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OBJECTIVE: To explore the effect of occupational lead exposure on the relative telomere length(RTL) and mRNA expression of telomere-binding protein POT1-interacting protein 1(TPP1) in peripheral blood of workers. METHODS: A total of 303 workers exposed to lead were selected as the exposure group and 72 administrative logisticians personnel in the same factory as the control group using the simple random sampling method. Their peripheral blood samples were collected and were used to detect the blood lead level by Graphite furnace atomic absorption spectrometry. RTL and the relative expression of TPP1 mRNA by real-time quantitative polymerase chain reaction. RESULTS: The blood lead level of the exposure group was higher [Media(M): 68.2 vs 266.1 μg/L, P<0.01], the RTL was shorter(M: 0.96 vs 0.70, P<0.01), and the relative mRNA expression of TPP1 was lower(M: 0.92 vs 0.51, P<0.01) compared with the control group. Spearman correlation analysis results showed that the blood lead level were both negatively correlated with RTL [Spearman correlation coefficient(r_S) =-0.18, P<0.01], and the relative mRNA expression of TPP1(r_S=-0.19, P<0.01), while the RTL was positively correlated with the risk of RTL shortening and the relative mRNA expression of TPP1 decline was increased in lead exposure(P<0.01). CONCLUSION: Lead exposure can shorten the RTL and reduce the relative mRNA expression of TPP1 in workers. The mechanism may be that lead interferes with telomere repair process by inhibiting the mRNA expression of TPP1.
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@#Introduction: Anterior cruciate ligament (ACL) tear is the most common knee ligament injury, especially in athletes. The objective of this study was to investigate relative telomere length (RTL) in blood leukocytes of patients with ACL injury compared with that of controls. Materials and Methods: A total of 187 subjects were invited to participate in this study. Ninety-two patients with clinically diagnosed ACL rupture were enrolled. Ninety-five age and gender-matched healthy controls were also recruited. Blood leukocyte RTL were analysed using quantitative real-time polymerase chain reaction. Results:Patients with ACL rupture had significantly longer relative telomere length than healthy controls (P=0.002). The patients with ACL rupture were classified into two groups according to the sport history of patients which are contact sports and non-contact sports. RTL in patients with non-contact sports was significantly greater than those with contact sports (P=0.006). Moreover, RTL was inversely correlated with body mass index of patients with ACL injury (r=-0.34, P=0.001). Logistic regression analysis indicated that long RTL was associated with a higher risk of ACL rupture. Conclusion: The present study showed that subjects with ACL rupture had significantly greater telomere length compared with their age and gender-matched controls. This finding may result from the increases in physical activity and overexpression of telomerase which acts as a protective mechanism against ACL injury. RTL in blood leukocytes is associated with a risk of ACL rupture.
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Several studies have demonstrated an association between physical activity and telomere length; however, the association remains inconsistent. A cross-sectional study consisting of 588 participants (375 females, median age of 33.8 years) was carried out to investigate the association between telomere length and physical activity in a general population from North China. The results show that relative telomere length is not significantly different in participants in the northern Chinese population with different levels of physical activity, either in the model only adjusted for age (F = 2.127, P = 0.120) or in the model adjusted for demographics and lifestyle (F = 1.227, P = 0.294). The gender-stratified analysis also produced insignificant results. Our study confirmed a non-significant association between physical activity and telomere length in the northern Chinese population, which adds to the inconsistent association between physical activity and telomere length across different ethnic populations.
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Adult , Female , Humans , Male , Middle Aged , Young Adult , Asian People , Genetics , China , Cohort Studies , Cross-Sectional Studies , Exercise , Physiology , TelomereABSTRACT
BACKGROUND AND OBJECTIVES: Adipose-derived mesenchymal stem cells (ADSCs) are promising candidates in regenerative medicine. The need for in vitro propagation to obtain therapeutic quantities of the cells imposes a risk of impaired functionality due to cellular senescence. The aim of the study was to analyze in vitro senescence of previously cryopreserved human ADSCs subjected to serial passages in cell culture. METHODS AND RESULTS: ADSC cultures from 8 donors were cultivated until proliferation arrest was reached. A gradual decline of ADSC fitness was observed by altered cell morphology, loss of proliferative, clonogenic and differentiation abilities and increased β-galactosidase expression all of which occurred in a donor-specific manner. Relative telomere length (RTL) analysis revealed that only three tested cultures encountered replicative senescence. The presence of two ADSC subsets with significantly different RTL and cell size was discovered. The heterogeneity of ADSC cultures was supported by the intermittent nature of aging seen in tested samples. CONCLUSION: We conclude that the onset of in vitro senescence of ADSCs is a strongly donor-specific process which is complicated by the intricate dynamics of cell subsets present in ADSC population. This complexity needs to be carefully considered when elaborating protocols for personalized cellular therapy.