Transcriptional profiling in human HaCaT keratinocytes in response to kaempferol and identification of potential transcription factors for regulating differential gene expression

Abstract

Kaempferol is the major flavonol in green tea and exhibits many biomedically useful properties such as antioxidative, cytoprotective and anti-apoptotic activities. To elucidate its effects on the skin, we investigated the transcriptional profiles of kaempferol-treated HaCaT cells using cDNA microarray analysis and identified 147 transcripts that exhibited significant changes in expression. Of these, 18 were up-regulated and 129 were down-regulated. These transcripts were then classified into 12 categories according to their functional roles: cell adhesion/cytoskeleton, cell cycle, redox homeostasis, immune/defense responses, metabolism, protein biosynthesis/modification, intracellular transport, RNA processing, DNA modification/ replication, regulation of transcription, signal transduction and transport. We then analyzed the promoter sequences of differentially-regulated genes and identified over-represented regulatory sites and candidate transcription factors (TFs) for gene regulation by kaempferol. These included c-REL, SAP-1, Ahr-ARNT, Nrf-2, Elk-1, SPI-B, NF-κB and p65. In addition, we validated the microarray results and promoter analyses using conventional methods such as real-time PCR and ELISA-based transcription factor assay. Our microarray analysis has provided useful information for determining the genetic regulatory network affected by kaempferol, and this approach will be useful for elucidating gene-phytochemical interactions.

Kaempferol from Semen cuscutae attenuates the immune function of dendritic cells

“…Kaempferol is a common flavonoid in human diet and has various biological activities including antioxidant, anticancer, and anti-inflammatory effects (Kang et al 2008;Mahat et al 2010). A number of reports have shown the immunomodulatory effect of kaempferol on T lymphocytes (Okamoto et al 2002), B cells (Zunino and Storms 2009), macrophages (Comalada et al 2006;Hamalainen et al 2007;Harasstani et al 2010;Kim et al 2005;Liang et al 2001), neutrophils (Moreira et al 2007;Selloum et al 2001;Wang et al 2006), basophils (Shim et al 2009), and mast cells (Kempuraj et al 2005;Lee et al 2010).…”

The role of transcription factor Nrf2 in skin cells metabolism

“…Overexpression of the Nrf2 gene in mice skin keratinocytes exposed to UVB radiation causes higher resistance to apoptosis [ 54 ]. Incubation of the keratinocytes line HaCaT with flavonoids, such as quercetin or kaempferol, significantly protects cells against UV radiation with the increase of Nrf2 level in the cytoplasm and cells viability [ 45 , 51 ]. Therefore, there is a constant search for a highly selective activator of Nrf2 in keratinocytes that not induce side effects.…”

Effects of Morus alba L. (Mulberry) Leaf Extract in Hypercholesterolemic Mice on Suppression of Cholesterol Synthesis

“…Quercetin functions as a PPARα agonist at the molecular level [9]. Kang et al [37] used a luciferase reporter gene assay to prove the agonist activity of kaempferol for PPARα. Induction of PPARα target genes was observed after quercetin or kaempferol supplementation [38,39].…”