β-adrenergic receptors in the up-regulation of COX2 expression and prostaglandin production in testicular macrophages: Possible relevance to male idiopathic infertility

Abstract

Catecholaminergic neuronal elements (CNE) and macrophages (MACs) are increased in testes of patients withidiopathic infertility. Now, we describe an anatomical proximity between CNE and MACs, expression of specificα- and β-adrenergic receptors (ADRs) subtypes in MACs, and a positive correlation between the number of MACsand cyclooxygenase (COX2) expression - key enzyme in prostaglandin (PG) synthesis and an inflammatorymarker - in testes of infertile men. To examine a potential effect of adrenergic input on COX2 expression, we usedtwo additional experimental models: non-testicular human MACs (THP1 cell line) and non-human testicularMACs purified from adult Syrian hamsters. We found that epinephrine and norepinephrine up-regulate COX2expression and PGD2 production through β1-and β2-ADRs.Our results demonstrate the existence of a yet unknown link between CNE and MACs in the human testis thatcould trigger inflammation and tissue homeostatic dysregulation associated with pathogenesis or maintenance of infertility states.