Histological Mapping and Subtype-Specific Functions of Galectins in Health and Disease

Abstract

Galectins, β-galactoside-binding lectins, consist of 15 members and are broadly distributed in the mammalian body in organand cell-specific manners. This minireview summarizes current knowledge on the cellular localization of galectin subtypes in various organs including the digestive tract, lymphatic system, respiratory system, urinary system, and reproductive system. We also summarize the specific localization of galectins in the epithelium with a focus on the characteristic morphologies of epithelia. In addition, we discuss the functions of galectins in the reproductive and endocrine systems, pathogenic angiogenesis, and the regulation of stem cells. The regulatory mechanism of galectin expression is also discussed based on findings obtained from luteal cells. Various glycoconjugate ligands for galectins have been identified, and notably the ligands for galectins differ in each galectin-expressing cell. The physiological and pathological states of cells affect the expression of galectin and glycoconjugate ligands, and the extracellular environment, such as the concentration of growth factors, nutrients, and oxygen also controls the expression levels. Future studies to identify the cellular and intracellular localization of galectins using histological analyses will provide a better understanding of the potential functions of galectins in healthy and disease states.

What Cyto- and Histochemistry Can Do to Crack the Sugar Code

“…The validity of this conclusion has further been solidified by comprehensive examination of expression profiles of galectins comprehensively during the course of differentiation from progenitor cells of ectodermal origin to the mature eye lens (Table 3 ) and the respective mapping for six galectins in organs of mice [ 79 ]. These insights give reason to suggest the fundamental concept of a functional interplay between lectins in situ that spans from additive cooperation (as seen for galectins-1, -3 and -8 in the pathogenesis of osteoarthritis [ 114 , 117 ]) to strict antagonism (as seen for galectins-1 and -3 in neuroblastoma and pancreatic carcinoma growth regulation in vitro [ 58 , 98 ]).…”

Exploring the molecular mechanisms and shared gene signatures between rheumatoid arthritis and diffuse large B cell lymphoma

“…LGALS family members contain two conserved structural domains: a domain that binds to the lactosamine unit within the glycan and a carbohydrate recognition domain (CRD) consisting of 130 amino acids ( 31 ). LGALS2 , a member of this family, encodes a protein that is abundantly expressed in various mammalian cells and is involved in immunomodulatory effects by regulating LGALS2 expression in different inflammatory immune cells in a way that induces cell migration, activation, and release of inflammatory factors ( 32 ). Furthermore, the regulatory role of LGALS2 in diseases has been well reported in previous studies.…”

Revealing biomedically relevant cell and lectin type-dependent structure–activity profiles for glycoclusters by using tissue sections as an assay platform

“…43,45 These results emphasise that simple extrapolations between related proteins are not possible, a strong caveat when considering activity on members of families of tissue lectins such as C-type lectins or galectins. Since they are found to be co-expressed in tissues by immunohistochemical monitoring with non-cross-reactive antibodies, as for example accomplished for galectins, [69][70][71] the individual testing of each protein will in the rst step be mandatory, as documented herein, then taking the methodological step to testing lectins in mixtures.…”