Panoply™ Human TRPC5 Over-expressing Stable Cell Line

The non-selective Ca²⁺-permeable transient receptor potential channel subfamily member 5 (TRPC5) belongs to the transient receptor potential canonical (TRPC) superfamily and is widely expressed in the brain. Substantial evidence indicates that TRPC5 plays a critical role in depression and other psychiatric disorders. To develop a TRPC5 radioligand, researchers synthesized the iodinated compound TZ66127 and its iodine-125-labeled derivative, [125I]TZ66127. TZ66127 was synthesized by replacing the chlorine atom in the HC608 structure with an iodine atom, while [125I]TZ66127 was prepared via radiosynthesis using the corresponding tert-butyltin precursor. The researchers established a HEK293-hTRPC5 cell line stably overexpressing human TRPC5 and evaluated TZ66127 using Ca²⁺ imaging and cellular binding assays. The results demonstrated that TZ66127 exhibits potent inhibitory activity against TRPC5 in a dose-dependent manner. In vitro autoradiography and immunohistochemistry studies on rat brain slices indicated that [125I]TZ66127 binds specifically to TRPC5. In summary, [125I]TZ66127 holds great potential as a radioligand for screening the binding activity of other novel compounds against TRPC5.

Ca²⁺ is a crucial intracellular messenger that drives various cellular functions. Consequently, quantifying cytosolic free Ca²⁺ levels by monitoring fluorescence changes in indicators such as Fura-2 AM has become a common method for characterizing TRPC channel activity in mammalian cells. Here, researchers evaluated the inhibitory effect of TZ66127 by examining Ca²⁺ responses in HEK293-hTRPC5 cells (a cell line stably transfected with human TRPC5). The results demonstrated that the compound itself did not induce calcium mobilization, confirming that TZ66127 acts as an antagonist in hTRPC5-expressing cells (figure 1).

Figure 1. Compounds inhibit efficacy on Riluzole-induced Ca2+ responses in overexpression HEK293-hTRPC5 cells. (Yu Y, et al., 2020)