The objective of this study was to synthesize and characterize novel polyurethane (PU)-nanofiber coated with l-arginine by electrospinning technique. This study determined whether l-arginine conjugated with PU-nanofiber could stimulate cell proliferation and prevent H2O2-induced cell death in satellite cells co-cultured with fibroblasts isolated from Hanwoo (Korean native cattle). Our results showed that l-arginine conjugated with PU nanofiber could reduce cytotoxicity of co-cultured satellite cells. Protein expression levels of bcl-2 were significantly upregulated whereas those of caspase-3 and caspase-7 were significantly downregulated in co-culture of satellite cells compared to those of monoculture cells after treatment with PU-nanofiber coated with l-arginine and which confirmed by Confocal microscope. These results suggest that co-culture of satellite cells with fibroblasts might be able to counter oxidative stress through translocation/penetration of antioxidant, collagen, and molecules secreted to satellite cells. Therefore, this nanofiber might be useful as a wound dressing in animals to counter oxidative stresses.
Salivary gland adenoid cystic carcinoma (SACC) is one of the most common malignancies in the oral and maxillofacial region. Carcinoma-associated fibroblast (CAF) is an important component in the tumor microenvironment and participates in SACC progression. In this study, we established a CAF cell line derived from a human SACC and named it CAF-SA. It was identified that CAF-SA expressed typical CAF biomarkers. Then, we studied the cellular communications between CAF-SA, tumor cells and endothelial cells. It was found that CAF-SA promoted the migration, invasion, and proliferation of SACC tumor cells in vitro. In addition, tube formation by endothelial cells was enhanced by CAF-SA. In vivo experiment showed that SACC cells formed larger xenografts in nude mice when they were transplanted with CAF-SA. Overall, we demonstrated that CAF-SA exhibited the most important defining feature of CAF by promoting cancer progression.
Krudppel like factor 4 (KLF4) is a transcription factor that regulates genes related to differentiation and proliferation. KLF4 also plays a role in metastasis via epithelial to mesenchymal transition. Here, we investigate the function of Klf4 in migration and invasion using mouse embryonic fibroblasts and the RKO human colon cancer cell line. Compared to wild-type, cells lacking Klf4 exhibited increased migration-associated phenotypes. In addition, overexpression of Klf4 in Klf4(-/-) MEFs attenuated the presence of stress fibers to wild-type levels. An invasion assay suggested that lack of Klf4 resulted in increased invasive capacity. Finally, analysis of RhoA showed elevated RhoA activity in both RKO and MEF cells. Taken together, our results strongly support the novel role of KLF4 in a post-translational regulatory mechanism where KLF4 indirectly modulates the actin cytoskeleton morphology via activity of RhoA in order to inhibit cellular migration and invasion.
Pannexin1 (Panx1), a membrane channel-forming protein permitting the passage of small-sized molecules, such as ATP, is expressed in human platelets. Recently, we showed that inhibiting Panx1 affects collagen-induced platelet aggregation but not aggregation triggered by other agonists. We also found that a single nucleotide polymorphism (SNP; rs1138800) in the Panx1 gene encoded for a gain-of-function channel (Panx1-400C) and was associated with enhanced collagen-induced platelet reactivity. Here, we assessed the association of this SNP with platelet reactivity in a cohort of 758 stable cardiovascular patients from the ADRIE study treated with aspirin and/or clopidogrel. We found that presence of the Panx1-400C allele was not associated with platelet reactivity in stable cardiovascular patients, irrespective of the platelet aggregation agonist used (collagen, ADP or arachidonic acid) or the anti-platelet drug regimen. Moreover, the Panx1-400A > C SNP did also not affect the re-occurrence of cardiac ischemic events in the same stable cardiovascular patient cohort.
Abstract As the initiation step of bacterial infection or biofouling, bacterial adhesion on cells or substrates is generally an optimal target for antibacterial design. Phosphatidylethanolamine (PE) is the principal phospholipid in bacteria, and its function in bacterial adhesion remains unclear. In this study, four E. coli strains including two PE-deficient mutants (PE−PC− and PE−PC+ strains) and two PE-containing wild-type controls (PE + PC− strains) were recruited to investigate the influence of PE deficiency on bacterial adhesion. We found that PE deficiency could impair E. coli adhesion on macrophages (human THP-1-derived and mouse RAW264.7 macrophages) or glass coverslips by downregulating lipopolysaccharide (LPS) biosynthesis, which could be reversible by high galactose/lactose but not glucose cultivation. The data imply that PE play important role in bacterial adhesion probably via affecting LPS biosynthesis and suggest that targeting PE biosynthesis is also a potential antibacterial strategy.
Although substrate stiffness has been previously reported to affect various cellular aspects, such as morphology, migration, viability, growth, and cytoskeletal structure, its influence on cell adherence has not been well examined. Here, we prepared three soft, medium, and hard polyacrylamide (PAAM) substrates and utilized AFM to study substrate elasticity and also the adhesion and mechanical properties of endothelial cells in response to changing substrate stiffness. Maximum detachment force and cell stiffness were increased with increasing substrate stiffness. Maximum detachment force values were 0.28 +/- 0.14, 0.94 +/- 0.27, and 1.99 +/- 0.59 nN while Young's moduli of cells were 218.85 +/- 38.73, 385.58 +/- 131.67, and 933.20 +/- 428.92 Pa for soft, medium, and hard substrates, respectively. Human umbilical vein endothelial cells (HUVECs) showed round to more spread shapes on soft to hard substrates, with the most organized and elongated actin structure on the hard hydrogel. Our results confirm the importance of substrate stiffness in regulating cell mechanics and adhesion for a successful cell therapy.
Gap junctions are a specialized group of cell-to-cell junctions that mediate direct intercellular communication between cells. They arise from the interaction of two hemichannels of adjacent cells, which in turn are composed of six connexin proteins. In liver, gap junctions are predominantly found in hepatocytes and play critical roles in virtually all phases of the hepatic life cycle, including cell growth, differentiation, liver-specific functionality and cell death. Liver gap junctions are directed through a broad variety of mechanisms ranging from epigenetic control of connexin expression to post-translational regulation of gap junction activity. This paper reviews established and novel aspects regarding the architecture, control and functional relevance of liver gap junctions.
Activated macrophages contribute to endothelial dysfunction; however, it is unclear how peroxynitrite contributes to macrophage-mediated human cardiac microvascular endothelial cell (HCMEC) injury in hypoxia. In macrophage-HCMEC co-cultures subjected to hypoxia, there was an increase in hypoxia-inducible factor (HIF)-1α, HIF-2α, inducible nitric oxide synthase (iNOS), endothelin-converting enzyme (ECE)-1 and cyclooxygenase-2 (COX-2), and concomitant decrease in prostacyclin synthase (PGIS). This was mimicked by a peroxynitrite donor and attenuated by its decomposition catalyst. Tongxinluo (TXL) could decrease HIF-2α, iNOS, ECE-1 and COX-2 and increase PGIS in a dose-dependent manner, with increase of vascular endothelial growth factor. The protein alterations verified the remarkably affected mRNAs, indicating that the effects of TXL were similar to but better than that of peroxynitrite decomposition catalyst. Furthermore, TXL inhibited macrophage-mediated nitrotyrosine accumulation and attenuated HCMEC injury. The results suggest that peroxynitrite contributes to macrophage-mediated HCMEC injury in hypoxia, and TXL attenuates HCMEC injury mainly by inhibiting peroxynitrite.
Advanced glycation end-products (AGEs) are involved in the development of vascular smooth muscle cell (VSMC) dysfunction and the progression of atherosclerosis. However, AGEs may indirectly affect VSMCs via AGEs-induced signal transduction between monocytes and human umbilical endothelial cells (HUVECs), rather than having a direct influence. This study was designed to elucidate the signaling pathway underlying AGEs-RAGE axis influence on VSMC dysfunction using a co-culture system with monocytes, HUVECs and VSMCs. AGEs stimulated production of reactive oxygen species and pro-inflammatory mediators such as tumor necrosis factor-α and interleukin-1β via extracellular-signal-regulated kinases phosphorylation and nuclear factor-κB activation in HUVECs. It was observed that AGEs-induced pro-inflammatory cytokines increase VSMC proliferation, inflammation and vascular remodeling in the co-culture system. This result implies that RAGE plays a role in AGEs-induced VSMC dysfunction. We suggest that the regulation of signal transduction via the AGEs-RAGE axis in the endothelium can be a therapeutic target for preventing atherosclerosis.
To enlighten interactions between autologous, allogeneic or T-cells from patients after stem cell transplantation with leukaemia-derived-dendritic-cells containing dendritic cells or blast containing mononuclear cells (n = 21, respectively), we determined cytokine-concentrations (interleukin 2, 4, 6, 10, tumor-necrosis-factor-alpha, interferon-c) in supernatants of mixed-lymphocyte-culture and in serum (n = 16) of 20 patients with acute myeloid leukaemia and three patients with myelodysplastic syndromes by cytometric-bead-assay. We correlated our data with lytic capabilities of stimulated T-cells in a fluorolysis-assay and clinical data:Dendritic-cell-/mononuclear-cell-stimulation of T-cells resulted in increased cytokine-levels in culture- medium compared to serum. There were no significant differences between cytokine-patterns of cases with/without lytic T-cell-activity, response to immunotherapy (stem cell transplantation/donor-lymphocyte-infusion) or graft-versus-host-disease. However, some predictive cytokine-cut-off-values for antileukaemic T-cell-activity, patients' response to immunotherapy and graft-versus-host-disease could be defined.Cytokine-profiles alone, without functional assays, are no useful tool to predict antileukaemic T-cell-function, although they can indicate lytic T-cell-activity, patients' response to immunotherapy and graft-versus-host-disease.
Dendritic cells (DCs) either boost the immune system (enhancing immunity) or dampen it (leading to tolerance). This dual effect explains their vital role in cancer development and progression. DCs have been tested as a predictor of outcomes for cancer progression. Eight studies evaluated tumour-infiltrating DCs (TIDCs) as a predictor for colorectal cancer (CRC) outcomes. The detection of TIDCs has not kept pace with the increased knowledge about the identification of DC subsets and their maturation status. For that reason, it is difficult to draw a conclusion about the performance of DCs as a predictor of outcome for CRC. In this review, we comprehensively examine the evidence for the in situ immune response due to DC infiltration, in predicting outcome in primary CRC and how such information may be incorporated into routine clinical assessment.
Desmosomes represent adhesive, spot-like intercellular junctions that in association with intermediate filaments mechanically link neighboring cells and stabilize tissue architecture. In addition to this structural function, desmosomes also act as signaling platforms involved in the regulation of cell proliferation, differentiation, migration, morphogenesis, and apoptosis. Thus, deregulation of desmosomal proteins has to be considered to contribute to tumorigenesis. Proteolytic fragmentation and downregulation of desmosomal cadherins and plaque proteins by transcriptional or epigenetic mechanisms were observed in different cancer entities suggesting a tumor-suppressive role. However, discrepant data in the literature indicate that context-dependent differences based on alternative intracellular, signal transduction lead to altered outcome. Here, modulation of Wnt/beta-catenin signaling by plakoglobin or desmoplakin and of epidermal growth factor receptor signaling appears to be of special relevance. This review summarizes current evidence on how desmosomal proteins participate in carcinogenesis, and depicts the molecular mechanisms involved.
Epithelial-to-mesenchymal transition (EMT) as well as the reverse process, mesenchymal-to-epithelial transition (MET) is important during embryogenesis. EMT is also involved in cancer invasion and metastasis, and can generate cells with properties similar to those of stem cells. Retrotransposons can rearrange the genome by inserting DNA in new loci, thus inducing mutations. This study examines the gene expression of transcription factors involved in EMT and MET. In the second experimental panel, the gene expression of L1 retrotransposon was studied. L1-open reading frame (ORF) 2 mRNA was found to be expressed both in cancer and cancer stem cells, while L1-ORF1 mRNA was expressed only in cancer cells. The suppression of L1-ORF2 gene expression demonstrated that this retrotransposon might affect EMT in colon cancer stem cells. This study highlights that the EMT process seems to differ between cancer cells and cancer stem cells, and that transposable elements seem to be involved in the process, influencing cellular plasticity.
The cDNA sequence of peroxinectin was obtained from the haemocytes of Indian white shrimp Fenneropenaeus indicus using RT-PCR and RACE. Fenneropenaeus indicus peroxinectin (Fi-Pxn) sequence has an open reading frame (ORF) of 2415 bp encoding a protein of 804 amino acids with 21 residues signal sequence. The mature protein has molecular mass of 89.8 kDa with an estimated pI of 8.6. Two putative integrin-binding motifs, RGD and KGD, were observed at the basic N-terminal and C-terminal part of the mature aminoacid sequence. Fi-Pxn nucleotide sequence comparison showed high homology to mud crab Scylla serrata (89%) and to various vertebrate and invertebrate species. qRT-PCR showed peroxinectin mRNA transcript in haemocytes of F. indicus increased at 6 h post injection of peptidoglycan and Vibrio harveyi. The Fi-Pxn was mainly expressed in the tissues of haemocytes and the heart. The moulting stage responses showed Fi-Pxn expression in premoult stages D0/1 and D0/2.
Desmosomes have long been appreciated as intercellular junctions that are vital for maintaining the structural integrity of stratified epithelia. More recent clinical investigations of patients with diseases such as arrhythmogenic cardiomyopathy have further highlighted the importance of desmosomes in cardiac tissue, where they help to maintain coordination of cardiac myocytes. Here, we review clinical and mechanistic studies that provide insight into the functions of desmosomal proteins in skin and heart during homeostasis and in disease. While intercellular junctions are organized differently in cardiac and epithelial tissues, studies conducted in epithelial systems may inform our understanding of cardiac desmosomes. We explore traditional and non-traditional roles of desmosomal proteins, ranging from adhesive capacities to nuclear functions. Finally, we discuss how these studies can guide future investigations focused on determining the molecular mechanisms by which desmosomal mutations promote the development of cardiac diseases.
Hyper-adhesion is a unique, strongly adhesive form of desmosomal adhesion that functions to maintain tissue integrity. In this short review, we define hyper-adhesion, summarise the evidence for it in culture and in vivo, discuss its role in development, wound healing, and skin disease, and speculate about its molecular and cellular basis.
Ruta graveolens silver nanoparticles (AgNPs) showed the color change within 30 min and characterized using UV-visible spectra, Fourier Transform Infrared (FTIR), X-ray Diffraction (XRD) and Transmission Electron Microscopy (TEM). UV-visible spectrum of R. graveolens AgNPs showed the sharp peak at the wavelength of 440-560 nm. XRD patterns confirmed that crystalline nature of R. graveolens AgNPs and FTIR results revealed that phytochemical reaction of these R. graveolens is responsible for the synthesis of AgNPs. TEM results showed the size of the R. graveolens AgNPs around 30-50 nm with spherical and triangular nature. Further, the antibacterial and antibiofilm activity of R. graveolens AgNPs showed the effective inhibitory activity against clinically important Staphylococcus aureus, Pseudomonas aeruginosa and Candida albicans. Our findings suggest that R. graveolens AgNPs can be exploited toward the development of potential antibacterial agents for various biomedical and environmental applications.
Abstract Bacillus anthracis is a pathogenic, Gram-positive bacterium which chiefly affects the livestock of animals and humans through acute disease anthrax. All around the globe this bio-threat organism damages millions of lives in every year and also most of the drugs were not responding properly in inhibition against this diseased pathogen. In recent development, phage therapy is considered as alternative solution to treat this serious infectious disease. In this study, we elucidated the binding of γ phage lysin plyG enzymes toward the SrtA along with its activator peptide LPXTG. Through protein–protein docking and molecular dynamics simulation studies, we showed the distinguished structure complementarity of SrtA and plyG complex. Especially, MD simulation relates strong and stable interaction occurs between the protein complex structures. These results suggest that additional experimental studies on our approach will lead to availability of better inhibitor against the SrtA.
