Endothelin 3 induces skin pigmentation in a keratin-driven inducible mouse model

Endothelin 3 (Edn3) is a ligand important to developing neural crest cells (NCC). Some NCC eventually migrate into the skin and give rise to the pigment-forming melanocytes found in hair follicles. Edn3's effects on NCC have been largely explored through spontaneous mutants and cell culture experiments. These studies have shown the Endothelin receptor B/Edn3 signaling pathway to be important in the proliferation/survival and differentiation of developing melanocytes. To supplement these investigations I have created doxycycline-responsive transgenic mice which conditionally over-express Edn3. These mice will help us clarify Edn3's role during the development of early embryonic melanoblasts, differentiating melanocyte precursors in the skin, and fully differentiated melanocytes in the hair follicle. The transgene mediated expression of Edn3 was predominantly confined to the roof plate of the neural tube and surface ectoderm in embryos and postnatally in the epidermal keratinocytes of the skin. Relative to littermate controls, transgenics develop increased pigmentation on most areas of the skin. My doxycycline-based temporal studies have shown that both embryonic and postnatal events are important for establishing and maintaining pigmented skin. The study of my Edn3 transgenic mice may offer some insight into the genetics behind benign dermal pigmentation and offer clues about the time periods important in establishing these conditions. This apparently abnormal development is echoed in a benign condition of human skin. Cases of dermal melanocytosis, such as common freckles, Mongolian spotting, and nevus of Ito demonstrate histological and etiological characteristics similar to those of the transgenic mice generated in this study.

Proteomic Analysis of Wolbachia Symbiosis within the Drosophila

Wolbachia pipientis are bacterial endosymbionts of arthropods and in some filarial nematodes. Wolbachia are of particular interest because nematodeWolbachia have been shown to cause the diseases African river blindness and Lymphatic Filariasis. Doxycycline can be used to eliminate nematode Wolbachia, however, more efficient treatments are needed. Ideally, we would like to repurpose another FDA approved drug that helps to shorten treatment duration. Vitamins are one of the best classes of FDA approved compounds, generally recognized as safe. Interestingly, prior work by Serbus and colleagues found that dietary yeast, which is highly enriched in vitamins, dramatically reducesWolbachia titer in Drosophila melanogaster ovarian tissue. Imaging data indicated that the Wolbachia nucleoids were disrupted in response to yeast. This raised the possibility that yeast cells contain a bio-reactive, anti-Wolbachiacompound. Our close examination of yeast nutritional information identified which vitamins are most highly enriched in yeast. We then administered several of these to D. melanogaster, and saw that two of these led to reduced ovarianWolbachia titers, analogous to yeast-fed flies. This was especially interesting, as both vitamins are critical for functioning of the same biochemical pathway. We used retested effect of one of these vitamins in oogenesis by performing a dilution series, and achieved positive correlation from this dilution series. This opens up the avenue for clarifying the mechanism of how vitamins suppressWolbachia titer, and for testing enhancement of Doxycycline, to hopefully provide faster, more affordable treatment for millions of patients.

Proteomic Analysis of Wolbachia Symbiosis within the Drosophila

Wolbachia pipientis are bacterial endosymbionts of arthropods and in some filarial nematodes. Wolbachia are of particular interest because nematodeWolbachia have been shown to cause the diseases African river blindness and Lymphatic Filariasis. Doxycycline can be used to eliminate nematode Wolbachia, however, more efficient treatments are needed. Ideally, we would like to repurpose another FDA approved drug that helps to shorten treatment duration. Vitamins are one of the best classes of FDA approved compounds, generally recognized as safe. Interestingly, prior work by Serbus and colleagues found that dietary yeast, which is highly enriched in vitamins, dramatically reducesWolbachia titer in Drosophila melanogaster ovarian tissue. Imaging data indicated that the Wolbachia nucleoids were disrupted in response to yeast. This raised the possibility that yeast cells contain a bio-reactive, anti-Wolbachiacompound. Our close examination of yeast nutritional information identified which vitamins are most highly enriched in yeast. We then administered several of these to D. melanogaster, and saw that two of these led to reduced ovarianWolbachia titers, analogous to yeast-fed flies. This was especially interesting, as both vitamins are critical for functioning of the same biochemical pathway. We used retested effect of one of these vitamins in oogenesis by performing a dilution series, and achieved positive correlation from this dilution series. This opens up the avenue for clarifying the mechanism of how vitamins suppressWolbachia titer, and for testing enhancement of Doxycycline, to hopefully provide faster, more affordable treatment for millions of patients.