Cutaneous fibrosis is a common complication seen in mixed connective tissue diseases. It often occurs as a result of TGF-β-induced deposition of excessive amounts of collagen in the skin. Lysyl oxidases (LOXs), a family of extracellular matrix (ECM)-modifying enzymes responsible for collagen cross-linking, are known to be increased in dermal fibroblasts from patients with fibrotic diseases, denoting a possible role of LOXs in fibrosis. To directly study this, we have developed two bioengineered, in vitro skin-like models: human skin equivalents (hSEs), and self-assembled stromal tissues (SASs) that contain either normal or systemic sclerosis (SSc; scleroderma) patient-derived fibroblasts. These tissues provide an organ-level structure that could be combined with non-invasive, label-free, multiphoton microscopy (SHG/TPEF) to reveal alterations in the organization and cross-linking levels of collagen fibers during the development of cutaneous fibrosis, which demonstrated increased stromal rigidity and activation of dermal fibroblasts in response to TGF-β1. Specifically, inhibition of specific LOXs isoforms, LOX and LOXL4, in foreskin fibroblasts (HFFs) resulted in antagonistic effects on TGF-β1-induced fibrogenic hallmarks in both hSEs and SASs. In addition, a translational relevance of these models was seen as similar antifibrogenic phenotypes were achieved upon knocking down LOXL4 in tissues containing SSc patient-derived-dermal fibroblasts (SScDFs). These findings point to a pivotal role of LOXs in TGF-β1-induced cutaneous fibrosis through impaired ECM homeostasis in skin-like tissues, and show the value of these tissue platforms in accelerating the discovery of antifibrosis therapeutics.

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This research was funded by a grant from Biogen. In addition, a seed grant from Tufts Collaborates funded part of this research. Mengqi Huang received support from the China Scholarship Council to perform this work. We would like to thank the CMDB program, Sackler School of Graduate Biomedical Sciences at Tufts University, and Scleroderma foundation for their support. We thank Ryan Imbriaco for his technical assistance in the preparation of this manuscript and Gilad Cohen, Lev Brown, and Kamar Reda for their help with tissue imaging.

Author information


  1. Department of Diagnostic Sciences, Tufts University School of Dental Medicine, Boston, MA, USA

    • Mengqi Huang
    • , Jason DeFuria
    • , Anna Maione
    • , Avi Smith
    • , Olga Kashpur
    •  & Jonathan Garlick
  2. Department of Molecular and Systems Biology, Geisel School of Medicine at Dartmouth, Hanover, NH, USA

    • Mengqi Huang
    •  & Michael L. Whitfield
  3. Department of Biomedical Engineering, Tufts University, Medford, MA, USA

    • Zhiyi Liu
    • , Lauren Baugh
    • , Lauren D. Black III
    •  & Irene Georgakoudi
  4. Cellular, Molecular, and Developmental Biology Program, Sackler School for Graduate Biomedical Sciences, Tufts University School of Medicine, Boston, MA, USA

    • Lauren D. Black III
  5. Department of Biomedical Data Science, Geisel School of Medicine at Dartmouth, Lebanon, NH, USA

    • Michael L. Whitfield
  6. Department of Stomatology, Tongji Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China

    • Mengqi Huang
  7. State Key Laboratory of Modern Optical Instrumentation, College of Optical Science and Engineering, Zhejiang University, Hangzhou, China

    • Zhiyi Liu


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Correspondence to Jonathan Garlick.

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