Lipin-1 deficiency deteriorates defect of fatty acid β-oxidation and lipid-related kidney damage in diabetic kidney disease

Diabetic lipo-toxicity is a fundamental pathophysiologic mechanism in DM and is now increasingly recognized a key determinant of DKD. Targeting lipid metabolic disorders is an important therapeutic strategy for the treatment of DM and its complications, including DKD. This study aimed to explore the molecular mechanism of lipid metabolic regulation in kidney, especially renal PTECs, and elucidate the role of lipid metabolic related molecule lipin-1 in diabetic lipid-related kidney damage. In this study, lipin-1-deficient db/db mouse model and STZ/HFD-induced T2DM mouse model were used to determine the effect of lipin-1 on DKD development. Then RPTCs and LPIN1 knockdown or overexpressed HK-2 cells induced by PA were used to investigate the mechanism. We found that the expression of lipin-1 increased early and then decreased in kidney during the progression of DKD. Glucose and lipid metabolic disorders and renal insufficiency were found in these 2 types of diabetic mouse models. Interestingly, lipin-1 deficiency might be a pathogenic driver of DKD-to-CKD transition, which could further accelerate the imbalance of renal lipid homeostasis, the dysfunction of mitochondrial and energy metabolism in PTECs. Mechanistically, lipin-1 deficiency resulted in aggravated PTECs injury to tubulointerstitial fibrosis in DKD by downregulating FAO via inhibiting PGC-1α/PPARα mediated Cpt1α/HNF4α signaling and upregulating SREBPs to promote fat synthesis. This study provided new insights into the role of lipin-1 as a regulator for maintaining lipid homeostasis in the kidney, especially PTECs, and its deficiency led to the progression of DKD.

Noninvasive tests to identify liver fibrosis in metabolic dysfunction-associated steatotic liver disease are affected by race

OBJECTIVE

The objective of this study was to assess the performance of noninvasive tests (NITs) across different racial and ethnic groups in a large multiethnic cohort.

METHODS

Data were derived from the National Health and Nutrition Examination Survey (NHANES) 2017 through 2020. Participants without valid transient elastography measurements or with alternative etiologies of liver steatosis disease were excluded from the study.

RESULTS

Among the 6359 adults included in the study, fatty liver index and nonalcoholic fatty liver disease liver fat scores performed well for the prediction of metabolic dysfunction-associated steatotic liver disease, without significant changes across racial and ethnic groups. However, significant differences were observed across racial and ethnic groups for the prediction of advanced fibrosis and cirrhosis. The fibrosis-4 (FIB-4) index, aspartate aminotransferase to platelet ratio index (APRI), and nonalcoholic fatty liver disease fibrosis score underperformed in non-Hispanic Black patients for the detection of cirrhosis. For the detection of advanced fibrosis, their performance was also numerically worse in non-Hispanic Black patients but only reached statistical significance for APRI. Using a cutoff point of 12 kPa for advanced fibrosis, both APRI and the FIB-4 index performed significantly worse in non-Hispanic Black patients.

CONCLUSIONS

In a large, diverse national cohort, the performance of NITs was overall poor compared with transient elastography, and NITs showed differences across racial and ethnic groups. Given the widespread use of NITs, it is imperative that the scores are equitable across racial and ethnic groups.

Sulforaphane reduces adipose tissue fibrosis via promoting M2 macrophages polarization in HFD fed-mice

Adipose tissue fibrosis has been identified as a novel contributor to the pathomechanism of obesity associated metabolic disorders. Sulforaphane (SFN) has been shown to have an anti-obesity effect. However, the impact of SFN on adipose tissue fibrosis is still not well understood. In this study, obese mice induced by high-fat diets (HFD) were used to examine the effects of SFN on adipose tissue fibrosis. According to the current findings, SFN dramatically enhanced glucose tolerance and decreased body weight in diet-induced-obesity (DIO) mice. Additionally, SFN therapy significantly reduced extracellular matrix (ECM) deposition and altered the expression of genes related to fibrosis. Furthermore, SFN also reduced inflammation and promoted macrophages polarization towards to M2 phenotype in adipose tissue, which protected adipose tissue from fibrosis. Notably, SFN-mediated nuclear factor E2-related factor 2 (Nrf2) activation was crucial in decreasing adipose tissue fibrosis. These results implied that SFN had favorable benefits in adipose tissue fibrosis, which consequently ameliorates obesity-related metabolic problems. Our research provides new treatment strategies for obesity and associated metabolic disorders.

The regulatory role of PI3K in ageing-related diseases

Ageing is a physiological/pathological process accompanied by the progressive damage of cell function, triggering various ageing-related disorders. Phosphatidylinositol 3-kinase (PI3K), which serves as one of the central regulators of ageing, is closely associated with cellular characteristics or molecular features, such as genome instability, telomere erosion, epigenetic alterations, and mitochondrial dysfunction. In this review, the PI3K signalling pathway was firstly thoroughly explained. The link between ageing pathogenesis and the PI3K signalling pathway was then summarized. Finally, the key regulatory roles of PI3K in ageing-related illnesses were investigated and stressed. In summary, we revealed that drug development and clinical application targeting PI3K is one of the focal points for delaying ageing and treating ageing-related diseases in the future.

Interaction Between Adipocytes and B Lymphocytes in Human Metabolic Diseases

Diseases associated with the disorders of carbohydrate and lipid metabolism are widespread in the modern world. Interaction between the cells of adipose tissue - adipocytes - and immune system cells is an essential factor in pathogenesis of such diseases. Long-term increase in the glucose and fatty acid levels leads to adipocyte hypertrophy and increased expression of pro-inflammatory cytokines and adipokines by these cells. As a result, immune cells acquire a pro-inflammatory phenotype, and new leukocytes are recruited. Inflammation of adipose tissue leads to insulin resistance and stimulates formation of atherosclerotic plaques and development of autoimmunity. New studies show that different groups of B lymphocytes play an essential role in regulation of adipose tissue inflammation. Decrease in the number of B-2 lymphocytes suppresses development of a number of metabolic diseases, whereas decreased numbers of the regulatory B lymphocytes and B-1 lymphocytes are associated with more severe pathology. Recent studies showed that adipocytes influence B lymphocyte activity both directly and by altering activity of other immune cells. These findings provide better understanding of the molecular mechanisms of human pathologies associated with impaired carbohydrate and lipid metabolism, such as type 2 diabetes mellitus.

Clinical and biochemical footprints of inherited metabolic diseases. IX. Metabolic ear disease

Damages to the ear are very diverse and can depend on the type of inherited metabolic diseases (IMD). Indeed, IMDs can affect all parts of the auditory system, from the outer ear to the central auditory process. We have identified 219 IMDs associated with various types of ear involvement which we classified into five groups according to the lesion site of the auditory system: congenital external ear abnormalities, acquired external ear abnormalities, middle ear involvement, inner ear or retrocochlear involvement, and unspecified hearing loss. This represents the ninth issue in a series of educational summaries providing a comprehensive and updated list of metabolic differential diagnoses according to system involvement.

Extracellular matrix remodeling facilitates obesity-associated cancer progression

Obesity, a global public health concern, is an important risk factor for metabolic diseases and several cancers. Fibro-inflammation in adipose tissues (ATs) is tightly associated with the pathologies of obesity; excessive or uncontrolled extracellular matrix (ECM) production in AT has a crucial role in this pathogenesis. The ECM is a critical and functional component of various tissues, providing a mechanical and chemical network of proteins that controls cell survival, development, and tissue repair. The ECM is tightly regulated and dynamically remodeled; this is an important factor for AT expansion and can result in modifications to the physical shape and biological function of AT. Here, we focus on ECM remodeling in AT and how it affects obesity-related cancer progression.

NAXE deficiency: A neurometabolic disorder of NAD(P)HX repair amenable for metabolic correction

The NAD(P)HX repair system is a metabolite damage repair mechanism responsible for restoration of NADH and NADPH after their inactivation by hydration. Deficiency in either of its two enzymes, NAD(P)HX dehydratase (NAXD) or NAD(P)HX epimerase (NAXE), causes a fatal neurometabolic disorder characterized by decompensations precipitated by inflammatory stress. Clinical findings include rapidly progressive muscle weakness, ataxia, ophthalmoplegia, and motor and cognitive regression, while neuroimaging abnormalities are subtle or nonspecific, making a clinical diagnosis challenging. During stress, nonenzymatic conversion of NAD(P)H to NAD(P)HX increases, and in the absence of repair, NAD(P)H is depleted, and NAD(P)HX accumulates, leading to decompensation; however, the contribution of each to the metabolic derangement is not established. Herein, we summarize the clinical knowledge of NAXE deficiency from 30 cases and lessons learned about disease pathogenesis from cell cultures and model organisms and describe a metabolomics signature obtained by untargeted metabolomics analysis in one case at the time of crisis and after initiation of treatment. Overall, biochemical findings support a model of acute depletion of NAD⁺, signs of mitochondrial dysfunction, and altered lipidomics. These findings are further substantiated by untargeted metabolomics six months post-crisis showing that niacin supplementation reverses primary metabolomic abnormalities concurrent with improved clinical status.

[Clinicopathological features of hepatic fibrinogen storage disease in children]

Objective: To investigate the clinicopathological and molecular characteristics of hepatic fibrinogen storage disease (FSD) in children. Methods: The clinical, histopathologic, immunophenotypic, ultrastructural and gene sequencing data of 4 FSD cases were collected from September 2019 to January 2021 in the Children's Hospital of Fudan University, Shanghai, China. Retrospective analysis and literature review were conducted. Results: There were 4 cases of FSD, 3 males and 1 female, aged 3 years and 3 months to 6 years (median age, 3 years and 4 months). The clinical manifestations were abnormal liver function and abnormal blood coagulation function, for which 2 cases had family genetic history. Liver biopsies revealed that, besides liver steatosis, fibrosis and inflammation, there were single or multiple eosinophilic inclusion bodies of various sizes and surrounding transparent pale halo in hepatocytes. Immunohistochemistry showed that the inclusion bodies were positive for anti-fibrinogen. Under the electron microscope, they corresponded to the dilated cisternae of the rough endoplasmic reticulum, which were occupied by compactly packed tubular structures and arranged into a fingerprint-like pattern with curved bundles. Gene sequencing revealed that the 2 cases of FGG mutation were located in exon 8 c.1106A>G (p.His369Arg) and c.905T>C (p.Leu302Pro), and 1 case was located in exon 9 c.1201C>T (p.Arg401Trp). No pathogenic variant was detected in the other case. Conclusions: FSD is a rare genetic metabolic disease and clinically manifests as abnormal liver function with hypofibrinogenemia. In the background of liver steatosis, fibrosis and inflammation, there are eosinophilic inclusions with pale halo in the hepatocytic cytoplasm, which can be identified by anti-fibrinogen immunohistochemical staining. The fingerprint-like structures under electron microscope are helpful for the diagnosis, while FGG sequencing detects the pathogenic mutation of exon 8 or 9 that can clearly explain the phenotype. However, the diagnosis of FSD cannot be completely ruled out if the relevant mutations are not detected.

Cancer as a Metabolic Disorder

Cancer has long been considered a genetic disease characterized by a myriad of mutations that drive cancer progression. Recent accumulating evidence indicates that the dysregulated metabolism in cancer cells is more than a hallmark of cancer but may be the underlying cause of the tumor. Most of the well-characterized oncogenes or tumor suppressor genes function to sustain the altered metabolic state in cancer. Here, we review evidence supporting the altered metabolic state in cancer including key alterations in glucose, glutamine, and fatty acid metabolism. Unlike genetic alterations that do not occur in all cancer types, metabolic alterations are more common among cancer subtypes and across cancers. Recognizing cancer as a metabolic disorder could unravel key diagnostic and treatments markers that can impact approaches used in cancer management.

The Action of Vitamin D in Adipose Tissue: Is There the Link between Vitamin D Deficiency and Adipose Tissue-Related Metabolic Disorders?

Adipose tissue plays an important role in systemic metabolism via the secretion of adipocytokines and storing and releasing energy. In obesity, adipose tissue becomes dysfunctional and characterized by hypertrophied adipocytes, increased inflammation, hypoxia, and decreased angiogenesis. Although adipose tissue is one of the major stores of vitamin D, its deficiency is detective in obese subjects. In the presented review, we show how vitamin D regulates numerous processes in adipose tissue and how their dysregulation leads to metabolic disorders. The molecular response to vitamin D in adipose tissue affects not only energy metabolism and adipokine and anti-inflammatory cytokine production via the regulation of gene expression but also genes participating in antioxidant defense, adipocytes differentiation, and apoptosis. Thus, its deficiency disturbs adipocytokines secretion, metabolism, lipid storage, adipogenesis, thermogenesis, the regulation of inflammation, and oxidative stress balance. Restoring the proper functionality of adipose tissue in overweight or obese subjects is of particular importance in order to reduce the risk of developing obesity-related complications, such as cardiovascular diseases and diabetes. Taking into account the results of experimental studies, it seemed that vitamin D may be a remedy for adipose tissue dysfunction, but the results of the clinical trials are not consistent, as some of them show improvement and others no effect of this vitamin on metabolic and insulin resistance parameters. Therefore, further studies are required to evaluate the beneficial effects of vitamin D, especially in overweight and obese subjects, due to the presence of a volumetric dilution of this vitamin among them.

Breakdown of the blood-brain barrier: A mediator of increased Alzheimer's risk in patients with metabolic disorders?

Metabolic disorders (MDs), including type 1 and 2 diabetes and chronic obesity, are among the faster growing diseases globally and are a primary risk factor for Alzheimer's disease (AD). The term "type-3 diabetes" has been proposed for AD due to the interrelated cellular, metabolic, and immune features shared by diabetes, insulin resistance (IR), and the cognitive impairment and neurodegeneration found in AD. Patients with MDs and/or AD commonly exhibit altered glucose homeostasis and IR; systemic chronic inflammation encompassing all of the periphery, blood-brain barrier (BBB), and central nervous system; pathological vascular remodeling; and increased BBB permeability that allows transfusion of neurotoxic molecules from the blood to the brain. This review summarizes the components of the BBB, mechanisms through which MDs alter BBB permeability via immune and metabolic pathways, the contribution of BBB dysfunction to the manifestation and progression of AD, and current avenues of therapeutic research that address BBB permeability. In addition, issues with the translational applicability of current animal models of AD regarding BBB dysfunction and proposals for future directions of research that address the relationship between MDs, BBB dysfunction, and AD are discussed.

The impact of obesity on adipocyte-derived extracellular vesicles

Recently, the emerging roles of adipocyte-derived extracellular vesicles (EVs) linking obesity and its comorbidities have been recognized. In obese subjects, adipocytes are having hypertrophic growth and are under stressed. The dysfunction adipocytes dysregulate the assembly of the biological components in the EVs including exosomes. This article critically reviews the current findings on the impact of obesity on the exosomal cargo contents that induce the pathophysiological changes. Besides, this review also summarizes the understanding on how obesity affects the biogenesis of adipocyte-derived exosomes and the exosome secretion. Furthermore, the differences of the exosomal contents in different adipose depots, and the impact of obesity on the exosomes that are derived from the stromal vascular fraction such as the adipose tissue macrophages and adipocyte-derived stem cells will also be discussed. The current development and potential application of exosome-based therapy will be summarized. This review provides crucial information for the design of novel exosome-based therapy for the treatment of obesity and its comorbidities.

Microvascular Ageing Links Metabolic Disease to Age-Related Disorders: The Role of Oxidative Stress and Inflammation in Promoting Microvascular Dysfunction

ABSTRACT

Longer life span and increased prevalence of chronic, noncommunicable, inflammatory diseases fuel cardiovascular mortality. The microcirculation is central in the cross talk between ageing, inflammation, cardiovascular, and metabolic diseases. Microvascular dysfunction, characterized by alteration in the microvascular endothelial function and wall structure, is described in an increasing number of chronic age-associated diseases, suggesting that it might be a marker of ageing superior to chronological age. The aim of this review is to thoroughly explore the connections between microvascular dysfunction, ageing, and metabolic disorders by detailing the major role played by inflammation and oxidative stress in their evolution. Older age, hypertension, nutrient abundance, and hyperglycemia concur in the induction of a persistent low-grade inflammatory response, defined as meta-inflammation or inflammageing. This increases the local generation of reactive oxygen species that further impairs endothelial function and amplifies the local inflammatory response. Mitochondrial dysfunction is a hallmark of many age-related diseases. The alterations of mitochondrial function promote irreversible modification in microvascular structure. The interest in the hypothesis of chronic inflammation at the center of the ageing process lies in its therapeutic implications. Inhibition of specific inflammatory pathways has been shown to lower the risk of many age-related diseases, including cardiovascular disease. However, the whole architecture of the inflammatory response underpinning the ageing process and its impact on the burden of age-related diseases remain to be fully elucidated. Additional studies are needed to unravel the connection between these biological pathways and to address their therapeutic power in terms of cardiovascular prevention.

Target Sestrin2 to Rescue the Damaged Organ: Mechanistic Insight into Its Function

Sestrin2 is a stress-inducible metabolic regulator and a conserved antioxidant protein which has been implicated in the pathogenesis of several diseases. Sestrin2 can protect against atherosclerosis, heart failure, hypertension, myocardial infarction, stroke, spinal cord injury neurodegeneration, nonalcoholic fatty liver disease (NAFLD), liver fibrosis, acute kidney injury (AKI), chronic kidney disease (CKD), and pulmonary inflammation. Oxidative stress and cellular damage signals can alter the expression of Sestrin2 to compensate for organ damage. Different stress signals such as those mediated by P53, Nrf2/ARE, HIF-1α, NF-κB, JNK/c-Jun, and TGF-β/Smad signaling pathways can induce Sestrin2 expression. Subsequently, Sestrin2 activates Nrf2 and AMPK. Furthermore, Sestrin2 is a major negative regulator of mTORC1. Sestrin2 indirectly regulates the expression of several genes and reprograms intracellular signaling pathways to attenuate oxidative stress and modulate a large number of cellular events such as protein synthesis, cell energy homeostasis, mitochondrial biogenesis, autophagy, mitophagy, endoplasmic reticulum (ER) stress, apoptosis, fibrogenesis, and lipogenesis. Sestrin2 vigorously enhances M2 macrophage polarization, attenuates inflammation, and prevents cell death. These alterations in molecular and cellular levels improve the clinical presentation of several diseases. This review will shed light on the beneficial effects of Sestrin2 on several diseases with an emphasis on underlying pathophysiological effects.

Tapping into 5-HT3 Receptors to Modify Metabolic and Immune Responses

5-hydroxytryptamine type 3 (5-HT₃) receptors are ligand gated ion channels, which clearly distinguish their mode of action from the other G-protein coupled 5-HT or serotonin receptors. 5-HT₃ receptors are well established targets for emesis and gastrointestinal mobility and are used as adjunct targets in treating schizophrenia. However, the distribution of these receptors is wider than the nervous system and there is potential that these additional sites can be targeted to modulate inflammatory and/or metabolic conditions. Recent progress in structural biology and pharmacology of 5-HT₃ receptors have provided profound insights into mechanisms of their action. These advances, combined with insights into clinical relevance of mutations in genes encoding 5-HT₃ subunits and increasing understanding of their implications in patient's predisposition to diseases and response to the treatment, open new avenues for personalized precision medicine. In this review, we recap on the current status of 5-HT₃ receptor-based therapies using a biochemical and physiological perspective. We assess the potential for targeting 5-HT₃ receptors in conditions involving metabolic or inflammatory disorders based on recent findings, underscoring the challenges and limitations of this approach.

Autophagy in metabolic disease and ageing

Autophagy is an evolutionarily conserved, lysosome-dependent catabolic process whereby cytoplasmic components, including damaged organelles, protein aggregates and lipid droplets, are degraded and their components recycled. Autophagy has an essential role in maintaining cellular homeostasis in response to intracellular stress; however, the efficiency of autophagy declines with age and overnutrition can interfere with the autophagic process. Therefore, conditions such as sarcopenic obesity, insulin resistance and type 2 diabetes mellitus (T2DM) that are characterized by metabolic derangement and intracellular stresses (including oxidative stress, inflammation and endoplasmic reticulum stress) also involve the accumulation of damaged cellular components. These conditions are prevalent in ageing populations. For example, sarcopenia is an age-related loss of skeletal muscle mass and strength that is involved in the pathogenesis of both insulin resistance and T2DM, particularly in elderly people. Impairment of autophagy results in further aggravation of diabetes-related metabolic derangements in insulin target tissues, including the liver, skeletal muscle and adipose tissue, as well as in pancreatic β-cells. This Review summarizes the role of autophagy in the pathogenesis of metabolic diseases associated with or occurring in the context of ageing, including insulin resistance, T2DM and sarcopenic obesity, and describes its potential as a therapeutic target.

Accelerated developmental adipogenesis programs adipose tissue dysfunction and cardiometabolic risk in offspring born to dams with metabolic dysfunction

This study determined if a perturbation in in utero adipogenesis leading to later life adipose tissue (AT) dysfunction underlies programming of cardiometabolic risk in offspring born to dams with metabolic dysfunction. Female mice heterozygous for the leptin receptor deficiency (Het_db) had 2.4-fold higher prepregnancy fat mass and in late gestation had higher plasma insulin and triglycerides compared with wild-type (Wt) females (P < 0.05). To isolate the role of the intrauterine milieu, wild-type (Wt) offspring from each pregnancy were studied. Differentiation potential in isolated progenitors and cell size distribution analysis revealed accelerated adipogenesis in Wt pups born to Het_db dams, accompanied by a higher accumulation of neonatal fat mass. In adulthood, whole body fat mass by NMR was higher in male (69%) and female (20%) Wt offspring born to Het_db versus Wt pregnancies, along with adipocyte hypertrophy and hyperlipidemia (all P < 0.05). Lipidomic analyses by gas chromatography revealed an increased lipogenic index (16:0/18:2n6) after high-fat/fructose diet (HFFD). Postprandial insulin, ADIPO-IR, and ex vivo AT lipolytic responses to isoproterenol were all higher in Wt offspring born to Het_db dams (P < 0.05). Intrauterine metabolic stimuli may direct a greater proportion of progenitors toward terminal differentiation, thereby predisposing to hypertrophy-induced adipocyte dysfunction.NEW & NOTEWORTHY This study reveals that accelerated adipogenesis during the perinatal window of adipose tissue development predisposes to later life hypertrophic adipocyte dysfunction, thereby compromising the buffering function of the subcutaneous depot.

Emerging roles of epigenetic regulation in obesity and metabolic disease

Adipose tissue dysfunction is a hallmark of obesity and contributes to obesity-related sequelae such as metabolic complications and insulin resistance. Compelling evidence indicates that adipose-tissue-specific gene expression is influenced by gene interactions with proximal and distal cis-regulatory elements; the latter exert regulatory effects via three-dimensional (3D) chromosome conformation. Recent advances in determining the regulatory mechanisms reveal that compromised epigenomes are molecularly interlinked to altered cis-regulatory element activity and chromosome architecture in the adipose tissue. This review summarizes the roles of epigenomic components, particularly DNA methylation, in transcriptional rewiring in adipose tissue. In addition, we discuss the emerging roles of DNA methylation in the maintenance of 3D chromosome conformation and its pathophysiological significance concerning adipose tissue function.

Pathophysiological Molecular Mechanisms of Obesity: A Link between MAFLD and NASH with Cardiovascular Diseases

Obesity is now a worldwide epidemic ensuing an increase in comorbidities’ prevalence, such as insulin resistance, type 2 diabetes (T2D), metabolic dysfunction-associated fatty liver disease (MAFLD), nonalcoholic steatohepatitis (NASH), hypertension, cardiovascular disease (CVD), autoimmune diseases, and some cancers, CVD being one of the main causes of death in the world. Several studies provide evidence for an association between MAFLD and atherosclerosis and cardio-metabolic disorders, including CVDs such as coronary heart disease and stroke. Therefore, the combination of MAFLD/NASH is associated with vascular risk and CVD progression, but the underlying mechanisms linking MAFLD/NASH and CVD are still under investigation. Several underlying mechanisms may probably be involved, including hepatic/systemic insulin resistance, atherogenic dyslipidemia, hypertension, as well as pro-atherogenic, pro-coagulant, and pro-inflammatory mediators released from the steatotic/inflamed liver. MAFLD is strongly associated with insulin resistance, which is involved in its pathogenesis and progression to NASH. Insulin resistance is a major cardiovascular risk factor in subjects without diabetes. However, T2D has been considered the most common link between MAFLD/NASH and CVD. This review summarizes the evidence linking obesity with MAFLD, NASH, and CVD, considering the pathophysiological molecular mechanisms involved in these diseases. We also discuss the association of MAFLD and NASH with the development and progression of CVD, including structural and functional cardiac alterations, and pharmacological strategies to treat MAFLD/NASH and cardiovascular prevention.

Cardiometabolic Outcomes and Mortality in Patients with Adrenal Adenomas in a Population-based Setting

CONTEXT

While adrenal adenomas have been linked with cardiovascular morbidity in convenience samples of patients from specialized referral centers, large-scale population-based data are lacking.

OBJECTIVE

To determine the prevalence and incidence of cardiometabolic disease and assess mortality in a population-based cohort of patients with adrenal adenomas.

DESIGN

Population-based cohort study.

SETTING

Olmsted County, Minnesota, USA.

PATIENTS

Patients diagnosed with adrenal adenomas without overt hormone excess and age- and sex-matched referent subjects without adrenal adenomas.

MAIN OUTCOME MEASURE

Prevalence, incidence of cardiometabolic outcomes, mortality.

RESULTS

(Adrenal adenomas were diagnosed in 1004 patients (58% women, median age 63 years) from 1/01/1995 to 12/31/2017. At baseline, patients with adrenal adenomas were more likely to have hypertension [adjusted odds ratio (aOR) 1.96, 95% CI 1.58-2.44], dysglycemia (aOR 1.63, 95% CI 1.33-2.00), peripheral vascular disease (aOR 1.59, 95% CI 1.32-2.06), heart failure (aOR 1.64, 95% CI 1.15-2.33), and myocardial infarction (aOR 1.50, 95% CI 1.02-2.22) compared to referent subjects. During median follow-up of 6.8 years, patients with adrenal adenomas were more likely than referent subjects to develop de novo chronic kidney disease [adjusted hazard ratio (aHR) 1.46, 95% CI 1.14-1.86], cardiac arrhythmia (aHR 1.31, 95% CI 1.08-1.58), peripheral vascular disease (aHR 1.28, 95% CI 1.05-1.55), cardiovascular events (aHR 1.33, 95% CI 1.01-1.73), and venous thromboembolic events (aHR 2.15, 95% CI 1.48-3.13). Adjusted mortality was similar between the 2 groups.

CONCLUSION

Adrenal adenomas are associated with an increased prevalence and incidence of adverse cardiometabolic outcomes in a population-based cohort.

Circulating Bile Acid Profiles: A Need for Further Examination

CONTEXT

Bile acids (BAs) are increasingly recognized as metabolic and chronobiologic integrators that synchronize the systemic metabolic response to nutrient availability. Alterations in the concentration and/or composition of circulating BAs are associated with a number of metabolic disorders, such as obesity, type 2 diabetes mellitus (T2DM), insulin resistance (IR), and metabolic associated fatty liver disease (MAFLD). This review summarizes recent evidence that links abnormal circulating BA profiles to multiple metabolic disorders, and discusses the possible mechanisms underlying the connections to determine the role of BA profiling as a novel biomarker for these abnormalities.

EVIDENCE ACQUISITION

The review is based on a collection of primary and review literature gathered from a PubMed search of BAs, T2DM, IR, and MAFLD, among other keywords.

EVIDENCE SYNTHESIS

Obese and IR subjects appear to have elevated fasting circulating BAs but lower postprandial increase when compared with controls. The possible underlying mechanisms are disruption in the synchronization between the feeding/fasting cycle and the properties of BA-regulated metabolic pathways. Whether BA alterations are associated per se with MAFLD remains inconclusive. However, increased fasting circulating BAs level was associated with higher risk of advanced fibrosis stage. Thus, for patients with MAFLD, dynamically monitoring the circulating BA profiles may be a promising tool for the stratification of MAFLD.

CONCLUSIONS

Alterations in the concentration, composition, and rhythm of circulating BAs are associated with adverse events in systemic metabolism. Subsequent investigations regarding these aspects of circulating BA kinetics may help predict future metabolic disorders and guide therapeutic interventions.

Hepatic Fat in Early Childhood Is Independently Associated With Estimated Insulin Resistance: The Healthy Start Study

BACKGROUND

Fatty liver disease is a common metabolic abnormality in adolescents with obesity but remains understudied in early childhood.

OBJECTIVES

To describe hepatic fat deposition in prepubertal children and examine cross-sectional associations with metabolic markers and body composition.

METHODS

Data were from 286 children ages 4 to 8 years old in the Healthy Start Study, a longitudinal prebirth cohort in Colorado (USA). Assessments included magnetic resonance imaging to quantify hepatic and abdominal fats, fasting blood draws to measure metabolic markers, and air displacement plethysmography to measure body composition (fat mass and fat-free mass).

RESULTS

The median (interquartile range) for hepatic fat was 1.65% (1.24%, 2.11%). Log-transformed hepatic fat was higher in Hispanic [mean (95% CI): 0.63 (0.52, 0.74)] vs non-Hispanic white children [0.46 (0.38, 0.53), P = 0.01] and children with overweight/obesity [0.64 (0.49, 0.79)] vs normal-weight [0.47 (0.40, 0.53), P = 0.02]. Higher log-hepatic fat was associated with higher insulin [β (95% CI): 1.47 (0.61, 2.33) uIU/mL, P = 0.001] and estimated insulin resistance (homeostatic model assessment) [0.40 (0.20, 0.60), P < 0.001] in the full sample and glucose [5.53 (2.84, 8.21) mg/dL, P < 0.001] and triglycerides [10.92 (2.92,18.91) mg/dL, P = 0.008] in boys, in linear regression models adjusted for sociodemographics, maternal/perinatal confounders, and percentage body fat. Log-hepatic fat was also associated with abdominal subcutaneous adipose tissue [SAT; 7.37 (1.12,13.60) mm2, P = 0.02] in unadjusted models, but this was attenuated and insignificant after adjusting for confounders.

CONCLUSIONS

While hepatic fat was low in children 4 to 8 years old, it was independently associated with estimated insulin resistance and exhibited sex-specific associations with glucose and triglycerides, suggesting hepatic fat may be an early indicator of metabolic dysfunction in youth.

An integrated approach to identify environmental modulators of genetic risk factors for complex traits

Complex traits and diseases can be influenced by both genetics and environment. However, given the large number of environmental stimuli and power challenges for gene-by-environment testing, it remains a critical challenge to identify and prioritize specific disease-relevant environmental exposures. We propose a framework for leveraging signals from transcriptional responses to environmental perturbations to identify disease-relevant perturbations that can modulate genetic risk for complex traits and inform the functions of genetic variants associated with complex traits. We perturbed human skeletal-muscle-, fat-, and liver-relevant cell lines with 21 perturbations affecting insulin resistance, glucose homeostasis, and metabolic regulation in humans and identified thousands of environmentally responsive genes. By combining these data with GWASs from 31 distinct polygenic traits, we show that the heritability of multiple traits is enriched in regions surrounding genes responsive to specific perturbations and, further, that environmentally responsive genes are enriched for associations with specific diseases and phenotypes from the GWAS Catalog. Overall, we demonstrate the advantages of large-scale characterization of transcriptional changes in diversely stimulated and pathologically relevant cells to identify disease-relevant perturbations.

Long non-coding RNAs in metabolic disorders: pathogenetic relevance and potential biomarkers and therapeutic targets

BACKGROUND

It has been suggested that dysregulation of long non-coding RNAs (lncRNAs) could be associated with the incidence and development of metabolic disorders.

AIM

Accordingly, this narrative review described the molecular mechanisms of lncRNAs in the development of metabolic diseases including insulin resistance, diabetes, obesity, non-alcoholic fatty liver disease (NAFLD), cirrhosis, and coronary artery diseases (CAD). Furthermore, we investigated the up-to-date findings on the association of deregulated lncRNAs in the metabolic disorders, and potential use of lncRNAs as biomarkers and therapeutic targets.

CONCLUSION

LncRNAs/miRNA/regulatory proteins axis plays a crucial role in progression of metabolic disorders and may be used in development of therapeutic and diagnostic approaches.

The clinical significance of the glucocorticoid receptors: Genetics and epigenetics

The impacts of glucocorticoids (GCs) are mainly mediated by a nuclear receptor (GR) existing in almost every tissue. The GR regulates a wide range of physiological functions, including inflammation, cell metabolism, and differentiation playing a major role in cellular responses to GCs and stress. Therefore, the dysregulation or disruption of GR can cause deficiencies in the adaptation to stress and the preservation of homeostasis. The number of GR polymorphisms associated with different diseases has been mounting per year. Tackling these clinical complications obliges a comprehensive understanding of the molecular network action of GCs at the level of the GR structure and its signaling pathways. Beyond genetic variation in the GR gene, epigenetic changes can enhance our understanding of causal factors involved in the development of diseases and identifying biomarkers. In this review, we highlight the relationships of GC receptor gene polymorphisms and epigenetics with different diseases.

Fasting-mimicking diet prevents high-fat diet effect on cardiometabolic risk and lifespan

Diet-induced obesity is a major risk factor for metabolic syndrome, diabetes and cardiovascular disease. Here, we show that a 5-d fasting-mimicking diet (FMD), administered every 4 weeks for a period of 2 years, ameliorates the detrimental changes caused by consumption of a high-fat, high-calorie diet (HFCD) in female mice. We demonstrate that monthly FMD cycles inhibit HFCD-mediated obesity by reducing the accumulation of visceral and subcutaneous fat without causing loss of lean body mass. FMD cycles increase cardiac vascularity and function and resistance to cardiotoxins, prevent HFCD-dependent hyperglycaemia, hypercholesterolaemia and hyperleptinaemia and ameliorate impaired glucose and insulin tolerance. The effect of monthly FMD cycles on gene expression associated with mitochondrial metabolism and biogenesis in adipocytes and the sustained ketogenesis in HFCD-fed mice indicate a role for fat cell reprogramming in obesity prevention. These effects of an FMD on adiposity and cardiac ageing could explain the protection from HFCD-dependent early mortality.

Metabolic dysfunction and inflammatory disease: the role of stromal fibroblasts

Mesenchymal stromal fibroblasts have emerged as key mediators of the inflammatory response and drivers of localised inflammation, in part through their interactions with resident and circulating immune cells at inflammatory sites. As such, they have been implicated in a number of chronic inflammatory conditions as well as in tumour progression through modifying the microenvironment. The connection between metabolic changes and altered phenotype of fibroblasts in inflammatory microenvironments has clear implications for our understanding of how chronic inflammation is regulated and for the development of new anti-inflammatory therapeutics. In this review, we consider the evidence that changes to fibroblast metabolic state underpin chronic inflammation. We examine recent research on fibroblast metabolism in inflammatory microenvironments and consider their involvement in inflammation, providing insight into the role of fibroblasts and metabolism in mediating inflammatory disease progression namely cancer, arthritis and fibrotic disorders including chronic kidney disease, pulmonary fibrosis, heart disease and liver disease.

Insulin Resistance in Skeletal Muscle Selectively Protects the Heart in Response to Metabolic Stress

Obesity and type 2 diabetes mellitus (T2DM) are the leading causes of cardiovascular morbidity and mortality. Although insulin resistance is believed to underlie these disorders, anecdotal evidence contradicts this common belief. Accordingly, obese patients with cardiovascular disease have better prognoses relative to leaner patients with the same diagnoses, whereas treatment of T2DM patients with thiazolidinedione, one of the popular insulin-sensitizer drugs, significantly increases the risk of heart failure. Using mice with skeletal musclespecific ablation of the insulin receptor gene (MIRKO), we addressed this paradox by demonstrating that insulin signaling in skeletal muscles specifically mediated cross talk with the heart, but not other metabolic tissues, to prevent cardiac dysfunction in response to metabolic stress. Despite severe hyperinsulinemia and aggregating obesity, MIRKO mice were protected from myocardial insulin resistance, mitochondrial dysfunction, and metabolic reprogramming in response to diet-induced obesity. Consequently, the MIRKO mice were also protected from myocardial inflammation, cardiomyopathy, and left ventricle dysfunction. Together, our findings suggest that insulin resistance in skeletal muscle functions as a double-edged sword in metabolic diseases.

Glaucoma Syndromes: Insights into Glaucoma Genetics and Pathogenesis from Monogenic Syndromic Disorders

Monogenic syndromic disorders frequently feature ocular manifestations, one of which is glaucoma. In many cases, glaucoma in children may go undetected, especially in those that have other severe systemic conditions that affect other parts of the eye and the body. Similarly, glaucoma may be the first presenting sign of a systemic syndrome. Awareness of syndromes associated with glaucoma is thus critical both for medical geneticists and ophthalmologists. In this review, we highlight six categories of disorders that feature glaucoma and other ocular or systemic manifestations: anterior segment dysgenesis syndromes, aniridia, metabolic disorders, collagen/vascular disorders, immunogenetic disorders, and nanophthalmos. The genetics, ocular and systemic features, and current and future treatment strategies are discussed. Findings from rare diseases also uncover important genes and pathways that may be involved in more common forms of glaucoma, and potential novel therapeutic strategies to target these pathways.

Tolerogenic Dendritic Cells Shape a Transmissible Gut Microbiota That Protects From Metabolic Diseases

Excess chronic contact between microbial motifs and intestinal immune cells is known to trigger a low-grade inflammation involved in many pathologies such as obesity and diabetes. The important skewing of intestinal adaptive immunity in the context of diet-induced obesity (DIO) is well described, but how dendritic cells (DCs) participate in these changes is still poorly documented. To address this question, we challenged transgenic mice with enhanced DC life span and immunogenicity (DC^hBcl-2 mice) with a high-fat diet. Those mice display resistance to DIO and metabolic alterations. The DIO-resistant phenotype is associated with healthier parameters of intestinal barrier function and lower intestinal inflammation. DC^hBcl-2 DIO-resistant mice demonstrate a particular increase in tolerogenic DC numbers and function, which is associated with strong intestinal IgA, T helper 17, and regulatory T-cell immune responses. Microbiota composition and function analyses reveal that the DC^hBcl-2 mice microbiota is characterized by lower immunogenicity and an enhanced butyrate production. Cohousing experiments and fecal microbial transplantations are sufficient to transfer the DIO resistance status to wild-type mice, demonstrating that maintenance of DCs' tolerogenic ability sustains a microbiota able to drive DIO resistance. The tolerogenic function of DCs is revealed as a new potent target in metabolic disease management.

Hearing loss in inherited metabolic disorders: A systematic review

Inherited metabolic disorders (IMDs) have been observed in individuals with hearing loss (HL), but IMDs are rarely the cause of syndromic HL. With early diagnosis, management of HL is more effective and cortical reorganization is possible with hearing aids or cochlear implants. This review describes relationships between IMDs and HL in terms of incidence, etiology of HL, pathophysiology, and treatment. Forty types of IMDs are described in the literature, mainly in case reports. Management and prognosis are noted where existing. We also describe IMDs with HL given age of occurrence of HL. Reviewing the main IMDs that are associated with HL may provide an additional clinical tool with which to better diagnose syndromic HL.

Association of hip fractures with cardiometabolic-renal risk factors in Southern Chinese patients with type 2 diabetes - the Hong Kong Diabetes Register

INTRODUCTION

Diabetes and bone health are closely related. We examined the incidence and risk factors of hip fractures in Chinese patients with type 2 diabetes (T2D).

MATERIALS AND METHODS

In this prospective cohort, we consecutively enrolled 22,325 adults with T2D above the age of 40 years in the Hong Kong Diabetes Register between 1994 and 2015 with crude hip fracture incidence rate censored in 2017.

RESULTS

At baseline, the mean age of this cohort was 60.9 ± 10.5 years (mean duration of diabetes 6 years, 52.4% male). During a mean ± standard deviation (SD) follow-up period of 8.7 ± 5.2 years with 193,553 person-years, 603 patients were hospitalized due to hip fractures with an incidence (95% confidence interval, CI) of 315.1 (290.4-341.3) per 100,000 person-years. On multivariable analysis with competing death risk adjusted, the independent hazard ratios (95% CI) for hip fractures in T2D were 2.01 (1.61-2.51) for female sex, 1.08 (1.07-1.09) for age, 0.93 (0.90-0.95) for body mass index, 1.52 (1.25-1.85) for albuminuria and 1.12 (1.02-1.23) for low density lipoprotein-cholesterol. In men, the 30-day, 1-year and 5-year post-hip fracture mortality rate (95% CI) were 5.8 (2.4-9.1) %, 29.2 (22.3-35.5) % and 65.9 (57.3-72.8) % respectively. The corresponding rates in women were 3.4 (1.6-5.1) %, 18.6 (14.7-22.4) %, and 46.8 (40.9-52.1) %.

CONCLUSIONS

Southern Chinese patients with T2D have a high risk of hip fracture associated with suboptimal cardiometabolic-renal risk factors and a high post-fracture mortality rate. The effects of improving modifiable risk factors on bone health warrants further evaluation.

Curcumin Alleviates Aβ42-Induced Neuronal Metabolic Dysfunction via the Thrb/SIRT3 Axis and Improves Cognition in APPTG Mice

Curcumin has been reported to have a therapeutic effect on Alzheimer's disease (AD), but the specific mechanism remains to be elucidated. In the present research, we aimed to investigate the effect and molecular mechanism of curcumin on AD. Mouse primary hippocampal neuron cells were treated with various concentrations of beta-amyloid 42 (Aβ₄₂) and the results found that Aβ₄₂ inhibited cell viability in a dose-dependent manner. Compared with 50 ng/mL Aβ₄₂, 500 ng/mL Aβ₄₂ could further promote cell apoptosis, reduce the ratio of Nicotinamide adenine dinucleotide (NAD(+))/Nicotinamide adenine diphosphate hydride (NADH) and Adenosine 5'-triphosphate (ATP) level, and inhibit Sirtuins 3 (SIRT3) deacetylation activity and protein expression of Thyroid hormone receptor beta (Thrb) and SIRT3. Hence, 500 ng/mL Aβ₄₂ was used to establish a cell model of AD. Curcumin significantly reversed the inhibitory effects of Aβ₄₂ on cell viability, SIRT3 deacetylation activity, the ratio of NAD⁺/NADH, ATP level and the protein expression of Thrb and SIRT3, and the promotive effect on apoptosis. ChIPBase was used to predict the binding region of Thrb and SIRT3. Dual luciferase reporter gene and Chromatin immune precipitation (ChIP) assays were employed to verify the relationship between Thrb and promoter of SIRT3 mRNA. Overexpression of Thrb recovered Aβ₄₂ induced metabolic dysfunction, while Thrb silence aggravated Aβ₄₂ induced metabolic dysfunction. Moreover, Thrb silence or 3-TYP (a selective inhibitor of SIRT3) treatment abolished the amelioration of curcumin on Aβ₄₂ induced metabolic dysfunction. Additionally, curcumin attenuated memory deficits in Amyloid precursor protein transgenic (APP_TG) mice. Collectively, curcumin alleviated Aβ₄₂-induced neuronal metabolic dysfunction through increasing Thrb expression and SIRT3 activity and improved cognition in APP_TG mice.

Metabolic Comorbidities in Vitiligo: A Brief Review and Report of New Data from a Single-Center Experience

Among disorders of pigmentation, vitiligo is the most common, with an estimated prevalence between 0.5% and 1%. The disease has gathered increased attention in the most recent years, leading to a better understanding of the disease’s pathophysiology and its implications and to the development of newer therapeutic strategies. A better, more integrated approach is already in use for other chronic inflammatory dermatological diseases such as psoriasis, for which metabolic comorbidities are well-established and part of the routine clinical evaluation. The pathogenesis of these might be linked to cytokines which also play a role in vitiligo pathogenesis, such as IL-1, IL-6, TNF-α, and possibly IL-17. Following the reports of intrinsic metabolic alterations reported by our group, in this brief review, we analyze the available data on metabolic comorbidities in vitiligo, accompanied by our single-center experience. Increased awareness of the metabolic aspects of vitiligo is crucial to improving patient care.

Organ Crosstalk and the Modulation of Insulin Signaling

A highly complex network of organ communication plays a key role in regulating metabolic homeostasis, specifically due to the modulation of the insulin signaling machinery. As a paradigm, the role of adipose tissue in organ crosstalk has been extensively investigated, but tissues such as muscles and the liver are equally important players in this scenario. Perturbation of organ crosstalk is a hallmark of insulin resistance, emphasizing the importance of crosstalk molecules in the modulation of insulin signaling, potentially leading to defects in insulin action. Classically secreted proteins are major crosstalk molecules and are able to affect insulin signaling in both directions. In this review, we aim to focus on some crosstalk mediators with an impact on the early steps of insulin signaling. In addition, we also summarize the current knowledge on the role of extracellular vesicles in relation to insulin signaling, a more recently discovered additional component of organ crosstalk. Finally, an attempt will be made to identify inter-connections between these two pathways of organ crosstalk and the potential impact on the insulin signaling network.

Cellular and Exosomal Regulations of Sepsis-Induced Metabolic Alterations

Sepsis is a sustained systemic inflammatory condition involving multiple organ failures caused by dysregulated immune response to infections. Sepsis induces substantial changes in energy demands at the cellular level leading to metabolic reprogramming in immune cells and stromal cells. Although sepsis-associated organ dysfunction and mortality have been partly attributed to the initial acute hyperinflammation and immunosuppression precipitated by a dysfunction in innate and adaptive immune responses, the late mortality due to metabolic dysfunction and immune paralysis currently represent the major problem in clinics. It is becoming increasingly recognized that intertissue and/or intercellular metabolic crosstalk via endocrine factors modulates maintenance of homeostasis, and pathological events in sepsis and other inflammatory diseases. Exosomes have emerged as a novel means of intercellular communication in the regulation of cellular metabolism, owing to their capacity to transfer bioactive payloads such as proteins, lipids, and nucleic acids to their target cells. Recent evidence demonstrates transfer of intact metabolic intermediates from cancer-associated fibroblasts via exosomes to modify metabolic signaling in recipient cells and promote cancer progression. Here, we review the metabolic regulation of endothelial cells and immune cells in sepsis and highlight the role of exosomes as mediators of cellular metabolic signaling in sepsis.

Therapeutic and diagnostic targeting of fibrosis in metabolic, proliferative and viral disorders

Fibrosis is a common denominator in many pathologies and crucially affects disease progression, drug delivery efficiency and therapy outcome. We here summarize therapeutic and diagnostic strategies for fibrosis targeting in atherosclerosis and cardiac disease, cancer, diabetes, liver diseases and viral infections. We address various anti-fibrotic targets, ranging from cells and genes to metabolites and proteins, primarily focusing on fibrosis-promoting features that are conserved among the different diseases. We discuss how anti-fibrotic therapies have progressed over the years, and how nanomedicine formulations can potentiate anti-fibrotic treatment efficacy. From a diagnostic point of view, we discuss how medical imaging can be employed to facilitate the diagnosis, staging and treatment monitoring of fibrotic disorders. Altogether, this comprehensive overview serves as a basis for developing individualized and improved treatment strategies for patients suffering from fibrosis-associated pathologies.

Copper, Iron, and Manganese Toxicity in Neuropsychiatric Conditions

Copper, manganese, and iron are vital elements required for the appropriate development and the general preservation of good health. Additionally, these essential metals play key roles in ensuring proper brain development and function. They also play vital roles in the central nervous system as significant cofactors for several enzymes, including the antioxidant enzyme superoxide dismutase (SOD) and other enzymes that take part in the creation and breakdown of neurotransmitters in the brain. An imbalance in the levels of these metals weakens the structural, regulatory, and catalytic roles of different enzymes, proteins, receptors, and transporters and is known to provoke the development of various neurological conditions through different mechanisms, such as via induction of oxidative stress, increased α-synuclein aggregation and fibril formation, and stimulation of microglial cells, thus resulting in inflammation and reduced production of metalloproteins. In the present review, the authors focus on neurological disorders with psychiatric signs associated with copper, iron, and manganese excess and the diagnosis and potential treatment of such disorders. In our review, we described diseases related to these metals, such as aceruloplasminaemia, neuroferritinopathy, pantothenate kinase-associated neurodegeneration (PKAN) and other very rare classical NBIA forms, manganism, attention-deficit/hyperactivity disorder (ADHD), ephedrone encephalopathy, HMNDYT1-SLC30A10 deficiency (HMNDYT1), HMNDYT2-SLC39A14 deficiency, CDG2N-SLC39A8 deficiency, hepatic encephalopathy, prion disease and “prion-like disease”, amyotrophic lateral sclerosis, Huntington’s disease, Friedreich’s ataxia, and depression.

Soy isoflavones recover pancreatic islet function and prevent metabolic dysfunction in male rats

We tested whether chronic supplementation with soy isoflavones could modulate insulin secretion levels and subsequent recovery of pancreatic islet function as well as prevent metabolic dysfunction induced by early overfeeding in adult male rats. Wistar rats raised in small litters (SL, three pups/dam) and normal litters (NL, nine pups/dam) were used as models of early overfeeding and normal feeding, respectively. At 30 to 90 days old, animals in the SL and NL groups received either soy isoflavones extract (ISO) or water (W) gavage serving as controls. At 90 days old, body weight, visceral fat deposits, glycemia, insulinemia were evaluated. Glucose-insulin homeostasis and pancreatic-islet insulinotropic response were also determined. The early life overnutrition induced by small litter displayed metabolic dysfunction, glucose, and insulin homeostasis disruption in adult rats. However, adult SL rats treated with soy isoflavones showed improvement in glucose tolerance, insulin sensitivity, insulinemia, fat tissue accretion, and body weight gain, compared with the SL-W group. Pancreatic-islet response to cholinergic, adrenergic, and glucose stimuli was improved in both isoflavone-treated groups. In addition, different isoflavone concentrations increased glucose-stimulated insulin secretion in islets of all groups with higher magnitude in both NL and SL isoflavone-treated groups. These results indicate that long-term treatment with soy isoflavones inhibits early overfeeding-induced metabolic dysfunction in adult rats and modulated the process of insulin secretion in pancreatic islets.

Discovering signaling mechanisms governing metabolism and metabolic diseases with Drosophila

There has been rapid growth in the use of Drosophila and other invertebrate systems to dissect mechanisms governing metabolism. New assays and approaches to physiology have aligned with superlative genetic tools in fruit flies to provide a powerful platform for posing new questions, or dissecting classical problems in metabolism and disease genetics. In multiple examples, these discoveries exploit experimental advantages as-yet unavailable in mammalian systems. Here, we illustrate how fly studies have addressed long-standing questions in three broad areas-inter-organ signaling through hormonal or neural mechanisms governing metabolism, intestinal interoception and feeding, and the cellular and signaling basis of sexually dimorphic metabolism and physiology-and how these findings relate to human (patho)physiology. The imaginative application of integrative physiology and related approaches in flies to questions in metabolism is expanding, and will be an engine of discovery, revealing paradigmatic features of metabolism underlying human diseases and physiological equipoise in health.

The progression and regression of metabolic dysfunction-associated fatty liver disease are associated with the development of subclinical atherosclerosis: A prospective analysis

BACKGROUND

Metabolic dysfunction-associated fatty liver disease (MAFLD) has been proposed and diagnosed based on modified criteria. However, evidence for the risks of developing subclinical atherosclerosis with MAFLD transitions according to its new definition has never been reported.

METHODS

Using data from a community-based cohort, 6232 participants aged 40 years or older were included and were followed up for a median of 4.3 years during 2010-2015. Participants were categorized into four groups (stable non-MAFLD, MAFLD regressed to non-MAFLD, non-MAFLD progressed to MAFLD, and stable MAFLD). Subclinical atherosclerosis was defined as elevated carotid intima-media thickness (CIMT), elevated brachial-ankle pulse wave velocity (ba-PWV), or microalbuminuria.

RESULTS

Compared with the stable non-MAFLD category, participants who progressed to MAFLD at follow-up visit had a 1.356-fold increased risk of developing elevated CIMT [odds ratio (OR) = 1.356; 95% confidence interval (CI) = 1.134-1.620], and a 1.458-fold increased risk of incident microalbuminuria (OR = 1.458; 95% CI = 1.034-2.056) after adjustment for confounders, respectively. In addition, participants with stable MAFLD showed 17.6%, 32.4%, and 35.4% increased risks of developing elevated CIMT, elevated ba-PWV and microalbuminuria, respectively. Compared with the stable MAFLD category, participants with MAFLD and low probability of fibrosis at baseline who regressed to non-MAFLD at follow-up visit had a 29.4% decreased risk of developing elevated CIMT (OR = 0.706; 95% CI = 0.507-0.984), a 43.1% decreased risk of developing elevated ba-PWV (OR = 0.569; 95% CI = 0.340-0.950), but was not significantly associated with incident microalbuminuria (OR = 0.709; 95% CI = 0.386-1.301). The decreased risks attributed to MAFLD regression were more evident in participants without diabetes or dyslipidemia, as well as in those with 0-1 metabolic risk abnormalities, respectively.

CONCLUSIONS

MAFLD was significantly associated with higher risks of developing subclinical atherosclerosis. Moreover, the regression of MAFLD might modify the risks of developing subclinical atherosclerosis, especially among those with low probability of fibrosis or less metabolic risk abnormalities. Since 40% of baseline participants with missing data on MAFLD measurement at follow-up were excluded, the conclusions should be speculated with caution.

Biglycan: an emerging small leucine-rich proteoglycan (SLRP) marker and its clinicopathological significance

Extracellular matrix (ECM) plays an important role in the structural organization of tissue and delivery of external cues to the cell. Biglycan, a class I small leucine-rich proteoglycans (SLRP), is a key component of the ECM that participates in scaffolding the collagen fibrils and mediates cell signaling. Dysregulation of biglycan expression can result in wide range of clinical conditions such as metabolic disorder, inflammatory disorder, musculoskeletal defects and malignancies. In this review, we aim to update our current understanding regarding the link between altered expression of biglycan and different clinicopathological states. Biglycan interacts with toll like receptors (TLR)-2 and TLR-4 on the immune cells which initiates inflammation and aggravates inflammatory disorders. ECM unbound soluble biglycan acts as a DAMP (danger associated molecular pattern) resulting in sterile inflammation. Dysregulation of biglycan expression is also observed in inflammatory metabolic conditions such as atherosclerosis and obesity. In cancer, high-biglycan expression facilitates tumor growth, invasion and metastasis which is associated with poor clinical outcome. As a pivotal structural component of the ECM, biglycan strengthens the musculoskeletal system and its absence is associated with musculoskeletal defects. Thus, SLRP biglycan is a potential marker which is significantly altered in different clinicopathological states.

Body fat distribution in trunk and legs are associated with cardiometabolic risk clustering among Chinese adolescents aged 10-18 years old

OBJECTIVES

The aim of the present study was to evaluate the association of body fat distribution with cardiometabolic risk factors clustering among Chinese adolescents.

METHODS

In this cross sectional study a total of 1,175 adolescents aged 10-18 years underwent a comprehensive assessment of cardimetabolic risk factors. Body fat analysis was performed with bioelectrical impedance analysis (BIA).

RESULTS

Individuals with the CVRFs≥1 or CVRFs≥2 had higher indices of body fat distribution such as body fat mass (BFM) compared to those with normal CVRFs (all p<0.001). The prevalence of CVRFs≥1, CVRFs≥2 increased with increasing of the quartile of BFM, TBFM, ABFM, LBFM, PBF, VFL compared to normal subjects. After adjusted for age and sex, the study indicated an linear relationship between TBFM (β = 0.693, 95% CI:0.363, 1.023), LBFM (β = -1.471, 95% CI:-2.768, -0.175) and CVRFs z-score. Logistic regression models suggested TBFM was associated with CVRFs≥1 and CVRFs≥2 by higher odds. Lower odds of LBFM was associated with CVRFs≥2.

CONCLUSIONS

The contribution of the fat mass in specific region on the cardiovascular risk factors clustering is different among adolescents. The trunk fat is associated with higher clustered cardiometabolic risk, while leg fat mass is the protective factor.

Restriction of Manganese Intake Prevents the Onset of Brain Manganese Overload in Zip14-/- Mice

As a newly identified manganese transport protein, ZIP14 is highly expressed in the small intestine and liver, which are the two principal organs involved in regulating systemic manganese homeostasis. Loss of ZIP14 function leads to manganese overload in both humans and mice. Excess manganese in the body primarily affects the central nervous system, resulting in irreversible neurological disorders. Therefore, to prevent the onset of brain manganese accumulation becomes critical. In this study, we used Zip14^−/− mice as a model for ZIP14 deficiency and discovered that these mice were born without manganese loading in the brain, but started to hyper-accumulate manganese within 3 weeks after birth. We demonstrated that decreasing manganese intake in Zip14^−/− mice was effective in preventing manganese overload that typically occurs in these animals. Our results provide important insight into future studies that are targeted to reduce the onset of manganese accumulation associated with ZIP14 dysfunction in humans.

Laminaria japonica polysaccharide prevents high-fat-diet-induced insulin resistance in mice via regulating gut microbiota

Insulin resistance has become a worldwide nutrition and metabolic health problem due to the lack of effective protective agents. Laminaria japonica is a well-known marine vegetable. Purified Laminaria japonica polysaccharide (LJP61A) can inhibit atherosclerosis in high-fat-diet (HFD)-fed mice via ameliorating insulin resistance. In this study, we aimed to clarify the mechanism by which LJP61A ameliorates HFD-induced insulin resistance. The results indicated that HFD-induced insulin resistance, obesity, systematic inflammation, metabolic endotoxemia, and gut permeability in mice could be reduced by LJP61A. Gut microbiota analysis showed that the gut microbiota dysbiosis of HFD-fed mice, especially the reduction in mucin-degrading Akkermansia, could be reversed by LJP61A. Additionally, the reduction in mucin-producing goblet cells in HFD-fed mice could also be reversed by LJP61A. Moreover, insulin resistance, obesity, systematic inflammation, metabolic endotoxemia, and gut microbiota dysbiosis in HFD-fed mice could also be alleviated by faecal transplant from LJP61A-treated mice. Overall, LJP61A might be used as a prebiotic to ameliorate HFD-induced insulin resistance and associated metabolic disorders via regulating gut microbiota, especially Akkermansia.

Pristimerin protects against inflammation and metabolic disorder in mice through inhibition of NLRP3 inflammasome activation

Excessive activation of NLRP3 inflammasome is associated with the pathogenesis of inflammatory diseases. Pristimerin (Pri) is a quinonoid triterpene derived from traditional Chinese medical herb Celastraceae and Hippocrateaceae. Pri has shown antifungal, antibacterial, antioxidant, and anticancer activities. In this study we investigated whether NLRP3 inflammasome was associated with the anti-inflammatory activity of Pri. We showed that Pri (0.1-0.4 μM) dose-dependently blocked caspase-1 activation and IL-1β maturation in LPS-primed mouse bone-marrow-derived macrophages (BMDMs). Pri specifically inhibited NLRP3 inflammasome activation, had no visible effects on NLRC4 and AIM2 inflammasome activation. Furthermore, we demonstrated that Pri blocked the assembly of the NLRP3 inflammasome via disturbing the interaction between NEK7 and NLRP3; the α, β-unsaturated carbonyl moiety of Pri was essential for NLRP3 inflammasome inactivation. In LPS-induced systemic inflammation mouse model and MSU-induced mouse peritonitis model, preinjection of Pri (500 μg/kg, ip) produced remarkable therapeutic effects via inhibition of NLRP3 inflammasome in vivo. In HFD-induced diabetic mouse model, administration of Pri (100 μg· kg-1 ·d-1, ip, for 6 weeks) reversed HFD-induced metabolic disorders via suppression of NLRP3 inflammasome activation. Taken together, our results demonstrate that Pri acts as a NLRP3 inhibitor, suggesting that Pri might be useful for the treatment of NLRP3-associated diseases.