IFNL1 rs30461 polymorphism as a risk factor for COVID-19 severity: A cross-sectional study.

INTRODUCTION: The molecular basis of the progression of some COVID-19 patients to worse outcomes is not entirely known. Interferons-lambda-1/interleukin-29 (IFN-λ1/IL-29) is a member of the type III IFNs with a strong antiviral activity. Given the scant data on the potential role of IFN-λ1/IL-29 in COVID-19, we investigated the association of IFN-λ1/IL-29 serum level and the IFNL1 single-nucleotide polymorphism (SNP) (rs30461) with severe course of COVID-19. MATERIAL AND METHODS: This cross-sectional study included 400 COVID-19 patients, in which 262 mild COVID-19 patients and 138 severe COVID-19 patients were recruited and compared. The IFN-λ1/IL-29 serum levels were assessed in both the mild and severe COVID-19 groups. All participants were genotyped for the IFNL1 SNP (rs30461) by allelic discrimination RT-PCR using specific Taqman probes and primers. The associations between IFNL1 variants and risk of severe COVID-19 were examined via the logistic regression analysis. RESULTS: The serum IFN-λ1/IL-29 levels showed no statistically significant difference between mild and severe COVID-19 patients (P = 0.993). The genotype and allele frequencies of IFNL1 SNP (rs30461) were significantly different between the mild and severe groups, in which the minor G allele carried a highly significant risk of severe COVID-19 compared with the wild A allele [OR (95 %CI): 2.1 (1.5-2.9), P ≤ 0.001]. In multivariate analysis, the A/G and G/G genotypes of IFNL1 SNP (rs30461) were independent predictors of COVID-19 severity (P < 0.05). CONCLUSION: The study concluded that the IFNL1 SNP (rs30461) may constitute an independent risk factor for COVID-19 severity.

The association between biomarker angiopoietin-like protein five and obstructive sleep apnea in patients undergoing bariatric surgery.

PURPOSE: Obstructive sleep apnea (OSA) is prevalent in the bariatric population. OSA should be recognized in patients undergoing bariatric surgery preoperatively to prevent peri- and post-operative complications. Lipid metabolism-related biomarkers are associated with OSA. Triglyceride metabolism is, among others, regulated by angiopoietin-like protein five (ANGPTL5). We aimed to evaluate the level of ANGPTL5 in patients with OSA of different severity levels before and after bariatric surgery. METHODS: We performed a single-center prospective cohort study including a consecutive series of patients who underwent bariatric surgery. We collected the clinical data, polysomnography (PSG) or polygraphy (PG) parameters, and plasma derived via venipuncture before and 6 to 12 months after surgery. Lipid profile, glucose levels, and ANGPTL5 levels were assessed. ANGPTL5 levels were measured using an enzyme-linked immunosorbent assay (ELISA). RESULTS: The study included 88 patients for analysis. The patients were divided into two subgroups: no or mild OSA (apnea-hypopnea index (AHI) < 15 events/hour, n = 57) and moderate-to-severe OSA (AHI ≥ 15 events/hour, n = 31). The ANGPTL5 level was higher in the moderate-to-severe OSA group (20.5 [15.6, 26.5] ng/mL) compared to the no or mild OSA group (16.3 [12.5, 19.4] ng/mL) (p = 0.008). A significant positive correlation was observed between ANGPTL5 and AHI (ρ = 0.256, p = 0.017), apnea index (AI) (ρ = 0.318, p = 0.003), and triglyceride levels (ρ = 0.240, p = 0.025). ANGPTL5 levels were reduced significantly after bariatric surgery in both moderate-to-severe OSA (15.6 [10.3, 18.7] ng/mL) and no or mild OSA (13.4 [9.2, 15.8] ng/mL) groups, though to a lower level in the group without or mild OSA. Post-surgery, the significant positive correlation between ANGPTL5 and AHI (ρ = 0.210, p = 0.047), AI (ρ = 0.230, p = 0.034), and triglyceride (ρ = 0.397, p < 0.001) remained. CONCLUSION: The data showed increased levels of ANGPTL5 in patients with moderate-to-severe OSA. Both AHI and ANGPTL5 levels decreased significantly after bariatric surgery. We also report an association between ANGPTL5 levels and OSA severity.

Prognostic impact of toll-like receptors gene polymorphism on outcome of COVID-19 pneumonia: A case-control study.

Toll-like receptor 3 (TLR3) and TLR7 genes are involved in the host immune response against viral infections including SARS-COV-2. This study aimed to investigate the association between the TLR3(rs3775290) and TLR7(rs179008) polymorphisms with the prognosis and susceptibility to COVID-19 pneumonia accompanying SARS-COV-2 infection. This case-control study included 236 individuals: 136 COVID-19 pneumonia patients and 100 age and sex-matched controls. Two polymorphisms (TLR3 rs3775290 and TLR7 rs179008) were genotyped by allelic discrimination through TaqMan real-time PCR. This study also investigated predictors of mortality in COVID-19 pneumonia through logistic regression. The mutant 'T/T' genotypes and the 'T' alleles of TLR3(rs3775290) and TLR7(rs179008) polymorphisms were significantly associated with increased risk of COVID-19 pneumonia. This study did not report association between the mutant 'T/T' genotypes of TLR3(rs3775290) and TLR7(rs179008) and the disease outcome. In multivariate analysis, the independent predictors of mortality in COVID-19 pneumonia were male sex, SPO2 ≤ 82%, INR > 1, LDH ≥ 1000 U/l, and lymphocyte count<900/mm3 (P < 0.05).

Discovery of natural products to block SARS-CoV-2 S-protein interaction with Neuropilin-1 receptor: A molecular dynamics simulation approach.

Neuropilin-1 (NRP1) is a widely expressed cell surface receptor protein characterized by its pleiotropic function. Recent reports highlighted NRP1 as an additional entry point of the SARS-CoV-2 virus, enhancing viral infectivity by interacting with the S-protein of SARS-CoV-2. The ubiquitous distribution and mechanism of action of NRP1 enable the SARS-CoV-2 virus to attack multiple organs in the body simultaneously. Therefore, blocking NRP1 is a potential therapeutic approach against SARS-CoV-2 infection. The current study screened the South African natural compounds database (SANCDB) for molecules that can disrupt the SARS-CoV-2 S protein-NRP1 interaction as a potential antiviral target for SARS-CoV-2 cellular entry. Following excessive screening and validation analysis 3-O-Methylquercetin and Esculetin were identified as potential compounds to disrupt the S-protein-NRP1 interaction. Furthermore, to understand the conformational stability and dynamic features between NRP1 interaction with the selected natural products, we performed 200 ns molecular dynamics (MD) simulations. In addition, molecular mechanics-generalized Born surface area (MM/GBSA) was utilized to calculate the free binding energies of the natural products interacting with NRP1. 3-O-methylquercetin showed an inhibitory effect with binding energies ΔG of -25.52 ±â€¯0.04 kcal/mol to NRP1, indicating the possible disruption of the NRP1-S-protein interaction. Our analysis demonstrated that 3-O-methylquercetin presents a potential antiviral compound against SARS-CoV-2 infectivity. These results set the path for future functional in-vitro and in-vivo studies in SARS-CoV-2 research.

Increased LRG1 Levels in Overweight and Obese Adolescents and Its Association with Obesity Markers, Including Leptin, Chemerin, and High Sensitivity C-Reactive Protein.

Leucine-rich α-2 glycoprotein1 (LRG1) is a member of the leucine-rich repeat (LRR) family that is implicated in multiple diseases, including cancer, aging, and heart failure, as well as diabetes and obesity. LRG1 plays a key role in diet-induced hepatosteatosis and insulin resistance by mediating the crosstalk between adipocytes and hepatocytes. LRG1 also promotes hepatosteatosis by upregulating de novo lipogenesis in the liver and suppressing fatty acid ß-oxidation. In this study, we investigated the association of LRG1 with obesity markers, including leptin and other adipokines in adolescents (11−14 years; n = 425). BMI-for-age classification based on WHO growth charts was used to define obesity. Plasma LRG1 was measured by ELISA, while other markers were measured by multiplexing assay. Median (IQR) of LRG1 levels was higher in obese (30 (25, 38) µg/mL) and overweight (30 (24, 39) µg/mL) adolescents, compared to normal-weight participants (27 (22, 35) µg/mL). The highest tertile of LRG1 had an OR [95% CI] of 2.55 [1.44, 4.53] for obesity. LRG1 was positively correlated to plasma levels of high sensitivity c-reactive protein (HsCRP) (ρ = 0.2), leptin (ρ = 0.2), and chemerin (ρ = 0.24) with p < 0.001. Additionally, it was positively associated with plasma level of IL6 (ρ = 0.17) and IL10 (ρ = 0.14) but not TNF-α. In conclusion, LRG1 levels are increased in obese adolescents and are associated with increased levels of adipogenic markers. These results suggest the usefulness of LRG1 as an early biomarker for obesity and its related pathologies in adolescents.

Fetuin-A levels are increased in the adipose tissue of diabetic obese humans but not in circulation.

BACKGROUND: The hepatokine fetuin-A is linked to obesity and type 2 diabetes, but its presence and expression in adipose tissue remain unclear. In this study, we aimed to assess the circulating levels of fetuin-A and its expression in subcutaneous adipose tissue (SAT) from diabetic and non-diabetic obese subjects and their modulation by exercise. METHODS: SAT and blood were obtained from adults obese (diabetic, n=118 and non-diabetic, n=166) before and after a 3-month exercise program (diabetic, n=40 and non-diabetic, n=36, respectively). Plasma fetuin-A was assayed using ELISA. The presence and expression of fetuin-A in SAT, peripheral blood mononuclear cells (PBMCs) and cell lines (3T3-L1, THP-1, HepG2, RAW 264.7) were analysed using confocal microscopy, immunoblotting and qRT-PCR. RESULTS: Plasma fetuin-A level did not significantly differ between diabetic and non-diabetic obese subjects. However, when the non-diabetic group was divided into metabolically healthy and unhealthy phenotypes, significantly higher fetuin-A level was observed in the unhealthy sub-group. Circulating fetuin-A was mainly associated with glycaemic markers. In SAT, fetuin-A protein level was significantly higher in the diabetic obese subjects but its mRNA was not detected. Similarly, fetuin-A protein was detected in PBMCs, but its mRNA was not. In line with this, the use of various cell lines and culture media indicated that the presence of fetuin-A in SAT and PBMCs was due to its uptake from circulation rather than its endogenous expression. Finally, physical exercise decreased fetuin-A levels in both plasma and SAT in both groups. CONCLUSIONS: Fetuin-A levels increased in association with diabetes in SAT but not in circulation in the obese subjects. Moreover, physical exercise decreased fetuin-A level. Fetuin-A potentially acts as a hepatokine taken up by other tissues, such as adipose tissue.

Physical exercise reduces the expression of RANTES and its CCR5 receptor in the adipose tissue of obese humans.

RANTES and its CCR5 receptor trigger inflammation and its progression to insulin resistance in obese. In the present study, we investigated for the first time the effect of physical exercise on the expression of RANTES and CCR5 in obese humans. Fifty-seven adult nondiabetic subjects (17 lean and 40 obese) were enrolled in a 3-month supervised physical exercise. RANTES and CCR5 expressions were measured in PBMCs and subcutaneous adipose tissue before and after exercise. Circulating plasma levels of RANTES were also investigated. There was a significant increase in RANTES and CCR5 expression in the subcutaneous adipose tissue of obese compared to lean. In PBMCs, however, while the levels of RANTES mRNA and protein were comparable between both groups, CCR5 mRNA was downregulated in obese subjects (P < 0.05). Physical exercise significantly reduced the expression of both RANTES and CCR5 (P < 0.05) in the adipose tissue of obese individuals with a concomitant decrease in the levels of the inflammatory markers TNF- α , IL-6, and P-JNK. Circulating RANTES correlated negatively with anti-inflammatory IL-1 ra (P = 0.001) and positively with proinflammatory IP-10 and TBARS levels (P < 0.05). Therefore, physical exercise may provide an effective approach for combating the deleterious effects associated with obesity through RANTES signaling in the adipose tissue.

Phytic acid attenuates acetaminophen-induced hepatotoxicity via modulating iron-mediated oxidative stress and SIRT-1 expression in mice.

Introduction: Administration of high doses of acetaminophen (APAP) results in liver injury. Oxidative stress and iron overload play roles in the pathogenesis of APAP-induced hepatotoxicity. The present study assessed the potential hepatoprotective effects of phytic acid (PA), a natural antioxidant and iron chelator, on APAP-induced hepatotoxicity and the possible underlying mechanism through its effects on CYP2E1 gene expression, iron homeostasis, oxidative stress, and SIRT-1 expression levels. Methods: Twenty-four adult male albino mice were used in this study. Mice were divided into four groups (six mice in each group): control, APAP-treated, PA-treated and APAP + PA-treated groups. Liver function tests, serum and liver tissue iron load were evaluated in all the study groups. Hepatic tissue homogenates were used to detect oxidative stress markers, including malondialdehyde (MDA) and reduced glutathione (GSH). Histological hepatic evaluation and immunohistochemistry of SIRT-1 were performed. Quantitative real-time PCR was used for the assessment of CYP2E1 and SIRT-1 gene expressions. APAP-induced biochemical and structural hepatic changes were reported. Results: PA administration showed beneficial effects on APAP-induced hepatotoxicity through improvements in liver functions, decreased CYP2E1 gene expression, decreased serum and liver iron load, decreased MDA, increased GSH, increased SIRT-1 expression level and improvement in hepatic architecture. Conclusion: Conclusively, PA can be considered a potential compound that can attenuate acetaminophen-induced hepatotoxicity through its role as an iron chelator and antioxidant, as well as the up-regulation of SIRT-1 and down-regulation of CYP2E1.

Role of chaperones in G protein coupled receptor signaling complex assembly.

G protein coupled receptors are involved in highly efficient and specific activation of signaling pathways. Yet, we do not fully understand the processes required to assemble the different partners of the GPCR signaling complex. In order to address this issue, we need to understand how receptors and their signaling -partners are synthesized, folded and regulated during quality control steps in order to generate functional proteins. Several molecular chaperones are involved in this process for most proteins, including GPCRs. Several membrane proteins require the assembly of different subunits to be functional. In recent years, GPCRs have been shown to form oligomers, which could be interpreted as subunits of a larger complex. Yet, those oligomers would not be functional without the association of other signaling partners; thus, there is a requirement for the specific assembly of the -different partners. In this chapter, we will cover some aspects of the current knowledge about how chaperones are involved in both the formation of GPCR oligomers and in the assembly of the receptors with their signaling complex components.

Artemisinin attenuates type 2 diabetic cardiomyopathy in rats through modulation of AGE-RAGE/HMGB-1 signaling pathway.

Diabetes mellitus is a common metabolic disorder. About two-thirds of diabetic patients develop diabetic cardiomyopathy (DCM), which becomes a challenging issue as it severely threatens the patient's life. Hyperglycemia and the resulting advanced glycated end products (AGE) and their receptor (RAGE)/High Mobility Group Box-1 (HMGB-1) molecular pathway are thought to be key players. Recently, artemisinin (ART) has gained more attention owing to its potent biological activities beyond its antimalarial effect. Herein, we aim to evaluate the effect of ART on DCM and the possible underlying mechanisms. Twenty-four male Sprague-Dawley rats were divided into: control, ART, type 2 diabetic and type 2 diabetic treated with ART groups. At the end of the research, the ECG was recorded, then the heart weight to body weight (HW/BW) ratio, fasting blood glucose, serum insulin and HOMA-IR were evaluated. Cardiac biomarkers (CK-MB and LDH), oxidative stress markers, IL-1ß, AGE, RAGE and HMGB-1 expression were also measured. The heart specimens were stained for H&E as well as Masson's trichrome. DCM induced disturbances in all studied parameters; contrary to this, ART improved these insults. Our study concluded that ART could improve DCM through modulation of the AGE-RAGE/HMGB-1 signaling pathway, with subsequent impacts on oxidative stress, inflammation and fibrosis. ART could therefore be a promising therapy for the management of DCM.

Neurotransmitters in Type 2 Diabetes and the Control of Systemic and Central Energy Balance.

Efficient signal transduction is important in maintaining the function of the nervous system across tissues. An intact neurotransmission process can regulate energy balance through proper communication between neurons and peripheral organs. This ensures that the right neural circuits are activated in the brain to modulate cellular energy homeostasis and systemic metabolic function. Alterations in neurotransmitters secretion can lead to imbalances in appetite, glucose metabolism, sleep, and thermogenesis. Dysregulation in dietary intake is also associated with disruption in neurotransmission and can trigger the onset of type 2 diabetes (T2D) and obesity. In this review, we highlight the various roles of neurotransmitters in regulating energy balance at the systemic level and in the central nervous system. We also address the link between neurotransmission imbalance and the development of T2D as well as perspectives across the fields of neuroscience and metabolism research.

Single nucleotide polymorphisms in vitamin D binding protein and 25-hydroxylase genes affect vitamin D levels in adolescents of Arab ethnicity in Kuwait.

Vitamin D deficiency (VDD) is widespread in the Arab world despite ample sunshine throughout the year. In our previous study, lifestyle and socio-demographic factors could explain only 45% of variability in vitamin D levels in Kuwaiti adolescents, suggesting that genetics might contribute to VDD in this region. Single nucleotide polymorphisms (SNP) in the 25-hydroxylase (CYP2R1) and the GC globulin (GC) genes have been reported to affect vitamin D levels in various ethnic groups in adults. In this study, we investigated the association of two SNPs from GC (rs4588 and rs7041) and three SNPs from CYP2R1 (rs10741657, rs11023374 and rs12794714) with vitamin D levels and VDD in a nationally representative sample of adolescents of Arab ethnicity from Kuwait. Multivariable linear regression, corrected for age, sex, parental education, governorate, body mass index, and exposure to sun, demonstrated that each of the 5 study variants showed significant associations with plasma 25(OH)D levels in one or more of the additive, recessive, and dominant genetic models - the rs10741657 under all the three models, rs12794714 under both the additive and recessive models, rs7041 under the recessive model; and rs4588 and rs11023374 under the dominant model. Minor alleles at rs4588 (T), rs7041 (A), rs11023374 (C), and rs12794714 (A) led to a decrease in plasma 25(OH)D levels - rs4588:[ß (95%CI) = -4.522 (-8.66,-0.38); p=0.033]; rs7041:[ß (95%CI) = -6.139 (-11.12,-1.15); p=0.016]; rs11023374:[ß (95%CI) = -4.296 (-8.18,-0.40); p=0.031]; and rs12794714:[ß (95%CI) = -3.498 (-6.27,-0.72); p=0.014]. Minor allele A at rs10741657 was associated with higher levels of plasma 25(OH)D levels [ß (95%CI) = 4.844 (1.62,8.06); p=0.003)] and lower odds of vitamin D deficiency (OR 0.40; p=0.002). These results suggest that the CYP2R1 and GC SNP variants are partly responsible for the high prevalence of VDD in Kuwait. Genotyping these variants may be considered for the prognosis of VDD in Kuwait.

The miR-668 binding site variant rs1046322 on WFS1 is associated with obesity in Southeast Asians.

The Wolfram syndrome 1 gene (WFS1) is the main causative locus for Wolfram syndrome, an inherited condition characterized by childhood-onset diabetes mellitus, optic atrophy, and deafness. Global genome-wide association studies have listed at least 19 WFS1 variants that are associated with type 2 diabetes (T2D) and metabolic traits. It has been suggested that miRNA binding sites on WFS1 play a critical role in the regulation of the wolframin protein, and loss of WFS1 function may lead to the pathogenesis of diabetes. In the Hungarian population, it was observed that a 3' UTR variant from WFS1, namely rs1046322, influenced the affinity of miR-668 to WFS1 mRNA, and showed a strong association with T2D. In this study, we genotyped a large cohort of 2067 individuals of different ethnicities residing in Kuwait for the WFS1 rs1046322 polymorphism. The cohort included 362 Southeast Asians (SEA), 1045 Arabs, and 660 South Asians (SA). Upon performing genetic association tests, we observed significant associations between the rs1046322 SNP and obesity traits in the SEA population, but not in the Arab or SA populations. The associated traits in SEA cohort were body mass index, BMI (ß=1.562, P-value=0.0035, Pemp=0.0072), waist circumference, WC (ß=3.163, P-value=0.0197, Pemp=0.0388) and triglyceride, TGL (ß=0.224, P-value=0.0340). The association with BMI remained statistically significant even after multiple testing correction. Among the SEA individuals, carriers of the effect allele at the SNP had significantly higher BMI [mean of 27.63 (3.6) Kg/m2], WC [mean of 89.9 (8.1) cm], and TGL levels [mean of 1.672 (0.8) mmol/l] than non-carriers of the effect allele. Our findings suggest a role for WFS1 in obesity, which is a risk factor for diabetes. The study also emphasizes the significant role the ethnic background may play in determining the effect of genetic variants on susceptibility to metabolic diseases.

Probiotics Attenuate Myopathic Changes in Aging Rats via Activation of the Myogenic Stellate Cells.

Aging represents a complex biological process associated with decline in skeletal muscle functions. Aging impairs satellite cells that serve as muscle progenitor cells. Probiotic supplementation may have many beneficial effects via various mechanisms. We examined the possible effects of probiotics in stimulating the proliferation of myogenic stellate cells in aging rats. Twenty-four male albino Sprague-Dawley rats were classified equally into four groups: adult control, old control, adult + probiotics, and old + probiotics. Probiotics (Lactobacillus LB) were administered gavage at a dose of 1 ml (1 × 109 CFU/ml/day) for 4 weeks. A significant increase in the relative gastrocnemius weight ratio and improvement of contractile parameters was detected in the old + probiotics group (0.6 ± 0.01) compared to the old control group (0.47 ± 0.01; P < 0.001). Probiotics significantly upregulated the activities of GSH, while NO and MDA were markedly decreased compared to control groups (P ≤ 0.001). Also, probiotics increased the mRNA and protein expressions of myogenin and CD34 (P < 0.05) as determined by real-time PCR and immunohistochemistry. Moreover, the old + probiotics group showed apparent restoration of the connective tissue spaces, reflecting the all-beneficial effects of probiotics. Our findings indicated that probiotics attenuated myopathic changes in aging rats probably through activation of the myogenic stellate cells. Probiotics improved the muscle weight, function, antioxidant activity, and myogenic transcription factors of the skeletal muscle.

LRG1 Associates with Iron Deficiency Anemia Markers in Adolescents.

Leucine-rich α-2 glycoprotein1 (LRG1) has been shown to be associated with several health conditions; however, its association with iron deficiency anemia, especially in children, has not been previously explored. In this study, we investigated the association between LRG1 and several iron deficiency anemia markers, including hemoglobin (Hb), albumin, red cell distribution width (RDW), iron, ferritin, and Hb transferrin saturation. A total of 431 participants were included in this analysis aged between 11 and 14 years. Higher LRG1 levels were observed in children diagnosed with anemia [31.1 (24.6, 43.2) µg/mL] compared to non-anemic children [29.2 (22.7-35.95) µg/mL]. Statistically significant differences of LRG1 level across the three groups (tertiles) of Hb, iron, transferrin saturation, albumin, RDW, ferritin, and WBC were observed. Strong negative correlations were observed between LRG1 and Hb (Spearman's rho = -0.11, p = 0.021), albumin (Spearman's rho = -0.24, p < 0.001), iron (Spearman's rho = -0.25, p < 0.001), and Hb transferrin saturation (Spearman's rho = -0.24, p < 0.001), whereas circulating LRG1 levels were positively associated with RDW (Spearman's rho = 0.21, p < 0.001). In conclusion, our findings demonstrate for the first time the strong association between iron deficiency anemia markers and LRG1 in otherwise healthy school-aged children. However, further studies are needed to corroborate those results and to look for similar associations in other population subgroups.

Adolescent obesity and ANGPTL8: correlations with high sensitivity C-reactive protein, leptin, and chemerin.

Angiopoietin-like proteins (ANGPTLs) mediate many metabolic functions. We had recently reported increased plasma levels of ANGPTL8 in obese adults of Arab ethnicity. However, data on ANGPTL8 levels in adolescent obesity is lacking. Arab population is characterized by a rapid transition, due to sudden wealth seen in the post-oil era, in lifestyle, food habits and extent of physical activity. We adopted a cross-sectional study on Arab adolescents from Kuwait to examine the role of ANGPTL8 in adolescent obesity. The study cohort included 452 adolescents, aged 11-14 years, recruited from Middle Schools across Kuwait. BMI-for-age growth charts were used to categorize adolescents as normal-weight, overweight, and obese. ELISA and bead-based multiplexing assays were used to measure plasma levels of ANGPTL8 and other inflammation and obesity-related biomarkers. Data analysis showed significant differences in the plasma levels of ANGPTL8 among the three subgroups, with a significant increase in overweight and obese children compared to normal-weight children. This observation persisted even when the analysis was stratified by sex. Multinomial logistic regression analysis illustrated that adolescents with higher levels of ANGPTL8 were 7 times more likely to become obese and twice as likely to be overweight. ANGPTL8 levels were correlated with those of hsCRP, leptin and chemerin. ANGPTL8 level had a reasonable prognostic power for obesity with an AUC of 0.703 (95%-CI=0.648-0.759). These observations relating to increased ANGPTL8 levels corresponding to increased BMI-for-age z-scores indicate that ANGPTL8, along with hsCRP, leptin and chemerin, could play a role in the early stages of obesity development in children. ANGPTL8 is a potential early marker for adolescent obesity and is associated with well-known obesity and inflammatory markers.

Rab1 interacts directly with the ß2-adrenergic receptor to regulate receptor anterograde trafficking.

Very little is understood about the trafficking of G protein-coupled receptors (GPCRs) from the endoplasmic reticulum (ER) to the plasma membrane. Rab guanosine triphosphatases (GTPases) are known to participate in the trafficking of various GPCRs via a direct interaction during the endocytic pathway, but whether this occurs in the anterograde pathway is unknown. We evaluated the potential interaction of Rab1, a GTPase known to regulate ß2-adrenergic receptor (ß2AR) trafficking, and its effect on export from the ER. Our results show that GTP-bound Rab1 interacts with the F(x)(6)LL motif of ß2AR. Receptors lacking the interaction motif fail to traffic properly, suggesting that a direct interaction with Rab1 is required for ß2AR anterograde trafficking.

Structural analysis of setmelanotide binding to MC4R variants in comparison to wild-type receptor.

AIMS: Melanocortin 4 receptor (MC4R) has a well-established role in regulating appetite, food intake and energy homeostasis. Setmelanotide is an MC4R agonist currently approved for weight loss in obese adults and children with mutations in components of the leptin-melanocortin pathway. This study aims to compare structural and functional aspects of the physiological MC4R agonist α-melanocyte-stimulating hormone (α-MSH) with setmelanotide. We also aim to show the binding affinity of setmelanotide to known MC4R human missense mutations associated with obesity. MAIN METHODS: AutoDock Vina was used in the structural analysis to calculate induced fit docking scores of ligand binding to MC4R wild type or the selected variants. HEK293-MC4R were utilized in the functional analysis of MC4R-actiavted pathways upon stimulating with α-MSH or setmelanotide. KEY FINDINGS: Our data shows that setmelanotide has a higher potency for cAMP formation and a weaker effect on ERK1/2 phosphorylation when compared to α-MSH indicating functional selectivity otherwise known as biased agonism. We also present structural data showing that setmelanotide has a higher binding affinity to MC4R compared to α-MSH. Lastly, we show that two loss-of-function and two gain-of-function MC4R variants change the conformation not only of the ligand binding pocket of the receptor but also of the peptide when bound to the receptor because the interaction network and the residues involved in the binding are altered. SIGNIFICANCE: Taken together, our study provides important insights into the diversity of MC4R signaling pathways which will facilitate the development of personalized anti-obesity drugs via refining MC4R agonists.

Potential Role of N-Cadherin in Diagnosis and Prognosis of Diabetic Nephropathy.

Diabetic nephropathy (DN) is a serious complication of diabetes affecting about half the people with diabetes and the leading cause of end stage renal disease (ESRD). Albuminuria and creatinine levels are currently the classic markers for the diagnosis of DN. However, many shortcomings are arising from the use of these markers mainly because they are not specific to DN and their levels are altered by multiple non-pathological factors. Therefore, the aim of this study is to identify better markers for the accurate and early diagnosis of DN. The study was performed on 159 subjects including 42 control subjects, 50 T2D without DN and 67 T2D subjects with DN. Our data show that circulating N-cadherin levels are significantly higher in the diabetic patients who are diagnosed with DN (842.6 ± 98.6 mg/l) compared to the diabetic patients who do not have DN (470.8 ± 111.5 mg/l) and the non-diabetic control group (412.6 ± 41.8 mg/l). We also report that this increase occurs early during the developmental stages of the disease since N-cadherin levels are significantly elevated in the microalbuminuric patients when compared to the healthy control group. In addition, we show a significant correlation between N-cadherin levels and renal markers including creatinine (in serum and urine), urea and eGFR in all the diabetic patients. In conclusion, our study presents N-cadherin as a novel marker for diabetic nephropathy that can be used as a valuable prognostic and diagnostic tool to slow down or even inhibit ESRD.

Urocortin Neuropeptide Levels Are Impaired in the PBMCs of Overweight Children.

The corticotropin-releasing hormone (CRH) and urocortins (UCNs) have been implicated in energy homeostasis and the cellular stress response. However, the expression of these neuropeptides in children remains unclear. Therefore, we determined the impact of obesity on their expression in 40 children who were normal weight, overweight, and had obesity. Peripheral blood mononuclear cells (PBMCs) and plasma were used to assess the expression of neuropeptides. THP1 cells were treated with 25 mM glucose and 200 µM palmitate, and gene expression was measured by real-time polymerase chain reaction (RT-PCR). Transcript levels of neuropeptides were decreased in PBMCs from children with increased body mass index as indicated by a significant decrease in UCN1, UCN3, and CRH mRNA in overweight and obese children. UCN3 mRNA expression was strongly correlated with UCN1, UCN2, and CRH. Exposure of THP1 cells to palmitate or a combination of high glucose and palmitate for 24 h increased CRH, UCN2, and UCN3 mRNA expression with concomitant increased levels of inflammatory and endoplasmic reticulum stress markers, suggesting a crosstalk between these neuropeptides and the cellular stress response. The differential impairment of the transcript levels of CRH and UCNs in PBMCs from overweight and obese children highlights their involvement in obesity-related metabolic and cellular stress.