Gene/Protein Disease Symptom Drug Enzyme Compound
Pivot Concepts:   Target Concepts:
Query: UMLS:C0030305 (pancreatitis)
 16,014 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

To characterize the emergency program set up by pancreatic cells in response to pancreatitis, we established the phenotype of the pancreatitis-affected pancreas by characterizing a large number of its transcripts. In this report, we describe the cloning, sequencing, and expression pattern of a new gene, named VMP1 (vacuole membrane protein 1). The VMP1 mRNA codes for a putative protein of 406 amino acids. In situ hybridization studies revealed that pancreatic expression of VMP1 mRNAs was restricted to the acinar cells. Interestingly, VMP1 mRNA was also overexpressed in kidney after transient ischemic injury. However, many healthy tissues express VMP1 mRNA. Structure analysis suggested that VMP1 is a transmembrane protein with six hydrophobic regions. VMP1/EGFP fusion protein was located to the Golgi apparatus and the endoplasmic reticulum area. Expression of this protein promoted the formation of intracytoplasmatic vacuoles and VMP1/EGFP was located to the membranes of these vacuoles. Cells overexpressing this protein died after 48 h. In conclusion, we have identified a new stress-induced gene which codes for a transmembrane protein that, when overexpressed, promotes formation of intracellular vacuoles followed by cell death.
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PMID:Cloning and expression of the rat vacuole membrane protein 1 (VMP1), a new gene activated in pancreas with acute pancreatitis, which promotes vacuole formation. 1178 47

Autophagy is a degradation process of cytoplasmic cellular constituents, which serves as a survival mechanism in starving cells, and it is characterized by sequestration of bulk cytoplasm and organelles in double-membrane vesicles called autophagosomes. Autophagy has been linked to a variety of pathological processes such as neurodegenerative diseases and tumorigenesis, which highlights its biological and medical importance. We have previously characterized the vacuole membrane protein 1 (VMP1) gene, which is highly activated in acute pancreatitis, a disease associated with morphological changes resembling autophagy. Here we show that VMP1 expression triggers autophagy in mammalian cells. VMP1 expression induces the formation of ultrastructural features of autophagy and recruitment of the microtubule-associated protein 1 light-chain 3 (LC3), which is inhibited after treatment with the autophagy inhibitor 3-methiladenine. VMP1 is induced by starvation and rapamycin treatments. Its expression is necessary for autophagy, because VMP1 small interfering RNA inhibits autophagosome formation under both autophagic stimuli. VMP1 is a transmembrane protein that co-localizes with LC3, a marker of the autophagosomes. It interacts with Beclin 1, a mammalian autophagy initiator, through the VMP1-Atg domain, which is essential for autophagosome formation. VMP1 endogenous expression co-localizes with LC3 in pancreas tissue undergoing pancreatitis-induced autophagy. Finally, VMP1 stable expression targeted to pancreas acinar cell in transgenic mice induces autophagosome formation. Our results identify VMP1 as a novel autophagy-related membrane protein involved in the initial steps of the mammalian cell autophagic process.
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PMID:The pancreatitis-induced vacuole membrane protein 1 triggers autophagy in mammalian cells. 1794 Feb 79

The Vacuole Membrane Protein 1 -VMP1- is a pancreatitis-associated transmembrane protein whose expression triggers autophagy in several human diseases. In the current study, we unveil the mechanism through which this protein induces autophagosome formation in mammalian cells. We show that VMP1 autophagy-related function requires its 20-aminoacid C-terminus hydrophilic domain (VMP1-AtgD). This is achieved through its direct binding to the BH3 motif of Beclin 1 leading to the formation of a complex with the Class III phosphatidylinositol-3 kinase (PI3K) hVps34, a key positive regulator of autophagy, at the site where autophagosomes are generated. This interaction also concomitantly promotes the dissociation of Bcl-2, an autophagy inhibitor, from Beclin 1. Moreover, we show that the VMP1-Beclin 1-hVps34 complex favors the association of Atg16L1 and LC3 with the autophagosomal membranes. Collectively, these findings reveal that VMP1 expression recruits and activates the Class III PI3K complex at the site of autophagosome formation during mammalian autophagy.
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PMID:The VMP1-Beclin 1 interaction regulates autophagy induction. 2331 80

Over a third of the US adult population has hypertriglyceridemia, resulting in an increased risk of atherosclerosis, pancreatitis, and metabolic syndrome. Lipoprotein lipase (LPL), a dimeric enzyme, is the main lipase responsible for TG clearance from the blood after food intake. LPL requires an endoplasmic reticulum (ER)-resident, transmembrane protein known as lipase maturation factor 1 (LMF1) for secretion and enzymatic activity. LMF1 is believed to act as a client specific chaperone for dimeric lipases, but the precise mechanism by which LMF1 functions is not understood. Here, we examine which domains of LMF1 contribute to dimeric lipase maturation by assessing the function of truncation variants. N-terminal truncations of LMF1 show that all the domains are necessary for LPL maturation. Fluorescence microscopy and protease protection assays confirmed that these variants were properly oriented in the ER. We measured cellular levels of LMF1 and found that it is expressed at low levels and each molecule of LMF1 promotes the maturation of 50 or more molecules of LPL. Thus we provide evidence for the critical role of the N-terminus of LMF1 for the maturation of LPL and relevant ratio of chaperone to substrate.
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PMID:Purification, cellular levels, and functional domains of lipase maturation factor 1. 2490 92

The study of autoimmunity mediated by immunoglobulin E (IgE) autoantibodies, which may be termed autoallergy, is in its infancy. It is now recognized that systemic lupus erythematosus, bullous pemphigoid (BP), and chronic urticaria, both spontaneous and inducible, are most likely to be mediated, at least in part, by IgE autoantibodies. The situation in other conditions, such as autoimmune uveitis, rheumatoid arthritis, hyperthyroid Graves' disease, autoimmune pancreatitis, and even asthma, is far less clear but evidence for autoallergy is accumulating. To be certain of an autoallergic mechanism, it is necessary to identify both IgE autoantibodies and their targets as has been done with the transmembrane protein BP180 and the intracellular protein BP230 in BP and IL-24 in chronic spontaneous urticaria. Also, IgE-targeted therapies, such as anti-IgE, must have been shown to be of benefit to patients as has been done with both of these conditions. This comprehensive review of the literature on IgE-mediated autoallergy focuses on three related questions. What do we know about the prevalence of IgE autoantibodies and their targets in different diseases? What do we know about the relevance of IgE autoantibodies in different diseases? What do we know about the cellular and molecular effects of IgE autoantibodies? In addition to providing answers to these questions, based on a broad review of the literature, we outline the current gaps of knowledge in our understanding of IgE autoantibodies and describe approaches to address them.
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PMID:Immunoglobulin E-Mediated Autoimmunity. 2968 78