Global analysis of urinary extracellular vesicle small RNAs in autosomal dominant polycystic kidney disease.

BACKGROUND: Autosomal dominant polycystic kidney disease (ADPKD) is the most prevalent monogenic renal disease progressing to end-stage renal disease. There is a pressing need for the identification of early ADPKD biomarkers to enable timely intervention and the development of effective therapeutic approaches. Here, we profiled human urinary extracellular vesicles small RNAs by small RNA sequencing in patients with ADPKD and compared their differential expression considering healthy control individuals to identify dysregulated small RNAs and analyze downstream interaction to gain insight about molecular pathophysiology. METHODS: This is a cross-sectional study where urine samples were collected from a total of 23 PKD1-ADPKD patients and 28 healthy individuals. Urinary extracellular vesicles were purified, and small RNA was isolated and sequenced. Differentially expressed Small RNA were identified and functional enrichment analysis of the critical miRNAs was performed to identify driver genes and affected pathways. RESULTS: miR-320b, miR-320c, miR-146a-5p, miR-199b-3p, miR-671-5p, miR-1246, miR-8485, miR-3656, has_piR_020497, has_piR_020496 and has_piR_016271 were significantly upregulated in ADPKD patient urine extracellular vesicles and miRNA-29c was significantly downregulated. Five 'driver' target genes (FBRS, EDC3, FMNL3, CTNNBIP1 and KMT2A) were identified. CONCLUSIONS: The findings of the present study make significant contributions to the understanding of ADPKD pathogenesis and to the identification of novel biomarkers and potential drug targets aimed at slowing disease progression in ADPKD.

PKD1 Truncating Mutations Accelerate eGFR Decline in Autosomal Dominant Polycystic Kidney Disease Patients.

INTRODUCTION: Autosomal dominant polycystic kidney disease (ADPKD) is a monogenic disease characterized by the accumulation of fluid-filled cysts in the kidneys, leading to renal volume enlargement and progressive kidney function impairment. Disease severity, though, may vary due to allelic and genetic heterogeneity. This study aimed to determine genotype-phenotype correlations between PKD1 truncating and non-truncating mutations and kidney function decline in ADPKD patients. METHODS: We established a single-center retrospective cohort study in Kuwait where we followed every patient with a confirmed PKD1-ADPKD diagnosis clinically and genetically. Renal function tests were performed annually. We fitted generalized additive mixed effects models with random intercepts for each individual to analyze repeated measures of kidney function across mutation type. We then calculated survival time to kidney failure in a cox proportional hazards model. Models were adjusted for sex, age at visit, and birth year. RESULTS: The study included 22 truncating and 20 non-truncating (42 total) patients followed for an average of 6.6 years (range: 1-12 years). Those with PKD1 truncating mutations had a more rapid rate of eGFR decline (-4.7 mL/min/1.73 m2 per year; 95% CI: -5.0, -4.4) compared to patients with PKD1 non-truncating mutations (-3.5 mL/min/1.73 m2 per year; 95% CI: -4.0, -3.1) (p for interaction <0.001). Kaplan-Meier survival analysis of time to kidney failure showed that patients with PKD1 truncating mutations had a shorter renal survival time (median 51 years) compared to those with non-truncating mutations (median 56 years) (P for log-rank = 0.008). CONCLUSION: In longitudinal and survival analyses, patients with PKD1 truncating mutations showed a faster decline in kidney function compared to patients PKD1 non-truncating mutations. Early identification of patients with PKD1 truncating mutations can, at best, inform early clinical interventions or, at least, help suggest aggressive monitoring.

mTOR: Its Critical Role in Metabolic Diseases, Cancer, and the Aging Process.

The mammalian target of rapamycin (mTOR) is a pivotal regulator, integrating diverse environmental signals to control fundamental cellular functions, such as protein synthesis, cell growth, survival, and apoptosis. Embedded in a complex network of signaling pathways, mTOR dysregulation is implicated in the onset and progression of a range of human diseases, including metabolic disorders such as diabetes and cardiovascular diseases, as well as various cancers. mTOR also has a notable role in aging. Given its extensive biological impact, mTOR signaling is a prime therapeutic target for addressing these complex conditions. The development of mTOR inhibitors has proven advantageous in numerous research domains. This review delves into the significance of mTOR signaling, highlighting the critical components of this intricate network that contribute to disease. Additionally, it addresses the latest findings on mTOR inhibitors and their clinical implications. The review also emphasizes the importance of developing more effective next-generation mTOR inhibitors with dual functions to efficiently target the mTOR pathways. A comprehensive understanding of mTOR signaling will enable the development of effective therapeutic strategies for managing diseases associated with mTOR dysregulation.

Investigating the Role of FABP4 in Diabetes and Obesity and the Influence of Age and Ethnicity: A Comprehensive Analysis of a Cohort from the KEDP-Study.

Adipocyte P2 (aP2), also known as FABP4, is an adipokine that adipose tissue produces and expresses in macrophages. Its primary role is to facilitate the transportation of fatty acids across cell membranes. Numerous studies have reported associations between FABP4 and the development of metabolic disorders. However, there is limited knowledge regarding FABP4 expression in diabetes and obesity, especially about different age groups, genders, and ethnicities. This study aims to investigate the association between FABP4 levels, diabetes mellitus, and obesity within various ethnic groups. We measured plasma FABP4 concentrations in a cohort of 2083 patients from the KDEP study and gathered anthropometric data. Additionally, we collected and analyzed clinical, biochemical, and glycemic markers using multivariate regression analysis. The average FABP4 concentration was significantly higher in female participants than in males (18.8 ng/mL vs. 14.4 ng/mL, p < 0.001, respectively), and in those over 50 years old compared to those under 50 years of age (19.3 ng/mL vs. 16.2 ng/mL, p < 0.001, respectively). In this study, significant positive associations were found between the plasma level of FABP4 and obesity markers: BMI (r = 0.496, p < 0.001), hip circumference (r = 0.463, p < 0.001), and waist circumference (WC) (r = 0.436, p < 0.001). Similar observations were also seen with glycemic markers, which included HbA1c (r = 0.126, p < 0.001), fasting blood glucose (FBG) (r = 0.184, p < 0.001), fasting insulin (r = 0.326, p < 0.001), and HOMA-IR (r = 0.333, p < 0.001). Importantly, these associations remained significant even after adjusting for age, gender, and ethnicity. Furthermore, FABP4 levels were negatively associated with male gender (ß: -3.85, 95% CI: -4.92, -2.77, p < 0.001), and positively associated with age (ß: 0.14, 95% CI: 0.096, 0.183, p < 0.001), BMI (ß: 0.74, 95% CI: 0.644, 0.836, p < 0.001), and fasting insulin (ß: 0.115, 95% CI: 0.091, 0.138, p < 0.001). In this study, plasma FABP4 levels were significantly higher in diabetic and obese participants, and they were strongly influenced by age, gender, and ethnicity. These findings suggest that FABP4 may serve as a valuable prognostic and diagnostic marker for obesity and diabetes, particularly among female patients, individuals over 50 years old, and specific ethnic groups.

Long-Term Mortality and SGLT2 Inhibitors in Type 2 Diabetes with and without Renal Impairment: An Observational Cohort Study.

AIM: Sodium-glucose co-transporter 2 (SGLT2) inhibitors have emerged as a vital part of management of type 2 diabetes, as they have been shown to have both cardiovascular and renal benefits along with an improved survival rate in several randomized clinical trials. We designed a retrospective cohort study to investigate the impact of SGLT2 inhibitors on mortality among type 2 diabetes patients. METHODS: Patients with type 2 diabetes who presented to the Dasman Diabetes Institute in Kuwait were followed from January 1st, 2015, until January 20th, 2023. To control for non-random allocation of SGLT2 inhibitors and measured confounders, we performed one-to-one propensity score matching and evaluated outcomes in the matched cohorts using a Cox proportional hazards model. The primary treatment variable was SGLT2 inhibitor use; time to mortality from any cause was used as the outcome of interest. RESULTS: 1,551 patients were taking SGLT2 inhibitors, and 1,687 patients were not. After propensity score matching, 845 patients were on SGLT2 inhibitors, and 845 patients were not. In post-matching analysis, all-cause mortality was higher among patients who did not take SGLT2 inhibitors compared to patients taking SGLT2 inhibitors (5.2 vs. 2.1%, p = 0.0012). The hazard ratio of all-cause mortality in patients taking SGLT2 inhibitors was 0.42 (95% confidence interval [95% CI], 0.24-0.72). Additional adjustment of matching factors did not change the results. CONCLUSION: This observational study demonstrated substantial long-term reduction in mortality risk among patients with type 2 diabetes treated with SGLT2 inhibitors. This is irrespective of the stage of their renal diseases or GLP1 agonist.

Plasma insulin is required for the increase in plasma angiopoietin-like protein 8 in response to nutrient ingestion.

BACKGROUND: Plasma levels of angiopoietin-like protein 8 (ANGPTL8) are regulated by feeding and they increase following glucose ingestion. Because both plasma glucose and insulin increase following food ingestion, we aimed to determine whether the increase in plasma insulin and glucose or both are responsible for the increase in ANGPTL8 levels. METHODS: ANGPTL8 levels were measured in 30 subjects, 14 with impaired fasting glucose (IFG), and 16 with normal fasting glucose (NFG); the subjects received 75g glucose oral Glucose tolerance test (OGTT), multistep euglycaemic hyperinsulinemic clamp and hyperglycaemic clamp with pancreatic clamp. RESULTS: Subjects with IFG had significantly higher ANGPTL8 than NGT subjects during the fasting state (p < 0.05). During the OGTT, plasma ANGPTL8 concentration increased by 62% above the fasting level (p < 0.0001), and the increase above fasting in ANGPTL8 levels was similar in NFG and IFG individuals. During the multistep insulin clamp, there was a dose-dependent increase in plasma ANGPTL8 concentration. During the 2-step hyperglycaemic clamp, the rise in plasma glucose concentration failed to cause any change in the plasma ANGPTL8 concentration from baseline. CONCLUSIONS: In response to nutrient ingestion, ANGPTL8 level increased due to increased plasma insulin concentration, not to the rise in plasma glucose. The incremental increase above baseline in plasma ANGLPTL8 during OGTT was comparable between people with normal glucose tolerance and IFG.

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.

Investigating the Relationship between Obstructive Sleep Apnoea, Inflammation and Cardio-Metabolic Diseases.

Obstructive sleep apnoea (OSA) is a prevalent underdiagnosed disorder whose incidence increases with age and weight. Uniquely characterised by frequent breathing interruptions during sleep-known as intermittent hypoxia (IH)-OSA disrupts the circadian rhythm. Patients with OSA have repeated episodes of hypoxia and reoxygenation, leading to systemic consequences. OSA consequences range from apparent symptoms like excessive daytime sleepiness, neurocognitive deterioration and decreased quality of life to pathological complications characterised by elevated biomarkers linked to endocrine-metabolic and cardiovascular changes. OSA is a well-recognized risk factor for cardiovascular and cerebrovascular diseases. Furthermore, OSA is linked to other conditions that worsen cardiovascular outcomes, such as obesity. The relationship between OSA and obesity is complex and reciprocal, involving interaction between biological and lifestyle factors. The pathogenesis of both OSA and obesity involve oxidative stress, inflammation and metabolic dysregulation. The current medical practice uses continuous positive airway pressure (CPAP) as the gold standard tool to manage OSA. It has been shown to improve symptoms and cardiac function, reduce cardiovascular risk and normalise biomarkers. Nonetheless, a full understanding of the factors involved in the deleterious effects of OSA and the best methods to eliminate their occurrence are still poorly understood. In this review, we present the factors and evidence linking OSA to increased risk of cardiovascular conditions.

Increased Levels of Circulating IGFBP4 and ANGPTL8 with a Prospective Role in Diabetic Nephropathy.

Diabetic nephropathy (DN) is a complicated condition related to type 2 diabetes mellitus (T2D). ANGPTL8 is a hepatic protein highlighted as a risk factor for DN in patients with T2D; additionally, recent evidence from DN studies supports the involvement of growth hormone/IGF/IGF-binding protein axis constituents. The potential link between ANGPTL8 and IGFBPs in DN has not been explored before. Here, we assessed changes in the circulating ANGPTL8 levels in patients with DN and its association with IGFBP-1, -3, and -4. Our data revealed a significant rise in circulating ANGPTL8 in people with DN, 4443.35 ± 396 ng/mL compared to 2059.73 ± 216 ng/mL in people with T2D (p < 0.001). Similarly, levels of IGFBP-3 and -4 were significantly higher in people with DN compared to the T2D group. Interestingly, the rise in ANGPTL8 levels correlated positively with IGFBP-4 levels in T2DM patients with DN (p < 0.001) and this significant correlation disappeared in T2DM patients without DN. It also correlated positively with serum creatinine and negatively with the estimated glomerular filtration rate (eGFR, All < 0.05). The area under the curve (AUC) on receiver operating characteristic (ROC) analysis of the combination of ANGPTL8 and IGFBP4 was 0.76 (0.69-0.84), p < 0.001, and the specificity was 85.9%. In conclusion, our results showed a significant increase in ANGPTL8 in patients with DN that correlated exclusively with IGFBP-4, implicating a potential role of both proteins in the pathophysiology of DN. Our findings highlight the significance of these biomarkers, suggesting them as promising diagnostic molecules for the detection of diabetic nephropathy.

Increased Glucagon Immunoreactivity in a Rat Model of Diet-induced Obesity following Sleeve Gastrectomy.

OBJECTIVE: Bariatric surgery is currently the most effective treatment for obesity, and procedures such as Roux-en Y gastric bypass and sleeve gastrectomy (SG) also result in rapid improvements in insulin sensitivity and glucose tolerance. In addition, these procedures cause changes in the secretion of various gut-derived hormones. The role these hormones play in the mechanism of the beneficial effects of bariatric surgery is still debated, but nonetheless, their importance provides inspiration for novel obesity-targeted pharmacotherapies. METHODS: Male Sprague Dawley rats were fed either regular chow or a cafeteria diet to induce obesity. A sub-group of the obese animals then underwent either sham surgery or SG. RESULTS: Following a 4-week recovery period, SG rats weighed significantly less than obese or sham-operated rats. Improvements in glucose tolerance and insulin sensitivity also occurred in the SG group, but these were not always statistically significant. We measured the intracellular lipid content of liver samples and found that obese rats showed signs of non-alcoholic fatty liver disease, which were significantly ameliorated by SG. There were significantly higher glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP) responses to a standard mixed meal in the SG group, as well as paradoxically higher glucagon secretion. CONCLUSION: These data highlight the need for more specific anti-glucagon antibodies to characterize the changes in proglucagon-derived peptide concentrations that occur following SG. Further studies are required to determine whether these peptides contribute to the therapeutic effects of SG.

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.

Development of a clinical risk score to predict death in patients with COVID-19.

OBJECTIVE: To build a clinical risk score to aid risk stratification among hospitalised COVID-19 patients. METHODS: The score was built using data of 417 consecutive COVID-19 in patients from Kuwait. Risk factors for COVID-19 mortality were identified by multivariate logistic regressions and assigned weighted points proportional to their beta coefficient values. A final score was obtained for each patient and tested against death to calculate an Receiver-operating characteristic curve. Youden's index was used to determine the cut-off value for death prediction risk. The score was internally validated using another COVID-19 Kuwaiti-patient cohort of 923 patients. External validation was carried out using 178 patients from the Italian CoViDiab cohort. RESULTS: Deceased COVID-19 patients more likely showed glucose levels of 7.0-11.1 mmol/L (34.4%, p < 0.0001) or >11.1 mmol/L (44.3%, p < 0.0001), and comorbidities such as diabetes and hypertension compared to those who survived (39.3% vs. 20.4% [p = 0.0027] and 45.9% vs. 26.6% [p = 0.0036], respectively). The risk factors for in-hospital mortality in the final model were gender, nationality, asthma, and glucose categories (<5.0, 5.5-6.9, 7.0-11.1, or 11.1 > mmol/L). A score of ≥5.5 points predicted death with 75% sensitivity and 86.3% specificity (area under the curve (AUC) 0.901). Internal validation resulted in an AUC of 0.826, and external validation showed an AUC of 0.687. CONCLUSION: This clinical risk score was built with easy-to-collect data and had good probability of predicting in-hospital death among COVID-19 patients.

Association of significantly elevated plasma levels of NGAL and IGFBP4 in patients with diabetic nephropathy.

BACKGROUND: Diabetic nephropathy (DN) is a type of progressive kidney disease affecting approximately 40% of patients with diabetes. Current DN diagnostic criteria predominantly rely on albuminuria and serum creatinine (sCr) levels. However, the specificity and reliability of both markers are limited. Hence, reliable biomarkers are required for early diagnosis to effectively manage DN progression. METHODS: In this study, a cohort of 159 individuals were clinically evaluated and the plasma levels of NGAL, IGFBP-1, IGFBP-3, and IGFBP-4 were determined using Multiplexing Assays. Additionally, the association between the plasma levels of NGAL, IGFBP-1, IGFBP-3, and IGFBP-4 in patients with DN were compared to those in patients with T2D without kidney disease and control participants. RESULTS: Circulating level of NGAL were significantly higher in people with DN compared to people with T2D and non-diabetic groups (92.76 ± 7.5, 57.22 ± 8.7, and 52.47 ± 2.9 mg/L, respectively; p <  0.0001). IGFBP-4 showed a similar pattern, where it was highest in people with DN (795.61 ng/ml ±130.7) compared to T2D and non-diabetic people (374.56 ng/ml ±86.8, 273.06 ng/ml ±27.8 respectively, ANOVA p <  0.01). The data from this study shows a significant positive correlation between NGAL and IGFBP-4 in people with DN (ρ = .620, p <  0.005). IGFBP-4 also correlated positively with creatinine level and negatively with eGFR, in people with DN supporting its involvement in DN. CONCLUSION: The data from this study shows a parallel increase in the plasma levels of NGAL and IGFBP-4 in DN. This highlights the potential to use these markers for early diagnosis of DN.

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.

Genome-wide landscape establishes novel association signals for metabolic traits in the Arab population.

While the Arabian population has a high prevalence of metabolic disorders, it has not been included in global studies that identify genetic risk loci for metabolic traits. Determining the transferability of such largely Euro-centric established risk loci is essential to transfer the research tools/resources, and drug targets generated by global studies to a broad range of ethnic populations. Further, consideration of populations such as Arabs, that are characterized by consanguinity and a high level of inbreeding, can lead to identification of novel risk loci. We imputed published GWAS data from two Kuwaiti Arab cohorts (n = 1434 and 1298) to the 1000 Genomes Project haplotypes and performed meta-analysis for associations with 13 metabolic traits. We compared the observed association signals with those established for metabolic traits. Our study highlighted 70 variants from 9 different genes, some of which have established links to metabolic disorders. By relaxing the genome-wide significance threshold, we identified 'novel' risk variants from 11 genes for metabolic traits. Many novel risk variant association signals were observed at or borderline to genome-wide significance. Furthermore, 349 previously established variants from 187 genes were validated in our study. Pleiotropic effect of risk variants on multiple metabolic traits were observed. Fine-mapping illuminated rs7838666/CSMD1 rs1864163/CETP and rs112861901/[INTS10,LPL] as candidate causal variants influencing fasting plasma glucose and high-density lipoprotein levels. Computational functional analysis identified a variety of gene regulatory signals around several variants. This study enlarges the population ancestry diversity of available GWAS and elucidates new variants in an ethnic group burdened with metabolic disorders.

Preliminary Structural Data Revealed That the SARS-CoV-2 B.1.617 Variant's RBD Binds to ACE2 Receptor Stronger Than the Wild Type to Enhance the Infectivity.

The evolution of new SARS-CoV-2 variants around the globe has made the COVID-19 pandemic more worrisome, further pressuring the health care system and immunity. Novel variations that are unique to the receptor-binding motif (RBM) of the receptor-binding domain (RBD) spike glycoprotein, i. e. L452R-E484Q, may play a different role in the B.1.617 (also known as G/452R.V3) variant's pathogenicity and better survival compared to the wild type. Therefore, a thorough analysis is needed to understand the impact of these mutations on binding with host receptor (RBD) and to guide new therapeutics development. In this study, we used structural and biomolecular simulation techniques to explore the impact of specific mutations (L452R-E484Q) in the B.1.617 variant on the binding of RBD to the host receptor ACE2. Our analysis revealed that the B.1.617 variant possesses different dynamic behaviours by altering dynamic-stability, residual flexibility and structural compactness. Moreover, the new variant had altered the bonding network and structural-dynamics properties significantly. MM/GBSA technique was used, which further established the binding differences between the wild type and B.1.617 variant. In conclusion, this study provides a strong impetus to develop novel drugs against the new SARS-CoV-2 variants.

Increased expression level of ANGPTL8 in white adipose tissue under acute and chronic cold treatment.

BACKGROUND: Angiopoietin-like proteins (ANGPTL), primarily 3, 4, and 8, play a major role in maintaining energy homeostasis by regulating triglyceride metabolism. This study evaluated the level of ANGPTL3, 4, and 8 in the liver, brown adipose tissue (BAT), and subcutaneous white adipose tissue (SAT) of mice maintained under acute and chronic cold conditions. METHODS: C57BL/6J mice were exposed to cold temperature (4 °C) for 10 days with food provided ad libitum. Animal tissues were harvested at Day 0 (Control group, n = 5) and Days 1, 3, 5, and 10 (cold treatment groups, n = 10 per group). The expression levels of various genes were measured in the liver, SAT, and BAT. ANGPTL3, 4, and 8 expressions were measured in the liver. ANGPTL4, 8, and genes involved in browning and lipid metabolism [uncoupling protein 1 (UCP1), lipoprotein lipase (LPL), and adipose triglyceride lipase (ATGL)] were measured in SAT and BAT. Western blotting (WB) analysis and immunohistochemistry (IHC) were performed to confirm ANGPTL8 expression in these tissues. RESULTS: The expressions of ANGPTL3 and 8 mRNA were significantly reduced in mouse liver tissues after cold treatment (P < 0.05); however, the expression of ANGPTL4 was not significantly altered. In BAT, ANGPTL8 expression was unchanged after cold treatment, whereas ANGPTL4 expression was significantly reduced (P < 0.05). ANGPTL4 levels were also significantly reduced in SAT, whereas ANGPTL8 gene expression exhibited over a 5-fold increase. Similarly, UCP1 gene expression was also significantly increased in SAT. The mRNA levels of LPL and ATGL showed an initial increase followed by a gradual decrease with an increase in the days of cold exposure. ANGPTL8 protein overexpression was further confirmed by WB and IHC. CONCLUSIONS: This study shows that exposure to acute and chronic cold treatment results in the differential expression of ANGPTL proteins in the liver and adipose tissues (SAT and BAT). The results show a significant reduction in ANGPTL4 in BAT, which is linked to improved thermogenesis in response to acute cold exposure. ANGPTL8 was activated under acute and chronic cold conditions in SAT, suggesting that it is involved in regulating lipolysis and enhancing SAT browning.

The Role of Lipid Metabolism in COVID-19 Virus Infection and as a Drug Target.

The current Coronavirus disease 2019 or COVID-19 pandemic has infected over two million people and resulted in the death of over one hundred thousand people at the time of writing this review. The disease is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Even though multiple vaccines and treatments are under development so far, the disease is only slowing down under extreme social distancing measures that are difficult to maintain. SARS-COV-2 is an enveloped virus that is surrounded by a lipid bilayer. Lipids are fundamental cell components that play various biological roles ranging from being a structural building block to a signaling molecule as well as a central energy store. The role lipids play in viral infection involves the fusion of the viral membrane to the host cell, viral replication, and viral endocytosis and exocytosis. Since lipids play a crucial function in the viral life cycle, we asked whether drugs targeting lipid metabolism, such as statins, can be utilized against SARS-CoV-2 and other viruses. In this review, we discuss the role of lipid metabolism in viral infection as well as the possibility of targeting lipid metabolism to interfere with the viral life cycle.

Soluble Epoxide Hydrolase 2 Expression Is Elevated in Obese Humans and Decreased by Physical Activity.

Epoxide hydrolase 2 (EPHX2) is an emerging therapeutic target in several immunometabolic disorders. EPHX2 metabolizes anti-inflammatory epoxyeicosatrienoic acids into pro-inflammatory diols. The contribution of EPHX2 activity to human obesity remains unexplored. We compared the expression of EPHX2 between lean and obese humans (n = 20 each) in subcutaneous adipose tissue (SAT) and peripheral blood mononuclear cells (PBMCs) using RT-PCR, Western Blot analysis, immunohistochemistry, and confocal microscopy before and after a 3-month physical activity regimen. We also assessed EPHX2 levels during preadipocyte differentiation in humans and mice. EPHX2 mRNA and protein expression were significantly elevated in obese subjects, with concomitant elevated endoplasmic reticulum (ER) stress components (the 78-kDa glucose-regulated protein; GRP78, and the Activating transcription factor 6; ATF6) and inflammatory markers (Tumor necrosis factor-α; TNFα, and Interleukin 6; IL6) as compared to controls (p < 0.05). EPHX2 mRNA levels strongly correlated with adiposity markers. In obese individuals, physical activity attenuated EPHX2 expression levels in both the SAT and PBMCs, with a parallel decrease in ER stress and inflammation markers. EPHX2 expression was also elevated during differentiation of both human primary and 3T3-L1 mouse preadipocytes. Mediators of cellular stress (palmitate, homocysteine, and macrophage culture medium) also increased EPHX2 expression in 3T3-L1 preadipocytes. Our findings suggest that EPHX2 upregulation is linked to ER stress in adiposity and that physical activity may attenuate metabolic stress by reducing EPHX2 expression.

Palmitic acid-induced lipotoxicity promotes a novel interplay between Akt-mTOR, IRS-1, and FFAR1 signaling in pancreatic ß-cells.

BACKGROUND: Free fatty acid receptor 1 (FFAR1) is G-protein coupled receptor predominantly expressed in pancreatic ß-cells that is activated by a variety of free fatty acids (FFAs). Once activated, it promotes glucose-stimulated insulin secretion (GSIS). However, increased levels of FFAs lead to lipotoxicity, inducing loss of ß-cell function. FFAR1 plays a key role in the development of type 2 diabetes (T2D), and previous studies have indicated the importance of developing anti-diabetic therapies against FFAR1, although its role in the regulation of ß-cell function remains unclear. The present study investigated the role of FFAR1 under lipotoxic conditions using palmitic acid (PA). The rat insulinoma 1 clone 832/13 (INS-1 832/13) cell line was used as a model as it physiologically resembles native pancreatic ß-cells. Key players of the insulin signaling pathway, such as mTOR, Akt, IRS-1, and the insulin receptor (INSR1ß), were selected as candidates to be analyzed under lipotoxic conditions. RESULTS: We revealed that PA-induced lipotoxicity affected GSIS in INS-1 cells and negatively modulated the activity of both IRS-1 and Akt. Reduced phosphorylation of both IRS-1 S636/639 and Akt S473 was observed, in addition to decreased expression of both INSR1ß and FFAR1. Moreover, transient knockdown of FFAR1 led to a reduction in IRS-1 mRNA expression and an increase in INSR1ß mRNA. Finally, PA affected localization of FFAR1 from the cytoplasm to the perinucleus. CONCLUSIONS: In conclusion, our study suggests a novel regulatory involvement of FFAR1 in crosstalk with mTOR-Akt and IRS-1 signaling in ß-cells under lipotoxic conditions.