Functional and genomic comparative study of the bitter taste receptor family TAS2R: Insight into the role of human TAS2R5.

Bitterness is perceived in humans by 25 subtypes of bitter taste receptors (hTAS2R) that range from broadly tuned to more narrowly tuned receptors. hTAS2R5 is one of the most narrowly tuned bitter taste receptors in humans. In this study, we review the literature on this receptor and show there is no consensus about its role. We then compare the possible role of hTAS2R5 with that of the proteins of the TAS2R family in rat, mouse, and pig. A phylogenetic tree of all mammalian TAS2R domain-containing proteins showed that human hTAS2R5 has no ortholog in pig, mouse, or rat genomes. By comparing the agonists that are common to hTAS2R5 and other members of the family, we observed that hTAS2R39 is the receptor that shares most agonists with hTAS2R5. In mouse, some of these agonists activate mTas2r105 and mTas2r144, which are distant paralogs of hTAS2R5. mTas2r144 seems to be the receptor that is most similar to hTAS2R5 because they are both activated by the same agonists and have affinities in the same range of values. Then, we can conclude that hTAS2R5 has a unique functional specificity in humans as it is activated by selective agonists and that its closest functional homolog in mouse is the phylogenetically distant mTas2r144.

GSPE Pre-Treatment Exerts Long-Lasting Preventive Effects against Aging-Induced Changes in the Colonic Enterohormone Profile of Female Rats.

The impact that healthy aging can have on society has raised great interest in understanding aging mechanisms. However, the effects this biological process may have on the gastrointestinal tract (GIT) have not yet been fully described. Results in relation to changes observed in the enteroendocrine system along the GIT are controversial. Grape seed proanthocyanidin extracts (GSPE) have been shown to protect against several pathologies associated with aging. Based on previous results, we hypothesized that a GSPE pre-treatment could prevent the aging processes that affect the enteroendocrine system. To test this hypothesis, we treated 21-month-old female rats with GSPE for 10 days. Eleven weeks after the treatment, we analyzed the effects of GSPE by comparing these aged animals with young animals. Aging induced a greater endocrine response to stimulation in the upper GIT segments (cholecystokinin (CCK) and glucagon-like peptide-1 (GLP-1)), a decrease in the mRNA abundance of GLP-1, peptide YY (PYY) and chromogranin A (ChgA) in the colon, and an increase in colonic butyrate. GSPE-treated rats were protected against a decrease in enterohormone expression in the colon. This effect is not directly related to the abundance of microbiome or short-chain fatty acids (SCFA) at this location. GSPE may therefore be effective in preventing a decrease in the colonic abundance of enterohormone expression induced by aging.

Administration of Alphitobius diaperinus or Tenebrio molitor before meals transiently increases food intake through enterohormone regulation in female rats.

BACKGROUND: It has been previously shown that acutely administered insect Alphitobius diaperinus protein increases food intake in rats and modifies the ex vivo enterohormone secretory profile differently than beef or almond proteins. In this study, we aimed to evaluate whether these effects could be maintained for a longer period and determine the underlying mechanisms. RESULTS: We administered two different insect species to rats for 26 days and measured food intake at different time points. Both insect species increased food intake in the first week, but the effect was later lost. Glucagon-like peptide 1 (GLP-1) and ghrelin were measured in plasma and ex vivo, and no chronic effects on their secretion or desensitization were found. Nevertheless, digested A. diaperinus acutely modified GLP-1 and ghrelin secretion ex vivo. CONCLUSION: Our results suggest that increases in food intake could be explained by a local ghrelin reduction acting in the small intestine. © 2022 The Authors. Journal of The Science of Food and Agriculture published by John Wiley & Sons Ltd on behalf of Society of Chemical Industry.

Revealing 2-dimethylhydrazino-2-alkyl alkynyl sphingosine derivatives as sphingosine kinase 2 inhibitors: Some hints on the structural basis for selective inhibition.

Sphingosine kinase (SphK), which catalyzes the transfer of phosphate from ATP to sphingosine (Sph) generating sphingosine-1-phosphate (S1P) has emerged as therapeutic target since the discovery of connections of S1P with cancer progress. So far, most effort has focused on the development of inhibitors of SphK1, and selective inhibitors of SphK2 have been much less explored. Here, we describe the syntheses of new sphingosine derivatives bearing a tetrasubstituted carbon atom at C-2, dimethylhydrazino or azo moieties in the polar head, and alkane, alkene or alkyne moieties as linkers between the polar ahead and the fatty tail. In vitro inhibitory assays based on a time resolved fluorescence energy transfer (TR-FRET) have revealed the hydrazino and alkynyl moieties as the best combination for the design of selective SphK2 inhibitors (19a and 19b). Docking studies showed that compounds 19a-b have the optimal binding to SphK2 through the exploitation of polar but also hydrophobic interactions of their head group with the head of the enzyme binding pocket, while also producing full contact of the fatty tail with the hydrophobic pocket of the enzyme. By contrast, this elongation causes loss of contact surface with the shorter hydrophobic toe of the SphK1 isoform, thus accounting for the SphK2-biased selectivity of these compounds. Cell viability assays of the most promising candidates 19a-b have shown that 19a is not cytotoxic to human endothelial cells at 30 µM.

Protective properties of grape-seed proanthocyanidins in human ex vivo acute colonic dysfunction induced by dextran sodium sulfate.

PURPOSE: Anti-inflammatory and barrier-protective properties have been attributed to proanthocyanidins in the context of intestinal dysfunction, however little information is available about the impact of these phytochemicals on intestinal barrier integrity and immune response in the human. Here we assessed the putative protective properties of a grape-seed proanthocyanidin extract (GSPE) against dextran sodium sulfate (DSS)-induced acute dysfunction of the human colon in an Ussing chamber system. METHODS: Human proximal and distal colon tissues from colectomized patients were submitted ex vivo for a 30-min preventive GSPE treatment (50 or 200 µg mL-1) followed by 1-h incubation with DSS (12% w v-1). Transepithelial electrical resistance (TEER), permeation of a fluorescently-labeled dextran (FD4) and proinflammatory cytokine release [tumor necrosis factor (TNF)-α and interleukin (IL)-1ß] of colonic tissues were determined. RESULTS: DSS reduced TEER (45-52%) in both the proximal and distal colon; however, significant increments in FD4 permeation (fourfold) and TNF-α release (61%) were observed only in the proximal colon. The preventive GSPE treatment decreased DSS-induced TEER loss (20-32%), FD4 permeation (66-73%) and TNF-α release (22-33%) of the proximal colon dose-dependently. The distal colon was not responsive to the preventive treatment but showed a reduction in IL-1ß release below basal levels with the highest GSPE concentration. CONCLUSIONS: Our results demonstrate potential preventive effects of GSPE on human colon dysfunction. Further studies are required to test whether administering GSPE could be a complementary therapeutic approach in colonic dysfunction associated with metabolic disorders and inflammatory bowel disease.

Glucagon-like peptide-1 regulation by food proteins and protein hydrolysates.

Glucagon-like peptide-1 (GLP-1) is an enterohormone with a key role in several processes controlling body homeostasis, including glucose homeostasis and food intake regulation. It is secreted by the intestinal cells in response to nutrients, such as glucose, fat and amino acids. In the present review, we analyse the effect of protein on GLP-1 secretion and clearance. We review the literature on the GLP-1 secretory effects of protein and protein hydrolysates, and the mechanisms through which they exert these effects. We also review the studies on protein from different sources that has inhibitory effects on dipeptidyl peptidase-4 (DPP4), the enzyme responsible for GLP-1 inactivation, with particular emphasis on specific sources and treatments, and the gaps there still are in knowledge. There is evidence that the protein source and the hydrolytic processing applied to them can influence the effects on GLP-1 signalling. The gastrointestinal digestion of proteins, for example, significantly changes their effectiveness at modulating this enterohormone secretion in both in vivo and in vitro studies. Nevertheless, little information is available regarding human studies and more research is required to understand their potential as regulators of glucose homeostasis.

Identification of Broad-Spectrum MMP Inhibitors by Virtual Screening.

Matrix metalloproteinases (MMPs) are the family of proteases that are mainly responsible for degrading extracellular matrix (ECM) components. In the skin, the overexpression of MMPs as a result of ultraviolet radiation triggers an imbalance in the ECM turnover in a process called photoaging, which ultimately results in skin wrinkling and premature skin ageing. Therefore, the inhibition of different enzymes of the MMP family at a topical level could have positive implications for photoaging. Considering that the MMP catalytic region is mostly conserved across different enzymes of the MMP family, in this study we aimed to design a virtual screening (VS) workflow to identify broad-spectrum MMP inhibitors that can be used to delay the development of photoaging. Our in silico approach was validated in vitro with 20 VS hits from the Specs library that were not only structurally different from one another but also from known MMP inhibitors. In this bioactivity assay, 18 of the 20 compounds inhibit at least one of the assayed MMPs at 100 µM (with 5 of them showing around 50% inhibition in all the tested MMPs at this concentration). Finally, this VS was used to identify natural products that have the potential to act as broad-spectrum MMP inhibitors and be used as a treatment for photoaging.

The Light and Dark Sides of Virtual Screening: What Is There to Know?

Virtual screening consists of using computational tools to predict potentially bioactive compounds from files containing large libraries of small molecules. Virtual screening is becoming increasingly popular in the field of drug discovery as in silico techniques are continuously being developed, improved, and made available. As most of these techniques are easy to use, both private and public organizations apply virtual screening methodologies to save resources in the laboratory. However, it is often the case that the techniques implemented in virtual screening workflows are restricted to those that the research team knows. Moreover, although the software is often easy to use, each methodology has a series of drawbacks that should be avoided so that false results or artifacts are not produced. Here, we review the most common methodologies used in virtual screening workflows in order to both introduce the inexperienced researcher to new methodologies and advise the experienced researcher on how to prevent common mistakes and the improper usage of virtual screening methodologies.

Activity and selectivity cliffs for DPP-IV inhibitors: Lessons we can learn from SAR studies and their application to virtual screening.

The inhibition of dipeptidyl peptidase-IV (DPP-IV) has emerged over the last decade as one of the most effective treatments for type 2 diabetes mellitus, and consequently (a) 11 DPP-IV inhibitors have been on the market since 2006 (three in 2015), and (b) 74 noncovalent complexes involving human DPP-IV and drug-like inhibitors are available at the Protein Data Bank (PDB). The present review aims to (a) explain the most important activity cliffs for DPP-IV noncovalent inhibition according to the binding site structure of DPP-IV, (b) explain the most important selectivity cliffs for DPP-IV noncovalent inhibition in comparison with other related enzymes (i.e., DPP8 and DPP9), and (c) use the information deriving from this activity/selectivity cliff analysis to suggest how virtual screening protocols might be improved to favor the early identification of potent and selective DPP-IV inhibitors in molecular databases (because they have not succeeded in identifying selective DPP-IV inhibitors with IC50 ≤ 100 nM). All these goals are achieved with the help of available homology models for DPP8 and DPP9 and an analysis of the structure-activity studies used to develop the noncovalent inhibitors that form part of some of the complexes with human DPP-IV available at the PDB.

Fluorinated triazole-containing sphingosine analogues. Syntheses and in vitro evaluation as SPHK inhibitors.

Sphingosine analogues with a rigid triazole moiety in the aliphatic chain and systematic modifications in the polar head and different degrees of fluorination at the terminus of the alkylic chain were synthesized from a common alkynyl aziridine key synthon. This key synthon was obtained by enantioselective organocatalyzed aziridination and it was subsequently ring opened in a regioselective manner in acidic medium. Up to 16 sphingosine analogues were prepared in a straightforward manner. The in vitro activity of the obtained products as SPHK1 and SPHK2 inhibitors was evaluated, displaying comparable activity to that of DMS.

Specific circulating microRNA signature of bicuspid aortic valve disease.

BACKGROUND: We aimed to determine the circulating miRNA expression profile associated with BAV and aortic dilation to provide diagnostic and prognostic biomarkers for BAV and/or aortic dilation. METHODS AND RESULTS: We applied a miRNome-wide microarray approach using plasma samples (n = 24) from healthy tricuspid aortic valve individuals, BAV patients and BAV patients with aortic dilation to compare and identify the specific miRNAs associated with BAV and aortic dilation. In a second stage, the expression patterns of the miRNA candidates were validated by RT-qPCR in an independent cohort (n = 43). The miRNA microarray data and RT-qPCR analyses revealed that the expression levels of circulating miR-122, miR-130a and miR-486 are significantly influenced by the morphology of the aortic valve (bicuspid/tricuspid) and could be functionally involved in the regulation of TGF-ß1 signalling. Furthermore, the expression pattern of miR-718 in the plasma was strongly influenced by dilation of the ascending aorta. miR-718 expression was inversely correlated with the aortic diameter (R = -0.63, p = 3.1 × 10-5) and was an independent predictor of aortic dilation (ß = -0.41, p = 0.022). The genes targeted by miR-718 are involved in the regulation of vascular remodelling. CONCLUSIONS: We propose that miR-122, miR-130a, miR-486 and miR-718 are new molecular features associated with BAV and aortic dilation principally by the activation of TGF-ß1 pathway and vascular remodelling mediated by VEGF signalling pathways.

Acute effect of static exercise on the cardiovascular system: assessment by cardiovascular magnetic resonance.

PURPOSE: The acute effect of static exercise on the global dynamics of the cardiovascular system is poorly understood. The use of cardiovascular magnetic resonance (CMR) may be useful for evaluating this effect. METHODS: A total of 12 healthy individuals underwent CMR imaging at rest and while performing a maximal sustained static exercise (weight elevation with both legs). We analyzed the effects on left and right ventricular function, ascending aorta dynamics, and venous capacitance using standard cine and phase-contrast sequences. RESULTS: We observed excellent reproducibility in the measurements of the images obtained at rest as well as during static exercise. During exercise, we observed reduced left (-35 ± 8 %, p < 0.001) and right (-44 ± 9 %, p < 0.001) ventricle end-diastolic volumes, reduced left (-35 ± 16 %, p < 0.001) and right (-43 ± 8 %, p < 0.001) ventricle end-systolic volumes (both with a significantly greater reduction in the right ventricle), a reduced superior vena cava cross-sectional area (-20 ± 17 %, p = 0.003), and increased left ventricle wall thickness. We estimated that there was an increase in left ventricle contractility. There were no significant changes in the left and right ventricular ejection fractions. During exercise, we noted a tendency toward decreased aortic distensibility and a reduction of ascending aorta systolic expansion. CONCLUSIONS: In healthy individuals, an acute maximal static exercise produced a reduction in the left ventricle, right ventricle, and superior vena cava volumes as well as signs of increased aortic stiffness without increasing left ventricular systolic wall stress. CMR is feasible and useful in evaluating the hemodynamic effects of static exercise.

Rosiglitazone and fenofibrate exacerbate liver steatosis in a mouse model of obesity and hyperlipidemia. A transcriptomic and metabolomic study.

Peroxisome proliferator-activated receptors (PPAR) play an important role in the regulation of lipid and glucose metabolism, inflammatory, and vascular responses. We show the effect of treatment with two PPAR agonists, fenofibrate (FF) and rosiglitazone (RSG), on ob/ob and LDLR-double deficient mice, by combined gene-expression and metabolomic analyses. Male mice were daily treated for 12 weeks with RSG (10 mg·kg(1-)·day(-1) per os (p.o.), n = 8) and FF (50 mg·kg(1-)·day(-1) p.o., n = 8). Twelve untreated ob/ob and LDLR-double deficient mice were used as controls. To integrate the transcriptomic and metabolomic results, we designed a hierarchical algorithm, based on the average linkage method in clustering. Data were also interpreted with the Ingenuity Pathway Analysis program. FF and RSG treatments significantly increased the hepatic triglyceride content in the liver when compared with the control group, and the treatments induced an increase in the number and size of hepatic lipid droplets. Both drugs simultaneously activate pro-steatotic and antisteatotic metabolic pathways with a well-ordered result of aggravation of the hepatic lipid accumulation. The present study is a cautionary note not only to researchers on the basic mechanism of the action of PPAR activators but also to the use of these compounds in clinical practice.

Intestinal Taste Receptor Expression and Its Implications for Health: An Integrative Analysis in Female Rats after Chronic Insect Supplementation.

Taste receptors are found in the gastrointestinal tract, where they are susceptible to dietary modulation, a key point that is crucial for diet-related responses. Insects are sustainable and good-quality protein sources. This study analyzed the impact of insect consumption on the modulation of taste receptor expression across various segments of the rat intestine under healthy or inflammatory conditions. Female Wistar rats were supplemented with Tenebrio molitor (T) or Alphitobius diaperinus (B), alongside a control group (C), over 21 days under healthy or LPS-induced inflammation. The present study reveals, for the first time, that insect consumption modulates taste receptor gene expression, mainly in the ascending colon. This modulation was not found under inflammation. Integrative analysis revealed colonic Tas1r1 as a key discriminator for insect consumption (C = 1.04 ± 0.32, T = 1.78 ± 0.72, B = 1.99 ± 0.82, p-value <0.05 and 0.01, respectively). Additionally, correlation analysis showed the interplay between intestinal taste receptors and metabolic and inflammatory responses. These findings underscore how insect consumption modulates taste receptors, influencing intestinal function and broader physiological mechanisms.

Multi-tissue profiling of oxylipins reveal a conserved up-regulation of epoxide:diol ratio that associates with white adipose tissue inflammation and liver steatosis in obesity.

BACKGROUND: Obesity drives maladaptive changes in the white adipose tissue (WAT) which can progressively cause insulin resistance, type 2 diabetes mellitus (T2DM) and metabolic dysfunction-associated liver disease (MASLD). Obesity-mediated loss of WAT homeostasis can trigger liver steatosis through dysregulated lipid pathways such as those related to polyunsaturated fatty acid (PUFA)-derived oxylipins. However, the exact relationship between oxylipins and metabolic syndrome remains elusive and cross-tissue dynamics of oxylipins are ill-defined. METHODS: We quantified PUFA-related oxylipin species in the omental WAT, liver biopsies and plasma of 88 patients undergoing bariatric surgery (female N = 79) and 9 patients (female N = 4) undergoing upper gastrointestinal surgery, using UPLC-MS/MS. We integrated oxylipin abundance with WAT phenotypes (adipogenesis, adipocyte hypertrophy, macrophage infiltration, type I and VI collagen remodelling) and the severity of MASLD (steatosis, inflammation, fibrosis) quantified in each biopsy. The integrative analysis was subjected to (i) adjustment for known risk factors and, (ii) control for potential drug-effects through UPLC-MS/MS analysis of metformin-treated fat explants ex vivo. FINDINGS: We reveal a generalized down-regulation of cytochrome P450 (CYP)-derived diols during obesity conserved between the WAT and plasma. Notably, epoxide:diol ratio, indicative of soluble epoxide hydrolyse (sEH) activity, increases with WAT inflammation/fibrosis, hepatic steatosis and T2DM. Increased 12,13-EpOME:DiHOME in WAT and liver is a marker of worsening metabolic syndrome in patients with obesity. INTERPRETATION: These findings suggest a dampened sEH activity and a possible role of fatty acid diols during metabolic syndrome in major metabolic organs such as WAT and liver. They also have implications in view of the clinical trials based on sEH inhibition for metabolic syndrome. FUNDING: Wellcome Trust (PS3431_WMIH); Duke-NUS (Intramural Goh Cardiovascular Research Award (Duke-NUS-GCR/2022/0020); National Medical Research Council (OFLCG22may-0011); National Institute of Environmental Health Sciences (Z01 ES025034); NIHR Imperial Biomedical Research Centre.

Plant-derived polyphenols regulate expression of miRNA paralogs miR-103/107 and miR-122 and prevent diet-induced fatty liver disease in hyperlipidemic mice.

BACKGROUND: MicroRNAs have the potential for clinical application. Probable modulation by plant-derived polyphenols might open preventive measures using simple dietary recommendations. METHODS: We assessed the ability of continuous administration of high-dose polyphenols to modulate hepatic metabolism and microRNA expression in diet-induced fatty liver disease in commercially available hyperlipidemic mice using well-established and accepted procedures that included the development of new antibodies against modified quercetin. RESULTS: Weight gain, liver steatosis, changes in the composition of liver tissue, and insulin resistance were all attenuated by the continuous administration of polyphenols. We also demonstrated that metabolites of polyphenols accumulate in immune cells and at the surface of hepatic lipid droplets indicating not only bioavailability but a direct likely action on liver cells. The addition of polyphenols also resulted in changes in the expression of miR-103, miR-107 and miR-122. CONCLUSIONS: Polyphenols prevent fatty liver disease under these conditions. The differential expression of mRNAs and miRNAs was also associated with changes in lipid and glucose metabolism and with the activation of 5'-adenosine monophosphate-activated protein kinase, effects that are not necessarily connected. miRNAs function via different mechanisms and miRNA-mRNA interactions are difficult to ascertain with current knowledge. Further, cell models usually elicit contradictory results with those obtained in animal models. GENERAL SIGNIFICANCE: Our data indicate that plant-derived polyphenols should be tested in humans as preventive rather than therapeutic agents in the regulation of hepatic fatty acid utilization. A multi-faceted mechanism of action is likely and the regulation of liver miRNA expression blaze new trails in further research.

The relevance of the association between inflammation and atrial fibrillation.

BACKGROUND: The relevance of the association between inflammation and atrial fibrillation (AF) is not firmly established. The clinical importance is considerable because inflammation is usually not targeted as a treatment option, minimizing a probable benefit. MATERIALS AND METHODS: We have used a case-control study with a Mendelian randomization rationale to assess whether proposed risk factors that have a genetic component and are readily detected in circulating blood are causally related to AF. The studied variables were C-reactive protein (CRP) and a representative of the chemokine system, the monocyte chemoattractant protein-1 (CCL2). RESULTS: Plasma CRP and CCL2 concentrations were significantly higher in AF patients than in the unaffected population. However, when segregated between paroxysmal and permanent, the difference for CRP was only observed in patients with a permanent condition. Plasma CCL2 was raised in both subgroups. Confounding factors were carefully considered, and multivariable analyses revealed that circulating CCL2 was significant and CRP was negligible to explain the presence of AF. The duration of the episode also bore a significant predictive value. Odd ratios for AF as a function of genotype did not differ from 1·0 for any of the individual CRP and CCL2 polymorphisms, or any combinations. CONCLUSIONS: Elevated plasma CRP concentration per se does not increase atrial fibrillation risk. Values obtained for CCL2 suggest that inflammation is probably a consequence of AF. Our data also suggest that the effect of the duration of the episode should be further studied in the assessment of the actual role of inflammation.

Factors related to the need for surgery after the diagnosis of bicuspid aortic valve: one center´s experience under a conservative approach.

BACKGROUND AND AIM: Bicuspid aortic valve (BAV) increases the risk of aortic valve dysfunction and ascending aorta aneurysm and, consequently, the need for aortic valve replacement and/or aortic repair. However, there is no universal consensus about the surgical criteria and the predictors for surgery. The aim of this study was to investigate related factors to the need for surgery in the setting of a strict long-term follow-up with relatively conservative surgical criteria. METHODS: We prospectively followed 120 patients after the diagnosis of BAV. Predisposing factors for a future need for aortic valve replacement and ascending aorta repair were assessed. Aortic surgery was indicated when the ascending aorta diameter was ≥ 55 mm and was recommended based on patient characteristics and in the presence of a severe aortic valve dysfunction with an aortic diameter ≥ 50 mm. RESULTS: During follow-up (mean, 86 months), 34 patients (28%) (mean age, 56 ± 12 years) were surgically treated. Aortic valve dysfunction (n=22; 64%) and ascending aorta dilatation (n=12; 36%) were the indications for surgery. Aortic regurgitation was the most frequent valve dysfunction at the time of diagnosis for BAV, but aortic stenosis was the most frequent indication for surgery. The presence at surgery of either aortic regurgitation or stenosis was clearly related to age, with regurgitation predominating in patients under 55 years, and aortic stenosis in older patients.Multivariate Cox analysis showed that aortic stenosis (hazard ratio 4.1, p=0.001), indexed ascending aorta dilatation (hazard ratio 3.0, p=0.03) and left ventricular end-diastolic diameter ≥ 60 mm (hazard ratio=4.0, p=0.01) at diagnosis were factors associated with future surgery. Aortic dissection was not observed in patients that did not undergo surgery. CONCLUSIONS: A relatively conservative approach for the indication of ascending aortic surgery in BAV is safe. In this setting, the presence of aortic or left ventricle dilatation and aortic stenosis at diagnosis of BAV were predictive of the need for surgery in the follow-up.

A possible role for CCR5 in the progression of atherosclerosis in HIV-infected patients: a cross-sectional study.

BACKGROUND: Chemokines can block viral entry by interfering with HIV co-receptors and are recognised mediators of atherosclerosis development. A number of experimental drugs that inhibit HIV entry arrest the development of atherosclerosis in animal models. We hypothesised that the expression of chemokine receptors in circulating leukocytes is associated with the rate of atherosclerosis progression in HIV-infected patients. METHODS: The increase in intima-media thickness during a 2-year follow-up was used to classify HIV-infected patients (n = 178) as progressors (n = 142) or non-progressors (n = 36) with respect to atherosclerosis. Logistic regression was used to assess variables associated with atherosclerosis progression. Mutations in the CCR5Δ32, CCR2 64I, and CX3CR1 (T280M and V249I) co-receptors as well as the levels of CCR5, CXCR4, CX3CR1, and CCR2 mRNA expression in circulating leukocytes were analysed as independent variables. RESULTS: Among the baseline variables, only genetic variants explained the dichotomous outcome. The expression of CCR2 and CXCR4 did not discriminate between progressors and non-progressors. Conversely, CCR5 and CX3CR1 expression was higher in not only progressors but also patients with detectable viral load. The logistic regression, however, demonstrated a significant role for CCR5 expression as a predictor of atherosclerosis progression (B = 2.1, OR = 8.1, p = 0.04) and a negligible effect for CXC3R1 and CCR2 expression. CONCLUSIONS: Available CCR5 antagonists should be investigated for their potential to delay the course of atherosclerosis in HIV-infected patients.

Ubiquitous transgenic overexpression of C-C chemokine ligand 2: a model to assess the combined effect of high energy intake and continuous low-grade inflammation.

Excessive energy management leads to low-grade, chronic inflammation, which is a significant factor predicting noncommunicable diseases. In turn, inflammation, oxidation, and metabolism are associated with the course of these diseases; mitochondrial dysfunction seems to be at the crossroads of mutual relationships. The migration of immune cells during inflammation is governed by the interaction between chemokines and chemokine receptors. Chemokines, especially C-C-chemokine ligand 2 (CCL2), have a variety of additional functions that are involved in the maintenance of normal metabolism. It is our hypothesis that a ubiquitous and continuous secretion of CCL2 may represent an animal model of low-grade chronic inflammation that, in the presence of an energy surplus, could help to ascertain the afore-mentioned relationships and/or to search for specific therapeutic approaches. Here, we present preliminary data on a mouse model created by using targeted gene knock-in technology to integrate an additional copy of the CCl2 gene in the Gt(ROSA)26Sor locus of the mouse genome via homologous recombination in embryonic stem cells. Short-term dietary manipulations were assessed and the findings include metabolic disturbances, premature death, and the manipulation of macrophage plasticity and autophagy. These results raise a number of mechanistic questions for future study.