Coordinate regulation of galectins in GAL3 deficient mouse keratinocytes exposed to UVB irradiation
Ontology highlight
ABSTRACT: Dr. Liu's research group is interested in studying the expression and functions of galectin-3, -7 and -12, in particular the roles of these proteins in inflammation and neoplasm. Members of the galectin family are known to participate in cellular homeostasis by modulating cell growth, controlling cell cycle progression, and inducing or inhibiting apoptosis. It is known that some galectins have similar functions. However, it is not fully understood whether they work cooperatively or not. Recent reports suggest that gal-3 deficiency may induce changes in cellular homeostatic mechanisms, leading to changes in expression of other galectins and galectin-related proteins. To analyze the coordinate regulation of galectins in the face of gal-3 deficiency, gene expression patterns of gal-3 / and gal-3 -/- keratinocytes exposed to UVB were compared. Murine epidermal keratinocytes from gal-3 / and gal-3 -/- mice will be irradiated with 200 J/m2 of UVB. Total RNA will be extracted at 0, 6, 12 and 24 h after irradiation. Classes were prepared in triplicate for a total of 24 samples. All samples were hybridized to the custom designed CFG GLYCOv2 glycogene array.
Project description:Dr. Liu's research group is interested in studying the expression and functions of galectin-3, -7 and -12, in particular the roles of these proteins in inflammation and neoplasm. Members of the galectin family are known to participate in cellular homeostasis by modulating cell growth, controlling cell cycle progression, and inducing or inhibiting apoptosis. It is known that some galectins have similar functions. However, it is not fully understood whether they work cooperatively or not. As the outermost barrier of the body, skin is directly and frequently exposed to a prooxidative environment, including solar ultraviolet A (UVA), ultraviolet B (UVB) radiation, and air pollution. Several reports have shown that exposure of cells to UV increase or decrease the levels of galectins. For example, the amounts of galectin-7 mRNA and protein are increased rapidly after UVB irradiation of keratinocytes (Proc. Natl. Acad. Sci. USA 1999; 96:11329-34). Heat shock and subculturing decrease, while alkylating agents and UV-light increase galectin-3 (Cell Physiol Biochem 2000; 10:149-58). To analyze the change of all galectin gene expression profiles after UVB irradiation and to determine the presence or absence of coordinate regulation, we analyzed the gene expression profiles of keratinocytes exposed to UVB. Normal human epidermal keratinocytes (NHEK) were irradiated with 200 J/m2 of UVB. Total RNA will be extracted at 0, 6, 12 and 24 h after irradiation (duplicate) for analysis on the Glyco gene chip. Several reports have shown that exposure to UV light can regulate levels of galectin in skin. This study seeks to analyze the changes in all galectin gene expression profiles post-UVB irradiation to determine the presence or absence of coordinate regulation. In this study, normal human keratinocytes were irradiated with 200J/m2 of UVB. Total RNA was extracted at 0, 6, 12, and 24-hour post irradiation time points, in duplicate. Samples were hybridized and analyzed using the GLYCOv2 array.
Project description:Dr. Liu's research group is interested in studying the expression and functions of galectin-3, -7 and -12, in particular the roles of these proteins in inflammation and neoplasm. Members of the galectin family are known to participate in cellular homeostasis by modulating cell growth, controlling cell cycle progression, and inducing or inhibiting apoptosis. It is known that some galectins have similar functions. However, it is not fully understood whether they work cooperatively or not. As the outermost barrier of the body, skin is directly and frequently exposed to a prooxidative environment, including solar ultraviolet A (UVA), ultraviolet B (UVB) radiation, and air pollution. Several reports have shown that exposure of cells to UV increase or decrease the levels of galectins. For example, the amounts of galectin-7 mRNA and protein are increased rapidly after UVB irradiation of keratinocytes (Proc. Natl. Acad. Sci. USA 1999; 96:11329-34). Heat shock and subculturing decrease, while alkylating agents and UV-light increase galectin-3 (Cell Physiol Biochem 2000; 10:149-58). To analyze the change of all galectin gene expression profiles after UVB irradiation and to determine the presence or absence of coordinate regulation, we analyzed the gene expression profiles of keratinocytes exposed to UVB. Normal human epidermal keratinocytes (NHEK) were irradiated with 200 J/m2 of UVB. Total RNA will be extracted at 0, 6, 12 and 24 h after irradiation (duplicate) for analysis on the Glyco gene chip.
Project description:Dr. Liu's research group is interested in studying the expression and functions of galectin-3, -7 and -12, in particular the roles of these proteins in inflammation and neoplasm. Members of the galectin family are known to participate in cellular homeostasis by modulating cell growth, controlling cell cycle progression, and inducing or inhibiting apoptosis. It is known that some galectins have similar functions. However, it is not fully understood whether they work cooperatively or not. Recent reports suggest that gal-3 deficiency may induce changes in cellular homeostatic mechanisms, leading to changes in expression of other galectins and galectin-related proteins.
Project description:Gene expression patterns were surveyed using RNA from 4 different murine sources. Four classes of RNA were analyzed: undifferentiated embryonic stem cells, differentiated ES cells, kidney and liver tissues. Classes were prepared in triplicate for a total of 12 samples. All samples were hybridized to the custom designed CFG GLYCOv2 glycogene array. Analysis results were used for comparison with parallel experiments using qRT-PCR.
Project description:Dr. Panjwani's laboratory is focusing on the mechanism by which galectins-3 and 7 mediate corneal epithelial cell migration. We are currently performing studies to: (i) identify and characterize the corneal epithelial cell surface and extracellular matrix (ECM) molecules which serve as counterreceptors of galectin-3 and -7, to establish whether the lectins modulate corneal epithelial cell migration by binding to well known integrins, growth factor receptors, and/or ECM molecules and (ii) determine whether galectin-3 mediates corneal epithelial cell migration indirectly by modulating the expression of key adhesion and/or signal transduction molecules by using small interfering RNA, cDNA microarrays and glycogene arrays. This study seeks the role of carbohydrate-based recognition system in the pathogenesis of glaucoma. In this study, RNA preparations of four normal and five glaucoma TM samples harvested over the last year from cadavers were hybridized and analyzed using the GLYCOv2 array. We have an NIH RO3 grant award to study the role of carbohydrate-based recognition system in the pathogenesis of glaucoma. In particular, it is known that a carbohydrate-binding protein, ELAM, serves as a marker for glaucoma. Other preliminary studies in my lab have shown that galectin-8 plays a role in the adhesion and spreading of trabecular meshwork cells (TM; the cells which modulate ocular pressure) and galectin-3 influences phagocytic capacity of TM cells. These studies suggest that galectins as well as ELAM and their counterreceptors may contribute to the pathogenesis of glaucoma. We would therefore like to compare glycogene expression patterns of normal and glaucomatous TM tissue. To this end, last month we submitted RNA preparations of five each of normal and glaucoma TM tissue harvested over the last year from cadavers. The data of these samples are now being analyzed. Meanwhile, we have analyzed RNA preparations of TM cells grown in culture from five normal and six glaucoma eyes. It is our hope that data from the two projects will enable us conclusively identify glycogenes which are differentially expressed in normal and glaucoma TM cell. Overall, the goal is to shed light on the role of carbohydrate-based recognition system and the carbohydrate-binding proteins in the pathogenesis of glaucoma.
Project description:Identification of interactors is a major attempt in cell biology. Not only protein-protein but also protein-carbohydrate interactions are of high relevance for signal transduction in biological systems. Here we aim to identify novel interacting binding partners for the β-galactoside-binding proteins Galectin-1 (Gal-1) and Galectin-3 (Gal-3) in context of the eye disease proliferative vitreoretinopathy (PVR). PVR is one of the most common failures after retinal detachment surgeries and is characterized by the migration, adhesion and epithelial-to-mesenchymal transition (EMT) of retinal pigment epithelial cells (RPE) and the subsequent formation of sub- and epiretinal fibrocellular membranes. Gal-1 and Gal-3 bind in a dose- and carbohydrate-dependent manner to mesenchymal RPE cells and inhibit cellular processes like attachment and spreading. Yet knowledge about glycan-dependent interactors of Gal-1 and Gal-3 on RPE cells is very limited, although this is a prerequisite to unravel the influence of galectins on distinct cellular processes in RPE cells. In this approach, we identified by galectin pull-down experiments and quantitative proteomic screening 131 Galectin-3 and 15 Galectin-1 interactors. They mainly play a role in multiple binding processes and are mostly membrane proteins. Here we focused on two novel identified interactors of Gal-1 and Gal-3 in the context of PVR: the low-density lipoprotein receptor LRP1 and the platelet-derived growth factor receptor beta PDGFRB. We observed crosslinking and lattice formation of exogenous Gal-1 and Gal-3 with LRP1/PDGFRB and ITGB1 on the cell surface of human RPE cells. Weaker binding of Gal-1 and Gal-3 on these interactors and no lattice formation on the cell surface was seen, when complex-type-N-glycosylation was inhibited by treatment of the cells with Kifunensine. In conclusion, the identified specific glycoprotein ligands for Gal-1 and Gal-3 give us new insights in the highly specific binding of galectins to dedifferentiated RPE cells and the resulting prevention of PVR-associated cellular events.
Project description:Dr. Panjwani's laboratory is focusing on the mechanism by which galectins-3 and 7 mediate corneal epithelial cell migration. We are currently performing studies to: (i) identify and characterize the corneal epithelial cell surface and extracellular matrix (ECM) molecules which serve as counterreceptors of galectin-3 and -7, to establish whether the lectins modulate corneal epithelial cell migration by binding to well known integrins, growth factor receptors, and/or ECM molecules and (ii) determine whether galectin-3 mediates corneal epithelial cell migration indirectly by modulating the expression of key adhesion and/or signal transduction molecules by using small interfering RNA, cDNA microarrays and glycogene arrays.
Project description:Dr. Panjwani's laboratory is focusing on the mechanism by which galectins-3 and 7 mediate corneal epithelial cell migration. We are currently performing studies to: (i) identify and characterize the corneal epithelial cell surface and extracellular matrix (ECM) molecules which serve as counterreceptors of galectin-3 and -7, to establish whether the lectins modulate corneal epithelial cell migration by binding to well known integrins, growth factor receptors, and/or ECM molecules and (ii) determine whether galectin-3 mediates corneal epithelial cell migration indirectly by modulating the expression of key adhesion and/or signal transduction molecules by using small interfering RNA, cDNA microarrays and glycogene arrays.
Project description:Dr. Panjwani's laboratory is focusing on the mechanism by which galectins-3 and 7 mediate corneal epithelial cell migration. We are currently performing studies to: (i) identify and characterize the corneal epithelial cell surface and extracellular matrix (ECM) molecules which serve as counterreceptors of galectin-3 and -7, to establish whether the lectins modulate corneal epithelial cell migration by binding to well known integrins, growth factor receptors, and/or ECM molecules and (ii) determine whether galectin-3 mediates corneal epithelial cell migration indirectly by modulating the expression of key adhesion and/or signal transduction molecules by using small interfering RNA, cDNA microarrays and glycogene arrays. We have prepared three independent preparations of total RNA of corneal epithelial cells from WT mice (total six samples) for analysis of glycogene expression. Samples are Normal Cornea (Left eye) and Laser ablation + 16-18 hours healing (right eye)
Project description:Galectins are a group of carbohydrate binding proteins with immunomodulatory functions. While the effects of galectins on the T cell compartment are well described, the interactions between galectins and antigen-presenting cells (APCs) remain elusive. Here we find increased expression of galectin-1(gal-1) in the stroma of a large selection of cancers, and investigating the effect of gal-1 on stroma localized antigen presenting cells, including monocyte derived dedritic cells and M1 and M2 macrophages (M1s and M2s, respectively). Using an in depth and dynamic proteomic and phosphoproteomic analysis of the effect of gal-1 on M2s we show that gal-1 induces global changes in the proteomic and signaling landscape of M2s, consistent with induction of a tolerogenic macrophage phenotype. Specifically, gal-1 induces expression of key immunomodulatory and tumor-associated proteins, including the key immune checkpoint protein, programmed cell death 1 ligand 1 (PD-L1/CD274) and the immunomodulator, indoleamine 2,3-dioxygenase-1 (IDO1). Gal-1 induced IDO1 and its active metabolite kynurenine in a dose dependent manner, an effect that was prevented by JAK/STAT inhibition. Analyzing gal-1 expression in human tumors we find that gal-1 is upregulated across multiple tumors, and in a 3D organotypic model system equipped with genetically engineered tumorigenic epithelial cells, we find that the tumor associated gal-1 is derived from both from epithelial and stromal cells. Our results highlight the potential of targeting gal-1 in immunotherapeutic treatment of human cancers.