OBJECTIVETo investigate the roles of telomere and telomerase in the effect of ginsenoside Rg1 to delay hematopoietic stem cell senescence.

METHODSca-1(+) HSC was isolated by magnetic cell sorting(MACS) and divided into five groups: the control group, the aged model group, the Rg1 group, the Rg1 treated aged group and the Rg1 delayed aged group. The changes of cells were observed by senescence-associated beta-Galactosidase (SA-beta-Gal) staining. Cell cycle assay and culture of mixed hematopoietic progenitor cell were used to investigate the effect of ginsenoside Rg1 to delay Sca-1(+) HSC senescence. Telomere length and telomerase activity were detected by southern blotting and TRAP-PCR-SYBR Green staining.

RESULTCompared with aged model group, the percentage of positive cells expressed SA-beta-Gal and the number of cells entered G1 phase were decreased and the number of colony of mixed hematopoietic progenitor was increased. It showed markedly decreased in the shortening of telomere length and reinforcing in the telomerase activity to Rg1 treated aged group and Rg1 delayed aged group. The change of Rg1 delayed aged group was significantly higher than Rg1 treated aged group.

CONCLUSIONActivation of telomerase and prolonging of telomere length might be involved in the process of ginsenoside Rg1 to delay and treat the senescence of Sca-1(+) HSC.

Cellular Senescence ; drug effects ; Ginsenosides ; pharmacology ; Hematopoietic Stem Cells ; drug effects ; physiology ; Telomerase ; metabolism ; Telomere ; drug effects

This study was aimed to investigate the modulating effects on telomere length and telomerase activity in K562 cells treated by arsenic trioxide, ginseng saponin, beta-elemene alone or in combination with cyclophosphamide (CTX) and to explore the possible mechanism and new therapy for acute leukemia. Human erythroleukemic cell line K562 was co-cultured with the above-mentioned drugs. Cells were collected after 24, 48 and 72 hours for further detection. Telomere length and telomerase activity were detected by Southern-blot and PCR-ELISA respectively. The effects of these drugs were observed at different concentrations and exposure time. The results showed that (1) ginseng saponin, arsenic trioxide, beta-elemene, or CTX could completely inhibit the telomerase activity of K562 cells at proper concentrations and exposure time. The inhibiting effects were enhanced when the three former drugs were used with CTX. Telomerase activity decreased proportionally with the concentrations and length of time. (2) viability of K562 cells was decreased after being co-cultured with arsenic trioxide, ginseng saponin, beta-elemene and CTX. The level of inhibition depends on the concentration and exposure time. (3) telomere length of K562 cells was 5.36 +/- 0.18 kb. After being co-cultured with those drugs for 72 hours, telomere length was 5.90 kb -6.50 kb, significantly longer than that of control (5.18 - 5.35 kb). It is concluded that arsenic trioxide, ginseng saponin, and beta-elemene can inhibit the growth and telomerase activity of K562 cells. The inhibiting effects were enhanced when they were used in combination with CTX. The depression of telomerase activity may be one of the mechanisms of anti-tumor effect. Less dosage and shorter course can be expected when arsenic trioxide, ginseng saponin, and beta-elemene are used in combination with CTX. When telomerase activity was depressed, the telomere length prolonged a little, indicating K562 cell line may extend telomeres by some alternative way other than telomerase activation.
Arsenicals ; pharmacology ; Cyclophosphamide ; pharmacology ; Drug Synergism ; Humans ; K562 Cells ; Oxides ; pharmacology ; Panax ; chemistry ; Saponins ; pharmacology ; Sesquiterpenes ; pharmacology ; Telomerase ; drug effects ; metabolism ; Telomere ; drug effects

The detection of sperm DNA damage, as an important supplement to semen routine examination strategies, has been applied in some clinical andrology laboratories. What factors may lead to sperm DNA damage remains one of the concerns among many andrologists. Present studies show a variety of factors of sperm DNA damage, including age, environmental pollutants such as organophosphorus and organochloride pesticides, plasticizer, heavy metals such as lead, carcinogens such as polycyclic aromatic hydrocarbons (c-PAHs) and zearalenone (ZEA), male reproductive system diseases or systemic diseases such as varicocele, infection, tumor, spermatogenesis and maturation dysfunction, spinal cord injury and endocrine disorders, seasons and temperature, lifestyle, abstinence time, semen refrigeration, semen handling in vitro, and certain medications. Among them, spermatogenesis and sperm maturation dysfunction may be the most secretive factors, which are involved in the molecular mechanisms of sperm chromatin packaging and restructuring, such as the transformation of histone to protamine, single nucleotide polymorphism of genes, and the role of telomere, which may be one of the hotspots in the future studies of sperm DNA damage. Relevant researches in the future are expected to focus on the prevention of sperm DNA damage and clarification of its specific pathogenic mechanisms so as to provide some evidence for its treatment.
Age Factors ; Chromatin ; chemistry ; DNA Damage ; Environmental Pollutants ; toxicity ; Humans ; Male ; Protamines ; Semen ; drug effects ; Specimen Handling ; Spermatogenesis ; Spermatozoa ; drug effects ; Telomere ; physiology ; Varicocele ; complications

The aim was to explore the modulating and inhibiting effects of arsenic trioxide, ginseng saponin and beta-elemene on telomere length and telomerase activity in K562 cell line, and to study their anti-tumor mechanism and seek new method of therapy for acute leukemia. Human erythroleukemia cell line K562 was co-cultured with arsenic trioxide, ginseng saponin, beta-elemene separately, cells were collected after 24, 48 and 72 hours for further detecting. Telomere length and telomerase activity were detected by the methods of Southern-blot and PCR-ELISA respectively. The effects of these drugs on telomere length and telomerase activity were observed at different concentrations and length of time. The results showed that (1) telomerase activity of K562 cells decreased after co-cultured with arsenic trioxide, ginseng saponin and beta-elemene. The inhibiting effects depended on drug concentrations and length of time. When co-cultured at proper concentration and period of time, telomerase activity could be inhibited; (2) viability of K562 cells decreased after co-cultured with arsenic trioxide, ginseng saponin and beta-elemene, the inhibiting effect depends on drug concentrations and length of time; (3) after co-cultured with arsenic trioxide, ginseng saponin, and beta-elemene for 72 hours, telomere length of K562 cell line prolonged a little. It is concluded that (1) arsenic trioxide, ginseng saponin and beta-elemene can inhibit telomerase activity in K562 cell line, the suppression of telomerase activity may be one of the mechanisms of anti-tumor effect; (2) arsenic trioxide, ginseng saponin and beta-elemene can inhibit the growth of K562 cell line, the inhibiting effect depends on concentration and time; (3) when telomerase activity was suppressed, the telomere length prolonged a little, indicating that in K562 cell line may exist another mechanism to regulate telomere length, except telomerase activation.
Arsenicals ; pharmacology ; Cell Survival ; drug effects ; Humans ; K562 Cells ; Oxides ; pharmacology ; Panax ; Saponins ; pharmacology ; Sesquiterpenes ; pharmacology ; Telomerase ; metabolism ; Telomere ; drug effects

OBJECTIVE: To investigate the cytotoxic effect and its mechanism of the micromolecule compound on the leukemia cells. METHODS: The cytotoxic effects of 28 Nilotinib derivatives on K562, KA, KG, HA and 32D cell lines were detected by MTT assays, and the compound Nilo 22 was screen out. Cell apoptosis and cell cycle on leukemia cells were detected by flow cytometry. The effect of compound screened out on leukemogenesis potential of MLL-AF9 leukemia mice GFP RESULTS: Nilo 22 serves as the most outstanding candidate out of 28 Nilotinib derivatives, which impairs leukemia cell lines, but spares normal hematopoietic cell line. Comparing with Nilotinib, Nilo 22 could induce the apoptosis of GFP CONCLUSION Nilo 22 shows a significant cytotoxic effect on mice and human leukemia cells, especially for drug resistance cells. Nilo 22 is a promising anti-leukemia agent to solve the common clinical problems of drug resistance and relapse of leukemia.
Animals ; Apoptosis/drug effects* ; Cell Cycle/drug effects* ; Cell Line, Tumor ; Humans ; Leukemia ; Mice ; Myeloid-Lymphoid Leukemia Protein/genetics* ; Telomerase/metabolism* ; Telomere/metabolism*

OBJECTIVETo explore the association between polycyclic aromatic hydrocarbons (PAHs) exposure and telomere length (TL), so as to investigate the effective biomarkers to evaluate the genetic damage in peripheral blood of workers exposed to PAHs.

METHODSThe exposure group consisted of 145 coke-oven workers (including 30 top-oven workers, 76 side-oven workers and 39 bottom-oven workers), and the non-exposure control group comprised 68 medical staffs. At 6 hours after the weekend duty shift, the samples of urine and 1 ml venous blood were collected from each subject. Airborne benzene-soluble matter (BSM) and particulate-phase B(a)P in the working environment of coke-oven and controls were sampled and analyzed. The concentration of urinary 1-hydroxypyrene (1-OHPyr) was determined. A real-time PCR method was used to determine the relative telomere length (RTL) of genomic DNA in peripheral blood. The relationship between the RTL and external exposure of PAHs, the potential factors which might have influence on TL were analyzed.

RESULTSThe medians of air BSM and particulate-phase B(a)P were higher in coke-oven (BSM: 328.6 µg/m(3); B(a)P: 926.9 ng/m(3)) than those in control working environment (BSM:97.8 µg/m(3); B(a)P: 49.1 ng/m(3)). The level of 1-OHPyr among coke-oven workers was significantly higher than that of non-exposed group (12.2 µmol/mol Cr vs 0.7 µmol/mol Cr; t = 26.971, P < 0.01). RTL in coke-oven workers were significantly shorter than those of controls (1.10 ± 0.75 vs 1.43 ± 1.06; t = 2.263, P = 0.026), and after adjusting for cigarettes per day and urinary 1-OHPyr, the significant difference was still observed (F(adju) = 5.496, P(adju) = 0.020). Stratification analysis found that RTL among the male and non-drinking groups in coke-oven workers were shorter than those the same sex and alcohol using status in controls (1.08 ± 0.73 vs 1.51 ± 1.10, F = 9.212, P = 0.003; 0.96 ± 0.38 vs 1.26 ± 0.46, F = 6.484, P = 0.012). Significant correlation between RTL and age was found (r = -0.284, P = 0.019) in non-exposure group.

CONCLUSIONPAH-exposure has effect on TL of genomic DNA in peripheral blood, which is mainly observed in the male and non-drinking groups between PAH-exposed workers and controls. It indicates that TL of genomic DNA in peripheral blood might be an effective biomarker as PAH-induced genetic damage.

Adult ; Benzene ; Case-Control Studies ; Coke ; DNA Damage ; Female ; Humans ; Male ; Occupational Exposure ; adverse effects ; analysis ; Polycyclic Aromatic Hydrocarbons ; adverse effects ; analysis ; Pyrenes ; analysis ; Telomere ; drug effects ; genetics

OBJECTIVETo study the effects of Cynomorium songaricum polysaccharide (CSP) on telomere length in blood and brain tissues of aged mice in order to provide some evidence for CSP's development and applying in the clinical uses.

METHODKunming mice were intraperitoneal injected D-galactose (500 mg x kg(-1) x d(-1)) to make the aging models, and different dosages of CSP (20, 40, 80 mg x kg(-1)) were given by gavage for 56 days. The average length of telomere was determined by real-time fluorescence quantitative PCR.

RESULTThe relative T/S ratio of the group high and middle dosages of CSP in blood were 1.64 +/- 0.36 and 1.33 +/0.28, respectively, and higher than that of the group of senescence 1.01 +/- 0.13 (P < 0.01). Values of the group of high, middle, and low dosages of CSP in brain tissues were 3.34 +/- 0.58, 2.30 +/- 0. 75 and 1.55 +/- 0.58, respectively, and significantly higher than that of the group of senescence 1.04 +/- 0.33 (P < 0.01).

CONCLUSIONCSP can exert the anti-aging effects by increase telomere length f senescence mice.

Aging ; drug effects ; Animals ; Animals, Newborn ; Brain ; drug effects ; pathology ; Cellular Senescence ; drug effects ; Cynomorium ; chemistry ; Disease Models, Animal ; Drugs, Chinese Herbal ; therapeutic use ; Galactose ; pharmacology ; Humans ; In Situ Hybridization, Fluorescence ; Mice ; Polysaccharides ; pharmacology ; therapeutic use ; Telomere ; drug effects ; physiology

BACKGROUNDThe accumulation of free radicals and advanced glycation end products (AGEs) in cell plays a very important role in replicative senescence. Aminoguanidine (AG) has potential antioxidant effects and decreases AGE levels. This study aimed to investigate its effect on replicative senescence in vitro.

METHODSThe effects of aminoguanidine on morphology, replicative lifespan, cell growth and proliferation, AGEs, DNA damage, DNA repair ability and telomere length were observed in human fetal lung diploid fibroblasts (2BS).

RESULTSAminoguanidine maintained the non-senescent phenotype of 2BS cells even at late population doubling (PD) and increased cumulative population doublings by at least 17 - 21 PDs. Aminoguanidine also improved the potentials of growth and proliferation of 2BS cells as detected by the MTT assay. The AGE levels of late PD cells grown from early PD in DMEM containing aminiguanidine decreased significantly compared with those of late PD control cells and were similar to those of young control cells. In addition, the cells pretreated with aminoguanidine had a significant reduction in DNA strand breaks when they were exposed to 200 micromol/L H(2)O(2) for 5 minutes which indicated that the compound had a strong potential to protect genomic DNA against oxidative stress. And most of the cells exposed to 100 micromol/L H(2)O(2) had much shorter comet tails and smaller tail areas after incubation with aminoguanidine-supplemented DMEM, which indicated that the compound strongly improved the DNA repair abilities of 2BS cells. Moreover, PD55 cells grown from PD28 in 2 mmol/L or 4 mmol/L aminoguanidine retain telomere lengths of 7.94 kb or 8.12 kb, which was 0.83 kb or 1.11 kb longer than that of the control cells.

CONCLUSIONAminoguanidine delays replicative senescence of 2BS cells and the senescence-delaying effect of aminoguanidine appear to be due to its many biological properties including its potential for proliferation improvement, its inhibitory effect of AGE formation, antioxidant effect, improvement of DNA repair ability and the slowdown of telomere shortening.

Cell Proliferation ; drug effects ; Cells, Cultured ; Cellular Senescence ; drug effects ; DNA Damage ; DNA Repair ; Diploidy ; Dose-Response Relationship, Drug ; Female ; Fibroblasts ; drug effects ; Glycation End Products, Advanced ; analysis ; Guanidines ; pharmacology ; Humans ; Hydrogen Peroxide ; toxicity ; Telomere

OBJECTIVETo investigate the promoter methylation of p16, FHIT and RASSF1A gene and telomere damage in the workers exposed to coal tar pitch, and to explore the effective biomarker of occupational exposure to coal tar pitch.

METHODS180 cases of workers exposed to coal tar pitch in a certain carbon plant named as exposure group, and 145 healthy cases with a medical examination in the first affiliated hospital of Zhengzhou University were selected as control group. Relative telomere length in peripheral blood DNA was detected using real-time quantitative PCR, and the promoter methylation rate of p16, RASSF1A and FHIT gene in peripheral blood DNA were determined by real-time quantitative methylation specific PCR. The relative telomere length and gene promoter methylation in two groups were compared, and influencing factors were analyzed.

RESULTSRelative telomere length in exposed group was lower than that in the control group, and the difference was statistically significant (Z = -5.395, P < 0.001). There was no significant difference in the promoter methylation rate of p16, FHIT and RASSF1A gene between the two groups (P > 0.05). Stratification analysis by gender, age, and smoking, we found that when the age was less than or equal to 40, the promoter methylation rate of p16 in exposed group was more than that in control group, and the difference was statistically significant (Z = -1.914, P = 0.011).

CONCLUSIONOccupational exposure to coal tar pitch may induce leukocyte DNA telomere length of human peripheral blood shortened, and may not change the promoter methylation rates of p16, FHIT and RASSF1A gene.

Acid Anhydride Hydrolases ; genetics ; Coal Tar ; adverse effects ; Cyclin-Dependent Kinase Inhibitor p16 ; genetics ; DNA Methylation ; Humans ; Leukocytes ; drug effects ; Neoplasm Proteins ; genetics ; Occupational Exposure ; adverse effects ; Promoter Regions, Genetic ; Telomere ; drug effects ; ultrastructure ; Tumor Suppressor Proteins ; genetics

Telomeres undergo attrition with each cell division, and telomere length is associated with age-related diseases and mortality in the elderly. Estrogen can influence the attrition of telomeres by diverse mechanisms. This is a retrospective case control study that investigated the influence of long-term hormone therapy (HT) on telomere length in postmenopausal women. We recruited 130 postmenopausal women from 55 to 69 years of age for this study, and divided them into two groups. The first group included 65 women who had been on estrogen and progesterone therapy for more than five years (HT group). The other group was composed of 65 women matched in age to the HT group who had never had HT (non- HT group). The relative ratios of telomere length of study subjects to a reference DNA from a healthy young female were measured using quantitative PCR. Plasma levels of lipid profiles, total antioxidant status (TAS), C-reactive proteins (CRP), fasting glucose levels, and estradiol levels were measured. Age at menopause, vitamin use, and exercise, alcohol, and cigarette smoking histories were also assessed in a questionnaire. Mean duration (+/- SD) of HT was 8.4 +/- 2.3 years. Prevalence of vitamin use and regular exercise were higher in the HT group than in the non-HT group (p < 0.01). Relative telomere length ratios in the HT group were significantly greater than those in the non-HT group (p < 0.01). HT was significantly correlated with the relative telomere length ratio in multivariate analysis when potential confounding variables were controlled for (p < 0.05). In conclusion, telomere lengths were longer in postmenopausal women who had a history of long-term HT than in postmenopausal women without HT. Long-term HT in postmenopausal women may alleviate telomere attrition.
Aged ; DNA Damage ; Estrogens/*administration & dosage ; Female ; *Hormone Replacement Therapy ; Humans ; Middle Aged ; Postmenopause ; Progesterone/*administration & dosage ; Research Support, Non-U.S. Gov't ; Telomere/*drug effects ; Time Factors