Telomerase Reverse Transcriptase Gene Research Articles

Telomerase reverse transcriptase gene knock-in unleashes enhanced longevity and accelerated damage repair in mice.

While previous research has demonstrated the therapeutic efficacy of telomerase reverse transcriptase (TERT) overexpression using adeno-associated virus and cytomegalovirus vectors to combat aging, the broader implications of TERT germline gene editing on the mammalian genome, proteomic composition, phenotypes, lifespan extension, and damage repair remain largely unexplored. In this study, we elucidate the functional properties of transgenic mice carrying the Tert transgene, guided by precise gene targeting into the Rosa26 locus via embryonic stem (ES) cells under the control of the elongation factor 1α (EF1α) promoter. The Tert knock-in (TertKI) mice harboring the EF1α-Tert gene displayed elevated telomerase activity, elongated telomeres, and extended lifespan, with no spontaneous genotoxicity or carcinogenicity. The TertKI mice showed also enhanced wound healing, characterized by significantly increased expression of Fgf7, Vegf, and collagen. Additionally, TertKI mice exhibited robust resistance to the progression of colitis induced by dextran sodium sulfate (DSS), accompanied by reduced expression of disease-deteriorating genes. These findings foreshadow the potential of TertKI as an extraordinary rejuvenation force, promising not only longevity but also rejuvenation in skin and intestinal aging.

HOOK3 Amplification in Bladder Urothelial Carcinoma: Insights from Gene Expression and Survival Analysis.

Bladder urothelial carcinoma (BUC) poses a significant health challenge, ranking as the fourth most common cancer among men in the United States, with a mortality rate of approximately 20%. Genetic abnormalities such as mutations in the telomerase reverse transcriptase (TERT) gene and loss of heterozygosity (LOH) on chromosome 9 are commonly observed in BUC; however, many genes involved remain unidentified. This study aimed to explore the role of HOOK3 in BUC and its impact on survival. Using data from The Cancer Genome Atlas (TCGA) and cBioPortal, we performed differential gene expression and survival analyses to compare the patients with and without HOOK3 amplification. Our findings revealed that 2.2% of genes were up-regulated and 5.3% down-regulated in the HOOK3-amplified group. These changes suggest that HOOK3 amplification is linked to distinct gene expression patterns, with a higher proportion of down-regulated genes. Pathway enrichment related to chromatin remodeling, ion transport, and mitochondrial function suggests that HOOK3 may promote genomic stability and transcriptional regulation, contributing to tumor suppression. The involvement of mitochondrial and ribosomal pathways in protein synthesis and chromosome segregation may also protect against chromosomal abnormalities and uncontrolled cell growth. HOOK3 amplification appears to correlate with improved patient survival. These results suggest a potential protective role of HOOK3 amplification in BUC. Further research is needed to explore the underlying mechanisms and their therapeutic potential for reducing BUC-related mortality.

Transcription factor AP-4 reactivates telomerase reverse transcriptase independently of genome alteration in non-HBV associated hepatocellular carcinoma

Recurrent genome alterations have been identified in the telomerase reverse transcriptase (TERT) promoter region, a common occurrence in various types of cancer. In addition to epigenetic alterations at the TERT promoter region, the recruitment of transcription factors to this region, which potentially drives the reactivation of TERT gene transcription in human hepatocellular carcinoma (HCC) remains unknown. In this study, using in-silico DNA binding sequence analysis at the TERT promoter and with confirmation with dual luciferase reporter and chromatin immunoprecipitation assays, we found that Transcription Factor AP-4 (TFAP4) physically interacted with the TERT promoter, driving telomerase reactivation. Furthermore, TFAP4 mRNA is upregulated in human HCCs and positively correlates with TERT mRNA expression, according to TCGA-LIHC database, our in-house clinical samples, and HCC cell lines. Interestingly, the knockdown of TFAP4 only suppressed TERT expression levels and telomere length in HCC cells which are not associated with HBV infection. Additionally, we identified that the CCCTC-binding factor (CTCF) physically interacted with the TFAP4 promoter, leading to induced TFAP4 gene transcription in HCC. Clinically, TFAP4 mRNA expression significantly correlated with TERT mRNA expression in alcohol-related HCCs, but not in HBV-associated HCCs, according to TCGA-LIHC cohort. Consistently, ethanol enhanced both TFAP4 and TERT mRNA expression in non-HBV-associated HCC cells but not HBV-associated HCC cells. In conclusion, our findings demonstrate that TFAP4 directly regulates TERT gene transcription via CTCF in non-HBV-associated HCCs. However, its role in regulating telomerase expression or activity through HBV DNA integration in HBV-associated cells might be limited.

The Annexin A1 Protein Mimetic Peptide Ac2-26 prevents cellular senescence of CHON-001 chondrocytes against tumor necrosis factor-α via the Nrf2/NF-κB pathway.

Osteoarthritis (OA) is a degenerative joint disorder characterized by progressive cartilage degradation. Excessive oxidative stress (OS), inflammatory responses, extracellular matrix breakdown, and cellular senescence of chondrocytes play crucial roles in the pathological development of OA. Currently, curing OA remains a significant challenge. In this study, we aimed to elucidate the protective effects of Annexin A1 protein Mimetic Peptide (Ac2-26) against tumor necrosis factor-α (TNF-α)-induced damage in CHON-001 chondrocytes by assessing cellular senescence, OS, and the expression levels of matrix metalloproteinase-13 (MMP-13) and a disintegrin and metalloproteinase with thrombospondin motifs (ADAMTS)-4. Our results show that Ac2-26 mitigated the reduction of telomerase activity and the exacerbation of cellular senescence induced by TNF-α in CHON-001 chondrocytes. Treatment with TNF-α led to decreased expression of the human telomerase reverse transcriptase gene and increased expression of the telomeric repeat-binding factor 2 gene, which were reversed by Ac2-26 treatment. The TNF-α-induced increases in the gene and protein expressions of p53 and p16 were restored by Ac2-26 in a dose-dependent manner. Additionally, we found that TNF-α caused elevations in the mRNA and protein levels of MMP-13 and ADAMTS-4, which were reduced by Ac2-26 in a dose-dependent fashion. Furthermore, TNF-α triggered the activation of nuclear factor κ-B (NF-κB) by increasing the levels of phosphorylated NF-κB p65 and the luciferase activity of NF-κB. Notably, Ac2-26 alleviated OS by reducing mitochondrial reactive oxygen species levels and promoting the activation of NF-E2-related factor 2 (Nrf2) in TNF-α-challenged CHON-001 chondrocytes. Silencing Nrf2 abolished the Ac2-26-induced activation of NF-κB and cellular senescence in CHON-001 chondrocytes. Collectively, these findings offer new insights into the potential therapeutic use of Ac2-26 for treating OA.

Effects of Glutamine or Glucose Deprivation on Inflammation and Tight Junction Disruption in Yak Rumen Epithelial Cells.

Yak is a special free-ranging cattle breed in the plateau areas of Qinghai and Tibet. Pasture withering in cold-season pastures results in energy deficiency in yaks, which undermines the rumen epithelial barrier. However, the leading factor causing rumen epithelial injury remains unknown. Glutamine (Gln), a conditionally essential amino acid, is insufficient under pathological conditions. Glucose (GLU) is an important energy source. Thus, we explored the effects of Gln or GLU deprivation on the barrier function of yak rumen epithelial cells and investigated the underlying mechanisms, as well as the differences in rumen epithelial barrier function between Gln deprivation (Gln-D) and GLU deprivation (GLU-D). In previous work, we constructed the yak rumen epithelial cells (YRECs) line by transferring the human telomerase reverse transcriptase gene (hTERT) and simian virus 40 large T antigen (SV40T) into primary YRECs. The YRECs were exposed to normal, Gln-D, GLU-D, and serum replacement (SR) media for 6, 12, and 24 h. Our data displayed that cell viability and tight junction protein expression in the SR group were not significantly changed compared to the normal group. Whereas, compared with the SR group, Gln-D treated for more than 12 h reduced cell viability and proliferation, and GLU-D treated for more than 12 h damaged the cell morphology and reduced cell viability and proliferation. The cell proliferation and cell viability were decreased more in GLU-D than in Gln-D. In addition, Gln-D treated for more than 12 h disrupted YREC cellular partially tight junctions by inducing oxidative stress and inflammation, and GLU-D treated for more than 12 h disrupted YREC cellular tight junctions by inducing apoptosis, oxidative stress, and inflammation. Compared with Gln-D, GLU-D more significantly induced cell injury and reduced tight junction protein levels. Our results provided evidence that GLU-D induced damage through the p38 mitogen-activated protein kinase (p38 MAPK)/c-junN-terminal kinase (JNK) signaling pathway, which was more serious than Gln-D treated for more than 12 h.

Effect of obesity and NAFLD on leukocyte telomere length and hTERT gene MNS16A VNTR variant

It is known that telomere length (TL) (evaluated with T/S ratio) is shortened in the presence of obesity. In this study, we aimed to investigate how obesity in adolescents and non-alcoholic liver disease (NAFLD) within the obese group affect TL and the clinical significance of the human telomerase reverse transcriptase (hTERT) gene MNS16A VNTR variant in terms of NAFLD. Adolescents with exogenous obesity and healthy controls (aged 10–19 years) who applied to our adolescent outpatient clinic between May-October 2023 were included in this study. We performed upper abdominal ultrasonography to investigate the presence of NAFLD in adolescents with obesity and divided into two groups: those without hepatosteatosis (obese NAFLD (-)) and those with hepatosteatosis (obese NAFLD (+)). We recorded body weight, height, waist circumference, and blood pressure measurements and measured the T/S ratio (telomere sequence copy number/gene single copy number) by the Quantitative Polymerase Chain Reaction method. The groups were compared using frequentist and Bayesian methods. Eighty-three obese adolescents [63 NAFLD(+) 20 NAFLD(-)] and 69 lean controls were included in the study. Pairwise comparisons revealed that T/S ratio was significantly lower in the obese NAFLD (-) group than the obese NAFLD (+) and the control group (p = 0.025, p = 0.007, respectively). T/S ratio was lower in the LL allele group than in the other alleles (p = 0.022) and slightly higher in the obese group with metabolic syndrome compared to the obese group without metabolic syndrome (p = 0.072). hTERT-MNS16A-VNTR gene variant LL allele had a negative correlation with T/S ratio among the obese adolescent group. Patients with LL alleles had higher ALT, GGT, HOMA-IR, and ALT/AST. Diastolic blood pressure had a significant correlation with the T/S ratio. The T/S ratio was shorter in the obese adolescent group compared to healthy ones but was higher in the NAFLD (+) obese compared to the NAFLD (-) obese. ALT level and ALT/AST ratio were higher, T/S ratio was lower in the hTERT MNS16A VNTR variant LL allele group among obese adolescents. In addition, there was a significant correlation between the T/S ratio and diastolic blood pressure in obese adolescents.

Association between human telomerase reverse transcriptase (hTERT) MNS16A polymorphism and risk of breast cancer.

It is well known that telomerase activity is suppressed in normal human tissues and reactivated in tumors, suggesting that the human telomerase reverse transcriptase (hTERT, MIM: 187270) gene may be involved in carcinogenesis. A polymorphic tandem repeat minisatellite located downstream of exon 16 of hTERT and upstream in the putative promoter region of an antisense hTERT transcript, termed MNS16A, results in a functional polymorphism. Because the association between the MNS16A genetic polymorphism and breast cancer (BC) risk remains an open question, the present case-control study was conducted in Shiraz (Fars Province, Southern Iran). A total of 711 samples were collected, including 362 BC patients and 349 healthy individuals. Genotyping was performed by polymerase chain reaction method. Alleles were determined by classifying DNA amplicons of less than and greater than 300bp as short (S) and long (L) alleles, respectively. Different inheritance models (codominant, dominant, recessive, overdominant genotype models and the allele model) were used to evaluate the association between the MNS16A polymorphism and the risk of BC. No significant association was observed in any of the analyses. It should be noted that the statistical power of the comparisons was low. The present study did not support the association between hTERT MNS16A polymorphism and breast cancer risk. Similar studies in other populations with larger sample sizes are needed to determine the association between the hTERT MNS16A polymorphism and susceptibility to breast cancer.

TERT upregulation promotes cell proliferation via degradation of p21 and increases carcinogenic potential.

Telomerase reverse transcriptase (TERT) gene aberration is detectable in >80% of cases with hepatocellular carcinoma (HCC). TERT reactivation is essential for cellular immortalization because it stabilizes telomere length, although the role of TERT in hepatocarcinogenesis remains unelucidated. To elucidate the significance of aberrant TERT expression in hepatocytes in inflammation-associated hepatocarcinogenesis, we generated Alb-Cre;TertTg mice, which overexpress TERT in the liver and examined their phenotype during chronic inflammation. Based on transcriptome data from the liver tissue of Alb-Cre;TertTg mice, we examined the role of TERT in hepatocarcinogenesis in vitro. We also evaluated the relationship between TERT and cell-cycle-related molecules, including p21, in HCC samples. The liver tumor development rate was increased by TERT overexpression during chronic inflammation, especially in the absence of p53 function. Gene set enrichment analysis of liver tissues revealed that gene sets related to TNF-NFκB signaling, cell cycle, and apoptosis were upregulated in Alb-Cre;TertTg liver. A luciferase reporter assay and immunoprecipitation revealed that TERT interacted with NFκB p65 and enhanced NFκB promoter activity. On the other hand, TERT formed protein complexes with p21, cyclin A2, and cyclin E and promoted ubiquitin-mediated degradation of p21, specifically in the G1 phase. In the clinical HCC samples, TERT was highly expressed but p21 was conversely downregulated, and TERT expression was associated with the upregulation of molecules related to the cell cycle. Taken together, the aberrant upregulation of TERT increased NFκB promoter activity and promoted cell cycle progression via p21 ubiquitination, leading to hepatocarcinogenesis. © 2024 The Author(s). The Journal of Pathology published by John Wiley & Sons Ltd on behalf of The Pathological Society of Great Britain and Ireland.

Whole Exome Sequencing of Adult Indians with Apparently Acquired Aplastic Anaemia: Initial Experience at Tertiary Care Hospital

Aplastic anaemia (AA) is a rare hypocellular bone marrow disease with a large number of mutations in the telomerase reverse transcriptase gene (TERT), leading to bone marrow failure. We used our benchmarked whole exome sequencing (WES) pipeline to identify variants in adult Indian subjects with apparently acquired AA. For 36 affected individuals, we sequenced coding regions to a mean coverage of 100× and a sufficient depth was achieved. Downstream validation and filtering to call mutations in patients treated with Cyclosporin A (CsA) identified variants associated with AA. We report four mutations across the genes associated with the AA, TERT and CYP3A5, in addition to other genes, viz., IFNG, PIGA, NBS/NBN, and MPL. We demonstrate the application of WES to discover the variants associated with CsA responders and non-responders in an Indian cohort.

Evaluation of a Cytology-Molecular Co-Test in Liquid-Based Cytology-Processed Urine for Defining Indeterminate Categories of the Paris System

Introduction: Urine cytology using the Paris system (TPS) classification is useful for the detection and monitoring of bladder urothelial carcinoma (UC). However, the categories “atypical urothelial cells” (AUCs) and “suspicious for high-grade urothelial carcinoma” (SHGUC) do not establish a clear diagnosis. This pilot study aimed to investigate whether the presence of mutations in fibroblast growth factor receptor 3 (FGFR3) and telomerase reverse transcriptase (TERT) genes, in urine processed with liquid-based cytology (LBC) could enhance the diagnostic performance of cytology, particularly in defining the indeterminate categories of AUC and SHGUC. Methods: Urine samples from 82 UC patients with primary tumors or under surveillance and 10 healthy individuals were examined. The ThinPrep method was used for cytology followed by DNA isolation from urine sediments. Targeted molecular analysis was achieved in 70 cases (63 patients and 7 controls) for exons 7 and 10 of the FGFR3 gene and the TERT gene promoter (pTERT), using PCR and Sanger sequencing. Molecular results were correlated with TPS cytology categories and validated by histopathological findings following cystoscopy. Results: In healthy subjects, cytology was negative for high-grade urothelial carcinoma (NHGUC) and no mutations were found. No mutations were found in patients with NHGUC cytology, except for one case with equivocal cystoscopy that carried a pTERT mutation. In high-grade urothelial carcinoma cytology (HGUC) (15/20, 75%) of the cases with histologically confirmed UC, molecular analysis revealed the presence of pTERT without FGFR3 mutations. In SHGUC and AUC cytology, FGFR3 and/or pTERT mutations were detected in 3/4 (75%) and 4/4 (100%) histologically confirmed UC cases, respectively. Cytology sensitivity was 85.7% increasing to 100% with the combined cytology-molecular test, whereas specificity remained unchanged at 86.3%. Conclusions: This pilot study suggests that the incorporation of FGFR3/pTERT molecular testing in urine LBC could enhance the diagnostic value of cytology by diagnosing bladder urothelial carcinoma in indeterminate cytology categories.

MicroRNAs role in telomere length maintenance and telomerase activity in tumor cells.

MiRNAs, a class of non-coding RNA molecules, have emerged as critical modulators of telomere length and telomerase activity by finely tuning the expression of target genes (and not gene targets) within signaling pathways involved in telomere homeostasis. The primary objective of this systematic review was to compile and synthesize the existing body of knowledge on the role, association, and involvement of miRNAs in telomere length. Additionally, the review explored the regulation, function, and activation mechanism of thehuman telomerase reverse transcriptase(hTERT) gene and telomerase activity in tumor cells. A comprehensive analysis of 47 selected articles revealed 40 distinct miRNAs involved in these processes. These miRNAs were shown to exert their function, in both clinical cases and cell line models, either directly or indirectly, regulating hTERT and telomerase activity through distinct molecular mechanisms. The regulatory roles of these miRNAs significantly affected major cancer phenotypes, with outcomes largely dependent on the tissue type and the cellular actions within the tumor cells, whereby they functioned as oncogenes or tumor suppressors. These findings strongly support the pivotal role of miRNAs in modulating telomere length and telomerase activity, thereby contributing to the intricate and complex regulation of telomere homeostasis in tumor cells.Moreover, they emphasize the potential of targeting miRNAs and key regulatory genes as therapeutic strategies to disrupt cancer cell growth and promote senescence, offering promising avenues for novel cancer treatments.

Synergistic effect of cobalt ferrite-graphene oxide based hyperthermia and capsaicin to induce apoptosis and inhibit telomerase activity in breast cancer cells

Capsaicin is a bioactive phytochemical of red and chili peppers. It has shown therapeutic properties, including anticancer activities. In this study, the potential anti-telomerase effect of capsaicin, as well as synergic inhibitory effect of this compound in combination with cobalt ferrite-graphene oxide nanocomposites was investigated on breast cancer cell line. For this purpose, cobalt ferrite/graphene oxide (CoFe2O4/GO) nanoparticles were synthesized and characterized. Then, the effect of different concentrations of capsaicin and CoFe2O4/GO nanoparticles, and their combination on the breast adenocarcinoma cell lines (MCF-7 and MCF-10A) were analyzed using MTT assay and quantitative real-time PCR for assessing their effect on the cell viability and the expression changes in telomerase reverse transcriptase (tert), Bax and Bcl2 genes, respectively. The results showed a synergistic effect of capsaicin and CoFe2O4/GO NPs on MCF-7 cell lines that reduced the IC50 value from 0.1 and 1 mg/ml for capsaicin and CoFe2O4/GO nanoparticles, to 0.05 and 0.5 mg ml−1, respectively. Moreover, telomerase and bcl2 genes expression decreased after capsaicin and CoFe2O4/GO NPs treatment; while in contrast, bax gene expression significantly increased. Consequently, capsaicin and CoFe2O4/GO NPs treatment could induce apoptosis and inhibit the growth of breast cancer cells. In conclusion, combinational treatment with capsaicin and CoFe2O4/GO NPs could be considered as an efficient therapeutic regimen for breast cancer.

Telomere biology and its maintenance in schizophrenia spectrum disorders: Exploring links to cognition

ObjectiveContemporary research suggests reduced telomere length in schizophrenia spectrum disorders (SZ) compared to age-adjusted non-affected individuals. However, the role of telomere maintenance and telomere repair in SZ is poorly understood as well as the involvement of telomere biology in cognitive abnormalities in SZ. MethodsThe study consisted of 758 participants (SZ [n = 357] and healthy controls, HC [n = 401]) collected as part of the Norwegian TOP study. Participants were assessed with standardized neuropsychological tests measuring five cognitive domains. Leucocyte telomere length (TL) was measured via blood and determined by quantitative real-time Polymerase Chain Reaction (qPCR) providing a telomere to single copy ratio (T/S ratio), used to estimate the mean telomere length. Telomerase activity was assessed by the expression levels of the Telomerase Reverse Transcriptase (TERT) and Telomerase RNA Component (TERC) genes. To assess telomere maintenance and telomere repair we calculated the telomerase expression to TL ratio (TERT/TL and TERC/TL respectively). ResultsPatients had reduced TERT (F = 5.03, p = 0.03), but not TERC expression (F = 1.04, p = 0.31), and higher TERT/TL (F = 6.68, p = 0.01) and TERC/TL (F = 6.71, p = 0.01), adjusted for age, sex, and ethnicity. No statistically significant association was observed between any of the telomere biology markers and the cognitive domains (p > 0.05). ConclusionOur study shows changes in TERT expression and telomere maintenance and telomere repair in SZ compared HC. However, the role of telomere biology in the mechanism underlying cognitive impairment in psychosis seems limited.

Association of telomerase reverse transcriptase gene rs10069690 variant with cancer risk: an updated meta-analysis

ObjectiveExisting evidence suggests telomerase activation is a crucial step in tumorigenesis. The telomerase reverse transcriptase (TERT), encoded by the human TERT gene, is critical for telomerase expression. The TERT rs10069690 (C > T) variant was identified to be associated with the risk of cancer, however, there have been inconsistent results. Therefore, we performed a comprehensive meta-analysis aiming to clarify the association between this variant and cancer susceptibility.MethodsWe conducted literature search in PubMed, EMbase, MEDLINE and Cochrane Library up to April 30, 2024. Overall, there are 55 studies involving 334,196 patients with cancer and 741,187 controls included in the present study. All statistical analyses were performed by STATA software (version 11.0).ResultsThe pooled results showed a significant association between rs10069690 and an increased risk of cancer under allele model (OR = 1.10, 95% CI: 1.07–1.13, P < 0.001), especially in European and Asian populations. When stratified by cancer types, this variant was associated with elevated risk of breast cancer (OR = 1.11, 95% CI: 1.07–1.15, P < 0.001), ovarian cancer (OR = 1.14, 95% CI: 1.10–1.19, P < 0.001), lung cancer (OR = 1.20, 95% CI: 1.07–1.35, P = 0.003), thyroid cancer (OR = 1.23, 95% CI: 1.15–1.32, P < 0.001), gastric cancer (OR = 1.31, 95% CI: 1.19–1.45, P < 0.001), and renal cell carcinoma (OR = 1.29, 95% CI: 1.07–1.55, P = 0.007), while decreased risk was found for hepatocellular carcinoma, prostate cancer and pancreatic cancer. Our results also indicated that this variant was significantly associated with solid cancer (OR = 1.11, 95% CI: 1.07–1.14, P < 0.001), but not with hematological tumor.ConclusionThis systematic meta-analysis demonstrated that the TERT rs10069690 variant was a risk factor for cancer. However, the effects of this variant may vary in different types of cancer and differ across ethnic populations.

Association and causal impact of TERT genetic variants on peripheral blood leukocyte telomere length and cerebral small vessel disease risk in a Chinese Han population: a mendelian randomization analysis

BackgroundPrevious observational studies have highlighted potential relationships between the telomerase reverse transcriptase (TERT) gene, short leukocyte telomere length (LTL), and cerebrovascular disease. However, it remains to be established as to whether TERT gene variants are associated with an elevated risk of cerebral small vessel disease (CSVD), and whether there is a causal relationship between LTL and CSVD.MethodsFive TERT single nucleotide polymorphisms (SNPs) were analyzed in 307 CSVD patients and 320 healthy controls in whom LTL values were quantified. Allele models and four genetic models were used to explore the relationship between these SNP genotypes and CSVD risk. A Mendelian randomization analysis of CSVD risk was then performed using LTL-related SNPs and the polygenic risk score (PRS) constructed from these SNPs as genetic instrumental variables to predict the causal relationship between LTL and CSVD risk.ResultsModel association analyses identified two SNPs that were significantly associated with CSVD risk. LTL was significantly correlated with age (P < 0.001), and the MR analysis revealed an association between short LTL and an elevated risk of CSVD. PRS-based genetic prediction of short LTLs was also significantly related to an elevated CSVD risk.ConclusionMultiple genetic models and MR results indicate that TERT gene SNPs may be related to an elevated risk of CSVD, and that shorter LTL may be causally linked to such CSVD risk.

Exploring the impact of diabetes on aging: insights from TERT and COL1A1 methylation.

Aging, a multifaceted biological process, leads to diminished physical performance, especially in older adults with diabetes, where a mismatch between biological and chronological age is noticeable. Numerous studies have demonstrated that diabetes accelerates aging at the cellular and organ levels. Notable aging markers are telomerase reverse transcriptase (TERT), related to telomere length, and type 1 chain collagen (COL1A1), a key component of skin collagen. Additionally, age-related methylation increases, as revealed through methylation analysis, augmenting aspects of aging. However, the detailed interplay between aging and diabetes, particularly regarding methylation, remains underexplored and warrants further study to elucidate the biological links between the two. In this study, we elucidate the modulatory influence of diabetes on the aging process, focusing specifically on the modifications in TERT in the kidney and COL1A1 in the skin using mice of Swiss Webster strain as the diabetes model. Specimens were categorized into three distinct chronological cohorts: chronologically young (16 weeks; n = 5), chronologically old (40 weeks; n = 5), and a periodically assessed group (16 weeks; n = 30), from which five mice were systematically sacrificed on a weekly basis. Our findings reveal a marked impact of diabetes on the methylation statuses of TERT and COL1A1, characterized by an elevation in methylation levels within the periodic group (1st-6th week) and a simultaneous, progressive attenuation in the expression of TERT and COL1A1 genes. The observed alterations in the methylation levels of TERT and COL1A1 propound the hypothesis that diabetes potentially expedites the aging process, concomitantly impinging on the production of TERT and COL1A, ostensibly through the mechanism of promoter gene hypermethylation.

Endoplasmic Reticulum Stress Promotes Telomerase Reverse Transcriptase Expression Contributes to Development of Allergic Rhinitis.

The Th2 cell polarization is a crucial factor in the pathogenesis of allergic diseases. The underlying mechanism requires further investigation. Telomerase has an immune-regulating ability. The aim of this study is to elucidate the association between telomerase and Th2 cell polarization in patients with allergic rhinitis (AR). CD4+ T cells were isolated from blood samples collected from AR patients and healthy control subjects. RNA sequencing was employed to analyze RNA samples extracted from CD4+ T cells. An AR mouse model was established using the ovalbumin-alum protocol. High telomerase gene activity and high endoplasmic reticulum (ER) stress status were observed in CD4+ T-cells in patients with AR. Positive correlation between the telomerase reverse transcriptase (TERT) gene expression in CD4+ T cells and AR response in patients with AR. TERT facilitated the degradation of Foxp3 proteins in CD4+ T cells, resulting in the polarization of Th2 cells. Sensitization with the ovalbumin-alum protocol enhanced the Tert expression in CD4+ T cells by exacerbating ER stress. Conditional inhibition of the Tert or eukaryotic translation initiation factor 2-α (Eif2a) expression in CD4+ T cells effectively attenuated experimental AR in mice. Elevated amounts of telomerase in CD4+ T cells were found in CD4+ T cells of subjects with AR. Telomerase promoted Th2 cell polarization by inducing Foxp3 protein degradation and promotes GATA3 activation. Inhibition of TERT or eIF2a alleviated experimental AR.

Establishment and Characterization of a Chicken Myoblast Cell Line.

Skeletal muscle, which is predominantly constituted by multinucleated muscle fibers, plays a pivotal role in sustaining bodily movements and energy metabolism. Myoblasts, which serve as precursor cells for differentiation and fusion into muscle fibers, are of critical importance in the exploration of the functional genes associated with embryonic muscle development. However, the in vitro proliferation of primary myoblasts is inherently constrained. In this study, we achieved a significant breakthrough by successfully establishing a chicken myoblast cell line through the introduction of the exogenous chicken telomerase reverse transcriptase (chTERT) gene, followed by rigorous G418-mediated pressure screening. This newly developed cell line, which was designated as chTERT-myoblasts, closely resembled primary myoblasts in terms of morphology and exhibited remarkable stability in culture for at least 20 generations of population doublings without undergoing malignant transformation. In addition, we conducted an exhaustive analysis that encompassed cellular proliferation, differentiation, and transfection characteristics. Our findings revealed that the chTERT-myoblasts had the ability to proliferate, differentiate, and transfect after multiple rounds of population doublings. This achievement not only furnished a valuable source of homogeneous avian cell material for investigating embryonic muscle development, but also provided valuable insights and methodologies for establishing primary cell lines.

Immortalization of Mesenchymal Stem Cell Lines from Sheep Umbilical Cord Tissue.

Mesenchymal stem cells (MSCs) possess significant differentiation potential, making them highly promising in medicine and immunotherapy due to their regenerative capabilities and exosome secretion. However, challenges such as limited cell divisions and complex testing hinder large-scale MSC production. In this study, we successfully established an immortalized MSC line by transfecting the human telomerase reverse transcriptase (TERT) gene into MSCs isolated from pregnant sheep umbilical cords. This approach effectively inhibits cell senescence and promotes cell proliferation, enabling the generation of umbilical cord mesenchymal stem cells (UCMSCs) on a larger scale. Our findings demonstrate that these transfected TERT-UCMSCs exhibit enhanced proliferative capacity and a reduced aging rate compared to regular UCMSCs while maintaining their stemness without tumorigenicity concerns. Consequently, they hold great potential for medical applications requiring large quantities of functional MSCs.

Transcript level of telomerase reverse-transcriptase (TERT) gene in the rainbow trout (Oncorhynchus mykiss) eggs with different developmental competence for gynogenesis

Expression of the telomerase reverse-transcriptase (TERT) gene and activity of telomerase have been reported in the somatic tissues and gonads in fish irrespective of their age and size. Nevertheless, little is known about TERT expression in the fish eggs. In the current study, the presence of the TERT transcripts was confirmed in the rainbow trout ovulated eggs before and after activation with nonirradiated and UV-irradiated (gynogenesis) sperm. Eggs originating from eight females had high and comparable quality expressed by similar hatching rates. However, survival of the gynogenetic larvae that hatched from eggs activated with UV-irradiated sperm and further exposed to the high hydrostatic pressure (HHP) shock for duplication of the maternal chromosomes varied between females from 2.1 ± 0.4 to 40.5 ± 2.2%. Increased level of TERT transcripts was observed in eggs originating from two females, and gametes from only one of them showed improved competence for gynogenesis (27.3 ± 1.9%). In turn, eggs from the female that exhibited the highest survival after gynogenetic activation were characterized by the lowest expression of the TERT gene. Telomerase in rainbow trout eggs may compensate erosion of the telomeres during early embryonic development; however, its upregulation does not assure better development after gynogenetic activation.