Pregnancy in women with systemic lupus erythematosus (SLE).

Galectin-2 (Gal-2) plays a role in cancer, myocardial infarction, immune response, and gastrointestinal tract diseases. The only reported crystal structure of Gal-2 shows that it is a dimer in which the monomer subunits have almost identical structures, each binding with one molecule of lactose. In this study, we crystallized Gal-2 under new conditions that produced three crystal structures. In each Gal-2 dimer structure, lactose was shown to be bound to only one of the carbohydrate recognition domain subunits. In solution studies, the thermal shift assay demonstrated that inequivalent monomer subunits in the Gal-2 dimer become equivalent upon ligand binding. In addition, galectin-mediated erythrocyte agglutination assays using lactose and larger complex polysaccharides as inhibitors showed the structural differences between Gal-1 and Gal-2. Overall, our results reveal some novel aspects to the structural differentiation in Gal-2 and expand the potential for different types of molecular interactions that may be specific to this lectin.

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Human galectin-2 interacts with carbohydrates and peptides non-classically: new insight from X-ray crystallography and hemagglutination

Systemic lupus erythematosus (SLE) is characterized by excessive production of various autoantibodies, which play important roles in the pathogenesis of SLE. Apart from classical autoantibodies such as anti-double stranded DNA antibody (anti-dsDNA), anti-Smith antibody (anti-Sm), and anti-phospholipid antibody (APL), recent studies focus on some novel autoantibodies including anti-complement (C) 1q antibody (anti-C1q), which is closely correlated with lupus nephritis; anti-N-methyl-D-asparate receptor antibody (NMDAR), which mediates neuropsychiatric manifestations in SLE to some extent; anti-galectin, which is involved in secondary anti-phospholipid syndrome (APS) in SLE; and anti-Mullerian hormone (AMH), which represents a more specific biomarker for subclinical ovarian damage caused by the disease itself or cytotoxic drugs in SLE patients. Correlation of these autoantibodies with disease activity and organ involvement of SLE may help to evaluate disease severity, efficacy of treatment, and long-term prognosis. Furthermore, combined measurement of a variety of autoantibodies is supposed to be more valuable in estimating disease activity and severity.

Possible novel biomarkers of organ involvement in systemic lupus erythematosus

Emerging role of galectin family in inflammatory autoimmune diseases.

Preeclampsia has the highest rate of obstetric morbidity and mortality.We recruited 21 women with preeclampsia and 27 women with uncomplicated pregnancies. We used a quantitative protein macroarray...

Syndecan 4, galectin 2, and death receptor 3 (DR3) as novel proteins in pathophysiology of preeclampsia.

Autoantibodies against opsonins of dying and dead cells mediate Fcγ receptor-dependent phagocytosis of autologous apoptotic and necrotic cells and hereby tend to elicit inflammation instead of silent clearance. We analysed sera of patients with chronic autoimmune diseases for the occurrence of IgG autoantibodies recognizing galectins. These pluripotent effectors can also bind to apoptotic or necrotic cells. Patients with antiphospholipid syndrome (APS; n = 104) and systemic lupus erythematosus (SLE; n = 62) were examined, healthy donors (n = 31) served as controls. Selected peptides of galectin (Gal)-2 were employed for peptide-based ELISAs. Levels of anti-Gal-2PEP-IgG were significantly increased in SLE and APS when compared with controls. In addition, patients with APS showed significantly higher levels of anti-Gal-2PEP-IgG compared with patients with SLE. Anti-Gal-2PEP-IgG may, therefore, be considered novel biomarkers for APS.

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Le Munoz

Papers

Autoantibodies against galectin-2 peptides as biomarkers for the antiphospholipid syndrome.