| 1. |
- Klionsky, Daniel J., et al.
(författare)
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Guidelines for the use and interpretation of assays for monitoring autophagy
- 2012
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Ingår i: Autophagy. - : Informa UK Limited. - 1554-8635 .- 1554-8627. ; 8:4, s. 445-544
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Forskningsöversikt (refereegranskat)abstract
- In 2008 we published the first set of guidelines for standardizing research in autophagy. Since then, research on this topic has continued to accelerate, and many new scientists have entered the field. Our knowledge base and relevant new technologies have also been expanding. Accordingly, it is important to update these guidelines for monitoring autophagy in different organisms. Various reviews have described the range of assays that have been used for this purpose. Nevertheless, there continues to be confusion regarding acceptable methods to measure autophagy, especially in multicellular eukaryotes. A key point that needs to be emphasized is that there is a difference between measurements that monitor the numbers or volume of autophagic elements (e.g., autophagosomes or autolysosomes) at any stage of the autophagic process vs. those that measure flux through the autophagy pathway (i.e., the complete process); thus, a block in macroautophagy that results in autophagosome accumulation needs to be differentiated from stimuli that result in increased autophagic activity, defined as increased autophagy induction coupled with increased delivery to, and degradation within, lysosomes (in most higher eukaryotes and some protists such as Dictyostelium) or the vacuole (in plants and fungi). In other words, it is especially important that investigators new to the field understand that the appearance of more autophagosomes does not necessarily equate with more autophagy. In fact, in many cases, autophagosomes accumulate because of a block in trafficking to lysosomes without a concomitant change in autophagosome biogenesis, whereas an increase in autolysosomes may reflect a reduction in degradative activity. Here, we present a set of guidelines for the selection and interpretation of methods for use by investigators who aim to examine macroautophagy and related processes, as well as for reviewers who need to provide realistic and reasonable critiques of papers that are focused on these processes. These guidelines are not meant to be a formulaic set of rules, because the appropriate assays depend in part on the question being asked and the system being used. In addition, we emphasize that no individual assay is guaranteed to be the most appropriate one in every situation, and we strongly recommend the use of multiple assays to monitor autophagy. In these guidelines, we consider these various methods of assessing autophagy and what information can, or cannot, be obtained from them. Finally, by discussing the merits and limits of particular autophagy assays, we hope to encourage technical innovation in the field.
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| 2. |
- Cernicharo, J., et al.
(författare)
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Discovery of time variation of the intensity of molecular lines in IRC+10216 in the submillimeter and far-infrared domains
- 2014
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Ingår i: Astrophysical Journal Letters. - : American Astronomical Society. - 2041-8213 .- 2041-8205. ; 796:1
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Tidskriftsartikel (refereegranskat)abstract
- We report on the discovery of strong intensity variations in the high rotational lines of abundant molecular species toward the archetypical circumstellar envelope of IRC+10216. The observations have been carried out with the Heterodyne Instrument for the Far-Infrared (HIFI) instrument on board Herschel and with the IRAM30 m telescope. They cover several observing periods spreading over three years. The line intensity variations for molecules produced in the external layers of the envelope most likely result from time variations in the infrared pumping rates. We analyze the main implications this discovery has on the interpretation of molecular line emission in the envelopes of Mira-type stars. Radiative transfer calculations must take into account both the time variability of infrared pumping and the possible variation of the dust and gas temperatures with stellar phase in order to reproduce the observation of molecular lines at different epochs. The effect of gas temperature variations with stellar phase could be particularly important for lines produced in the innermost regions of the envelope. Each layer of the circumstellar envelope sees the stellar light radiation with a different lag time (phase). Our results show that this effect must be included in the models. The submillimeter and far infrared lines of asymptotic giant branch stars can no longer be considered as safe intensity calibrators.
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| 3. |
- Gonzales Prieto, Alberto, et al.
(författare)
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Toward Decentralized Probabilistic Management
- 2011
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Ingår i: IEEE Communications Magazine. - 0163-6804 .- 1558-1896. ; 49:7, s. 80-96
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Tidskriftsartikel (refereegranskat)abstract
- In recent years, data communication networks have grown to immense size and have been diversified by the mobile revolution. Existing management solutions are based on a centralized deterministic paradigm, which is appropriate for networks of moderate size operating in relatively stable conditions. However, it is becoming increasingly apparent that these management solutions are not able to cope with the large dynamic networks that are emerging. In this article, we argue that the adoption of a decentralized and probabilistic paradigm for network management will be crucial to meet the challenges of future networks, such as efficient resource usage, scalability, robustness, and adaptability. We discuss the potential of decentralized probabilistic management and its impact on management operations, and illustrate the paradigm by three example solutions for real-time monitoring and anomaly detection.
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| 4. |
- Gonzalez Prieto, Alberto, et al.
(författare)
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Towards Decentralized Probabilistic Management
- 2011. - 9
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Ingår i: IEEE Communications Magazine. - : IEEE Communications Society. - 0163-6804 .- 1558-1896. ; 49, s. 80-86
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Tidskriftsartikel (refereegranskat)
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| 5. |
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| 6. |
- Keller, Annika, et al.
(författare)
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Mutations in the gene encoding PDGF-B cause brain calcifications in humans and mice
- 2013
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Ingår i: Nature Genetics. - : Springer Science and Business Media LLC. - 1061-4036 .- 1546-1718. ; 45:9, s. 1077-
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Tidskriftsartikel (refereegranskat)abstract
- Calcifications in the basal ganglia are a common incidental finding and are sometimes inherited as an autosomal dominant trait ( idiopathic basal ganglia calcification (IBGC)). Recently, mutations in the PDGFRB gene coding for the platelet-derived growth factor receptor beta (PDGF-R beta) were linked to IBGC. Here we identify six families of different ancestry with nonsense and missense mutations in the gene encoding PDGF-B, the main ligand for PDGF-R beta. We also show that mice carrying hypomorphic Pdgfb alleles develop brain calcifications that show age-related expansion. The occurrence of these calcium depositions depends on the loss of endothelial PDGF-B and correlates with the degree of pericyte and blood-brain barrier deficiency. Thus, our data present a clear link between Pdgfb mutations and brain calcifications in mice, as well as between PDGFB mutations and IBGC in humans.
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| 7. |
- Oki, Koichi, et al.
(författare)
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Human Induced Pluripotent Stem Cells form Functional Neurons and Improve Recovery After Grafting in Stroke-Damaged Brain.
- 2012
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Ingår i: Stem Cells. - : Oxford University Press (OUP). - 1549-4918 .- 1066-5099. ; 30:6, s. 1120-1133
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Tidskriftsartikel (refereegranskat)abstract
- Reprogramming of adult human somatic cells to induced pluripotent stem cells (iPSCs) is a novel approach to produce patient-specific cells for autologous transplantation. Whether such cells survive long-term, differentiate to functional neurons, and induce recovery in the stroke-injured brain is unclear. We have transplanted long-term self-renewing neuroepithelial-like stem (lt-NES) cells, generated from adult human fibroblast-derived iPSCs, into the stroke-damaged mouse and rat striatum or cortex. Recovery of forepaw movements was observed already at 1 week after transplantation. Improvement was most likely not due to neuronal replacement but was associated with increased vascular endothelial growth factor levels, probably enhancing endogenous plasticity. Transplanted cells stopped proliferating, could survive without forming tumors for at least 4 months, and differentiated to morphologically mature neurons of different subtypes. Neurons in intrastriatal grafts sent axonal projections to the globus pallidus. Grafted cells exhibited electrophysiological properties of mature neurons and received synaptic input from host neurons. Our study provides the first evidence that transplantation of human iPSC-derived cells is a safe and efficient approach to promote recovery after stroke and can be used to supply the injured brain with new neurons for replacement.
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| 8. |
- Tornero Prieto, Daniel, et al.
(författare)
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Human induced pluripotent stem cell-derived cortical neurons integrate in stroke-injured cortex and improve functional recovery.
- 2013
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Ingår i: Brain. - : Oxford University Press (OUP). - 1460-2156 .- 0006-8950. ; 136:12, s. 3561-3577
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Tidskriftsartikel (refereegranskat)abstract
- Stem cell-based approaches to restore function after stroke through replacement of dead neurons require the generation of specific neuronal subtypes. Loss of neurons in the cerebral cortex is a major cause of stroke-induced neurological deficits in adult humans. Reprogramming of adult human somatic cells to induced pluripotent stem cells is a novel approach to produce patient-specific cells for autologous transplantation. Whether such cells can be converted to functional cortical neurons that survive and give rise to behavioural recovery after transplantation in the stroke-injured cerebral cortex is not known. We have generated progenitors in vitro, expressing specific cortical markers and giving rise to functional neurons, from long-term self-renewing neuroepithelial-like stem cells, produced from adult human fibroblast-derived induced pluripotent stem cells. At 2 months after transplantation into the stroke-damaged rat cortex, the cortically fated cells showed less proliferation and more efficient conversion to mature neurons with morphological and immunohistochemical characteristics of a cortical phenotype and higher axonal projection density as compared with non-fated cells. Pyramidal morphology and localization of the cells expressing the cortex-specific marker TBR1 in a certain layered pattern provided further evidence supporting the cortical phenotype of the fated, grafted cells, and electrophysiological recordings demonstrated their functionality. Both fated and non-fated cell-transplanted groups showed bilateral recovery of the impaired function in the stepping test compared with vehicle-injected animals. The behavioural improvement at this early time point was most likely not due to neuronal replacement and reconstruction of circuitry. At 5 months after stroke in immunocompromised rats, there was no tumour formation and the grafted cells exhibited electrophysiological properties of mature neurons with evidence of integration in host circuitry. Our findings show, for the first time, that human skin-derived induced pluripotent stem cells can be differentiated to cortical neuronal progenitors, which survive, differentiate to functional neurons and improve neurological outcome after intracortical implantation in a rat stroke model.
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