LncRNA NONRATT021972 involved the pathophysiologic processes mediated by P2X<Subscript>7</Subscript> receptors in stellate ganglia after myocardial ischemic injury

Adenosine triphosphate (ATP) acts on P2X receptors to initiate signal transmission. P2X₇ receptors play a role in the pathophysiological process of myocardial ischemic injury. Long noncoding RNAs (lncRNAs) participate in numerous biological functions independent of protein translation. LncRNAs are implicated in nervous system diseases. This study investigated the effects of NONRATT021972 small interference RNA (siRNA) on the pathophysiologic processes mediated by P2X₇ receptors in stellate ganglia (SG) after myocardial ischemic injury. Our results demonstrated that the expression of NONRATT021972 in SG was significantly higher in the myocardial ischemic (MI) group than in the control group. Treatment of MI rats with NONRATT021972 siRNA, the P2X₇ antagonist brilliant blue G (BBG), or P2X₇ siRNA improved the histology of injured ischemic cardiac tissues and decreased the elevated concentrations of serum myocardial enzymes, creatine kinase (CK), CK isoform MB (CK-MB), lactate dehydrogenase (LDH) and aspartate aminotransferase (AST) compared to the MI rats. NONRATT021972 siRNA, BBG, or P2X₇ siRNA treatment in MI rats decreased the expression levels of P2X₇ immunoreactivity, P2X₇ messenger RNA (mRNA), and P2X₇ protein, interleukin-6 (IL-6), tumor necrosis factor-α (TNF-α), and phosphorylated p38 mitogen-activated protein kinase (p38 MAPK) in the SG compared to MI rats. NONRATT021972 siRNA treatment prevented the pathophysiologic processes mediated by P2X₇ receptors in the SG after myocardial ischemic injury.     

A Unique Feature of Iron Loss via Close Adhesion of Helicobacter pylori to Host Erythrocytes

Iron deficiency anemia is an extra-stomach disease experienced in H. pylori carriers. Individuals with type A blood are more prone to suffering from H. pylori infection than other individuals. To clarify the molecular mechanisms underlying H. pylori-associated anemia, we collected erythrocytes from A, B, O, and AB blood donors and analyzed morphology, the number of erythrocytes with H. pylori colonies attached to them, and iron contents in erythrocytes and H. pylori (NCTC11637 and SS1 strains) by means of optical microscopy, scanning electron microscopy, and synchrotron radiation soft X-ray imaging. The number of type A erythrocytes with H. pylori attached to them was significantly higher than that of other erythrocytes (P<0.05). Far more iron distribution was observed in H. pylori bacteria using dual energy analysis near the iron L2, 3 edges by soft X-ray imaging. Iron content was significantly reduced in host erythrocytes after 4 hours of exposure to H. pylori. H. pylori are able to adhere more strongly to type A erythrocytes, and this is related to iron shift from the host to the bacteria. This may explain the reasons for refractory iron deficiency anemia and elevated susceptibility to H. pylori infection in individuals with type A blood.     

Rewiring central carbon metabolism for tyrosol and salidroside production in Saccharomyces cerevisiae

Metabolic engineering of Saccharomyces cerevisiae for high-level production of aromatic chemicals has received increasing attention in recent years. Tyrosol production from glucose by S. cerevisiae is considered an environmentally sustainable and safe approach. However, the production of tyrosol and salidroside by engineered S. cerevisiae has been reported to be lower than 2 g/L to date. In this study, S. cerevisiae was engineered with a push-pull-restrain strategy to efficiently produce tyrosol and salidroside from glucose. The biosynthetic pathways of ethanol, phenylalanine, and tryptophan were restrained by disrupting PDC1, PHA2, and TRP3. Subsequently, tyrosol biosynthesis was enhanced with a metabolic pull strategy of introducing PcAAS and EcTyrA^M53I/A354V. Moreover, a metabolic push strategy was implemented with the heterologous expression of phosphoketolase (Xfpk), and then erythrose 4-phosphate was synthesized simultaneously by two pathways, the Xfpk-based pathway and the pentose phosphate pathway, in S. cerevisiae. Furthermore, the heterologous expression of Xfpk alone in S. cerevisiae efficiently improved tyrosol production compared with the coexpression of Xfpk and phosphotransacetylase. Finally, the tyrosol yield increased by approximately 135-folds, compared with that of parent strain. The total amount of tyrosol and salidroside with glucose fed-batch fermentation was over 10 g/L and reached levels suitable for large-scale production.     

Methylation of <Emphasis Type="Italic">Cdkn1c</Emphasis> may be involved in the regulation of tooth development through cell cycle inhibition

Cdkn1c, a member of the Cip/Kip cyclin-dependent kinase inhibitor family, is critically involved in regulating cell cycle and cellular differentiation during development in mammals. However, the functional role of Cdkn1c and the underlying mechanisms by which Cdkn1c affects odontogenesis remain largely unknown. In our study, we found that Cdkn1c expression dynamically changes from embryonic day 11.5 (E11.5) to postnatal day 3 (P3), and exhibits tissue-specific expression profiles. Evaluation of CDKN1C protein by immunohistochemistry and western blot, revealed that CDKN1C protein expression peaks at P3 and then is reduced at P5 and P7. Interestingly, we observed that CDKN1C expression is higher in immature odontoblasts than preodontoblasts, is lower in mature odontoblasts, and is practically absent from ameloblasts. We evaluated cell cycle progression to further investigate the mechanisms underlying CDKN1C-mediated regulation of odontogenesis, and found that pRB, cyclin D1 and CDK2 expression decreased from P1 to P3, and reduced at P5 and P7. In addition, we observed increased methylation of KvDMR1 at P1 and P3, and reduced KvDMR1 methylation at P5 and P7. However, the methylation levels of Cdkn1c-sDMR were relatively low from P1 to P7. In summary, we demonstrated that Cdkn1c expression and methylation status may be involved in early postnatal tooth development through regulating the cell cycle inhibition activity of Cdkn1c. Notably, Cdkn1c expression and methylation may associate with cell cycle exit and differentiation of odontoblasts.     

Inhibition of α-glucosidase activity by curcumin loaded on ZnO@rGO nanocarrier for potential treatment of diabetes mellitus

Curcumin (Cur) is an acidic polyphenol with some effects on α-glucosidase (α-Glu), but Cur has disadvantages such as being a weak target, lacking passing the blood–brain barrier and having low bioavailability. To enhance the curative effect of Cur, the hybrid composed of ZnO nanoparticles decorated on rGO was used to load Cur (ZnO@rGO-Cur). The use of the multispectral method and enzyme inhibition kinetics analysis certify the inhibitory effect and interaction mechanism of ZnO@rGO-Cur with α-Glu. The static quenching of α-Glu with both Cur and ZnO@rGO-Cur is primarily driven by hydrogen bond and van der Waals interactions. The conformation-changing ability by binding to the neighbouring phenolic hydroxyl group of Cur increased their ability to alter the secondary structure of α-Glu, resulting in the inhibition of enzyme activity. The inhibition constant (K_{i, Cur} > K_{is,ZnO@rGO-Cur} ) showed that the inhibition effect of ZnO@rGO-Cur on α-Glu was larger than that of Cur. The CCK-8 experiments proved that ZnO@rGO nanocomposites have good biocompatibility. These results suggest that the therapeutic potential of ZnO@rGO-Cur composite is an emerging nanocarrier platform for drug delivery systems for the potential treatment of diabetes mellitus.     

Correction to: Long noncoding NONRATT021972 siRNA normalized abnormal sympathetic activity mediated by the upregulation of P2X7 receptor in superior cervical ganglia after myocardial ischemia

Purinergic Signalling - Due to the authors’ carelessness, we used mistakenly images in Fig. 5B(B1) for P2X7 immunoreactivity in MI group(the second on the upper left) and MI+BBG group (The...     

B 细胞膜CD20 抗原的分布与单分子力谱探测

CD20抗原分子在B细胞上表达下降是慢性B淋巴细胞白血病 (B-CLL) 的标志性特征。采用激光扫描共聚焦显微镜 (LSCM) 和量子点标记相结合的方法对正常和B-CLL外周血CD20+B淋巴细胞膜表面CD20抗原分子的表达及分布进行了荧光成像。同时,采用原子力显微镜 (AFM) 对CD20+B细胞的形貌及超微结构特征进行了表征,并且将AFM针尖用生物素化的单克隆抗体进行修饰,对CD20+B细胞表面的CD20抗原-抗体之间的单分子力谱进行了探测。LSCM荧光图像显示,B-CLL CD20+B淋巴细胞上CD20分子的表达量比正常CD20+B淋巴细胞显著降低。AFM结果显示,B-CLL CD20+B淋巴细胞超微结构比正常的粗糙。力谱结果显示,CD20抗原-抗体的相互作用力大约是非特异性黏附力的5倍,CD20分子在正常CD20+B淋巴细胞膜上分布比较均匀,小部分有聚集现象,反之,在B-CLL CD20+B淋巴细胞膜表面分布稀疏。利用以上两种方法能进一步观察到B-CLL外周血B淋巴细胞的异常,并在一定程度上解释临床上B-CLL病人对利妥昔的低反应现象,为针对抗原CD20的治疗用药选择提供参考。     

Characterization of the heparin-binding site of the protein z-dependent protease inhibitor

High-molecular weight heparins promote the protein Z-dependent protease inhibitor (ZPI) inhibition of factors Xa (FXa) and XIa (FXIa) by a template mechanism. To map the heparin-binding site of ZPI, the role of basic residues of the D-helix (residues Lys-113, Lys-116, and Lys-125) in the interaction with heparin was evaluated by either substituting these residues with Ala (ZPI-3A) or replacing the D-helix with the corresponding loop of the non-heparin-binding serpin α(1)-proteinase inhibitor (ZPI-D-helix(α1-PI)). Furthermore, both the C-helix (contains two basic residues, Lys-104 and Arg-105) and the D-helix of ZPI were substituted with the corresponding loops of α(1)-proteinase inhibitor (ZPI-CD-helix(α1-PI)). All mutants exhibited near normal reactivity with FXa and FXIa in the absence of cofactors and in the presence of protein Z and membrane cofactors. By contrast, the mutants interacted with heparin with a lower affinity and the ~48-fold heparin-mediated enhancement in the rate of FXa inhibition by ZPI was reduced to ~30-fold for ZPI-3A, ~15-fold for ZPI-D-helix(α1-PI), and ~8-fold for ZPI-CD-helix(α1-PI). Consistent with a template mechanism for heparin cofactor action, ZPI-CD-helix(α1-PI) inhibition of a FXa mutant containing a mutation in the heparin-binding site (FXa-R240A) was minimally affected by heparin. A significant decrease (~2-5-fold) in the heparin template effect was also observed for the inhibition of FXIa by ZPI mutants. Interestingly, ZPI derivatives exhibited a markedly elevated stoichiometry of inhibition with FXIa in the absence of heparin. These results suggest that basic residues of both helices C and D of ZPI interact with heparin to modulate the inhibitory function of the serpin.