Project description:Although ADAMTS-4 and ADAMTS-5 are the principal aggrecanases in mice and humans, mice lacking both these enzymes (ADAMTS-4/-5Dcat) are healthy, viable, with no overt skeletal phenotype, suggesting the presence of an alternative aggrecanase in these mice. We previously identified a novel aggrecanase activity that was regulated by retinoic acid, but not IL-1a. The upregulated activity cleaved aggrecan at E↓A bonds. This study aimed to identify the alternative aggrecanase. Femoral head cartilage from TS-4/5Dcat mice was stimulated with IL-1a or retinoic acid and total RNA was analysed by microarray. Candidate, upregulated genes identified by Quantile Normalisation included ADAMTS, MMPm cathepsin and calpain families as putative aggrecanases. Three criteria, including quantitative RT-PCR analyses, sensitivity to retinoic acid treatment and sensitivity to TIMP-3 inhibition, were then used as readouts to identify candidate extracellular proteinases whose mRNA expression levels were increased by retinoic acid, but not by IL-1a treatment. Thereafter, gene silencing was used to identify the most likely aggrecanase in chondrocytes from TS-4/5Dcat mice. Aggrecanase activity was monitored by Western blotting and immunohistochemistry with neoepitope antibodies. The microarray analyses identified ADAMTS-9, MMP-11 and calpain-5 as candidate aggrecanases that were upregulated by retinoic acid. While qPCR confirmed this finding, calpain 5 was excluded from the candidate list because it was not inhibited by TIMP-3. MMP-11 was also excluded because it was upregulated by IL-1a. ADAMTS-9 therefore emerged as a candidate for the novel aggrecanase. Gene silencing confirmed ADAMTS-9 as the putative aggrecanase. Immunohistochemistry revealed that ADAMTS-9 in mouse knee joints was expressed in the proliferative zone of both wildtype and TS-4/5Dcat growth plates, and also in the calcified cartilage of the wildtype hypertrophic zone. In conclusion, ADAMTS-9 is an aggrecanase that cleaves at FREEE1467↓1468GLGS in the chondroitin sulphate-rich region of aggrecan.
Project description:Insulin degrading enzyme (IDE) is a major enzyme responsible for insulin degradation in the liver. The modulation of insulin degrading enzyme activity is hypothesized to be a link between T2DM and liver cancer. Results provide insight into role of IDE in proliferation and other cell functions.
Project description:Insulin-degrading enzyme (IDE) is a protein with proteolytic and non-proteolytic functions that regulates primary cilium.We hypothesize that IDE deficiency alter expression of genes involved in the formation of the primary cilium . To test this hypothesis we performed microarray studies in mouse alphaTC1.9 cells with a partial deficiency of IDE gene. Results show that IDE knocdown led to regulation of genes involved in cellular functions related to primary cilium. We used microarrays to explore whether expression of genes related to cilliogenesis is affected by reduced expression of IDE gene in alpha pancreatic cells
Project description:Insulin degrading enzyme (IDE) is a major enzyme responsible for insulin degradation in the liver. The modulation of insulin degrading enzyme activity is hypothesized to be a link between T2DM and liver cancer. Results provide insight into role of IDE in proliferation and other cell functions. HepG2 cells were transfected with 96nM siRNA for IDE or AllStars Negative Control siRNA (Qiagen) using Lipofectamine 2000 (Invitrogen). 16 h after transfection, cells were treated with 10 nM insulin (Sigma Aldrich) or vehicle for 24 h in serum starvation condition. Total RNA was extracted. For each of the 4 conditions, 3 biological replicates were included.
Project description:Insulin-degrading enzyme (IDE) is a protein with proteolytic and non-proteolytic functions that regulates glucose homeostasis.We hypothesize that IDE deficiency alters glucagon signaling and thereby gluconeogenesis. To test this hypothesis we performed microarray studies in HepG2 cells with a complete deficiency of IDE gene. Results show that IDE deficiency led to upregulation of genes involved in cellular functions related to membranes, organelles and signaling receptors. We used microarrays to find genes whose expression is affected by the absence of IDE gene expression in hetapome human cells
Project description:Insulin-degrading enzyme is a zinc metallo protease degrading low molecular weight substrates including insulin. Ubiquitous expression, high evolutionary conservation, upregulation of Ide in stress situations, and literature findings suggest a broader function of Ide in cell physiology and protein homeostasis that remains to be elucidated. We used proteomics and transcriptomics approaches searching for leads related to a broader role of Ide in protein homeostasis. We combined an analysis of the proteome and single-cell transcriptome of Ide+/+ and Ide-/- pancreatic islet cells with an examination of the interactome of human cytosolic Ide using proximity biotinylation. We observe an upregulation of pathways related to RNA processing, translation and splicing in Ide+/+ relative to Ide-/- islet cells. Corroborating these results and providing a potential mechanistic explanation, proximity biotinylation reveals interaction of Ide with several subunits of CCR4-NOT, a key mRNA deadenylase regulating gene expression "from birth to death". We propose a speculative model in which human and murine Ide and CCR4-NOT cooperate to control protein expression in proteotoxic and metabolic stress situations through cooperation between their deadenylase and protease functions.
Project description:RATIONALE: Shark cartilage extract may help shrink or slow the growth of colorectal cancer or breast cancer cells.
PURPOSE: Randomized phase III trial to determine the effectiveness of shark cartilage in treating patients who have advanced colorectal cancer or advanced breast cancer.