Impact of One Versus Two Consecutive Doses of Endothelial Cells (EPCs) and EPCs-Derived Condition Medium on Protecting Myocardium from Acute Ischemia-Reperfusion Injury in Rat.

This study tested the impact of single dose and two doses of endothelial progenitor cells (EPCs) and EPCs-derived condition medium (CM) on protecting the left-ventricular myocardium (LVM) from acute ischemia-reperfusion (IR) injury. In vitro study showed EPCs and CM had comparably higher capacity for enhancement of angiogenesis as compared with the controls (all P < .001). Adult-male SD rats (n = 36) were equally categorized into groups 1 (sham-operated control), 2 (IR+vehicle), 3 [IR+EPCs/1.2 × 106/intravenous administration at 3 h after IR procedure), 4 (IR+EPCs/1.2 × 106/at 3 h/24 h after IR), 5 (IR+CM/3.0cc/intravenous administration at 3 h after IR), 6 (IR+EPCs/3.0cc/at 3h/24 h after IR), and euthanized by day 3 after IR. The left-ventricular-ejection-fraction, protein and cellular expressions of endothelial-cell markers (CD31/vWF), small vessel number and protein expression of mitochondrial (mitochondrial-cytochrome-C) integrity were highest in group 1, lowest in group 2, significantly higher in group 4 than in groups 3/5/6 and significantly higher in groups 3/6 than in group 5 but they showed no differences in groups3/6, whereas the protein expressions of apoptotic (cleaved-caspase 3/cleaved-PARP), fibrotic (Smad3/TGF-ß), mitochondrial-damaged (cytosolic-cytochrome-C), heart-failed/pressure-overload (BNP), oxidative-stress (p47phox/NOX-1/NOX-2/oxidized protein), and autophagic (LCB3-II/LCB3-I) biomarkers and fibrotic/collagen-deposition areas exhibited an opposite pattern to endothelial-cell markers (all P < .0001). The protein expressions of angiogenesis (VEGF/SDF-1α/CXCR4/HIF-1α) were lowest in group 1, highest in group 4, significantly higher in groups 3/6 than in groups 2/5, significantly higher in group 5 than in group 2, but they showed no difference between groups 3/6 (all P < .0001). These results demonstrate that two consecutive doses of EPC/CM were superior to just one at protecting LVM against IR injury.

Influencing Mechanism of Justice Sensitivity on Knowledge Hiding in the Chinese Context.

Good knowledge management is important for enterprises to maintain competitive advantage; however, the knowledge hiding behavior may hinder this process. Based on the conservation of resources and psychological ownership theories, using a chain intermediary model, this study investigates the effect of justice sensitivity on knowledge hiding through perceived time pressure and territoriality, and further tests the moderating role of territoriality. For the study, we collected 436 questionnaires from China through the Wenjuanxing Sample Service, of which 391 were valid. We then conducted multiple regression analysis and employed the bootstrap method for our tests. The results show that victim sensitivity has a significant effect on perceived time pressure, territoriality, and knowledge hiding, and that a chain mediating effect of perceived time pressure and territoriality is established between justice sensitivity and knowledge hiding. Further, territoriality has a positive moderating effect on perceived time pressure and knowledge hiding, while the mediating effect of perceived time pressure on justice sensitivity and knowledge hiding is also moderated by territoriality. Further, the study offers important practical implications in that enterprises should not blindly pursue results by making employees work excessively overtime. And there should have rationalized regulations in organization to ensure justice. The management should pay close attention to the psychological problems of victim and perpetrator. Instead, enterprises should have a certain degree of control, offer rationales for overtime work, and give high wages to the employees to compensate for their time, thus making the employees feel the worthiness of their overtime work and reducing the probability of engaging in knowledge hiding behaviors.

CLDN6-induced apoptosis via regulating ASK1-p38/JNK signaling in breast cancer MCF-7 cells.

Claudin 6 (CLDN6), a member of tight junction protein claudin (CLDN) family, inhibits proliferation and induces apoptosis of MCF-7 breast cancer cells. However, these molecular mechanisms of CLDN6-induced apoptosis remain largely elusive. We previously found that restoration of human CLDN6 gene expression was correlated with the expression level of apoptosis signal-regulating kinase 1 (ASK1) using cDNA array and bioinformatics analysis. ASK1, a mitogen-activated protein kinase kinase kinase, is involved in environmental stress-activation of the c-jun N-terminal kinase (JNK) and p38 pathways, which contribute to apoptosis-associated tumor cell death. In the present study, we show that the restoration of CLDN6 gene expression in MCF-7 cells marhedly decreased ASK1 phosphorylation at Ser967. Activated ASK1ser967 further induced the activation of downstream targets, JNK and p38 kinase. MCF-7/CLDN6 stable transfection cell clone treated with TRX1, an ASK1 inhibitor, showed suppressed JNK and p38 activation, and showed substantially increased survival and colony formation and reduced percent of apoptotic cells using TUNEL staining and DNA ladder. Furthermore, TRX1 treatment increased Bcl-2/Bax ratio and reduced caspase-3 cleavage in MCF-7/CLDN6 stable transfection cell clone. Therefore, these data show that CLDN6 mediates ASK1-p38/JNK apoptotic signaling in MCF-7 cells, and it is correlated with constitutive deregulation of the balance of Bcl-2 family proteins and activation of caspase-3.

Antimicrobial peptide LL-37 and IDR-1 ameliorate MRSA pneumonia in vivo.

BACKGROUND: The only human cathelicidin, LL-37, and the innate defense regulator peptide IDR-1, which have been proven to have antimicrobial activity, represent essential elements of immunity. Our previous study showed that the peptide LL-37 was protective in vitro to attenuate LTA-induced inflammatory effects. Methicillin-resistant staphylococcus aureus (MRSA) causes a multitude of serious and sometimes life-threatening diseases around the globe. However, the effect of LL-37 and IDR-1 in MRSA-induced pneumonia is unknown. In the present study, we explored the potential of LL-37 and IDR-1 in ameliorating MRSA-induced pneumonia in vivo. METHODS: C57BL/6 mice were randomly divided into four groups and perfused intratracheally with PBS, peptide, MRSA and MRSA plus peptide, respectively. Pulmonary tissue pathology, ELISA and quantitative RT-PCR were employed. The relative signal pathways were further explored by western blot analysis. RESULTS: Pathological analysis of the lung tissue sections demonstrated that, when compared with the MRSA-treated group, both the LL-37 and IDR-1 could ameliorate the MRSA-induced pneumonia. The phosphorylation of JNK and Akt were markedly decreased in the peptide plus MRSA-treated group compared with the MRSA-treated group. Furthermore, both of them also reduced TNF-α and IL-6 production in the bronchoalveolar lavage fluid (BALF) and serum in vivo. CONCLUSION: We report the first evidence of peptides inhibiting inflammation, decreasing the release of inflammatory cytokines and restoring pulmonary function in vivo. The antimicrobial peptide LL-37 and IDR-1 could ameliorate MRSA-induced pneumonia by exerting an anti-inflammatory property and attenuating pro-inflammatory cytokine release, thus providing support for the hypothesis that both innate and synthetic peptides could protect against MRSA in vivo.