Lipid accumulation in non-adipose tissue and lipotoxicity

Obesity and dyslipidemia in early life: Impact on cardiometabolic risk

Childhood obesity with its growing prevalence worldwide presents one of the most important health challenges nowadays. Multiple mechanisms are involved in the development of this condition, as well as in its associations with various cardiometabolic complications, such as insulin resistance, diabetes, metabolic dysfunction-associated steatotic liver disease and cardiovascular diseases. Recent findings suggest that childhood obesity and associated dyslipidemia at least partly originate from epigenetic modifications that take place in the earliest periods of life, namely prenatal and perinatal periods. Hence, alterations of maternal metabolism could be fundamentally responsible for fetal and neonatal metabolic programming and consequently, for metabolic health of offspring in later life. In this paper, we will review recent findings on the associations among intrauterine and early postnatal exposure to undesirable modulators of metabolism, development of childhood obesity and later cardiometabolic complications. Special attention will be given to maternal dyslipidemia as a driven force for undesirable epigenetic modulations in offspring. In addition, newly proposed lipid biomarkers of increased cardiometabolic risk in obese children and adolescents will be analyzed, with respect to their predictive potential and clinical applicability.

Relation Between Obesity and Type 2 Diabetes: Evolutionary Insights, Perspectives and Controversies

PURPOSE OF REVIEW

Since the mid-twentieth century, obesity and its related comorbidities, notably insulin resistance (IR) and type 2 diabetes (T2D), have surged. Nevertheless, their underlying mechanisms remain elusive. Evolutionary medicine (EM) sheds light on these issues by examining how evolutionary processes shape traits and diseases, offering insights for medical practice. This review summarizes the pathogenesis and genetics of obesity-related IR and T2D. Subsequently, delving into their evolutionary connections. Addressing limitations and proposing future research directions aims to enhance our understanding of these conditions, paving the way for improved treatments and prevention strategies.

RECENT FINDINGS

Several evolutionary hypotheses have been proposed to unmask the origin of obesity-related IR and T2D, e.g., the "thrifty genotype" hypothesis suggests that certain "thrifty genes" that helped hunter-gatherer populations efficiently store energy as fat during feast-famine cycles are now maladaptive in our modern obesogenic environment. The "drifty genotype" theory suggests that if thrifty genes were advantageous, they would have spread widely, but proposes genetic drift instead. The "behavioral switch" and "carnivore connection" hypotheses propose insulin resistance as an adaptation for a brain-dependent, low-carbohydrate lifestyle. The thrifty phenotype theory suggests various metabolic outcomes shaped by genes and environment during development. However, the majority of these hypotheses lack experimental validation. Understanding why ancestral advantages now predispose us to diseases may aid in drug development and prevention of disease. EM helps us to understand the evolutionary relation between obesity-related IR and T2D. But still gaps and contradictions persist. Further interdisciplinary research is required to elucidate complete mechanisms.

Hepatic effects of acetochlor chiral isomers in zebrafish and L02 cells

The pesticide acetochlor (ACT) is a chiral isomer commonly detected in the global environment, yet its specific impacts on liver function remain poorly understood. We utilized zebrafish and L02 cells as research models to comprehensively investigate how ACT and its chiral isomers affect the liver. Our investigations unveiled that the R, Rac, and S isomers of ACT disrupt hepatic lipid transport, catabolism, and synthesis, leading to delayed yolk sac absorption and the accumulation of lipids in zebrafish embryos. These isomers induce oxidative stress in the liver of zebrafish embryos, reducing antioxidant levels and enzyme activity. The accumulated lipids in the liver render it susceptible to oxidative stress, further exacerbating hepatocyte damage. Hepatocyte damage manifests as extensive vacuolization of liver cells and alterations in liver morphology, which are induced by R, Rac, and S. Furthermore, we elucidated the molecular mechanisms underpinning the disturbance of hepatic lipid metabolism by R, Rac, and S in L02 cells. These compounds stimulate lipid synthesis through the upregulation of the AMPK/SREBP-1c/FAS pathway while inhibiting lipolysis via downregulation of the PPAR-α/CPT-1a pathway. Remarkably, our results highlight that S exhibits significantly higher hepatotoxicity in comparison to R. This study provides valuable insights into the hepatic effects of ACT chiral isomers.

Hypothyroidism and subclinical hypothyroidism are associated with fatty pancreas (Non-Alcoholic Fatty Pancreas Disease)

OBJECTIVES

Increasing visceral fat deposition with raised prevalence of obesity and metabolic syndrome is associated with many adverse conditions, especially cardiovascular diseases and diabetes. Although there are many studies that investigate hepatic steatosis in hypothyroidism and subclinical hypothyroidism, to the best of our knowledge, there is no study investigating its relationship with pancreatic steatosis. In the present study, the purpose was to investigate this relationship.

METHODS

Physical and biochemical characteristics of 30 hypothyroid, 30 subclinical hypothyroid, and 30 euthyroid volunteers were recorded in this cross-sectional study. Liver and pancreatic steatosis were evaluated with ultrasonography.

RESULTS

It was found that pancreatic steatosis was increased in hypothyroid and subclinical groups when compared to the control group, and hepatic steatosis was increased in the subclinical group when compared to the control group (steatosis; p = 0.002, p = 0.004, p = 0.001, p = 0.002, p = 0.002, p = 0.004). Pancreatic steatosis was positively correlated with age, hepatic steatosis, height, weight, BMI, waist circumference, hip circumference, hemoglobin, Insulin, alanine aminotransferase, Triglyceride, Creatinine, and gamma-glutamyltransferase and was negatively correlated with total cholesterol, high-density lipoproteins.

CONCLUSIONS

The prevalence of pancreatic steatosis was found to be increased in hypothyroidism and subclinical hypothyroidism when compared with the euthyroid control group.

Influence of Borassus flabellifer Endocarps Hydrolysate on Fungal Biomass and Fatty Acids Production by the Marine Fungus Aspergillus sp

Polyunsaturated Fatty Acids (PUFAs) are important nutrients for human health. We aimed to evaluate the efficiency of marine water fungus Aspergillus sp. (Accession no: MZ505709) for lipid biosynthesis. The Yeast Extract Glucose (YEG) medium was supplemented with different concentration of Borassus flabellifer Endocarps Hydrolysate (BFEH; 1-5%) to evaluate the fungal biomass and its lipid accumulation. The combination of glucose and BFEH as carbon source increased the fresh weight (25.43 ± 0.33 g/L), dry weight (21.39 ± 0.77 g/L) and lipid yield (3.14 ± 0.09 g/L) of fungal biomass. The lipid content of dried fungal biomass has shown 91.08 ± 5.07 mg cod liver oil equivalents/g and 125.98 ± 5.96 mg groundnut oil equivalents/g biomass. GC-MS and NMR spectrometry analysis revealed the compounds involved in fatty acid metabolism and lipid signaling pathways along with the presence of linolenic acid. Interestingly, fungus grown in BFEH enriched medium has recorded the maximum amount of lipids with major fatty acid derivatives. Increase in the growth rate of Artemia franciscana was observed, when the extracted fungal lipid was supplemented as a food supplement. Therefore, this study suggests that marine fungal lipid may serve as potential natural compound as nutraceuticals and aquafeeds.

The Intersection of Genetic Factors, Aberrant Nutrient Metabolism and Oxidative Stress in the Progression of Cardiometabolic Disease

Cardiometabolic disease (CMD), which encompasses metabolic-associated fatty liver disease (MAFLD), chronic kidney disease (CKD) and cardiovascular disease (CVD), has been increasing considerably in the past 50 years. CMD is a complex disease that can be influenced by genetics and environmental factors such as diet. With the increased reliance on processed foods containing saturated fats, fructose and cholesterol, a mechanistic understanding of how these molecules cause metabolic disease is required. A major pathway by which excessive nutrients contribute to CMD is through oxidative stress. In this review, we discuss how oxidative stress can drive CMD and the role of aberrant nutrient metabolism and genetic risk factors and how they potentially interact to promote progression of MAFLD, CVD and CKD. This review will focus on genetic mutations that are known to alter nutrient metabolism. We discuss the major genetic risk factors for MAFLD, which include Patatin-like phospholipase domain-containing protein 3 (PNPLA3), Membrane Bound O-Acyltransferase Domain Containing 7 (MBOAT7) and Transmembrane 6 Superfamily Member 2 (TM6SF2). In addition, mutations that prevent nutrient uptake cause hypercholesterolemia that contributes to CVD. We also discuss the mechanisms by which MAFLD, CKD and CVD are mutually associated with one another. In addition, some of the genetic risk factors which are associated with MAFLD and CVD are also associated with CKD, while some genetic risk factors seem to dissociate one disease from the other. Through a better understanding of the causative effect of genetic mutations in CMD and how aberrant nutrient metabolism intersects with our genetics, novel therapies and precision approaches can be developed for treating CMD.

Benzyl isothiocyanate inhibits TNFα-driven lipolysis via suppression of the ERK/PKA/HSL signaling pathway in 3T3-L1 adipocytes

Tumor necrosis factor α (TNFα), an inflammatory cytokine, induces lipolysis and increases circulating concentrations of free fatty acids. In addition, TNFα is the first adipokine produced by adipose tissue in obesity, contributing to obesity-associated metabolic disease. Given that benzyl isothiocyanate (BITC) is a well-known anti-inflammatory agent, we hypothesized that BITC can ameliorate TNFα-induced lipolysis and investigated the working mechanisms involved. We first challenged 3T3-L1 adipocytes with TNFα to induce lipolysis, which was confirmed by increased glycerol release, decreased protein expression of peroxisome proliferator-activated receptor γ (PPARγ) and perilipin 1 (PLIN1), and increased phosphorylation of ERK, protein kinase A (PKA), and hormone-sensitive lipase (HSL). However, inhibition of ERK or PKA significantly attenuated the lipolytic activity of TNFα. Meanwhile, pretreatment with BITC significantly ameliorated the lipolytic activity of TNFα; the TNFα-induced phosphorylation of ERK, PKA, and HSL; the TNFα-induced ubiquitination of PPARγ; the TNFα-induced decrease in PPARγ nuclear protein binding to PPAR response element; and the TNFα-induced decrease in PLIN1 protein expression. Our results indicate that BITC ameliorates TNFα-induced lipolysis by inhibiting the ERK/PKA/HSL signaling pathway, preventing PPARγ proteasomal degradation, and maintaining PLIN1 protein expression.

Metabolic Syndrome: A Narrative Review from the Oxidative Stress to the Management of Related Diseases

Metabolic syndrome (MS) is a growing disorder affecting thousands of people worldwide, especially in industrialised countries, increasing mortality. Oxidative stress, hyperglycaemia, insulin resistance, inflammation, dysbiosis, abdominal obesity, atherogenic dyslipidaemia and hypertension are important factors linked to MS clusters of different pathologies, such as diabesity, cardiovascular diseases and neurological disorders. All biochemical changes observed in MS, such as dysregulation in the glucose and lipid metabolism, immune response, endothelial cell function and intestinal microbiota, promote pathological bridges between metabolic syndrome, diabesity and cardiovascular and neurodegenerative disorders. This review aims to summarise metabolic syndrome's involvement in diabesity and highlight the link between MS and cardiovascular and neurological diseases. A better understanding of MS could promote a novel strategic approach to reduce MS comorbidities.

Quantification of ectopic fat storage in the liver and pancreas using six-point Dixon MRI and its association with insulin sensitivity and β-cell function in patients with central obesity

OBJECTIVES

To assess the association of ectopic fat deposition in the liver and pancreas quantified by Dixon magnetic resonance imaging (MRI) with insulin sensitivity and β-cell function in patients with central obesity.

MATERIALS AND METHODS

A cross-sectional study of 143 patients with central obesity with normal glucose tolerance (NGT), prediabetes (PreD), and untreated type 2 diabetes mellitus (T2DM) was conducted between December 2019 and March 2022. All participants underwent routine medical history taking, anthropometric measurements, and laboratory tests, including a standard glucose tolerance test to quantify insulin sensitivity and β-cell function. The fat content in the liver and pancreas was measured with MRI using the six-point Dixon technique.

RESULTS

Patients with T2DM and PreD had a higher liver fat fraction (LFF) than those with NGT, while those with T2DM had a higher pancreatic fat fraction (PFF) than those with PreD and NGT. LFF was positively correlated with homeostatic model assessment of insulin resistance (HOMA-IR), while PFF was negatively correlated with homeostatic model assessment of insulin secretion (HOMA-β). Furthermore, using a structured equation model, we found LFF and PFF to be positively associated with glycosylated hemoglobin via HOMA-IR and HOMA-β, respectively.

CONCLUSIONS

In patients with central obesity, the effects of LFF and PFF on glucose metabolism. were associated with HOMA-IR and HOMA-β, respectively. Ectopic fat storage in the liver and pancreas quantified by MR Dixon imaging potentially plays a notable role in the onset ofT2DM.

CLINICAL RELEVANCE STATEMENT

We highlight the potential role of ectopic fat deposition in the liver and pancreas in the development of type 2 diabetes in patients with central obesity, providing valuable insights into the pathogenesis of the disease and potential targets for intervention.

KEY POINTS

• Ectopic fat deposition in the liver and pancreas is associated with T2DM. • T2DM and prediabetes patients had higher liver and pancreatic fat fractions than normal individuals. • The results provide valuable insights into pathogenesis of T2DM and potential targets for intervention.

Branched-chain amino acid modulation of lipid metabolism, gluconeogenesis, and inflammation in a finishing pig model: targeting leucine and valine

Branched-chain amino acids (BCAAs) play a regulatory role in adipogenesis and energy balance. Therefore, this study aimed to investigate the impact of BCAA supplements, especially leucine (Leu) and valine (Val) supplementation, on lipid metabolism and related disorders in a finishing pig model. The results demonstrated that Leu (1%) and Val decreased serum as well as hepatic lipid accumulation. Moreover, metabolomics and lipidomics analyses revealed that Leu and Val markedly downregulated the level of various lipid species in the liver. This outcome may be explained by Leu and Val promoting cyclic adenosine monophosphate (cAMP)/protein kinase A (PKA)/hormone-sensitive triglyceride lipase (HSL) signaling pathways. Leu and Val altered the fatty acid composition in distinct adipose tissues and decreased the levels of inflammatory factors. Additionally, they significantly decreased back fat thickness, and the results of the fatty acid profiles demonstrated that Leu and Val significantly increased the levels of monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) while decreasing those of saturated fatty acids (SFAs), especially in back fat and abdominal fat. Besides, Leu and Val restored glucose homeostasis by suppressing gluconeogenesis through the serine/threonine protein kinase (AKT)/transcription factor forkhead box O1 (FOXO1) signaling pathway in the liver and back fat. In summary, these results suggest that Leu and Val may serve as key regulators for modulating lipid metabolism and steatosis.

Identifying possible thresholds for nonstructural carbohydrates in the insulin dysregulated horse

BACKGROUND

Identifying intake levels of nonstructural carbohydrates (NSCs) that limit the postprandial insulinaemic response in the insulin dysregulated (ID) horse may help reduce hyperinsulinaemia-associated laminitis (HAL) risk.

OBJECTIVE

To determine if ID horses have thresholds for pure sources of starch and sugar, above which there is an augmented insulin response.

STUDY DESIGN

Randomised crossover experiment.

METHODS

Fourteen adult horses (6 ID and 8 noninsulin dysregulated, NID; matched for bodyweight) were randomly fed eight dietary treatments. Dietary treatments were formulated using a base of low-nonstructural carbohydrate pellet (LNSC; 0.04 g of water-soluble carbohydrates (WSCs)/kg bwt and 0.01 g of starch/kg bwt), to which pure sugar (dextrose) or starch (50:50 mix of waxy-maize and oat starch powder) sources were titrated to create diets with increasing amounts of either WSC (0.06-0.17 g WSC/kg bwt), or starch (0.03-0.1 g starch/kg bwt). Horses were fed each dietary treatment at a rate of 1 g/kg bwt once over 12 weeks. Serial blood samples were collected pre- and up to 240 min postprandially. Insulin was determined via RIA and diet analytes were determined via wet chemistry. Statistical analysis was performed with a mixed effect model. Positive incremental area under the curve for insulin (IAUCi) was calculated for all horses and dietary treatments.

RESULTS

There was no significant effect of diet in NID horses but diets with NSC >0.1 g/kg bwt produced an augmented response in ID horses compared with the LNSC (p < 0.05). ID horses IAUCi were also significantly different to all NID IAUCi for diets with NSC >0.1 g/kg (p < 0.04). Apparent thresholds for sugar and starch addition varied.

CONCLUSIONS

Based on this study, using supplemental pure starch and sugar sources, ID horses seem to have an apparent threshold for NSC of around 0.1 g/kg bwt/meal, above which significantly increased insulin responses are seen compared with NID horses.

Insight on sarcopenic obesity and epicatechin as a promising treatment option

BACKGROUND AND AIM

Sarcopenic Obesity (SO) in the elderly population is a complex and multifactorial condition which refers to the loss of skeletal muscle mass, strength, and function associated with aging, while obesity involves excessive adipose tissue accumulation. The simultaneous occurrence of these two conditions presents a unique set of challenges to public health and clinical management. This narrative review aims to provide an overview of the use of epicatechin (EC) in the treatment of SO and its related complications.

METHOD

A survey of studies related to preclinical and clinical evidence of Epicatechin in sarcopenic obesity and its complications was performed in the following database Medline, Scopus, ProQuest, Embase, Web of Science, and Google scholar. Followed by structural activity relationship and pharmacokinetic profile of Epicatechin was discussed in this paper.

RESULTS

The main pharmacological effect of Epicatechin is myostatin inhibition activity which has been described by both in vitro and in vivo studies earlier. The SO is directly correlated with the alteration of Myostatin. The pre-clinical and clinical studies suggest that epicatechin can be a potential candidate in the management of SO and its related complication.

CONCLUSION

The present review describes the pharmacokinetic profile and structural activity of epicatechin respective to SO and its related complications. The goal of this review is to update the scientific community on the therapeutic potential of epicatechin in SO and age-related factors. Conduction of clinical and pre-clinical trials, also drug dosage optimization may provide with insights on the use of epicatechin in SO.

Ectopic lipid deposition in muscle and liver, quantified by proton magnetic resonance spectroscopy

Advances in the development of noninvasive imaging techniques have spurred investigations into ectopic lipid deposition in the liver and muscle and its implications in the development of metabolic diseases such as type 2 diabetes. Computed tomography and ultrasound have been applied in the past, though magnetic resonance-based methods are currently considered the gold standard as they allow more accurate quantitative detection of ectopic lipid stores. This review focuses on methodological considerations of magnetic resonance-based methods to image hepatic and muscle fat fractions, and it emphasizes anatomical and morphological aspects and how these may influence data acquisition, analysis, and interpretation.

Adipose Tissue Hyperplasia and Hypertrophy in Common and Syndromic Obesity-The Case of BBS Obesity

Obesity is a metabolic state generated by the expansion of adipose tissue. Adipose tissue expansion depends on the interplay between hyperplasia and hypertrophy, and is mainly regulated by a complex interaction between genetics and excess energy intake. However, the genetic regulation of adipose tissue expansion is yet to be fully understood. Obesity can be divided into common multifactorial/polygenic obesity and monogenic obesity, non-syndromic and syndromic. Several genes related to obesity were found through studies of monogenic non-syndromic obesity models. However, syndromic obesity, characterized by additional features other than obesity, suggesting a more global role of the mutant genes related to the syndrome and, thus, an additional peripheral influence on the development of obesity, were hardly studied to date in this regard. This review summarizes present knowledge regarding the hyperplasia and hypertrophy of adipocytes in common obesity. Additionally, we highlight the scarce research on syndromic obesity as a model for studying adipocyte hyperplasia and hypertrophy, focusing on Bardet-Biedl syndrome (BBS). BBS obesity involves central and peripheral mechanisms, with molecular and mechanistic alternation in adipocyte hyperplasia and hypertrophy. Thus, we argue that using syndromic obesity models, such as BBS, can further advance our knowledge regarding peripheral adipocyte regulation in obesity.

Association of Hepatic Steatosis with Adipose and Muscle Mass and Distribution in Children

Background: Pediatric studies have shown associations between hepatic steatosis and total body fat, visceral fat, and lean mass. However, these associations have not been assessed simultaneously, leaving their relative importance unknown. Objective: To evaluate associations between hepatic steatosis and total-body adiposity, visceral adiposity, and lean mass in children. Method: In children at risk for fatty liver, hepatic steatosis, adipose, and lean mass were estimated with magnetic resonance imaging and dual-energy X-ray absorptiometry. Results: Two hundred twenty-seven children with mean age 12.1 years had mean percent body fat of 38.9% and mean liver fat of 8.4%. Liver fat was positively associated with total-body adiposity, visceral adiposity, and lean mass (P < 0.001), and negatively associated with lean mass percentage (P < 0.001). After weight adjustment, liver fat was only positively associated with measures of central adiposity (P < 0.001). Visceral adiposity also had the strongest association with liver fat (P < 0.001). Conclusions: In children, hepatic steatosis is more strongly associated with visceral adiposity than total adiposity, and the association of lean mass is not independent of weight or fat mass. These relationships may help guide the choice of future interventions to target hepatic steatosis.

Linoleic acid-induced ANGPTL4 inhibits C2C12 skeletal muscle differentiation by suppressing Wnt/β-catenin

Skeletal muscle differentiation is an essential process in embryonic development as well as regeneration and repair throughout the lifespan. It is well-known that dietary fat intake impacts biological and physiological function in skeletal muscle, however, understanding of the contribution of nutritional factors in skeletal muscle differentiation is limited. Therefore, the objective of the current study was to evaluate the effects of free fatty acids (FFAs) on skeletal muscle differentiation in vitro. We used C2C12 murine myoblasts and treated them with various FFAs, which revealed a unique response of angiopoietin-like protein-4 (ANGPTL4) with linoleic acid (LA) treatment that was associated with reduced differentiation. LA significantly inhibited myotube formation and lowered the protein expression of myogenic regulatory factors, including MyoD and MyoG and increased Pax7 during cell differentiation. Next, recombinant ANGPTL4 protein or siRNA knockdown of ANGPTL4 was employed to examine its role in skeletal muscle differentiation, and we confirmed that ANGPTL4 knockdown at day 2 and -6 of differentiation restored myotube formation in the presence of LA. RNA-sequencing analysis revealed that ANGPTL4-mediated inhibition of skeletal muscle differentiation at day 2 as well as LA at day 2 or -6 led to a reduction in Wnt/β-catenin signaling pathways. We confirmed that LA reduced Wnt11 and Axin2 while increasing expression of the Wnt inhibitor, Dkk2. ANGPTL4 knockdown increased β-catenin protein in the nucleus in response to LA and increased Axin2 and Wnt11 expression. Taken together, these results demonstrate that LA induced ANGPTL4 inhibits C2C12 differentiation by suppressing Wnt/β-catenin signaling.

Structural characterization and anti-lipotoxicity effects of a pectin from okra (Abelmoschus esculentus (L.) Moench)

Okra (Abelmoschus esculentus (L.) Moench) is rich in various bioactive ingredients and used as a medicinal plant in traditional medicine. In the present study, to find the polysaccharide with anti-lipotoxicity effects from okra and clarify its structure, a pectin OP-1 was purified from okra, which had a backbone containing →4)-α-GalpA-(1 → residues, and 1,5-Ara linked the main chain through the O-3 of the residue →3,4)-α-GalpA-(1→, and the C-6 of residue 1, 4-α-GalpA replaced by methyl ester. In vitro experiments showed that OP-1 pretreatment alleviated oleic acid (OA)-induced lipid accumulation, ROS generation, apoptosis, transaminase leakage, and inflammatory cytokine secretion in HepG2 cells, resulting in reduced lipotoxicity. Further molecular results revealed that OP-1 increased Adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) phosphorylation and affected the expression of AMPK downstream targets, including inhibit SREBP1c and FAS, as well as activate CPT-1A. Impressively, AMPK inhibitor dorsomorphin (Compound C) blocked the effects of OP-1 against lipotoxicity. The effects of OP-1 on lipid metabolism were also diminished by dorsomorphin. Our results demonstrated that OP-1 possesses a potent function in preventing lipotoxicity via regulating AMPK-mediated lipid metabolism and provide a novel insight into the future utilization of okra polysaccharide.

Partial replacement of high-fat diet with n-3 PUFAs enhanced beef tallow attenuates dyslipidemia and endoplasmic reticulum stress in tunicamycin-injected rats

Introduction

Metabolic syndrome (MetS) is considered as a complex, intertwined multiple risk factors that directly increase the risk of various metabolic diseases, especially cardiovascular atherosclerotic diseases and diabetes mellitus type 2. While lifestyle changes, including dietary intervention are effective in mitigating or preventing MetS, there are no specific therapies against MetS. Typical western diets comprise of high saturated fatty acid, cholesterol, and simple sugar; consequently their consumption may increase the potential pathological developmental risk of MetS. Partial replacement of dietary fatty acids with polyunsaturated fatty acids (PUFAs) is widely recommended measure to manage MetS-related disorders.

Methods

In the present study, we used rat model to investigate the role of n-3 PUFA enriched beef tallows (BT) on MetS and tunicamycin (TM)-induced endoplasmic reticulum (ER) stress, by partially replacing dietary fat (lard) with equal amounts of two different BTs; regular BT or n-3 PUFA-enriched BT. The experimental rats were randomly assigned to three different dietary groups (n = 16 per group): (1) high-fat and high-cholesterol diet (HFCD); (2) HFCD partially replaced with regular BT (HFCD + BT1); (3) HFCD partially replaced with n-3 enhanced BT (w/w) (HFCD + BT2). After 10 weeks of dietary intervention, each experimental rodent was intraperitoneally injected with either phosphate-buffered saline or 1 mg/kg body weight of TM.

Results

HFCD + BT2 showed improved dyslipidemia before TM injection, and increased serum high-density lipoprotein cholesterol (HDL-C) levels after TM injection. BT replacement groups had significantly reduced hepatic triglyceride (TG) levels, and decreased total cholesterol (TC) and TG levels in epididymal adipose tissue (EAT). Furthermore, BT replacement remarkably attenuated TM-induced unfolded protein responses (UPRs) in liver, showing reduced ER stress, with BT2 being more effective in the EAT.

Discussion

Therefore, our findings suggest that partially replacing dietary fats with n-3 PUFA to lower the ratio of n-6/n-3 PUFAs is beneficial in preventing pathological features of MetS by alleviating HFCD- and/or TM-induced dyslipidemia and ER stress.

Pancreatic fat in type 2 diabetes: Causal or coincidental?

Type 2 diabetes (T2D) is a multifactorial metabolic disorder affecting more than 450 million people across the globe. With the increasing prevalence of T2D and obesity, the role of fat accumulation at sites other than subcutaneous adipose tissue has received significant attention in the pathophysiology of T2D. Over the past decade and a half, a pressing concern has emerged on investigating the association of pancreatic fat accumulation or pancreatic steatosis with the development of disease. While a few reports have suggested a possible association between pancreatic fat and T2D and/or impaired glucose metabolism, a few reports suggest a lack of such association. Pancreatic fat has also been linked with genetic risk of developing T2D, prediabetes, reduced insulin secretion, and beta cell dysfunction albeit some confounding factors such as age and ethnicity may affect the outcome. With the technological advancements in clinical imaging and progress in assessment of pancreatic beta cell function, our understanding of the role of pancreatic fat in causing insulin resistance and development of various etiologies of T2D has significantly improved. This review summarizes various findings on the possible association of pancreatic fat accumulation with the pathophysiology of T2D.

Long-term exercise preserves pancreatic islet structure and β-cell mass through attenuation of islet inflammation and fibrosis

Islet fibrosis is associated with the disruption of islet structure and contributes to β-cell dysfunction, playing an essential role in the pathogenesis of type 2 diabetes. Physical exercise has been shown to attenuate fibrosis in various organs; however, the effect of exercise on islet fibrosis has not been defined. Male Sprague-Dawley rats were divided into four groups: normal diet sedentary [N-Sed], normal diet + exercise [N-Ex], high-fat diet sedentary [H-Sed], and high-fat diet + exercise [H-Ex]. After 60 weeks of exercise, 4452 islets from Masson-stained slides were analyzed. Exercise led to a 68% and 45% reduction in islet fibrosis in the normal and high-fat diet groups and was correlated with a lower serum blood glucose. Fibrotic islets were characterized by irregular shapes and substantial loss of β-cell mass, which were significantly reduced in the exercise groups. Remarkably, the islets from exercised rats at week 60 were morphologically comparable to those of sedentary rats at 26 weeks. In addition, the protein and RNA levels of collagen and fibronectin, and the protein levels of hydroxyproline in the islets were also attenuated by exercise. This was accompanied by a significant reduction in inflammatory markers in the circulation Interleukin-1 beta (IL-1β)] and pancreas [IL-1β, Tumor Necrosis Factor-alpha, Transforming Growth Factor-β, and Phosphorylated Nuclear Factor Kappa-B p65 subunit], lower macrophage infiltration, and stellate cell activation in the islets of exercised rats. In conclusion, we have demonstrated that long-term exercise preserves pancreatic islet structure and β-cell mass through anti-inflammatory and anti-fibrotic actions, suggesting additional rationales for the success of exercise training in the prevention and treatment of type 2 diabetes that should be further explored.

Deacetylase-dependent and -independent role of HDAC3 in cardiomyopathy

Cardiomyopathy is a common disease of cardiac muscle that negatively affects cardiac function. HDAC3 commonly functions as corepressor by removing acetyl moieties from histone tails. However, a deacetylase-independent role of HDAC3 has also been described. Cardiac deletion of HDAC3 causes reduced cardiac contractility accompanied by lipid accumulation, but the molecular function of HDAC3 in cardiomyopathy remains unknown. We have used powerful genetic tools in Drosophila to investigate the enzymatic and nonenzymatic roles of HDAC3 in cardiomyopathy. Using the Drosophila heart model, we showed that cardiac-specific HDAC3 knockdown (KD) leads to prolonged systoles and reduced cardiac contractility. Immunohistochemistry revealed structural abnormalities characterized by myofiber disruption in HDAC3 KD hearts. Cardiac-specific HDAC3 KD showed increased levels of whole-body triglycerides and increased fibrosis. The introduction of deacetylase-dead HDAC3 mutant in HDAC3 KD background showed comparable results with wild-type HDAC3 in aspects of contractility and Pericardin deposition. However, deacetylase-dead HDAC3 mutants failed to improve triglyceride accumulation. Our data indicate that HDAC3 plays a deacetylase-independent role in maintaining cardiac contractility and preventing Pericardin deposition as well as a deacetylase-dependent role to maintain triglyceride homeostasis.

Long non-coding RNA FABP5P3/miR-22 axis improves TGFβ1-induced fatty acid oxidation deregulation and fibrotic changes in proximal tubular epithelial cells of renal fibrosis

Severe hydronephrosis increases the risk of urinary tract infection and irretrievable renal fibrosis. While TGFβ1-mediated fibrotic changes in proximal tubular epithelial cells and fatty acid oxidation (FAO) deregulation contribute to renal fibrosis and hydronephrosis. Firstly, a few elements were analyzed in this paper, including differentially-expressed long non-coding RNAs (lncRNAs), and miRNAs correlated to CPT1A, RXRA, and NCOA1. This paper investigated TGFβ1 effects on lncRNA FABP5P3, CPT1A, RXRA, and NCOA1 expression and fibrotic changes in HK-2 cells and FABP5P3 overexpression effects on TGFβ1-induced changes. Moreover, this paper predicted and proved that miR-22 binding to lncRNA FABP5P3, 3'UTR of CPT1A, RXRA, and NCOA1 was validated. The dynamic effects of the FABP5P3/miR-22 axis on TGFβ1-induced changes were investigated. A Renal fibrosis model was established in unilateral ureteral obstruction (UUO) mice, and FABP5P3 effects were investigated. Eventually, this paper concluded that TGFβ1 inhibited lncRNA FABP5P3, CPT1A, RXRA, and NCOA1 expression, induced fibrotic changes in HK-2 cells, and induced metabolic reprogramming within HK-2 cells, especially lower FAO. FABP5P3 overexpression partially reversed TGFβ1-induced changes. miR-22 targeted lncRNA FABP5P3, CPT1A, RXRA, and NCOA1. LncRNA FABP5P3 counteracted miR-22 inhibition of CPT1A, NCOA1, and RXRA through competitive binding. TGFβ1 stimulation induced the activation of TGFβ/SMAD and JAG/Notch signaling pathways; Nocth2 knockdown reversed TGFβ1 suppression on lncRNA FABP5P3. FABP5P3 overexpression attenuated renal fibrosis in unilateral ureteral obstruction mice. The LncRNA FABP5P3/miR-22 axis might be a potent target for improving the FAO deregulation and fibrotic changes in proximal TECs under TGFβ1 stimulation.

A low-intensity lifelong exercise routine changes miRNA expression in aging and prevents osteosarcopenic obesity by modulating inflammation

Osteosarcopenic obesity (OSO) has been associated with increase immobility, falls, fractures, and other dysfunctions, which could increase mortality risk during aging. However, its etiology remains unknown. Recent studies revealed that sedentarism, fat gain, and epigenetic regulators are critical in its development. One effective intervention to prevent and treat OSO is exercise. Therefore, in the present study, by keeping rats in conditions of sedentarism and others under a low-intensity exercise routine, we established an experimental model of OSO. We determined the degree of sarcopenia, obesity, and osteopenia at different ages and analyzed the miRNA expression during the lifespan using miRNA microarrays from gastrocnemius muscle. Interestingly microarrays results showed that there is a set of miRNAs that changed their expression with exercise. The pathway enrichment analysis showed that these miRNAs are strongly associated with immune regulation. Further inflammatory profiles with IL-6/IL-10 and TNF-α/IL-10 ratios showed that exercised rats presented a lower pro-inflammatory profile than sedentary rats. Also, the body fat gain in the sedentary group increased the inflammatory profile, ultimately leading to muscle dysfunction. Exercise prevented strength loss over time and maintained skeletal muscle functionality over time. Differential expression of miRNAs suggests that they might participate in this process by regulating the inflammatory response associated with aging, thus preventing the development of OSO.

Thermogenic Adipose Redox Mechanisms: Potential Targets for Metabolic Disease Therapies

Metabolic diseases, such as diabetes and non-alcoholic fatty liver disease (NAFLD), have several negative health outcomes on affected humans. Dysregulated energy metabolism is a key component underlying the pathophysiology of these conditions. Adipose tissue is a fundamental regulator of energy homeostasis that utilizes several redox reactions to carry out the metabolism. Brown and beige adipose tissues, in particular, perform highly oxidative reactions during non-shivering thermogenesis to dissipate energy as heat. The appropriate regulation of energy metabolism then requires coordinated antioxidant mechanisms to counterbalance the oxidation reactions. Indeed, non-shivering thermogenesis activation can cause striking changes in concentrations of both oxidants and antioxidants in order to adapt to various oxidative environments. Current therapeutic options for metabolic diseases either translate poorly from rodent models to humans (in part due to the challenges of creating a physiologically relevant rodent model) or tend to have numerous side effects, necessitating novel therapies. As increased brown adipose tissue activity results in enhanced energy expenditure and is associated with beneficial effects on metabolic health, such as decreased obesity, it has gathered great interest as a modulator of metabolic disease. One potential reason for the beneficial health effects may be that although non-shivering thermogenesis is enormously oxidative, it is also associated with decreased oxidant formation after its activation. However, targeting its redox mechanisms specifically to alter metabolic disease remains an underexplored area. Therefore, this review will discuss the role of adipose tissue in energy homeostasis, non-shivering thermogenesis in adults, and redox mechanisms that may serve as novel therapeutic targets of metabolic disease.

The Dark Side of Sphingolipids: Searching for Potential Cardiovascular Biomarkers

Cardiovascular diseases (CVDs) are the leading cause of death and illness in Europe and worldwide, responsible for a staggering 47% of deaths in Europe. Over the past few years, there has been increasing evidence pointing to bioactive sphingolipids as drivers of CVDs. Among them, most studies place emphasis on the cardiovascular effect of ceramides and sphingosine-1-phosphate (S1P), reporting correlation between their aberrant expression and CVD risk factors. In experimental in vivo models, pharmacological inhibition of de novo ceramide synthesis averts the development of diabetes, atherosclerosis, hypertension and heart failure. In humans, levels of circulating sphingolipids have been suggested as prognostic indicators for a broad spectrum of diseases. This article provides a comprehensive review of sphingolipids' contribution to cardiovascular, cerebrovascular and metabolic diseases, focusing on the latest experimental and clinical findings. Cumulatively, these studies indicate that monitoring sphingolipid level alterations could allow for better assessment of cardiovascular disease progression and/or severity, and also suggest them as a potential target for future therapeutic intervention. Some approaches may include the down-regulation of specific sphingolipid species levels in the circulation, by inhibiting critical enzymes that catalyze ceramide metabolism, such as ceramidases, sphingomyelinases and sphingosine kinases. Therefore, manipulation of the sphingolipid pathway may be a promising strategy for the treatment of cardio- and cerebrovascular diseases.

High circulating fibroblast growth factor-21 levels as a screening marker in fatty pancreas patients

Background

The study aimed to detect the serum levels of fibroblast growth factor-21 (FGF-21) in fatty pancreas (FP) patients and to investigate their potential clinical value.

Methods

We screened patients with FP using transabdominal ultrasound. The anthropometric, biochemical and serum levels of FGF-21 were compared between the FP group and the normal control (NC) group. A receiver operating characteristic (ROC) curve was used to evaluate the predictive value of serum FGF-21 for FP patients.

Results

Compared with the NC group, body mass index, fasting blood glucose levels, uric acid levels and cholesterol levels of the FP group were significantly higher, while the high-density lipoprotein level was lower. In addition, levels of serum FGF-21, resistin, leptin and tumor necrosis factor-α were significantly higher than those in the NC group, while the serum adiponectin level was lower. Pearson analysis showed serum FGF-21 levels in FP patients were negatively correlated with leptin. The ROC curve showed the best critical value of the serum FGF-21 level in FP patients was 171 pg/mL (AUC 0.744, P = 0.002, 95% confidence intervals 0.636-0.852).

Conclusion

Serum FGF-21 was closely related to fatty pancreas. Detecting serum FGF-21 levels may help identify the population susceptible to FP.

Time-dependent metabolome and fatty acid profile changes following a high-fat diet exposure in Drosophila melanogaster

High-fat diets (HFDs) are often used to study metabolic disorders using different animal models. However, the underlying cellular mechanisms pertaining to the concurrent loss of metabolic homeostasis characteristics of these disorders are still unclear mainly because the effects of such diets are also dependent on the time frame of the experiments. Here, we used the fruit fly, Drosophila melanogaster, to investigate the metabolic dynamic effects following 0, 2, 4, 7 and 9 days of an exposure to a HFD (standard diet supplemented with 20% w/v coconut oil, rich in 12:0 and 14:0) by combining NMR metabolomics and GC-FID fatty acid profiling. Our results show that after 2 days, the ingested 12:0 and 14:0 fatty acids are used for both lipogenesis and fatty acid oxidation. After 4 days, metabolites from several different pathways are highly modulated in response to the HFD, and an accumulation of 12:0 is also observed, suggesting that the balance of lipid, amino acid and carbohydrate metabolism is profoundly perturbed at this specific time point. Following a longer exposure to the HFD (and notably after 9 days), an accumulation of many metabolites is observed indicating a clear dysfunction of the metabolic system. Overall, our study highlights the relevance of the Drosophila model to study metabolic disorders and the importance of the duration of the exposure to a HFD to study the dynamics of the fundamental mechanisms that control metabolism following exposure to dietary fats. This knowledge is crucial to understand the development and progression of metabolic diseases.

Andrographolide Inhibits Lipotoxicity-Induced Activation of the NLRP3 Inflammasome in Bone Marrow-Derived Macrophages

Andrographolide is the major bioactive component of the herb Andrographis paniculata and is a potent anti-inflammatory agent. Obesity leads to an excess of free fatty acids, particularly palmitic acid (PA), in the circulation. Obesity also causes the deposition of ectopic fat in nonadipose tissues, which leads to lipotoxicity, a condition closely associated with inflammation. Here, we investigated whether andrographolide could inhibit PA-induced inflammation by activating autophagy, activating the antioxidant defense system, and blocking the activation of the NLRP3 inflammasome. Bone marrow-derived macrophages (BMDMs) were primed with lipopolysaccharide (LPS) and then activated with PA. LPS/PA treatment increased both the mRNA expression of NLRP3 and IL-1[Formula: see text] and the release of IL-1[Formula: see text] in BMDMs. Andrographolide inhibited the LPS/PA-induced protein expression of caspase-1 and the release of IL-1[Formula: see text]. Furthermore, andrographolide attenuated LPS/PA-induced mtROS generation by first promoting autophagic flux and catalase activity, and ultimately inhibiting activation of the NLRP3 inflammasome. Our results suggest that the mechanisms by which andrographolide downregulates LPS/PA-induced IL-1[Formula: see text] release in BMDMs involve promoting autophagic flux and catalase activity. Andrographolide may thus be a candidate to prevent obesity- and lipotoxicity-driven chronic inflammatory disease.

Lipotoxicity-related sarcopenia: a review

A body of literature supports the postulation that a persistent lipid metabolic imbalance causes lipotoxicity, "an abnormal fat storage in the peripheral organs". Hence, lipotoxicity could somewhat explain the process of sarcopenia, an aging-related, gradual, and involuntary decline in skeletal muscle strength and mass associated with several health complications. This review focuses on the recent mechanisms underlying lipotoxicity-related sarcopenia. A vicious cycle occurs between sarcopenia and ectopic fat storage via a complex interplay of mitochondrial dysfunction, pro-inflammatory cytokine production, oxidative stress, collagen deposition, extracellular matrix remodeling, and life habits. The repercussions of lipotoxicity exacerbation of sarcopenia can include increased disability, morbidity, and mortality. This suggests that appropriate lipotoxicity management should be considered the primary target for the prevention and/or treatment of chronic musculoskeletal and other aging-related disorders. Further advanced research is needed to understand the molecular details of lipotoxicity and its consequences for sarcopenia and sarcopenia-related comorbidities.

Macrophages, Chronic Inflammation, and Insulin Resistance

The prevalence of obesity has reached alarming levels, which is considered a major risk factor for several metabolic diseases, including type 2 diabetes (T2D), non-alcoholic fatty liver, atherosclerosis, and ischemic cardiovascular disease. Obesity-induced chronic, low-grade inflammation may lead to insulin resistance, and it is well-recognized that macrophages play a major role in such inflammation. In the current review, the molecular mechanisms underlying macrophages, low-grade tissue inflammation, insulin resistance, and T2D are described. Also, the role of macrophages in obesity-induced insulin resistance is presented, and therapeutic drugs and recent advances targeting macrophages for the treatment of T2D are introduced.

Free Fatty Acid Overload Targets Mitochondria: Gene Expression Analysis of Palmitic Acid-Treated Endothelial Cells

Lipotoxicity is known to cause cellular dysfunction and death in non-adipose tissue. A major cause of lipotoxicity is the accumulation of saturated free fatty acids (FFA). Palmitic acid (PA) is the most common saturated fatty acid found in the human body. Endothelial cells form the blood vessels and are the first non-adipose cells to encounter FFA in the bloodstream. FFA overload has a direct impact on metabolism, which is evident through the changes occurring in mitochondria. To study these changes, the PA-treated human coronary artery endothelial cell (HCAEC) dataset was obtained from the Gene Expression Omnibus (GEO), and it was analyzed to obtain differentially expressed genes (DEGs) from the nucleus and mitochondria. Functional and pathway enrichment analyses were performed on DEGs. Results showed that nuclear and mitochondrial DEGs were implicated in several processes, e.g., reactive oxygen species (ROS) production, mitochondrial fusion and fission, Ca2+ sequestering, membrane transport, the electron transport chain and the process of apoptosis. To better understand the role of FFA in endothelial cell damage, these DEGs can lead to future experiments based on these findings.

Approaches to Measuring the Activity of Major Lipolytic and Lipogenic Enzymes In Vitro and Ex Vivo

Since the 1950s, one of the goals of adipose tissue research has been to determine lipolytic and lipogenic activity as the primary metabolic pathways affecting adipocyte health and size and thus representing potential therapeutic targets for the treatment of obesity and associated diseases. Nowadays, there is a relatively large number of methods to measure the activity of these pathways and involved enzymes, but their applicability to different biological samples is variable. Here, we review the characteristics of mean lipogenic and lipolytic enzymes, their inhibitors, and available methodologies for assessing their activity, and comment on the advantages and disadvantages of these methodologies and their applicability in vivo, ex vivo, and in vitro, i.e., in cells, organs and their respective extracts, with the emphasis on adipocytes and adipose tissue.

Use of Magnetic Resonance Imaging to Quantify Fat and Steatosis in the Pancreas in Patients after Bariatric Surgery: a Retrospective Study

INTRODUCTION

Pancreatic steatosis (PS) has both metabolic consequences and local effects on the pancreas itself. Magnetic resonance imaging (MRI) is the most reliable non-invasive method for diagnosing PS. We investigated the impact of metabolic syndrome (MS) on the presence of PS, differences in individuals with and without PS, and the metabolic effects of bariatric procedures.

METHODS

Changes in anthropometric and basic biochemistry values and MS occurrence were evaluated in 34 patients with obesity who underwent a bariatric procedure. After the procedure, patients underwent MRI with manual 3D segmentation mask creation to determine the pancreatic fat content (PFC). We compared the differences in the PFC and the presence of PS in individuals with and without MS and compared patients with and without PS.

RESULTS

We found no significant difference in the PFC between the groups with and without MS or in the occurrence of PS. There were significant differences in patients with and without PS, especially in body mass index (BMI), fat mass, visceral adipose tissue (VAT), select adipocytokines, and lipid spectrum with no difference in glycemia levels. Significant metabolic effects of bariatric procedures were observed.

CONCLUSIONS

Bariatric procedures can be considered effective in the treatment of obesity, MS, and some of its components. Measuring PFC using MRI did not show any difference in relation to MS, but patients who lost weight to BMI < 30 did not suffer from PS and had lower overall fat mass and VAT. Glycemia levels did not have an impact on the presence of PS.

Morchella esculenta polysaccharide attenuate obesity, inflammation and modulate gut microbiota

Edible mushrooms have now been suggested as promising sources of biological functional ingredients and are the subject of the most recent nutrition research and novel functional foods. Polysaccharides from mushrooms exhibit impressive biological effects, notably against obesity. Obesity is a chronic metabolic disorder characterized by chronic inflammation, gut dysbiosis, and hyperpermeability of the colon. Here, we prove that mushrooms Morchella esculenta polysaccharide (MEP) effects on HFD-induced obesity, colonic inflammation, and gut microbiota dysbiosis. Our findings demonstrate MEP supplementation attenuates obesity parameters and reduces inflammation in the colon via regulation of Toll-like receptor 4 (TLR4), nitric oxide synthase (iNOS), cyclooxygenase-2 (COX-2), and inactivation of nuclear factor kappa B (NF-κB). Furthermore, MEP administration restores gut microbiota dysregulation by ameliorating Firmicutes to Bacteroidetes proportion as well as enhancing beneficial bacteria, like Lactobacillus, and inhibiting pathogenic bacteria like Enterococcus. MEP improves gut integrity by increasing tight junction proteins (TJs) and reducing endotoxin levels by controlling Lipopolysaccharide (LPS) in HFD-induced obese mice. These results demonstrated the therapeutic efficacy of MEP in attenuating HFD-induced obesity via regulating inflammatory cascades, ameliorating the gut microbiome, and modulating gut integrity.

Docosahexaenoic Acid Delivery Systems, Bioavailability, Functionality, and Applications: A Review

Docosahexaenoic acid (DHA), mainly found in microalgae and fish oil, is crucial for the growth and development of visual, neurological, and brain. In addition, DHA has been found to improve metabolic disorders associated with obesity and has anti-inflammatory, anti-obesity, and anti-adipogenesis effects. However, DHA applications in food are often limited due to its low water solubility, instability, and poor bioavailability. Therefore, delivery systems have been developed to enhance the remainder of DHA activity and increase DHA homeostasis and bioavailability. This review focused on the different DHA delivery systems and the in vitro and in vivo digestive characteristics. The research progress on cardiovascular diseases, diabetes, visual, neurological/brain, anti-obesity, anti-inflammatory, food applications, future trends, and the development potential of DHA delivery systems were also reviewed. DHA delivery systems could overcome the instability of DHA in gastrointestinal digestion, improve the bioavailability of DHA, and better play the role of its functionality.

Shared pathobiology identifies AMPK as a therapeutic target for obesity and autosomal dominant polycystic kidney disease

Autosomal dominant polycystic kidney disease (ADPKD) is the most common Mendelian kidney disease, affecting approximately one in 1,000 births and accounting for 5% of end-stage kidney disease in developed countries. The pathophysiology of ADPKD is strongly linked to metabolic dysregulation, which may be secondary to defective polycystin function. Overweight and obesity are highly prevalent in patients with ADPKD and constitute an independent risk factor for progression. Recent studies have highlighted reduced AMP-activated protein kinase (AMPK) activity, increased mammalian target of rapamycin (mTOR) signaling, and mitochondrial dysfunction as shared pathobiology between ADPKD and overweight/obesity. Notably, mTOR and AMPK are two diametrically opposed sensors of energy metabolism that regulate cell growth and proliferation. However, treatment with the current generation of mTOR inhibitors is poorly tolerated due to their toxicity, making clinical translation difficult. By contrast, multiple preclinical and clinical studies have shown that pharmacological activation of AMPK provides a promising approach to treat ADPKD. In this narrative review, we summarize the pleiotropic functions of AMPK as a regulator of cellular proliferation, macromolecule metabolism, and mitochondrial biogenesis, and discuss the potential for pharmacological activation of AMPK to treat ADPKD and obesity-related kidney disease.

Linking mitochondrial dynamics and fertility: promoting fertility by phoenixin through modulation of ovarian expression of GnRH receptor and mitochondrial dynamics proteins DRP-1 and Mfn-2

Obesity is linked to reproductive disorders. Novel neuropeptide phoenixin demonstrated many therapeutic actions. In this study, we aim to evaluate phoenixin’s potential effect in obesity-induced infertility through modulating mitochondrial dynamics. Ninety adult female rats were divided to 4 groups: (I), fed with normal pellet diet; (II), given phoenixin; (III), fed with high-fat diet. Rats that developed obesity and infertility were divided to 2 groups: (III-A), received no further treatment; (III-B), given phoenixin. Our results showed that phoenixin treatment in obese infertile rats significantly decreased serum levels of insulin and testosterone and ovarian levels of dynamin-related protein1(Drp1),reactive oxygen species ROS, TNF-α, MDA, and caspase-3. Phoenixin treatment also significantly increased serum estrogen progesterone, LH, and FSH together with ovarian levels of GnRH receptor (GnRHR), mitofusin2(Mfn2), mitochondrial transmembrane potential (ΔΨm), and electron transport chain (ETC) complex-I significantly when compared with obese group. Ovarian histopathological changes were similarly improved by phoenixin. Our data demonstrate phoenixin’s role in improving obesity-induced infertility.

The role of protein kinases as key drivers of metabolic dysfunction-associated fatty liver disease progression: New insights and future directions

Metabolic dysfunction-associated fatty liver disease (MAFLD), proposed in 2020 is a novel term for non-alcoholic fatty liver disease (NAFLD) which was coined for the first time in 1980. It is a leading cause of the most chronic liver disease and hepatic failure all over the world, and unfortunately, with no licensed drugs for treatment yet. The progress of the disease is driven by the triggered inflammatory process, oxidative stress, and insulin resistance in many pathways, starting with simple hepatic steatosis to non-alcoholic steatohepatitis, fibrosis, cirrhosis, and liver cancer. Protein kinases (PKs), such as MAPK, ErbB, PKC, PI3K/Akt, and mTOR, govern most of the pathological pathways by acting on various downstream key points in MAFLD and regulating both hepatic gluco- lipo-neogenesis and inflammation. Therefore, modulating the function of those potential protein kinases that are effectively involved in MAFLD might be a promising therapeutic approach for tackling this disease. In the current review, we have discussed the key role of protein kinases in the pathogenesis of MAFLD and performed a protein-protein interaction (PPI) network among the main proteins of each kinase pathway with MAFLD-related proteins to predict the most likely targets of the PKs in MAFLD. Moreover, we have reported the experimental, pre-clinical, and clinical data for the most recent investigated molecules that are activating p38-MAPK and AMPK proteins and inhibiting the other PKs to improve MAFLD condition by regulating oxidation and inflammation signalling.

Lycopus lucidus Turcz Water Extract Ameliorates the Metabolic Disorder by Up-Regulated Major Urinary Protein Expression in High-Fat Diet-Induced Obesity

Despite a century of research on obesity, metabolic disorders and their complications, including dyslipidemia, insulin resistance, and fatty liver disease remain a serious global health problem. Lycopus lucidus Turcz (LT) is a traditional medicine used for its anti-inflammatory properties that has not been evaluated for its efficacy in improving obesity. In this study, mice were fed a normal diet (n = 10) or obesity was induced with a high-fat diet (HFD, n = 20, 60% kcal from fat) for 4 weeks. The HFD mice were then divided into two groups, one of which received LT supplementation with water extract for 13 weeks [HFD (n = 10) or HFD with LT water extract (n = 10, 1.5%)]. LT reduced body and adipose tissue weight by elevating energy expenditure by increasing fatty oxidation in epididymal white adipose tissue (eWAT) and muscle. LT ameliorated dyslipidemia and hepatic steatosis by restricting lipogenesis. Additionally, LT normalized the impaired glucose homeostasis by diet-induced obesity to improve pancreatic islet dysfunction with increasing hepatic major urinary protein expression. Moreover, LT attenuated the inflammation and collagen accumulation in the liver and eWAT. In conclusion, these results suggest that LT can treat obesity-related metabolic disorders such as adiposity, dyslipidemia, hepatic steatosis, insulin resistance, and inflammation.

Chronic systemic low-grade inflammation and modern lifestyle: the dark role of gut microbiota on related diseases with a focus on pandemic COVID-19

Inflammation is a physiological, beneficial and auto-limiting response of the host to alarming stimuli. Conversely, a chronic systemic low-grade inflammation (CSLGI), known as a long-time persisting condition, causes organs and host tissues' damage, representing a major risk for chronic diseases. Currently, a worldwide a high incidence of inflammatory chronic diseases is observed, often linked to the lifestyle-related changes occurred in the last decade's society. The mains lifestyle-related factors are a proinflammatory diet, psychological stress, tobacco smoking, alcohol abuse, physical inactivity, and finally indoor living and working with its related consequences such as indoor pollution, artificial light exposure and low vitamin D production. Recent scientific evidences found that gut microbiota (GM) has a main role in shaping the host's health, particularly as CSLGI mediator. As a matter of facts, based on the last discoveries regarding the remarkable GM activity, in this manuscript we focused on the elements of actual lifestyle that influence the composition and function of intestinal microbial community, in order to elicit the CSLGI and its correlated pathologies. In this scenario, we provide a broad review of the interplay between modern lifestyle, GM and CSLGI with a special focus on the COVID symptoms and emerging long-COVID syndrome.

Canine Geriatric Syndrome: A Framework for Advancing Research in Veterinary Geroscience

Biological aging is the single most important risk factor for disease, disability, and ultimately death in geriatric dogs. The effects of aging in companion dogs also impose significant financial and psychological burdens on their human caregivers. The underlying physiologic processes of canine aging may be occult, or early signs of aging may be ignored because of the misconception that biological aging is natural and therefore inevitable. The ability to detect, quantify, and mitigate the deleterious processes of canine aging would greatly enhance veterinary preventative medicine and animal welfare. In this paper we propose a new conceptual framework for aging in dogs, the Canine Geriatric Syndrome (CGS). CGS consists of the multiple, interrelated physical, functional, behavioral, and metabolic changes that characterize canine aging as well as the resulting clinical manifestations, including frailty, diminished quality of life, and age-associated disease. We also identify potential key components of a CGS assessment tool, a clinical instrument that would enable veterinarians to diagnose CGS and would facilitate the development and testing of interventions to prolong healthspan and lifespan in dogs by directly targeting the biological mechanisms of aging. There are many gaps in our knowledge of the mechanisms and phenotype of aging in dogs that must be bridged before a CGS assessment tool can be deployed. The conceptual framework of CGS should facilitate identifying these gaps and should stimulate research to better characterize the processes and effects of aging in dogs and to identify the most promising preventative strategies to target these.

Characterization of lipid droplets from a Taxus media cell suspension and their potential involvement in trafficking and secretion of paclitaxel

Our paper describes the potential roles of lipid droplets of Taxus media cell suspension in the biosynthesis and secretion of paclitaxel and, therefore, highlights their involvement in improving its production. Paclitaxel (PTX) is a highly potent anticancer drug that is mainly produced using Taxus sp. cell suspension cultures. The main purpose of the current study is to characterize cellular LDs from T. media cell suspension with a particular focus on the biological connection of their associated proteins, the caleosins (CLOs), with the biosynthesis and secretion of PTX. A pure LD fraction obtained from T. media cells and characterized in terms of their proteome. Interestingly, the cellular LD in T. media sequester the PTX. This was confirmed in vitro, where about 96% of PTX (C⁰_PTX,_aq [mg L^-1]) in the aqueous solution was partitioned into the isolated LDs. Furthermore, silencing of CLO-encoding genes in the T. media cells led to a net decrease in the number and size of LDs. This coincided with a significant reduction in expression levels of TXS, DBAT and DBTNBT, key genes in the PTX biosynthesis pathway. Subsequently, the biosynthesis of PTX was declined in cell culture. In contrast, treatment of cells with 13-hydroperoxide C18:3, a substrate of the peroxygenase activity, induced the expression of CLOs, and, therefore, the accumulation of cellular LDs in the T. media cells cultures, thus increasing the PTX secretion. The accumulation of stable LDs is critically important for effective secretion of PTX. This is modulated by the expression of caleosins, a class of LD-associated proteins with a dual role conferring the structural stability of LDs as well as regulating lipidic bioactive metabolites via their enzymatic activity, thus enhancing the biosynthesis of PTX.

The effects of the Green-Mediterranean diet on cardiometabolic health are linked to gut microbiome modifications: a randomized controlled trial

BACKGROUND

Previous studies have linked the Mediterranean diet (MED) with improved cardiometabolic health, showing preliminary evidence for a mediating role of the gut microbiome. We recently suggested the Green-Mediterranean (Green-MED) diet as an improved version of the healthy MED diet, with increased consumption of plant-based foods and reduced meat intake. Here, we investigated the effects of MED interventions on the gut microbiota and cardiometabolic markers, and the interplay between the two, during the initial weight loss phase of the DIRECT-PLUS trial.

METHODS

In the DIRECT-PLUS study, 294 participants with abdominal obesity/dyslipidemia were prospectively randomized to one of three intervention groups: healthy dietary guidelines (standard science-based nutritional counseling), MED, and Green-MED. Both isocaloric MED and Green-MED groups were supplemented with 28g/day walnuts. The Green-MED group was further provided with daily polyphenol-rich green tea and Mankai aquatic plant (new plant introduced to a western population). Gut microbiota was profiled by 16S rRNA for all stool samples and shotgun sequencing for a select subset of samples.

RESULTS

Both MED diets induced substantial changes in the community structure of the gut microbiome, with the Green-MED diet leading to more prominent compositional changes, largely driven by the low abundant, "non-core," microorganisms. The Green-MED diet was associated with specific microbial changes, including enrichments in the genus Prevotella and enzymatic functions involved in branched-chain amino acid degradation, and reductions in the genus Bifidobacterium and enzymatic functions responsible for branched-chain amino acid biosynthesis. The MED and Green-MED diets were also associated with stepwise beneficial changes in body weight and cardiometabolic biomarkers, concomitantly with the increased plant intake and reduced meat intake. Furthermore, while the level of adherence to the Green-MED diet and its specific green dietary components was associated with the magnitude of changes in microbiome composition, changes in gut microbial features appeared to mediate the association between adherence to the Green-MED and body weight and cardiometabolic risk reduction.

CONCLUSIONS

Our findings support a mediating role of the gut microbiome in the beneficial effects of the Green-MED diet enriched with Mankai and green tea on cardiometabolic risk factors.

TRIAL REGISTRATION

The study was registered on ClinicalTrial.gov ( NCT03020186 ) on January 13, 2017.

Evaluation of lifespan promoting effects of biofortified wheat in Drosophila melanogaster

Evaluation of nutritionally enhanced biofortified dietary interventions that increase lifespan may uncover cost-effective and sustainable approaches for treatment of age-related morbidities and increasing healthy life expectancy. In this study, we report that anthocyanin rich, high yielding crossbred blue wheat prolongs lifespan of Drosophila melanogaster in different dietary contexts. In addition to functioning as an antioxidant rich intervention, the biofortified blue wheat also works through modulating expression of DR pathway genes including AMPK alpha, SREBP, PEPCK and Cry. Supplementation with blue- or purple-colored wheat provided better protection against paraquat-induced oxidative stress than control diet and increased survivability of flies in which superoxide dismutase 2 was knocked down conditionally in adults. Lastly, our findings indicate that supplementing biofortified blue wheat formulated diet prevented the decrease in lifespan and cardiac structural pathologies associated with intake of high fat diet. Overall, our findings indicate that plant-based diets formulated with biofortified cereal crops promote healthy ageing and delay progression of diseases that are exacerbated by accumulation of oxidative damage.

Pancreatic Steatosis Is Associated with Both Metabolic Syndrome and Pancreatic Stiffness Detected by Ultrasound Elastography

INTRODUCTION

There is increasing evidence that pancreatic steatosis (PS) is associated with metabolic syndrome (MS). However, it is not known whether it is associated with PS grade and pancreatic stiffness, or not. We aimed to evaluate the relationship between PS and its grade detected by transabdominal ultrasound, and pancreatic stiffness determined by two-dimensional shearwave elastography (2D-SWE), whether it has clinical significance and its relationship with MS.

METHODS

Patients with and without PS were evaluated prospectively.

RESULTS

Patients with PS had higher odds ratio for MS (OR 5.49). Also, ultrasonographic grade of PS was associated with MS parameters and hepatosteatosis. Pancreatic SWE value was significantly higher in PS group and positively correlated with PS grade, liver fat, MS, number of MS criteria.

DISCUSSION/CONCLUSION

PS and its grade were associated with MS. In this first comprehensive PS-SWE study, we found that pancreas stiffness increased in the presence of PS, in correlation with PS grade and MS.

Diabetic Complications: An Update on Pathobiology and Therapeutic Strategies

Despite the advent of novel therapies which manage and control diabetes well, the increased risk of morbidity and mortality in diabetic subjects is associated with the devastating secondary complications it produces. Long-standing diabetes majorly drives cellular and molecular alterations, which eventually damage both small and large blood vessels. The complications are prevalent both in type I and type II diabetic subjects. The microvascular complications include diabetic neuropathy, diabetic nephropathy, diabetic retinopathy, while the macrovascular complications include diabetic heart disease and stroke. The current therapeutic strategy alleviates the complications to some extent but does not cure or prevent them. Also, the recent clinical trial outcomes in this field are disappointing. Success in the drug discovery of diabetic complications may be achieved by a better understanding of the underlying pathophysiology and by recognising the crucial factors contributing to the development and progression of the disease. In this review, we discuss the well-studied cellular mechanisms leading to the development and progression of diabetic complications. In addition, we also highlight the various therapeutic paradigms currently in clinical practice.

Pancreatic steatosis: A frequent finding in a Chilean population

INTRODUCTION AND AIMS

Pancreatic steatosis is an incidental radiologic finding in asymptomatic patients, and its clinical importance is unclear. Primary aim: to study the prevalence of pancreatic steatosis (PS) in consecutive patients registered at our hospital, that underwent computed axial tomography (CAT) scanning of the abdomen and pelvis, excluding known pancreatic diseases. Secondary aim: to review the association of PS with the demographic and clinical data of the patients, as well as with hepatic steatosis (HS).

MATERIALS AND METHODS

An observational study was conducted on adult patients that had CAT scans of the abdomen and pelvis.

DEFINITIONS

a) tissue density was measured in Hounsfield units (HU) in five 1 cm² areas of the pancreas, three areas of the spleen, and in segments VI and VII of the liver; b) fatty pancreas: a difference < -10 HU between the mean pancreas and mean spleen densities; and c) fatty liver: density < 40 HU. We registered the epidemiologic and laboratory data of the patients. The association of those factors with the presence of PS was analyzed using SPSS version 24.0 software, and statistical significance was set at a p < 0.05.

RESULTS

Of the 203 patients, PS was found in 61 (30%). The patients with PS were significantly older and had a higher body mass index. We found no significant association with the rest of the parameters studied, nor with HS (55 patients). None of the patients had symptoms attributable to a disease of the exocrine pancreas.

CONCLUSIONS

Fatty infiltration of the pancreas is a frequent finding in CAT scans, and its clinical importance is unclear. Aging of the population and the increase in obesity underline the need for future studies on PS.

Dietary Intake of Hydrolyzable Tannins and Condensed Tannins to Regulate Lipid Metabolism

Lipid metabolism disorder is a multifactor issue, which contributes to several serious health consequences, such as obesity, hyperlipidemia, atherosclerosis diabetes, non-alcoholic fatty liver etc. Tannins, applied as natural derived plant, are commonly used in the study of lipid metabolism disease with excellent safety and effectiveness, while producing less toxic and side effects. Meanwhile, recognition of the significance of dietary tannins in lipid metabolism disease prevention has increased. As suggested by existing evidence, dietary tannins can reduce lipid accumulation, block adipocyte differentiation, enhance antioxidant capacity, increase the content of short-chain fatty acids, and lower blood lipid levels, thus alleviating lipid metabolism disorder. This study is purposed to sum up and analyze plenty of documents on tannins, so as to provide the information required to assess the lipid metabolism of tannins.