Effects of rs7903146 Variation in the Tcf7l2 Gene in the Lipid Metabolism of Three Different Populations

Background

TCF7L2 rs7903146 is an important genetic factor predicting type 2 diabetes (T2DM) which has also been linked to higher cardiovascular risk. To date, there is little information about the additional impact of this single nucleotide polymorphism (SNP) beyond glucose metabolism.

Methodology/Principal Findings

We studied whether rs7903146 influenced postprandial lipid metabolism in three different populations (healthy young men, metabolic syndrome (MetS) patients and elderly persons). Eighty-eight healthy males were submitted to a single saturated fatty acid-rich test meal. Additionally, 110 middle-aged MetS patients and 20 healthy elderly persons (≥65 years) were submitted to three different dietary models followed by test meals. Minor allele homozygotes for rs7903146 showed a worse postprandial lipemia profile in young males, as seen by a lower HDL-cholesterol and Apo A1 concentration during the postprandial lipemia and a trend towards higher triglycerides (TG), than the other genotypes. In healthy elderly persons, carriers of the minor allele showed higher total cholesterol, LDL-cholesterol, Apo B and TG in the fasting state, and a higher postprandial area under the curve for total cholesterol, Apo B, small-triglyceride rich lipoprotein (TRL) cholesterol and small-(TRL) triglycerides. These results were accompanied by differential changes in adipokines. We did not observe any influence of rs7903146 on the postprandium of MetS patients.

Conclusions/Significance

Healthy young males and elderly persons who are carriers of the mutant allele for rs7903146 have an impaired postprandial lipid metabolism that may be mediated by an alteration in adipokine regulation, and may be related to the higher cardiovascular risk observed in these persons.

Trial Registration

ClinicalTrials.gov {"type":"clinical-trial","attrs":{"text":"NCT00429195","term_id":"NCT00429195"}}NCT00429195     

Dicarbonyl stress in clinical obesity

The glyoxalase system in the cytoplasm of cells provides the primary defence against glycation by methylglyoxal catalysing its metabolism to D-lactate. Methylglyoxal is the precursor of the major quantitative advanced glycation endproducts in physiological systems - arginine-derived hydroimidazolones and deoxyguanosine-derived imidazopurinones. Glyoxalase 1 of the glyoxalase system was linked to anthropometric measurements of obesity in human subjects and to body weight in strains of mice. Recent conference reports described increased weight gain on high fat diet-fed mouse with lifelong deficiency of glyoxalase 1 deficiency, compared to wild-type controls, and decreased weight gain in glyoxalase 1-overexpressing transgenic mice, suggesting a functional role of glyoxalase 1 and dicarbonyl stress in obesity. Increased methylglyoxal, dicarbonyl stress, in white adipose tissue and liver may be a mediator of obesity and insulin resistance and thereby a risk factor for development of type 2 diabetes and non-alcoholic fatty liver disease. Increased methylglyoxal formation from glyceroneogenesis on adipose tissue and liver and decreased glyoxalase 1 activity in obesity likely drives dicarbonyl stress in white adipose tissue increasing the dicarbonyl proteome and related dysfunction. The clinical significance will likely emerge from on-going clinical evaluation of inducers of glyoxalase 1 expression in overweight and obese subjects. Increased transcapillary escape rate of albumin and increased total body interstitial fluid volume in obesity likely makes levels of glycation of plasma protein unreliable indicators of glycation status in obesity as there is a shift of albumin dwell time from plasma to interstitial fluid, which decreases overall glycation for a given glycemic exposure.     

A review of non-DLVO interactions in environmental colloidal systems

The interaction and behavior of surfaces orcolloids is of quantitative significance inunderstanding the transport and fate ofcompounds and microorganisms in environmentalsystems. Historically, the DLVO model ofcolloid stability has described theseinteractions. This model finds its basis in aforce (energy) balance that comprisesattractive van der Waals and repulsiveelectrostatic interactions. Recently, the DLVOmodel has been found unable to fully describebiotic and abiotic colloidal behavior inaqueous media. The suspending phase (commonlywater) is often treated as a force (energy)transmitting or propagating medium. It isreasonable to believe that the structure ofwater may participate in a more significantfashion. Moreover, other moieties (sorbed anddissolved) may also have non-DLVO effects. Significant work has been focused on extendingthe precepts of the traditional DLVO model toaccommodate these non-DLVO forces (energies). This paper reviews many of the interactionsthat play a role in environmental systems andare not commonly subsumed by the traditionalDLVO model: e.g., hydrogen bonding and thehydrophobic effect, hydration pressure,non-charge transfer Lewis acid baseinteractions, and steric interactions.     

Case report of a woman with monoclonal gammapathy and papillary thyroid carcinoma, diagnosed because of detection of CHEK2 (I157T) mutation in genetic examinations

The CHEK2 gene encodes the CHK2 protein, which is kinase involved in DNA repair processes. By activating a lot of cell substrates, it can regulate the cell cycle, demonstrates suppressive effects, and participates in the senescence and apoptosis processes. Mutations in the CHEK2 gene are associated with increased risk of numerous cancers. The case described herein is that of a woman with a missense mutation that results in the substitution of isoleucine for threonine at position 157. This variant of the mutation doubles the risk of papillary thyroid carcinoma two times and causes up to 9% of these cancer. It is also associated with a two-fold increased risk of cancers of the kidney (10%), colon (10%), and ovary (10% - G1), a 1.6-fold increased risk of prostate cancer (8% of all of them and 12% of familiar ones), and a 1.5-fold increased risk of breast cancer (7%). The screening procedures were initiated in a carrier who revealed papillary thyroid carcinoma. Genetic screening of the family diagnosed her daughter as the carrier of this mutation. Until now no active cancer disease has been recognized in the daughter. On the example of the presented case we discuss indications for screening in cases of positive family history. The group especially predisposed seem to be patients with at least two coexisting carcinomas. Having diagnosed the mutation, it is necessary to do genetic screening of family members. Continuous oncological observation of the carriers of CHEK 2 mutation is essential.     

Phenolic acid and DNA contents of micropropagated Eryngium planum L.

A protocol for in vitro production of genetically uniform populations of the medicinal plant Eryngium planum, rich in selected phenolic acids, has been established. Shoot-tips were collected from axenic seedlings and grown on a Murashige and Skoog basal medium supplemented with 6-Benzyladenine (BA) and Indole-3-acetic acid (IAA). The highest shoot proliferation efficiency (17 shoots per explant) was obtained when 1.0 mg L^?1 BA and 0.1 mg L^?1 were added. Proliferating shoots were rooted and transferred to soil (89 % frequency of survival). Flow cytometric analysis of intact (field-grown) and microrpropagated plants revealed that all plants were uniform in genome size and had similar DNA contents. Thin-layer chromatography (TLC) analysis indicated that multiple shoots and roots from in vitro-derived plants produced high amounts of phenolic acids, primarily of rosmarinic acid (RA). Levels of phenolic acids in in vitro-derived plants were similar to those of intact plants. Furthermore, high-performance liquid chromatography revealed that root cultures in liquid medium accumulated substantial levels of RA. Thus, rapid establishment of in vitro-grown organ cultures of E. planum can also serve as reliable sources for bioactive compounds.