Factors Involved in Lung Development and Alveolarization / 소아과

Lung development is a sum of processes that involve harmonized orchestration of expressions of various factors in time and space. The mastermind governing these phenomena is not known, but cumulative efforts so far have helped us gain some insights as to what are involved in and how complex the developmental process is. Beginning as primitive foregut, lungs undergo processes called branching morphogenesis and alveolarization to attain complex structures that enable effective gas exchange through conducting airways and acini. Some transcription factors, peptide growth factors, extracellular matrix proteins, and integrin and related factors are among many factors that are known to be involved. They are spatially localized and compartmentalized to render specific actions such as cellular proliferation, differentiation and apoptosis, meanwhile timely expressions of the same factors at specified time intervals are essential. Some are expressed in epithelial cells whereas others in mesenchymal cells; the crosstalks among them seem critical in coordination of developmental processes. Understanding these molecular mechanisms of lung development under normal and abnormal conditions may help devise methods to prevent as well as to revert aberrant development seen in many clinical conditions known as bronchopulmonary dysplasia, pulmonary fibrosis, and emphysema.

Molecular Analysis of Salivary Gland Branching Morphogenesis / Oral Science International

Recently, clinicians and scientists have focused on tissue engineering for regenerative medical therapy. This approach promises to provide remarkable clinical breakthroughs for the future. In oral and craniofacial medicine, most scientific approaches to tissue engineering currently involve tooth and bone, while little progress has been made toward regenerating organs such as salivary gland. To develop strategies for salivary gland regeneration, it will be important to understand the molecular mechanisms of normal salivary development. This mini-review describes a recently developed and tested set of approaches for identifying and characterizing molecules essential for branching morphogenesis and other developmental processes. It shows the value of using laser microdissection and the new process of T7-SAGE for gene discovery of putative candidate molecules that may be crucial regulators or mediators. We describe a stepwise series of associated strategies for reliable identification and functional testing of a candidate molecule, as well as its successful application to a specific candidate molecule originally identified by T7-SAGE.