Differential transcriptome analysis of Sporocytophaga sp. CX11 and identification of candidate genes involved in lignocellulose degradation.

Cellulose is the most abundant renewable bioresources on earth, and the biodegradation and utilization of cellulose would contribute to the sustainable development of global environment. Sporocytophaga species are common aerobic cellulose-degrading bacteria in soil, which can adhere to the surface of cellulose matrix and motile by gliding. In this study, a differential transcriptome analysis of Sporocytophaga sp. CX11 was performed and a total of 4,217 differentially expressed genes (DEGs) were identified. Gene Ontology enrichment results showed that there are three GO categories related to cellulose degradation function among the annotated DEGs. A total of 177 DEGs were identified as genes encoding carbohydrate-active enzymes (CAZymes), among which 54 significantly upregulated CAZymes were mainly cellulases, hemicellulases, pectinases, etc. 39 DEGs were screened to associate with gliding function. In order to explore unannotated genes potentially related to cellulose metabolism, cluster analysis was performed using the Short-Time Series Expression Miner algorithm (STEM). 281 unannotated genes were predicted to be associated with the initial-middle stage of cellulose degradation and 289 unannotated genes might function in the middle-last stage of cellulose degradation. Sporocytophaga sp. CX11 could produce extracellular endo-xylanase, endo-glucanase, FPase and ß-glucosidase, respectively, according to different carbon source conditions. Altogether, this study provides valuable insights into the transcriptome information of Sporocytophaga sp. CX11, which would be useful to explore its application in biodegradation and utilization of cellulose resources.

IGF-1C domain-modified hydrogel enhances therapeutic potential of mesenchymal stem cells for hindlimb ischemia.

BACKGROUND: Poor cell engraftment and survival after transplantation limited the application of stem cell therapy. Synthetic biomaterials could provide an artificial microenvironment for stem cells, thereby improve cell survival and enhance the therapeutic efficiency of stem cells. METHODS: We synthesized a hydrogel by conjugating C domain peptide of insulin-like growth factor-1 (IGF-1C) onto chitosan (CS-IGF-1C hydrogel). Human placenta-derived mesenchymal stem cells (hP-MSCs), which constitutively express a red fluorescent protein (RFP) and renilla luciferase (Rluc), were co-transplanted with CS-IGF-1C hydrogel into a murine hindlimb ischemia model. Transgenic mice expressing firefly luciferase (Fluc) under the promoter of vascular endothelial growth factor receptor 2 (VEGFR2-Luc) were used. Dual bioluminescence imaging (BLI) was applied for tracking the survival of hP-MSCs by Rluc imaging and the VEGFR2 signal pathway activation by Fluc imaging. To investigate the therapeutic mechanism of CS-IGF-1C hydrogel, angiographic, real-time PCR, and histological analysis were carried out. RESULTS: CS-IGF-1C hydrogel could improve hP-MSCs survival as well as promote angiogenesis as confirmed by dual BLI. These results were consistent with accelerated skeletal muscle structural and functional recovery. Histology analysis confirmed that CS-IGF-1C hydrogel robustly prevented fibrosis as shown by reduced collagen deposition, along with increased angiogenesis. In addition, the protective effects of CS-IGF-1C hydrogel, such as inhibiting H2O2-induced apoptosis and reducing inflammatory responses, were proved by in vitro experiments. CONCLUSIONS: Taken together, IGF-1Cs provides a conducive niche for hP-MSCs to exert pro-mitogenic, anti-apoptotic, and pro-angiogenic effects, as well as to inhibit fibrosis. Thus, the incorporation of functional peptide into bioscaffolds represents a safe and feasible approach to augment the therapeutic efficacy of stem cells.

Comparison of Teratoma Formation between Embryonic Stem Cells and Parthenogenetic Embryonic Stem Cells by Molecular Imaging.

With their properties of self-renewal and differentiation, embryonic stem (ES) cells hold great promises for regenerative therapy. However, teratoma formation and ethical concerns of ES cells may restrict their potential clinical applications. Currently, parthenogenetic embryonic stem (pES) cells have attracted the interest of researchers for its self-renewing and pluripotent differentiation while eliciting less ethic concerns. In this study, we established a model with ES and pES cells both stably transfected with a double-fusion reporter gene containing renilla luciferase (Rluc) and red fluorescent protein (RFP) to analyze the mechanisms of teratoma formation. Transgenic Vegfr2-luc mouse, which expresses firefly luciferase (Fluc) under the promoter of vascular endothelial growth factor receptor 2 (Vegfr2-luc), was used to trace the growth of new blood vessel recruited by transplanted cells. Bioluminescence imaging (BLI) of Rluc/Fluc provides an effective tool in estimating the growth and angiogenesis of teratoma in vivo. We found that the tumorigenesis and angiogenesis capacity of ES cells were higher than those of pES cells, in which VEGF/VEGFR2 signal pathway plays an important role. In conclusion, pES cells have the decreased potential of teratoma formation but meanwhile have similar differentiating capacity compared with ES cells. These data demonstrate that pES cells provide an alternative source for ES cells with the risk reduction of teratoma formation and without ethical controversy.

P2X7 receptor regulates sympathoexcitatory response in myocardial infarction rats via NF-κB and MAPK pathways.

Previous studies have provided evidence for the regulatory effect of P2X7 receptor (P2X7R) on cardiovascular activities. Our study focused on exploring the function and fundamental mechanism of microglial P2X7R in controlling sympathoexcitatory response using rats with acute myocardial infarction (AMI). Coronary artery ligation was used in rats to cause AMI. And before that, rats were administrated with P2X7R siRNA that targeted P2X7R mRNA into paraventricular nucleus (PVN) or BBG (Brilliant Blue G, a P2X7 receptor antagonist). Increased expression levels of P2X7R and adenosine triphosphate (ATP) were observed in the hypothalamic PVN of AMI rats. Moreover, the knockdown of P2X7R expression by P2X7-siRNA or suppression of P2X7 receptor by BBG attenuated the elevation of both vasopressin and oxytocin levels in the PVNs of AMI rats. There was also a decrease in renal sympathetic nerve activity (RSNA) by P2X7-siRNA and BBG. Besides, inflammation was alleviated by P2X7-siRNA and BBG through suppressing pro-inflammatory cytokines IL-1ß and IL-6 in PVN of AMI rats. Furthermore, blockade of P2X7R moderated the process of cardiac remodeling. This was achieved due to the regulatory effect of P2X7R on sympathoexcitatory response by influencing NF-κB and mitogen-activated protein kinase (MAPK) signaling. These findings suggest that P2X7R can act as a new regulator of sympathoexcitatory response via NF-κB and MAPK signaling pathways in AMI rats.

Blocking beta 2-adrenergic receptor inhibits dendrite ramification in a mouse model of Alzheimer's disease.

Dendrite ramification affects synaptic strength and plays a crucial role in memory. Previous studies revealed a correlation between beta 2-adrenergic receptor dysfunction and Alzheimer's disease (AD), although the mechanism involved is still poorly understood. The current study investigated the potential effect of the selective ß2-adrenergic receptor antagonist, ICI 118551 (ICI), on Aß deposits and AD-related cognitive impairment. Morris water maze test results demonstrated that the performance of AD-transgenic (TG) mice treated with ICI (AD-TG/ICI) was significantly poorer compared with NaCl-treated AD-TG mice (AD-TG/NaCl), suggesting that ß2-adrenergic receptor blockage by ICI might reduce the learning and memory abilities of mice. Golgi staining and immunohistochemical staining revealed that blockage of the ß2-adrenergic receptor by ICI treatment decreased the number of dendritic branches, and ICI treatment in AD-TG mice decreased the expression of hippocampal synaptophysin and synapsin 1. Western blot assay results showed that the blockage of ß2-adrenergic receptor increased amyloid-ß accumulation by downregulating hippocampal α-secretase activity and increasing the phosphorylation of amyloid precursor protein. These findings suggest that blocking the ß2-adrenergic receptor inhibits dendrite ramification of hippocampal neurons in a mouse model of AD.

Identification of Stem-Like Cells in Atrial Myxoma by Markers CD44, CD19, and CD45.

Atrial myxoma is the most frequent tumor arising mainly in atrial septum and its origin remains uncertain. It has been reported that a subpopulation of stem-like cells are present in benign tumors and responsible for tumor initiation and maintenance. In this study, we investigated whether stem-like cells could contribute to the atrial cardiac myxoma. Immunohistology data confirmed that a population of cells bearing the surface markers CD19, CD45, and CD44 resided in a mucopolysaccharide-rich matrix of myxoma. Moreover, we isolated myxoma cells with phase-bright culture method and confirmed that myxoma derived cells express robust level of CD19, CD45, and CD44. Furthermore, the pluripotency of this population of cells also was validated by cardiomyocytes and smooth muscle cells differentiation in vitro. Our results indicate that primary cardiac myxoma may arise from mesenchymal stem cells with the ability to generate tumors with multilineage differentiation. In conclusion, this study for the first time verified that stem-like cells are present in atrial myxoma and this population of cells may have the capacity for myxoma initiation and progression.

Negative modulation of NO for diaphragmatic contractile reduction induced by sepsis and restraint position.

In practice of forensic medicine, potential disease can be associated with fatal asphyxia in restraint position. Research has demonstrated that nitric oxide (NO) and nitric oxide synthase (NOS) are plentifully distributed in skeletal muscle, contributing to the regulation of contractile and relaxation. In the current study, respiratory functions, indices of diaphragmatic biomechanical functions ex vivo, as well as NO levels in serum, the expressions of diaphragmatic inducible NOS (iNOS) mRNA, and the effects of L-NNA on contractility of the diaphragm were observed in sepsis induced by cecal ligation and puncture (CLP) under the condition of restraint position. The results showed that in the CLP12-18h rats, respiratory dysfunctions; indices of diaphragmatic biomechanical functions (Pt, +dT/dt(max), -dT/dt(max), CT, Po, force over the full range of the force-frequency relationship and fatigue resistance) declined progressively; the NO level in serum, and iNOS mRNA expression in the diaphragm increased progressively; force increased significantly at all stimulation frequencies after L-NNA pre-incubation. Restraint position 1 h in CLP12 h rats resulted in severe respiratory dysfunctions after relative stable respiratory functions, almost all the indices of diaphragmatic biomechanical functions declined further, whereas little change took place in NO level in serum and diaphragmatic iNOS mRNA expression; and the effects of L-NNA were lack of statistical significance compared with those of CLP12 h, but differed from CLP18 h group. These results suggest that restraint position and sepsis act together in a synergistic manner to aggravate the great reduction of diaphragmatic contractility via, at least in part, the negative modulation of NO, which may contribute to the pathogenesis of positional asphyxia.

[Effects of restraint position on changes of diaphragmatic mechanical characteristic in rats].

OBJECTIVE: To observe effects of restraint position on the changes of diaphragmatic mechanical characteristic in rats, and try to explore the role of nitric oxide (NO). METHODS: Rat model of restraint position was established. Rats were divided into control group, restraint position 12h and 24h groups. The markers of respiratory functions in vivo and the biomechanical markers of diaphragmatic characteristic ex vivo were evaluated. Serum NO levels were measured with spectrophotometry. The expressions of nNOS and iNOS mRNA in diaphragm were detected using RT-PCR. RESULTS: Compared with control group, respiratory rate, tidal volume and minute ventilation were significantly decreased in the restraint position 12h and 24h groups. Pt of diaphragm significantly decreased and force-generating capacity reduced at low frequency stimulation in 12h group. Force-generating capacity over the full range reduced at low and high frequency stimulation in 24h group. Pt of diaphragm in control and restraint position groups increased after L-NNA pre-incubation. Force-frequency relationship after L-NNA pre-incubation reduced in 24h group. NO level in serum increased significantly in the restraint position groups. Diaphragmatic nNOS mRNA expression was upregulated significantly in the restraint position groups. CONCLUSION: Restraint position induces the decreasement of diaphragmatic contractility and the decreasement is mediated by NO from diaphragm or circulation blood.

Expression of paxillin and FAK mRNA and the related clinical significance in esophageal carcinoma.

The objective of the present study was to investigate the expression of paxillin and focal adhesion kinase (FAK) mRNA in esophageal carcinoma tissues, and their relationship with clinicopathological parameters, as well as to analyze the correlation of paxillin and FAK mRNA levels in esophageal carcinoma. By using reverse transcription polymerase chain reaction (RT-PCR), the mRNA expression levels of paxillin and FAK were detected in 121 samples of esophageal carcinoma, 43 samples of atypical hyperplasia and 56 samples of normal esophageal mucosa. The results showed that the positive rates of paxillin and FAK mRNA expression in esophageal carcinoma were 87.6 and 80.17%, respectively, which were significantly higher (P<0.05) than those in atypical hyperplasia (44.19 and 39.53%) and normal esophageal mucosa (5.36 and 12.5%). Notably, paxillin and FAK mRNA expression levels were significantly correlated with the differentiation degree and depth of invasion of esophageal carcinoma and with lymph node metastasis (P<0.05). In addition, paxillin and FAK mRNA expression levels in esophageal carcinoma were positively correlated (r=0.4804, P=0.000). In conclusion, the combined detection of paxillin and FAK mRNA expression is expected to provide a theoretical basis for the molecular diagnosis of esophageal carcinoma.

[Differentiation of human embryonic stem cells to endothelial cells via improved three-dimension approach].

OBJECTIVE: To establish an improved three-dimension (3D) and serum-free approach to differentiate human embryonic stem cells (hESCs) into endothelial cells, and detect the endothelial functions of the obtained cells. METHODS: We cultured undifferentiated H9 human embryonic stem cell line in low-adhesion dishes to form embryonic bodies (EBs). After 12 days, EBs were harvested, re-suspended into rat tail collagen type I, and put into the incubator (37℃). After 30 minutes, EGM-2 culture medium was added to the solidified collagen, and the EBs were cultured for another 3 days to form embryonic body-sproutings (EB-sproutings). EB-sproutings were digested with 0.25% collagenase I and 0.56 U/ml Liberase Blendzyme for 20 minutes respectively, and the CD31(+) cells were sorted by FACS. The endothelial functions were tested by Dil-ac-LDL uptake assay and tube formation assay. RESULTS: This approach raised the efficiency of endothelial differentiation to 18%, and also avoided the contamination with animal materials. The obtained hESC-derived endothelial cells (hESC-ECs) had the similar pattern of surface biomarkers as human umbilical vein endothelial cells (HUVECs), and their endothelial functions were confirmed by the uptake of Dil-ac-LDL and the tube formation on Matrigel. CONCLUSIONS: The improved 3D approach can enhance the efficiency of differentiation from hESCs into endothelial cells. Furthermore, serum free differentiation system may be applied in future hESC-based therapies for various ischemic diseases.

[Pulse wave: the bridge connecting traditional Chinese medicine with Western medicine].

Pulse wave, a research focus in both traditional Chinese medicine and Western medicine, which contains a wealth of human physiological and pathological information, has always been the concern of medical practitioners. On the basis of the review on the development of the pulse wave theory and its applications, the existing problems in this field are discussed in this paper. On the basis of the status quo of pulse wave information extraction methods and the utilization of pulse wave in traditional Chinese and Western medicine, a more in-depth study on pulse wave is proposed to make it a bridge connecting traditional Chinese medicine with Western medicine.