Galectin Animal studies Human studies Therapeutic potential
Galectin-1 Administration of galectin-1 suppressed CIA by enhancing T cell apoptosis and inhibiting IL-2 secretion [55].

Galectin-1 limited neutrophil recruitment to
inflammatory tissue by in vitro experiment and galectin-1-deficient mice [69].

Galectin-1 deficient mice were more susceptible to CIA [70].
Down-regulated expression of galectin-1 in the synovial fluid from RA/JIA patients [71,73,74]. Administration of galectin-1 or its derivates ameliorated CIA [55,75,78,79].

Galectin-1 induced chondrogenic differentiation of MSCs from RA bone marrow [80].
Galectin-3 Galectin-3 Over-expression of galectin-3 was detected in CIA [93].

Galectin-3 deficient mice displayed reduced
disease severity of antigen-induced arthritis [94].
Increased expression of galectin-3 in sera and synovial fluid in RA/JIA patients [71,72,91,95-97].
A galectin-3 gene allele (LGALS3 +292C) is more prevalent in RA patients [99].
RA patients had a higher number of galectin-3-expressing FLS [100].
Galectin-3 induced FLS to secret a set of pro-inflammatory cytokines and chemokines [101].
Intra-articular lentivirus-mediated delivery of galectin-3 shRNA ameliorated CIA in rats [75].

Downregulation of galectin-3 inhibited IL-6 secretion in FLSs from RA synovium [102].
Galectin-9 Galectin-9 deficiency promoted Th1 and Th17; and inhibited Treg differentiation, rendering susceptibility to CIA [103].

Galectin-9 induced apoptosis of FLS and downregulated pro-inflammatory cytokine production [104].

Galectin-9 ameliorated immune-complex-induced arthritis by regulating the expression profile of macrophage Fc receptors [118]
Galectin-9 induced apoptosis of FLS from RA patients in cell culture [104].
Decreased expression of galectin-9 was detected in RA patients with high disease activities [119].
Down-regulated expression of Tim-3 led to defective galectin-9-induced apoptosis of CD4+ T cells [120].
Administration of galectin-9 ameliorated CIA or
immune complex-induced arthritis [104,118].
Galectin-2   Galectin-2 3279C/T gene polymorphism is correlated with diastolic blood pressure in patients with RA [123].  

CD44vRA, a CD44 variant prevalent in RA patients, can neutralize the galectin-8 induced apoptosis of synoviocytes [125].

Autoantibodies against galectin-8 were detected in the sera of about 20% of RA patients [126,127].

A galectin-8 gene variant is prevalent in RA patients and associates with the early onset of RA [128]

Table 1: Pathogenic role and therapeutic potential of galectins in RA.