The metabolic syndrome, thiazolidinediones, and implications for intersection of chronic and inflammatory disease

Effects of nanocurcumin supplementation on metabolic syndrome: A systematic review and meta-analysis of randomized controlled trials

BACKGROUND

Metabolic syndrome (MetS) encompasses metabolic risk factors like elevated blood glucose, abnormal lipid levels, and hypertension. Nanocurcumin, a nanoscale formulation of curcumin, may offer therapeutic benefits for MetS management. This systematic review and meta-analysis evaluates the impact of nanocurcumin supplementation on key MetS parameters.

METHODS

A systematic literature search identified 20 randomized controlled trials (RCTs) with 1394 participants. Data were pooled using a random-effects model, and standardized mean differences (SMDs) were calculated for key outcomes.

RESULTS

Nanocurcumin supplementation significantly improved waist circumference (WC) (standardized mean difference (SMD): -0.30 cm), fasting blood sugar (FBS) (SMD: -0.34 mg/dL), HbA1c (SMD: -0.33 %), and quantitative insulin sensitivity check index (QUICKI) score (SMD: 0.73). Lipid profile parameters, including total cholesterol (SMD: -0.18 mg/dL), LDL-C (SMD: -0.16 mg/dL), and HDL-C (SMD: 0.32 mg/dL), also reduced significantly. Improvement in diastolic blood pressure (DBP) (SMD: -0.32 mmHg), total antioxidant capacity (TAC) (SMD: 0.44 mmol/L), malondialdehyde (MDA) (SMD: -0.37 mmol/L), tumor necrosis factor-α (TNF-α) (SMD: -2.30 ng/L), interleukin-6 (IL-6) (SMD: -1.07 ng/L), and high-sensitivity C-reactive protein (hs-CRP) (SMD: -0.34 mg/L) were observed.

CONCLUSION

Nanocurcumin supplementation significantly improves multiple MetS-related parameters, including anthropometric measures, glycemic control, lipid profile, blood pressure, oxidative stress markers, and inflammatory biomarkers. These findings highlight nanocurcumin's potential as an effective adjunctive therapy for managing MetS. However, the variability in study participant ages, treatment durations, and sample sizes suggests the need for further well-designed RCTs to establish optimal usage guidelines.

Metabolic dysfunction and insulin sensitizers in acute and chronic disease

INTRODUCTION

The concept of insulin resistance has been a major topic for more than 5 decades. While there are several treatments that may impact insulin resistance, this pathology is uniquely addressed by mitochondrially directed thiazolidinedione (TZD) insulin sensitizers. Understanding of this mechanism of action and consideration of 'insulin resistance' as a consequence of metabolic inflammation allows a new paradigm for approaching chronic diseases.

AREAS COVERED

We review evolving understanding of the mitochondrial pyruvate carrier (MPC) as a mitochondrial mechanism of action of the TZD insulin sensitizers and discuss how reprogramming of mitochondrial metabolism impacts pleotropic pharmacology in multiple tissues. Additional lines of investigation are proposed.

EXPERT OPINION

A change in paradigm can facilitate rethinking of insulin sensitizers in clinical trials, specifically beyond the treatment of frank type 2 diabetes. There should be broader clinical evaluation of insulin sensitizers in combination with weight loss and lifestyle approaches across diseases/syndromes associated with insulin resistance. Finally, 'connecting all the dots' to unwind the interconnectedness of cell biology involved in the syndromes impacted by metabolic dysfunction and the efficacy of TZD insulin sensitizers may also uncover new molecular targets. New studies should facilitate the discovery and development of novel pharmacologic agents.

Insulin resistance has closer correlation with the occurrence of metabolic dysfunction associated steatotic liver disease diagnosed by liver biopsy

OBJECTIVE

To explore any correlation between serum urate (SU) level or insulin resistance (IR) and metabolic dysfunction associated steatotic liver disease (MASLD) in patients with metabolic syndrome (MS).

METHODS

Data from all MASLD patients, diagnosed by liver biopsy, were enrolled and divided into MASLD alone group and MASLD with MS group. They were subdivided into hyperuricemia group and normal SU group to find correlation between SU/IR and MASLD in patients with MS and independent risk factors for MASLD.

RESULTS

Data from 539 MASLD patients were analyzed. Body mass index (BMI) (p = 0.000), waist circumference (WC) (p = 0.004), and low-density lipoprotein (LDL) (p = 0.000) were dramatically higher in MASLD with MS group than those with MASLD alone; MASLD with MS patients had significantly more family history of diabetes (p = 0.000) and hypertension (p = 0.000) than patients with MASLD alone. Height (p = 0.000), weight (p = 0.000), BMI (p = 0.000) and WC (p = 0.001), and LDL (p = 0.007) were dramatically higher in hyperuricemia patients than those with normal SU. SU was inversely associated with age (p = 0.000) and high-density lipoprotein (HDL) (p = 0.003), and positively correlated with weight (p = 0.000), BMI (p = 0.000) and WC (p = 0.000), TG (p = 0.000), and LDL (p = 0.000). Logistic Regression analysis showed that age (p = 0.031), TG (p = 0.002), LDL (p = 0.010), HbA1c (p = 0.026), and family history of hypertension (p = 0.000) may be independent risk factors for MASLD in patient with MS.

CONCLUSION

Insulin resistance (IR) in MASLD patients with MS, but not higher SU levels, has closer correlation with the occurrence of MASLD in patients with family history of hypertension and diabetes having higher BMI, LDL, HbA1c.

Pioglitazone alleviates lacrimal gland impairments induced by high-fat diet by suppressing M1 polarization

A high-fat diet (HFD) contributes to the pathogenesis of various inflammatory and metabolic diseases. Previous research confirms that under HFD conditions, the extraorbital lacrimal glands (ELGs) can be impaired, with significant infiltration of pro-inflammatory macrophages (Mps). However, the relationship between HFD and Mps polarization in the ELGs remains unexplored. We first identified and validated the differential expression of PPAR-γ in murine ELGs fed ND and HFD through RNA sequencing. Tear secretion was measured using the Schirmer test. Lipid droplet deposition within the ELGs was observed through Oil Red O staining and transmission electron microscopy. Mps phenotypes were determined through quantitative RT-PCR, immunofluorescence, and flow cytometric analysis. An in vitro high-fat culture system for Mps was established using palmitic acid (PA), with supernatants collected for co-culture with lacrimal gland acinar cells. Gene expression was determined through ELISA, immunofluorescence, immunohistochemistry, quantitative RT-PCR, and Western blot analysis. Pioglitazone reduced M1-predominant infiltration induced by HFD by increasing PPAR-γ levels in ELGs, thereby alleviating lipid deposition and enhancing tear secretion. In vitro tests indicated that PPAR-γ agonist shifted Mps from M1-predominant to M2-predominant phenotype in PA-induced Mps, reducing lipid synthesis in LGACs and promoting lipid catabolism, thus alleviating lipid metabolic disorders within ELGs. Conversely, the PPAR-γ antagonist induced opposite effects. In summary, the lacrimal gland is highly sensitive to high-fat and lipid metabolic disorders. Downregulation of PPAR-γ expression in ELGs induces Mps polarization toward predominantly M1 phenotype, leading to lipid metabolic disorder and inflammatory responses via the NF-κb/ERK/JNK/P38 pathway.

The cellular and molecular targets of natural products against metabolic disorders: a translational approach to reach the bedside

Metabolic disorders, including obesity, dyslipidemia, diabetes, nonalcoholic fatty liver disease, and metabolic syndrome, are characterized by insulin resistance, abnormalities in circulating cholesterol and lipid profiles, and hypertension. The most common pathophysiologies of metabolic disorders are glucose/lipid metabolism dysregulation, insulin resistance, inflammatory response, and oxidative stress. Although several agents have been approved for the treatment of metabolic disorders, there is still a strong demand for more efficacious drugs with less side effects. Natural products have been critical sources of drug research and discovery for decades. However, the usefulness of bioactive natural products is often limited by incomplete understanding of their direct cellular targets. In this review, we highlight the current understanding of the established and emerging molecular mechanisms of metabolic disorders. We further summarize the therapeutic effects and underlying mechanisms of natural products on metabolic disorders, with highlights on their direct cellular targets, which are mainly implicated in the regulation of glucose/lipid metabolism, insulin resistance, metabolic inflammation, and oxidative stress. Finally, this review also covers the clinical studies of natural products in metabolic disorders. These progresses are expected to facilitate the application of these natural products and their derivatives in the development of novel drugs against metabolic disorders.

Chronic kidney disease combined with metabolic syndrome is a non-negligible risk factor

Metabolic syndrome (MetS) is a group of conditions characterized by hypertension (HTN), hyperglycaemia or insulin resistance (IR), hyperlipidaemia, and abdominal obesity. MetS is associated with a high incidence of cardiovascular events and mortality and is an independent risk factor for chronic kidney disease (CKD). MetS can cause CKD or accelerate the progression of kidney disease. Recent studies have found that MetS and kidney disease have a cause-and-effect relationship. Patients with CKD, those undergoing kidney transplantation, or kidney donors have a significantly higher risk of developing MetS than normal people. The present study reviewed the possible mechanisms of MetS in patients with CKD, including the disorders of glucose and fat metabolism after kidney injury, IR, HTN and the administration of glucocorticoid and calcineurin inhibitors. In addition, this study reviewed the effect of MetS in patients with CKD on important target organs such as the kidney, heart, brain and blood vessels, and the treatment and prevention of CKD combined with MetS. The study aims to provide strategies for the diagnosis, treatment and prevention of CKD in patients with MetS.

Adipose tissue macrophages secrete small extracellular vesicles that mediate rosiglitazone-induced insulin sensitization

The obesity epidemic continues to worsen worldwide, driving metabolic and chronic inflammatory diseases. Thiazolidinediones, such as rosiglitazone (Rosi), are PPARγ agonists that promote 'M2-like' adipose tissue macrophage (ATM) polarization and cause insulin sensitization. As ATM-derived small extracellular vesicles (ATM-sEVs) from lean mice are known to increase insulin sensitivity, we assessed the metabolic effects of ATM-sEVs from Rosi-treated obese male mice (Rosi-ATM-sEVs). Here we show that Rosi leads to improved glucose and insulin tolerance, transcriptional repolarization of ATMs and increased sEV secretion. Administration of Rosi-ATM-sEVs rescues obesity-induced glucose intolerance and insulin sensitivity in vivo without the known thiazolidinedione-induced adverse effects of weight gain or haemodilution. Rosi-ATM-sEVs directly increase insulin sensitivity in adipocytes, myotubes and primary mouse and human hepatocytes. Additionally, we demonstrate that the miRNAs within Rosi-ATM-sEVs, primarily miR-690, are responsible for these beneficial metabolic effects. Thus, using ATM-sEVs with specific miRNAs may provide a therapeutic path to induce insulin sensitization.

Hyperinsulinemia, an overlooked clue and potential way forward in metabolic dysfunction-associated steatotic liver disease

Metabolic dysfunction-associated steatotic liver disease is closely associated with other features of the metabolic syndrome such as type 2 diabetes. The progression of the disease may lead to liver fibrosis, which is the main predictor of major adverse liver outcomes. Insulin resistance plays a major role in the pathogenesis of the disease. A component of fasting hyperinsulinemia is a failure of the liver to adjust the peripheral level of insulin due to reduced clearance. The associated fasting hyperinsulinemia has been independently associated as a predictor of major adverse liver outcomes and major adverse cardiovascular events. In this review, we discuss the potential mechanism and entanglement between liver fibrosis and hyperinsulinemia, and we hypothesize that the measure of fasting insulin could become a hepatic functional test within the armamentarium of noninvasive tests for the assessment of Metabolic dysfunction-associated steatotic liver disease.

Biomarkers of glucose homeostasis as mediators of the relationship of body mass index and waist circumference with COVID-19 outcomes among postmenopausal women: The Women's Health Initiative

BACKGROUND & AIMS

Systematic reviews, meta-analyses and Mendelian randomization studies suggest that cardiometabolic diseases may be associated with COVID-19 risk and prognosis, with evidence implicating insulin resistance (IR) as a common biological mechanism. As driving factors for IR, we examined body mass index (BMI) and waist circumference (WC) among postmenopausal women in association with COVID-19 outcomes (positivity and hospitalization), and the role of glucose homeostasis as a mediator of this relationship.

METHODS

Associations of BMI and WC at baseline (1993-1998) with COVID-19 outcomes collected at Survey 1 (June-December, 2020) and/or Survey 2 (September-December, 2021) were evaluated among 42,770 Women's Health Initiative (WHI) participants (baseline age: 59.36 years) of whom 16,526 self-reported having taken ≥1 COVID-19 test, with 1242 reporting ≥1 positive COVID-19 test and 362 reporting ≥1 COVID-19 hospitalization. We applied logistic regression and causal mediation analyses to sub-samples with available fasting biomarkers of glucose homeostasis (glucose, insulin, Homeostatic Model Assessment for Insulin Resistance, Homeostasis Model Assessment for β-cell function, Quantitative Insulin-sensitivity Check Index, Triglyceride-Glucose index (TyG)) at baseline, whereby 57 of 759 reported COVID-19 test positivity and 23 of 1896 reported COVID-19 hospitalization.

RESULTS

In fully adjusted models, higher BMI, WC and TyG were associated with COVID-19 test positivity and hospitalization. Glucose concentrations mediated associations of BMI and WC with COVID-19 positivity, whereas TyG mediated BMI and WC's associations with COVID-19 hospitalization.

CONCLUSIONS

Obesity and central obesity markers collected an average of 24 years prior were associated with COVID-19 outcomes among postmenopausal women. Glucose concentration and TyG partly mediated these associations.

Insulin sensitizers in 2023: lessons learned and new avenues for investigation

INTRODUCTION

'Insulin sensitizers' derived discoveries of the Takeda Company in 1970s. Pioglitazone remains the best in class with beneficial pleiotropic pharmacology, although use is limited by tolerability issues. Various attempts to expand out of this class assumed the primary molecular target was the transcription factor, PPARγ. Findings over the last 10 years have identified new targets of thiazolidinediones (TZDs) that should alter the drug discovery paradigm.

AREAS COVERED

We review structural classes of experimental insulin sensitizer drugs, some of which have attained limited approval in some markets. The TZD pioglitazone, originally approved in 1999 as a secondary treatment for type 2 diabetes, has demonstrated benefit in apparently diverse spectrums of disease from cardiovascular to neurological issues. New TZDs modulate a newly identified mitochondrial target (the mitochondrial pyruvate carrier) to reprogram metabolism and produce insulin sensitizing pharmacology devoid of tolerability issues.

EXPERT OPINION

Greater understanding of the mechanism of action of insulin sensitizing drugs can expand the rationale for the fields of treatment and potential for treatment combinations. This understanding can facilitate the registration and broader use of agents with that impact the pathophysiology that underlies chronic metabolic diseases as well as host responses to environmental insults including pathogens, insulin sensitizer, MPC, mitochondrial target, metabolic reprogramming, chronic and infectious disease.

NLRP3 Inflammasome in Atherosclerosis: Putting Out the Fire of Inflammation

Atherosclerosis (AS) is a chronic inflammatory disease with thickening or hardening of the arteries, which led to the built-up of plaques in the inner lining of an artery. Among all the clarified pathogenesis, the over-activation of inflammatory reaction is one of the most acknowledged one. The nucleotide-binding domain leucine-rich repeat (NLR) and pyrin domain containing receptor 3 (NLRP3) inflammasome, as a vital and special form of inflammation and innate immunity, has been widely revealed to participate in the onset and development of AS. This review will introduce the process of the pathogenesis and progression of AS, and will describe the biological features of the NLRP3 inflammasome. Furthermore, the role of the NLRP3 inflammasome in AS and the possible mechanisms will be discussed. In addition, several kinds of agents with the effect of anti-atherosclerotic taking advantage of the NLRP3 inflammasome intervention will be described and discussed in detail, including natural compounds (baicalin, dihydromyricetin, luteolin, 5-deoxy-rutaecarpine (R3) and Salvianolic acid A, etc.), microRNAs (microRNA-30c-5p, microRNA-9, microRNA-146a-5p, microRNA-16-5p and microRNA-181a, etc.), and autophagy regulators (melatonin, dietary PUFA and arglabin, etc.). We aim to provide novel insights in the exploration of the specific mechanisms of AS and the development of new treatments of AS.

An Egg White-Derived Peptide Enhances Systemic Insulin Sensitivity and Modulates Markers of Non-Alcoholic Fatty Liver Disease in Obese, Insulin Resistant Mice

Non-alcoholic fatty liver disease (NAFLD), the hepatic manifestation of the metabolic syndrome, is a global health problem. Currently, no pharmacological treatment is approved for NAFLD. Natural health products, including bioactive peptides, are potential candidates to aid in the management of metabolic syndrome-related conditions, including insulin resistance and obesity. In this study, we hypothesized that an egg-white-derived bioactive peptide QAMPFRVTEQE (Peptide 2) would improve systemic and local white adipose tissue insulin sensitivity, thereby preventing high-fat diet-induced exacerbation of pathological features associated with NAFLD, such as lipid droplet size and number, inflammation, and hepatocyte hypertrophy in high-fat diet-fed mice. Similar to rosiglitazone, Peptide 2 supplementation improved systemic insulin resistance during the hyperinsulinemic-euglycemic clamp and enhanced insulin signalling in white adipose tissue, modulating ex vivo lipolysis. In the liver, compared with high-fat diet fed animals, Peptide 2 supplemented animals presented decreased hepatic cholesterol accumulation (p < 0.05) and area of individual hepatic lipid droplet by around 50% (p = 0.09) and reduced hepatic inflammatory infiltration (p < 0.05) whereas rosiglitazone exacerbated steatosis. In conclusion, Peptide 2 supplementation improved insulin sensitivity and decreased hepatic steatosis, unlike the insulin-sensitizing drug rosiglitazone.

Preclinical activities of Cassia tora Linn against aging-related diseases

Globally, an aging population is increasing, and aging is a natural physiological process and a major risk factor for all age-related diseases. It seriously threatens personal health and imposes a great economic burden. Therefore, there is a growing scientific interest in strategies for well-aging with prevention and treatment of age-related diseases. The seed, root, stem or leaves of Cassia tora Linn. are useful for anti-bacteria, anti-hyperlipidemia and anti-obesity due to its pharmacological activities such as anti-inflammation and anti-oxidant both in vitro and in vivo. Nevertheless, no clinical trials have been attempted so far, therefore here we would like to understand the current preclinical activities for aging-related disease models including cataract, metabolic dysfunction and neurodegeneration, then discuss their preparation for clinical trials and perspectives.

PPAR-γ Partial Agonists in Disease-Fate Decision with Special Reference to Cancer

Peroxisome proliferator-activated receptor-γ (PPAR-γ) has emerged as one of the most extensively studied transcription factors since its discovery in 1990, highlighting its importance in the etiology and treatment of numerous diseases involving various types of cancer, type 2 diabetes mellitus, autoimmune, dermatological and cardiovascular disorders. Ligands are regarded as the key determinant for the tissue-specific activation of PPAR-γ. However, the mechanism governing this process is merely a contradictory debate which is yet to be systematically researched. Either these receptors get weakly activated by endogenous or natural ligands or leads to a direct over-activation process by synthetic ligands, serving as complete full agonists. Therefore, fine-tuning on the action of PPAR-γ and more subtle modulation can be a rewarding approach which might open new avenues for the treatment of several diseases. In the recent era, researchers have sought to develop safer partial PPAR-γ agonists in order to dodge the toxicity induced by full agonists, akin to a balanced activation. With a particular reference to cancer, this review concentrates on the therapeutic role of partial agonists, especially in cancer treatment. Additionally, a timely examination of their efficacy on various other disease-fate decisions has been also discussed.

Waist-to-Hip Ratio and Inflammatory Parameters Are Associated with Risk of Non-Alcoholic Fatty Liver Disease in Patients with Morbid Obesity

Non-alcoholic fatty liver disease (NAFLD) is associated with several other metabolic disorders, which are typically pro-inflammatory states. Body fat content is an important marker of metabolic health and abdominal fat is associated with harmful cardiometabolic outcomes. We aimed to evaluate the association between the risk of NAFLD (through Fatty Liver Index (FLI), and BMI, AST/ALT ratio, and presence of diabetes (BARD)), and anthropometric parameters, predictors of metabolic status, in patients with morbid obesity, and to evaluate the association of FLI and BARD scores with pro-inflammatory markers. We have retrospectively studied patients with morbid obesity followed in our center. In total, 2184 participants were included, with an average age of 42.8 ± 10.6 years, 84.5% being females. We report a positive association of FLI with waist circumference (β = 0.10 [0.09 to 0.11], p < 0.01) and waist-to-hip ratio (β = 8.68 [6.85 to 10.52, p < 0.01]), even after adjusting for age, sex, body mass index, diabetes, and dyslipidemia (p < 0.01 for both adjusted models). The associations of BARD with anthropometric measures were significant only in the non-adjusted model. There was a positive association between both FLI and BARD and C-reactive protein. Our results point towards a positive association between waist-to-hip ratio and the risk of hepatic steatosis, and between pro-inflammatory markers and both hepatic steatosis and fibrosis.

Novel thiazolidinedione analog reduces a negative impact on bone and mesenchymal stem cell properties in obese mice compared to classical thiazolidinediones

Objective

The use of thiazolidinediones (TZDs) as insulin sensitizers has been shown to have side effects including increased accumulation of bone marrow adipocytes (BMAds) associated with a higher fracture risk and bone loss. A novel TZD analog MSDC-0602K with low affinity to PPARγ has been developed to reduce adverse effects of TZD therapy. However, the effect of MSDC-0602K on bone phenotype and bone marrow mesenchymal stem cells (BM-MSCs) in relation to obesity has not been intensively studied yet.

Methods

Here, we investigated whether 8-week treatment with MSDC-0602K has a less detrimental effect on bone loss and BM-MSC properties in obese mice in comparison to first generation of TZDs, pioglitazone. Bone parameters (bone microstructure, bone marrow adiposity, bone strength) were examined by μCT and 3-point bending test. Primary BM-MSCs were isolated and measured for osteoblast and adipocyte differentiation. Cellular senescence, bioenergetic profiling, nutrient consumption and insulin signaling were also determined.

Results

The findings demonstrate that MSDC-0602K improved bone parameters along with increased proportion of smaller BMAds in tibia of obese mice when compared to pioglitazone. Further, primary BM-MSCs isolated from treated mice and human BM-MSCs revealed decreased adipocyte and higher osteoblast differentiation accompanied with less inflammatory and senescent phenotype induced by MSDC-0602K vs. pioglitazone. These changes were further reflected by increased glycolytic activity differently affecting glutamine and glucose cellular metabolism in MSDC-0602K-treated cells compared to pioglitazone, associated with higher osteogenesis.

Conclusion

Our study provides novel insights into the action of MSDC-0602K in obese mice, characterized by the absence of detrimental effects on bone quality and BM-MSC metabolism when compared to classical TZDs and thus suggesting a potential therapeutical use of MSDC-0602K in both metabolic and bone diseases.

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MSDC-0602K improves bone quality and increases proportion of smaller BMAds in obese mice.

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MSDC-0602K-treated mice show lower adipogenic differentiation with less senescent phenotype in primary BM-MSCs.

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MSDC-0602K induces higher glycolytic activity in BM-MSCs compared to pioglitazone.

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MSDC-0602-treated BM-MSCs prefer glutamine over glucose uptake in comparison to AT-MSCs.

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Beneficial effect of MSDC-06002K in BM-MSCs manifests by absence of MPC inhibition.

A dominant negative ADIPOQ mutation in a diabetic family with renal disease, hypoadiponectinemia, and hyperceramidemia

Adiponectin, encoded by ADIPOQ, is an insulin-sensitizing, anti-inflammatory, and renoprotective adipokine that activates receptors with intrinsic ceramidase activity. We identified a family harboring a 10-nucleotide deletion mutation in ADIPOQ that cosegregates with diabetes and end-stage renal disease. This mutation introduces a frameshift in exon 3, resulting in a premature termination codon that disrupts translation of adiponectin's globular domain. Subjects with the mutation had dramatically reduced circulating adiponectin and increased long-chain ceramides levels. Functional studies suggest that the mutated protein acts as a dominant negative through its interaction with non-mutated adiponectin, decreasing circulating adiponectin levels, and correlating with metabolic disease.

Metabolic Mechanisms Connecting Alzheimer's and Parkinson's Diseases: Potential Avenues for Novel Therapeutic Approaches

Alzheimer's (AD) and Parkinson's Diseases (PD) are common neurodegenerative disorders growing in incidence and prevalence and for which there are no disease-modifying treatments. While there are considerable complexities in the presentations of these diseases, the histological pictures of these pathologies, as well as several rare genetic predispositions for each, point to the involvement of maladaptive protein processing and inflammation. Importantly, the common presentations of AD and PD are connected to aging and to dysmetabolism, including common co-diagnosis of metabolic syndrome or diabetes. Examination of anti-diabetic therapies in preclinical models and in some observational clinical studies have suggested effectiveness of the first generation insulin sensitizer pioglitazone in both AD and PD. Recently, the mitochondrial pyruvate carrier (MPC) was shown to be a previously unrecognized target of pioglitazone. New insulin sensitizers are in development that can be dosed to full engagement of this previously unappreciated mitochondrial target. Here we review molecular mechanisms that connect modification of pyruvate metabolism with known liabilities of AD and PD. The mechanisms involve modification of autophagy, inflammation, and cell differentiation in various cell types including neurons, glia, macrophages, and endothelium. These observations have implications for the understanding of the general pathology of neurodegeneration and suggest general therapeutic approaches to disease modification.

Post-acute sequelae of COVID-19: A metabolic perspective

The SARS-CoV-2 pandemic continues to rage around the world. At the same time, despite strong public health measures and high vaccination rates in some countries, a post-COVID-19 syndrome has emerged which lacks a clear definition, prevalence, or etiology. However, fatigue, dyspnea, brain fog, and lack of smell and/or taste are often characteristic of patients with this syndrome. These are evident more than a month after infection, and are labeled as Post-Acute Sequelae of CoV-2 (PASC) or commonly referred to as long-COVID. Metabolic dysfunction (i.e., obesity, insulin resistance, and diabetes mellitus) is a predisposing risk factor for severe acute COVID-19, and there is emerging evidence that this factor plus a chronic inflammatory state may predispose to PASC. In this article, we explore the potential pathogenic metabolic mechanisms that could underly both severe acute COVID-19 and PASC, and then consider how these might be targeted for future therapeutic approaches.

Non-alcoholic fatty liver disease (NAFLD): a review of pathophysiology, clinical management and effects of weight loss

Given the increasing prevalence of diabetes and obesity worldwide, the deleterious effects of non-alcoholic fatty liver disease (NAFLD) are becoming a growing challenge for public health. NAFLD is the most common chronic liver disease in the Western world. NAFLD is closely associated with metabolic disorders, including central obesity, dyslipidaemia, hypertension, hyperglycaemia and persistent abnormalities of liver function tests.In general NAFLD is a common denominer for a broad spectrum of damage to the liver, which can be due to hepatocyte injury, inflammatory processes and fibrosis. This is normally seen on liver biopsy and can range from milder forms (steatosis) to the more severe forms (non-alcoholic steatohepatitis (NASH), advanced fibrosis, cirrhosis and liver failure). In these patients, advanced fibrosis is the major predictor of morbidity and liver-related mortality, and an accurate diagnosis of NASH and NAFLD is mandatory. Histologic evaluation with liver biopsy remains the gold standard to diagnose NAFLD. Diagnosis of NAFLD is defined as presence of hepatic steatosis, ballooning and lobular inflammation with or without fibrosis. Weight loss, dietary modification, and the treatment of underlying metabolic syndrome remain the mainstays of therapy once the diagnosis is established. Dietary recommendations and lifestyle interventions, weight loss, and the treatment of underlying metabolic syndrome remain the mainstays of therapy once the diagnosis is established with promising results but are difficult to maintain. Pioglitazone and vitamin E are recommended by guidelines in selected patients. This review gives an overview of NAFLD and its treatment options.