CREB1 and mucopolysaccharidosis: NE regulates the formation of cyclic adenosine monophosphate (cAMP) to promote angiogenic gene expression during physiological and pathological processes,36,47 and the activation of protein kinase A (PKA) and subsequent phosphorylation of the transcription factor CREB by PKA mediates the proangiogenic effect of cAMP.48,49 Here, ELISAs for cellular cAMP showed that NE-treated ECs had significantly increased cAMP levels relative to the vehicle-treated controls, and NE cotreatment caused notably elevated cAMP levels in response to MPS treatment (Fig. 6t).