Treatment with estrogen protects against ovariectomy-induced hepatic steatosis by increasing AQP7 expression

Elderly Women Have a Higher Survival Rate of Grafted Donor Fat than Do Young Women Under the Influence of Low Estrogen Conditions

BACKGROUND

Fat grafting is widely used in breast reconstruction and aesthetic plastic surgery. However, the success rate and effects of fat grafting, especially in elderly female donors, are observed. This study aimed to explore the difference in the survival rate of donor fat from elderly women and young women in fat grafting.

METHODS

We collected adipose tissue samples from two healthy Chinese women: a young woman and an elderly woman. In addition, adipose tissue samples were collected from female nude mice in four experimental groups-CON-Y, CON-O, OVX-Y, and OVX-O-after fat transplantation. Grafts were harvested, weighed, and subjected to assessment of histology and angiogenesis.

RESULTS

An ovariectomy model was successfully established to validate the effect of low estrogen levels on fat grafting results. Due to the influence of low estrogen levels, the graft survival rate of donor site fat was significantly higher in elderly women than in young women, accompanied by a lesser degree of angiogenesis. Low estrogen levels led to adipocyte hypertrophy, which may be related to decreased AQP-7 expression.

CONCLUSIONS

AQP-7 downregulation due to low estrogen levels induces adipocyte hypertrophy, and donor fat from elderly women exhibits a higher survival rate after fat transplantation.

LEVEL OF EVIDENCE V

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Anti-Inflammatory and Therapeutic Effects of a Novel Small-Molecule Inhibitor of Inflammation in a Male C57BL/6J Mouse Model of Obesity-Induced NAFLD/MAFLD

Purpose

Non-alcoholic fatty liver disease (NAFLD), recently renamed metabolic (dysfunction) associated fatty liver disease (MAFLD), is the most common chronic liver disease in the United States. Presently, there is an intense and ongoing effort to identify and develop novel therapeutics for this disease. In this study, we explored the anti-inflammatory activity of a new compound, termed IOI-214, and its therapeutic potential to ameliorate NAFLD/MAFLD in male C57BL/6J mice fed a high fat (HF) diet.

Methods

Murine macrophages and hepatocytes in culture were treated with lipopolysaccharide (LPS) ± IOI-214 or DMSO (vehicle), and RT-qPCR analyses of inflammatory cytokine gene expression were used to assess IOI-214's anti-inflammatory properties in vitro. Male C57BL/6J mice were also placed on a HF diet and treated once daily with IOI-214 or DMSO for 16 weeks. Tissues were collected and analyzed to determine the effects of IOI-214 on HF diet-induced NAFL D/MAFLD. Measurements such as weight, blood glucose, serum cholesterol, liver/serum triglyceride, insulin, and glucose tolerance tests, ELISAs, metabolomics, Western blots, histology, gut microbiome, and serum LPS binding protein analyses were conducted.

Results

IOI-214 inhibited LPS-induced inflammation in macrophages and hepatocytes in culture and abrogated HF diet-induced mesenteric fat accumulation, hepatic inflammation and steatosis/hepatocellular ballooning, as well as fasting hyperglycemia without affecting insulin resistance or fasting insulin, cholesterol or TG levels despite overall obesity in vivo in male C57BL/6J mice. IOI-214 also decreased systemic inflammation in vivo and improved gut microbiota dysbiosis and leaky gut.

Conclusion

Combined, these data indicate that IOI-214 works at multiple levels in parallel to inhibit the inflammation that drives HF diet-induced NAFLD/MAFLD, suggesting that it may have therapeutic potential for NAFLD/MAFLD.

Single neonatal estrogen implant sterilizes female animals by decreasing hypothalamic KISS1 expression

Reproductive sterilization by surgical gonadectomy is strongly advocated to help manage animal populations, especially domesticated pets, and to prevent reproductive behaviors and diseases. This study explored the use of a single-injection method to induce sterility in female animals as an alternative to surgical ovariohysterectomy. The idea was based on our recent finding that repetitive daily injection of estrogen into neonatal rats disrupted hypothalamic expression of Kisspeptin (KISS1), the neuropeptide that triggers and regulates pulsatile secretion of GnRH. Neonatal female rats were dosed with estradiol benzoate (EB) either by daily injections for 11 days or by subcutaneous implantation of an EB-containing silicone capsule designed to release EB over 2-3 weeks. Rats treated by either method did not exhibit estrous cyclicity, were anovulatory, and became infertile. The EB-treated rats had fewer hypothalamic Kisspeptin neurons, but the GnRH-LH axis remained responsive to Kisspeptin stimulation. Because it would be desirable to use a biodegradable carrier that is also easier to handle, an injectable EB carrier was developed from PLGA microspheres to provide pharmacokinetics comparable to the EB-containing silicone capsule. A single neonatal injection of EB-microspheres at an equivalent dosage resulted in sterility in the female rat. In neonatal female Beagle dogs, implantation of an EB-containing silicone capsule also reduced ovarian follicle development and significantly inhibited KISS1 expression in the hypothalamus. None of the treatments produced any concerning health effects, other than infertility. Therefore, further development of this technology for sterilization in domestic female animals, such as dogs and cats is worthy of investigation.

Synthesis, Regulatory Factors, and Signaling Pathways of Estrogen in the Ovary

New insights have been thrown for understanding the significant role of estrogen on various systems of humans. Increasing evidences have determined the significant roles of estrogen in female reproductive system. So, the normal synthesis and secretion of estrogen play important roles in maintaining the function of tissues and organs. The ovaries are the main synthetic organs of estrogen. In this review, we summarized the current knowledge of the estrogen synthesis in the ovaries. A series of factors and signaling pathways that regulate the synthesis of estrogen are expounded in detail. Understanding the regulating factors and potential mechanism related to estrogen synthesis will be beneficial for understanding estrogen disorder related diseases and may provide novel therapeutic targets.

Aquaglyceroporin Modulators as Emergent Pharmacological Molecules for Human Diseases

Aquaglyceroporins, a sub-class of aquaporins that facilitate the diffusion of water, glycerol and other small uncharged solutes across cell membranes, have been recognized for their important role in human physiology and their involvement in multiple disorders, mostly related to disturbed energy homeostasis. Aquaglyceroporins dysfunction in a variety of pathological conditions highlighted their targeting as novel therapeutic strategies, boosting the search for potent and selective modulators with pharmacological properties. The identification of selective inhibitors with potential clinical applications has been challenging, relying on accurate assays to measure membrane glycerol permeability and validate effective functional blockers. Additionally, biologicals such as hormones and natural compounds have been revealed as alternative strategies to modulate aquaglyceroporins via their gene and protein expression. This review summarizes the current knowledge of aquaglyceroporins’ involvement in several pathologies and the experimental approaches used to evaluate glycerol permeability and aquaglyceroporin modulation. In addition, we provide an update on aquaglyceroporins modulators reported to impact disease, unveiling aquaglyceroporin pharmacological targeting as a promising approach for innovative therapeutics.

The interplay between metabolic dysregulations and non-alcoholic fatty liver disease in women after menopause

The hypoestrogenic period after menopause and associated metabolic imbalance might facilitate the onset of non-alcoholic fatty liver disease (NAFLD) and its progression. The prevalence of NAFLD increases in patients experiencing premature ovarian insufficiency, as well as surgical or natural menopause. The postmenopausal period is characterized by dyslipidemia and insulin resistance associated with an increased influx of free fatty acids to the liver with consequent steatosis and further progression of NAFLD. More than half of postmenopausal women with diabetes mellitus type 2 suffer from NAFLD. It is suggested that estrogens slow the progression of chronic liver diseases by suppression of inflammation, improvement of mitochondrial function, alleviation of oxidative stress, insulin resistance, and fibrogenesis. The hyperandrogenic state of polycystic ovary syndrome (PCOS) is associated with the development of NAFLD in women of reproductive age, but it is difficult to extend these findings to menopause due to inappropriate diagnosis of PCOS after menopause. Lifestyle intervention, including physical activity and dietary regimens, remains the first-line preventive and therapeutic option for NAFLD. There are contradictory reports on the use of menopausal hormonal therapy (MHT) and NAFLD. It is necessary to investigate the potential effects of estradiol dose, progesterone type, selective estrogen receptor modulators and tissue-selective estrogen complex compounds on NAFLD development and progression in postmenopausal women. The present review aims to explore the pathophysiological and clinical aspects of liver metabolic disturbances in women after menopause, focusing on the possible preventive and therapeutic strategies in NAFLD, including the potential role of MHT.

Involvement of aquaglyceroporins in energy metabolism in health and disease

Aquaglyceroporins are a group of the aquaporin (AQP) family of transmembrane water channels. While AQPs facilitate the passage of water, small solutes, and gases across biological membranes, aquaglyceroporins allow passage of water, glycerol, urea and some other solutes. Thanks to their glycerol permeability, aquaglyceroporins are involved in energy homeostasis. This review provides an overview of what is currently known concerning the functional implication and control of aquaglyceroporins in tissues involved in energy metabolism, i.e. liver, adipose tissue and endocrine pancreas. The expression, role and (dys)regulation of aquaglyceroporins in disorders affecting energy metabolism, and the potential relevance of aquaglyceroporins as drug targets to treat the alterations of the energy balance is also addressed.

A comprehensive review of long non-coding RNAs in the pathogenesis and development of non-alcoholic fatty liver disease

One of the most prevalent diseases worldwide without a fully-known mechanism is non-alcoholic fatty liver disease (NAFLD). Recently, long non-coding RNAs (lncRNAs) have emerged as significant regulatory molecules. These RNAs have been claimed by bioinformatic research that is involved in biologic processes, including cell cycle, transcription factor regulation, fatty acids metabolism, and-so-forth. There is a body of evidence that lncRNAs have a pivotal role in triglyceride, cholesterol, and lipoprotein metabolism. Moreover, lncRNAs by up- or down-regulation of the downstream molecules in fatty acid metabolism may determine the fatty acid deposition in the liver. Therefore, lncRNAs have attracted considerable interest in NAFLD pathology and research. In this review, we provide all of the lncRNAs and their possible mechanisms which have been introduced up to now. It is hoped that this study would provide deep insight into the role of lncRNAs in NAFLD to recognize the better molecular targets for therapy.

Transcriptomic analysis of the liver in aged laying hens with different intensity of brown eggshell color

OBJECTIVE

Eggshell color is an important indicator of egg quality for consumers, especially for brown eggs. Various factors related to laying hens and their environment affect brown eggshell coloration. However, there have been no studies investigating hepatic functions of laying hens with variable intensity of brown eggshell color. Therefore, this study was aimed to identify potential factors affecting brown eggshell coloration in aged laying hens at the hepatic transcriptomic level.

METHODS

Five hundred 92-wk-old Hy-line Brown laying hens were screened to select laying hens with different intensity of brown eggshell color based on eggshell color fans. Based on eggshell color scores, hens with dark brown eggshells (DBE; eggshell color fan score = 14.8) and hens with light brown eggshells (LBE; eggshell color fan score = 9.7) were finally selected for the liver sampling. We performed RNA-seq analysis using the liver samples through the paired-end sequencing libraries. Differentially expressed genes (DEGs) profiling was carried out to identify their biological meaning by bioinformatics.

RESULTS

A total of 290 DEGs were identified with 196 being up-regulated and 94 being down-regulated in DBE groups as compared to LBE groups. The Kyoto encyclopedia of genes and genomes (KEGG) analysis revealed that these DEGs belong to several biological pathways including herpes simplex infection (toll-like receptor 3 [TLR3], cyclin-dependent kinase 1, etc.) and influenza A (TLR3, radical S-adenosyl methionine domain containing 2, myxovirus [influenza virus] resistance 1, etc.). Genes related to stress response (ceremide kinase like) and nutrient metabolism (phosphoenolpyruvate carboxy-kinase 1, methylmalonic aciduria [cobalamin deficiency] cblB type, glycine receptor alpha 2, solute carrier family 7 member 11, etc.) were also identified to be differentially expressed.

CONCLUSION

The current results provide new insights regarding hepatic molecular functions related to different intensity of brown eggshell color in aged laying hens. These insights will contribute to future studies aiming to optimize brown eggshell coloration in aged laying hens.

NAFLD and NASH in Postmenopausal Women: Implications for Diagnosis and Treatment

Nonalcoholic fatty liver disease (NAFLD) prevalence in women is increasing worldwide. Women of reproductive age have lower rates of NAFLD compared with men; however, this protection is lost following the menopausal transition when NAFLD prevalence in postmenopausal women becomes similar to or surpasses that in age-matched male counterparts. Ongoing epidemiological, clinical, and experimental studies indicate greater NAFLD risk and higher rates of severe hepatic fibrosis in postmenopausal women relative to premenopausal women, and that older women with NAFLD experience greater mortality than men. Investigations involving ovariectomized animal models demonstrate a causal relationship between estrogen deficiency and heightened susceptibility to the development of fatty liver and steatohepatitis, although dietary factors may exacerbate this complex relationship. The accumulated findings suggest that a better understanding of the interplay among menopausal status, metabolic comorbidities, and sex steroids in NAFLD pathogenesis is needed. Further, the mechanisms underlying the difference in NAFLD risk between postmenopausal and premenopausal women remain incompletely understood. The goals of this review are to summarize studies of NAFLD risk in postmenopausal women, discuss results from animal models of estrogen deficiency, and explore the development of NAFD within the context of altered sex hormone profiles resulting from the menopausal transition. Potential implications for the prevention, diagnosis, and treatment of NAFLD in this relatively understudied cohort are also addressed.

Standardized rice bran extract improves hepatic steatosis in HepG2 cells and ovariectomized rats

BACKGROUD/OBJECTIVES

Hepatic steatosis is the most common liver disorder, particularly in postmenopausal women. This study investigated the protective effects of standardized rice bran extract (RBS) on ovariectomized (OVX)-induced hepatic steatosis in rats.

MATERIALS/METHODS

HepG2 cells were incubated with 200 µM oleic acid to induce lipid accumulation with or without RBS and γ-oryzanol. OVX rats were separated into three groups and fed a normal diet (ND) or the ND containing 17β-estradiol (E2; 10 µg/kg) and RBS (500 mg/kg) for 16 weeks.

RESULTS

RBS supplementation improved serum triglyceride and free fatty acid levels in OVX rats. Histological analysis showed that RBS significantly attenuated hepatic fat accumulation and decreased hepatic lipid, total cholesterol, and triglyceride levels. Additionally, RBS suppressed the estrogen deficiency-induced upregulation of lipogenic genes, such as sterol regulatory element-binding protein 1 (SREBP1), acetyl-CoA carboxylase 1, fatty acid synthase, glycerol-3-phosphate acyltransferase, and stearoyl-CoA desaturase 1.

CONCLUSIONS

RBS and γ-oryzanol effectively reduced lipid accumulation in a HepG2 cell hepatic steatosis model. RBS improves OVX-induced hepatic steatosis by regulating the SREBP1-mediated activation of lipogenic genes, suggesting the benefits of RBS in preventing fatty liver in postmenopausal women.

Menopause and Non-Alcoholic Fatty Liver Disease: A Review Focusing on Therapeutic Perspectives

There is increasing evidence that menopause is associated with the progression and severity of non-alcoholic fatty liver disease (NAFLD). Estrogen deficiency worsens non-alcoholic steatohepatitis (NASH) in mice models with fatty liver. The prevalence of NAFLD seems to be higher in postmenopausal compared with premenopausal women. Although more data are needed, lower serum estradiol levels are associated with NASH in postmenopausal women. Apart from estrogen deficiency, relative androgen excess and decrease in sex hormone-binding protein are observed in postmenopausal women. These hormonal changes seem to interplay with an increase in abdominal adipose mass, also observed in postmenopausal women, and aging, which are both closely related to the severity and progressive forms of NAFLD. NAFLD adds extra morbidity to postmenopausal women, possibly increasing the risk of type 2 diabetes mellitus and cardiovascular disease. Improving parameters of the metabolic syndrome via modifications in diet and physical exercise may reduce the risk of NAFLD and its related morbidity. Limited studies have shown a beneficial effect of hormone replacement therapy (HRT) on NAFLD, although adverse hepatic effects have been attributed to progesterone in one study. Phytoestrogens may be alternatives to HRT, but their long-term efficacy and safety remain to be shown. The aim of this review was to summarize evidence linking menopause with NAFLD with a special focus on potential therapeutic perspectives.

The influence of biological sex and sex hormones on bile acid synthesis and cholesterol homeostasis

Obesity and elevated serum lipids are associated with a threefold increase in the risk of developing atherosclerosis, a condition that underlies stroke, myocardial infarction, and sudden cardiac death. Strategies that aim to reduce serum cholesterol through modulation of liver enzymes have been successful in decreasing the risk of developing atherosclerosis and reducing mortality. Statins, which inhibit cholesterol biosynthesis in the liver, are considered among the most successful compounds developed for the treatment of cardiovascular disease. However, recent debate surrounding their effectiveness and safety prompts consideration of alternative cholesterol-lowering therapies, including increasing cholesterol catabolism through bile acid (BA) synthesis. Targeting the enzymes that convert cholesterol to BAs represents a promising alternative to other cholesterol-lowering approaches that treat atherosclerosis as well as fatty liver diseases and diabetes mellitus. Compounds that modify the activity of these pathways have been developed; however, there remains a lack of consideration of biological sex. This is necessary in light of strong evidence for sexual dimorphisms not only in the incidence and progression of the diseases they influence but also in the expression and activity of the proteins affected and in the manner in which men and women respond to drugs that modify lipid handling in the liver. A thorough understanding of the enzymes involved in cholesterol catabolism and modulation by biological sex is necessary to maximize their therapeutic potential.

In vitro and in vivo approaches for identifying the role of aryl hydrocarbon receptor in the development of nonalcoholic fatty liver disease

Nonalcoholic fatty liver disease (NAFLD) is a chronic hepatic disease associated with the excessive accumulation of lipids in the liver. Premenopausal women are protected from the liver metabolic complications of obesity compared with body mass index (BMI)-matched men. This protection may be related to estrogen's ability to limit liver fat accumulation. Aryl hydrocarbon receptor (AhR), a novel regulator of NAFLD, may be an important target for regulating estrogen homeostasis. In present study, we used benzo[a]pyrene (BaP), a classic and potent ligand of AhR, to activate AhR pathway causes overexpression of the estrogen-metabolizing enzyme cytochrome P450 1A1 (CYP1A1) and affects the expression of important genes involved in hepatic lipid regulation. BaP induces CYP1A1 expression through AhR signaling and inhibits the protective effect of 17β-estradiol (E2) on hepatic steatosis, characterized by triglyceride accumulation, and markers of liver damage are significantly elevated. The expression of adipogenic genes involved in the hepatic lipid metabolism of sterol regulatory element-binding protein-1c (SREBP-1c) was increased compared with that in the control group. Furthermore, the mRNA and protein levels of peroxisome proliferator-activated receptor alpha (PPARα), which is involved in fatty acid oxidation, were significantly reduced. Taken together, our results revealed that the steatotic effect of AhR is likely due to overexpression of the E2 metabolic enzyme CYP1A1, which affects the estrogen signaling pathway, leading to the suppression of fatty acid oxidation, inhibition of the hepatic export of triglycerides, and an increase in peripheral fat mobilization. The results from this study may help establish AhR as a novel therapeutic and preventive target for fatty liver disease.

Long non-coding RNA NEAT1 promotes steatosis via enhancement of estrogen receptor alpha-mediated AQP7 expression in HepG2 cells

Hepatic steatosis is one of the most important features of the pathogenesis for non-alcoholic fatty liver disease. Fat deposition in liver cells can influence hepatic lipogenesis along with other metabolic pathways and further lead to the irreversible liver cirrhosis and injury. However, the underlying mechanism of steatosis remains largely unexplored. Our previous study revealed that AQP7 played an important role in liver steatosis. In this study, we determined that the transcriptional level of AQP7 was up-regulated by estrogen receptor alpha (ERα) upon 17β-estradiol (E2) and oleic acids treated HepG2 cells. Furthermore, we identified long non-coding RNA nuclear enriched abundant transcript 1 (NEAT1) as a potential hallmark which was down-regulated in ERα silencing HepG2 cells by RNA-Seq. Finally, we validated that the 3' terminal nucleotides of NEAT1 were contributed for the interaction with ERα to facilitate AQP7 transcription to suppress liver steatosis. Overall, our study gave evidence that NEAT1 played an important role in the activation of ERα to regulate AQP7-mediated hepatic steatosis.

Aquaglyceroporins: Drug Targets for Metabolic Diseases?

Aquaporins (AQPs) are a family of transmembrane channel proteins facilitating the transport of water, small solutes, and gasses across biological membranes. AQPs are expressed in all tissues and ensure multiple roles under normal and pathophysiological conditions. Aquaglyceroporins are a subfamily of AQPs permeable to glycerol in addition to water and participate thereby to energy metabolism. This review focalizes on the present knowledge of the expression, regulation and physiological roles of AQPs in adipose tissue, liver and endocrine pancreas, that are involved in energy metabolism. In addition, the review aims at summarizing the involvement of AQPs in metabolic disorders, such as obesity, diabetes and liver diseases. Finally, challenges and recent advances related to pharmacological modulation of AQPs expression and function to control and treat metabolic diseases are discussed.

Implications of Aquaglyceroporin 7 in Energy Metabolism

The aquaglyceroporin AQP7 is a pore-forming transmembrane protein that facilitates the transport of glycerol across cell membranes. Glycerol is utilized both in carbohydrate and lipid metabolism. It is primarily stored in white adipose tissue as part of the triglyceride molecules. During states with increased lipolysis, such as fasting and diabetes, glycerol is released from adipose tissue and metabolized in other tissues. AQP7 is expressed in adipose tissue where it facilitates the efflux of glycerol, and AQP7 deficiency has been linked to increased glycerol kinase activity and triglyceride accumulation in adipose tissue, leading to obesity and secondary development of insulin resistance. However, AQP7 is also expressed in a wide range of other tissues, including kidney, muscle, pancreatic β-cells and liver, where AQP7 also holds the potential to influence whole body energy metabolism. The aim of the review is to summarize the current knowledge on AQP7 in adipose tissue, as well as AQP7 expressed in other tissues where AQP7 might play a significant role in modulating whole body energy metabolism.

Tissue-specific effects of estrogen on glycerol channel aquaporin 7 expression in an ovariectomized mouse model of menopause

OBJECTIVE

Elevated fat mass and redistribution of body fat are commonly observed in postmenopausal women. Aquaporin 7 (AQP7), a unique glycerol permeable integral membrane protein, has been associated with the onset of obesity. We hypothesized that estrogen supplementation could counteract this fat accumulation and redistribution through tissue-specific modulation of AQP7.

METHODS

We measured fat depot weight, adipocyte size, and the expression of AQP7 and glycerol kinase (GK) in visceral and subcutaneous fat tissues of ovariectomized mice supplemented with or without 17β-estradiol.

RESULTS

Removal of the ovaries resulted in a significant decrease in AQP7 expression and an increase in GK expression in visceral adipocyte tissue; expression of AQP7 and GK in subcutaneous adipose tissue remained unaltered. Supplementation with estrogen significantly restored the visceral, but not subcutaneous, fat depot mass and adipocyte size to those of sham-operated mice. A marked increase in the expression of AQP7 and a reduction of GK were observed selectively in the visceral fat depots in estrogen-treated mice.

CONCLUSIONS

Our results suggest that estrogen has tissue-specific effects on AQP7 expression, and modulation of AQP7 by estrogen alters the balance of adipocyte metabolism between adipose tissue depots.

Activation of Estrogen Response Element-Independent ERα Signaling Protects Female Mice From Diet-Induced Obesity

17β-estradiol (E2) regulates central and peripheral mechanisms that control energy and glucose homeostasis predominantly through estrogen receptor α (ERα) acting via receptor binding to estrogen response elements (EREs). ERα signaling is also involved in mediating the effects of E2 on diet-induced obesity (DIO), although the roles of ERE-dependent and -independent ERα signaling in reducing the effects of DIO remain largely unknown. We hypothesize that ERE-dependent ERα signaling is necessary to ameliorate the effects of DIO. We addressed this question using ERα knockout (KO) and ERα knockin/knockout (KIKO) female mice, the latter expressing an ERα that lacks a functional ERE binding domain. Female mice were ovariectomized, fed a low-fat diet (LFD) or a high-fat diet (HFD), and orally dosed with vehicle or estradiol benzoate (EB) (300 μg/kg). After 9 weeks, body composition, glucose and insulin tolerance, peptide hormone and inflammatory cytokine levels, and hypothalamic arcuate nucleus and liver gene expression were assessed. EB reduced body weight and body fat in wild-type (WT) female mice, regardless of diet, and in HFD-fed KIKO female mice, in part by reducing energy intake and feeding efficiency. EB reduced fasting glucose levels in KIKO mice fed both diets but augmented glucose tolerance only in HFD-fed KIKO female mice. Plasma insulin and interleukin 6 were elevated in KIKO and KO female mice compared with LFD-fed WT female mice. Expression of arcuate neuropeptide and receptor genes and liver fatty acid biosynthesis genes was altered by HFD and by EB through ERE-dependent and -independent mechanisms. Therefore, ERE-independent signaling mechanisms in both the brain and peripheral organs mediate, in part, the effects of E2 during DIO.