Obesity, insulin resistance and diabetes: sex differences and role of oestrogen receptors

Metabolic Syndrome: Does it Differ Between Women and Men?

Cardiovascular disease represents a massive healthcare burden worldwide. Gender differences in the pathophysiology, presentation and prognosis of cardiovascular disease have been described in the literature. Metabolic syndrome, characterized by a cluster of metabolic abnormalities is associated with increased risk for type 2 diabetes mellitus and atherosclerotic cardiovascular disease. With the global obesity epidemic, the prevalence of metabolic syndrome is rising rapidly in the developed as well as developing world. However, there is considerable variation in the prevalence based on geography, age, sex and, definition used for diagnosis. Data on gender related differences in metabolic syndrome is relatively scarce. Here, we aim to review the gender differences in epidemiology and pathophysiology of metabolic syndrome as well as its individual components. Knowledge of gender differences in metabolic syndrome can help design gender specific preventative and therapeutic strategies that will have a positive impact on overall population health.

Association of menopause age and N-terminal pro brain natriuretic peptide: the Multi-Ethnic Study of Atherosclerosis

OBJECTIVE

Menopause age can affect the risk of developing cardiovascular disease (CVD). The purpose of this study was to investigate the associations of early menopause (menopause occurring before age 45 y) and menopause age with N-terminal pro brain natriuretic peptide (NT-proBNP), a potential risk marker of CVD and heart failure.

METHODS

Our cross-sectional study included 2,275 postmenopausal women, aged 45 to 85 years and without clinical CVD (2000-2002), from the Multi-Ethnic Study of Atherosclerosis. Participants were classified as having or not having early menopause. NT-proBNP was log-transformed. Multivariable linear regression was used for analysis.

RESULTS

Five hundred sixty-one women had early menopause. The median (25th-75th percentiles) NT-proBNP value was 79.0 (41.1-151.6) pg/mL for all participants, 83.4 (41.4-164.9) pg/mL for women with early menopause, and 78.0 (40.8-148.3) pg/mL for women without early menopause. The mean (SD) age was 65 (10.1) and 65 (8.9) years for women with and without early menopause, respectively. No significant interactions between menopause age and ethnicity were observed. In multivariable analysis, early menopause was associated with a 10.7% increase in NT-proBNP levels, whereas each 1-year increase in menopause age was associated with a 0.7% decrease in NT-proBNP levels.

CONCLUSIONS

Early menopause is associated with greater NT-proBNP levels, whereas each 1-year increase in menopause age is associated with lower NT-proBNP levels, in postmenopausal women.

GPER/GPR30 Knockout Mice: Effects of GPER on Metabolism

Endogenous estrogens, predominantly 17β-estradiol (E2), mediate various diverse effects throughout the body in both normal physiology and disease. Actions include development (including puberty) and reproduction as well as additional effects throughout life in the metabolic, endocrine, musculoskeletal, nervous, cardiovascular, and immune systems. The actions of E2 have traditionally been attributed to the classical nuclear estrogen receptors (ERα and ERβ) that largely mediate transcriptional/genomic activities. However, more recently the G protein-coupled estrogen receptor GPER/GPR30 has become recognized as an essential mediator of certain, and particularly rapid, signaling events in response to E2. Murine genetic knockout (KO) models represent an important approach to understand the mechanisms of E2 action in physiology and disease. Studies of GPER KO mice over the last years have revealed functions for GPER in the regulation of obesity, insulin resistance and glucose intolerance, among other areas of (patho)physiology. This chapter focuses on methods for the evaluation of metabolic parameters in vivo and ex vivo with an emphasis on glucose homeostasis and metabolism through the use of glucose and insulin tolerance tests, pancreatic islet and adipocyte isolation and characterization.

Modulation of rat liver urea cycle and related ammonium metabolism by sex and cafeteria diet

Liver amino acid metabolism decreased with cafeteria diet through lower ammonium production (even lower in females) and urea cycle activity.

Obesity and sex interact in the regulation of Alzheimer's disease

Alzheimer's disease (AD) is a progressive neurodegenerative disorder, for which a number of genetic, environmental, and lifestyle risk factors have been identified. A significant modifiable risk factor is obesity in mid-life. Interestingly, both obesity and AD exhibit sex differences and are regulated by sex steroid hormones. Accumulating evidence suggests interactions between obesity and sex in regulation of AD risk, although the pathways underlying this relationship are unclear. Inflammation and the E4 allele of apolipoprotein E have been identified as independent risk factors for AD and both interact with obesity and sex steroid hormones. We review the individual and cooperative effects of obesity and sex on development of AD and examine the potential contributions of apolipoprotein E, inflammation, and their interactions to this relationship.

The G-protein coupled estrogen receptor, GPER: The inside and inside-out story

GPER possesses structural and functional characteristics shared by members of the G-protein-coupled receptor (GPCR) superfamily, the largest class of plasma membrane receptors. This newly appreciated estrogen receptor is localized predominately within intracellular membranes in most, but not all, cell types and its surface expression is modulated by steroid hormones and during tissue injury. An intracellular staining pattern is not unique among GPCRs, which employ a diverse array of molecular mechanisms that restrict cell surface expression and effectively regulating receptor binding and activation. The finding that GPER displays an intracellular predisposition has created some confusion as the estrogen-inducible transcription factors, ERα and ERβ, also reside intracellularly, and has led to complex suggestions of receptor interaction. GPER undergoes constitutive retrograde trafficking from the plasma membrane to the endoplasmic reticulum and recent studies indicate its interaction with PDZ binding proteins that sort transmembrane receptors to synaptosomes and endosomes. Genetic targeting and selective ligand approaches as well as cell models that express GPER in the absence of ERs clearly supports GPER as a bonafide "stand alone" receptor. Here, the molecular details that regulate GPER action, its cell biological activities and its implicated roles in physiological and pathological processes are reviewed.

Effects of sex and site on amino acid metabolism enzyme gene expression and activity in rat white adipose tissue

Background and Objectives. White adipose tissue (WAT) shows marked sex- and diet-dependent differences. However, our metabolic knowledge of WAT, especially on amino acid metabolism, is considerably limited. In the present study, we compared the influence of sex on the amino acid metabolism profile of the four main WAT sites, focused on the paths related to ammonium handling and the urea cycle, as a way to estimate the extent of WAT implication on body amino-nitrogen metabolism. Experimental Design. Adult female and male rats were maintained, undisturbed, under standard conditions for one month. After killing them under isoflurane anesthesia. WAT sites were dissected and weighed. Subcutaneous, perigonadal, retroperitoneal and mesenteric WAT were analyzed for amino acid metabolism gene expression and enzyme activities. Results. There was a considerable stability of the urea cycle activities and expressions, irrespective of sex, and with only limited influence of site. Urea cycle was more resilient to change than other site-specialized metabolic pathways. The control of WAT urea cycle was probably related to the provision of arginine/citrulline, as deduced from the enzyme activity profiles. These data support a generalized role of WAT in overall amino-N handling. In contrast, sex markedly affected WAT ammonium-centered amino acid metabolism in a site-related way, with relatively higher emphasis in males' subcutaneous WAT. Conclusions. We found that WAT has an active amino acid metabolism. Its gene expressions were lower than those of glucose-lipid interactions, but the differences were quantitatively less important than usually reported. The effects of sex on urea cycle enzymes expression and activity were limited, in contrast with the wider variations observed in other metabolic pathways. The results agree with a centralized control of urea cycle operation affecting the adipose organ as a whole.

Development of a PubMed Based Search Tool for Identifying Sex and Gender Specific Health Literature

Background: An effective literature search strategy is critical to achieving the aims of Sex and Gender Specific Health (SGSH): to understand sex and gender differences through research and to effectively incorporate the new knowledge into the clinical decision making process to benefit both male and female patients. The goal of this project was to develop and validate an SGSH literature search tool that is readily and freely available to clinical researchers and practitioners.

Methods: PubMed, a freely available search engine for the Medline database, was selected as the platform to build the SGSH literature search tool. Combinations of Medical Subject Heading terms, text words, and title words were evaluated for optimal specificity and sensitivity. The search tool was then validated against reference bases compiled for two disease states, diabetes and stroke.

Results: Key sex and gender terms and limits were bundled to create a search tool to facilitate PubMed SGSH literature searches. During validation, the search tool retrieved 50 of 94 (53.2%) stroke and 62 of 95 (65.3%) diabetes reference articles selected for validation. A general keyword search of stroke or diabetes combined with sex difference retrieved 33 of 94 (35.1%) stroke and 22 of 95 (23.2%) diabetes reference base articles, with lower sensitivity and specificity for SGSH content.

Conclusions: The Texas Tech University Health Sciences Center SGSH PubMed Search Tool provides higher sensitivity and specificity to sex and gender specific health literature. The tool will facilitate research, clinical decision-making, and guideline development relevant to SGSH.

Teneligliptin improves metabolic abnormalities in a mouse model of postmenopausal obesity

A decrease in serum estrogen levels in menopause is closely associated with the development of visceral obesity and the onset of type 2 diabetes in women. In the present study, we demonstrated the therapeutic effects of the novel DPP4 inhibitor, teneligliptin, on the features of postmenopausal obesity in mice. In the control group, female C57BL/6 mice were sham-operated and maintained on a standard diet. In the postmenopausal obese group, ovariectomized (OVX) mice were maintained on a high-fat diet, and were referred to as OVX-HF. In the treated group, teneligliptin at 60 mg/kg per day was administrated to OVX-HF, and were referred to as Tene. After a 12-week food challenge, the metabolic phenotypes of these mice were analyzed. Body weight, fat accumulation, and glucose intolerance were greater in OVX-HF than in control, while these abnormalities were markedly improved without alterations in calorie intake in Tene. Teneligliptin effectively ameliorated the characteristics of metabolic abnormalities associated with postmenopausal obesity. Regarding chronic inflammation in visceral adipose tissue, the numbers of F4/80(+)CD11c(+)CD206(-) M1-macrophages in flow cytometry, crown-like structure formation in immunohistochemistry, and proinflammatory cytokine expression were significantly attenuated in Tene. Hepatic steatosis was also markedly improved. Furthermore, decreased energy consumption in the dark and light phases, reduced locomotor activity in the dark phase, and lowered core body temperature in OVX-HF were ameliorated in Tene. Since obesity and reduced energy metabolism are a common physiology of menopause, teneligliptin appears to be beneficial as a treatment for type 2 diabetes in postmenopausal obesity.

What have we learned about GPER function in physiology and disease from knockout mice?

Estrogens, predominantly 17β-estradiol, exert diverse effects throughout the body in both normal and pathophysiology, during development and in reproductive, metabolic, endocrine, cardiovascular, nervous, musculoskeletal and immune systems. Estrogen and its receptors also play important roles in carcinogenesis and therapy, particularly for breast cancer. In addition to the classical nuclear estrogen receptors (ERα and ERβ) that traditionally mediate predominantly genomic signaling, the G protein-coupled estrogen receptor GPER has become recognized as a critical mediator of rapid signaling in response to estrogen. Mouse models, and in particular knockout (KO) mice, represent an important approach to understand the functions of receptors in normal physiology and disease. Whereas ERα KO mice display multiple significant defects in reproduction and mammary gland development, ERβ KO phenotypes are more limited, and GPER KO exhibit no reproductive deficits. However, the study of GPER KO mice over the last six years has revealed that GPER deficiency results in multiple physiological alterations including obesity, cardiovascular dysfunction, insulin resistance and glucose intolerance. In addition, the lack of estrogen-mediated effects in numerous tissues of GPER KO mice, studied in vivo or ex vivo, including those of the cardiovascular, endocrine, nervous and immune systems, reveals GPER as a genuine mediator of estrogen action. Importantly, GPER KO mice have also demonstrated roles for GPER in breast carcinogenesis and metastasis. In combination with the supporting effects of GPER-selective ligands and GPER knockdown approaches, GPER KO mice demonstrate the therapeutic potential of targeting GPER activity in diseases as diverse as obesity, diabetes, multiple sclerosis, hypertension, atherosclerosis, myocardial infarction, stroke and cancer.

Menopause, obesity and inflammation: interactive risk factors for Alzheimer's disease

Alzheimer’s disease (AD) is a multifactorial neurodegenerative disorder, the development of which is regulated by several environmental and genetic risk factors. Two factors theorized to contribute to the initiation and/or progression of AD pathogenesis are age-related increases in inflammation and obesity. These factors may be particularly problematic in women. The onset of menopause in mid-life elevates the vulnerability of women to AD, an increased risk that is likely associated with the depletion of estrogens. Menopause is also linked with an abundance of additional changes, including increased central adiposity and inflammation. Here, we review the current literature to explore the interactions between obesity, inflammation, menopause and AD.

International Union of Basic and Clinical Pharmacology. XCVII. G Protein-Coupled Estrogen Receptor and Its Pharmacologic Modulators

Estrogens are critical mediators of multiple and diverse physiologic effects throughout the body in both sexes, including the reproductive, cardiovascular, endocrine, nervous, and immune systems. As such, alterations in estrogen function play important roles in many diseases and pathophysiological conditions (including cancer), exemplified by the lower prevalence of many diseases in premenopausal women. Estrogens mediate their effects through multiple cellular receptors, including the nuclear receptor family (ERα and ERβ) and the G protein-coupled receptor (GPCR) family (GPR30/G protein-coupled estrogen receptor [GPER]). Although both receptor families can initiate rapid cell signaling and transcriptional regulation, the nuclear receptors are traditionally associated with regulating gene expression, whereas GPCRs are recognized as mediating rapid cellular signaling. Estrogen-activated pathways are not only the target of multiple therapeutic agents (e.g., tamoxifen, fulvestrant, raloxifene, and aromatase inhibitors) but are also affected by a plethora of phyto- and xeno-estrogens (e.g., genistein, coumestrol, bisphenol A, dichlorodiphenyltrichloroethane). Because of the existence of multiple estrogen receptors with overlapping ligand specificities, expression patterns, and signaling pathways, the roles of the individual receptors with respect to the diverse array of endogenous and exogenous ligands have been challenging to ascertain. The identification of GPER-selective ligands however has led to a much greater understanding of the roles of this receptor in normal physiology and disease as well as its interactions with the classic estrogen receptors ERα and ERβ and their signaling pathways. In this review, we describe the history and characterization of GPER over the past 15 years focusing on the pharmacology of steroidal and nonsteroidal compounds that have been employed to unravel the biology of this most recently recognized estrogen receptor.

Obesity Early in Adulthood Increases Risk but Does Not Affect Outcomes of Hepatocellular Carcinoma

BACKGROUND & AIMS

Despite the significant association between obesity and several cancers, it has been difficult to establish an association between obesity and hepatocellular carcinoma (HCC). Patients with HCC often have ascites, making it a challenge to determine body mass index (BMI) accurately, and many factors contribute to the development of HCC. We performed a case-control study to investigate whether obesity early in adulthood affects risk, age of onset, or outcomes of patients with HCC.

METHODS

We interviewed 622 patients newly diagnosed with HCC from January 2004 through December 2013, along with 660 healthy controls (frequency-matched by age and sex) to determine weights, heights, and body sizes (self-reported) at various ages before HCC development or enrollment as controls. Multivariable logistic and Cox regression analyses were performed to determine the independent effects of early obesity on risk for HCC and patient outcomes, respectively. BMI was calculated, and patients with a BMI of 30 kg/m(2) or greater were considered obese.

RESULTS

Obesity in early adulthood (age, mid-20s to mid-40s) is a significant risk factor for HCC. The estimated odds ratios were 2.6 (95% confidence interval [CI], 1.4-4.4), 2.3 (95% CI, 1.2-4.4), and 3.6 (95% CI, 1.5-8.9) for the entire population, for men, and for women, respectively. Each unit increase in BMI at early adulthood was associated with a 3.89-month decrease in age at HCC diagnosis (P < .001). Moreover, there was a synergistic interaction between obesity and hepatitis virus infection. However, we found no effect of obesity on the overall survival of patients with HCC.

CONCLUSIONS

Early adulthood obesity is associated with an increased risk of developing HCC at a young age in the absence of major HCC risk factors, with no effect on outcomes of patients with HCC.

The Ontogeny of Brown Adipose Tissue

There are three different types of adipose tissue (AT)-brown, white, and beige-that differ with stage of development, species, and anatomical location. Of these, brown AT (BAT) is the least abundant but has the greatest potential impact on energy balance. BAT is capable of rapidly producing large amounts of heat through activation of the unique uncoupling protein 1 (UCP1) located within the inner mitochondrial membrane. White AT is an endocrine organ and site of lipid storage, whereas beige AT is primarily white but contains some cells that possess UCP1. BAT first appears in the fetus around mid-gestation and is then gradually lost through childhood, adolescence, and adulthood. We focus on the interrelationships between adipocyte classification, anatomical location, and impact of diet in early life together with the extent to which fat development differs between the major species examined. Ultimately, novel dietary interventions designed to reactivate BAT could be possible.

High-risk drinking is associated with a higher risk of diabetes mellitus in Korean men, based on the 2010-2012 KNHANES

We examined the association between alcohol-drinking pattern and diabetes mellitus (DM) in Korean adults. This cross-sectional study included 12,486 participants (5551 men and 6935 women) who participated in the 2010-2012 Korean National Health and Nutrition Examination Survey. We categorized alcohol-drinking pattern into three groups based on the alcohol-use disorders identification test (AUDIT): low-risk (score: 0-7), intermediate-risk (score: 8-14), and high-risk (score: ≥15). DM was defined as having fasting plasma glucose ≥126 mg/dL or taking glucose-lowering medication, including insulin therapy. In the study population, 25.2% of men and 4.7% of women were high-risk drinkers. DM prevalence was 9.2% in men and 5.4% in women. DM prevalence was 9.0% and 5.7% in the low-risk drinking group, 7.6% and 4.1% in the intermediate-risk drinking group, and 11.2% and 3.5% in the high-risk drinking group in men and women, respectively. Compared to the low-risk drinking group, odds ratios (95% confidence intervals) of men and women in the intermediate-risk drinking group for DM were 1.043 (0.779-1.396) and 1.139 (0.712-1.824), respectively, and 1.480 (1.133-1.933) and 0.827 (0.296-2.311) in the high-risk drinking group, after adjusting for age and other confounding factors. In conclusion, high-risk drinking appears to be associated with a higher risk of DM in men, but not in women.

Emerging roles of GPER in diabetes and atherosclerosis

The G protein-coupled estrogen receptor (GPER) is a 7-transmembrane receptor implicated in rapid estrogen signaling. Originally cloned from vascular endothelial cells, GPER plays a central role in the regulation of vascular tone and cell growth as well as lipid and glucose homeostasis. This review highlights our knowledge of the physiological and pathophysiological functions of GPER in the pancreas, peripheral and immune tissues, and the arterial vasculature. Recent findings on its roles in obesity, diabetes, and atherosclerosis, including GPER-dependent regulation of lipid metabolism and inflammation, are presented. The therapeutic potential of targeting GPER-dependent pathways in chronic diseases such as coronary artery disease and diabetes and in the context of menopause is also discussed.

Plasma isoflavone concentration is associated with decreased risk of type 2 diabetes in Korean women but not men: results from the Korean Genome and Epidemiology Study

AIMS/HYPOTHESIS

To examine the association between soybean products and risk of type 2 diabetes, we measured four isoflavone biological markers--genistein, daidzein, glycitein and equol--in a nested case-control study.

METHODS

The study population was composed of 693 cases (316 women and 377 men) and 698 matched controls (317 women and 381 men) within the Korean Genome and Epidemiology Study. The concentrations of isoflavone biomarkers were measured using HPLC-MS/MS on plasma samples that were collected at baseline. A stratified analysis was undertaken to examine the association between plasma isoflavone concentrations and risk of type 2 diabetes according to sex and equol production. Logistic regression models were used to compute ORs and 95% CIs adjusted for confounders.

RESULTS

In women, compared with the lowest quartile of plasma concentration of genistein, the highest quartile exhibited a significantly decreased risk of diabetes (OR 0.58, 95% CI 0.35, 0.95). When stratified by equol-producing status in women, the OR for diabetes in the highest vs the lowest quartile of genistein concentration was 0.31 (95% CI 0.16, 0.60) in equol producers, but genistein concentration was not associated with risk of diabetes in equol non-producers (p for interaction = 0.013). In men, isoflavone concentrations were not associated with risk of diabetes, regardless of equol-producing status.

CONCLUSIONS/INTERPRETATION

High plasma concentrations of genistein were associated with a decreased risk of type 2 diabetes in women. This inverse association was prominent in equol-producing participants. These results suggest a beneficial effect of a high intake of soybean products on risk of type 2 diabetes in women.

The Impact of Gender and Protein Intake on the Success of Weight Maintenance and Associated Cardiovascular Risk Benefits, Independent of the Mode of Food Provision: The DiOGenes Randomized Trial

OBJECTIVE

Maintenance of weight loss and associated cardiovascular benefits after following energy-restricted diets is still a challenging field, and thorough investigation is needed. The present research aimed to determine the role of protein and gender in relation to two different intervention models related to food supply, in a weight maintenance trial.

SUBJECTS AND METHODS

The DiOGenes trial was a long-term, multicenter, randomized, dietary intervention study, conducted in eight European countries (Clinical Trials.gov, NCT00390637), focusing on assessing the effectiveness of weight maintenance over 6 months. This secondary analysis intended to evaluate the different benefits for weight maintenance and cardiometabolic markers of two dietary advice delivery models: "shop + instruction intervention" vs "instruction-alone intervention," which were further categorized for gender and macronutrient intake.

RESULTS

The weight maintenance intervention based on different macronutrient intake showed, independently of the advice delivery model, in both sexes that higher protein consumption was more effective for weight stability, showing better results in obese women (low protein: 1.65 kg in males and 0.73 Kg in females vs high protein: 1.45 kg in males and -0.93 Kg in females) . Measurements concerning cardiovascular risk markers from subjects on both structured models produced similar trends in the subsequent follow-up period, with a lower rebound in women for most of the markers analyzed.

CONCLUSION

The reported dietary benefits for weight sustainability should be ascribed to the macronutrient distribution (higher protein diets) rather than to the structured mode of delivery. Higher weight regain in males was noted, as well as a metabolic divergence attributable to the sex, with a better biochemical outcome in women.

Role of G protein-coupled orphan receptors in intestinal inflammation: novel targets in inflammatory bowel diseases

A large number of proteins were classified into the family of G protein-coupled receptors (GPCRs). Based on their characteristic serpentine domain, they are called 7 TM receptors. Presently, their ligands and physiological functions remain unknown. In this review, we summarize what is known on these receptors and discuss the potential use of these orphan GPCRs (GPRs) in the induction or maintenance of remission in inflammatory bowel diseases. We focus on GPRs 30, 41, 43, 55, 119, and 120, where scientific evidence supports a potential role in intestinal inflammation.

Sex, eyes, and vision: male/female distinctions in ophthalmic disorders

There is growing recognition: (1) that sex (male and female) and sex hormones (androgens and estrogens) are important for physiologic functions outside those pertaining expressly to reproduction, and (2) that both classes of sex hormones are active in both sexes, and moreover are produced locally in non-gonadal tissues throughout the body. The visual system, in addition to being of tremendous inherent importance, is unique in a very distinctive way; it possesses an organ - the eye - having a window allowing its interior to be examined with exquisite precision and control in both laboratory and clinical settings. Plus, many diseases manifest in the eye or are exclusive to the eye. This special issue of Current Eye Research contains 12 review articles, each addressing a different topical area important for Sex, Eyes, and Vision: Male/Female Distinctions in Ophthalmic Disorders. Of course, the distinctions between topical areas are blurred, and the overlap between the various lines of knowledge and investigation likewise is substantial. Eye diseases can be both neurodegenerative and involve altered blood flow, for instance. In fact, the thematic overlap is greater yet, in that the articles for this special issue address matters of interest to clinicians and scientists who may identify more with women's health or sex & gender fields than with eye & vision fields. Nevertheless, because this special issue needs a home, the following 12 topical areas each have here their own dedicated review: age-related maculopathy, central nervous system function and cognition & perception, diabetic retinopathy, dry eye, glaucoma, inherited diseases, lens and cataract, neuro-ophthalmology, ocular blood flow, ocular inflammatory disorders, optical coherence tomography, and sex/gender eye care disparities. This overview article itself raises additional points expressly concerning: (1) the estrogen therapy timing hypothesis, and (2) breast cancer treatment with aromatase inhibitors.

The effect of Momordica charantia intake on the estrogen receptors ESRα/ESRβ gene levels and apoptosis on uterine tissue in ovariectomy rats

Estrogen or combinational hormone therapy can protect to menopausal symptoms but exogenous estrogen therapy has some potential risks which in turns lead to the appearance of various diseases. In recent years plants with high phytoestrogen content are recommended as therapeutic agents for postmenopausal hormonal treatment. In this research, we investigated the effects of Momordica charantia (MC) on the estrogen production and E2 as well as anti-oxidative and anti-apoptotic role on the ovariectomy rat model. The rats were ovariectomized and fed on 2 g/kg of fruit extra of MC for 30 days by gavage. 17-β estradiol (E2) and 8-OHdG levels in serum, markers of oxidative damage of ROS and ESRα, ESRβ and NF-kB gene levels were measured in uterus horn tissue. Caspase-3, caspase-9, TNF-α, IL-6, IL-10, Bcl-2 and Nf-kB proteins expression were assessed by western blotting. Structural changes in tissue were examined with H&E staining. MC administration also stimulated the E2 production and ESRα/ESRβ gene levels and the inhibited oxidative damage. Furthermore, MC treatment enhanced anti-apoptotic and anti-inflammatory process and tissue regeneration. Data herein support that MC directly regulates uterine estrogen response and may serve as a new phytoestrogenic substance for the treatment of post-menopausal symptoms.

Osteosarcopenic obesity: the role of bone, muscle, and fat on health

Osteopenia/osteoporosis, sarcopenia, and obesity are commonly observed in the process of aging, and recent evidence suggests a potential interconnection of these syndromes with common pathophysiology. The term osteosarcopenic obesity has been coined to describe the concurrent appearance of obesity in individuals with low bone and muscle mass. Although our understanding of osteosarcopenic obesity's etiology, prevalence, and consequences is extremely limited, it is reasonable to infer its negative impact in a population that is aging in an obesogenic environment. It is likely that these individuals will present with poorer clinical outcomes caused by the cascade of metabolic abnormalities associated with these changes in body composition. Clinical outcomes include but are not limited to increased risk of fractures, impaired functional status (including activities of daily living), physical disability, insulin resistance, increased risk of infections, increased length of hospital stay, and reduced survival. These health outcomes are likely to be worse when compared to individuals with obesity, sarcopenia, or osteopenia/osteoporosis alone. Interventions that utilize resistance training exercise in conjunction with increased protein intake appear to be promising in their ability to counteract osteosarcopenic obesity.

Characterization of adipose-derived stem cells of anatomical region from mice

Background

Stem cells constitute a group of great capacity for self-renewal, long-term viability, and multi-lineage potential. Several studies have provided evidence that adipose tissue represents an alternative source of stem cells, with the main benefit of adipose-derived stem cells being that they can be easily harvested from patients by a simple minimally invasive method and can be easily cultured. The aim of this study was to establish a culture protocol for obtaining and characterizing adipose-derived stem cells (ADSCs) from C57BL/6 J mice.

Results

The results showed that the yield, viability, and cell morphology obtained differ according to the age of isolated anatomic regions of the adipose tissue from ovarian and epididymis. The results of determination of cyclin D1 showed uniformity in the expression between different populations of ADSCs. A significant increase in the expression of caspase-3 active, was also observed in large cell populations from mice after 120 days. ADSCs were positive for mesenchymal markers CD90 and CD105, Nanog, SSEA-1, CD106, and VEGFR-1, and negative for hematopoietic markers CD34 and CD45. A large number of cells in S + G2/M phases was also observed for both sexes, demonstrating high proliferative capacity of ADSCs.

Conclusions

We observed that the adipose tissue of C57BL/6 J mice, isolated from the studied anatomic regions, is a promising source for obtaining pluripotent mesenchymal stem cells with high viability and proliferative response.

Supplementing with Opuntia ficus-indica Mill and Dioscorea nipponica Makino extracts synergistically attenuates menopausal symptoms in estrogen-deficient rats

ETHNOPHARMACOLOGICAL RELEVANCE

Prickly pear cactus grown in Korea (Opuntia ficus-indica Mill, KC) and Buchema (Dioscorea nipponica Makino, B) have been traditionally used in East Asia and South America to treat various metabolic diseases. The aim of the present study was to determine whether the extracts of KC, B, and KC+B can prevent the impairments of energy, glucose, lipid and bone homeostasis in estrogen-deficient ovariectomized (OVX) rats and to explore their mechanisms.

MATERIALS AND METHODS

OVX rats were divided into 4 groups and fed high fat diets supplemented with either 3% dextrin (control), 3% KC, 3% B or 1.5% KC+1.5% B. Sham rats were fed 3% dextrin. After 12 weeks of diet consumption, energy, lipid, glucose and bone metabolisms were analyzed and Wnt signaling in the femur and hepatic signaling were determined.

RESULTS

OVX impaired energy, glucose and lipid metabolism and decreased uterine and bone masses. B and KC+B prevented the decrease in energy expenditure, especially from fat oxidation, in OVX rats, but did not affect food intake. KC+B and B reduced body weight and visceral fat levels, as compared to the OVX-control, by decreasing fat synthesis and inhibiting FAS and SREBP-1c expression. KC+B and B prevented the increases in serum lipid levels and insulin resistance by improving hepatic insulin signaling (pIRS→pAkt→pGSK-3β). KC and KC+B also prevented decreases in bone mineral density (BMD) in the femur and lumbar spine in OVX rats. This was related to decreased expressions of bone turnover markers such as serum osteocalcin, alkaline phosphatase (ALP) and bone-specific ALP levels, and increased serum P levels. KC and KC+B upregulated low-density lipoprotein receptor-related protein 5 and β-catenin in OVX rats, but suppressed the expression of dickkopf-related protein 1. B alone improved energy, lipid and glucose homeostasis, but not bone loss, whereas KC alone enhanced BMD, but not energy, lipid or glucose homeostasis.

CONCLUSION

KC+B synergistically attenuated impairments of bone, energy, lipid and glucose metabolism by OVX, suggesting potential efficacy of the combination for alleviating menopausal symptoms.

GPER-targeted, 99mTc-labeled, nonsteroidal ligands demonstrate selective tumor imaging and in vivo estrogen binding

Our understanding of estrogen (17β-estradiol, E2) receptor biology has evolved in recent years with the discovery and characterization of a 7-transmembrane-spanning G protein-coupled estrogen receptor (GPER/GPR30) and the development of GPER-selective functional chemical probes. GPER is highly expressed in certain breast, endometrial, and ovarian cancers, establishing the importance of noninvasive methods to evaluate GPER expression in vivo. Here, we developed (99m)Tc-labeled GPER ligands to demonstrate the in vivo status of GPER as an estrogen receptor (ER) and for GPER visualization in whole animals. A series of (99m)Tc(I)-labeled nonsteroidal tetrahydro-3H-cyclopenta[c]quinolone derivatives was synthesized utilizing pyridin-2-yl hydrazine and picolylamine chelates. Radioligand receptor binding studies revealed binding affinities in the 10 to 30 nmol/L range. Cell signaling assays previously demonstrated that derivatives retaining a ketone functionality displayed agonist properties, whereas those lacking such a hydrogen bond acceptor were antagonists. In vivo biodistribution and imaging studies performed on mice bearing human endometrial and breast cancer cell xenografts yielded significant tumor uptake (0.4-1.1%ID/g). Blocking studies revealed specific uptake in multiple organs (adrenals, uterus, and mammary tissue), as well as tumor uptake with similar levels of competition by E2 and G-1, a GPER-selective agonist. In conclusion, we synthesized and evaluated a series of first-generation (99m)Tc-labeled GPER-specific radioligands, demonstrating GPER as an estrogen-binding receptor for the first time in vivo using competitive binding principles, and establishing the utility of such ligands as tumor imaging agents. These results warrant further investigation into the role of GPER in estrogen-mediated carcinogenesis and as a target for diagnostic/therapeutic/image-guided drug delivery.

IMPLICATIONS

These studies provide a molecular basis to evaluate GPER expression and function as an ER through in vivo imaging.

Biochemical alterations during the obese-aging process in female and male monosodium glutamate (MSG)-treated mice

Obesity, from children to the elderly, has increased in the world at an alarming rate over the past three decades, implying long-term detrimental consequences for individual’s health. Obesity and aging are known to be risk factors for metabolic disorder development, insulin resistance and inflammation, but their relationship is not fully understood. Prevention and appropriate therapies for metabolic disorders and physical disabilities in older adults have become a major public health challenge. Hence, the aim of this study was to evaluate inflammation markers, biochemical parameters and glucose homeostasis during the obese-aging process, to understand the relationship between obesity and health span during the lifetime. In order to do this, the monosodium glutamate (MSG) obesity mice model was used, and data were evaluated at 4, 8, 12, 16 and 20 months in both female and male mice. Our results showed that obesity was a major factor contributing to premature alterations in MSG-treated mice metabolism; however, at older ages, obesity effects were attenuated and MSG-mice became more similar to normal mice. At a younger age (four months old), the Lee index, triglycerides, total cholesterol, TNF-α and transaminases levels increased; while adiponectin decreased and glucose tolerance and insulin sensitivity levels were remarkably altered. However, from 16 months old-on, the Lee index and TNF-α levels diminished significantly, while adiponectin increased, and glucose and insulin homeostasis was recovered. In summary, MSG-treated obese mice showed metabolic changes and differential susceptibility by gender throughout life and during the aging process. Understanding metabolic differences between genders during the lifespan will allow the discovery of specific preventive treatment strategies for chronic diseases and functional decline.

Chronic rapamycin treatment causes diabetes in male mice

Current evidence indicates that the mammalian target of rapamycin inhibitor rapamycin both increases longevity and, seemingly contradictorily, impairs glucose homeostasis. Most studies exploring the dimensions of this paradox have been based on rapamycin treatment in mice for up to 20 wk. We sought to better understand the metabolic effects of oral rapamycin over a substantially longer period of time in HET3 mice. We observed that treatment with rapamycin for 52 wk induced diabetes in male mice, characterized by hyperglycemia, significant urine glucose levels, and severe glucose and pyruvate intolerance. Glucose intolerance occurred in male mice by 4 wk on rapamycin and could be only partially reversed with cessation of rapamycin treatment. Female mice developed moderate glucose intolerance over 1 yr of rapamycin treatment, but not diabetes. The role of sex hormones in the differential development of diabetic symptoms in male and female mice was further explored. HET3 mice treated with rapamycin for 52 wk were gonadectomized and monitored over 10 wk. Castrated male mice remained glucose intolerant, while ovariectomized females developed significant glucose intolerance over the same time period. Subsequent replacement of 17β-estradiol (E2) in ovariectomized females promoted a recovery of glucose tolerance over a 4-wk period, suggesting the protective role of E2 against rapamycin-induced diabetes. These results indicate that 1) oral rapamycin treatment causes diabetes in male mice, 2) the diabetes is partially reversible with cessation of treatment, and 3) E2 plays a protective role against the development of rapamycin-induced diabetes.

The pathophysiology of hypertension in patients with obesity

The combination of obesity and hypertension is associated with high morbidity and mortality because it leads to cardiovascular and kidney disease. Potential mechanisms linking obesity to hypertension include dietary factors, metabolic, endothelial and vascular dysfunction, neuroendocrine imbalances, sodium retention, glomerular hyperfiltration, proteinuria, and maladaptive immune and inflammatory responses. Visceral adipose tissue also becomes resistant to insulin and leptin and is the site of altered secretion of molecules and hormones such as adiponectin, leptin, resistin, TNF and IL-6, which exacerbate obesity-associated cardiovascular disease. Accumulating evidence also suggests that the gut microbiome is important for modulating these mechanisms. Uric acid and altered incretin or dipeptidyl peptidase 4 activity further contribute to the development of hypertension in obesity. The pathophysiology of obesity-related hypertension is especially relevant to premenopausal women with obesity and type 2 diabetes mellitus who are at high risk of developing arterial stiffness and endothelial dysfunction. In this Review we discuss the relationship between obesity and hypertension with special emphasis on potential mechanisms and therapeutic targeting that might be used in a clinical setting.

Modulation of the activities of catalase, cu-zn, mn superoxide dismutase, and glutathione peroxidase in adipocyte from ovariectomised female rats with metabolic syndrome

The aim of this study was to evaluate the association between estrogen removal, antioxidant enzymes, and oxidative stress generated by obesity in a MS female rat model. Thirty two female Wistar rats were divided into 4 groups: Control (C), MS, MS ovariectomized (Ovx), and MS Ovx plus estradiol (E2). MS was induced by administering 30% sucrose to drinking water for 24 weeks. After sacrifice, intra-abdominal fat was dissected; adipocytes were isolated and lipid peroxidation, non-enzymatic antioxidant capacity, and the activities of Cu-Zn and Mn superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GPx) were determined. There were no significant differences in the activities of Cu-Zn, Mn SOD, CAT, and GPx between the C and MS groups, but in the MS Ovx group there was a statistically significant decrease in the activities of these enzymes when compared to MS and MS Ovx+E2. The increased lipid peroxidation and nonenzymatic antioxidant capacity found in MS Ovx was significantly decreased when compared to MS and MS Ovx+E2. In conclusion, the removal of E2 by ovariectomy decreases the activity of the antioxidant enzymes in the intra-abdominal tissue of MS female rats; this is reflected by increased lipid peroxidation and decreased nonenzymatic antioxidant capacity.

Estrogen biology: new insights into GPER function and clinical opportunities

Estrogens play an important role in the regulation of normal physiology, aging and many disease states. Although the nuclear estrogen receptors have classically been described to function as ligand-activated transcription factors mediating genomic effects in hormonally regulated tissues, more recent studies reveal that estrogens also mediate rapid signaling events traditionally associated with G protein-coupled receptors. The G protein-coupled estrogen receptor GPER (formerly GPR30) has now become recognized as a major mediator of estrogen's rapid cellular effects throughout the body. With the discovery of selective synthetic ligands for GPER, both agonists and antagonists, as well as the use of GPER knockout mice, significant advances have been made in our understanding of GPER function at the cellular, tissue and organismal levels. In many instances, the protective/beneficial effects of estrogen are mimicked by selective GPER agonism and are absent or reduced in GPER knockout mice, suggesting an essential or at least parallel role for GPER in the actions of estrogen. In this review, we will discuss recent advances and our current understanding of the role of GPER and the activity of clinically used drugs, such as SERMs and SERDs, in physiology and disease. We will also highlight novel opportunities for clinical development towards GPER-targeted therapeutics, for molecular imaging, as well as for theranostic approaches and personalized medicine.

Comprehensive analysis of circulating adipokines and hsCRP association with cardiovascular disease risk factors and metabolic syndrome in Arabs

Background

Cardiovascular diseases (CVD) are a leading cause of death worldwide including the Middle East. This is caused in part by the dysregulation of adipose tissue leading to increased production of pro-inflammatory adipokines and reduction in cardio-protective adipokines such as adiponectin. Ethnicity has been recognized as a major factor in the association between CVD risk factors and the different circulating adipokines. In this study, for the first time, the relationship between traditional cardiovascular risk factors, Metabolic Syndrome (MetS) and circulating level of adipokines in Arab ethnicity was investigated.

Methods

We conducted a population-based cross-sectional survey on 379 adult Arab participants living in Kuwait. Traditional cardiovascular risk factors such as blood pressure (BP), low density lipoprotein (LDL) and triglyceride (TG) were measured. Plasma levels of circulating Leptin, Plasminogen Activator Inhibitor (PAI-1) visfatin, adiponectin, resistin and adipsin were assessed using the multiplexing immunobead-based assay.

Results

Circulating levels of High sensitivity C-Reactive Protein (hsCRP), Leptin, PAI-1 and adiponectin were significantly higher in Arab women than men (p < 0.0001). In multi-variate analysis, the homeostasis model assessment-insulin resistance (HOMA-IR) and body mass index (BMI) showed strong association with most of the biomarkers (p < 0.05). HsCRP showed significant association with all risk factors (p < 0.05). Leptin, PAI-1 and adipsin showed significant positive correlation with BMI, unlike adiponectin which showed inverse correlation (p < 0.05). Subjects in the highest tertile of leptin, PAI-1 and hsCRP had higher odds of having Metabolic Syndrome (MetS) (odd ratio [OR] = 3.02, 95% confidence interval [CI] = 1.47 – 6.19) and (OR = 2.52, 95% CI = 1.45 – 4.35), (OR = 4.26, 95% CI = 2.39 – 7.59) respectively. On the other hand subjects with highest tertile of adiponectin had lower odds of having MetS (OR = 0.22, 95% CI = 0.12 – 0.40). Leptin, PAI-1 and hsCRP showed significant positive association with increased MetS components (P-trend <0.05), while adiponectin was negatively associated with increased MetS components (P-trend <0.0001).

Conclusion

Our results show positive association between hsCRP, leptin, PAI-1 with increased MetS components and increase the odds of having MetS. Adiponectin on the other hand showed inverse correlation with MetS components and associated with reduction in MetS. Overall, our data highlights the significant clinical value these markers have in MetS especially hsCRP which can be used as good marker of low grade inflammation in Arabs.

Aldehyde dehydrogenase 1A1: friend or foe to female metabolism?

In this review, we summarize recent advances in understanding vitamin A-dependent regulation of sex-specific differences in metabolic diseases, inflammation, and certain cancers. We focus on the characterization of the aldehyde dehydrogenase-1 family of enzymes (ALDH1A1, ALDH1A2, ALDH1A3) that catalyze conversion of retinaldehyde to retinoic acid. Additionally, we propose a “horizontal transfer of signaling” from estrogen to retinoids through the action of ALDH1A1. Although estrogen does not directly influence expression of Aldh1a1, it has the ability to suppress Aldh1a2 and Aldh1a3, thereby establishing a female-specific mechanism for retinoic acid generation in target tissues. ALDH1A1 regulates adipogenesis, abdominal fat formation, glucose tolerance, and suppression of thermogenesis in adipocytes; in B cells, ALDH1A1 plays a protective role by inducing oncogene suppressors Rara and Pparg. Considering the conflicting responses of Aldh1a1 in a multitude of physiological processes, only tissue-specific regulation of Aldh1a1 can result in therapeutic effects. We have shown through successful implantation of tissue-specific Aldh1a1^−/− preadipocytes that thermogenesis can be induced in wild-type adipose tissues to resolve diet-induced visceral obesity in females. We will briefly discuss the emerging role of ALDH1A1 in multiple myeloma, the regulation of reproduction, and immune responses, and conclude by discussing the role of ALDH1A1 in future therapeutic applications.

Association between type 2 diabetes mellitus-related SNP variants and obesity traits in a Saudi population

Obesity, commonly measured as body mass index (BMI), has been on a rapid rise around the world and is an underlying cause of several chronic non-communicable diseases, including type 2 diabetes mellitus (T2DM). In addition to the environmental factors, genetic factors may also contribute to the ongoing obesity epidemic in Saudi Arabia. This study investigated the association between variants of 36 previously established T2DM SNPs and obesity phenotypes in a population of Saudi subjects. Study subjects consisted of 975 obese (BMI: ≥30), 825 overweight (25-30) and 423 lean controls (18-25) and of these 927 had a history of T2DM. Subjects were genotyped for 36 SNPs, which have been previously proved to be T2DM linked, using the KASPar method and the means of BMI and waist circumference (WC) corresponding to each of the genotypes were compared by additive, recessive and dominant genetic models. Five and seven of 36 T2DM-related SNPs were significantly associated with the BMI and WC, respectively. Variants of SNPs rs7903146, rs1552224 and rs11642841 in the control group and rs7903146 in T2DM group showed significant association with both BMI and WC. Variant of SNP rs10440833 was significantly associated with BMI in T2DM group of both males [OR = 1.8 (1.0, 3.3); P = 0.04] and females [OR = 2.0 (1.0, 3.9); P = 0.04]. Genetic risk scores explained 19 and 14% of WC and hip size variance in this population. Variants of a number of established T2DM related SNPs were associated with obesity phenotypes and may be significant hereditary factors in the pathogenesis of T2DM.

Sex differences in type 2 diabetes: focus on disease course and outcomes

BACKGROUND

Women with type 2 diabetes (T2D) are less likely to reach the goals for hemoglobin A1c compared with men, and have higher all-cause mortality. The risk of cardiovascular disease is elevated among both men and women with T2D, however, the risk has declined among men over recent years while it remains stationary in women. Reasons for these sex differences remain unclear, and guidelines for diabetes treatment do not differentiate between sexes. Possible causes for varying outcome include differences in physiology, treatment response, and psychological factors. This review briefly outlines sex differences in hormonal pathophysiology, and thereafter summarizes the literature to date on sex differences in disease course and outcome.

METHODS

Systematic searches were performed on PubMed using "sex", "gender", and various glucose-lowering therapies as keywords. Earlier reviews are summarized and results from individual studies are reported. Reference lists from studies were used to augment the search.

RESULTS

There is an increased risk of missing the diagnosis of T2D when screening women with only fasting plasma glucose instead of with an oral glucose tolerance test. The impact of various risk factors for complications may differ by sex. Efficacy and side effects of some glucose-lowering drugs differ between men and women. Men with T2D appear to suffer more microvascular complications, while women have higher morbidity and mortality in cardiovascular disease and also fare worse psychologically.

CONCLUSION

Few studies to date have focused on sex differences in T2D. Several questions demand further study, such as whether risk factors and treatment guidelines should be sex-specific. There is a need for clinical trials designed specifically to evaluate sex differences in efficacy and outcome of the available treatments.

Estrogen: a master regulator of bioenergetic systems in the brain and body

Estrogen is a fundamental regulator of the metabolic system of the female brain and body. Within the brain, estrogen regulates glucose transport, aerobic glycolysis, and mitochondrial function to generate ATP. In the body, estrogen protects against adiposity, insulin resistance, and type II diabetes, and regulates energy intake and expenditure. During menopause, decline in circulating estrogen is coincident with decline in brain bioenergetics and shift towards a metabolically compromised phenotype. Compensatory bioenergetic adaptations, or lack thereof, to estrogen loss could determine risk of late-onset Alzheimer's disease. Estrogen coordinates brain and body metabolism, such that peripheral metabolic state can indicate bioenergetic status of the brain. By generating biomarker profiles that encompass peripheral metabolic changes occurring with menopause, individual risk profiles for decreased brain bioenergetics and cognitive decline can be created. Biomarker profiles could identify women at risk while also serving as indicators of efficacy of hormone therapy or other preventative interventions.

Estrogen and mitochondria function in cardiorenal metabolic syndrome

The cardiorenal metabolic syndrome (CRS) consists of a constellation of cardiac, renal, and metabolic disorders including insulin resistance (IR), obesity, metabolic dyslipidemia, high-blood pressure, and evidence of early cardiac and renal disease. Mitochondria dysfunction often occurs in the CRS, and this dysfunction is promoted by excess reactive oxygen species, genetic factors, IR, aging, and altered mitochondrial biogenesis. Recently, it has been shown that there are important sex-related differences in mitochondria function and metabolic, cardiovascular, and renal components. Sex differences in the CRS have mainly been attributed to the estrogen's effects that are mainly mediated by estrogen receptor (ER) α, ERβ, and G-protein coupled receptor 30. In this review, we discuss the effects of estrogen on the mitochondrial function, insulin metabolic signaling, glucose transport, lipid metabolism, and inflammatory responses from liver, pancreatic β cells, adipocytes, skeletal muscle, and cardiovascular tissue.

The role of estrogen in adipose tissue metabolism: insights into glucose homeostasis regulation

Adipose tissue is an organ with active endocrine function involved in the regulation of energy balance and glucose homeostasis via multiple metabolic signaling pathways targeting the brain, liver, skeletal muscle, pancreas, and other organs. There is increasing evidence demonstrating that the female sex hormone, estrogen, regulates adipose development and improves systemic glucose homeostasis in both males and females. The underlying mechanism linking estrogenic regulation in adipose tissue and systemic glucose metabolism has not been fully elucidated, but is thought to include interactions of estrogen receptor signaling events involving lipolytic and/or lipogenic enzyme activity, free fatty acid metabolism, and adipocytokine production. Thus, understanding the effects of estrogen replacement on adipose tissue biology and metabolism is important in determining the risk of developing obesity-related metabolic disorders in patients undergoing treatment for sex hormone deficiency. In this report, we review literature regarding the role of estrogens and their corresponding receptors in the control of adipose metabolism and glucose homeostasis in both rodents and humans. We also discuss the effects of selective estrogen receptor modulators on glucose metabolism.

Mechanisms of estrogen effects on the endothelium: an overview

In this review, we aim to provide an overview of the recent advances in understanding estrogen effects on the vascular endothelium. Epidemiological studies suggest the female sex hormone estrogen mediates the relative protection of premenopausal women against cardiovascular disease, compared with age-matched men. However, results from clinical trials of exogenous estrogen supplementation in postmenopausal women have been disappointing, generating much controversy about the role of estrogen and demonstrating the need for further research in this field. Here we have discussed the roles of different estrogen receptors (ERs) such as ERα, ERβ, and G-protein coupled receptor 30; the complex genomic and nongenomic signalling pathways downstream to ER activation and the factors such as age, menopause, pregnancy, and diabetes that might alter estrogen responses. The common themes of this discussion are the complexity and diversity of endothelial estrogen responses and their modulation by 1 or more coexisting factors. Finally, we summarize the emerging therapeutic options including improved targeting of individual ERs and signalling pathways that might maximize the therapeutic potential of estrogenic compounds while minimizing their harmful side effects.

Prunus mume and Lithospermum erythrorhizon Extracts Synergistically Prevent Visceral Adiposity by Improving Energy Metabolism through Potentiating Hypothalamic Leptin and Insulin Signalling in Ovariectomized Rats

We investigated the antiobesity and hypoglycemic properties of Prunus mume Sieb. et Zucc (PMA; Japanese apricot) and Lithospermum erythrorhizon Sieb. et Zucc (LES; gromwell) extracts in ovariectomized (OVX) rats that impaired energy and glucose homeostasis. OVX rats consumed either 5% dextrose, 5% PMA extract, 5% LES extract, or 2.5% PMA+2.5% LES extract in the high fat diet. After 8 weeks of treatment, PMA+LES prevented weight gain and visceral fat accumulation in OVX rats by lowering daily food intake and increasing energy expenditure and fat oxidation. PMA+LES prevented the attenuation of leptin and insulin signaling by increasing the expression of leptin receptor in the hypothalamus in OVX rats. PMA+LES significantly reversed the decrease of energy expenditure in OVX rats by increasing expression of UCP-1 in the brown adipose tissues and UCP-2 and UCP-3 in the quadriceps muscles. PMA+LES also increased CPT-1 expression and decreased FAS, ACC, and SREBP-1c in the liver and quadriceps muscles to result in reducing triglyceride accumulation. PMA+LES improved insulin sensitivity in OVX rats. In conclusion, PMA+LES synergistically prevented the impairment of energy, lipid, and glucose metabolism by OVX through potentiating hypothalamic leptin and insulin signaling. PMA+LES may be a useful intervention for alleviating the symptoms of menopause in women.

Maladaptive immune and inflammatory pathways lead to cardiovascular insulin resistance

Insulin resistance is a hallmark of obesity, the cardiorenal metabolic syndrome and type 2 diabetes mellitus (T2DM). The progression of insulin resistance increases the risk for cardiovascular disease (CVD). The significance of insulin resistance is underscored by the alarming rise in the prevalence of obesity and its associated comorbidities in the Unites States and worldwide over the last 40-50 years. The incidence of obesity is also on the rise in adolescents. Furthermore, premenopausal women have lower CVD risk compared to men, but this protection is lost in the setting of obesity and insulin resistance. Although systemic and cardiovascular insulin resistance is associated with impaired insulin metabolic signaling and cardiovascular dysfunction, the mechanisms underlying insulin resistance and cardiovascular dysfunction remain poorly understood. Recent studies show that insulin resistance in obesity and diabetes is linked to a metabolic inflammatory response, a state of systemic and tissue specific chronic low grade inflammation. Evidence is also emerging that there is polarization of macrophages and lymphocytes towards a pro-inflammatory phenotype that contributes to progression of insulin resistance in obesity, cardiorenal metabolic syndrome and diabetes. In this review, we provide new insights into factors, such as, the renin-angiotensin-aldosterone system, sympathetic activation and incretin modulators (e.g., DPP-4) and immune responses that mediate this inflammatory state in obesity and other conditions characterized by insulin resistance.

Detection of an ABCA1 variant associated with type 2 diabetes mellitus susceptibility for biochemistry and genetic laboratory courses

We selected diabetes mellitus for this laboratory exercise to provide students with an explicit model for scientific research concerning the association between the R230C polymorphism and susceptibility to type 2 diabetes mellitus, which is highly prevalent in the Mexican population. We used a collaborative project-based learning to engage students to direct their own learning process. Students worked in small groups with the same learning goal to research, organize data, and present seminars to experimentally genotype the C230 variant and correctly interpret their results. At the conclusion of this laboratory exercise, the students were able to demonstrate a clear understanding of the relevant biological molecular principles to genotype the C230 variant, showed technical competency to carry out the experimental protocols with proficiency, and interpret their results using statistical analyses. The students discussed their understanding of the genetic technologies and the broader social and ethical implications of the research. A randomly selected team was trained to work as a "sentinel" to monitor their classmates and ensure the proper application of techniques. Moreover, the evaluation of this exercise is shared between the students and the instructors; the students evaluate their own work and the performance of their classmates. At the end of the course, the students complete a questionnaire to anonymously provide feedback and information regarding their perception of the learning outcomes. Overall, the student feedback was positive, indicating that the exercise was useful and that it would help to prepare the students for professional practice.

The role of tissue Renin-Angiotensin-aldosterone system in the development of endothelial dysfunction and arterial stiffness

Epidemiological studies support the notion that arterial stiffness is an independent predictor of adverse cardiovascular events contributing significantly to systolic hypertension, impaired ventricular-arterial coupling and diastolic dysfunction, impairment in myocardial oxygen supply and demand, and progression of kidney disease. Although arterial stiffness is associated with aging, it is accelerated in the presence of obesity and diabetes. The prevalence of arterial stiffness parallels the increase of obesity that is occurring in epidemic proportions and is partly driven by a sedentary life style and consumption of a high fructose, high salt, and high fat western diet. Although the underlying mechanisms and mediators of arterial stiffness are not well understood, accumulating evidence supports the role of insulin resistance and endothelial dysfunction. The local tissue renin-angiotensin-aldosterone system (RAAS) in the vascular tissue and immune cells and perivascular adipose tissue is recognized as an important element involved in endothelial dysfunction which contributes significantly to arterial stiffness. Activation of vascular RAAS is seen in humans and animal models of obesity and diabetes, and associated with enhanced oxidative stress and inflammation in the vascular tissue. The cross talk between angiotensin and aldosterone underscores the importance of mineralocorticoid receptors in modulation of insulin resistance, decreased bioavailability of nitric oxide, endothelial dysfunction, and arterial stiffness. In addition, both innate and adaptive immunity are involved in this local tissue activation of RAAS. In this review we will attempt to present a unifying mechanism of how environmental and immunological factors are involved in this local tissue RAAS activation, and the role of this process in the development of endothelial dysfunction and arterial stiffness and targeting tissue RAAS activation.

Biomarkers of diabetes risk in the National Diet and Nutrition Survey rolling programme (2008-2011)

This study describes the distribution of glycosylated haemoglobin (Hb_A1c) and glucose concentrations in the combined year 1 (2008–2009), year 2 (2009–2010) and year 3 (2010–2011) of the National Diet and Nutrition Survey (NDNS) rolling programme. The NDNS rolling programme is a nationally representative survey of food consumption, nutrient intakes and nutritional status of people aged 1.5 years and over living in England, Wales, Scotland and Northern Ireland. The study population comprised survey members who completed three or four days of dietary recording and who provided a blood sample. After excluding survey members with self-reported diabetes (n=25), there were 1016 results for Hb_A1c and 942 for glucose (not the same individuals in each case). Around 5.4% of men and 1.7% of women aged 19–64 years, and 5.1% of men and 5.9% of women aged ≥65 years had impaired fasting glucose (glucose concentrations 6.1–6.9 mmol/L). Over 20% of men aged ≥65 years had fasting glucose concentrations above the clinical cut-off for diabetes (≥7 mmol/L) compared to 2.1% of women of similar age (p=0.007). Similarly, 16.4% of men had Hb_A1c concentrations ≥6.5%, compared to 1.5% of women (p=0.003). Children and teenagers had fasting glucose and Hb_A1c values largely within the normal range. To conclude, this is the first study to provide data on the distribution of Hb_A1c and glucose concentrations in a nationally representative sample of the British population. The high prevalence of men aged ≥65 years with Hb_A1c and glucose concentrations above the clinical cut-off of diabetes warrants further attention.

Life satisfaction and risk of chronic diseases in the European prospective investigation into cancer and nutrition (EPIC)-Germany study

OBJECTIVE

The aim of the study was to examine the prospective association between life satisfaction and risk of type 2 diabetes mellitus, myocardial infarction, stroke, and cancer. Previous studies suggested that psychosocial factors may affect the development of chronic diseases but the impact of positive attitudes, in particular life satisfaction, is yet to be determined.

METHODS

The analysis included 50,358 participants of the European Prospective Investigation into Cancer and Nutrition (EPIC)-Germany study in Potsdam and Heidelberg. Life satisfaction was assessed in a baseline interview and incident cases of chronic diseases were identified and verified during follow-up. Hazard ratios were calculated using Cox proportional hazards regression models that were systematically multivariable-adjusted for established risk factors and prevalent diseases.

RESULTS

During an average of 8 years of follow-up 2,293 cases of cancer, 1,840 cases of type 2 diabetes mellitus, 440 cases of stroke, and 562 cases of myocardial infarction were observed. Women who were unsatisfied with life at baseline showed in all models a significantly increased risk of cancer (HR: 1.45; 95% CI: 1.18-1.78) and stroke (HR: 1.69; 95% CI: 1.05-2.73) as well as an increased risk of type 2 diabetes mellitus by trend across categories (p-trend=0.04) compared to women very satisfied with life. In men, a relationship between life satisfaction and stroke was found but did not persist after consideration of lifestyle factors and prevalent diseases. No significant association was observed between life satisfaction and risk of myocardial infarction.

CONCLUSIONS

The results of this study suggest that reduced life satisfaction is related to the development of chronic diseases--particularly in women and partly mediated by established risk factors.