Psoriasis in humans is associated with down‐regulation of galectins in dendritic cells

Abstract

2 ABSTRACT.We have investigated the expression and role of galectin-1 and other galectins in psoriasis and in the Th1/Th17 effector and dendritic cell responses associated with this chronic inflammatory skin condition. To determine differences between psoriasis patients and healthy donors, galectins expression was analyzed by RT-PCR assays in skin samples and specifically on epidermal and peripheral blood dendritic cells by immunofluorescence and flow cytometry.In skin of healthy donors galectins 1, 3 and 9 were expressed in a high proportion of Langerhans cells. Also, galectins were differentially expressed in peripheral blood dendritic cell subsets; galectin-1 and galectin-9 were highly expressed in peripheral myeloid dendritic cells compared with plasmacytoid dendritic cells. We found that non-lesional as well as lesional skin samples from psoriasis patients had low levels of galectin-1 at mRNA and protein level in parallel with low levels of IL-10 mRNA compared with skin from healthy patients. However, only lesional skin samples expressed high levels of

Novel role for galectin-1 in T-cells under physiological and pathological conditions

“…Previous studies have indicated that Gal-1 expression is diminished at the sites of severe chronic inflammation such as psoriatic skin ( [28] and Krenacs L et al, unpublished data). However, Gal-1 expression in pathological T-cells has not yet been specifically investigated.…”

Presence of galectin-1 in the epidermal and dermal thickening of keloid tissues

“…It is important to highlight that in the keratinocytes from normal adult skin, Gal-1 was not evidenced. Remarkably, previous studies in human skin have shown that Gal-1 is not expressed by keratinocytes in normal skin [37] but can be expressed by cells in psoriasis [37,38], cutaneous malignant lesions including squamous cell carcinoma [39], mycosis fungoides [40,41], and melanoma [42], while in keloid tissues, proteome analysis of keloid proteins performed by Ong et al revealed that the expression of Gal-1 is upregulated compared to normal skin [43]. However, the role of Gal-1 in skin lesions is still unclear.…”

“…Gal-1, like others galectins, participates in signaling pathways and regulates a variety of biological responses including cell growth, cell-cell and cell-matrix adhesion, cell differentiation, migration, proliferation and survival [31][32][33][34] and plays a critical role in inflammation, angiogenesis, and tumor development and progression [27,33,35,36]. In human skin, Gal-1 has been implicated in psoriasis [37,38] and malignant lesions including cutaneous cancer [39], mycosis fungoides [40,41], and melanoma [42], and scarce studies have shown that the expression of Gal-1 is upregulated in keloid tissue [43]. However, the presence, distribution, and localization of Gal-1 as well as its possible role in benign dermal fibroproliferative tumors such as keloids, have not been completely elucidated.…”

Human immunosuppressive protein, galectin-1 emerges as a novel regulatory factor in autoimmune disorders

“…Previous studies have shown that expression of Gal-1 is decreased at sites of chronic inflammation [139]. However, expression of Gal-1 in T-cells has not been studied even though dysfunctional T-cell apoptosis has been documented as a crucial defect in SLE pathogenesis.…”