2,631 research outputs found

    A RUNX2 stabilization pathway mediates physiologic and pathologic bone formation

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    The osteoblast differentiation capacity of skeletal stem cells (SSCs) must be tightly regulated, as inadequate bone formation results in low bone mass and skeletal fragility, and over-exuberant osteogenesis results in heterotopic ossification (HO) of soft tissues. RUNX2 is essential for tuning this balance, but the mechanisms of posttranslational control of RUNX2 remain to be fully elucidated. Here, we identify that a CK2/HAUSP pathway is a key regulator of RUNX2 stability, as Casein kinase 2 (CK2) phosphorylates RUNX2, recruiting the deubiquitinase herpesvirus-associated ubiquitin-specific protease (HAUSP), which stabilizes RUNX2 by diverting it away from ubiquitin-dependent proteasomal degradation. This pathway is important for both the commitment of SSCs to osteoprogenitors and their subsequent maturation. This CK2/HAUSP/RUNX2 pathway is also necessary for HO, as its inhibition blocked HO in multiple models. Collectively, active deubiquitination of RUNX2 is required for bone formation and this CK2/HAUSP deubiquitination pathway offers therapeutic opportunities for disorders of inappropriate mineralization

    Bee venom attenuates neuroinflammatory events and extends survival in amyotrophic lateral sclerosis models

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    <p>Abstract</p> <p>Background</p> <p>Amyotrophic lateral sclerosis (ALS) is a disease affecting the central nervous system that is either sporadic or familial origin and causing the death of motor neurons. One of the genetic factors contributing to the etiology of ALS is mutant SOD1 (mtSOD1), which induces vulnerability of motor neurons through protein misfolding, mitochondrial dysfunction, oxidative damage, cytoskeletal abnormalities, defective axonal transport, glutamate excitotoxicity, inadequate growth factor signaling, and neuroinflammation. Bee venom has been used in the practice of Oriental medicine and evidence from the literature indicates that BV plays an anti-inflammatory or anti-nociceptive role against inflammatory reactions associated with arthritis and other inflammatory diseases. The purpose of the present study was to determine whether bee venom suppresses motor neuron loss and microglial cell activation in hSOD1<sup>G93A </sup>mutant mice.</p> <p>Methods</p> <p>Bee venom (BV) was bilaterally injected (subcutaneously) into a 14-week-old (98 day old) male hSOD1<sup>G93A </sup>animal model at the Zusanli (ST36) acupoint, which is known to mediate an anti-inflammatory effect. For measurement of motor activity, rotarod test was performed and survival statistics were analyzed by Kaplan-Meier survival curves. The effects of BV treatment on anti-neuroinflammation of hSOD1<sup>G93A </sup>mice were assessed via immunoreactions using Iba 1 as a microglia marker and TNF-Ī± antibody. Activation of ERK, Akt, p38 MAP Kinase (MAPK), and caspase 3 proteins was evaluated by western blotting.</p> <p>Results</p> <p>BV-treated mutant hSOD1 transgenic mice showed a decrease in the expression levels of microglia marker and phospho-p38 MAPK in the spinal cord and brainstem. Interestingly, treatment of BV in symptomatic ALS animals improved motor activity and the median survival of the BV-treated group (139 Ā± 3.5 days) was 18% greater than control group (117 Ā± 3.1 days). Furthermore, we found that BV suppressed caspase-3 activity and blocked the defects of mitochondrial structure and cristae morphology in the lumbar spinal cord of hSOD1<sup>G93A </sup>mice at the symptomatic stage.</p> <p>Conclusion</p> <p>From these findings, our research suggests BV could be a potential therapeutic agent for anti-neuroinflammatory effects in an animal model of ALS.</p

    The ERK MAPK Pathway Is Essential for Skeletal Development and Homeostasis

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    Mitogen-activated protein kinases (MAPKs) are a family of protein kinases that function as key signal transducers of a wide spectrum of extracellular stimuli, including growth factors and pro-inflammatory cytokines. Dysregulation of the extracellular signal-regulated kinase (ERK) MAPK pathway is associated with human skeletal abnormalities including Noonan syndrome, neurofibromatosis type 1, and cardiofaciocutaneous syndrome. Here, we demonstrate that ERK activation in osteoprogenitors is required for bone formation during skeletal development and homeostasis. Deletion of Mek1 and Mek2, kinases upstream of ERK MAPK, in osteoprogenitors (Mek1(Osx)Mek2(-/-)), resulted in severe osteopenia and cleidocranial dysplasia (CCD), similar to that seen in humans and mice with impaired RUNX2 function. Additionally, tamoxifen-induced deletion of Mek1 and Mek2 in osteoprogenitors in adult mice (Mek1(Osx-ERT)Mek2(-/-)) significantly reduced bone mass. Mechanistically, this corresponded to decreased activation of osteoblast master regulators, including RUNX2, ATF4, and beta-catenin. Finally, we identified potential regulators of osteoblast differentiation in the ERK MAPK pathway using unbiased phospho-mass spectrometry. These observations demonstrate essential roles of ERK activation in osteogenesis and bone formation

    Cases of Hemolytic Anemia with Periprosthetic Leaks Evaluated by Real-Time 3-Dimensional Transesophageal Echocardiography

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    Hemolytic anemia is recognized as a rare complication of mitral valve replacement or repair. We report on a 44-year-old man with shortness of breath and hemolytic anemia, 23 years after mitral valve replacement (Hall-Kaster), and a 63-year-old woman diagnosed of hemolytic anemia, 4 years after mitral and tricuspid annuloplasty (Tailor ring, An-core ring). Routine 2-dimensional transthoracic echocardiography revealed paravalvular leakage around the prosthesis. Subsequent real-time 3-dimensional (3D)transesophageal echocardiography helped the perceptional appreciation of the leakage and the measuring of the regurgitant orifice area using the anatomically correct plane. Surgical findings of each case fit those of 3D volumetric images

    Newly developed post-operative atrial fibrillation is associated with an increased risk of late recurrence of atrial fibrillation in patients who underwent open heart surgery: Long-term follow up

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    Background: Herein is sought to determine whether the occurrence of post-operative atrial fibrillation (POAF) increases the risk of late recurrence of atrial fibrillation (AF) in patients undergoing open heart surgery (OHS). Methods: This study included 938 patients (56.7 Ā± 13.1 years old, 550 males) with no history of AF who underwent OHS. All patients were monitored continuously for development of POAF after surgery until the time of hospital discharge and received clinical follow up with serial evaluation of rhythm status. Results: Among the total population, POAF occurred in 207 (22.1%) patients and late AF in 88 (9.4%) patients during the mean follow up period of 78.1 Ā± 39.1 months. Development of late AF ocĀ¬curred more frequently in patients with POAF than in those without [29.0% (60/207) vs. 3.8% (28/731), p < 0.01]. Higher septal E/eā€™ ratio (HR 1.04, 95% CI 1.00ā€“1.08, p = 0.04) was an independent predicĀ¬tor of late occurrence of AF and an episode of POAF (HR 27.12, 95% CI 8.46ā€“86.96, p < 0.01) was the most powerful predictor. Conclusions: POAF is significantly associated with an increased risk of late AF recurrence during long-term follow up. Careful concern regarding late recurrence of AF with serial evaluation of rhythm status is required in patients with POAF

    Bone-targeting AAV-mediated silencing of Schnurri-3 prevents bone loss in osteoporosis

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    RNAi-based bone anabolic gene therapy has demonstrated initial success, but many practical challenges are still unmet. Here, we demonstrate that a recombinant adeno-associated virus 9 (rAAV9) is highly effective for transducing osteoblast lineage cells in the bone. The adaptor protein Schnurri-3 (SHN3) is a promising therapeutic target for osteoporosis, as deletion of shn3 prevents bone loss in osteoporotic mice and short-term inhibition of shn3 in adult mice increases bone mass. Accordingly, systemic and direct joint administration of an rAAV9 vector carrying an artificial-microRNA that targets shn3 (rAAV9-amiR-shn3) in mice markedly enhanced bone formation via augmented osteoblast activity. Additionally, systemic delivery of rAAV9-amiR-shn3 in osteoporotic mice counteracted bone loss and enhanced bone mechanical properties. Finally, we rationally designed a capsid that exhibits improved specificity to bone by grafting the bone-targeting peptide motif (AspSerSer)6 onto the AAV9-VP2 capsid protein. Collectively, our results identify a bone-targeting rAAV-mediated gene therapy for osteoporosis

    Selection of high berberine yielding phellodendron insulare nak. lines and the antimicrobial activity of their extracts

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    High berberine yielding Phellodendron insulare Nak. lines were selected by aggregate cloning method and the antimicrobial activity of their extracts was assessed. The berberine producing cork tree lines were selected by adopting a colorimetric method. In all 300 high berberine producing lines were selected with a colorimetric reagent containing 5M HCl and H2O2 and established from dissociated cell aggregates. The crude extracts from these lines showed antibacterial activities against tested Escherichia coli, Staphylococcus aureus, Salmonella typhimulium, and Listeria monocytogenes. The cork tree extracts were found to be inhibitory to these test organisms. Further the antimicrobial activity of plant extracts was on par with the berberine isolated from the extracts from native cork trees. These results have potential for developing alternative plant products as antimicrobial substances for application in agriculture and food industry

    Down-regulation of phospholipase D during differentiation of mouse F9 teratocarcinoma cells

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    AbstractPhospholipase D has been recognized as playing an important role in signal transduction in many types of cells. We investigated the expression of phospholipase D during the differentiation of F9 embryonal teratocarcinoma cells. The ADP ribosylation factor-dependent phospholipase D activity, as measured by an in vitro assay, and H2O2-induced phospholipase D activity and phospholipase D protein content in whole cells were decreased during the differentiation of F9 cells induced by a combination of dibutyryl cyclic AMP and all-trans retinoic acid. In contrast, these changes were not observed when cells were induced by retinoic acid. These results suggest that down-regulation of phospholipase D protein is associated with differentiation of F9 cells to a parietal endoderm lineage
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