Author
Lelio Orci
Other affiliations: University Medical Center, Geneva College, University of Dundee ...read more
Bio: Lelio Orci is an academic researcher from University of Geneva. The author has contributed to research in topics: Golgi apparatus & Insulin. The author has an hindex of 128, co-authored 495 publications receiving 57552 citations. Previous affiliations of Lelio Orci include University Medical Center & Geneva College.
Topics: Golgi apparatus, Insulin, Glucagon, Vesicle, Pancreas
Papers published on a yearly basis
Papers
More filters
••
TL;DR: In vitro synthesis of endoplasmic reticulum-derived transport vesicles has been reconstituted with washed membranes and three soluble proteins and it is proposed that the coat structures be called COPI and COPII.
1,277 citations
••
TL;DR: Cardiac dysfunction in obesity is caused by lipoapoptosis and is prevented by reducing cardiac lipids and Troglitazone therapy lowered myocardial TG and ceramide and completely prevented DNA laddering and loss of cardiac function.
Abstract: To determine the mechanism of the cardiac dilatation and reduced contractility of obese Zucker Diabetic Fatty rats, myocardial triacylglycerol (TG) was assayed chemically and morphologically. TG was high because of underexpression of fatty acid oxidative enzymes and their transcription factor, peroxisome proliferator-activated receptor-α. Levels of ceramide, a mediator of apoptosis, were 2–3 times those of controls and inducible nitric oxide synthase levels were 4 times greater than normal. Myocardial DNA laddering, an index of apoptosis, reached 20 times the normal level. Troglitazone therapy lowered myocardial TG and ceramide and completely prevented DNA laddering and loss of cardiac function. In this paper, we conclude that cardiac dysfunction in obesity is caused by lipoapoptosis and is prevented by reducing cardiac lipids.
1,247 citations
••
TL;DR: An immunocytochemical technique for the demonstration of intracellular antigens (secretory proteins) on thin sections is reported and the protein A-gold technique is proposed as a general method for visualization of antigenic sites onthin sections.
Abstract: An immunocytochemical technique for the demonstration of intracellular antigens (secretory proteins) on thin sections is reported. Staphylococcal protein A which reacts with the Fc fragment of IgG molecules was labeled with colloidal gold as a marker. The antigenic sites were visualized on aldehyde-fixed and Epon-embedded tissue in a two step procedure. The specific antisera were applied to thin sections for binding to the antigens and then visualized by the protein A-gold complex. By using this technique different secretory proteins of the exocrine and endocrine pancreas were localized. The protein A-gold technique is proposed as a general method for visualization of antigenic sites on thin sections.
987 citations
••
TL;DR: The trafficking of proteins within eukaryotic cells is achieved by the capture of cargo and targeting molecules into vesicles that bud from a donor membrane and deliver their contents to a receiving compartment.
Abstract: The trafficking of proteins within eukaryotic cells is achieved by the capture of cargo and targeting molecules into vesicles that bud from a donor membrane and deliver their contents to a receiving compartment. This process is bidirectional and may involve multiple organelles within a cell. Distinct coat proteins mediate each budding event, serving both to shape the transport vesicle and to select by direct or indirect interaction the desired set of cargo molecules. Secretion, which has been viewed as a default pathway, may require sorting and packaging signals on transported molecules to ensure their rapid delivery to the cell surface.
974 citations
••
TL;DR: It is demonstrated that VEGF‐C‐induced lymphangiogenesis mediates tumour cell dissemination and the formation of lymph node metastases.
Abstract: Metastasis is a frequent and lethal complication of cancer. Vascular endothelial growth factor-C (VEGF-C) is a recently described lymphangiogenic factor. Increased expression of VEGF-C in primary tumours correlates with dissemination of tumour cells to regional lymph nodes. However, a direct role for VEGF-C in tumour lymphangiogenesis and subsequent metastasis has yet to be demonstrated. Here we report the establishment of transgenic mice in which VEGF-C expression, driven by the rat insulin promoter (Rip), is targeted to beta-cells of the endocrine pancreas. In contrast to wild-type mice, which lack peri-insular lymphatics, RipVEGF-C transgenics develop an extensive network of lymphatics around the islets of Langerhans. These mice were crossed with Rip1Tag2 mice, which develop pancreatic beta-cell tumours that are neither lymphangiogenic nor metastatic. Double-transgenic mice formed tumours surrounded by well developed lymphatics, which frequently contained tumour cell masses of beta-cell origin. These mice frequently developed pancreatic lymph node metastases. Our findings demonstrate that VEGF-C-induced lymphangiogenesis mediates tumour cell dissemination and the formation of lymph node metastases.
942 citations
Cited by
More filters
••
TL;DR: A new aspect of cell membrane structure is presented, based on the dynamic clustering of sphingolipids and cholesterol to form rafts that move within the fluid bilayer that function as platforms for the attachment of proteins when membranes are moved around inside the cell and during signal transduction.
Abstract: A new aspect of cell membrane structure is presented, based on the dynamic clustering of sphingolipids and cholesterol to form rafts that move within the fluid bilayer. It is proposed that these rafts function as platforms for the attachment of proteins when membranes are moved around inside the cell and during signal transduction.
9,436 citations
••
TL;DR: It is suggested that EC progenitors may be useful for augmenting collateral vessel growth to ischemic tissues (therapeutic angiogenesis) and for delivering anti- or pro-angiogenic agents, respectively, to sites of pathologic or utilitarianAngiogenesis.
Abstract: Putative endothelial cell (EC) progenitors or angioblasts were isolated from human peripheral blood by magnetic bead selection on the basis of cell surface antigen expression In vitro, these cells differentiated into ECs In animal models of ischemia, heterologous, homologous, and autologous EC progenitors incorporated into sites of active angiogenesis These findings suggest that EC progenitors may be useful for augmenting collateral vessel growth to ischemic tissues (therapeutic angiogenesis) and for delivering anti- or pro-angiogenic agents, respectively, to sites of pathologic or utilitarian angiogenesis
8,598 citations
••
TL;DR: The work from the authors' laboratories reviewed herein was supported by grants from the National Cancer Institute.
6,895 citations
••
TL;DR: The approach was to apply the techniques of cell culture to unravel the postulated regulatory defect in FH, which led to the discovery of a cell surface receptor for a plasma cholesterol transport protein called low density lipoprotein (LDL) and to the elucidation of the mechanism by which this receptor mediates feedback control of cholesterol synthesis.
Abstract: In 1901 a physician, Archibald Garrod, observed a patient with black urine. He used this simple observation to demonstrate that a single mutant gene can produce a discrete block in a biochemical pathway, which he called an “inborn error of metabolism”. Garrod’s brilliant insight anticipated by 40 years the one gene-one enzyme concept of Beadle and Tatum. In similar fashion the chemist Linus Pauling and the biochemist Vernon Ingram, through study of patients with sickle cell anemia, showed that mutant genes alter the amino acid sequences of proteins. Clearly, many fundamental advances in biology were spawned by perceptive studies of human genetic diseases (1). We began our work in 1972 in an attempt to understand a human genetic disease, familial hypercholesterolemia or FH. In these patients the concentration of cholesterol in blood is elevated many fold above normal and heart attacks occur early in life. We postulated that this dominantly inherited disease results from a failure of end-product repression of cholesterol synthesis. The possibility fascinated us because genetic defects in feedback regulation had not been observed previously in humans or animals, and we hoped that study of this disease might throw light on fundamental regulatory mechanisms. Our approach was to apply the techniques of cell culture to unravel the postulated regulatory defect in FH. These studies led to the discovery of a cell surface receptor for a plasma cholesterol transport protein called low density lipoprotein (LDL) and to the elucidation of the mechanism by which this receptor mediates feedback control of cholesterol synthesis (2,3). FH was shown to be caused by inherited defects in the gene encoding the LDL receptor, which disrupt the normal control of cholesterol metabolism. Study of the LDL receptor in turn led to the understanding of receptor-mediated endocytosis, a genera! process by which cells communicate with each other through internalization of regulatory and nutritional molecules (4). Receptor-mediated endocytosis differs from previously described biochemical pathways because it depends upon the continuous and highly controlled movement of membraneembedded proteins from one cell organelle to another in a process termed
5,488 citations
••
TL;DR: The primary goals of the treatment of wounds are rapid wound closure and a functional and aesthetically satisfactory scar.
Abstract: The primary function of the skin is to serve as a protective barrier against the environment. Loss of the integrity of large portions of the skin as a result of injury or illness may lead to major disability or even death. Every year in the United States more than 1.25 million people have burns1 and 6.5 million have chronic skin ulcers caused by pressure, venous stasis, or diabetes mellitus.2 The primary goals of the treatment of wounds are rapid wound closure and a functional and aesthetically satisfactory scar. Recent advances in cellular and molecular biology have greatly expanded our understanding . . .
5,462 citations