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Highlights • Periapical lesions promotes higher T-bet expression and lower GATA3 and FOXP3 expression. • Periapical lesion promotes increased GATA3 and decreased FOXP3 expression in the group with 4 periapical lesions (4PL) • The adaptive immune system, with a predominance of the Th1 polarization, may be involved in the development of insulin resistance in rats with Periapical lesions., Objective Apical periodontitis (AP) is a chronic or acute inflammatory disease usually developed from endodontic infections, predominantly due to gram-negative anaerobic bacteria invading the dental pulp. This study aimed to evaluate lymphocyte markers to assess the involvement of adaptive immunity in insulin resistance (IR) in a rat model of AP. Design. Forty-five male Wistar albino rats were divided into 3 groups (control, 1AP and 4AP). AP was induced in the upper right first molar (1AP), and in the first and second upper and lower right molars (4AP). The spleen was collected to evaluate the expression of transcription factors involved in lymphocyte polarization, including T-bet (Th1), GATA3 (Th2), and FOXP3 (Treg). Blood samples were assessed for serum cytokine levels transcribed by the respective lymphocyte polarizations, INF-γ (Th1), IL-4 (Th2) and TGF-β (Treg). In addition, glucose and insulin levels were measured to evaluate IR by the HOMA-IR method. Results The results showed higher T-bet expression on AP groups, along with lower GATA3 and FOXP3 expression in the 1AP, in addition to increased GATA3 and decreased FOXP3 expression in the 4AP group compared to the CN group. There was no difference in the INF-γ levels, while IL-4 was decreased in the AP groups. Taken together, these results suggest that the adaptive immune system, with a predominance of the Th1 polarization, may be involved in the development of IR in rats with AP. Conclusions AP promotes increase in the expression of T-bet (4AP) and decrease of FOXP3 expressions and IL-4 levels (1AP and 4AP). However, depending on the number of lesions (1 or 4 lesions), the expression of GATA3 appears differently. Thus, innate immunity and adaptive immunity may contribute to the IR observed in rats with AP.

Graphical abstract, Highlights • MetS occurs in a 1 out of 4 obese children and increases the future risk of serious health complications. • The serum level of adiponectin decreases while leptin increases as body weight increases, in the understudy children group. • The serum level of the inflammatory marker CRP increases significantly as body weight increases in the understudy population. • Adipokines and CRP can distinguish the children with Metabolic Syndrome as compared to children with no Metabolic Syndrome., Background Metabolic syndrome (MetS) occurs in a proportion of overweight and obese children and increases their future risk of serious health complications, even in adolescence and young adulthood. We aimed to explore the role of certain adipokines and inflammatory markers in identifying children with MetS. Methods This study is a secondary analysis of data coming from the Healthy Growth Study, a cross-sectional study conducted with schoolchildren in Greece. The present study included data from a representative sample of 1376 schoolchildren (mean age: 11.19 ± 0.66 years), recruited from 77 primary schools in four large regions in Greece. Anthropometric, clinical and biochemical data were recorded. Children’s body weight status and the presence of MetS were determined and their correlation with the serum levels of leptin, adiponectin and C-reactive protein (CRP) was explored. Results The prevalence of the MetS was 21.7 % and 3.7 % in obese and overweight children, respectively. The balance of adipokines was disturbed in obesity, as the serum level of adiponectin decreased as body weight increased, while the serum level of leptin increased. The serum level of the inflammatory marker CRP increased significantly as body weight increased. Discriminant analysis showed that these factors could distinguish the children with MetS as compared to children with no MetS. Conclusions In the under study Mediterranean childhood population, monitoring of the levels of adipokines and CRP could identify the overweight and obese children with MetS. Appropriate individualized dietary and lifestyle interventions can be applied in these children to prevent health complications associated with MetS.

Objective Insulin antibody (IA)-mediated insulin resistance (IR) is a rare condition for which immunosuppressive regimens have been described. However, these raise the risk of infection, and the drugs may not be effectively metabolized in patients with liver disease. A 61-year old male with type 2 diabetes mellitus and antibody-mediated IR who required >800 units of daily insulin presented with acute decompensation of his preexisting cirrhosis from recurrent diabetic ketoacidosis. Laboratory tests confirmed an IA level of >625 μU/mL (reference: Methods Centrifugal plasmapheresis and mycophenolate mofetil (MMF) were used to treat the patient to achieve glycemic control. Continuous glucose monitoring was implemented to monitor glycemic control pre- and posttherapy. Laboratory evaluation included levels of IA, C-peptide, insulin-like growth factor-1, growth hormone, salivary cortisol, zinc transporter 8, glutamic acid decarboxylase 65-kilodalton isoform antibody, and islet-cell antibodies. Results We initiated MMF followed by 5 sessions of plasmapheresis, leading to an overall 77.3% reduction from pretherapy insulin requirements after 6 months without further episodes of diabetic ketoacidosis or infection. The cirrhosis stabilized, and there was an improvement in HbA1C from 8.7% (72 mmol/mol) to 6.6% (49 mmol/mol) and time in euglycemic range from 30% to 61%. Conclusion This is the first report of MMF and centrifugal plasmapheresis use to mitigate the effects of IA-mediated IR in a patient with cirrhosis. We recommend further studies to determine the utility of this treatment to improve care for patients at high risk for IA-mediated IR.

Highlights • Definition and pathogenesis of metabolic syndrome is briefly described. • Sesquiterpene lactones isolated from medicinal plants used in traditional medicine. • In vivo and in vitro biological activities of sesquiterpene lactones are considered. • Chemical and biological properties of natural sesquiterpene lactones are documented., Metabolic syndrome comprises a cluster of metabolic disorders related to the development of cardiovascular disease and type 2 diabetes mellitus. In latter years, plant secondary metabolites have become of special interest because of their potential role in preventing and managing metabolic syndrome. Sesquiterpene lactones constitute a large and diverse group of biologically active compounds widely distributed in several medicinal plants used for the treatment of metabolic disorders. The structural diversity and the broad spectrum of biological activities of these compounds drew significant interests in the pharmacological applications. This review describes selected sesquiterpene lactones that have been experimentally validated for their biological activities related to risk factors of metabolic syndrome, together with their mechanisms of action. The potential beneficial effects of sesquiterpene lactones discussed in this review demonstrate that these substances represent remarkable compounds with a diversity of molecular structure and high biological activity, providing new insights into the possible role in metabolic syndrome management.

Graphical abstract, Highlights • Hypothyroidism is the most frequent toxic effect of a large variety of chemical compounds. • The polyherbal bioactive fraction exhibited a pro-thyroid effect in hypothyroidic rats. • The polyherbal fraction restored the propylthiouracil-depleted thyroid hormone levels significantly. • The polyherbal fraction may act through multiple mechanisms to exhibit a pro-thyroid effect., Hypothyroidism is the most frequent consequence of the interaction of a large variety of drugs, environmental pollutants and industrial chemicals with the thyroid gland. It is associated with diminished endocrine function which may lead to hyperlipidemia, diabetes, Alzheimer’s disease, weight gain, and other metabolic disorders. The present study evaluates the pro-thyroid activity of a bioactive fraction from a polyherbal teabag in rats with hypothyroidism induced by propylthiouracil. The teabag was formulated to stimulate synthesis and/or release of T4 and affectthe conversion of T4 to T3. Phytoconstituents of the polyherbal teabag are potent antioxidants that may be responsible for the pro-thyroid activity. The tea-extract (1000 mg) was found to contain 1076 μg of gallic acid and 1131 μg of rutin from HPTLC analysis. Rats received propylthiouracil (8 mg/kg) for the first 15days followed by the polyherbal tea-extract (500, 1000 and 1500 mg/kg), the standard drug levothyroxine (0.1 mg/kg), aerobic exercise, and a combination of tea-extract (1000 mg/kg) and aerobic exercise daily along with propylthiouracil for the next 30 days. Finally, rats received their respective treatments alone without propylthiouracil for 15 more days. Lipid profile and levels of glucose, insulin, T3, T4, TSH, cortisol, homocysteine, creatinine, uric acid, malondialdehyde, glucose-6 phosphatase, and endogenous antioxidants were determined. All treatments attenuated significantly the propylthiouracil-elevated TSH, homocysteine, creatinine, uric acid, glucose-6-phosphatase, insulin, and malondialdehyde levels, and restored favorably the propylthiouracil-altered lipid profile, T3, T4, and endogenous antioxidant levels. The polyherbal tea-extract (1000 and 1500 mg/kg) treatment and thecombination treatment of tea-extract (1000 mg/kg) with aerobic exercise displayed significant restoration of the suboptimalthyroid function. This may be due to a favorablemodulation ofthe hypothalamic-pituitary–thyroid and the hypothalamic–pituitary–adrenal axes.

The incidence of Alzheimer’s disease (AD) has risen exponentially worldwide over the past decade. A growing body of research indicates that AD is linked to diabetes mellitus (DM) and suggests that impaired insulin signaling acts as a crucial risk factor in determining the progression of this devastating disease. Many studies suggest people with diabetes, especially type 2 diabetes, are at higher risk of eventually developing Alzheimer's dementia or other dementias. Despite nationwide efforts to increase awareness, the prevalence of Diabetes Mellitus (DM) has risen significantly in the Middle East and North African (MENA) region which might be due to rapid urbanization, lifestyle changes, lack of physical activity and rise in obesity. Growing body of evidence indicates that DM and AD are linked because both conditions involve impaired glucose homeostasis and altered brain function. Current theories and hypothesis clearly implicate that defective insulin signaling in the brain contributes to synaptic dysfunction and cognitive deficits in AD. In the periphery, low-grade chronic inflammation leads to insulin resistance followed by tissue deterioration. Thus insulin resistance acts as a bridge between DM and AD. There is pressing need to understand on how DM increases the risk of AD as well as the underlying mechanisms, due to the projected increase in age related disorders. Here we aim to review the incidence of AD and DM in the Middle East and the possible link between insulin signaling and ApoE carrier status on Aβ aggregation, tau hyperphosphorylation, inflammation, oxidative stress and mitochondrial dysfunction in AD. We also critically reviewed mutation studies in Arab population which might influence DM induced AD. In addition, recent clinical trials and animal studies conducted to evaluate the efficiency of anti-diabetic drugs have been reviewed. Keywords: Diabetes mellitus, Alzheimer’s disease, Insulin signaling, Arab population, Anti-diabetic drugs

Objective The molecular pathogenesis of late complications associated with type 2 diabetes mellitus (T2DM) is not yet fully understood. While high glucose levels indicated by increased HbA1c only poorly explain disease progression and late complications, a pro-inflammatory status, oxidative stress, and reactive metabolites generated by metabolic processes were postulated to be involved. Individuals with metabolic syndrome (MetS) frequently progress to T2DM, whereby 70% of patients with T2DM show non-alcoholic fatty liver disease (NAFLD), the hepatic manifestation of MetS, and insulin resistance (IR). Epidemiological studies have shown that T2DM and steatosis are associated with alterations in iron metabolism and hepatic iron accumulation. Excess free iron triggers oxidative stress and a switch towards a macrophage pro-inflammatory status. However, so far it remains unclear whether hepatic iron accumulation plays a causative role in the generation of IR and T2DM or whether it is merely a manifestation of altered hepatic metabolism. To address this open question, we generated and characterized a mouse model of T2DM with IR, steatosis, and iron overload. Methods Leprdb/db mice hallmarked by T2DM, IR and steatosis were crossed with Fpnwt/C326S mice with systemic iron overload to generate Leprdb/db/Fpnwt/C326S mice. The resulting progeny was characterized for major diabetic and iron-related parameters. Results We demonstrated that features associated with T2DM in Leprdb/db mice, such as obesity, steatosis, or IR, reduce the degree of tissue iron overload in Fpnwt/C326S mice, suggesting an ‘iron resistance’ phenotype. Conversely, we observed increased serum iron levels that strongly exceeded those in the iron-overloaded Fpnwt/C326S mice. Increased hepatic iron levels induced oxidative stress and lipid peroxidation and aggravated IR, as indicated by diminished IRS1 phosphorylation and AKT activation. Additionally, in the liver, we observed gene response patterns indicative of de novo lipogenesis and increased gluconeogenesis as well as elevated free glucose levels. Finally, we showed that iron overload in Leprdb/db/Fpnwt/C326S mice enhances microvascular complications observed in retinopathy, suggesting that iron accumulation can enhance diabetic late complications associated with the liver and the eye. Conclusion Taken together, our data show that iron causes the worsening of symptoms associated with the MetS and T2DM. These findings imply that iron depletion strategies together with anti-diabetic drugs may ameliorate IR and diabetic late complications., Highlights • T2DM causes an iron resistance phenotype. • Iron affects hepatic insulin resistance. • Systemic iron accumulation aggravates diabetic pericyte loss.

Background The prevalence of obesity and metabolic diseases continues to rise globally. The increased consumption of unhealthy energy-rich diets that are high in fat and sugars results in oxidative stress and inflammation leading to hypothalamic dysfunction, which has been linked with these diseases. Conversely, diets rich in polyphenols, which are phytochemicals known for their antioxidant and anti-inflammatory properties, are associated with a reduced risk for developing metabolic diseases. Scope of review This review provides an overview of the effects of polyphenols against diet-induced hypothalamic dysfunction with respect to neural inflammation and mitochondrial dysfunction. Results show that polyphenols ameliorate oxidative stress and inflammation within the hypothalamus, thereby improving leptin signaling and mitochondrial biogenesis. Furthermore, they protect against neurodegeneration by decreasing the production of reactive oxygen species and enhancing natural antioxidant defense systems. Major conclusions The potential of polyphenols as nutraceuticals against hypothalamic inflammation, mitochondrial dysfunction, and neurodegeneration could hold tremendous value. With hypothalamic inflammation increasing naturally with age, the potential to modulate these processes in order to extend longevity is exciting and warrants exploration. The continued escalation of mental health disorders, which are characterized by heightened neuronal inflammation, necessitates the furthered investigation into polyphenol therapeutic usage in this regard., Graphical abstract Image 1, Highlights • Unhealthy diets high in fat and sugar can cause hypothalamic inflammation. • Hypothalamic dysfunction causes obesity, cardiovascular and neurological disorders. • Diets high in phytochemicals can reduce the risk of obesity and metabolic diseases. • Polyphenols allay harmful dietary effects by preventing hypothalamic inflammation. • Polyphenols protects against neuron damage and can improve overall human health.

Non-alcoholic steatohepatitis (NASH) is a chronic metabolic syndrome and the CFLAR-JNK pathway can reverse the process of NASH. Although silibinin is used for the treatment of NASH in clinical, its effect on CFLAR-JNK pathway in NASH remains unclear. This study aimed to investigate the effect of silibinin on CFLAR-JNK pathway in NASH models both in vivo and in vitro. The in vivo study was performed using male C57BL/6 mice fed with methionine– choline-deficient diet and simultaneously treated with silibinin for 6 weeks. The in vitro study was performed by using mouse NCTC-1469 cells which were respectively pretreated with oleic acid plus palmitic acid, and adenovirus-down Cflar for 24 h, then treated with silibinin for 24 h. After the drug treatment, the key indicators involved in CFLAR-JNK pathway including hepatic injury, lipid metabolism and oxidative stress were determined. Silibinin significantly activated CFLAR and inhibited the phosphorylation of JNK, up-regulated the mRNA expression of Pparα, Fabp5, Cpt1α, Acox, Scd-1, Gpat and Mttp, reduced the activities of serum ALT and AST and the contents of hepatic TG, TC and MDA, increased the expression of NRF2 and the activities of CAT, GSH-Px and HO-1, and decreased the activities and expression of CYP2E1 and CYP4A in vivo. These effects were confirmed by the in vitro experiments. Silibinin prevented NASH by regulating CFLAR-JNK pathway, and thereby on one hand promoting the β-oxidation and efflux of fatty acids in liver to relieve lipid accumulation, and on the other hand inducing antioxidase activity (CAT, GSH-Px and HO-1) and inhibiting pro-oxidase activity (CYP2E1 and CYP4A) to relieve oxidative stress., Graphical abstract Silibinin could regulate CFLAR-JNK pathway to ameliorates hepatic lipid accumulation, insulin resistence and oxidative stress in C57BL/6 mice treated by methionine- and choline-deficient diet, and NCTC-1469 cells treated by the mixture of oleic acid and palmitic acid and adenovirus-down Cflar.fx1

Background & Aims The first-line treatment for non-alcoholic fatty liver disease (NAFLD) is weight reduction. Several diets have been proposed, with various effects specifically on liver steatosis. This trial compared the effects of intermittent calorie restriction (the 5:2 diet) and a low-carb high-fat diet (LCHF) on reduction of hepatic steatosis. Methods We conducted an open-label randomised controlled trial that included 74 patients with NAFLD randomised in a 1:1:1 ratio to 12 weeks’ treatment with either a LCHF or 5:2 diet, or general lifestyle advice from a hepatologist (standard of care; SoC). The primary outcome was reduction of hepatic steatosis as measured by magnetic resonance spectroscopy. Secondary outcomes included transient elastography, insulin resistance, blood lipids, and anthropometrics. Results The LCHF and 5:2 diets were both superior to SoC treatment in reducing steatosis (absolute reduction: LCHF: −7.2% [95% CI = −9.3 to −5.1], 5:2: −6.1% [95% CI = −8.1 to −4.2], SoC: −3.6% [95% CI = −5.8 to −1.5]) and body weight (LCHF: −7.3 kg [95% CI = −9.6 to −5.0]; 5:2: −7.4 kg [95% CI = −8.7 to −6.0]; SoC: −2.5 kg [95% CI =−3.5 to −1.5]. There was no difference between 5:2 and LCHF (p = 0.41 for steatosis and 0.78 for weight). Liver stiffness improved in the 5:2 and SoC but not in the LCHF group. The 5:2 diet was associated with reduced LDL levels and was tolerated to a higher degree than LCHF. Conclusions The LCHF and 5:2 diets were more effective in reducing steatosis and body weight in patients with NAFLD than SoC, suggesting dietary advice can be tailored to meet individual preferences. Lay summary For a person with obesity who suffers from fatty liver, weight loss through diet can be an effective treatment to improve the condition of the liver. Many popular diets that are recommended for weight reduction, such as high-fat diets and diets based on intermittent fasting, have not had their effects on the liver directly evaluated. This study shows that both a low-carb high-fat and the 5:2 diet are effective in treating fatty liver caused by obesity. Clinical Trials Registration This study is registered at Clinicaltrials.gov (NCT03118310)., Graphical abstract, Highlights • Weight reduction is the only generally available treatment for NAFLD today. • High-fat diets, such as the LCHF, are controversial in treating NAFLD. • The 5:2 diet has become popular and is widely used to achieve weight loss. • In this RCT, both the LCHF and 5:2 diets were highly effective in treating NAFLD. • The 5:2 diet reduced LDL and liver stiffness and was tolerated to a higher degree.

Background & Aims Plasma bile acids (BAs) have been extensively studied as pathophysiological actors in non-alcoholic steatohepatitis (NASH). However, results from clinical studies are often complicated by the association of NASH with type 2 diabetes (T2D), obesity, and insulin resistance (IR). Here, we sought to dissect the relationship between NASH, T2D, and plasma BA levels in a large patient cohort. Methods Four groups of patients from the Biological Atlas of Severe Obesity (ABOS) cohort (Clinical Trials number NCT01129297) were included based on the presence or absence of histologically evaluated NASH with or without coincident T2D. Patients were matched for BMI, homeostatic model assessment 2 (HOMA2)-assessed IR, glycated haemoglobin, age, and gender. To study the effect of IR and BMI on the association of plasma BA and NASH, patients from the HEPADIP study were included. In both cohorts, fasting plasma BA concentrations were measured. Results Plasma BA concentrations were higher in NASH compared with No-NASH patients both in T2D and NoT2D patients from the ABOS cohort. As we previously reported that plasma BA levels were unaltered in NASH patients of the HEPADIP cohort, we assessed the impact of BMI and IR on the association of NASH and BA on the combined BA datasets. Our results revealed that NASH-associated increases in plasma total cholic acid (CA) concentrations depend on the degree of HOMA2-assessed systemic IR, but not on β-cell function nor on BMI. Conclusions Plasma BA concentrations are elevated only in those NASH patients exhibiting pronounced IR. Lay summary Non-alcoholic steatohepatitis (NASH) is a progressive liver disease that frequently occurs in patients with obesity and type 2 diabetes. Reliable markers for the diagnosis of NASH are needed. Plasma bile acids have been proposed as NASH biomarkers. Herein, we found that plasma bile acids are only elevated in patients with NASH when significant insulin resistance is present, limiting their utility as NASH markers., Graphical abstract, Highlights • Bile acids have been studied as pathophysiological actors and biomarkers in NASH. • Plasma BAs have been reported to be higher in NASH vs. No-NASH patients. • Plasma BAs are altered in patients with T2D, IR, and obesity, risk factors for NASH. • Thus, the independent association between plasma BA increases and NASH is unclear. • NASH-associated increases in plasma BA depend on the degree of insulin sensitivity.

Cyclic AMP-responsive element-binding protein H (CREBH encoded by Creb3l3) is a transcription factor that regulates the expression of genes that control lipid and glucose metabolism as well as inflammation. CREBH is upregulated in the liver under conditions of overnutrition, and mice globally lacking the gene (CREBH-/-) are highly susceptible to diet-induced obesity, insulin resistance, and hepatic steatosis. The net protective effects of CREBH have been attributed in large part to the activities of fibroblast growth factor (Fgf)-21 (Fgf21), a target gene that promotes weight loss, improves glucose homeostasis, and reduces hepatic lipid accumulation. To explore the possibility that activation of the CREBH–Fgf21 axis could ameliorate established effects of high-fat feeding, we generated an inducible transgenic hepatocyte-specific CREBH overexpression mouse model (Tg-rtTA). Acute overexpression of CREBH in livers of Tg-rtTA mice effectively reversed diet-induced obesity, insulin resistance, and hepatic steatosis. These changes were associated with increased activities of thermogenic brown and beige adipose tissues in Tg-rtTA mice, leading to reductions in fat mass, along with enhanced insulin sensitivity and glucose tolerance. Genetically silencing Fgf21 in Tg-rtTA mice abrogated the CREBH-mediated reductions in body weight loss, but only partially reversed the observed improvements in glucose metabolism. These findings reveal that the protective effects of CREBH activation may be leveraged to mitigate diet-induced obesity and associated metabolic abnormalities in both Fgf21-dependent and Fgf21-independent pathways.

Purpose We present 3 cases of Alstrom syndrome (ALMS) that highlight the importance of the ophthalmic exam, as well as the diagnostic challenges and management considerations of this ultra-rare disease. Observations The first case is of a 2-year-old boy with history of spasmus nutans who presented with head bobbing and nystagmus. The second patient is a 5-year-old boy with history of infantile dilated cardiomyopathy status post heart transplant, Burkitt lymphoma status post chemotherapy, obesity, global developmental delay, and high hyperopia previously thought to have cortical visual impairment secondary to heart surgery/possible ischemic event. This patient presented with nystagmus, photophobia, and reduced vision. The third case involves a 8-year-old boy with history of obesity, bilateral optic nerve atrophy, hyperopic astigmatism, exotropia, and nystagmus. Upon presentation to the consulting pediatric ophthalmologist, none of the patients had yet been diagnosed with ALMS. All 3 cases were subsequently found to have an electroretinogram (ERG) that exhibited severe global depression and to carry ALMS1 pathogenic variants. Conclusions and Importance: ALMS is an autosomal recessive disease caused by ALMS1 variations, characterized by cone-rod dystrophy, obesity, progressive sensorineural hearing loss, cardiomyopathy, insulin resistance, and multiorgan dysfunction. Retinal dystrophy diagnosis is critical given clinical criteria and detection rates of genetic testing. Early diagnosis is extremely important because progression to flat ERG leads to the inability to differentiate between rod-cone or cone-rod involvement, either of which have their own differential diagnoses. In our series, the ophthalmic exam and abnormal ERG prompted further genetic testing and the subsequent diagnosis of ALMS. Multidisciplinary care ensures the best possible outcome with the ophthalmologist playing a key role.

Highlights • PCOS women could be more exposed to SARS-CoV-2 infection: hyperandrogenism and insulin resistance could play a determining role in the pathophysiogenesis of the infection., The new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has been associated with acute respiratory distress syndrome and infected patients have a relatively high risk of death. Emerging risk factors for poor outcome in this disease include age, male gender, cardiovascular co-morbidities including hypertension, prior cardiovascular disease, diabetes and more recently obesity. To date there are no data relating to SARS-CoV-2 in PCOS women. The present Clinical Opinion represents a summary of the epidemiological evidence and possible pathophysiological mechanisms regarding PCOS and COVID-19. PCOS women could be more susceptible to infections compared to non-PCOS women. Insulin resistance and the associated hyperinsulinaemia are drivers for enhanced steroidogenesis in women with PCOS. Weight-gain and obesity, through their worsening effects on insulin resistance, thereby drive enhanced steroidogenesis and hyperandrogenism. All these features represent key points to provide an explanation for the possible association between PCOS and SARS-CoV-2. Indeed, androgens may drive clinical results in COVID-19, through the expression of TMPRSS2, a cellular co-receptor necessary for SARS-CoV-2 infection and through androgen-mediated immune modulation. In women with PCOS the endocrine-immune axis leads to immune dysfunction with a state of chronic inflammation, and hyperandrogenism and IR with compensatory hyperglycaemia could play a determining role in the pathophysiogenesis of the infection. However, it is possible that only specific PCOS phenotypes may be more susceptible. In addition, vitamin D deficiency and gut dysbiosis are another important factor potentially involved in the increased risk of developing severe forms of COVID-19 in PCOS women. Further scientific investigations are needed with the aim of understanding which women are most at risk of becoming infected or developing complications, what are the causal mechanisms on which it is possible to intervene with prophylactic and therapeutic measures and what the long-term consequences will be on the health of these patients.

• This is a special issue of “Metabolism” dedicated to nonalcoholic fatty liver disease. • Experts in the field provide an overview of recent progress and developments in NAFLD and offer their expert opinion on future directions. • NAFLD remains a highly prevalent disease without an approved treatment.

Metabolic syndrome (MS) refers to a clustering of at least three of the following medical conditions: high blood pressure, abdominal obesity, hyperglycemia, low high-density lipoprotein level, and high serum triglycerides. MS is related to a wide range of diseases which includes obesity, diabetes, insulin resistance, cardiovascular disease, dyslipidemia, or non-alcoholic fatty liver disease. There remains an ongoing need for improved treatment strategies for MS. The most important risk factors are dietary pattern, genetics, old age, lack of exercise, disrupted biology, medication usage, and excessive alcohol consumption, but pathophysiology of MS has not been completely identified. Korean Red Ginseng (KRG) refers to steamed/dried ginseng, traditionally associated with beneficial effects such as anti-inflammation, anti-fatigue, anti-obesity, anti-oxidant, and anti-cancer effects. KRG has been often used in traditional medicine to treat multiple metabolic conditions. This paper summarizes the effects of KRG in MS and related diseases such as obesity, cardiovascular disease, insulin resistance, diabetes, dyslipidemia, or non-alcoholic fatty liver disease based on experimental research and clinical studies., Graphical abstract Image 1

Type 2 diabetes (T2D) has become a global epidemic. Although several drugs are available to manage T2D, problems associated with person-to-person variability in drug efficacy and potential side-effects remain unresolved. Owing to the emerging role of the gut microbiome in obesity and T2D, the interaction between gut microbes and anti-diabetic drugs and its influence on drugs' functions remains of immediate research interest. On one hand, drugs can manipulate gut microbiome composition and metabolic capacity. Conversely, the metabolic activities of the microbiome and its metabolites can also influence drug metabolism and effects. Hence, understanding this bi-directional drug-microbiome interaction and how it influences the clinical outcomes of antidiabetic drugs can pave the way to develop next-generation strategies to ameliorate diabetes. This review presents evidences demonstrating the putative interactions between anti-diabetic drugs and the gut microbiome, and discusses the potential of microbiome modulators to manipulate drug-microbiome interactions and the drug metabolism., Graphical abstract Unlabelled Image, Highlights • Gut microbes interact with medications used to treat T2D, that at least partially mediates potential benefits of these drugs. • Anti-diabetic drugs impact gut microbiome and its metabolic activity and vice-versa. • Understanding the dynamics of drug-microbiome cross-talk would offer better therapeutic outcomes for diabetes.

Summary Background & aims Postoperative hyperglycaemia is common in patients having major surgery and is associated with adverse outcomes. This study aimed to determine whether bacteraemia contributed to postoperative systemic inflammation, and whether increases in the expression of muscle mRNAs and proteins reflecting increased muscle inflammation, atrophy and impaired carbohydrate oxidation were evident at the time of surgery, and both local and distant to the site of trauma, and could be associated with impaired glucoregulation. Methods Fifteen adult patients without diabetes undergoing major abdominal surgery participated in this observational study set in a university teaching hospital. Arterialised-venous blood samples and muscle biopsies were obtained before and after major elective abdominal surgery, from sites local (rectus abdominis – RA) and remote to the site of surgery (vastus lateralis – VL). The main outcome measures included blood glucose concentrations, gut permeability and changes in expression of muscle mRNAs and proteins linked to inflammation and glucose regulation. Results Immediately postoperatively, RA demonstrated markedly increased mRNA expression levels of cathepsin-L (7.5-fold, P

Background Children exposed to gestational diabetes mellitus (GDM) in utero are at increased risk of neurodevelopmental difficulties, including autism and impaired motor control. However, the underlying neurophysiology is unknown. Methods Using transcranial magnetic stimulation, we assessed cortical excitability, long-term depression (LTD)-like neuroplasticity in 45 GDM-exposed and 12 control children aged 11–13 years. Data were analysed against salivary cortisol and maternal diabetes severity and treatment (insulin [N = 22] or metformin [N = 23]) during pregnancy. Findings GDM-exposed children had reduced cortical excitability (p = .003), LTD-like neuroplasticity (p = .005), and salivary cortisol (p, Highlights • Children exposed to gestational diabetes (GDM) had lower cortical excitability, measured as higher resting motor thresholds. • The GDM group also exhibited smaller LTD-like neuroplastic responses to repetitive brain stimulation. • These were associated with lower salivary cortisol and with maternal diabetes severity, especially insulin resistance. Our results suggest that gestational diabetes, even when detected and treated as per clinical guidelines, has subtle effects on important neurophysiological processes persisting into early adolescence, including neuroplasticity and possibly cortisol secretion. The extent of these effects is related to the severity of maternal diabetes, particularly insulin resistance, during mid pregnancy. These results may aid in understanding how insulin resistance and hyperglycemia affect the developing brain. Further, our results indicate that earlier detection and pharmacologic treatment of gestational diabetes may attenuate or prevent these changes to neurodevelopment, and that maternal metformin treatment does not influence these aspects of development.

The metabolic risk factors (RF) to the diagnosis of metabolic syndrome (MetS) have been evidenced at early ages, including children. The aim of the present study was to identify the prevalence of RF to the diagnosis of MetS and its association with nutritional status of schoolchildren from 6 to 10 years old. A cross-sectional study was carried out in 505 students of municipal schools in Macae, Brazil, conducted from 2013 to 2014. The RF evaluated were: blood pressure (mm Hg), triglycerides (mmol/L), HDL-cholesterol (mmol/L) fasting glucose (mmol/L) and waist circumference (cm). At least one RF was present in 61% (n = 308) of the sample. By nutritional status, there was higher prevalence of RF in overweight/obese schoolchildren compared to those with normal weight, except in the concentration of HDL-c. The prevalence of one, two and three RF (MetS) were 34.7% (n = 175), 21.0% (n = 106) and 5.3% (n = 27), respectively. Two RF were more present in overweight (28.2% 95%CI 19.0; 39.0) and obese (41.5% 95%CI 31.4; 52.1) compared to normal weight children (13.5% 95%CI 9.9; 17.8). Three or more RF were more frequent among obese (25.5% 95%CI 17.0; 35.5) in relation to overweight (2.4% 95%CI 0.2; 8.2) and normal weight children (0.3% 95%CI 0; 1.7). The data indicate high prevalence of RF and its relationship with the magnitude of body weight excess. Therefore, the identification and early treatment of these RF might minimize the risk of MetS and related diseases., Highlights • Overweight and obesity are associated with metabolic syndrome's risk factors. • Overweight/obesity is associated with the concomitant presence of two risk factors. • Obesity is associated with the concomitant presence of three risk factors. • Avoiding overweight/obesity in children can reduce cardiometabolic risks.

Background & Aims The inverse association between non-alcoholic fatty liver disease (NAFLD) and diets rich in fruit and vegetables has been demonstrated, but the specific compounds that may be responsible for this association need to be elucidated. The aim of this study was to test the association between phenolic acid consumption, NAFLD, and insulin resistance (IR). Methods A cross-sectional cohort of individuals included in a metabolic screening program was studied. Liver steatosis was evaluated by ultrasonography and quantified by the hepatorenal index (HRI); fibrosis was assessed by FibroTest; IR by the sample upper quartile of the homeostatic model assessment score. Dietary intake was measured by a food frequency questionnaire. The phenolic acid content of food was calculated according to Phenol-Explorer. Results A total of 789 individuals were included (52.6% men, age 58.83 ± 6.58 years). Higher (above the upper median) phenolic acid intake was inversely associated with the presence of NAFLD (odds ratio [OR] 0.69; 95% CI 0.49–0.98; p = 0.036), higher HRI (OR 0.64; 95% CI 0.45–0.91; p = 0.013) and higher IR (OR 0.61; 95% CI 0.42–0.87; p = 0.007), when adjusted for age, gender, body mass index, and lifestyle factors. Considering specific classes of phenolic acids, higher hydroxybenzoic acid intake was independently associated with lower odds of NAFLD, higher HRI and fibrosis. Higher hydroxycinnamic acid intake was independently associated with lower odds of IR. Conclusion A higher intake of phenolic acids is associated with a lower prevalence of liver steatosis and IR in a cross-sectional study, suggesting a possible protective effect that requires confirmation in prospective studies. Lay summary High dietary intake of total phenolic acids is associated with a lower prevalence of non-alcoholic fatty liver disease and insulin resistance. A high intake of hydroxybenzoic acids, a class of phenolic acids, is associated with a lower prevalence of steatosis and clinically significant fibrosis, while a high intake of hydroxycinnamic acids, another class of phenolic acids, is associated with a lower prevalence of insulin resistance., Graphical abstract, Highlights • High intake of total phenolic acids is associated with a lower prevalence of NAFLD and insulin resistance. • High intake of hydroxybenzoic acids is associated with a lower prevalence of steatosis and fibrosis. • High intake of hydroxycinnamic acids is associated with lower prevalence of insulin resistance.

Introduction Male obesity has a negative correlation with plasma testosterone (T) levels and sexual function (SF). Aim To evaluate the effect of weight loss through bariatric surgery (BS) on SF, low T symptoms, and hormonal profiles in obese men. Methods Thirty-three men who underwent BS participated in this cohort study. Before surgery, all participants underwent clinical examinations, including anthropometric, lipid, glycemic, and hormonal evaluations. SF was evaluated using the International Index of Erectile Function (IIEF) questionnaire; low T symptoms were evaluated using the Aging Males’ Symptoms (AMS) and Androgen Deficiency in the Aging Male (ADAM) questionnaires. The participants were reevaluated 6 months post-surgery. Main outcome measures Sex hormone profile, SF, and low T symptoms Results After BS, a significant increase in mean total T (201 ± 111–548 ± 190 ng/dL, P < .001), free T (5.8 ± 2.8–9.3 ± 3.4 ng/dL, P < .001), bioavailable T (110.3 ± 57.8–198.6 ± 74.3 ng/dL, P < .001), and sexual hormone-binding globulin (19.8 ± 13.7–54.6 ± 23.2 nmol/L, P < .001) levels. There was a significant decrease in estradiol (64.6 ± 27.4–29.2 ± 20.0 [pg/mL], P < .001). SF significantly improved. The total IIEF score increased 5.2 points (62.3 ± 7.4–67.5 ± 7.4, P = .004), erectile function subdomain increased 2.4 points (25.7 ± 4.1–28.1 ± 3.9, P = .011), desire subdomain increased 1.0 points (8.3 ± 1.5–9.3 ± 1.6, P = .006), and intercourse satisfaction subdomain increased 1.2 points (11.4 ± 1.9–12.6 ± 1.8, P = .012). Post-surgery, a 44% reduction (P = .001) was observed in the positive ADAM questionnaire, and improvements in all domains of the AMS questionnaire were found (P < .001). Conclusion Significant weight loss through BS improves erectile function, hormonal profile, and symptoms of T deficiency. Machado FP, Rhoden EL, Pioner SR, et al. Weight Loss Through Bariatric Surgery in Men Presents Beneficial Effects on Sexual Function, Symptoms of Testosterone Deficiency, and Hormonal Profile. Sex Med 2021;9:100400.

Background The rs17618244 G>A β-Klotho (KLB) variant has been associated with increased risk of ballooning and inflammation in pediatric patients with metabolic associated fatty liver disease (MAFLD), by reducing KLB expression. In hepatocytes, KLB downregulation induced fat accumulation and the expression of inflammatory and lipotoxic genes. We aimed to examine firstly the impact of the KLB rs17618244 variation on liver damage in adult patients with MAFLD and secondly its effect on hepatic stellate cells (HSCs) activation. Methods The impact of the KLB rs17618244 variant on histological liver damage was surveyed in a retrospective cohort of 1111 adult patients with MAFLD. Subgroup analysis was performed according to the presence of obesity (BMI>35; n = 708). Immortalized HSCs (LX-2) were transfected with the KLB wild type (LX-2_KLBwt), or with the mutant one carrying the rs17618244 (LX-2_KLBmut). Findings At ordinal regression analysis the KLB rs17618244 variant was associated with hepatic fibrosis (OR 1.23, 95% C.I.1.004–1.51; p = 0.04), but not with steatosis, inflammation and ballooning. By stratifying patients according to the presence of obesity, the KLB A allele was further associated with lobular inflammation (OR 1.32, 95% C.I.1.02–1.72; p = 0.03) and cirrhosis (OR 2.51, 95% C.I.1.23–5.05; p = 0.01) Moreover, hepatic KLB expression correlated with that of fibrogenic genes. LX-2_KLBmut cells showed reduced KLB protein levels paralleled by an induction of pro-fibrogenic genes and enhanced proliferative rate. Interpretation The KLB rs17618244 variant is associated with hepatic fibrosis, inflammation and cirrhosis mainly in obese patients with MAFLD and HSCs which carry this mutation are highly proliferative and acquire a myofibroblast-like phenotype. Funding Ricerca Finalizzata Ministero della Salute GR-2019–12,370,172 (NP), Ricerca Corrente Fondazione IRCCS Ca Granda (PD and ALF), Ricerca Finalizzata Ministero della Salute RF-2013–02,358,319 (ALF), and Ricerca Corrente and 5 × 1000 Ministero della Salute (AA).

Objective Elevated serum ferritin has been linked to type 2 diabetes (T2D) and adverse health outcomes in subjects with the Metabolic Syndrome (MetS). As the mechanisms underlying the negative impact of excess iron have so far remained elusive, we aimed to identify potential links between iron homeostasis and metabolic pathways. Methods In a cross-sectional study, data were obtained from 163 patients, allocated to one of three groups: (1) lean, healthy controls (n = 53), (2) MetS without hyperferritinemia (n = 54) and (3) MetS with hyperferritinemia (n = 56). An additional phlebotomy study included 29 patients with biopsy-proven iron overload before and after iron removal. A detailed clinical and biochemical characterization was obtained and metabolomic profiling was performed via a targeted metabolomics approach. Results Subjects with MetS and elevated ferritin had higher fasting glucose (p, Highlights • This metabolomic study focuses on pathways linking iron status to insulin resistance. • Metabolomic differences in Metabolic Syndrome with/without iron overload are shown. • Phlebotomy changes methionine, glutamate and long-chain phosphatidylcholines levels. • Phosphatidylcholines are involved in the interaction of iron and glucose homeostasis.

It is not known if the mitochondria-targeted antioxidants such as mitoquinone (MitoQ) can modulate oxidative stress and leukocyte-endothelium interactions in T2D patients. We aimed to evaluate the beneficial effect of MitoQ on oxidative stress parameters and leukocyte-endothelium interactions in leukocytes of T2D patients. The study population consisted of 98 T2D patients and 71 control subjects. We assessed metabolic and anthropometric parameters, mitochondrial reactive oxygen species (ROS) production, glutathione peroxidase 1 (GPX-1), NFκB-p65, TNFα and leukocyte-endothelium interactions. Diabetic patients exhibited higher weight, BMI, waist circumference, SBP, DBP, glucose, insulin, HOMA-IR, HbA1c, triglycerides, hs-CRP and lower HDL-c with respect to controls. Mitochondrial ROS production was enhanced in T2D patients and decreased by MitoQ. The antioxidant also increased GPX-1 levels and PMN rolling velocity and decreased PMN rolling flux and PMN adhesion in T2D patients. NFκB-p65 and TNFα were augmented in T2D and were both reduced by MitoQ treatment. Our findings support that the antioxidant MitoQ has an anti-inflammatory and antioxidant action in the leukocytes of T2D patients by decreasing ROS production, leukocyte-endothelium interactions and TNFα through the action of NFκB. These data suggest that mitochondria-targeted antioxidants such as MitoQ should be investigated as a novel means of preventing cardiovascular events in T2D patients., Graphical abstract fx1, Highlights • Mitochondrial ROS production was enhanced in diabetic leukocytes and reduced by MitoQ. • MitoQ treatment increased GPX-1 levels in T2D leukocytes. • MitoQ increased PMN rolling velocity and decreased PMN rolling flux and adhesion. • NFκB-p65 and TNFα were augmented in T2D and were both reduced by MitoQ treatment. • MitoQ should be investigated as a novel means of reducing cardiovascular risk in T2D.

A low-sodium (LS) diet has been shown to reduce blood pressure (BP) and the incidence of cardiovascular diseases. However, severe dietary sodium restriction promotes insulin resistance (IR) and dyslipidemia in animal models and humans. Thus, further clarification of the long-term consequences of LS is needed. Here, we investigated the effects of chronic LS on gastrocnemius gene and protein expression and lipidomics and its association with IR and plasma lipids in LDL receptor knockout mice. Three-month-old male mice were fed a normal sodium diet (NS; 0.5% Na; n = 12–19) or LS (0.06% Na; n = 14–20) over 90 days. Body mass (BM), BP, plasma total cholesterol, triacylglycerol (TG), glucose, hematocrit, and IR were evaluated. LS increased BM (9%), plasma TG (51%), blood glucose (19%), and IR (46%) when compared with the NS. RT-qPCR analysis revealed that genes involved in lipid uptake and oxidation were increased by the LS: Fabp3 (106%), Prkaa1 (46%), and Cpt1 (74%). Genes and proteins (assessed by Western blotting) involved in insulin signaling were not changed by the LS. Similarly, lipid species classically involved in muscle IR, such as diacylglycerols and ceramides detected by ultra-high-performance liquid chromatography coupled to mass spectrometry, were also unchanged by LS. Species of phosphatidylcholines (68%), phosphatidylinositol (90%), and free fatty acids (59%) increased while cardiolipins (41%) and acylcarnitines (9%) decreased in gastrocnemius in response to LS and were associated with glucose disposal rate. Together these results suggest that chronic LS alters glycerophospholipid and fatty acids species in gastrocnemius that may contribute to glucose and lipid homeostasis derangements in mice.

Vitamin D is well known for its traditional role in bone mineral homeostasis; however, recent evidence suggests that vitamin D also plays a significant role in metabolic control. This study served to investigate putative linkages between vitamin D deficiency (VDD) and metabolic disruption of bioactive lipids by mass spectrometry imaging (MSI). Our approach employed infrared-matrix-assisted laser desorption electrospray ionization (IR-MALDESI) MSI for lipid metabolite profiling in 6-month-old zebrafish fed either a vitamin D-deficient (VDD) or a vitamin D-sufficient (VDS) diet. Using a lipidomics pipeline, we found that VDD zebrafish had a greater abundance of bioactive lipids (N-acyls, endocannabinoids (ECs), diacylglycerols/triacylglycerols, bile acids/bile alcohols, and vitamin D derivatives) suggestive of increased endocannabinoid tone compared to VDS zebrafish. Tandem mass spectrometry (MS2) was performed on several differentially expressed metabolites with sufficient ion abundances to aid in structural elucidation and provide additional support for MS1 annotations. To confirm activation of the EC pathways, we subsequently examined expression of genes involved in EC biosynthesis, metabolism, and receptor signaling in adipose tissue and liver from VDD and VDS zebrafish. Gene expression changes were congruent with increased endocannabinoid tone, with VDD zebrafish demonstrating increased synthesis and metabolism of anandamide compared to VDS zebrafish. Taken together, our data suggest that VDD may promote accumulation of bioactive lipids and increased endocannabinoid tone in zebrafish.

Objective Insulin signalling via phosphoinositide 3-kinase (PI3K) requires PIK3R1-encoded regulatory subunits. C-terminal PIK3R1 mutations cause SHORT syndrome, as well as lipodystrophy and insulin resistance (IR), surprisingly without fatty liver or metabolic dyslipidaemia. We sought to investigate this discordance. Methods The human pathogenic Pik3r1 Y657∗ mutation was knocked into mice by homologous recombination. Growth, body composition, bioenergetic and metabolic profiles were investigated on chow and high-fat diet (HFD). We examined adipose and liver histology, and assessed liver responses to fasting and refeeding transcriptomically. Results Like humans with SHORT syndrome, Pik3r1WT/Y657∗ mice were small with severe IR, and adipose expansion on HFD was markedly reduced. Also as in humans, plasma lipid concentrations were low, and insulin-stimulated hepatic lipogenesis was not increased despite hyperinsulinemia. At odds with lipodystrophy, however, no adipocyte hypertrophy nor adipose inflammation was found. Liver lipogenic gene expression was not significantly altered, and unbiased transcriptomics showed only minor changes, including evidence of reduced endoplasmic reticulum stress in the fed state and diminished Rictor-dependent transcription on fasting. Increased energy expenditure, which was not explained by hyperglycaemia nor intestinal malabsorption, provided an alternative explanation for the uncoupling of IR from dyslipidaemia. Conclusions Pik3r1 dysfunction in mice phenocopies the IR and reduced adiposity without lipotoxicity of human SHORT syndrome. Decreased adiposity may not reflect bona fide lipodystrophy, but rather, increased energy expenditure, and we suggest that further study of brown adipose tissue in both humans and mice is warranted., Highlights • SHORT syndrome features insulin resistance and reduced adiposity without dyslipidaemia and fatty liver. • A mouse model with a pathogenic human PI 3-Kinase mutation recapitulates this uncoupling. • Surprisingly, no adipose injury nor increased liver de novo lipogenesis is seen. • Energy expenditure is increased, causing resistance to diet-induced obesity. • This increases evidence for some beneficial metabolic effects of PI 3-Kinase inhibition.

Objective Expansion of visceral adipose tissue (VAT) and metabolic inflammation are consequences of obesity and associated with type 2 diabetes (T2DM). Metabolically activated adipose tissue macrophages (ATMs) undergo qualitative and quantitative changes that influence their inflammatory responses. How these cells contribute to insulin resistance (IR) in humans is not well understood. Cholesterol 25-Hydroxylase (CH25H) converts cholesterol into 25-Hydroxycholesterol (25-HC), an oxysterol that modulates immune responses. Using human and murine models, we investigated the role of CH25H in metabolic inflammation. Methods We performed transcriptomic (RNASeq) analysis on the human whole AT biopsies and sorted ATMs from obese non-diabetic (NDM) and obese diabetic (DM) subjects to inquire if CH25H was increased in DM. We challenged mice lacking Ch25h with a high-fat diet (HFD) to characterize their metabolic and immunologic profiling. Ch25h KO mice and human adipose tissue biopsies from NDM and DM subjects were analyzed. LC-MS was conducted to measure 25-HC level in AT. In vitro analysis permitted us to investigate the effect of 25-HC on cytokine expression. Results In our RNASeq analysis of human visceral and subcutaneous biopsies, gene pathways related to inflammation were increased in obese DM vs. non-DM subjects that included CH25H. CH25H was enriched in the stromal vascular fraction of human adipose tissue and highly expressed in CD206+ human ATMs by flow cytometry analysis. We measured the levels of the oxysterols, 25-HC and 7α25diHC, in human visceral adipose tissue samples and showed a correlation between BMI and 25-HC. Using mouse models of diet-induced obesity (DIO), we found that HFD-induced Ch25h expression in eWAT and increased levels of 25-HC in AT. On HFD, Ch25h KO mice became obese but exhibited reduced plasma insulin levels, improved insulin action, and decreased ectopic lipid deposit. Improved insulin sensitivity in Ch25h KO mice was due to attenuation of CD11c+ adipose tissue macrophage infiltration in eWAT. Finally, by testing AT explants, bone marrow-derived macrophages (BMDMs) and SVF cells from Ch25h deficient mice, we observed that 25-HC is required for the expression of pro-inflammatory genes. 25-HC was also able to induce inflammatory genes in preadipocytes. Conclusions Our data suggest a critical role for CH25H/25-HC in the progression of meta-inflammation and insulin resistance in obese humans and mouse models of obesity. In response to obesogenic stimuli, CH25H/25-HC could exert a pro-inflammatory role., HIGHLIGHTS • CH25H upregulation in visceral adipose tissue is associated with diabetes in humans. • ATMs are the primary site of CH25H expression in humans and mice. • DIO in mice activates Ch25h expression and 25-HC production in visceral adipose tissue. • Obese Ch25h KO mice have improved insulin sensitivity due to attenuated adipose tissue inflammation. • In response to inflammatory stimuli, Ch25h/25-HC potentiates myeloid activation.

Background: An average adult American consumes sulfur amino acids (SAA) at levels far above the Estimated Average Requirement (EAR) and recent preclinical data suggest that higher levels of SAA intake may be associated with a variety of aging-related chronic diseases. However, there are little data regarding the relationship between SAA intake and chronic disease risk in humans. The aim of this study was to examine the associations between consumption of SAA and risk factors for cardiometabolic diseases. Methods: The sample included 11,576 adult participants of the Third National Examination and Nutritional Health Survey (NHANES III) Study (1988–1994). The primary outcome was cardiometabolic disease risk score (composite risk factor based on blood cholesterol, triglycerides, HDL, C-reactive protein (CRP), uric acid, glucose, blood urea nitrogen (BUN), glycated hemoglobin, insulin, and eGFR). Group differences in risk score by quintiles of energy-adjusted total SAA, methionine (Met), and cysteine (Cys) intake were determined by multiple linear regression after adjusting for age, sex, BMI, smoking, alcohol intake, and dietary factors. We further examined for associations between SAA intake and individual risk factors. Findings: Mean SAA consumption was > 2.5-fold higher than the EAR. After multivariable adjustment, higher intake of SAA, Met, and Cys were associated with significant increases in composite cardiometabolic disease risk scores, independent of protein intake, and with several individual risk factors including serum cholesterol, glucose, uric acid, BUN, and insulin and glycated hemoglobin (p

Objectives Hypothalamic lipotoxicity has been shown to induce central insulin resistance and dysregulation of glucose homeostasis; nevertheless, elucidation of the regulatory mechanisms remains incomplete. Here, we aimed to determine the role of de novo ceramide synthesis in hypothalamus on the onset of central insulin resistance and the dysregulation of glucose homeostasis induced by obesity. Methods Hypothalamic GT1-7 neuronal cells were treated with palmitate. De novo ceramide synthesis was inhibited either by pharmacological (myriocin) or molecular (si-Serine Palmitoyl Transferase 2, siSPT2) approaches. Obese Zucker rats (OZR) were intracerebroventricularly infused with myriocin to inhibit de novo ceramide synthesis. Insulin resistance was determined by quantification of Akt phosphorylation. Ceramide levels were quantified either by a radioactive kinase assay or by mass spectrometry analysis. Glucose homeostasis were evaluated in myriocin-treated OZR. Basal and glucose-stimulated parasympathetic tonus was recorded in OZR. Insulin secretion from islets and β-cell mass was also determined. Results We show that palmitate impaired insulin signaling and increased ceramide levels in hypothalamic neuronal GT1-7 cells. In addition, the use of deuterated palmitic acid demonstrated that palmitate activated several enzymes of the de novo ceramide synthesis pathway in hypothalamic cells. Importantly, myriocin and siSPT2 treatment restored insulin signaling in palmitate-treated GT1-7 cells. Protein kinase C (PKC) inhibitor or a dominant-negative PKCζ also counteracted palmitate-induced insulin resistance. Interestingly, attenuating the increase in levels of hypothalamic ceramides with intracerebroventricular infusion of myriocin in OZR improved their hypothalamic insulin-sensitivity. Importantly, central myriocin treatment partially restored glucose tolerance in OZR. This latter effect is related to the restoration of glucose-stimulated insulin secretion and an increase in β-cell mass of OZR. Electrophysiological recordings also showed an improvement of glucose-stimulated parasympathetic nerve activity in OZR centrally treated with myriocin. Conclusion Our results highlight a key role of hypothalamic de novo ceramide synthesis in central insulin resistance installation and glucose homeostasis dysregulation associated with obesity., Highlights • de novo ceramide synthesis induces hypothalamic insulin resistance through PKCζ. • Hypothalamic ceramides induce glucose homeostasis dysregulation seen with obesity. • Hypothalamic ceramides mediate inhibition of insulin secretion induced by obesity. • Hypothalamic ceramides decreases β cell mass in obese rats. • Hypothalamic ceramides decreases parasympathetic tonus.

Pioglitazone, a thiazolidinedione (TZD), is widely used as an insulin sensitizer in the treatment of type 2 diabetes. However, body weight gain is frequently observed in TZD-treated patients. Fish oil improves lipid metabolism dysfunction and obesity. In this study, we demonstrated suppression of body weight gain in response to pioglitazone administration by combination therapy of pioglitazone and fish oil in type 2 diabetic KK mice. Male KK mice were fed experimental diets for 8 weeks. In safflower oil (SO), safflower oil/low-dose pioglitazone (S/PL), and safflower oil/high-dose pioglitazone (S/PH) diets, 20% of calories were provided by safflower oil containing 0%, 0.006%, or 0.012% (wt/wt) pioglitazone, respectively. In fish oil (FO), fish oil/low-dose pioglitazone (F/PL), and fish oil/high-dose pioglitazone (F/PH) diets, 20% of calories were provided by a mixture of fish oil and safflower oil. Increased body weight and subcutaneous fat mass were observed in the S/PL and S/PH groups; however, diets containing fish oil were found to ameliorate these changes. Hepatic mRNA levels of lipogenic enzymes were significantly decreased in fish oil-fed groups. These findings demonstrate that the combination of pioglitazone and fish oil decreases subcutaneous fat accumulation, ameliorating pioglitazone-induced body weight gain, through fish oil-mediated inhibition of hepatic de novo lipogenesis., Open Access.

Background & Aims The lysosome is an acidic organelle that is important for maintaining cellular and metabolic homeostasis in hepatocytes. Lysosomal dysfunction and chronic inflammation coexist, and both contribute to obesity-associated hepatic insulin resistance. However, in the context of obesity, the interplay between inflammatory signals and hepatic lysosomal function remains largely unknown. Inducible nitric oxide synthase (iNOS) is a hallmark for inflammation, and is activated in obesity. The aim of this study is to understand the molecular link between iNOS-mediated lysosomal nitric oxide (NO) production, hepatic lysosomal function, and autophagy in the context of obesity-associated insulin resistance. Methods The role of iNOS in hepatic autophagy, as related to insulin and glucose homeostasis were studied in mice with diet-induced obesity (DIO). The effects and mechanisms of iNOS-mediated lysosomal NO production on lysosomal function and hepatic autophagy were studied in primary hepatocytes as well as in a mouse model of DIO. Results We demonstrate that obesity promotes iNOS localization to the lysosome and decreases levels of lysosomal arginine, resulting in an accumulation of NO in hepatic lysosomes. This lysosomal NO production is attenuated by treatment with a NO scavenger, while co-overexpression of mTOR and a lysosomal arginine transporter (SLC38A9) enhances lysosomal NO production and suppresses autophagy. In addition, we show that deletion of iNOS ameliorates lysosomal nitrosative stress in the livers of DIO mice, promotes lysosomal biogenesis by activating transcription factor EB (TFEB), and enhances lysosomal function and autophagy. Lastly, deletion of iNOS in mice with DIO improves hepatic insulin sensitivity, which is diminished by suppression of TFEB or autophagy related 7 (Atg7). Conclusions Our studies suggest that lysosomal iNOS-mediated NO signaling disrupts hepatic lysosomal function, contributing to obesity-associated defective hepatic autophagy and insulin resistance., Graphical abstract