No abstract

c BHLHE40 and BHLHE41 (BHLHE40/41) are basic helix-loop-helix type transcription factors that play key roles in multiple cell behaviors. BHLHE40/41 were recently shown to be involved in an epithelial-to-mesenchymal transition (EMT). However, the precise mechanism of EMT control by BHLHE40/41 remains unclear. In the present study, we demonstrated that BHLHE40/41 expression was controlled in a pathological stage-dependent manner in human endometrial cancer (HEC). Our in vitro assays showed that BHLHE40/41 suppressed tumor cell invasion. BHLHE40/41 also suppressed the transcription of the EMT effectors SNAI1, SNAI2, and TWIST1. We identified the critical promoter regions of TWIST1 for its basal transcriptional activity. We elucidated that the transcription factor SP1 was involved in the basal transcriptional activity of TWIST1 and that BHLHE40/41 competed with SP1 for DNA binding to regulate gene transcription. This study is the first to report the detailed functions of BHLHE40 and BHLHE41 in the suppression of EMT effectors in vitro. Our results suggest that BHLHE40/41 suppress tumor cell invasion by inhibiting EMT in tumor cells. We propose that BHLHE40/41 are promising markers to predict the aggressiveness of each HEC case and that molecular targeting strategies involving BHLHE40/41 and SP1 may effectively regulate HEC progression. Basic helix-loop-helix (bHLH) type transcription factors play key roles in cell differentiation, proliferation, apoptosis, and metabolism. BHLHE40 (basic helix-loop-helix family member e40 gene) and BHLHE41 are members of the Hairy/E(spl)/HES family. BHLHE40 and BHLHE41 (BHLHE40/41) exhibit more than 90% similarity in the bHLH region and approximately 50% in total. BHLHE40/41 have been shown to function as transcriptional repressors by binding to the class B E-box. BHLHE40/41 interact with TF2B, TBP, or TF2D or recruit a histone deacetylase at the E-box site (1-5). On the other hand, BHLHE40/41 were previously reported to modulate the expression of some genes in an E-box-independent manner. BHLHE40 has been shown to associate with SP1 binding sites in the BIRC5 promoter to activate its transcription (6) and with STAT3 to regulate the transcription of STAT3-dependent target genes (7). BHLHE41 suppressed VEGF transcription by interacting with HIF1A (8). BHLHE40 and BHLHE41 were reported to associate with retinoid X receptor (RXR), MYOD1, or CEBP in order to regulate the transcription of their target genes (9-12).In diverse types of cancer species, such as colon, oral, and liver cancer or brain tumors, BHLHE40 expression levels were found to be higher in tumors than in adjacent normal tissues (13-15). On the other hand, in human endometrial cancer (HEC) and nonsmall-cell lung cancer, no changes in BHLHE40 expression were reported between cancer and normal tissues (16,17). Regarding expression profiles with the development of cancer, studies on oral, lung, liver, and esophageal cancer showed that BHLHE40 expression inversely correlated with the tumor stage or differentiation grade (18-21)...

Recently, numerous studies have identified that immature cell populations including stem cells and progenitor cells can be found among “side-population” (SP) cells. Although SP cells isolated from some adult tissues have been reported elsewhere, isolation and characterization of human trophoblast SP remained to be reported. In this study, HTR-8/SVneo cells and human primary villous cytotrophoblasts (vCTBs) were stained with Hoechst 33342 and SP and non-SP (NSP) fractions were isolated using a cell sorter. A small population of SP cells was identified in HTR-8/SVneo cells and in vCTBs. SP cells expressed several vCTB-specific markers and failed to express syncytiotrophoblast (STB) or extravillous cytotrophopblast (EVT)-specific differentiation markers. SP cells formed colonies and proliferated on mouse embryonic fibroblast (MEF) feeder cells or in MEF conditioned medium supplemented with heparin/FGF2, and they also showed long-term repopulating property. SP cells could differentiate into both STB and EVT cell lineages and expressed several differentiation markers. Microarray analysis revealed that IL7R and IL1R2 were exclusively expressed in SP cells and not in NSP cells. vCTB cells sorted as positive for both IL7R and IL1R2 failed to express trophoblast differentiation markers and spontaneously differentiated into both STB and EVT in basal medium. These features shown by the SP cells suggested that IL7R and IL1R2 are available as markers to detect the SP cells and that vCTB progenitor cells and trophoblast stem cells were involved in the SP cell population.

A considerable proportion of the patients with traumatic cervical SCI without major bone injury were shown to have various types of soft-tissue damage associated with cervical segmental instability at the early stages of the injury. The severity of paralysis greatly depended on these discoligamentous injuries.

The oral cavity provides an entrance to the alimentary tract to serve as a protective barrier against harmful environmental stimuli. The oral mucosa is susceptible to injury because of its location; nonetheless, it has faster wound healing than the skin and less scar formation. However, the molecular pathways regulating this wound healing are unclear. Here, we show that transient receptor potential vanilloid 3 (TRPV3), a thermosensitive Ca 2+ -permeable channel, is more highly expressed in murine oral epithelia than in the skin by quantitative RT-PCR. We found that temperatures above 33°C activated TRPV3 and promoted oral epithelial cell proliferation. The proliferation rate in the oral epithelia of TRPV3 knockout (TRPV3KO) mice was less than that of wild-type (WT) mice. We investigated the contribution of TRPV3 to wound healing using a molar tooth extraction model and found that oral wound closure was delayed in TRPV3KO mice compared with that in WT mice. TRPV3 mRNA was up-regulated in wounded tissues, suggesting that TRPV3 may contribute to oral wound repair. We identified TRPV3 as an essential receptor in heat-induced oral epithelia proliferation and wound healing. Our findings suggest that TRPV3 activation could be a potential therapeutic target for wound healing in skin and oral mucosa.-Aijima, R., Wang, B., Takao, T., Mihara, H., Kashio, M., Ohsaki, Y., Zhang, J.-Q., Mizuno, A., Suzuki, M., Yamashita, Y., Masuko, S., Goto, M., Tominaga, M., Kido, M. A. The thermosensitive TRPV3 channel contributes to rapid wound healing in oral epithelia. FASEB J. 29, 182-192 (2015). www.fasebj.org Key Words: ambient temperature • oral mucosa • wound repair THE ORAL MUCOSA HAS a highly specialized epithelium that performs essential protective functions against diverse changes, such as chemical, thermal, or mechanical stimuli, in the oral environment. The oral cavity is also the site for sentient responses (1, 2). The oral epithelium is a moist lining membrane in the oral cavity and consists of a stratified squamous epithelium and underlying connective tissues similar to the skin. Although it is continuous with the skin, the oral epithelium is more susceptible to injury because it is exposed to more extensive stimuli than the skin. However, wound repair of the oral mucosa is faster than the skin and recovers with less scar formation (3, 4). Although components in the saliva or a rich vascular supply may contribute to this rapid wound healing (4-6), the molecular mechanisms regulating oral mucosa wound repair are still largely unknown.Transient receptor potential (TRP) channels are a family of Ca 2+ -permeable nonselective cation channels that are responsive to a broad range of environmental stimuli such as temperature, tonicity, or pain (7-9). Among the 28 different mammalian TRP channels, transient receptor potential vanilloid 3 (TRPV3) is uniquely expressed predominantly in keratinocytes and is activated by innocuous warm temperatures above 33°C and natural herbs such as oregano or thyme (10-14). Furthermore, it h...