reflects the physiological state of an individual rather than the chronological time since birth. It can help assess the risk of age-related diseases and mortality and the effects of interventions to slow down or reverse aging. However, there is no consensus on measuring biological age best, and different methods may yield different results. In this paper, which includes 140 relevant pieces of literature, out of 33,000, we review some new methods to measure biological age based on recent advances in biotechnology and data science. We discussed some novel biomarkers and algorithms that can capture the dynamic and multidimensional aspects of aging at different levels. We evaluate their performance and validity using various datasets and criteria and compare them with existing methods. We also discuss their potential applications and implications for aging research and clinical practice. We conclude that the new methods offer more accurate and reliable estimates of biological age and open new avenues for understanding and modulating the aging process.

Telomeres: an organized string linking plants and mammals

Telomeres are pivotal determinants of cell stemness, organismal aging, and lifespan. Herein, we examined similarities in telomeres of Arabidopsis thaliana, mice, and humans. We report the common traits, which include their composition in multimers of TTAGGG sequences and their protection by specialized proteins. Moreover, given the link between telomeres, on the one hand, and cell proliferation and stemness on the other, we discuss the counterintuitive convergence between plants and mammals in this regard, focusing on the impact of niches on cell stemness. Finally, we suggest that tackling the study of telomere function and cell stemness by taking into consideration both plants and mammals can aid in the understanding of interconnections and contribute to research focusing on aging and organismal lifespan determinants.

The expression of shelterin genes and telomere repeat analysis and their effect on Alzheimer's disease

BACKGROUND

Alzheimer's disease (AD) is an age-related dementia disorder characterized by memory loss and behavioral changes. Maintaining the integrity of telomere shortening in AD is important for cellular survival and homeostasis in all cells, especially glial cells. The shelterin protein complex provides telomere integrity. Measuring the expression levels of shelterin genes and determining the telomere lengths regulated by this complex will reveal their effects on AD progression and adult neurogenesis and will allow the detection of the disease or the determination of the progression process from an accessible tissue.

METHODS AND RESULTS

The study population included 111 patients and 91 healthy controls (male and female, < 50 age). The clinical histories (age, gender, hypertension, diabetes mellitus, obesity, cardiovascular disease, MMSE, medication use, family history, sleep disorders, seizure), covariates (HGB, ESR, Na, P, Cl, BUN, CRP, B12, TSH, Glucose, and MRI findings) and the expressional changes of shelterin genes (TERF1, TERF2, TINF2, POT1, TPP1, and RAP1) between the patient and control groups were evaluated relatively. ROC analyses determined the diagnostic power of telomere repeats and gene expressions.

CONCLUSIONS

In conclusion, upregulation of expression of shleterin complex genes was detected in AD, where telomeres are significantly shorter than in controls (P < 0.05). However, only TERF2 and RAP1 were significant (P < 0.05). A positive relationship was detected between telomere repeats and these genes (P < 0.05). Telomere repeats may be a strong diagnostic criterion to distinguish AD individuals from healthy individuals (AUC = 1.000). The upregulation of TERF2 and RAP1 core genes required for telomere integrity results in the instability of excessively shortened telomeres. Expression silencing of these genes may increase telomerase activity and maintain cellular survival. Also, the detection of telomere repeats has potential in the early diagnosis of AD patients.

Investigating the differential therapeutic efficacy and mechanisms of human umbilical cord mesenchymal stem cells at various passages in osteoarthritis treatment

This study aimed to assess the clinical efficacy of umbilical cord mesenchymal stem cells (hUC-MSCs) from different passages (P3, P8, and P13) in the treatment of knee osteoarthritis (OA) and explore the underlying mechanisms. The hUC-MSCs from each passage were characterized and evaluated for their stemness, migration, proliferation, and marker expression. Rats with OA were treated with hUC-MSCs from each passage, and the therapeutic effects were assessed based on knee swelling, discomfort, and pathological examination of the knee joint. Co-culture experiments were conducted to examine the ability of hUC-MSCs to stimulate type II collagen synthesis and inhibit MMP13 expression in chondrocytes. Telomere length and telomerase activity of hUC-MSCs from each passage were measured to investigate the reasons for the observed differences in clinical efficacy. The results revealed that P3 and P8 hUC-MSCs exhibited superior osteogenic and chondrogenic differentiation potential compared to P13, while P13 demonstrated stronger adipogenic differentiation. The wound healing rate was significantly higher in the P3 and P8 groups compared to P13. All hUC-MSC groups expressed high levels of CD90 and CD105, indicating their mesenchymal stem cell characteristics, while CD31 and CD45 were not expressed. CD105 expression was significantly reduced in the P13 group. In the treatment of rat osteoarthritis, there were no significant differences in knee swelling, discomfort, Mankin scores, and pathological findings between P3 and P8 hUC-MSC treatments. However, there was a significant difference between the 8th and 13th passages. Co-culture experiments showed that hUC-MSCs from P3 and P8 enhanced type II collagen synthesis and reduced MMP13 expression in chondrocytes. Although no significant difference was observed between the P3 and P8 groups, a significant difference was found between the P13 and P8 groups. Telomere length analysis revealed that P13 samples had significantly shorter telomeres compared to both P3 and P8. The telomerase activity was positive in P3 and P8 hUC-MSCs, indicating no significant difference between these passages, while it was negative in P13 hUC-MSCs. In conclusion, P3 and P8 hUC-MSCs exhibited superior therapeutic potential for knee osteoarthritis compared to P13, possibly due to their enhanced differentiation capacity and telomerase activity.

Emerging Landscape of Mesenchymal Stem Cell Senescence Mechanisms and Implications on Therapeutic Strategies

Mesenchymal stem cells (MSCs) hold significant promise for regenerative medicine and tissue engineering due to their unique multipotent differentiation ability and immunomodulatory properties. MSC therapy is widely discussed and utilized in clinical treatment. However, during both in vitro expansion and in vivo transplantation, MSCs are prone to senescence, an irreversible growth arrest characterized by morphological, gene expression, and functional changes in genomic regulation. The microenvironment surrounding MSCs plays a crucial role in modulating their senescence phenotype, influenced by factors such as hypoxia, inflammation, and aging status. Numerous strategies targeting MSC senescence have been developed, including senolytics and senomorphic agents, antioxidant and exosome therapies, mitochondrial transfer, and niche modulation. Novel approaches addressing replicative senescence have also emerged. This paper comprehensively reviews the current molecular manifestations of MSC senescence, addresses the environmental impact on senescence, and highlights potential therapeutic strategies to mitigate senescence in MSC-based therapies. These insights aim to enhance the efficacy and understanding of MSC therapies.

Telomere Dynamics in Sickle Cell Anemia: Unraveling Molecular Aging and Disease Progression

Sickle Cell Anemia (SCA) is a hereditary blood disorder characterized by the presence of abnormal hemoglobin, leading to the formation of sickle-shaped red blood cells. While extensive research has unraveled many aspects of the genetic and molecular basis of SCA, the role of telomere dynamics in disease progression remains a relatively unexplored frontier. This review seeks to provide a comprehensive examination of telomere biology within the context of SCA, aiming to elucidate its potential impact on molecular aging and the progression of the disease. The impact of oxidative stress on telomere dynamics in SCA is explored, with a particular focus on how increased reactive oxygen species (ROS) may contribute to accelerated telomere shortening and genomic instability. Furthermore, the potential relationship between telomere dysfunction and cellular senescence in SCA is investigated, shedding light on how telomere dynamics may contribute to the premature aging of cells in this population. The review concludes by summarizing key findings and proposing potential therapeutic strategies targeting telomere dynamics to mitigate disease progression in SCA. It also identifies gaps in current understanding and suggests avenues for future research, emphasizing the importance of further investigating telomere biology to advance our understanding of molecular aging and disease progression in Sickle Cell Anemia. This comprehensive exploration of telomere dynamics in SCA offers insights into potential mechanisms of molecular aging and disease progression, paving the way for targeted therapeutic interventions and improved disease management.

Telomerase inhibitors induce mitochondrial oxidation and DNA damage-dependent cell death rescued by Bcl-2/Bcl-xL

BACKGROUND

Reactivation of telomerase is a hallmark of cancer and the majority of cancers over-express telomerase. Telomerase-dependent telomere length maintenance confers immortality to cancer cells. However, telomere length-independent cell survival functions of telomerase also play a critical role in tumorigenesis. Multiple telomerase inhibitors have been developed as therapeutics and include anti-sense oligonucleotides, telomerase RNA component targeting agents, chemical inhibitors of telomerase, small molecule inhibitors of hTERT, and telomerase vaccine. In general, telomerase inhibitors affect cell proliferation and survival of cells depending on the telomere length reduction, culminating in replicative senescence or cell death by crisis. However, most telomerase inhibitors kill cancer cells prior to significant reduction in telomere length, suggesting telomere length independent role of telomerase in early telomere dysfunction-dependent cell death.

METHODS

In this study, we explored the mechanism of cell death induced by three prominent telomerase inhibitors utilizing a series of genetically encoded sensor cells including redox and DNA damage sensor cells.

RESULTS

We report that telomerase inhibitors induce early cell cycle inhibition, followed by redox alterations at cytosol and mitochondria. Massive mitochondrial oxidation and DNA damage induce classical cell death involving mitochondrial transmembrane potential loss and mitochondrial permeabilization. Real-time imaging of the progression of mitochondrial oxidation revealed that treated cells undergo a biphasic mitochondrial redox alteration during telomerase inhibition, emphasizing the potential role of telomerase in the redox regulation at mitochondria. Additionally, silencing of hTERT confirmed its predominant role in maintaining mitochondrial redox homeostasis. Interestingly, the study also demonstrated that anti-apoptotic Bcl-2 family proteins still confer protection against cell death induced by telomerase inhibitors.

CONCLUSION

The study demonstrates that redox alterations and DNA damage contribute to early cell death by telomerase inhibitors and anti-apoptotic Bcl-2 family proteins confer protection from cell death by their ability to safeguard mitochondria from oxidation damage.

Can CD133 Be Regarded as a Prognostic Biomarker in Oncology: Pros and Cons

The CD133 cell membrane glycoprotein, also termed prominin-1, is expressed on some of the tumor cells of both solid and blood malignancies. The CD133-positive tumor cells were shown to exhibit higher proliferative activity, greater chemo- and radioresistance, and enhanced tumorigenicity compared to their CD133-negative counterparts. For this reason, CD133 is regarded as a potential prognostic biomarker in oncology. The CD133-positive cells are related to the cancer stem cell subpopulation in many types of cancer. Recent studies demonstrated the involvement of CD133 in the regulation of proliferation, autophagy, and apoptosis in cancer cells. There is also evidence of its participation in the epithelial-mesenchymal transition associated with tumor progression. For a number of malignant tumor types, high CD133 expression is associated with poor prognosis, and the prognostic significance of CD133 has been confirmed in a number of meta-analyses. However, some published papers suggest that CD133 has no prognostic significance or even demonstrate a certain correlation between high CD133 levels and a positive prognosis. This review summarizes and discusses the existing evidence for and against the prognostic significance of CD133 in cancer. We also consider possible reasons for conflicting findings from the studies of the clinical significance of CD133.

Regulation of self-renewal and senescence in primitive mesenchymal stem cells by Wnt and TGFβ signaling

BACKGROUND

The therapeutic application of multipotent mesenchymal stem cells (MSCs) encounters significant challenges, primarily stemming from their inadequate growth and limited self-renewal capabilities. Additionally, as MSCs are propagated, their ability to self-renew declines, and the exact cellular and molecular changes responsible for this are poorly understood. This study aims to uncover the complex molecular mechanisms that govern the self-renewal of primitive (p) MSCs.

METHODS

We grew pMSCs using two types of medium, fetal bovine serum (FM) and xeno-free (XM), at both low passage (LP, P3) and high passage (HP, P20). To evaluate LP and HP pMSCs, we examined their physical characteristics, cell surface markers, growth rate, colony-forming ability, BrdU assays for proliferation, telomerase activity, and potential to differentiate into three lineages. Moreover, we conducted RNA-seq to analyze their transcriptome and MNase-seq analysis to investigate nucleosome occupancies.

RESULTS

When grown in FM, pMSCs underwent changes in their cellular morphology, becoming larger and elongated. This was accompanied by a decrease in the expression of CD90 and CD49f, as well as a reduction in CFE, proliferation rate, and telomerase activity. In addition, these cells showed an increased tendency to differentiate into the adipogenic lineage. However, when grown in XM, pMSCs maintained their self-renewal capacity and ability to differentiate into multiple lineages while preserving their fibroblastoid morphology. Transcriptomic analysis showed an upregulation of genes associated with self-renewal, cell cycle regulation, and DNA replication in XM-cultured pMSCs, while senescence-related genes were upregulated in FM-cultured cells. Further analysis demonstrated differential nucleosomal occupancies in self-renewal and senescence-related genes for pMSCs grown in XM and FM, respectively. These findings were confirmed by qRT-PCR analysis, which revealed alterations in the expression of genes related to self-renewal, cell cycle regulation, DNA replication, differentiation, and senescence. To understand the underlying mechanisms, we investigated the involvement of Wnt and TGFβ signaling pathways by modulating them with agonists and antagonists. This experimental manipulation led to the upregulation and downregulation of self-renewal genes in pMSCs, providing further insights into the signaling pathways governing the self-renewal and senescence of pMSCs.

CONCLUSION

Our study shows that the self-renewal potential of pMSCs is associated with the Wnt pathway, while senescence is linked to TGFβ.

Lipids and the hallmarks of ageing: From pathology to interventions

Lipids are critical structural and functional architects of cellular homeostasis. Change in systemic lipid profile is a clinical indicator of underlying metabolic pathologies, and emerging evidence is now defining novel roles of lipids in modulating organismal ageing. Characteristic alterations in lipid metabolism correlate with age, and impaired systemic lipid profile can also accelerate the development of ageing phenotype. The present work provides a comprehensive review of the extent of lipids as regulators of the modern hallmarks of ageing viz., cellular senescence, chronic inflammation, gut dysbiosis, telomere attrition, genome instability, proteostasis and autophagy, epigenetic alterations, and stem cells dysfunctions. Current evidence on the modulation of each of these hallmarks has been discussed with emphasis on inherent age-dependent deficiencies in lipid metabolism as well as exogenous lipid changes. There appears to be sufficient evidence to consider impaired lipid metabolism as key driver of the ageing process although much of knowledge is yet fragmented. Considering dietary lipids, the type and quantity of lipids in the diet is a significant, but often overlooked determinant that governs the effects of lipids on ageing. Further research using integrative approaches amidst the known aging hallmarks is highly desirable for understanding the therapeutics of lipids associated with ageing.

CRISPR-based m6A modification and its potential applications in telomerase regulation

Telomerase determines cell lifespan by controlling chromosome stability and cell viability, m⁶A epigenetic modification plays an important role in the regulation of telomerase activity. Using CRISPR epigenome editing to analyze specific m⁶A modification sites in telomerase will provide an important tool for analyzing the molecular mechanism of m⁶A modification regulating telomerase activity. In this review, we clarified the relevant applications of CRISPR system, paid special attention to the regulation of m⁶A modification in stem cells and cancer cells based on CRISPR system, emphasized the regulation of m⁶A modification on telomerase activity, pointed out that m⁶A modification sites regulate telomerase activity, and discussed strategies based on telomerase activity and disease treatment, which are helpful to promote the research of anti-aging and tumor related diseases.

Post-Transcriptional and Post-Translational Modifications in Telomerase Biogenesis and Recruitment to Telomeres

Telomere length is associated with the proliferative potential of cells. Telomerase is an enzyme that elongates telomeres throughout the entire lifespan of an organism in stem cells, germ cells, and cells of constantly renewed tissues. It is activated during cellular division, including regeneration and immune responses. The biogenesis of telomerase components and their assembly and functional localization to the telomere is a complex system regulated at multiple levels, where each step must be tuned to the cellular requirements. Any defect in the function or localization of the components of the telomerase biogenesis and functional system will affect the maintenance of telomere length, which is critical to the processes of regeneration, immune response, embryonic development, and cancer progression. An understanding of the regulatory mechanisms of telomerase biogenesis and activity is necessary for the development of approaches toward manipulating telomerase to influence these processes. The present review focuses on the molecular mechanisms involved in the major steps of telomerase regulation and the role of post-transcriptional and post-translational modifications in telomerase biogenesis and function in yeast and vertebrates.

Special Issue: "Telomerase: Role in Health and Aging"

We would like to introduce the new volume: "Telomerase and Telomeres: Its Role in Health and Aging 2 [...].