👤 Akeem Sanni

About 30% of patients with active acromegaly experience paradoxically increased growth hormone (GH) secretion during the diagnostic oral glucose tolerance test (OGTT). Endogenous glucose-dependent insulinotropic polypeptide (GIP) is implicated in this paradoxical secretion. We used the GIP receptor (GIPR) antagonist GIP(3-30)NH2 to test the hypothesis that GIP mediates this paradoxical response when GIPR is abundantly expressed in somatotropinomas. A total of 25 treatment-naive patients with acromegaly were enrolled. Each patient underwent one OGTT during simultaneous placebo infusion and one OGTT during a GIP(3-30)NH2 infusion. Blood samples were drawn at baseline and regularly after infusions to measure GH. We assessed pituitary adenoma size by magnetic resonance imaging and GIPR expression by immunohistochemistry on resected somatotropinomas. For mechanistic confirmation, we applied in vitro and ex vivo approaches. The main outcome measure was the effect of GIP(3-30)NH2 on paradoxical GH secretion during OGTT as a measure of GIP involvement. In 4 of 7 patients with paradoxical GH secretion, GIP(3-30)NH2 infusion completely abolished the paradoxical response (P = .0003). Somatotrophs were available from 3 of 4 of these patients, all showing abundant GIPR expression. Adenoma size did not differ between patients with and without paradoxical GH secretion. Of 25 patients with acromegaly, 7 had paradoxical GH secretion during OGTT, and pharmaceutical GIPR blockade abolished this secretion in 4. Corresponding somatotroph adenomas abundantly expressed GIPR, suggesting a therapeutic target in this subpopulation of patients. In vitro and ex vivo analyses confirmed the role of GIP and the effects of the antagonist. Show less

Alzheimer's Disease (AD), the leading cause of dementia, is characterized by complex pathological mechanisms that extend beyond amyloid-β plaques and tau tangles. This study investigates the dysregulation of lipids with a focus on phospholipids and sphingolipids, in human post-mortem AD brain tissue using lipidomics methodology. By employing a ZIC-HILIC LC-MS/MS platform, the lipidome of AD ( Show less

Obesity represents a global health crisis with significant patient burdens and healthcare costs. Despite the advances with glucagon-like peptide-1 (GLP-1) receptor agonists in treating obesity, unmet needs remain. This study characterizes a novel glucose-dependent insulinotropic polypeptide receptor (GIPR) peptide antagonist, AT-7687, evaluating its potential to enhance obesity treatment. We assessed the in vitro potency and pharmacokinetics of AT-7687, alongside its therapeutic effects when administered subcutaneously (SC) alone and in combination with liraglutide to high-fat-diet-fed obese non-human primates (NHP). The study spanned a 42-day treatment period and a 15-day washout period. AT-7687 demonstrated a subnanomolar cAMP antagonistic potency (pKB of 9.5) in HEK-293 cells and a 27.4 h half-life in NHPs. It effectively maintained weight stability in obese monkeys, whereas placebo recipients had an 8.6% weight increase by day 42 (P = 0.01). Monotherapy with liraglutide resulted in a 12.4% weight reduction compared to placebo (P = 0.03) and combining AT-7687 with liraglutide led to a 16.3% weight reduction (P = 0.0002). The combination therapy significantly improved metabolic markers, reducing insulin levels by 52% (P = 0.008), glucose by 30% (P = 0.02), triglycerides by 39% (P = 0.05), total cholesterol by 29% (P = 0.03), and LDL cholesterol by 48% (P = 0.003) compared to placebo. AT-7687 treatment was well tolerated and not associated with any side effects. This study underscores the potential of AT-7687 as a promising addition to current obesity treatments. Show less