No abstract

Obesity is an epidemic problem affecting millions of people in the Western hemisphere and costs the United States economy more than $200 billion annually. Currently, there are no effective treatments to combat obesity. Recent studies have implicated the constitutive activity of estrogen receptor (ER) ␤ as an important regulator of metabolic diseases. However, the potential of ER-␤-selective ligands to offset obesity is not clear. We evaluated the pharmacological effect of ER-␤-selective ligands (␤-LGNDs) in animal models of high-fat diet-and ovariectomyinduced obesity. Ligand binding, transactivation, and uterotrophic studies with ␤-LGNDs demonstrated selectivity for ER-␤ over ER-␣. Animals fed a high-fat diet showed a significant increase in body weight, and this weight gain was attenuated by ␤-LGNDs. High-fat diet-mediated increases in serum cholesterol, leptin, glucose, and fat accumulation in organs were also reduced by ␤-LGNDs. In addition, MRI scanning indicated that ␤-LGNDs altered body composition by reducing fat mass and increasing lean body mass. Organ weights and gene expression analyses demonstrated that adipose tissue is the center of action for ␤-LGNDs, and the reduction in body weight is likely due to increased energy expenditure. In vitro and in vivo mechanistic studies indicated that the anti-obesity effects of ␤-LGNDs were due to indirect peroxisome proliferator-activated receptor ␥ antagonistic actions requiring the ligand binding domain of ER-␤ and through abrogation of the ability of PGC-1 to coactivate peroxisome proliferator-activated receptor ␥. In conclusion, these studies indicate that ligand-activated ER-␤ is a potential therapeutic target to combat obesity and obesity-related metabolic diseases.Obesity is an epidemic disease affecting over 400 million people globally (1). Two-thirds of adults and children in the United States are either overweight or obese, making it a serious health risk and economic burden to society (2). Obesity is not a standalone disease, as its emergence leads to various complications, including type 2 diabetes mellitus (T2DM), 3 hypertension, atherosclerosis, and other cardiovascular diseases, osteoporosis, and clinical depression (3, 4). The United States Food and Drug Administration required an anti-obesity drug to reduce the body weight by 5% and/or better results than placebo in 12 months, indicating that even a marginal reduction in body weight will cause a significant improvement in the welfare of these patients (5). Despite the exponentially growing global obesity pharmaceutical market, only two Food and Drug Administration-approved drugs are available for this indication: 1) amphetamines and sibutramine that act on the hypothalamus to control appetite stimulation in the central nervous system, and 2) Orlistat, which is a lipase inhibitor that blocks gastrointestinal absorption of fat and decreases energy uptake (6). Despite mediocre performance, these drugs are commonly associated with side effects such as tachycardia, hypertension, fecal incontinence, ...

These results indicate that 17β-E(2) protects ARPE-19 cells from oxidative stress through an ERβ-dependent mechanism. 17β-E(2)-mediated cytoprotection occurred through the preservation of mitochondrial function, reduction of ROS production, and induction of cellular antioxidant genes.

Non-invasive imaging using radiolabels is a common technique used to study the biodistribution of biologics. Due to the limited shelf-life of radiolabels and the requirements of specialized labs, non-invasive optical imaging is an attractive alternative for preclinical studies. Previously, we demonstrated the utility of fluorescence molecular tomography (FMT) an optical imaging modality in evaluating the biodistribution of antibody-drug conjugates. As FMT is a relatively new technology, few fluorophores have been validated for in vivo imaging. The goal of this study was to characterize and determine the utility of near-infrared (NIR) fluorophores for biodistribution studies using interleukin-13 receptor subunit alpha-2 antibody (IL13Rα2-Ab). Eight fluorophores (ex/em: 630/800 nm) with an N-hydroxysuccinimide (NHS) linker were evaluated for Ab conjugation. The resulting antibody-fluorophore (Ab-F) conjugates were evaluated in vitro for degree of conjugation, stability and target-binding, followed by in vivo/ex vivo FMT imaging to determine biodistribution in a xenograft model. The Ab-F conjugates (except Ab-DyLight800) showed good in vitro stability and antigen binding. All Ab-F conjugates (except for Ab-BOD630) resulted in a quantifiable signal in vivo and had similar biodistribution profiles, with peak tumor accumulation between 6 and 24 h post-injection. In vivo/ex vivo FMT imaging showed 17-34% ID/g Ab uptake by the tumor at 96 h. Overall, this is the first study to characterize the biodistribution of an Ab using eight NIR fluorophores. Our results show that 3-dimensional optical imaging is a valuable technology to understand biodistribution and targeting, but a careful selection of the fluorophore for each Ab is warranted.

Age-related Macular Degeneration (AMD) is the leading cause of visual impairment and blindness in the elderly in developed countries. Neovascular/exudative (wet) AMD is the aggressive form of AMD and can involve choroidal neovascularization and vascular leakage. Anti-vascular endothelial growth factor (anti-VEGF) medications have significantly improved treatment of wet-AMD. However, only approximately 40% of patients obtain full benefit from anti-VEGF therapy and the medications are given by intravitreal injection. Axitinib, a small molecule multi-receptor tyrosine kinase inhibitor used for the treatment of advanced renal cell carcinoma, is taken orally and inhibits VEGF activity by blocking VEGF receptors. Axitinib also has the advantage of blocking platelet derived growth factor (PDGF) receptors which play a role in neovascularization. Using in vitro human retinal microvascular endothelial cells (HRMVECs), human brain vascular pericytes (HBVRs), 3D co-culture vessel sprout assay, and in vivo laser induced rat choroidal neovascularization (CNV) models, the effect of axitinib on neovascularization was evaluated. Axitinib inhibited neovascularization better than anti-VEGF and/or anti-hPDGF-B mAb in the in vitro models demonstrating that combined inhibition of both VEGF and PDGF pathways may be synergistic in treating wet-AMD. Additionally, axitinib showed good efficacy at a low dose (0.875 mg/day) in laser-induced CNV model in rats. In conclusion our data shows that axitinib, an inhibitor of VEGF and PDGF-B pathways may be useful in ameliorating wet-AMD therapy.