Presence of β-arrestin-1 immunoreactivity in the cutaneous nerve fibers of rat glabrous skin

Abstract

β-Arrestin-1 (βArr1) plays a major role in the desensitization and internalization of G protein-coupled receptors. We previously localized βArr1 in the sensory neurons of rat lumbar 4 and 5 dorsal root ganglia (DRG) and reported the predominant presence of βArr1 in the small-diameter DRG neurons that are often implicated with nociception. Because of βArr1’s crucial role in regulating the initiation of cellular signaling, in the current study we evaluated the distribution of βArr1 in the peripheral sensory terminals where various receptors are present. Western blotting confirmed the presence of βArr1 immunoreactivity in the rat skin. Sciatic nerve ligation demonstrated that βArr1 is transported peripherally from the DRG, and immunohistochemistry showed βArr1 immunoreactivity in the glabrous skin of the rat hindpaw. In the glabrous skin, strong βArr1 immunoreactivity was detected in nerve fibers in the dermal nerve plexus and dermal papillae. Fine varicose immunoreactive fibers were found in the epidermis. In addition, βArr1 was observed in specialized sensory receptors such as Meissner corpuscles. Our observations thus indicate that βArr1 may be involved in modulation of specific tactile stimulation from the skin in addition to nociception.