端粒和端粒酶在女性生殖健康中的作用

端粒是维持染色体长度的DNA-蛋白质复合体,在染色体末端形成保护帽,其长度决定了细胞寿命;端粒酶是一种维持端粒长度和完整性的核糖核蛋白复合物,在抵御细胞复制性衰老过程中意义重大。研究表明,端粒和端粒酶的功能失调将影响细胞的生物学行为,包括细胞周期的稳定性、细胞增殖、凋亡以及衰老。近年来学者关注二者与女性生殖的联系,发现在多囊卵巢综合征、子宫内膜异位症、复发性流产及宫颈癌等不同病理状态下,颗粒细胞与白细胞中端粒长度缩短、端粒酶活性降低。综述端粒和端粒酶功能特点及其在生殖领域研究进展,对一些女性生殖系统疾病的治疗具有指导意义。     

行为生活方式对端粒长度影响的研究进展

端粒是位于染色体末端维持基因稳定的DNA-蛋白质复合体。正常体细胞端粒长度由于“末端复制问题”会随着年龄的增加而缩短。端粒长度缩短的速度受到遗传因素和非遗传因素的影响，由于非遗传因素（如行为生活方式等）可以通过人为干预进行改善，故探明非遗传因素与端粒长度的关联性具有十分重要的意义。相关性研究分析了睡眠、体力活动、吸烟、压力、膳食等行为生活方式与端粒长度的关系，本文对以上研究结果进行比较归纳，并进一步探讨不同行为生活方式对端粒长度的影响，为延缓端粒损伤、促进健康衰老提供理论依据。     

发酵食品的抗衰老研究进展

目的 综述发酵食品在抗衰老领域的研究进展,为进一步深入研究发酵食品的抗衰老机制,创新研发天然健康的抗衰老膳食产品奠定基础。方法 分别以“发酵食品”、“衰老”、“衰老相关疾病”、“发酵乳制品”等为关键词检索Pubmed、万方数据库、中国知网(CNKI)数据库,获取并阅读相关文献。结果 多项人群流行病学、动物及细胞实验等从不同层面分别报道发酵食品在延缓衰老、预防衰老相关疾病方面具有独特优势。结论 发酵食品有望用于衰老相关疾病预防和治疗,对人群健康具有重要意义。     

营养延缓衰老：端粒调控的研究进展

端粒为一种生物衰老的标志物,其长度会随着细胞分裂及年龄的增加而缩短,研究表明营养干预在一定程度上能够影响端粒长度。本文综述端粒与延缓衰老的关系、营养（营养成分、食物和膳食模式）对端粒长度的影响以及营养调控端粒长度的潜在作用机制,旨在为研究延缓衰老的营养策略提供理论依据和方向。[营养学报,2022,44(5):515-519]     

端粒酶在石英致细胞恶性转化中的作用

目的　观察在石英诱发人胚肺成纤维细胞恶性转化中端粒酶的作用。方法　将端粒酶功能片段(hTERT)导入人胚肺成纤维细胞 (HELF)中。经细胞毒性实验确定染毒剂量后 ,用石英粉尘 (1 6 0 μg cm2 )对导入 未导入hTERT的HELF进行染毒 ,分离转化灶 ,观察细胞生物性状 ,测定细胞生长曲线、端粒酶活性和端粒长度 ,进行软琼脂集落形成实验 ,判定转化性质。结果　将hTERT成功地导入了人胚肺成纤维细胞系(HELF T+ ) ,发现石英刺激后 ,导入端粒酶功能片段的人胚肺成纤维细胞的恶性转化率高于未导入端粒酶功能片段的人胚肺成纤维细胞 (P <0 0 5 )且有较高的端粒酶活性和端粒长度。结论　端粒酶在石英诱导细胞发生恶性转化的过程中发挥了重要作用。建立的端粒酶基因导入的细胞系可用于其它环境与职业危害因素相关疾病发病过程中的端粒酶作用的研究     

饮酒行为与癌症发生关系的Meta分析——以胰腺癌和肺癌为例

目的 癌症是目前最重要的公共卫生问题之一,饮酒行为已经被证实是乳腺癌、结肠癌等癌症发病的重要影响因素。然而,以胰腺癌和肺癌为代表的多种其他癌症与饮酒之间的关系并未得到证实。本文以胰腺癌与肺癌为例,探究饮酒行为与癌症的发生是否相关。方法 本研究通过主题检索,根据“饮酒”“肺癌”“胰腺癌”“危险因素”等关键词,搜索了中国知网、维普、万方、CBM数据库,收集并筛选了2002年1月至2019年4月国内已发表的关于饮酒与胰腺癌和肺癌的病例对照研究,并对目标文献进行Meta分析。结果 纳入12篇研究饮酒与胰腺癌发病关系的中文文献,均为来自中文数据库的病例对照研究,研究地区均在中国,共纳入13240名研究对象。随机效应模型显示饮酒与胰腺癌的发病存在相关性（OR=1.35,95% CI:1.07~ 1.72）;纳入12篇研究饮酒与肺癌发病关系的中文文献,均为来自中文数据库的病例对照研究,研究地区均在中国,共纳入315862名研究对象。随机效应模型结果显示饮酒与肺癌的发生存在相关性（OR=1.47,95% CI:1.17~ 1.86）。结论 在中国人群中,饮酒行为与肺癌和胰腺癌的发生均具有显著的正相关性,是两种癌症的危险因素。     

早期成长逆境与端粒长度关联的研究进展

早期成长逆境是多种疾病的危险因素,但相关机制尚未明确。有研究线索提示早期成长逆境与生物学老化相关,而目前较为公认的生物学老化指标是端粒长度,故探究早期逆境与端粒长度的关联对揭示逆境的相关作用机制具有重要意义。本文通过对既往文献进行综述,探讨不同逆境类型、暴露时间及研究设计对早期逆境与端粒长度关联的可能影响,为早期成长逆境的干预提供一定依据。     

端粒、端粒酶及靶向抗衰老研究

端粒是细胞染色体末端一段高度保守的重复核苷酸序列,在基因结构的完整性及染色体稳定性方面起重要作用。端粒酶是具有逆转录酶活性的核糖核蛋白复合体,它合成端粒重复序列添至染色体末端,维持端粒长度。端粒长度与细胞衰老密切相关,是分子老化的标志物,基于端粒酶延长端粒长度是近年来抗衰老的研究热点。因此,本文查阅近几年来有关端粒与衰老研究相关文献,对端粒及端粒酶生物学功能和影响因素及与衰老关联作一归纳总结,并探讨以端粒酶为靶点的抗衰老治疗的最新进展,对今后抗衰老研究作出展望。     

职业流行病学队列研究中计算机数据的管理方法

在职业流行病学中,队列研究（Cohort study,也称为定群研究或群组研究）占有重要地位[1,2],其中的前瞻性调查能够直接估计职业危害因素与发病的联系及其强度,较少信息偏倚,可以了解职业因素导致疾病的自然史,同时获得多种疾病的结局资料.前瞻性研究涉及的人群大（可到几万人甚至十几万人或更多）、延续时间长,特别是对于慢性病包括癌症效应可能需要观察几十年或更长时间.     

膳食炎症指数与慢性肾脏病发病之间的研究进展

目的 对膳食炎症指数(DII)与慢性肾脏病发病之间的研究进行综述,探究两者之间的关系。方法 以“膳食炎症指数”、“促炎饮食”和“慢性肾脏病”、“肾小球滤过率”为检索词,在PubMed, Web of Science和EMBASE等数据库进行检索,查询并严格筛选合格文献,进一步综述膳食炎症指数与慢性肾病的流行病学关系,并从炎症因子方面解释阐述了膳食炎症指数与慢性肾病之间可能的相关机制。结果 促炎饮食会造成慢性肾脏病的发病风险升高,相反,抗炎饮食可以有效降低慢性肾脏病的发病风险,特定的炎症因子标志物对慢性肾脏病的发病有特定作用。结论 膳食炎症指数对慢性肾脏病的发生有一定的影响,未来可能作为慢性肾病发病的预防控制策略之一,并可能给肾脏疾病的防治提供重要的科学依据。     

Telomeres and biological ageing in cardiovascular disease

The striking variability in the age of onset of and the manifestation/ absence of manifestation of cardiovascular diseases is inadequately explained by conventional risk factors, but may be explained by variation in biological age. Telomere length is possibly a reliable marker of biological age, shorter telomeres reflecting more advanced age. The initial telomere length ofa person is mainly determined by genetic factors. Moreover, the telomere length shortens with each cell division, and exposition to harmful environmental factors also results in shorter telomeres. Leukocytes of patients with atherosclerosis and heart failure display remarkably shorter telomeres compared to leukocytes of healthy subjects of similar age. Conventional cardiovascular risk factors are also associated with telomere length. If telomeres are indeed causally involved in the pathogenesis of cardiovascular disease, this might provide new avenues for future preventive and therapeutic strategies.     

人外周血基因组DNA端粒长度与肺癌关系

目的 观察外周血基因组DNA端粒长度与肺癌危险性的关系.方法 用荧光定量PCR法检测145例肺癌患者、145名正常对照和145名焦炉工人外周血基因组DNA相对端粒长度.结果 肺癌组端粒长度明显短于对照组(P =0.028),职业暴露组端粒长度明显短于肺癌组(P=0.005)和对照组(P＜0.001);按对照组端粒长度分4组,随着端粒的缩短,肺癌的危险性增加(Ptrend＜0.001);按对照组端粒长度中位数把样本分为2组发现,与长端粒组比较,端粒变短明显增加肺癌的危险性(调整OR=2.337,95％ CI为1.413 ～3.866);对照组中,随着年龄增加,端粒缩短(P＜0.001).结论 端粒缩短可增加肺癌的危险性,可能是肺癌发展早期过程中的一项重要的生物标志.     

Diet and Leukocyte Telomere Length in a Population with Extended Longevity: The Costa Rican Longevity and Healthy Aging Study (CRELES)

Elderly Costa Ricans have lower mortality rates compared to their counterparts from developed countries. Reasons for this survival advantage are not completely known. In the present study, we aimed to identify dietary factors associated with leukocyte telomere length (LTL), a marker of biologic aging, in the elderly population of Costa Rica. We conducted prospective analysis in 909 participants aged 60+ years from the Costa Rican Longevity and Healthy Aging Study (CRELES). We used a food frequency questionnaire to assess usual diet. We calculated dietary patterns using Principal Component Analysis (PCA). We used generalized linear models to examine the association of dietary patterns and food groups with leukocyte telomere length. We found two major dietary patterns explaining 9.15% and 7.18% of the total variation of food intake, respectively. The first dietary pattern, which represents a traditional Costa Rican rice and beans pattern, was more frequent in rural parts of the country and was positively associated with baseline LTL: β (95% CI) = 42.0 base-pairs (bp) (9.9 bp, 74.1 bp) per one-unit increase of the traditional dietary pattern. In analysis of individual food groups, intake of grains was positively associated with baseline LTL: β (95% CI) = 43.6 bp (13.9 bp, 73.3 bp) per one-serving/day increase of consumption of grains. Our results suggest that dietary factors, in particular a traditional food pattern, are associated with telomere length and may contribute to the extended longevity of elderly Costa Ricans.     

Consumption of nuts and seeds and telomere length in 5,582 men and women of the National Health and Nutrition Examination Survey (NHANES)

Objectives

Consumption of nuts and seeds is associated favorably with all-cause mortality. Nuts and seeds could reduce disease and prolong life by influencing telomeres. Telomere length is a good indicator of the senescence of cells. The purpose of the present study was to determine the relationship between nuts and seeds intake and leukocyte telomere length, a biomarker of biologic aging.

Design

Cross-sectional.

Setting and Participants

A total of 5,582 randomly selected men and women from the National Health and Nutrition Examination Survey (NHANES), 1999-2002, were studied.

Measurements

DNA was obtained via blood samples. Telomere length was assessed using the quantitative polymerase chain reaction method. A validated, multi-pass, 24-h recall dietary assessment, administered by NHANES, was employed to quantify consumption of nuts and seeds.

Results

Nuts and seeds intake was positively and linearly associated with telomere length. For each 1-percent of total energy derived from nuts and seeds, telomere length was 5 base pairs longer (F=8.6, P=0.0065). Given the age-related rate of telomere shortening was 15.4 base pairs per year (F=581.1, P<0.0001), adults of the same age had more than 1.5 years of reduced cell aging if they consumed 5% of their total energy from nuts and seeds.

Conclusions

Consumption of nuts and seeds accounts for meaningful decreases in biologic aging and cell senescence. The findings reinforce the recommendations of the 2015-2020 Dietary Guidelines for Americans, which encourage the consumption of nuts and seeds as part of a healthy diet.

     

Leukocyte telomere length and ideal cardiovascular health in American Indians: the Strong Heart Family Study

Telomere length, a marker of biological aging, has been associated with cardiovascular disease (CVD) and its risk factors. Ideal cardiovascular health (CVH), defined by the American Heart Association (AHA), has also been associated with a reduced risk of CVD, but the relationship between telomere length and ideal CVH is unclear. We measured leukocyte telomere length (LTL) by qPCR in 2568 American Indians in the Strong Heart Family Study (SHFS). All participants were free of overt CVD at enrollment (2001–2003). CVH indices included four behavioral factors (smoking, physical activity, diet, BMI) and three health factors (blood pressure, cholesterol, fasting glucose). Each index was categorized as poor, intermediate, or ideal according to the AHA’s guideline. CVH was further categorized into below average (0–1), average (2–3) and above average (≥4) based on the total number of ideal indices. Results showed that, 29, 50 and 21 % of study participants had below average, average, and above average CVH, respectively. Participants with above average CVH had significantly longer LTL than those with below average CVH (β = 0.034, P = 0.042) after adjusting for age, sex, education level, marital status, processed meat consumption, alcohol consumption, and study site. Compared to the U.S. general population, American Indians achieved lower rates for five out of the seven ideal CVH metrics, including smoking, BMI, physical activity, diet, and blood pressure. Achieving four or more ideal CVH metrics was significantly associated with longer LTL. This finding suggests that achieving an ideal CVH may prevent or delay CVD, probably through promoting healthy aging.     

Telomere Length and Frailty: The Helsinki Birth Cohort Study

Objectives

Telomere length is associated with aging-related pathologies. Although the association between telomere length and frailty has been studied previously, only a few studies assessing longitudinal changes in telomere length and frailty exist.

Diet, Lifestyle, and Colorectal Cancer: Is Hyperinsulinemia the Missing Link?

Several dietary and other lifestyle factors have been implicated in the development of colorectal cancer. However, the precise nature and actual magnitude of the relationship between individual nutrient intakes and other lifestyle factors and colorectal cancer risk are not clear. A unifying hypothesis has recently been proposed that explains why obesity, physical inactivity, alcohol, and consumption of a typical Western diet increase colorectal cancer risk. This hypothesis suggests that these dietary and other lifestyle factors are associated with insulin resistance and hyperinsulinemia and that hyperinsulinemia, in turn, may stimulate growth of colorectal tumors. Two recently published large prospective epidemiologic studies indicate a significant increase in colorectal cancer risk in subjects with diabetes mellitus, thereby supporting this hypothesis.     

No association between telomere length and survival among the elderly and oldest old

BACKGROUND: The consistent findings of a negative correlation between telomere length and replicative potential of cultured cells, as well as a decreasing telomere length in a number of different tissues in humans with age, have led to the suggestion that telomeres play a role in cellular aging in vivo and ultimately even in organismal aging. Furthermore, one small longitudinal study of elderly individuals has suggested that longer telomeres are associated with better survival. METHODS: Telomere length was measured as mean terminal restriction fragment length on blood cells from 812 persons, age 73 to 101 years, who participated in population-based surveys in 1997-1998. Among the participants were 652 twins. The participants were followed up through the Danish Civil Registration system until January 2005, at which time 412 (51%) were dead. RESULTS: Univariate Cox regression analyses revealed that longer telomeres were associated with better survival (hazard ratios = 0.89 [95% confidence interval = 0.76-1.04] per 1 kb in males and 0.79 [0.72-0.88] per 1 kb in females, respectively). However, including age in the analyses changed the estimates to 0.97 (0.83-1.14) and 0.93 (0.85-1.03), respectively. Intrapair comparison showed that among 175 twin pairs in which at least one died during follow up, it was the twin with the shorter telomere length who died first in 97 (55%) of the pairs (95% confidence interval = 48-63%). We could not confirm the recently reported negative correlation between telomere length and obesity or between telomere length and smoking. CONCLUSION: This longitudinal study of the elderly and oldest old does not support the hypothesis that telomere length is a predictor for remaining lifespan once age is controlled for.