To study gene expression differences in various dermal equivalents prepared by the individual's laboratory
Ontology highlight
ABSTRACT: We have prepared tissue engineered self assembled dermal equivalents with high similarity to the human dermis (skin). We have manipulated the culture conditions to prepare dermal equivalents with varying amounts of hyaluronic acid and potentially other glycosaminoglycans (GAGs). We are interested in using array technology to determine which genes responsible for carbohydrate and GAG (and if available protein/glycoprotein) synthesis are being either up-or down-regulated in these constructs as compared to a Normal base construct.
Project description:Cutaneous lupus erythematosus (CLE) is an autoimmune disease that localizes to the skin and is known to contain elevated glycosaminoglycans (GAGs) on Hale’s stain of skin biopsy specimens. Recently, different GAG species have been shown to have distinct effects on the recruitment and activation of immune cells and stimulation of cytokine production (Taylor and Gallo, FASEB, 2006; 20: 9-22). Thus, we speculate that the elevated GAGs observed in CLE play a role in the local inflammatory process that produces skin lesions in these patients. In order to further investigate a molecular basis for the elevated expression of these GAGs in CLE skin lesions, we would like to determine the gene expression profiles of GAG synthesis, degradation, and modifier genes in lesional and non-lesional skin samples from CLE patients and compare to those from healthy controls. A microarray approach will give us a broader understanding of the genetic regulation of the expression of various GAG species in CLE skin. We will then be able to target future quantitative gene expression experiments by real-time RT-PCR to the genes that are shown to be involved in CLE. In order to accomplish our goal, we would like to examine the GAG gene expression profiles of DLE, TLE, and SCLE subtypes due to the differences in CS and HA staining that we found among these subtypes. Since HA and CS are elevated in DLE and HA in TLE, but not in SCLE, the SCLE samples will also serve as an internal control. We would like to examine both lesional and non-lesional skin biopsies to determine if CLE skin prior to developing a lesion is different at the genetic level from healthy control skin and how it changes once a lesion does develop. We will separate the dermis from the epidermis of the skin biopsies and extract RNA just from the dermis to enrich for dermal fibroblast RNA. We aim to submit four patient biopsies per subtype as well as four samples from healthy control skin for comparison. This number is necessary in order to account for the biologic variability among different patients. We would submit more samples per subtype but are limited by availability of patients in clinic. Thus, we will have a total of 28 samples to submit for microarray. This study design will allow us to analyze the GAG gene expression profiles among different CLE subtypes and enable us to identify which GAc
Project description:UV irradiation is a major environmental effector of skin damage and aging. Elevated levels of glycosaminoglycans (GAGs), as measured by Hale’s stain, are seen following cutaneous photodamage. Preliminary data from our lab indicates that this is a complex response involving differential regulation of both GAGs and proteoglycans. Recently, different GAG species have been shown to have distinct effects on the recruitment and activation of immune cells and stimulation of cytokine production (Taylor and Gallo, FASEB, 2006; 20: 9-22). We speculate that the elevated GAGs and proteoglycans observed after ultraviolet B (UVB) irradiation are involved in the inflammatory and healing responses to photodamage.
Project description:The degradation of glycosaminoglycans (GAGs) by intestinal bacteria is critical for their colonization in the human gut and the health of the host. Both Bacteroides and Firmicutes have been reported to degrade GAGs, while the enzymatic details of the latter remain largely unknown. In this study, we isolated a Firmicutes strain, Hungatella hathewayi N2-326, that can catabolize various GAGs. While H. hathewayi N2-326 was less efficient in utilizing chondroitin sulfate A (CSA) and dermatan sulfate (DS) than Bacteroides thetaiotaomicron, a characterized GAG degrader, it outperformed B. thetaiotaomicron in assimilating hyaluronic acid. Unlike B. thetaiotaomicron, H. hathewayi N2-326 could not utilize heparin. The chondroitin lyase activity of H. hathewayi N2-326 was found to be induced by CSA and displayed both cell-associated and extracellular distributions. We further identified and characterized the first chondroitin ABC lyase from Firmicutes. The recombinant H. hathewayi chondroitin ABC lyase was found to be a predominantly exolyase and exhibited higher specific activity than any other characterized chondroitin ABC lyase. Thus, the HH-chondroitin ABC lyase offers a viable commercial option for the production of chondroitin, dermatan, and hyaluronan oligosaccharides and potential medical applications.
Project description:Cutaneous lupus erythematosus (CLE) is an autoimmune disease that localizes to the skin and is known to contain elevated glycosaminoglycans (GAGs) on Hale’s stain of skin biopsy specimens. Recently, different GAG species have been shown to have distinct effects on the recruitment and activation of immune cells and stimulation of cytokine production (Taylor and Gallo, FASEB, 2006; 20: 9-22). Thus, we speculate that the elevated GAGs observed in CLE play a role in the local inflammatory process that produces skin lesions in these patients.
Project description:UV irradiation is a major environmental effector of skin damage and aging. Elevated levels of glycosaminoglycans (GAGs), as measured by Hale’s stain, are seen following cutaneous photodamage. Preliminary data from our lab indicates that this is a complex response involving differential regulation of both GAGs and proteoglycans. Recently, different GAG species have been shown to have distinct effects on the recruitment and activation of immune cells and stimulation of cytokine production (Taylor and Gallo, FASEB, 2006; 20: 9-22). We speculate that the elevated GAGs and proteoglycans observed after ultraviolet B (UVB) irradiation are involved in the inflammatory and healing responses to photodamage. Chondroitin sulfate synthases (CSSs) are not increased by UVB in mice or in cultured human fibroblasts. To determine whether genomic upregulation of CSSs is responsible for the post-UVB CS increase, we measured the dermal expression of CSS1 and CSS3 mRNA in C57Bl6 mice after 5 days of UV-B exposure. Irradiation caused no change in either CSS1 or CSS3 mRNA expression. We also studied CSS RNA expression in cultured human fibroblasts. We compared control cells to cells treated with 30 mJ/cm2 UVB, cells treated with 1 ng/mL IL-1α, and cells co-stimulated with UVB and IL-1α. In vivo, UV-B induces IL-1α production by keratinocytes and inflammatory cells, and this IL-1α interacts with fibroblasts. Co-stimulation with IL-1α + UVB induces TNF-α production by the fibroblasts, mirroring the in vivo interaction. CSS1 mRNA was suppressed 60% and CSS3 mRNA expression dropped 87% relative to sham at 24 hours post-treatment (p<0.001, Dunnet q’). Since CS is not upregulated by its synthases, we postulated an alternative mode of induction whereby one or more CS proteoglycans are transcriptionally increased and bind more CS in the dermis. We used the N-13 goat monoclonal anti-serglycin antibody to visualize changes in cutaneous serglycin content following acute UV-B exposure. Serglycin is one example of CS-binding dermal proteoglycans that is induced by UVB, and there are likely others. Diffuse upper-dermal serglycin staining, like upper-dermal CS, was induced continuously at 24, 48, and 72 hours after irradiation. Serglycin-expressing inflammatory cells are recruited to the dermis following irradiation, peaking at 48 hours post-exposure. A statistically significant 1.70 fold increase in serglycin mRNA was measured in cultured human fibroblasts 6 hours after co-stimulation with UVB and IL-1α. Realtime PCR also revealed a significant 2.04 fold upregulation at 24 hours after co-stimulation, and serglycin was increased 4.63 times 6 hours after Il-1α treatment alone.
Project description:Here we report a simple and versatile approach for domain mapping of complex mixtures of glycosaminoglycans (GAGs), GAGDoMa. The approach is based on orthogonal enzymatic depolymerization of the GAGs, generating internal oligosaccharide, non-reducing end, and linkage region GAG domains, nanoflow reversed-phase dibutylamine ion-pairing chromatography and negative mode higher-energy collision dissociation (HCD) MS/MS. GAGDoMa provides a detailed insight into the GAGome, and will be an important tool for the understanding of GAGs in cellular physiology and pathology.
Project description:Mucopolysaccharidosis type I (MPS I) is caused by genetic defects in alpha-L-iduronidase (IDUA), a lysosomal enzyme involved in the breakdown and recycling of glycosaminoglycans (GAGs). Although an enzyme replacement therapy is available, the efficacy for the treatment of neuropathic symptoms is limited. To facilitate drug discovery and model disease pathophysiology, we have generated neural stem cells (NSCs) from MPS I patient-derived iPSCs. NSCs exhibited characteristic disease phenotypes with deficiency of alpha-L-iduronidase (IDUA), accumulation of glycosaminoglycans (GAGs) and enlargement of lysosomes, correlating with the severity of clinical symptoms. Transcriptome profiling of NSCs revealed differential expression of 429 genes that changed more extensively in the more severe Hurler syndrome subgroup compared to the Hurler-Scheie (median severe) and Scheie (less severe) subgroups. Clustering and pathway analyses demonstrated high concordance of the severity of neurological defects with marked dysregulation of GAG biosynthesis and degradation, lysosomal function and extracellular matrix. Gene Ontology (GO) analysis identified a dramatic upregulation of autophagy pathway, especially in the Hurler syndrome. Thus, GAG accumulation in the patient cells disrupts lysosomal homeostasis affecting multiple related cellular pathways which compensates for IDUA deficiency. These dysregulated process likely lead to enhanced autophagy and more severe disease states. Our studies provide useful tools for clinical biomarker development and potential targets for drug development.
Project description:Lipids are essential components of cancer cells due to their structural and signaling roles. To meet metabolic demands, many cancers take up extracellular lipids; however, how these lipids contribute to cancer growth and progression remains poorly understood. Here, using functional genetic screens, we identify lipoprotein uptake—the primary mechanism for lipid transport in circulation—as a key determinant of ferroptosis sensitivity in cancer. Lipoprotein supplementation robustly inhibits ferroptosis across diverse cancer types, primarily through the delivery of α-tocopherol (α-toc), the most abundant form of vitamin E in human lipoproteins. Mechanistically, cancer cells take up lipoproteins through a pathway dependent on sulfated glycosaminoglycans (GAGs) linked to cell-surface proteoglycans. Disrupting GAG biosynthesis or acutely degrading surface GAGs reduces lipoprotein uptake, sensitizes cancer cells to ferroptosis, and impairs tumour growth in mice. Notably, human clear cell renal cell carcinomas, a lipid-rich malignancy, exhibit elevated levels of chondroitin sulfate and increased lipoprotein-derived α-toc compared to normal kidney tissue. Altogether, our work establishes lipoprotein uptake as a critical anti-ferroptotic mechanism in cancer and implicates GAG biosynthesis as a therapeutic target.
Project description:Osteoarthritis (OA) affects nearly 500 million people worldwide and is characterized by an irreversible loss of glycosaminoglycans (GAGs) at articular cartilage surfaces. Despite advances, preserving cartilage GAGs and controlling their turnover in living cells remain challenging. Based on the hypothesis that GAGs can interact with cationic molecules, we demonstrated a cost-effective strategy to increase human cartilage GAGs using a molecular machine hexadimethrine bromide (HDMBr). HDMBr promoted stem cell chondrogenesis by attracting pericellular GAGs and upregulating vesicle formation, leading to increased matrix secretion. To determine how HDMBr influenced cellular protein expression, we performed proteomics by mass spectrometry on cultured human mesenchymal stem cells. Based on the results, HDMBr induced widespread proteomic changes and might stimulate intracellular GAG metabolism, intracellular trafficking, and GAG secretion. The proteomics data were also consistent with the evaluation of HDMBr in two animal models. In a rabbit model of large cartilage defects, HDMBr promoted the intrinsic regeneration of GAG-rich hyaline-like cartilage and improved tissue integration. In a rat OA model, low-dose HDMBr treatment increased cartilage thickness, supported cartilage matrix homeostasis, and improved the efficiency of cell-based therapy, evidently slowing OA progression compared to other tested clinical treatments. Overall, this study introduces a cost-effective GAG manipulation approach to cartilage repair and joint preservation, offering new insights into the mechanisms of cell-material interactions.