Increased Level of Angiopoietin Like Proteins 4 and 8 in People With Sleep Apnea

Objective: Obstructive sleep apnea (OSA) is a sleep disorder caused by the complete or partial obstruction of the upper airways. The worldwide prevalence of OSA is increasing due to its close association with obesity epidemic and multiple health complications, such as hypertension, cardiovascular disease, and Type 2 diabetes. Angiopoietin-like protein (ANGPTL)-4 and ANGPTL8 (betatrophin) have been suggested to play a role in the development of these diseases through their role in regulating the metabolism of plasma lipid molecules. This study was designed to evaluate ANGPTL4 and 8 levels in an OSA group and a control group to clarify the effect of OSA on ANGPTL4 and 8 levels.Methods: In total, 74 subjects were enrolled in this study, including 22 age- and body mass index (BMI)-matched controls with the Apnea Hypopnea Index (AHI) score of <5 events/h and 52 subjects with an AHI score of >5 events/h. Sleep apnea was assessed using a portable sleep test. ANGPTL4 and 8 levels were measured in plasma samples using enzyme-linked immunosorbent assay.Results: Mean AHI score (2.5 ± 1.6) in the control group was significantly lower than that in the OSA group (22.9 ± 17.9; p < 0.0001). Leptin, interleukin-(IL) 6, insulin, and HOMA-IR values were higher in the OSA group than in the control group. ANGPTL8 level was higher in the OSA group (1130.0 ± 108.61 pg/mL) than in the control group (809.39 ± 108.78 pg/mL; p = 0.041). Similarly, ANGPTL4 was higher in the OSA group (179.26 ± 12.89 ng/mL) than in the control group (142.63 ±7.99 ng/mL; p = 0.018).Conclusion: Our findings demonstrate that ANGPTL4 and 8 levels were increased in subjects with OSA, suggesting that the upregulation of these lipid metabolism regulators might play a role in lipid dysregulation observed in people with OSA

1674-P: Stearate Potentiates MIP-1a Production with TNF-a via TLR4/TBK1/IKKe /IRF3 Signal Axis: Significance for Insulin Resistance

Increased levels of plasma free fatty acids (FAs) are an important contributor to chronic inflammation, insulin resistance and other obesity-related complications. However, the molecular mechanisms by which individual FAs contribute to obesity-associated inflammation and disorders remain incompletely understood. Here we report that dietary saturated FAs specifically stearate led to a profound production of macrophage inflammatory protein (MIP)-1α (CCL3) in the presence of TNF-α in monocytes, macrophages and adipose tissues. Using pharmacologic and genetic approaches, we identified the involvement of TLR4/TBK1/IKKε/IRF3 signal axis in this production of MIP-1α in response to stearate and TNF-α. Consistent with this, cultured adipose tissues from TLR4 knockout (KO) mice revealed that stearate and TNF-α treatment did not induce MIP-1α compared with TLR2 KO or wild type (C57BL/6) mice. Moreover, C57BL/6 mice fed a high fat diet (HFD) for 16 weeks showed elevated levels of plasma fatty acids, TNF-α and MIP-1α along with insulin resistance. MIP-1α was significantly correlated with TNF-α. Our human data shows that expression of TLR4/p-IRF3 was elevated in the PBMCs of obese individuals as compared to lean. Furthermore, elevated MIP-1α expression levels in obese fat tissues were significantly correlated with TNF-α and macrophage markers. In conclusion, these findings provide a mechanistic link between stearate and TNF-α for the overproduction of obesity associated MIP-1α, which could be used as a new target for the treatment of obesity-related chronic inflammation/insulin resistance. Disclosure S.P. Kochumon: None. F. Almulla: None. Funding Kuwait Foundation for the Advancement of Science (RA-AH-2016-007) </jats:sec

Associations of TERC Single Nucleotide Polymorphisms with Human Leukocyte Telomere Length and the Risk of Type 2 Diabetes Mellitus

<div><p>Previous Studies have mapped putative loci that may probably regulate leukocyte telomere length (LTL). The strongest associations with LTL were reported for SNP rs12696304 and rs16847897 near the non-coding Ribose Nucleic Acid (RNA) molecule component (<i>TERC</i>) of telomerase enzyme on 3q26. It is unclear whether these identified loci coding functional components of telomerase, exert a similar effect on LTL in other populations or influence risk factors of Type 2 Diabetes Mellitus (T2DM). The present study was performed to: study the influence of <i>TERC</i> polymorphisms on LTL, human telomerase reverse transcriptase (hTERT), indices of obesity and explore the potential associations with T2DM. 225 T2DM patients and 245 age and sex matched controls were studied. Allelic Discrimination (AD) genotyping was utilized to determine <i>TERC</i> SNPs [rs12696304 and rs16847897]. hTERT, adiponectin, Insulin, Homeostasis Model Assessment (HOMA-IR), and LTL were measured. Body Mass Index (BMI) and waist circumference (WC) were recorded. [CC] genotype of rs16847897 was significantly associated with shorter LTL [OR = 1.6, p = 0.004], lower hTERT levels [OR = 0.4, p = 0.006], higher BMI [OR = 2.2, p = 0.006], larger WC [OR = 23.4, p = 0.007] and hypo-adiponectemia [OR = 0.6, p = 0.006]. [GG] genotype of rs12696304 was also significantly associated with shorter LTL [OR = 1.5, p = 0.004], lower hTERT [OR = 0.7, p = 0.006] but with larger WC[OR = 5.3, p = 0.004]. [CC] genotype of rs16847897 and [GG] genotype of rs12696304 together increased the risk of T2DM significantly [OR = 1.7, p = 0.004]. We provide insights connecting a structure that is critically involved in maintaining genomic stability with obesity and T2DM. Given the central role of telomere length in determining telomere function our findings may expand our understanding of the pathological mechanisms underlying age associated conditions such as T2DM.</p></div

478-P: GALNT2 Variant Associates with Increased ANGPTL3 Circulation Level and Obesity

Background: Polypeptide N-Acetylgalactosaminyltransferase 2 (GALNT2) gene has been associated with serum lipid levels, insulin resistance, and adipogenesis. One of its variants, rs4846914 has been shown to associate with Triglycerides and HDL levels in global genome-wide association studies. ANGPTL proteins have emerged as important regulators of lipid metabolism through its regulation of lipoprotein lipase activity. In this study we aimed to evaluate the association between GALNT2 variant with plasma level of ANGPTL3, 8 and apolipoproteins in individuals of Arab ethnicity. Methods: GALNT2 rs4846914 variant was genotyped in a cohort of 278 Arab individuals from Kuwait. Plasma levels of ANGPTL3 and 8 were measured by ELISA. Apolipoproteins were measured by Luminex multiplexing assay. Significance of association signals was assessed using Bonferroni-corrected P-values. Results: The GALNT2 rs4846914_G allele was associated with increased ANGPTL3 but not ANGPTL8 plasma levels. It was associated with obesity status with an odds ratio of 1.45 (CI:1.024-2.055) (P-value =0.036) . It also associated with increased levels of ApoC1 (P-values ≤0.006) and lower levels of HDL (P-values ≤0.05) . Levels of HDL were found to be mediated by interactions between genotypes (AG+GG) at rs4846914 and measures of percentage body fat (PBF) , apolipoproteins A1a, C1 and B48. Conclusions: Association between GALNT2 variant and lipid metabolism could be mediated through the increased ANGPTL3 protein level. Disclosure A.T.Thangavel: None. M.Abu-farha: None. P.Hebbar: None. M.G.Qaddoumi: None. F.Almulla: None. J.Abubaker: None. </jats:sec

Box plots show the distribution of Leukocyte Telomere Length [LTL].

<p>The horizontal line within the box corresponds to the median value. Vertical bars represent the values between 2.5^th to 97.5^th percentiles excluding outliers.</p

Demographic, anthropometric and biochemical characteristics of the study population.

<p>Demographic, anthropometric and biochemical characteristics of the study population.</p

1288-P: Increased Adipose Tissue Expression of IL-23 and Its Association with Inflammation in Individuals with High LDL Cholesterol

Obesity induced chronic low-grade inflammation is a central risk factor for the development of metabolic syndrome. It has been well documented that high LDL-c induces inflammation. The proinflammatory cytokine Il-23 plays a pivotal role in the pathogenesis of inflammatory diseases. IL-23 and its relationship with LDL- c has not been reported yet. In this cross-sectional study we investigated whether adipose tissue expression of IL-23 associated with the other inflammatory mediators in individuals with high serum levels of low-density lipoprotein cholesterol (LDL-c) . Subcutaneous adipose samples were collected from 67 individuals and divided into two groups based on their serum LDL-c levels (LDL-c: &amp;lt; 2.9 or ≥2.9 mmol/L) . Expression of IL-23 and inflammatory markers was determined using real-time RT-PCR. Plasma lipid measurements included total cholesterol (TC) , triglyceride (TG) , high-density lipoprotein cholesterol (HDL-c) and LDL-c by standard methods, and serum adiponectin was measured by enzyme-linked immunosorbent assay (ELISA) . Individuals with increased serum levels of LDL-c showed high IL-23 expression levels in adipose tissue (p &amp;lt; 0.011) . AT IL-23 expression was correlated positively with LDL-c (r= 0.39, p &amp;lt; 0.0001) . IL-23 expression levels were positively correlated with macrophage markers (CD11c, CD68, CD86, CD127; (r ≥0.37, p≤ 0.02) , TLRs (TLR8, TLR10; (r ≥ 0.39, p ≤ 0.022) , IRF3 (r= 0.46, p&amp;lt; 0.01) , cytokines (TNF-α, IL-12, IL-18; (r ≥ 0.35, p ≤ 0.04) , chemokines (CXCL8, CCL3, CCL5, CCL15, CCL20; (r ≥0.43, p ≤ 0.01) . Notably, IL-23 is negatively correlated with adiponectin (r=-0.44, p &amp;lt; 0.03) in the individuals with high LDL-c. However, such association of IL-23 with inflammatory markers was not found in the individuals with low LDL-c. In conclusion, adipose tissue IL-23 may be a biomarker for inflammation progression in the individuals with high LDL-c and could be used as a therapeutic target for the treatment of metabolic syndrome. Disclosure R.Ahmad: None. S.P.Kochumon: None. A.Hasan: None. S.T.Sindhu: None. H.Arefanian: None. F.Alrashed: None. F.Almulla: None. Funding Kuwait Foundation for Advancement of Sciences (RA-2010-003) </jats:sec

Box plots show the distribution of serum levels of human telomerase reverse transcriptase [hTERT].

<p>The horizontal line within the box corresponds to the median value. Vertical bars represent the values between 2.5^th to 97.5^th percentiles excluding outliers.</p

ORs [95CI] for associations of <i>TERC</i> SNPs rs16847897 and rs12696304 with LTL, hTERT, anthropometric indices and metabolic factors of obesity.

<p>ORs [95CI] for associations of <i>TERC</i> SNPs rs16847897 and rs12696304 with LTL, hTERT, anthropometric indices and metabolic factors of obesity.</p

ORs [95%CI] for associations of haplotypes with LTL, hTERT, anthropometric indices and metabolic factors of obesity.

<p>ORs [95%CI] for associations of haplotypes with LTL, hTERT, anthropometric indices and metabolic factors of obesity.</p