Involvement of TRPC channels in CCL2-mediated neuroprotection against tat toxicity

H Yao, F Peng, N Dhillon, S Callen… - Journal of …, 2009 - Soc Neuroscience
H Yao, F Peng, N Dhillon, S Callen, S Bokhari, L Stehno-Bittel, SO Ahmad, JQ Wang, S Buch
Journal of Neuroscience, 2009Soc Neuroscience
Chemokine (CC motif) ligand 2 (CCL2), also known as monocyte chemoattractant protein-1,
plays a critical role in leukocyte recruitment and activation. In the present study, we identify
an additional role for CCL2 that of neuroprotection against HIV-1 transactivator protein (Tat)
toxicity in rat primary midbrain neurons. Furthermore, we report the involvement of transient
receptor potential canonical (TRPC) channels in CCL2-mediated neuroprotection. TRPC are
Ca2+-permeable, nonselective cation channels with a variety of physiological functions …
Chemokine (C-C motif) ligand 2 (CCL2), also known as monocyte chemoattractant protein-1, plays a critical role in leukocyte recruitment and activation. In the present study, we identify an additional role for CCL2 that of neuroprotection against HIV-1 transactivator protein (Tat) toxicity in rat primary midbrain neurons. Furthermore, we report the involvement of transient receptor potential canonical (TRPC) channels in CCL2-mediated neuroprotection. TRPC are Ca2+-permeable, nonselective cation channels with a variety of physiological functions. Blockage of TRPC channels resulted in suppression of both CCL2-mediated neuroprotection and intracellular Ca2+ elevations. Parallel but distinct extracellular signal-regulated kinase (ERK)/cAMP response element-binding protein (CREB) and Akt/nuclear factor κB (NF-κB) pathways were involved in the CCL2-mediated neuroprotection. Blocking TRPC channels and specific downregulation of TRPC channels 1 and 5 resulted in suppression of CCL2-induced ERK/CREB activation but not Akt/NF-κB activation. In vivo relevance of these findings was further corroborated in wild-type and CCR2 knock-out mice. In the wild-type but not CCR2 knock-out mice, exogenous CCL2 exerted neuroprotection against intrastriatal injection of HIV-1 Tat. These findings clearly demonstrate a novel role of TRPC channels in the protection of neurons against Tat through the CCL2/CCR2 axis.
Soc Neuroscience