1. Academic Validation
  2. Lysyl Oxidase (LOX) Family Members: Rationale and Their Potential as Therapeutic Targets for Liver Fibrosis

Lysyl Oxidase (LOX) Family Members: Rationale and Their Potential as Therapeutic Targets for Liver Fibrosis

  • Hepatology. 2020 Aug;72(2):729-741. doi: 10.1002/hep.31236.
Wei Chen 1 2 Aiting Yang 1 2 Jidong Jia 3 Yury V Popov 4 Detlef Schuppan 4 5 Hong You 1 2 3
Affiliations

Affiliations

  • 1 Experimental and Translational Research Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
  • 2 Beijing Key Laboratory of Tolerance Induction and Organ Protection in Transplantation, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
  • 3 Beijing Key Laboratory of Translational Medicine in Liver Cirrhosis, National Clinical Research Center of Digestive Diseases, Liver Research Center, Beijing Friendship Hospital, Capital Medical University, Beijing, China.
  • 4 Division of Gastroenterology, Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA.
  • 5 Institute of Translational Immunology and Research, Center for Immunotherapy, University of Mainz Medical Center, Mainz, Germany.
Abstract

The cross-linking of structural extracellular matrix (ECM) components, especially fibrillar collagens and elastin, is strongly implicated in fibrosis progression and resistance to fibrosis reversal. Lysyl oxidase family members (LOX and LOXL1 [lysyl oxidase-like 1], LOXL2 [lysyl oxidase-like 2], LOXL3 [lysyl oxidase-like 3], and LOXL4 [lysyl oxidase like 4]) are extracellular copper-dependent Enzymes that play a key role in ECM cross-linking, but have also other intracellular functions relevant to fibrosis and carcinogenesis. Although the expression of most LOX family members is elevated in experimental liver fibrosis of diverse etiologies, their individual contribution to fibrosis is incompletely understood. Inhibition of the LOX family as a whole and of LOX, LOXL1, and LOXL2 specifically has been shown to suppress fibrosis progression and accelerate its reversal in rodent models of cardiac, renal, pulmonary, and liver fibrosis. Recent disappointing clinical trials with a monoclonal antibody against LOXL2 (simtuzumab) in patients with pulmonary and liver fibrosis dampened enthusiasm for LOX family member inhibition. However, this unexpected negative outcome may be related to the inefficient antibody, rather than to LOXL2, not qualifying as a relevant antifibrotic target. Moreover, LOX family members other than LOXL2 may prove to be attractive therapeutic targets. In this review, we summarize the structural hallmarks, expression patterns, covalent cross-linking activities, and modes of regulation of LOX family members and discuss the clinical potential of their inhibition to treat fibrosis in general and liver fibrosis in particular.

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