Membrane estrogen receptor-α contributes to female protection against high-fat diet-induced metabolic disorders

Background

Estrogen Receptor α (ERα) is a significant modulator of energy balance and lipid/glucose metabolisms. Beyond the classical nuclear actions of the receptor, rapid activation of intracellular signaling pathways is mediated by a sub-fraction of ERα localized to the plasma membrane, known as Membrane Initiated Steroid Signaling (MISS). However, whether membrane ERα is involved in the protective metabolic actions of endogenous estrogens in conditions of nutritional challenge, and thus contributes to sex differences in the susceptibility to metabolic diseases, remains to be clarified.

Methods

Male and female C451A-ERα mice, harboring a point mutation which results in the abolition of membrane localization and MISS-related effects of the receptor, and their wild-type littermates (WT-ERα) were maintained on a normal chow diet (NCD) or fed a high-fat diet (HFD). Body weight gain, body composition and glucose tolerance were monitored. Insulin sensitivity and energy balance regulation were further investigated in HFD-fed female mice.

Results

C451A-ERα genotype had no influence on body weight gain, adipose tissue accumulation and glucose tolerance in NCD-fed mice of both sexes followed up to 7 months of age, nor male mice fed a HFD for 12 weeks. In contrast, compared to WT-ERα littermates, HFD-fed C451A-ERα female mice exhibited: 1) accelerated fat mass accumulation, liver steatosis and impaired glucose tolerance; 2) whole-body insulin resistance, assessed by hyperinsulinemic-euglycemic clamps, and altered insulin-induced signaling in skeletal muscle and liver; 3) significant decrease in energy expenditure associated with histological and functional abnormalities of brown adipose tissue and a defect in thermogenesis regulation in response to cold exposure.

Conclusion

Besides the well-characterized role of ERα nuclear actions, membrane-initiated ERα extra-nuclear signaling contributes to female, but not to male, protection against HFD-induced obesity and associated metabolic disorders in mouse.

Ephrin-B1 regulates the adult diastolic function through a late postnatal maturation of cardiomyocyte surface crests

The rod-shaped adult cardiomyocyte (CM) harbors a unique architecture of its lateral surface with periodic crests, relying on the presence of subsarcolemmal mitochondria (SSM) with unknown role. Here, we investigated the development and functional role of CM crests during the postnatal period. We found in rodents that CM crest maturation occurs late between postnatal day 20 (P20) and P60 through both SSM biogenesis, swelling and crest-crest lateral interactions between adjacent CM, promoting tissue compaction. At the functional level, we showed that the P20-P60 period is dedicated to the improvement of relaxation. Interestingly, crest maturation specifically contributes to an atypical CM hypertrophy of its short axis, without myofibril addition, but relying on CM lateral stretching. Mechanistically, using constitutive and conditional CM-specific knock-out mice, we identified ephrin-B1, a lateral membrane stabilizer, as a molecular determinant of P20-P60 crest maturation, governing both the CM lateral stretch and the diastolic function, thus highly suggesting a link between crest maturity and diastole. Remarkably, while young adult CM-specific Efnb1 KO mice essentially exhibit an impairment of the ventricular diastole with preserved ejection fraction and exercise intolerance, they progressively switch toward systolic heart failure with 100% KO mice dying after 13 months, indicative of a critical role of CM-ephrin-B1 in the adult heart function. This study highlights the molecular determinants and the biological implication of a new late P20-P60 postnatal developmental stage of the heart in rodents during which, in part, ephrin-B1 specifically regulates the maturation of the CM surface crests and of the diastolic function.

Initiation of the Fixed Combination IDegLira in Patients with Type 2 Diabetes on Prior Injectable Therapy: Insights from the EASY French Real-World Study

INTRODUCTION

Combining basal insulin (BI) with glucagon-like peptide-1 receptor agonist (GLP-1RA) is recognized as a relevant option to optimize glucose control in type 2 diabetes (T2D). The EASY real-world study aimed to evaluate the modalities of initiation and the effectiveness of the insulin Degludec plus Liraglutide (IDegLira) fixed-ratio combination in the French health care system.

METHODS

A retrospective analysis included all patients with T2D and prior injectable therapy (GLP1-RA and/or insulin) who started treatment with IDegLira from September 2016 to December 2017 in 11 French diabetes centers. Baseline characteristics, reasons for IDegLira initiation, and modes of implementation were collected from the medical records. Changes in HbA_1c and body weight were determined in patients with available follow-up data (nearest 6-month visit).

RESULTS

IDegLira was initiated in 629 patients previously treated with GLP-1RA alone (11.6%), insulin alone (31.5% including 16.5% with BI and 14.9% with multiple daily injections [MDI]) or a free combination of GLP-1RA and insulin (56.9% including 44.8% with BI and 12.1% with MDI), associated or not with oral agents. IDegLira starting dose (mean of 29 ± 11 dose steps) most often exceeded the recommended dose, and was significantly correlated with prior BI but not GLP-1RA dosage. At initiation, mean age, body mass index (BMI) and HbA_1c were 60.1 ± 10.2 years, 33.4 ± 6.2 kg/m² and 8.8 ± 1.7%, respectively. In 461 patients with available follow-up (median 178 days), HbA_1c decreased in all subgroups submitted to treatment intensification (- 1.7 ± 1.8% [p < 0.0001], - 1.2 ± 1.8% [p < 0.001] and - 0.8 ± 1.8% [p = 0.0026] in patients with prior GLP-1RA, BI or MDI therapy, respectively) but also in those switching from BI and GLP-1RA free combination (- 0.2 ± 0.9%, p = 0.0419). Significant body weight gain occurred in patients previously treated with GLP-1RA alone (+ 1.5 ± 5.8 kg, p = 0.0572) or combined to BI (+ 1.0 ± 3.1 kg, p < 0.0001) while those on BI (- 1.4 ± 4.6 kg, p = 0.0139) or MDI (- 1.4 ± 5.0 kg, p = 0.0484) experienced weight loss.

CONCLUSIONS

While providing new information on the use of IDegLira in the French healthcare system, these data confirm the effectiveness of this fixed-ratio combination in the management of T2D.

Smoking and diabetes interplay: A comprehensive review and joint statement

Evidence shows that smoking increases the risk of pre-diabetes and diabetes in the general population. Among persons with diabetes, smoking has been found to increase the risk of all-cause mortality and aggravate chronic diabetic complications and glycemic control. The current paper, which is a joint position statement by the French-Speaking Society on Tobacco (Société Francophone de Tabacologie) and the French-Speaking Society of Diabetes (Société Francophone du Diabète), summarizes the data available on the association between smoking and diabetes and on the impact of smoking and smoking cessation among individuals with type 1, type 2, and gestational diabetes mellitus. It also provides evidence-based information about the pharmacological and behavioral strategies for smoking cessation in these patients.

Impact of diabetes on COVID-19 prognosis beyond comorbidity burden: the CORONADO initiative

AIMS/HYPOTHESIS

Diabetes has been recognised as a pejorative prognostic factor in coronavirus disease 2019 (COVID-19). Since diabetes is typically a disease of advanced age, it remains unclear whether diabetes remains a COVID-19 risk factor beyond advanced age and associated comorbidities. We designed a cohort study that considered age and comorbidities to address this question.

METHODS

The Coronavirus SARS-CoV-2 and Diabetes Outcomes (CORONADO) initiative is a French, multicentric, cohort study of individuals with (exposed) and without diabetes (non-exposed) admitted to hospital with COVID-19, with a 1:1 matching on sex, age (±5 years), centre and admission date (10 March 2020 to 10 April 2020). Comorbidity burden was assessed by calculating the updated Charlson comorbidity index (uCCi). A predefined composite primary endpoint combining death and/or invasive mechanical ventilation (IMV), as well as these two components separately, was assessed within 7 and 28 days following hospital admission. We performed multivariable analyses to compare clinical outcomes between patients with and without diabetes.

RESULTS

A total of 2210 pairs of participants (diabetes/no-diabetes) were matched on age (mean±SD 69.4±13.2/69.5±13.2 years) and sex (36.3% women). The uCCi was higher in individuals with diabetes. In unadjusted analysis, the primary composite endpoint occurred more frequently in the diabetes group by day 7 (29.0% vs 21.6% in the no-diabetes group; HR 1.43 [95% CI 1.19, 1.72], p<0.001). After multiple adjustments for age, BMI, uCCi, clinical (time between onset of COVID-19 symptoms and dyspnoea) and biological variables (eGFR, aspartate aminotransferase, white cell count, platelet count, C-reactive protein) on admission to hospital, diabetes remained associated with a higher risk of primary composite endpoint within 7 days (adjusted HR 1.42 [95% CI 1.17, 1.72], p<0.001) and 28 days (adjusted HR 1.30 [95% CI 1.09, 1.55], p=0.003), compared with individuals without diabetes. Using the same adjustment model, diabetes was associated with the risk of IMV, but not with risk of death, within 28 days of admission to hospital.

CONCLUSIONS/INTERPRETATION

Our results demonstrate that diabetes status was associated with a deleterious COVID-19 prognosis irrespective of age and comorbidity status.

TRIAL REGISTRATION

ClinicalTrials.gov NCT04324736.

ATGL-dependent white adipose tissue lipolysis controls hepatocyte PPARα activity

In hepatocytes, peroxisome proliferator-activated receptor α (PPARα) orchestrates a genomic and metabolic response required for homeostasis during fasting. This includes the biosynthesis of ketone bodies and of fibroblast growth factor 21 (FGF21). Here we show that in the absence of adipose triglyceride lipase (ATGL) in adipocytes, ketone body and FGF21 production is impaired upon fasting. Liver gene expression analysis highlights a set of fasting-induced genes sensitive to both ATGL deletion in adipocytes and PPARα deletion in hepatocytes. Adipose tissue lipolysis induced by activation of the β3-adrenergic receptor also triggers such PPARα-dependent responses not only in the liver but also in brown adipose tissue (BAT). Intact PPARα activity in hepatocytes is required for the cross-talk between adipose tissues and the liver during fat mobilization.

The hepatocyte insulin receptor is required to program the liver clock and rhythmic gene expression

Liver physiology is circadian and sensitive to feeding and insulin. Food intake regulates insulin secretion and is a dominant signal for the liver clock. However, how much insulin contributes to the effect of feeding on the liver clock and rhythmic gene expression remains to be investigated. Insulin action partly depends on changes in insulin receptor (IR)-dependent gene expression. Here, we use hepatocyte-restricted gene deletion of IR to evaluate its role in the regulation and oscillation of gene expression as well as in the programming of the circadian clock in the adult mouse liver. We find that, in the absence of IR, the rhythmicity of core-clock gene expression is altered in response to day-restricted feeding. This change in core-clock gene expression is associated with defective reprogramming of liver gene expression. Our data show that an intact hepatocyte insulin receptor is required to program the liver clock and associated rhythmic gene expression.

Integrative study of diet-induced mouse models of NAFLD identifies PPARα as a sexually dimorphic drug target

OBJECTIVE

We evaluated the influence of sex on the pathophysiology of non-alcoholic fatty liver disease (NAFLD). We investigated diet-induced phenotypic responses to define sex-specific regulation between healthy liver and NAFLD to identify influential pathways in different preclinical murine models and their relevance in humans.

DESIGN

Different models of diet-induced NAFLD (high-fat diet, choline-deficient high-fat diet, Western diet or Western diet supplemented with fructose and glucose in drinking water) were compared with a control diet in male and female mice. We performed metabolic phenotyping, including plasma biochemistry and liver histology, untargeted large-scale approaches (liver metabolome, lipidome and transcriptome), gene expression profiling and network analysis to identify sex-specific pathways in the mouse liver.

RESULTS

The different diets induced sex-specific responses that illustrated an increased susceptibility to NAFLD in male mice. The most severe lipid accumulation and inflammation/fibrosis occurred in males receiving the high-fat diet and Western diet, respectively. Sex-biased hepatic gene signatures were identified for these different dietary challenges. The peroxisome proliferator-activated receptor α (PPARα) co-expression network was identified as sexually dimorphic, and in vivo experiments in mice demonstrated that hepatocyte PPARα determines a sex-specific response to fasting and treatment with pemafibrate, a selective PPARα agonist. Liver molecular signatures in humans also provided evidence of sexually dimorphic gene expression profiles and the sex-specific co-expression network for PPARα.

CONCLUSIONS

These findings underscore the sex specificity of NAFLD pathophysiology in preclinical studies and identify PPARα as a pivotal, sexually dimorphic, pharmacological target.

TRIAL REGISTRATION NUMBER

NCT02390232.

History of bariatric surgery and COVID-19 outcomes in patients with type 2 diabetes: Results from the CORONADO study

OBJECTIVE

This study assessed the impact of a history of metabolic and bariatric surgery (MBS) on the clinical outcomes in patients with type 2 diabetes (T2D) and severe obesity hospitalized for COVID-19.

METHODS

In this post hoc analysis from the nationwide observational CORONADO (Coronavirus SARS-CoV2 and Diabetes Outcomes) study, patients with T2D and a history of MBS were matched with patients without MBS for age, sex, and BMI either at the time of MBS or on admission for COVID-19. The composite primary outcome (CPO) combined invasive mechanical ventilation and/or death within 7 and 28 days following admission.

RESULTS

Out of 2,398 CORONADO participants, 20 had a history of MBS. When matching for BMI at the time of MBS and after adjustment for diabetes duration, the CPO occurred less frequently within 7 days (3 vs. 17 events, OR: 0.15 [0.01 to 0.94], p = 0.03) and 28 days (3 vs. 19 events, OR: 0.11 [0.01 to 0.71], p = 0.02) in patients with MBS (n = 16) vs. controls (n = 44). There was no difference in CPO rate between patients with MBS and controls when matching for BMI on admission.

CONCLUSIONS

These data are reassuring regarding COVID-19 prognosis in patients with diabetes and a history of MBS compared with those without MBS.

COVID-19 and Diabetes Outcomes: Rationale for and Updates from the CORONADO Study

PURPOSE OF REVIEW

In France, in order to describe the phenotypic characteristics of patients with diabetes hospitalized for coronavirus disease-2019 (COVID-19) and to identify the prognostic factors in this specific population, the CORONADO (CORONAvirus and Diabetes Outcomes) study was launched. This review will summarize the key findings from the CORONADO study and put them in perspectives with others studies published on the subject.

RECENT FINDINGS

For almost 2 years, the new SARS-CoV-2 (Severe Acute Respiratory Syndrome-CoronaVirus-2), which causes COVID-19, has spread all around the world leading to a pandemic. From the first epidemiological reports, diabetes mellitus has rapidly emerged as a major risk factor associated with severe forms of COVID-19 but few data were available about diabetes characteristics in hospitalized people with COVID-19. Between March 10 and April 10, 2020, 2951 patients were included in 68 centers throughout the national territory, including overseas territories. In the CORONADO study, the primary outcome was a composite endpoint combining invasive mechanical ventilation (IMV) and/or death within day 7 (D7). Secondary outcomes included death, IMV, intensive care unit (ICU) admission, and hospital discharge, all considered within D7 and day 28 (D28). The primary outcome occurred in 29.0% participants within D7 following hospital admission. Within D28, the end of the follow-up period, the mortality rate was 20.6%, while 50.2% of patients were discharged. In multivariable analysis, advanced age, microvascular complications, treatment with insulin or statin prior to admission, dyspnea on admission, as well as biological markers reflecting the severity of the infection (high levels of transaminases, leukocytes and CRP, and low platelet levels) were associated with an increased risk of death. Several exploratory analyses were performed to clarify the influence of some parameters such as weight status, sex, type of diabetes, and some routine drugs, including metformin or statins.

Sex disparities in COVID-19 outcomes of inpatients with diabetes: insights from the CORONADO study

OBJECTIVE

Male sex is one of the determinants of severe coronavirus diseas-e-2019 (COVID-19). We aimed to characterize sex differences in severe outcomes in adults with diabetes hospitalized for COVID-19.

METHODS

We performed a sex-stratified analysis of clinical and biological features and outcomes (i.e. invasive mechanical ventilation (IMV), death, intensive care unit (ICU) admission and home discharge at day 7 (D7) or day 28 (D28)) in 2380 patients with diabetes hospitalized for COVID-19 and included in the nationwide CORONADO observational study (NCT04324736).

RESULTS

The study population was predominantly male (63.5%). After multiple adjustments, female sex was negatively associated with the primary outcome (IMV and/or death, OR: 0.66 (0.49-0.88)), death (OR: 0.49 (0.30-0.79)) and ICU admission (OR: 0.57 (0.43-0.77)) at D7 but only with ICU admission (OR: 0.58 (0.43-0.77)) at D28. Older age and a history of microvascular complications were predictors of death at D28 in both sexes, while chronic obstructive pulmonary disease (COPD) was predictive of death in women only. At admission, C-reactive protein (CRP), aspartate amino transferase (AST) and estimated glomerular filtration rate (eGFR), according to the CKD-EPI formula predicted death in both sexes. Lymphocytopenia was an independent predictor of death in women only, while thrombocytopenia and elevated plasma glucose concentration were predictors of death in men only.

CONCLUSIONS

In patients with diabetes admitted for COVID-19, female sex was associated with lower incidence of early severe outcomes, but did not influence the overall in-hospital mortality, suggesting that diabetes mitigates the female protection from COVID-19 severity. Sex-associated biological determinants may be useful to optimize COVID-19 prevention and management in women and men.

Predictors of hospital discharge and mortality in patients with diabetes and COVID-19: updated results from the nationwide CORONADO study

AIMS/HYPOTHESIS

This is an update of the results from the previous report of the CORONADO (Coronavirus SARS-CoV-2 and Diabetes Outcomes) study, which aims to describe the outcomes and prognostic factors in patients with diabetes hospitalised for coronavirus disease-2019 (COVID-19).

METHODS

The CORONADO initiative is a French nationwide multicentre study of patients with diabetes hospitalised for COVID-19 with a 28-day follow-up. The patients were screened after hospital admission from 10 March to 10 April 2020. We mainly focused on hospital discharge and death within 28 days.

RESULTS

We included 2796 participants: 63.7% men, mean age 69.7 ± 13.2 years, median BMI (25th-75th percentile) 28.4 (25.0-32.4) kg/m². Microvascular and macrovascular diabetic complications were found in 44.2% and 38.6% of participants, respectively. Within 28 days, 1404 (50.2%; 95% CI 48.3%, 52.1%) were discharged from hospital with a median duration of hospital stay of 9 (5-14) days, while 577 participants died (20.6%; 95% CI 19.2%, 22.2%). In multivariable models, younger age, routine metformin therapy and longer symptom duration on admission were positively associated with discharge. History of microvascular complications, anticoagulant routine therapy, dyspnoea on admission, and higher aspartate aminotransferase, white cell count and C-reactive protein levels were associated with a reduced chance of discharge. Factors associated with death within 28 days mirrored those associated with discharge, and also included routine treatment by insulin and statin as deleterious factors.

CONCLUSIONS/INTERPRETATION

In patients with diabetes hospitalised for COVID-19, we established prognostic factors for hospital discharge and death that could help clinicians in this pandemic period.

TRIAL REGISTRATION

Clinicaltrials.gov identifier: NCT04324736.

Relationship between obesity and severe COVID-19 outcomes in patients with type 2 diabetes: Results from the CORONADO study

AIM

To assess the relationship between body mass index (BMI) classes and early COVID-19 prognosis in inpatients with type 2 diabetes (T2D).

METHODS

From the CORONAvirus-SARS-CoV-2 and Diabetes Outcomes (CORONADO) study, we conducted an analysis in patients with T2D categorized by four BMI subgroups according to the World Health Organization classification. Clinical characteristics and COVID-19-related outcomes (i.e. intubation for mechanical ventilation [IMV], death and discharge by day 7 [D7]) were analysed according to BMI status.

RESULTS

Among 1965 patients with T2D, 434 (22.1%) normal weight (18.5-24.9 kg/m² , reference group), 726 (36.9%) overweight (25-29.9 kg/m² ) and 805 (41.0%) obese subjects were analysed, including 491 (25.0%) with class I obesity (30-34.9 kg/m² ) and 314 (16.0%) with class II/III obesity (≥35 kg/m² ). In a multivariable-adjusted model, the primary outcome (i.e. IMV and/or death by D7) was significantly associated with overweight (OR 1.65 [1.05-2.59]), class I (OR 1.93 [1.19-3.14]) and class II/III obesity (OR 1.98 [1.11-3.52]). After multivariable adjustment, primary outcome by D7 was significantly associated with obesity in patients aged younger than 75 years, while such an association was no longer found in those aged older than 75 years.

CONCLUSIONS

Overweight and obesity are associated with poor early prognosis in patients with T2D hospitalized for COVID-19. Importantly, the deleterious impact of obesity on COVID-19 prognosis was no longer observed in the elderly, highlighting the need for specific management in this population.

Correction to: Phenotypic characteristics and prognosis of inpatients with COVID-19 and diabetes: the CORONADO study

The authors regret a mistake in Table 1.

Phenotypic characteristics and prognosis of inpatients with COVID-19 and diabetes: the CORONADO study

AIMS/HYPOTHESIS

Coronavirus disease-2019 (COVID-19) is a life-threatening infection caused by the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) virus. Diabetes has rapidly emerged as a major comorbidity for COVID-19 severity. However, the phenotypic characteristics of diabetes in COVID-19 patients are unknown.

METHODS

We conducted a nationwide multicentre observational study in people with diabetes hospitalised for COVID-19 in 53 French centres in the period 10-31 March 2020. The primary outcome combined tracheal intubation for mechanical ventilation and/or death within 7 days of admission. Age- and sex-adjusted multivariable logistic regressions were performed to assess the prognostic value of clinical and biological features with the endpoint. ORs are reported for a 1 SD increase after standardisation.

RESULTS

The current analysis focused on 1317 participants: 64.9% men, mean age 69.8 ± 13.0 years, median BMI 28.4 (25th-75th percentile: 25.0-32.7) kg/m²; with a predominance of type 2 diabetes (88.5%). Microvascular and macrovascular diabetic complications were found in 46.8% and 40.8% of cases, respectively. The primary outcome was encountered in 29.0% (95% CI 26.6, 31.5) of participants, while 10.6% (9.0, 12.4) died and 18.0% (16.0, 20.2) were discharged on day 7. In univariate analysis, characteristics prior to admission significantly associated with the primary outcome were sex, BMI and previous treatment with renin-angiotensin-aldosterone system (RAAS) blockers, but not age, type of diabetes, HbA_1c, diabetic complications or glucose-lowering therapies. In multivariable analyses with covariates prior to admission, only BMI remained positively associated with the primary outcome (OR 1.28 [1.10, 1.47]). On admission, dyspnoea (OR 2.10 [1.31, 3.35]), as well as lymphocyte count (OR 0.67 [0.50, 0.88]), C-reactive protein (OR 1.93 [1.43, 2.59]) and AST (OR 2.23 [1.70, 2.93]) levels were independent predictors of the primary outcome. Finally, age (OR 2.48 [1.74, 3.53]), treated obstructive sleep apnoea (OR 2.80 [1.46, 5.38]), and microvascular (OR 2.14 [1.16, 3.94]) and macrovascular complications (OR 2.54 [1.44, 4.50]) were independently associated with the risk of death on day 7.

CONCLUSIONS/INTERPRETATIONS

In people with diabetes hospitalised for COVID-19, BMI, but not long-term glucose control, was positively and independently associated with tracheal intubation and/or death within 7 days.

TRIAL REGISTRATION

clinicaltrials.gov NCT04324736.

Sex differences in metabolic regulation and diabetes susceptibility

Gender and biological sex impact the pathogenesis of numerous diseases, including metabolic disorders such as diabetes. In most parts of the world, diabetes is more prevalent in men than in women, especially in middle-aged populations. In line with this, considering almost all animal models, males are more likely to develop obesity, insulin resistance and hyperglycaemia than females in response to nutritional challenges. As summarised in this review, it is now obvious that many aspects of energy balance and glucose metabolism are regulated differently in males and females and influence their predisposition to type 2 diabetes. During their reproductive life, women exhibit specificities in energy partitioning as compared with men, with carbohydrate and lipid utilisation as fuel sources that favour energy storage in subcutaneous adipose tissues and preserve them from visceral and ectopic fat accumulation. Insulin sensitivity is higher in women, who are also characterised by higher capacities for insulin secretion and incretin responses than men; although, these sex advantages all disappear when glucose tolerance deteriorates towards diabetes. Clinical and experimental observations evidence the protective actions of endogenous oestrogens, mainly through oestrogen receptor α activation in various tissues, including the brain, the liver, skeletal muscle, adipose tissue and pancreatic beta cells. However, beside sex steroids, underlying mechanisms need to be further investigated, especially the role of sex chromosomes, fetal/neonatal programming and epigenetic modifications. On the path to precision medicine, further deciphering sex-specific traits in energy balance and glucose homeostasis is indeed a priority topic to optimise individual approaches in type 2 diabetes prevention and treatment.

Regulation of hepatokine gene expression in response to fasting and feeding: Influence of PPAR-α and insulin-dependent signalling in hepatocytes

AIM

In hepatocytes, the peroxisome proliferator-activated receptor (PPAR)-α and insulin receptor (IR) are critical for transcriptional responses to fasting and feeding, respectively. The present report analyzes the effects of nutritional status (fasting vs feeding) on the expression of a large panel of hepatokines in hepatocyte-specific PPAR-α (Pparα^hep-/-) and IR (IR^hep-/-) null mice.

METHODS

Pparα^hep-/- and IR^hep-/- mice, and their wild-type littermates, were subjected to fasting or feeding metabolic challenges, then analyzed for hepatokine gene expression. Experiments were conducted in mice of both genders.

RESULTS

Our data confirmed that PPAR-α is essential for regulating fasting-induced Fgf21 and Angptl4 expression. In mice lacking PPAR-α, fasting led to increased Igfbp1 and Gdf15 gene expression. In the absence of hepatic IR, feeding induced overexpression of Igfbp1, follistatin (Fst) and adropin (Enho), and reduced activin E (Inhbe) expression. Gender had only a modest influence on hepatokine gene expression in the liver.

CONCLUSION

The present results highlight the potential roles of hepatokines as a class of hormones that substantially influence nutritional regulation in both female and male mice.

Selective Liver Estrogen Receptor α Modulation Prevents Steatosis, Diabetes, and Obesity Through the Anorectic Growth Differentiation Factor 15 Hepatokine in Mice

Hepatocyte estrogen receptor α (ERα) was recently recognized as a relevant molecular target for nonalcoholic fatty liver disease (NAFLD) prevention. The present study defined to what extent hepatocyte ERα could be involved in preserving metabolic homeostasis in response to a full (17β-estradiol [E2]) or selective (selective estrogen receptor modulator [SERM]) activation. Ovariectomized mice harboring a hepatocyte-specific ERα deletion (LERKO mice) and their wild-type (WT) littermates were fed a high-fat diet (HFD) and concomitantly treated with E2, tamoxifen (TAM; the most used SERM), or vehicle. As expected, both E2 and TAM prevented all HFD-induced metabolic disorders in WT mice, and their protective effects against steatosis were abolished in LERKO mice. However, while E2 still prevented obesity and glucose intolerance in LERKO mice, hepatocyte ERα deletion also abrogated TAM-mediated control of food intake as well as its beneficial actions on adiposity, insulin sensitivity, and glucose homeostasis, suggesting a whole-body protective role for liver-derived circulating factors. Moreover, unlike E2, TAM induced a rise in plasma concentration of the anorectic hepatokine growth differentiation factor 15 (Gdf15) through a transcriptional mechanism dependent on hepatocyte ERα activation. Accordingly, ERα was associated with specific binding sites in the Gdf15 regulatory region in hepatocytes from TAM-treated mice but not under E2 treatment due to specific epigenetic modifications. Finally, all the protective effects of TAM were abolished in HFD-fed GDF15-knockout mice. Conclusion: We identified the selective modulation of hepatocyte ERα as a pharmacologic strategy to induce sufficient anorectic hepatokine Gdf15 to prevent experimental obesity, type 2 diabetes, and NAFLD.

Sight-threatening Graves' orbitopathy: Twenty years' experience of a multidisciplinary thyroid-eye outpatient clinic

CONTEXT

Sight-threatening Graves' orbitopathy affects 3% to 5% of patients with Graves' orbitopathy.

OBJECTIVES

To describe the management of patients with sight-threatening Graves' orbitopathy seen in a multidisciplinary thyroid-eye outpatient clinic dedicated to Graves' orbitopathy (GO).

PATIENTS AND METHODS

We enrolled all patients with sight-threatening GO (dysthyroid optic neuropathy and corneal ulcer as defined in the EUGOGO statement) seen and treated in our GO multidisciplinary thyroid-eye outpatient clinic over the last two decades.

RESULTS

A total of 31 patients (median age 51 years old) including 24 women (77%) and 58% active smokers. This population represented 47 cases (case = eye) of sight-threatening GO. Dysthyroid optic neuropathy (DON) occurred in 40 eyes, corneal ulcer in 15 eyes and both in 8. At presentation, the clinical features of DON were reduced visual acuity (85%), visual field defects (80%), optic disc swelling (42%) and reduced colour vision (100%). At one year, surgical orbital decompression (OD) was performed in 82.5% of DON cases. Only seven eyes with DON were treated with pulses of intra-venous glucocorticoids. For 10 patients, several therapeutic strategies (OD n = 4, punctal plug n = 1, amniotic membrane graft n = 2, tarsorrhaphy n = 2, botulinum toxin injection = 3 and eyelid surgery n = 2) were used to treat corneal ulcer. For each ophthalmological parameter, more than 85% of DON cases had recovery or improvement after treatment. For visual acuity in corneal ulcer, it was 71.4%.

CONCLUSION

We report 47 cases of sight-threatening GO. Orbital decompression was performed in the majority of DON cases and several therapeutic strategies were necessary to treat corneal ulcer. The results are satisfactory in sight-threatening Graves' orbitopathy due to multidisciplinary management.

Local recurrence of pheochromocytoma in multiple endocrine neoplasia type 2A: a diagnostic and therapeutic challenge

In a patient with multiple endocrine neoplasia type 2A (MEN2A), an inverted physiological ratio between urinary normetanephrines and metanephrines is an early marker of recurrence in epinephrine‐secreting pheochromocytoma, and 131I MIBG treatment appears to be a useful therapeutic option in order to avoid multiple invasive surgical procedures in pheochromocytomatosis.

Impact of Carbohydrate Content and Glycemic Load on Postprandial Glucose After Roux-en-Y Gastric Bypass

BACKGROUND

Abnormal glucose profiles have been described after Roux-en-Y gastric bypass (RYGB) with intense postprandial hyperglycemic peaks in some but not all the patients. The underlying mechanisms of these anomalies are not totally understood.

OBJECTIVE

The aim of this study is to determine whether or not the composition of the meal impacts the existence and maximum interstitial glucose (IG) concentration, measured under real-life conditions.

DESIGN

Retrospective cohort.

SETTING

Referral bariatric surgery left.

METHODS

Continuous glucose monitoring (CGM) and meal composition were recorded for at least 3 days on an outpatient basis in 56 patients after RYGB. The presence of postprandial peaks defined by IG above 140 mg/dl, the maximum postprandial IG, the carbohydrate content, and the glycemic load of the meals were analyzed.

RESULTS

Thirty-two patients had a hyperglycemic peak (PEAK), and 24 did not (NO PEAK). The average max IG was 159.6 ± 33.0 mg/dl in PEAK individuals and 111.8 ± 13.0 mg/dl in NO PEAK. Age was significantly higher in PEAK, but no other parameter was different between the two groups, including meal composition. In the PEAK patients, in multivariate analyses, carbohydrate content in model one and glucose load in model two explained respectively 50 and 26 % of maximum IG variance. For each gram of ingested carbohydrates, interstitial glucose increased by 1.68 mg/dl.

CONCLUSIONS

Following a gastric bypass, under real-life conditions, irrespective of the carbohydrate content of the meal, some patients develop postprandial hyperglycemic peaks, whereas others do not. In patients with postprandial hyperglycemic peaks, the maximum IG depends on the carbohydrate content of the meal.

[Neonatal stage IV and IVs neuroblastoma: surgical treatment with silo and liver reduction]

Hepatic metastases of neonatal neuroblastoma can cause multiple organ failure due to rapid growth and severe hepatomegaly. The objective of this work is to present two infants with neuroblastoma stage IV and IVs in a critical situation that needed a decompressive abdominal silo and surgical liver reduction for definitive abdominal closure. Currently both children are 6 years old and they are free from disease.

CONCLUSION

The placement of a silo for abdominal decompression is still an indication for salvage. Surgical hepatic reduction is an alternative for the early closure of the abdomen avoiding complications due to infection or dehiscence of the silo.

Management of child optic pathway gliomas: new therapeutical option

OBJECTIVE

To present our experience in the treatment of child optic pathway gliomas in the last 25 years.

MATERIAL AND METHODS

Seventeen children under 10 years of age have been analyzed and assessed from clinic, ophthalmologic, endocrinologic, neurological, neuropathologic, and imaginologic points of view.

RESULTS

Predominance of female patients, 10 girls and 7 boys between 6 and 122 months old; mean age was 3 years and 8 months. The most frequent symptoms have been ophthalmologic and visual alterations in all 17 patients, endocrine alterations in 10, and neurological signs in 6. One of the patients presented neurofibromatosis type 1 (NF1), another patient had Down syndrome. Diagnosed using computed tomography or/and magnetic resonance imaging, histological studies showed pilocytic astrocytomas in 13 cases and a fibrillary astrocytoma grade II in 1 case. There were three patients without histological diagnosis; one of them had NF1. The treatment consisted of surgery, external beam radiotherapy, chemotherapy, and brachytherapy with iodine 125, separately or combined. Five patients died; the causes were secondary tumors in two children, tumor recurrence in one, sepsis secondary to respiratory and urinary tract infections in the child with Down syndrome, and finally, hydrocephaly due to hyperproteinorachia of tumor origin in one. Average survival was 89 months.

CONCLUSION

Chemotherapy and brachytherapy are therapeutic methods to be considered, especially in children under 5. Marsupialization of the residual cyst into the ventricular system postradio or oncolytic treatment through endoscopic or stereotactic techniques is useful in the treatment of endocranial hypertension and/or hypothalamic compression in these patients.

[Gardner syndrome]

Three patients, sisters of B, 12 and 14 years of age with a diagnosis of Gardner's Syndrome are reported. The family history indicated that their mother died of a carcinoma of the intestine at the age of 30. This Syndrome, which is of dominant autosomic inheritance, can be seen in aur city, with so heterogeneous hereditary features. Dentists must know the oral cavity characteristics of this disease (odontomas, cementomas, cysts, supernumerary teeth) that accompany gastric, intestinal, skeletal and tissular disturbances an of other organs (polyps, osteomas, cysts, adenomas), being intestinal poliposis of the colon the most important feature that becomes an "Adenocarcinoma", in the third ald fourth decade in a 100% of the cases. Its incidence in our city is real. The proper diagnosis is made when the clinical study is completed and the dentist may be the first one to watch this syndrome's feature in the oral cavity. A proper medical diagnosis would allow a preventive procedure and a patient's control until the "total surgery of the colon", which is the appropriate therapeutic procedure, is achieved; although there are controversies as regards the time to be carried out.