Lysyl oxidase (LO) stabilizes the extracellular matrix by crosslinking collagen and elastin. To assess the transcriptional regulation of LO, we cloned the 5-flanking region with 3,979 bp of the rat LO gene. LO transcription started at multiple sites clustered at the region from ؊78 to ؊51 upstream of ATG. The downstream core promoter element functionally independent of the initiator predominantly activated the TATA-less LO gene. 5 Deletion assays illustrated a sequence of 804 bp upstream of ATG sufficient for eliciting the maximal promoter activity and the region ؊709/؊598 exhibiting strongly enhancing effects on the reporter gene expression in transiently transfected RFL6 cells. DNase I footprinting assays showed a protected pattern existing in the fragment ؊612/؊580, which contains a nuclear factor I (NFI)-binding site at the region ؊594/؊580 confirmed by electrophoretic mobility supershift assays. Mutations on this acting site decreased both NFI binding affinity in gel shift assays and stimulation of SV40 promoter activities in cells transfected with the NFI-binding site-SV40 promoter chimeric construct. Furthermore, at least two functional NFI-binding sites, including another one located at ؊147/؊133, were identified in the LO promoter region ؊804/ ؊1. Only NFI-A and NFI-B were expressed in rat lung fibroblasts, and their interaction with the LO gene was sensitively modulated by exogenous stimuli such as cigarette smoke condensate. In conclusion, the isolated rat LO gene promoter contains functionally independent initiator and downstream core promoter elements, and the conserved NFI-binding sites play a critical role in the LO gene activation. Lysyl oxidase (LO)2 (EC 1.4.3.13) is a copper-dependent enzyme secreted by fibrogenic cells such as fibroblasts (1). This enzyme catalyzes the initiation of cross-linking of collagen and elastin, major structural components of the extracellular matrix (ECM), by oxidizing peptidyl lysine residues within these proteins to peptidyl ␣-aminoadipic-␦-semialdehyde, leading to the formation of condensation products stabilizing polymeric collagen or elastin as insoluble fibers. Thus, LO plays a central role in ECM morphogenesis and tissue repair (1).In addition to the major function in stabilizing the ECM, LO also exhibits other biological activities. As reported, expression of transfected LO cDNA inhibited Ha-ras-induced cell transformation indicating an anti-tumorigenic effect of LO (2). LO can oxidize lysine residues in various globular proteins other than collagen and elastin (1). Oxidation of basic fibroblast growth factor (bFGF) by LO blocks the proliferation of bFGFstimulated cells and highly tumorigenic bFGF autocrine-transformed cells (3). Purified mature bovine LO displays chemotactic activity for monocytes and vascular smooth muscle cells (4, 5). LO and its oxidized substrates exist within the nuclei, potentially using histone H1 as a substrate and modulating the promoter activity of the collagen type III gene (6 -8). Increased LO activity is associated with fibrotic...

Accuracy of unstructured finite volume discretization is greatly influenced by the gradient reconstruction. For the commonly used k-exact reconstruction method, the cell centroid is always chosen as the reference point to formulate the reconstructed function. But in some practical problems, such as the boundary layer, cells in this area are always set with high aspect ratio to improve the local field resolution, and if geometric centroid is still utilized for the spatial discretization, the severe grid skewness cannot be avoided, which is adverse to the numerical performance of unstructured finite volume solver. In previous work [Chinese Physics B. 2020, In press], we explored a novel global-direction stencil and combined it with the face-area-weighted centroid on unstructured finite volume methods from differential form to realize the skewness reduction and a better reflection of flow anisotropy. Greatly inspired by the differential form, in this research, we demonstrate that it is also feasible to extend this novel method to the unstructured finite volume discretization from integral form on both second and third-order finite volume solver. Numerical examples governed by linear convective, Euler and Laplacian equations

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Accuracy of unstructured finite volume discretization is greatly influenced by the gradient reconstruction. For the commonly used k-exact reconstruction method, the cell centroid is always chosen as the reference point to formulate the reconstructed function. But in some practical problems, such as the boundary layer, cells in this area are always set with high aspect ratio to improve the local field resolution, and if geometric centroid is still utilized for the spatial discretization, the severe grid skewness cannot be avoided, which is adverse to the numerical performance of unstructured finite volume solver. In previous work [Chinese Physics B. 2020, In press] , we explored a novel global-direction stencil and combined it with the face-area-weighted centroid on unstructured finite volume methods from differential form to realize the skewness reduction and a better reflection of flow anisotropy. Greatly inspired by the differential form, in this research, we demonstrate that it is also feasible to extend this novel method to the unstructured finite volume discretization from integral form on both second and third-order finite volume solver. Numerical examples governed by linear convective, Euler and Laplacian equations are utilized to examine the correctness as well as effectiveness of this extension. Compared with traditional vertex-neighbor and face-neighbor stencils based on the geometric centroid, the grid skewness is almost eliminated and computational accuracy as well as convergence rate is greatly improved by the global-direction stencil with face-area-weighted centroid. As a result, on unstructured finite volume discretization from integral form, the method also has superiorities on both computational accuracy and convergence rate.