106 research outputs found
Ninjurin1 positively regulates osteoclast development by enhancing the survival of prefusion osteoclasts
Osteoclasts (OCs) are bone-resorbing cells that originate from hematopoietic stem cells and develop through the fusion of mononuclear myeloid precursors. Dysregulation of OC development causes bone disorders such as osteopetrosis, osteoporosis, and rheumatoid arthritis. Although the molecular mechanisms underlying osteoclastogenesis have been well established, the means by which OCs maintain their survival during OC development remain unknown. We found that Ninjurin1 (Ninj1) expression is dynamically regulated during osteoclastogenesis and that Ninj1(-/-) mice exhibit increased trabecular bone volume owing to impaired OC development. Ninj1 deficiency did not alter OC differentiation, transmigration, fusion, or actin ring formation but increased Caspase-9-dependent intrinsic apoptosis in prefusion OCs (preOCs). Overexpression of Ninj1 enhanced the survival of mouse macrophage/preOC RAW264.7 cells in osteoclastogenic culture, suggesting that Ninj1 is important for the survival of preOCs. Finally, analysis of publicly available microarray data sets revealed a potent correlation between high NINJ1 expression and destructive bone disorders in humans. Our data indicate that Ninj1 plays an important role in bone homeostasis by enhancing the survival of preOCs
Solitary Extramedullary Plasmacytoma of the Liver without Systemic Monoclonal Gammopathy
Extramedullary plasmacytoma of the liver is a very rare tumor. Although a few cases of extramedullary plasmacytoma of the liver have been reported, we could not find any report on truly localized extramedullary plasmacytoma of the liver in the literature. The patient was a 63-yr-old man who exhibited a solitary liver mass on dynamic computed tomography and magnetic resonance imaging. Histologically, the tumor was composed of mature plasma cells with mild atypia. Immunohistochemistry demonstrated monoclonal IgG and Kappa light chain expression. Bone marrow examination revealed no abnormalities. There was no evidence of a monoclonal protein in the serum and urine, lytic bone lesions, anemia, renal insufficiency, and hypercalcemia. The patient was treated with 5,000 cGy of radiotherapy, and the tumor disappeared 6 months after treatment
Xenopus gpx3 Mediates Posterior Development by Regulating Cell Death during Embryogenesis
Glutathione peroxidase 3 (GPx3) belongs to the glutathione peroxidase family of selenoproteins and is a key antioxidant enzyme in multicellular organisms against oxidative damage. Downregulation of GPx3 affects tumor progression and metastasis and is associated with liver and heart disease. However, the physiological significance of GPx3 in vertebrate embryonic development remains poorly understood. The current study aimed to investigate the functional roles of gpx3 during embryogenesis. To this end, we determined gpx3's spatiotemporal expression using Xenopus laevis as a model organism. Using reverse transcription polymerase chain reaction (RT-PCR), we demonstrated the zygotic nature of this gene. Interestingly, the expression of gpx3 enhanced during the tailbud stage of development, and whole mount in situ hybridization (WISH) analysis revealed gpx3 localization in prospective tail region of developing embryo. gpx3 knockdown using antisense morpholino oligonucleotides (MOs) resulted in short post-anal tails, and these malformed tails were significantly rescued by glutathione peroxidase mimic ebselen. The gene expression analysis indicated that gpx3 knockdown significantly altered the expression of genes associated with Wnt, Notch, and bone morphogenetic protein (BMP) signaling pathways involved in tailbud development. Moreover, RNA sequencing identified that gpx3 plays a role in regulation of cell death in the developing embryo. Terminal deoxynucleotidyl transferase dUTP nick end labeling (TUNEL) and phospho-histone 3 (PH3) staining confirmed the association of gpx3 knockdown with increased cell death and decreased cell proliferation in tail region of developing embryos, establishing the involvement of gpx3 in tailbud development by regulating the cell death. Furthermore, these findings are inter-related with increased reactive oxygen species (ROS) levels in gpx3 knockdown embryos, as measured by using a redox-sensitive fluorescent probe HyPer. Taken together, our results suggest that gpx3 plays a critical role in posterior embryonic development by regulating cell death and proliferation during vertebrate embryogenesis
Co-transplantation of Human Mesenchymal Stem Cells Promotes Human CD34+ Cells Engraftment in a Dose-dependent Fashion in NOD/SCID Mice
Mesenchymal stem cells (MSCs) have recently been identified and characterized in humans. Moreover, MSC secrete cytokines that can support hematopoietic progenitor growth. In the present study, we evaluated whether the efficacy of hematopoietic stem cell transplantation is improved by their co-transplantation with MSC, and whether this is positively correlated with the dose of infused MSCs. Accordingly, irradiated NOD/SCID mice were transplanted with 1ร105 human CD34+ cells in the presence or absence of culture expanded MSCs (1ร106 or 5ร106). We evaluated human hematopoietic cell engraftment by flow cytometry and assessed MSC tissue distributions by fluorescence in situ hybridization. We found that CD45+ and CD34+ cell levels were significantly elevated in a dose-dependent manner in cotransplanted mice 4 weeks after transplantation. The engraftments of CD33+ and CD19+ cells also increased dose-dependently. However, the engraftment of CD3+ cells did not increase after co-transplantation with MSCs. Human Y chromosome+ cells were observed in multiple tissues and were more frequently observed in mice co-transplanted with 5ร106 rather than 1ร106 MSCs. These results suggest that MSCs are capable of enhancing hematopoietic cell engraftment and distribution in multiple organs in a dose-dependent fashion
Ginseng Berry Extract Prevents Atherogenesis via Anti-Inflammatory Action by Upregulating Phase II Gene Expression
Ginseng berry possesses higher ginsenoside content than its root, which has been traditionally used in herbal medicine for many human diseases, including atherosclerosis. We here examined the antiatherogenic effects of the Korean ginseng berry extract (KGBE) and investigated its underlying mechanism of action in vitro and in vivo. Administration of KGBE decreased atherosclerotic lesions, which was inversely correlated with the expression levels of phase II genes to include heme oxygenase-1 (HO-1) and glutamine-cysteine ligase (GCL). Furthermore, KGBE administration suppressed NF-ฮบB-mediated expression of atherogenic inflammatory genes (TNF-ฮฑ, IL-1ฮฒ, iNOS, COX-2, ICAM-1, and VCAM-1), without altering serum cholesterol levels, in ApoE-/- mice fed a high fat-diet. Treatment with KGBE increased phase II gene expression and suppressed lipopolysaccharide-induced reactive oxygen species production, NF-ฮบB activation, and inflammatory gene expression in primary macrophages. Importantly, these cellular events were blocked by selective inhibitors of HO-1 and GCL. In addition, these inhibitors reversed the suppressive effect of KGBE on TNF-ฮฑ-mediated induction of ICAM-1 and VCAM-1, resulting in decreased interaction between endothelial cells and monocytes. These results suggest that KGBE ameliorates atherosclerosis by inhibiting NF-ฮบB-mediated expression of atherogenic genes via upregulation of phase II enzymes and thus has therapeutic or preventive potential for atherosclerosis
Physiological Functions of Thiol Peroxidases (Gpx1 and Prdx2) during Xenopus laevis Embryonic Development
Glutathione peroxidase 1 (Gpx1) and peroxiredoxin 2 (Prdx2) belong to the thiol peroxidase family of antioxidants, and have been studied for their antioxidant functions and roles in cancers. However, the physiological significance of Gpx1 and Prdx2 during vertebrate embryogenesis are lacking. Currently, we investigated the functional roles of Gpx1 and Prdx2 during vertebrate embryogenesis using Xenopus laevis as a vertebrate model. Our investigations revealed the zygotic nature of gpx1 having its localization in the eye region of developing embryos, whereas prdx2 exhibited a maternal nature and were localized in embryonic ventral blood islands. Furthermore, the gpx1-morphants exhibited malformed eyes with incompletely detached lenses. However, the depletion of prdx2 has not established its involvement with embryogenesis. A molecular analysis of gpx1-depleted embryos revealed the perturbed expression of a cryba1-lens-specific marker and also exhibited reactive oxygen species (ROS) accumulation in the eye regions of gpx1-morphants. Additionally, transcriptomics analysis of gpx1-knockout embryos demonstrated the involvement of Wnt, cadherin, and integrin signaling pathways in the development of malformed eyes. Conclusively, our findings indicate the association of gpx1 with a complex network of embryonic developmental pathways and ROS responses, but detailed investigation is a prerequisite in order to pinpoint the mechanistic details of these interactions.</p>
Hepatoprotective Activity of Licorice Water Extract against Cadmium-induced Toxicity in Rats
Licorice is commonly used as a cure for digestive disorders and as a detoxification agent in East Asia. This study investigated the protective effect of licorice water extract against cadmium (CdCl2, Cd)-induced liver toxicity in rats. To induce acute toxicity, Cd (4 mg/kg body weight) was dissolved in normal saline and intravenously (i.v.) injected into rats. The rats then received either a vehicle or licorice water extract (50, 100 mg/kg/day) for 3 days, and were subsequently exposed to a single injection of Cd 24 h after the last licorice/vehicle treatment. Alanine aminotransferase (ALT), aspartate aminotransferase (AST) and lactate dehydrogenase (LDH) were significantly increased by Cd treatment. In contrast, pretreatment with licorice reduced ALT, AST and LDH. In histopathological analysis, licorice decreased the central necrosis around central veins, the peripheral hemorrhage around portal triads, the percentage of degenerative hepatic regions (%/mm2 hepatic parenchyma) and the number of degenerative hepatic cells (N/100 hepatic cells). Licorice also inhibited the increment of Bad (a BH3 domain-containing protein) translocation by Cd in liver cells. These results demonstrate that licorice could have a hepatoprotective effect by inhibiting the translocation of Bad to the mitochondria in Cd-intoxificated rats
Transmodulation between phospholipase D and c-Src enhances cell proliferation
Phospholipase D (PLD) has been implicated in the signal transduction pathways initiated by several mitogenic protein tyrosine kinases. We demonstrate for the first time that most notably PLD2 and to a lesser extent the PLD1 isoform are tyrosine phosphorylated by c-Src tyrosine kinase via direct association. Moreover, epidermal growth factor induced tyrosine phosphorylation of PLD2 and its interaction with c-Src in A431 cells. Interaction between these proteins is via the pleckstrin homology domain of PLD2 and the catalytic domain of c-Src. Coexpression of PLD1 or PLD2 with c-Src synergistically enhances cellular proliferation compared with expression of either molecule. While PLD activity as a lipid-hydrolyzing enzyme is not affected by c-Src, wildtype PLDs but not catalytically inactive PLD mutants significantly increase c-Src kinase activity, up-regulating c-Src-mediated paxillin phosphorylation and extracellular signal-regulated kinase activity. These results demonstrate the critical role of PLD catalytic activity in the stimulation of Src signaling. In conclusion, we provide the first evidence that c-Src acts as a kinase of PLD and PLD acts as an activator of c-Src. This transmodulation between c-Src and PLD may contribute to the promotion of cellular proliferation via amplification of mitogenic signaling pathwaysclos
Roles of Arrest-Defective Protein 1225 and Hypoxia-Inducible Factor 1ฮฑ in Tumor Growth and Metastasis
Background Vascular endothelial growth factor A (VEGFA), a critical mediator of tumor angiogenesis, is a well-characterized target of hypoxia-inducible factor 1 (HIF-1). Murine arrest-defective protein 1A (mARD1A225) acetylates HIF-1??, triggering its degradation, and thus may play a role in decreased expression of VEGFA.Methods We generated ApcMin/+/mARD1A225 transgenic mice and quantified growth of intestinal polyps. Human gastric MKN74 and murine melanoma B16F10 cells overexpressing mARD1A225 were injected into mice, and tumor growth and metastasis were measured. VEGFA expression and microvessel density in tumors were assessed using immunohistochemistry. To evaluate the role of mARD1A 225 acetylation of Lys532 in HIF-1??, we injected B16F10-mARD1A225 cell lines stably expressing mutant HIF-1??/K532R into mice and measured metastasis. All statistical tests were two-sided, and P values less than. 05 were considered statistically significant.Results ApcMin/+/mARD1A225 transgenic mice (n = 25) had statistically significantly fewer intestinal polyps than Apc Min/+ mice (n = 21) (number of intestinal polyps per mouse: Apc Min/+ mice vs ApcMin/+/mARD1A225 transgenic mice, mean = 83.4 vs 38.0 polyps, difference = 45.4 polyps, 95% confidence interval [CI] = 41.8 to 48.6; P <. 001). The growth and metastases of transplanted tumors were also statistically significantly reduced in mice injected with mARD1A225-overexpressing cells than in mice injected with control cells (P <. 01). Moreover, overexpression of mARD1A 225 decreased VEGFA expression and microvessel density in tumor xenografts (P <. 04) and ApcMin/+ intestinal polyps (P =. 001). Mutation of lysine 532 of HIF-1?? in B16F10-mARD1A225 cells prevented HIF-1?? degradation and inhibited the antimetastatic effect of mARD1A225 (P <. 001).Conclusion mARD1A225 may be a novel upstream target that blocks VEGFA expression and tumor-related angiogenesis
- โฆ