Gastrokine 1 regulates NF‐κB signaling pathway and cytokine expression in gastric cancers

Gastrokine 1 (GKN1) plays an important role in the gastric mucosal defense mechanism and also acts as a functional gastric tumor suppressor. In this study, we examined the effect of GKN1 on the expression of inflammatory mediators, including NF‐κB, COX‐2, and cytokines in GKN1‐transfected AGS cells and shGKN1‐transfected HFE‐145 cells. Lymphocyte migration and cell viability were also analyzed after treatment with GKN1 and inflammatory cytokines in AGS cells by transwell chemotaxis and an MTT assay, respectively. In GKN1‐transfected AGS cells, we observed inactivation and reduced expression of NF‐κB and COX‐2, whereas shGKN1‐transfected HFE‐145 cells showed activation and increased expression of NF‐κB and COX‐2. GKN1 expression induced production of inflammatory cytokines including IL‐8 and ‐17A, but decreased expression of IL‐6 and ‐10. We also found IL‐17A expression in 9 (13.6%) out of 166 gastric cancer tissues and its expression was closely associated with GKN1 expression. GKN1 also acted as a chemoattractant for the migration of Jurkat T cells and peripheral B lymphocytes in the transwell assay. In addition, GKN1 significantly reduced cell viability in both AGS and HFE‐145 cells. These data suggest that the GKN1 gene may inhibit progression of gastric epithelial cells to cancer cells by regulating NF‐κB signaling pathway and cytokine expression. J. Cell. Biochem. 114: 1800–1809, 2013. © 2013 Wiley Periodicals, Inc.     

The importance of being kinked: role of Pro residues in the selectivity of the helical antimicrobial peptide P5

Antimicrobial peptides (AMPs) are promising compounds for developing new antibiotic drugs against drug‐resistant bacteria. Many of them kill bacteria by perturbing their membranes but exhibit no significant toxicity towards eukaryotic cells. The identification of the features responsible for this selectivity is essential for their pharmacological development. AMPs exhibit few conserved features, but a statistical analysis of an AMP sequence database indicated that many α‐helical AMPs surprisingly have a helix‐breaking Pro residue in the middle of their sequence. To discriminate among the different possible hypotheses for the functional role of this feature, we designed an analogue of the antimicrobial peptide P5, in which the central Pro was deleted (analogue P5Del). Pro removal resulted in a dramatic increase of toxicity. This was explained by the observation that P5Del binds both charged and neutral membranes, whereas P5 has no appreciable affinity towards neutral bilayers. CD and simulative data provided a rationalization of this behavior. In solution P5, due to the presence of Pro, attains compact conformations, in which its apolar residues are partially shielded from the solvent, whereas P5Del is more helical. These structural differences reduce the hydrophobic driving force for association of P5 to neutral membranes, whereas its binding to anionic bilayers can still take place because of electrostatic attraction. After membrane binding, the Pro residue does not preclude the attainment of a membrane‐active amphiphilic helical conformation. These findings shed light on the role of Pro residues in the selectivity of AMPs and provide hints for the design of new, highly selective compounds. Copyright © 2013 European Peptide Society and John Wiley & Sons, Ltd.     

Anti-hypercholesterolemic and anti-atherosclerotic effects of polarized-light therapy in rabbits fed a high-cholesterol diet

The effects of polarized-light therapy (PLT) on high-cholesterol diet (HCD)-induced hypercholesterolemia and atherosclerosis were investigated in comparison with that of lovastatin in rabbits. Hypercholesterolemia was induced by feeding male New Zealand white rabbits with 1% cholesterol in diet for 2 weeks and maintained with 0.5% cholesterol for 6 weeks, followed by normal diet for 2 weeks for recovery. Lovastatin (0.002% in diet) or daily 5-min or 20-min PLT on the outside surface of ears was started 2 weeks after induction of hypercholesterolemia. Hypercholesterolemic rabbits exhibited great increases in serum cholesterol and low-density lipoproteins (LDL) levels, and finally severe atheromatous plaques formation covering 57.5% of the arterial walls. Lovastatin markedly reduced both the cholesterol and LDL, but the reducing effect (47.5%) on atheroma formation was relatively low. By comparison, 5-min PLT preferentially decreased LDL, rather than cholesterol, and thereby potentially reduced the atheroma area to 42.2%. Notably, 20-min PLT was superior to lovastatin in reducing both the cholesterol and LDL levels as well as the atheromatous plaque formation (26.4%). In contrast to the increases in blood alanine transaminase and aspartate transaminase following lovastatin treatment, PLT did not cause hepatotoxicity. In addition, PLT decreased platelets and hematocrit level. The results indicate that PLT attenuates atherosclerosis not only by lowering blood cholesterol and LDL levels, but also by improving blood flow without adverse effects. Therefore, it is suggested that PLT could be a safe alternative therapy for the improvement of hypercholesterolemia and atherosclerosis.     

小黑杨PsnHB13基因在烟草中的遗传转化与功能分析

克隆小黑杨HD-ZIP家族基因PsnHB13,对该基因进行生物信息学分析、过表达载体构建、烟草的遗传转化。结果表明小黑杨PsnHB13基因cDNA全长870 bp,编码289个氨基酸。成功构建植物过表达载体pROKⅡ-PsnHB13,并通过农杆菌介导的叶盘法将外源基因转入野生型烟草。检测结果显示PsnHB13已成功整合入烟草基因组中,并在mRNA水平表达。通过观察转基因烟草的生长,发现过表达PsnHB13基因的烟草与野生型相比出现叶面积变小、叶型变长,根系生长缓慢,花朵变小等明显表型。说明PsnHB13基因主要对烟草叶片、根系及花的生长发育起到负调控作用。本文为研究PsnHB13基因对杨树生长发育的影响提供理论基础。     

Liver engraftment potential of hepatic cells derived from patient-specific induced pluripotent stem cells

Human induced pluripotent stem cells (iPSCs) are potential renewable sources of hepatocytes for drug development and cell therapy. Differentiation of human iPSCs into different developmental stages of hepatic cells has been achieved and improved during the last several years. We have recently demonstrated the liver engraftment and regenerative capabilities of human iPSC-derived multistage hepatic cells in vivo. Here we describe the in vitro and in vivo activities of hepatic cells derived from patientspecific iPSCs, including multiple lines established from either inherited or acquired liver diseases, and discuss basic and clinical applications of these cells for disease modeling, drug screening and discovery, gene therapy and cell replacement therapy.Key words: induced pluripotent stem cells (iPSCs), hepatic differentiation, liver ngraftment, disease modeling, drug testing, alpha-1 antitrypsin, liver cirrhosis, hepatocellular carcinoma, cell therapy     

Stimulatory Effects of Extracellular Vesicles Derived from Leuconostoc holzapfelii That Exists in Human Scalp on Hair Growth in Human Follicle Dermal Papilla Cells

Human hair follicle dermal papilla cells (HFDPCs) located in hair follicles (HFs) play a pivotal role in hair follicle morphogenesis, hair cycling, and hair growth. Over the past few decades, probiotic bacteria (PB) have been reported to have beneficial effects such as improved skin health, anti-obesity, and immuno-modulation for conditions including atopic dermatitis and inflammatory bowel disease (IBD). PB can secrete 50~150 nm sized extracellular vesicles (EVs) containing microbial DNA, miRNA, proteins, lipids, and cell wall components. These EVs can regulate communication between bacteria or between bacteria and their host. Although numerous biological effects of PB-EVs have been reported, the physiological roles of Leuconostoc holzapfelii (hs-Lh), which is isolated from human scalp tissue, and the extracellular vesicles derived from them (hs-LhEVs) are largely unknown. Herein, we investigated the effects of hs-LhEVs on hair growth in HFDPCs. We show that hs-LhEVs increase cell proliferation, migration, and regulate the cell cycle. Furthermore, hs-LhEVs were found to modulate the mRNA expression of hair-growth-related genes in vitro. These data demonstrate that hs-LhEVs can reduce apoptosis by modulating the cell cycle and promote hair growth by regulation via the Wnt/β-catenin signal transduction pathway.     

Nanoscale mapping and organization analysis of target proteins on cancer cells from B-cell lymphoma patients

CD20, a membrane protein highly expressed on most B-cell lymphomas, is an effective target demonstrated in clinical practice for treating B-cell non-Hodgkin's lymphoma (NHL). Rituximab is a monoclonal antibody against CD20. In this work, we applied atomic force microscopy (AFM) to map the nanoscale distribution of CD20 molecules on the surface of cancer cells from clinical B-cell NHL patients under the assistance of ROR1 fluorescence recognition (ROR1 is a specific cell surface marker exclusively expressed on cancer cells). First, the ROR1 fluorescence labeling experiments showed that ROR1 was expressed on cancer cells from B-cell lymphoma patients, but not on normal cells from healthy volunteers. Next, under the guidance of ROR1 fluorescence, the rituximab-conjugated AFM tips were moved to cancer cells to image the cellular morphologies and detect the CD20-rituximab interactions on the cell surfaces. The distribution maps of CD20 on cancer cells were constructed by obtaining arrays of (16×16) force curves in local areas (500×500 nm²) on the cell surfaces. The experimental results provide a new approach to directly investigate the nanoscale distribution of target protein on single clinical cancer cells.     

Reduced Neural Synchrony in Patients with Restless Legs Syndrome during a Visual Oddball Task

Background

Restless legs syndrome (RLS) is a sensorimotor neurological disorder characterized by an irresistible urge to move the legs. It has been reported that RLS patients show cognitive deficits, presumably due to hyperactivity causing loss of attention, or malfunctions in the frontal region resulting from sleep deprivation. However, the mechanism underlying cognitive deficits in RLS patients is mostly unknown. As an effort to clarifying this, we investigated the differences in neural activity and phase synchrony between healthy controls and RLS patients during cognitive task performances.

Methodology/Principal Findings

Seventeen female drug-naive RLS patients were enrolled in the study, and an age-matched group of thirteen healthy female volunteers served as controls. Multichannel event-related potentials (ERPs) were recorded from RLS patients and normal controls while performing a visual oddball task. In addition to conventional analyses of ERP waveforms and spectra, interregional gamma-band phase synchrony (GBPS) was investigated to observe the differences in interregional neural synchronies between normal and RLS patient groups. Strong GBPS was observed primarily between anterior and posterior regions along the midline for both groups. Along with significant reduction and delay of P300 ERP and induced gamma-band activity (GBA), the GBPS was considerably decreased in RLS patients compared to normal subjects, especially at frontal region.

Conclusions

Overall, our results support that cognitive dysfunction in RLS patients is associated with reduced interregional neural synchrony as well as alterations in local neural activity.     

Acetylation changes tau interactome to degrade tau in Alzheimer’s disease animal and organoid models

Alzheimer's disease (AD) is an age‐related neurodegenerative disease. The most common pathological hallmarks are amyloid plaques and neurofibrillary tangles in the brain. In the brains of patients with AD, pathological tau is abnormally accumulated causing neuronal loss, synaptic dysfunction, and cognitive decline. We found a histone deacetylase 6 (HDAC6) inhibitor, CKD‐504, changed the tau interactome dramatically to degrade pathological tau not only in AD animal model (ADLP^APT) brains containing both amyloid plaques and neurofibrillary tangles but also in AD patient‐derived brain organoids. Acetylated tau recruited chaperone proteins such as Hsp40, Hsp70, and Hsp110, and this complex bound to novel tau E3 ligases including UBE2O and RNF14. This complex degraded pathological tau through proteasomal pathway. We also identified the responsible acetylation sites on tau. These dramatic tau‐interactome changes may result in tau degradation, leading to the recovery of synaptic pathology and cognitive decline in the ADLP^APT mice.