G protein–coupled receptor 21 in macrophages: An in vitro study

GPR21 is an orphan and constitutively active receptor belonging to the superfamily of G-Protein Coupled Receptors (GPCRs). GPR21 couples to the Gq family of G proteins and is markedly expressed in macrophages. Studies of GPR21 knock-out mice indicated that GPR21 may be involved in promoting macrophage migration. The aim of this study was to evaluate the role of GPR21 in human macrophages, analyzing (i) its involvement in cell migration and cytokine release and (ii) the consequence of its pharmacological inhibition by using the inverse agonist GRA2. THP-1 cells were activated and differentiated into either M1 or M2 macrophages. GPR21 expression was evaluated at gene and protein level, the signalling pathway was investigated by an IP1 assay, and cytokine release by ELISA. Cell migration was detected by the Boyden chamber migration assay, performed on macrophages derived from both the THP-1 cell line and human peripheral blood monocytes. In addition, we compared the effect of the pharmacological inhibition of GPR21 with the effect of the treatment with a specific GPR21 siRNA to downregulate the receptor expression, thus confirming that GRA2 acts as an inverse agonist of GPR21. GRA2 does not affect cell viability at the tested concentrations, but significantly reduces the release of TNF-α and IL-1β from M1 macrophages. The analysis of the migratory ability highlighted opposite effects of GRA2 on M1 and M2 macrophages since it decreased M1, while it promoted M2 cell migration. Therefore, the pharmacological inhibition of GPR21 could be of interest for pathological conditions characterized by low grade chronic inflammation

Evidence-Based Anti-Diabetic Properties of Plant from the Occitan Valleys of the Piedmont Alps

Data on urban and rural diabetes prevalence ratios show a significantly lower presence of diabetes in rural areas. Several bioactive compounds of plant origin are known to exert anti-diabetic properties. Interestingly, most of them naturally occur in different plants present in mountainous areas and are linked to traditions of herbal use. This review will aim to evaluate the last 10 years of evidence-based data on the potential anti-diabetic properties of 9 plants used in the Piedmont Alps (North-Western Italy) and identified through an ethnobotanical approach, based on the Occitan language minority of the Cuneo province (Sambucus nigra L., Achillea millefolium L., Cornus mas L., Vaccinium myrtillus L., Fragaria vesca L., Rosa canina L., Rubus idaeus L., Rubus fruticosus/ulmifolius L., Urtica dioica L.), where there is a long history of herbal remedies. The mechanism underlying the anti-hyperglycemic effects and the clinical evidence available are discussed. Overall, this review points to the possible use of these plants as preventive or add-on therapy in treating diabetes. However, studies of a single variety grown in the geographical area, with strict standardization and titration of all the active ingredients, are warranted before applying the WHO strategy 2014–2023

Alendronate-Grafted Nanoemulsions for Bone-Targeted Vincristine Delivery: Preliminary Studies on Cell and Animal Models

Bone is a site of distant metastases, which are a common cause of morbidity and mortality with a high socio-economic impact, for many malignant tumours. In order to engineer pharmacological therapies that are suitable for this debilitating disease, this experimental work presents injectable lipid nanoemulsions, which are endowed with a long history of safe clinical usage in parenteral nutrition, their loading with vincristine and their grafting with alendronate, with a dual purpose: merging the anticancer activity of bisphosphonates and vincristine, and enhancing bone-targeted delivery. In cell studies, alendronate synergised with the anti-migration activity of vincristine, which is important as migration plays a key role in the metastatisation process. In preliminary animal studies, carried out thanks to IVIS technology, alendronate conjugation enhanced the bone targeting of fluorescently labelled nanoemulsions. These encouraging results will drive further studies on suitable animal models of the disease

Sedentariness and urinary metabolite profile in type 2 Diabetic Patients, a cross-sectional study

Recent findings indicate a significant association between sedentary (SED)-time and type 2 diabetes mellitus(T2DM). The aim of this study was to investigate whether different levels of SED-time could impact on biochemical and physiological processes occurring in sedentary and physically inactive T2DM patients. In particular, patients from the "Italian Diabetes and Exercise Study (IDES)_2 trial belonging to the first and fourth quartile of SED-time were compared. Urine samples were analyzed by comprehensive two-dimensional gas chromatography(GC×GC) with parallel detection by mass spectrometry and flame ionization detection(GC×2GC-MS/FID). This platform enables accurate profiling and fingerprinting of urinary metabolites while maximizing the overall information capacity, quantitation reliability, and response linearity. Moreover, using advanced pattern recognition, the fingerprinting process was extended to untargeted and targeted features, revealing diagnostic urinary fingerprints between groups. Quantitative metabolomics was then applied to analytes of relevance for robust comparisons. Increased levels of glycine, L-valine,L-threonine, L-phenylalanine, L-leucine, L-alanine, succinic acid, 2-ketoglutaric acid, xylitol, and ribitol were revealed in samples from less sedentary women. In conclusion, SED-time is associated with changes in urine metabolome signatures. These preliminary results suggest that reducing SED-time could be a strategy to improve the health status of a large proportion of diabetic patients

Effects of diet manipulation and 1,25 (OH)₂ vitamin D supplementation on NF-κB activation (panel A) and TNF-alpha levels (panel B) in the mouse gastrocnemious.

<p>(A) Representative western blotting analysis for the expression of NF-κB p65 subunit. Protein expression was analyzed by Western blot on cytosol and nucleus homogenates of gastrocnemious from animals fed a control diet or HFHS diet with or without vitamin D supplementation (7 μg/kg, 3 times per week). Densitometric analysis of the bands is expressed as relative optical density (O.D.) corrected for the GADPH (cytosol) or histone (nucleus) contents, and normalized using the related control band. NF-κB p65 subunit translocation was expressed as nucleus/cytosol ratio normalized using the related control band. (B) TNF-alpha levels were measured by ELISA in the mouse gastrocnemious homogenates. The data are expressed by medians and interquartile range) of 5–6 randomly selected animals per group. Statistical analysis was performed with Kruskal–Wallis test with Dunn’s post hoc test. *p<0.05 <i>vs</i> Control; #p<0.05 <i>vs</i> HFHS.</p

Effects of diet manipulation and 1,25 (OH)₂ vitamin D supplementation on SCAP/SREBP pathway activation in the mouse gastrocnemious.

<p>(A) Representative Western blotting analysis for the expression of SCAP and active/inactive SREBP1c. Protein expression was evaluated on gastrocnemious homogenates of animals fed a control diet or HFHS diet with or without vitamin D supplementation (7 μg/kg, 3 times per week). (B) Densitometric analysis of the bands is expressed as relative optical density (O.D.), corrected for the GADPH contents, and normalized using the related control band. The data are means ± S.E.M. of 6–8 randomly selected animals per group. Statistical analysis was performed by One-way analysis of variance with Bonferroni's post-hoc test. **p<0.01, ***p<0.001 <i>vs</i> Control; ^##p<0.01, ^###p<0.001 <i>vs</i> HFHS.</p

Effects of vitamin D on insulin resistance and myosteatosis in diet-induced obese mice

<div><p>Epidemiological studies pointed out to a strong association between vitamin D deficiency and type 2 diabetes prevalence. However, the role of vitamin D supplementation in the skeletal muscle, a tissue that play a crucial role in the maintenance of glucose homeostasis, has been scarcely investigated so far. On this basis, this study aimed to evaluate the effect of vitamin D supplementation in a murine model of diet-induced insulin resistance with particular attention to the effects evoked on the skeletal muscle. Male C57BL/6J mice (n = 40) were fed with a control or a High Fat-High Sugar (HFHS) diet for 4 months. Subsets of animals were treated for 2 months with vitamin D (7 μg·kg-1, i.p. three times/week). HFHS diet induced body weight increase, hyperglycemia and impaired glucose tolerance. HFHS animals showed an impaired insulin signaling and a marked fat accumulation in the skeletal muscle. Vitamin D reduced body weight and improved systemic glucose tolerance. In addition, vitamin D restored the impaired muscle insulin signaling and reverted myosteatosis evoked by the diet. These effects were associated to decreased activation of NF-κB and lower levels of TNF-alpha. Consistently, a significantly decreased activation of the SCAP/SREBP lipogenic pathway and lower levels of CML protein adducts and RAGE expression were observed in skeletal muscle of animals treated with vitamin D.</p><p>Collectively, these data indicate that vitamin D-induced selective inhibition of signaling pathways (including NF-κB, SCAP/SREBP and CML/RAGE cascades) within the skeletal muscle significantly contributed to the beneficial effects of vitamin D supplementation against diet-induced metabolic derangements.</p></div

Effects of diet manipulation and 1,25 (OH)₂ vitamin D supplementation on insulin signaling transduction in the mouse gastrocnemious.

<p>The expression of total IRS-1 protein and its Ser³⁰⁷ phosphorylation (panel A), total Akt protein and its Ser⁴⁷³ phosphorylation (panel B), and total GSK-3β protein and its Ser⁹ phosphorylation (panel C) were analyzed by Western blot on gastrocnemious homogenates of animals fed a control diet or HFHS diet, with or without vitamin D supplementation (7 μg/kg, 3 times per week). Densitometric analysis of the bands is expressed as relative optical density (O.D.) and normalized using the related control band. The data are expressed by medians and interquartile range of 5–8 randomly selected animals per group. Statistical analysis was performed with Kruskal–Wallis test with Dunn’s post hoc test. *p<0.05, **p<0.01 <i>vs</i> Control; #p<0.05, ##p<0.01 <i>vs</i> HFHS.</p