Quantitative analysis of TRP channel genes in mouse organs

Abstract

The transient receptor potential (TRP) channel superfamily is a set of channel genes that mediate numerous physiological functions such as sensing irritants or detecting temperature changes. Despite their functions, expressional information on TRP channels in various organs is largely elusive. Therefore, we conducted a systematic quantitative comparison of each mRNA expression level of 22 mouse TRP channels in various organs. As a result, we found that average levels of TRP channel transcripts were very low reaching ∼3% of the GAPDH transcript level. Among 22 TRP channels, TRPC1 and TRPM7 were most abundant in the majority of organs. In contrast, TRPV3, TRPV5, TRPV6, TRPC7, TRPM1, and TRPM5 elicited very low message profiles throughout the major organs. Consistent with their functions as molecular sensors for irritants and temperature changes, TRPV1, TRPM8 and TRPA1 showed exclusive expression in sensory ganglia. TRPC3 and TRPM3 were abundant in the sensory ganglia and brain. High levels of transcripts of TRPV2, TRPC6, TRPM4, and TRPM6 were observed in the lung. In addition, channel transcript levels were very low except TRPM7 in the liver. In summary, the expression profile of TRP channels in major tissues provides insight to their physiological functions and therefore application to new drug development.

Increased biological response to 1,25(OH)2D3in genetic hypercalciuric stone-forming rats

“…Ca is extruded from the cell by the Na/Ca exchanger NCX1 and the plasma membrane Ca ATPase PMCA. While expression of TRPV5 is limited to kidney (41) and mouse testis (49), a second apical Ca transporter, TRPV6, is found in multiple tissues (49,93) with highest kidney expression in TALH (75). While the apical distribution of renal TRPV6 and its known role in intestinal Ca absorption (66,95) is consistent with renal tubular Ca reabsorption, direct evidence is lacking.…”

The Phosphatidylinositol(4,5)Bisphosphate–Binding Sequence of Transient Receptor Potential Channel Canonical 4α Is Critical for Its Contribution to Cardiomyocyte Hypertrophy

“…The channels have considerable structural similarity (Toko et al, 2007;Eder and Molkentin, 2011) and similar channel activity (Plant and Schaefer, 2005;Abramowitz and Birnbaumer, 2009), and are expressed at relatively low level in cardiomyocytes (Jang et al, 2012). TrpC channels form complexes that often include more than one subtype (Abramowitz and Birnbaumer, 2009), which means that overexpression or inhibition of a particular subtype may influence responses of other family members.…”

Trpm3

“…However, in mouse kidney Trpm3 expression was not detectable by Northern (Gilliam and Wensel 2011;Grimm et al 2003;Oberwinkler et al 2005) and Western analysis (Grimm et al 2003). Using standard RT-PCR at least, a weak signal could be amplified from mouse kidney, but RT-qPCR could not substantiate this finding (Jang et al 2012). Thus, it may be assumed that TRPM3 may fulfill additional functions in human but not in mouse kidney.…”