Oxidative Stress-Mediated Brain Dehydroepiandrosterone (DHEA) Formation in Alzheimer’s Disease Diagnosis

Neurosteroids are steroids made by brain cells independently of peripheral steroidogenic sources. The biosynthesis of most neurosteroids is mediated by proteins and enzymes similar to those identified in the steroidogenic pathway of adrenal and gonadal cells. Dehydroepiandrosterone (DHEA) is a major neurosteroid identified in the brain. Over the years we have reported that, unlike other neurosteroids, DHEA biosynthesis in rat, bovine, and human brain is mediated by an oxidative stress-mediated mechanism, independent of the cytochrome P450 17α-hydroxylase/17,20-lyase (CYP17A1) enzyme activity found in the periphery. This alternative pathway is induced by pro-oxidant agents, such as Fe2+ and β-amyloid peptide. Neurosteroids are involved in many aspects of brain function, and as such, are involved in various neuropathologies, including Alzheimer’s disease (AD). AD is a progressive, yet irreversible neurodegenerative disease for which there are limited means for ante-mortem diagnosis. Using brain tissue specimens from control and AD patients, we provided evidence that DHEA is formed in the AD brain by the oxidative stress-mediated metabolism of an unidentified precursor, thus depleting levels of the precursor in the blood stream. We tested for the presence of this DHEA precursor in human serum using a Fe2+-based reaction and determined the amounts of DHEA formed. Fe2+ treatment of the serum resulted in a dramatic increase in DHEA levels in control patients, whereas only a moderate or no increase was observed in AD patients. The DHEA variation after oxidation correlated with the patients’ cognitive and mental status. In this review, we present the cumulative evidence for oxidative stress as a natural regulator of DHEA formation and the use of this concept to develop a blood-based diagnostic tool for neurodegenerative diseases linked to oxidative stress, such as AD

Identification of a Benzamide Derivative that Inhibits Stress- Induced Adrenal Corticosteroid Synthesis

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Study protocol: the biologics in severe chronic rhinosinusitis with nasal polyps survey

International audienceIntroduction Chronic rhinosinusitis with nasal polyps (CRSwNP) is a frequent condition affecting approximately 2% of the population. Medical treatment consists long-term use of intranasal corticosteroids and short-term use of oral corticosteroids, in adjunct with saline solution rinses. Surgical management is proposed in patients who failed after medical treatment. In France, two biologics are reimbursed in case of severe uncontrolled CRSwNP despite medical treatment and endoscopic sinus surgery. Waiting for head-to-head biologics comparison, studies should report the efficacy and safety of biologics in large real-life cohorts. This study protocol describes the aims and methods of a prospective, observational, national, multicentric cohort of patients with CRSwNP treated with biologics. Methods and analysis The BIOlogics in severe nasal POlyposis SurvEy is a French multicentre prospective observational cohort study. The main aim is to assess the efficacy and tolerance of biologics in patients with CRSwNP, with or without association with other type 2 diseases, and to determine the strategies in case of uncontrolled disease under biologics. Patients over 18 years old requiring biologics for CRSwNP in accordance with its marketing approval in France (ie, severe nasal polyposis, with lack of control under nasal corticosteroid, systemic corticosteroids and surgery) are invited to participate. Collected data include topical history of surgical procedures and biologics, medication and use of systemic corticosteroids, visual analogical scales for specific symptoms, Sino-Nasal Outcome Test-22 questionnaire, nasal polyp score, asthma control test, Lund-Mackay score on CT scan and IgE concentration and eosinophilic count on blood sample. Trial registration NCT05228041 /DRI_2021/0030