Activated astrocytes play a key role in diabetic neuropathic pain and depression. We aimed to assess the protective effects of dihydromyricetin (DHM) on primary hippocampal astrocytes cultured with high glucose (HG), substance P (SP), and corticosterone (CORT). Culturing with HG + SP + CORT resulted in damage to primary hippocampal astrocytes, which simulates the clinical damage caused by comorbidity of diabetic neuropathic pain and depression. Western blot, qPCR, and immunofluorescence analyses revealed that HG + SP + CORT increased P2X7 receptor expression in primary hippocampal astrocytes, which was reversed by DHM treatment. Further, HG + SP + CORT elevated TNF-α, IL-1β, free Ca2+, and ERK1/2 phosphorylation levels, which was inhibited by DHM or P2X7 shRNA treatment. Moreover, DHM significantly reduced the P2X7 agonist-activated currents in HEK293 cells transfected with the P2X7 receptor. These findings suggest that DHM can protect primary hippocampal astrocytes cultured with HG + SP + CORT from P2X7 receptor-mediated damage. Culturing cells with HG + SP + CORT might be a viable cell model for cellular injury exploration of diabetic comorbid pain and depression.
Keywords: Depression; Diabetic neuropathic pain; Dihydromyricetin; Hippocampal astrocyte; P2X7 receptor.