Impact of Glucocorticoid Excess on Glucose Tolerance: Clinical and Preclinical Evidence

Pharmacotherapy causing weight gain and metabolic alteration in those with obesity and obesity-related conditions: A review

This review aims to summarize pharmacological interventions that may affect adiposity and metabolic equilibrium in individuals with obesity. Pharmacological therapy is frequently used to treat medical conditions that are both directly related to obesity (such as hypertension and type 2 diabetes) and indirectly related to obesity (such as asthma, insomnia, and type 1 diabetes). This pharmacological therapy may result in weight gain and alterations in the metabolic profile. Many medication classes are implicated in the pharmacologic causes of weight gain, including antipsychotics, glucocorticoids, beta-adrenergic blockers, tricyclic antidepressants, antihistamines, insulin, neuropathic agents, sleep agents, and steroids. This article describes the mechanisms of action and pathways of pharmacological interventions causing obesity.

Bacillus amyloliquefaciens Probiotics Mix Supplementation in a Broiler Leaky Gut Model

The supplementation of antimicrobial growth promoters (AGPs) has been banned in many countries because of the emergence of antimicrobial-resistant pathogens in poultry products and the environment. Probiotics have been broadly studied and demonstrated as a promising AGP substitute. Our study is centred on the effects of a multi-strain Bacillus-based probiotic product on broiler production performance and gut microbial profile in a dexamethasone-induced leaky gut challenge. Two hundred and fifty-six broiler chicks were hatched and randomly assigned into four groups (wheat-soybean meal basal diet (BD) = non-supplemented control (C), BD supplemented with dexamethasone in week 4 (CD), BD containing a probiotic from day one (P), and BD containing a probiotic from day one and supplemented with dexamethasone during challenge week 4 (PD)). The production performance and caecal, gizzard, jejunal lumen and jejunal mucosa swab microbiota were studied by 16S rRNA gene sequencing. The Bacillus probiotic product significantly improved production performance and altered caecal gut microbiota (p ≤ 0.05), but no significant impact on microbiota was observed in other gut sections.

Zein nanoparticles as oral carrier for mometasone furoate delivery

Mometasone furoate (MF) is a synthetic glucocorticoid used clinically to treat specific inflammatory disorders including superior and inferior respiratory tract. Due to its poor bioavailability we further investigated whether nanoparticles (NPs) made of zein protein may constitute a safe and effective choice to incorporate MF. Thus, in this work, we loaded MF into zein NPs aiming to evaluate possible advantages that could result from oral delivery and extend the range of MF application such as inflammatory gut diseases. MF-loaded zein NPs presented an average size in the range of 100 and 135 nm, narrow size distribution (polydispersity index < 0.300), zeta potential of around + 10 mV and association efficiency of MF over 70%. Transmission electron microscopy imaging revealed that NPs had a round shape and presented a smooth surface. The zein NPs showed low MF release in a buffer that mimics the gastric condition (pH = 1.2) and slower and controlled MF release in the intestinal condition (pH = 6.8). The short and intermediate safety of zein NPs was confirmed assessing the incubation against Caco-2 and HT29-MTX intestinal cells up to 24 h. Permeability studies of MF across Caco-2/HT29-MTX co-culture monolayer evidenced that zein NPs modulated MF transport across cell monolayer resulting in a stronger and prolonged interaction with mucus, potentially extending the time of absorption and overall local and systemic bioavailability. Overall, zein NPs showed to be suitable to carry MF to the intestine and future studies can be developed to investigate the use of MF-loaded zein NPs to treat intestinal inflammatory diseases.

Lithium treatment mitigates the diabetogenic effects of chronic cortico-therapy

BACKGROUND AND PURPOSE

Glucocorticoids (GCs) are the main treatment for autoimmune and inflammatory disorders and are also used as immunosuppressive therapy for patients with organ transplantation. However, these treatments have several side effects, including metabolic disorders. Indeed, cortico-therapy may induce insulin resistance, glucose intolerance, disrupted insulin and glucagon secretion, excessive gluconeogenesis, leading to diabetes in susceptible individuals. Recently, lithium has been shown to alleviate deleterious effects of GCs in various diseased conditions.

EXPERIMENTAL APPROACH

In this study, using two rat models of GC-induced metabolic disorders, we investigated the effects of Lithium Chloride (LiCl) in the mitigation of deleterious effects of GCs. Rats were treated either with corticosterone or dexamethasone, and with or without LiCl. Animals were then assessed for glucose tolerance, insulin sensitivity, in vivo and ex vivo glucose-induced insulin secretion and hepatic gluconeogenesis.

KEY RESULTS

We showed that in rats chronically treated with corticosterone, lithium treatment markedly reduced insulin resistance. In addition, in rats treated with dexamethasone, lithium administration improved glucose tolerance, associated with enhanced insulin secretion in vivo. Moreover, liver gluconeogenesis was reduced upon LiCl treatment. The improvement of insulin secretion in vivo appeared to be due to an indirect regulation of β cell function, since the ex vivo assessment of insulin secretion and β cell mass in islets from animals treated with LiCl revealed no difference compared to untreated animals.

CONCLUSION AND IMPLICATIONS

Collectively, our data provide evidences for the beneficial effects of lithium to mitigate the adverse metabolic effects of chronic cortico-therapy.

Oral mometasone furoate administration preserves anti-inflammatory action with fewer metabolic adverse effects in rats

BACKGROUND

Exogenous glucocorticoids (CGs) possess relevant therapeutic effects but exert diabetogenic actions when in excess. Thus, ligands with potential therapeutic applications and fewer adverse effects are needed. To this, we analyzed whether mometasone furoate (MF), a CG expected to cause fewer side effects, given through systemic routes, could maintain the anti-inflammatory actions without relevant repercussions on metabolism.

METHODS

The anti-inflammatory effect of MF was evaluated with both peritonitis and colitis models in rodents. Glucose and lipid metabolism were investigated in male and female rats treated daily with MF with different doses and routes of administration for seven days. The involvement of glucocorticoid receptor (GR) on MF actions was assessed in animals pretreated with mifepristone. Also, the potential reversibility of the adverse effects was assessed. Dexamethasone was used as a positive control.

RESULTS

MF treatment resulted in glucose intolerance in male rats treated through intraperitoneal (ip) but not oral gavage route (og). In female rats, none of the routes led to glucose intolerance. MF treatment attenuated insulin sensitivity and increased pancreatic β-cell mass, regardless of the sex and route of administration. MF treatment through og route did not result in dyslipidemia, as observed in rats treated through the ip route (both sexes). The anti-inflammatory and metabolic adverse effects of MF were GR-dependent, and metabolic outcomes altered by MF administration were reversible.

CONCLUSION

MF maintains anti-inflammatory activity when administered by systemic routes and exerts less impact on metabolism when administered orally in male and female rats, effects that are GR-dependent and reversible. Category: Metabolic Disorders and Endocrinology.

The Association of Acute Phase Proteins in Stress and Inflammation-Induced T2D

Acute phase proteins (APPs), such as plasminogen activator inhibitor-1 (PAI-1), serum amyloid A (SAA), and C-reactive protein (CRP), are elevated in type-2 diabetes (T2D) and are routinely used as biomarkers for this disease. These APPs are regulated by the peripheral mediators of stress (i.e., endogenous glucocorticoids (GCs)) and inflammation (i.e., pro-inflammatory cytokines), with both implicated in the development of insulin resistance, the main risk factor for the development of T2D. In this review we propose that APPs, PAI-1, SAA, and CRP, could be the causative rather than only a correlative link between the physiological elements of risk (stress and inflammation) and the development of insulin resistance.

Trends in insulin resistance: insights into mechanisms and therapeutic strategy

The centenary of insulin discovery represents an important opportunity to transform diabetes from a fatal diagnosis into a medically manageable chronic condition. Insulin is a key peptide hormone and mediates the systemic glucose metabolism in different tissues. Insulin resistance (IR) is a disordered biological response for insulin stimulation through the disruption of different molecular pathways in target tissues. Acquired conditions and genetic factors have been implicated in IR. Recent genetic and biochemical studies suggest that the dysregulated metabolic mediators released by adipose tissue including adipokines, cytokines, chemokines, excess lipids and toxic lipid metabolites promote IR in other tissues. IR is associated with several groups of abnormal syndromes that include obesity, diabetes, metabolic dysfunction-associated fatty liver disease (MAFLD), cardiovascular disease, polycystic ovary syndrome (PCOS), and other abnormalities. Although no medication is specifically approved to treat IR, we summarized the lifestyle changes and pharmacological medications that have been used as efficient intervention to improve insulin sensitivity. Ultimately, the systematic discussion of complex mechanism will help to identify potential new targets and treat the closely associated metabolic syndrome of IR.

Network Pharmacology and ­Experimental Analyses of the Mechanism of Analgesic and Glucose Intolerance Through Glucocorticoid Signaling in C57 Mice Treated with Water Extract of Prunella vulgaris L. Spica

The aim of this study was to confirm the anti-inflammatory effect and explore the adverse effects and underlying mechanisms of Prunella vulgaris L., which has been extensively used for hundreds of years in East Asia. Network pharmacology studies predicted that glucocorticoids (GCs), GC-targeting molecules, and brain-derived neurotrophic factor (BDNF) were intensively involved in the anti-inflammation and glucose intolerance. To attest the effects and underlying mechanisms, C57 male mice were randomly divided into 5 groups, control (C), dexamethasone (Dex), water extract of P. vulgaris (PE 35 or 70 mg), and PE (70 mg) + mifepristone (PEM). After a 3-week treatment, acetic acid-induced writhing and hot plate tests confirmed the peripheral and central analgesic effects, respectively. Plasma GCs and BDNF were significantly increased. Coincidently, plasma pro-inflammatory cytokines, including IL1β, IL6, and IL10, were decreased by PE treatment, which were blocked by the application of mifepristone ( P < 0.5). Western blots confirmed GC receptor (GR) translocation, and decreased cyclooxygenase 2 in the lumber spine by PE treatment. Food intake was impeded after a 4-week PE treatment, but the ratio of bodyweight gain to food intake was increased in a time-dependent manner. An intraperitoneal glucose tolerance test disclosed that PE treatment impaired glucose disposal in mice. Quantitative polymerase chain reaction (PCR) showed that hepatic GC-responsive genes such as GC-induced leucine zipper protein and glucose-6-phosphatase catalytic subunit 1 were up-regulated, and hypothalamic neuropeptide Y and agouti-related protein expressions were decreased by PE treatment. Hypothalamic BDNF was up-regulated, whereas hepatic BDNF was down-regulated. The regulation of these genes by PE was reversed by mifepristone administration. In conclusion, PE treatment plays analgesic and glucose regulation roles simultaneously through GC-induced signaling pathways, and P. vulgaris may provide a natural ligand of GR for the treatment of inflammation with glucose dysregulation.

The Synergetic Effect of Egyptian Portulaca oleracea L. (Purslane) and Cichorium intybus L. (Chicory) Extracts against Glucocorticoid-Induced Testicular Toxicity in Rats through Attenuation of Oxidative Reactions and Autophagy

Long-term glucocorticoids can alter sperm motility, vitality, or morphology, disrupting male reproductive function. This study scrutinized the synergistic benefits of two Egyptian plants against dexamethasone (Dexa)-induced testicular and autophagy dysfunction in male rats. Phytochemical ingredients and the combination index were estimated for Purslane ethanolic extract (PEE) and Chicory water extract (CWE). Four control groups received saline and 100 mg/kg of each PEE, CWE, and PEE/CWE, daily for 8 weeks. Dexa (1 mg/kg daily for 6 weeks) induced infertility where PEE, CWE, and PEE/CWE were given. Seminal analysis, male hormones, glycemic and oxidative stress markers, endoplasmic reticulum (ER) stress markers (Sigma 1R and GRP78), and autophagy regulators (Phospho-mTOR, LC3I/II, PI3KC3, and Beclin-1, P62, ATG5, and ATG7) were measured. The in vitro study illustrated the synergistic (CI < 1) antioxidant capacity of the PEE/CWE combination. Dexa exerts testicular damage by inducing oxidative reactions, a marked reduction in serum testosterone, TSH and LH levels, insulin resistance, ER stress, and autophagy. In contrast, the PEE and CWE extracts improve fertility hormones, sperm motility, and testicular histological alterations through attenuating oxidative stress and autophagy, with a synergistic effect upon combination. In conclusion, the administration of PEE/CWE has promised ameliorative impacts on male infertility and can delay disease progression.

Association of Septic Shock with Mortality in Hospitalized COVID-19 Patients in Wuhan, China

Purpose

Septic shock is a severe complication of COVID-19 patients. We aim to identify risk factors associated with septic shock and mortality among COVID-19 patients.

Methods

A total of 212 COVID-19 confirmed patients in Wuhan were included in this retrospective study. Clinical outcomes were designated as nonseptic shock and septic shock. Log-rank test was conducted to determine any association with clinical progression. A prediction model was established using random forest.

Results

The mortality of septic shock and nonshock patients with COVID-19 was 96.7% (29/30) and 3.8% (7/182). Patients taking hypnotics had a much lower chance to develop septic shock (HR = 0.096, p=0.0014). By univariate logistic regression analysis, 40 risk factors were significantly associated with septic shock. Based on multiple regression analysis, eight risk factors were shown to be independent risk factors and these factors were then selected to build a model to predict septic shock with AUC = 0.956. These eight factors included disease severity (HR = 15, p < 0.001), age > 65 years (HR = 2.6, p=0.012), temperature > 39.1°C (HR = 2.9, p=0.047), white blood cell count > 10 × 10⁹ (HR = 6.9, p < 0.001), neutrophil count > 75 × 10⁹ (HR = 2.4, p=0.022), creatine kinase > 5 U/L (HR = 1.8, p=0.042), glucose > 6.1 mmol/L (HR = 7, p < 0.001), and lactate > 2 mmol/L (HR = 22, p < 0.001).

Conclusions

We found 40 risk factors were significantly associated with septic shock. The model contained eight independent factors that can accurately predict septic shock. The administration of hypnotics could potentially reduce the incidence of septic shock in COVID-19 patients.

Factors affecting glycemic control in diabetes mellitus complicated by autoimmune pancreatitis

Aims/Introduction

To investigate factors influencing glycemic control in diabetes mellitus complicated by autoimmune pancreatitis.

Materials and Methods

This retrospective cohort study investigated 33 patients with diabetes mellitus complicated by autoimmune pancreatitis who had received steroid therapy at Toranomon Hospital between January 1, 2011, and December 31, 2020. The course of glycemic control at 12 months after starting steroids was classified into three groups: Improved, Unchanged, or Worsened. Factors affecting these groups were investigated. Furthermore, we created two scores: (1) time of diabetes mellitus onset and baseline body mass index; (2) time of diabetes mellitus onset and baseline C‐peptide index. Diabetes mellitus occurring at the same time as autoimmune pancreatitis, body mass index ≥22 kg/m², and C‐peptide index ≥1.1 were each worth 1 point. Scores were summed and totals of 0–2 were compared between groups.

Results

Ten patients were in the Improved group, 10 were in the Unchanged group, and 13 were in the Worsened group. The baseline body mass index and baseline C‐peptide index were lower in the Worsened group than in the Improved group (P < 0.05 each). In addition, the scores were lower in the Worsened group than in the other groups (P < 0.05).

Conclusions

Patients with a lower baseline body mass index and a decreased baseline C‐peptide index may experience worse glycemic control on steroid therapy.

Coincidence of juvenile idiopathic arthritis and type 1 diabetes: a case-based review

The study was aimed to review a rare coexistence of type 1 diabetes (T1D) and juvenile idiopathic arthritis (JIA) regarding different clinical approaches to the management and treatment options. Medical complications of the two autoimmune disorders in children and adolescents have been evaluated, particularly in those treated with glucocorticosteroids (GCS) and insulin. A review of the literature regarding reports on concomitant T1D and JIA was conducted using resources available in Medline, Google Scholar, and Web of Science databases, with a specific focus on the combination of T1D and JIA in a pediatric population. The review was extended by our analysis of two patients treated in a single center for this comorbidity. Eligible reports of four cases were found, and including our two original records, a total of six pediatric patients (5 females) were analyzed, of which three had also other autoimmune diseases (thyroiditis, coeliac disease, autoimmune hepatitis), whereas four had been treated with a long-term GCS, and two were receiving biological therapy (etanercept or adalimumab). Only one of them had good metabolic control of diabetes. Diabetes in childhood may coexist with other autoimmune diseases, including rheumatologic conditions. Hyperglycemia can worsen JIA therapy by induction and maintaining inflammation. Using modern diabetes technologies (like personal insulin pumps and continuous glucose monitoring) helps to minimize the deteriorating effect of JIA exacerbations and the rheumatoid treatment on metabolic control of diabetes.

Underlying mechanisms of glucocorticoid-induced β-cell death and dysfunction: a new role for glycogen synthase kinase 3

Glucocorticoids (GCs) are widely prescribed for their anti-inflammatory and immunosuppressive properties as a treatment for a variety of diseases. The use of GCs is associated with important side effects, including diabetogenic effects. However, the underlying mechanisms of GC-mediated diabetogenic effects in β-cells are not well understood. In this study we investigated the role of glycogen synthase kinase 3 (GSK3) in the mediation of β-cell death and dysfunction induced by GCs. Using genetic and pharmacological approaches we showed that GSK3 is involved in GC-induced β-cell death and impaired insulin secretion. Further, we unraveled the underlying mechanisms of GC-GSK3 crosstalk. We showed that GSK3 is marginally implicated in the nuclear localization of GC receptor (GR) upon ligand binding. Furthermore, we showed that GSK3 regulates the expression of GR at mRNA and protein levels. Finally, we dissected the proper contribution of each GSK3 isoform and showed that GSK3β isoform is sufficient to mediate the pro-apoptotic effects of GCs in β-cells. Collectively, in this work we identified GSK3 as a viable target to mitigate GC deleterious effects in pancreatic β-cells.

Coadministration of sitagliptin or metformin has no major impact on the adverse metabolic outcomes induced by dexamethasone treatment in rats

AIMS

Glucocorticoids (GC) in excess cause glucose intolerance and dyslipidemia due to their diabetogenic actions. Conceptually, antidiabetic drugs should attenuate these side effects. Thus, we evaluated whether the coadministration of metformin or sitagliptin (or both) with dexamethasone could attenuate GC-induced adverse effects on metabolism.

MATERIALS AND METHODS

Adult male rats were treated for 5 consecutive days with dexamethasone (1 mg/kg, body mass (bm), intraperitoneally). Additional groups were coadministered with metformin (300 mg/kg, bm, by oral gavage (og)) or sitagliptin (20 mg/kg, bm, og) or with both compounds in combination. The day after the last treatments, rats were submitted to glucose tolerance tests, pyruvate tolerance test, and euthanized for biometric, biochemical, morphologic, and molecular analyses.

KEY FINDINGS

Dexamethasone treatment resulted in reduced body mass and food intake, increased blood glucose and plasma insulin, dyslipidemia, glucose intolerance, pyruvate intolerance, and increased hepatic content of glycogen and fat. Sitagliptin coadministration improved glucose tolerance compared with the control group, an effect paralleled with higher levels of active GLP-1 during an oral GTT. Overall, sitagliptin or metformin coadministration did not prevent any of the dexamethasone-induced metabolic disturbances.

SIGNIFICANCE

Coadministration of sitagliptin or metformin result in no major improvement of glucose and lipid metabolism altered by dexamethasone treatment in male adult rats.

Early adversity and insulin: neuroendocrine programming beyond glucocorticoids

Exposure to direct or contextual adversities during early life programs the functioning of the brain and other biological systems, contributing to the development of physical as well as mental health issues in the long term. While the role of glucocorticoids in mediating the outcomes of early adversity has been explored for many years, less attention has been given to insulin. Beyond its metabolic effects in the periphery, central insulin action affects synaptic plasticity, brain neurotransmission, and executive functions. Knowledge about the interactions between the peripheral metabolism and brain function from a developmental perspective can contribute to prevention and diagnosis programs, as well as early interventions for vulnerable populations.

The Skeletal Cellular and Molecular Underpinning of the Murine Hindlimb Unloading Model

Bone adaptation to spaceflight results in bone loss at weight bearing sites following the absence of the stimulus represented by ground force. The rodent hindlimb unloading model was designed to mimic the loss of mechanical loading experienced by astronauts in spaceflight to better understand the mechanisms causing this disuse-induced bone loss. The model has also been largely adopted to study disuse osteopenia and therefore to test drugs for its treatment. Loss of trabecular and cortical bone is observed in long bones of hindlimbs in tail-suspended rodents. Over the years, osteocytes have been shown to play a key role in sensing mechanical stress/stimulus via the ECM-integrin-cytoskeletal axis and to respond to it by regulating different cytokines such as SOST and RANKL. Colder experimental environments (~20-22°C) below thermoneutral temperatures (~28-32°C) exacerbate bone loss. Hence, it is important to consider the role of environmental temperatures on the experimental outcomes. We provide insights into the cellular and molecular pathways that have been shown to play a role in the hindlimb unloading and recommendations to minimize the effects of conditions that we refer to as confounding factors.

Thioredoxin interacting protein drives astrocytic glucose hypometabolism in corticosterone-induced depressive state

Brain energetics disturbance is a hypothesized cause of depression. Glucose is the predominant fuel of brain energy metabolism, however, the cell-specific change of glucose metabolism and underlying molecular mechanism in depression remain unclear. In this study, we firstly applied ¹⁸ F-FDG PET and observed brain glucose hypometabolism in prefrontal cortex (PFC) of corticosterone-induced depression of rats. Next, astrocytic glucose hypometabolism was identified in PFC slices in in both corticosterone-induced depression of rats and cultured primary astrocytes from newborn rat PFC after stress-level corticosterone (100 nM) stimulation. Furthermore, we found the blockage of glucose uptake and the decrease of plasma membrane (PM) translocation of glucose transporter 1 (GLUT1) in astrocytic glucose hypometabolism under depressive condition. Interestingly, thioredoxin interacting protein (TXNIP), a glucose metabolism sensor and controller, was found to be overexpressed in corticosterone-stimulated astrocytes in vivo and in vitro. High TXNIP level could restrict GLUT1-mediated glucose uptake in primary astrocytes in vitro. Adeno-associated virus vector-mediated astrocytic TXNIP overexpression in rat medial PFC suppressed GLUT1 PM translocation, consequently developed depressive-like behavior. Conversely, TXNIP siRNA facilitated GLUT1 PM translocation to recover glucose hypometabolism in corticosterone-exposed cultured astrocytes. Notably, astrocyte-specific knockdown of TXNIP in medial PFC of rats facilitated astrocytic GLUT1 PM translocation, showing obvious antidepressant activity. These findings provide a new astrocytic energetic perspective in the pathogenesis of depression, more importantly, provide TXNIP as a promising molecular target for novel depression therapy.

Chronic glucocorticoid treatment induces hepatic lipid accumulation and hyperinsulinaemia in part through actions on AgRP neurons

Glucocorticoids (GCs) are widely prescribed anti-inflammatory medicines, but their use can lead to metabolic side-effects. These may occur through direct actions of GCs on peripheral organs, but could also be mediated by the hypothalamic AgRP neurons, which can increase food intake and modify peripheral metabolism. Therefore, the aim of this study was to examine the metabolic effects of chronic treatment with the GC corticosterone (Cort, 75 μg/ml in drinking water) in mice lacking the glucocorticoid receptor (GR) on AgRP neurons. Female AgRP-GR KO mice had delayed onset of Cort-induced hyperphagia. However, AgRP-GR KO had little impact on the increased body weight or adiposity seen with 3 weeks Cort treatment. Cort caused hepatic steatosis in control mice, but in Cort treated female AgRP-GR KO mice there was a 25% reduction in liver lipid content and lower plasma triglycerides. Additionally, Cort treatment led to hyperinsulinaemia, but compared to controls, Cort-treated AgRP-GR KO mice had both lower fasting insulin levels and lower insulin levels during a glucose tolerance test. In conclusion, these data indicate that GCs do act through AgRP neurons to contribute, at least in part, to the adverse metabolic consequences of chronic GC treatment.

20(s)‑ginseonside‑Rg3 modulation of AMPK/FoxO3 signaling to attenuate mitochondrial dysfunction in a dexamethasone‑injured C2C12 myotube‑based model of skeletal atrophy in vitro

Muscle atrophy, a side effect from administration of the anti-inflammatory medication dexamethasone (DEX), is preventable by concomitant administration of the major monomeric constituent of Panax ginseng C.A. Meyer, 20(S)-ginsenoside Rg3 (S-Rg3). Putative S-Rg3-associated prevention of DEX-induced muscle atrophy may involve S-Rg3 mitigation of DEX-induced mitochondrial dysfunction. In the present study, MTT assays revealed enhanced cell viability following S-Rg3 treatment of DEX-injured C2C12 myotubes. Subsequent PCR and western blotting results demonstrated S-Rg3-induced reduction of expression of muscle atrophy F-box protein (atrogin-1) and muscle RING-finger protein-1, proteins previously linked to muscle atrophy. Additionally, S-Rg3 treatment of DEX-injured myotubes led to aggregation of Rg3 monomers in cells and dose-dependent increases in cellular mitochondrial basal respiratory oxygen consumption rate and intracellular ATP levels compared with their levels in untreated DEX-injured myotubes. In addition, S-Rg3 treatment significantly reversed DEX-induced reductions of expression of key mitochondrial respiratory electron transport chain subunits of protein complexes II, III and V in DEX-injured myotube cells. Furthermore, S-Rg3 alleviation of mitochondrial dysfunction associated with DEX-induced injury of C2C12 myotubes was linked to S-Rg3-associated decreases in both forkhead box O3 (FoxO3) protein expression and phosphorylation of AMP-activated protein kinase (AMPK). Collectively, these results implicate S-Rg3 modulation of signaling within the AMPK-FoxO3 pathway as a putative mechanism underlying S-Rg3 alleviation of DEX-induced muscle atrophy.

A physiological glucocorticoid rhythm is an important regulator of brown adipose tissue function

Objective

Brown adipose tissue (BAT) displays a strong circadian rhythm in metabolic activity, but it is unclear how this rhythm is regulated. As circulating levels of corticosterone coincide with the rhythm of triglyceride-derived fatty acid (FA) uptake by BAT, we investigated whether corticosterone regulates BAT circadian rhythm.

Methods

Corticosterone levels were flattened by implanting mice with subcutaneous corticosterone-releasing pellets, resulting in constant circulating corticosterone levels.

Results

Flattened corticosterone rhythm caused a complete loss of circadian rhythm in triglyceride-derived fatty acid uptake by BAT. This effect was independent of glucocorticoid receptor expression in (brown) adipocytes and was not caused by deregulation of clock gene expression or overexposure to glucocorticoids, but rather seemed mediated by reduced sympathetic innervation of BAT. In a mouse model of hyperlipidemia and metabolic syndrome, long-term experimental flattening of corticosterone − and thus rhythm in BAT function − resulted in adiposity.

Conclusions

This study highlights that a physiological rhythm in glucocorticoids is an important regulator of BAT function and essential for the maintenance of metabolic health.

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Flattening of corticosterone rhythm blunts circadian activity of brown adipose tissue.

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Disturbed corticosterone rhythm − rather than overexposure− is responsible for blunted brown adipose tissue activity.

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The metabolic effect of flattened corticosterone levels is independent of adipocyte glucocorticoid receptor expression.

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Long-term flattening of corticosterone levels results in increased adiposity in a female mouse model for metabolic syndrome.

Sedum takesimense Protects PC12 Cells against Corticosterone-Induced Neurotoxicity by Inhibiting Neural Apoptosis

Neuronal cell death induced by chronic stress in the central nervous system is a cause of neurological dysfunction. We investigated the neuroprotective potential of a water extract of S. takesimense (WEST) against corticosterone-induced apoptosis in PC12 cells and the possible underlying mechanisms. Cells were pretreated with 50 µg/mL of WEST to evaluate its neuroprotective effect based on endoplasmic reticulum (ER) stress inhibition and mitochondrial function improvement. Pretreatment with WEST prevented corticosterone-induced injury in PC12 cells, resulting in increased cell survival, decreased lactate dehydrogenase (LDH) release, and potent apoptosis inhibition by a reduction in apoptotic nuclei demonstrated by Hoechst 33342 and propidium iodide (PI) double staining, and TUNEL staining. WEST strongly attenuated calcium (Ca²⁺) elevation, inducing the closure of mitochondrial permeability transition pores (mPTPs), which were opened by corticosterone. It also stabilized mitochondrial membrane potential (MMP) loss and inhibited the corticosterone-induced decrease in adenosine triphosphate (ATP) levels. Furthermore, the increased reactive oxygen species (ROS) production induced by corticosterone was prevented in PC12 cells treated with WEST. WEST also downregulated the expression of glucose-regulated protein 78 (GRP78), growth arrest- and DNA damage-inducible gene 153 (GADD153), the pro-apoptotic protein Bcl-2-associated X (Bax), cytochrome c, cysteine-aspartic protease (caspase)-9, and caspase-3, and upregulated the expression of the anti-apoptotic protein B-cell lymphoma 2 (Bcl-2). Thus, WEST exerts a neuroprotective effect by inhibiting the apoptosis pathway in ER stress and the mitochondrial dysfunction induced by corticosterone. These results demonstrate that WEST reduces neuronal damage from the neurotoxicity caused by chronic stress.

Chia seeds as a potential cognitive booster in the APP23 Alzheimer's disease model

Glucose hypometabolism potentially contributes to Alzheimer's disease (AD) and might even represent an underlying mechanism. Here, we investigate the relationship of diet-induced metabolic stress and AD as well as the therapeutic potential of chia seeds as a modulator of glucose metabolism in the APP23 mouse model. 4-6 (pre-plaque stage, PRE) and 28-32 (advanced-plaque stage, ADV) weeks old APP23 and wild type mice received pretreatment for 12 weeks with either sucrose-rich (SRD) or control diet, followed by 8 weeks of chia seed supplementation. Although ADV APP23 mice generally showed functioning glucose homeostasis, they were more prone to SRD-induced glucose intolerance. This was accompanied by elevated corticosterone levels and mild insulin insensitivity. Chia seeds improved spatial learning deficits but not impaired cognitive flexibility, potentially mediated by amelioration of glucose tolerance, attenuation of corticosterone levels and reversal of SRD-induced elevation of pro-inflammatory cytokine levels. Since cognitive symptoms and plaque load were not aggravated by SRD-induced metabolic stress, despite enhanced neuroinflammation in the PRE group, we conclude that impairments of glucose metabolism do not represent an underlying mechanism of AD in this mouse model. Nevertheless, chia seeds might provide therapeutic potential in AD as shown by the amelioration of cognitive symptoms.

Glucocorticoid-Induced Obesity Develops Independently of UCP1

An excess of glucocorticoids leads to the development of obesity in both mice and humans, but the mechanism for this is unknown. Here, we determine the extent to which decreased BAT thermogenic capacity (as a result of glucocorticoid treatment) contributes to the development of obesity. Contrary to previous suggestions, we show that only in mice housed at thermoneutrality (30°C) does corticosterone treatment reduce total BAT UCP1 protein. This reduction is reflected in reduced brown adipocyte cellular and mitochondrial UCP1-dependent respiration. However, glucocorticoid-induced obesity develops to the same extent in animals housed at 21°C and 30°C, whereas total BAT UCP1 protein levels differ 100-fold between the two groups. In corticosterone-treated wild-type and UCP1 knockout mice housed at 30°C, obesity also develops to the same extent. Thus, our results demonstrate that the development of glucocorticoid-induced obesity is not caused by a decreased UCP1-dependent thermogenic capacity.

Enriched environment ameliorates dexamethasone effects on emotional reactivity and metabolic parameters in mice

Convincing evidence shows that stress is associated with the development and course of psychiatric and metabolic disorders. The hypothalamic-pituitary-adrenal (HPA) axis mediates the stress response, a cascade of events that culminate in the release of glucocorticoids from the adrenal cortex. Chronic hypercortisolism typically characterizes stress-related illnesses, such as depression, anxiety, and metabolic syndrome. Considering previous studies pointing that environmental enrichment (EE) mitigates the deleterious effects of stress on neurobiological systems, we hypothesized that EE can confer resiliency against prolonged glucocorticoid administration-induced behavioral and metabolic alterations in mice. In this regard, three-month-old male Swiss mice were exposed to a four-week period of standard environment (SE) or EE. After this period, still in the respective environments, dexamethasone was administered intraperitoneally (i.p.) at a dose of 4 mg/kg, for 21 consecutive days, in order to generate the emotional-related behavioral outcomes, as previously described. It is demonstrated herein that EE prevents the dexamethasone-induced anxiety-like and passive stress-coping behaviors, as observed in the open field and tail suspension tests. Moreover, EE mitigated the hyperproteinemia and body weight loss induced by excess dexamethasone and decreased basal glucose levels. Taken together, these results support the hypothesis that EE attenuates the effects of chronic administration of synthetic glucocorticoids in mice, a strategy that may be translated to the clinical perspective.

In vivo vascular rarefaction and hypertension induced by dexamethasone are related to phosphatase PTP1B activation not endothelial metabolic changes

Glucocorticoids have important anti-inflammatory and immunomodulatory activities. Dexamethasone (Dex), a synthetic glucocorticoid, induces insulin resistance, hyperglycemia, and hypertension. The hypertensive mechanisms of Dex are not well understood. Previously, we showed that exercise training prior to Dex treatment significantly decreases blood vessel loss and hypertension in rats. In this study, we examined whether the salutary effects of exercise are associated with an enhanced metabolic profile. Analysis of the NAD and ATP content in the tibialis anterior muscle of trained and non-trained animals indicated that exercise increases both NAD and ATP; however, Dex treatment had no effect on any of the experimental groups. Likewise, Dex did not change NAD and ATP in cultured endothelial cells following 24 h and 48 h of incubation with high concentrations. Reduced VEGF-stimulated NO production, however, was verified in endothelial cultured cells. Reduced NO was not associated with changes in survival or the BH4 to BH2 ratio. Moreover, Dex had no effect on bradykinin- or shear-stress-stimulated NO production, indicating that VEGF-stimulated eNOS phosphorylation is a target of Dex's effects. The PTP1B inhibitor increased NO in Dex-treated cells in a dose-dependent fashion, an effect that was replicated by the glucocorticoid receptor inhibitor, RU486. In combination, these results indicate that Dex-induced endothelial dysfunction is mediated by glucocorticoid receptor and PTP1B activation. Moreover, since exercise reduces the expression of PTP1B and normalized insulin resistance in aging rats, our findings indicate that exercise training by reducing PTP1B activity counteracts Dex-induced hypertension in vivo.

Crocin-I ameliorates the disruption of lipid metabolism and dysbiosis of the gut microbiota induced by chronic corticosterone in mice

Glucocorticoids (GCs) are widely used as anti-inflammatory and immunosuppressive drugs. However, chronic treatment with GCs in clinical settings has a series of side effects, such as metabolic disorders, gut microbiota dysbiosis and neurological impairment. Therefore, searching for a functional substance that can alleviate these side effects is greatly meaningful to clinical patients. Crocin is the main active ingredient of saffron, which has been reported to have numerous pharmacological activities. However, the action of crocin-I, one major member of the crocin family, on the physiological mediation in the individuals receiving GC treatment remains unclear. In this study, we aimed to evaluate the efficacy of crocin-I on lipid metabolism and the gut microbiota in a mouse model of chronic corticosterone (CORT) treatment. Our findings showed that crocin-I reduced the levels of triglycerides and total cholesterol and the ratio of low density lipoprotein to high density lipoprotein in the serum of CORT-treated mice. In addition, transcriptome analysis revealed that crocin-I was effective in mediating the amelioration of lipid metabolism, mainly in fatty acid metabolism and steroid biosynthesis in CORT-treated mice. Moreover, metabolome analysis demonstrated that crocin-I could restore the disturbed metabolites in the liver of CORT-treated mice, most of which are long-chain fatty acids. Furthermore, high-throughput sequencing of 16s rRNA revealed that crocin-I could mitigate the dysbiosis of the gut microbiota caused by CORT at a dose of 40 mg kg-1, by resulting in a significant increase in the alpha diversity of the microbes in the cecal contents and a significant reduction in the abundance of Firmicutes, whereas by increasing the abundance of Bacteroidetes. These results indicated that oral administration of crocin-I could modify the composition of the gut microbiota and alleviate hepatic lipid disorder in mice treated with a high dose of GCs.

Resveratrol ameliorates inflammatory and oxidative stress in type 2 diabetic Goto-Kakizaki rats

Type 2 diabetes is associated with inflammatory and oxidative stress. Resveratrol, a naturally occurring diphenolic compound, was shown to improve glycemic control and alleviate metabolic disturbances in Goto-Kakizaki (GK) rats, a non-obese model of type 2 diabetes. However, in GK rats effects of resveratrol addressing inflammatory and oxidative stress were not explored. The present study aimed to determine anti-inflammatory and anti-oxidative properties of resveratrol in these rats. GK and Sprague-Dawley (SD) rats were divided into 4 groups: GK control, GK treated with resveratrol, SD control and SD treated with resveratrol. Resveratrol (20 mg/kg b.w.) was given once a day for 10 weeks. It was shown that contents of inflammatory markers, interleukin 6 (IL-6), interleukin 1 β (IL-1β), tumor necrosis factor α (TNF-α) and nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB), were increased in the skeletal muscle of diabetic rats, but these effects were prevented by resveratrol therapy. Similarly, amounts of IL-1β and TNF-α were elevated in livers of GK rats; however, this rise was alleviated in resveratrol-treated animals. Moreover, the contents of inflammation-related factors (IL-6, IL-1β, TNF-α and NF-κB) were augmented in adipose tissue of GK rats; nevertheless, in this tissue resveratrol was ineffective. Resveratrol reduced also lipid peroxidation in the skeletal muscle, reduced activities of glutathione peroxidase in blood serum and catalase in the livers of GK rats. Our new findings show that resveratrol therapy results in relieving inflammatory and oxidative stress in GK rats, which may be largely associated with the alleviation of metabolic disturbances in this model of diabetes. Nevertheless, it was demonstrated that the efficacy of resveratrol action is tissue-specific.

Impact of insulin and glucocorticoid signalling on hepatic glucose homeostasis in the rat exposed to high-fructose diet and chronic stress

Overconsumption of fructose-enriched beverages and everyday stress are involved in the pathogenesis of metabolic disorders through modulation of hepatic glucose metabolism. The aim of the study was to investigate whether interaction of high-fructose diet and chronic stress alter insulin and glucocorticoid signalling thus affecting hepatic glucose homeostasis. High-fructose diet led to hyperinsulinemia, increased glucose transporter 2 level, elevated protein kinase B (Akt) phosphorylation, increased glucokinase mRNA and phospho-to-total glycogen synthase kinase 3 ratio and decreased expression of gluconeogenic genes. Fructose diet also led to stimulated glucocorticoid prereceptor metabolism, but downstream signalling remained unchanged due to increased glucocorticoid clearance. Stress did not affect hepatic insulin and glucocorticoid signalling nor glucose metabolism, while the interaction of the factors was observed only for glucokinase expression. The results suggest that, under conditions of fructose-induced hyperinsulinemia, suppression of gluconeogenesis and glycogen synthase activation contribute to the maintenance of glucose homeostasis. The increased glucocorticoid inactivation may represent an adaptive mechanism to prevent hyperglycaemia.

Insulin secretion improvement during steroid therapy for autoimmune pancreatitis according to the onset of diabetes mellitus

BACKGROUND

Autoimmune pancreatitis (AIP) is frequently complicated by diabetes mellitus (DM), but DM associated with AIP is reported to improve after steroid therapy. The aim of this study is to investigate glucose intolerance during steroid therapy according to the onset of DM.

METHODS

Sixty-one patients who underwent steroid therapy for AIP were included into this study. We evaluated C peptide index (CPI), homeostasis model assessment for insulin resistance (HOMA-R), and the pancreatic diameter at AIP diagnosis and after 4 weeks, 1 year, and 2 years of steroid therapy. Patients were categorized into three groups according to DM onset: Pre-existing DM (pDM), concurrent DM (cDM), and non-DM (nDM).

RESULTS

Forty-three patients (71%) had DM: 15 pDM and 28 cDM. At AIP diagnosis, CPI was lower in patients with pDM (0.7, P = 0.007) and cDM (0.9, P = 0.018) than nDM (1.3). After 4 weeks of steroid therapy, CPI improved in cDM (P < 0.001) and in nDM (P = 0.021). After 2 years of steroid therapy, HOMA-R increased (2.1-3.0, P = 0.007) but CPI gradually improved (1.0-2.1, P = 0.004). DM improved in 23% of cDM, and 55% of insulin users in cDM discontinued using insulin. Pancreatic atrophy was seen in 30%, and was associated with DM.

CONCLUSION

DM in patients with AIP was associated with impaired insulin secretion rather than insulin resistance. Insulin secretion improved during steroid therapy for AIP in patients with concurrent DM. Thus, glucose intolerance can be an indication for AIP treatment.

Performance, intestinal permeability, and gene expression of selected tight junction proteins in broiler chickens fed reduced protein diets supplemented with arginine, glutamine, and glycine subjected to a leaky gut model

Changing dietary protein and amino acids may impact intestinal barrier function. Experiments were conducted in broiler chickens to evaluate supplementation of L-glutamine, glycine, and L-arginine in a reduced protein (RP) diet. Experiment 1 examined the growth performance of broilers fed 5 dietary treatments: 1) a standard diet; 2) an RP diet (193.9 g/kg CP in grower and 176.9 g/kg CP in finisher); 3) RP diet supplemented with 10 g/kg L-Gln; 4) RP diet supplemented with 10 g/kg Gly; 5) RP diet supplemented with 5 g/kg L-Arg. Each experimental diet was replicated 6 times with 10 birds per replicate. In a subset of 96 birds, experiment 2 tested the 4 RP diets with and without dexamethasone (DEX) to induce leaky gut. Each diet was replicated 24 times. Fluorescein isothiocyanate dextran (FITC-d) was used to test intestinal permeability (IP). Gene expression of selected tight junction proteins in ileal and jejunal tissues was assayed by quantitative PCR. From day 7 to 35, the RP diet increased feed intake (FI) (P < 0.05) and body weight gain (BWG) compared with the standard diet while Gln reduced FI and BWG (P < 0.05) compared with RP. Gly had no effect on BWG or FCR. Supplementation of Arg improved FCR from day 21 to 35 and day 7 to 35. In experiment 2, Arg tended to lower FITC-d (P = 0.086). DEX increased passage of FITC-d into the serum (P < 0.001). The villi surface area was increased in birds fed higher Arg (P < 0.05). DEX and diet interacted (P < 0.01) for jejunal claudin-3 mRNA level where DEX upregulated claudin-3 for all diets except the Arg diet. In summary, with a moderate reduction of protein, satisfactory performance can be obtained. Although Gln and Gly had no demonstrable positive effect on IP and performance of broilers, increasing the dietary Arg by approximately 140% improved FCR and showed indications of improved intestinal barrier function of birds fed an RP diet under a stress model.

When glycosylated hemoglobin is a true roller coaster

Corticosteroids negatively interfere with glycemic control. We report a case of a patient with type 2 diabetes mellitus with poor glycemic control caused by coercion to intramuscular corticosteroid administration at work. The relationship established with the patient allowed her to speak openly about her working environment, allowing her to trust the information provided by her family physician ensuring that she rejected new attempts to medicate her with that drug.

Panax ginseng Total Protein Facilitates Recovery from Dexamethasone-Induced Muscle Atrophy through the Activation of Glucose Consumption in C2C12 Myotubes

Background

The clinical anti-inflammatory drug dexamethasone (DEX) can cause many side effects such as muscle atrophy for long-term use. Muscle atrophy induced by DEX may be caused by decrease of glucose consumption. Panax ginseng C.A. Meyer was previously considered to be an antiatrophic agent for glucocorticoid- (GC-) treated therapies. As one of the main components, it remains unclear whether ginseng total protein (GP) facilitates recovery from muscle atrophy induced by DEX.

Methods

In this study, GP was extracted and purified with Sephadex-G50. C2C12 myoblasts was induced with 2% horse serum to differentiate into C2C12 myotubes. Cell viability was analyzed by the MTT assay, and Ca²⁺ concentration was analyzed by a flow cytometer. The release of lactic dehydrogenase (LDH) and the glucose consumption were analyzed by spectrophotometry. The phosphorylation of AMP-activated protein kinase (AMPK), phosphoinositide 3-kinase (PI3K), and protein kinase B (Akt) and the expression of glucose transporter 4 (GLUT4) were analyzed by Western blotting. The phosphorylation of AS160 was quantified by Immunofluorescence staining.

Results

We found that GP increased cell viability and increased myotube diameter in high-dose DEX-treated C2C12 myotubes for 24 h, but this activity was not found in the enzymatic hydrolyzed GP group. GP reduced muscle atrophy by decreasing the expression of key proteins such as muscle RING-finger protein-1 and muscle atrophy F-box, reducing the Ca²⁺ concentration, and decreasing the release of LDH in DEX-injured C2C12 myotubes. Moreover, GP improved glucose consumption and increased the phosphorylation of AMPK, PI3K, Akt, and AS160 and the expression of GLUT4 in DEX-treated C2C12 myotubes.

Conclusion

The results of this study suggest that GP has effects on recovering DEX-induced muscle atrophy and cell injury, which may improve glucose consumption via the AMPK and PI3K/Akt pathways in high-dose DEX-treated C2C12 myotubes. This study provides in vitro mechanistic insights into the recovery of muscle atrophy with GP treatment.

Glucocorticoids and Brown Adipose Tissue: Do glucocorticoids really inhibit thermogenesis?

A reduction in the thermogenic activity of brown adipose tissue (BAT) is presently discussed as a possible determinant for the development of obesity in humans. One group of endogenous factors that could potentially affect BAT activity is the glucocorticoids (e.g. cortisol). We analyse here studies examining the effects of alterations in glucocorticoid signaling on BAT recruitment and thermogenic capacity. We find that irrespective of which manipulation of glucocorticoid signaling is examined, a seemingly homogeneous picture of lowered thermogenic capacity due to glucocorticoid stimulation is apparently obtained: e.g. lowered uncoupling protein 1 (UCP1) protein levels per mg protein, and an increased lipid accumulation in BAT. However, further analyses generally indicate that these effects result from a dilution effect rather than a true decrease in total capacity; the tissue may thus be said to be in a state of pseudo-atrophy. However, under conditions of very low physiological stimulation of BAT, glucocorticoids may truly inhibit Ucp1 gene expression and consequently lower total UCP1 protein levels, but the metabolic effects of this reduction are probably minor. It is thus unlikely that glucocorticoids affect organismal metabolism and induce the development of obesity through alterations of BAT activity.

Metabolic Abnormalities of Chronic High-Dose Glucocorticoids Are Not Mediated by Hypothalamic AgRP in Male Mice

Glucocorticoids are potent and widely used medicines but often cause metabolic side effects. A murine model of corticosterone treatment resulted in increased hypothalamic expression of the melanocortin antagonist AgRP in parallel with obesity and hyperglycemia. We investigated how these adverse effects develop over time, with particular emphasis on hypothalamic involvement. Wild-type and Agrp-/- male mice were treated with corticosterone for 3 weeks. Phenotypic, biochemical, protein, and mRNA analyses were undertaken on central and peripheral tissues, including white and brown adipose tissue, liver, and muscle, to determine the metabolic consequences. Corticosterone treatment induced hyperphagia within 1 day in wild-type mice, which persisted for 3 weeks. Despite this early increase in food intake, the body weight only started to increase after 10 days. Hyperinsulinemia occurred at day 1. Also, although after 2 days, alterations were present in the genes often associated with insulin resistance in several peripheral tissues, hyperglycemia only developed at 3 weeks. Throughout, sustained elevation in hypothalamic Agrp expression was present. Mice with Agrp deleted [using clustered regularly interspaced short palindromic repeats (CRISPR)-Cas9, Agrp-/-] were partially protected against corticosterone-induced hyperphagia. However, Agrp-/- mice still had corticosterone-induced increases in body weight and adiposity similar to those of the Agrp+/+ mice. Loss of Agrp did not diminish corticosterone-induced hyperinsulinemia or correct changes in hepatic gluconeogenic genes. Chronic glucocorticoid treatment in mice mimics many of the metabolic side effects seen in patients and leads to a robust increase in Agrp. However, AgRP does not appear to be responsible for most of the glucocorticoid-induced adverse metabolic effects.

Key metabolic parameters change significantly in early breast cancer survivors: an explorative PILOT study

Background

With increasing number of breast cancer survivors, more attention is drawn to long-term consequences of curative cancer treatment. Adjuvant treatment of breast cancer patients is associated with several unfavorable medical conditions, including dyslipidemia, insulin resistance, and obesity, potentially leading to cardiovascular disease and/or the metabolic syndrome. The aim of this explorative study is to investigate metabolic side effects of adjuvant treatment in breast cancer patients.

Methods

A cohort of 13 premenopausal and 20 postmenopausal women with early stage breast cancer were extensively examined prior to, immediately after and 1 year after ended adjuvant chemotherapy and compared with healthy controls (N = 36) matched by age and menopausal status. Repeated examinations included: anthropometric measures, DEXA scans, 24-h blood pressure measurements, and blood samples [high sensitivity CRP, lipid profile and glucose metabolism, including homeostatic model assessment (HOMA)].

Results

At baseline, breast cancer patients were similar to healthy controls regarding all measures. From baseline to 1-year post-treatment specific components of the metabolic syndrome increased significantly in premenopausal breast cancer patients; body fat (P = 0.01), triglycerides (P = 0.03), waist circumference (P = 0.008) and diastolic blood pressure (P = 0.04). In postmenopausal patients, waist circumference also increased significantly (P = 0.03), and High density lipoprotein (HDL) cholesterol decreased significantly (P = 0.05).

Conclusions

Specific components of the metabolic syndrome changed significantly during chemotherapy in early stage breast cancer patients. After 1 year, several key parameters remained pathologically changed. Premenopausal breast cancer patients seemed to be especially prone to develop these unfavorable changes.

Trial registration ClinicalTrial.gov, registration number NCT02652975. Registered 15 December 2015—Retrospectively registered, https://clinicaltrials.gov/.

Insulin Tolerance Test under Anaesthesia to Measure Tissue-specific Insulin-stimulated Glucose Disposal

Insulin resistance is a pathophysiological state defined by impaired responses to insulin and is a risk factor for several metabolic diseases, most notably type 2 diabetes. Insulin resistance occurs in insulin target tissues including liver, adipose and skeletal muscle. Methods such as insulin tolerance tests and hyperinsulinaemic-euglycaemic clamps permit assessment of insulin responses in specific tissues and allow the study of the progression and causes of insulin resistance. Here we detail a protocol for assessing insulin action in adipose and muscle tissues in anesthetized mice administered with insulin intravenously.

Glucose Homeostasis Is Not Affected in a Murine Model of Parkinson's Disease Induced by 6-OHDA

There is a mutual relationship between metabolic and neurodegenerative diseases. However, the causal relationship in this crosstalk is unclear and whether Parkinson’s disease (PD) causes a posterior impact on metabolism remains unknown. Considering that, this study aimed to evaluate the appearance of possible changes in metabolic homeostasis due to 6-hydroxydopamine (6-OHDA) administration, a neurotoxin that damage dopaminergic neurons leading to motor impairments that resemble the ones observed in PD. For this, male Wistar rats received bilateral 6-OHDA administration in the dorsolateral striatum, and the motor and metabolic outcomes were assessed at 7, 21, or 35 days post-surgical procedure. Dexamethasone, a diabetogenic glucocorticoid (GC), was intraperitoneally administered in the last 6 days to challenge the metabolism and reveal possible metabolic vulnerabilities caused by 6-OHDA. Controls received only vehicles. The 6-OHDA-treated rats displayed a significant decrease in locomotor activity, exploratory behavior, and motor coordination 7 and 35 days after neurotoxin administration. These motor impairments paralleled with no significant alteration in body mass, food intake, glucose tolerance, insulin sensitivity, and biochemical parameters (plasma insulin, triacylglycerol, and total cholesterol levels) until the end of the experimental protocol on days 35–38 post-6-OHDA administration. Moreover, hepatic glycogen and fat content, as well as the endocrine pancreas mass, were not altered in rats treated with 6-OHDA at the day of euthanasia (38th day after neurotoxin administration). None of the diabetogenic effects caused by dexamethasone were exacerbated in rats previously treated with 6-OHDA. Thus, we conclude that bilateral 6-OHDA administration in the striatum causes motor deficits in rats with no impact on glucose and lipid homeostasis and does not exacerbate the adverse effects caused by excess GC. These observations indicate that neurodegeneration of dopaminergic circuits in the 6-OHDA rats does not affect the metabolic outcomes.

Hyperglycemia Induced by Chronic Restraint Stress in Mice Is Associated With Nucleus Tractus Solitarius Injury and Not Just the Direct Effect of Glucocorticoids

Chronic restraint stress (CRS) can affect hypothalamic-pituitary-adrenal (HPA) axis activity and increase glucocorticoid levels. Glucocorticoids are stress hormones that regulate multiple aspects of energy homeostasis. Stress also impairs glucose tolerance. The aim of this study was to investigate the cause of insulin-resistant hyperglycemia during CRS. We produced the CRS models (a 7-day restraint followed by a 3-day free moving procedure, total of 4 cycles for 40 days) in mice, detected the parameters related to glucose metabolism, and compared them to those of the dexamethasone (DEX) injection (0.2 mg/kg i.p., also a 4 cycle procedure as the CRS). The results showed that the CRS induced a moderate (not higher than 11 mmol/L) and irreversible insulin-resistant hyperglycemia in about 1/3 of the individuals, and all the restrained mice had adrenal hypertrophy. CRS induced the apoptosis of neurons in the anterior part of commissural subnucleus of nucleus tractus solitarius (acNTS) in the hyperglycemic mice, and acNTS mechanical damage also led to insulin-resistant hyperglycemia. In contrast, in the DEX-treated mice, adrenal gland atrophy was evident. The glucose and insulin tolerance varied with the delay of determination. DEX exposure in vivo does not induce the apoptosis of neurons in NTS. This study indicates that restraint stress and DEX induce metabolic disorders through different mechanisms. During CRS, injury (apoptosis) of glucose-sensitive acNTS neurons cause dysregulation of blood glucose. This study also suggests the mouse restraint stress model has value as a potential application in the study of stress-induced hyperglycemia.

Insulin signaling pathway in the masseter muscle of dexamethasone-treated rats

Background and aims

The treatment with glucocorticoids may induce molecular changes in the level and/or degree of phosphorylation of proteins located downstream of the insulin receptor/insulin-like growth factor receptor (IR/IGF1R) in many tissues. However, few studies have investigated the intracellular insulin pathway in the masseter muscle. Therefore, this study aimed to analyze the IR/IGF1R signaling pathway in the masseter muscle of rats treated with dexamethasone.

Materials and methods

Male Wistar rats were divided into two groups: control group (intraperitoneally injected with 0.9% NaCl solution) and dexamethasone group [intraperitoneally injected with 1 mg/kg (bw) dexamethasone solution] for 10 consecutive days. Sections of the masseter muscle were removed at time zero and after the infusion of regular insulin into the portal vein.

Results

Dexamethasone administration induces body weight loss without changing masseter muscle weight and reduces the expression of total IR and PI3K proteins; total levels of IRS1, Akt, and ERK1 remain unchanged between groups. The degree of phosphorylation/activity of IRS1 after insulin stimulus increased only in the control group; degree of phosphorylation of Akt increased in both groups, but this increase was attenuated in the dexamethasone group.

Discussion and conclusion

The degree of phosphorylation/activity in the masseter muscle is different from that in other muscle territories.

The effect of polydeoxyribonucleotide on the treatment of radiating leg pain due to cystic mass lesion in inner aspect of right sciatic foramen: A CARE compliant case report

RATIONALE

Radiating leg pain usually originates from the lumbar spine and occasionally from peripheral lesions. Here we report a case involving a patient with radiating pain in the right leg who exhibited 2 suspicious lesions, including 1 spinal lesion and 1 extraspinal cystic mass lesion, on magnetic resonance imaging. Polydeoxyribonucleotide sodium (PDRN) was recently noted as such a substitute. PDRN has anti-inflammatory effects, as it lowers the expression of inflammatory cytokines including interleukin-6 and tumor necrosis factor-alpha.

PATIENT CONCERNS

A 51-year-old man (weight, 93 kg; height, 168 cm) working as a bus driver presented at the pain clinic with continuous right buttock pain, radiating leg pain and a tingling sensation involving the calf and dorsum of the foot, since 1 week.

DIAGNOSES

He was definitively diagnosed using differential blocks, which revealed the cyst to be the actual cause of the pain.

INTERVENTIONS

Surgical resection was not feasible because of the position of the cyst; therefore, corticosteroid injection under ultrasonographic guidance was attempted. However, this provided short-term relief. Subsequently, a solution containing PDRN was injected around the piriformis muscle and repeated 3 more times at intervals of 2 weeks.

OUTCOMES

After PDRN injection, we conducted two follow-up monitoring every two months for 2 months. Last follow-up, the patient no longer complained of pain. this resulted in relatively long-term relief from pain.

LESSONS

The findings from this case suggest that PDRN is an effective alternative for steroids in patients with radiating leg pain, although its efficacy and safety needs to be evaluated in further large-scale studies.

Dexamethasone Administration During Late Gestation Has No Major Impact on Lipid Metabolism, but Reduces Newborn Survival Rate in Wistar Rats

A rise in plasma triacylglycerol levels is a common physiological occurrence during late gestation and excess of glucocorticoids (GCs) has been shown to impair lipid metabolism. Based on those observations, we investigated whether the administration of dexamethasone during the late gestational period could exacerbate this pregnancy associated hypertriacylglycerolemia in rats. For this, female Wistar rats were treated with dexamethasone (0.2 mg/kg of body mass in the drinking water on days 14-19 of pregnancy; DP group) or equivalent days in the virgin rats (DV group). Untreated pregnant rats (control pregnant group) and age-matched virgin rats (control virgin group) were used as controls. Functional, biochemical, and molecular analyses were carried out after treatment with GC and in the control groups. Euthanasia was performed on day 20 of pregnancy. The metabolic parameters of the mothers (dams) at the time of weaning and 6 months later, as well as newborn survival, were evaluated. We observed that neither dexamethasone nor pregnancy affected blood glucose or glucose tolerance. Hypertriacylglycerolemia associated with lipid intolerance or reduced hepatic triacylglycerol clearance was observed during the late gestational period. GC treatment caused a further increase in basal plasma triacylglycerol levels, but did not have a significant effect on lipid tolerance and hepatic triacylglycerol clearance in pregnant rats. GC, but not pregnancy, caused few significant changes in mRNA expression of proteins involved in lipid metabolism. Dexamethasone during pregnancy had no impact on lipid metabolism later in the dams' life; however, it led to intra-uterine growth restriction and reduced pup survival rate. In conclusion, GC exposure during the late gestational period in rats has no major impact on maternal lipid homeostasis, soon after parturition at weaning, or later in the dams' life, but GC exposure is deleterious to the newborn when high doses are administered at late gestation. These data highlight the importance of performing an individualized and rigorous control of a GC treatment during late pregnancy considering its harmful impact on the fetuses' health.

Gestational glucocorticoid exposure disrupts glucose homeostasis that is accompanied by increased endoglin and DPP-4 activity instead of GSK-3 in rats

Gestational glucocorticoid (GC) treatment has been associated with cardiometabolic disorder (CMD) in offspring's in later life. Elevated dipeptidyl peptidase-4 (DPP-4) activity, endoglin and glycogen synthase kinase-3 (GSK-3) has also been implicated in the development of insulin resistance (IR) and/or vascular inflammation. We aimed to investigate the impact of GC exposure on glucose metabolism and the circulating levels of inflammatory biomarkers, DPP-4 activity and GSK-3 in pregnant rats. Pregnant Wistar rats received either vehicle or dexamethasone (DEX; 0.2 mg/kg; po) between gestational days 14 and 19. Gestational GC exposure resulted in impaired glucose homeostasis that is accompanied with elevated circulating levels of inflammatory biomarkers (endoglin, uric acid, and platelet/lymphocyte ratio), oxidative stress (malondialdehyde), blood viscosity, reduced NO level and increased DPP-4 activity. However, these effects were associated with atherogenic dyslipidemia and reduced GSK-3.We conclude that plasma endoglin, a marker of vascular inflammation, and plasma DPP-4 activity are increased in pregnant rats treated with GC during late gestation. Therefore, glucose deregulation associated with gestational GC exposure is through endoglin-/DPP-4-dependent but GSK-3-independent pathway.

Development and validation of a scoring system for prediction of insulin requirement for optimal control of blood glucose during glucocorticoid treatments

AIMS

We have developed and validated a novel scoring system to predict insulin requirement for optimal control of blood glucose during glucocorticoid (GC) treatments, by retrospective analyses of clinical parameters before GC treatment.

METHODS

Three hundred-three adults (the Developing set) undergoing their first treatment of prednisolone (PSL) were divided into two groups, depending on treatment with or without insulin. Independent risk factors for insulin requirement were identified by a stepwise logistic regression analysis after univariate analyses between the two groups. We constructed a point-addition scoring system consisting of several categories and their coefficients in each risk factor derived from another logistic regression analysis. We validated it to two validation sets, A and B.

RESULTS

Male, higher levels of fasting plasma glucose (FPG), HbA1c, and serum creatinine (CRE) and a higher initial dose of PSL were identified as the risk factors. The sensitivity, specificity, and accuracy were 90.0%, 88.1%, and 88.4%; 87.5%, 66.7%, and 70.5%; 83.3%, 76.1%, and 76.6% in the Developing set, Validation set A, and Validation set B, respectively, when the scoring system was applied.

CONCLUSIONS

The scoring system is a valid and reliable tool to predict insulin requirements in advance during GC treatment.

Steroid-induced hyperglycemia: An underdiagnosed problem or clinical inertia? A narrative review

Corticosteroids are widely diffused drugs. An important side effect is the impairment of glycemic control both in patients with known diabetes and in normoglycemic ones potentially leading to steroid-induced diabetes mellitus (SIDM). In this review based on papers released on PubMed, MEDLINE, and EMBASE from January 2015 to October 2017, we summarized and discussed main updates about the definition, the diagnosis, and the pathophysiology of steroid-induced hyperglycemia (SIH), with a look to new therapies. Main alterations responsible for the diabetogenic effect of corticosteroids are a negative impact on insulin sensitivity along with a derangement on insulin secretion, explaining the typical post-prandial hyperglycemia linked to the promotion of gluconeogenesis. An early and precise diagnosis of SIH and/or SIDM is necessary, but current criteria do not seem sensible enough. As an afterthought, the treatment should be reasoned and tailored according to proposed glycemic thresholds and patient comorbidities, choosing between antidiabetic oral drugs and insulin, the latter being preferable among hospitalized patients. SIDM and SIH are frequent problems, but often underdiagnosed due to old diagnostic criteria. Dedicated guidelines universally shared are mandatory in order to harmonize the treatment of these conditions, thus overtaking single therapeutic strategies mostly arising from literature.

Use of parenteral glucocorticoids and the risk of new onset type 2 diabetes mellitus: A case-control study

BACKGROUND

Use of oral glucocorticoids (GCs) has been associated with hyperglycaemia and type 2 diabetes mellitus (T2DM). However, unlike oral GCs, there is minimal or no data on the effect of parenteral GC use on T2DM.

OBJECTIVE

To assess the association between use of parenteral GCs and the risk of receiving a first prescription of a non-insulin antidiabetic drug (NIAD) as a proxy for new onset of T2DM.

METHODS

A population based case-control study was performed using the Clinical Practice Research Datalink (CPRD). Cases (n = 177,154) were defined as patients >18 years of age who had their first ever NIAD prescription between January 1987 and October 2013. Controls were matched by age, gender and general practitioner practice. Conditional logistic regression analyses were used to estimate the risk of NIAD prescription and use of parenteral GCs. Our analyses were statistically adjusted for lifestyle factors, comorbidities and concomitant drug use.

RESULTS

Although this study confirmed that oral GCs increases the risk of receiving a first prescription of a NIAD (OR 2.63 [95% CI 2.53-2.73]), there was no association between the use of parenterally administered GCs and the risk of receiving a first prescription of a NIAD (OR 0.88 [95% CI 0.76-1.02]). The number of GC prescriptions was not associated with risk of new onset T2DM compared to no parenteral GCs use; neither the type of GC.

CONCLUSION

Our study does not demonstrate an association between the use of parenteral GCs and the risk of new onset of T2DM.

Prevention of Elevation in Plasma Triacylglycerol with High-Dose Bezafibrate Treatment Abolishes Insulin Resistance and Attenuates Glucose Intolerance Induced by Short-Term Treatment with Dexamethasone in Rats

OBJECTIVE

Fibrates are used as lipid-lowering drugs and are well tolerated as cotreatments when glucose metabolism disturbances are also present. Synthetic glucocorticoids (GCs) are diabetogenic drugs that cause dyslipidemia, dysglycemia, glucose intolerance, and insulin resistance when in excess. Thus, we aimed to describe the potential of bezafibrate in preventing or attenuating the adverse effects of GCs on glucose and lipid homeostasis.

METHODS

Male Wistar rats were treated with high-dose bezafibrate (300 mg/kg, body mass (b.m.)) daily for 28 consecutive days. In the last five days, the rats were also treated with dexamethasone (1 mg/kg, b.m.).

RESULTS

Dexamethasone treatment reduced the body mass gain and food intake, and bezafibrate treatment exerted no impact on these parameters. GC treatment caused an augmentation in fasting and fed glycemia, plasma triacylglycerol and nonesterified fatty acids, and insulinemia, and bezafibrate treatment completely prevented the elevation in plasma triacylglycerol and attenuated all other parameters. Insulin resistance and glucose intolerance induced by GC treatment were abolished and attenuated, respectively, by bezafibrate treatment.

CONCLUSION

High-dose bezafibrate treatment prevents the increase in plasma triacylglycerol and the development of insulin resistance and attenuates glucose intolerance in rats caused by GC treatment, indicating the involvement of dyslipidemia in the GC-induced insulin resistance.