Increased expression of TRPV1 channel in intrinsically aged and photoaged human skin in vivo

Abstract

Transient receptor potential vanilloid type 1 (TRPV1) is activated by various stimuli including capsaicin, heat and acid. While TRPV1 has been localized in the epidermis, little is known about the physiological role of TRPV1 in the skin, especially in skin ageing. In this study, we investigated the effect of acute UV irradiation on TRPV1 expression in human skin and the changes in TRPV1 mRNA and protein in intrinsic ageing and photoageing using human sun-protected (upper inner arm) and sun-exposed (forearm) skin of young and elderly subjects. Western blot analysis of UV-irradiated young buttock skin revealed that the expression of TRPV1 protein was increased at 24 h (2.3-fold) and 48 h (2.4-fold) after UV irradiation. Real-time PCR analysis also showed that the mRNA level of TRPV1 was augmented by 2.4-fold at 4 h after UV irradiation. TRPV1 protein was expressed at higher levels by 2.6-fold in the sun-protected skin of the elderly subjects than in that of young people according to western blotting, real-time PCR analysis and immunohistochemical staining. In addition, the photoaged skin of elderly showed increased expression of TRPV1 mRNA and protein compared with that of the sun-protected skin of the same individuals. Also, we found increased expression of TRPV1 in nerve fibres of elderly persons using double staining of TRPV1 and nerve fibres. Based on the above results, our data suggest that the expression of TRPV1 is affected by both the intrinsic ageing and photoageing processes.

Upregulation of Transient Receptor Potential Vanilloid Type-1 Channel Activity and Ca2+Influx Dysfunction in Human Pterygial Cells

“…[14][15][16] Furthermore, changes of TRPV1 expression (in human skin) can be detected after UV irradiation. 17 Transient receptor potential V1 mediates heat shock-induced matrix metalloproteinase-1 (MMP-1) expression in human keratinocytes. 18 However, diverse TRPV1 activation mechanisms induced through various (physical) stimuli have not yet iovs.arvojournals.org j ISSN: 1552-5783 been elucidated.…”

Unravelling the Mystery of Capsaicin: A Tool to Understand and Treat Pain

“…However, photoaged skin of older subjects showed increased expression of TRPV1 mRNA and protein compared with that of the sun-protected skin of the same people. Therefore, the expression of TRPV1 is affected by both the intrinsic aging and photoaging processes (Lee et al, 2009). The increased TRPV1 expression in skin from older people implies that TRPV1 may be related to senile skin symptoms, such as senile pruritus and neurogenic inflammation; therefore TRPV1 has been proposed as an intriguing novel target for the prevention of skin aging and inflammation.…”

“…Outside of the CNS, TRPV1-expressing afferents have been reported to be present in different human tissues including vascular smooth muscle, bronchial epithelial cells (Seki et al, 2007), the epidermis (Lee et al, 2009), and the gastrointestinal tract (Yiangou et al, 2001;Chan et al, 2003;Matthews et al, 2004). This suggests other roles for TRPV1 besides nociception (for a full review on the subject, see Fernandes et al, 2012).…”

Sensory Systems of Epidermal Keratinocytes

“…Thus, TRPV1 might be associated with skin infl ammatory responses. Ultraviolet (UV) radiation appears to induce the expression of TRPV1 in human epidermal keratinocytes [ 73 ] ; acute UV radiation increased TRPV1 in human skin, and moreover, TRPV1 expression in sunexposed skin was signifi cantly higher than that in sun-protected skin. They also demonstrated that UV radiation induced matrix metalloproteinase-1 in cultured HaCaT cells [ 74 ] .…”