Mesenchymal stromal cells are present in the heart and promote growth of adult stem cells in vitro

Background aimsFor many years the human heart has been considered a terminally differentiated organ with no regenerative potential after injury. Recent studies, however, have cast doubt on this long-standing dogma. The objective of this study was to investigate the presence of and characterize mesenchymal stromal cells (MSC) in the adult mouse heart. The impact of MSC on growth and differentiation of adult cardiac stem cells (CSC) was also analyzed.MethodsA combination of lineage-negative/c-kit-negative (Lin^?/c-kit^?) immunoselection with a plastic-adhesion technique was used to isolate cardiac-derived MSC. The differentiation capacity and expression of surface markers were analyzed. To investigate the impact of MSC on growth and differentiation of adult CSC, Green Fluorescent Protein (GFP⁺) adult CSC were co-cultured with GFP^? cardiac-derived MSCResultsMSC were present in the adult mouse heart and they met the criteria established to define mouse MSC. They expressed surface markers and were able to differentiate, in a controlled manner, into multiple lineages. In addition, cardiac-derived MSC promoted the survival and expansion of adult CSC in vitroConclusionsMSC can be isolated from the mouse heart and they promote growth and differentiation of adult CSC. The findings from this study could have a significant beneficial impact on future heart failure treatment. Co-culture and co-implantation of cardiac-derived MSC with adult CSC could provide extensive cardiac regeneration and maintenance of the CSC population after implanted into the heart.     

Mesenchymal stromal cells and fibroblasts: a case of mistaken identity?

The plastic-adherent fibroblast-looking cells that can be isolated and culture-expanded from bone marrow and many other tissues are widely known as mesenchymal stromal cells (MSC). In addition to their fibroblast-like morphology, they are characterized by a panel of cell-surface markers and their potential to differentiate into bone, fat and cartilage. Based on their intriguing immunomodulatory and regenerative properties, MSC are being investigated as cellular therapeutics for a variety of clinical indications. However, many questions regarding the true identity and functionality of these cells in vivo remain unanswered. Fibroblasts, known for a much longer time but still poorly characterized, are also considered to be a ubiquitous stromal element of almost all tissues and are believed to play a role in tissue homeostasis. Despite the presence of MSC and fibroblasts in almost all tissues, similar morphology and other shared characteristics, the exact relationship between MSC and fibroblasts has remained undetermined. In this review, based on recent and old, but often neglected, literature it is suggested that ex vivo culture-expanded MSC and fibroblasts are indistinguishable by morphology, cell-surface markers, differentiation potential and immunologic properties.     

Revealing phosphoproteins playing role in tobacco pollen activated in vitro

The transition between the quiescent mature and the metabolically active germinating pollen grain most probably involves changes in protein phosphorylation status, since phosphorylation has been implicated in the regulation of many cellular processes. Given that, only a minor proportion of cellular proteins are phosphorylated at any one time, and that phosphorylated and nonphosphorylated forms of many proteins can co‐exist within a cell, the identification of phosphoproteins requires some prior enrichment from a crude protein extract. Here, we have used metal oxide/hydroxide affinity chromatography (MOAC) based on an aluminum hydroxide matrix for this purpose, and have generated a population of phosphoprotein candidates from both mature and in vitro activated tobacco pollen grains. Both electrophoretic and nonelectrophoretic methods, allied to MS, were applied to these extracts to identify a set of 139 phosphoprotein candidates. In vitro phosphorylation was also used to validate the spectrum of phosphoprotein candidates obtained by the MOAC phosphoprotein enrichment. Since only one phosphorylation site was detected by the above approach, titanium dioxide phosphopeptide enrichment of trypsinized mature pollen crude extract was performed as well. It resulted in a detection of additional 51 phosphorylation sites giving a total of 52 identified phosphosites in this set of 139 phosphoprotein candidates.     

IGF1在脑缺血大鼠脑组织中的表达与通络救脑注射液的脑保护作用

目的:观察脑缺血模型大鼠血清及脑组织中IGF1蛋白表达水平,以及通络救脑注射液对该因子表达水平的影响,分析通络救脑注射液的脑保护作用途径。方法:以线栓法制作大鼠大脑中动脉缺血模型(MCAO),将SD大鼠随机分为空白对照组、模型组及通络救脑注射药组,分别在造模后12小时、24小时、3天、7天4个时间点采取动物血清和脑组织,以免疫组化、酶联免疫(ELISA)以及RTPCR的方法,分别检测IGF1的表达部位及定量检测该因子的蛋白及mRNA表达水平,并测定血清NSE含量。结果:IGF1在正常脑组织有表达,在脑缺血后24小时表达增多,此后随脑缺血时间的延长不断减少;通络救脑组IGF1各时间点表达均高于模型组。模型组血清NSE水平显著升高,各时间点与正常组均有显著差异,通络救脑注射液组血清NSE水平在12小时、1天和7天时显著低于模型组。结论:大鼠脑缺血损伤后IGF1表达减少与神经元的坏死有相关性,通络救脑注射液能够提高其表达水平,对缺血损伤的脑组织发挥保护作用。     

诱导耐药K562/ADM和转基因耐药K562/MDR细胞株的生物学行为和耐药机制的比较研究

目的探讨转多药耐药基因mdr1的K562/MDR细胞株作为单机制耐药模型的可行性,为进一步研究肿瘤耐药及其逆转奠定基础。方法实验分为3部分:(1)在电子显微镜下观察慢性髓细胞白血病急性红白变敏感细胞系K562,阿霉素(adriamycin,ADM)诱导耐药细胞株K562/ADM和K562/MDR耐药细胞株的生物学行为;同时测定3种细胞系的群体倍增时间;以观察药物诱导和基因转移是否对细胞的生物学行为造成影响。(2)以K562细胞为对照,用MTT法分别测定阿霉素、柔红霉素(daunorubicin,DNR)、长春新碱(vincristine,VCR)对3种细胞的半数致死量(IC50)。(3)多药耐药相关基因与蛋白的检测。免疫细胞化学法观察mdr1基因编码的P-糖蛋白(P-gp)的表达;流式细胞术检测P-gp、bcl-2的表达百分率;生化法测定细胞内谷胱甘肽S-转移酶(GSTs)活性;RT-PCR法检测拓扑异构酶(to-poisomeraseⅡ,topoⅡ)mRNA的表达变化。结果(1)在超微结构上,K562/ADM的细胞器—线粒体出现水肿,K562和K562/MDR未见明显异常;K562的群体倍增时间为19.67±3.10d;K562/MDR为20.40±1.80d;K562/ADM为28.47±1.75d;(2)K562/ADM和K562/MDR细胞对ADM的耐药倍数分别为23.1和1.2倍;对DNR为84.9和14.4倍;对VCR为298.3和10.1倍。(3)与K562比较,K562/ADM细胞的P-gp和Bcl-2蛋白表达率高且topoⅡcDNA片段大小发生变化;K562/MDR仅P-gp表达率高。结论K562/MDR的生物学行为与亲本细胞K562相似,耐药机制单一,可作为单机制耐药模型,对某一耐药基因进行更为深入精确的研究,也可针对该耐药基因准确地筛选相应的逆转剂。     

Sulphur nutrition and iron plaque formation on roots of rice seedlings and their consequences for immobilisation and uptake of chromium in solution culture

Plant and Soil - The contribution of sulphur (S)-induced responses to chromium (Cr) tolerance of rice plants is not yet fully elucidated. It is hypothesised that S nutrition mitigates the...     

Biologic and immunomodulatory properties of mesenchymal stromal cells derived from human pancreatic islets

Background aims. Mesenchymal stromal cells (MSC) have now been shown to reside in numerous tissues throughout the body, including the pancreas. Ex vivo culture-expanded MSC derived from many tissues display important interactions with different types of immune cells in vitro and potentially play a significant role in tissue homeostasis in vivo. In this study, we investigated the biologic and immunomodulatory properties of human pancreatic islet-derived MSC. Methods. We culture-expanded MSC from cadaveric human pancreatic islets and characterized them using flow cytometry, differentiation assays and nuclear magnetic resonance-based metabolomics. We also investigated the immunologic properties of pancreatic islet-derived MSC compared with bone marrow (BM) MSC. Results. Pancreatic islet and BM-derived MSC expressed the same cell-surface markers by flow cytometry, and both could differentiate into bone, fat and cartilage. Metabolomics analysis of MSC from BM and pancreatic islets also showed a similar set of metabolic markers but quantitative polymerase chain reactions showed that pancreatic islet MSC expressed more interleukin(IL)-1b, IL-6, STAT3 and FGF9 compared with BM MSC, and less IL-10. However, similar to BM MSC, pancreatic islet MSC were able to suppress proliferation of allogeneic T lymphocytes stimulated with anti-CD3 and anti-CD28 antibodies. Conclusions. Our in vitro analysis shows pancreatic islet-derived MSC have phenotypic, biologic and immunomodulatory characteristics similar, but not identical, to BM-derived MSC. We propose that pancreatic islet-derived MSC could potentially play an important role in improving the outcome of pancreatic islet transplantation by promoting engraftment and creating a favorable immune environment for long-term survival of islet allografts.     

Olfactory mucosa stem cells: An available candidate for the treatment of the Parkinson's disease

Olfactory ectomesenchymal stem cells (OE-MSCs) possess the immunosuppressive activity and regeneration capacity and hold a lot of promises for neurodegenerative disorders treatment. This study aimed to determine OE-MSCs which are able to augment and differentiate into functional neurons and regenerate the CNS and also examine whether the implantation of OE-MSCs in the pars compacta of the substantia nigra (SNpc) can improve Parkinson's symptoms in a rat model-induced with 6-hydroxydopamine. We isolated OE-MSCs from lamina propria in olfactory mucosa and characterized them using flow cytometry and immunocytochemistry. The therapeutic potential of OE-MSCs was evaluated by the transplantation of isolated cells using a rat model of acute SN injury as a Parkinson's disease. Significant behavioral improvement in Parkinsonian rats was elicited by the OE-MSCs. The results demonstrate that the expression of PAX2, PAX5, PITX3, dopamine transporter, and tyrosine hydroxylase was increased by OE-MSCs compared to the control group which is analyzed with real-time polymerase chain reaction technique and immunohistochemical staining. In the outcome, the transplantation of 1,1′-dioctadecyl-3,3,3′3'-tetramethyl indocarbocyanine perchlorate labeled OE-MSCs that were fully differentiated to dopaminergic neurons contribute to a substantial improvement in patients with Parkinson's. Together, our results provide that using OE-MSCs in neurodegenerative disorders might lead to better neural regeneration.     

Comprehensive Mutational Analysis Reveals p6Gag Phosphorylation To Be Dispensable for HIV-1 Morphogenesis and Replication

The structural polyprotein Gag of human immunodeficiency virus type 1 (HIV-1) is necessary and sufficient for formation of virus-like particles. Its C-terminal p6 domain harbors short peptide motifs that facilitate virus release from the plasma membrane and mediate incorporation of the viral Vpr protein. p6 has been shown to be the major viral phosphoprotein in HIV-1-infected cells and virions, but the sites and functional relevance of p6 phosphorylation are not clear. Here, we identified phosphorylation of several serine and threonine residues in p6 in purified virus preparations using mass spectrometry. Mutation of individual candidate phosphoacceptor residues had no detectable effect on virus assembly, release, and infectivity, however, suggesting that phosphorylation of single residues may not be functionally relevant. Therefore, a comprehensive mutational analysis was conducted changing all potentially phosphorylatable amino acids in p6, except for a threonine that is part of an essential peptide motif. To avoid confounding changes in the overlapping pol reading frame, mutagenesis was performed in a provirus with genetically uncoupled gag and pol reading frames. An HIV-1 derivative carrying 12 amino acid changes in its p6 region, abolishing all but one potential phosphoacceptor site, showed no impairment of Gag assembly and virus release and displayed only very subtle deficiencies in viral infectivity in T-cell lines and primary lymphocytes. All mutations were stable over 2 weeks of culture in primary cells. Based on these findings, we conclude that phosphorylation of p6 is dispensable for HIV-1 assembly, release, and infectivity in tissue culture.