Molecular and Physiological Determinants of Pulmonary Developmental Biology: a Review

Abstract

The lungs undergo an extensive endodermal diverging morphogenesis along with alveogenesis, angiogenesis, and vasculogenesis to secure a sufficient diffusion surface for gaseous exchange. Any aberration in the course of normal development inculcating structural and functional abnormalities of lungs in antenatal life has potential morbidity in adult life. Factors such as IUGR, nutrient deficiency, FLM, Hypoxemia, ETS, surfactant deficiency, allergy and infections can adversely affect in-utero lungs development. Peculiar local and systemic inflammatory immune responses may elicit persistent architectural and physiological abnormalities. Lung surfactant produced by AEC-II cells is a mixture of phospholipids, surfactant proteins, and neutral lipids. Surfactant lowers alveolar surface tension, a crucial step for the prevention of alveolar collapse. Surfactant proteins are part of the innate immune defense of the lung. Surfactant deficiency and dysfunction is known to implicate a number of respiratory diseases especially allergic asthma and NRDS. The present article provides a state of the art review of the current knowledge of biology of normal lung development, its anatomical and molecular aspects, factors that regulate normal organogenesis of pulmonary system and molecular basis of respiratory allergic disorders including asthma.

Early-life Exposure to Organophosphate Pesticides and Pediatric Respiratory Symptoms in the CHAMACOS Cohort

“…OP pesticides can readily pass through the placenta ( Rauh et al 2006 ; Whyatt et al 2009 ), and DAP metabolites can be found in amniotic fluid ( Bradman et al 2003 ). Furthermore, during the second half of pregnancy the alveoli are forming and surfactant is being synthesized; lung surfactant dysfunction is known to be related to the pathophysiology of asthma ( Hameed et al 2013 ; Wright et al 2000 ).…”

Pre‐ and Postnatal Lung Development: An Updated Species Comparison

“…Addressing the multitude of molecular determinants of pulmonary development in detail would greatly strain the capacity of this review. A summary is given in Figure and greater details are explained, for example, in Cardoso (), McMurtry (), Roth‐Kleiner and Post (), and Hameed et al, ().…”

Presence of N-acetylneuraminic acid in the lung during postnatal development

“…It is known that the expression of these mediators is directly or indirectly related to sialic acid content. 6,34,41 In human fetuses, a slight decrease in total sialic acid expression was reported to occur in lung epithelial structures during intra-uterine development with a relative minimum before birth. An increased expression of sialic acid residues during development of alveoli and differentiation of pneumocytes I and pneumocytes II -with the latter expressing high amounts of sialic acids -was also described.…”

“…However, during alveolarization, rat lung undergoes similar modifications as those of humans, making rats one of the most useful animal models in this field. 6 Alveolarization comprises a biphasic behavior with a first phase termed classical or "bulk" alveolarization, in which alveoli are formed apace, and a second phase, named continued alveolarization, which involves a slower formation of alveoli. These phases overlap and, in rats, the first phase elapses from postnatal day 4 to day 14 (P4-P14).…”