The role of the mitochondria and the endoplasmic reticulum contact sites in the development of the immune responses

Abstract Mitochondria and endoplasmic reticulum (ER) contact sites (MERCs) are dynamic modules enriched in subset of lipids and specialized proteins that determine their structure and functions. The MERCs regulate lipid transfer, autophagosome formation, mitochondrial fission, Ca2+ homeostasis and apoptosis. Since these functions are essential for cell biology, it is therefore not surprising that MERCs also play a critical role in organ physiology among which the immune system stands by its critical host defense function. This defense system must discriminate and tolerate host cells and beneficial commensal microorganisms while eliminating pathogenic ones in order to preserve normal homeostasis. To meet this goal, the immune system has two lines of defense. First, the fast acting but unspecific innate immune system relies on anatomical physical barriers and subsets of hematopoietically derived cells expressing germline-encoded receptors called pattern recognition receptors (PRR) recognizing conserved motifs on the pathogens. Second, the slower but very specific adaptive immune response is added to complement innate immunity. Adaptive immunity relies on another set of specialized cells, the lymphocytes, harboring receptors requiring somatic recombination to be expressed. Both innate and adaptive immune cells must be activated to phagocytose and process pathogens, migrate, proliferate, release soluble factors and destroy infected cells. Some of these functions are strongly dependent on lipid transfer, autophagosome formation, mitochondrial fission, and Ca2+ flux; this indicates that MERCs could regulate immunity

Guidelines for the use and interpretation of assays for monitoring autophagy (4th edition)1.

In 2008, we published the first set of guidelines for standardizing research in autophagy. Since then, this topic has received increasing attention, and many scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Thus, it is important to formulate on a regular basis updated guidelines for monitoring autophagy in different organisms. Despite numerous reviews, there continues to be confusion regarding acceptable methods to evaluate autophagy, especially in multicellular eukaryotes. Here, we present a set of guidelines for investigators to select and interpret methods to examine autophagy and related processes, and for reviewers to provide realistic and reasonable critiques of reports that are focused on these processes. These guidelines are not meant to be a dogmatic set of rules, because the appropriateness of any assay largely depends on the question being asked and the system being used. Moreover, no individual assay is perfect for every situation, calling for the use of multiple techniques to properly monitor autophagy in each experimental setting. Finally, several core components of the autophagy machinery have been implicated in distinct autophagic processes (canonical and noncanonical autophagy), implying that genetic approaches to block autophagy should rely on targeting two or more autophagy-related genes that ideally participate in distinct steps of the pathway. Along similar lines, because multiple proteins involved in autophagy also regulate other cellular pathways including apoptosis, not all of them can be used as a specific marker for bona fide autophagic responses. Here, we critically discuss current methods of assessing autophagy and the information they can, or cannot, provide. Our ultimate goal is to encourage intellectual and technical innovation in the field

Identification of nuclear factor-kappa B sites in the Slc2a4 gene promoter

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Glucose transporter GLUT4 protein, codified by Slc2a4 gene plays a key role in glycemic homeostasis. Insulin resistance, as in obesity, has been associated to inflammatory state, in which decreased GLUT4 is a feature. Inflammatory NF-kappa B transcriptional factor has been proposed as a repressor of Slc2a4; although, the binding site(s) in Slc2a4 promoter and the direct repressor effect have never been reported yet. A motif-based sequence analysis of mouse Slc2a4 promoter revealed two putative kappa B sites located inside -83/-62 and -134/-113 bp. Eletrophoretic mobility assay showed that p50 and p65 NF-kappa B subunits bind to both putative kappa B sites. Chromatin immunoprecipitation assay using genomic DNA from adipocytes confirmed p50- and p65-binding to Slc2a4 promoter. Moreover, transfection experiments revealed that NF-kappa B binds to the -134/-113 bp region of the mouse Slc2a4 gene promoter, inhibiting the Slc2a4 gene transcription. The current findings demonstrate the existence of two kappa B sites in Slc2a4 gene promote, and that NF-kappa B has a direct repressor effect upon the Slc2a4 gene, providing an important link between insulin resistance and inflammation. (C) 2013 Elsevier Ireland Ltd. All rights reserved.370416718795Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)FAPESP [07/50554-1, 08/09194-4, 11/08570-5

An overview of viral oncology in Italy - report from the Pavia meeting on solid tumors

<p>Abstract</p> <p>This is a report on some of the research activities currently ongoing in Italy as outlined at the “Viruses and solid tumors” meeting jointly organized by the Oncology Sections of IRCCS Policlinico “San Matteo” (Pavia) and IRCCS National Cancer Institute (Aviano), held in Pavia, Italy, on October 2011. Experts from the various disciplines involved in the study of the complex relationships between solid tumors and viruses met to discuss recent developments in the field and to report their personal contributions to the specified topics. Secondary end point was to establish a multidisciplinary work group specifically devoted to solid tumors and infectious agents, aimed to identify areas of common interest, promoting and establishing collaborative projects and programs, and to coordinate clinical and research activities. The group, which will be named IVOG (Italian Viral Oncology Group), will operate under the patronage of the various scientific societies of interest.</p