%0 PDF %T FIBROGENIC PATHWAYS IN 3D TISSUE MODELS: FROM LYSYL OXIDASE ENZYMES TO SCLERODERMA %A Huang, Mengqi. %D 2017-04-18T11:39:08.260Z %8 2017-04-18 %R http://localhost/files/c247f465s %X Abstract: Scleroderma (SSc) is a heterogeneous, progressive disease characterized by collagen accumulation in skin. The majority of the patients with this condition present with debilitating cutaneous fibrosis and contractual changes that affect tendons and subcutaneous tissues. In the past decade, tremendous progress has been achieved to understand this devastating disease. Unfortunately, no effective therapy has been developed to treat fibrotic progression in skin. Recent studies have identified that lysyl oxidases (LOXs), a family of extracellular matrix (ECM)-modifying enzymes responsible for collagen cross-linking, were upregulated in dermal fibroblasts from patients with fibrotic diseases including SSc. To better understand mechanisms linked to fibrosis, we have adapted two bioengineered, in vivo-like, 3D tissue models for human skin (hSE) and human dermis (SA) to study the ECM expression, organization and remodeling that occurs in the presence of fibroblasts derived from SSc (SScDF) in comparison to age-and-site matched, normal donors (NDF). We validated multiphoton microscopy (SHG/TPEF) in 3D tissue models as a non-invasive tool to evaluate human foreskin fibroblast (HFF) responses to TGF- in ECM by assessing collagen fiber density, organization, and cross-linking level, that were correlated with tissue stiffness measured by Atomic Force Microscopy (AFM). These TGF--induced changes were detected in the dermis of 3D tissues (hSE) and found that increasing collagen content and crosslinks were accompanied by elevated rigidity that were inhibited by suppression of LOX using the inhibitor BAPN or by specific siRNA knockdown of LOX and lysyl oxidase-like 4 (LOXL4), which abolished TGF--induced ECM alteration and dermal stiffness. In the initial stage of SSc, a fibroblasts transition to myofibroblasts can be activated by increasing circulating levels of TGF- in patient serum. In SScDF, expression of alpha smooth muscle actin (SMA) and LOXL4 were increased in both 2D and 3D. Knockdown LOXL4 in SScDF not only inhibited the rigidity and contraction in hSE by comparing them to NDF, but also abolished TGF--induced ECM deposition and organization in SA tissues. Thus, LOXs plays a pivotal role in the pathogenesis of dermal fibrosis in 3D skin-like tissues that were directly monitored by SHG/TPEF and AFM, which may serve as new prognostic and diagnostic platforms for studying and treating fibrotic diseases.; Thesis (Ph.D.)--Tufts University, 2017.; Submitted to the Dept. of Cell, Molecular & Developmental Biology.; Advisors: Jonathan Garlick, and Lauren Black.; Committee: Lauren Black, Peter Brooks, and John Castellot.; Keyword: Cellular biology. %[ 2022-10-12 %9 Text %~ Tufts Digital Library %W Institution