2011

Seven projects were received and 3 were selected for funding:

Project 1: Combined cell and gene therapy as a novel approach for the treatment of human 21-hydroxylase-deficiency

Congenital adrenal hyperplasia due to 21-hydroxylase-deficiency is an autosomal-recessive disorder characterized by cortisol deficiency, aldosterone deficiency, chronic stimulation of the adrenal by corticotropin and hyperandrogenism. Patients with such disease are compelled to life-long glucocorticoid replacement therapy to prevent death by cardiovascular collapsus. However, available treatment is far from ideal, and recent studies have pointed out excess mortality due to inappropriate glucocorticoid replacement therapy As a logical consequence from the current experiences, a treatment strategy that has fewer side effects and will correct the underlying genetic defect would be highly desirable. We are now proposing to develop a novel therapeutic approach based on an adrenal cell-based transplantation approach.

We will introduce the CYP21A2 gene into cells isolated from patients after unilateral adrenalectomy to restore the 21-hydroxylase activity prior autotransplantation. We will explore the feasibility of this approach by using the mouse model we developed and our expertise in genetically modification of adrenocortical cells.

Project 2 Gene Therapy for the severe virilizing forms of Congenital Adrenal Hyperplasia using direct intra-adrenal injection of recombinant AAV vector encoding human CYP21.

21-OHase deficiency (21-OH-d) blocks cortisol and aldosterone synthesis, which leads to super active ACTH feedback, adrenal hyperplasia, intra-uterine masculinization of female fetuses, and requires immediate neonatal gluco and mineralocorticoids treatment. In the most severe loss-of-function CYP21 gene defects, overabundant androgen production by the hyperplasic adrenals leads to complete sexual ambiguity (called “Prader V” where the baby girl looks like a boy without testes) needing surgical correction. Despite medical treatment, even in the best centers, the girl’s body and genitalia remain exposed to a marked lifelong tendency for virilization. Thus more than 95% of Prader V women suffer almost complete restriction of sexual and marital life, and rarely carry pregnancy (Gastaud et al. 2007), a situation that could justify gene therapy attempts. Milder forms of 21-OH-d (Prader I-III) are easy to regulate with appropriate treatment and are not targets for gene therapy (GT). The aim of our project is to develop a gene therapy approach based on intra-adrenal injection of a therapeutic vector (Adeno Associated Virus, AAV) encoding the human CYP21 cDNA. The objective of GT is to restore enzymatic activity, allow near normal secretion of gluco-and mineralocorticoids and minimize androgen excess. If successful in preclinical research stages, GT could result in early administration of the vector at time of surgical reparation of the genitalia. In a preliminary study in rats, we selected two serotypes of AAV (5 and 8) having a strong tropism for adrenal fasciculate and glomerular zones, where cortisol is normally produced. We will evaluate GT in a mouse CYP21-/- model of the disease. In case of positive results, we will perform a scale-up study in non-human primate.

Project 3 Early metabolic alterations and cardiovascular risk in patients with classic 21-hydroxylase deficiency. Are they reversible by life-style intervention?

Literature data point out to some traits of metabolic syndrome in patients with congenital adrenal hyperplasia. Overweight/obesity, elevated blood pressure, insulin resistance and dyslipidemia have been described. When these traits appear and if they are reversible through a non-pharmacologic life-style intervention have not been investigated to date. We aim to characterize a group of children, adolescents and young patients with only classic forms of 21-hydroxylase deficiency with respect to lipid metabolism (including analysis of LDL-subfractions), insulin resistance, adipokine levels and markers of subclinical inflammation and oxidative stress as well as surrogate markers of cardiovascular risk (intima-media-thickness, flow mediated vasodilatation). This characterization will be performed in a cross-sectional manner, in comparison to a matched control group as well as in a longitudinal manner in comparison with most of these patients five years ago. Patients with traits of metabolic syndrome will be subjected to a structured life style intervention for one year with reevaluation thereafter.

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