The presence of micronuclei in mammalian cells is related to several mutagenetic stresses. In order to understand how micronuclei emerge, behave in cells, and affect cell fate, we performed extensive time-lapse microscopy of HeLa H2B-GFP cells in the presence of hydroxyurea at low concentration. Micronuclei formed after mitosis from lagging chromatids or chromatin bridges between anaphase chromosomes and were stably maintained in the cells for up to one cell cycle. Nuclear buds also formed from chromatin bridges or during interphase. If the micronuclei-bearing cells entered mitosis, they either produced daughter cells without micronuclei or, more frequently, produced cells with additional micronuclei. Low concentrations of hydroxyurea efficiently induced multipolar mitosis, which generated lagging chromatids or chromatin bridges, and also generated multinuclear cells that were tightly linked to apoptosis. We found that the presence of micronuclei is related to apoptosis but not to multipolar mitosis. Furthermore, the structural heterogeneity among micronuclei, with respect to chromatin condensation or the presence of lamin B, derived from the mechanism of micronuclei formation. Our study reinforces the notion that micronucleation has important implications in the genomic plasticity of tumor cells.

Telomere (TL) is a biomarker of biological aging, and its shortening is associated with major risk factors for cardiovascular diseases (CVD). This study aimed to identify whether TL is associated with arterial stiffness as reflected by brachial–ankle pulse wave velocity (baPWV). This population-based cross-sectional study involved 1065 individuals in the Iwaki area, Japan. Total TL length and TL G-tail length were measured by hybridization protection assay. The baPWV was measured on the right and left sides using a non-invasive vascular screening device. The associations between TL and baPWV were assessed by multivariate linear regression. Compared with the shortest total TL tertile, the longest total TL group showed a significant decrease in baPWV (lowest vs. highest tertile: adjusted beta: −41.24, 95% confidence interval (CI): −76.81, −5.68). The mean baPWV decreased with a longer TL (TL G-tail length: p trend < 0.001, total TL: p trend < 0.001). TL G-tail and total TL lengths were inversely associated with baPWV, implicating TL shortening in the development of CVD. This study provides evidence of the factors influencing CVD risks at a very early stage when individuals can still take necessary precautions before CVD gives rise to a symptomatic health outcome.

Telomeres, repeated TTAGGG sequences at chromosomal ends, shorten with age and indicate cellular lifespan. Zinc can protect against telomere damage through its anti-oxidative effect. Meanwhile, telomere shortening was correlated with metabolic diseases of hypertension and type 2 diabetes. The objective of this study was to investigate whether the association between zinc and telomere length differs by the presence or absence of hypertension/type 2 diabetes. This is a cross-sectional study with 1064 participants of the Iwaki area, Japan. Multiple linear regression models were performed to test the hypothesis. A higher serum zinc concentration was significantly associated with a longer G-tail length (β = 48.11, 95% confidence intervals [CI]: 25.69, 70.54, p < 0.001). By multivariate linear regression analysis, there was a significant positive association between zinc and G-tail length in both hypertensive (β = 46.84, 95%CI: 9.69, 84.0, p = 0.014) and non-hypertensive groups (β = 49.47, 95%CI: 20.75, 78.18, p = 0.001), while the association was significant only in the non-diabetes group (β = 50.82, 95%CI: 27.54, 74.11, p < 0.001). In conclusion, higher zinc concentration was significantly associated with longer G-tail length. The protective effect of zinc on G-tail did not differ by hypertension status; however, it disappeared in individuals with type 2 diabetes.