Previous studies mainly used β-amyloid and α-synuclein as the biomarkers for the diagnosis of neurodegenerative diseases. In recent years，studies have shown that telomeres at the end of chromosome can be used as an index to measure the degree of biological aging，and telomere length and telomerase activity may also be used as the blood markers to evaluate the risk，progression，and poor prognosis of neurodegenerative diseases in the elderly；however，there is still a lack of consistency between the research findings in China and globally. Understanding the role of telomere-related biomarkers in age-related diseases can help clinicians learn more about the mechanism of disease development and progression. This article reviews the latest research advances in the telomere-telomerase system in neurodegenerative diseases，in order to introduce the influence of telomere length and telomerase activity on neurodegenerative diseases and their potential mechanisms of action.
Telomere ; Telomerase ; Neurodegenerative Diseases ; Alzheimer Disease ; Parkinson Disease

OBJECTIVE: To explore the genetic characteristics of idic(X)(p11.22) in Turner syndrome (TS). METHODS: Two fetuses suspected for sex chromosome abnormalities or ultrasound abnormalities were selected from Chengdu Women's and Children's Central Hospital in October 2020 and June 2020, and amniotic fluid samples were collected for G-banded chromosomal karyotyping analysis, chromosomal microarray analysis (CMA), and fluorescence in situ hybridization (FISH). RESULTS: The two fetuses were respectively found to have a karyotype of 45,X[47]/46,X,psu idic(X)(p11.2)[53] and 46,X,psu idic(X)(p11.2). CMA found that both had deletions in the Xp22.33p11.22 region and duplications in the p11.22q28 region. FISH showed that the centromeres in both fetuses had located on an isochromosome. CONCLUSION The combination of karyotyping analysis, FISH, and CMA is useful for the delineation of complex structural chromosomal aberrations. High-resolution CMA can accurately identify chromosomal breakpoints, which can provide a clue for elucidating the mechanism of chromosomal breakage and rearrangement.
Female ; Pregnancy ; Humans ; Turner Syndrome/genetics* ; In Situ Hybridization, Fluorescence ; Sex Chromosome Aberrations ; Centromere ; Prenatal Diagnosis

Prostate cancer is one of the most common diseases in men worldwide. Surgery, radiation therapy, and hormonal therapy are effective treatments for early-stage prostate cancer. However, the development of castration-resistant prostate cancer has increased the mortality rate of prostate cancer. To develop novel drugs for castration-resistant prostate cancer, the molecular mechanisms of prostate cancer progression must be elucidated. Among the signaling pathways regulating prostate cancer development, recent studies have revealed the importance of noncanonical wingless-type MMTV integration site family (WNT) signaling pathways, mainly that involving WNT5A, in prostate cancer progression and metastasis; however, its role remains controversial. Moreover, chromatin remodelers such as the switch/sucrose nonfermentable (SWI/SNF) complex and chromodomain helicase DNA-binding proteins 1 also play important roles in prostate cancer progression through genome-wide gene expression changes. Here, we review the roles of noncanonical WNT signaling pathways, chromatin remodelers, and epigenetic enzymes in the development and progression of prostate cancer.
Male ; Humans ; Wnt Signaling Pathway ; Chromatin ; Prostatic Neoplasms, Castration-Resistant ; Chromatin Assembly and Disassembly

Objective: To analyze the contribution and interaction of polycyclic aromatic hydrocarbons (PAH)-DNA adducts and changes of telomere length (TL) on missed abortion. Methods: From March to December 2019, patients with missed abortion in the First Hospital of Shanxi Medical University and pregnant women with normal pregnancy but voluntary abortion in the same department during the same period were selected and divided into a case group and a control group. Questionnaire was used to investigate the general situation and the pregnancy situation of the subjects. The abortion villi were collected and the content of PAH-DNA adducts and TL was detected. Logistic regression model was used to analyze the associated factors of missed abortion. R epiR package and Mediation package were used to analyze the effect and relationship between PAH-DNA adducts and TL on missed abortion. Results: The age of the subjects was(29.92±5.69)years old. The M(Q₁,Q₃)of PAH-DNA adducts was 453.75(404.61, 504.72) pg/ml. The M(Q₁,Q₃)of TL was 1.21(0.77, 1.72). The content of PAH-DNA adducts in the case group was higher than that in the control group (Z=-2.10, P=0.036), while the TL was lower than that in the control group (Z=-4.05, P<0.001). Multivariate logistic regression showed that low, medium and high levels of PAH-DNA adducts (OR=3.17,95%CI:1.41-7.14;OR=2.85,95%CI:1.25-6.52;OR=2.46,95%CI:1.07-5.64), and long, medium and short levels of TL (OR=2.50,95%CI:1.11-5.63;OR=3.32,95%CI:1.45-7.56;OR=3.22,95%CI:1.42-7.26) were all risk factors for missed abortion. The medium level of PAH-DNA adducts had a 2.76-fold higher risk of shortened TL than those with the lowest level, and no mediating role of TL was found. The stratified analysis showed that when the TL level was longer (>1.21), the low and high levels of PAH-DNA adducts were associated with missed abortion (all P<0.05); when the TL level was shorter (<1.21), the medium level of PAH-DNA adducts was associated with abortion (P=0.025). At lower levels of PAH-DNA adducts, no effect of TL on missed abortion was observed, while, at higher levels, TL was strongly associated with missed abortion (OR=7.50,95%CI:1.95-28.82;OR=6.04,95%CI:1.54-23.65;OR=9.05,95%CI:2.34-35.04). The interaction analysis found that the AP was 0.72 (95%CI: 0.46-0.99), and the SI was 5.21 (95%CI: 2.30-11.77). Conclusion: The high level of PAH-DNA adducts and shortened TL may increase the risk of missed abortion, and there may be a positive additive interaction between the two factors on missed abortion.
Humans ; Female ; Pregnancy ; Young Adult ; Adult ; DNA Adducts ; Abortion, Missed/chemically induced* ; Polycyclic Aromatic Hydrocarbons ; Abortion, Spontaneous/chemically induced* ; Telomere/chemistry*

Previous studies have shown that long-term spermatogonial stem cells (SSCs) have the potential to spontaneously transform into pluripotent stem cells, which is speculated to be related to the tumorigenesis of testicular germ cells, especially when p53 is deficient in SSCs which shows a significant increase in the spontaneous transformation efficiency. Energy metabolism has been proved to be strongly associated with the maintenance and acquisition of pluripotency. Recently, we compared the difference in chromatin accessibility and gene expression profiles between wild-type (p53^+/+) and p53 deficient (p53^-/-) mouse SSCs using the Assay for Targeting Accessible-Chromatin with high-throughput sequencing (ATAC-seq) and transcriptome sequencing (RNA-seq) techniques, and revealed that SMAD3 is a key transcription factor in the transformation of SSCs into pluripotent cells. In addition, we also observed significant changes in the expression levels of many genes related to energy metabolism after p53 deletion. To further reveal the role of p53 in the regulation of pluripotency and energy metabolism, this paper explored the effects and mechanism of p53 deletion on energy metabolism during the pluripotent transformation of SSCs. The results of ATAC-seq and RNA-seq from p53^+/+ and p53^-/- SSCs revealed that gene chromatin accessibility related to positive regulation of glycolysis and electron transfer and ATP synthesis was increased, and the transcription levels of genes encoding key glycolytic enzymes and regulating electron transport-related enzymes were markedly increased. Furthermore, transcription factors SMAD3 and SMAD4 promoted glycolysis and energy homeostasis by binding to the chromatin of the Prkag2 gene which encodes the AMPK subunit. These results suggest that p53 deficiency activates the key enzyme genes of glycolysis in SSCs and enhances the chromatin accessibility of genes associated with glycolysis activation to improve glycolysis activity and promote transformation to pluripotency. Moreover, SMAD3/SMAD4-mediated transcription of the Prkag2 gene ensures the energy demand of cells in the process of pluripotency transformation and maintains cell energy homeostasis by promoting AMPK activity. These results shed light on the importance of the crosstalk between energy metabolism and stem cell pluripotency transformation, which might be helpful for clinical research of gonadal tumors.
Animals ; Mice ; AMP-Activated Protein Kinases ; Chromatin ; Energy Metabolism ; Gene Deletion ; Stem Cells ; Tumor Suppressor Protein p53/genetics* ; Spermatogonia/cytology* ; Male

OBJECTIVE: To present on a prenatally diagnosed case with complex structural rearrangements of chromosome 8. METHODS: Chromosome karyotyping, chromosomal microarray analysis (CMA) and fluorescence in situ hybridization (FISH) were carried out for a fetus with increased nuchal thickness. RESULTS: The karyotype of the amniotic fluid sample showed extra materials on 8p. FISH revealed a centromeric signal at the terminal of 8p with absence of telomeric signal. CMA revealed partial deletion of 8p23.3 [(208049_2256732)×1], partial duplication of 8p23.3p23.2 [(2259519_3016818)×3], and partial duplication of 8q [8q11.1q12.2(45951900_60989083)×3]. CONCLUSION The complex structural rearrangements of chromosome 8 in this case has differed from the commonly seen inv dup del(8p).
Female ; Pregnancy ; Humans ; Chromosomes, Human, Pair 8/genetics* ; In Situ Hybridization, Fluorescence ; Gene Rearrangement ; Prenatal Diagnosis ; Centromere

METTL3 and METTL14 are two components that form the core heterodimer of the main RNA m6A methyltransferase complex (MTC) that installs m6A. Surprisingly, depletion of METTL3 or METTL14 displayed distinct effects on stemness maintenance of mouse embryonic stem cell (mESC). While comparable global hypo-methylation in RNA m6A was observed in Mettl3 or Mettl14 knockout mESCs, respectively. Mettl14 knockout led to a globally decreased nascent RNA synthesis, whereas Mettl3 depletion resulted in transcription upregulation, suggesting that METTL14 might possess an m6A-independent role in gene regulation. We found that METTL14 colocalizes with the repressive H3K27me3 modification. Mechanistically, METTL14, but not METTL3, binds H3K27me3 and recruits KDM6B to induce H3K27me3 demethylation independent of METTL3. Depletion of METTL14 thus led to a global increase in H3K27me3 level along with a global gene suppression. The effects of METTL14 on regulation of H3K27me3 is essential for the transition from self-renewal to differentiation of mESCs. This work reveals a regulatory mechanism on heterochromatin by METTL14 in a manner distinct from METTL3 and independently of m6A, and critically impacts transcriptional regulation, stemness maintenance, and differentiation of mESCs.
Animals ; Mice ; Methylation ; Chromatin ; Histones/metabolism* ; RNA, Messenger/genetics* ; Methyltransferases/metabolism* ; RNA/metabolism*

Humans ; Neuroendocrine Tumors/genetics* ; Prognosis ; X-linked Nuclear Protein/genetics* ; Pancreatic Neoplasms/pathology* ; Telomere/pathology*

Humans ; Stroke, Lacunar ; Mendelian Randomization Analysis ; Leukocytes ; Telomere/genetics* ; Genome-Wide Association Study ; Polymorphism, Single Nucleotide

Lamin B1 (LMNB1) is highly expressed in liver cancer tissues, and its influence and mechanism on the proliferation of hepatocellular carcinoma cells were explored by knocking down the expression of the protein. In liver cancer cells, siRNAs were used to knock down LMNB1. Knockdown effects were detected by Western blotting. Changes in telomerase activity were detected by telomeric repeat amplification protocol assay (TRAP) experiments. Telomere length changes were detected by quantitative real-time polymerase chain reaction (qPCR). CCK8, cloning formation, transwell and wound healing were performed to detect changes in its growth, invasion and migration capabilities. The lentiviral system was used to construct HepG2 cells that steadily knocked down LMNB1. Then the changes of telomere length and telomerase activity were detected, and the cell aging status was detected by SA-β-gal senescence staining. The effects of tumorigenesis were detected by nude mouse subcutaneous tumorigenesis experiments, subsequent histification staining of tumors, SA-β-gal senescence staining, fluorescence in situ hybridization (FISH) for telomere analysis and other experiments. Finally, the method of biogenesis analysis was used to find the expression of LMNB1 in clinical liver cancer tissues, and its relationship with clinical stages and patient survival. Knockdown of LMNB1 in HepG2 and Hep3B cells significantly reduced telomerase activity, cell proliferation, migration and invasion abilities. Experiments in cells and tumor formation in nude mice had demonstrated that stable knockdown of LMNB1 reduced telomerase activity, shortened telomere length, senesced cells, reduced cell tumorigenicity and KI-67 expression. Bioinformatics analysis showed that LMNB1 was highly expressed in liver cancer tissues and correlated with tumor stage and patient survival. In conclusion, LMNB1 is overexpressed in liver cancer cells, and it is expected to become an indicator for evaluating the clinical prognosis of liver cancer patients and a target for precise treatment.
Animals ; Mice ; Telomerase/metabolism* ; Carcinoma, Hepatocellular/genetics* ; Liver Neoplasms/genetics* ; Telomere Shortening ; In Situ Hybridization, Fluorescence ; Mice, Nude ; Telomere/pathology* ; Carcinogenesis