Male Tg Research Articles

Low dose radioactive iodine ablation therapy (1.11GBq) for differentiated thyroid cancer in Western Turkey

ObjectiveAblation therapy is employed in low-risk differentiated thyroid cancer (DTC) cases to facilitate patient monitoring by reducing thyroglobulin (Tg) levels to measurable levels below after surgery by eliminating residual thyroid tissue. However, there is still uncertainty about the minimum activity dose required for effective ablation. Opting for low-dose [131I]-NaI for ablation offers several advantages for both patients and healthcare services. Particularly in this tumor group with a high life expectancy (approximately 90–95 % at 10 years), [131I]-NaI treatment should not pose a risk to the patient's post-treatment life and should not compromise their quality of life. However, there is a need for a well-defined identification of factors predicting successful ablation. MethodsClinical data, laboratory findings, and imaging tests of 287 patients with low-dose 1110 MBq (30 mCi) [131I]-NaI ablation therapy for DTC were retrospectively reviewed. Post-ablation imaging and laboratory findings categorized ablation success/failure. The successful ablation group was determined according to the excellent response criteria outlined in ATA criteria. Relationships between clinical, pathological findings, biochemical common variables, and treatment failure were analyzed. ResultsAn excellent response was achieved in 77% of the entire group according to ATA criteria post-ablation. Male gender and high Tg levels on the day of ablation (Tg cut-off: 10 ng/mL and 5.35 ng/mL) were associated with unsuccessful ablation. ConclusionsOur results indicate that a 1110MBq (30mCi) ablation dose is sufficient to achieve an excellent response in most low-risk DTC cases 6–12 months later. When selecting the dose for ablation, besides the histological markers mentioned in guidelines and age, we observed that stimulated Tg values and gender may be important in predicting ablation success.

The Association of Brain Insulin Resistance with Anesthesia/Surgery-Induced Cognitive Deterioration Is Female-Specific in 5XFAD Transgenic Mice.

Our previous studies indicated that anesthesia/surgery could aggravate cognitive impairment and tau pathology in female 5XFAD transgenic (Tg) mice. However, it is unknown whether there are sex differences in the susceptibility of developing postoperative cognitive dysfunction in 5XFAD Tg mice. In this study, we aim to determine whether anesthesia/surgery can have different effects on female and male 5XFAD Tg mice, and to explore the underpinning mechanisms. The mice received abdominal surgery under isoflurane anesthesia. Morris water maze was used to assess the cognitive function. Hippocampal levels of p-tau (AT8), p-IRS1 (Ser612), IRS1, p-GSK3β (Tyr216), and p-GSK3β (Ser9) at postoperative day 1 were evaluated by western blot assays. Anesthesia/surgery exaggerated cognitive impairment and tau pathology in female, but not male 5XFAD Tg mice. The anesthesia/surgery led to elevated hippocampus protein levels of p-IRS1 (Ser612)/IRS1 ratio and p-GSK3β (Tyr216) and reduced hippocampus protein levels of p-GSK3β (Ser9) in female, but not male 5XFAD Tg mice. This study demonstrated that female 5XFAD Tg mice were more susceptible to anesthesia/surgery-induced cognitive deterioration and tau pathology aggravation, potentially due to female-specific brain insulin resistance.

Abstract Mo120: Overexpression of Prostaglandin E2 EP3 Receptor Subtype Alters Calcium-Handling Proteins in Mouse Hearts

Prostaglandin E2 (PGE2) is an autacoid that acts through G-protein coupled receptors (EP1-EP4) in various cell types within the heart, including cardiomyocytes in which EP3 and EP4 predominate. We previously reported that mice with cardiomyocyte-specific overexpression of the EP3 receptor (EP3 TG) demonstrate reduced cardiac function and diminished cardiomyocyte contractility in isolated cardiomyocytes. We therefore hypothesized that PGE2 via the EP3 receptor regulates calcium handling proteins to reduce contractility. To test our hypothesis, we performed RNA sequencing (RNA seq) on the left ventricle of fifteen-week-old male EP3 TG mice along with their WT controls. Western blots were used to confirm changes in the expression of calcium-handling proteins such as Sarcoplasmic/endoplasmic reticulum calcium ATPase (SERCA2a), Ryanodine receptor 2 (RYR2), Phospholamban (PLB), Troponins (C, I, T) and voltage-gated calcium channel (CACNB2). For RNA seq, all data is reported as Log2Fold change, adjusted P value, and western blot data is reported as mean ± standard error (SE) of the mean. Additionally, isolated cardiomyocyte contractility was assessed using the IonOptix system, and data is reported as the mean ± SE. RNA seq data shows that SERCA2a and RYR2 expression were significantly downregulated in TG mice (SERCA2a -0.44, p=4.72 x 10 -6 ; RYR2: -0.86, p=4.08 x 10 -5 ) in addition to significant reductions in Troponin I (-0.43, p=0.038) and the Voltage-gated calcium channel (CACNB2: -0.71,p=0.0055). Western blot analyses confirmed the reductions in SERCA2a, RYR2, and CACNB2 although these changes were only significant for CACNB2 (1.0 ± 0.03 for WT vs 0.59 ± 0.04 for TG, p = 0.016). Expression of Troponins did not change in TG mice. Consistent with our previous data, IonOptix analysis shows reduced contractility of myocytes from EP3 TG mice (bl% peak h is 3.47 ± 0.20 for WT vs 1.0 ± 0.14 for TG, p<0.0001) despite a similar increase in the Ca 2+ transients (Ca 2+ peak h for WT= 0.86 ± 0.04 and TG=0.86 ± 0.07) suggesting potential changes in the sensitivity of the myofilament to Ca 2+ . In conclusion, the reduced contractility observed in EP3 TG mice may be due to alterations in calcium handling proteins and/or changes in calcium sensitivity at the level of the myofilament.

Sex-specific cardiovascular remodeling leads to a divergent sex-dependent development of heart failure in aged hypertensive rats

IntroductionThe prevalence of heart failure with preserved ejection fraction (HFpEF) is continuously rising and predominantly affects older women often hypertensive and/or obese or diabetic. Indeed, there is evidence on sex differences in the development of HF. Hence, we studied cardiovascular performance dependent on sex and age as well as pathomechanisms on a cellular and molecular level.MethodsWe studied 15-week- and 1-year-old female and male hypertensive transgenic rats carrying the mouse Ren-2 renin gene (TG) and compared them to wild-type (WT) controls at the same age. We tracked blood pressure and cardiac function via echocardiography. After sacrificing the 1-year survivors we studied vascular smooth muscle and endothelial function. Isolated single skinned cardiomyocytes were used to determine passive stiffness and Ca2+-dependent force. In addition, Western blots were applied to analyse the phosphorylation status of sarcomeric regulatory proteins, titin and of protein kinases AMPK, PKG, CaMKII as well as their expression. Protein kinase activity assays were used to measure activities of CaMKII, PKG and angiotensin-converting enzyme (ACE).ResultsTG male rats showed significantly higher mortality at 1 year than females or WT male rats. Left ventricular (LV) ejection fraction was specifically reduced in male, but not in female TG rats, while LV diastolic dysfunction was evident in both TG sexes, but LV hypertrophy, increased LV ACE activity, and reduced AMPK activity as evident from AMPK hypophosphorylation were specific to male rats. Sex differences were also observed in vascular and cardiomyocyte function showing different response to acetylcholine and Ca2+-sensitivity of force production, respectively cardiomyocyte functional changes were associated with altered phosphorylation states of cardiac myosin binding protein C and cardiac troponin I phosphorylation in TG males only. Cardiomyocyte passive stiffness was increased in TG animals. On a molecular level titin phosphorylation pattern was altered, though alterations were sex-specific. Thus, also the reduction of PKG expression and activity was more pronounced in TG females. However, cardiomyocyte passive stiffness was restored by PKG and CaMKII treatments in both TG sexes.ConclusionHere we demonstrated divergent sex-specific cardiovascular adaptation to the over-activation of the renin-angiotensin system in the rat. Higher mortality of male TG rats in contrast to female TG rats was observed as well as reduced LV systolic function, whereas females mainly developed HFpEF. Though both sexes developed increased myocardial stiffness to which an impaired titin function contributes to a sex-specific molecular mechanism. The functional derangements of titin are due to a sex-specific divergent regulation of PKG and CaMKII systems.

Abstract 088: Modulatory Effects Of The Gut Microbiota-derived Short Chain Fatty Acids On Heart Rate And Vascular Tone In Larval Zebrafish

Introduction: Short chain fatty acids (SCFAs), such as acetic, propionic, and butyric acid, areproduced by fermentation of dietary fibers by the gut bacteria. Deregulation in production andhandling of SCFAs is associated with cardiovascular dysfunction in humans and rodents.However, limited studies have investigated the effect of SCFAs on cardiovascular parameters inthe zebrafish (ZF), an increasingly popular model in cardiovascular and gut microbiota research. Methods: Bacterial 16s sequencing and GC-MS were performed in adult male and female Tg(NFkB:EGFP) ZF fecal samples for analysis of the gut microbiota and SCFAs respectively. Inanaesthetized ZF larvae (7-9 dpf; MS-222, 0.3mM), measurements of heart rate (HR, bpm) andvascular tone (width of dorsal aorta, pixels) were performed every 10 minutes for an hour usinglive imaging (Nikon, 4x magnification) following administration of physiologic concentrations ofacetate (27.4 μM), butyrate (2.2 μM) and propionate (1.7 μM; pH=7.5) via immersion. Results: Relative proportions of SCFAs in the ZF were similar to those previously reported in rats andhumans, with highest levels of acetic acid (27.43 μM) followed by butyric (2.19 μM) and propionic(1.65 μM) acid. At the phylum level, the observed abundances of Proteobacteria, Firmicutes, andFusobacteria were similar to those reported in rodents and humans. Administration of selectSCFAs resulted in a ~20% decrease in HR at all time points following administration of butyrate(P<0.0001), and at 40-60min following administration of acetate (P<0.05), with no effect ofpropionate. In addition, a ~25% decrease in the width of the dorsal aorta was observed at 60 minfollowing administration of butyrate (P<0.05), with no effect of acetate or propionate. Conclusion: We report a similar composition and abundances of the gut microbiota and SCFAs between ZF,rodents and humans. In addition, both butyrate and acetate produced a bradycardia in the ZF,while the observed butyrate-dependent decrease in the vascular tone may be compensatory tobradycardia. Our findings demonstrate the potential for ZF as a model to study host-microbiotainteractions in regulation of cardiovascular function.

Abstract 062: Lower Middle Cerebral Artery Resistance In A Transgenic Rat Model Of Preeclampsia: A Platform For Studying Long-term Preeclampsia Induced Cerebrovascular Disease

Preeclampsia (PE) is a pregnancy disorder characterized by new onset hypertension and end-organ dysfunction. PE patients have increased risk of cerebrovascular disease (CVD) later in life; however, the mechanisms are unclear. We determined whether exposure to a PE-like syndrome in transgenic rat (TGA-PE: female TG for angiotensinogen mated to male TG for renin) alters left middle cerebral artery (LMCA) or left internal carotid (LICA) artery hemodynamics at 2 or 5 months post-pregnancy. The analyses of systolic (SBP) and diastolic (DBP) blood pressures and heart rate (HR) (by tail cuff; NIBP-8 Columbus Instruments), and LMCA and LICA pulsatility index (PI) (by transcranial Doppler (TCD); Vevo 2100), were performed at late gestation, and at 2 and 5 months post-pregnancy. SBP and DBP were elevated in TGA-PE vs. Sprague-Dawley (SD) in late pregnancy (n=5-6), and at 2 (n=4-6), and 5 months (n=2-3) post-pregnancy (p<0.05). HR was elevated in TGA-PE vs. SD in late pregnancy (493.5±10.6 vs. 392.5±14.2, p<0.05, n=5-6), but not at 2 or 5 months post-pregnancy. However, LMCA PI was lower in TGA-PE vs. SD at 2 months post-pregnancy (p<0.05), and tended to decrease in late gestation and at 5 months post-pregnancy. LICA PI was lower in TGA-PE vs. SD during pregnancy (0.729 ± 0.086 vs 1.34 ± 0.095, p<0.05, n=4-5). In summary, PE-like syndrome in TGA-PE resulted in higher SBP and lower LMCA resistance versus SD at 2 months post-pregnancy, suggesting a dysfunctional autoregulation of cerebral blood flow. Since women with history of PE have lower MCA resistance, we conclude that TGA-PE model may provide a suitable platform to investigate the mechanistic link between PE and future development of CVD.

The relationship between red blood cell distribution width and islet β-cell function indexes in patients with latent autoimmune diabetes in adults

AimsThe objective of this study is to explore the relationship between red blood cell distribution and islet β-cell function indexes in patients with Latent Autoimmune Diabetes in Adults.MethodsA total of 487 LADA patients were enrolled in this cross-sectional study. Patients were divided into three groups according to RDW tertiles. Clinical and laboratory measurements of age, height, weight, duration of diabetes, blood pressure, RDW, glycosylated hemoglobin A1c (HbA1c), C-peptide and blood lipids were performed. Homeostasis model assessment of insulin resistance (HOMA-IR) and homeostasis model assessment of β-cell function (HOMA-β) were assessed using homeostasis model assessment (HOMA) based on fasting blood glucose (FBG) and fasting C-peptide index (FCP). Correlations and multiple linear regressions were implemented to determine the association of RDW and islet function indexes.ResultsAs the increase of serum RDW level, the presence of β-cell secretion increased(P < 0.05). Correlation analysis indicated that there were significant correlations between RDW and male sex, age, duration, TG, Cr, FCP, and HOMA-β in all subjects. Multiple linear regressions indicated that RDW was significantly correlated with HOMA-β in the total population in both unadjusted and adjusted analysis. This finding could be reproduced in the subgroup of low GAD titers for HOMA-β. RDW were significantly associated with HbA1c in LADA patients with high GAD titers, but the correlation was not found in subgroup with low GAD titers in either unadjusted analyses or adjusted analysis.ConclusionsRDW is associated with β-cell function assessed by HOMA-β after adjusting for covariates in LADA patients with low GAD titers.

Transgenic disruption of endogenous glucocorticoid signaling in osteoblasts does not alter long-term K/BxN serum transfer-induced arthritis

BackgroundDisruption of glucocorticoid (GC) signaling in osteoblasts results in a marked attenuation of acute antibody-induced arthritis. The role of endogenous GCs in chronic inflammatory arthritis is however not fully understood. Here, we investigated the impact of endogenous GC signaling in osteoblasts on inflammation and bone integrity under chronic inflammatory arthritis by inactivating osteoblastic GC signaling in a long-term K/BxN serum transfer-induced induced arthritis (STIA) model.MethodsIntracellular GC signaling in osteoblasts was disrupted by transgenic (tg) overexpression of 11beta-hydroxysteroid dehydrogenase type 2 (11ß-HSD2). Inflammatory arthritis was induced in 5-week-old male tg mice and their wild type (WT) littermates by intraperitoneal (i.p.) injection of K/BxN serum while controls (CTRLs) received phosphate-buffered saline (PBS). In a first cohort, K/BxN STIA was allowed to abate until the endpoint of 42 days (STIA). To mimic rheumatic flares, a second cohort was additionally injected on days 14 and 28 with K/BxN serum (STIA boost). Arthritis severity was assessed daily by clinical scoring and ankle size measurements. Ankle joints were assessed histopathologically. Systemic effects of inflammation on long bone metabolism were analyzed in proximal tibiae by micro-computed tomography (μCT) and histomorphometry.ResultsAcute arthritis developed in both tg and WT mice (STIA and STIA boost) and peaked around day 8. While WT STIA and tg STIA mice showed a steady decline of inflammation until day 42, WT STIA boost and tg STIA boost mice exhibited an arthritic phenotype over a period of 42 days. Clinical arthritis severity did not differ significantly between WT and tg mice, neither in the STIA nor in the STIA boost cohorts. Correspondingly, histological indices of inflammation, cartilage damage, and bone erosion showed no significant difference between WT and tg mice on day 42. Histomorphometry revealed an increased bone turnover in tg CTRL and tg STIA boost compared to WT CTRL and WT STIA boost animals, respectively.ConclusionsIn contrast to the previously reported modulating effects of endogenous GC signaling in osteoblasts during acute K/BxN STIA, this effect seems to perish during the chronic inflammatory and resolution phase. These findings indicate that endogenous GC signaling in osteoblasts may mainly be relevant during acute and subacute inflammatory processes.

The Pattern of Dyslipidemia and its Association with Dietary Habits in Individuals Attending BSMMU Outpatient Department

Introduction: Abnormal level of circulating lipids refers to dyslipidemia. Dyslipidemia mostly affects non-communicable diseases like CHD, CVD, cancer, autoimmune disease, etc. The population group most affected by non-communicable diseases (NCDs) in Bangladesh comprises middle-aged persons and the elderly, having a major share of the disease burden and mortality in the country. Changing dietary habits and lifestyle, rapid urbanization, growth of commuting, tobacco use, uncontrolled growth and consumption of processed foods and beverages, indoor air pollution, road-traffic injuries, lack of awareness about healthful behavioral patterns, and psychological pressure are among the important factors responsible for such non-communicable diseases. The present study was conducted with the goal of observing any association between dyslipidemia and dietary habits in men and women. Aim of the study: The aim of the study was to observe the association of dyslipidemia with dietary habits. Methods: This cross-sectional analytical study was conducted at the Department of Biochemistry, Bangabandhu Sheikh Mujib Medical University (BSMMU), Dhaka, Bangladesh. The study duration was one year, from March 2016 to February 2017. Non-probability sampling method was used to select a total of 245 dyslipidemia cases from the adult population attending the BSMMU outpatient department during the study period. Result: The majority of the dyslipidemic patients had isolated hypercholesterolemia. All types of dyslipidemia had a significantly higher prevalence among the male population. Mixed hyperlipidemia was significantly higher among the older population. Statistical significance was only observed among the total cholesterol levels and the male population and TG level and the female population of mixed hyperlipidemic subjects in regards to healthy food consumption. Unhealthy food consumption had a high correlation with dyslipidemia in both male and female population. Conclusion: The study shows that isolated hypercholesterolemia is prevalent. Food habits also have an impact on lipid profile among study subjects. Healthy foods are mostly associated with high HDL-C. Unhealthy food consumption has a high correlation with dyslipidemia in both male and female populations.

High Intensity Exercise Improves Cardiorespiratory Capacity in a Mouse Model of Hypertrophic Cardiomyopathy

IntroductionCardiorespiratory capacity (pVO2) is an important prognostic indicator in patients with HCM. Individuals with HCM that have a lower pVO2 possess a greater risk for heart failure (HF) and mortality. High intensity exercise (HIE) can increase pVO2 to a greater degree compared to other training modalities, including when used for cardiac rehabilitation for in cardiac disease states (e.g., HF and Cardiovascular disease). The effects of HIE on HCM, however, are largely unknown. Our study sought to evaluate the effects of High Intensity Interval Training (HIIT) on pVO2, as well as cardiac structural and functional parameters, in a preclinical mouse model of HCM.MethodsFemale and male C57BL/6J non‐transgenic nTG (n=27) and TG (n=32) mice were subjected to HIIT protocol that mirrored methods used clinically in cardiac rehabilitation. A single treadmill training session included 4‐4 minute high intensity intervals (~80% preVO2 max speed) interspersed by 5‐3 minute recovery intervals (~50% preVO2 max speed) for 31 total minutes. Exercise training sessions were repeated 3 times per week for 6 weeks. Pre and post pVO2 and murine echocardiography were measured and analyzed by a blinded technician.ResultsFollowing 6 weeks of the HIIT, nTG female (+13.5 mL/kg/min ± 3.6, p&lt;0.01), nTG male (+13.5 mL/kg/min ± 3.6, p&lt;0.01) and TG female (+7.06 ± 3.3 mL/kg/min, p&lt;0.05) mice demonstrated an average increase in pVO2. A change in pVO2 observed in TG male mice did not reach statistical significance (+4.34 ± p=0.12). Sedentary female (‐15.9 mL/kg/min ± 3.3, p&lt;0.001) and male (‐13.1 mL/kg/min ± 3.9, p&lt;0.01) TG control mice experienced a significant decrease in pVO2 following the same period, while no change was observed in nTG sedentary controls. Independent of sex, nTG and TG HIIT mice had a significantly greater change in pVO2 compared to sedentary counterparts. HIIT training did not result in changes to the following echocardiography measures in either nTG or TG mice: LV mass, LA volume, cardiac output, or stroke volume.ConclusionOur results indicate that a translationally derived HIIT protocol improved cardiorespiratory capacity in a preclinical HCM mouse model, absent of adverse events or worsening of organ level disease pathology.

S-SCAM inhibits Axin-dependent synaptic function of GSK3\u03b2 in a sex-dependent manner

S-SCAM/MAGI-2 gene duplication is associated with schizophrenia (SCZ). S-SCAM overexpression in the forebrain induces SCZ-like phenotypes in a transgenic (Tg) mouse model. Interestingly, S-SCAM Tg mice show male-specific impairments in synaptic plasticity and working memory. However, mechanisms underlying the sex-specific deficits remain unknown. Here we report that S-SCAM Tg mice have male-specific deficits in synaptic GSK3β functions, as shown by reduced synaptic protein levels and increased inhibitory phosphorylation of GSK3β. This GSK3β hyper-phosphorylation was associated with increased CaMKII activities. Notably, synaptic levels of Axin1, to which GSK3β binds in competition with S-SCAM, were also reduced in male S-SCAM Tg mice. We demonstrated that Axin-binding is required for the S-SCAM overexpression-induced synaptic GSK3β reduction. Axin stabilization using XAV939 rescued the GSK3β deficits and restored the temporal activation of GSK3β during long-term depression in S-SCAM overexpressing neurons. Interestingly, synaptic Axin2 levels were increased in female S-SCAM Tg mice. Female sex hormone 17β-estradiol increased Axin2 expression and increased synaptic GSK3β levels in S-SCAM overexpressing neurons. These results reveal the role of S-SCAM in controlling Axin-dependent synaptic localization of GSK3β. Moreover, our studies point out the pathological relevance of GSK3β hypofunction found in humans and contribute to understanding the molecular underpinnings of sex differences in SCZ.

Chronic exposure to ambient traffic-related air pollution (TRAP) alters gut microbial abundance and bile acid metabolism in a transgenic rat model of Alzheimer’s disease

BackgroundTraffic-related air pollution (TRAP) is linked to increased risk for age-related dementia, including Alzheimer’s disease (AD). The gut microbiome is posited to influence AD risk, and an increase in microbial-derived secondary bile acids (BAs) is observed in AD patients. We recently reported that chronic exposure to ambient TRAP modified AD risk in a sex-dependent manner in the TgF344 AD (TG) rat. ObjectivesIn this study, we used samples from the same cohort to test our hypothesis that TRAP sex-dependently produces gut dysbiosis and increases secondary BAs to a larger extent in the TG rat relative to wildtype (WT) controls. MethodsMale and female TG and age-matched WT rats were exposed to either filtered air (FA) or TRAP from 28 days up to 15 months of age (n = 5–6). Tissue samples were collected after 9 or 14months of exposure. ResultsAt 10 months of age, TRAP tended to decrease the alpha diversity as well as the beneficial taxa Lactobacillus and Ruminococcus flavefaciens uniquely in male TG rats as determined by 16 S rDNA sequencing. A basal decrease in Firmicutes/Bacteroidetes (F/B) ratio was also noted in TG rats at 10 months. At 15 months of age, TRAP altered inflammation-related bacteria in the gut of female rats from both genotypes. BAs were more affected by chronic TRAP exposure in females, with a general trend of increase in host-produced unconjugated primary and microbiota-produced secondary BAs. Most of the mRNAs of the hepatic BA-processing genes were not altered by TRAP, except for a down-regulation of the BA-uptake transporter Ntcp in males. ConclusionIn conclusion, chronic TRAP exposure produced distinct gut dysbiosis and altered BA homeostasis in a sex and host genotype-specific manner.

Effects of Overexpression of Fibroblast Growth Factor 15/19 on Hepatic Drug Metabolizing Enzymes.

Fibroblast growth factors 15 (FGF15) and 19 (FGF19) are endocrine growth factors that play an important role in maintaining bile acid homeostasis. FGF15/19-based therapies are currently being tested in clinical trials for the treatment of nonalcoholic steatohepatitis and cholestatic liver diseases. To determine the physiologic impact of long-term elevations of FGF15/19, a transgenic mouse model with overexpression of Fgf15 (Fgf15 Tg) was used in the current study. The RNA sequencing (RNA-seq) analysis revealed elevations of the expression of several genes encoding phase I drug metabolizing enzymes (DMEs), including Cyp2b10 and Cyp3a11, in Fgf15 Tg mice. We found that the induction of several Cyp2b isoforms resulted in increased function of CYP2B in microsomal metabolism and pharmacokinetics studies. Because the CYP2B family is known to be induced by constitutive androstane receptor (CAR), to determine the role of CAR in the observed inductions, we crossed Fgf15 Tg mice with CAR knockout mice and found that CAR played a minor role in the observed alterations in DME expression. Interestingly, we found that the overexpression of Fgf15 in male mice resulted in a phenotypical switch from the male hepatic expression pattern of DMEs to that of female mice. Differences in secretion of growth hormone (GH) between male and female mice are known to drive sexually dimorphic, STAT5b-dependent expression patterns of hepatic genes. We found that male Fgf15 Tg mice presented with many features similar to GH deficiency, including lowered body length and weight, Igf-1 and Igfals expression, and STAT5 signaling. SIGNIFICANCE STATEMENT: The overexpression of Fgf15 in mice causes an alteration in DMEs at the mRNA, protein, and functional levels, which is not entirely due to CAR activation but associated with lower GH signaling.

Abstract 14346: High Intensity Exercise Increases Cardiorespiratory Capacity in a Preclinical Hypertrophic Cardiomyopathy Mouse Model

Introduction: Patients with Hypertrophic Cardiomyopathy (HCM) who possess greater cardiorespiratory capacity (pVO 2 ) are at lower risk for heart transplant and mortality. High intensity exercise (HIE) training used in cardiac rehabilitation for heart failure and cardiovascular disease results in superior increases in pVO 2. The purpose of this investigation was to evaluate the effects of high intensity interval training (HIIT) on pVO 2 , as well as cardiac structural and functional parameters known to be altered by exercise in a transgenic cardiac troponin T (TG) HCM mouse model. Methods: Female and male C57BL/6J non-transgenic nTG (n=27) and TG (n=32) mice underwent a translationally parallel cardiac rehabilitation HIIT protocol. One treadmill training bout included 4-4 minute high intensity intervals (~80% preVO2 max speed) interspersed by 5-3 minute recovery intervals (~50% preVO2 max speed) for 31 total minutes. Bouts were repeated 3 times/wk for 6 wks. Pre and post HIIT pVO 2 and murine echocardiography were measured and analyzed by a blinded technician. Results: Following 6 weeks of the HIIT, nTG female (+13.5 mL/kg/min ± 3.6, p&lt;0.01), nTG male (+13.5 mL/kg/min ± 3.6, p&lt;0.01) and TG female (+7.06 ± 3.3 mL/kg/min, p&lt;0.05) mice demonstrated an average increase in pVO 2 . TG male mice did not reach statistical significance (+4.34 ± p=0.12). Sedentary female (-15.9 mL/kg/min ± 3.3,p&lt;0.001) and male (-13.1 mL/kg/min ± 3.9, p&lt;0.01) TG control mice experienced a significant decrease in pVO 2 following the same period, while no change was observed in nTG sedentary controls. Independent of sex, nTG and TG HIIT mice had a significantly greater change in pVO 2 compared to sedentary counterparts. HIIT training did not result in changes to the following echocardiography measures in either nTG or TG mice: LV mass, LA volume, cardiac output, or stroke volume. Conclusions: Our results indicate that a translationally derived HIIT protocol improves cardiorespiratory capacity in HCM mice, absent of any adverse events or worsening of organ level disease pathology.

Macrophage polarization in obesity induced inflammation: The effect of HSP70

Abstract Obesity is a chronic inflammatory disease that plagues our nation’s healthcare system. Tissue macrophages and recruited monocytes are implicated in the systemic release of pro-inflammatory cytokines that foster disease progression. Diet-induced obesity (DIO) is prevented in heat shock protein 70 over-expressing (HSP70 transgenic; TG) mice. While there are several mechanisms responsible for this protective response, prevention of macrophage polarization to a pro-inflammatory phenotype (M1) may be one contributory mechanism that warrants further investigation. Using a TG mouse line with selective over-expression of HSP70 in villin-expressing epithelial cells, male TG and non-transgenic (NTG) littermates were fed a low fat (LF; 10 kcal% fat) or high fat (HF; 60 kcal% fat) diet for 13 weeks (Research Diets, Inc). Peritoneal cavity macrophages were harvested from these mice and analyzed by flow cytometry (Beckman Coulter Cytoflex) using the following markers: total (F4/80 APC), M1 (CD38 PE), and M2 (CD301 APC/Fire 750) macrophages. TG mice demonstrated increased F4/80+high macrophages and more F4/80+high M2 cells in comparison to their NTG littermates (p=0.051). These results demonstrate HSP70 over-expression in vivo increases the population of macrophages, particularly anti-inflammatory M2 macrophages, in the peritoneal cavity. Preferential M2 phenotype could be a significant contributory factor to HSP70-mediated protection from DIO.

Biological Sex Mediates Cancer Cachexia Muscle Autophagy

Cancer cachexia, a catastrophic wasting disorder which affects roughly 80 percent of cancer patients, is characterized by the excessive catabolism of fat and muscle for energy. Unfortunately, cancer cachexia can cause irreversible damage to the body, decrease survival rate, and cause significant decline in quality of life. Therefore a great need exists to better understand the underlying mechanisms of cancer cachexia. Emerging evidence indicates that cancer cachexia also presents in a sexually dimorphic manner. Therefore, the purpose of this study was to determine the underlying mechanisms of sex-mediated mechanisms in cancer cachexia. Male and female LC3 Tg+ mice and sibling-matched wildtype mice implanted with tumors (T; 1x106 LLC cells in flank) or remained non-tumor (NT) for 3 weeks. In this dual tagged LC3 Tg+ autophagy reporter mouse model, early phase autophagosomes appear yellow (GFP+RFP) while late phase autolysosomes appear red (RFP only. Confocal analysis revealed that tumor bearing (T) resulted in a significant increase in late phase autolysosomes in the hearts of both sexes compared to NT hearts (P<0.05). However, males T hearts exhibited significantly greater early phase autolysosomes compared to female T hearts (P<0.001), while female T hearts exhibited significantly greater late phase autolysosomes compared to male T hearts (P<0.05). This coincided with increased inflammatory protein IL-1beta in female T hearts compared to female NT hearts (P<0.05). In skeletal muscle, tumor bearing led to significant increases in both early and late phase phagosomes in both sexes compared to NT skeletal muscles (P<0.05). However, female T skeletal muscle exhibited significantly greater early phase autophagosomes compared to male T muscles (P<0.05), while male T muscle exhibited significantly greater late phase autolysosomes compared to female T muscles (P<0.05). Interestingly, this coincided with increased inflammatory proteins IL-1beta (P<0.01) and NF-kB (P<0.05) in male T skeletal muscle compared to male NT muscle. Therefore, it is possible that inflammatory pathways mediate cancer cachexia associated autophagy in a sexually dimorphic manner. Such data are critical in elucidating how cancer cachexia variably presents and progresses by biological sex, and in the identification of therapeutic targets aimed at muscle wasting in a sex specific manner.

Exercise Preconditioning Preserves Skeletal Muscle Function and Stunts Tumor Growth in Male Mice

BACKGROUND Cancer cachexia is a complex muscle and fat wasting disorder that results in death in up to one-third of cancer patients. Currently, there are no clear diagnostic criteria, its effects are irreversible, and it cannot be treated. Therefore, a great need exists to better understand this disease. Research has shown that exercise has a positive impact on preserving muscle mass and inhibiting tumor growth, but questions remain regarding the timing, safety, and underlying mechanisms of benefits of exercise in cancer survivors. Therefore, the purpose of this study was to examine the effects of preconditioning exercise as a protective measure for cancer cachexia. METHODS To examine the effects of preconditioning exercise on skeletal muscle wasting and tumor growth, male LC3 Tg+ and sibling matched wildtype mice were randomly separated into four groups: sedentary non-tumor bearing (SED+NT), sedentary tumor bearing (SED+T), exercise non-tumor bearing (TM+NT), and exercise tumor bearing (TM+T). Mice underwent either 8 weeks of progressive treadmill trained exercise (TM) or remained sedentary. This was followed by 4-week sedentary period of tumor bearing (1x105 LLC cells in flank) or non-tumor bearing (NT). Grip strength, muscle mass, and tumor growth characteristics were measured to examine the protective effects of exercise in cancer cachexia skeletal muscle wasting. RESULTS Tumor bearing led to significant declines in muscle strength. Both SED+T and TM+T showed a significantly lower grip strength compared to non-tumor bearing groups (P <0.05). More importantly, the TM+T group showed a significant improvement (preservation) in grip strength versus the SED+T group (p<0.05), which were the weakest of all groups. In step with this finding, SED+T exhibited significantly smaller gastrocnemius muscle mass compared to TM+T (P<0.05). When comparing tumor characteristics, TM+T exhibited 2-fold smaller tumor mass (P<0.05) and 16-fold smaller tumor volume (P<0.001) compared to SED+T tumors. CONCLUSION These data indicate that preconditioning exercise is capable of eliciting a protective effect against cancer cachexia-mediated declines in muscle function and mass. This may be related to the massive stunt in tumor growth that was associated with exercise preconditioning, indicating that the protective effects of exercise may last for a period even when exercise is ceased. Such data are critical in understanding the importance of exercise in cancer cachexia and how the timing of exercise (preconditioning) can play a major role in protecting survivors against the effects of cachexia.

μ-Crystallin in Mouse Skeletal Muscle Promotes a Shift from Glycolytic toward Oxidative Metabolism.

μ-Crystallin, encoded by the CRYM gene, binds the thyroid hormones, T3 and T4. Because T3 and T4 are potent regulators of metabolism and gene expression, and CRYM levels in human skeletal muscle can vary widely, we investigated the effects of overexpression of Crym. We generated transgenic mice, Crym tg, that expressed Crym protein specifically in skeletal muscle at levels 2.6–147.5 fold higher than in controls. Muscular functions, Ca2+ transients, contractile force, fatigue, running on treadmills or wheels, were not significantly altered, although T3 levels in tibialis anterior (TA) muscle were elevated ~190-fold and serum T4 was decreased 1.2-fold. Serum T3 and thyroid stimulating hormone (TSH) levels were unaffected. Crym transgenic mice studied in metabolic chambers showed a significant decrease in the respiratory exchange ratio (RER) corresponding to a 13.7% increase in fat utilization as an energy source compared to controls. Female but not male Crym tg mice gained weight more rapidly than controls when fed high fat or high simple carbohydrate diets. Although labeling for myosin heavy chains showed no fiber type differences in TA or soleus muscles, application of machine learning algorithms revealed small but significant morphological differences between Crym tg and control soleus fibers. RNA-seq and gene ontology enrichment analysis showed a significant shift towards genes associated with slower muscle function and its metabolic correlate, β-oxidation. Protein expression showed a similar shift, though with little overlap. Our study shows that μ-crystallin plays an important role in determining substrate utilization in mammalian muscle and that high levels of μ-crystallin are associated with a shift toward greater fat metabolism.

Thioredoxin down-regulation in the cytosol in thioredoxin 2 transgenic mice did not have beneficial effects to extend lifespan in male C57BL/6 mice

Background: This study was conducted to test the effects of thioredoxin (Trx)1 down-regulation in Trx2 transgenic [Tg(TXN2)+/0] mice on lifespan and age-related diseases. Our previous study with Tg(TXN2)+/0 mice showed that mitochondrial Trx overexpression produced minimal life-extending effects with a slightly elevated severity of lymphoma and another study with a limited number of Trx1KO mice showed that there was a slight reduction of neoplastic lesions. Thus, this study was aimed to test if reduced Trx1 expression in combination with elevated Trx2 has beneficial effects on lifespan in mice by attenuating age-related diseases, specifically cancer. Methods: Trx2 hemizygous transgenic and Trx1 heterozygous knockout mice [Tg(TXN2)+/0 x Trx1KO] were generated for survival and cross-sectional pathology experiments. Results: Tg(TXN2)+/0 x Trx1KO mice showed significantly higher (approximately 1.5- to 3-fold) Trx2 levels and significantly less (approximately 50% less) Trx1 levels in all of the tissues we examined compared to wildtype (WT) littermates. Trx1 down-regulation along with Trx2 overexpression did not change the levels of glutathione or other major antioxidant enzymes. Male Tg(TXN2)+/0 x Trx1KO mice demonstrated only a slight extension of lifespan in the early part of life and no significant effects on the later part of life were observed,which was similar to our previous study with Tg(TXN2)+/0 mice. Tg(TXN2)+/0 x Trx1KO mice had similar tumor burden, disease burden, incidence and severity of lymphoma, and severity of glomerulonephritis compared to WT mice at 22-26 months. Conclusions: Our findings suggest that the combined Trx down-regulation in cytosol along with upregulation in mitochondria of Tg(TXN2)+/0 x Trx1KO mice did not provide beneficial effects on aging, i.e., extend the lifespan or reduce age-related pathology compared to WT mice. Keywords: Thioredoxin, transgenic mouse, knockout mouse, aging, cancer

SRY is a Key Mediator of Sexual Dimorphism in Hepatic Ischemia/Reperfusion Injury.

To identify the role and mechanism of a male specific gene, SRY, in I/R-induced hepatic injury. Males are more vulnerable to I/R injury than females. However, the mechanism of these sex-based differences remains poorly defined. Clinicopathologic data of patients who underwent hepatic resection were identified from an international multi-institutional database. Liver specific SRY TG mice were generated, and subjected to I/R insult with their littermate WT controls in vivo. In vitro experiments were performed by treating primary hepatocytes from TG and WT mice with hypoxia/reoxygen-ation stimulation. Clinical data showed that postoperative aminotransferase level, incidence of overall morbidity and liver failure were markedly higher among 1267 male versus 508 female patients who underwent hepatic resection. SRY was dramatically upregulated during hepatic I/R injury. Overexpression of SRY in male TG mice and ectopic expression of SRY in female TG mice exacerbated liver I/R injury compared with WTs as manifested by increased inflammatory reaction, oxidative stress and cell death in vivo and in vitro. Mechanistically, SRY interacts with Glycogen synthase kinase-3β (GSK-3β) and β-catenin, and promotes phosphorylation and degradation of β-catenin, leading to suppression of the downstream FOXOs, and activation of NF-κBand TLR4 signaling. Furthermore, activation of β-catenin almost completely reversed the SRYoverexpression-mediated exacerbation of hepatic I/R damage. SRY is a novel hepatic I/R mediator that promotes hepatic inflammatory reaction, oxidative stress and cell necrosis via inhibiting Wnt/β-catenin signaling, which accounts for the sex-based disparity in hepatic I/R injuries.