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Aggregation‐induced changes in the chemical exchange saturation transfer (CEST) signals of proteins 下载免费PDF全文
Steffen Goerke Katharina S. Milde Raul Bukowiecki Patrick Kunz Karel D. Klika Thomas Wiglenda Axel Mogk Erich E. Wanker Bernd Bukau Mark E. Ladd Peter Bachert Moritz Zaiss 《NMR in biomedicine》2017,30(1)
Chemical exchange saturation transfer (CEST) is an MRI technique that allows mapping of biomolecules (small metabolites, proteins) with nearly the sensitivity of conventional water proton MRI. In living organisms, several tissue‐specific CEST effects have been observed and successfully applied to diagnostic imaging. In these studies, particularly the signals of proteins showed a distinct correlation with pathological changes. However, as CEST effects depend on various properties that determine and affect the chemical exchange processes, the origins of the observed signal changes remain to be understood. In this study, protein aggregation was identified as an additional process that is encoded in the CEST signals of proteins. Investigation of distinct proteins that are involved in pathological disorders, namely amyloid beta and huntingtin, revealed a significant decrease of all protein CEST signals upon controlled aggregation. This finding is of particular interest with regard to diagnostic imaging of patients with neurodegenerative diseases that involve amyloidogenesis, such as Alzheimer's or Huntington's disease. To investigate whether the observed CEST signal decrease also occurs in heterogeneous mixtures of aggregated cellular proteins, and thus prospectively in tissue, heat‐shocked yeast cell lysates were employed. Additionally, investigation of different cell compartments verified the assignment of the protein CEST signals to the soluble part of the proteome. The results of in vitro experiments demonstrate that aggregation affects the CEST signals of proteins. This observation can enable hypotheses for CEST imaging as a non‐invasive diagnostic tool for monitoring pathological alterations of the proteome in vivo. 相似文献
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目的:采用维生素C处理体外培养的去分化脂肪(dedifferentiated fat,DFAT)细胞,以期进一步提高DFAT细胞的心肌分化效率。方法:用天花板贴壁培养法使大鼠成熟脂肪细胞去分化为DFAT细胞,并体外培养增殖至第3代,然后在培养基中添加维生素C或(和)乳鼠心脏细胞裂解液诱导DFAT细胞心肌分化。3周后,用倒置相差显微镜观察DFAT细胞的形态变化,用real-time PCR、免疫荧光和Western blot检测DFAT细胞的心肌特异性标志物c Tn T、GATA-4及NKx2.5 mRNA和蛋白的表达。结果:大鼠脂肪细胞经天花板贴壁培养后形态转变为成纤维细胞样的DFAT细胞。DFAT细胞在普通培养条件下可自发表达少量心肌特异性标志物。经乳鼠心脏细胞裂解液诱导后,DFAT细胞体积增大、变长,可见肌管样结构,c Tn T、GATA-4及NKx2.5 mRNA和蛋白的表达水平较普通培养的DFAT细胞显著升高。在维生素C的作用下,DFAT细胞c Tn T、GATA-4及NKx2.5的表达水平进一步升高。未观察到自发性搏动细胞。结论:维生素C可促进DFAT细胞分化为心肌样细胞。 相似文献
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Human platelet lysate supports the formation of robust human periodontal ligament cell sheets 下载免费PDF全文
Xiao‐Tao He Yuan Yin Fa‐Ming Chen 《Journal of tissue engineering and regenerative medicine》2018,12(4):961-972
The use of stem cell‐derived sheets has become increasingly common in a wide variety of biomedical applications. Although substantial evidence has demonstrated that human platelet lysate (PL) can be used for therapeutic cell expansion, either as a substitute for or as a supplement to xenogeneic fetal bovine serum (FBS), its impact on cell sheet production remains largely unexplored. In this study, we manufactured periodontal ligament stem cell (PDLSC) sheets in vitro by incubating PDLSCs in sheet‐induction media supplemented with various ratios of PL and FBS, i.e. 10% PL without FBS, 7.5% PL + 2.5% FBS, 5% PL + 5% FBS, 2.5% PL + 7.5% FBS or 10% FBS without PL. Cultures with the addition of all the designed supplements led to successful cell sheet production. In addition, all the resultant cellular materials exhibited similar expression profiles of matrix‐related genes and proteins, such as collagen I, fibronectin and integrin β1. Interestingly, the cell components within sheets generated by media containing both PL and FBS exhibited improved osteogenic potential. Following in vivo transplantation, all sheets supported significant new bone formation. Our data suggest that robust PDLSC sheets can be produced by applying PL as either an alternative or an adjuvant to FBS. Further examination of the relevant influences of human PL that benefit cell behaviour and matrix production will pave the way towards optimized and standardized conditions for cell sheet production. 相似文献
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Mandana Haack-Sørensen Morten Juhl Bjarke Follin Rebekka Harary Søndergaard Maria Kirchhoff Jens Kastrup 《Scandinavian journal of clinical and laboratory investigation》2018,78(4):293-300
In vitro expanded adipose-derived stromal cells (ASCs) are a useful resource for tissue regeneration. Translation of small-scale autologous cell production into a large-scale, allogeneic production process for clinical applications necessitates well-chosen raw materials and cell culture platform. We compare the use of clinical-grade human platelet lysate (hPL) and fetal bovine serum (FBS) as growth supplements for ASC expansion in the automated, closed hollow fibre quantum cell expansion system (bioreactor). Stromal vascular fractions were isolated from human subcutaneous abdominal fat. In average, 95?×?106 cells were suspended in 10% FBS or 5% hPL medium, and loaded into a bioreactor coated with cryoprecipitate. ASCs (P0) were harvested, and 30?×?106 ASCs were reloaded for continued expansion (P1). Feeding rate and time of harvest was guided by metabolic monitoring. Viability, sterility, purity, differentiation capacity, and genomic stability of ASCs P1 were determined. Cultivation of SVF in hPL medium for in average nine days, yielded 546?×?106 ASCs compared to 111?×?106 ASCs, after 17?days in FBS medium. ASCs P1 yields were in average 605?×?106 ASCs (PD [population doublings]: 4.65) after six days in hPL medium, compared to 119?×?106 ASCs (PD: 2.45) in FBS medium, after 21?days. ASCs fulfilled ISCT criteria and demonstrated genomic stability and sterility. The use of hPL as a growth supplement for ASCs expansion in the quantum cell expansion system provides an efficient expansion process compared to the use of FBS, while maintaining cell quality appropriate for clinical use. The described process is an obvious choice for manufacturing of large-scale allogeneic ASC products. 相似文献
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目的 探索顺磁性氧化铁纳米颗粒是否能调节由肿瘤裂解蛋白所诱发的针对人乳腺癌细胞(MCF-7)的抗肿瘤免疫反应。方法 将纳米铁颗粒与肿瘤裂解蛋白进行共价连接形成纳米铁-蛋白复合物,用裂解蛋白、纳米铁、纳米铁-蛋白复合物分别刺激人外周血单个核细胞(PBMC),再将刺激后的PBMC与MCF-7细胞相混合,用MTS方法检测对肿瘤细胞的杀伤率。结果 纳米铁能与60%的肿瘤裂解蛋白相连接,并形成较大的纳米颗粒。与单纯的肿瘤蛋白相比,纳米铁-肿瘤蛋白的复合物能够显著提升PBMC对MCF-7细胞的杀伤,而纳米铁本身对MCF-7无直接杀伤作用。结论 纳米铁-肿瘤蛋白的复合物能够显著增强PBMC在体外杀伤人乳腺癌细胞的能力。 相似文献
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Elsa D. Silva Pedro S. Babo Raquel Costa-Almeida Rui M.A. Domingues Bárbara B. Mendes Elvira Paz Paulo Freitas Márcia T. Rodrigues Pedro L. Granja Manuela E. Gomes 《Nanomedicine : nanotechnology, biology, and medicine》2018,14(7):2375-2385
Photocrosslinkable magnetic hydrogels are attracting great interest for tissue engineering strategies due to their versatility and multifunctionality, including their remote controllability ex vivo, thus enabling engineering complex tissue interfaces. This study reports the development of a photocrosslinkable magnetic responsive hydrogel made of methacrylated chondroitin sulfate (MA-CS) enriched with platelet lysate (PL) with tunable features, envisioning their application in tendon-to-bone interface. MA-CS coated iron-based magnetic nanoparticles were incorporated to provide magnetic responsiveness to the hydrogel. Osteogenically differentiated adipose-derived stem cells and/or tendon-derived cells were encapsulated within the hydrogel, proliferating and expressing bone- and tendon-related markers. External magnetic field (EMF) application modulated the swelling, degradation and release of PL-derived growth factors, and impacted both cell morphology and the expression and synthesis of tendon- and bone-like matrix with a more evident effect in co-cultures. Overall, the developed magnetic responsive hydrogel represents a potential cell carrier system for interfacial tissue engineering with EMF-controlled properties. 相似文献
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目的:建立注射用兰索拉唑的细菌内毒素检查法。方法:按照2010年版《中国药典》(二部)附录细菌内毒素检查法,采用2个厂家的鲎试剂对5个厂家的5批样品,通过预干扰和干扰试验确定样品最大无干扰质量浓度,并进行细菌内毒素检查。结果:将供试品溶液稀释到质量浓度为0.1 mg/ml时,不干扰细菌内毒素试验,其细菌内毒素限值为5 EU/mg。结论:采用细菌内毒素检查法检查注射用兰索拉唑中的细菌内毒素方法可行。 相似文献