β-Adrenergic receptor gene expression in HIV-associated neurocognitive impairment and encephalitis: implications for MOR-1K subcellular localization.

We previously reported that mRNA expression of the unique alternatively spliced OPRM1 isoform μ-opioid receptor-1K (MOR-1K), which exhibits excitatory cellular signaling, is elevated in HIV-infected individuals with combined neurocognitive impairment (NCI) and HIV encephalitis (HIVE). It has recently been shown that the β-adrenergic receptor (β-AR) chaperones MOR-1K, normally localized intracellularly, to the cell surface. Here, we found mRNA expression of the adrenoceptor beta 2 (ADRB2) gene is also elevated in NCI-HIVE individuals, as well as that β-AR protein expression is elevated in HIV-1-infected primary human astrocytes treated with morphine, and discuss the implications for MOR-1K subcellular localization in this condition.