Fibroblast growth factor 2 modulates extracellular purine metabolism by upregulating ecto-5′-nucleotidase and adenosine deaminase in cultured rat spinal cord astrocytes

Purinergic signaling via ATP and adenosine produced by astrocytes is one pathway underlying neuron–glia interactions in the central nervous system (CNS). In production of purines, extracellular metabolism of released purines via ecto-enzymes is important. The expression and activities of these enzymes are altered under pathological conditions. Production of fibroblast growth factor 2 (FGF2) is increased under pathological conditions, and this has various effects on astrocytes. Here, we investigated the effects of FGF2 on purine metabolism in cultured rat spinal cord astrocytes. Astrocytes rapidly metabolized purines added to the extracellular solution. FGF2 increased extracellular metabolism of AMP to adenosine and of adenosine to inosine by upregulating ecto-5′-nucleotidase and adenosine deaminase (ADA), respectively. ADA activity and protein were detected both in the cytosol and external solution of astrocytes, and their levels were markedly increased by FGF2. FGF2 also increased metabolism of endogenously released ATP, resulting in a transient increase in adenosine and substantial accumulation of extracellular inosine. Moreover, FGF2 increased ATP release by upregulating the activity of gap junction hemichannels. These data show that FGF2 regulates purine production in astrocytes and suggest that extracellular ADA released by astrocytes plays an important role in extracellular purine metabolism in the CNS.     

Comparison of oral flora before and after triple therapy for Helicobacter pylori eradication in patient with gastric disease

Odontology - The oral cavity is recognized as a major route for infection by Helicobacter pylori, which colonizes the gastric mucosa. Therapeutic options for elimination in patients with digestive...     

Vascular Ehlers-Danlos Syndrome Without the Characteristic Facial Features: A Case Report

As a type of Ehlers-Danlos syndrome (EDS), vascular EDs (vEDS) is typified by a number of characteristic facial features (eg, large eyes, small chin, sunken cheeks, thin nose and lips, lobeless ears). However, vEDs does not typically display hypermobility of the large joints and skin hyperextensibility, which are features typical of the more common forms of EDS. Thus, colonic perforation or aneurysm rupture may be the first presentation of the disease. Because both complications are associated with a reduced life expectancy for individuals with this condition, an awareness of the clinical features of vEDS is important.Here, we describe the treatment of vEDS lacking the characteristic facial attributes in a 24-year-old healthy man who presented to the emergency room with abdominal pain. Enhanced computed tomography revealed diverticula and perforation in the sigmoid colon. The lesion of the sigmoid colon perforation was removed, and Hartmann procedure was performed. During the surgery, the control of bleeding was required because of vascular fragility. Subsequent molecular and genetic analysis was performed based on the suspected diagnosis of vEDS. These analyses revealed reduced type III collagen synthesis in cultured skin fibroblasts and identified a previously undocumented mutation in the gene for a1 type III collagen, confirming the diagnosis of vEDS. After eliciting a detailed medical profile, we learned his mother had a history of extensive bruising since childhood and idiopathic hematothorax. Both were prescribed oral celiprolol. One year after admission, the patient was free of recurrent perforation.This case illustrates an awareness of the clinical characteristics of vEDS and the family history is important because of the high mortality from this condition even in young people. Importantly, genetic assays could help in determining the surgical procedure and offer benefits to relatives since this condition is inherited in an autosomal dominant manner.     

Mutations in the FHA-domain of ectopically expressed NBS1 lead to radiosensitization and to no increase in somatic mutation rates via a partial suppression of homologous recombination

Ionizing radiation induces DNA double-strand breaks (DSBs). Mammalian cells repair DSBs through multiple pathways, and the repair pathway that is utilized may affect cellular radiation sensitivity. In this study, we examined effects on cellular radiosensitivity resulting from functional alterations in homologous recombination (HR). HR was inhibited by overexpression of the forkhead-associated (FHA) domain-mutated NBS1 (G27D/R28D: FHA-2D) protein in HeLa cells or in hamster cells carrying a human X-chromosome. Cells expressing FHA-2D presented partially (but significantly) HR-deficient phenotypes, which were assayed by the reduction of gene conversion frequencies measured with a reporter assay, a decrease in radiation-induced Mre11 foci formation, and hypersensitivity to camptothecin treatments. Interestingly, ectopic expression of FHA-2D did not increase the frequency of radiation-induced somatic mutations at the HPRT locus, suggesting that a partial reduction of HR efficiency has only a slight effect on genomic stability. The expression of FHA-2D rendered the exponentially growing cell population slightly (but significantly) more sensitive to ionizing radiation. This radiosensitization effect due to the expression of FHA-2D was enhanced when the cells were irradiated with split doses delivered at 24-h intervals. Furthermore, enhancement of radiation sensitivity by split dose irradiation was not seen in contact-inhibited G0/G1 populations, even though the cells expressed FHA-2D. These results suggest that the FHA domain of NBS1 might be an effective molecular target that can be used to induce radiosensitization using low molecular weight chemicals, and that partial inhibition of HR might improve the effectiveness of cancer radiotherapy.     

Carbon monoxide-bound hemoglobin-vesicles for the treatment of bleomycin-induced pulmonary fibrosis

Carbon monoxide (CO) has potent anti-inflammatory and anti-oxidant effects. We report herein on the preparation of a nanotechnology-based CO donor, CO-bound hemoglobin-vesicles (CO-HbV). We hypothesized that CO-HbV could have a therapeutic effect on idiopathic pulmonary fibrosis (IPF), an incurable lung fibrosis, that is thought to involve inflammation and the production of reactive oxygen species (ROS). Pulmonary fibril formation and respiratory function were quantitatively evaluated by measuring hydroxyproline levels and forced vital capacity, respectively, using a bleomycin-induced pulmonary fibrosis mice model. CO-HbV suppressed the progression of pulmonary fibril formation and improved respiratory function compared to saline and HbV. The suppressive effect of CO-HbV on pulmonary fibrosis can be attributed to a decrease in ROS generation by inflammatory cells, NADPH oxidase 4 and the production of inflammatory cells, cytokines and transforming growth factor-β in the lung. This is the first demonstration of the inhibitory effect of CO-HbV on the progression of pulmonary fibrosis via the anti-oxidative and anti-inflammatory effects of CO in the bleomycin-induced pulmonary fibrosis mice model. CO-HbV has the potential for use in the treatment of, not only IPF, but also a variety of other ROS and inflammation-related disorders.     

Possible involvement of ΔNp63 downregulation in the invasion and metastasis of oral squamous cell carcinoma via induction of a mesenchymal phenotype

Epithelial-to-mesenchymal transition (EMT), an essential developmental program, is involved in tumor progression. ΔNp63, a homolog of p53, is associated with the EMT program, but the detailed mechanism remains to be elucidated. In this study, we investigated the role of ΔNp63 in EMT during progression of oral squamous cell carcinoma (OSCC). Five OSCC cell lines and specimens from 78 patients with OSCC were used. The expressions of ΔNp63, p63α, p63β and epithelial markers (cytokeratins 5 and 14) was detected in the OSCC cells, but not in SQUU-B cells (high metastatic potential). E-cadherin was expressed in all OSCC cells. Mesenchymal markers were strongly expressed in the SQUU-B cells. Knockdown of endogenous ΔNp63 in HSC-2 cells induced morphological changes to the spindle shape, decreased the expression of epithelial markers, increased the expression of mesenchymal markers, increased migration and reduced proliferation. By contrast, SQUU-B cells overexpressing ΔNp63β showed changed their morphology from stromal cell-like to epithelial cells. However, E-cadherin expression was not affected by ΔNp63 knockdown or overexpression. Immunohistochemical staining revealed that cancer cells expressing vimentin were found at the invasive front in the OSCC specimens. The intensity of ΔNp63 expression was also decreased in these cells. Interestingly, the vimentin positivity or decreased intensity of ΔNp63 was positively associated with metastases and poor prognosis in the OSCC patients. These results indicated that ΔNp63 downregulation in cancer cells induces a mesenchymal phenotype that is related to tumor progression of OSCC.