Real-Time In Vivo Imaging of the Developing Pupal Wing Tissues in the Pale Grass Blue Butterfly Zizeeria maha: Establishing the Lycaenid System for Multiscale Bioimaging

To systematically analyze biological changes with spatiotemporal dynamics, it is important to establish a system that is amenable for real-time in vivo imaging at various size levels. Herein, we focused on the developing pupal wing tissues in the pale grass blue butterfly, Zizeeria maha, as a system of choice for a systematic multiscale approach in vivo in real time. We showed that the entire pupal wing could be monitored throughout development using a high-resolution bright-field time-lapse imaging system under the forewing-lift configuration; we recorded detailed dynamics of the dorsal and ventral epithelia that behaved independently for peripheral adjustment. We also monitored changes in the dorsal hindwing at the compartmental level and directly observed evaginating scale buds. We also employed a confocal laser microscopy system with multiple fluorescent dyes for three-dimensional observations at the tissue and cellular levels. We discovered extensive cellular clusters that may be functionally important as a unit of cellular communication and differentiation. We also identified epithelial discal and marginal dents that may function during development. Together, this lycaenid forewing system established a foundation to study the differentiation process of epithelial cells and can be used to study biophysically challenging mechanisms such as the determination of color patterns and scale nanoarchitecture at the multiscale levels

Hypoxia-Inducible Factors Activate CD133 Promoter through ETS Family Transcription Factors

CD133 is a cellular surface protein that has been reported to be a cancer stem cell marker, and thus it is considered to be a potential target for cancer treatment. However, the mechanism regulating CD133 expression is not yet understood. In this study, we analyzed the activity of five putative promoters (P1-P5) of CD133 in human embryonic kidney (HEK) 293 cells and colon cancer cell line WiDr, and found that the activity of promoters, particularly of P5, is elevated by overexpression of hypoxia-inducible factors (HIF-1 alpha and HIF-2 alpha). Deletion and mutation analysis identified one of the two E-twenty six (ETS) binding sites (EBSs) in the P5 region as being essential for its promoter activity induced by HIF-1 alpha and HIF-2 alpha. In addition, a chromatin imunoprecipitation assay demonstrated that HIF-1 alpha and HIF-2 alpha bind to the proximal P5 promoter at the EBSs. The immunoprecipitation assay showed that HIF-1 alpha physically interacts with Elk1; however, HIF-2 alpha did not bind to Elk1 or ETS1. Furthermore, knockdown of both HIF-1 alpha and HIF-2 alpha resulted in a reduction of CD133 expression in WiDr. Taken together, our results revealed that HIF-1 alpha and HIF-2 alpha activate CD133 promoter through ETS proteins

Effect of HIFs and dominant-negative forms of ETS families on the P5 −98 bp promoter.

<p>(A) Luciferase activity of the P5 −98 bp promoter with mutation at the two putative EBSs (mEBS1 and mEBS2) after overexpression of HIF-1α or HIF-2α, using human embryonic kidney (HEK) 293 cells. (B, C) Luciferase activity of the P5 −98 bp promoter in HEK293 cells after overexpression of HIF-1α or HIF-2α together with dominant-negative forms of ETS families (ETS1-DN and Elk1-DN).</p