Olive fly transcriptomics analysis implicates energy metabolism genes in spinosad resistance.

BACKGROUND: The olive fly, Bactrocera oleae, is the most devastating pest of cultivated olives. Its control has been traditionally based on insecticides, mainly organophosphates and pyrethroids. In recent years, the naturalyte spinosad is used against the olive fly. As with other insecticides, spinosad is subject to selection pressures that have led to resistance development. Mutations in the α6 subunit of the nicotinic acetylcholine receptor (nAChR) have been implicated in spinosad resistance in several species (e.g., Drosophila melanogaster) but excluded in others (e.g., Musca domestica). Yet, additional mechanisms involving enhanced metabolism of detoxification enzymes (such as P450 monooxygenases or mixed function oxidases) have also been reported. In order to clarify the spinosad resistance mechanisms in the olive fly, we searched for mutations in the α6-subunit of the nAChR and for up-regulated genes in the entire transcriptome of spinosad resistant olive flies. RESULTS: The olive fly α6-subunit of the nAChR was cloned from the laboratory sensitive strain and a spinosad selected resistant line. The differences reflected silent nucleotide substitutions or conserved amino acid changes. Additionally, whole transcriptome analysis was performed in the two strains in order to reveal any underlying resistance mechanisms. Comparison of over 13,000 genes showed that in spinosad resistant flies nine genes were significantly over-expressed, whereas ~40 were under-expressed. Further functional analyses of the nine over-expressed and eleven under-expressed loci were performed. Four of these loci (Yolk protein 2, ATP Synthase FO subunit 6, Low affinity cationic amino acid transporter 2 and Serine protease 6) showed consistently higher expression both in the spinosad resistant strain and in wild flies from a resistant California population. On the other side, two storage protein genes (HexL1 and Lsp1) and two heat-shock protein genes (Hsp70 and Hsp23) were unfailingly under-expressed in resistant flies. CONCLUSION: The observed nucleotide differences in the nAChR-α6 subunit between the sensitive and spinosad resistant olive fly strains did not advocate for the involvement of receptor mutations in spinosad resistance. Instead, the transcriptome comparison between the two strains indicated that several immune system loci as well as elevated energy requirements of the resistant flies might be necessary to lever the detoxification process.

Substantial variation in qPCR measured mean blood telomere lengths in young men from eleven European countries.

OBJECTIVES: Telomeres, repetitive DNA sequences found at the ends of chromosomes, shorten with age in proliferating human tissues and are implicated in senescence. Previous studies suggest that shorter telomeres impair immune and cardiovascular function and result in increased mortality. Although few, prior studies have documented ethnic/population differences in human telomere lengths. The nature and cause(s) of these population differences remain poorly understood. METHODS: Here, we extend the work of Salpea et al. (2008) by reporting variation in mean blood telomere lengths (BTL) from 765 individuals from 14 study centers across 11 European countries. Subjects are male students (ages 18­28), half of whom had fathers with myocardial infarction before 55 and the remainder age-matched controls. Controlling for age and case­control status, telomere lengths averaged 10.20 kilobases (interpolated from qPCR measures) across study centers and ranged from 5.10 kilobases in Naples, Italy to 18.64 kilobases in Ghent, Belgium--a greater than threefold difference across populations. These population level differences in BTLs were neither explained by national level measures of population genetic structure nor by national level ecological analysis of indices of infection/economic status. CONCLUSIONS: These findings suggest considerable population variation in BTL in Europe that is not obviously a result of broad measures of population structure or infection/economic exposure measured in early life or in adulthood.Studying telomere dynamics in a wider variety of populations, and with greater attention to life-cycle dynamics, will be important to help elucidate the causes and possible consequences of human population variation in telomere length.

The association of telomere length with paternal history of premature myocardial infarction in the European Atherosclerosis Research Study II.

Inter-individual variability in telomere length is highly heritable and has been correlated with risk of coronary heart disease (CHD). Our aim was to determine the association of mean leukocyte telomere length with paternal history of premature myocardial infarction (MI). Mean leukocyte telomere length was measured with real-time polymerase chain reactions in 369 male students (18-28 years) with a paternal history of MI before the age of 55, recruited from 14 European universities, serving as cases and 396 age-matched controls with no paternal history of CHD. Overall, cases had borderline significantly shorter mean length (approximately 550 bp), adjusted for age and geographical region, than controls (p = 0.05). A significant difference in telomere length across the geographical regions of Europe was observed (p < 0.0001), with shorter mean length in the Baltic and South and the longest in the Middle. The case-control difference ( approximately 2.24 kb) in mean length was highly significant only in the Baltic region (p < 0.0001). There is suggestive evidence that, in young men, the biological expression of a paternal history of premature MI is at least in part mediated through inherited short telomeres. The association with paternal history of MI is strongly seen only in the Baltic compared to the rest of Europe, but this is not explained by shorter telomere length in this region.

The effect of WNT5B IVS3C>G on the susceptibility to type 2 diabetes in UK Caucasian subjects.

BACKGROUND AND AIMS: The wnt signaling pathway regulates adipogenesis and insulin secretion. The WNT5B gene has been reported to confer susceptibility to type 2 diabetes (T2D) in the Japanese population, and we therefore evaluated this in Caucasian subjects with respect to obesity status. METHODS AND RESULTS: Two thousand seven hundred and one Caucasian middle-aged men from the prospective Northwick Park Heart Study II (NPHSII) of whom 153 developed T2D over 15 years and 1268 Caucasian middle-aged patients with T2D (60% male) were genotyped using a TaqMan assay for the IVS3C>G variant (rs2270031) in the WNT5B gene. The frequency of the G allele was 0.026 (0.022-0.031) in controls and 0.031 (0.025-0.039) in patients with diabetes, p=0.24. In the prospective analysis, G allele carriers with BMI below 26 kg/m(2) had significantly higher T2D hazard risk [3.46 (1.34-8.96), p=0.01]. Comparing T2D cases with NPHSII controls, the G allele was associated with a significantly higher T2D odds ratio (OR) of 1.50 (1.06-2.12), p=0.02 in subjects with BMI lower than 30 kg/m(2). Increasing BMI had a smaller effect on risk in G allele carriers. The effect on risk was not explained by genotype being associated with any classical T2D risk factor. When the combined effect of this SNP and the TCF7L2 IVS3C>T SNP (rs7903146) was evaluated, a 2.07 (1.40-3.07), p<0.0001 fold higher OR was observed in carriers of both the rare alleles. CONCLUSION: Variation in WNT5B predisposes to T2D in the absence of obesity. The increase in risk conferred by the presence of both WNT5B and TCF7L2 variants strengthens the role of wnt signaling in T2D.

Body mass index is negatively associated with telomere length: a collaborative cross-sectional meta-analysis of 87 observational studies.

Background: Even before the onset of age-related diseases, obesity might be a contributing factor to the cumulative burden of oxidative stress and chronic inflammation throughout the life course. Obesity may therefore contribute to accelerated shortening of telomeres. Consequently, obese persons are more likely to have shorter telomeres, but the association between body mass index (BMI) and leukocyte telomere length (TL) might differ across the life span and between ethnicities and sexes. Objective: A collaborative cross-sectional meta-analysis of observational studies was conducted to investigate the associations between BMI and TL across the life span. Design: Eighty-seven distinct study samples were included in the meta-analysis capturing data from 146,114 individuals. Study-specific age- and sex-adjusted regression coefficients were combined by using a random-effects model in which absolute [base pairs (bp)] and relative telomere to single-copy gene ratio (T/S ratio) TLs were regressed against BMI. Stratified analysis was performed by 3 age categories ("young": 18-60 y; "middle": 61-75 y; and "old": >75 y), sex, and ethnicity. Results: Each unit increase in BMI corresponded to a -3.99 bp (95% CI: -5.17, -2.81 bp) difference in TL in the total pooled sample; among young adults, each unit increase in BMI corresponded to a -7.67 bp (95% CI: -10.03, -5.31 bp) difference. Each unit increase in BMI corresponded to a -1.58 × 10(-3) unit T/S ratio (0.16% decrease; 95% CI: -2.14 × 10(-3), -1.01 × 10(-3)) difference in age- and sex-adjusted relative TL in the total pooled sample; among young adults, each unit increase in BMI corresponded to a -2.58 × 10(-3) unit T/S ratio (0.26% decrease; 95% CI: -3.92 × 10(-3), -1.25 × 10(-3)). The associations were predominantly for the white pooled population. No sex differences were observed. Conclusions: A higher BMI is associated with shorter telomeres, especially in younger individuals. The presently observed difference is not negligible. Meta-analyses of longitudinal studies evaluating change in body weight alongside change in TL are warranted.

The prevalence of metabolic syndrome in various populations.

The insulin resistance/metabolic syndrome is characterized by the variable co-existence of hyperinsulinemia, obesity, dyslipidemia (small dense low-density lipoprotein, hypertriglyceridemia, and decreased high-density lipoprotein cholesterol), and hypertension. The pathogenesis of the syndrome has multiple origins. However, obesity and sedentary lifestyle coupled with diet and still largely unknown genetic factors clearly interact to produce the syndrome. This multifactorial and complex trait of metabolic syndrome leads to increased risk of cardiovascular disease. The scope of this review is to examine the differences in prevalence of the metabolic syndrome in various groups (eg, according to age, sex, ethnicity, social status, or presence of obesity) that could help with the better understanding of the pathogenesis of this syndrome. This review also considers the impact of metabolic syndrome on cardiovascular disease.

Postprandial lipaemia in menopausal women with metabolic syndrome.

BACKGROUND: The metabolic syndrome (MetS) is associated with an increased incidence of coronary heart disease (CHD). Postprandial hypertriglyceridaemia is also associated with CHD. The aim of this study was to evaluate the postprandial lipaemia after an oral fat tolerance test (OFTT) in women with MetS. METHODS: OFTT, was given to 21 menopausal women with MetS (defined by the Adult Treatment Panel III) and to 12 healthy menopausal women. Triglyceride (TG) levels were measured before and 2, 4, 6 and 8h after the OFTT. The postprandial response was quantified by the areas under the curve (AUC) of TG levels. MetS women were subdivided according to body mass index (BMI) < or > or =30kg/m(2), and to fasting TG levels < or > or =150mg/dl. RESULTS: The response to the OFTT was significantly higher in the MetS group compared to healthy [AUC(S.D.), in mg/dl/h; 2014(933) versus 732(197), p<0.001]. The subjects with BMI < or > or =30kg/m(2) had similar fasting TG levels [157(60)mg/dl versus 158(67) mg/dl] and AUC [1975(898) versus 2072(1044), respectively]. The MetS women with TG> or =150mg/dl had higher AUC compared to those with TG<150mg/dl [2502(854) versus 1281(441), p=0.002]. In linear regression analysis, where BMI, high-density lipoprotein cholesterol, fasting TG, HOMA-IR and QUICKI were the independent variables, only fasting TGs significantly predicted the AUC (coefficient B=11.866, p=0.008). CONCLUSIONS: The fasting TG concentration is the main determinant of postprandial lipaemia. The obesity state was not an additional determinant for exaggerated postprandial response in MetS women. The abnormal postprandial lipaemia could be added as an important metabolic disturbance to the MetS.

Postprandial lipemia in postmenopausal women with high fasting high-density lipoprotein cholesterol.

BACKGROUND: Several groups of patients at high risk for cardiovascular disease have been found to show an exaggerated postprandial hypertriglyceridemia. Postprandial lipemia (PPL) therefore has been implicated as a potential additional risk factor that has been evading us. The purpose of this study was to test the effect of high fasting high-density lipoprotein cholesterol (HDL-C) levels on PPL in postmenopausal females. METHODS: Oral fat tolerance test, as quantified by the areas under the curve (AUC) of triglyceride (TG) levels, was given to 3 groups: normal postmenopausal females (control), postmenopausal females with exceptionally high HDL-C and a familial history of longevity (longevity syndrome), and postmenopausal females that were heterozygotes of familial hypercholesterolemia (hFH) with exceptionally high HDL-C. RESULTS: The PPL was not different between the control and longevity syndrome groups but was significantly higher in the hFH group; AUC (SD), in mg/dl/h; 749 (195), 882 (278) and 1244 (497) respectively, p=0.002. In linear regression analysis only fasting TG levels were a significant predictor of the AUC (Coefficient B = 11.779, p < 0.001). CONCLUSIONS: In subjects with longevity syndrome the PPL is similar to controls, which means that high fasting HDL-C has not any beneficial influence on PPL. The fasting TG concentration is the main determinant of PPL. Furthermore, postmenopausal females with hFH have higher TG response postprandially, even in the case of high fasting HDL-C. Whether there is a threshold below or above, where HDL-C becomes a significant independent determinant of PPL is a question to be answered by future research.

Management of a patient with a null low-density lipoprotein receptor mutation: a case report.

A 13-year-old Greek boy with severe dyslipidemia, large tuberous xanthomas over the knees and elbows, Achilles' tendon xanthomas, and a bilateral corneal arcus was referred to the Lipid Clinic. He had a supravalvular aortic stenosis, 50% to 60% stenosis of both carotid arteries, and normal coronary arteries. Familial hypercholesterolemia was clinically diagnosed. A V408M null low-density lipoprotein receptor (LDLR) mutation was identified in homozygosity. He responded to lipid-lowering drugs by decreasing total cholesterol by 32%, low-density lipoprotein cholesterol by 33%, and triglyceride levels by 30%. Additional treatment with low-density lipoprotein-apheresis further decreased total cholesterol by 52%, low-density lipoprotein cholesterol by 55%, and triglycerides by 43%. Low-density lipoprotein cholesterol levels between apheresis sessions showed a declining pattern. A significant regression of tuberous xanthomas was noted. A suitable combination of lipid-lowering drugs is effective even in this case of homozygosity for a null LDLR mutation. Furthermore, the coadministration of statins, cholestyramine, and ezetimibe during low-density lipoprotein-apheresis tends to counterbalance the postapheresis relapse in low-density lipoprotein cholesterol levels.

Lipid profile of women qualifying for hypolipidaemic treatment.

OBJECTIVE: Death rates from coronary heart disease continue to rise in women despite a marked decrease in men for the past two decades. Our study aimed to evaluate essential risk factors in high-risk adult women. METHODS: Lipid profiles of 547 dyslipidaemic adult women aged 57.5 +/- 10.6 years (mean +/- standard deviation) were evaluated and stratified according to fasting plasma lipid levels. Classification of the cohort was performed based on triglycerides (TG) and high-density lipoprotein cholesterol (HDL-C) levels and correlations between TG and HDL-C were estimated. RESULTS: Patients with TG > or =150 mg/dl had lower HDL-C levels compared to those with TG <150 mg/dl (p < 0.001). Patients with HDL-C <40 mg/dl had lower TC levels and higher TG levels compared to those with HDL-C > or =40 mg/dl (p = 0.012 and p < 0.001, respectively). In the cohort and the subgroups an inverse correlation between TG and HDL-C was observed (r = -0.428, slope = -0.048, p < 0.001). CONCLUSIONS: The expected inverse correlation between fasting high TG and low HDL levels was confirmed. The novelty of the study is that this correlation persists even in the case of low fasting TG levels.

Postprandial lipemia in men with metabolic syndrome, hypertensives and healthy subjects.

BACKGROUND: The metabolic syndrome (MetS), as well as postprandial hypertriglyceridemia, is associated with coronary heart disease. This study aimed to evaluate the postprandial lipemia after oral fat tolerance test (OFTT) in subjects with MetS and compare them to hypertensive (HTN) and healthy subjects. RESULTS: OFTT was given to 33 men with MetS (defined by the Adult Treatment Panel III), 17 HTN and 14 healthy men. The MetS group was further divided according to fasting triglycerides (TG) into TG > or = 150 [MetS+TG, (n = 22)] or < 150 mg/dl [MetS-TG (n = 11)], and into those with or without hypertension [MetS+HTN (n = 24), MetS-HTN (n = 9), respectively]. TG concentrations were measured before and at 4, 6 and 8 h after OFTT and the postprandial response was quantified using the area under the curve (AUC) for TG. The postprandial response was significantly higher in MetS compared to HTN and healthy men [AUC (SD) in mg/dl/h; 2534 +/- 1016 vs. 1620 +/- 494 and 1019 +/- 280, respectively, p < or = 0.001]. The TG levels were increased significantly in MetS+TG compared to MetS-TG subjects at 4 (p = 0.022), 6 (p < 0.001) and 8 hours (p < 0.001). The TG were increased significantly in MetS-TG compared to healthy subjects at 4 (p = 0.011), 6 (p = 0.001) and 8 hours (p = 0.015). In linear regression analysis only fasting TG levels were a significant predictor of the AUC (Coefficient B = 8.462, p < 0.001). CONCLUSION: Fasting TG concentration is the main determinant of postprandial lipemia. However, an exaggeration of TG postprandialy was found in normotriglyceridemic MetS and HTN compared to healthy subjects. This suggests that intervention to lower fasting TG levels should be recommended in MetS subjects.

Apolipoprotein E genotype in matched men and women with coronary heart disease.

Apolipoprotein E (apo E) plays an important role in lipid metabolism and its polymorphism may be a risk determinant of coronary heart disease (CHD). Since evidence suggested a gender-specific effect of apo E polymorphism, we studied the influence of gender-specific interaction of the polymorphism on CHD. From a total of 463 Greek Caucasians (314 men and 149 postmenopausal women) with angiographically documented CHD, we selected 79 women (68+/- 9 yr old) and 79 men (66+/- 9 yr old) who were matched for clinical characteristics. Apo E genotyping was performed by PCR and RFLP analysis. Biochemical parameters were also measured. The results were as follows: the E3/3 genotype occurred in 78.5% of the patients, followed by E3/4, E2/3, E2/4, and E4/4 genotypes, which occurred in 9.5%, 9.5%, 1.9%, and 0.6% of the patients, respectively. No significant differences were observed in the apo E allele or apo E genotype distributions between the matched Greek men and women with CHD. The E3/3 men patients were more frequently part of a family with a history of CHD, compared to women (p=0.035).

Fasting serum triglyceride and high-density lipoprotein cholesterol levels in patients intended to be treated for dyslipidemia.

OBJECTIVE: The aim of the present investigation was to evaluate the influence of serum triglycerides (TG) on other plasma lipids in patients to be treated for dyslipidemia. METHODOLOGY: Lipid profiles of a cohort of 801 patients (487 males and 314 females) aged 57 +/- 9 years (mean +/- SD) were evaluated. Patients were stratified according to their plasma lipid levels. They were divided into various groups on the basis of serum TG (> or = 150 or < 150 mg/dL) and high-density lipoprotein cholesterol (HDL-C) (> or = 40 or < 40 mg/dL). RESULTS: Patients with TG > or = 150 mg/dL had a higher total cholesterol and lower HDL-C levels compared with those with TG < 150 mg/dL, (p < 0.001). Patients with HDL-C < 40 mg/dL had a lower serum total cholesterol and higher TG compared with those with HDL-C > or = 40 mg/dL (p = 0.011 and p < 0.0001, respectively). In all patients as well as in the subgroups, an inverse correlation between TG and HDL-C was found (r = -0.377, p < 0.001). CONCLUSIONS: Although, the metabolic pathway for TG and HDL-C is closely linked, an inverse correlation between TG and HDL-C levels seems to exist in the entire sampled population. This correlation also appears to persist in fasting patients with low levels of TG.

The effect of alcohol and gemfibrozil co-administration in Wistar rats.

INTRODUCTION: The ingestion of alcohol (Alc) as well as gemfibrozil (Gem), a fibrate drug used to treat hypertriglyceridaemia, may occur on a long-term basis in humans. Since both Alc and Gem can disturb liver function, we assessed the effects of administering Alc together with Gem in Wistar rats. MATERIALS AND METHODS: Male Wistar rats were randomized and divided into 4 groups of 10 each. They were fed (once a day) via a stomach tube with: i) 2 ml of polyethylene glycol (Peg); group Peg, ii) 2 ml of Peg + 2 ml of 25% v/v pure Alc in water; group Alc + Peg, iii) 2 ml of Gem solution in Peg (3.4 mg/100 g body weight); group Gem +Peg, iv) 2 ml of Gem solution in Peg 2 + 2 ml of Alc; group Gem +Alc +Peg. Another 13 male Wistar rats were only fed a standard laboratory diet (control group). After 8 weeks, blood samples were drawn and the livers removed. Alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (AP), total cholesterol (TC) and triglycerides (TG) were measured. Liver histopathology was also assessed. RESULTS: All tube-fed groups had higher body mass index compared to controls (p<0.001). The control group had lower AP compared to Gem+Peg and Gem +Alc+Peg groups (p=0.005 and p=0.018, respectively). The Peg group had lower AP compared to G+Peg (p=0.041). All tube-fed groups had lower ALT compared to controls (p<0.001). The TC levels were lower in tube-fed groups with Gem (Gem +Peg and Gem+Alc +Peg) compared to controls (p=0.002 and p=0.039, respectively). Among the tube-fed groups, the TC level was lower in Gem +Peg compared to Peg and Alc+Peg groups (p=0.047 and p=0.01, respectively). No differences were found among tube-fed groups and control rats in blood AST and TG. Liver histopathology was similar in all groups and within the normal range. CONCLUSION: A moderate amount of Alc daily together with Gem is safe in rats. Peg administration in Wistar rats protects from the Alc-induced TG and AST rises.

Association between short leukocyte telomere length, endotoxemia, and severe periodontitis in people with diabetes: a cross-sectional survey.

OBJECTIVE Shortened leukocyte telomere length (LTL) and diagnosis of periodontitis are associated with an increased risk of complications and mortality in diabetes. This study investigated the association between LTL, endotoxemia, and severity of periodontitis in a large cohort of people with diabetes. RESEARCH DESIGN AND METHODS Six hundred thirty individuals (371 with type 2 and 259 with type 1 diabetes) were recruited from the University College Hospital in London, U.K. During a baseline visit, blood was collected for standard biochemical tests and DNA extraction, while a dental examination was performed to determine diagnosis and extent of periodontitis. LTL was measured by real-time PCR, and endotoxemia was assessed by the limulus amoebocyte lysate method. RESULTS Two hundred fifty-five individuals were diagnosed with gingivitis, 327 with periodontitis (114 with moderate and 213 with severe disease), and 48 with edentulous. Diagnosis of periodontitis was associated with shorter LTL (P = 0.04). A negative association between LTL and endotoxemia was found in the severe periodontitis and type 2 diabetes groups (P = 0.01 for both). Shorter LTL was associated with increased extent of periodontitis (P = 0.01) and increased insulin resistance (homeostatic model assessment). Multiple adjustments for biochemical, anthropometric, and medication-use variables did not affect the results. CONCLUSIONS LTL is associated with endotoxemia and diagnosis of periodontitis in people with diabetes. LTL shortening might represent a novel biological pathway accounting for previous epidemiological data that documented higher prevalence of diabetes and its complications in people with periodontitis and vice versa.

Genome-wide association study identifies variants in casein kinase II (CSNK2A2) to be associated with leukocyte telomere length in a Punjabi Sikh diabetic cohort.

BACKGROUND: Telomere length is a heritable trait, and short telomere length has been associated with multiple chronic diseases. We investigated the relationship of relative leukocyte telomere length with cardiometabolic risk and performed the first genome-wide association study and meta-analysis to identify variants influencing relative telomere length in a population of Sikhs from South Asia. METHODS AND RESULTS: Our results revealed a significant independent association of shorter relative telomere length with type 2 diabetes mellitus and heart disease. Our discovery genome-wide association study (n=1616) was followed by stage 1 replication of 25 top signals (P<10(-6)) in an additional Sikhs (n=2397). On combined discovery and stage 1 meta-analysis (n= 4013), we identified a novel relative telomere length locus at chromosome 16q21 represented by an intronic variant (rs74019828) in the CSNK2A2 gene (ß=-0.38; P=4.5×10(-8)). We further tested 3 top variants by genotyping in UK cardiovascular disease (UKCVD) (whites n=2952) for stage 2. Next, we performed in silico replication of 139 top signals (P<10(-5)) in UK Twin, Nurses Heart Study, Prostate, Lung, Colorectal, and Ovarian Cancer Screening Trial, and MD Anderson Cancer Controls (n=10 033) and joint meta-analysis (n=16 998). The observed signal in CSNK2A2 was confined to South Asians and could not be replicated in whites because of significant difference in allele frequencies (P<0.001). CSNK2A2 phosphorylates telomeric repeat binding factor 1 and plays an important role for regulation of telomere length homoeostasis. CONCLUSIONS: By identification of a novel signal in telomere pathway genes, our study provides new molecular insight into the underlying mechanism that may regulate telomere length and its association with human aging and cardiometabolic pathophysiology.

The effect of pro-inflammatory conditioning and/or high glucose on telomere shortening of aging fibroblasts.

UNLABELLED: Cardiovascular disease and diabetes have been linked to shorter telomeres, but it is not yet clear which risk factors contribute to shorter telomeres in patients. Our aim was to examine whether pro-inflammatory conditioning, in combination or not with high glucose, result in a higher rate of telomere shortening during in vitro cellular ageing. Human fibroblasts from four donors were cultured for 90 days in: 1) medium lacking ascorbic acid only, 2) 10 mM buthionine sulphoximine (BSO) (pro-oxidant), 3) 25 mM D-glucose, 4) 1 ng/ml IL1B and 5) 25 mM D-glucose+1 ng/ml IL1B. Telomere length was measured with qPCR and intracellular reactive oxygen species (ROS) content and cell death with flow cytometry. Cultures treated with high glucose and BSO displayed a significantly lower growth rate, and cultures treated with IL1B showed a trend towards a higher growth rate, compared to the control [Glucose:0.14 PD/day, p<0.001, BSO: 0.11 PD/day, p = 0.006 and IL1B: 0.19 PD/day, p = 0.093 vs. CONTROL: 0.16 PD/day]. Telomere shortening with time was significantly accelerated in cultures treated with IL1B compared to the control [IL1B:-0.8%/day (95%CI:-1.1, -0.5) vs. CONTROL: -0.6%/day (95%CI:-0.8, -0.3), p = 0.012]. The hastening of telomere shortening by IL1B was only in part attenuated after adjustment for the number of cell divisions [IL1B:-4.1%/PD (95%CI:-5.7, -2.4) vs. CONTROL: -2.5%/PD (95%CI:-4.4, -0.7), p = 0.067]. The intracellular ROS content displayed 69% increase (p = 0.033) in BSO compared to the control. In aging fibroblasts, pro-inflammatory conditioning aggravates the shortening of telomeres, an effect which was only in part driven by increased cell turnover. High glucose alone did not result in greater production of ROS or telomere shortening.

Association of TERC and OBFC1 haplotypes with mean leukocyte telomere length and risk for coronary heart disease.

OBJECTIVE: To replicate the associations of leukocyte telomere length (LTL) with variants at four loci and to investigate their associations with coronary heart disease (CHD) and type II diabetes (T2D), in order to examine possible causal effects of telomere maintenance machinery on disease aetiology. METHODS: Four SNPs at three loci BICD1 (rs2630578 GγC), 18q12.2 (rs2162440 GγT), and OBFC1 (rs10786775 CγG, rs11591710 AγC) were genotyped in four studies comprised of 2353 subjects out of which 1148 had CHD and 566 T2D. Three SNPs (rs12696304 CγG, rs10936601G>T and rs16847897 GγC) at the TERC locus were genotyped in these four studies, in addition to an offspring study of 765 healthy students. For all samples, LTL had been measured using a real-time PCR-based method. RESULTS: Only one SNP was associated with a significant effect on LTL, with the minor allele G of OBFC1 rs10786775 SNP being associated with longer LTL (ß=0.029, P=0.04). No SNPs were significantly associated with CHD or T2D. For OBFC1 the haplotype carrying both rare alleles (rs10786775G and rs11591710C, haplotype frequency 0.089) was associated with lower CHD prevalence (OR: 0.77; 95% CI: 0.61-0.97; P= 0.03). The TERC haplotype GTC (rs12696304G, rs10936601T and rs16847897C, haplotype frequency 0.210) was associated with lower risk for both CHD (OR: 0.86; 95% CI: 0.75-0.99; P=0.04) and T2D (OR: 0.74; 95% CI: 0.61-0.91; P= 0.004), with no effect on LTL. Only the last association remained after adjusting for multiple testing. CONCLUSION: Of reported associations, only that between the OBFC1 rs10786775 SNP and LTL was confirmed, although our study has a limited power to detect modest effects. A 2-SNP OBFC1 haplotype was associated with higher risk of CHD, and a 3-SNP TERC haplotype was associated with both higher risk of CHD and T2D. Further work is required to confirm these results and explore the mechanisms of these effects.

Oxidative stress, chronic inflammation, and telomere length in patients with periodontitis.

The aim of this study was to determine leukocyte telomere length (LTL) in individuals with periodontitis and controls, exploring its relationship with systemic inflammation and oxidative stress. Five hundred sixty-three participants were recruited for this case-control study: 356 subjects with and 207 subjects without periodontitis. LTL was measured by a qPCR technique from leukocytes' DNA. Global measures of oxidative stress (reactive oxygen metabolites) and biological antioxidant potential in plasma were performed together with high-sensitivity assays for C-reactive protein (CRP). Leukocyte counts and lipid profiles were performed using standard biochemistry. Cases had higher levels of CRP (2.1±3.7mg/L vs 1.3±5.4mg/L, P<0.001) and reactive oxygen metabolites (378.1±121.1 U Carr vs 277.4±108.6 U Carr, P<0.001) compared to controls. Overall, cases had shorter LTL with respect to controls (1.23±0.42 vs 1.12±0.31T/S ratio, P=0.006), independent of age, gender, ethnicity, and smoking habit. When divided by subgroup of periodontal diagnosis (chronic, n=285; aggressive, n=71), only chronic cases displayed shorter LTL (P=0.01). LTL was negatively correlated with age (P=0.001; R=-0.2), oxidative stress (P=0.008; R=-0.2), and severity of periodontitis (P=0.003; R=-0.2) in both the whole population and the subgroups (cases and controls). We conclude that shorter telomere lengths are associated with a diagnosis of periodontitis and their measures correlate with the oxidative stress and severity of disease.

Association of telomere length with type 2 diabetes, oxidative stress and UCP2 gene variation.

OBJECTIVE: High oxidative stress potentially leads to accelerated telomere shortening and consequent premature cell senescence, implicated in type 2 diabetes (T2D) development. Therefore, we studied the association of leukocyte telomere length (LTL) with the presence of T2D, as well as the effect on the patients' LTL of plasma oxidative stress and of variation in UCP2, a gene involved in the mitochondrial production of reactive oxygen species. METHODS: Mean LTL was determined in 569 Caucasian, 103 South Asian and 70 Afro-Caribbean T2D patients aged from 24 to 92 years, 81 healthy Caucasian male students aged from 18 to 28 years and 367 healthy Caucasian men aged from 40 to 61 years by real-time PCR. Plasma total antioxidant status (TAOS) was measured in the T2D patients by a photometric microassay. The patients were also genotyped for the UCP2 functional variants -866G>A and A55V. RESULTS: Afro-Carribeans had 510bp longer mean length compared to Caucasians (p<0.0001) and 500bp longer than South Asians (p=0.004). T2D subjects displayed shorter age-adjusted LTL compared to controls [6.94(6.8-7.03) vs. 7.72(7.53-7.9), p<0.001] with subjects in the middle and the lowest tertile of LTL having significantly higher odds ratios for T2D compared to those in the highest tertile [1.50(1.08-2.07) and 5.04(3.63-6.99), respectively, p<0.0001]. In the patients, LTL was correlated negatively with age (r=-0.18, p<0.0001) and positively with TAOS measures (r=0.12, p=0.01) after adjusting for age, while carriers of the UCP2 -866A allele had shorter age-adjusted LTL than common homozygotes [6.86(6.76-6.96)kb vs. 7.03(6.91-7.15)kb, p=0.04]. CONCLUSION: The present data suggest that shorter LTL is associated with the presence of T2D and this could be partially attributed to the high oxidative stress in these patients. The association of the UCP2 functional promoter variant with the LTL implies a link between mitochondrial production of reactive oxygen species and shorter telomere length in T2D.