Characterization of the CDAA Diet-Induced Non-alcoholic Steatohepatitis Model: Sex-Specific Differences in Inflammation, Fibrosis, and Cholesterol Metabolism in Middle-Aged Mice

BackgroundThe prevalence of non-alcoholic steatohepatitis (NASH) rapidly increases with associated metabolic disorders such as dyslipidemia; therefore, NASH is now considered an independent risk factor of cardiovascular diseases. NASH displays sex-linked epidemiological, phenotypical, and molecular differences; however, little is known about the background of these sex-specific differences on the molecular level.ObjectivesWe aimed to assess sex-specific differences in the expression of inflammatory and fibrotic genes, as well as in cholesterol metabolism, focusing on the expression of Pcsk9 in several tissues in a mouse model of NASH that shows the typical features of the human condition.Methods and ResultsWe fed 10-months-old male and female C57Bl/6J mice with a NASH-inducing CDAA or corresponding control diet for 8 weeks. We found that, compared to the control male mice baseline, hepatic Pcsk9 expression as well as serum PCSK9 level was significantly higher in females, and both circulating PCSK9 level and the hepatic Pcsk9 gene were markedly decreased in female mice during NASH development. Histological analysis revealed that male and female mice develop a similar degree of steatosis; however, fibrosis was more pronounced in males upon CDAA diet feeding. Strikingly, female mice have higher hepatic expression of the pro-inflammatory cytokines (Il1b, Ifng), and increased IL-1β cleavage by the NLRP3 inflammasome, and a decrease in Clec4f+ resident Kupffer cell population in comparison to males in the CDAA-fed groups.ConclusionThis is the first demonstration that there are critical sex-specific differences during NASH development in middle-aged mice regarding inflammation, fibrosis, and cholesterol metabolism and that changes in PCSK9 and IL-1β are likely important contributors to sex-specific changes during the transition to NASH.

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Sexually Dimorphic Relationships Among Saa3 (Serum Amyloid A3) Inflammation, and Cholesterol Metabolism Modulate Atherosclerosis in Mice

Arteriosclerosis Thrombosis and Vascular Biology ◽

10.1161/atvbaha.121.316066 ◽

2021 ◽

Author(s):

Alan Chait ◽

Shari Wang ◽

Leela Goodspeed ◽

Diego Gomes ◽

Katherine E. Turk ◽

...

Keyword(s):

Plasma Lipids ◽

Cholesterol Metabolism ◽

Saturated Fat ◽

Serum Amyloid ◽

Male And Female ◽

Female Mice ◽

Inflammatory Stimuli ◽

Elevated Cholesterol ◽

Hybrid Mouse Diversity Panel ◽

Adipose Inflammation

Objective: Expression of the extrahepatic acute-phase protein Saa3 (serum amyloid A3) increases in response to acute and chronic inflammatory stimuli and is elevated in adipose tissue and macrophages in obese mice. A recent report suggested that Saa3 is proatherogenic in male ApoE −/− mice. Because of our previous observation that female but not male Saa3-deficient mice are protected from obesity, adipose inflammation, and hyperlipidemia, we sought to determine whether Saa3 differentially modulates atherosclerosis in mice of both sexes. Approach and Results: To promote atherosclerosis, Saa3 +/+ and Saa3 −/− male and female mice were crossed with Ldlr −/− mice. All mice consumed a diet high in saturated fat and sucrose with 0.15% added cholesterol for 16 weeks. Plasma lipids and atherosclerosis levels were assessed. Female Saa3 −/− Ldlr − /− mice exhibited elevated cholesterol levels relative to Saa3 +/+ Ldlr −/− controls and exhibited increased atherosclerosis, while male Saa3 −/− Ldlr −/− mice were protected from atherosclerosis. Data from the hybrid mouse diversity panel revealed that Saa3 associates strongly with inflammatory, Trem2-associated, and tissue remodeling genes and pathways in males but not females, an effect confirmed in liver tissue, atherosclerotic lesions, and cultured macrophages. Macrophages isolated from male and female mice showed differential inflammatory effects of Saa3 deficiency, an effect linked with sex steroid signaling. Cholesterol efflux capacity was increased in Saa3 −/− males only. Conclusions: Saa3 is proatherogenic in male but atheroprotective in female mice, effects that may be related to sex-specific relationships between Saa3, cholesterol metabolism, inflammatory genes, and Trem2 macrophages.

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The Role of Histone Deacetylase 9 in the Therapeutic Effects of Astaxanthin on Non-Alcoholic Steatohepatitis

Current Developments in Nutrition ◽

10.1093/cdn/nzaa058_015 ◽

2020 ◽

Vol 4 (Supplement_2) ◽

pp. 1257-1257

Author(s):

Siqi Hu ◽

Hyunju Kang ◽

Hyungryun Jang ◽

Minkyung Bae ◽

Mi-Bo Kim ◽

...

Keyword(s):

Histone Deacetylase ◽

Control Diet ◽

Genotypic Differences ◽

Therapeutic Effects ◽

Inflammatory Genes ◽

Female Mice ◽

Hepatic Expression ◽

Alcoholic Steatohepatitis ◽

Histone Deacetylase 9

Abstract Objectives The objectives of this study were to determine the role of histone deacetylase 9 (HDAC9) in the development of non-alcoholic steatohepatitis (NASH); and to evaluate the therapeutic effects of astaxanthin (ASTX), a xanthophyll carotenoid, on NASH via the modulation of HDAC9 in vivo. Methods Eight-week-old male and female wild-type (WT) and global Hdac9 knockout (KO) mice (n = 30/sex/genotype) were fed a high-fat/high-sucrose/high-cholesterol (HFHSHC) diet for 20 weeks to induce NASH. Subsequently, subsets of WT (n = 10/sex) and KO (n = 10/sex) mice were sacrificed to examine NASH features and served as baseline controls. The rest of the mice were randomly assigned into two diet groups for another 10 weeks: One continued on the HFHSHC diet, while the other group was fed an HFHSHC containing 0.03% ASTX (w/w). Results After 20 weeks on the HFHSHC diet, male KO mice had lower liver weights and triglycerides than WT, but no genotypic differences were observed in the female. Male KO mice showed less liver steatosis and fibrosis with significant decreases in the hepatic expression of lipogenic genes than male WT mice, but Hdac9 deletion did not inhibit NASH development in female mice. Compared with male KO baseline controls, consumption of control diet for an additional 10 week increased hepatic expression of lipogenic and pro-inflammatory genes in male KO mice, losing the beneficial effect of Hdac9 deletion shown at week 20 on the HFHSHC diet. However, the ASTX diet abrogated the induction. There were no significant differences in hepatic lipid contents and histological features of NASH between any genotypes regardless of ASTX supplementation. Also, additional control diet feeding did not induce any changes in hepatic gene expression in female mice, compared with those on the ASTX diet. Conclusions Hdac9 deletion protected male, but not female, mice from diet-induced hepatic steatosis and fibrosis, which may be attributable to decreased lipogenesis in the liver. However, the protection did not exist when liver damages progressed. Hdac9 deletion or ASTX alone did not alleviate the liver damage progression, but they together inhibited the induction of lipogenic and pro-inflammatory genes in the liver of male mice, indicating that they may have synergistic effects on ameliorating NASH progression. Funding Sources The study was supported by National Institutes of Health.

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Abstract 411: Absence of Sexual Dimorphism in Isoproterenol-induced Cardiac Dysfunction in C57BL/6 Mice

Circulation Research ◽

10.1161/res.127.suppl_1.411 ◽

2020 ◽

Vol 127 (Suppl_1) ◽

Author(s):

Marianne K Grant ◽

Davis Seelig ◽

Ibrahim Abdelgawad ◽

Beshay Zordoky

Keyword(s):

Cardiac Hypertrophy ◽

Sex Hormones ◽

Cardiac Dysfunction ◽

Cardiovascular Effects ◽

Current Work ◽

Similar Degree ◽

Adrenergic Stimulation ◽

Male And Female ◽

Female Mice ◽

Significant Difference

Sex-related differences in cardiovascular diseases are complex and highly context-dependent. The objective of this work was to comprehensively determine key sex differences in the response to acute and chronic adrenergic stimulation in C57Bl/6 mice. In the current work, there was no statistically significant difference in key echocardiographic parameters between male and female C57Bl/6 mice in response to acute adrenergic stimulation (a single sub-cutaneous dose of isoproterenol 10 mg/kg). After chronic adrenergic administration (sub-cutaneous injections of isoproterenol 10 mg/kg/day for 14 days), there was similar degree of cardiac dysfunction, cardiac hypertrophy, and myocardial fibrosis in male and female mice. Similarly, chronic isoproterenol administration induced hypertrophic and fibrotic genes in hearts of male and female mice to the same extent. Intriguingly, gonadectomy of male and female mice did not have a significant impact on isoproterenol-induced cardiac dysfunction as compared to sham-operated animals. In conclusion, the current work demonstrated lack of sex-related differences in isoproterenol-induced cardiac hypertrophy, dysfunction, and fibrosis in C57Bl/6 mice. This study challenges the conventional dogma of the detrimental cardiovascular effects of male sex hormones and the beneficial effects of female sex hormones.

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Gender-Specific Response to Isoflurane Preconditioning in Focal Cerebral Ischemia

Journal of Cerebral Blood Flow & Metabolism ◽

10.1038/sj.jcbfm.9600444 ◽

2007 ◽

Vol 27 (7) ◽

pp. 1377-1386 ◽

Cited By ~ 62

Author(s):

Hideto Kitano ◽

Jennifer M Young ◽

Jian Cheng ◽

Lan Wang ◽

Patricia D Hurn ◽

...

Keyword(s):

Cerebral Ischemia ◽

Quantitative Polymerase Chain Reaction ◽

Specific Response ◽

Male Mice ◽

Middle Aged ◽

Male And Female ◽

Akt Phosphorylation ◽

Akt Activation ◽

Female Mice ◽

Middle Aged Male

Inhalation anesthetics are effective chemical preconditioning agents in experimental cerebral ischemia. However, previous work has been performed exclusively in male animals. We determined if there is a gender difference in ischemic outcome after isoflurane preconditioning (IsoPC), and if this sex-specific response is linked to differences in Akt phosphorylation or expression of neuronal inducible cell-death putative kinase (NIPK), a negative modulator of Akt activation. Young and middle-aged male and female mice were preconditioned for 4 h with air (sham PC) or 1.0% IsoPC and recovered for 24 h. Cortices were subdissected from preconditioned young male and female mice for measurement of Akt phosphorylation (Western blot) and NIPK mRNA (quantitative polymerase chain reaction). Additional cohorts underwent 2 h of reversible middle cerebral artery occlusion. Lastly, male and female Akt1+/+ and Akt1−/– mice were studied to determine if gender differences in ischemic outcome after IsoPC is Akt1-dependent. Infarction volume was determined at 22 h reperfusion (2,3,5-triphenyltetrazolium chloride). As expected, IsoPC decreased ischemic damage as compared with sham PC in young and middle-aged male mice. In contrast, IsoPC markedly increased infarction in young female mice and had no effect in middle-aged female mice. Cortical phospho-Akt was increased by IsoPC versus sham PC only in male mice. No increase was observed in IsoPC female mice. NIPK mRNA was higher in female mice than in male mice regardless of preconditioning status. Male IsoPC neuroprotection was lost in Akt1-deficient male mice. We conclude that IsoPC is beneficial only in ischemic male brain and that sex differences in IsoPC are mediated through Akt activation and basal NIPK expression.

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Comparative Phosphoproteomic Profiling of Type III Adenylyl Cyclase Knockout and Control, Male, and Female Mice

Frontiers in Cellular Neuroscience ◽

10.3389/fncel.2019.00034 ◽

2019 ◽

Vol 13 ◽

Cited By ~ 2

Author(s):

Yuxin Zhou ◽

Liyan Qiu ◽

Ashley Sterpka ◽

Haiying Wang ◽

Feixia Chu ◽

...

Keyword(s):

Adenylyl Cyclase ◽

Control Male ◽

Male And Female ◽

Female Mice ◽

Type Iii ◽

And Control

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Chronic Treatment With the ACE Inhibitor Enalapril Attenuates the Development of Frailty and Differentially Modifies Pro- and Anti-inflammatory Cytokines in Aging Male and Female C57BL/6 Mice

The Journals of Gerontology Series A ◽

10.1093/gerona/gly219 ◽

2018 ◽

Vol 74 (8) ◽

pp. 1149-1157 ◽

Cited By ~ 18

Author(s):

Kaitlyn Keller ◽

Alice Kane ◽

Stefan Heinze-Milne ◽

Scott A Grandy ◽

Susan E Howlett

Keyword(s):

Chronic Treatment ◽

Ace Inhibitor ◽

Frailty Index ◽

Protective Effects ◽

Aging Male ◽

Male Mice ◽

Middle Aged ◽

Male And Female ◽

Female Mice ◽

Anti Inflammatory

Abstract Studies on interventions that can delay or treat frailty in humans are limited. There is evidence of beneficial effects of angiotensin converting enzyme (ACE) inhibitors on aspects related to frailty, such as physical function, even in those without cardiovascular disease. This study aimed to longitudinally investigate the effect of an ACE inhibitor on frailty in aging male and female mice. Frailty was assessed with a clinical frailty index (FI) which quantifies health-related deficits in middle-aged (9–13 months) and older (16–25 months) mice. Chronic treatment with enalapril (30 mg/kg/day in feed) attenuated frailty in middle-aged and older female mice, and older male mice, without a long-term effect on blood pressure. Enalapril treatment resulted in a reduction in the proinflammatory cytokines interleukin (IL)-1α, monocyte chemoattractant protein-1 and macrophage inflammatory protein-1a in older female mice, and an increase in the anti-inflammatory cytokine IL-10 in older male mice compared with control animals. These sex-specific effects on inflammation may contribute to the protective effects of enalapril against frailty. This is the first study to examine the longitudinal effect of an intervention on the FI in mice, and provides preclinical evidence that enalapril may delay the onset of frailty, even when started later in life.

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