CL316,243 (CL), a beta 3 adrenergic receptor (B3-AR) agonist, has 'exercise mimetic' effects in adipose tissue. CL may also positively affect skeletal muscle (SM), yet the role of estrogen receptor beta (ERβ) in mediating SM-specific effects of CL is not known. We investigated the effects of CL on SM metabolism, as well as the role played by ERβ. High-fat diet-fed male and female wild-type (WT) and ERβ DBD knockout (KO) mice were administered CL daily for 2 weeks. Quadriceps SM protein markers of fatty acid oxidation (FatOx), protein synthesis, and protein catabolism were assessed. CL increased relative lean mass in both sexes (P = 0.012). In females, CL increased FatOx in WT, yet reduced FatOx in KO, while among males, CL reduced FatOx independent of genotype (P = 0.04). Uncoupling protein 2 (UCP2) and fatty acid synthase (FASN) abundance were higher in females (P = 0.004 and 0.037, respectively), and in both sexes, KO mice had higher SM UCP2 abundance (P = 0.022). CL increased phosphorylated acetyl-CoA carboxylase in males, yet reduced it in females (P = 0.015). Similarly, CL affected p706S kinase abundance (indicative of anabolic signaling) in a sexually dimorphic manner, increasing in males and decreasing in females. CL robustly increased SM FASN across sexes and genotypes (P < 0.001). In summary, the most salient finding was that CL increased SM FASN content independent of sex and ERβ genomic activity; additional novel sex-divergent effects of CL on SM metabolism were identified, some of which were affected by ERβ genomic activity.

Supplementary Tables 1-3, Figures 1-8 from Common Botanical Compounds Inhibit the Hedgehog Signaling Pathway in Prostate Cancer

PURPOSE: CL316,243 (CL), a beta 3 adrenergic receptor (B3AR) agonist has ‘exercise mimetic’ effects in adipose tissue (AT). We demonstrated that male (M) and female (F) mice benefit metabolically from CL treatment, which also induced AT fatty acid synthase (FAS) expression. Further, CL had a lean mass preserving effect, which may involve its effects on skeletal muscle (SM). Estrogen receptor beta (ERβ) is present in SM, yet its role in mediating SM-specific effects of CL is not known. We aimed to compare the effects of CL on SM markers of fat oxidation and protein synthesis, and investigated the role played by genomic ERβ activity. METHODS: High-fat diet-fed M and F wild-type (WT) and ERβ DNA binding domain knockout (KO) mice were administered CL (1 mg/kg) daily for 2 weeks. Systemic physiological assessments of body composition (EchoMRI) and bioenergetics (metabolic chambers) were performed, alongside assessment of quadricep SM protein markers of fat oxidation and protein synthesis (Western blot). Statistical analyses were performed using 2 × 3 analysis of variance for main effects of genotype (G), treatment (T) and sex (S), as well as interactions (int) (SPSS V24). RESULTS: CL significantly increased relative lean mass in both sexes, independent of genotype (12.4% increase; T, P = 0.012). There was a SxTxG int (P = 0.04) for systemic fat oxidation (respiratory quotient (RQ)) such that, in F/WT, CL tended to reduce RQ, whereas in F/KO, CL increased RQ. M/KO mice tended to have a higher RQ, whereas CL increased RQ in both genotypes, resulting in greater CL-induced fat oxidation in F/WT compared M/KO (post-hoc, P = 0.039). F also had higher SM UCP2 (S, P = 0.004) and FAS (S, P = 0.037) content in both genotypes; KO had higher SM UCP2 expression in both sexes (G, P = 0.022); CL-mediated increase in UCP2 was not significant (P = 0.094). Coinciding with RQ sex differences, CL increased SM fat oxidation (assessed via fasted pACC) in F and reduced it in M (SxT int, P = 0.015). Finally, CL robustly increased FAS across sexes and genotypes (T, P < 0.001). No differences in expression of fasted state markers SM anabolism were observed. CONCLUSION: We demonstrate for the first time that CL increases SM FAS content, there are sex-divergent effects of CL on SM metabolism, and that loss of ERβ genomic activity may affect some sex-specific SM responses to CL.

White adipose tissue (WAT) dysfunction independently predicts cardiometabolic disease, yet there is a lack of effective adipocyte-targeting therapeutics. B3AR agonists enhance adipocyte mitochondrial function and hold potential in this regard. Based on enhanced sensitivity to B3AR-mediated browning in estrogen receptor (ER)alpha-null mice, we hypothesized that ERβ may enhance the WAT response to the B3AR ligand, CL316,243 (CL). Methods: Male and female wild-type (WT) and ERβ DNA binding domain knock-out (ERβDBDKO) mice fed high-fat diet (HFD) to induce obesity were administered CL (1 mg/kg) daily for 2 weeks. Systemic physiological assessments of body composition (EchoMRI), bioenergetics (metabolic chambers), adipocyte mitochondrial respiration (oroboros) and glucose tolerance were performed, alongside perigonadal (PGAT), subcutaneous (SQAT) and brown adipose tissue (BAT) protein expression assessment (Western blot). Mechanisms were tested in vitro using primary adipocytes isolated from WT mice, and from Esr2-floxed mice in which ERβ was knocked down. Statistical analyses were performed using 2 × 2 analysis of variance (ANOVA) for main effects of genotype (G) and treatment (T), as well as GxT interactions; t-tests were used to determine differences between in vitro treatment conditions (SPSS V24). Results: There were no genotype differences in HFD-induced obesity or systemic rescue effects of CL, yet ERβDBDKO females were more sensitive to CL-induced increases in energy expenditure and WAT UCP1 induction (GxT, p < 0.05), which coincided with greater WAT B3AR protein content among the KO (G, p < 0.05). Among males, who were more insulin resistant to begin with (no genotype differences before treatment), tended to be more sensitive to CL-mediated reduction in insulin resistance. With sexes combined, basal WAT mitochondrial respiration trended toward being lower in the ERβDBDKO mice, but this was completely rescued by CL (p < 0.05). Confirming prior work, CL increased adipose tissue ERβ protein (T, p < 0.05, all), an effect that was enhanced in WAT and BAT the female KO (GxT, p < 0.01). In vitro experiments indicated that an inhibitor of ERβ genomic function (PHTPP) synergized with CL to further increase UCP1 mRNA (p = 0.043), whereas full ERβ protein was required for UCP1 expression (p = 0.042). Conclusion: Full ERβ activity appears requisite and stimulatory for UCP1 expression via a mechanism involving non-classical ERβ signaling. This novel discovery about the role of ERβ in adipocyte metabolism may have important clinical applications.

Estrogen receptor β (ERb), one of the two major estrogen receptors, acts via genomic and non-genomic signaling pathways to affect many metabolic functions, including mitochondrial biogenesis and respiration. This study assessed the effect of ERb classical genomic activity on adipocyte-specific and -systemic metabolic responses to wheel running exercise in a rodent model of menopause. Female mice lacking the ERb DNA-binding domain (ERbDBDKO, n = 20) and WT (n = 21) littermate controls were fed a high-fat diet (HFD), ovariectomized (OVX), and randomized to control (no running wheel) and exercise (running wheel access) groups and were followed for 8 weeks. Wheel running did not confer protection against metabolic dysfunction associated with HFD+OVX in either ERbDBDKO or WT mice, despite increased energy expenditure. Unexpectedly, in the ERbDBDKO group, wheel running increased fasting insulin and surrogate measures of insulin resistance, and modestly increased adipose tissue inflammatory gene expression (P ≤ 0.05). These changes were not accompanied by significant changes in adipocyte mitochondrial respiration. It was demonstrated for the first time that female WT OVX mice do experience exercise-induced browning of white adipose tissue, indicated by a robust increase in uncoupling protein 1 (UCP1) (P ≤ 0.05). However, KO mice were completely resistant to this effect, indicating that full ERb genomic activity is required for exercise-induced browning. The inability to upregulate UCP1 with exercise following OVX may have resulted in the increased insulin resistance observed in KO mice, a hypothesis requiring further investigation.

Beta-3 adrenergic receptor activation via exercise or CL316,243 (CL) induces white adipose tissue (WAT) browning, improves glucose tolerance, and reduces visceral adiposity. Our aim was to determine if sex or adipose tissue depot differences exist in response to CL. Daily CL injections were administered to diet-induced obese male and female mice for two weeks, creating four groups: male control, male CL, female control, and female CL. These groups were compared to determine the main and interaction effects of sex (S), CL treatment (T), and WAT depot (D). Glucose tolerance, body composition, and energy intake and expenditure were assessed, along with perigonadal (PGAT) and subcutaneous (SQAT) WAT gene and protein expression. CL consistently improved glucose tolerance and body composition. Female PGAT had greater protein expression of the mitochondrial uncoupling protein 1 (UCP1), while SQAT (S, p < 0.001) was more responsive to CL in increasing UCP1 (S×T, p = 0.011) and the mitochondrial biogenesis induction protein, PPARγ coactivator 1α (PGC1α) (S×T, p = 0.026). Females also displayed greater mitochondrial OXPHOS (S, p < 0.05) and adiponectin protein content (S, p < 0.05). On the other hand, male SQAT was more responsive to CL in increasing protein levels of PGC1α (S×T, p = 0.046) and adiponectin (S, p < 0.05). In both depots and in both sexes, CL significantly increased estrogen receptor beta (ERβ) and glucose-related protein 75 (GRP75) protein content (T, p < 0.05). Thus, CL improves systemic and adipose tissue-specific metabolism in both sexes; however, sex differences exist in the WAT-specific effects of CL. Furthermore, across sexes and depots, CL affects estrogen signaling by upregulating ERβ.

Estrogen receptor-α knockout (ERKO) in female, but not male, mice results in an impaired osteogenic response to exercise, but the mechanisms behind this ability in males are unknown. We explored the main and interactive effects of ERKO and exercise on cortical geometry, trabecular microarchitecture, biomechanical strength, and sclerostin expression in male mice. At 12 weeks of age, male C57BL/6J ERKO and WT animals were randomized into two groups: exercise treatment (EX) and sedentary (SED) controls, until 22 weeks of age. Cortical geometry and trabecular microarchitecture were measured via μCT; biomechanical strength was assessed via three-point bending; sclerostin expression was measured via immunohistochemistry. Two-way ANOVA was used to assess sclerostin expression and trabecular microarchitecture; two-way ANCOVA with body weight was used to assess cortical geometry and biomechanical strength. ERKO positively impacted trabecular microarchitecture, and exercise had little effect on these outcomes. ERKO significantly impaired cortical geometry, but exercise was able to partially reverse these negative alterations. EX increased cortical thickness regardless of genotype. There were no effects of genotype or exercise on sclerostin expression. In conclusion, male ERKO mice retain the ability to build bone in response to exercise, but altering sclerostin expression is not one of the mechanisms involved.

Loss of ovarian hormones leads to increased adiposity and insulin resistance (IR), increasing the risk for cardiovascular and metabolic diseases. The purpose of this study was to investigate whether the molecular mechanism behind the adverse systemic and adipose tissue-specific metabolic effects of ovariectomy requires loss of signaling through estrogen receptor alpha (ERα) or estrogen receptor β (ERβ). We examined ovariectomized (OVX) and ovary-intactwild-type (WT), ERα-null (αKO), and ERβ-null (βKO) female mice (age ~49 weeks; n = 7-12/group). All mice were fed a phytoestrogen-free diet (<15 mg/kg) and either remained ovary-intact (INT) or were OVX and followed for 12 weeks. Body composition, energy expenditure, glucose tolerance, and adipose tissue gene and protein expression were analyzed. INT αKO were ~25% fatter with reduced energy expenditure compared to age-matched INT WT controls and βKO mice (all P < 0.001). Following OVX, αKO mice did not increase adiposity or experience a further increase in IR, unlike WT and βKO, suggesting that loss of signaling through ERα mediates OVX-induced metabolic dysfunction. In fact, OVX in αKO mice (i.e., signaling through ERβ in the absence of ERα) resulted in reduced adiposity, adipocyte size, and IR (P < 0.05 for all). βKO mice responded adversely to OVX in terms of increased adiposity and development of IR. Together, these findings challenge the paradigm that ERα mediates metabolic protection over ERβ in all settings. These findings lead us to suggest that, following ovarian hormone loss, ERβ may mediate protective metabolic benefits.

Aromatase catalyzes conversion of testosterone to estradiol and is expressed in a variety of tissues, including the brain. Suppression of aromatase adversely affects metabolism and physical activity behavior, but mechanisms remain uncertain. The hypothesis tested herein was that whole body aromatase deletion would cause gene expression changes in the nucleus accumbens (NAc), a brain regulating motivated behaviors such as physical activity, which is suppressed with loss of estradiol. Metabolic and behavioral assessments were performed in male and female wild-type (WT) and aromatase knockout (ArKO) mice. NAc-specific differentially expressed genes (DEGs) were identified with RNAseq, and associations between the measured phenotypic traits were determined. Female ArKO mice had greater percent body fat, reduced spontaneous physical activity (SPA), consumed less energy, and had lower relative resting energy expenditure (REE) than WT females. Such differences were not observed in ArKO males. However, in both sexes, a top DEG was Pts, a gene encoding an enzyme necessary for catecholamine (e.g., dopamine) biosynthesis. In comparing male and female WT mice, top DEGs were related to sexual development/fertility, immune regulation, obesity, dopamine signaling, and circadian regulation. SPA correlated strongly with Per3, a gene regulating circadian function, thermoregulation, and metabolism (r = -0.64, P = .002), which also correlated with adiposity (r = 0.54, P = .01). In conclusion, aromatase ablation leads to gene expression changes in NAc, which may in turn result in reduced SPA and related metabolic abnormalities. These findings may have significance to post-menopausal women and those treated with an aromatase inhibitor.

In vivo, ERb activation protects against obesity and white adipose tissue (WAT) dysfunction. Mechanisms are unknown, but we hypothesize that it involves adipocyte‐specific mitochondrial activity via induction of OXPHOS and UCP1– proteins that characterize WAT “browning,” a process sufficient to rescue metabolic dysfunction. In cancer cells, increasing mitochondrial ERb increases OXPHOS transcription and mitochondrial activity via a mechanism requiring mitochondrial transporter, GRP75. We sought to determine whether this mechanism applies to adipocytes in vitro, and the potential in vivo implications. In wild type (WT) mice, the adipocyte‐specific B3AR ligand, CL316,243 (CL) induced WAT UCP1 and ERb protein (Western blot), and GRP75 mRNA (qPCR) (all n=10/grp, P<0.05). In primary adipocytes from WT mice (n=3/treatment), CL increased UCP1 (~2‐fold; P<0.05) and ERb protein (~4‐fold; trend, P=0.097). In vivo, we show that adipocytes harvested from mutant mice missing ERb DNA binding domain (ERbDBDKO) display suppressed mitochondrial O2 consumption (via Oroboros; n=6–8/grp, P<0.05) and lower OXPHOS protein expression (P<0.05). We next tested whether ERbDBDKO mice would have impaired exercise‐induced WAT browning. Remarkably, unlike WT (~3‐fold UCP1 increase; P<0.05), ERbDBDKO mice were nonresponsive to exercise induction of UCP1 protein in WAT. Taken together, our data support a critical role for adipocyte ERb in mediating lipolysis driven mitochondrial responses. We hypothesize that the mechanism involves GRP75. Identifying the mechanism by which ERb enhances adipocyte mitochondrial activity has enormous potential to treat a spectrum of metabolic diseases.

Estrogen receptor-α knockout (ERKO) in female rodents results in bone loss associated with increased osteocyte sclerostin expression; whether this also occurs in males is unknown. Here, we examined the effects of ERKO on femoral cortical geometry, trabecular microarchitecture, and osteocyte sclerostin expression of the femur and lumbar vertebrae. At 14 months of age, male ERKO and wild-type (WT) littermates ( n = 6 per group) were sacrificed, and femora and vertebra were collected. Cortical geometry and trabecular microarchitecture were assessed via micro-computed tomography; osteocyte sclerostin expression was assessed via immunohistochemistry. ANCOVA with body weight was used to compare ERKO and WT for cortical geometry; t-tests were used for all other outcomes. Regardless of skeletal site, ERKO mice had greater trabecular bone volume and trabecular number and decreased trabecular separation compared with WT. In the femoral diaphysis, ERKO had lower total area, cortical area, and cortical thickness compared with WT. The percentage of sclerostin+ osteocytes was increased in ERKO animals in cortical bone but not in cancellous bone of the femur or the lumbar vertebrae. In conclusion, ERKO improved trabecular microarchitecture in aged male mice, but negatively altered femoral cortical geometry associated with a trend towards increased cortical sclerostin expression.

Metabolic disease risk escalates following menopause. The mechanism is not fully known, but likely involves reduced signaling through estrogen receptor alpha (ERα), which is highly expressed in brown and white adipose tissue (BAT and WAT). Objective: Test the hypothesis that uncoupling protein (UCP1) activation mitigates metabolic dysfunction caused by loss of signaling through ERα. Methods: At 8 weeks of age, female ERα knock out (KO) and wild-type mice were housed at 28°C and fed a Western-style high-fat, high sucrose diet (HFD) or a normal low-fat chow diet (NC) for 10 weeks. During the final 2 weeks, they received daily injections of CL 316,256 (CL), a selective β3 adrenergic agonist, or vehicle control (CTRL), creating eight groups: WT-CTRL, WT-CL, KO-CTRL, and KO-CL on HFD or NC; n = 4-10/group. Results: ERαKO demonstrated exacerbated HFD-induced adiposity gain (P < 0.001) and insulin resistance (P = 0.006). CL treatment improved insulin sensitivity (P < 0.05) and normalized ERαKO-induced adiposity increase (P < 0.05). In both genotypes, CL increased resting energy expenditure (P < 0.05) and induced WAT beiging indicated by increased UCP1 protein in both perigonadal (PGAT) and subcutaneous (SQAT) depots. These effects were attenuated under HFD conditions (P < 0.05). In KO, CL reduced HFD energy consumption compared to CTRL (P < 0.05). Remarkably, CL increased WAT ERβ protein levels of both WT and KO (P < 0.001), revealing CL-mediated changes in estrogen signaling may have protective metabolic effects. Conclusion: CL completely restored metabolic dysfunction in ERαKO mice. Thus, UCP1 may be a therapeutic target for treating metabolic dysfunction following loss of estrogen receptor signaling.

3,3′-Diindolylmethane (DIM) is an acid-derived dimer of indole-3-carbinol, found in many cruciferous vegetables, such as broccoli, and has been shown to inhibit prostate cancer (PCa) in several in vitro and in vivo models. We demonstrated that DIM stimulated both estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ) transcriptional activities and propose that ERβ plays a role in mediating DIM’s inhibition on cancer cell growth. To further study the effects of DIM on inhibiting advanced PCa development, we tested DIM in TRAMP (TRansgenic Adenocarcinoma of the Mouse Prostate) mice. The control group of mice were fed a high fat diet. Three additional groups of mice were fed the same high fat diet supplemented with 0.04%, 0.2% and 1% DIM. Incidence of advanced PCa, poorly differentiated carcinoma (PDC), in the control group was 60%. 1% DIM dramatically reduced PDC incidence to 24% (p=0.0012), while 0.2% and 0.04% DIM reduced PDC incidence to 38% (p=0.047) and 45% (p=0.14) respectively. Though DIM did affect mice weights, statistical analysis showed a clear negative association between DIM concentration and PDC incidence with p=0.004, while the association between body weight and PDC incidence was not significant (p=0.953). In conclusion, our results show that dietary DIM can inhibit the most aggressive stage of prostate cancer at concentration lower than previously demonstrated, possibly working through an estrogen receptor mediated mechanism.

High levels of docosahexaenoic acid (DHA) in the phospholipids of mammalian brain have generated increasing interest in the search for its role in regulating brain functions. Recent studies have provided evidence for enhanced protective effects when DHA is administered in combination with phytochemicals, such as quercetin. DHA and quercetin can individually suppress lipopolysaccharide (LPS)–induced oxidative/inflammatory responses and enhance the antioxidative stress pathway involving nuclear factor erythroid-2 related factor 2 (Nrf2). However, studies with BV-2 microglial cells indicated rather high concentrations of DHA (IC50 in the range of 60–80 µM) were needed to produce protective effects. To determine whether quercetin combined with DHA can lower the levels of DHA needed to produce protective effects in these cells is the goal for this study. Results showed that low concentrations of quercetin (2.5 µM), in combination with DHA (10 µM), could more effectively enhance the expression of Nrf2 and heme oxygenase 1 (HO-1), and suppress LPS–induced nitric oxide, tumor necrosis factor-α, phospho-cytosolic phospholipase A2, reactive oxygen species, and 4-hydroxynonenal, as compared to the same levels of DHA or quercetin alone. These results provide evidence for the beneficial effects of quercetin in combination with DHA, and further suggest their potential as nutraceuticals for improving health.

The role of estrogen receptor-α (ERα) signaling in immunometabolic function is established in females. However, its necessity in males, while appreciated, requires further study. Accordingly, we first determined whether lower metabolic function in male mice compared with females is related to reduced ERα expression. ERα protein expression in metabolically active tissues was lower in males than in females, and this lower expression was associated with worse glucose tolerance. Second, we determined whether ERα is required for optimal immunometabolic function in male mice consuming a chow diet. Despite lower expression of ERα in males, its genetic ablation (KO) caused an insulin-resistant phenotype characterized by enhanced adiposity, glucose intolerance, hepatic steatosis, and metaflammation in adipose tissue and liver. Last, we determined whether ERα is essential for exercise-induced metabolic adaptations. Twelve-week-old wild-type (WT) and ERα KO mice either remained sedentary (SED) or were given access to running wheels (WR) for 10 wk while fed an obesogenic diet. Body weight and fat mass were lower in WR mice regardless of genotype. Daily exercise obliterated immune cell infiltration and inflammatory gene transcripts in adipose tissue in both genotypes. In the liver, however, wheel running suppressed hepatic steatosis and inflammatory gene transcripts in WT but not in KO mice. In conclusion, the present findings indicate that ERα is required for optimal immunometabolic function in male mice despite their reduced ERα protein expression in metabolically active tissues. Furthermore, for the first time, we show that ERα signaling appears to be obligatory for exercise-induced prevention of hepatic steatosis.

Estrogens bind to two nuclear estrogen receptor (ER) subtypes, ER alpha and ER beta, which are expressed in differing amounts in various tissues. The endogenous estrogen, 17 beta-estradiol (E2), binds to both subtypes with nearly equal affinity and is the prototypical agonist. Selective estrogen receptor modulators (SERMs) may bind to both subtypes with equivalent affinities but have agonist activities in some tissues while having antagonist activities in others. In the present study, we demonstrate that the first reported endogenous SERM, 27-hydroxycholesterol (27-OHC), binds preferentially (> 100-fold) to ER beta over ER alpha. Furthermore, 27-OHC is not able to fully compete with E2 binding, suggesting the two may bind at different sites. We provide an allosteric ternary complex model for the simultaneous binding of 27-OHC and E2 to ER beta, which accurately describes the binding data we have observed. We conclude that 27-OHC is a negative allosteric modifier of E2 binding, with an inhibitor constantof 50 nM and cooperativity factor (alpha) of 0.036. We also propose an in silico three-dimensional model of the simultaneous binding to guide future experiments. Further study of this unique binding model may allow for the discovery of novel ER beta-selective ligands and potentially explain the lack of effectiveness of ER beta-selective agonists in humans vs preclinical models.

Sutherlandia frutescens (S. frutescens) has been traditionally used as an herbal medicine to ameliorate symptoms associated with cancer, infectious diseases, as well as inflammation. The objective of this investigation was to explore the impact of S. frutescens on the expression of genes in a murine macrophage cell line (i.e., RAW 264.7). We found that treatment with an ethanolic-extract of S. frutescens (SFE) 1 h prior to the stimulation with LPS and IFNγ for 24 h significantly affected the expression of 715 genes in RAW 264.7 cells. When the post-stimulation period was shortened to 8 h, the number of genes that were significantly impacted by SFE diminished to 50. Pathway analysis revealed that inflammatory signaling pathways, such as NF-κB, MAPK, and TNF, as well as signaling pathways associated with immune-related responses, were inhibited by SFE treatment. These findings are consistent with previously reported anti-inflammatory activity of SFE and enable better understanding of the immune-modulating properties of this botanical. To our knowledge, this represents the first report on the impact of S. frutescens on global gene expression in an immune cell population.