Nitrosylation of b2-Tubulin Promotes Microtubule Disassembly and Differentiated Cardiomyocyte Beating in Ischemic Mice

BACKGROUND@#Beating cardiomyocyte regeneration therapies have revealed as alternative therapeutics for heart transplantation. Nonetheless, the importance of nitric oxide (NO) in cardiomyocyte regeneration has been widely suggested, little has been reported concerning endogenous NO during cardiomyocyte differentiation. @*METHODS@#Here, we used P19CL6 cells and a Myocardiac infarction (MI) model to confirm NO-induced protein modification and its role in cardiac beating. Two tyrosine (Tyr) residues of b2-tubulin (Y106 and Y340) underwent nitrosylation (Tyr-NO) by endogenously generated NO during cardiomyocyte differentiation from pre-cardiomyocyte-like P19CL6 cells. @*RESULTS@#Tyr-NO-b2-tubulin mediated the interaction with Stathmin, which promotes microtubule disassembly, and was prominently observed in spontaneously beating cell clusters and mouse embryonic heart (E11.5d). In myocardial infarction mice, Tyr-NO-b2-tubulin in transplanted cells was closely related with cardiac troponin-T expression with their functional recovery, reduced infarct size and thickened left ventricular wall. @*CONCLUSION@#This is the first discovery of a new target molecule of NO, b2-tubulin, that can promote normal cardiac beating and cardiomyocyte regeneration. Taken together, we suggest therapeutic potential of Tyr-NO-b2-tubulin, for ischemic cardiomyocyte, which can reduce unexpected side effect of stem cell transplantation, arrhythmogenesis.

Bone Morphogenic Protein-2-Conjugated Three-DimensionalPrinted Poly (L-Lactic Acid) (PLLA) Scaffold is likely Promising as an Effective Bone Substitute

Bone morphogenic protein-2 (BMP-2)-conjugated three-dimensional (3-D)-printed poly (L-lactic acid)(PLLA) scaffold is likely promising as an effective bone substitute for enhancing bone regeneration of massive bone defects caused by tumor resection, traumatic injury, or congenital diseases. The authors developed a new bone substitute using a novel strategy composed of 3-D-printed PLLA scaffolds through a sequential coating of catechol-conjugated alginate (C-AL), BMP-2, and collagen (CO). The 3-D-printed PLLA scaffold was successfully obtained with 5 mm of diameter, 1 mm of thickness, 400 lm of pore size, 187–230 lm of grid thickness, and 82% of porosity. Alkaline phosphatase (ALP) activity of the BMP-2-immobilized PLLA scaffold in MC3T3-E1 and W-20-17 cells was more increased than BMP-2 itself due to the controlled release of BMP-2 from the scaffold. Tenfold new bone formation for the BMP-2-immobilized PLLA scaffold was obtained by micro-CT analysis than PLLA scaffold without BMP-2 weeks after 4 weeks of transplantation model mouse. Further another big animal model study should be performed before clinical trials.

A Novel Method to Differentiate Tonsil-Derived Mesenchymal Stem Cells In Vitro into Estrogen-Secreting Cells

BACKGROUND@#The advantages of tonsil-derived mesenchymal stem cells (TMSCs) over other mesenchymal stem cells (MSCs) include higher proliferation rates, various differentiation potentials, efficient immune-modulating capacity, and ease of obtainment. Specifically, TMSCs have been shown to differentiate into the endodermal lineage. Estrogen deficiency is a major cause of postmenopausal osteoporosis and is associated with higher incidences of ischemic heart disease and cerebrovascular attacks during the postmenopausal period. Therefore, stem cell-derived, estrogen-secreting cells might be used for estrogen deficiency. @*METHODS@#Here, we developed a novel method that utilizes retinoic acid, insulin-like growth factor-1, basic fibroblast growth factor, and dexamethasone to evaluate the differentiating potential of TMSCs into estrogen-secreting cells. The efficacy of the novel differentiating method for generation of estrogen-secreting cells was also evaluated with bone marrow- and adipose tissue-derived MSCs. @*RESULTS@#Incubating TMSCs in differentiating media induced the gene expression of cytochrome P450 19A1 (CYP19A1), which plays a key role in estrogen biosynthesis, and increased 17b-estradiol secretion upon testosterone addition. Furthermore, CYP11A1, CYP17A1, and 3b-hydroxysteroid dehydrogenase type-1 gene expression levels were significantly increased in TMSCs. In bone marrow-derived and adipose tissue-derived MSCs, this differentiation method also induced the gene expression of CYP19A1, but not CYP17A1, suggesting TMSCs are a superior source for estrogen secretion. @*CONCLUSION@#These results imply that TMSCs can differentiate into functional estrogen-secreting cells, thus providing a novel, alternative cell therapy for estrogen deficiency.

A Novel Method to Differentiate Tonsil-Derived Mesenchymal Stem Cells In Vitro into Estrogen-Secreting Cells

BACKGROUND@#The advantages of tonsil-derived mesenchymal stem cells (TMSCs) over other mesenchymal stem cells (MSCs) include higher proliferation rates, various differentiation potentials, efficient immune-modulating capacity, and ease of obtainment. Specifically, TMSCs have been shown to differentiate into the endodermal lineage. Estrogen deficiency is a major cause of postmenopausal osteoporosis and is associated with higher incidences of ischemic heart disease and cerebrovascular attacks during the postmenopausal period. Therefore, stem cell-derived, estrogen-secreting cells might be used for estrogen deficiency. @*METHODS@#Here, we developed a novel method that utilizes retinoic acid, insulin-like growth factor-1, basic fibroblast growth factor, and dexamethasone to evaluate the differentiating potential of TMSCs into estrogen-secreting cells. The efficacy of the novel differentiating method for generation of estrogen-secreting cells was also evaluated with bone marrow- and adipose tissue-derived MSCs. @*RESULTS@#Incubating TMSCs in differentiating media induced the gene expression of cytochrome P450 19A1 (CYP19A1), which plays a key role in estrogen biosynthesis, and increased 17b-estradiol secretion upon testosterone addition. Furthermore, CYP11A1, CYP17A1, and 3b-hydroxysteroid dehydrogenase type-1 gene expression levels were significantly increased in TMSCs. In bone marrow-derived and adipose tissue-derived MSCs, this differentiation method also induced the gene expression of CYP19A1, but not CYP17A1, suggesting TMSCs are a superior source for estrogen secretion. @*CONCLUSION@#These results imply that TMSCs can differentiate into functional estrogen-secreting cells, thus providing a novel, alternative cell therapy for estrogen deficiency.

Activation of ATM/Akt/CREB/eNOS Signaling Axis by Aphidicolin Increases NO Production and Vessel Relaxation in Endothelial Cells and Rat Aortas

Although DNA damage responses (DDRs) are reported to be involved in nitric oxide (NO) production in response to genotoxic stresses, the precise mechanism of DDR-mediated NO production has not been fully understood. Using a genotoxic agent aphidicolin, we investigated how DDRs regulate NO production in bovine aortic endothelial cells. Prolonged (over 24 h) treatment with aphidicolin increased NO production and endothelial NO synthase (eNOS) protein expression, which was accompanied by increased eNOS dimer/monomer ratio, tetrahydrobiopterin levels, and eNOS mRNA expression. A promoter assay using 5’-serially deleted eNOS promoters revealed that Tax-responsive element site, located at −962 to −873 of the eNOS promoter, was respon-sible for aphidicolin-stimulated eNOS gene expression. Aphidicolin increased CREB activity and ectopic expression of dominantnegative inhibitor of CREB, A-CREB, repressed the stimulatory effects of aphidicolin on eNOS gene expression and its promoter activity. Co-treatment with LY294002 decreased the aphidicolin-stimulated increase in p-CREB-Ser133 level, eNOS expression, and NO production. Furthermore, ectopic expression of dominant-negative Akt construct attenuated aphidicolin-stimulated NO production. Aphidicolin increased p-ATM-Ser1981 and the knockdown of ATM using siRNA attenuated all stimulatory effects of aphidicolin on p-Akt-Ser473 , p-CREB-Ser133 , eNOS expression, and NO production. Additionally, these stimulatory effects of aphidicolin were similarly observed in human umbilical vein endothelial cells. Lastly, aphidicolin increased acetylcholine-induced vessel relaxation in rat aortas, which was accompanied by increased p-ATM-Ser1981 , p-Akt-Ser473 , p-CREB-Ser 133 , and eNOS expression. In conclusion, our results demonstrate that in response to aphidicolin, activation of ATM/Akt/CREB/eNOS signaling cascade mediates increase of NO production and vessel relaxation in endothelial cells and rat aortas.

Optimization of Microenvironments Inducing Differentiation of Tonsil-Derived Mesenchymal Stem Cells into Endothelial Cell-Like Cells

BACKGROUND: Stem cell engineering is appealing consideration for regenerating damaged endothelial cells (ECs) because stem cells can differentiate into EC-like cells. In this study, we demonstrate that tonsil-derived mesenchymal stem cells (TMSCs) can differentiate into EC-like cells under optimal physiochemical microenvironments.METHODS: TMSCs were preconditioned with Dulbecco's Modified Eagle Medium (DMEM) or EC growth medium (EGM) for 4 days and then replating them on Matrigel to observe the formation of a capillary-like network under light microscope. Microarray, quantitative real time polymerase chain reaction, Western blotting and immunofluorescence analyses were used to evaluate the expression of gene and protein of EC-related markers.RESULTS: Preconditioning TMSCs in EGM for 4 days and then replating them on Matrigel induced the formation of a capillary-like network in 3 h, but TMSCs preconditioned with DMEM did not form such a network. Genome analyses confirmed that EGM preconditioning significantly affected the expression of genes related to angiogenesis, blood vessel morphogenesis and development, and vascular development. Western blot analyses revealed that EGM preconditioning with gelatin coating induced the expression of endothelial nitric oxide synthase (eNOS), a mature EC-specific marker, as well as phosphorylated Akt at serine 473, a signaling molecule related to eNOS activation. Gelatin-coating during EGM preconditioning further enhanced the stability of the capillary-like network, and also resulted in the network more closely resembled to those observed in human umbilical vein endothelial cells.CONCLUSION: This study suggests that under specific conditions, i.e., EGM preconditioning with gelatin coating for 4 days followed by Matrigel, TMSCs could be a source of generating endothelial cells for treating vascular dysfunction.

Aberrant Promoter Hypomethylation of Sortilin 1: A Moyamoya Disease Biomarker / 대한뇌졸중학회지

BACKGROUND AND PURPOSE: The pathogenesis of moyamoya disease (MMD) remains poorly understood, and no reliable molecular biomarkers for MMD have been identified to date. The present study aimed to identify epigenetic biomarkers for use in the diagnosis of MMD. METHODS: We performed integrated analyses of gene expression profiles and DNA methylation profiles in endothelial colony forming cells (ECFCs) from three patients with MMD and two healthy individuals. Candidate gene mRNA expression and DNA methylation status were further validated using reverse transcription-quantitative polymerase chain reaction (RT-qPCR) and pyrosequencing analysis of an expanded ECFC sample set from nine patients with MMD and ten controls. We evaluated the diagnostic accuracy of the potential biomarkers identified here using receiver operating characteristic curve analyses and further measured major angiogenic factor expression levels using a tube formation assay and RT-qPCR. RESULTS: Five candidate genes were selected via integrated analysis; all five were upregulated by hypomethylation of specific promoter CpG sites. After further validation in an expanded sample set, we identified a candidate biomarker gene, sortilin 1 (SORT1). DNA methylation status at a specific SORT1 promoter CpG site in ECFCs readily distinguished patients with MMD from the normal controls with high accuracy (area under the curve 0.98, sensitivity 83.33%, specificity 100%). Furthermore, SORT1 overexpression suppressed endothelial cell tube formation and modulated major angiogenic factor and matrix metalloproteinase-9 expression, implying SORT1 involvement in MMD pathogenesis. CONCLUSIONS: Our findings suggest that DNA methylation status at the SORT1 promoter CpG site may be a potential biomarker for MMD.

Effect of Individual and District-level Socioeconomic Disparities on Cognitive Decline in Community-dwelling Elderly in Seoul

This study was to investigate the effects of individual and district-level socioeconomic status (SES) on the development of cognitive impairment among the elderly. A 3-year retrospective observational analysis (2010–2013) was conducted which included 136,217 community-dwelling healthy elderly who participated in the Seoul Dementia Management Project. Cognitive impairment was defined as 1.5 standard deviations below the norms on the Mini-mental status examination. In the individual lower SES group, the cumulative incidence rate (CIR) of cognitive impairment was 8.7% (95% confidence interval [CI], 8.64–8.70), whereas the CIR in the individual higher SES group was 4.1% (95% CI, 4.08–4.10). The CIR for lower district-level SES was 4.7% (95% CI, 4.52–4.86), while that in the higher district-level SES was 4.3% (95% CI, 4.06–4.44). There were no additive or synergistic effects between individual and district-level SES. From this study, the individual SES contributed 1.9 times greater to the development of cognitive impairment than the district-level SES, which suggests that individual SES disparities could be considered as one of the important factors in public health related to cognitive impairment in the elderly.

Expression of Tenocyte Lineage-Related Factors from Tonsil-Derived Mesenchymal Stem Cells

Human palatine tonsil-derived mesenchymal stem cells (TMSCs) are known to be a new source of progenitor cells. Using waste tissue after tonsillectomy as a cell provider can be the biggest benefit of TMSCs, compared with other stem cells. The purpose of this study was to investigate tenogenic differentiation of TMSCs and to access the differential effects of transforming growth factor beta 3 (TGF-β3) on the tenogenesis of TMSCs. Human tonsil was obtained after tonsillectomy. Using a cytometric analysis, we were able to find that the TMSCs had typical mesenchymal stem cell markers: positive for CD73, CD90, and CD105, and negative for CD14, CD34, and CD45. Using TGF-β3, the expressions of tenocyte-specific genes and proteins, such as collagen type 1 (COL1), tenomodulin (TNMD), and scleraxis (SCX), were measured by a quantitative polymerase chain reaction (PCR), immunofluorescence staining, immunohistochemistry and Western blot analyses. Quantitative PCR assay showed that TGF-β3 significantly increased the expressions of tenocyte lineage marker genes, including COL1, TNMD, and SCX, at a 3-day treatment, compared with control. However, these increases were not found at long-term exposures (7 or 10 days), except that TNMD expression was maintained at 50 ng/mL at a 7-day exposure to TGF-β3. Like genes, the protein expression levels of COL1, TNMD, and SCX were also induced in TGF-β3-treated TMSCs in a 3-day treatment, which were maintained for 10 days, as evidenced by immunofluorescence staining, immunohistochemistry and Western blot analyses. This study demonstrated that TMSCs in tenogenic stimulation with TGF-β3 have a high tenogenic differentiation potential.

Low-Density-Lipoprotein Particle Size Predicts a Poor Outcome in Patients with Atherothrombotic Stroke

BACKGROUND AND PURPOSE: Low-density lipoprotein (LDL) particle size is considered to be one of the more important cardiovascular risk factors, and small LDL particles are known to have atherogenic potential. The aim of this study was to determine whether LDL particle size is associated with stroke severity and functional outcome in patients with atherothrombotic stroke. METHODS: Between January 2009 and May 2011, 248 patients with first-episode cerebral infarction who were admitted to our hospital within 7 days after symptom onset were prospectively enrolled. LDL particle size was measured using the nondenaturing polyacrylamide gradient gel electrophoresis assay. Stroke severity was assessed by applying the National Institutes of Health Stroke Scale (NIHSS) at admission. Functional outcome was investigated at 3 months after the index stroke using the modified Rankin Scale (mRS), and poor functional outcome was defined as an mRS score of > or =3. RESULTS: The LDL particle size in the 248 patients was 25.9+/-0.9 nm (mean+/-SD). LDL particle size was inversely correlated with the degree of cerebral artery stenosis (p=0.010). Multinomial multivariate logistic analysis revealed that after adjustment for age, sex, and variables with p or =5; reference, NIHSS score 0-2; odds ratio=0.38, p=0.028) and poor functional outcome (odds ratio=0.44, p=0.038). CONCLUSIONS: The results of this study demonstrate that small LDL particles are independently correlated with stroke outcomes. LDL particle size is thus a potential biomarker for the prognosis of atherothrombotic stroke.

Arsenite Acutely Decreases Nitric Oxide Production via the ROS-Protein Phosphatase 1-Endothelial Nitric Oxide Synthase-Thr497 Signaling Cascade

Chronic (>24 h) exposure of arsenite, an environmental toxicant, has shown the decreased nitric oxide (NO) production in endothelial cells (EC) by decreasing endothelial NO synthase (eNOS) expression and/or its phosphorylation at serine 1179 (eNOS-Ser1179 in bovine sequence), which is associated with increased risk of vascular diseases. Here, we investigated the acute (<24 h) effect of arsenite on NO production using bovine aortic EC (BAEC). Arsenite acutely increased the phosphorylation of eNOS-Thr497, but not of eNOS-Ser116 or eNOS-Ser1179, which was accompanied by decreased NO production. The level of eNOS expression was unaltered under this condition. Treatment with arsenite also induced reactive oxygen species (ROS) production, and pretreatment with a ROS scavenger N-acetyl-L-cysteine (NAC) completely reversed the observed effect of arsenite on eNOS-Thr497 phosphorylation. Although protein kinase C (PKC) and protein phosphatase 1 (PP1) were reported to be involved in eNOS-Thr497 phosphorylation, treatment with PKC inhibitor, Ro318425, and overexpression of various PKC isoforms did not affect the arsenite-stimulated eNOS-Thr497 phosphorylation. In contrast, treatment with PP1 inhibitor, calyculin A, mimicked the observed effect of arsenite on eNOS-Thr497 phosphorylation. Lastly, we found decreased cellular PP1 activity in arsenite-treated cells, which was reversed by NAC. Overall, our study demonstrates firstly that arsenite acutely decreases NO production at least in part by increasing eNOS-Thr497 phosphorylation via ROS-PP1 signaling pathway, which provide the molecular mechanism underlying arsenite-induced increase in vascular disease.

Effect of Aging on the Pluripotential Capacity of Human Bone Marrow Derived Mesenchymal Stem Cells / 대한정형외과학회잡지

PURPOSE: The aim of study was to compare the differentiation capacity of mesenchymal stem cells (MSCs) obtained from human bone marrow (BM) according to the age of the donors. MATERIALS AND METHODS: MSCs were isolated from the BM of young (n=16, 12.5+/-5.8 years) and elder (n=4, 48.5+/-7.2 years) patients with the consent of them. We analyzed the cell morphology and the cell surface markers of the MSCs. In addition, we assessed the cell senescence with serial cultures from both age groups. Cell pluripotentiality was analyzed by osteogenic, chondrogenic, and adipogenic induction media. We performed RT-PCR, a measurement of expression of alkaline phosphatase, and staining with von Kossa, safranin O, and oil red O stain. RESULTS: All of the MSC samples tested, irrespective of the age of the donors, MSCs were all successfully isolated from twenty bone marrows. However, the number of cells of from the young donors was five times greater than that of the elderly donors. Senescence was observed over 10 passages in both age groups. The immunophenotypes of both age groups showed similar patterns. MSCs obtained from young and older donors showed the potential to differentiate into osteogenic, chondrogenic, and adipogenic lineages with no difference for both age groups. CONCLUSION: Our study supports that age does not influence the pluripotential capacity of human BM derived MSCs.

Survey of Public Health Service Needs of Live-Alone Elders in Urban Area

BACKGROUND: The number and proportion of live-alone elders in Korea have been increasing dramatically. We tried to identify the physical health status of live-alone elders in community and their needs for public health service in order to provide basic data for effective public health service to promote health and quality of life. METHODS: The subjects for this study were 38 nurses who provide visit-nursing service to live-alone elders in Seoul and Kyunggi Province. Data were collected by semi-structured questionnaires. RESULTS: The half of live-alone elders had disease, but only half of them took appropriate treatment. Barrier to treatment were difficulty to access to medical center, immobility, lack of drive and also poor insight. CONCLUSION: To solve the problems related to the elderly living alone in community, the instillation of public health policy that encompass professional medical service and comprehensive team approach are needed.

Association of the Gene Polymorphisms of Platelet Glycoprotein Ia and IIb/IIIa with Myocardial Infarction and Extent of Coronary Artery Disease in the Korean Population

Platelet membrane receptor glycoproteins (GP) are essential for the platelet activation process, and the genetic polymorphisms in the genes that encode platelet glycoproteins have been proposed to influence the risk of acute coronary syndrome and atherosclerosis. In this study, we investigated the role of GPIa, HPA-1 and HPA-3 polymorphisms as putative risk factors for myocardial infarction (MI) and the extent of coronary artery disease. We selected 1, 073 subjects who underwent coronary angiography; 242 had normal or minimal coronary atherosclerosis, and 831 patients had significant coronary artery disease (CAD). The genotype was determined by the methods of single base extension for C807T/G873A polymorphisms of GPIa, and restriction fragment length polymorphism for HPA-1 and HPA-3. The C807T and G873A polymorphisms of GPIa showed complete linkage in the Korean population. For HPA-1 gene polymorphism, only the HPA-1a/a (PlA1/A1) genotype was observed in 192 selected subjects from our study population. The distribution of GPIa (C807T/G873A) and HPA-3 genotypes did not differ significantly between normal subjects and CAD subjects. No significant association between MI and both gene polymorphisms was present. However, for the subgroup analysis of young male patients whose age was less than 56 years, the genotype frequency of HPA-3b/b was significantly lower in patients with MI compared to patients without a history of MI (7.5% vs. 20.0%, p=0.04). The odds ratio for HPA-3 b homozygosity versus the HPA-3a carrier was 0.32 (95% CI, 0.10- 0.99, p=0.04). Conclusively, HPA-3 polymorphism was associated with MI in Korean individuals younger than 56 years of age, but other polymorphisms of GP, which we studied, were not associated with both the extent of coronary atherosclerosis or MI.

Quantitative Analysis of SMN1 Gene and Estimation of SMN1 Deletion Carrier Frequency in Korean Population based on Real-Time PCR

Spinal muscular atrophy (SMA) is an autosomal recessive disorder, caused by homozygous absence of the survival motor neuron gene (SMN1) in approximately 94% of patients. Since most carriers have only one SMN1 gene copy, several SMN1 quantitative analyses have been used for the SMA carrier detection. We developed a reliable quantitative real-time PCR with SYBR Green I dye and studied 13 patients with SMA and their 24 parents, as well as 326 healthy normal individuals. The copy number of the SMN1 gene was determined by the comparative threshold cycle (Ct) method and albumin was used as a reference gene. The homozygous SMN1 deletion ratio of patients was 0.00 and the hemizygous SMN1 deletion ratio of parents ranged from 0.39 to 0.59. The delta delta Ct ratios of 7 persons among 326 normal individuals were within the carrier range, 0.41-0.57. According to these data, we estimated the carrier and disease prevalence of SMA at 1/47 and 1/8,496 in Korean population, respectively. These data indicated that there would be no much difference in disease prevalence of SMA compared with western countries. Since the prevalence of SMA is higher than other autosomal recessive disorders, the carrier detection method using real-time PCR could be a useful tool for genetic counseling.