Study design and methods of the Ansan Geriatric Study (AGE study)

Background  

The overall objective of the Ansan Geriatric Study (AGE study) was to describe the prevalence, incidence, and related risk factors for geriatric diseases in elderly Koreans.     

Comparative proteomic analysis of mesenchymal stem cells derived from human bone marrow,umbilical cord,and placenta: Implication in the migration

Umbilical cord (UC) and placenta (P) have been suggested as alternatives to bone marrow (BM) as sources of mesenchymal stem cells (MSC) for cell therapy, with both UC‐ and P‐MSC possess immunophenotypic and functional characteristics similar to BM‐MSC. However, their migration capacity, which is indispensable during tissue regeneration process, is unclear. Under defined conditions, the migration capacity of BM‐ and P‐MSC was found 5.9‐ and 3.2‐folds higher than that of UC‐MSC, respectively. By the use of 2‐DE and combined MS and MS/MS analysis, six differentially expressed proteins were identified among these MSC samples, with five of them known to be involved in cell migration as migration enhancing or inhibiting proteins. Consistent with their migration capacity, the levels of migration enhancing proteins including cathepsin B, cathepsin D and prohibitin,were significantly lower in UC‐MSC when compared with those in BM‐ and P‐MSC. For the migration inhibiting proteins such as plasminogen activator inhibitor‐1 (PAI‐1) and manganese superoxide dismutase, higher expression was found in the UC‐MSC. We also showed that the overexpression of the PAI‐1 impaired the migration capacity of BM‐ and P‐MSC while silencing of PAI‐1 enhanced the migration capacity of UC‐MSC. Our study indicates that PAI‐1 and other migration‐related proteins are pivotal in governing the migration capacity of MSC.     

Chemoselective regulation of TREK2 channel: Activation by sulfonate chalcones and inhibition by sulfonamide chalcones

Although it has not been extensively studied, a significant volume of literature suggests that TREK2 will probably turn out to be an important channel in charge of tuning neuronal transmitter and hormone levels. Thus, pharmacological tools which can manipulate this channel, such as selective agonists are essential both in drug design and to further our understanding of this system. Our investigations have shown that sulfonate (‘O’) chalcone and sulfonamide (‘N’) chalcones regulate the TREK2 channel in remarkably different ways: sulfonamide chalcone 5 behaved as an inhibitor with an IC₅₀ of 62 μM, whereas the sulfonate analogue 11 activated TREK2 with EC₅₀ value of 167 μM.     

Functional reconstitution of the human serotonin receptor 5-HT6 using synthetic transmembrane peptides

Seven transmembrane (7TM) synthetic peptides mimicking the α-helical TM domains of the human serotonin receptor subtype-6 (5-HT₆) were autonomously reconstituted in detergent micelle and liposome environments. The degree of assembly of the 7TM peptides was characterized by monitoring the fluorescence resonance energy transfer (FRET) between donor and acceptor probes labeled at the amino termini of the second and fourth TM-peptides, respectively. The FRET efficiency of these peptides significantly increased when the 7TM peptides were reconstituted in liposome compare to detergent micelles. Furthermore, the 7TM peptides reconstituted in liposomes selectively bound to free serotonin and serotonin-conjugated magnetic beads, yielding a dissociation constant of 0.84 μM. These results show that the seven individual TM domains of 5-HT₆ can spontaneously assemble into liposomes in a conformation that mimics a native structure, and further demonstrate that specific interactions between TM helices play a critical role in the folding and stabilizing of GPCRs. The autonomous assembly of 7TM-peptides can be applied to the screening of agonists for GPCRs that are difficult to manipulate.     

Syndecan-4 promotes the retention of phosphatidylinositol 4,5-bisphosphate in the plasma membrane

Although phosphatidylinositol 4,5-bisphosphate (PIP₂) regulates syndecan-4 function, the potential influence of syndecan-4 on PIP₂ remains unknown. GFP containing PIP₂-binding-PH domain of phospholipase Cδ (GFP-PHδ) was used to monitor PIP₂. Syndecan-4 overexpression in COS-7 cells enhanced membrane translocation of GFP-PHδ, while the opposite was observed when syndecan-4 was knocked-down. PIP₂ levels were higher in total phospholipids extracted from rat embryo fibroblasts expressing syndecan-4. Syndecan-4-induced membrane targeting of GFP-PHδ was further enhanced by phosphoinositide-3-kinase inhibitor, but not by phospholipase C (PLC) inhibitor. Besides, both ionomycin and epidermal growth factor caused dissociation of GFP-PHδ from plasma membrane, an effect that was significantly delayed by syndecan-4 over-expression. Collectively, these data suggest that syndecan-4 promotes plasma membrane retention of PIP₂ by negatively regulating PLC-dependent PIP₂ degradation.     

P21蛋白在不同级别宫颈组织中的表达及其与高危HPV感染相关性的研究

目的通过检测宫颈组织中p21waf基因表达与高危HPV感染的情况,研究P21蛋白与高危HPV感染在宫颈组织恶性转化过程中的作用及其相互关系。方法应用免疫组化检测P21蛋白及基因杂交捕获Ⅱ代技术(HC-Ⅱ)检测高危HPV在正常宫颈组、宫颈炎、宫颈上皮内瘤样病变(CIN)及宫颈癌组这4组中的表达情况。结果在正常宫颈组、宫颈炎、宫颈上皮内瘤样病变(CIN)、及宫颈癌组中P21的阳性表达率分别为11.8%、15.4%、39.1%和57.7%;高危HPV的阳性表达率分别为20%、23.5%、65.2%和88.5%,这两项指标在CIN、宫颈癌组有明显的升高趋势且与正常宫颈和宫颈炎两组相比差异具有显著性统计学意义(P<0.05);各级别宫颈组织中高危HPV阳性组的P21蛋白阳性率明显高于阴性组的P21蛋白阳性率。差异在统计学上具有显著性意义(P<0.05)。结论P21蛋白的表达和高危HPV感染与宫颈病变的恶化均有高度的相关性,其检出率和阳性表达率随着宫颈病变恶性程度的增加而升高。在CIN向宫颈癌恶性转化过程中,P21与高危HPV共同促进肿瘤的发生。     

Phenotype and functional evaluation of ex vivo generated antigen-specific immune effector cells with potential for therapeutic applications

Ex vivo activation and expansion of lymphocytes for adoptive cell therapy has demonstrated great success. To improve safety and therapeutic efficacy, increased antigen specificity and reduced non-specific response of the ex vivo generated immune cells are necessary. Here, using a complete protein-spanning pool of pentadecapeptides of the latent membrane protein 2A (LMP2A) of Epstein-Barr virus (EBV), a weak viral antigen which is associated with EBV lymphoproliferative diseases, we investigated the phenotype and function of immune effector cells generated based on IFN-γ or CD137 activation marker selection and dendritic cell (DC) activation. These ex vivo prepared immune cells exhibited a donor- and antigen-dependent T cell response; the IFN-γ-selected immune cells displayed a donor-related CD4- or CD8-dominant T cell phenotype; however, the CD137-enriched cells showed an increased ratio of CD4 T cells. Importantly, the pentadecapeptide antigens accessed both class II and class I MHC antigen processing machineries and effectively activated EBV-specific CD4 and CD8 T cells. Phenotype and kinetic analyses revealed that the IFN-γ and the CD137 selections enriched more central memory T (Tcm) cells than did the DC-activation approach, and after expansion, the IFN-γ-selected effector cells showed the highest level of antigen-specificity and effector activities. While all three approaches generated immune cells with comparable antigen-specific activities, the IFN-γ selection followed by ex vivo expansion produced high quality and quantity of antigen-specific effector cells. Our studies presented the optimal approach for generating therapeutic immune cells with potential for emergency and routine clinical applications.     

Definition of Eight Mulberry Species in the Genus Morus by Internal Transcribed Spacer-Based Phylogeny

Mulberry, belonging to the order Rosales, family Moraceae, and genus Morus, has received attention because of both its economic and medicinal value, as well as for its important ecological function. The genus Morus has a worldwide distribution, however, its taxonomy remains complex and disputed. Many studies have attempted to classify Morus species, resulting in varied numbers of designated Morus spp. To address this issue, we used information from internal transcribed spacer (ITS) genetic sequences to study the taxonomy of all the members of generally accepted genus Morus. We found that intraspecific 5.8S rRNA sequences were identical but that interspecific 5.8S sequences were diverse. M. alba and M. notabilis showed the shortest (215 bp) and the longest (233 bp) ITS1 sequence length, respectively. With the completion of the mulberry genome, we could identify single nucleotide polymorphisms within the ITS locus in the M. notabilis genome. From reconstruction of a phylogenetic tree based on the complete ITS data, we propose that the Morus genus should be classified into eight species, including M. alba, M. nigra, M. notabilis, M. serrata, M. celtidifolia, M. insignis, M. rubra, and M. mesozygia. Furthermore, the classification of the ITS sequences of known interspecific hybrid clones into both paternal and maternal clades indicated that ITS variation was sufficient to distinguish interspecific hybrids in the genus Morus.