Biomedical Sciences

Background Oxidative phosphorylation is central to the energy metabolism of the cell. Due to adaptation to different life-styles and environments, fungal species have shaped their respiratory pathways in the course of evolution. To identify the main mechanisms behind the evolution of respiratory pathways, we conducted a phylogenomics survey of oxidative phosphorylation components in the genomes of sixty fungal species. Results Besides clarifying orthology and paralogy relationships among respiratory proteins, our results reveal three parallel losses of the entire complex I, two of which are coupled to duplications in alternative dehydrogenases. Duplications in respiratory proteins have been common, affecting 76% of the protein families surveyed. We detect several instances of paralogs of genes coding for subunits of respiratory complexes that have been recruited to other multi-protein complexes inside and outside the mitochondrion, emphasizing the role of evolutionary tinkering. Conclusions Processes of gene loss and gene duplication followed by functional divergence have been rampant in the evolution of fungal respiration. Overall, the core proteins of the respiratory pathways are conserved in most lineages, with major changes affecting the lineages of microsporidia, Schizosaccaromyces and Saccharomyces/Kluyveromyces due to adaptation to anaerobic life-styles. We did not observe specific adaptations of the respiratory metabolism common to all pathogenic species.

Objective. Even though the validity of accelerometers for the measurement of energy expenditure (EE) has been demonstrated for normal-weight individuals, the applicability of this instrument in obese individuals remains controversial. This review aims to summarize the level of agreement between accelerometers and the gold standards (indirect calorimetry and doubly labelled water) for the measurement of energy expenditure (EE) in obese or overweight individuals. Methods. The literature search was limited to comparison studies assessing agreement in EE determination between accelerometers and indirect calorimetry (IC) or doubly labelled water (DLW). We searched in PubMed and in Scopus until March 1, 2019. The analysis was restricted to obese or overweight adult individuals. The following descriptive information was extracted for each study: sample size, characteristics of participants (sex, age, BMI, fat mass percentage, any pathological conditions, modality of recruitment in the stud...

Although it is known that the gut microbiota (GM) can be modulated by diet, the efficacy of specific dietary interventions in determining its composition and diversity in obese patients remains to be ascertained. The present work aims to evaluate the impact of a moderately hypocaloric Mediterranean diet on the GM of obese and overweight patients (OB). The GM of 23 OB patients (F/M= 20/3) was compared before (T0) and after 3 months (T3) of the nutritional intervention (NI). Fecal samples were analyzed by Illumina MiSeq sequencing of the 16S rRNA gene. At baseline, the GM characterization confirmed the typical obesity-associated dysbiosis. After 3 months of NI, patients presented a statistically significant reduction of the body weight and fat mass, along with changes in the relative abundance of many microbial patterns. In fact, we observed an increased abundance in several Bacteroidetes taxa (i.e. Sphingobacteriaceae, Sphingobacterium, Bacteroides spp., Prevotella stercorea) and dep...

It is generally accepted that gut microbiota, inflammation and obesity are linked to the development of cardiovascular diseases and other chronic/non-communicable pathological conditions, including cancer, neurodegenerative diseases and ageing-related disorders. In this scenario, oxidative stress plays a pivotal role. Evidence suggests that the global dietary patterns may represent a tool in counteracting oxidative stress, thus preventing the onset of diseases related to oxidative stress. More specifically, dietary patterns based on the regular consumption of fruits and vegetables (i.e., Mediterranean diet) have been licensed by various national nutritional guidelines in many countries for their health-promoting effects. Such patterns, indeed, result in being rich in specific components, such as fiber, minerals, vitamins and antioxidants, whose beneficial effects on human health have been widely reported. This suggests a potential nutraceutical power of specific dietary components. ...

In the present study, we characterized the distinctive signatures of the gut microbiota (GM) from overweight/obese patients (OB), and normal-weight controls (NW), both of Sardinian origin. Fecal bacterial composition of 46 OB patients (BMI = 36.6 ± 6.0; F/M = 40/6) was analyzed and compared to that of 46 NW subjects (BMI = 21.6 ± 2.1; F/M = 41/5), matched for sex, age and smoking status, by using 16S rRNA gene sequencing on MiSeq Illumina platform. The gut microbial community of OB patients exhibited a significant decrease in the relative abundance of several Bacteroidetes taxa (i.e. Flavobacteriaceae, Porphyromonadaceae, Sphingobacteriaceae, Flavobacterium, Rikenella spp., Pedobacter spp., Parabacteroides spp., Bacteroides spp.) when compared to NW; instead, several Firmicutes taxa were significantly increased in the same subjects (Lachnospiraceae, Gemellaceae, Paenibacillaceae, Streptococcaceae, Thermicanaceae, Gemella, Mitsuokella, Streptococcus, Acidaminococcus spp., Eubacterium...

The obesity epidemic, mainly due to lifestyle changes in recent decades, leads to serious comorbidities that reduce life expectancy. This situation is affecting the health policies of many nations around the world. Traditional measures such as diet, physical activity, and drugs are often not enough to achieve weight loss goals and to maintain the results over time. Bariatric surgery (BS) includes various techniques, which favor rapid and sustained weight loss. BS is a useful and, in most cases, the best treatment in severe and complicated obesity. In addition, it has a greater benefit/risk ratio than non-surgical traditional therapies. BS can allow the obese patient to lose weight quickly compared with traditional lifestyle changes, and with a greater probability of maintaining the results. Moreover, BS promotes improvements in metabolic parameters, even diabetes remission, and in the quality of life. These changes can lead to an increase of life expectancy by over 6 years on averag...

Background: Hidradenitis Suppurativa is a chronic inflammatory skin disease with a strong negative impact on physical and psychological health. Obesity, especially visceral adiposity, but also smoking or unhealthy nutritional habits, have been reported to be significantly associated with hidradenitis suppurativa.Design and Method: Case-control study in 35 patients of both sexes affected with hidradenitis suppurativa, and 35 healthy subjects matched for sex, age, and geographic origin (Sardinia, Italy).Results: Several anthropometric measures (body mass index, waist circumference, body composition), lifestyle (Mediterranean diet adherence, and physical activity level), and the perceived physical and mental health status were evaluated in case and controls. Hidradenitis patients showed significantly higher values of body mass index, waist circumference, body composition, fat mass, and lower values of physical and mental health status compared to controls, while both groups showed a si...

After a low-calorie diet, only 25% of patients succeed in maintaining the result of weight loss for a long time. This systematic review and meta-analysis aims to explore whether patients undergoing intensive intervention during the maintenance phase have a greater preservation of the weight achieved during the previous slimming phase than controls. A bibliographic search was conducted using PubMed, Scopus, and Cochrane databases for clinical trials and randomised, controlled trials investigating the role of choice in weight-loss-maintenance strategies. Only studies with a follow-up of at least 12 months were considered. A total of eight studies, for a total of 1454 patients, was identified, each comparing a group that followed a more intensive protocol to a control group. Our metanalysis highlighted that an intensive approach even in the maintenance phase could be important to ensure greater success in the phase following the weight-loss period. However, it should be pointed out tha...

Smell plays a critical role in food choice and intake by influencing energy balance and body weight. Malnutrition problems or modified eating behaviors have been associated with olfactory impairment or loss. The obesity epidemic is a serious health problem associated with an increased risk of mortality and major physical comorbidities. The etiopathogenesis of obesity is complex and multifactorial, and one of the main factors contributing to the rapid increase in its incidence is the environment in which we live, which encourages the overconsumption of foods rich in energy, such as saturated fats and sugars. By means of the “Sniffin’ Sticks” test, we measured the olfactory threshold, discrimination and identification score (TDI score) in patients of the Obesity Center of the University Hospital (OC; n = 70) and we compared them with that of healthy normal weight controls (HC; n = 65). OC patients demonstrated a significantly lower olfactory function than HC subjects both general and ...

Objective Even though the validity of accelerometers for the measurement of energy expenditure (EE) has been demonstrated for normal-weight individuals, the applicability of this instrument in obese individuals remains controversial. This review aims to summarize the level of agreement between accelerometers and the gold standards (indirect calorimetry and doubly labelled water) for the measurement of energy expenditure (EE) in obese or overweight individuals. Methods The literature search was limited to comparison studies assessing agreement in EE determination between accelerometers and indirect calorimetry (IC) or doubly labelled water (DLW). We searched in PubMed and in Scopus until March 1, 2019. The analysis was restricted to obese or overweight adult individuals. The following descriptive information was extracted for each study: sample size, characteristics of participants (sex, age, BMI, fat mass percentage, any pathological conditions, modality of recruitment in the study,...

Besides being involved in analgesia, δ-opioid receptors have recently been shown to exert antidepressant-like and neuroprotective effects. Glycogen synthase kinase-3β (GSK-3β), a key enzyme involved in cellular apoptosis and in mood disorders, may constitute a molecular target of δ-opioid receptors. However, relatively little is known on how δ-opioid receptors affect the multiple signaling pathways regulating GSK-3β. In the present study, we show that activation of human δ-opioid receptors stably expressed in Chinese hamster ovary (CHO) cells induced a rapid GSK-3β phosphorylation on Ser9 and a significant inhibition of the kinase activity. This effect was dependent on G proteins Gi/Go, unaffected by cell transfection with the Gβγ scavenger transducin, required the Src non-receptor tyrosine kinase and the specific involvement of the α isoform of phosphatidylinositol 3-kinase. δ-Opioid agonists activated the protein kinase Akt in a Src-dependent manner and chemical inhibition of Akt or stable expression of a dominant negative Akt1 mutant reduced the stimulation of GSK-3β phosphorylation. Moreover, δ-opioid receptor regulation of Akt and GSK-3β was dependent on transphosphorylation and transactivation of platelet-derived growth factor and insulin-like growth factor-1 receptor tyrosine kinases. AMP-activated protein kinase (AMPK) activity was also required, as δ-opioid effects on Akt and GSK-3β were mimicked by the AMPK activator A-769662 and reduced by the AMPK inhibitor Compound C. Conversely, inhibition of protein kinase C isoforms, extracellular signal-regulated protein kinases 1/2 and mammalian target of rapamycin was without effect, although the latter two kinases were activated by δ-opioid agonists. The results identify Src-dependent transactivation of receptor tyrosine kinases as a key process in δ-opioid receptor inhibitory control of GSK-3β and reveal a novel δ-opioid regulatory mechanism mediated by AMPK.This article is part of a Special Issue entitled ‘Trends in Neuropharmacology: In Memory of Erminio Costa’.► We show that δ-opioid receptors (DOR) cause GSK-3β phosphorylation and inactivation. ► The effect is dependent on Gi/Go and requires the activity of Src and PI3Kα. ► Inhibition of PDGF and IGF-1 receptor tyrosine kinases (RTK) impair the DOR effect. ► The AMPK inhibitor Compound C also attenuates DOR regulation of GSK-3β. ► We conclude that DOR-induced GSK-3β inhibition involves RTK transactivation and AMPK.

We have previously reported that N-desmethylclozapine (NDMC), a major clozapine metabolite, acts as a δ-opioid receptor agonist. Here, we show that in different cellular systems NDMC regulates protein kinase B/Akt (Akt) signaling through the activation of δ-opioid receptors. In Chinese hamster ovary cells transfected with the human δ-opioid receptor (CHO/DOR), NDMC induced a time- and concentration-dependent phosphorylation of Akt at Thr308 and glycogen synthase kinase-3β (GSK-3β) at Ser9 and these effects were fully blocked by the δ-opioid receptor antagonist naltrindole. NDMC-induced Akt and GSK-3β phosphorylations were completely prevented by pertussis toxin, the Src tyrosine kinase inhibitor PP2 and the selective insulin-like growth factor-I (IGF-I) receptor tyrosine kinase inhibitor tyrphostin AG 1024. NDMC stimulated IGF-I receptor β subunit tyrosine phosphorylation and this effect was prevented by either naltrindole or PP2. Blockade of phosphatidylinositol 3-kinase (PI3K) α, but not PI3Kγ, suppressed NDMC-induced Akt and GSK-3β phosphorylation, whereas inhibition of Akt curtailed the stimulation of GSK-3β phosphorylation. In rat nucleus accumbens, NDMC induced Akt and GSK-3β phosphorylation either in vitro or in vivo and these effects were prevented by naltrindole. NDMC also regulated Akt and GSK-3β phosphorylation through δ-opioid receptors in NG108-15 cells. In these cells NDMC counteracted oxidative stress-induced apoptosis and the effect was lost following PI3K inhibition. These data demonstrate that in different cell systems NDMC can stimulate Akt signaling by activating Gi/Go-coupled δ-opioid receptors, which, at least in CHO/DOR cells, regulate PI3Kα through Src-dependent transactivation of the IGF-I receptor, and indicate that through this mechanism NDMC can exert neuroprotective effects.

Opioid receptors located in the ventral tegmental area are known to regulate dopamine (DA) release from mesocortical afferents to medial prefrontal cortex (mPFC) but little is known on whether in this cortical region activation of opioid receptors affect DA receptor signaling. In the present study we show that in mouse mPFC concomitant activation of either δ- or μ-opioid receptors, but not κ-opioid receptors, potentiated DA D1-like receptor-induced stimulation of adenylyl cyclase activity through a G protein βγ subunit-dependent mechanism. In tissue slices of mPFC, the combined addition of the opioid agonist leu-enkephalin and the DA D1-like receptor agonist SKF 81297 produced more than additive increase in the phosphorylation state of AMPA and NMDA receptor subunits GluR1 and NR1, respectively. Moreover, in primary cultures of mouse frontal cortex neurons, DA D1-like receptor-induced Ser133 phosphorylation of the transcription factor cyclic AMP responsive element binding protein was potentiated by concurrent stimulation of opioid receptors. Double immunofluorescence analysis of cultured cortical cells indicated that a large percentage of DA D1 receptor positive cells expressed either δ- or μ-opioid receptor immunoreactivity. These data indicate that in mouse mPFC activation of μ- and δ-opioid receptors enhances DA D1-like receptor signaling likely through converging regulatory inputs on βγ-stimulated adenylyl cyclase isoforms. This previously unrecognized synergistic interaction may selectively affect DA D1 transmission at specific postsynaptic sites where the receptors are co-localized and may play a role in prefrontal DA D1 regulation of opioid addiction.► The study investigates the interaction between opioid and DA D1 receptors in mPFC. ► δ- and μ-opioid receptors potentiate DA D1-stimulated cyclic AMP formation. ► D1 stimulation of GluR1, NR1 and CREB phosphorylation is enhanced by leu-enkephalin. ► Cultured cortical cells show co-expression of D1, δ- and μ- receptor immunoreactivity.

BACKGROUND AND PURPOSE Although opioids have been reported to affect glucose homeostasis, relatively little is known on the role of δ-opioid receptors. We have investigated the regulation of glucose transport by human δ-opioid receptors expressed in Chinese hamster ovary cells.EXPERIMENTAL APPROACH The uptake of [3H]-2-deoxy-D-glucose and 3-O-[methyl-[3H]]-D-glucose in response to δ-opioid receptor ligands and the expression of GLUT1, GLUT3 and GLUT4 glucose transporters were examined. Moreover, the effects of intracellular signal transduction inhibitors on δ-opioid receptor-regulated [3H]-2-deoxy-D-glucose uptake and protein phosphorylation were investigated.KEY RESULTS Activation of δ-opioid receptors rapidly stimulated [3H]-2-deoxy-D-glucose and 3-O-[methyl-[3H]]-D-glucose uptakes, which were blocked by the GLUT inhibitors cytochalasin B and phloretin. The stimulation of [3H]-2-deoxy-D-glucose uptake that occurred without a change in plasma membrane GLUT1 – required the coupling to Gi/Go proteins – was independent of cAMP and extracellular signal-regulated protein kinases, and was suppressed by blockade of Src and insulin-like growth factor-1 receptor (IGF-1R) tyrosine kinases. Inhibition of phosphatidylinositol 3-kinase (PI3K) by wortmannin or LY294002 and by PI3Kα, but not γ, isoform-selective inhibitors greatly reduced the δ-opioid receptor stimulation of glucose uptake. Moreover, the response was attenuated by overexpressing a dominant-negative kinase-deficient Akt form and by chemical inhibition of Akt. Stimulation of δ-opioid receptors increased protein kinase Cζ/λ (PKCζ/λ) phosphorylation and a selective PKCζ/λ inhibitor slightly reduced opioid stimulation of glucose uptake.CONCLUSIONS AND IMPLICATIONS δ-Opioid receptors stimulated glucose transport probably by enhancing GLUT1 intrinsic activity through a signalling cascade involving Gi/Go, Src, IGF-1R, PI3Kα, Akt and, to a minor extent, PKCζ/λ. This effect may contribute to the opioid regulation of glucose homeostasis in physio-pathological conditions.