Interestingly, a similar relationship between these pathways has been observed in limb proximal-distal development where Fgf and Wnt pathways promote distal outgrowth while RA has an opposing proximalizing role (reviewed in [ 53]).
In cultured mouse cells, Wnt5A [a 'distal' Wnt (expressed in distally located tissues and is required for distal limb development)] can rescue the expression of distal markers in epidermal cells that have been co-cultured with dermal fibroblasts with depleted HoxA13 (a 'distal' Hox protein) (Rinn et al., 2008).
Thus, in both BPD infants and animal models, altered distal lung development is associated to opposite changes in MMP16 expression as those normally observed in the corresponding lung development stage.
The arrest of postnatal distal lung development is the hallmark of the so-called new BPD [2].
However, in transgenic assays, the GCR was unable to fully recapitulate all aspects of the endogenous Hoxd expression patterns during distal limb development.
Another prominent phenotype, involving abnormal distal limb development, appears to be identical in the null and hypomorph [11], [12].
The proteinases produced by these two genes play an important role in the control of distal lung development [4], [7] [9].
A detailed analysis of the respiratory phenotype in fetal Creb1−/− mice has been performed and shows severely disrupted conducting and distal airway development, evident by E17.5.
In this study, we used mouse models of cancer to determine whether salivary biomarker profiles are affected by distal disease development.
Thus, there is reasonably a difference in distal basin development between MFI-K171 and TF 6171-7, the quantified difference (0.078) being greater than two standard deviations of the Pongo sample.
Tetracycline-inducible expression of DKK1, in lung epithelium, resulted in disruption of distal airway development and expansion of proximal airways through an N-myc, BMP-4 and FGF dependent mechanism [35].
