Figure 5.

TRPM8 channels participate in the regulation of specific proteins expression in a cold-dependent and cold-independent way. A) Immunoblot analysis showing the variation of key protein expression in testis of 4 CTL and 4 KOM8 mice 3 d after cold shock (scrotum temperatures were 29, 17, or 4°C). β-Actin and Prm2 were used as invariant reporters. FKBP-rapamycin–associated protein was detected in its nonphosphorylated and phosphorylated (Ser²⁴⁴⁸) forms. B) Quantification of the protein levels and statistical significance are reported in (B). Protein amount was normalized with Prm2, which appeared much more stable than actin or GAPDH (not shown). Values are presented as means ± sd for CTL (n = 4) and KOM8 (n = 4) mice. Statistical significance was assumed when P < 0.05 and is shown above the tested column as the number of the CTL column it is paired to. C, D) Immunohistofluorescence confirmed the decreased expression of HSPA2 (C, green) in CTL germ cells subjected to hypothermia (C, right) compared to CTL (left). CIRBP (red) expression appears stable in both conditions. However, CIRBP was down-regulated in KOM8 testis (D, right) when compared to CTL (D, left). Nuclei were counterstained with DAPI. Scale bars, 20 µm. Statistical analysis was achieved with 1-way ANOVA.