Imaging structural and functional relationships between cells and ECM

Eunice Kennedy Shriver National Institute Of Child Health & Human Development

Investigators

Abstract

This project has just been initiated based on studies of lunag pathology in a mouse model of osteogenesis imperfecta (OI). By combining histological and immunofluorescence imaging of ECM with fluorescence in-situ hybridization of messanger RNA (mRNA-FISH) in the same tissue section we were able to identify that neonatal lung pathology (lethal in homozygous animals) is caused by deficient lung inflation during fetal breathing movements. We are now working on expanding the study to include confocal Raman spectroscopic imaging for quantifying the amount and organization of collagen in fibers in the same sections (since the deficient lung inflation appears to be caused deficient collagen deposition in the ECM). Additionally we are working on integration of these imaging modalities with quantitative spatial transcriptomic imaging based on the new Xenium assay from 10X Genomics and with ultrasound backscatter microscopy of lungs in live E18.5 embryos. Acute respitary distress in neonates is a common feature of OI and other skeletal dysplasias, which is primarily responsible for neonatal lethality in these disorders. Traditionally, it has been attributed to rib cage fractures and deformities affecting the babies after birth but not to lung hypoplasia associated with deficient fetal breathing movements before the birth. Having discovered severe lung hypoplasia in newborn mice, we realized that collagen deficiency and rib cage deformities and fractures may have even more pronounced effect on lungs in utero. If confirmed, these findings may dramatically affect the treatment of newborns with skeletal dysplasias by suggesting that lung hypoplasia should be expected, immediately evaluated by neonatal pulmonologists, and treated to improve the survival likelyhood and reduce secondary lung pathology later in life. The wealth of information revealed by combining histological, spectroscopic, RNA, and functional imaging of tissue sections in this project suggested the importance of further advancing and developing the technology and methods for such multimodal imaging. This project has been initiated only a week ago. While he wave no results and publications to report yet, we anticipate that the project will have a major impact on studies of connective tissue pathology in our and other laborotories similar to the lung findings that prompted its initiation.