Akt1 Is Essential for Postnatal Mammary Gland Development, Function, and the Expression of Btn1a1

Akt1, a serine-threonine protein kinase member of the PKB/Akt gene family, plays critical roles in the regulation of multiple cellular processes, and has previously been implicated in lactation and breast cancer development. In this study, we utilized Akt1+/+ and Akt1−/− C57/Bl6 female mice to assess the role that Akt1 plays in normal mammary gland postnatal development and function. We examined postnatal morphology at multiple time points, and analyzed gene and protein expression changes that persist into adulthood. Akt1 deficiency resulted in several mammary gland developmental defects, including ductal outgrowth and defective terminal end bud formation. Adult Akt1−/− mammary gland composition remained altered, exhibiting fewer alveolar buds coupled with increased epithelial cell apoptosis. Microarray analysis revealed that Akt1 deficiency altered expression of genes involved in numerous biological processes in the mammary gland, including organismal development, cell death, and tissue morphology. Of particular importance, a significant decrease in expression of Btn1a1, a gene involved in milk lipid secretion, was observed in Akt1−/− mammary glands. Additionally, pseudopregnant Akt1−/− females failed to induce Btn1a1 expression in response to hormonal stimulation compared to their wild-type counterparts. Retroviral-mediated shRNA knockdown of Akt1 and Btn1a1 in MCF-7 human breast epithelial further illustrated the importance of Akt1 in mammary epithelial cell proliferation, as well as in the regulation of Btn1a1 and subsequent expression of ß-casein, a gene that encodes for milk protein. Overall these findings provide mechanistic insight into the role of Akt1 in mammary morphogenesis and function

Human periodontal ligament fibroblasts stimulated by nanocrystalline hydroxyapatite paste or enamel matrix derivative. An in vitro assessment of PDL attachment, migration, and proliferation

Item does not contain fulltextWe determined the effects of soluble or coated nanocrystalline hydroxyapatite paste (nano-HA) and enamel matrix derivative (EMD) on proliferation, adhesion, and migration of periodontal ligament fibroblasts (PDLs). Cultured PDLs were stimulated with nano-HA paste or EMD in a soluble form or were coated to the surface of cell culture dishes. Proliferation of PDLs on coated nano-HA and EMD was quantified by various methods including bromodeoxyuridine (BrdU) incorporation and Western blot. Cell migration was investigated in a modified Boyden chamber. The surface integrin profile of PDLs was determined using an integrin-specific ELISA, and integrin-specific signaling was measured by immunoblotting of phosphorylated focal adhesion kinase (FAK). Coated nano-HA stimulated PDL proliferation to a larger extent as compared with coated EMD. PDL migration towards a nano-HA or EMD gradient was more efficiently mediated by soluble EMD as compared with nano-HA but vice versa, adhesion of PDLs to compound-coated dishes was more effectively mediated by nano-HA as compared with EMD. Mechanistically, majorly integrin alpha5beta1-mediated adhesion of PDL and both coated compounds mediated a significant increase in FAK activation though to a different extent. Current findings offer two different modes of action for EMD and nano-HA paste. EMD efficiently acts as a chemoattractant in its soluble form, while nano-HA paste effectively serves as a synthetic extracellular matrix component in its coated form. Our findings suggest that EMD and nano-HA paste display different molecular characteristics and apply alternative routes to mediate their beneficial effects on periodontal tissues

Laser/Light Applications in Otolaryngology

Lasers have been ubiquitous in otolaryngology since Jako and Strong first introduced the CO2 laser in 1970. Since that time lasers have traditionally been used like a scalpel, able to cut and cauterize precisely. More recently, the role of lasers has been expanded in otolaryngology depending on the specific laser wavelength and dosimetry parameters. Not only can lasers be utilized to extirpate cancer, but also used to recover hearing, improve the airway, treat epistaxis, and even break up salivary stones for easy removal. The individual characteristics of the laser are important for the specific application. However, the otolaryngologist often works in areas that are either difficult to access using classic methods or require extreme precision, and the mechanism and method for delivering the laser energy is often equally important. In this chapter, we describe the many ways lasers are used in otolaryngology treat both benign conditions to life-threatening diseases. New and innovative applications are also discussed