QPCR array study for cell cycle related genes in Caco-2 cells treated with human lectin ZG16p
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ABSTRACT: ZG16p (zymogen granule protein 16) is a mannose- and heparin/heparan sulfate-binding lectin highly expressed in the human gut. In this study, the cell cycle related genes regulated by ZG16p were identified by qPCR array. Caco-2, a human adenocarcinoma cell line, was cultured in medium containing ZG16p for 72 h. qPCR array profiling revealed that, with an arbitrary fold change cut-off of 2, ZG16p significantly (p<0.05) up-regulated the expression of 6 genes, while down-regulated that of 3 genes.
Project description:Animal cells express heparan sulfate proteoglycans that perform many important cellular functions by way of heparan sulfate-protein interactions. The identification of membrane heparan-sulfate binding proteins is challenging because of their low abundance and the need for extensive enrichment. Here, we report a proteomics workflow for the identification and characterization of membrane-anchored and extracellular proteins that bind heparan sulfate. The technique is based on limited proteolysis of live cells in the absence of denaturation and fixation, heparin-affinity chromatography, and high-resolution LC–MS/MS, and we designate it LPHAMS. Application of LPHAMS to U937 monocytic and primary murine and human endothelial cells identified 55 plasma membrane, extracellular matrix, and soluble secreted proteins, including many previously unidentified heparin-binding proteins. The method also facilitated the mapping of the heparin-binding domains, making it possible to predict the location of the heparin-binding site. To validate the discovery feature of LPHAMS, we characterized one of the newly discovered heparin-binding proteins, C-type lectin 14a (CLEC14A), a member of the C-type lectin family that modulates angiogenesis. We found that the C-type lectin domain of CLEC14A binds one-to-one to heparin with nanomolar affinity, and, using molecular modeling and mutagenesis, we mapped its heparin-binding site. CLEC14A physically interacted with other glycosaminoglycans, including endothelial heparan sulfate and chondroitin sulfate E, but not with neutral or sialylated oligosaccharides. The LPHAMS technique should be applicable to other cells and glycans and provides a way to expand the repertoire glycan-binding proteins for further study.
Project description:The general area of research interests of my lab is the glycobiology of HSPGs in cell-cell/cell-matrix interactions and growth factor signalling. Heparan sulfate binding proteins in neural development and differentiation. We used the Glyco-gene Chips to study the gene expression responses of mouse neural cells to heparin-binding growth factors. The experimental systems studied is in vivo (developing mouse brain). The goal is to examine the global responses of neural cells to particular growth factors during differentiation in terms of effects on HS biosynthetic enzymes and proteoglycan core proteins, as well as growth factors and their receptors. Analysis of A) P1 mouse brain wild type for Heparan sulfate 2-O sulfotransferase (HS2ST) and B) heterozygous for Heparan sulfate 2-O sulfotransferase (HS2ST) loss of function mutation.
Project description:H1299 cells were overexpressed miR-138 or silenced AGO2. The expression of 92 genes associated with p53 using the “Human p53 Signaling Pathway PCR Array” qPCR gene expression profiling. H1299 cells were transfected with NC mimics, AGO2 siRNA or miR-138 for 48h. Equal amount total RNA from each group was pooled prior to gene expression analysis.
Project description:Downregulation or gene mutation of MUC6, a major component of gastric mucin, is often identified in human gastric cancers. However, the mechanistic role of MUC6 alteration in gastric carcinogenesis remains unclear. Here, using Muc6-deficient mice, we revealed that dysregulated glycosylation in Muc6-deficient gastric epithelium causes aberrant golgi stress responses, resulting in spontaneous gastric cancer development. Muc6-deficient tumor growth is dependent on MAPK activation, which is mediated by golgi stress-induced golph3 upregulation. Glycomic analysis and lectin-binding assays revealed abnormal expression of mannose-rich N-type glycans in Muc6-deficient gastric tumors. Banana lectin-drug conjugates, which bind to mannose-rich glycans, dramatically suppress mannose-rich murine and human gastric cancer growth. Thus, we propose golgi stress responses and aberrant sugar chains as promising therapeutic targets in gastric cancers accompanied with mucin expression disorder.
Project description:Downregulation or gene mutation of MUC6, a major component of gastric mucin, is often identified in human gastric cancers. However, the mechanistic role of MUC6 alteration in gastric carcinogenesis remains unclear. Here, using Muc6-deficient mice, we revealed that dysregulated glycosylation in Muc6-deficient gastric epithelium causes aberrant golgi stress responses, resulting in spontaneous gastric cancer development. Muc6-deficient tumor growth is dependent on MAPK activation, which is mediated by golgi stress-induced golph3 upregulation. Glycomic analysis and lectin-binding assays revealed abnormal expression of mannose-rich N-type glycans in Muc6-deficient gastric tumors. Banana lectin-drug conjugates, which bind to mannose-rich glycans, dramatically suppress mannose-rich murine and human gastric cancer growth. Thus, we propose golgi stress responses and aberrant sugar chains as promising therapeutic targets in gastric cancers accompanied with mucin expression disorder.
Project description:Downregulation or gene mutation of MUC6, a major component of gastric mucin, is often identified in human gastric cancers. However, the mechanistic role of MUC6 alteration in gastric carcinogenesis remains unclear. Here, using Muc6-deficient mice, we revealed that dysregulated glycosylation in Muc6-deficient gastric epithelium causes aberrant golgi stress responses, resulting in spontaneous gastric cancer development. Muc6-deficient tumor growth is dependent on MAPK activation, which is mediated by golgi stress-induced golph3 upregulation. Glycomic analysis and lectin-binding assays revealed abnormal expression of mannose-rich N-type glycans in Muc6-deficient gastric tumors. Banana lectin-drug conjugates, which bind to mannose-rich glycans, dramatically suppress mannose-rich murine and human gastric cancer growth. Thus, we propose golgi stress responses and aberrant sugar chains as promising therapeutic targets in gastric cancers accompanied with mucin expression disorder.
Project description:Embryonic stem (ES) cells continuously decide whether to maintain pluripotency or differentiate. While exogenous LIF and BMP4 perpetuate a pluripotent state, less is known about factors initiating differentiation. We show that heparan sulfate (HS) proteoglycans are critical co-receptors for signals inducing ES cell differentiation. Genetic targeting of NDST1 and 2, two enzymes required for N-sulfation of proteoglycans, blocked differentiation. This phenotype was rescued by HS presented in trans or by soluble heparin. NaClO3-, which reduces sulfation of proteoglycans, potently blocked differentiation of wild type cells. Mechanistically, N-sulfation was identified to be critical for functional autocrine FGF4 signalling. Micro array analysis identified the pluripotency maintaining transcription factors Nanog, KLF2/4/8, Tbx3 and Tcf3 to be negatively regulated, whereas markers of differentiation such as Gbx2, Dnmt3b, FGF5 and Brachyury were induced by sulfation-dependent-FGFR signalling. We show that several of these genes are heterogeneously expressed in ES cells and targeting of heparan sulfation or FGFR-signalling facilitated a homogenous Nanog/KLF4/Tbx3 positive ES cell state. This finding suggests that the recently discovered heterogeneous state of ES cells is regulated by HS-dependent FGFR signalling. Similarly, culturing blastocysts with NaClO3- eliminated GATA6 positive primitive endoderm progenitors generating a homogenous Nanog positive inner cell mass. Functionally, reduction of sulfation robustly improved de novo ES cell derivation efficiency. We conclude that N-sulfated HS is required for FGF4 signalling to maintain ES cells primed for differentiation in a heterogeneous state. Inhibiting this pathway facilitates a more naïve ground state. Four groups with three biological replicates and a technical duplicate in each