Higher Insulin Concentrations Research Articles

Improving human mesenchymal stem cell-derived hepatic cell energy metabolism by manipulating glucose homeostasis and glucocorticoid signaling.

The development of reliable hepatic in vitro models may provide insights into disease mechanisms, linking hepatocyte dysmetabolism and related pathologies. However, several of the existing models depend on using high concentrations of hepatocyte differentiation-promoting compounds, namely glucose, insulin, and dexamethasone, which is among the reasons that have hampered their use for modeling metabolism-related diseases. This work focused on modulating glucose homeostasis and glucocorticoid concentration to improve the suitability of a mesenchymal stem-cell (MSC)-derived hepatocyte-like cell (HLC) human model for studying hepatic insulin action and disease modeling. We have investigated the role of insulin, glucose and dexamethasone on mitochondrial function, insulin signaling and carbohydrate metabolism, namely AKT phosphorylation, glycogen storage ability, glycolysis and gluconeogenesis, as well as fatty acid oxidation and bile acid metabolism gene expression in HLCs. In addition, we evaluated cell morphological features, albumin and urea production, the presence of hepatic-specific markers, biotransformation ability and mitochondrial function. Using glucose, insulin and dexamethasone levels close to physiological concentrations improved insulin responsiveness in HLCs, as demonstrated by AKT phosphorylation, upregulation of glycolysis and downregulation of Irs2 and gluconeogenesis and fatty acid oxidation pathways. Ammonia detoxification, EROD and UGT activities and sensitivity to paracetamol cytotoxicity were also enhanced under more physiologically relevant conditions. HLCs kept under reduced concentrations of glucose, insulin and dexamethasone presented an improved hepatic phenotype and insulin sensitivity demonstrating superior potential as an in vitro platform for modeling energy metabolism-related disorders, namely for the investigation of the insulin signaling pathway.

Abnormal prolactin secretion is associated with changes in metabolic health biomarkers in acyclic female African elephants (Loxodonta africana)

Circulating prolactin aberrations (chronically high or low concentrations) have been shown to have strong associations with ovarian dysfunction in African female elephants. However, despite the well-established pleiotropic role that prolactin plays in human health, comprehensive metabolic effects from chronically elevated or suppressed prolactin have yet to be investigated in this species. In humans, in addition to amenorrhea, hyperprolactinemic women have shown increased risks for accelerated atherosclerosis, hyperandrogenemia, lowered metabolism, and insulin resistance. The aim of the study was to determine if elephants with long-term abnormal prolactin secretion were also experiencing alterations in metabolic biomarkers. One year of serum samples, collected biweekly, were obtained from female African elephants (n = 74) housed in North American zoos and categorized based on ovarian cyclicity and prolactin status: normal cycling, normal prolactin (NORMAL, n = 25), acyclic, high prolactin (HIGH, n = 25), or acyclic, low prolactin (LOW, n = 24). Each sample was further analyzed for measures of metabolic function, glucose metabolism, and cardiovascular health. Overall, thyroid hormones were significantly lower in both HIGH (TSH, T3, T4) and LOW (TSH) prolactin elephants compared to NORMAL counterparts. Additionally, HIGH prolactin elephants exhibited lower glucose, G:I ratios, and low-density lipoprotein values, but higher cholesterol concentrations compared to normal cycling females. Overall, LOW prolactin elephants exhibited higher body condition scores and G:I ratios, and higher concentrations of insulin, high-density lipoproteins, cortisol and testosterone, but decreased triglyceride values compared to NORMAL elephants in the study. Data suggest that HIGH prolactin elephants may be experiencing hypothyroidism as a comorbidity, whereas LOW prolactin elephants may be exhibiting aspects of insulin resistance, albeit different from human clinical data. Specific studies are suggested that would help elucidate the underlying mechanisms at play and increase our understanding of prolactin’s role in elephant physiology.

Appetite-regulating hormones modulate odor perception and odor-evoked activity in hypothalamus and olfactory cortices.

Odors guide food seeking, and food intake modulates olfactory function. This interaction is mediated by appetite-regulating hormones like ghrelin, insulin, and leptin, which alter activity in the rodent olfactory bulb, but their effects on downstream olfactory cortices have not yet been established in humans. The olfactory tract connects the olfactory bulb to the cortex through 3 main striae, terminating in the piriform cortex (PirC), amygdala (AMY), olfactory tubercule (OT), and anterior olfactory nucleus (AON). Here, we test the hypothesis that appetite-regulating hormones modulate olfactory processing in the endpoints of the olfactory tract and the hypothalamus. We collected odor-evoked functional magnetic resonance imaging (fMRI) responses and plasma levels of ghrelin, insulin, and leptin from human subjects (n = 25) after a standardized meal. We found that a hormonal composite measure, capturing variance relating positively to insulin and negatively to ghrelin, correlated inversely with odor intensity ratings and fMRI responses to odorized vs. clean air in the hypothalamus, OT, and AON. No significant correlations were found with activity in PirC or AMY, the endpoints of the lateral stria. Exploratory whole-brain analyses revealed significant correlations near the diagonal band of Broca and parahippocampal gyrus. These results demonstrate that high (low) blood plasma concentrations of insulin (ghrelin) decrease perceived odor intensity and odor-evoked activity in the cortical targets of the medial and intermediate striae of the olfactory tract, as well as the hypothalamus. These findings expand our understanding of the cortical mechanisms by which metabolic hormones in humans modulate olfactory processing after a meal.

LBSUN294 Insulin-induced Abdominal Acanthosis Nigricans From High Doses Of Insulin U-500

Abstract Introduction Dermatological complications associated with insulin therapy include lipoatrophy, lipohypertrophy, and acanthosis nigricans. We have a rare case of severe acanthosis nigricans from repeated insulin injection. Case A 63-year-old man with diabetes mellitus type 2 presented with an elevated blood glucose of 584mg/dL. He reported "high" glucose levels, despite adherence to his insulin regimen. He only injected insulin in his abdomen. Over 20 years, his insulin doses increased from Lantus 65 units BID and Humalog 35 units TID to Lantus units 110 BID and Humalog 65 units TID. It was later changed to U-500 at 160 units TID. His Hba1c ranged from 10.7% to 15.4%, most recently 13.6%. Physical examination revealed hyperpigmented and thickened plaques, localized to two large areas lateral to his umbilicus. During his hospital stay, insulin was administered on his arms and thighs. Glucose levels improved on Levemir 55 units daily and Lispro 20 units TID. He was discharged on Insulin U-500 40 units TID with instructions to avoid injecting on his abdomen and to rotate injection sites. Discussion Acanthosis nigricans is associated with insulin resistance or hyperinsulinemia. Insulin has a similar structure to insulin-like growth factor (IGF-1). At higher insulin concentrations, it can bind to IGF-1 receptors on keratinocytes and fibroblasts, leading to skin proliferation. Other suggested mechanisms include the involvement of fibroblast and epidermal growth factor. Histopathological findings show hyperkeratosis, papillomatosis, and thickened dermis. Immunochemical findings show positive IGF-1 antibodies in basal epithelial and prickle cell layers. In patients with poor glycemic control and increasing doses of insulin, it is important to assess for insulin-related skin changes. Besides routine visual inspection, skin thickening can be assessed by stroking the skin side-to-side in a sweeping motion instead of palpation. Conclusion Our patient with poorly type 2 diabetes required escalating doses of insulin over the years. He developed severe acanthosis nigricans on his abdomen leading to poor absorption of insulin. This case highlights the importance of routine visual inspection and tactile examination of insulin injection sites for skin changes, as well as repeated counseling regarding insulin site rotation.

PSUN237 Hirata's Disease: A rare case of IAS in An African-American

Abstract Background Endogenous insulin autoimmune syndrome (IAS), also known as Hirata's disease, is a rare condition characterized by hypoglycemic episodes due to the presence of high titers of insulin autoantibodies. It is a form of immune-mediated hypoglycemia and can be induced with certain medications or vital infection. Often misdiagnosed or late diagnosis after extensive workup. IAS is more prevalent in people of Asian heritage, more specifically Japanese individuals, and rarely seen in Caucasians. We present a case of IAS in an African-American man.Clinical case: 51 years old African-American man with high blood pressure and marijuana use presented to the Emergency Department after a syncopal episode. He stated to have recurrent episodes of fatigue, lightheadedness, blurred vision and diaphoresis mostly within 4-5 hours post-prandial or early morning and improved with food intake. He was not taking any medication or supplementation which can cause hypoglycemia. He was found to be tachycardic with blood glucose of 25 mg/dl, treated with IV dextrose and admitted with hypoglycemia. Endocrinology service recommended to obtain insulin, c-peptide, proinsulin, hydroxybutyrate, screen for oral hypoglycemic agents during hypoglycemic episode. His blood glucose decreased to 27 mg/dL within 6 hours of fasting and work-up was completed. Significant laboratory data revealed; insulin 1000 μIU/ml (2.6-24.9), c-peptide 7 ng/dL (1.1 - 4.4), proinsulin 229.7 mmol/L (0.0-10.0), beta hydroxybutyrate acid 0.09 mmol/L (0.02-0.27), insulin receptor antibody 173 nU/ml (<95), screen of hypoglycemic agent Negative. Conclusion The pathogenesis of IAS has not been fully understood. Interaction of a genetic predisposition with environmental triggers leads to the production of insulin autoantibodies. Incidence of IAS is higher in Asia compared to the western countries. Medications (methimazole, alpha-lipoic acid) and viral infections (measles, mump, rubella, varicella, coxsackie, HCV) are shown to trigger the development of IAS. Although rare, IAS should be suspected in any patient presenting with hypoglycemia in order to avoid any unnecessary diagnostic and therapeutic procedure. Patients with IAS has extremely high insulin concentrations, often above 170 μIU/ml which is a rare finding in other forms of endogenous hyperinsulinemic hypoglycemia. The measurement of insulin autoantibodies is mandatory for the diagnosis of IAS since it is the only lab test that allows a reliable diagnosis. Once confirmed, the patients should be evaluated carefully in order to assess the indication to pharmacologic therapy however no study have currently compared different treatment regimens. No data regarding its survival rate are currently available. Initial clinical suspicion of IAS can avoid unnecessary costs associated with imaging examinations and/or invasive surgical procedures.

Hyper-glycemia and insulinemia induce morphological changes and modulate secretion of S100B, S100A8, amyloid β 1–40 and amyloid β 1–42, in a model of human dopaminergic neurons

Glucose metabolism in neuronal tissue declines during neurodegenerative disorders in a progressive, region-specific, and disease-specific manner. Studies have shown that extracellular hyper-glycemia affects the functioning of adenosine triphosphate (ATP) sensitive potassium channels located in neurons and astrocytes. Also, hyper-insulinemia contributes to the formation and progression of Alzheimer’s disease (AD) via competition with amyloid β (Aβ) for insulin-degrading enzyme. Aβ disruption is phosphatidylinositol 3-kinase pathway dependent, and increased circulatory insulin concentrations lead to Aβ accumulation. In 2008, based on assessment of brain glucose utilization disorders and insulin signaling disruptions, it was proposed that AD could be called "type III diabetes". Proteins from the S100 family are actively secreted during metabolic and oxidative stress, but their role in neuronal cells has yet to be clarified. However, it has been demonstrated that they act in a dose-dependent manner, which may be crucial in the modulation of glucose and insulin metabolism in the brain. The goal of this paper was to elucidate the association between high glucose and insulin concentrations with extra- and intracellular S100B and S100A8 proteins levels as well as the correlation with toxic (Aβ42) and physiologic (Aβ40) forms of Aβ. Medium and high glucose concentrations mimicking pre-diabetic and diabetic state, caused statistically significant discharge of S100b and S100A8 protein to the extracellular compartment. Similar effect was observed after 50 nM insulin incubation. Furthermore, the correlation coefficient patterns between those proteins shows similar associations which highlights possible effective and modulating role of S100 family in the metabolic disturbances occurring in neuropathological disorders.

Association between vitamin D serum levels and insulin resistance assessed by HOMA-IR among non-diabetic adults in the United States: Results from NHANES 2007-2014.

Insulin resistance, a pathological response to insulin hormone in insulin-dependent cells, is characterized by the presence of high glucose and insulin concentrations. The homeostasis model of insulin resistance (HOMA-IR) is one of the most used indexes to estimate insulin resistance by assessing the fasting glucose and insulin levels. An association was observed between vitamin D levels and insulin resistance, which varied in different ethnic groups, and there is some evidence that vitamin D supplementation could contribute to the improvement of insulin resistance. This study assessed the association between 25-hydroxyvitamin D (25[OH]D) concentration and HOMA-IR in American adults aged 20 years and older, without diabetes and other chronic diseases that can influence insulin resistance. The data from the National Health and Nutrition Examination Survey (NHANES) 2007–2014 were used by exploiting the free and publicly-accessible web datasets. Linear regression models were performed to evaluate the association between serum 25(OH)D concentration and HOMA-IR, and a negative association was observed, which remained significant following the adjustment for age, gender, race/ethnicity, education, body mass index (BMI), physical activity, the season of examination, current smoking, hypertension, the use of drugs which can influence insulin resistance, serum bicarbonates, triglycerides, and calcium and phosphorus levels. Only in non-Hispanic Blacks was this inverse association between vitamin D and HOMA-IR not observed in the fully adjusted model. Further studies are needed to explain the mechanisms of the observed ethnic/racial differences in the association of vitamin D levels with HOMA-IR.

Age-dependent effect of insulin in the regulation of intracellular calcium in ventricular cardiomyocytes.

In this study, we wanted to verify whether the effect of insulin on calcium homeostasis depends on the heart's development stage. Using a quantitative 3D confocal microscopy, we tested the effect of a high insulin concentration (100 µU) in freshly cultured ventricular cardiomyocytes from newborn and adult rats. Our results showed that the cytosolic basal level of calcium was higher in newborn cardiomyocytes with no change in the nuclear basal calcium level compared with the adult cardiomyocytes; in addition, insulin induced a slow increase of cytosolic and nuclear calcium in newborn ventricular cardiomyocytes, followed by two phases. However, the first phase of slow cytosolic and nuclear calcium increase was absent in adult rat ventricular cardiomyocytes. Furthermore, the time to the onset of increase of cytosolic and nuclear calcium was longer in newborn cardiomyocytes compared with adults. Moreover, the time to peak of the calcium transient was shorter in newborns than in adult cardiomyocytes. These results demonstrate that insulin differently regulates calcium homeostasis in newborns than in adult cardiomyocytes. Thus, newborn rat cardiomyocytes, commonly used in research as a model for adult cardiomyocytes, should be used with caution when dealing with insulin in normal and disease conditions.

Temporal evaluation of follicular dynamics and endocrine patterns of Holstein (Bos taurus), Gir (Bos indicus), and Murrah (Bubalus bubalis) heifers kept under the same nutritional, management and environmental conditions

The objective of the study was to simultaneously compare ovarian follicular dynamics and endocrine parameters of taurine (Holstein; n = 14), zebuine (Gir; n = 5), and bubaline (Murrah; n = 15) heifers kept under the same environmental, nutritional and management conditions. Heifers were synchronized with two PGF treatments 14 days apart. Ovaries of cyclic heifers were scanned daily during two consecutive ovulations and blood samples were collected every 24 h from each animal. No significant difference was found for length of interovulatory interval, however, zebuine heifers presented a greater number of follicular waves, number of antral follicles on day of ovulation, and higher insulin concentration than the other two breeds. Taurine heifers had highest maximal diameter of first wave dominant and ovulatory follicles and CL volume. Taurine and bubaline heifer's dominant follicle of first wave had longer static and regression phases than zebuine heifers. Bubaline heifers presented overall lowest progesterone concentrations and CL volume, but higher IGF1 levels. No difference was observed between taurine and zebuine heifers regarding IGF1 concentration. Despite higher CL volume found in taurine heifers, no difference in mean progesterone concentration was observed between them and zebuine heifers. Insulin and IGF1 concentrations were greater in follicular phase than in luteal phase when breed was not evaluated. After evaluating the three breeds simultaneously, at the same nutritional and management status it is possible to conclude that each genetic group has a specific follicular development and endocrinology of the estrous cycle.

1336-P: FoxO1-ATGL-Sirt1-FoxO1 Feed Forward Signaling Mediates Effects on Hepatic Gene Expression and Glucose Homeostasis in LIRKO Mice

FoxO1 is a major target of insulin action and regulates expression of ATGL and its inhibitor, G0S2, in the liver (Cell Rep 15:349, 2016) . Here, we asked whether ATGL mediates effects of FoxO1 in liver-specific insulin receptor knockout (LIRKO) mice. Studies in LIRKO and IR/FoxO1 double knockout (LIRFKO) mice show ATGL expression is increased and G0S2 is suppressed in a FoxO1-dependent fashion when insulin signaling is disrupted in the liver. ATGL knockdown (KD) reduces high plasma glucose and insulin concentrations, HOMA-IR and fatty acid oxidation, and improves glucose tolerance in LIRKO mice. Hyperinsulinemic-euglycemic clamp studies show ATGL KD improves insulin sensitivity due to effects on both HGP and glucose utilization, reflecting changes in WAT lipolysis, BAT metabolism and hepatic gene expression. The expression of FoxO1-regulated gluconeogenic genes (PEPCK, G6Pase, PCO, PGC-1α) , hepatokines (e.g., follistatin) and IGFBP-1 is increased in LIRKO mice and reduced by ATGL KD, reflecting changes in acetylation of FoxO1 and its co-activator, PGC-1α (decreased in LIRKO, increased by ATGL KD) . Rictor acetylation, which promotes activation of Akt and phosphorylation of FoxO1, also is increased by ATGL KD in LIRKO mice and isolated hepatocytes. Since ATGL promotes activation of Sirt1 (Mol Cell 77:810, 2020) and Sirt1 deacetylates FoxO1, PGC-1α and rictor, these studies suggest FoxO1 promotes increased ATGL and Sirt1 activity, and that Sirt1 activation enhances the effects of FoxO1 on gene expression and glucose homeostasis in a feed forward fashion (FoxO1 -> ATGL -> Sirt1 -> FoxO1) . Targeting the FoxO1/ATGL/Sirt1 pathway may provide a useful strategy for improving glucose homeostasis when insulin signaling is impaired in the liver. Disclosure I.O-sullivan: None. S.Bhattacharyya: None. C.Liew: None. S.M.Lee: None. J.Cordoba-chacon: None. R.J.Perry: None. G.I.Shulman: Advisory Panel; 89bio, Inc., AstraZeneca, Equator Therapeutics, Inc., Janssen Research & Development, LLC, Merck & Co., Inc., Consultant; DiCerna Pharmaceuticals, Inc., Novo Nordisk, Other Relationship; Generian Pharmaceuticals, iMetabolic Biopharma Corporation, Maze Therapeutics, The Liver Company, Stock/Shareholder; Levels Health, Inc. . T.Unterman: None. Funding Department of Veterans Affairs (5I01BX001968)

Effects of Bromocriptine on Glucose and Insulin Dynamics in Normal and Insulin Dysregulated Horses.

The objectives of the study were to study the effects of the synthetic ergot alkaloid (EA), bromocriptine, on glucose and lipid metabolism in insulin dysregulated (ID, n = 7) and non-ID (n = 8) mares. Horses were individually housed and fed timothy grass hay and two daily concentrate meals so that the total diet provided 120% of daily DE requirements for maintenance. All horses were given intramuscular bromocriptine injections (0.1 mg/kg BW) every 3 days for 14 days. Before and after 14 days of treatment horses underwent a combined glucose-insulin tolerance test (CGIT) to assess insulin sensitivity and a feed challenge (1 g starch/kg BW from whole oats) to evaluate postprandial glycemic and insulinemic responses. ID horses had higher basal plasma concentrations of insulin (P = 0.01) and triglycerides (P = 0.02), and lower concentrations of adiponectin (P = 0.05) compared with non-ID horses. The CGIT response curve showed that ID horses had slower glucose clearance rates (P = 0.02) resulting in a longer time in positive phase (P = 0.03) and had higher insulin concentrations at 75 min (P = 0.0002) compared with non-ID horses. Glucose (P = 0.02) and insulin (P = 0.04) responses to the feeding challenge were lower in non-ID compared to ID horses. Regardless of insulin status, bromocriptine administration increased hay intake (P = 0.03) and decreased grain (P < 0.0001) and total DE (P = 0.0002) intake. Bromocriptine treatment decreased plasma prolactin (P = 0.0002) and cholesterol (P = 0.10) and increased (P = 0.02) adiponectin concentrations in all horses. Moreover, in both groups of horses, bromocriptine decreased glucose clearance rates (P = 0.02), increased time in positive phase (P = 0.04) of the CGIT and increased insulin concentrations at 75 min (P = 0.001). The postprandial glycemic (P = 0.01) and insulinemic (P = 0.001) response following the oats meal was lower after bromocriptine treatment in all horses. In conclusion, in contrast to data in humans and rodents, bromocriptine treatment reduced insulin sensitivity in all horses, regardless of their insulin status. These results indicate that the physiological effects of EA might be different in horses compared to other species. Moreover, because bromocriptine shares a high degree of homology with natural EA, further investigation is warranted in horses grazing endophyte-infected grasses.

Behavior of Regular Insulin in a Parenteral Nutrition Admixture: Validation of an LC/MS-MS Assay and the In Vitro Evaluation of Insulin Glycation.

Parenteral-nutrition (PN)-induced hyperglycemia increases morbidity and mortality and must be treated with insulin. Unfortunately, the addition of insulin to a ternary PN admixture leads to a rapid decrease in insulin content. Our study’s objective was to determine the mechanistic basis of insulin’s disappearance. The literature data suggested the presence of a glycation reaction; we therefore validated an LC-MS/MS assay for insulin and glycated insulin. In a 24-h stability study, 20 IU/L of insulin was added to a binary PN admixture at pH 3.6 or 6.3. When the samples were diluted before analysis with a near-neutral diluent, insulin was fully stable at pH 3.6, while a loss of around 50% was observed at pH 6.3. Its disappearance was shown to be inversely correlated with the appearance of monoglycated insulin (probably a Schiff base adduct). Monoglycated insulin might also undergo a back-reaction to form insulin after acidic dilution. Furthermore, a second monoglycated insulin species appeared in the PN admixture after more than 24 h at high temperature (40 °C) and a high insulin concentration (1000 IU/L). It was stable at acidic pH and might be an Amadori product. The impact of insulin glycation under non-forced conditions on insulin’s bioactivity requires further investigation.

Combined Effects of High-Intensity Aerobic Exercise Training and Ziziphus jujuba Extract on Tissue Nesfatin-1 in Rats.

Nesfatin-1 is involved in metabolic/feeding regulation and prevention of cardiovascular disease. Previous studies have shown that exercise and herb supplementation can influence nesfatin-1 concentration. The present study investigated the effects of high-intensity training (HIT) and Ziziphus jujuba (ZJ) extract on tissue nesfatin-1 in rats. Twenty-eight female rats were randomly assigned to one of four groups i.e. 1) Saline-Control (SC), 2) Saline-High Intensity Training (ST), 3) Ziziphus jujuba-Control (ZJC), and 4) Ziziphus jujuba-High Intensity Training (ZJT). Rats performed exercise on a treadmill and/or administered supplements intragastrically for 6 weeks, depending on group category. Seventy-two hours after the last training session, rats were anesthetized. Blood, hypothafi 2lamus tissue, heart and gastrocnemius muscles were sent to the laboratory for analyses. Significantly higher nesfatin-1 gene expression and concentration and ATP concentration were found in trained rat. HIT increased plasma High Density Lipoprotein (HDL) and insulin concentration and reduced plasma Triglyceride (TG) and cortisol. ZJ increased tissue nesftain-1 gene expression and concentration while only increasing heart ATP. The combination of exercise and ZJ showed an additive effect compared to each intervention alone on hypothalamus, heart and gastrocnemius NUCB2 gene expression, heart and gastrocnemius nesfatin-1 concentration, plasma HDL and cortisol concentration. The authors recommend both interventions as a means to improve cardiovascular health in rats with further work needed to confirm similar findings in homo sapiens.

Abstract P157: Racial Differences In Atrial Natriuretic Peptide And Insulin

Low circulating concentrations of the natriuretic peptides (NPs) have been associated with greater risk for Type 2 diabetes (T2D). As a group, African Americans (AA) have lower NP levels and are disproportionately burdened by T2D. Insulin, which is higher in AA, has been shown to regulate NP concentration by increasing the NP clearance receptor. This secondary analysis tests the hypothesis that higher insulin in AA will be associated with lower levels of plasma N-terminal pro-atrial natriuretic peptide (NT-proANP). Participants were 120 AA and European American (EA) men and women ages 19-45 years. Measures of insulin, including fasting insulin and insulin total and incremental area under the curve (AUC and iAUC, respectively, at 30 and 120 m), were derived from an oral glucose tolerance test (OGTT). Insulin sensitivity (SI Clamp ) was assessed using the euglycemic glucose clamp. NT-proANP was measured from fasting samples obtained during the OGTT. Differences in NT-proANP by race was evaluated with analysis of covariance while adjusting for age, sex, and BMI. Linear regression models were used to examine associations between NT-proANP and insulin measures while adjusting for age, sex, race, and BMI. Relative to EA, AA had higher insulin concentrations, lower insulin sensitivity, and lower NT-proANP levels (p&lt;0.05). Fasting insulin and 30 m insulin AUC were inversely associated with NT-proANP (p=0.02, p=0.02, and p=0.04, respectively). These results suggest that the lower NT-proANP observed in AA is related to higher insulin. Future research is needed to investigate the relationship between insulin, ANP, and the NP clearance receptor, particularly in populations at risk for chronic disease.

Impact of Genetic Risk Score and Dietary Protein Intake on Vitamin D Status in Young Adults from Brazil.

Given the relationship between vitamin D deficiency (VDD) and adverse outcomes of metabolic diseases, we investigated the interplay of dietary and genetic components on vitamin D levels and metabolic traits in young adults from Brazil. Genetic analysis, dietary intake, and anthropometric and biochemical measurements were performed in 187 healthy young adults (19–24 years). Genetic risk scores (GRS) from six genetic variants associated with vitamin D (vitamin D-GRS) and 10 genetic variants associated with metabolic disease (metabolic-GRS) were constructed. High vitamin D-GRS showed a significant association with low 25(OH)D concentrations (p = 0.001) and high metabolic-GRS showed a significant association with high fasting insulin concentrations (p = 0.045). A significant interaction was found between vitamin D-GRS and total protein intake (g/day) (adjusted for non-animal protein) on 25(OH)D (pinteraction = 0.006), where individuals consuming a high protein diet (≥73 g/d) and carrying >4 risk alleles for VDD had significantly lower 25(OH)D (p = 0.002) compared to individuals carrying ≤4 risk alleles. Even though our study did not support a link between metabolic-GRS and vitamin D status, our study has demonstrated a novel interaction, where participants with high vitamin D-GRS and consuming ≥73 g of protein/day had significantly lower 25(OH)D levels. Further research is necessary to evaluate the role of animal protein consumption on VDD in Brazilians.

Development of in vitro three-dimensional drug screening system for obesity-related metabolic syndrome

Metabolic syndrome is increasingly common, and closely related with overweight or obesity. In the obese state, macrophages infiltrate to the adipose tissue (AT), resulting in chronic inflammation and insulin resistance in the AT cells. Recently, attention has been paid to the role of AT macrophages in metabolic disorders should be applied to the initial drug screening step, but it was difficult to mimic the inflammatory adipocytes using the traditional 2-dimensional (2D) culture. In this study, we developed the 3-dimensional (3D) culture system to overcome this limitation. After adipogenic differentiation, lipid droplets were highly accumulated in cells, and differentiation of preadipocytes was not declined by macrophage co-culture. However, only co-cultured cells expressed the insulin resistance features. Compare to mono-cultured adipocytes, co-cultured adipocytes showed reduced glucose uptake and GLUT4 did not translocated to cell membrane even though treatment of high concentration of insulin. Using 3D co-culture model, we develop a microwell-scale drug screening protocol to test anti-obesity effect. 3D cultured cells reacted more sensitive to drugs, and PPARγ antagonist GW9662 (10, 20 μM) repressed adipogenic differentiation in a concentration-dependent manner in 3D co-cultured cells.

Structural characterization and tartary buckwheat polysaccharides alleviate insulin resistance by suppressing SOCS3-induced IRS1 protein degradation

Tartary buckwheat is an alternative cereal crop. This study sought to establish the mechanisms whereby tartary buckwheat root polysaccharide (TBRP-1) treatment can alleviate diabetes mellitus. TBRP-1 was extracted and purified by hot water and gel permeation column chromatography. Its structure was determined by Fourier transform-infrared spectroscopy (FT-IR), monosaccharide analysis, and nuclear magnetic resonance (NMR) spectroscopy. TBRP-1 was composed of fucose, arabinose, rhamnose, galactose, glucose, xylose, mannose, galacturonic acid, and glucuronic acid. The molecular weight was 2.731 × 104 Da. In addition, for in vitro, HepG2 cells were treated with high insulin concentrations to establish a model of insulin resistance. For in vivo modeling, diabetic mice were established by injecting with streptozotocin (STZ). Body weight, blood glucose levels, glycosylated hemoglobin (HbA1c) levels, and changes in hepatic lipids were analyzed. The expression of suppressor of cytokine signaling 3 (SOCS3), insulin receptor substrate 1 (IRS1), and glucose transporter type 4 (GLUT4) was assessed via qPCR and western blotting. TBRP-1 treatment was sufficient to enhance the ability of insulin resistant HepG2 cells to take up glucose. TBRP-1 also lowered levels of blood glucose, HbA1c, and hepatic lipids in diabetic mice. The underlying molecular mechanisms suggested that TBRP-1 was able to suppress SOCS3 expression to thereby enhance IRS1 expression, thus alleviating insulin resistance.

Intrapancreatic accessory spleen mimicking pancreatic insulinoma with intrapancreatic metastasis in a cat.

An 11-year-old neutered male Domestic Shorthair cat presented with a 3-month history of hypoglycemia, two episodes of seizure, and intermittent tick-like signs. Serum biochemistry revealed severe hypoglycemia associated with high insulin concentrations. Dynamic abdominal computed tomography (CT) indicated two pancreatic masses, which were enhanced most during the late arterial phase but had different degrees and variations of attenuation. Partial pancreatectomy was performed. Histopathology and immunohistochemistry confirmed that one mass was an insulinoma and the other was an ectopic splenic tissue, consistent with the differences in imaging findings. When an intrapancreatic lesion with hyper-attenuation on dynamic abdominal CT is detected, not only insulinoma or metastasis of malignancies but also intrapancreatic accessory spleen (IPAS) should be considered as differential diagnoses.

Role of MicroRNA-134-5p in Metabolic Syndrome-Associated Pulmonary Hypertension in Heart Failure with Preserved Ejection Fraction

Background: Pulmonary hypertension in heart failure with preserved ejection fraction (PH-HFpEF) is the most common cause of PH worldwide. It is closely linked to risk factors for metabolic syndrome, including obesity and diabetes - factors known to increase proliferation and migration of pulmonary artery smooth muscle cells (PASMCs), leading to pulmonary vascular remodeling. Qualitative studies have shown that patients with progressive vascular abnormalities develop more severe symptoms and suffer frequent hospitalization. However, underlying mechanisms involved in the regulation of pulmonary vascular remodeling in metabolic syndrome-associated PH-HFpEF are still unclear.&#x0D; Aim: We have recently observed decreased levels of the tumor suppressor WW domain-containing oxidoreductase (WWOX), which plays a housekeeping role in repressing cellular proliferation, in PASMCs isolated from rats with experimental PH-HFpEF and human subjects with obesity and diabetes. As microRNAs (miRNAs) have been shown to regulate WWOX expression in cancers, here we aimed at examining the involvement of miRNAs in WWOX-associated pulmonary vasculature regulation in metabolic syndrome-associated PH-HFpEF.&#x0D; Methods and Results: Among miRNAs that have been associated with reduced WWOX expression, including miR -134-5p, -153-3p, -29a-3b, -29b-3p and -187-5p, we found that miR-134-5p was significantly increased in PASMCs of obese and diabetic subjects. To determine the role of miR-134-5p in the regulation of WWOX in the pulmonary vasculature, we applied exogenous miR-134-5p to human PASMCs. Treatment with miR-134-5p decreased WWOX expression, increased PCNA expression (a cell proliferation marker) and enhanced cellular proliferation. Additionally, human PASMCs challenged with high concentration of glucose, palmitic acid and insulin, which mimic hyperglycemic, hyperlipidemic and hyperinsulinemic conditions, exhibited increased miR-134-5p, accompanied by elevated cellular proliferation. &#x0D; Conclusions: These studies suggest that miR-134-5p may have a potential role in metabolic syndrome-associated PH-HFpEF through regulating WWOX in the pulmonary vasculature. These studies identify miR-134-5p as a potential therapeutic target for the treatment of metabolic syndrome-associated PH-HFpEF.&#x0D; This project was funded, in part, with support from the NIH NHLBI Short-Term Training Program in Biomedical Sciences Grant funded, in part by T35HL110854 from the National Institutes of Health. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health.

Gene cascade analysis in human granulosa tumor cells (KGN) following exposure to high levels of free fatty acids and insulin

Maternal metabolic disorders such as obesity and diabetes are detrimental factors that compromise fertility and the success rates of medically assisted procreation procedures. During metabolic stress, adipose tissue is more likely to release free fatty acids (FFA) in the serum resulting in an increase of FFA levels not only in blood, but also in follicular fluid (FF). In humans, high concentrations of palmitic acid and stearic acid reduced granulosa cell survival and were associated with poor cumulus-oocyte complex (COC) morphology. Obesity and high levels of circulating FFA were also causatively linked to hampered insulin sensitivity in cells and compensatory hyperinsulinemia. To provide a global picture of the principal upstream signaling pathways and genomic mechanisms involved in this metabolic context, human granulosa-like tumor cells (KGN) were treated with a combination of palmitic acid, oleic acid, and stearic acid at the higher physiological concentrations found in the follicular fluid of women with a higher body mass index (BMI) (≥ 30.0 kg/m2). We also tested a high concentration of insulin alone and in combination with high concentrations of fatty acids. Transcription analysis by RNA-seq with a cut off for fold change of 1.5 and p-value 0.05 resulted in thousands of differentially expressed genes for each treatment. Using analysis software such as Ingenuity Pathway Analysis (IPA), we were able to establish that high concentrations of FFA affected the expression of genes mainly related to glucose and insulin homoeostasis, fatty acid metabolism, as well as steroidogenesis and granulosa cell differentiation processes. The combination of insulin and high concentrations of FFA affected signaling pathways related to apoptosis, inflammation, and oxidative stress. Taken together, our results provided new information on the mechanisms that might be involved in human granulosa cells exposed to high concentrations of FFA and insulin in the contexts of metabolism disorders.