TY - JOUR AU - Bram, Zakariae AU - Louiset, Estelle AU - Ragazzon, Bruno AU - Renouf, Sylvie AU - Wils, Julien AU - Duparc, Céline AU - Boutelet, Isabelle AU - Rizk-Rabin, Marthe AU - Libé, Rossella AU - Young, Jacques AU - Carson, Dennis AU - Vantyghem, Marie-Christine AU - Szarek, Eva AU - Martinez, Antoine AU - Stratakis, Constantine A. AU - Bertherat, Jérôme AU - Lefebvre, Hervé T1 - PKA regulatory subunit 1A inactivating mutation induces serotonin signaling in primary pigmented nodular adrenal disease PY - 2016/09/22/ AB - Primary pigmented nodular adrenocortical disease (PPNAD) is a rare cause of ACTH-independent hypercortisolism. The disease is primarily caused by germline mutations of the protein kinase A (PKA) regulatory subunit 1A (PRKAR1A) gene, which induces constitutive activation of PKA in adrenocortical cells. Hypercortisolism is thought to result from PKA hyperactivity, but PPNAD tissues exhibit features of neuroendocrine differentiation, which may lead to stimulation of steroidogenesis by abnormally expressed neurotransmitters. We hypothesized that serotonin (5-HT) may participate in the pathophysiology of PPNAD-associated hypercortisolism. We show that PPNAD tissues overexpress the 5-HT synthesizing enzyme tryptophan hydroxylase type 2 (Tph2) and the serotonin receptors types 4, 6, and 7, leading to formation of an illicit stimulatory serotonergic loop whose pharmacological inhibition in vitro decreases cortisol production. In the human PPNAD cell line CAR47, the PKA inhibitor H-89 decreases 5-HT4 and 5-HT7 receptor expression. Moreover, in the human adrenocortical cell line H295R, inhibition of PRKAR1A expression increases the expression of Tph2 and 5-HT4/6/7 receptors, an effect that is blocked by H-89. These findings show that the serotonergic process observed in PPNAD tissues results from PKA activation by PRKAR1A mutations. They also suggest that Tph inhibitors may represent efficient treatments of hypercortisolism in patients with PPNAD. JF - JCI Insight JA - JCI Insight SN - 2379-3708 DO - 10.1172/jci.insight.87958 VL - 1 IS - 15 UR - https://doi.org/10.1172/jci.insight.87958 PB - The American Society for Clinical Investigation ER -