Photochem Photobiol 2014 Nov-Dec;90(6):1340-8. Epub 2014 Oct 27.
The Base of "111 Project" for Biomechanics and Tissue Repair Engineering, Key Laboratory of Biorheological Science and Technology, Ministry of Education, Bioengineering College, Chongqing University, Chongqing, 400044, China; Department of Pharmacy and Pharmacology, University of Bath, Bath, UK; Dermatology Institute, Sichuan Provincial People's Hospital, Chengdu, Sichuan, China.
UVA treatment of cultured human skin fibroblasts (FEK4) has been shown previously to reduce transcriptional activation of heme oxygenase 1 (HO-1) following a second dose of UVA radiation, a phenomenon known as refractoriness. This study demonstrates that the levels of HO-1 protein are also reduced after a second dose of UVA radiation as are Nrf2 levels, and there is less accumulation of Nrf2 in the nucleus where as Bach1 does accumulate in the nucleus. Cell viability is further reduced and cell membrane damage increased as compared with a single UVA treatment when an initial UVA treatment was followed by a second dose. Read More