Reproducible science requires transparent reporting. The ARRIVE guidelines (Animal Research: Reporting of In Vivo Experiments) were originally developed in 2010 to improve the reporting of animal ...research. They consist of a checklist of information to include in publications describing in vivo experiments to enable others to scrutinise the work adequately, evaluate its methodological rigour, and reproduce the methods and results. Despite considerable levels of endorsement by funders and journals over the years, adherence to the guidelines has been inconsistent, and the anticipated improvements in the quality of reporting in animal research publications have not been achieved. Here, we introduce ARRIVE 2.0. The guidelines have been updated and information reorganised to facilitate their use in practice. We used a Delphi exercise to prioritise and divide the items of the guidelines into 2 sets, the "ARRIVE Essential 10," which constitutes the minimum requirement, and the "Recommended Set," which describes the research context. This division facilitates improved reporting of animal research by supporting a stepwise approach to implementation. This helps journal editors and reviewers verify that the most important items are being reported in manuscripts. We have also developed the accompanying Explanation and Elaboration (E&E) document, which serves (1) to explain the rationale behind each item in the guidelines, (2) to clarify key concepts, and (3) to provide illustrative examples. We aim, through these changes, to help ensure that researchers, reviewers, and journal editors are better equipped to improve the rigour and transparency of the scientific process and thus reproducibility.
Celotno besedilo
Dostopno za:
DOBA, IZUM, KILJ, NUK, PILJ, PNG, SAZU, SIK, UILJ, UKNU, UL, UM, UPUK
Ca2+ signalling is perhaps the most universal and versatile mechanism regulating a wide range of cellular processes. Because of the many different calcium‐binding proteins distributed throughout ...cells, signalling precision requires localized rises in the cytosolic Ca2+ concentration. In electrically non‐excitable cells, for example epithelial cells, this is achieved by primary release of Ca2+ from the endoplasmic reticulum via Ca2+ release channels placed close to the physiological target. Because any rise in the cytosolic Ca2+ concentration activates Ca2+ extrusion, and in order for cells not to run out of Ca2+, there is a need for compensatory Ca2+ uptake from the extracellular fluid. This Ca2+ uptake occurs through a process known as store‐operated Ca2+ entry. Ideally Ca2+ entering the cell should not diffuse to the target site through the cytosol, as this would potentially activate undesirable processes. Ca2+ tunnelling through the lumen of the endoplasmic reticulum is a mechanism for delivering Ca2+ entering via store‐operated Ca2+ channels to specific target sites, and this process has been described in considerable detail in pancreatic acinar cells and oocytes. Here we review the most important evidence and present a generalized concept.
The figure illustrates the principle by which Ca2+ tunnelling through the lumen of the endoplasmic reticulum (ER) can deliver Ca2+ entering through store‐operated Ca2+ channels (Orai1) to a site remote from the entry site, thereby activating a specific physiological process (Ca2+‐sensitive Cl− channels (ANO1)) via release through IP3 receptors (IP3R) placed close to the target. The primary step is Ca2+ release from the ER via IP3R caused by agonist stimulation, which generates IP3 (not shown in the figure). This causes a reduction in the Ca2+ concentration in the ER lumen, which triggers translocation of STIM1 molecules in the ER membrane, so that they come very close to Ca2+ entry channels and activate these. Ca2+ entering through the Orai1 channels is immediately taken up into the ER by powerful Ca2+ pumps (SERCA) and move with relative ease through the ER lumen by simple diffusion. The mobility of Ca2+ in the ER lumen is significantly higher than in the cytosol due to the much lower Ca2+ binding capacity.
Calcium and ATP control multiple vital functions Petersen, Ole H.; Verkhratsky, Alexei
Philosophical transactions of the Royal Society of London. Series B. Biological sciences,
08/2016, Letnik:
371, Številka:
1700
Journal Article
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Life on Planet Earth, as we know it, revolves around adenosine triphosphate (ATP) as a universal energy storing molecule. The metabolism of ATP requires a low cytosolic Ca2+ concentration, and hence ...tethers these two molecules together. The exceedingly low cytosolic Ca2+ concentration (which in all life forms is kept around 50–100 nM) forms the basis for a universal intracellular signalling system in which Ca2+ acts as a second messenger. Maintenance of transmembrane Ca2+ gradients, in turn, requires ATP-dependent Ca2+ transport, thus further emphasizing the inseparable links between these two substances. Ca2+ signalling controls the most fundamental processes in the living organism, from heartbeat and neurotransmission to cell energetics and secretion. The versatility and plasticity of Ca2+ signalling relies on cell specific Ca2+ signalling toolkits, remodelling of which underlies adaptive cellular responses. Alterations of these Ca2+ signalling toolkits lead to aberrant Ca2+ signalling which is fundamental for the pathophysiology of numerous diseases from acute pancreatitis to neurodegeneration. This paper introduces a theme issue on this topic, which arose from a Royal Society Theo Murphy scientific meeting held in March 2016.
This article is part of the themed issue ‘Evolution brings Ca2+ and ATP together to control life and death’.
This review deals with the roles of calcium ions and ATP in the control of the normal functions of the different cell types in the exocrine pancreas as well as the roles of these molecules in the ...pathophysiology of acute pancreatitis. Repetitive rises in the local cytosolic calcium ion concentration in the apical part of the acinar cells not only activate exocytosis but also, via an increase in the intramitochondrial calcium ion concentration, stimulate the ATP formation that is needed to fuel the energy-requiring secretion process. However, intracellular calcium overload, resulting in a global sustained elevation of the cytosolic calcium ion concentration, has the opposite effect of decreasing mitochondrial ATP production, and this initiates processes that lead to necrosis. In the last few years it has become possible to image calcium signaling events simultaneously in acinar, stellate, and immune cells in intact lobules of the exocrine pancreas. This has disclosed processes by which these cells interact with each other, particularly in relation to the initiation and development of acute pancreatitis. By unraveling the molecular mechanisms underlying this disease, several promising therapeutic intervention sites have been identified. This provides hope that we may soon be able to effectively treat this often fatal disease.
Acute pancreatitis is a human disease in which the pancreatic pro‐enzymes, packaged into the zymogen granules of acinar cells, become activated and cause autodigestion. The main causes of ...pancreatitis are alcohol abuse and biliary disease. A considerable body of evidence indicates that the primary event initiating the disease process is the excessive release of Ca2+ from intracellular stores, followed by excessive entry of Ca2+ from the interstitial fluid. However, Ca2+ release and subsequent entry are also precisely the processes that control the physiological secretion of digestive enzymes in response to stimulation via the vagal nerve or the hormone cholecystokinin. The spatial and temporal Ca2+ signal patterns in physiology and pathology, as well as the contributions from different organelles in the different situations, are therefore critical issues. There has recently been significant progress in our understanding of both physiological stimulus–secretion coupling and the pathophysiology of acute pancreatitis. Very recently, a promising potential therapeutic development has occurred with the demonstration that the blockade of Ca2+ release‐activated Ca2+ currents in pancreatic acinar cells offers remarkable protection against Ca2+ overload, intracellular protease activation and necrosis evoked by a combination of alcohol and fatty acids, which is a major trigger of acute pancreatitis.
Cytosolic Ca2+ signals are crucial for the control of fluid and enzyme secretion from exocrine glands. The highly polarized exocrine acinar cells have evolved sophisticated and complex Ca2+ signaling ...mechanisms that exercise precise control of the secretory events occurring across the apical plasma membrane bordering the gland lumen. Ca2+ stores in the endoplasmic reticulum, the secretory granules, the lysosomes, and the endosomes all play important roles in the generation of the local apical Ca2+ spikes that switch on Cl(-) channels in the apical plasma membrane as well as exocytotic export of enzymes. The mitochondria are crucial not only for ATP generation but also for the physiologically important subcellular compartmentalization of the cytosolic Ca2+ signals.
Science has undergone remarkable changes both in scale, organization and influence over the last half century. It has changed the way we live and is more essential than ever before. Although the ...scientific effort today is more international than it was 50 years ago, only a small part of the world is fully engaged in this process. It is of course impossible in a single article to provide an overall balanced account of these developments and this is not an attempt to do so. Instead, certain trends are illustrated here, based solely on the personal experiences of an individual who – during a long career in the Life Sciences, and through work in many international science organizations – has been a witness and played a role in some of the changes that have occurred, often influenced by major political events.
Reproducible science requires transparent reporting. The ARRIVE guidelines (Animal Research: Reporting of In Vivo Experiments) were originally developed in 2010 to improve the reporting of animal ...research. They consist of a checklist of information to include in publications describing in vivo experiments to enable others to scrutinise the work adequately, evaluate its methodological rigour, and reproduce the methods and results. Despite considerable levels of endorsement by funders and journals over the years, adherence to the guidelines has been inconsistent, and the anticipated improvements in the quality of reporting in animal research publications have not been achieved. Here, we introduce ARRIVE 2.0. The guidelines have been updated and information reorganised to facilitate their use in practice. We used a Delphi exercise to prioritise and divide the items of the guidelines into 2 sets, the “ARRIVE Essential 10,” which constitutes the minimum requirement, and the “Recommended Set,” which describes the research context. This division facilitates improved reporting of animal research by supporting a stepwise approach to implementation. This helps journal editors and reviewers verify that the most important items are being reported in manuscripts. We have also developed the accompanying Explanation and Elaboration (E&E) document, which serves (1) to explain the rationale behind each item in the guidelines, (2) to clarify key concepts, and (3) to provide illustrative examples. We aim, through these changes, to help ensure that researchers, reviewers, and journal editors are better equipped to improve the rigour and transparency of the scientific process and thus reproducibility.
Sir Michael Berridge was a giant in the fields of physiology and biochemistry who, by his discovery in 1983 of inositol 1,4,5-trisphosphate (IP 3 ) as the ubiquitous intracellular messenger releasing ...Ca 2+ from intracellular stores, revolutionized our concepts of signal transduction mechanisms. Mike, as he was universally known, discovered one of the most important regulatory mechanisms in animal cells, involved in the control of virtually all bodily functions, including secretion, contraction and memory. Mike, working at the Department of Zoology at the University of Cambridge, personally identified IP 3 as one of the two initial products of hormone- or neurotransmitter-elicited inositol phospholipid breakdown and then, in collaboration with the research group led by Irene Schulz at the Max Planck Institute for Biophysics in Frankfurt, demonstrated directly the Ca 2+ -releasing effect of IP 3 in pancreatic acinar cells. Subsequently, in collaborations with research groups in Switzerland and the USA, Mike confirmed the Ca 2 + -releasing action of IP 3 in insulin-secreting cells, hepatocytes and photoreceptors. The IP 3 –Ca 2 + -releasing pathway became accepted amazingly quickly as one of the key elements of cellular signal transduction mechanisms and is now featured in virtually all textbooks of physiology and biochemistry. Mike was also a great synthesizer, who created an entirely new field, namely calcium signalling. Through his numerous, highly cited review articles, and his insightful keynote lectures at the most important biomedical congresses, he dominated this large and increasingly important research field for more than 30 years following his momentous 1983 discovery.
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