Increased Glucose Intolerance Research Articles

LEW.1WR1 Rats Have Decreased Normalized Beta Cell Area

Obesity in humans can lead to metabolic problems such as glucose intolerance and insulin resistance, which may result from pancreatic islet dysregulation and reduced insulin sensitivity in the liver. Increased fat10 expression is associated with adiposity, insulin resistance, and inflammation that increases with age as well as type 1 diabetes. The effect of increased fat10 expression on beta cell physiology, however, is not well understood. LEW.1WR1 (1WR1) rats possess a defect in the fat10 promoter which leads to sustained expression of diubiquitin. We suggested previously that fat10 may play a role in increased glucose intolerance, insulin sensitivity, age-related fat deposition, and changes in beta cell size and density in 1WR1 rats. In that study, we identified through semiquantitative analysis that the 1WR1 rats seemed to have fewer islets compared to the LEW/SsNHsd (SsNHsd) rats. The purpose of this project was to compare normalized beta cell area from these rodents and analyze this data to confirm that the perceived changes in islet number corresponded to differences in beta cell area. We hypothesized that, since the 1WR1 rats had a lower islet number, they would also have lower normalized beta cell area, dysregulated insulin signaling, and an altered cell cycle. Seven week old 1WR1 and SsNHsd rats were given a control diet for 12 weeks. Once the animals were sacrificed, the pancreases were harvested, fixed in formalin, and sent to Histowiz (New York, NY) for immunohistochemical staining against insulin. These stained slides were obtained digitally and opened in ImageJ, which was used to measure beta cell and pancreas area. Comparing these showed that the 1WR1 rats indeed have a lower average normalized beta cell area than SsNHsd rats on a moderate sucrose diet. Using qRT-PCR, we determined the islets of 1WR1 rats had 3 fold increased insulin and glucagon gene expression. Yet, the β-cell area (22.05+/-6.408 vs. 2.276 +/-1.284mm2; p=0.0016; n=3,4) was significantly reduced in 1WR1 rats. Islet Plin5 expression was upregulated in 1WR1 rats (5.388+/-0.3806 F.C.; p<0.0001; n=3,3) indicating increased lipid droplet production, while Cyclin D (0.5726+/-0.08797 F.C.; p=0.0035; n=3,2) was downregulated indicating decreased cell cycle proliferation. These results indicate that the islets of the 1WR1 rats were insensitive to insulin signaling, which may have been caused by increased lipid droplets and a decrease in compensatory islet area. This experiment increases our understanding of the characteristics of the pancreas of LEW.1WR1 rats, which may help us better understand the impact of unregulated fat10 expression on beta cell physiology.

The gallbladder in diabetes

The gallbladder in diabetes

Comparative study of dietary fat: lard and sugar as a better obesity and metabolic syndrome mice model

Background Diet macronutrient heterogeneity hinders animal studies’ data extrapolation from metabolic disorders to human diseases. Objective The present study aimed to evaluate different fat-diet compositions’ effect on inducing lipid/glucose metabolism alterations in mice. Methods Swiss male mice were fed for 12 weeks with five different diets: Standard Diet (ST), American Institute of Nutrition 93 for growth (AIN93G) high-butter/high-sugar (HBHS), high-lard/high-sugar (HLHS), and high-oil/high-sugar diet (soybean oil) (HOHS). Several parameters, such as serum biochemistry, histology, and liver mRNA expression, were accessed. Results The main findings revealed that the HLHS diet dramatically altered liver metabolism inducing hepatic steatosis and increased total cholesterol, triglycerides, VLDL, increasing liver CCAAT/enhancer binding protein (CEBP-α), Acetyl-CoA carboxylase (ACC) and Catalase (CAT) mRNA expression. Moreover, the HLHS diet increased glucose intolerance and reduced insulin sensitivity. Conclusions High-fat/high-sugar diets are efficient to induce obesity and metabolic syndrome-associated alterations, and diets enriched with lard and sugar showed more effective results.

1927-P: Protective Role of DNAJB3 Cochaperone against Obesity-Induced Insulin Resistance and Diabetes

The last decade has witnessed a dramatic increase in the prevalence of obesity and type 2 diabetes (T2D) in some Middle Eastern countries. In the GCC countries, over 35% and 20% develop obesity and T2D, respectively. Of extreme concern, the disease starts affecting the population at a relatively younger age (∼40 years), and vulnerable individuals manifest severe insulin resistance (IR). We previously showed that subjects with obesity and T2D among the Kuwaiti population have reduced expression of DNAJB3 that was associated with increased metabolic stress and poor clinical outcomes. Furthermore, physical exercise was effective in restoring the normal expression of DNAJB3 with the concomitant metabolic improvements. These observations suggest a therapeutic value of DNAJB3 against obesity-associated metabolic diseases. To gain further insights into this protective role, we generated mice lacking DNAJB3 using CRISPR/Cas9 approach, and challenged them with high fat diet (HFD). We also determined the in vitro effects of DNAJB3 overexpression/knockdown in modulating metabolic stress, mitochondrial and glucose homeostasis in C2C12 cells. Accordingly, DNAJB3 KO mice showed increased body weight and fat mass in response to HFD, compared to wild type. In addition, DNAJB3 KO mice on HFD exhibited increased glucose intolerance. Moreover, overexpression of DNAJB3 prevented the activation of both JNK and IKK in response to palmitate and inflammatory cytokines, respectively; while it promoted the PI3K/AKT pathway and both basal and insulin-stimulated glucose uptake. These observations were consistent with DNAJB3 knockdown experiments. Mechanistically, we showed a significant effect of DNAJB3 on enhancing Glut4 translocation and stimulating expression of key mitochondrial markers including PPARγ, PGC1α and OXPHOS. Together, these data indicate an important physiological role of DNAJB3 in obesity-induced IR and T2D and warrant further in vivo animal and clinical investigations. Disclosure M. Dehbi: None. A. Diane: None. S. Scoggin: None. I. Bensmail: None. N. Khattab: None. L. Ramalingam: None. A. Efotte: None. N. Moustaid-Moussa: None. Funding Qatar Biomedical Research Institute (IGP 2014-001)

0613 The Effects of Diabetes on Obstructive Sleep Apnea Severity and Progression: A Propensity Score Analysis

Abstract Introduction Obstructive sleep apnea (OSA) is associated with increased glucose intolerance and insulin resistance, and commonly coexists with type 2 diabetes mellitus (T2DM). Research suggests an independent association between these two conditions. However, more research into the role of T2DM in the development of OSA, or vice versa, is needed. Methods Leveraging data from 139 participants with T2DM from the Sleep AHEAD cohort and 5,085 participants without T2DM from the Sleep Heart Health Study (SHHS), we conducted two complementary propensity score (PS) subclassification analyses to estimate the effect of T2DM on the oxygen desaturation index (ODI), both at baseline and over 4-5 years of follow-up. PS models included age, sex, race, body mass index, neck circumference, waist circumference, total cholesterol, HDL cholesterol, triglycerides, Epworth Sleepiness Scale, and comorbid hypertension or cardiovascular disease. Models evaluating ODI progression also included baseline ODI. Results The PS subclassification analysis identified 109 participants with T2DM and 480 without T2DM, balanced with respect to baseline covariates, for evaluation of the effect of T2DM on baseline ODI. On average, those with T2DM had a 9 events/hour greater ODI compared to those without (24.3 [20.8, 27.9] vs. 15.3 [13.6, 16.9] events/hour; p&amp;lt;0.0001). Among patients with baseline ODI≥5, a second PS subclassification identified 99 with T2DM and 227 without for evaluating the effect of T2DM on ODI progression. No difference in change in ODI was observed between those with and without T2DM (mean [95% CI] difference -0.25 [-10.7, 10.2] events/hour; p=0.963). Conclusion Using two robust PS subclassification designs to minimize selection bias, we evaluated the effect of T2DM on baseline ODI and ODI progression in adults with OSA after 4-5 years. Those with T2DM had more severe baseline ODI, but there were no meaningful differences in ODI progression. Results further our understanding of the association between these coexisting conditions. Support NIH grant HL070301

Lipocalin-type prostaglandin D2 synthase deletion induces dyslipidemia and non-alcoholic fatty liver disease

Non-alcoholic fatty liver disease (NAFLD) is an emerging risk factor for type 2 diabetes mellitus, cardiovascular disease, and all-cause mortality. Previously, we demonstrated that lipocalin-type prostaglandin D2 synthase (L-PGDS) knockout mice show increased glucose intolerance and accelerated atherosclerosis. In the present study, we investigated the role of L-PGDS in mediating NAFLD utilizing L-PGDS knockout (KO) and control C57BL/6 mice fed either low fat (LFD) or high fat diet (HFD) for 14 weeks. Our present study demonstrates that L-PGDS KO mice remain slightly lighter in weight compared to control mice, yet develop NAFLD faster and eventually progress to the more severe non-alcoholic steatohepatitis (NASH). We found increased lipid accumulation in the liver of KO mice over time on both diets, as compared to control mice. The L-PGDS KO mice showed elevated fasting glucose and insulin levels and developed insulin resistance on both LFD and HFD. Lipogenesis marker proteins such as SREBP-1c and LXRα were increased in L-PGDS KO mice after 14 weeks on both diets, when compared to control mice. We replicated our in vivo findings in vitro using HepG2 cells treated with a combination of free fatty acids (oleic and palmitic acid) and exposure to a L-PGDS inhibitor and prostaglandin D2 receptor (DP1) antagonists. We conclude that the absence or inhibition of L-PGDS results in dyslipidemia, altered expression of lipogenesis genes and the acceleration of NAFLD to NASH, independent of diet and obesity. We propose L-PGDS KO mice as a useful model to explore the pathogenesis of NAFLD and NASH, and L-PGDS as a potential therapeutic target for treatment.

Consumption of salt leads to ameliorate symptoms of metabolic disorder and change of gut microbiota.

Metabolic diseases caused by high-carbohydrate and/or high-salt diets are becoming major public health concerns. However, the effects of salt on high-carbohydrate diet-induced obesity are unclear. Accordingly, in this study, we investigated the effects of high-salt intake on high-carbohydrate diet-induced obesity. We performed a 12-week study on gut microbiota and metabolic changes in high-rice diet (HRD) or HRD supplemented with high-salt (HRS)-fed C57BL/6J mice by 16S rRNA analysis, glucose and insulin tolerance testing, gut barrier function, western blot and histological analysis. Moreover, the effects of salt on lipid metabolism were confirmed in vitro using 3T3-L1 cells. High salt intake decreased HRD-induced increases in body and white adipose tissue (WAT) weight. Alternatively, HRS did not reverse the observed increases in glucose intolerance and insulin resistance. Moreover, HRD caused changes in the gut microbiota, thereby impairing gut barrier function and increasing inflammation in the liver. HRS altered HRD-induced microbial composition, however, did not ameliorate gut barrier dysfunction or hepatic inflammation. HRS diets regulated the HRD-induced increase in peroxisome proliferator-activated receptor-γ (PPAR-γ) and lipid metabolism-related protein expression. Moreover, within WAT, HRS was found to reverse the observed decrease in adiponectin and increase in PPAR-γ expression induced by HRD. In vitro, high NaCl concentration also significantly reduced 3T3-L1 cell differentiation and modulated lipid metabolism without causing cytotoxicity. These results indicate that high salt intake ameliorates metabolic changes associated with a high-rice diet, including changes in fecal microbiota composition.

Glycoregulation During Pregnancy

Abstract Pregnancy is a period marked by profound changes in a woman’s hormonal status and metabolism, including the development of a carbohydrate-intolerant state. Gestational diabetes mellitus (GDM) is defined as any degree of glucose intolerance with onset or first recognition during pregnancy. The aim of this study was to estimate and analyse the parameters of glycaemic control during pregnancy. We stratified patients into the following three groups according to OGTT results: normal glucose tolerance (NTG), gestational impaired glucose tolerance (GIGT) and GDM. We investigated 92 pregnant women, diagnosed with vital and desired pregnancy up to 12 weeks of gestation, who had signed informed consent forms. Among them, 7 pregnant women had a spontaneous abortion, while 8 pregnant women dropped out, so a total of 77 pregnant women completed the trial. Most of the women examined had no risk factors (48%), while 35% of the women had one risk factor. The current study demonstrates that normal glucose tolerance was shown in 59 (76.6%) participants, while some form of glucose intolerance (GIGT or GDM) was shown in 18 (23.4%) patients. Our findings revealed an increase in glucose intolerance with advancing pregnancy (in the second and third trimester). In conclusion, we demonstrate that the difference in the quality of glycaemic control during pregnancy is manifested in the second and third trimester, until it manifests in the first trimester. These findings underpin the clinical significance of discovering GDM.

1890-P: Lipocalin-Type Prostaglandin D2 Synthase Deficient Mice Develop Dyslipidemia Resulting in Nonalcoholic Fatty Liver Disease Independent of Obesity

Nonalcoholic fatty liver disease (NAFLD) is an emerging risk factor for type 2 diabetes mellitus (T2DM), cardiovascular disease, and all-cause mortality. Obesity is a major determinant of the high prevalence of NAFLD and T2DM worldwide. Previously, we demonstrated that lipocalin-type prostaglandin D2 synthase (L-PGDS) knockout mice show increased glucose intolerance and accelerated atherosclerosis. In the present study, we investigated the role of L-PGDS in causing NAFLD in L-PGDS knockout (KO) and control C57BL/6 mice (n=6/group) on both low fat and high fat diets for 14 weeks. We observed that L-PGDS KO mice remain slightly lighter in weight compared to control mice, yet develop NAFLD faster, even on the low fat diet. In addition, we found elevated fasting glucose and insulin levels in L-PGDS KO mice with increased lipid accumulation in the liver with time on both diets as compared to controls. We also found total cholesterol and LDL levels were significantly elevated in L-PGDS KO mice. Finally, lipogenesis marker proteins such as SREBP-1c and LXRα, and CD36, a fatty acid transporter protein, were also found to be increased in L-PGDS KO mice on both diets as compared to control mice. These data confirm that absence of L-PGDS results in hyperinsulinemia and dyslipidemia. Therefore, we conclude that L-PGDS plays a significant role in developing NAFLD independent of obesity and may serve as a novel therapeutic target for the treatment of NAFLD. Disclosure A. Srivastava: None. T. Palaia: None. C. Hall: None. J. Lee: None. M. Stevenson: None. L. Ragolia: None. Funding George Link, Jr. Foundation, Inc.; American Heart Association

SAT-LB032 Young Adult LEW.1WR1 Rats Develop Increased Glucose Intolerance on a Moderately Increased Sucrose Diet

FAT10 is an ubiquitin-like protein and Type 1 Diabetes (T1D) susceptibility gene that may play a role in age-related inflammation, adiposity, and cancer risk. The LEW.1WR1(1WR1) rat overexpresses FAT10 and has higher fasting concentrations of blood insulin and triglyceride during the induction of T1D. FAT10 is hypothesized to play a role in the expression of adipogenic genes; however, it is unclear if overexpression of FAT10 directly affects insulin sensitivity and glucose metabolism. We hypothesize that young adult 1WR1 rats will have increased glucose intolerance due to the poor regulation of insulin secretion which over time leads to reduced insulin sensitivity and increased adiposity. To test this hypothesis, we monitored glucose and insulin tolerance by glucose (GTT) or insulin tolerance (ITT) test and weight gain throughout 12 weeks on high fat and high sucrose (HFD) or moderate sucrose (MS) diet. The LEW/ssNHsd (SsNHsd) rat serves as a control rat. All experiments contain seven rats per group. We observed that at four weeks, the HFD diet rat groups had increased but non-significant fasting blood glucose levels during an ITT (109 +/- 4 mg/dL 1WR1-MS; 113 +/- 5 mg/dL SsNHsd-MS; 132 +/- 6 mg/dL 1WR1 HFD; or 131 +/- 13 mg/dL SsNHsd-HFD.) At ten weeks, the 1WR1-MS rats were more glucose intolerant than the control SsNHsd-MS rat (311.7 +/- 64 mg/dL vs. 194 +/- 53 mg/dL; p=0.09.) We compared the eight week GTT of the 1WR1-MS rats to a GTT before starting the diets (zero weeks) and the thirty minute time points are significantly different for the 1WR1-MS after 8 weeks on the MS diet compared to both the 1WR1-MS and SsNHsd-MS prior to the MS diet ( 164 +/- 27 mg/dL zero weeks 1WR1; 167 +/- 26 mg/dL zero weeks SsNHsd; 311 +/-64 mg/dL eight weeks 1WR1-MS p< 0.0001). 1WR1 rats on both diets also gained weight at similar rates, yet the total abdominal fat mass of the 1WR1-MS rats was not increased compared to the SsNHsd-MS (17.43 +/- 3.48 g 1WR1-MS vs. 16.42 +/- 2.73 g SsNHsd-MS p=0.94 and 24.64 +/- 4.27 g 1WR1-HFD p=0.004) and 1WR1 rat epididymal fat was not significantly different between the two diets compared to the significant difference in SsNHsd rats groups (5.85+/-1.01 1WR1-MS vs. 7.27+/- 1.42 1WR1-HFD p=0.07; 4.63 +/- 0.81 vs. 6.77 +/- 0.65 p=0.0052.) This data suggests that metabolic shifts are occurring in the 1WR1 rat, due to either increased sucrose intake or aging. These shifts reflected the increased glucose intolerance after eight weeks and the changes in abdominal fat pads relative to body mass. This study lays the groundwork for characterizing how alterations in FAT10 increase metabolic dysfunction through aging, glucose metabolism, insulin secretion/signaling, and lipid metabolism/catabolism. Unless otherwise noted, all abstracts presented at ENDO are embargoed until the date and time of presentation. For oral presentations, the abstracts are embargoed until the session begins. s presented at a news conference are embargoed until the date and time of the news conference. The Endocrine Society reserves the right to lift the embargo on specific abstracts that are selected for promotion prior to or during ENDO.

Adipose Tissue in Persons With HIV Is Enriched for CD4+ T Effector Memory and T Effector Memory RA+ Cells, Which Show Higher CD69 Expression and CD57, CX3CR1, GPR56 Co-expression With Increasing Glucose Intolerance.

Chronic T cell activation and accelerated immune senescence are hallmarks of HIV infection, which may contribute to the increased risk of cardiometabolic diseases in people living with HIV (PLWH). T lymphocytes play a central role in modulating adipose tissue inflammation and, by extension, adipocyte energy storage and release. Here, we assessed the CD4+ and CD8+ T cell profiles in the subcutaneous adipose tissue (SAT) and blood of non-diabetic (n = 9; fasting blood glucose [FBG] < 100 mg/dL), pre-diabetic (n = 8; FBG = 100–125 mg/dL) and diabetic (n = 9; FBG ≥ 126 mg/dL) PLWH, in addition to non- and pre-diabetic, HIV-negative controls (n = 8). SAT was collected by liposuction and T cells were extracted by collagenase digestion. The proportion of naïve (TNai) CD45RO−CCR7+, effector memory (TEM) CD45RO+CCR7−, central memory (TCM) CD45RO+CCR7+, and effector memory revertant RA+(TEMRA) CD45RO−CCR7− CD4+ and CD8+ T cells were measured by flow cytometry. CD4+ and CD8+ TEM and TEMRA were significantly enriched in SAT of PLWH compared to blood. The proportions of SAT CD4+ and CD8+ memory subsets were similar across metabolic status categories in the PLWH, but CD4+ T cell expression of the CD69 early-activation and tissue residence marker, particularly on TEM cells, increased with progressive glucose intolerance. Use of t-distributed Stochastic Neighbor Embedding (t-SNE) identified a separate group of predominantly CD69lo TEM and TEMRA cells co-expressing CD57, CX3CR1, and GPR56, which were significantly greater in diabetics compared to non-diabetics. Expression of the CX3CR1 and GPR56 markers indicate these TEM and TEMRA cells may have anti-viral specificity. Compared to HIV-negative controls, SAT from PLWH had an increased CD8:CD4 ratio, but the distribution of CD4+ and CD8+ memory subsets was similar irrespective of HIV status. Finally, whole adipose tissue from PLWH had significantly higher expression of TLR2, TLR8, and multiple chemokines potentially relevant to immune cell homing compared to HIV-negative controls with similar glucose tolerance.

Serum Lipid Profile and Its Association with Diabetes and Prediabetes in a Rural Bangladeshi Population.

Dyslipidemia is commonly associated with diabetes (T2DM). This has been demonstrated for the Caucasian population, but few data are available for Asian Indians. The paper aims to investigate serum lipids (separately or in combination) and their association with glucose intolerance status (T2DM and prediabetes) in a rural Bangladeshi population. A sample of 2293 adults (≥20 years) were included in a community based cross-sectional survey in 2009. Anthropometric measures, blood pressure, blood glucose (fasting and 2-h oral glucose tolerance test) and fasting serum lipids (total cholesterol, T-Chol; triglycerides, Tg; low density lipoprotein cholesterol, LDL-C and high density lipoprotein cholesterol, HDL-C) were registered. Analysis of covariance (ANCOVA) and regression analysis were performed. High Tg levels were seen in 26% to 64% of the participants, depending on glucose tolerance status. Low HDL-C levels were seen in all groups (>90%). Significant linear trends were observed for high T-Chol, high Tg and low HDL-C with increasing glucose intolerance (p for trend <0.001). T2DM was significantly associated with high T-Chol (Odds ratio (OR): 2.43, p < 0.001), high Tg (OR: 3.91, p < 0.001) and low HDL-C (OR: 2.17, p = 0.044). Prediabetes showed a significant association with high Tg (OR: 1.96, p < 0.001) and low HDL-C (OR: 2.93, p = 0.011). Participants with combined high Tg and low HDL-C levels had a 12.75-fold higher OR for T2DM and 4.89 OR for prediabetes. In Asian Indian populations an assessment of serum lipids is warranted not only for T2DM patients, but also for those with prediabetes.

Glutathione S-transferase P deficiency induces glucose intolerance via JNK-dependent enhancement of hepatic gluconeogenesis.

Hepatic glutathione S-transferases (GSTs) are dysregulated in human obesity, nonalcoholic fatty liver disease, and diabetes. The multifunctional GST pi-isoform (GSTP) catalyzes the conjugation of glutathione with acrolein and inhibits c-Jun NH2-terminal kinase (JNK) activation. Herein, we tested whether GSTP deficiency disturbs glucose homeostasis in mice. Hepatic GST proteins were downregulated by short-term high-fat diet in wild-type (WT) mice concomitant with increased glucose intolerance, JNK activation, and cytokine mRNAs in the liver. Genetic deletion of GSTP did not affect body composition, fasting blood glucose levels, or insulin levels in mice maintained on a normal chow diet; however, compared with WT mice, the GSTP-null mice were glucose intolerant. In GSTP-null mice, pyruvate intolerance, reflecting increased hepatic gluconeogenesis, was accompanied by elevated levels of activated JNK, cytokine mRNAs, and glucose-6-phosphatase proteins in the liver. Treatment of GSTP-null mice with the JNK inhibitor 1,9-pyrazoloanthrone (SP600125) significantly attenuated pyruvate-induced hepatic gluconeogenesis and significantly altered correlations between hepatic cytokine mRNAs and metabolic outcomes in GSTP-null mice. Collectively, these findings suggest that hepatic GSTP plays a pivotal role in glucose handling by regulating JNK-dependent control of hepatic gluconeogenesis. Thus, hepatic GSTP-JNK dysregulation may be a target of new therapeutic interventions during early stages of glucose intolerance to prevent the worsening metabolic derangements associated with human obesity and its relentless progression to diabetes.

High lipid and low carbohydrate content diet, immediately after weaning, causes hepatic injury, systemic oxidative stress and diminishment of lipids in white adipose tissue

As obesity is now a global pandemic, greater research efforts are needed in order to fully understand the physiological effects of diets with high lipid and low carbohydrate contents, giving special attention to the factors that can lead to a condition of systemic oxidative stress. This condition is related to the onset and development of important diseases including diabetes, dyslipidemia, hypertension, stroke, and heart attack. In this work, immediately after weaning, Wistar rats (n = 8) were submitted to a hyperlipidic diet (34.5% lipids, 23.3% carbohydrates, 24.9% proteins) during 155 days. A control group (n = 8) consumed a standard diet for rodents (4.5% lipids, 48.0% carbohydrates, 25.3% proteins). The hyperlipidic diet did not cause obesity during the period of the experiment, but was detrimental to the development of mass and length of the animals during the first 57 days. A condition of oxidative stress was established, as demonstrated by decreases of plasma proteins and reduced thiols, as well as alterations of hemoglobin. Additional systemic damage was exhibited, including increased glucose intolerance and dyslipidemia, as well as hepatic damage evidenced by the plasma activities of the enzymes alanine transaminase, aspartate transaminase, and alkaline phosphatase. Decrease in lipid concentration ion white adipose tissue, which would allow increased triacylglycerol synthesis and storage if dietary carbohydrates were increased. It could be concluded that the hyperlipidic diet induced severe hepatic damage and might contribute to the future development of obesity and diabetes if the content of carbohydrates in the diet was increased.

Silencing Mediator of Retinoid and Thyroid Hormone Receptors (SMRT)—A Link between Adipocytes, Inflammation, and Glucose Intolerance

Silencing Mediator of Retinoid and Thyroid Hormone Receptors (SMRT) is a nuclear corepressor, which regulates the transcriptional activity of metabolically essential transcription factors. While SMRT has been shown to modulate adipocyte function, in vivo experiments utilizing knock-out (KO) models have led to conflicting results. To more rigorously define the role of SMRT in the adipocyte, we generated adipocyte-specific SMRT KO (adSMRT KO) mice by crossing adiponectin-Cre mice with floxed SMRT mice on a C57/BL6 background. When adSMRT KO mice are challenged with a 45% high-fat diet, we observe 20% increase in glucose intolerance (p=0.006) compared to wild type (WT) counterparts. Additionally, RNA-Seq data of adipose tissue from these mice indicate a dramatic up-regulation of inflammatory gene expression. To further characterize the pro-inflammatory phenotype, we utilized flow cytometry to identify infiltration of specific populations of adipose tissue inflammatory cells. We found that overall macrophage infiltration in the adipose tissue of KO mice increased two-fold (p=0.026), with anti-inflammatory M2 macrophages infiltrating in significantly lower proportions (p=0.017), indicating a higher ratio of M1:M2 cells in the KO mice compared to WT. In contrast, body weight and total fat mass were not altered. These data suggest a role for SMRT in the cross-talk between adipocytes and pro-inflammatory macrophages for the regulation of systemic glucose tolerance, distinct from the development of obesity. SMRT therefore integrates metabolic and inflammatory signals to maintain physiological homeostasis. Disclosure J. Kahn: None. A.A. Goddi: None. R.N. Cohen: None.

Short‐term Western Diet Induces Cardiometabolic Syndrome in Female Rats is Associated with Increased Cardiovascular Protein Lysine Acetylation.

The western diet (WD), which is rich in fat, carbohydrates, and refined sugars, is a major contributor to the global epidemic of metabolic syndrome in our modern society. Despite the well‐documented cardioprotection exhibited by the pre‐menopausal female population, studies have indicated that certain stressors may abolish this cardiovascular protection. Studies on the impact of the WD on the cardiometabolic profile of female cohorts remains limited. Lysine acetylation, a reversible posttranslational modification of histone and non‐histone proteins, has been closely associated with metabolic disorders. Based on these factors, we hypothesized that short‐term exposure to the WD alters cardiometabolic parameters in premenopausal rats and alters levels of lysine acetylation in the cardiovascular tissues. Adult female Wistar rats were randomized in two groups: Control Group (n=8) was assigned a regular chow diet and WD Group (n=12) received WD (40% fat, 43% carbohydrates, and 17% protein) for 17 weeks. Results showed that WD group exhibited increased body weight (376 ± 49 vs 305 ± 41g, p&lt;0.05), periabdominal fat content (30 ±11 vs 11 ±2g, p&lt;0.01), % body fat (8.1 ±1.0 vs 3.6 ±0.4%, p&lt;0.01), and serum triglyceride levels (56 ± 13 vs 25 ± 4 mg/dl, p&lt;0.01) compared to controls. Although the WD group exhibited significant increases in glucose intolerance (AUC: 17068.5 ± 730 vs. 13787.67± 814 a.u, p&lt;0.01) and insulin resistance (HOMA‐IR: 5.75 ± 0.9 vs. 3.25 ± 0.62 control, p&lt;0.05), no differences in fasting blood glucose and hemoglobin A1C were found. Using direct arterial blood pressure measurements via carotid artery catheterization, we observed increased systolic blood pressure (146.19 ±9.4 vs 126.22 ± 9.8 mmHg controls, p&lt;0.001), which is contradictory with previous studies. Our vascular reactivity studies revealed that short‐term WD markedly impaired endothelial‐dependent relaxation. Additionally, using DHE staining we found that aortas from the WD group exhibited augmented levels of oxidative stress (3.1‐fold increase vs. control, p&lt;0.001). Strikingly, levels of global lysine acetylation were markedly elevated in the aortas (2.2‐fold increase vs. control, p&lt;0.01) and heart (1.4‐fold increase vs. control, p&lt;0.05) of WD group. Levels of acetyltransferase PCAF were significantly upregulated in the aortas (2.2‐fold increase vs. control, p&lt;0.05). Interestingly, PCAF and deacetylase HDAC9 expression was diminished in hearts from WD group (30% reduction vs. control, p&lt;0.05) and (85% reduction vs. control, p&lt;0.05), respectively. Besides these cardiovascular alterations, the WD also led to the development of non‐alcoholic fatty liver disease (NAFLD) and robust increases in hepatic global lysine acetylation (3.0‐fold increase vs. control, p&lt;0.001). Taken together, our results demonstrated that, even under short‐term exposure, the WD negatively affects the metabolic and cardiovascular parameters of female rats and it is associated with elevated levels of global lysine acetylation in cardiometabolic tissues. This study will be further conducted to identify the specific proteins acetylated in blood vessels and heart from female population under WD regimes.Support or Funding InformationIn‐house Grant NYIT to MACSThis abstract is from the Experimental Biology 2018 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Effects of dietary saturated fatty acid consumption on cartilage health and trauma-induced osteoarthritis in rats

Purpose: Experimental studies show that administering diets rich in lipids (high fat diets) leads to osteoarthritis (OA). Thus, it appears from the available literature that the source, or type of dietary fat and its level of saturation may be a critical factor in the development of an underlying inflammatory condition in the body that may lead to OA development. There are different types of saturated fatty acids. Western diet predominantly consist of fats rich in stearic acid, palmitic acid, myristic acid and lauric acid. However, so far no studies have investigated what type of saturated fatty acid in particular lead to cartilage damage. Therefore the goal of this present study is to evaluate the effects of administering different types of saturated diets on the morphology of the cartilage, subchondral bone and pain related behavior. Methods: The current study evaluates the chronic impact of high saturated fat feeding on joint cartilage health using a rat model. Male wistar rats weighing 330–340g received either corn starch diet or a diet rich in simple sugars including fructose together with either lauric acid (C12), myristic acid (C14), palmitic acid (C16), stearic acid (C18) or beef tallow (mainly stearic and trans fatty acids). After 16 weeks, knee OA was assessed by cartilage and synovium histology in addition to bone morphology. Serum cytokine concentrations were determined with multiplex assay. We further monitored lipid profile, glucose levels, and body weight and food consumption throughout the study period. Furthermore, the influence of different saturated fatty acid (SFA) types on the progression of OA was evaluated in menisectomy OA model by monitoring pain-related behavior, the changes in glial activity in the spinal cord (SC) and the dorsal root ganglions (DRG) of rats fed with the different saturated fat diets. Results: Our results indicate that the rats on a high-carbohydrate diet, stearic acid rich and plamitic acid diet showed cartilage degenerative changes that are similar to OA cartilage. Surprisingly, the rats that were fed with lauric acid and myristic acid saturated fats showed similar cartilage structure to control rats that were fed with corn starch diet, indicating marked differences in OA risk depending on the type of dietary fatty acids. As cartilage changes progress, we found that supplementation with stearic acid and palmitic acid markedly increased glucose intolerance, abdominal obesity, hypertension and fatty liver. However such effects were decreased in the rats that are fed with lauric and myristic acid fats. Furthermore, the rats on palmitic (PA) and stearic acid (SA) diets increased the progression of OA in menisectomy rats, which was characterized by increased knee cartilage degeneration and decreased bone volume density (BMD). In addition, these diet groups also exhibited decreased hind paw withdrawal thresholds, grip strength, and increased joint hypersensitivity compared to the other saturated fat groups. Furthermore, significant spinal astrogliosis and microgliosis were also observed in these diet groups. On the contrary, lauric acid (LA) diet group rats exhibited decreased degeneration of the cartilage, increased hind paw withdrawal thresholds, grip strength and decreased joint hypersensitivity. In addition, lower number of spinal GFAP and IBA-1 positive cells were observed signifying decreased astrogliosis and microgliosis respectively. Conclusions: In conclusion, our study indicates that effect of saturated fats on OA risk and pain depends on the kind of fatty acids present in the blood. Thus, reducing or modulating certain types of saturated fatty acids in the diet may help in preventing or slowing the progression of OA.

Nox4 genetic inhibition in experimental hypertension and metabolic syndrome

Metabolic syndrome is a combination of symptoms including obesity, dyslipidaemia, glucose intolerance and hypertension. Oxidative stress appears to be a pathophysiological factor that links these signs and encourages progression towards heart failure and diabetes. Nox4 is a hydrogen peroxide nicotinamide adenine dinucleotide phosphate(NADPH) oxidase isoform -found in various cardiovascular cells and tissues, but also in tissues such as the liver- which is involved in glucose and lipid homeostasis. To test whether inhibition of the Nox4 enzyme could improve blood pressure and metabolic parameters in mice receiving either angiotensinII or a high-fat diet. Systolic and diastolic arterial pressures, pulse rate and heart rate were obtained in 24male mice (12wild-type [WT] and 12Nox4-/-) before and during 14days of angiotensinII infusion. After angiotensinII infusion, cardiac histological remodeling was assessed. Weight and biochemical parameters were measured in 18male and 18female mice (nine WT and nine Nox4-/- per gender) after 10weeks on a standard chow diet, then 15weeks on a high-fat diet. Glucose tolerance and insulin sensitivity were tested at age 25weeks. Knock-out animals did not demonstrate a baseline blood pressure phenotype, but blocking Nox4 protected against angiotensinII-mediated arterial and pulse pressure increases. No protection against angiotensinII-induced cardiac fibrosis was observed. From a metabolic point of view, Nox4 inhibition reduced plasma triglycerides in male and female mice under a chow diet. However, Nox4 deletion did not affect the metabolic profile under a high-fat diet in males or females, but increased glucose intolerance in females. Our data identify Nox4 as a key source of radical oxygen species involved in hypertension and some metabolic problems.

Atherogenesis and metabolic dysregulation in LDL receptor-knockout rats.

Mechanisms of atherogenesis have been studied extensively in genetically engineered mice with disturbed cholesterol metabolism such as those lacking either the LDL receptor (Ldlr) or apolipoprotein E (apoe). Few other animal models of atherosclerosis are available. WT rabbits or rats, even on high-fat or high-cholesterol diets, develop sparse atherosclerotic lesions. We examined the effects of Ldlr deletion on lipoprotein metabolism and atherosclerotic lesion formation in Sprague-Dawley rats. Deletion of Ldlr resulted in the loss of the LDLR protein and caused a significant increase in plasma total cholesterol and triglycerides. On normal chow, Ldlr-KO rats gained more weight and were more glucose intolerant than WT rats. Plasma proprotein convertase subtilisin kexin 9 (PCSK9) and leptin levels were higher and adiponectin levels were lower in KO than WT rats. On the Western diet, the KO rats displayed exaggerated obesity and age-dependent increases in glucose intolerance. No appreciable aortic lesions were observed in KO rats fed normal chow for 64 weeks or Western diet for 16 weeks; however, after 34-52 weeks of Western diet, the KO rats developed exuberant atherosclerotic lesions in the aortic arch and throughout the abdominal aorta. The Ldlr-KO rat may be a useful model for studying obesity, insulin resistance, and early-stage atherosclerosis.

Hypothalamic ΔFosB prevents age-related metabolic decline and functions via SNS.

The ventral hypothalamus (VHT) integrates several physiological cues to maintain glucose homeostasis and energy balance. Aging is associated with increased glucose intolerance but the underlying mechanisms responsible for age-related metabolic decline, including neuronal signaling in the VHT, remain elusive. We have shown that mice with VHT-targeted overexpression of ΔFosB, a splice variant of the AP1 transcription factor FosB, exhibit increased energy expenditure, leading to decreased adiposity. Here, we show that VHT-targeted overexpression of ΔFosB also improves glucose tolerance, increases insulin sensitivity in target organs and thereby suppresses insulin secretion. These effects are also observed by the overexpression of dominant negative JunD, demonstrating that they occur via AP1 antagonism within the VHT. Furthermore, the improved glucose tolerance and insulin sensitivity persisted in aged animals overexpressing ΔFosB in the VHT. These beneficial effects on glucose metabolism were abolished by peripheral sympathectomy and α-adrenergic, but not β-adrenergic, blockade. Taken together, our results show that antagonizing AP1 transcription activity in the VHT leads to a marked improvement in whole body glucose homeostasis via activation of the SNS, conferring protection against age-related impairment in glucose metabolism. These findings may open novel avenues for therapeutic intervention in diabetes and age-related glucose intolerance.