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Biology subjects

Finan, B.

Publications and source records attributed to Finan, B..

4 recordsLinked to original sources

Conjugated GLP-1 and Estradiol Treatment as a Novel Treatment for Age-related Cognitive Decline in Males and Females

Middle age represents a critical window for metabolic and cognitive health, particularly in the context of rising obesity and diabetes rates. Glucagon-like peptide-1 (GLP-1)-based therapies, which regulate blood glucose and body weight, show sex-specific effects, with estradiol potentiating their metabolic benefits. However, research on GLP-1s cognitive and neuroprotective roles has largely been conducted in males. Here, we investigated the effects of GLP-1 conjugated to estradiol (GE2) on metabolism, cognition, cytokine levels and neurogenesis in the dentate gyrus of middle-aged male and female rats fed a standard (SD) or Western (WD) diet. In both sexes, WD increased body weight and plasma leptin levels, regardless of sex. GE2 treatment led to weight loss, enhanced cued and contextual fear memory, reduced cytokine levels in the hippocampus in SD rats, and increased neurogenesis in the dorsal dentate gyrus (DG), regardless of sex. Sex-specific differences were observed in fat distribution, glucose regulation, central cytokine levels, and neuroplasticity after WD and GE2 treatment. In females only, GE2 reduced visceral (gonadal) fat, reduced cytokines in the dorsal hippocampus, and improved basal blood glucose in response to a WD. In males only, GE2 restored neurogenesis in the DG after WD exposure, and reduced cytokine levels in the amygdala. These findings suggest that although WD increased body weight and GE2 improved associative learning in both sexes, both WD and GE2 had differential affects on metabolic hormones, insulin regulation, cytokine levels and neuroplasticity. Our findings underscore the importance of sex-specific approaches in metabolic and neuroprotective therapeutics in middle age.

neuroscience↗

Ectopic, hepatic GLP-1R agonism enhances the weight loss efficacy of GLP-1 analogues.

ObjectiveUnimolecular triagonists drive substantial weight loss in patients with obesity (PwO) by engaging the glucagon-like peptide 1 (GLP-1) and glucose dependent insulinotropic polypeptide (GIP) receptors to reduce food intake (FI) and the hepatic glucagon (Gcg) receptor to enhance energy expenditure (EE). However, their development has been challenged by deleterious cardiovascular (CV) effects including increased heart rate (HR), elongated QTc, and arrhythmia mediated by GcgR agonism. GLP-1R monoagonists on the other hand improve both obesity and CV outcomes with negligible effects on EE. We sought to imbue peptide GLP-1R agonists with an EE enhancing effect by combining them with ectopic GLP-1R expression and agonism in hepatocytes. MethodsWe used an attenuated adenovirus (AAV) to induce the expression of a functional, liver-specific GLP-1R combined with traditional peptide agonist treatment to drive greater body weight loss via reduced energy intake and increased energy expenditure. ResultsAgonism of the ectopic GLP-1R with either semaglutide, a low internalization GLP-1R agonist (Sema584), or a dual GLP-1R/GIPR agonist in wild-type (WT) diet induced obese (DIO) mice led to enhanced EE and improved weight loss compared to agonist treatment alone. ConclusionsThis represents a novel mechanism for achieving polypharmacy to treat obesity. HighlightsO_LIA Glp1r encoding AAV induces expression of a functional receptor mouse livers. C_LIO_LIEndogenous GLP-1R does not mediate semaglutide clearance. C_LIO_LIEctopic GLP-1R mediates semaglutide clearance. C_LIO_LIEctopic, hepatic Glp1r plus semaglutide enhances weight loss in mice. C_LIO_LIEctopic, hepatic Glp1r plus a dual incretin agonist enhances weight loss in mice. C_LI

zoology↗

GIP receptor agonism improves dyslipidemia and atherosclerosis independently of body weight in obese mice

Agonism at the receptors for the glucose-dependent insulinotropic polypeptide (GIPR) is a key component of the novel unimolecular co-agonists which are among the most promising drugs in clinical development for the treatment of obesity and diabetes. The therapeutic effect of chronic GIPR agonism to treat dyslipidemia, and thus to reduce the cardiovascular disease risk, has not been explored yet. Herein we found that treatment with a long-acting acylated GIP analog (Acyl-GIP) reduced dyslipidemia and atherogenesis in male LDL receptor knockout mice. Acyl-GIP administration resulted in smaller adipocytes within the inguinal fat depot and RNAseq analysis of the latter revealed that Acyl-GIP may improve dyslipidemia by directly modulating lipid metabolism in this fat depot. This study identified an unanticipated efficacy of chronic GIPR agonist administration to improve dyslipidemia and cardiovascular disease.

pharmacology and toxicology↗

Pharmacological but not physiological GDF15 suppresses feeding and the motivation to exercise

Growing evidence supports that pharmacological application of growth differentiation factor 15 (GDF15) suppresses appetite but also promotes sickness-like behaviors in rodents via GDNF family receptor -like (GFRAL)-dependent mechanisms1,2. Conversely, the endogenous regulation and secretion of GDF15 and its physiological effects on energy homeostasis and behavior remain elusive. Here we show, in four independent studies that prolonged, moderate- to high-intensity endurance exercise substantially increases circulating GDF15, in a time-dependent and reversible fashion, to peak levels otherwise only observed in pathophysiological conditions. This exercise-induced increase can be recapitulated in mice following forced treadmill running and is accompanied by increased Gdf15 expression in the liver, skeletal muscle, and heart muscle. Compared to other metabolic stressors, like fasting, acute high-fat diet feeding, severe caloric excess and temperature changes, exercise has a greater impact on circulating GDF15 levels. However, whereas pharmacological GDF15 inhibits appetite and suppresses wheel running activity via GFRAL, in response to exercise, the physiological induction of GDF15 does not. In summary, exercise-induced circulating GDF15 correlates with the duration of endurance exercise. However, higher GDF15 levels after exercise are not sufficient to evoke canonical pharmacological GDF15 effects on appetite or responsible for exercise aversion/fatigue. Thus, the physiological effects of GDF15 as an exerkine remain elusive.

physiology↗