The effect of age and emphysematous and fibrotic injury on the re-cellularization of de-cellularized lungs

Abstract

Use of de-cellularized cadaveric lungs as 3-dimensional scaffolds for ex vivo lung tissue generation offers a new potential therapeutic approach for clinical lung transplantation. However, it is likely that some of the available cadaveric human lungs may be from older donors or from donors with previously existing structural lung diseases such as emphysema or pulmonary fibrosis. It is not known whether these lungs will be suitable for either de-cellularization or re-cellularization. To investigate this, we assessed the effects of advanced age, representative emphysematous and fibrotic injuries, and the combination of advanced age and emphysematous injury and found significant differences both in histologic appearance and in the retention of extracellular matrix (ECM) and other proteins, as assessed by immunohistochemistry and mass spectrometry, between the different conditions. However, despite these differences, binding, retention and growth of bone marrow-derived mesenchymal stromal cells (MSCs) over a 1-month period following intratracheal inoculation were similar between the different experimental conditions. In contrast, significant differences occurred in the growth of C10 mouse lung epithelial cells between the different conditions. Therefore, age, lung injury, and the cell type used for re-cellularization may significantly impact the usefulness of de-cellularized whole lungs for ex vivo lung tissue regeneration.

Hallmarks of the ageing lung

“…the stroma, as one hallmark of tumourigenesis, which directly affects cancer-enabling pathomechanisms and metastasis. Moreover, the ECM within decellularised lungs of aged mice compromised proper repopulation of lung epithelial cells, similarly to emphysematous scaffolds [289]. This supports the notion that the ECM not only serves as a scaffold and essential mirror of cell-specific changes and phenotypes, but actively signals to the cell via integrins or mechanoreceptor-mediated outside-in signalling [290][291][292].…”

“…Beyond the gain of skin wrinkles due to loss of matrix elasticity, enhanced matrix deposition and altered matrix composition have been reported for the ageing heart, kidney, skeletal muscle, and, most importantly, for the lung in humans and animal models [284][285][286][287][288][289]. With respect to lung cancer, HANAHAN and WEINBERG [163] emphasised the influence of the tumour microenvironment, i.e.…”

Residual Detergent Detection Method for Nondestructive Cytocompatibility Evaluation of Decellularized Whole Lung Scaffolds

“…14,18,20 To generate standard curves, 2% SDC and 1% SDS solutions were diluted in de-ionized (DI) water over a range consistent with use in decellularization schemes. 4,5,7,8,10,13,[20][21][22][23][24][25][26][27][28][29] The samples were then mixed with 0.0125% MB (Sigma-Aldrich) in DI water (w/v) at a ratio of either 1:1, 1:10, or 1:100 (sample:MB solution, v/v). After vortexing of the samples with MB, chloroform (Sigma-Aldrich) was added at a ratio of 1:2 (sample: chloroform, v/v).…”

Coming to terms with tissue engineering and regenerative medicine in the lung

“…MSCs within lungs have also been identified that have the ability to express markers of ATI and ATII cells (73,95,214). In this regard, a particularly relevant finding is that MSCs may be less finicky toward the scaffold milieu in terms of attachment (19,21,170,180,213,217). However, what is not yet established is whether MSCs fully redifferentiate into specific lung cell types within a scaffold and recapitulate the functions of the native cell type.…”