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Elevated postprandial triacylglycerols (TAG) are an important risk factor for cardiovascular disease. Men have higher plasma TAG and impaired TAG clearance compared to women, which may contribute to sex differences in risk of cardiovascular disease. Understanding mechanisms of sex differences in TAG metabolism may yield novel therapeutic targets to prevent cardiovascular disease. Cholesteryl ester transfer protein (CETP) is a lipid shuttling protein known for its effects on high‐density lipoprotein (HDL) cholesterol levels. Although mice lack CETP, we previously demonstrated that transgenic CETP expression in female mice alters TAG metabolism. The impact of CETP on TAG metabolism in males, however, is not well understood. Here, we demonstrate that CETP expression increases plasma TAG in males, especially in very‐low density lipoprotein (VLDL), by impairing postprandial plasma TAG clearance compared to wild‐type (WT) males. Gonadal hormones were required for CETP to impair TAG clearance, suggesting a role for sex hormones for this effect. Testosterone replacement in the setting of gonadectomy was sufficient to restore the effect of CETP on TAG. Lastly, liver androgen receptor (AR) was required for CETP to increase plasma TAG. Thus, expression of CETP in males raises plasma TAG by impairing TAG clearance via testosterone signaling to AR. Further understanding of how CETP and androgen signaling impair TAG clearance may lead to novel approaches to reduce TAG and mitigate risk of cardiovascular disease.

Mounting evidence has shown that CETP has important physiological roles in adapting to chronic nutrient excess, specifically, to protect against diet-induced insulin resistance. However, the underlying mechanisms for the protective roles of CETP in metabolism are not yet clear. Mice naturally lack CETP expression. We used transgenic mice with a human CETP minigene (huCETP) controlled by its natural flanking region to further understand CETP-related physiology in response to obesity. Female huCETP mice and their wild-type littermates were fed a high-fat diet for 6 months. Blood lipid profile and liver lipid metabolism were studied. Insulin sensitivity was analyzed with euglycemic-hyperinsulinemic clamp studies combined with 3H-glucose tracer techniques. While high-fat diet feeding induced obesity for huCETP mice and their wild-type littermates lacking CETP expression, insulin sensitivity was higher for female huCETP mice than for their wild-type littermates. There was no difference in insulin sensitivity for male huCETP mice vs. littermates. The increased insulin sensitivity in females was largely caused by the better insulin-mediated suppression of hepatic glucose production. In huCETP females, CETP in the circulation decreased HDL-cholesterol content and increased liver cholesterol uptake and liver cholesterol and oxysterol contents, which was associated with the upregulation of LXR target genes in long-chain polyunsaturated fatty acid biosynthesis and PPARα target genes in fatty acid β-oxidation in the liver. The upregulated fatty acid β-oxidation may account for the improved fatty liver and liver insulin action in female huCETP mice. This study provides further evidence that CETP has beneficial physiological roles in the metabolic adaptation to nutrient excess by promoting liver fatty acid oxidation and hepatic insulin sensitivity, particularly for females.

We previously showed that global deletion of the cytochrome P450 epoxygenase Cyp2c44, a major epoxyeicosatrienoic acid (EET) producing enzyme in mice, leads to impaired hepatic insulin signaling resulting in insulin resistance. This finding led us to investigate whether administration of a water soluble EET analog restores insulin signaling in vivo in Cyp2c44(-/-) mice and investigated the underlying mechanisms by which this effect is exerted. Cyp2c44(-/-) mice treated with the analog EET-A for 4 weeks improved fasting glucose and glucose tolerance compared to Cyp2c44(-/-) mice treated with vehicle alone. This beneficial effect was accompanied by enhanced hepatic insulin signaling, decreased expression of gluconeogenic genes and increased expression of glycogenic genes. Mechanistically, we show that insulin-stimulated phosphorylation of insulin receptor β (IRβ) is impaired in primary Cyp2c44(-/-) hepatocytes and this can be restored by cotreatment with EET-A and insulin. Plasma membrane fractionations of livers indicated that EET-A enhances the retention of IRβ in membrane rich fractions, thus potentiating its activation. Altogether, EET analogs ameliorate insulin signaling in a genetic model of hepatic insulin resistance by stabilizing membrane-associated IRβ and potentiating insulin signaling.

We hypothesized that a healthy diet and exercise improve energy metabolism through different pathways in males and females. Understanding the mechanism for a how healthy diet vs. exercise improves metabolic outcomes is important for intervention through lifestyle change to target risk factors for obesity-associated diseases in specific populations. Mice were fed a high-fat diet (HFD) for 12 weeks, then divided into 4 groups, followed for 6 weeks: a. HFD; b. HFD + exercise; c. the diet was switched to chow; d. diet-switch + exercise. Instead of acute metabolic effects, we investigated sustained effects of exercise by examining tissue glucose uptake and metabolism 48 hours after the last exercise session. Diet-switch and exercise reduced obesity and fat contents in tissues in both sexes. Muscle glucose uptake was higher in males than females and not different between treatments 48 hours after exercise session. Liver glucose uptake was higher in males than females. Exercise, but not diet-switch, lowered liver glucose uptake, which effect was greater in males than females. Glucose uptake in subcutaneous, visceral, and brown adipose tissues was higher in females than males. Diet-switch, but not exercise, reduced glucose uptake in brown fat, which effect was greater in females than males. Furthermore, Diet-switch decreased the pathways for adipocyte differentiation (PPARγ) and lipogenesis (DGAT1/2) in subcutaneous adipose tissues in females. Muscle protein levels of CPT1β and pACC were increased by diet-switch in both sexes, and by exercise in males only. Our data indicate: 1) adipose tissue nutrient storage is the major energy reservoir that protects against obesity-related metabolic changes in females; 2) with regard to improving metabolic outcomes, diet-switch benefits females more and exercise benefits males more; for both sexes 3) exercise training is more effective in preventing fatty liver than diet-switch, and 4) both diet-switch and exercise promote fat oxidation in muscles. Disclosure J. An: None. L. Zhu: None. S. Yu: None. E. Edington: None. B. Litts: None. J. M. Stafford: None. Funding National Institutes of Health (R01HL144846)

Objective To examine the effect of postoperative steroid dosage on postoperative telephone calls, emergency department (ED) visits, and hemorrhage rates for two groups receiving different steroid dosing following radiofrequency ablation tonsillectomy. Study design Retrospective chart review between January 1, 2014 and January 1, 2019. Setting Tertiary care pediatric hospital. Methods Two postoperative steroid dosing protocols studied: 1) three postoperative doses of 0.5 mg/kg dexamethasone, or 2) three postoperative doses of 4 mg dexamethasone. Otherwise, postoperative care and pain control were similar for all patients. We hypothesized that standardized steroid dosing would achieve similar postoperative outcomes when compared to weight-based dosing with regards to patient phone calls, ED visits, readmission rates, and bleeding rates. Results Overall, 279 patients were included (n = 100 at 4 mg, n = 179 at 0.5 mg/kg). There were no differences between groups in age, gender, race, BMI, or comorbidities (P > 0.05). Readmission and ED visit rates were 2.8% and 12.2% respectively, with no significant difference between groups (P > 0.05)). The overall hemorrhage rate was 6.3%, including those patients presenting to the ED but not requiring intervention for bleeding concerns. There was no difference in hemorrhage rates between groups (P = 0.22); the hemorrhage rate requiring operative intervention was 1.4% with no difference between groups (P = 0.27). Postoperative phone calls to physicians’ office occurred in 13.3% of cases with no difference between groups (P = 0.41). Conclusion Comparable rates of readmission, ED visits, hemorrhage, and patient phone calls were seen with a standard dose of 4 mg versus 0.5 mg/kg weight-based dosing of a short course of postoperative dexamethasone following radiofrequency ablation tonsillectomy.

A heterozygous missense mutation producing a variant of the islet β-cell- enriched MAFA transcription factor (p.Ser64Phe (S64F)) was identified in patients who developed adult-onset, β-cell dysfunction (diabetes or insulinomatosis), with men more prone to diabetes than women. This mutation engenders increased stability to the normally unstable MAFA protein. To obtain insight into how this variant impacts β cell function, we developed a mouse model expressing S64F MafA and found sex- dependent phenotypes, with heterozygous mutant males (MafAS64F/+) displaying impaired glucose tolerance while females were slightly hypoglycemic with improved blood glucose clearance. Only MafAS64F/+ males showed transiently higher MafA protein levels preceding the onset of glucose intolerance and sex-dependent, differential expression of genes involved in Ca2+ signaling, DNA damage, aging, and senescence. Functional changes in islet Ca2+ handling and signs of islet aging and senescence processes were uniquely observed in male animals. In addition, MAFAS64F expression in male human β cells accelerated cellular senescence and increased production of WT senescence-associated secretory proteins compared to cells expressing MAFA Together, these results implicate a conserved mechanism of accelerated islet aging and senescence in promoting diabetes in MAFAS64F carriers in a sex-dependent manner.

Hearing loss is a disabling condition that increases with age and has been linked to difficulties in walking and increased risk of falls. The purpose of this study is to investigate changes in gait parameters associated with hearing loss in a group of older adults aged 60 or greater. Custom-engineered footwear was used to collect spatiotemporal gait data in an outpatient clinical setting. Multivariable linear regression was used to determine the relationship between spatiotemporal gait parameters and high and low frequency hearing thresholds of the poorer hearing ear, the left ear, and the right ear, respectively, adjusting for age, sex, race/ethnicity, and the Dizziness Handicap Inventory&ndash, Screening version score. Worsening high and low frequency hearing thresholds were associated with increased variability in double support period. Effects persisted after adjusting for the effects of age and perceived vestibular disability and were greater for increases in hearing thresholds for the right ear compared to the left ear. These findings illustrate the importance of auditory feedback for balance and coordination and may suggest a right ear advantage for the influence of auditory feedback on gait.

Elevated triglycerides (TGs) and impaired TG clearance increase the risk of cardiovascular disease in both men and women, but molecular mechanisms remain poorly understood. Cholesteryl ester transfer protein (CETP) is a lipid shuttling protein known for its effects on high‐density lipoprotein cholesterol. Although mice lack CETP, transgenic expression of CETP in mice alters TG metabolism in males and females by sex‐specific mechanisms. A unifying mechanism explaining how CETP alters TG metabolism in both males and females remains unknown. Since low‐density lipoprotein receptor (LDLR) regulates both TG clearance and very low density lipoprotein (VLDL) production, LDLR may be involved in CETP‐mediated alterations in TG metabolism in both males and females. We hypothesize that LDLR is required for CETP to alter TG metabolism in both males and females. We used LDLR null mice with and without CETP to demonstrate that LDLR is required for CETP to raise plasma TGs and to impair TG clearance in males. We also demonstrate that LDLR is required for CETP to increase TG production and to increase the expression and activity of VLDL synthesis targets in response to estrogen. Additionally, we show that LDLR is required for CETP to enhance β‐oxidation. These studies support that LDLR is required for CETP to regulate TG metabolism in both males and females., Transgenic CETP expression in mice raises TGs in both males and females, but through distinct mechanisms. LDLR is required for CETP to impair TG clearance in males. In females, LDLR is required to raise TG production in response to estrogen and is required to enhance beta‐oxidation. LDLR represents a unifying target through which CETP alters TG metabolism.

A missense mutation of the pancreatic islet-enriched transcription factor MAFA (S64F) was identified in patients characterized by familial diabetes or insulinomatosis, with males more prone to diabetes. This variant converts the normally unstable MAFA protein to be unusually stable. A heterozygous germline mouse model expressing this variant (S64F MafA Het) mimics the sex-dependent phenotype in humans: Het males have impaired glucose tolerance while Het females have hypoglycemia. Het males also showed increased MafA protein stability preceding glucose intolerance (Figure 1) and upregulation of genes involved in aging/senescence (Figure 2). These results implicate accelerated aging/senescence in islet β-cell dysfunction in males with the S64F MAFA mutation. Future studies will evaluate the broader significance of these processes in diabetes. Disclosure J. Cha: None. E.M. Walker: None. X. Tong: None. M. Guo: None. J. Liu: None. S. Yu: None. D. Iacovazzo: None. F. Mauvais-Jarvis: None. S.E. Flanagan: None. M. Korbonits: None. J.M. Stafford: None. R. Stein: None. Funding National Institutes of Health (T32DK007061, F32DK109577, R01DK090570); JDRF (3-PDF-2019-738-A-NDK109577)

Background: We previously showed that mice lacking MΦLRP1 -/- (low-density lipoprotein receptor–related protein 1 in macrophages) undergo accelerated atherosclerotic plaque formation due to changes in macrophages including increased apoptosis, decreased efferocytosis, and exaggerated transition to the inflammatory M1 phenotype. Here we sought to explore the role of macrophage low-density lipoprotein receptor–related protein 1 during regression of atherosclerosis since regressing plaques are characterized by transitioning of macrophages to M2 status as inflammation resolves. Methods: Apolipoprotein E -/- mice on a high-fat diet for 12 weeks were reconstituted with bone marrow from apolipoprotein E–producing wild-type or MΦLRP1 -/- mice, and then placed on a chow diet for 10 weeks (n=9 to 11 mice/group). A cohort of apolipoprotein E -/- mice reconstituted with apolipoprotein E -/- bone marrow served as baseline controls (n=9). Results: Plaques of both wild-type and MΦLRP1 -/- bone marrow recipients regressed compared with controls (11% and 22%, respectively; P -/- recipients were 13% smaller than those of wild-type recipients ( P -/- marrow had 36% fewer M1 macrophages ( P P + macrophages in mediastinal lymph nodes. Finally, in vivo studies of reverse cholesterol transport showed a 1.4-fold higher reverse cholesterol transport in MΦLRP1 -/- recipient mice ( P Conclusions: Absence of macrophage low-density lipoprotein receptor–related protein 1 unexpectedly accelerates atherosclerosis regression, enhances reverse cholesterol transport, and increases expression of the motility receptor CCR7, which drives macrophage egress from lesions.

Background: Endogenous sex hormones are important for metabolic health in men and women. Before menopause, women are protected from atherosclerotic cardiovascular disease (ASCVD) relative to men. Women have fewer cardiovascular complications of obesity compared to men with obesity. Endogenous estrogens have been proposed as a mechanism that lessens ASCVD risk, as risk of glucose and lipid abnormalities increases when endogenous estrogens decline with menopause. While baseline risk is higher in males than females, endogenously produced androgens are also protective against fatty liver, diabetes and ASCVD, as risk goes up with androgen deprivation and with the decline in androgens with age. Scope of Review: In this review, we discuss evidence of how endogenous sex hormones and hormone treatment approaches impact fatty acid, triglyceride, and cholesterol metabolism to influence metabolic and cardiovascular risk. We also discuss potential reasons for why treatment strategies with estrogens and androgens in older individuals fail to fully recapitulate the effects of endogenous sex hormones. Major Conclusions: The pathways that confer ASCVD protection for women are of potential therapeutic relevance. Despite protection relative to men, ASCVD is still the major cause of mortality in women. Additionally, diabetic women have similar ASCVD risk as diabetic men, suggesting that the presence of diabetes may offset the protective cardiovascular effects of being female through unknown mechanisms. Keywords: Estrogen, Androgens, Sex differences, Cardiovascular disease, Lipid metabolism, Obesity

A heterozygous missense mutation producing a variant of the islet β-cell-enriched MAFA transcription factor (Ser(S)64Phe(F) MAFA) was identified in humans who developed adult-onset, β-cell dysfunction (diabetes or insulinomatosis), with men more prone to diabetes. This mutation engenders increased stability to the normally unstable MAFA protein. To obtain insight into how this variant impacts β cell function, we developed a mouse model expressing S64F MafA and found sex-dependent phenotypes, with heterozygous mutant males displaying impaired glucose tolerance while females were slightly hypoglycemic with improved blood glucose clearance. Only heterozygous males showed transiently higher MafA protein levels preceding the onset of glucose intolerance and sex-dependent, differential expression of genes involved in calcium signaling, DNA damage, aging, and senescence. Functional changes in islet calcium handling and signs of islet aging and senescence processes were uniquely observed in male animals. In addition, S64F MAFA expression in human, male EndoC-βH2 β cells accelerated cellular senescence and increased production of senescence-associated secretory proteins compared to cells expressing wild-type MAFA. Together, these results implicate a conserved mechanism of accelerated islet aging and senescence in promoting diabetes in S64F MAFA carriers in a sex-dependent manner.

To evaluate the association between Dizziness Handicap Inventory-Screening version (DHI-S) score and spatiotemporal gait parameters using SoleSound, a newly developed, inexpensive, portable footwear-based gait analysis system.Cross-sectional.One hundred eighteen patients recruited from otology clinic.Subjects completed the DHI-S survey and four uninterrupted walking laps wearing SoleSound instrumented footwear on a hard, flat surface for 100 m.For each subject, mean and coefficient of variation (CV) of stride length, cadence, walking speed, foot-ground clearance, double-support time, swing period, and stance-to-swing were computed by considering 40 strides of steady-state walking within each lap. Linear regression models were employed to study correlations between these variables and DHI-S scores after adjusting for age, sex, and race/ethnicity.Patients with higher DHI-S score took shorter steps and less steps per minute (-0.017 m and -1.1 steps/min per every four-point increase in DHI-S score, p 0.05) than patients with a lower DHI-S score, with slower walking speed (-0.025 m/s per every four-point increase in DHI-S score, p 0.01). Additionally, patients with higher DHI-S scores showed larger variability in all analyzed temporal parameters (+0.1% for CV of cadence, +0.5% for CV of double support period, +0.2% for CV of swing period, and +0.4% for CV of stance-to-swing, per every four-point increase in DHI-S score, p 0.01).SoleSound was effective in measuring a wide range of gait parameters. Patients' self-perception of vestibular handicap, as assessed with DHI-S, is associated with deterioration in measurable gait parameters independent of age.

The influenza A virus has accounted for the majority of influenza infections in the 2017 to 2018 flu season, with the typical clinical presentation including fever, myalgias, malaise, and nonproductive cough. Notably this season, we have recognized a cluster of influenza A cases presenting as severe neck and facial swelling, with the subsequent diagnosis of sialadenitis. Whereas previous authors have demonstrated isolated case reports of sialadenitis associated with influenza A infection, herein we describe the clinical history, laboratory values, and radiographic findings of four patients presenting to our institution in January 2018 with acute sialadenitis and influenza A infection. Laryngoscope, 2500-2502, 2018.

Mechanisms of sex differences in hypertriglyceridemia remain poorly understood. Small heterodimer partner (SHP) is a nuclear receptor that regulates bile acid, glucose, and lipid metabolism. SHP also regulates transcriptional activity of sex hormone receptors and may mediate sex differences in triglyceride (TG) metabolism. Here, we test the hypothesis that hepatic SHP mediates sex differences in TG metabolism using hepatocyte-specific SHP knockout mice. Plasma TGs in wild-type males were higher than in wild-type females and hepatic deletion of SHP lowered plasma TGs in males but not in females, suggesting hepatic SHP mediates plasma TG metabolism in a sex-specific manner. Additionally, hepatic deletion of SHP failed to lower plasma TGs in gonadectomized male mice or in males with knockdown of the liver androgen receptor, suggesting hepatic SHP modifies plasma TG via an androgen receptor pathway. Furthermore, the TG lowering effect of hepatic deletion of SHP was caused by increased clearance of postprandial TG and accompanied with decreased plasma levels of ApoC1, an inhibitor of lipoprotein lipase activity. These data support a role for hepatic SHP in mediating sex-specific effects on plasma TG metabolism through androgen receptor signaling. Understanding how hepatic SHP regulates TG clearance may lead to novel approaches to lower plasma TGs and mitigate cardiovascular disease risk.

Objective— Antiatherosclerotic effects of tumor necrosis factor-α (TNF-α) blockade in patients with systemic inflammatory states are not conclusively demonstrated, which suggests that effects depend on the cause of inflammation. Macrophage LRP1 (low-density lipoprotein receptor–related protein 1) and apoE contribute to inflammation through different pathways. We studied the antiatherosclerosis effects of TNF-α blockade in hyperlipidemic mice lacking either LRP1 (MΦLRP1 −/− ) or apoE from macrophages. Approach and Results— Lethally irradiated low-density lipoprotein receptor (LDLR) −/− mice were reconstituted with bone marrow from either wild-type, MΦLRP1 −/− , apoE −/− or apoE −/− /MΦLRP1 −/− (DKO) mice, and then treated with the TNF-α inhibitor adalimumab while fed a Western-type diet. Adalimumab reduced plasma TNF-α concentration, suppressed blood ly6C hi monocyte levels and their migration into the lesion, and reduced lesion cellularity and inflammation in both wild-type→LDLR −/− and apoE −/− →LDLR −/− mice. Overall, adalimumab reduced lesion burden by 52% to 57% in these mice. Adalimumab reduced TNF-α and blood ly6C hi monocyte levels in MΦLRP1 −/− →LDLR −/− and DKO→LDLR −/− mice, but it did not suppress ly6C hi monocyte migration into the lesion or atherosclerosis progression. Conclusions— Our results show that TNF-α blockade exerts antiatherosclerotic effects that are dependent on the presence of macrophage LRP1.

Elevated plasma TGs increase risk of cardiovascular disease in women. Estrogen treatment raises plasma TGs in women, but molecular mechanisms remain poorly understood. Here we explore the role of cholesteryl ester transfer protein (CETP) in the regulation of TG metabolism in female mice, which naturally lack CETP. In transgenic CETP females, acute estrogen treatment raised plasma TGs 50%, increased TG production, and increased expression of genes involved in VLDL synthesis, but not in nontransgenic littermate females. In CETP females, estrogen enhanced expression of small heterodimer partner (SHP), a nuclear receptor regulating VLDL production. Deletion of liver SHP prevented increases in TG production and expression of genes involved in VLDL synthesis in CETP mice with estrogen treatment. We also examined whether CETP expression had effects on TG metabolism independent of estrogen treatment. CETP increased liver β-oxidation and reduced liver TG content by 60%. Liver estrogen receptor α (ERα) was required for CETP expression to enhance β-oxidation and reduce liver TG content. Thus, CETP alters at least two networks governing TG metabolism, one involving SHP to increase VLDL-TG production in response to estrogen, and another involving ERα to enhance β-oxidation and lower liver TG content. These findings demonstrate a novel role for CETP in estrogen-mediated increases in TG production and a broader role for CETP in TG metabolism.

Type 2 diabetes is characterized by insulin resistance, hyperglycemia, and progressive β cell dysfunction. Excess glucose and lipid impair β cell function in islet cell lines, cultured rodent and human islets, and in vivo rodent models. Here, we examined the mechanistic consequences of glucotoxic and lipotoxic conditions on human islets in vivo and developed and/or used 3 complementary models that allowed comparison of the effects of hyperglycemic and/or insulin-resistant metabolic stress conditions on human and mouse islets, which responded quite differently to these challenges. Hyperglycemia and/or insulin resistance impaired insulin secretion only from human islets in vivo. In human grafts, chronic insulin resistance decreased antioxidant enzyme expression and increased superoxide and amyloid formation. In human islet grafts, expression of transcription factors NKX6.1 and MAFB was decreased by chronic insulin resistance, but only MAFB decreased under chronic hyperglycemia. Knockdown of NKX6.1 or MAFB expression in a human β cell line recapitulated the insulin secretion defect seen in vivo. Contrary to rodent islet studies, neither insulin resistance nor hyperglycemia led to human β cell proliferation or apoptosis. These results demonstrate profound differences in how excess glucose or lipid influence mouse and human insulin secretion and β cell activity and show that reduced expression of key islet-enriched transcription factors is an important mediator of glucotoxicity and lipotoxicity.

In clinical trials, inhibition of cholesteryl ester transfer protein (CETP) raises HDL cholesterol levels but does not robustly improve cardiovascular outcomes. Approximately two-thirds of trial participants are obese. Lower plasma CETP activity is associated with increased cardiovascular risk in human studies, and protective aspects of CETP have been observed in mice fed a high-fat diet (HFD) with regard to metabolic outcomes. To define whether CETP inhibition has different effects depending on the presence of obesity, we performed short-term anacetrapib treatment in chow- and HFD-fed CETP transgenic mice. Anacetrapib raised HDL cholesterol and improved aspects of HDL functionality, including reverse cholesterol transport, and HDL’s antioxidative capacity in HFD-fed mice was better than in chow-fed mice. Anacetrapib worsened the anti-inflammatory capacity of HDL in HFD-fed mice. The HDL proteome was markedly different with anacetrapib treatment in HFD- versus chow-fed mice. Despite benefits on HDL, anacetrapib led to liver triglyceride accumulation and insulin resistance in HFD-fed mice. Overall, our results support a physiologic importance of CETP in protecting from fatty liver and demonstrate context selectivity of CETP inhibition that might be important in obese subjects.

Before menopause, women are protected from atherosclerotic heart disease associated with obesity relative to men. Sex hormones have been proposed as a mechanism that differentiates this risk. In this review, we discuss the literature around how the endogenous sex hormones and hormone treatment approaches after menopause regulate fatty acid, triglyceride, and cholesterol metabolism to influence cardiovascular risk.The important regulatory functions of estrogen signaling pathways with regard to lipid metabolism have been in part obscured by clinical trials with hormone treatment of women after menopause, due to different formulations, routes of delivery, and pairings with progestins. Oral hormone treatment with several estrogen preparations increases VLDL triglyceride production. Progestins oppose this effect by stimulating VLDL clearance in both humans and animals. Transdermal estradiol preparations do not increase VLDL production or serum triglycerides.Many aspects of sex differences in atherosclerotic heart disease risk are influenced by the distributed actions of estrogens in the muscle, adipose, and liver. In humans, 17β-estradiol (E2) is the predominant circulating estrogen and signals through estrogen receptor alpha (ERα), estrogen receptor beta (ERβ), and G-protein-coupled estrogen receptor (GPER). Over 1000 human liver genes display a sex bias in their expression, and the top biological pathways are in lipid metabolism and genes related to cardiovascular disease. Many of these genes display variation depending on estrus cycling in the mouse. Future directions will likely rely on targeting estrogens to specific tissues or specific aspects of the signaling pathways in order to recapitulate the protective physiology of premenopause therapeutically after menopause.

Objective Hepatocyte deletion of estrogen receptor alpha (LKO-ERα) worsens fatty liver, dyslipidemia, and insulin resistance in high-fat diet fed female mice. However, whether or not hepatocyte ERα regulates reverse cholesterol transport (RCT) in mice has not yet been reported. Methods and results Using LKO-ERα mice and wild-type (WT) littermates fed a Western-type diet, we found that deletion of hepatocyte ERα impaired in vivo RCT measured by the removal of 3H-cholesterol from macrophages to the liver, and subsequently to feces, in female mice but not in male mice. Deletion of hepatocyte ERα decreased the capacity of isolated HDL to efflux cholesterol from macrophages and reduced the ability of isolated hepatocytes to accept cholesterol from HDL ex vivo in both sexes. However, only in female mice, LKO-ERα increased serum cholesterol levels and increased HDL particle sizes. Deletion of hepatocyte ERα increased adiposity and worsened insulin resistance to a greater degree in female than male mice. All of the changes lead to a 5.6-fold increase in the size of early atherosclerotic lesions in female LKO-ERα mice compared to WT controls. Conclusions Estrogen signaling through hepatocyte ERα plays an important role in RCT and is protective against lipid retention in the artery wall during early stages of atherosclerosis in female mice fed a Western-type diet., Highlights • Hepatocyte ERα contributes to reverse cholesterol transport and protects against atherosclerosis development. • Hepatocyte ERα promotes HDL function as well as liver cholesterol uptake and whole-body cholesterol removal. • Hepatocyte ERα may be a control point in atherosclerosis for females.

We previously showed that mice lacking macrophage LDL receptor-related protein 1 (LRP1) undergo accelerated lesion formation due to increased apoptosis, decreased efferocytosis, and enhanced macrophage transformation into the inflammatory M1 phenotype. In vitro, LRP1-deficient macrophages (MΦLRP1 -/- ) show enhanced plasticity with exaggerated polarization towards either the inflammatory M1- or the anti-inflammatory M2-phenotype depending on the stimulant (LPS or IL-4, respectively). During atherosclerosis regression, the M2:M1 macrophage ratio increases as lesion M1 macrophages egress and inflammation resolves. Thus, we hypothesize that atherosclerosis regression is accelerated in MΦLRP1 -/- mice via enhanced macrophage M2 polarization and CCR7-dependent M1 macrophage egress. ApoE-/- mice on high fat diet for 12 weeks were reconstituted with bone marrow from wildtype (WT) or MΦLRP1 -/- mice and then placed on chow diet for 8 weeks. In this model, apoE is reintroduced into circulation to correct the hyperlipidemia and induce regression of atherosclerotic lesions. A cohort of apoE -/- mice reconstituted with apoE -/- bone marrow served as baseline controls. Lesions in both WT and MΦLRP1 -/- mice regressed relative to controls (11% and 22%, respectively; p-/- lesions were 13% smaller than those of WT mice (p-/- lesions contained 36% fewer M1 macrophages compared to WT (pIn vivo studies of reverse cholesterol transport (RCT) revealed that MΦLRP1 -/- have a 1.4-fold higher RCT compared to WT mice (p-/- lesions contained 2.5-fold more CCR7 + macrophages relative to WT lesions (pin vivo egress assay 4.6-fold more CCR7 + macrophages were found in mediastinal lymph nodes. In vitro , M1-differentiated MΦLRP1 -/- macrophages expressed 1.6-fold higher Ccr7 mRNA compared to WT controls (p

Attention is usually drawn to the negative relationship between Richard Hooker and his Puritan opponents. Such concerns dominate the polemical landscape of the late 16th and 17th centuries. However, the extent to which later Puritans appear to converge on Hooker’s epistemology and overall attitude to the place of reason, Scripture and sacrament is often overlooked. This paper consider some key affirmations from Richard Baxter, John Owen and Hooker’s contemporary William Perkins. The paper concludes that in more settled times substantive agreement might have been found on issues that during the reigns of Elizabeth and James I were profoundly divisive including the question of ministry orders

The Psalms are the most cited portions of Scripture in the New Testament. This paper investigates Paul’s use of the Psalms and seeks to answer the concern that his citation strategy is both arbitrary and self-serving. Inasmuch as it has sometimes been concluded that Paul, in midrashic fashion, forced his citations to say something contrary to a more natural reading. This paper suggests that Paul uses citation criteria very carefully. Preliminary results point to the use of texts that lie well within their natural reading, yet exegeted in such a way that the resulting exegesis is folded back into the text as the apostle cites it. Thus rather than citing texts arbitrarily, Paul uses great skill and sophistication in selecting and utilising texts with exegetical precision. In so doing, Paul is not using midrash but may actually be developing a characteristically Christian approach to the citation of sacred text

Over the last number of years, multiple research projects have begun to create augmented reality (AR) applications that use augmented reality agents, or AuRAs, as their principle interaction and development paradigm. This paper aims to address this new and distinct field of AuRAs by asking three questions: why should AuRAs be researched, when are they a useful paradigm, and how can they be developed? The first question explores the motivation behind applying AuRAs to AR. Specifically, it investigates whether AuRAs are purely an interaction paradigm, or whether they can also serve as a development paradigm, by outlining in which circumstances it is appropriate for a project to use AuRAs and where their addition would only add unnecessary complexity. A navigational experiment, performed in simulated AR, explores the second question of when AuRAs can be a useful concept in AR applications. Results from this experiment suggest that an embodied virtual character allows for faster navigation along a shorter route than directional arrows or marking the target with an AR "bubble". An exploration of the limitations of the simulated AR environment illuminates how faithfully the experiment recreated the environmental challenges that AuRAs can help to address. Finally, the question of how to develop such applications is addressed through the introduction of the agent factory augmented reality toolkit that allows the rapid prototyping of such applications. Results from a usability study on the toolkit are also presented.

In this reflection paper, the author considers the language and content relating to the sacred and the transcendent and the expectations arising from such language. Contending that its secular usage is sufficiently unreferenced author asks whether such language can still be used in Christian discourse which by nature is particular. The author concludes that human discourse on transcendence is common to all people in various ways sometimes mutually inclusive yet often exclusive. Christian discourse is able to use the terms available to depict the essence of human desire but historically has defended the particularity of biblical language as necessary to preserve its Christological imperative which is its distinctive departure from secular appropriation of mystery

In the Lawes of Ecclesiastical Polity, Richard Hooker defended the Elizabethan Settlement against what he took to be the excesses of Puritan reform. In this paper, it is argued that the theological cohesion of the Lawes took its centre from Hooker’s dynamic and pervasive understanding of God’s providence through both the objective reality of Scripture, sacrament, noetic redemption, church and Holy Spirit. Yet it was also the secret and mystical operations of the Holy Spirit that created and transformed objectivity into lived experience by which divine grace could be understood and received, joining us to Christ, and incorporating believers in mystical union.

Historicist approaches to the reading of sacred texts, rapidly attain a point where further research produces diminishing returns, resulting in more historical speculation rather than less. This is the opposite of the desired result. The cause of this impasse lies in a failure to discern the rhetorical techniques of the author as a basic reading strategy. Similarly, it is necessary to discern that the author has already made key determinations as to historicity. What is now required of the reader is a deepened appreciation of the intentional theological, ontological and existential implications of the narrative. This paper examines how a literary/rhetorical approach may yield positive results in the case of the call of Nathanael, a narrative fragment that poses intriguing critical questions, both theological and Christological. The results suggest a dominical encounter that supplies the reader with pre-emptive eschatological intensity through deliberate juxtaposition of Nathanael’s disbelief and Jesus’ selfawareness held together in a matrix of scriptural fulfilment

Pathway-selective insulin resistance where insulin fails to suppress hepatic glucose production but promotes liver fat storage may underlie glucose and lipid abnormalities after menopause. We tested the mechanisms by which estrogen treatment may alter the impact of a high-fat diet (HFD) when given at the time of ovariectomy (OVX) in mice. Female C57BL/6J mice underwent sham operation, OVX, or OVX with estradiol (E2) treatment and were fed an HFD. Hyperinsulinemic-euglycemic clamps were used to assess insulin sensitivity, tracer incorporation into hepatic lipids, and liver triglyceride export. OVX mice had increased adiposity that was prevented with E2 at the time of OVX. E2 treatment increased insulin sensitivity with OVX and HFD. In sham and OVX mice, HFD feeding induced fatty liver, and insulin reduced hepatic apoB100 and liver triglyceride export. E2 treatment reduced liver lipid deposition and prevented the decrease in liver triglyceride export during hyperinsulinemia. In mice lacking the liver estrogen receptor α, E2 after OVX limited adiposity but failed to improve insulin sensitivity, to limit liver lipid deposition, and to prevent insulin suppression of liver triglyceride export. In conclusion, estrogen treatment may reverse aspects of pathway-selective insulin resistance by promoting insulin action on glucose metabolism but limiting hepatic lipid deposition.

Obesity in women is increased by the loss of circulating estrogen after menopause. Shift work, which disrupts circadian rhythms, also increases the risk for obesity. It is not known whether ovarian hormones interact with the circadian system to protect females from obesity. During high-fat feeding, male C57BL/6J mice develop profound obesity and disruption of daily rhythms. Since C57BL/6J female mice did not develop diet-induced obesity (during 8 weeks of high-fat feeding), we first determined if daily rhythms in female mice were resistant to disruption from high-fat diet. We fed female PERIOD2:LUCIFERASE mice 45% high-fat diet for 1 week and measured daily rhythms. Female mice retained robust rhythms of eating behavior and locomotor activity during high-fat feeding that were similar to chow-fed females. In addition, the phase of the liver molecular timekeeping (PER2::LUC) rhythm was not altered by high-fat feeding in females. To determine if ovarian hormones protected daily rhythms in female mice from high-fat feeding, we analyzed rhythms in ovariectomized mice. During high-fat feeding, the amplitudes of the eating behavior and locomotor activity rhythms were reduced in ovariectomized females. Liver PER2::LUC rhythms were also advanced by ~4 hours by high-fat feeding, but not chow, in ovariectomized females. Together these data show circulating ovarian hormones protect the integrity of daily rhythms in female mice during high-fat feeding.

Aims: Cognitive decline disproportionately affects older adult type 2 diabetes. We tested whether randomized intensive glucose-lowering reduces the rate(s) of cognitive decline in adults with advanced type 2 diabetes (mean: age, 60 years; diabetes duration, 11 years) from the Veterans Affairs Diabetes Trial. Methods: A battery of neuropsychological tests (digit span, digit symbol substitution (DSym), and Trails-making Part B (TMT-B)) was administered at baseline in ~1700 participants and repeated at year 5. Thirty-six risk factors were evaluated as predictors of cognitive decline in multivariable regression analyses.Results: The mean age-adjusted, DSym or TMT-B declined significantly in all study participants (P < 0.001). Randomized intensive glucose-lowering did not significantly alter the rate of cognitive decline. The final model of risk factors associated with 5-year decline in age-adjusted TMT-B included as significant predictors: longer baseline diabetes duration (beta = -0.028; P = 0.0057), lower baseline diastolic blood pressure (beta = 0.028; P < 0.001), and baseline calcium channel blocker medication use (beta = -0.639; P < 0.001). Higher baseline pulse pressure was significantly associated with decline in age-adjusted TMT-B suggesting a role for both higher systolic and lower diastolic blood pressure. Baseline thiazide diuretic use (beta= -0.549; P =0.015) was an additional significant predictor of 5-year decline in age-adjusted digit symbol score. Post-baseline systolic blood pressure-lowering was significantly associated (P < 0.001) with decline in TMT-B performance. There was a significant inverse association between post-baseline plasma triglyceride- lowering (P = 0.045) and decline in digit symbol substitution task performance.Conclusions: A five-year period of randomized intensive glucose-lowering did not significantly reduce the rate of cognitive decline in older-aged adults with type 2 diabetes. Systolic and diastolic blood pressure as well as plasma triglycerides were modifiable risk factors of the rate of cognitive decline in older adult type 2 diabetes.

Background: Triglycerides are an important risk factor for cardiovascular disease, especially in women. Hormone replacement therapy raises triglycerides (TG) in postmenopausal women, but mechanisms responsible remain poorly understood. Cholesteryl Ester Transfer Protein (CETP) is a serum protein that shuttles TG and cholesteryl ester between lipoproteins in humans and plays an important role in lipoprotein metabolism. The role of CETP in regulating whole body triglyceride homeostasis remains unclear. Mice (which naturally lack CETP) expressing a transgenic copy of CETP or their wild-type (WT) littermates were used to determine the role of CETP in regulating plasma and liver TG metabolism in response to estrogen. Methods and Results: Female CETP and WT mice were ovariectomized and given vehicle or estrogen treatment. Estrogen raised plasma TG in CETP females, but not in WT females. CETP expression impaired TG clearance independent of estrogen. Estrogen treatment raised very-low density lipoprotein (VLDL) TG production in CETP females, but not in WT females. Estrogen treatment augmented mRNA expression and protein activity of VLDL assembly and secretion targets (Apob, Mttp, PDI) in CETP females, but not in WT females. Additionally, CETP expression lowered liver TG content and increased mRNA expression of TG oxidation targets (Ppara, Acox1, Acadm, Cpt2). Deletion of liver estrogen receptor alpha prevented CETP-mediated decreases in liver TG content and increases in mRNA expression of TG oxidation targets. Liver-specific deletion of estrogen receptor alpha did not attenuate estrogen-mediated increases in plasma TG and VLDL-TG production in female mice expressing CETP. Deletion of liver small heterodimer partner attenuated CETP-mediated increases in plasma TG and VLDL-TG production with estrogen treatment. Deletion of small heterodimer partner also attenuated CETP-mediated increases in mRNA expression and protein activity of VLDL synthesis and assembly targets with estrogen treatment. Conclusion: These studies indicate several novel functions of CETP in regulating plasma and liver TG homeostasis. We also discovered that CETP expression in female mice also augments several aspects of estrogen action in liver that impact liver TG biology.

CETP inhibition has been used as a strategy to raise HDL cholesterol, but trials with two CETP inhibitors torcetrapib and dalcetrapib failed to prevent cardiovascular events for high-risk individuals. Of note, approximately 2/3 of patients in these clinical trials were obese. Obesity and fatty liver are known to significantly impact aspects of liver cholesterol metabolism and HDL biology. We propose that high-fat diet feeding (HFD) might adversely impact the effects of CETP inhibition on HDL composition and function. Mice naturally lack CETP expression, so we used CETP transgenic mice to evaluate the effects of administering the CETP inhibitor torcetrapib on HDL composition in chow- and HFD-fed CETP-transgenic mice. Because of the very short half-life of torcetrapib we used acute intravenous infusion of torcetrapib. In both diet groups torcetrapib infusion suppressed plasma CETP activity and raised HDL cholesterol content. In chow-fed CETP mice we found that torcetrapib resulted in changes in HDL composition that would be predicted to be favorable, including increases in apoA1, apoM and apoE protein levels for 2.5-fold ( P P P

Elevated plasma triglyceride (TG) levels contribute to an atherogenic dyslipidemia that is associated with obesity, diabetes, and metabolic syndrome. Numerous models of obesity are characterized by increased central nervous system (CNS) neuropeptide Y (NPY) tone that contributes to excess food intake and obesity. Previously, we demonstrated that intracerebroventricular (icv) administration of NPY in lean fasted rats also elevates hepatic production of very low-density lipoprotein (VLDL)-TG. Thus, we hypothesize that elevated CNS NPY action contributes to not only the pathogenesis of obesity but also dyslipidemia. Here, we sought to determine whether the effects of NPY on feeding and/or obesity are dissociable from effects on hepatic VLDL-TG secretion. Pair-fed, icv NPY-treated, chow-fed Long-Evans rats develop hypertriglyceridemia in the absence of increased food intake and body fat accumulation compared with vehicle-treated controls. We then modulated CNS NPY signaling by icv injection of selective NPY receptor agonists and found that Y1, Y2, Y4, and Y5 receptor agonists all induced hyperphagia in lean, ad libitum chow-fed Long-Evans rats, with the Y2 receptor agonist having the most pronounced effect. Next, we found that at equipotent doses for food intake NPY Y1 receptor agonist had the most robust effect on VLDL-TG secretion, a Y2 receptor agonist had a modest effect, and no effect was observed for Y4 and Y5 receptor agonists. These findings, using selective agonists, suggest the possibility that the effect of CNS NPY signaling on hepatic VLDL-TG secretion may be relatively dissociable from effects on feeding behavior via the Y1 receptor.

In recent years, an increasing number of Mixed Reality (MR) applications have been developed using agent technology—both for the underlying software and as an interface metaphor. However, no unifying field or theory currently exists that can act as a common frame of reference for these varied works. As a result, much duplication of research is evidenced in the literature. This paper seeks to fill this important gap by outlining ‘‘for the first time’’ a formal field of research that has hitherto gone unacknowledged, namely the field of Mixed Reality Agents (MiRAs), which are defined as agents embodied in a Mixed Reality environment. Based on this definition, a taxonomy is offered that classifies MiRAs along three axes: agency, based on the weak and strong notions outlined by Wooldridge and Jennings (1995); corporeal presence, which describes the degree of virtual or physical representation (body) of a MiRA; and interactive capacity, which characterises its ability to sense and act on the virtual and physical environment. Furthermore, this paper offers the first comprehensive survey of the state-of-the-art of MiRA research and places each project within the proposed taxonomy. Finally, common trends and future directions for MiRA research are discussed. By defining Mixed Reality Agents as a formal field, establishing a common taxonomy, and retrospectively placing existing MiRA projects within it, future researchers can effectively position their research within this landscape, thereby avoiding duplication and fostering reuse and interoperability. Science Foundation Ireland au,ti,ke,SB-09/09/2011

OBJECTIVE—Elevated triglyceride (TG) is the major plasma lipid abnormality in obese and diabetic patients and contributes to cardiovascular morbidity in these disorders. We sought to identify novel mechanisms leading to hypertriglyceridemia. Resistance to negative feedback signals from adipose tissue in key central nervous system (CNS) energy homeostatic circuits contributes to the development of obesity. Because triglycerides both represent the largest energy depot in the body and are elevated in both the plasma and adipose in obesity and diabetes, we hypothesized that the same neural circuits that regulate energy balance also regulate the secretion of TGs into plasma. RESEARCH DESIGN AND METHODS—In normal fasting rats, the TG secretion rate was estimated by serial blood sampling after intravascular tyloxapol pretreatment. Neuropeptide Y (NPY) signaling in the CNS was modulated by intracerebroventricular injection of NPY, receptor antagonist, and receptor agonist. RESULTS—A single intracerebroventricular injection of NPY increased TG secretion by 2.5-fold in the absence of food intake, and this was determined to be VLDL by fast performance liquid chromatography (FPLC). This effect was recapitulated by activating NPY signaling in downstream neurons with an NPY-Y5 receptor agonist. An NPY-Y1 receptor antagonist decreased the elevated TGs in the form of VLDL secretion rate by 50% compared with vehicle. Increased TG secretion was due to increased secretion of VLDL particles, rather than secretion of larger particles, because apolipoprotein B100 was elevated in FPLC fractions corresponding to VLDL. CONCLUSIONS—We find that a key neuropeptide system involved in energy homeostasis in the CNS exerts control over VLDL-TG secretion into the bloodstream.

John M Stafford1, Tom Elasy21Division of Diabetes Endocrinology and Metabolism, Vanderbilt University; 2Vanderbilt Eskind Diabetes Clinic, Vanderbilt University Medical CenterAbstract: Type 2 diabetes mellitus (DM2) is characterized by excessive hepatic gluconeogenesis, increased insulin resistance and a progressive inability of pancreatic beta cells to produce sufficient insulin. DM2 evolves as a progression from normal glucose tolerance, to impaired glucose tolerance (IGT) to frank diabetes mellitus, reflecting the establishment of insulin resistance and beta cell dysfunction. Insulin resistance not only contributes to impaired glycemic control in DM2, but to the development of hypertension, dyslipidemia and endothelial dysfunction. Cardiovascular disease is the primary morbidity for patients with DM2. The onset of insulin resistance and cardiovascular insult likely occurs well before the onset of IGT is detected clinically. Biguanides and thiazolidinediones (TZDs) are two classes of oral agents for the management of DM2 that improve insulin resistance, and thus have potential cardiovascular benefits beyond glycemic control alone. Metformin additionally inhibits hepatic gluconeogenesis. The combined use of two of these agents targets key pathophysiologic defects in DM2. Single pill combinations of rosiglitazone/metformin and pioglitazone/metformin have recently been approved for use in the US and Europe. This article reviews the clinical data behind the use of metformin in combination with TZDs for the management of diabetes, its impact on vascular health, side effects and potential mechanisms of action for combined use.Keywords: thiazolidinediones; metformin; Type 2 diabetes

Pharmacological approaches to reduce obesity have not resulted in dramatic reductions in the risk of coronary heart disease (CHD). Exercise, in contrast, reduces CHD risk even in the setting of obesity. Cholesteryl Ester Transfer Protein (CETP) is a lipid transfer protein that shuttles lipids between serum lipoproteins and tissues. There are sexual-dimorphisms in the effects of CETP in humans. Mice naturally lack CETP, but we previously reported that transgenic expression of CETP increases muscle glycolysis in fasting and protects against insulin resistance with high-fat diet (HFD) feeding in female but not male mice. Since glycolysis provides an important energy source for working muscle, we aimed to define if CETP expression protects against the decline in exercise capacity associated with obesity. We measured exercise capacity in female mice that were fed a chow diet and then switched to a HFD. There was no difference in exercise capacity between lean, chow-fed CETP female mice and their non-transgenic littermates. Female CETP transgenic mice were relatively protected against the decline in exercise capacity caused by obesity compared to WT. Despite gaining similar fat mass after 6 weeks of HFD-feeding, female CETP mice showed a nearly two-fold increase in run distance compared to WT. After an additional 6 weeks of HFD-feeding, mice were subjected to a final exercise bout and muscle mitochondria were isolated. We found that improved exercise capacity in CETP mice corresponded with increased muscle mitochondrial oxidative capacity, and increased expression of peroxisome proliferator-activated receptor gamma coactivator 1-alpha (PGC-1α). These results suggest that CETP can protect against the obesity-induced impairment in exercise capacity and may be a target to improve exercise capacity in the context of obesity.

Hepatic glucose and lipid metabolism are altered in metabolic disease (e.g. obesity, metabolic syndrome, and Type 2 diabetes). Insulin-dependent regulation of glucose metabolism is impaired. In contrast, lipogenesis, hypertriglyceridemia, and hepatic steatosis are increased. Because insulin promotes lipogenesis and liver fat accumulation, to explain the elevation in plasma and tissue lipids, investigators have suggested the presence of pathway-selective insulin resistance. In this model, insulin signaling to glucose metabolism is impaired, but insulin signaling to lipid metabolism is intact. We discuss the evidence for the differential regulation of hepatic lipid and glucose metabolism. We suggest that the primary phenotypic driver is altered substrate delivery to the liver, as well as the repartitioning of hepatic nutrient handling. Specific alterations in insulin signaling serve to amplify the alterations in hepatic substrate metabolism. Thus, hyperinsulinemia and its resultant increased signaling may facilitate lipogenesis, but are not the major drivers of the phenotype of pathway-selective insulin resistance.

The development of insulin resistance in the liver is a key event that drives dyslipidemia and predicts diabetes and cardiovascular risk with obesity. Clinical data show that estrogen signaling in males helps prevent adiposity and insulin resistance, which may be mediated through estrogen receptor-α (ERα). The tissues and pathways that mediate the benefits of estrogen signaling in males with obesity are not well defined. In female mice, ERα signaling in the liver helps to correct pathway-selective insulin resistance with estrogen treatment after ovariectomy. We assessed the importance of liver estrogen signaling in males using liver ERα-knockout (LKO) mice fed a high-fat diet (HFD). We found that the LKO male mice had decreased insulin sensitivity compared with their wild-type floxed (fl/fl) littermates during hyperinsulinemic euglycemic clamps. Insulin failed to suppress endogenous glucose production in LKO mice, indicating liver insulin resistance. Insulin promoted glucose disappearance in LKO and fl/fl mice similarly. In the liver, insulin failed to induce phosphorylation of Akt-Ser473and exclude FOXO1 from the nucleus in LKO mice, a pathway important for liver glucose and lipid metabolism. Liver triglycerides and diacylglycerides were also increased in LKO mice, which corresponded with dysregulation of insulin-stimulated ACC phosphorylation and DGAT1/2 protein levels. Our studies demonstrate that estrogen signaling through ERα in the liver helps prevent whole body and hepatic insulin resistance associated with HFD feeding in males. Augmenting hepatic estrogen signaling through ERα may lessen the impact of obesity on diabetes and cardiovascular risk in males.

Glucocorticoid induction of the phosphoenolpyruvate carboxykinase (PEPCK) gene requires a glucocorticoid response unit (GRU) comprised of two non-consensus glucocorticoid receptor (GR) binding sites, GR1 and GR2, and at least three accessory factor elements (gAF1-3). DNA-binding accessory proteins are commonly required for the regulation of genes whose products play an important role in metabolism, development, and a variety of defense responses, but little is known about why they are necessary. Quantitative, real time homogenous assays of cooperative protein-DNA interactions in complex media (e.g. nuclear extracts) have not previously been reported. Here we perform quantitative, real time equilibrium and stopped-flow fluorescence anisotropy measurements of protein-DNA interactions in nuclear extracts to demonstrate that GR binds to the GR1-GR2 elements poorly as compared with a palindromic or consensus glucocorticoid response element (GRE). Inclusion of either the gAF1 or gAF2 element with GR1-GR2, however, creates a high affinity binding environment for GR. GR can undergo multiple rounds of binding and dissociation to the palindromic GRE in less than 100 ms at nanomolar concentrations. The dissociation rate of GR is differentially slowed by the gAF1 or gAF2 elements that bind two functionally distinct accessory factors, COUP-TF/HNF4 and HNF3, respectively.

In the liver, glucocorticoids induce a 10-15-fold increase in the rate of transcription of the phosphoenolpyruvate carboxykinase (PEPCK) gene, which encodes a key gluconeogenic enzyme. This induction requires a multicomponent glucocorticoid response unit (GRU) comprised of four glucocorticoid accessory factor (AF) elements and two glucocorticoid receptor binding sites. We show that the AFs that bind the gAF1, gAF2, and gAF3 elements (hepatocyte nuclear factor [HNF]4/chicken ovalbumin upstream promoter transcription factor 1 and HNF3beta) all interact with steroid receptor coactivator 1 (SRC1). This suggests that the AFs function in part by recruiting coactivators to the GRU. The binding of a GAL4-SRC1 chimeric protein completely restores the glucocorticoid induction that is lost when any one of these elements is replaced with a GAL4 binding site. Thus, when SRC1 is recruited directly to gAF1, gAF2, or gAF3, the requirement for the corresponding AF is bypassed. Surprisingly, glucocorticoid receptor is still required when SRC1 is recruited directly to the GAL4 site, suggesting a role for the receptor in activating SRC1 in the context of the GRU. Structural variants of GAL4-SRC1 were used to identify requirements for the basic-helix-loop-helix and histone acetyltransferase domains of SRC1, and these are specific to the region of the promoter to which the coactivator is recruited.

Glucocorticoids stimulate gluconeogenesis by increasing the rate of transcription of genes that encode gluconeogenic enzymes such as phosphoenolpyruvate carboxykinase (PEPCK) and glucose-6-phosphatase. Previous studies have shown that hepatic nuclear factor 3 (HNF3) is required as an accessory factor for several glucocorticoid-stimulated genes, including PEPCK. Here, we show that adenovirus-mediated expression of an HNF3beta protein with a deleted C-terminal transactivation domain (HNF3betaDeltaC) reduces the glucocorticoid-induced expression of the PEPCK and glucose-6-phosphatase genes in H4IIE hepatoma cells. Furthermore, expression of this truncated HNF3 protein results in a proportionate reduction of glucocorticoid-stimulated glucose production from lactate and pyruvate in these cells. The expression of HNF3betaDeltaN, in which the N-terminal transactivation domain is deleted, does not exhibit any of these effects. These results provide direct evidence that members of the HNF3 family are required for proper regulation of hepatic gluconeogenesis. Modulation of the function of the HNF3 family of proteins might be used to reduce the excessive hepatic production of glucose that is an important pathophysiologic feature of diabetes mellitus.

Glucocorticoids exert their effects on gene transcription through ubiquitous receptors that bind to regulatory sequences present in many genes. These glucocorticoid receptors are present in all cell types, yet glucocorticoid action is controlled in a tissue-specific way. One mechanism for this control relies on tissue-specific transcriptional activators that bind in the vicinity of the glucocorticoid receptor and are required for receptor action. We now describe a gene-specific and tissue-specific inhibitory mechanism through which glucocorticoid action is repressed by a tissue-restricted transcription factor, hepatocyte nuclear factor-6 (HNF-6). HNF-6 inhibits the glucocorticoid-induced stimulation of two genes coding for enzymes of liver glucose metabolism, namely 6-phosphofructo-2-kinase and phospho enol pyruvate carboxykinase. Binding of HNF-6 to DNA is required for inhibition of glucocorticoid receptor activity. In vitro and in vivo experiments suggest that this inhibition is mediated by a direct HNF-6/glucocorticoid receptor interaction involving the amino-terminal domain of HNF-6 and the DNA-binding domain of the receptor. Thus, in addition to its known property of stimulating transcription of liver-expressed genes, HNF-6 can antagonize glucocorticoid-stimulated gene transcription.

Using HPLC chiral separation screening, various columns representing the polysaccharide, macrocyclic antibiotic and brush classes were assessed in multiple chromatographic modes for the separation of evacetrapib, a potential cardiovascular drug, from its enantiomer, two diastereomers and several impurities. Screening data consistently pointed to the brush-type Whelk-O 1 chiral column as most promising for this task. A systematic separation optimization process is outlined using the (S,S) Whelk-O 1 chiral column, first for the resolution of the isomers, and later including six potential impurities. A relatively complex yet rugged separation system was eventually identified that effectively resolves all compounds within a reasonable analysis time, and should serve as an adequate tool for evacetrapib bulk drug enantiopurity measurement.