An acute increase in the circulating concentration of glucocorticoid hormones is essential for the survival of severe somatic stresses. Circulating concentrations of GDF15, a hormone that acts in the brain to reduce food intake, are frequently elevated in stressful states. We now report that GDF15 potently activates the hypothalamic–pituitary–adrenal (HPA) axis in mice and rats. A blocking antibody to the GDNF-family receptor α-like receptor completely prevented the corticosterone response to GDF15 administration. In wild-type mice exposed to a range of stressful stimuli, circulating levels of both corticosterone and GDF15 rose acutely. In the case of Escherichia coli or lipopolysaccharide injections, the vigorous proinflammatory cytokine response elicited was sufficient to produce a near-maximal HPA response, regardless of the presence or absence of GDF15. In contrast, the activation of the HPA axis seen in wild-type mice in response to the administration of genotoxic or endoplasmic reticulum toxins, which do not provoke a marked rise in cytokines, was absent in Gdf15−/− mice. In conclusion, consistent with its proposed role as a sentinel hormone, endogenous GDF15 is required for the activation of the protective HPA response to toxins that do not induce a substantial cytokine response. In the context of efforts to develop GDF15 as an antiobesity therapeutic, these findings identify a biomarker of target engagement and a previously unrecognized pharmacodynamic effect, which will require monitoring in human studies.

Background:There are limited data on the effect of dual antiplatelet treatment with clopidogrel plus aspirin in patients with ischemic cerebrovascular disease and intracranial and extracranial arteriostenosis. The aim of our study was to evaluate the efficacy and safety of aspirin plus clopidogrel in the treatment of ischemic cerebrovascular disease with intracranial and extracranial arteriostenosis.Methods:Patients with clinically evident acute cerebral infarction or transient ischemic attack combined with intracranial and extracranial arteriostenosis (greater than 50%) who were unsuitable or reluctance to perform stent implantation were enrolled in this study. We randomly assigned these patients to receive clopidogrel (75 or 50 mg) plus aspirin (100 mg) or aspirin (100 mg) once daily through 90 days, and followed them for 90 days. We examined the main endpoints including the recurrence of stroke, death from cardiovascular causes, and bleeding events.Results:In all, 200 patients were recruited and followed for 90 days. Ischemic stroke occurred in 6 patients (9.1%) treated with 50 mg clopidogrel and aspirin, 6 patients (9.1%) receiving 75 mg clopidogrel and aspirin, whereas 19 patients (27.9%) in the aspirin group (aspirin alone vs copidogrel 50 mg plus aspirin; 95% confidence intervals 1.704–23.779, P < 0.05; aspirin alone vs copidogrel 75 mg plus aspirin; 95% confidence intervals 1.190–13.240, P < 0.05). There were more hemorrhagic events among recipients (3 patients [2.3%]) in the copidogrel plus aspirin group than aspirin recipients (0 patient [0%]), including 1 subcutaneous hemorrhage in the group of 50 mg clopidogrel and aspirin, doubling the number of nasal and gum bleeding in the group of 75 mg clopidogrel and aspirin (P > 0.05). No intracranial hemorrhage and gastro-intestinal hemorrhage occurred in these 3 groups.Conclusion:Accordingly, 50 mg clopidogrel plus aspirin, and 75 mg clopidogrel plus aspirin were all superior to aspirin alone as stroke prevention in patients with cerebral infarction or transient ischemic attack combined with intracranial and extracranial arteriostenosis. The effect of secondary stroke prevention was similar between 50 mg clopidogrel plus aspirin and 75 mg clopidogrel plus aspirin. The therapy of 75 mg clopidogrel plus aspirin resulted in a worrisome tread in bleeding events.