LHVS is a potent, non-selective, irreversible, and cell-permeable cysteine protease and cathepsin inhibitor. LHVS also inhibits T. gondii invasion (IC₅₀=10μM)[1-2]. Through its vinyl sulfone moiety, LHVS covalently modifies the thiol group at the active site of cathepsin S, thereby achieving high selectivity in inhibiting cathepsin S activity. LHVS can be used in research related to neuropathic pain and the autophagy/lysosomal degradation pathway[3-4].
In vitro, treatment of the B-lymphoblastoid cell line HOM2 with LHVS (1–5nM) for 1 hour specifically inhibited cathepsin S activity, prevented complete proteolysis of the invariant chain, and significantly reduced the formation of SDS-stable αβ dimers[5]. Treatment of MCF7 tumor cells and U-937 macrophage-like cells with LHVS (10nM) for 72 hours did not show a significant effect on cell proliferation[6].
In vivo, a single intracerebroventricular (i.c.v.) injection of LHVS (10–50nM; 6μL) was administered to male ICR mice 10 minutes before the induction of traumatic brain injury (TBI). LHVS significantly reduced the levels of the pro-inflammatory cytokines IL-1β and TNF-α in the injured cortex, alleviated brain edema at 24 hours post-TBI, suppressed neuronal degeneration in the cortex, and improved neurobehavioral scores in mice at 24 hours after injury[7]. Daily intraperitoneal injection of LHVS (25mg/kg), starting from day 0 to day 15 of MOG₃₅₋₅₅ immunization to induce experimental autoimmune encephalomyelitis (EAE), was administered to both wild-type (WT) and cathepsin S-deficient (Cat S⁻/⁻) C57BL/6 mice. LHVS completely prevented the clinical onset of MOG₃₅₋₅₅-induced EAE in both WT and Cat S⁻/⁻ mice and significantly reduced the number of infiltrating macrophages, microglia, CD4⁺ T cells, CD8⁺ T cells, and B cells in the spinal cord[8].
References:
[1] Wilson SR, Peters C, Saftig P, et al. Cathepsin K activity-dependent regulation of osteoclast actin ring formation and bone resorption. J Biol Chem. 2009 Jan 23;284(4):2584-92.
[2] Teo CF, Zhou XW, Bogyo M, et al. Cysteine protease inhibitors block Toxoplasma gondii microneme secretion and cell invasion. Antimicrob Agents Chemother. 2007 Feb;51(2):679-88.
[3] Barclay J, Clark AK, Ganju P, et al. Role of the cysteine protease cathepsin S in neuropathic hyperalgesia. Pain. 2007 Aug;130(3):225-234.
[4] Fujii H, Ivison SM, Shimizu H, et al. Inhibition of cathepsin S reduces allogeneic T cell priming but not graft-versus-host disease against minor histocompatibility antigens. Biol Blood Marrow Transplant. 2012 Apr;18(4):546-56.
[5] Riese RJ, Wolf PR, Brömme D, et al. Essential role for cathepsin S in MHC class II-associated invariant chain processing and peptide loading. Immunity. 1996 Apr;4(4):357-66.
[6] Mitrović A, Senjor E, Jukić M, et al. New inhibitors of cathepsin V impair tumor cell proliferation and elastin degradation and increase immune cell cytotoxicity. Comput Struct Biotechnol J. 2022 Aug 28;20:4667-4687.
[7] Xu J, Wang H, Ding K, et al. Inhibition of cathepsin S produces neuroprotective effects after traumatic brain injury in mice. Mediators Inflamm. 2013;2013:187873.
[8] Allan ER, Yates RM. Redundancy between Cysteine Cathepsins in Murine Experimental Autoimmune Encephalomyelitis. PLoS One. 2015 Jun 15;10(6):e0128945.