Morphologic characterization and quantification of superficial calcifications of the coronary artery--in vivo assessment using optical coherence tomography.

Coronary calcification is proportional to the extent and severity of atherosclerotic disease, and is a predictor of cardiac events. Furthermore, coronary calcification protruding into the lumen is considered as one type of vulnerable plaque. Optical coherence tomography (OCT) can provide in vivo imaging of the detailed vessel wall structure of the coronary artery with high resolution, as in the histological approach. We analyzed coronary calcification in that fashion using OCT in vivo. This study consisted of 70 superficial coronary calcifications of 39 consecutive patients who underwent percutaneous coronary intervention. After revascularization, OCT was performed in the treated vessel. We analyzed morphologic characteristics and the quantification of OCT-determined coronary calcification. Superficial coronary calcifications were classified into two groups depending on whether they did not intrude the lumen (type I) or did (type II). The distance from the lumen and the volume of each calcification were then measured. Superficial coronary calcifications were classified into two groups; type I, n = 39 (56%) and type II, n = 31 (44%). Type II calcifications were located significantly closer to the lumen [80 microm (60-130) vs.130 microm (90-260), p = 0.015], and tended to be smaller, but did not show a significant difference [0.65 (0.2631.3) mm3 vs. 1.2 (0.47-1.9) mm3, p = 0.153] compared to those of type I. In conclusion, OCT could visualize superficial coronary calcifications in detail and enable us to evaluate in vivo morphologic characterizations and quantify them.

Low-intensity pulsed ultrasound accelerates osteoblast differentiation and promotes bone formation in an osteoporosis rat model.

OBJECTIVE: We examined the effects of low-intensity pulsed ultrasound (LIPUS) on cell differentiation, bone mineralized nodule formation and core-binding factor A1 (Cbfa1) expression in a normal human osteoblast (NHOst) cell line and bone formation in an osteoporosis animal model. METHODS: NHOst cells were cultured in vitro in medium with or without LIPUS stimulation. The ultrasound stimulation frequency was 1.0 MHz at an intensity of 30 mW/cm(2) for 20 min. Rats were divided into a sham-operated group (Sham) and an ovariectomized group (OVX). The right femur was treated with LIPUS (Sham-LIPUS and OVX-LIPUS) and the left femur was left untreated (Sham-CON and OVX-CON). RESULTS: LIPUS stimulation accelerated bone nodule formation and enhanced alkaline phosphatase activity. The expression levels of Cbfa1 decreased and calcification occurred earlier and more frequently in the LIPUS than in the CON groups. The wet weight of the femur increased in OVX rats with LIPUS stimulation. Morphological images showed an increase in trabecular spongiosa in the OVX-LIPUS group. CONCLUSION: LIPUS accelerated osteogenesis. Moreover, since LIPUS prevents bone loss, it may be a promising treatment for osteoporosis.

Inhibitory modulation of human estrogen receptor α and ß activities by dicyclohexyl phthalate in human breast cancer cell lines.

Phthalate esters (PAEs) are man-made compounds that are used widely in industry, and the ubiquitous exposure of humans to PAEs has been reported. Although some PAEs have been suggested to function as xenoestrogens in in vitro systems, such as human estrogen receptors (ERs) expressed in Chinese hamster ovary (CHO)-K1 cells, few studies have attempted to elucidate whether PAEs affect human ERα/ERß-mediated signaling in human breast cancer cells (i.e., combination between human ERs and human cells). Thus, further experiments are needed in order to clarify the activities of PAEs. Among the 9 PAEs (carbon# in the side chains: 2-8) investigated, dibutyl phthalate (DBP), dipentyl phthalate (DPENP), and dicyclohexyl phthalate (DCHP) were found to exhibit strong anti-estrogenic activities in MCF-7 cells (ER-positive) in the presence of 1 nM 17ß-estradiol (E2). Since limited information is currently available on DPENP and DCHP, we herein focused on these two PAEs. Experiments using MDA-MB-231 cells (ER-negative) transfected with human ERα or ERß expression plasmids revealed that DCHP was a markedly stronger anti-estrogenic PAE than DPENP; DCHP inhibited ERα and ERß activities stimulated by 1 nM E2 with IC50 values of ~5 and 11.2 µM, respectively. Furthermore, DCHP abrogated diarylpropionitrile (DPN)-stimulated ERß activity with an IC50 value of 5.17 µM, which was approximately 2-fold stronger than that of DPENP (IC50 = 10 µM). The results of the present study suggest that PAEs (DCHP) function not only as an anti-estrogen for ERα, but also for ERß, at least in human breast cancer cell lines.

Simulated microgravity facilitates cell migration and neuroprotection after bone marrow stromal cell transplantation in spinal cord injury.

INTRODUCTION: Recently, cell-based therapy has gained significant attention for the treatment of central nervous system diseases. Although bone marrow stromal cells (BMSCs) are considered to have good engraftment potential, challenges due to in vitro culturing, such as a decline in their functional potency, have been reported. Here, we investigated the efficacy of rat BMSCs (rBMSCs) cultured under simulated microgravity conditions, for transplantation into a rat model of spinal cord injury (SCI). METHODS: rBMSCs were cultured under two different conditions: standard gravity (1G) and simulated microgravity attained by using the 3D-clinostat. After 7 days of culture, the rBMSCs were analyzed morphologically, with RT-PCR and immunostaining, and were used for grafting. Adult rats were used for constructing SCI models by using a weight-dropping method and were grouped into three experimental groups for comparison. rBMSCs cultured under 1 g and simulated microgravity were transplanted intravenously immediately after SCI. We evaluated the hindlimb functional improvement for 3 weeks. Tissue repair after SCI was examined by calculating the cavity area ratio and immunohistochemistry. RESULTS: rBMSCs cultured under simulated microgravity expressed Oct-4 and CXCR4, in contrast to those cultured under 1 g conditions. Therefore, rBMSCs cultured under simulated microgravity were considered to be in an undifferentiated state and thus to possess high migration ability. After transplantation, grafted rBMSCs cultured under microgravity exhibited greater survival at the periphery of the lesion, and the motor functions of the rats that received these grafts improved significantly compared with the rats that received rBMSCs cultured in 1 g. In addition, rBMSCs cultured under microgravity were thought to have greater trophic effects on reestablishment and survival of host spinal neural tissues because cavity formations were reduced, and apoptosis-inhibiting factor expression was high at the periphery of the SCI lesion. CONCLUSIONS: Here we show that transplantation of rBMSCs cultured under simulated microgravity facilitates functional recovery from SCI rather than those cultured under 1 g conditions.

Electrical stimulation accelerates neuromuscular junction formation through ADAM19/neuregulin/ErbB signaling in vitro.

The mechanism by which electrical stimulation affects formation of neuromuscular junctions (NMJs) remains unknown. NG108-15, a neural cell line, is commonly used in in vitro co-culture models of myotubes to observe synapse formation; therefore, we employed this model to observe the effects of electrical stimulation on NMJ formation. Initially, L6 cells were differentiated and NG108-15 cells were then added to the same culture dish. After 2 and 3 days of co-culture, the cells were electrically stimulated at 50 V and 0.5 Hz for 0, 5, 30, and 60 min (C, ES5, ES30, and ES60 groups, respectively) and were analyzed after co-culture for 4 days. Immunofluorescence experiments showed significantly increased aggregation of acetylcholine receptors and inhibition of neural outgrowth in the ES30 and ES60 groups. Furthermore, ADAM19 and phospho-ErbB3 were found to be specifically localized in co-cultured NG108-15 cells. Immunoblotting demonstrated that synapsin 1, ADAM19 precursor and its activated form, phospho-ErbB3, and ERK1 protein levels had increased in an electrical stimulation period-dependent manner. Thus, we found that electrical stimulation accelerated NMJ formation, possibly through activation of ADAM19/neuregulin/ErbB signaling in NG108-15 cells.

Electrical stimulation enhances neurogenin2 expression through ß-catenin signaling pathway of mouse bone marrow stromal cells and intensifies the effect of cell transplantation on brain injury.

Bone marrow stromal cells (BMSCs) have received significant attention for its use in neural regeneration. However, neural replacement by transplanted BMSCs was not very effective. Recently, the gene transfection method has improved the capability of cell transplantation; however, this method results in canceration and immune rejection. We induced the differentiation of mouse BMSCs into neural cells using electrical stimulation and transplanted the cells into traumatic brain injury (TBI) model mice. We found that the electrically stimulated cells have good potential to differentiate into neural cells and contribute to recovery from TBI without differentiating into astrocytes. In addition, we found that electrical stimulation enhanced neurogenin2 (Ngn2) expression. Ngn2 is involved in neural differentiation and inhibits astrocytic differentiation during cell growth. Furthermore, we found that this enhancement of Ngn2 expression occurred through ß-catenin signaling pathway. This study may contribute to the use of BMSCs for neural replacement in central nervous system diseases.

Relation of plasma indoxyl sulfate levels and estimated glomerular filtration rate to left ventricular diastolic dysfunction.

The prognosis of patients with diastolic heart failure (HF) is as poor as that of patients with systolic HF. Greater chronic kidney disease-associated mortality occurs in patients with left ventricular (LV) diastolic HF than in those with systolic HF. Indoxyl sulfate (IS), a uremic toxin, directly affects cardiac cells adversely in in vitro experiments. We investigated the association of IS, a uremic toxin, and chronic kidney disease with LV diastolic dysfunction in the clinical setting. The present study included 204 consecutive patients with preserved LV systolic function. To evaluate LV function, all patients underwent echocardiography. To measure the plasma IS levels and estimated glomerular filtration rate (eGFR), blood samples were obtained. Of the 204 patients, 75 (37%) had LV diastolic dysfunction. A significantly lower prevalence of LV diastolic dysfunction was present in patients with lower plasma IS levels (≤1.0 µg/ml) than those with greater plasma IS levels (38 [29%] vs 37 [51%], p <0.001). Furthermore, a significantly lower prevalence of LV diastolic dysfunction was present in patients with lower plasma IS levels and preserved eGFR than those with greater plasma IS levels and preserved eGFR, those with lower plasma IS levels and a reduced eGFR, or those with greater plasma IS levels and reduced eGFR (20 [21%] vs 18 [53%], p = 0.001; 20 [21%] vs 18 [46%], p = 0.004; and 20 [21%] vs 19 [56%], p <0.001, respectively). In conclusion, greater plasma IS levels or a reduced eGFR, or both, represent an increased risk of LV diastolic dysfunction.

Interactive effects of cell therapy and rehabilitation realize the full potential of neurogenesis in brain injury model.

The therapeutic effect of rehabilitation after cell therapy for brain injury remains unclear. Here, we report the neural stem/progenitor cells transplantation into a brain injury mouse model followed by treadmill exercise training. Among all experimental groups, mice that underwent transplantation and treadmill exercise demonstrated significant functional motor and electrophysiological improvement. Transplanted cells at the brain injury site were observed and differentiated into neurons and astrocytes. Transplanted cells significantly differentiated into neurons in the mice that underwent transplantation and treadmill exercise compared with those treated with only transplantation. Furthermore, the expression of brain-derived neurotrophic factor and growth-associated protein 43 mRNAs were significantly up-regulated in the mice that underwent transplantation and treadmill exercise than in those in other experimental groups during the early recovery stage. These results suggest that rehabilitation after neural stem/progenitor cell transplantation enhances neurogenesis and promotes the recovery of motor function in brain injury model mice.

Regulation of hematopoietic stem cells using protein transduction domain-fused Polycomb.

The Polycomb-group complex is a chromatin regulatory factor that is classified into two different complexes: Polycomb repressive complex 1 and 2. Components of Polycomb repressive complex 1 are involved in the self-renewal of hematopoietic stem cells. Bmi1, one of these components, maintains the immaturity of neural and cancer stem cells as well as that of hematopoietic stem cells. We constructed recombinant protein transduction domain (PTD)-Polycomb proteins and transduced them into murine bone marrow (BM) cells. We designed and fused the PTD-protein transduction domain to three proteins (i.e., green fluorescent protein, Bmi1, and Mel18). Murine BM cells were incubated for 48 h and each PTD-Polycomb protein was added. Then, we analyzed the function of hematopoiesis using the colony assay and transplantation. BM cells exposed to PTD-Bmi1 showed an increased number of colonies. In contrast, BM cells exposed to PTD-Mel18 or to both proteins showed a decreased number of colonies. Hematopoietic cells derived from PTD-Bmi1-transduced BM cells were significantly increased in the peripheral blood at 6 weeks after transplantation. Moreover, 80% of mice transplanted with PTD-Bmi1-transduced BM cells died at 8 to 24 weeks after transplantation. However, only a few early deaths were observed in the mice transplanted with BM cells exposed to both PTD-Bmi1 and PTD-Mel18. We expect that hematopoietic stem cells could proliferate after transduction with PTD-Bmi1, but this may generate undesirable effects, e.g., tumorigenesis. Thus, Bmi1 and Mel18 have opposing functions and are present in distinct complexes.

Association of plasma ω-3 to ω-6 polyunsaturated fatty acid ratio with complexity of coronary artery lesion.

OBJECTIVE: Eicosapentaenoic acid (EPA) of the omega-3 polyunsaturated fatty acids (ω-3 PUFA) family plays important roles in the prevention of cardiovascular disease (CVD), while, arachidonic acid (AA) of the ω-6 PUFA family promotes inflammatory and prothrombotic influences. The complexity of coronary lesions represents the vulnerability of patients. The aim of this study was to investigate the association between the plasma EPA/AA ratio and the prevalence of complex coronary lesion morphology. METHODS: This study consisted of 206 consecutive patients with stable angina pectoris (sAP). Each coronary lesion was determined either as complex or simple based on angiographic findings. To examine the plasma fatty acid level, blood samples were obtained. Patients were divided into three groups according to the obtained plasma EPA/AA ratio: the highest tertile, n=67, the 2nd tertile, n=70, or the lowest tertile, n=69. RESULTS: A higher incidence of complex coronary lesion was obtained from patients with a lower plasma EPA/AA ratio [43 (62%) vs. 31 (44%) vs. 25 (37%), p=0.011]. High-sensitivity CRP levels and a low plasma EPA/AA ratio could independently predict the prevalence of complex coronary lesions on multivariate logistic regression analysis [odds ratio 1.83 (95%CI 1.03-3.25), p=0.038 and odds ratio 2.10 (95%CI 1.11-3.94), p=0.02)]. CONCLUSION: In patients with sAP, a low plasma EPA/AA ratio was significantly associated with a high prevalence of complex coronary lesions.

Impact of the first-generation drug-eluting stent implantation on periprocedural myocardial injury in patients with stable angina pectoris.

BACKGROUND AND PURPOSE: Percutaneous coronary intervention (PCI) with a drug-eluting stent (DES) is one of the standard treatments for patients with stable angina pectoris (AP). In spite of a notable effect in preventing restenosis after PCI, DES cannot improve the mortality of patients compared to a bare-metal stent (BMS). On the other hand, periprocedural myocardial injury (PMI) is related to poor prognosis in patients undergoing PCI. We compared DES to BMS in the incidence of PMI in patients with stable AP. METHODS AND SUBJECTS: We enrolled 265 consecutive patients with AP undergoing successful stent implantation. A blood sample was obtained from all patients immediately before and 24h after PCI. PMI was defined as an increase in creatine kinase-myocardial band isozyme fraction (CK-MB) greater than the upper limit of reference range 24h after PCI. During the study period, sirolimus- and paclitaxel-eluting stents were used as DES. The strategy of PCI including the type of stent to implant was left to the discretion of the operator. RESULTS: Patients were divided into two groups (DES group, n=136 and BMS group, n=129). The incidence of PMI was significantly higher in the DES group than in the BMS group (24% vs. 12%, p=0.015). Use of DES remained an independent predictor of PMI on multivariate logistic regression analysis after adjustment for confounding factors (odds ratio 2.20, 95% CI, 1.07-4.51, p=0.032). CONCLUSIONS: Implantation of the first-generation DES including sirolimus- and paclitaxel-eluting stents was associated with a higher incidence of PMI in patients with AP compared to BMS.

Simulated microgravity maintains the undifferentiated state and enhances the neural repair potential of bone marrow stromal cells.

Recently, regenerative medicine with bone marrow stromal cells (BMSCs) has gained significant attention for the treatment of central nervous system diseases. Here, we investigated the activity of BMSCs under simulated microgravity conditions. Mouse BMSCs (mBMSCs) were isolated from C57BL/6 mice and harvested in 1G condition. Subjects were divided into 4 groups: cultured under simulated microgravity and 1G condition in growth medium and neural differentiation medium. After 7 days of culture, the mBMSCs were used for morphological analysis, reverse transcription (RT)-polymerase chain reaction, immunostaining analysis, and grafting. Neural-induced mBMSCs cultured under 1G conditions exhibited neural differentiation, whereas those cultured under simulated microgravity did not. Moreover, under simulated microgravity conditions, mBMSCs could be cultured in an undifferentiated state. Next, we intravenously injected cells into a mouse model of cerebral contusion. Graft mBMSCs cultured under simulated microgravity exhibited greater survival in the damaged region, and the motor function of the grafted mice improved significantly. mBMSCs cultured under simulated microgravity expressed CXCR4 on their cell membrane. Our study indicates that culturing cells under simulated microgravity enhances their survival rate by maintaining an undifferentiated state of cells, making this a potentially attractive method for culturing donor cells to be used in grafting.

LIF-free embryonic stem cell culture in simulated microgravity.

BACKGROUND: Leukemia inhibitory factor (LIF) is an indispensable factor for maintaining mouse embryonic stem (ES) cell pluripotency. A feeder layer and serum are also needed to maintain an undifferentiated state, however, such animal derived materials need to be eliminated for clinical applications. Therefore, a more reliable ES cell culture technique is required. METHODOLOGY/PRINCIPAL FINDINGS: We cultured mouse ES cells in simulated microgravity using a 3D-clinostat. We used feeder-free and serum-free media without LIF. CONCLUSIONS/SIGNIFICANCE: Here we show that simulated microgravity allows novel LIF-free and animal derived material-free culture methods for mouse ES cells.