rBMSCs/ITGA5B1 Promotes Human Vascular Smooth Muscle Cell Differentiation via Enhancing Nitric Oxide Production

BACKGROUND AND OBJECTIVES: Previous studies have shown that integrins alpha5beta1 (ITGA5B1) gene-modified rat bone marrow mesenchymal stem cells (rBMSCs) could prevent cell anoikis and increase the nitric oxide (NO) production. Here we examined the capability of rBMSCs/ITGA5B1 on the phenotype modulation of Human Pulmonary Artery Smooth Muscle Cell (HPASMC) in vitro. METHODS AND RESULTS: The synthetic (dedifferentiated) phenotype of HPASMC was induced by monocrotaline (MCT, 1μM) for 24 h and then co-cultured with rBMSCs/ITGA5B1 in a transwell culture system. The activation of NO/cGMP (nitric oxide/Guanosine-3′, 5′-cyclic monophosphate) signaling was investigated in HPASMC. The changes of pro-inflammatory factors, oxidative stress, vasodilator, vasoconstrictor, contractile and synthetic genes, and the morphological changes of HPASMC were investigated. The results of this study showed that the NO/cGMP signal, endothelial nitric oxide synthase (eNOS) expression, the expression of the vasoprotective genes heme oxygenase-1 (HMOX1) and prostaglandin-endoperoxide synthase 2 (PTGS2) were increased, but the expression of transforming growth factor-β1 (TGF-β1), CCAAT/enhancer-binding proteins delta (Cebpd), Krüppel-like factor 4 (KLF4), and activating transcription factor 4 (ATF4) were reduced in MCT treated HPASMC co-cultured with rBMSCs/ITGA5B1. The synthetic smooth muscle cells (SMCs) phenotype markers thrombospondin-1, epiregulin and the vasoconstrictor endothelin (ET)-1, thromboxane A2 receptor (TbxA2R) were down-regulated, whereas the contractile SMCs phenotype marker transgelin expression was up-regulated by rBMSCs/ITGA5B1. Furthermore, rBMSCs/ITGA5B1 promoted the morphological restoration from synthetic (dedifferentiation) to contractile (differentiation) phenotype in MCT treated HPASMC. CONCLUSIONS: rBMSCs/ITGA5B1 could inhibit inflammation and oxidative stress related genes to promote the HPASMC cell differentiation by activation NO/cGMP signal.

In silico target fishing for the potential bioactive components contained in Huanglian Jiedu Tang (HLJDD) and elucidating molecular mechanisms for the treatment of sepsis / 中国天然药物

The present study was designed to target fish for potential bioactive components contained in a Huang Lian Jie Du decoction (HLJDD) and identify the underlying mechanisms of action for the treatment of sepsis at the molecular level. he bioactive components database of HLJDD was constructed and the sepsis-associated targets were comprehensively investigated. The 3D structures of the PAFR and TXA2R proteins were established using the homology modelling (HM) method, and the molecular effects for sepsis treatment were analysed by comparing the bioactive components database and the sepsis targets using computational biology methods. The results of the screening were validated with biological testing against the human oral epidermal carcinoma cell line KB in vitro. We found that multiple bioactive compounds contained in the HLJDD interacted with multiple targets. We also predicted the promising compound leads for sepsis treatment, and the first 28 compounds were characterized. Several compounds, such as berberine, berberrubine and epiberberine, dose-dependently inhibited PGE2 production in human KB cells, and the effects were similar in the presence or absence of TPA. This study demonstrates a novel approach to identifying natural chemical compounds as new leads for the treatment of sepsis.

The role of oxide stress during the pathogenesis of chronic pancreatic injuries induced by chronic high-fat diets in rat / 中华外科杂志

<p><b>OBJECTIVE</b>To provide more detailed information on the roles of lipid peroxidation in the pathogenesis of chronic pancreatic injuries in a pre-clinical rat model.</p><p><b>METHODS</b>Totally 72 rats were divided into 6 groups (12 in each group) Rats in 5 experimental groups (n = 12) were fed with a high-fat diet (1% cholesterol, 10% lard, 0.3% sodium tauroglycocholate, 87.3% standard rodent chow as the control group) for 2, 4, 6, 10 and 16 weeks, respectively. Morphological studies in the pancreas tissue samples from rats were investigated by using various histological methods. Pancreatic stellate cells (PSCs) were identified by immunohistochemical staining for Desmin and α-smooth muscle actin (α-SMA). The expression of the lipid peroxidation was detected by immunostaining for 4-hydroxy-2-nonenal (4-HNE) and thromboxane A2 receptor (TxA2r). The co-localization of α-SMA and 4-HNE or α-SMA and TxA2r in PSCs was also analyzed in this study.</p><p><b>RESULTS</b>Pancreatic cells with positive staining for Desmin and α-SMA in HFD rats were distributed in a more extensive way when compared to that in the control group. The levels of pancreatic 4-HNE and TxA2r were increased in rats from HFD groups significantly. The co-localization of 4-HNE and TxA2r were also found within activated PSCs in both of groups.</p><p><b>CONCLUSION</b>The results showed that a chronic HFD feeding may increase the lipid peroxidation process and collagen synthesis through a critical signaling pathway of activated PSCs following pancreatic injuries in rats.</p>

Stroke Update 2011: New Antithrombotics / 대한뇌졸중학회지

Several new antithrombotic drugs have been developed and approved to use in clinical practice recently. Dabigatran, a direct thrombin inhibitor, and rivaroxaban, a factor Xa inhibitor, have been approved in many countries including Korea to prevent stroke in patient with atrial fibrillation. Apixaban, another factor Xa inhibitor, showed good results in clinical trial and is waiting for approval for clinical use. New antiplatelet agent, terutroban, selective thromboxane A2 receptor inhibitor, failed to prove the efficacy over the aspirin in secondary stroke prevention. Vorapaxar, a new antiplatelet agent that inhibits thrombin through PAR-1 antagonism, showed a high incidence of intracranial hemorrhage in patient with a history of stroke.

Effect of polymorphism and type II diabetes on aspirin resistance in patients with unstable coronary artery disease / 中华医学杂志(英文版)

<p><b>BACKGROUND</b>Aspirin is widely used in the secondary prevention of coronary artery diseases, including myocardial infarction, stroke, and vascular related deaths. However, the antiplatelet effect of aspirin appears to be variable and aspirin resistance (AR) is currently still controversial for Chinese patients. The aim of this study was to describe the prevalence of AR, and identify possible risk factors associated with a lack of response to aspirin treatments in patients with unstable coronary artery disease.</p><p><b>METHODS</b>Platelet function tests with arachidonic acid (ARA) and urinary 11-dehydro-thromboxane B2 (11-DH-TXB2) concentrations were performed in 262 patients with unstable coronary artery disease who had not been taking aspirin before admission. ARA induced platelet aggregation and 11-DH-TXB2 were detected to evaluate the functional and biochemical responses to aspirin before and on days 1, 4, and 10 after aspirin administration. Six-month follow-up was completed in patients who developed AR to evaluate the effect of aspirin in a long-term treatment. GP1Bα (C1018T), Pl (A1/A2), P2Y1 (A1622G), TBXA2R (T924C) were also detected to evaluate the influence of genetic variant on aspirin responsiveness.</p><p><b>RESULTS</b>A total of 8.8% of patients were indentified as AR at the first day after aspirin treatment. The level of urine 11-DH-TXB2 in the AR group was higher compared to non-AR group (P < 0.05). There was no relationship between ARA induced platelet aggregation and urinary 11-DH-TXB2 levels (r = 0.038, P = 0.412). The results of DNA sequencing showed that TBXA2R-924TT homozygotes had a significantly high rate of AR. Logistic regression demonstrated that diabetes was an independent risk factor of AR.</p><p><b>CONCLUSIONS</b>In the beginning period of administration, aspirin was not a sufficient factor that inhibits platelet aggregation. TBXA2R-924T allele was involved in AR. Diabetes was an independent risk factor of AR.</p>

Correlation between oligohydramnios and abnormal expressions of TXA2, PGI2 and TXA2R in the umbilical arterial blood and placenta / 南方医科大学学报

<p><b>OBJECTIVE</b>To investigate the roles of thromboxane A(2) (TXA(2)) and prostaglandin I(2) (PGI(2)) in development of oligohydramnios.</p><p><b>METHODS</b>The concentration of TXB(2) and 6-keto-PGF1 in umbilical cord blood collected from 30 normal parturients (control) and 30 parturients with oligohydramnios was detected by radioimmunoassay to calculate the TXA(2)/PGI(2) ratio. Immunohistochemistry was performed to detect the contents of TXA(2)R in vascular endothelial cell in the placental villi.</p><p><b>RESULTS</b>Compared with the control group, the concentration of umbilical cord blood TXB(2) in oligohydramnios group was significantly increased (P<0.01), but the elevation of 6-keto-PGF(2) concentration was not statistically significant (P>0.05). The oligohydramnios group showed significantly higher positivity rates of TXB2 and 6-keto-PGF1 in than the control group (P<0.01), and the positivity rate of TXA(2)R in the vascular endothelial cells in the placental villi was also significantly higher in the oligohydramnios group (22/30, 77.3% vs 11/30, 36.7%, P<0.05). Most of the TXA(2)R-positive cases in the oligohydramnios group showed strong positivities of TXA(2)R.</p><p><b>CONCLUSION</b>Abnormal elevation of TXA(2) concentration in the umbilical cord blood and the TXA(2)/PGI(2) imbalance are responsible for the development of oligohydramnios.</p>

Thromboxane A2 modulates migration, proliferation, and differentiation of adipose tissue-derived mesenchymal stem cells

Prostanoid metabolites are key mediators in inflammatory responses, and accumulating evidence suggests that mesenchymal stem cells (MSCs) can be recruited to injured or inflamed tissues. In the present study, we investigated whether prostanoid metabolites can regulate migration, proliferation, and differentiation potentials of MSCs. We demonstrated herein that the stable thromboxane A2 (TxA2) mimetic U46619 strongly stimulated migration and proliferation of human adipose tissue-derived MSCs (hADSCs). Furthermore, U46619 treatment increased expression of alpha-smooth muscle actin (alpha-SMA), a smooth muscle marker, in hADSCs, suggesting differentiation of hADSCs into smooth muscle-like cells. U46619 activated ERK and p38 MAPK, and pretreatment of the cells with the MEK inhibitor U0126 or the p38 MAPK inhibitor SB202190 abrogated the U46619-induced migration, proliferation, and alpha-SMA expression. These results suggest that TxA2 plays a key role in the migration, proliferation, and differentiation of hADSCs into smooth muscle-like cells through signaling mechanisms involving ERK and p38 MAPK.