Physical properties of poly(N-isopropylacrylamide) hydrogel promote its effects on cardiac protection after myocardial infarction

OBJECTIVE

Studies have demonstrated the protective effects of biomaterials against myocardial infarction (MI), but the relationship between their physical characteristics and their function is incompletely understood. This study investigated such relationships for a hydrogel preparation.

METHODS

Two types of poly(N-isopropylacrylamide) (PNIPAAm) hydrogel with different degradation times (Gel A and Gel B) were synthesized. In vivo hydrogel formation and maintenance were observed and confirmed in mice. The solutions were also injected into the infarct area immediately after MI induction in rats.

RESULTS

PNIPAAm hydrogel exhibited a three-dimensional structure resembling native extracellular matrix (ECM). Compared with phosphate-buffered saline, Gel A and Gel B increased contractility of isolated infarcted myocardium, reduced collagen deposition, increased neovascularization, inhibited left ventricle expansion and improved cardiac function. Myocardial contractility was greater with Gel B than with Gel A.

CONCLUSIONS

Intramyocardial injection of PNIPAAm hydrogel provides structural support and some functional repair of damaged ECM, suggesting that it might be useful for cardiac tissue engineering.

Overexpression of 4EBP1, p70S6K, Akt1 or Akt2 differentially promotes Coxsackievirus B3-induced apoptosis in HeLa cells

Our previous studies have shown that the inhibition of phosphatidylinositol 3-kinase (PI3K) or mTOR complex 1 can obviously promote the Coxsackievirus B3 (CVB3)-induced apoptosis of HeLa cells by regulating the expression of proapoptotic factors. To further illustrate it, Homo sapiens eIF4E-binding protein 1 (4EBP1), p70S6 kinase (p70S6K), Akt1 and Akt2 were transfected to HeLa cells, respectively. And then, we established the stable transfected cell lines. Next, after CVB3 infection, apoptosis in different groups was determined by flow cytometry; the expressions of Bim, Bax, caspase-9 and caspase-3 were examined by real-time fluorescence quantitative PCR and western blot analysis; the expression of CVB3 mRNA and viral capsid protein VP1 were also analyzed by real-time fluorescence quantitative PCR, western blot analysis and immunofluorescence, respectively. At the meantime, CVB3 replication was observed by transmission electron microscope. We found that CVB3-induced cytopathic effect and apoptosis in transfected groups were more obvious than that in controls. Unexpectedly, apoptosis rate in Akt1 group was higher than others at the early stage after viral infection and decreased with the viral-infected time increasing, which was opposite to other groups. Compared with controls, the expression of CVB3 mRNA was increased at 3, 6, 12 and 24 h postinfection (p. i.) in all groups. At the meantime, VP1 expression in 4EBP1 group was higher than control during the process of infection, while the expressions in the other groups were change dynamically. Moreover, overexpression of 4EBP1 did not affect the mRNA expressions of Bim, Bax, caspase-9 and caspase-3; while protein expressions of Bim and Bax were decreased, the self-cleavages of caspase-9 and caspase-3 were stimulated. Meanwhile, overexpression of p70S6K blocked the CVB3-induced Bim, Bax and caspase-9 expressions but promoted the self-cleavage of caspase-9. In the Akt1 group, it is noteworthy that the expressions of Bim protein were higher than controls at 3 and 6 h p. i. but lower at 24 h p. i., and the expression of Bax protein were higher at 6 and 24 h p. i., while their mRNA expressions were all decreased. Furthermore, overexpression of Akt1 stimulated the procaspase-9 and procaspase-3 expression but blocked their self-cleavages. Overexpression of Akt2, however, had little effect on Bim, Bax and caspase-3, while prevented caspase-9 from self-cleavage at the late stage of CVB3 infection. As stated above, our results demonstrated that overexpression of 4EBP1, p70S6K, Akt1 or Akt2 could promote the CVB3-induced apoptosis in diverse degree via different mediating ways in viral replication and proapoptotic factors in BcL-2 and caspase families. As 4EBP1, p70S6K and Akt are the important substrates of PI3K and mammalian target of rapamycin (mTOR), we further illustrated the role of PI3K/Akt/mTOR signaling pathway in the process of CVB3-induced apoptosis.

Dissecting x-ray-emitting gas around the center of our galaxy

Most supermassive black holes (SMBHs) are accreting at very low levels and are difficult to distinguish from the galaxy centers where they reside. Our own Galaxy's SMBH provides an instructive exception, and we present a close-up view of its quiescent x-ray emission based on 3 megaseconds of Chandra observations. Although the x-ray emission is elongated and aligns well with a surrounding disk of massive stars, we can rule out a concentration of low-mass coronally active stars as the origin of the emission on the basis of the lack of predicted iron (Fe) Kα emission. The extremely weak hydrogen (H)-like Fe Kα line further suggests the presence of an outflow from the accretion flow onto the SMBH. These results provide important constraints for models of the prevalent radiatively inefficient accretion state.

Anti-inflammatory effect of purified dietary anthocyanin in adults with hypercholesterolemia: a randomized controlled trial

BACKGROUND AND AIM

Atherosclerosis is a chronic inflammatory disease and previous studies have demonstrated that anthocyanin inhibits atherosclerosis. In the present study, we explored the effects of anthocyanins on inflammatory cytokines in hypercholesterolemic adults and cell lines.

METHODS AND RESULTS

A total of 150 subjects with hypercholesterolemia consumed a purified anthocyanin mixture (320 mg/d) or a placebo twice a day for 24 weeks in a randomized, double-blind trial. Anthocyanin consumption significantly decreased the levels of serum high sensitivity C-reactive protein (hsCRP) (-21.6% vs. -2.5%, P = 0.001), soluble vascular cell adhesion molecule-1 (sVCAM-1) (-12.3% vs. 0.4%, P = 0.005) and plasma IL-1β (-12.8% vs. -1.3%, P = 0.019) compared to the placebo. We also found a significant difference in the LDL-cholesterol (-10.4% vs. 0.3%, P = 0.030) and HDL-cholesterol level changes (14.0% vs. -0.9%, P = 0.036) between the two groups. In cell culture assays in vitro, purified anthocyanin mixture, delphinidin-3-Ο-β-glucoside (Dp-3g) and cyanidin-3-Ο-β-glucoside (Cy-3g) inhibited IL-6 and IL-1β-induced CRP production (P < 0.05) in HepG2 cell line and LPS-induced VCAM-1 secretion (P < 0.05) in porcine iliac artery endothelial cell line respectively in a dose-dependent manner. In addition, the reduction of inflammatory cytokines associated with anthocyanin mixture was stronger when compared with the effects of Dp-3g and Cy-3g separately (P < 0.05).

CONCLUSIONS

Anthocyanin mixture reduced the inflammatory response in hypercholesterolemic subjects. In addition, different anthocyanin compounds were found to have additive or synergistic effects in mediating anti-inflammatory responses in vitro cell culture assays.

Association and interaction analysis of metabolic syndrome and serum uric acid on diastolic heart failure

BACKGROUND

We aimed to assess the extent to which metabolic syndrome (MetS) and serum uric acid (UA) and its interaction impact on diastolic heart failure (DHF).

MATERIALS AND METHODS

A total of 133 patients with DHF and 118 age- and gender-matched control subjects were studied. Echocardiography was used to assess left ventricular (LV) diastolic function. MetS was defined by suggestions of international diabetes federation (IDF, 2005). The association between MetS or UA and DHF was assessed by multivariate logistic regression analysis (MLR) controlling confounders. The interaction between MetS and UA on DHF was assessed by generalized linear model (GLM) and MLR analysis.

RESULTS

MetS and UA were independent predictors of DHF after adjustment for all variables (OR=0.833~2.27, ORUA=1.003 and p<0.05 for all). There was an interaction effect of MetS and UA on DHF (ORInt=2.41~2.66, pInt<0.05).

CONCLUSION

The findings of the present study suggested that MetS or UA is associated with DHF, and that MetS interacts with UA to impact on DHF.

Bone marrow-derived endothelial progenitor cells promote hematopoietic reconstitution after hematopoietic stem cell transplantation

OBJECTIVE

A hematopoietic deficit is a serious complication after hematopoietic stem cell transplantation. It has been shown that fetal blood-derived endothelial progenitor cells (EPCs) can promote hematopoietic reconstitution after transplantation. This study investigated whether EPCs from bone marrow (BM) of adult mice could promote hematopoietic reconstitution.

METHODS

Lethally irradiated BALB/c mice were administered BM cells or BM cells plus EPCs.

RESULTS

The results showed that EPC-treated mice displayed accelerated recovery of peripheral blood white blood cells and reticulocytes. But the platelets were not significantly different with versus without EPCs. Accelerated recovery of BM sinusoidal vessels, promotion of stem cell implantation, and decreased adipocyte formation were associated with the mechanism. Systemic administration of anti-vascular endothelial cadherin antibody neutralized these effects significantly.

CONCLUSION

These data showed that BM-derived EPC infusions augmented hematopoiesis suggesting a new approach to promote hematopoiesis.

Pharmacokinetic/pharmacodynamic relationship of marbofloxacin against Pasteurella multocida in a tissue-cage model in yellow cattle

The fluoroquinolone antimicrobial drug marbofloxacin was administered to yellow cattle intravenously and intramuscularly at a dose of 2 mg/kg of body weight in a two-period crossover study. The pharmacokinetic properties of marbofloxacin in serum, inflamed tissue-cage fluid (exudate), and noninflamed tissue-cage fluid (transudate) were studied by using a tissue-cage model. The in vitro and ex vivo activities of marbofloxacin in serum, exudate, and transudate against a pathogenic strain of Pasteurella multocida (P. multocida) were determined. Integration of in vivo pharmacokinetic data with the in vitro MIC provided mean values for the area under the curve (AUC)/MIC for serum, exudate, and transudate of 155.75, 153.00, and 138.88, respectively, after intravenous dosing and 160.50, 151.00, and 137.63, respectively, after intramuscular dosing. After intramuscular dosing, the maximum concentration/MIC ratios for serum, exudate, and transudate were 21.13, 9.13, and 8.38, respectively. The ex vivo growth inhibition data after intramuscular dosing were fitted to the inhibitory sigmoid Emax equation to provide the values of AUC/MIC required to produce bacteriostasis, bactericidal activity, and elimination of bacteria. The respective values for serum were 17.25, 31.29, and 109.62, and slightly lower values were obtained for transudate and exudate. It is proposed that these findings might be used with MIC50 or MIC90 data to provide a rational approach to the design of dosage schedules which optimize efficacy in respect of bacteriological as well as clinical cures.

Genomic full-length sequence of two HLA-A alleles, A*30:01:01 and A*30:04:01, identified by cloning and sequencing

Genomic full-length sequences of HLA-A*30:01:01 and A*30:04:01, were identified by cloning and sequencing from two Chinese donors.

Chinese SLE Treatment and Research group (CSTAR) registry: I. Major clinical characteristics of Chinese patients with systemic lupus erythematosus

The Chinese systemic lupus erythematosus (SLE) treatment and research group (CSTAR) provides major clinical characteristics of SLE in China and establishes a platform to provide resources for future basic and clinical studies. CSTAR originated as a multicentre, consecutive, and prospective design. The data were collected online from 104 rheumatology centers, which covered 30 provinces in China. The registered patients were required to meet four or more of the American College of Rheumatology (ACR) criteria for the classification of SLE. All CSTAR centers use the same protocol-directed methods to provide uniform evaluations, which included demographic data, clinical features, laboratory examinations, and disease activity evaluations. The patient samples, including DNA samples and sera, were also collected for further quality controls and additional studies. Preliminary analysis from 2104 baseline evaluations was available for this analysis. Of 1914 female and 190 male patients (F:M=10.1), the mean age at onset was 29.2 y with confirmed diagnosis one year later at the age of 30.3 y. Eighty four (4.2%) of 2002 patients had a family history of rheumatic diseases, including 34 (1.7%) cases with SLE. In addition, one hundred and seven (5.2%) abnormal pregnancies were recorded among 2026 experiences. The characteristics of the CSTAR cohort were compared to similarly sized cohorts from other studies. We found that 56.1% of patients presented with concurrent hematological disorders compared to only 18.2% of European patients. Moreover, 47.4% of patients presented with nephropathy compared to 27.9% of European patients. Conversely, neurological manifestations were only seen in 4.8% of Chinese SLE patients compared to 19.4% of European patients, 12.1% of U.S. patients, 22.8% of Malaysian patients and 26.4% of Latin Americans. Pulmonary arterial hypertension and interstitial lung diseases were complications identified in 3.8% and 4.2% of Chinese lupus patients, respectively. The CSTAR registry has provided epidemiological data and phenotypes of Chinese patients with SLE, and has demonstrated several differences between ethnicities. Clinical data and biologic samples would be valuable resources for future translational studies with national and international collaboration.

An inductive signalling network regulates mammalian tooth morphogenesis with implications for tooth regeneration

Sequential and reciprocal epithelial-mesenchymal interactions, essential throughout such aspects of tooth morphogenesis as patterning, size and number of teeth, involves a well-ordered series of inductive and permissive signals that exert global control over cell proliferation, differentiation and organogenesis. In particular, growth factors, transcription factors and their corresponding receptors, as well as other soluble morphogens, make up a regulatory network at the molecular level that synergistically or antagonistically controls intra-/inter-cellular signal transduction during odontogenesis. This review summarizes recent advances in the study of crucial signalling pathways, for example of BMPs, Wnt, Notch, Shh and FGF, with emphasis on the potential integrated signalling network responsible for tooth formation. Our work probes into the complexity of these inductive signalling pathways to promote the understanding of tooth regeneration. Additionally, our study provides further insights into therapeutic strategies for various dental abnormalities in patterning and number, such as tooth agenesis and supernumerary teeth.

Sodium selenite induces apoptosis in colon cancer cells via Bax-dependent mitochondrial pathway

OBJECTIVES

We aimed to elucidate a possible mechanism of action by investigating the effects of selenium (Se) on cell cycle arrest and apoptosis in colorectal cancer cells (HCT116 cells and SW620 cells).

MATERIALS AND METHODS

The colorectal cancer cells were treated with varying concentrations of Se (1 microM, 5 microM and 10 microM) for 24 hours. The effects of Se on cell cycle, apoptosis, mitochondrial transmembrane potential and apoptosis related proteins were examined by flow cytometry assessment and immunoblotting.

RESULTS

Se induced G2/M cell cycle arrest and apoptosis in colorectal cancer cells (HCT116 cells and SW620 cells) in a dose-dependent manner. Bax (Bcl2 associated X protein) was up-regulated and Bcl-2 (B cell linphoma gene-2) was down-regulated after Se treatment in both cells in a dose-dependent manner. Se caused increased loss of MMP (matrix metalloproteinase) and induced Bax translocation from cytosol into mitochondria and caspase 3 activation in both colorectal cancer cells in a dose-dependent manner.

CONCLUSIONS

Se induced G2/M cell cycle arrest and apoptosis in both colorectal cancer cells via Bax-dependent mitochondrial pathway.

In vitro proliferation and differentiation of hepatic oval cells and their potential capacity for intrahepatic transplantation

Hepatic oval cells (HOCs) are recognized as facultative liver progenitor cells that play a role in liver regeneration after acute liver injury. Here, we investigated the in vitro proliferation and differentiation characteristics of HOCs in order to explore their potential capacity for intrahepatic transplantation. Clusters or scattered HOCs were detected in the portal area and interlobular bile duct in the liver of rats subjected to the modified 2-acetylaminofluorene and partial hepatectomy method. Isolated HOCs were positive for c-kit and CD90 staining (99.8% and 88.8%, respectively), and negative for CD34 staining (3.6%) as shown by immunostaining and flow cytometric analysis. In addition, HOCs could be differentiated into hepatocytes and bile duct epithelial cells after leukemia inhibitory factor deprivation. A two-cuff technique was used for orthotopic liver transplantation, and HOCs were subsequently transplanted into recipients. Biochemical indicators of liver function were assessed 4 weeks after transplantation. HOC transplantation significantly prolonged the median survival time and improved the liver function of rats receiving HOCs compared to controls (P=0.003, Student t-test). Administration of HOCs to rats also receiving liver transplantation significantly reduced acute allograft rejection compared to control liver transplant rats 3 weeks following transplantation (rejection activity index score: control=6.3±0.9; HOC=3.5±1.5; P=0.005). These results indicate that HOCs may be useful in therapeutic liver regeneration after orthotopic liver transplantation.

Development of a novel adenovirus-alphavirus hybrid vector with RNA replicon features for malignant hematopoietic cell transduction

To improve the expression levels of transgenes in malignant hematopoietic cells, we developed a novel adenoviral-alphavirus hybrid vector Ad5/F11p-SFV-GFP that contains a Semliki Forest Virus (SFV) replicon and chimeric fibers of Ad5 and Ad11p. Ad5/F11p-SFV-GFP infected >95% of K562, U937 or Jurkat cells and 23.65% of HL-60 cells, and led to moderate Enhanced Green Fluorescent Protein (EGFP) transgene expression intensity. The infection efficiency of Ad5/F11p-SFV-GFP in primary human leukemia cells ranged from 9.34-89.63% (median, 28.58%) at a multiplicity of infection (MOI) of 100, compared with only 3.37-44.54% (median, 10.42%) in cells infected by Ad5/F11p-GFP. Importantly, Ad5/F11p-SFV-GFP led to a significantly higher transgene expression level in primary leukemia cells, as indicated by the relative fluorescence intensity, compared to cells infected with Ad5/F11p-GFP. The increased expression of EGFP in Ad5/F11p-SFV-GFP-infected cells was associated with the accumulation of abundant subgenomic mRNA. Additionally, infection of K562, U937 or Jurkat cells by Ad5/F11p-SFV-GFP was significantly inhibited by blocking CD46 receptor; however, other factors may affect the gene-transfer efficiency of Ad5/F11p-SFV-GFP in primary leukemia cells. In conclusion, we successfully developed a novel adenoviral-alphavirus hybrid vector with RNA replicon features, which represents a promising vector for gene modifications during the production of cell-based vaccines for leukemia patients.