| 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. |
- Cui, Wen, et al.
(författare)
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Reversible pressure-induced polymerization of Fe(C5H5)(2) doped C-70
- 2013
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Ingår i: Carbon. - : Pergamon-Elsevier Science. - 0008-6223 .- 1873-3891. ; 62, s. 447-454
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Tidskriftsartikel (refereegranskat)abstract
- High pressure Raman, IR and X-ray diffraction (XRD) studies have been carried out on C-70(Fe(C5H5)(2))(2) (hereafter, "C-70(Fc)(2)") sheets. Theoretical calculation is further used to analyze the Electron Localization Function (ELF) and charge transfer in the crystal and thus to understand the transformation of C-70(Fc)(2) under pressure. Our results show that even at room temperature dimeric phase and one dimensional (1D) polymer phase of C-70 molecules can be formed at about 3 and 8 GPa, respectively. The polymerization is found to be reversible Upon decompression and the reversibility is related to the pressure-tuned charge transfer, as well as the overridden steric repulsion of counter ions. According to the layered structure of the intercalated ferrocene molecules formed in the crystal, we suggest that ferrocene acts as not only a spacer to restrict the polymerization of C-70 molecules within a layer, but also as charge reservoir to tune the polymerization process. This supplies a possible way for us to design the polymerization of fullerenes at suitable conditions.
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| 3. |
- Li, Jian-Fang, et al.
(författare)
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Soy isoflavone delays the progression of thioacetamide-induced liver fibrosis in rats
- 2011
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Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 1502-7708 .- 0036-5521. ; 46:3, s. 341-349
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Tidskriftsartikel (refereegranskat)abstract
- Objective. Our aim was to investigate the effect of soy isoflavone (SI) on liver fibrosis in a thioacetamide (TAA)-induced rat model. Materials and methods. Twenty-eight rats were assigned to four groups: sham group, fibrosis group, low-dose treatment group (LDg) and high-dose treatment group (HDg). SI (90 or 270 mg/kg) was administered daily during the model development by TAA. Standard liver tests, platelet derived growth factor-BB (PDGF-BB) and tissue inhibitor of metalloproteinase-1 (TIMP-1) were measured. The expression of collagen, alpha alpha-smooth muscle actin (alpha alpha-SMA) and transforming growth factor-beta beta 1 (TGF-beta beta 1) in liver tissue was determined. Electron microscopy was used to perform ultrastructural analysis of the livers. Results. Hepatic fibrosis was induced by 8 weeks of TAA administration. However, following the administration of SI, collagen staining significantly declined as compared with the fibrosis group (p < 0.01). Less collagen fibers around the hepatic stellate cells (HSCs) were observed in HDg as compared to the fibrosis group and LDg. There was no significant difference in standard liver tests between the fibrosis group and the two treatment groups. The levels of PDGF-BB and TIMP-1 in the two SI-treated groups were significantly lower than in the fibrosis group (p < 0.01). The expression of alpha alpha-SMA and TGF-beta beta 1 in HDg was less than that in the fibrosis group and LDg (p < 0.01). Conclusion. Administration of a high dose of SI resulted in an obvious inhibitory effect on liver fibrosis induced by TAA in rats. One hypothesis is that the effect may be related to the inhibition of HSC activation and proliferation.
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| 4. |
- Ma, Tao, et al.
(författare)
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Genomic insights into salt adaptation in a desert poplar
- 2013
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Ingår i: Nature Communications. - : Springer Science and Business Media LLC. - 2041-1723. ; 4, s. 2797-
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Tidskriftsartikel (refereegranskat)abstract
- Despite the high economic and ecological importance of forests, our knowledge of the genomic evolution of trees under salt stress remains very limited. Here we report the genome sequence of the desert poplar, Populus euphratica, which exhibits high tolerance to salt stress. Its genome is very similar and collinear to that of the closely related mesophytic congener, P. trichocarpa. However, we find that several gene families likely to be involved in tolerance to salt stress contain significantly more gene copies within the P. euphratica lineage. Furthermore, genes showing evidence of positive selection are significantly enriched in functional categories related to salt stress. Some of these genes, and others within the same categories, are significantly upregulated under salt stress relative to their expression in another salt-sensitive poplar. Our results provide an important background for understanding tree adaptation to salt stress and facilitating the genetic improvement of cultivated poplars for saline soils.
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| 5. |
- Zhang, Xiao-Dong, et al.
(författare)
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Establishment and assessments of a new model for the postoperative fatigue syndrome by major small intestinal resection in rats
- 2011
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Ingår i: Scandinavian Journal of Gastroenterology. - : Informa UK Limited. - 1502-7708 .- 0036-5521. ; 46:11, s. 1302-1309
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Tidskriftsartikel (refereegranskat)abstract
- Objective. Postoperative fatigue syndrome (POFS) is a general and main complication after surgery. However, there is no stable and standardized animal model for POFS. The aim of the present study was to establish a rodent model of POFS by small intestinal resection, with POFS evaluated by acknowledged physical and behavioral methods. Material and Methods. Forty-two Sprague-Dawley rats were randomly divided into four groups according to the length of a "middle" small intestinal resection: 0% (sham group; i.e., laparotomy alone), 10%, 40% and 70% groups, with corresponding lengths of small intestinal resections. Following surgery, the general state of health was evaluated. Tail suspension test, open field test and Morris water maze test were used to evaluate the degree of POFS. Serum albumin, transferrin, prealbumin and fibronectin were measured to assess the nutritional status, and superoxide dismutase (SOD) and malondialdehyde (MDA) were also measured. Results. As compared with the other three groups, the 70% small intestinal resection group showed the worst general state of health, decreased strength of the tail suspension test and decreased score of Morris water maze test (p < 0.05) after operation. All rats in whom the small intestinal resection was done demonstrated a certain degree of malnutrition and behavior of depression, and the 70% resection group had the lowest levels of transferrin, prealbumin and fibronectin as compared with the other groups (p < 0.05), as well as decreased SOD and increased MDA in serum (p < 0.05). Conclusions. Resection of 70% of the small intestine resulted in typical characteristics of POFS. As this procedure is simple, stable and easily reproducible, it may serve as a model for research on POFS.
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