Sample records for human myogenic precursor

  1. Derivation of Skeletal Myogenic Precursors from Human Pluripotent Stem Cells Using Conditional Expression of PAX7.

    PubMed

    Darabi, Radbod; Perlingeiro, Rita C R

    2016-01-01

    Cell-based therapies are considered as one of the most promising approaches for the treatment of degenerating pathologies including muscle disorders and dystrophies. Advances in the approach of reprogramming somatic cells into induced pluripotent stem (iPS) cells allow for the possibility of using the patient's own pluripotent cells to generate specific tissues for autologous transplantation. In addition, patient-specific tissue derivatives have been shown to represent valuable material for disease modeling and drug discovery. Nevertheless, directed differentiation of pluripotent stem cells into a specific lineage is not a trivial task especially in the case of skeletal myogenesis, which is generally poorly recapitulated during the in vitro differentiation of pluripotent stem cells.Here, we describe a practical and efficient method for the derivation of skeletal myogenic precursors from differentiating human pluripotent stem cells using controlled expression of PAX7. Flow cytometry (FACS) purified myogenic precursors can be expanded exponentially and differentiated in vitro into myotubes, enabling researchers to use these cells for disease modeling as well as therapeutic purposes.

  2. A new pro-migratory activity on human myogenic precursor cells for a synthetic peptide within the E domain of the mechano growth factor

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mills, Philippe; Lafreniere, Jean-Francois; Benabdallah, Basma Fattouma

    2007-02-01

    Duchenne muscular dystrophy (DMD) is an inherited disease that leads to progressive muscle wasting. Myogenic precursor cell transplantation is an approach that can introduce the normal dystrophin gene in the muscle fibers of the patients. Unfortunately, these myogenic precursor cells do not migrate well in the muscle and thus many injections have to be done to enable a good graft success. Recent reports have shown that there is extensive splicing of the IGF-1 gene in muscles. The MGF isoform contains a C-terminal 24 amino acids peptide in the E domain (MGF-Ct24E) that has intrinsic properties. It can promote the proliferationmore » while delaying the differentiation of C{sub 2}C{sub 12} cells. Here, we demonstrated that this synthetic peptide is a motogenic factor for human precursor myogenic cells in vitro and in vivo. Indeed, MGF-Ct24E peptide can modulate members of the fibrinolytic and metalloproteinase systems, which are implicated in the migration of myogenic cells. MGF-Ct24E peptide enhances the expression of u-PA, u-PAR and MMP-7 while reducing PAI-1 activity. Moreover, it has no effect on the gelatinases MMP-2 and -9. Those combined effects can favour cell migration. Finally, we present some results suggesting that the MGF-Ct24E peptide induces these cell responses through a mechanism that does not involve the IGF-1 receptor. Thus, this MGF-Ct24E peptide has a new pro-migratory activity on human myogenic precursor cells that may be helpful in the treatment of DMD. Those results reinforce the possibility that the IGF-1Ec isoform may produce an E domain peptide that can act as a cytokine.« less

  3. Smad1/5/8 are myogenic regulators of murine and human mesoangioblasts

    PubMed Central

    Costamagna, Domiziana; Quattrocelli, Mattia; van Tienen, Florence; Umans, Lieve; de Coo, Irineus F. M.; Zwijsen, An; Huylebroeck, Danny; Sampaolesi, Maurilio

    2016-01-01

    Mesoangioblasts (MABs) are vessel-associated stem cells that express pericyte marker genes and participate in skeletal muscle regeneration. Molecular circuits that regulate the myogenic commitment of MABs are still poorly characterized. The critical role of bone morphogenetic protein (BMP) signalling during proliferation and differentiation of adult myogenic precursors, such as satellite cells, has recently been established. We evaluated whether BMP signalling impacts on the myogenic potential of embryonic and adult MABs both in vitro and in vivo. Addition of BMP inhibited MAB myogenic differentiation, whereas interference with the interactions between BMPs and receptor complexes induced differentiation. Similarly, siRNA-mediated knockdown of Smad8 in Smad1/5-null MABs or inhibition of SMAD1/5/8 phosphorylation with Dorsomorphin (DM) also improved myogenic differentiation, demonstrating a novel role of SMAD8. Moreover, using a transgenic mouse model of Smad8 deletion, we demonstrated that the absence of SMAD8 protein improved MAB myogenic differentiation. Furthermore, once injected into α-Sarcoglycan (Sgca)-null muscles, DM-treated MABs were more efficacious to restore α-sarcoglycan (αSG) protein levels and re-establish functional muscle properties. Similarly, in acute muscle damage, DM-treated MABs displayed a better myogenic potential compared with BMP-treated and untreated cells. Finally, SMADs also control the myogenic commitment of human MABs (hMABs). BMP signalling antagonists are therefore novel candidates to improve the therapeutic effects of hMABs. PMID:26450990

  4. Retained Myogenic Potency of Human Satellite Cells from Torn Rotator Cuff Muscles Despite Fatty Infiltration.

    PubMed

    Koide, Masashi; Hagiwara, Yoshihiro; Tsuchiya, Masahiro; Kanzaki, Makoto; Hatakeyama, Hiroyasu; Tanaka, Yukinori; Minowa, Takashi; Takemura, Taro; Ando, Akira; Sekiguchi, Takuya; Yabe, Yutaka; Itoi, Eiji

    2018-01-01

    Rotator cuff tears (RCTs) are a common shoulder problem in the elderly that can lead to both muscle atrophy and fatty infiltration due to less physical load. Satellite cells, quiescent cells under the basal lamina of skeletal muscle fibers, play a major role in muscle regeneration. However, the myogenic potency of human satellite cells in muscles with fatty infiltration is unclear due to the difficulty in isolating from small samples, and the mechanism of the progression of fatty infiltration has not been elucidated. The purpose of this study was to analyze the population of myogenic and adipogenic cells in disused supraspinatus (SSP) and intact subscapularis (SSC) muscles of the RCTs from the same patients using fluorescence-activated cell sorting. The microstructure of the muscle with fatty infiltration was observed as a whole mount condition under multi-photon microscopy. Myogenic differentiation potential and gene expression were evaluated in satellite cells. The results showed that the SSP muscle with greater fatty infiltration surrounded by collagen fibers compared with the SSC muscle under multi-photon microscopy. A positive correlation was observed between the ratio of muscle volume to fat volume and the ratio of myogenic precursor to adipogenic precursor. Although no difference was observed in the myogenic potential between the two groups in cell culture, satellite cells in the disused SSP muscle showed higher intrinsic myogenic gene expression than those in the intact SSC muscle. Our results indicate that satellite cells from the disused SSP retain sufficient potential of muscle growth despite the fatty infiltration.

  5. ANKK1 is found in myogenic precursors and muscle fibers subtypes with glycolytic metabolism.

    PubMed

    Rubio-Solsona, Estrella; Martí, Salvador; Vílchez, Juan J; Palau, Francesc; Hoenicka, Janet

    2018-01-01

    Ankyrin repeat and kinase domain containing 1 (ANKK1) gene has been widely related to neuropsychiatry disorders. The localization of ANKK1 in neural progenitors and its correlation with the cell cycle has suggested its participation in development. However, ANKK1 functions still need to be identified. Here, we have further characterized the ANKK1 localization in vivo and in vitro, by using immunolabeling, quantitative real-time PCR and Western blot in the myogenic lineage. Histologic investigations in mice and humans revealed that ANKK1 is expressed in precursors of embryonic and adult muscles. In mice embryos, ANKK1 was found in migrating myotubes where it shows a polarized cytoplasmic distribution, while proliferative myoblasts and satellite cells show different isoforms in their nuclei and cytoplasm. In vitro studies of ANKK1 protein isoforms along the myogenic progression showed the decline of nuclear ANKK1-kinase until its total exclusion in myotubes. In adult mice, ANKK1 was expressed exclusively in the Fast-Twitch muscles fibers subtype. The induction of glycolytic metabolism in C2C12 cells with high glucose concentration or treatment with berberine caused a significant increase in the ANKK1 mRNA. Similarly, C2C12 cells under hypoxic conditions caused the increase of nuclear ANKK1. These results altogether show a relationship between ANKK1 gene regulation and the metabolism of muscles during development and in adulthood. Finally, we found ANKK1 expression in regenerative fibers of muscles from dystrophic patients. Future studies in ANKK1 biology and the pathological response of muscles will reveal whether this protein is a novel muscle disease biomarker.

  6. Isolation and Quantitative Immunocytochemical Characterization of Primary Myogenic Cells and Fibroblasts from Human Skeletal Muscle

    PubMed Central

    Agley, Chibeza C.; Rowlerson, Anthea M.; Velloso, Cristiana P.; Lazarus, Norman L.; Harridge, Stephen D. R.

    2015-01-01

    The repair and regeneration of skeletal muscle requires the action of satellite cells, which are the resident muscle stem cells. These can be isolated from human muscle biopsy samples using enzymatic digestion and their myogenic properties studied in culture. Quantitatively, the two main adherent cell types obtained from enzymatic digestion are: (i) the satellite cells (termed myogenic cells or muscle precursor cells), identified initially as CD56+ and later as CD56+/desmin+ cells and (ii) muscle-derived fibroblasts, identified as CD56– and TE-7+. Fibroblasts proliferate very efficiently in culture and in mixed cell populations these cells may overrun myogenic cells to dominate the culture. The isolation and purification of different cell types from human muscle is thus an important methodological consideration when trying to investigate the innate behavior of either cell type in culture. Here we describe a system of sorting based on the gentle enzymatic digestion of cells using collagenase and dispase followed by magnetic activated cell sorting (MACS) which gives both a high purity (>95% myogenic cells) and good yield (~2.8 x 106 ± 8.87 x 105 cells/g tissue after 7 days in vitro) for experiments in culture. This approach is based on incubating the mixed muscle-derived cell population with magnetic microbeads beads conjugated to an antibody against CD56 and then passing cells though a magnetic field. CD56+ cells bound to microbeads are retained by the field whereas CD56– cells pass unimpeded through the column. Cell suspensions from any stage of the sorting process can be plated and cultured. Following a given intervention, cell morphology, and the expression and localization of proteins including nuclear transcription factors can be quantified using immunofluorescent labeling with specific antibodies and an image processing and analysis package. PMID:25650991

  7. Pax-3 expression in segmental mesoderm marks early stages in myogenic cell specification.

    PubMed

    Williams, B A; Ordahl, C P

    1994-04-01

    Specification of the myogenic lineage begins prior to gastrulation and culminates in the emergence of determined myogenic precursor cells from the somites. The myoD family (MDF) of transcriptional activators controls late step(s) in myogenic specification that are closely followed by terminal muscle differentiation. Genes expressed in myogenic specification at stages earlier than MDFs are unknown. The Pax-3 gene is expressed in all the cells of the caudal segmental plate, the early mesoderm compartment that contains the precursors of skeletal muscle. As somites form from the segmental plate and mature, Pax-3 expression is progressively modulated. Beginning at the time of segmentation, Pax-3 becomes repressed in the ventral half of the somite, leaving Pax-3 expression only in the dermomyotome. Subsequently, differential modulation of Pax-3 expression levels delineates the medial and lateral halves of the dermomyotome, which contain precursors of axial (back) muscle and limb muscle, respectively. Pax-3 expression is then repressed as dermomyotome-derived cells activate MDFs. Quail-chick chimera and ablation experiments confirmed that the migratory precursors of limb muscle continue to express Pax-3 during migration. Since limb muscle precursors do not activate MDFs until 2 days after they leave the somite, Pax-3 represents the first molecular marker for this migratory cell population. A null mutation of the mouse Pax-3 gene, Splotch, produces major disruptions in early limb muscle development (Franz, T., Kothary, R., Surani, M. A. H., Halata, Z. and Grim, M. (1993) Anat. Embryol. 187, 153-160; Goulding, M., Lumsden, A. and Paquette, A. (1994) Development 120, 957-971). We conclude, therefore, that Pax-3 gene expression in the paraxial mesoderm marks earlier stages in myogenic specification than MDFs and plays a crucial role in the specification and/or migration of limb myogenic precursors.

  8. Tumor necrosis factor-alpha inhibits differentiation of myogenic cells in human urethral rhabdosphincter.

    PubMed

    Shinohara, Mayuka; Sumino, Yasuhiro; Sato, Fuminori; Kiyono, Tohru; Hashimoto, Naohiro; Mimata, Hiromitsu

    2017-06-01

    To examine the inhibitory effects of tumor necrosis factor-α on myogenic differentiation of human urethral rhabdosphincter cells. A rhabdosphincter sample was obtained from a patient who underwent total cystectomy. To expand the lifespan of the primary cultured cells, rhabdosphincter myogenic cells were immortalized with mutated cyclin-dependent kinase 4, cyclin D1 and telomerase. The differential potential of the cells was investigated. The transfected human rhabdosphincter cells were induced for myogenic differentiation with recombinant human tumor necrosis factor-α and/or the tumor necrosis factor-α antagonist etanercept at different concentrations, and activation of signaling pathways was monitored. Human rhabdosphincter cells were selectively cultured for at least 40 passages. Molecular analysis confirmed the expression of myosin heavy chain, which is a specific marker of differentiated muscle cells, significantly increased after differentiation induction. Although tumor necrosis factor-α treatment reduced the myosin heavy chain expression in a concentration-dependent manner, etanercept inhibited this suppression. Tumor necrosis factor-α suppressed phosphorylation of protein kinase B and p38, whereas etanercept pretreatment promoted phosphorylation and myosin heavy chain expression in a concentration-dependent manner. Tumor necrosis factor-α inhibits differentiation of urethral rhabdosphincter cells in part through the p38 mitogen-activated protein kinase and phosphoinositide 3-kinase pathways. Inhibition of tumor necrosis factor-α might be a useful strategy to treat stress urinary incontinence. © 2017 The Japanese Urological Association.

  9. Human Myocardial Pericytes: Multipotent Mesodermal Precursors Exhibiting Cardiac Specificity

    PubMed Central

    Chen, William C.W.; Baily, James E.; Corselli, Mirko; Diaz, Mary; Sun, Bin; Xiang, Guosheng; Gray, Gillian A.; Huard, Johnny; Péault, Bruno

    2015-01-01

    Perivascular mesenchymal precursor cells (i.e. pericytes) reside in skeletal muscle where they contribute to myofiber regeneration; however, the existence of similar microvessel-associated regenerative precursor cells in cardiac muscle has not yet been documented. We tested whether microvascular pericytes within human myocardium exhibit phenotypes and multipotency similar to their anatomically and developmentally distinct counterparts. Fetal and adult human heart pericytes (hHPs) express canonical pericyte markers in situ, including CD146, NG2, PDGFRβ, PDGFRα, αSMA, and SM-MHC, but not CD117, CD133 and desmin, nor endothelial cell (EC) markers. hHPs were prospectively purified to homogeneity from ventricular myocardium by flow cytometry, based on a combination of positive- (CD146) and negative-selection (CD34, CD45, CD56, and CD117) cell lineage markers. Purified hHPs expanded in vitro were phenotypically similar to human skeletal muscle-derived pericytes (hSkMPs). hHPs express MSC markers in situ and exhibited osteo- chondro-, and adipogenic potentials but, importantly, no ability for skeletal myogenesis, diverging from pericytes of all other origins. hHPs supported network formation with/without ECs in Matrigel cultures; hHPs further stimulated angiogenic responses under hypoxia, markedly different from hSkMPs. The cardiomyogenic potential of hHPs was examined following 5-azacytidine treatment and neonatal cardiomyocyte co-culture in vitro, and intramyocardial transplantation in vivo. Results indicated cardiomyocytic differentiation in a small fraction of hHPs. In conclusion, human myocardial pericytes share certain phenotypic and developmental similarities with their skeletal muscle homologs, yet exhibit different antigenic, myogenic, and angiogenic properties. This is the first example of an anatomical restriction in the developmental potential of pericytes as native mesenchymal stem cells. PMID:25336400

  10. Efficient and Reproducible Myogenic Differentiation from Human iPS Cells: Prospects for Modeling Miyoshi Myopathy In Vitro

    PubMed Central

    Tanaka, Akihito; Woltjen, Knut; Miyake, Katsuya; Hotta, Akitsu; Ikeya, Makoto; Yamamoto, Takuya; Nishino, Tokiko; Shoji, Emi; Sehara-Fujisawa, Atsuko; Manabe, Yasuko; Fujii, Nobuharu; Hanaoka, Kazunori; Era, Takumi; Yamashita, Satoshi; Isobe, Ken-ichi; Kimura, En; Sakurai, Hidetoshi

    2013-01-01

    The establishment of human induced pluripotent stem cells (hiPSCs) has enabled the production of in vitro, patient-specific cell models of human disease. In vitro recreation of disease pathology from patient-derived hiPSCs depends on efficient differentiation protocols producing relevant adult cell types. However, myogenic differentiation of hiPSCs has faced obstacles, namely, low efficiency and/or poor reproducibility. Here, we report the rapid, efficient, and reproducible differentiation of hiPSCs into mature myocytes. We demonstrated that inducible expression of myogenic differentiation1 (MYOD1) in immature hiPSCs for at least 5 days drives cells along the myogenic lineage, with efficiencies reaching 70–90%. Myogenic differentiation driven by MYOD1 occurred even in immature, almost completely undifferentiated hiPSCs, without mesodermal transition. Myocytes induced in this manner reach maturity within 2 weeks of differentiation as assessed by marker gene expression and functional properties, including in vitro and in vivo cell fusion and twitching in response to electrical stimulation. Miyoshi Myopathy (MM) is a congenital distal myopathy caused by defective muscle membrane repair due to mutations in DYSFERLIN. Using our induced differentiation technique, we successfully recreated the pathological condition of MM in vitro, demonstrating defective membrane repair in hiPSC-derived myotubes from an MM patient and phenotypic rescue by expression of full-length DYSFERLIN (DYSF). These findings not only facilitate the pathological investigation of MM, but could potentially be applied in modeling of other human muscular diseases by using patient-derived hiPSCs. PMID:23626698

  11. Premyogenic progenitors derived from human pluripotent stem cells expand in floating culture and differentiate into transplantable myogenic progenitors.

    PubMed

    Sakai-Takemura, Fusako; Narita, Asako; Masuda, Satoru; Wakamatsu, Toshifumi; Watanabe, Nobuharu; Nishiyama, Takashi; Nogami, Ken'ichiro; Blanc, Matthias; Takeda, Shin'ichi; Miyagoe-Suzuki, Yuko

    2018-04-26

    Human induced pluripotent stem cells (hiPSCs) are a potential source for cell therapy of Duchenne muscular dystrophy. To reliably obtain skeletal muscle progenitors from hiPSCs, we treated hiPS cells with a Wnt activator, CHIR-99021 and a BMP receptor inhibitor, LDN-193189, and then induced skeletal muscle cells using a previously reported sphere-based culture. This protocol greatly improved sphere formation efficiency and stably induced the differentiation of myogenic cells from hiPS cells generated from both healthy donors and a patient with congenital myasthenic syndrome. hiPSC-derived myogenic progenitors were enriched in the CD57(-) CD108(-) CD271(+) ERBB3(+) cell fraction, and their differentiation was greatly promoted by TGF-β inhibitors. TGF-β inhibitors down-regulated the NFIX transcription factor, and NFIX short hairpin RNA (shRNA) improved the differentiation of iPS cell-derived myogenic progenitors. These results suggest that NFIX inhibited differentiation of myogenic progenitors. hiPSC-derived myogenic cells differentiated into myofibers in muscles of NSG-mdx 4Cv mice after direct transplantation. Our results indicate that our new muscle induction protocol is useful for cell therapy of muscular dystrophies.

  12. Efficient myogenic differentiation of human adipose-derived stem cells by the transduction of engineered MyoD protein

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sung, Min Sun; Biosystems and Bioengineering Program, University of Science and Technology; Mun, Ji-Young

    2013-07-19

    Highlights: •MyoD was engineered to contain protein transduction domain and endosome-disruptive INF7 peptide. •The engineered MyoD-IT showed efficient nuclear targeting through an endosomal escape by INF7 peptide. •By applying MyoD-IT, human adipose-derived stem cells (hASCs) were differentiated into myogenic cells. •hASCs differentiated by applying MyoD-IT fused to myotubes through co-culturing with mouse myoblasts. •Myogenic differentiation using MyoD-IT is a safe method without the concern of altering the genome. -- Abstract: Human adipose-derived stem cells (hASCs) have great potential as cell sources for the treatment of muscle disorders. To provide a safe method for the myogenic differentiation of hASCs, we engineeredmore » the MyoD protein, a key transcription factor for myogenesis. The engineered MyoD (MyoD-IT) was designed to contain the TAT protein transduction domain for cell penetration and the membrane-disrupting INF7 peptide, which is an improved version of the HA2 peptide derived from influenza. MyoD-IT showed greatly improved nuclear targeting ability through an efficient endosomal escape induced by the pH-sensitive membrane disruption of the INF7 peptide. By applying MyoD-IT to a culture, hASCs were efficiently differentiated into long spindle-shaped myogenic cells expressing myosin heavy chains. Moreover, these cells differentiated by an application of MyoD-IT fused to myotubes with high efficiency through co-culturing with mouse C2C12 myoblasts. Because internalized proteins can be degraded in cells without altering the genome, the myogenic differentiation of hASCs using MyoD-IT would be a safe and clinically applicable method.« less

  13. Skeletal myogenic differentiation of human urine-derived cells as a potential source for skeletal muscle regeneration.

    PubMed

    Chen, Wei; Xie, Minkai; Yang, Bin; Bharadwaj, Shantaram; Song, Lujie; Liu, Guihua; Yi, Shanhong; Ye, Gang; Atala, Anthony; Zhang, Yuanyuan

    2017-02-01

    Stem cells are regarded as possible cell therapy candidates for skeletal muscle regeneration. However, invasive harvesting of those cells can cause potential harvest-site morbidity. The goal of this study was to assess whether human urine-derived stem cells (USCs), obtained through non-invasive procedures, can differentiate into skeletal muscle linage cells (Sk-MCs) and potentially be used for skeletal muscle regeneration. In this study, USCs were harvested from six healthy individuals aged 25-55. Expression profiles of cell-surface markers were assessed by flow cytometry. To optimize the myogenic differentiation medium, we selected two from four different types of myogenic differentiation media to induce the USCs. Differentiated USCs were identified with myogenic markers by gene and protein expression. USCs were implanted into the tibialis anterior muscles of nude mice for 1 month. The results showed that USCs displayed surface markers with positive staining for CD24, CD29, CD44, CD73, CD90, CD105, CD117, CD133, CD146, SSEA-4 and STRO-1, and negative staining for CD14, CD31, CD34 and CD45. After myogenic differentiation, a change in morphology was observed from 'rice-grain'-like cells to spindle-shaped cells. The USCs expressed specific Sk-MC transcripts and protein markers (myf5, myoD, myosin, and desmin) after being induced with different myogenic culture media. Implanted cells expressed Sk-MC markers stably in vivo. Our findings suggest that USCs are able to differentiate into the Sk-MC lineage in vitro and after being implanted in vivo. Thus, they might be a potential source for cell injection therapy in the use of skeletal muscle regeneration. Copyright © 2014 John Wiley & Sons, Ltd. Copyright © 2014 John Wiley & Sons, Ltd.

  14. Spontaneous myogenic differentiation of Flk-1-positive cells from adult pancreas and other nonmuscle tissues.

    PubMed

    Di Rocco, Giuliana; Tritarelli, Alessandra; Toietta, Gabriele; Gatto, Ilaria; Iachininoto, Maria Grazia; Pagani, Francesca; Mangoni, Antonella; Straino, Stefania; Capogrossi, Maurizio C

    2008-02-01

    At the embryonic or fetal stages, autonomously myogenic cells (AMCs), i.e., cells able to spontaneously differentiate into skeletal myotubes, have been identified from several different sites other than skeletal muscle, including the vascular compartment. However, in the adult animal, AMCs from skeletal muscle-devoid tissues have been described in only two cases. One is represented by thymic myoid cells, a restricted population of committed myogenic progenitors of unknown derivation present in the thymic medulla; the other is represented by a small subset of adipose tissue-associated cells, which we recently identified. In the present study we report, for the first time, the presence of spontaneously differentiating myogenic precursors in the pancreas and in other skeletal muscle-devoid organs such as spleen and stomach, as well as in the periaortic tissue of adult mice. Immunomagnetic selection procedures indicate that AMCs derive from Flk-1(+) progenitors. Individual clones of myogenic cells from nonmuscle organs are morphologically and functionally indistinguishable from skeletal muscle-derived primary myoblasts. Moreover, they can be induced to proliferate in vitro and are able to participate in muscle regeneration in vivo. Thus, we provide evidence that fully competent myogenic progenitors can be derived from the Flk-1(+) compartment of several adult tissues that are embryologically unrelated to skeletal muscle.

  15. Dose-dependent Effect of Boric Acid on Myogenic Differentiation of Human Adipose-derived Stem Cells (hADSCs).

    PubMed

    Apdik, Hüseyin; Doğan, Ayşegül; Demirci, Selami; Aydın, Safa; Şahin, Fikrettin

    2015-06-01

    Boron, a vital micronutrient for plant metabolism, is not fully elucidated for embryonic and adult body development, and tissue regeneration. Although optimized amount of boron supplement has been shown to be essential for normal gestational development in zebrafish and frog and beneficial for bone regeneration in higher animals, effects of boron on myogenesis and myo-regeneration remains to be solved. In the current study, we investigated dose-dependent activity of boric acid on myogenic differentiation of human adipose-derived stem cells (hADSCs) using immunocytochemical, gene, and protein expression analysis. The results revealed that while low- (81.9 μM) and high-dose (819.6 μM) boron treatment increased myogenic gene expression levels such as myosin heavy chain (MYH), MyoD, myogenin, and desmin at day 4 of differentiation, high-dose treatment decreased myogenic-related gene and protein levels at day 21 of differentiation, confirmed by immunocytochemical analysis. The findings of the study present not only an understanding of boron's effect on myogenic differentiation but also an opportunity for the development of scaffolds to be used in skeletal tissue engineering and supplements for embryonic muscle growth. However, fine dose tuning and treatment period arranging are highly warranted as boron treatment over required concentrations and time might result in detrimental outcomes to myogenesis and myo-regeneration.

  16. Sparing of extraocular muscle in aging and muscular dystrophies: A myogenic precursor cell hypothesis

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Kallestad, Kristen M.; Hebert, Sadie L.; McDonald, Abby A.

    2011-04-01

    The extraocular muscles (EOM) are spared from pathology in aging and many forms of muscular dystrophy. Despite many studies, this sparing remains an enigma. The EOM have a distinct embryonic lineage compared to somite-derived muscles, and we have shown that they continuously remodel throughout life, maintaining a population of activated satellite cells even in aging. These data suggested the hypothesis that there is a population of myogenic precursor cells (mpcs) in EOM that is different from those in limb, with either elevated numbers of stem cells and/or mpcs with superior proliferative capacity compared to mpcs in limb. Using flow cytometry,more » EOM and limb muscle mononuclear cells were compared, and a number of differences were seen. Using two different cell isolation methods, EOM have significantly more mpcs per mg muscle than limb skeletal muscle. One specific subpopulation significantly increased in EOM compared to limb was positive for CD34 and negative for Sca-1, M-cadherin, CD31, and CD45. We named these the EOMCD34 cells. Similar percentages of EOMCD34 cells were present in both newborn EOM and limb muscle. They were retained in aged EOM, whereas the population decreased significantly in adult limb muscle and were extremely scarce in aged limb muscle. Most importantly, the percentage of EOMCD34 cells was elevated in the EOM from both the mdx and the mdx/utrophin{sup -/-} (DKO) mouse models of DMD and extremely scarce in the limb muscles of these mice. In vitro, the EOMCD34 cells had myogenic potential, forming myotubes in differentiation media. After determining a media better able to induce proliferation in these cells, a fusion index was calculated. The cells isolated from EOM had a 40% higher fusion index compared to the same cells isolated from limb muscle. The EOMCD34 cells were resistant to both oxidative stress and mechanical injury. These data support our hypothesis that the EOM may be spared in aging and in muscular dystrophies due to a

  17. PKCalpha-mediated ERK, JNK and p38 activation regulates the myogenic program in human rhabdomyosarcoma cells.

    PubMed

    Mauro, Annunziata; Ciccarelli, Carmela; De Cesaris, Paola; Scoglio, Arianna; Bouché, Marina; Molinaro, Mario; Aquino, Angelo; Zani, Bianca Maria

    2002-09-15

    We have previously suggested that PKCalpha has a role in 12-O-Tetradecanoylphorbol-13-acetate (TPA)-mediated growth arrest and myogenic differentiation in human embryonal rhabdomyosarcoma cells (RD). Here, by monitoring the signalling pathways triggered by TPA, we demonstrate that PKCalpha mediates these effects by inducing transient activation of c-Jun N-terminal protein kinases (JNKs) and sustained activation of both p38 kinase and extracellular signal-regulated kinases (ERKs) (all referred to as MAPKs). Activation of MAPKs following ectopic expression of constitutively active PKCalpha, but not its dominant-negative form, is also demonstrated. We investigated the selective contribution of MAPKs to growth arrest and myogenic differentiation by monitoring the activation of MAPK pathways, as well as by dissecting MAPK pathways using MEK1/2 inhibitor (UO126), p38 inhibitor (SB203580) and JNK and p38 agonist (anisomycin) treatments. Growth-arresting signals are triggered either by transient and sustained JNK activation (by TPA and anisomycin, respectively) or by preventing both ERK and JNK activation (UO126) and are maintained, rather than induced, by p38. We therefore suggest a key role for JNK in controlling ERK-mediated mitogenic activity. Notably, sarcomeric myosin expression is induced by both TPA and UO126 but is abrogated by the p38 inhibitor. This finding indicates a pivotal role for p38 in controlling the myogenic program. Anisomycin persistently activates p38 and JNKs but prevents myosin expression induced by TPA. In accordance with this negative role, reactivation of JNKs by anisomycin, in UO126-pre-treated cells, also prevents myosin expression. This indicates that, unlike the transient JNK activation that occurs in the TPA-mediated myogenic process, long-lasting JNK activation supports the growth-arrest state but antagonises p38-mediated myosin expression. Lastly, our results with the MEK inhibitor suggest a key role of the ERK pathway in regulating

  18. Evaluation of the effects of different culture media on the myogenic differentiation potential of adipose tissue- or bone marrow-derived human mesenchymal stem cells.

    PubMed

    Stern-Straeter, Jens; Bonaterra, Gabriel Alejandro; Juritz, Stephanie; Birk, Richard; Goessler, Ulrich Reinhart; Bieback, Karen; Bugert, Peter; Schultz, Johannes; Hörmann, Karl; Kinscherf, Ralf; Faber, Anne

    2014-01-01

    The creation of functional muscles/muscle tissue from human stem cells is a major goal of skeletal muscle tissue engineering. Mesenchymal stem cells (MSCs) from fat/adipose tissue (AT-MSCs), as well as bone marrow (BM-MSCs) have been shown to bear myogenic potential, which makes them candidate stem cells for skeletal muscle tissue engineering applications. The aim of this study was to analyse the myogenic differentiation potential of human AT-MSCs and BM-MSCs cultured in six different cell culture media containing different mixtures of growth factors. The following cell culture media were used in our experiments: mesenchymal stem cell growth medium (MSCGM)™ as growth medium, MSCGM + 5-azacytidine (5-Aza), skeletal muscle myoblast cell growth medium (SkGM)-2 BulletKit™, and 5, 30 and 50% conditioned cell culture media, i.e., supernatant of human satellite cell cultures after three days in cell culture mixed with MSCGM. Following the incubation of human AT-MSCs or BM-MSCs for 0, 4, 8, 11, 16 or 21 days with each of the cell culture media, cell proliferation was measured using the alamarBlue® assay. Myogenic differentiation was evaluated by quantitative gene expression analyses, using quantitative RT-PCR (qRT-PCR) and immunocytochemical staining (ICC), using well-defined skeletal markers, such as desmin (DES), myogenic factor 5 (MYF5), myosin, heavy chain 8, skeletal muscle, perinatal (MYH8), myosin, heavy chain 1, skeletal muscle, adult (MYH1) and skeletal muscle actin-α1 (ACTA1). The highest proliferation rates were observed in the AT-MSCs and BM-MSCs cultured with SkGM-2 BulletKit medium. The average proliferation rate was higher in the AT-MSCs than in the BM-MSCs, taking all six culture media into account. qRT-PCR revealed the expression levels of the myogenic markers, ACTA1, MYH1 and MYH8, in the AT-MSC cell cultures, but not in the BM-MSC cultures. The muscle-specific intermediate filament, DES, was only detected (by ICC) in the AT-MSCs, but not in the BM

  19. Wnt/beta-catenin pathway activation and myogenic differentiation are induced by cholesterol depletion.

    PubMed

    Mermelstein, Cláudia S; Portilho, Débora M; Mendes, Fábio A; Costa, Manoel L; Abreu, José Garcia

    2007-03-01

    Myogenic differentiation is a multistep process that begins with the commitment of mononucleated precursors that withdraw from cell cycle. These myoblasts elongate while aligning to each other, guided by the recognition between their membranes. This step is followed by cell fusion and the formation of long and striated multinucleated myotubes. We have recently shown that cholesterol depletion by methyl-beta-cyclodextrin (MbetaCD) induces myogenic differentiation by enhancing myoblast recognition and fusion. Here, we further studied the signaling pathways responsible for early steps of myogenesis. As it is known that Wnt plays a role in muscle differentiation, we used the chemical MbetaCD to deplete membrane cholesterol and investigate the involvement of the Wnt/beta-catenin pathway during myogenesis. We show that cholesterol depletion promoted a significant increase in expression of beta-catenin, its nuclear translocation and activation of the Wnt pathway. Moreover, we show that the activation of the Wnt pathway after cholesterol depletion can be inhibited by the soluble protein Frzb-1. Our data suggest that membrane cholesterol is involved in Wnt/beta-catenin signaling in the early steps of myogenic differentiation.

  20. Tissue-specific epigenetics in gene neighborhoods: myogenic transcription factor genes

    PubMed Central

    Chandra, Sruti; Terragni, Jolyon; Zhang, Guoqiang; Pradhan, Sriharsa; Haushka, Stephen; Johnston, Douglas; Baribault, Carl; Lacey, Michelle; Ehrlich, Melanie

    2015-01-01

    Myogenic regulatory factor (MRF) genes, MYOD1, MYOG, MYF6 and MYF5, are critical for the skeletal muscle lineage. Here, we used various epigenome profiles from human myoblasts (Mb), myotubes (Mt), muscle and diverse non-muscle samples to elucidate the involvement of multigene neighborhoods in the regulation of MRF genes. We found more far-distal enhancer chromatin associated with MRF genes in Mb and Mt than previously reported from studies in mice. For the MYF5/MYF6 gene-pair, regions of Mb-associated enhancer chromatin were located throughout the adjacent 236-kb PTPRQ gene even though Mb expressed negligible amounts of PTPRQ mRNA. Some enhancer chromatin regions inside PTPRQ in Mb were also seen in PTPRQ mRNA-expressing non-myogenic cells. This suggests dual-purpose PTPRQ enhancers that upregulate expression of PTPRQ in non-myogenic cells and MYF5/MYF6 in myogenic cells. In contrast, the myogenic enhancer chromatin regions distal to MYOD1 were intergenic and up to 19 kb long. Two of them contain small, known MYOD1 enhancers, and one displayed an unusually high level of 5-hydroxymethylcytosine in a quantitative DNA hydroxymethylation assay. Unexpectedly, three regions of MYOD1-distal enhancer chromatin in Mb and Mt overlapped enhancer chromatin in umbilical vein endothelial cells, which might upregulate a distant gene (PIK3C2A). Lastly, genes surrounding MYOG were preferentially transcribed in Mt, like MYOG itself, and exhibited nearby myogenic enhancer chromatin. These neighboring chromatin regions may be enhancers acting in concert to regulate myogenic expression of multiple adjacent genes. Our findings reveal the very different and complex organization of gene neighborhoods containing closely related transcription factor genes. PMID:26041816

  1. A Comparative Study to Evaluate Myogenic Differentiation Potential of Human Chorion versus Umbilical Cord Blood-derived Mesenchymal Stem Cells.

    PubMed

    Bana, Nikoo; Sanooghi, Davood; Soleimani, Mansoureh; Hayati Roodbari, Nasim; Alavi Moghaddam, Sepideh; Joghataei, Mohammad Taghi; Sayahpour, Forough Azam; Faghihi, Faezeh

    2017-08-01

    Musculodegenerative diseases threaten the life of many patients in the world. Since drug administration is not efficient in regeneration of damaged tissues, stem cell therapy is considered as a good strategy to restore the lost cells. Since the efficiency of myogenic differentiation potential of human Chorion- derived Mesenchymal Stem Cells (C-MSCs) has not been addressed so far; we set out to evaluate myogenic differentiation property of these cells in comparison with Umbilical Cord Blood- derived Mesenchymal Stem Cells (UCB-MSCs) in the presence of 5-azacytidine. To do that, neonate placenta Umbilical Cord Blood were transferred to the lab. After characterization of the isolated cells using flowcytometry and multilineage differentiation capacity, the obtained Mesenchymal Stem Cells were cultured in DMEM/F12 supplemented with 2% FBS and 10μM of 5-azacytidine to induce myogenic differentiation. Real-time PCR and immunocytochemistry were used to assess the myogenic properties of the cells. Our data showed that C-MSCs and UCB-MSCs were spindle shape in morphology. They were positive for CD90, CD73 and CD44 antigens, and negative for hematopoietic markers. They also differentiated into osteoblast and adipoblast lineages. Real-time PCR results showed that the cells could express MyoD, desmin and α-MHC at the end of the first week (P<0.05). No significant upregulation was detected in the expression of GATA-4 in both groups. Immunocytochemical staining revealed the expression of Desmin, cTnT and α-MHC. Results showed that these cells are potent to differentiate into myoblast- like cells. An upregulation in the expression of some myogenic markers (desmin, α- MHC) was observed in C-MSCs in comparison with UCB-MSCs. Copyright © 2017. Published by Elsevier Ltd.

  2. Confined Sandwichlike Microenvironments Tune Myogenic Differentiation.

    PubMed

    Ballester-Beltrán, José; Trujillo, Sara; Alakpa, Enateri V; Compañ, Vicente; Gavara, Rafael; Meek, Dominic; West, Christopher C; Péault, Bruno; Dalby, Matthew J; Salmerón-Sánchez, Manuel

    2017-08-14

    Sandwichlike (SW) cultures are engineered as a multilayer technology to simultaneously stimulate dorsal and ventral cell receptors, seeking to mimic cell adhesion in three-dimensional (3D) environments in a reductionist manner. The effect of this environment on cell differentiation was investigated for several cell types cultured in standard growth media, which promotes proliferation on two-dimensional (2D) surfaces and avoids any preferential differentiation. First, murine C2C12 myoblasts showed specific myogenic differentiation. Human mesenchymal stem cells (hMSCs) of adipose and bone marrow origin, which can differentiate toward a wider variety of lineages, showed again myodifferentiation. Overall, this study shows myogenic differentiation in normal growth media for several cell types under SW conditions, avoiding the use of growth factors and cytokines, i.e., solely by culturing cells within the SW environment. Mechanistically, it provides further insights into the balance between integrin adhesion to the dorsal substrate and the confinement imposed by the SW system.

  3. Confined Sandwichlike Microenvironments Tune Myogenic Differentiation

    PubMed Central

    2017-01-01

    Sandwichlike (SW) cultures are engineered as a multilayer technology to simultaneously stimulate dorsal and ventral cell receptors, seeking to mimic cell adhesion in three-dimensional (3D) environments in a reductionist manner. The effect of this environment on cell differentiation was investigated for several cell types cultured in standard growth media, which promotes proliferation on two-dimensional (2D) surfaces and avoids any preferential differentiation. First, murine C2C12 myoblasts showed specific myogenic differentiation. Human mesenchymal stem cells (hMSCs) of adipose and bone marrow origin, which can differentiate toward a wider variety of lineages, showed again myodifferentiation. Overall, this study shows myogenic differentiation in normal growth media for several cell types under SW conditions, avoiding the use of growth factors and cytokines, i.e., solely by culturing cells within the SW environment. Mechanistically, it provides further insights into the balance between integrin adhesion to the dorsal substrate and the confinement imposed by the SW system. PMID:28824958

  4. A simple model for the generation of the vestibular evoked myogenic potential (VEMP).

    PubMed

    Wit, Hero P; Kingma, Charlotte M

    2006-06-01

    To describe the mechanism by which the vestibular evoked myogenic potential is generated. Vestibular evoked myogenic potential generation is modeled by adding a large number of muscle motor unit action potentials. These action potentials occur randomly in time along a 100 ms long time axis. But because between approximately 15 and 20 ms after a loud short sound stimulus (almost) no action potentials are generated during VEMP measurements in human subjects, no action potentials are present in the model during this time. The evoked potential is the result of the lack of amplitude cancellation in the averaged surface electromyogram at the edges of this 5 ms long time interval. The relatively simple model describes generation and some properties of the vestibular evoked myogenic potential very well. It is shown that, in contrast with other evoked potentials (BAEPs, VERs), the vestibular evoked myogenic potential is the result of an interruption of activity and not that of summed synchronized neural action potentials.

  5. From supine to standing: in vivo segregation of myogenic and baroreceptor vasoconstriction in humans.

    PubMed

    Estañol, Bruno; Rivera, Ana Leonor; Martínez Memije, Raúl; Fossion, Ruben; Gómez, Fermín; Bernal, Katherine; Murúa Beltrán, Sofía; Delgado-García, Guillermo; Frank, Alejandro

    2016-12-01

    Myogenic vascular response is a form of systemic and regional vasoconstriction produced increasing the intra-arterial pressure by gravity. Here, the vasoconstriction due to the myogenic response, induced by the gravitational action in a dependent limb, is separated from that caused by the baroreceptor reflex. Regional changes of skin blood flow (SBF), total blood volume of the finger (TBVF), pulse pressure (PP), heart rate (HR), systolic, and diastolic blood pressure (BP) were analyzed in 10 healthy young subjects in supine and upright positions. By lowering the arm in supine position, SBF decreased compared to its basal measurement, PR increased, and PP contracted, indicating arterial vasoconstriction that rise BP TBVF increased, demonstrating an increment in venous volume. HR did not change, reflecting no action of the baroreceptor reflex. In upright position with lowered arm, there was an additional increase in BP variables, demonstrating vasoconstriction. Moreover, BP and HR showed oscillations at 0.1 Hz reflecting the entrance of the baroreceptor reflex. The action of gravity in a dependent limb in supine position induces a regional vasoconstriction and an increase of BP due to activation of the myogenic response, while the baroreceptor reflex or other neural factors do not appear to operate. In the upright position with the arm dependent, there is a further increase in regional vasoconstriction and BP with reciprocal changes in HR, indicating the entrance of the baroreceptor superimposed to the myogenic response. This study demonstrates that the myogenic and baroreceptor vasoconstriction can be separated in vivo. © 2016 The Authors. Physiological Reports published by Wiley Periodicals, Inc. on behalf of The Physiological Society and the American Physiological Society.

  6. Role of Coronary Myogenic Response in Pressure-Flow Autoregulation in Swine: A Meta-Analysis With Coronary Flow Modeling

    PubMed Central

    Dick, Gregory M.; Namani, Ravi; Patel, Bhavesh; Kassab, Ghassan S.

    2018-01-01

    Myogenic responses (pressure-dependent contractions) of coronary arterioles play a role in autoregulation (relatively constant flow vs. pressure). Publications on myogenic reactivity in swine coronaries vary in caliber, analysis, and degree of responsiveness. Further, data on myogenic responses and autoregulation in swine have not been completely compiled, compared, and modeled. Thus, it has been difficult to understand these physiological phenomena. Our purpose was to: (a) analyze myogenic data with standard criteria; (b) assign results to diameter categories defined by morphometry; and (c) use our novel multiscale flow model to determine the extent to which ex vivo myogenic reactivity can explain autoregulation in vivo. When myogenic responses from the literature are an input for our model, the predicted coronary autoregulation approaches in vivo observations. More complete and appropriate data are now available to investigate the regulation of coronary blood flow in swine, a highly relevant model for human physiology and disease. PMID:29875686

  7. Low-dose benzo(a)pyrene and its epoxide metabolite inhibit myogenic differentiation in human skeletal muscle-derived progenitor cells.

    PubMed

    Chiu, Chen-Yuan; Yen, Yuan-Peng; Tsai, Keh-Sung; Yang, Rong-Sen; Liu, Shing-Hwa

    2014-04-01

    The risk of low birth weights is elevated in prenatal exposure to polycyclic aromatic hydrocarbons (PAHs), which are ubiquitous environmental pollutants generated from combustion of organic compounds, including cigarette smoke. We hypothesized that benzo(a)pyrene (BaP), a member of PAHs existing in cigarette smoke, may affect the myogenesis to cause low birth weights. We investigated the effects of BaP and its main metabolite, benzo(a)pyrene-7,8-dihydrodiol-9,10-epoxide (BPDE), on the myogenic differentiation of human skeletal muscle-derived progenitor cells (HSMPCs). HSMPCs were isolated by a modified preplate technique and cultured in myogenic differentiation media with or without BaP and BPDE (0.25 and 0.5 μM) for 4 days. The multinucleated myotube formation was morphologically analyzed by hematoxylin and eosin staining. The expressions of myogenic differentiation markers and related signaling proteins were determined by Western blotting. Both BaP and BPDE at the submicromolar concentrations (0.25 and 0.5 μM) dose-dependently repressed HSMPCs myogenic differentiation without obvious cell toxicity. Both BaP and BPDE inhibited the muscle-specific protein expressions (myogenin and myosin heavy chain) and phosphorylation of Akt (a known modulator in myogenesis), which could be significantly reversed by the inhibitors for aryl hydrocarbon receptor (AhR), estrogen receptor (ER), and nuclear factor (NF)-κB. BaP- and BPDE-activated NF-κB-p65 protein phosphorylation could also be attenuated by both AhR and ER inhibitors. The inhibitory effects of BaP and BPDE on myogenesis were reversed after withdrawing BaP exposure, but not after BPDE withdrawal. These results suggest that both BaP and BPDE are capable of inhibiting myogenesis via an AhR- or/and ER-regulated NF-κB/Akt signaling pathway.

  8. Skeletal Myogenic Progenitors Originating from Embryonic Dorsal Aorta Coexpress Endothelial and Myogenic Markers and Contribute to Postnatal Muscle Growth and Regeneration

    PubMed Central

    De Angelis, Luciana; Berghella, Libera; Coletta, Marcello; Lattanzi, Laura; Zanchi, Malvina; Gabriella, M.; Ponzetto, Carola; Cossu, Giulio

    1999-01-01

    Skeletal muscle in vertebrates is derived from somites, epithelial structures of the paraxial mesoderm, yet many unrelated reports describe the occasional appearance of myogenic cells from tissues of nonsomite origin, suggesting either transdifferentiation or the persistence of a multipotent progenitor. Here, we show that clonable skeletal myogenic cells are present in the embryonic dorsal aorta of mouse embryos. This finding is based on a detailed clonal analysis of different tissue anlagen at various developmental stages. In vitro, these myogenic cells show the same morphology as satellite cells derived from adult skeletal muscle, and express a number of myogenic and endothelial markers. Surprisingly, the latter are also expressed by adult satellite cells. Furthermore, it is possible to clone myogenic cells from limbs of mutant c-Met−/− embryos, which lack appendicular muscles, but have a normal vascular system. Upon transplantation, aorta-derived myogenic cells participate in postnatal muscle growth and regeneration, and fuse with resident satellite cells. The potential of the vascular system to generate skeletal muscle cells may explain observations of nonsomite skeletal myogenesis and raises the possibility that a subset of satellite cells may derive from the vascular system. PMID:10562287

  9. Myogenic specification in somites: induction by axial structures.

    PubMed

    Buffinger, N; Stockdale, F E

    1994-06-01

    Specification of the myogenic phenotype in somites was examined in the early chick embryo using organotypic explant cultures stained with monoclonal antibodies to myosin heavy chain. It was found that myogenic specification (formation of muscle fibers in explants of somites or segmental plates cultured alone) does not occur until Hamburger and Hamilton stage 11 (12-14 somites). At this stage, only the somites in the rostral half of the embryo are myogenically specified. By Hamburger and Hamilton stage 12 (15-17 somites), the three most caudal somites were not specified to be myogenic while most or all of the more rostral somites are specified to myogenesis. Somites from older embryos (stage 13-15, 18-26 somites) showed the same pattern of myogenic specification--all but the three most caudal somites were specified. We investigated the effects of the axial structures, the notochord and neural tube, on myogenic specification. Both the notochord and neural tube were able to induce myogenesis in unspecified somites. In contrast, the neural tube, but not the notochord, was able to induce myogenesis in explants of segmental plate, a structure which is not myogenic when cultured alone. When explants of specified somites were stained with antibodies to slow or fast MyHC, it was found that myofiber diversity (fast and fast slow fibers) was established very early in development (as early as Hamburger and Hamilton stage 11). We also found fiber diversity in explants of unspecified somites (the three most caudal somites from stage 11 to 15) when they were recombined with notochord or neural tube. We conclude that myogenic specification in the embryo results in diverse fiber types and is an inductive process which is mediated by factors produced by the neural tube and notochord.

  10. Loss of MyoD and Myf5 in Skeletal Muscle Stem Cells Results in Altered Myogenic Programming and Failed Regeneration.

    PubMed

    Yamamoto, Masakazu; Legendre, Nicholas P; Biswas, Arpita A; Lawton, Alexander; Yamamoto, Shoko; Tajbakhsh, Shahragim; Kardon, Gabrielle; Goldhamer, David J

    2018-03-13

    MyoD and Myf5 are fundamental regulators of skeletal muscle lineage determination in the embryo, and their expression is induced in satellite cells following muscle injury. MyoD and Myf5 are also expressed by satellite cell precursors developmentally, although the relative contribution of historical and injury-induced expression to satellite cell function is unknown. We show that satellite cells lacking both MyoD and Myf5 (double knockout [dKO]) are maintained with aging in uninjured muscle. However, injured muscle fails to regenerate and dKO satellite cell progeny accumulate in damaged muscle but do not undergo muscle differentiation. dKO satellite cell progeny continue to express markers of myoblast identity, although their myogenic programming is labile, as demonstrated by dramatic morphological changes and increased propensity for non-myogenic differentiation. These data demonstrate an absolute requirement for either MyoD or Myf5 in muscle regeneration and indicate that their expression after injury stabilizes myogenic identity and confers the capacity for muscle differentiation. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  11. Glucocorticoid-induced Leucine Zipper (GILZ) and Long GILZ Inhibit Myogenic Differentiation and Mediate Anti-myogenic Effects of Glucocorticoids*

    PubMed Central

    Bruscoli, Stefano; Donato, Valerio; Velardi, Enrico; Di Sante, Moises; Migliorati, Graziella; Donato, Rosario; Riccardi, Carlo

    2010-01-01

    Myogenesis is a process whereby myoblasts differentiate and fuse into multinucleated myotubes, the precursors of myofibers. Various signals and factors modulate this process, and glucocorticoids (GCs) are important regulators of skeletal muscle metabolism. We show that glucocorticoid-induced leucine zipper (GILZ), a GC-induced gene, and the newly identified isoform long GILZ (L-GILZ) are expressed in skeletal muscle tissue and in C2C12 myoblasts where GILZ/L-GILZ maximum expression occurs during the first few days in differentiation medium. Moreover, we observed that GC treatment of myoblasts, which increased GILZ/L-GILZ expression, resulted in reduced myotube formation, whereas GILZ and L-GILZ silencing dampened GC effects. Inhibition of differentiation caused by GILZ/L-GILZ overexpression correlated with inhibition of MyoD function and reduced expression of myogenin. Notably, results indicate that GILZ and L-GILZ bind and regulate MyoD/HDAC1 transcriptional activity, thus mediating the anti-myogenic effect of GCs. PMID:20124407

  12. Myogenic transcription factors regulate pro-metastatic miR-182.

    PubMed

    Dodd, R D; Sachdeva, M; Mito, J K; Eward, W C; Brigman, B E; Ma, Y; Dodd, L; Kim, Y; Lev, D; Kirsch, D G

    2016-04-07

    Approximately 30% of patients with soft-tissue sarcoma die from pulmonary metastases. The mechanisms that drive sarcoma metastasis are not well understood. Recently, we identified miR-182 as a driver of sarcoma metastasis in a primary mouse model of soft-tissue sarcoma. We also observed elevated miR-182 in a subset of primary human sarcomas that metastasized to the lungs. Here, we show that myogenic differentiation factors regulate miR-182 levels to contribute to metastasis in mouse models. We find that MyoD directly binds the miR-182 promoter to increase miR-182 expression. Furthermore, mechanistic studies revealed that Pax7 can promote sarcoma metastasis in vivo through MyoD-dependent regulation of pro-metastatic miR-182. Taken together, these results suggest that sarcoma metastasis can be partially controlled through Pax7/MyoD-dependent activation of miR-182 and provide insight into the role that myogenic transcription factors have in sarcoma progression.

  13. Comparison of Genome-Wide Binding of MyoD in Normal Human Myogenic Cells and Rhabdomyosarcomas Identifies Regional and Local Suppression of Promyogenic Transcription Factors

    PubMed Central

    MacQuarrie, Kyle L.; Yao, Zizhen; Fong, Abraham P.; Diede, Scott J.; Rudzinski, Erin R.; Hawkins, Douglas S.

    2013-01-01

    Rhabdomyosarcoma is a pediatric tumor of skeletal muscle that expresses the myogenic basic helix-loop-helix protein MyoD but fails to undergo terminal differentiation. Prior work has determined that DNA binding by MyoD occurs in the tumor cells, but myogenic targets fail to activate. Using MyoD chromatin immunoprecipitation coupled to high-throughput sequencing and gene expression analysis in both primary human muscle cells and RD rhabdomyosarcoma cells, we demonstrate that MyoD binds in a similar genome-wide pattern in both tumor and normal cells but binds poorly at a subset of myogenic genes that fail to activate in the tumor cells. Binding differences are found both across genomic regions and locally at specific sites that are associated with binding motifs for RUNX1, MEF2C, JDP2, and NFIC. These factors are expressed at lower levels in RD cells than muscle cells and rescue myogenesis when expressed in RD cells. MEF2C is located in a genomic region that exhibits poor MyoD binding in RD cells, whereas JDP2 exhibits local DNA hypermethylation in its promoter in both RD cells and primary tumor samples. These results demonstrate that regional and local silencing of differentiation factors contributes to the differentiation defect in rhabdomyosarcomas. PMID:23230269

  14. Functional myogenic engraftment from mouse iPS cells.

    PubMed

    Darabi, Radbod; Pan, Weihong; Bosnakovski, Darko; Baik, June; Kyba, Michael; Perlingeiro, Rita C R

    2011-11-01

    Direct reprogramming of adult fibroblasts to a pluripotent state has opened new possibilities for the generation of patient- and disease-specific stem cells. However the ability of induced pluripotent stem (iPS) cells to generate tissue that mediates functional repair has been demonstrated in very few animal models of disease to date. Here we present the proof of principle that iPS cells may be used effectively for the treatment of muscle disorders. We combine the generation of iPS cells with conditional expression of Pax7, a robust approach to derive myogenic progenitors. Transplantation of Pax7-induced iPS-derived myogenic progenitors into dystrophic mice results in extensive engraftment, which is accompanied by improved contractility of treated muscles. These findings demonstrate the myogenic regenerative potential of iPS cells and provide rationale for their future therapeutic application for muscular dystrophies.

  15. Dexamethasone induces dysferlin in myoblasts and enhances their myogenic differentiation

    PubMed Central

    Belanto, Joseph J.; Diaz-Perez, Silvia V.; Magyar, Clara E.; Maxwell, Michele M.; Yilmaz, Yasemin; Topp, Kasey; Boso, Guney; Jamieson, Catriona H.; Cacalano, Nicholas A.; Jamieson, Christina A.M.

    2010-01-01

    Glucocorticoids are beneficial in many muscular dystrophies but they are ineffective in treating dysferlinopathy, a rare muscular dystrophy caused by loss of dysferlin. We sought to understand the molecular basis for this disparity by studying the effects of a glucocorticoid on differentiation of the myoblast cell line, C2C12, and dysferlin-deficient C2C12s. We found that pharmacologic doses of dexamethasone enhanced the myogenic fusion efficiency of C2C12s and increased the induction of dysferlin, along with specific myogenic transcription factors, sarcolemmal and structural proteins. In contrast, the dysferlin-deficient C2C12 cell line demonstrated a reduction in long myotubes and early induction of particular muscle differentiation proteins, most notably, myosin heavy chain. Dexamethasone partially reversed the defect in myogenic fusion in the dysferlin-deficient C2C12 cells. We hypothesize that a key therapeutic benefit of glucocorticoids may be the up-regulation of dysferlin as an important component of glucocorticoid-enhanced myogenic differentiation. PMID:20080405

  16. Derivation of Multipotent Mesenchymal Precursors from Human Embryonic Stem Cells

    PubMed Central

    Barberi, Tiziano; Willis, Lucy M; Socci, Nicholas D; Studer, Lorenz

    2005-01-01

    Background Human embryonic stem cells provide access to the earliest stages of human development and may serve as a source of specialized cells for regenerative medicine. Thus, it becomes crucial to develop protocols for the directed differentiation of embryonic stem cells into tissue-restricted precursors. Methods and Findings Here, we present culture conditions for the derivation of unlimited numbers of pure mesenchymal precursors from human embryonic stem cells and demonstrate multilineage differentiation into fat, cartilage, bone, and skeletal muscle cells. Conclusion Our findings will help to elucidate the mechanism of mesoderm specification during embryonic stem cell differentiation and provide a platform to efficiently generate specialized human mesenchymal cell types for future clinical applications. PMID:15971941

  17. MyoD expression restores defective myogenic differentiation of human mesoangioblasts from inclusion-body myositis muscle.

    PubMed

    Morosetti, Roberta; Mirabella, Massimiliano; Gliubizzi, Carla; Broccolini, Aldobrando; De Angelis, Luciana; Tagliafico, Enrico; Sampaolesi, Maurilio; Gidaro, Teresa; Papacci, Manuela; Roncaglia, Enrica; Rutella, Sergio; Ferrari, Stefano; Tonali, Pietro Attilio; Ricci, Enzo; Cossu, Giulio

    2006-11-07

    Inflammatory myopathies (IM) are acquired diseases of skeletal muscle comprising dermatomyositis (DM), polymyositis (PM), and inclusion-body myositis (IBM). Immunosuppressive therapies, usually beneficial for DM and PM, are poorly effective in IBM. We report the isolation and characterization of mesoangioblasts, vessel-associated stem cells, from diagnostic muscle biopsies of IM. The number of cells isolated, proliferation rate and lifespan, markers expression, and ability to differentiate into smooth muscle do not differ among normal and IM mesoangioblasts. At variance with normal, DM and PM mesoangioblasts, cells isolated from IBM, fail to differentiate into skeletal myotubes. These data correlate with lack in connective tissue of IBM muscle of alkaline phosphatase (ALP)-positive cells, conversely dramatically increased in PM and DM. A myogenic inhibitory basic helix-loop-helix factor B3 is highly expressed in IBM mesoangioblasts. Indeed, silencing this gene or overexpressing MyoD rescues the myogenic defect of IBM mesoangioblasts, opening novel cell-based therapeutic strategies for this crippling disorder.

  18. MyoD expression restores defective myogenic differentiation of human mesoangioblasts from inclusion-body myositis muscle

    PubMed Central

    Morosetti, Roberta; Mirabella, Massimiliano; Gliubizzi, Carla; Broccolini, Aldobrando; De Angelis, Luciana; Tagliafico, Enrico; Sampaolesi, Maurilio; Gidaro, Teresa; Papacci, Manuela; Roncaglia, Enrica; Rutella, Sergio; Ferrari, Stefano; Tonali, Pietro Attilio; Ricci, Enzo; Cossu, Giulio

    2006-01-01

    Inflammatory myopathies (IM) are acquired diseases of skeletal muscle comprising dermatomyositis (DM), polymyositis (PM), and inclusion-body myositis (IBM). Immunosuppressive therapies, usually beneficial for DM and PM, are poorly effective in IBM. We report the isolation and characterization of mesoangioblasts, vessel-associated stem cells, from diagnostic muscle biopsies of IM. The number of cells isolated, proliferation rate and lifespan, markers expression, and ability to differentiate into smooth muscle do not differ among normal and IM mesoangioblasts. At variance with normal, DM and PM mesoangioblasts, cells isolated from IBM, fail to differentiate into skeletal myotubes. These data correlate with lack in connective tissue of IBM muscle of alkaline phosphatase (ALP)-positive cells, conversely dramatically increased in PM and DM. A myogenic inhibitory basic helix–loop–helix factor B3 is highly expressed in IBM mesoangioblasts. Indeed, silencing this gene or overexpressing MyoD rescues the myogenic defect of IBM mesoangioblasts, opening novel cell-based therapeutic strategies for this crippling disorder. PMID:17077152

  19. Immortalized myogenic cells from congenital muscular dystrophy type1A patients recapitulate aberrant caspase activation in pathogenesis: a new tool for MDC1A research.

    PubMed

    Yoon, Soonsang; Stadler, Guido; Beermann, Mary Lou; Schmidt, Eric V; Windelborn, James A; Schneiderat, Peter; Wright, Woodring E; Miller, Jeffrey Boone

    2013-12-06

    Congenital muscular dystrophy Type 1A (MDC1A) is a severe, recessive disease of childhood onset that is caused by mutations in the LAMA2 gene encoding laminin-α2. Studies with both mouse models and primary cultures of human MDC1A myogenic cells suggest that aberrant activation of cell death is a significant contributor to pathogenesis in laminin-α2-deficiency. To overcome the limited population doublings of primary cultures, we generated immortalized, clonal lines of human MDC1A myogenic cells via overexpression of both CDK4 and the telomerase catalytic component (human telomerase reverse transcriptase (hTERT)). The immortalized MDC1A myogenic cells proliferated indefinitely when cultured at low density in high serum growth medium, but retained the capacity to form multinucleate myotubes and express muscle-specific proteins when switched to low serum medium. When cultured in the absence of laminin, myotubes formed from immortalized MDC1A myoblasts, but not those formed from immortalized healthy or disease control human myoblasts, showed significantly increased activation of caspase-3. This pattern of aberrant caspase-3 activation in the immortalized cultures was similar to that found previously in primary MDC1A cultures and laminin-α2-deficient mice. Immortalized MDC1A myogenic cells provide a new resource for studies of pathogenetic mechanisms and for screening possible therapeutic approaches in laminin-α2-deficiency.

  20. MURC/cavin-4 Is Co-Expressed with Caveolin-3 in Rhabdomyosarcoma Tumors and Its Silencing Prevents Myogenic Differentiation in the Human Embryonal RD Cell Line

    PubMed Central

    Faggi, Fiorella; Codenotti, Silvia; Poliani, Pietro Luigi; Cominelli, Manuela; Chiarelli, Nicola; Colombi, Marina; Vezzoli, Marika; Monti, Eugenio; Bono, Federica; Tulipano, Giovanni; Fiorentini, Chiara; Zanola, Alessandra; Lo, Harriet P.; Parton, Robert G.; Keller, Charles; Fanzani, Alessandro

    2015-01-01

    The purpose of this study was to investigate whether MURC/cavin-4, a plasma membrane and Z-line associated protein exhibiting an overlapping distribution with Caveolin-3 (Cav-3) in heart and muscle tissues, may be expressed and play a role in rhabdomyosarcoma (RMS), an aggressive myogenic tumor affecting childhood. We found MURC/cavin-4 to be expressed, often concurrently with Cav-3, in mouse and human RMS, as demonstrated through in silico analysis of gene datasets and immunohistochemical analysis of tumor samples. In vitro expression studies carried out using human cell lines and primary mouse tumor cultures showed that expression levels of both MURC/cavin-4 and Cav-3, while being low or undetectable during cell proliferation, became robustly increased during myogenic differentiation, as detected via semi-quantitative RT-PCR and immunoblotting analysis. Furthermore, confocal microscopy analysis performed on human RD and RH30 cell lines confirmed that MURC/cavin-4 mostly marks differentiated cell elements, colocalizing at the cell surface with Cav-3 and labeling myosin heavy chain (MHC) expressing cells. Finally, MURC/cavin-4 silencing prevented the differentiation in the RD cell line, leading to morphological cell impairment characterized by depletion of myogenin, Cav-3 and MHC protein levels. Overall, our data suggest that MURC/cavin-4, especially in combination with Cav-3, may play a consistent role in the differentiation process of RMS. PMID:26086601

  1. MURC/cavin-4 Is Co-Expressed with Caveolin-3 in Rhabdomyosarcoma Tumors and Its Silencing Prevents Myogenic Differentiation in the Human Embryonal RD Cell Line.

    PubMed

    Faggi, Fiorella; Codenotti, Silvia; Poliani, Pietro Luigi; Cominelli, Manuela; Chiarelli, Nicola; Colombi, Marina; Vezzoli, Marika; Monti, Eugenio; Bono, Federica; Tulipano, Giovanni; Fiorentini, Chiara; Zanola, Alessandra; Lo, Harriet P; Parton, Robert G; Keller, Charles; Fanzani, Alessandro

    2015-01-01

    The purpose of this study was to investigate whether MURC/cavin-4, a plasma membrane and Z-line associated protein exhibiting an overlapping distribution with Caveolin-3 (Cav-3) in heart and muscle tissues, may be expressed and play a role in rhabdomyosarcoma (RMS), an aggressive myogenic tumor affecting childhood. We found MURC/cavin-4 to be expressed, often concurrently with Cav-3, in mouse and human RMS, as demonstrated through in silico analysis of gene datasets and immunohistochemical analysis of tumor samples. In vitro expression studies carried out using human cell lines and primary mouse tumor cultures showed that expression levels of both MURC/cavin-4 and Cav-3, while being low or undetectable during cell proliferation, became robustly increased during myogenic differentiation, as detected via semi-quantitative RT-PCR and immunoblotting analysis. Furthermore, confocal microscopy analysis performed on human RD and RH30 cell lines confirmed that MURC/cavin-4 mostly marks differentiated cell elements, colocalizing at the cell surface with Cav-3 and labeling myosin heavy chain (MHC) expressing cells. Finally, MURC/cavin-4 silencing prevented the differentiation in the RD cell line, leading to morphological cell impairment characterized by depletion of myogenin, Cav-3 and MHC protein levels. Overall, our data suggest that MURC/cavin-4, especially in combination with Cav-3, may play a consistent role in the differentiation process of RMS.

  2. Local myogenic pulp-derived cell injection enhances craniofacial muscle regeneration in vivo.

    PubMed

    Jung, J E; Song, M J; Shin, S; Choi, Y J; Kim, K H; Chung, C J

    2017-02-01

    To enhance myogenic differentiation in pulp cells isolated from extracted premolars by epigenetic modification using a DNA demethylation agent, 5-aza-2'-deoxycytidine (5-Aza), and to evaluate the potent stimulatory effect of 5-Aza-treated pulp cell injection for craniofacial muscle regeneration in vivo. Pulp cells were isolated from premolars extracted for orthodontic purposes from four adults (age range, 18-22.1 years). Levels of myogenic differentiation and functional contraction response in vitro were compared between pulp cells with or without pre-treatment of 5-Aza. Changes in muscle regeneration in response to green fluorescent protein (GFP)-labelled myogenic pulp cell injection in vivo were evaluated using a cardiotoxin (CTX)-induced muscle injury model of the gastrocnemius as well as the masseter muscle in mice. Pre-treatment of 5-Aza in pulp cells stimulated myotube formation, myogenic differentiation in terms of desmin and myogenin expression, and the level of collagen gel contraction. The local injection of 5-Aza pre-treated myogenic pulp cells was engrafted into the host tissue and indicated signs of enhanced muscle regeneration in both the gastrocnemius and the masseter muscles. The epigenetic modification of pulp cells from extracted premolars and the local injection of myogenic pulp cells may stimulate craniofacial muscles regeneration in vivo. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  3. CD36 is required for myoblast fusion during myogenic differentiation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Park, Seung-Yoon; Yun, Youngeun; Kim, In-San, E-mail: iskim@knu.ac.kr

    2012-11-02

    Highlights: Black-Right-Pointing-Pointer CD36 expression was induced during myogenic differentiation. Black-Right-Pointing-Pointer CD36 expression was localized in multinucleated myotubes. Black-Right-Pointing-Pointer The expression of myogenic markers is attenuated in CD36 knockdown C2C12 cells. Black-Right-Pointing-Pointer Knockdown of CD36 significantly inhibited myotube formation during differentiation. -- Abstract: Recently, CD36 has been found to be involved in the cytokine-induced fusion of macrophage. Myoblast fusion to form multinucleated myotubes is required for myogenesis and muscle regeneration. Because a search of gene expression database revealed the attenuation of CD36 expression in the muscles of muscular dystrophy patients, the possibility that CD36 could be required for myoblast fusion wasmore » investigated. CD36 expression was markedly up-regulated during myoblast differentiation and localized in multinucleated myotubes. Knockdown of endogenous CD36 significantly decreased the expression of myogenic markers as well as myotube formation. These results support the notion that CD36 plays an important role in cell fusion during myogenic differentiation. Our finding will aid the elucidation of the common mechanism governing cell-to-cell fusion in various fusion models.« less

  4. Immortalized myogenic cells from congenital muscular dystrophy type1A patients recapitulate aberrant caspase activation in pathogenesis: a new tool for MDC1A research

    PubMed Central

    2013-01-01

    Background Congenital muscular dystrophy Type 1A (MDC1A) is a severe, recessive disease of childhood onset that is caused by mutations in the LAMA2 gene encoding laminin-α2. Studies with both mouse models and primary cultures of human MDC1A myogenic cells suggest that aberrant activation of cell death is a significant contributor to pathogenesis in laminin-α2-deficiency. Methods To overcome the limited population doublings of primary cultures, we generated immortalized, clonal lines of human MDC1A myogenic cells via overexpression of both CDK4 and the telomerase catalytic component (human telomerase reverse transcriptase (hTERT)). Results The immortalized MDC1A myogenic cells proliferated indefinitely when cultured at low density in high serum growth medium, but retained the capacity to form multinucleate myotubes and express muscle-specific proteins when switched to low serum medium. When cultured in the absence of laminin, myotubes formed from immortalized MDC1A myoblasts, but not those formed from immortalized healthy or disease control human myoblasts, showed significantly increased activation of caspase-3. This pattern of aberrant caspase-3 activation in the immortalized cultures was similar to that found previously in primary MDC1A cultures and laminin-α2-deficient mice. Conclusions Immortalized MDC1A myogenic cells provide a new resource for studies of pathogenetic mechanisms and for screening possible therapeutic approaches in laminin-α2-deficiency. PMID:24314268

  5. PAX3 is expressed in the stromal compartment of the developing kidney and in Wilms tumors with myogenic phenotype.

    PubMed

    Hueber, Pierre-Alain; Fukuzawa, Ryuji; Elkares, Reyhan; Chu, Leelee; Blumentkrantz, Miriam; He, Shu-Jie; Anaka, Matthew R; Reeve, Anthony E; Eccles, Michael; Jabado, Nada; Iglesias, Diana M; Goodyer, Paul R

    2009-01-01

    Wilms tumor (WT) is the most frequent renal neoplasm of childhood; a myogenic component is observed in 5% to 10% of tumors. We demonstrate for the first time that myogenic WTs are associated with expression of PAX3, a transcription factor known to specify myoblast cell fate during muscle development. In a panel of 20 WTs, PAX3 was identified in 13 of 13 tumor samples with myogenic histopathology but was absent in 7 of 7 tumors lacking a myogenic component. Furthermore, we show that PAX3 is expressed in the metanephric mesenchyme and stromal compartment of developing mouse kidney. Modulation of endogenous PAX3 expression in human embryonic kidney (HEK293) cells influenced cell migration in in vitro assays. Mutations of WT1 were consistently associated with PAX3 expression in WTs, and modulation of WT1 expression in HEK293 cells was inversely correlated with the level of endogenous PAX3 protein. We demonstrate abundant PAX3 and absence of PAX2 expression in a novel cell line (WitP3) isolated from the stromal portion of a WT bearing a homozygous deletion of the WT1 gene. We hypothesize that PAX3 sets stromal cell fate in developing kidney but is normally suppressed by WT1 during the mesenchyme-to-epithelium transition leading to nephrogenesis. Loss of WT1 permits aberrant PAX3 expression in a subset of WTs with myogenic phenotype.

  6. Does altered myogenic activity contribute to OAB symptoms from detrusor overactivity? ICI-RS 2013.

    PubMed

    Chacko, Sam; Cortes, Eduard; Drake, Marcus J; Fry, Christopher H

    2014-06-01

    To highlight novel experimental approaches that test if the Myogenic Hypothesis remains viable as a contributor to the aetiology of detrusor overactivity. To summarise the conclusions of a workshop held under the auspices of ICI-RS in 2013. Several theories may explain the pathology of detrusor overactivity and include a myogenic theory with fundamental changes to detrusor muscle excitation-contraction coupling. The isolated bladder displays micromotions that do not normally translate into significant changes of intravesical pressure. However, their amplitude and frequency are altered in animal models of bladder dysfunction. The origin of micromotions, if they generate significant changes of intravesical pressure and contribute to urinary tract sensations remain unanswered. Within the myocyte, changes to contractile protein phosphorylation through accessory proteins and cytoplasmic regulatory pathways occur in lower urinary tract pathologies associated with detrusor overactivity. Furthermore, myocytes isolated from overactive human bladders generate greater spontaneous activity, but a complete description of changes to ionic currents remains to be characterised. Finally, several growth factors, including mechano-growth factor, are released when bladder wall stress is increased, as with outflow obstruction. However the phenotype of the transformed detrusor myocytes remains to be measured. A number of lines of evidence suggest that the Myogenic Hypothesis remains viable as a contributor to detrusor overactivity. © 2014 Wiley Periodicals, Inc.

  7. The construction and partial characterization of plasmids containing complementary DNA sequences to human calcitonin precursor polyprotein.

    PubMed Central

    Allison, J; Hall, L; MacIntyre, I; Craig, R K

    1981-01-01

    (1) Total poly(A)-containing RNA isolated from human thyroid medullary carcinoma tissue was shown to direct the synthesis in the wheat germ cell-free system of a major (Mr 21000) and several minor forms of human calcitonin precursor polyproteins. Evidence for processing of these precursor(s) by the wheat germ cell-free system is also presented. (2) A small complementary DNA (cDNA) plasmid library has been constructed in the PstI site of the plasmid pAT153, using total human thyroid medullary carcinoma poly(A)-containing RNA as the starting material. (3) Plasmids containing abundant cDNA sequences were selected by hybridization in situ, and two of these (ph T-B3 and phT-B6) were characterized by hybridization--translation and restriction analysis. Each was shown to contain human calcitonin precursor polyprotein cDNA sequences. (4) RNA blotting techniques demonstrate that the human calcitonin precursor polyprotein is encoded within a mRNA containing 1000 bases. (5) The results demonstrate that human calcitonin is synthesized as a precursor polyprotein. Images Fig. 1. Fig. 2. Fig. 3. PMID:6896146

  8. Refractory episodic vertigo: role of intratympanic gentamicin and vestibular evoked myogenic potentials.

    PubMed

    Celis-Aguilar, Erika; Hinojosa-González, Ramon; Vales-Hidalgo, Olivia; Coutinho-Toledo, Heloisa

    Even today, the treatment of intractable vertigo remains a challenge. Vestibular ablation with intratympanic gentamicin stands as a good alternative in the management of refractory vertigo patients. To control intractable vertigo through complete saccular and horizontal canal vestibular ablation with intratympanic gentamicin treatment. Patients with refractory episodic vertigo were included. The inclusion criteria were: unilateral ear disease, moderate to profound sensorineural hearing loss, and failure to other treatments. Included patients underwent 0.5-0.8mL of gentamicin intratympanic application at a 30mg/mL concentration. Vestibular ablation was confirmed by the absence of response on cervical vestibular evoked myogenic potentials and no response on caloric tests. Audiometry, electronystagmography with iced water, and vestibular evoked myogenic potentials were performed in all patients. Ten patients were included; nine patients with Meniere's disease and one patient with (late onset) delayed hydrops. Nine patients showed an absent response on vestibular evoked myogenic potentials and no response on caloric tests. The only patient with low amplitude on cervical vestibular evoked myogenic potentials had vertigo recurrence. Vertigo control was achieved in 90% of the patients. One patient developed hearing loss >30dB. Cervical vestibular evoked myogenic potentials confirmed vestibular ablation in patients treated with intratympanic gentamicin. High-grade vertigo control was due to complete saccular and horizontal canal ablation (no response to iced water in electronystagmography and no response on cervical vestibular evoked myogenic potentials). Copyright © 2016 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  9. Transcriptome analysis of post-hatch breast muscle in legacy and modern broiler chickens reveals enrichment of several regulators of myogenic growth.

    PubMed

    Davis, Richard V N; Lamont, Susan J; Rothschild, Max F; Persia, Michael E; Ashwell, Chris M; Schmidt, Carl J

    2015-01-01

    Agriculture provides excellent model systems for understanding how selective pressure, as applied by humans, can affect the genomes of plants and animals. One such system is modern poultry breeding in which intensive genetic selection has been applied for meat production in the domesticated chicken. As a result, modern meat-type chickens (broilers) exhibit enhanced growth, especially of the skeletal muscle, relative to their legacy counterparts. Comparative studies of modern and legacy broiler chickens provide an opportunity to identify genes and pathways affected by this human-directed evolution. This study used RNA-seq to compare the transcriptomes of a modern and a legacy broiler line to identify differentially enriched genes in the breast muscle at days 6 and 21 post-hatch. Among the 15,945 genes analyzed, 10,841 were expressed at greater than 0.1 RPKM. At day 6 post-hatch 189 genes, including several regulators of myogenic growth and development, were differentially enriched between the two lines. The transcriptional profiles between lines at day 21 post-hatch identify 193 genes differentially enriched and still include genes associated with myogenic growth. This study identified differentially enriched genes that regulate myogenic growth and differentiation between the modern and legacy broiler lines. Specifically, differences in the ratios of several positive (IGF1, IGF1R, WFIKKN2) and negative (MSTN, ACE) myogenic growth regulators may help explain the differences underlying the enhanced growth characteristics of the modern broilers.

  10. Mesenchymal Stromal Cells for Sphincter Regeneration: Role of Laminin Isoforms upon Myogenic Differentiation

    PubMed Central

    Seeger, Tanja; Hart, Melanie; Patarroyo, Manuel; Rolauffs, Bernd; Aicher, Wilhelm K.; Klein, Gerd

    2015-01-01

    Multipotent mesenchymal stromal cells (MSCs) are well known for their tri-lineage potential and ability to differentiate in vitro into osteogenic, chondrogenic or adipogenic lineages. By selecting appropriate conditions MSCs can also be differentiated in vitro into the myogenic lineage and are therefore a promising option for cell-based regeneration of muscle tissue such as an aged or damaged sphincter muscle. For the differentiation into the myogenic lineage there is still a need to evaluate the effects of extracellular matrix proteins such as laminins (LM) which are crucial for different stem cell types and for normal muscle function. The laminin family consists of 16 functionally different isoforms with LM-211 being the most abundant isoform of adult muscle tissues. In the sphincter tissue a strong expression of the isoforms LM-211/221, LM-411/421 and LM-511/521 can be detected in the different cell layers. Bone marrow-derived MSCs in culture, however, mainly express the isoforms LM-411 and LM-511, but not LM-211. Even after myogenic differentiation, LM-211 can hardly be detected. All laminin isoforms tested (LM-211, LM-411, LM-511 and LM-521) showed a significant inhibition of the proliferation of undifferentiated MSCs but, with the exception of LM-521, they had no influence on the proliferation of MSCs cultivated in myogenic medium. The strongest cellular adhesion of MSCs was to LM-511 and LM-521, whereas LM-211 was only a weakly-adhesive substrate for MSCs. Myogenic differentiation of MSCs even reduced the interaction with LM-211, but it did not affect the interaction with LM-511 and LM-521. Since during normal myogenesis the latter two isoforms are the major laminins surrounding developing myogenic progenitors, α5 chain-containing laminins are recommended for further improvements of myogenic differentiation protocols of MSCs into smooth muscle cells. PMID:26406476

  11. Hypoxia promotes proliferation of human myogenic satellite cells: a potential benefactor in tissue engineering of skeletal muscle.

    PubMed

    Koning, Merel; Werker, Paul M N; van Luyn, Marja J A; Harmsen, Martin C

    2011-07-01

    Facial paralysis is a physically, psychologically, and socially disabling condition. Innovative treatment strategies based on regenerative medicine, in particular tissue engineering of skeletal muscle, are promising for treatment of patients with facial paralysis. The natural source for tissue-engineered muscle would be muscle stem cells, that is, human satellite cells (SC). In vivo, SC respond to hypoxic, ischemic muscle damage by activation, proliferation, differentiation to myotubes, and maturation to muscle fibers, while maintaining their reserve pool of SC. Therefore, our hypothesis is that hypoxia improves proliferation and differentiation of SC. During tissue engineering, a three-dimensional construct, or implanting SC in vivo, SC will encounter hypoxic environments. Thus, we set out to test our hypothesis on SC in vitro. During the first five passages, hypoxically cultured SC proliferated faster than their counterparts under normoxia. Moreover, also at higher passages, a switch from normoxia to hypoxia enhanced proliferation of SC. Hypoxia did not affect the expression of SC markers desmin and NCAM. However, the average surface expression per cell of NCAM was downregulated by hypoxia, and it also downregulated the gene expression of NCAM. The gene expression of the myogenic transcription factors PAX7, MYF5, and MYOD was upregulated by hypoxia. Moreover, gene expression of structural proteins α-sarcomeric actin, and myosins MYL1 and MYL3 was upregulated by hypoxia during differentiation. This indicates that hypoxia promotes a promyogenic shift in SC. Finally, Pax7 expression was not influenced by hypoxia and maintained in a subset of mononucleated cells, whereas these cells were devoid of structural muscle proteins. This suggests that during myogenesis in vitro, at least part of the SC adopt a quiescent, that is, reserve cells, phenotype. In conclusion, tissue engineering under hypoxic conditions would seem favorable in terms of myogenic proliferation

  12. Myogenic potential of mesenchymal stem cells isolated from porcine adipose tissue.

    PubMed

    Milner, Derek J; Bionaz, Massimo; Monaco, Elisa; Cameron, Jo Ann; Wheeler, Matthew B

    2018-06-01

    Advances in stem cell biology and materials science have provided a basis for developing tissue engineering methods to repair muscle injury. Among stem cell populations with potential to aid muscle repair, adipose-derived mesenchymal stem cells (ASC) hold great promise. To evaluate the possibility of using porcine ASC for muscle regeneration studies, we co-cultured porcine ASC with murine C 2 C 12 myoblasts. These experiments demonstrated that porcine ASC display significant myogenic potential. Co-culture of ASC expressing green fluorescent protein (GFP) with C 2 C 12 cells resulted in GFP + myotube formation, indicating fusion of ASC with myoblasts to form myotubes. The presence of porcine lamin A/C positive nuclei in myotubes and RTqPCR analysis of porcine myogenin and desmin expression confirmed that myotube nuclei derived from ASC contribute to muscle gene expression. Co-culturing GFP + ASC with porcine satellite cells demonstrated enhanced myogenic capability of ASC, as the percentage of labeled myotubes increased compared to mouse co-cultures. Enhancing myogenic potential of ASC through soluble factor treatment or expansion of ASC with innate myogenic capacity should allow for their therapeutic use to regenerate muscle tissue lost to disease or injury.

  13. High-Density ZnO Nanowires as a Reversible Myogenic-Differentiation Switch.

    PubMed

    Errico, Vito; Arrabito, Giuseppe; Fornetti, Ersilia; Fuoco, Claudia; Testa, Stefano; Saggio, Giovanni; Rufini, Stefano; Cannata, Stefano; Desideri, Alessandro; Falconi, Christian; Gargioli, Cesare

    2018-04-25

    Mesoangioblasts are outstanding candidates for stem-cell therapy and are already being explored in clinical trials. However, a crucial challenge in regenerative medicine is the limited availability of undifferentiated myogenic progenitor cells because growth is typically accompanied by differentiation. Here reversible myogenic-differentiation switching during proliferation is achieved by functionalizing the glass substrate with high-density ZnO nanowires (NWs). Specifically, mesoangioblasts grown on ZnO NWs present a spherical viable undifferentiated cell state without lamellopodia formation during the entire observation time (8 days). Consistently, the myosin heavy chain, typically expressed in skeletal muscle tissue and differentiated myogenic progenitors, is completely absent. Remarkably, NWs do not induce any damage while they reversibly block differentiation, so that the differentiation capabilities are completely recovered upon cell removal from the NW-functionalized substrate and replating on standard culture glass. This is the first evidence of a reversible myogenic-differentiation switch that does not affect the viability. These results can be the first step toward for the in vitro growth of a large number of undifferentiated stem/progenitor cells and therefore can represent a breakthrough for cell-based therapy and tissue engineering.

  14. [Analysis of perfluoroalkyl substances precursors in human milk from 12 provinces of China].

    PubMed

    Yang, Lin; Yu, Xinping; Wang, Meng; Li, Jingguang; Wang, Yuxin; Zhao, Yunfeng; Wu, Yongning

    2015-06-01

    To explore the level of perfluoroalkyl substances (PFASs) precursors in Chinese human milk samples. The human milk samples were collected during the performance of Stockholm convention on survey of human milk in China in 2007. Based on the geographical location and dietary habits, China was divided into the south area and north area which 6 provinces were chosen from each area and there were 12 provinces in all. In each province, one urban site and two rural sites were selected to collect 80-110 samples. Mothers were randomly selected in each site to collect their breast milk. There were 1 237 individual human milk samples in all. For each province, the individual samples from the urban areas and the rural areas were pooled separately resulting in 24 pooled human milk samples. 11 PFAS precursors were measured in pooled samples by ultra-high performance liquid chromatography-tandem quadruple mass spectrometry (UPLC-MS/MS). The dietary exposure assessment of newborns was made. Three PFAS precursors were found above the detection limits, namely, 6:2 FTS, FHUEA, and 6:2 diPAP. Their concentration ranges were < Limit of determination (LOD) -47.46 pg/ml, < LOD -70.68 pg/ml and < LOD -35.08 pg/ml, respectively. The highest total PFAS precursor concentration 77.70 pg/ml was found in urban area samples from Shannxi Province. Rural area samples from Hubei had the lowest total PFAS precursor concentration, which was below the LOD. There were significant differences between rural and urban areas in many provinces, such as Shannxi (rural: 1.51 pg/ml; urban: 77.70 pg/ml), Shanghai (rural: 1.13 pg/ml; urban: 71.88 pg/ml), Jiangxi (rural: 65.39 pg/ml; urban: 0.55 pg/ml) and so on. The ranges estimated daily intake of 6:2 FTS, FHUEA and 6:2 diPAP of the samples from 12 provinces were 0.05-4.51, 1.13-6.72 and 1.15-3.34 ng · kg⁻¹ · d⁻¹. The results suggested the human exposure of PFAS precursors in China and the potential health impact of postnatal exposure through

  15. Accelerated Evolution of the Pituitary Adenylate Cyclase-Activating Polypeptide Precursor Gene During Human Origin

    PubMed Central

    Wang, Yin-qiu; Qian, Ya-ping; Yang, Su; Shi, Hong; Liao, Cheng-hong; Zheng, Hong-Kun; Wang, Jun; Lin, Alice A.; Cavalli-Sforza, L. Luca; Underhill, Peter A.; Chakraborty, Ranajit; Jin, Li; Su, Bing

    2005-01-01

    Pituitary adenylate cyclase-activating polypeptide (PACAP) is a neuropeptide abundantly expressed in the central nervous system and involved in regulating neurogenesis and neuronal signal transduction. The amino acid sequence of PACAP is extremely conserved across vertebrate species, indicating a strong functional constraint during the course of evolution. However, through comparative sequence analysis, we demonstrated that the PACAP precursor gene underwent an accelerated evolution in the human lineage since the divergence from chimpanzees, and the amino acid substitution rate in humans is at least seven times faster than that in other mammal species resulting from strong Darwinian positive selection. Eleven human-specific amino acid changes were identified in the PACAP precursors, which are conserved from murine to African apes. Protein structural analysis suggested that a putative novel neuropeptide might have originated during human evolution and functioned in the human brain. Our data suggested that the PACAP precursor gene underwent adaptive changes during human origin and may have contributed to the formation of human cognition. PMID:15834139

  16. Role of sensory C fibers in hypoxia/ reoxygenation-impaired myogenic constriction of cerebral arteries

    PubMed Central

    Xie, Hui; Ray, Patricio E.; Short, Billie Lou

    2009-01-01

    Objective Hypoxia/reoxygenation (H/R) associated with extracorporeal membrane oxygenation disrupts cerebral autoregulation. However, the underlying mechanisms remain poorly understood. The present study was designed to investigate the role of sensory C-fibers in myogenic responsiveness of cerebral arteries. Methods Arterial diameter and intraluminal pressure were simultaneously measured in vitro on rat posterior cerebral arteries. Results Cerebral arteries constricted in response to graded increase in intraluminal pressure (20–100 mmHg, in 20 mmHg increments). In vitro C-fiber desensitization with capsaicin (1 μmol/l, 20 minutes) significantly suppressed myogenic constriction by over 50%, but did not affect 5-hydroxytryptamine (0.01–10 μmol/l) and KCl (120 mmol/l)-induced constriction. Capsazepine (5 μmol/l, 30 minutes), a selective blocker of neuronal vanilloid receptor TRPV1, had similar inhibitory effect on cerebral myogenic constriction to elevated pressure. Cerebral myogenic constriction was significantly attenuated by H/R; the impairment by H/R was further enhanced after C-fiber desensitization (except at a pressure level of 100 mmHg). Discussion These findings indicate that C-fiber activity contributes to myogenic constriction of cerebral arteries under normal and H/R conditions. H/R-impaired myogenic responsiveness is exaggerated by C-fiber dysfunction. These results raise the possibility that therapeutic strategies directed toward preserving C-fiber nerve endings or supplying its constituent neuropeptides could be developed. PMID:19570322

  17. Bovine gallbladder muscularis: Source of a myogenic receptor for cholecystokinin

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Schjoldager, B.; Shaw, M.J.; Powers, S.P.

    1988-03-01

    Despite being a classic target for the gastrointestinal peptide hormone, cholecystokinin (CCK), the gallbladder CCK receptor is not well characterized. Pharmacological studies of small species suggest that CCK action can be mediated by direct myogenic or by both myogenic and neurogenic receptors. To prepare for the biochemical characterization of a gallbladder CCK receptor and to define the subtype of the receptor being studied. The authors have performed autoradiographic localization and pharmacological characterization of CCK receptors on bovine gallbladder. Autoradiography demonstrated high-affinity specific CCK-binding sites only on the muscularis. CCK-8 stimulated tonic contraction of longitudinal strips of gallbladder muscularis in amore » concentration-dependent manner. Antagonism at the cholinergic receptor with 1{mu}M atropine or axonal transmission with 1{mu}M tetrodotoxin did not modify CCK-induced contraction, supporting a direct myogenic effect of this hormone. Optimal electrical field stimulation to elicit a neuronal response resulted in muscle strip relaxation, which was abolished with adrenergic blockade. Although acetylcholine administration stimulated contraction, electrical field stimulation did not, even in the presence of phentolamine, propranolol, and/or CCK. Thus, in bovine gallbladder muscularis, there is evidence for a functional CCK receptor only on smooth muscle cells. Demonstration of a single, high-affinity specific CCK-binding site on an enriched plasma membrane preparation of bovine gallbladder muscularis is consistent with this representing a myogenic CCK receptor.« less

  18. Apelin impairs myogenic response to induce diabetic nephropathy in mice.

    PubMed

    Zhang, Jia; Yin, Jiming; Wang, Yangjia; Li, Bin; Zeng, Xiangjun

    2018-03-09

    The cause of the invalid reaction of smooth muscle cells to mechanical stimulation that results in a dysfunctional myogenic response that mediates the disruption of renal blood flow (RBF) in patients with diabetes is debatable. The present study revealed that increased apelin concentration in serum of diabetic mice neutralized the myogenic response mediated by apelin receptor (APJ) and resulted in increased RBF, which promoted the progression of diabetic nephropathy. The results showed that apelin concentration, RBF, and albuminuria:creatinine ratio were all increased in kkAy mice, and increased RBF correlated positively with serum apelin both in C57 and diabetic mice. The increased RBF was accompanied by decreased phosphorylation of myosin light chain (MLC), β-arrestin, and increased endothelial NOS in glomeruli. Meanwhile, calcium, phosphorylation of MLC, and β-arrestin were decreased by high glucose and apelin treatment in cultured smooth muscle cells, as well. eNOS was increased by high glucose and increased by apelin in cultured endothelial cells (ECs). Knockdown of β-arrestin expression in smooth muscle cells cancelled phosphorylation of MLC induced by apelin. Therefore, apelin may induce the progression of diabetic nephropathy by counteracting the myogenic response in smooth muscle cells.-Zhang, J., Yin, J., Wang, Y., Li, B., Zeng, X. Apelin impairs myogenic response to induce diabetic nephropathy in mice.

  19. Testing the vestibular evoked myogenic potential (VEMP) to identify subclinical neurological alterations in different phases of human T-lymphotropic virus type 1 infection.

    PubMed

    Felipe, Lilian; Kingma, Herman; Lambertucci, José R; Carneiro-Proietti, Anna B; Gonçalves, Denise U

    2013-04-01

    The diagnosis of human T-lymphotropic virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) is based on clinical signs and the confirmation of HTLV-1 infection in the central nervous system. Electrophysiological tests may facilitate an earlier diagnosis of spinal cord involvement. Vestibular evoked myogenic potential (VEMP) testing evaluates the vestibulospinal tract, which is correlated with the motor tract; the target of damage by HAM/TSP. This study examines the subclinical neurological alterations related to HTLV-1 infection in individuals with asymptomatic HTLV-1 infections, possible HAM/TSP, and confirmed HAM/TSP. Vestibular evoked myogenic potential testing was performed at the beginning of the study and repeated every 6 months for 18 months. Ninety volunteers were selected for the study: 30 were HTLV-1 seronegative (the control group) and 60 were HTLV-1 seropositive (of these, 18 were asymptomatic, 25 had possible HAM/TSP, and 17 had confirmed HAM/TSP). The VEMP response was classified as normal or abnormal (latency prolongation or no response). A change in the VEMP response from normal to abnormal was the event of interest. To perform a survival analysis, the subjects with normal VEMP responses at the first assessment were selected. The results were analyzed blindly. Vestibular evoked myogenic potential was measured using short tone bursts as acoustic stimuli (1 kHz, 118 dBHL, a rise-fall of 1 millisecond, and a plateau of 2 milliseconds). The stimulation rate was 5 Hz, and the analysis time for each response was 60 milliseconds; each trial averaged 200 responses. The mean age of the subjects in the control group was 38 ± 11 years (median 35), and 13 (43%) were men. In the study group, the mean age was 51 ± 12 years (median 53), and 12 (20%) were men. An analysis of the survival curve indicated that the median time for a change in VEMP response from normal to abnormal was 18 months, which is in agreement with the slow

  20. Zinc promotes proliferation and activation of myogenic cells via the PI3K/Akt and ERK signaling cascade

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Ohashi, Kazuya, E-mail: asuno10k@yahoo.co.jp; Nagata, Yosuke, E-mail: cynagata@mail.ecc.u-tokyo.ac.jp; Wada, Eiji, E-mail: gacchu1@yahoo.co.jp

    2015-05-01

    Skeletal muscle stem cells named muscle satellite cells are normally quiescent but are activated in response to various stimuli, such as injury and overload. Activated satellite cells enter the cell cycle and proliferate to produce a large number of myogenic progenitor cells, and these cells then differentiate and fuse to form myofibers. Zinc is one of the essential elements in the human body, and has multiple roles, including cell growth and DNA synthesis. However, the role of zinc in myogenic cells is not well understood, and is the focus of this study. We first examined the effects of zinc onmore » differentiation of murine C2C12 myoblasts and found that zinc promoted proliferation, with an increased number of cells incorporating EdU, but inhibited differentiation with reduced myogenin expression and myotube formation. Furthermore, we used the C2C12 reserve cell model of myogenic quiescence to investigate the role of zinc on activation of myogenic cells. The number of reserve cells incorporating BrdU was increased by zinc in a dose dependent manner, with the number dramatically further increased using a combination of zinc and insulin. Akt and extracellular signal-regulated kinase (ERK) are downstream of insulin signaling, and both were phosphorylated after zinc treatment. The zinc/insulin combination-induced activation involved the phosphoinositide 3-kinase (PI3K)/Akt and ERK cascade. We conclude that zinc promotes activation and proliferation of myogenic cells, and this activation requires phosphorylation of PI3K/Akt and ERK as part of the signaling cascade. - Highlights: • Zinc has roles for promoting proliferation and inhibition differentiation of C2C12. • Zinc promotes activation of reserve cells. • Insulin and zinc synergize activation of reserve cells. • PI3K/Akt and ERK cascade affect zinc/insulin-mediated activation of reserve cells.« less

  1. Nitric oxide blunts myogenic autoregulation in rat renal but not skeletal muscle circulation via tubuloglomerular feedback

    PubMed Central

    Just, Armin; Arendshorst, William J

    2005-01-01

    This rat renal blood flow (RBF) study quantified the impact of nitric oxide synthase (NOS) inhibition on the myogenic response and the balance of autoregulatory mechanisms in the time domain following a 20 mmHg-step increase or decrease in renal arterial pressure (RAP). When RAP was increased, the myogenic component of renal vascular resistance (RVR) rapidly rose within the initial 7–10 s, exhibiting an ∼5 s time constant and providing ∼36% of perfect autoregulation. A secondary rise between 10 and 40 s brought RVR to 95% total autoregulatory efficiency, reflecting tubuloglomerular feedback (TGF) and possibly one or two additional mechanisms. The kinetics were similar after the RAP decrease. Inhibition of NOS (by l-NAME) increased RAP, enhanced the strength (79% autoregulation) and doubled the speed of the myogenic response, and promoted the emergence of RVR oscillations (∼0.2 Hz); the strength (52%) was lower at control RAP. An equi-pressor dose of angiotensin II had no effect on myogenic or total autoregulation. Inhibition of TGF (by furosemide) abolished the l-NAME effect on the myogenic response. RVR responses during furosemide treatment, assuming complete inhibition of TGF, suggest a third mechanism that contributes 10–20% and is independent of TGF, slower than the myogenic response, and abolished by NOS inhibition. The hindlimb circulation displayed a solitary myogenic response similar to the kidney (35% autoregulation) that was not enhanced by l-NAME. We conclude that NO normally restrains the strength and speed of the myogenic response in RBF but not hindlimb autoregulation, an action dependent on TGF, thereby allowing more and slow RAP fluctuations to reach glomerular capillaries. PMID:16223765

  2. Effect of cooling rate on human and murine hemopoietic precursor cell recovery

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Niskanen, E.; Pirsch, G.

    1983-08-01

    The effect of cooling rate on recovery of human and murine hemopoietic precursor cells was studied. In the presence of 10% Me2SO, a cooling rate of 7 degrees C/min from -4 to -30 degrees C was optimal for recovery of both human and murine precursor cells which give rise to colonies in diffusion chambers implanted in mice (CFU-DG). Cooling of human marrow at a rate between 3 and 7 degrees C/min resulted in the best CFU-C recovery, although no good correlation between the cooling rate and murine CFU-C recovery was demonstrated. These data suggest that recovery of the primitive hemopoieticmore » precursor cells can be improved by changing the standard cryopreservation programs used presently. However, improved recovery of CFU-DG does not necessarily translate into faster reconstitution of hemopoiesis. No significant difference was observed in overall recovery of bone marrow cellularity in lethally irradiated mice following injection of untreated marrow and marrow cooled at a rate of 1 and 7 degrees C/min.« less

  3. SOD1 overexpression prevents acute hyperglycemia-induced cerebral myogenic dysfunction: relevance to contralateral hemisphere and stroke outcomes

    PubMed Central

    Coucha, Maha; Li, Weiguo; Hafez, Sherif; Abdelsaid, Mohammed; Johnson, Maribeth H.; Fagan, Susan C.

    2014-01-01

    Admission hyperglycemia (HG) amplifies vascular injury and neurological deficits in acute ischemic stroke, but the mechanisms remain controversial. We recently reported that ischemia-reperfusion (I/R) injury impairs the myogenic response in both hemispheres via increased nitration. However, whether HG amplifies contralateral myogenic dysfunction and whether loss of tone in the contralateral hemisphere contributes to stroke outcomes remain to be determined. Our hypothesis was that contralateral myogenic dysfunction worsens stroke outcomes after acute hyperglycemic stroke in an oxidative stress-dependent manner. Male wild-type or SOD1 transgenic rats were injected with saline or 40% glucose solution 10 min before surgery and then subjected to 30 min of ischemia/45 min or 24 h of reperfusion. In another set of animals (n = 5), SOD1 was overexpressed only in the contralateral hemisphere by stereotaxic adenovirus injection 2–3 wk before I/R. Myogenic tone and neurovascular outcomes were determined. HG exacerbated myogenic dysfunction in contralateral side only, which was associated with infarct size expansion, increased edema, and more pronounced neurological deficit. Global and selective SOD1 overexpression restored myogenic reactivity in ipsilateral and contralateral sides, respectively, and enhanced neurovascular outcomes. In conclusion, our results show that SOD1 overexpression nullified the detrimental effects of HG on myogenic tone and stroke outcomes and that the contralateral hemisphere may be a novel target for the management of acute hyperglycemic stroke. PMID:25552308

  4. Human proinsulin C-peptide from a precursor overexpressed in Pichia pastoris.

    PubMed

    Huang, Yang-Bin; Li, Jiang; Gao, Xin; Sun, Jiu-Ru; Lu, Yi; Feng, Tao; Fei, Jian; Cui, Da-Fu; Xia, Qi-Chang; Ren, Jun; Zhang, You-Shang

    2006-08-01

    In this article we report the production of human proinsulin C-peptide with 31 amino acid residues from a precursor overexpressed in Pichia pastoris. A C-peptide precursor expression plasmid containing nine C-peptide genes in tandem was constructed and used to transform P. pastoris. Transformants with a high copy number of the C-peptide precursor gene integrated into the chromosome of P. pastoris were selected. In high-density fermentation in a 300 liter fermentor using a simple culture medium composed mainly of salt and methanol, the C-peptide precursor was overexpressed to a level of 2.28 g per liter. A simple procedure was established to purify the expression product from the culture medium. The purified C-peptide precursor was converted into C-peptide by trypsin and carboxypeptidase B joint digestion. The yield of C-peptide with a purity of 96% was 730 mg per liter of culture. The purified C-peptide was characterized by mass spectrometry, N- and C-terminal amino acid sequencing, and sodium dodecylsulfate-polyacrylamide gel electrophoresis.

  5. Characterization of the Methylation Status of Pax7 and Myogenic Regulator Factors in Cell Myogenic Differentiation.

    PubMed

    Chao, Zhe; Zheng, Xin-Li; Sun, Rui-Ping; Liu, Hai-Long; Huang, Li-Li; Cao, Zong-Xi; Deng, Chang-Yan; Wang, Feng

    2016-07-01

    Epigenetic processes in the development of skeletal muscle have been appreciated for over a decade. DNA methylation is a major epigenetic modification important for regulating gene expression and suppressing spurious transcription. Up to now, the importance of epigenetic marks in the regulation of Pax7 and myogenic regulatory factors (MRFs) expression is far less explored. In the present study, semi-quantitative the real-time polymerase chain reaction (RT-PCR) analyses showed MyoD and Myf5 were expressed in activated and quiescent C2C12 cells. MyoG was expressed in a later stage of myogenesis. Pax7 was weakly expressed in differentiated C2C12 cells. To further understand the regulation of expression of these genes, the DNA methylation status of Pax7, MyoD, and Myf5 was determined by bisulfite sequencing PCR. During the C2C12 myoblasts fusion process, the changes of promoter and exon 1 methylation of Pax7, MyoD, and Myf5 genes were observed. In addition, an inverse relationship of low methylation and high expression was found. These results suggest that DNA methylation may be an important mechanism regulating Pax7 and MRFs transcription in cell myogenic differentiation.

  6. Patterns of Positive Selection of the Myogenic Regulatory Factor Gene Family in Vertebrates

    PubMed Central

    Zhao, Xiao; Yu, Qi; Huang, Ling; Liu, Qing-Xin

    2014-01-01

    The functional divergence of transcriptional factors is critical in the evolution of transcriptional regulation. However, the mechanism of functional divergence among these factors remains unclear. Here, we performed an evolutionary analysis for positive selection in members of the myogenic regulatory factor (MRF) gene family of vertebrates. We selected 153 complete vertebrate MRF nucleotide sequences from our analyses, which revealed substantial evidence of positive selection. Here, we show that sites under positive selection were more frequently detected and identified from the genes encoding the myogenic differentiation factors (MyoG and Myf6) than the genes encoding myogenic determination factors (Myf5 and MyoD). Additionally, the functional divergence within the myogenic determination factors or differentiation factors was also under positive selection pressure. The positive selection sites were more frequently detected from MyoG and MyoD than Myf6 and Myf5, respectively. Amino acid residues under positive selection were identified mainly in their transcription activation domains and on the surface of protein three-dimensional structures. These data suggest that the functional gain and divergence of myogenic regulatory factors were driven by distinct positive selection of their transcription activation domains, whereas the function of the DNA binding domains was conserved in evolution. Our study evaluated the mechanism of functional divergence of the transcriptional regulation factors within a family, whereby the functions of their transcription activation domains diverged under positive selection during evolution. PMID:24651579

  7. CD133+ cells derived from skeletal muscles of Duchenne muscular dystrophy patients have a compromised myogenic and muscle regenerative capability.

    PubMed

    Meng, Jinhong; Muntoni, Francesco; Morgan, Jennifer

    2018-05-12

    Cell-mediated gene therapy is a possible means to treat muscular dystrophies like Duchenne muscular dystrophy. Autologous patient stem cells can be genetically-corrected and transplanted back into the patient, without causing immunorejection problems. Regenerated muscle fibres derived from these cells will express the missing dystrophin protein, thus improving muscle function. CD133+ cells derived from normal human skeletal muscle contribute to regenerated muscle fibres and form muscle stem cells after their intra-muscular transplantation into an immunodeficient mouse model. But it is not known whether CD133+ cells derived from DMD patient muscles have compromised muscle regenerative function. To test this, we compared CD133+ cells derived from DMD and normal human muscles. DMD CD133+ cells had a reduced capacity to undergo myogenic differentiation in vitro compared with CD133+ cells derived from normal muscle. In contrast to CD133+ cells derived from normal human muscle, those derived from DMD muscle formed no satellite cells and gave rise to significantly fewer muscle fibres of donor origin, after their intra-muscular transplantation into an immunodeficient, non-dystrophic, mouse muscle. DMD CD133+ cells gave rise to more clones of smaller size and more clones that were less myogenic than did CD133+ cells derived from normal muscle. The heterogeneity of the progeny of CD133+ cells, combined with the reduced proliferation and myogenicity of DMD compared to normal CD133+ cells, may explain the reduced regenerative capacity of DMD CD133+ cells. Copyright © 2018 The Authors. Published by Elsevier B.V. All rights reserved.

  8. Reporter-Based Isolation of Developmental Myogenic Progenitors

    PubMed Central

    Kheir, Eyemen; Cusella, Gabriella; Messina, Graziella; Cossu, Giulio; Biressi, Stefano

    2018-01-01

    The formation and activity of mammalian tissues entail finely regulated processes, involving the concerted organization and interaction of multiple cell types. In recent years the prospective isolation of distinct progenitor and stem cell populations has become a powerful tool in the hands of developmental biologists and has rendered the investigation of their intrinsic properties possible. In this protocol, we describe how to purify progenitors with different lineage history and degree of differentiation from embryonic and fetal skeletal muscle by fluorescence-activated cell sorting (FACS). The approach takes advantage of a panel of murine strains expressing fluorescent reporter genes specifically in the myogenic progenitors. We provide a detailed description of the dissection procedures and of the enzymatic dissociation required to maximize the yield of mononucleated cells for subsequent FACS-based purification. The procedure takes ~6–7 h to complete and allows for the isolation and the subsequent molecular and phenotypic characterization of developmental myogenic progenitors. PMID:29674978

  9. Selection of reference genes for expression studies with fish myogenic cell cultures.

    PubMed

    Bower, Neil I; Johnston, Ian A

    2009-08-10

    Relatively few studies have used cell culture systems to investigate gene expression and the regulation of myogenesis in fish. To produce robust data from quantitative real-time PCR mRNA levels need to be normalised using internal reference genes which have stable expression across all experimental samples. We have investigated the expression of eight candidate genes to identify suitable reference genes for use in primary myogenic cell cultures from Atlantic salmon (Salmo salar L.). The software analysis packages geNorm, Normfinder and Best keeper were used to rank genes according to their stability across 42 samples during the course of myogenic differentiation. Initial results showed several of the candidate genes exhibited stable expression throughout myogenic culture while Sdha was identified as the least stable gene. Further analysis with geNorm, Normfinder and Bestkeeper identified Ef1alpha, Hprt1, Ppia and RNApolII as stably expressed. Comparison of data normalised with the geometric average obtained from combinations of any three of these genes showed no significant differences, indicating that any combination of these genes is valid. The geometric average of any three of Hprt1, Ef1alpha, Ppia and RNApolII is suitable for normalisation of gene expression data in primary myogenic cultures from Atlantic salmon.

  10. Myogenesis in the sea urchin embryo: the molecular fingerprint of the myoblast precursors

    PubMed Central

    2013-01-01

    Background In sea urchin larvae the circumesophageal fibers form a prominent muscle system of mesodermal origin. Although the morphology and later development of this muscle system has been well-described, little is known about the molecular signature of these cells or their precise origin in the early embryo. As an invertebrate deuterostome that is more closely related to the vertebrates than other commonly used model systems in myogenesis, the sea urchin fills an important phylogenetic gap and provides a unique perspective on the evolution of muscle cell development. Results Here, we present a comprehensive description of the development of the sea urchin larval circumesophageal muscle lineage beginning with its mesodermal origin using high-resolution localization of the expression of several myogenic transcriptional regulators and differentiation genes. A few myoblasts are bilaterally distributed at the oral vegetal side of the tip of the archenteron and first appear at the late gastrula stage. The expression of the differentiation genes Myosin Heavy Chain, Tropomyosin I and II, as well as the regulatory genes MyoD2, FoxF, FoxC, FoxL1, Myocardin, Twist, and Tbx6 uniquely identify these cells. Interestingly, evolutionarily conserved myogenic factors such as Mef2, MyoR and Six1/2 are not expressed in sea urchin myoblasts but are found in other mesodermal domains of the tip of the archenteron. The regulatory states of these domains were characterized in detail. Moreover, using a combinatorial analysis of gene expression we followed the development of the FoxF/FoxC positive cells from the onset of expression to the end of gastrulation. Our data allowed us to build a complete map of the Non-Skeletogenic Mesoderm at the very early gastrula stage, in which specific molecular signatures identify the precursors of different cell types. Among them, a small group of cells within the FoxY domain, which also express FoxC and SoxE, have been identified as plausible myoblast

  11. The effect of nutritional status and myogenic satellite cell age on turkey satellite cell proliferation, differentiation, and expression of myogenic transcriptional regulatory factors and heparan sulfate proteoglycans syndecan-4 and glypican-1.

    PubMed

    Harthan, Laura B; McFarland, Douglas C; Velleman, Sandra G

    2014-01-01

    Posthatch satellite cell mitotic activity is a critical component of muscle development and growth. Satellite cells are myogenic stem cells that can be induced by nutrition to follow other cellular developmental pathways, and whose mitotic activity declines with age. The objective of the current study was to determine the effect of restricting protein synthesis on the proliferation and differentiation, expression of myogenic transcriptional regulatory factors myogenic determination factor 1, myogenin, and myogenic regulatory factor 4, and expression of the heparan sulfate proteoglycans syndecan-4 and glypican-1 in satellite cells isolated from 1-d-, 7-wk-, and 16-wk-old turkey pectoralis major muscle (1 d, 7 wk, and 16 wk cells, respectively) by using variable concentrations of Met and Cys. Four Met concentrations-30 (control), 7.5, 3, or 0 mg/L with 3.2 mg/L of Cys per 1 mg/L of Met-were used for culture of satellite cells to determine the effect of nutrition and age on satellite cell behavior during proliferation and differentiation. Proliferation was reduced by lower Met and Cys concentrations in all ages at 96 h of proliferation. Differentiation was increased in the 1 d Met-restricted cells, whereas the 7 wk cells treated with 3 mg/L of Met had decreased differentiation. Reduced Met and Cys levels from the control did not significantly affect the 16 wk cells at 72 h of differentiation. However, medium with no Met or Cys suppressed differentiation at all ages. The expression of myogenic determination factor 1, myogenin, myogenic regulatory factor 4, syndecan-4, and glypican-1 was differentially affected by age and Met or Cys treatment. These data demonstrate the age-specific manner in which turkey pectoralis major muscle satellite cells respond to nutritional availability and the importance of defining optimal nutrition to maximize satellite cell proliferation and differentiation for subsequent muscle mass accretion.

  12. Developmental potential of muscle cell progenitors and the myogenic factor SUM-1 in the sea urchin embryo.

    PubMed

    Venuti, J M; Gan, L; Kozlowski, M T; Klein, W H

    1993-04-01

    During sea urchin development, esophageal muscle arises from secondary mesenchyme cells, descendants of the vegetal plate that delaminate from the coelomic epithelium at the end of gastrulation. In lithium-induced exogastrulae, where vegetal plate descendants evert rather than invaginate, myogenesis occurs normally, indicating that myocyte progenitors do not have to be near the future stomodeum for differentiation to occur. Vegetal plate descendants isolated along with the extracellular matrix at different times during gastrulation produce differentiated myocytes in culture as monitored by staining with a myosin heavy chain antibody. Vegetal isolates prepared at mid-gastrulation or later consistently produce differentiated myocytes whose form and position resembled their counterparts in the intact embryo, whereas vegetal isolates prepared a few hours earlier while capable of gut differentiation, as evidenced by the de novo synthesis of the endodermal surface marker Endo 1, did not produce differentiated myocytes. These results suggest that sometime after early gastrulation, a subset of secondary mesenchyme cells are competent to differentiate into muscle cells. RNase protection assays showed that the accumulation of sea urchin myogenic factor (SUM-1) mRNA is likely to be coincident with the earliest demonstrable commitment of myogenic precursors. Premature expression of SUM-1 coding sequences in mesenchyme blastulae resulted in the activation of muscle-specific enhancer elements, demonstrating that SUM-1 can function precociously in the early embryo. However, SUM-1 expressed in this manner did not activate the endogenous MHC gene, nor induce premature or ectopic production of muscle cells.

  13. Vestibular evoked myogenic potential (VEMP) in patients with acoustic neuromas.

    PubMed

    Takeichi, N; Sakamoto, T; Fukuda, S; Inuyama, Y

    2001-05-01

    To study the utility of VEMP (vestibular-evoked myogenic potential) in the diagnosis of acoustic neuromas. Eighteen patients with unilateral acoustic neuromas were subjected to this study. Myogenic potential responding to loud click stimuli was recorded at ipsilateral sternocleidomastoid muscle. A normal range of VEMP was obtained from 20 controls. VEMP responses were compared with both, clinical symptoms and results of caloric tests. Thirteen out of 18 patients showed decreased responses of VEMP at the affected side. VEMP responses seemed to have little relation with dysequilibrium, spontaneous nystagmus, canal paresis and pure-tone hearing. VEMP is useful for detecting dysfunction of inferior vestibular nerve in patients with acoustic neuromas.

  14. PC-PLC/sphingomyelin synthase activity plays a central role in the development of myogenic tone in murine resistance arteries

    PubMed Central

    Zacharia, Joseph; Fairfax, Seth; Wier, Withrow Gil

    2015-01-01

    Myogenic tone is an intrinsic property of the vasculature that contributes to blood pressure control and tissue perfusion. Earlier investigations assigned a key role in myogenic tone to phospholipase C (PLC) and its products, inositol 1,4,5-trisphosphate (IP3) and diacylglycerol (DAG). Here, we used the PLC inhibitor, U-73122, and two other, specific inhibitors of PLC subtypes (PI-PLC and PC-PLC) to delineate the role of PLC in myogenic tone of pressurized murine mesenteric arteries. U-73122 inhibited depolarization-induced contractions (high external K+ concentration), thus confirming reports of nonspecific actions of U-73122 and its limited utility for studies of myogenic tone. Edelfosine, a specific inhibitor of PI-PLC, did not affect depolarization-induced contractions but modulated myogenic tone. Because PI-PLC produces IP3, we investigated the effect of blocking IP3 receptor-mediated Ca2+ release on myogenic tone. Incubation of arteries with xestospongin C did not affect tone, consistent with the virtual absence of Ca2+ waves in arteries with myogenic tone. D-609, an inhibitor of PC-PLC and sphingomyelin synthase, strongly inhibited myogenic tone and had no effect on depolarization-induced contraction. D-609 appeared to act by lowering cytoplasmic Ca2+ concentration to levels below those that activate contraction. Importantly, incubation of pressurized arteries with a membrane-permeable analog of DAG induced vasoconstriction. The results therefore mandate a reexamination of the signaling pathways activated by the Bayliss mechanism. Our results suggest that PI-PLC and IP3 are not required in maintaining myogenic tone, but DAG, produced by PC-PLC and/or SM synthase, is likely through multiple mechanisms to increase Ca2+ entry and promote vasoconstriction. PMID:25888510

  15. Myogenic Growth Factor Present in Skeletal Muscle is Purified by Heparin-Affinity Chromatography

    NASA Astrophysics Data System (ADS)

    Kardami, Elissavet; Spector, Dennis; Strohman, Richard C.

    1985-12-01

    A myogenic growth factor has been purified from a skeletal muscle, the anterior latissimus dorsi, of adult chickens. In the range of 1-10 ng, this factor stimulates DNA synthesis as well as protein and muscle-specific myosin accumulation in myogenic cell cultures. Purification is achieved through binding of the factor to heparin. The factor is distinct from transferrin and works synergistically with transferrin in stimulating myogenesis in vitro.

  16. Analysis of secondary structural elements in human microRNA hairpin precursors.

    PubMed

    Liu, Biao; Childs-Disney, Jessica L; Znosko, Brent M; Wang, Dan; Fallahi, Mohammad; Gallo, Steven M; Disney, Matthew D

    2016-03-01

    MicroRNAs (miRNAs) regulate gene expression by targeting complementary mRNAs for destruction or translational repression. Aberrant expression of miRNAs has been associated with various diseases including cancer, thus making them interesting therapeutic targets. The composite of secondary structural elements that comprise miRNAs could aid the design of small molecules that modulate their function. We analyzed the secondary structural elements, or motifs, present in all human miRNA hairpin precursors and compared them to highly expressed human RNAs with known structures and other RNAs from various organisms. Amongst human miRNAs, there are 3808 are unique motifs, many residing in processing sites. Further, we identified motifs in miRNAs that are not present in other highly expressed human RNAs, desirable targets for small molecules. MiRNA motifs were incorporated into a searchable database that is freely available. We also analyzed the most frequently occurring bulges and internal loops for each RNA class and found that the smallest loops possible prevail. However, the distribution of loops and the preferred closing base pairs were unique to each class. Collectively, we have completed a broad survey of motifs found in human miRNA precursors, highly expressed human RNAs, and RNAs from other organisms. Interestingly, unique motifs were identified in human miRNA processing sites, binding to which could inhibit miRNA maturation and hence function.

  17. Localized cyclic AMP-dependent protein kinase activity is required for myogenic cell fusion

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mukai, Atsushi; Hashimoto, Naohiro

    2008-01-15

    Multinucleated myotubes are formed by fusion of mononucleated myogenic progenitor cells (myoblasts) during terminal skeletal muscle differentiation. In addition, myoblasts fuse with myotubes, but terminally differentiated myotubes have not been shown to fuse with each other. We show here that an adenylate cyclase activator, forskolin, and other reagents that elevate intracellular cyclic AMP (cAMP) levels induced cell fusion between small bipolar myotubes in vitro. Then an extra-large myotube, designated a 'myosheet,' was produced by both primary and established mouse myogenic cells. Myotube-to-myotube fusion always occurred between the leading edge of lamellipodia at the polar end of one myotube and themore » lateral plasma membrane of the other. Forskolin enhanced the formation of lamellipodia where cAMP-dependent protein kinase (PKA) was accumulated. Blocking enzymatic activity or anchoring of PKA suppressed forskolin-enhanced lamellipodium formation and prevented fusion of multinucleated myotubes. Localized PKA activity was also required for fusion of mononucleated myoblasts. The present results suggest that localized PKA plays a pivotal role in the early steps of myogenic cell fusion, such as cell-to-cell contact/recognition through lamellipodium formation. Furthermore, the localized cAMP-PKA pathway might be involved in the specification of the fusion-competent areas of the plasma membrane in lamellipodia of myogenic cells.« less

  18. Neurogenic and myogenic motor patterns of rabbit proximal, mid, and distal colon.

    PubMed

    Dinning, P G; Costa, M; Brookes, S J; Spencer, N J

    2012-07-01

    The rabbit colon consists of four distinct regions. The motility of each region is controlled by myogenic and neurogenic mechanisms. Associating these mechanisms with specific motor patterns throughout all regions of the colon has not previously been achieved. Three sections of the colon (the proximal, mid, and distal colon) were removed from euthanized rabbits. The proximal colon consists of a triply teniated region and a single tenia region. Spatio-temporal maps were constructed from video recordings of colonic wall diameter, with associated intraluminal pressure recorded from the aboral end. Hexamethonium (100 μM) and tetrodotoxin (TTX; 0.6 μM) were used to inhibit neural activity. Four distinct patterns of motility were detected: 1 myogenic and 3 neurogenic. The myogenic activity consisted of circular muscle (CM) contractions (ripples) that occurred throughout the colon and propagated in both antegrade (anal) and retrograde (oral) directions. The neural activity of the proximal colon consisted of slowly (0.1 mm/s) propagating colonic migrating motor complexes, which were abolished by hexamethonium. These complexes were observed in the region of the proximal colon with a single band of tenia. In the distal colon, tetrodotoxin-sensitive, thus neurally mediated, but hexamethonium-resistant, peristaltic (anal) and antiperistaltic (oral) contractions were identified. The distinct patterns of neurogenic and myogenic motor activity recorded from isolated rabbit colon are specific to each anatomically distinct region. The regional specificity motor pattern is likely to facilitate orderly transit of colonic content from semi-liquid to solid composition of feces.

  19. Inhibition of connective tissue growth factor (CTGF/CCN2) expression decreases the survival and myogenic differentiation of human rhabdomyosarcoma cells.

    PubMed

    Croci, Stefania; Landuzzi, Lorena; Astolfi, Annalisa; Nicoletti, Giordano; Rosolen, Angelo; Sartori, Francesca; Follo, Matilde Y; Oliver, Noelynn; De Giovanni, Carla; Nanni, Patrizia; Lollini, Pier-Luigi

    2004-03-01

    Connective tissue growth factor (CTGF/CCN2), a cysteine-rich protein of the CCN (Cyr61, CTGF, Nov) family of genes, emerged from a microarray screen of genes expressed by human rhabdomyosarcoma cells. Rhabdomyosarcoma is a soft tissue sarcoma of childhood deriving from skeletal muscle cells. In this study, we investigated the role of CTGF in rhabdomyosarcoma. Human rhabdomyosarcoma cells of the embryonal (RD/12, RD/18, CCA) and the alveolar histotype (RMZ-RC2, SJ-RH4, SJ-RH30), rhabdomyosarcoma tumor specimens, and normal skeletal muscle cells expressed CTGF. To determine the function of CTGF, we treated rhabdomyosarcoma cells with a CTGF antisense oligonucleotide or with a CTGF small interfering RNA (siRNA). Both treatments inhibited rhabdomyosarcoma cell growth, suggesting the existence of a new autocrine loop based on CTGF. CTGF antisense oligonucleotide-mediated growth inhibition was specifically due to a significant increase in apoptosis, whereas cell proliferation was unchanged. CTGF antisense oligonucleotide induced a strong decrease in the level of myogenic differentiation of rhabdomyosarcoma cells, whereas the addition of recombinant CTGF significantly increased the proportion of myosin-positive cells. CTGF emerges as a survival and differentiation factor and could be a new therapeutic target in human rhabdomyosarcoma.

  20. Formation and Human Risk of Carcinogenic Heterocyclic Amines Formed from Natural Precursors in Meat

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Knize, M G; Felton, J S

    2004-11-22

    A group of heterocyclic amines that are mutagens and rodent carcinogens form when meat is cooked to medium and well-done states. The precursors of these compounds are natural meat components: creatinine, amino acids and sugars. Defined model systems of dry-heated precursors mimic the amounts and proportions of heterocyclic amines found in meat. Results from model systems and cooking experiments suggest ways to reduce their formation and, thus, to reduce human intake. Human cancer epidemiology studies related to consumption of well-done meat products are listed and compared.

  1. Generation, Release, and Uptake of the NAD Precursor Nicotinic Acid Riboside by Human Cells.

    PubMed

    Kulikova, Veronika; Shabalin, Konstantin; Nerinovski, Kirill; Dölle, Christian; Niere, Marc; Yakimov, Alexander; Redpath, Philip; Khodorkovskiy, Mikhail; Migaud, Marie E; Ziegler, Mathias; Nikiforov, Andrey

    2015-11-06

    NAD is essential for cellular metabolism and has a key role in various signaling pathways in human cells. To ensure proper control of vital reactions, NAD must be permanently resynthesized. Nicotinamide and nicotinic acid as well as nicotinamide riboside (NR) and nicotinic acid riboside (NAR) are the major precursors for NAD biosynthesis in humans. In this study, we explored whether the ribosides NR and NAR can be generated in human cells. We demonstrate that purified, recombinant human cytosolic 5'-nucleotidases (5'-NTs) CN-II and CN-III, but not CN-IA, can dephosphorylate the mononucleotides nicotinamide mononucleotide and nicotinic acid mononucleotide (NAMN) and thus catalyze NR and NAR formation in vitro. Similar to their counterpart from yeast, Sdt1, the human 5'-NTs require high (millimolar) concentrations of nicotinamide mononucleotide or NAMN for efficient catalysis. Overexpression of FLAG-tagged CN-II and CN-III in HEK293 and HepG2 cells resulted in the formation and release of NAR. However, NAR accumulation in the culture medium of these cells was only detectable under conditions that led to increased NAMN production from nicotinic acid. The amount of NAR released from cells engineered for increased NAMN production was sufficient to maintain viability of surrounding cells unable to use any other NAD precursor. Moreover, we found that untransfected HeLa cells produce and release sufficient amounts of NAR and NR under normal culture conditions. Collectively, our results indicate that cytosolic 5'-NTs participate in the conversion of NAD precursors and establish NR and NAR as integral constituents of human NAD metabolism. In addition, they point to the possibility that different cell types might facilitate each other's NAD supply by providing alternative precursors. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  2. Generation, Release, and Uptake of the NAD Precursor Nicotinic Acid Riboside by Human Cells*

    PubMed Central

    Kulikova, Veronika; Shabalin, Konstantin; Nerinovski, Kirill; Dölle, Christian; Niere, Marc; Yakimov, Alexander; Redpath, Philip; Khodorkovskiy, Mikhail; Migaud, Marie E.; Ziegler, Mathias; Nikiforov, Andrey

    2015-01-01

    NAD is essential for cellular metabolism and has a key role in various signaling pathways in human cells. To ensure proper control of vital reactions, NAD must be permanently resynthesized. Nicotinamide and nicotinic acid as well as nicotinamide riboside (NR) and nicotinic acid riboside (NAR) are the major precursors for NAD biosynthesis in humans. In this study, we explored whether the ribosides NR and NAR can be generated in human cells. We demonstrate that purified, recombinant human cytosolic 5′-nucleotidases (5′-NTs) CN-II and CN-III, but not CN-IA, can dephosphorylate the mononucleotides nicotinamide mononucleotide and nicotinic acid mononucleotide (NAMN) and thus catalyze NR and NAR formation in vitro. Similar to their counterpart from yeast, Sdt1, the human 5′-NTs require high (millimolar) concentrations of nicotinamide mononucleotide or NAMN for efficient catalysis. Overexpression of FLAG-tagged CN-II and CN-III in HEK293 and HepG2 cells resulted in the formation and release of NAR. However, NAR accumulation in the culture medium of these cells was only detectable under conditions that led to increased NAMN production from nicotinic acid. The amount of NAR released from cells engineered for increased NAMN production was sufficient to maintain viability of surrounding cells unable to use any other NAD precursor. Moreover, we found that untransfected HeLa cells produce and release sufficient amounts of NAR and NR under normal culture conditions. Collectively, our results indicate that cytosolic 5′-NTs participate in the conversion of NAD precursors and establish NR and NAR as integral constituents of human NAD metabolism. In addition, they point to the possibility that different cell types might facilitate each other's NAD supply by providing alternative precursors. PMID:26385918

  3. Postmitotic Expression of SOD1G93A Gene Affects the Identity of Myogenic Cells and Inhibits Myoblasts Differentiation

    PubMed Central

    Martini, Martina; Dobrowolny, Gabriella; Aucello, Michela; Musarò, Antonio

    2015-01-01

    To determine the role of mutant SOD1 gene (SOD1G93A) on muscle cell differentiation, we derived C2C12 muscle cell lines carrying a stably transfected SOD1G93A gene under the control of a myosin light chain (MLC) promoter-enhancer cassette. Expression of MLC/SOD1G93A in C2C12 cells resulted in dramatic inhibition of myoblast differentiation. Transfected SOD1G93A gene expression in postmitotic skeletal myocytes downregulated the expression of relevant markers of committed and differentiated myoblasts such as MyoD, Myogenin, MRF4, and the muscle specific miRNA expression. The inhibitory effects of SOD1G93A gene on myogenic program perturbed Akt/p70 and MAPK signaling pathways which promote differentiation cascade. Of note, the inhibition of the myogenic program, by transfected SOD1G93A gene expression, impinged also the identity of myogenic cells. Expression of MLC/SOD1G93A in C2C12 myogenic cells promoted a fibro-adipogenic progenitors (FAPs) phenotype, upregulating HDAC4 protein and preventing the myogenic commitment complex BAF60C-SWI/SNF. We thus identified potential molecular mediators of the inhibitory effects of SOD1G93A on myogenic program and disclosed potential signaling, activated by SOD1G93A, that affect the identity of the myogenic cell population. PMID:26491230

  4. Postmitotic Expression of SOD1(G93A) Gene Affects the Identity of Myogenic Cells and Inhibits Myoblasts Differentiation.

    PubMed

    Martini, Martina; Dobrowolny, Gabriella; Aucello, Michela; Musarò, Antonio

    2015-01-01

    To determine the role of mutant SOD1 gene (SOD1(G93A)) on muscle cell differentiation, we derived C2C12 muscle cell lines carrying a stably transfected SOD1(G93A) gene under the control of a myosin light chain (MLC) promoter-enhancer cassette. Expression of MLC/SOD1(G93A) in C2C12 cells resulted in dramatic inhibition of myoblast differentiation. Transfected SOD1(G93A) gene expression in postmitotic skeletal myocytes downregulated the expression of relevant markers of committed and differentiated myoblasts such as MyoD, Myogenin, MRF4, and the muscle specific miRNA expression. The inhibitory effects of SOD1(G93A) gene on myogenic program perturbed Akt/p70 and MAPK signaling pathways which promote differentiation cascade. Of note, the inhibition of the myogenic program, by transfected SOD1(G93A) gene expression, impinged also the identity of myogenic cells. Expression of MLC/SOD1(G93A) in C2C12 myogenic cells promoted a fibro-adipogenic progenitors (FAPs) phenotype, upregulating HDAC4 protein and preventing the myogenic commitment complex BAF60C-SWI/SNF. We thus identified potential molecular mediators of the inhibitory effects of SOD1(G93A) on myogenic program and disclosed potential signaling, activated by SOD1(G93A), that affect the identity of the myogenic cell population.

  5. Mapping the vestibular evoked myogenic potential (VEMP).

    PubMed

    Colebatch, James G

    2012-01-01

    Effects of different electrode placements and indifferent electrodes were investigated for the vestibular evoked myogenic potential (VEMP) recorded from the sternocleidomastoid muscle (SCM). In 5 normal volunteers, the motor point of the left SCM was identified and an electrode placed there. A grid of 7 additional electrodes was laid out, along and across the SCM, based upon the location of the motor point. One reference electrode was placed over the sternoclavicular joint and another over C7. There were clear morphological changes with differing recording sites and for the two reference electrodes, but the earliest and largest responses were recorded from the motor point. The C7 reference affected the level of rectified EMG and was associated with an initial negativity in some electrodes. The latencies of the p13 potentials increased with distance from the motor point but the n23 latencies did not. Thus the p13 potential behaved as a travelling wave whereas the n23 behaved as a standing wave. The C7 reference may be contaminated by other evoked myogenic activity. Ideally recordings should be made with an active electrode over the motor point.

  6. Identification of myogenic-endothelial progenitor cells in the interstitial spaces of skeletal muscle.

    PubMed

    Tamaki, Tetsuro; Akatsuka, Akira; Ando, Kiyoshi; Nakamura, Yoshihiko; Matsuzawa, Hideyuki; Hotta, Tomomitsu; Roy, Roland R; Edgerton, V Reggie

    2002-05-13

    Putative myogenic and endothelial (myo-endothelial) cell progenitors were identified in the interstitial spaces of murine skeletal muscle by immunohistochemistry and immunoelectron microscopy using CD34 antigen. Enzymatically isolated cells were characterized by fluorescence-activated cell sorting on the basis of cell surface antigen expression, and were sorted as a CD34+ and CD45- fraction. Cells in this fraction were approximately 94% positive for Sca-1, and mostly negative (<3% positive) for CD14, 31, 49, 144, c-kit, and FLK-1. The CD34+/45- cells formed colonies in clonal cell cultures and colony-forming units displayed the potential to differentiate into adipocytes, endothelial, and myogenic cells. The CD34+/45- cells fully differentiated into vascular endothelial cells and skeletal muscle fibers in vivo after transplantation. Immediately after sorting, CD34+/45- cells expressed only c-met mRNA, and did not express any other myogenic cell-related markers such as MyoD, myf-5, myf-6, myogenin, M-cadherin, Pax-3, and Pax-7. However, after 3 d of culture, these cells expressed mRNA for all myogenic markers. CD34+/45- cells were distinct from satellite cells, as they expressed Bcrp1/ABCG2 gene mRNA (Zhou et al., 2001). These findings suggest that myo-endothelial progenitors reside in the interstitial spaces of mammalian skeletal muscles, and that they can potentially contribute to postnatal skeletal muscle growth.

  7. * Tissue-Specific Extracellular Matrix Enhances Skeletal Muscle Precursor Cell Expansion and Differentiation for Potential Application in Cell Therapy.

    PubMed

    Zhang, Deying; Zhang, Yong; Zhang, Yuanyuan; Yi, Hualin; Wang, Zhan; Wu, Rongpei; He, Dawei; Wei, Guanghui; Wei, Shicheng; Hu, Yun; Deng, Junhong; Criswell, Tracy; Yoo, James; Zhou, Yu; Atala, Anthony

    2017-08-01

    Skeletal muscle precursor cells (MPCs) are considered a key candidate for cell therapy in the treatment of skeletal muscle dysfunction due to injury, disease, or age. However, expansion of a sufficient number of functional skeletal muscle cells in vitro from a small tissue biopsy has been challenging due to changes in phenotypic expression of these cells under traditional culture conditions. Thus, the aim of the study was to develop a better culture system for the expansion and myo-differentiation of MPCs that could further be used for therapy. For this purpose, we developed an ideal method of tissue decellularization and compared the ability of different matrices to support MPC growth and differentiation. Porcine-derived skeletal muscle and liver and kidney extracellular matrix (ECM) were generated by decellularization methods consisting of distilled water, 0.2 mg/mL DNase, or 5% fetal bovine serum. Acellular matrices were further homogenized, dissolved, and combined with a hyaluronic acid-based hydrogel decorated with heparin (ECM-HA-HP). The cell proliferation and myogenic differentiation capacity of human MPCs were assessed when grown on gel alone, ECM, or each ECM-HA-HP substrate. Human MPC proliferation was significantly enhanced when cultured on the ECM-HA-HP substrates compared to the other substrates tested, with the greatest proliferation on the muscle ECM-HA-HP (mECM-HA-HP) substrate. The number of differentiated myotubes was significantly increased on the mECM-HA-HP substrate compared to the other gel-ECM substrates, as well as the numbers of MPCs expressing specific myogenic cell markers (i.e., myosin, desmin, myoD, and myf5). In conclusion, skeletal mECM-HA-HP as a culture substrate provided an optimal culture microenvironment potentially due to its similarity to the in vivo environment. These data suggest a potential use of skeletal muscle-derived ECM gel for the expansion and differentiation of human MPCs for cell-based therapy for skeletal muscle

  8. A nonlinear model for myogenic regulation of blood flow to bone: equilibrium states and stability characteristics.

    PubMed

    Harrigan, T P

    1996-01-01

    A simple compartmental model for myogenic regulation of interstitial pressure in bone is developed, and the interaction between changes in interstitial pressure and changes in arterial and venous resistance is studied. The arterial resistance is modeled by a myogenic model that depends on transmural pressure, and the venous resistance is modeled by using a vascular waterfall. Two series capacitances model blood storage in the vascular system and interstitial fluid storage in the extravascular space. The static results mimic the observed effect that vasodilators work less well in bone than do vasoconstrictors. The static results also show that the model gives constant flow rates over a limited range of arterial pressure. The dynamic model shows unstable behavior at small values of bony capacitance and at high enough myogenic gain. At low myogenic gain, only a single equilibrium state is present, but a high enough myogenic gain, two new equilibrium states appear. At additional increases in gain, one of the two new states merges with and then separates from the original state, and the original state becomes a saddle point. The appearance of the new states and the transition of the original state to a saddle point do not depend on the bony capacitance, and these results are relevant to general fluid compartments. Numerical integration of the rate equations confirms the stability calculations and shows limit cycling behavior in several situations. The relevance of this model to circulation in bone and to other compartments is discussed.

  9. Placental Ischemia Impairs Middle Cerebral Artery Myogenic Responses in the Pregnant Rat

    PubMed Central

    Ryan, Michael J.; Gilbert, Emily L.; Glover, Porter H.; George, Eric M.; Masterson, C. Warren; McLemore, Gerald R.; LaMarca, Babbette; Granger, Joey P.; Drummond, Heather A.

    2011-01-01

    One potential mechanism contributing to the increased risk for encephalopathies in women with preeclampsia is altered cerebral vascular autoregulation resulting from impaired myogenic tone. Whether placental ischemia, a commonly proposed initiator of preeclampsia, alters cerebral vascular function is unknown. This study tested the hypothesis that placental ischemia in pregnant rats (induced by reducing uterine perfusion pressure, RUPP) leads to impaired myogenic responses in middle cerebral arteries (MCA). Mean arterial pressure (in mmHg) was increased by RUPP (135±3) compared with normal pregnant rats (NP, 103±2) and non-pregnant controls (Ctrl, 116±1). MCA from rats sacrificed on gestation day 19 were assessed in a pressure ateriograph under active (+ Ca2+) and passive (0 Ca2+) conditions while luminal pressure was varied between 25 and 150 mmHg. The slope of the relationship between tone and pressure in the MCA was 0.08±0.01 in CTRL rats and was similar in NP rats (0.05±0.01). In the RUPP model of placental ischemia, this relationship was markedly reduced (slope = 0.01±0.00, p<0.05). Endothelial dependent and independent dilation was not different between groups nor was there evidence of vascular remodeling assessed by the wall:lumen ratio and calculated wall stress. The impaired myogenic response associated with brain edema measured by % water content (RUPP p<0.05 vs. CTRL and NP). This study demonstrates that placental ischemia in pregnant rats leads to impaired myogenic tone in the MCA and that the RUPP model is a potentially important tool to examine mechanisms leading to encephalopathy during preeclamptic pregnancies. PMID:22068864

  10. Bone morphogenic protein-2 regulates the myogenic differentiation of PMVECs in CBDL rat serum-induced pulmonary microvascular remodeling

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Liu, Chang; Chen, Lin; Zeng, Jing

    Hepatopulmonary syndrome (HPS) is characterized by an arterial oxygenation defect induced by intrapulmonary vasodilation (IPVD) that increases morbidity and mortality. In our previous study, it was determined that both the proliferation and the myogenic differentiation of pulmonary microvascular endothelial cells (PMVECs) play a key role in the development of IPVD. However, the molecular mechanism underlying the relationship between IPVD and the myogenic differentiation of PMVECs remains unknown. Additionally, it has been shown that bone morphogenic protein-2 (BMP2), via the control of protein expression, may regulate cell differentiation including cardiomyocyte differentiation, neuronal differentiation and odontoblastic differentiation. In this study, we observedmore » that common bile duct ligation (CBDL)-rat serum induced the upregulation of the expression of several myogenic proteins (SM-α-actin, calponin, SM-MHC) and enhanced the expression levels of BMP2 mRNA and protein in PMVECs. We also observed that both the expression levels of Smad1/5 and the activation of phosphorylated Smad1/5 were significantly elevated in PMVECs following exposure to CBDL-rat serum, which was accompanied by the down-regulation of Smurf1. The blockage of the BMP2/Smad signaling pathway with Noggin inhibited the myogenic differentiation of PMVECs, a process that was associated with relatively low expression levels of both SM-α-actin and calponin in the setting of CBDL-rat serum exposure, although SM-MHC expression was not affected. These findings suggested that the BMP2/Smad signaling pathway is involved in the myogenic differentiation of the PMVECs. In conclusion, our data highlight the pivotal role of BMP2 in the CBDL-rat serum-induced myogenic differentiation of PMVECs via the activation of both Smad1 and Smad5 and the down-regulation of Smurf1, which may represent a potential therapy for HPS-induced pulmonary vascular remodeling. - Highlights: • CBDL-rat serum promotes the

  11. Anatomical location of LPA1 activation and LPA phospholipid precursors in rodent and human brain.

    PubMed

    González de San Román, Estibaliz; Manuel, Iván; Giralt, María Teresa; Chun, Jerold; Estivill-Torrús, Guillermo; Rodríguez de Fonseca, Fernando; Santín, Luis Javier; Ferrer, Isidro; Rodríguez-Puertas, Rafael

    2015-08-01

    Lysophosphatidic acid (LPA) is a signaling molecule that binds to six known G protein-coupled receptors: LPA1 -LPA6 . LPA evokes several responses in the CNS, including cortical development and folding, growth of the axonal cone and its retraction process. Those cell processes involve survival, migration, adhesion proliferation, differentiation, and myelination. The anatomical localization of LPA1 is incompletely understood, particularly with regard to LPA binding. Therefore, we have used functional [(35) S]GTPγS autoradiography to verify the anatomical distribution of LPA1 binding sites in adult rodent and human brain. The greatest activity was observed in myelinated areas of the white matter such as corpus callosum, internal capsule and cerebellum. MaLPA1 -null mice (a variant of LPA1 -null) lack [(35) S]GTPγS basal binding in white matter areas, where the LPA1 receptor is expressed at high levels, suggesting a relevant role of the activity of this receptor in the most myelinated brain areas. In addition, phospholipid precursors of LPA were localized by MALDI-IMS in both rodent and human brain slices identifying numerous species of phosphatides and phosphatidylcholines. Both phosphatides and phosphatidylcholines species represent potential LPA precursors. The anatomical distribution of these precursors in rodent and human brain may indicate a metabolic relationship between LPA and LPA1 receptors. Lysophosphatidic acid (LPA) is a signaling molecule that binds to six known G protein-coupled receptors (GPCR), LPA1 to LPA6 . LPA evokes several responses in the central nervous system (CNS), including cortical development and folding, growth of the axonal cone and its retraction process. We used functional [(35) S]GTPγS autoradiography to verify the anatomical distribution of LPA1 -binding sites in adult rodent and human brain. The distribution of LPA1 receptors in rat, mouse and human brains show the highest activity in white matter myelinated areas. The basal and

  12. Estimating human exposure to PFOS isomers and PFCA homologues: the relative importance of direct and indirect (precursor) exposure.

    PubMed

    Gebbink, Wouter A; Berger, Urs; Cousins, Ian T

    2015-01-01

    Contributions of direct and indirect (via precursors) pathways of human exposure to perfluorooctane sulfonic acid (PFOS) isomers and perfluoroalkyl carboxylic acids (PFCAs) are estimated using a Scenario-Based Risk Assessment (SceBRA) modelling approach. Monitoring data published since 2008 (including samples from 2007) are used. The estimated daily exposures (resulting from both direct and precursor intake) for the general adult population are highest for PFOS and perfluorooctanoic acid (PFOA), followed by perfluorohexanoic acid (PFHxA) and perfluorodecanoic acid (PFDA), while lower daily exposures are estimated for perfluorobutanoic acid (PFBA) and perfluorododecanoic acid (PFDoDA). The precursor contributions to the individual perfluoroalkyl acid (PFAA) daily exposures are estimated to be 11-33% for PFOS, 0.1-2.5% for PFBA, 3.7-34% for PFHxA, 13-64% for PFOA, 5.2-66% for PFDA, and 0.7-25% for PFDoDA (ranges represent estimated precursor contributions in a low- and high-exposure scenario). For PFOS, direct intake via diet is the major exposure pathway regardless of exposure scenario. For PFCAs, the dominant exposure pathway is dependent on perfluoroalkyl chain length and exposure scenario. Modelled PFOS and PFOA concentrations in human serum using the estimated intakes from an intermediate-exposure scenario are in agreement with measured concentrations in different populations. The isomer pattern of PFOS resulting from total intakes (direct and via precursors) is estimated to be enriched with linear PFOS (84%) relative to technical PFOS (70% linear). This finding appears to be contradictory to the observed enrichment of branched PFOS isomers in recent human serum monitoring studies and suggests that either external exposure is not fully understood (e.g. there are unknown precursors, missing or poorly quantified exposure pathways) and/or that there is an incomplete understanding of the isomer-specific human pharmacokinetic processes of PFOS, its precursors and

  13. TMEM16A Channels Contribute to the Myogenic Response in Cerebral Arteries

    PubMed Central

    Bulley, Simon; Neeb, Zachary P.; Burris, Sarah K.; Bannister, John P.; Thomas-Gatewood, Candice M.; Jangsangthong, Wanchana; Jaggar, Jonathan H.

    2013-01-01

    Rationale Pressure-induced arterial depolarization and constriction (the myogenic response), is a smooth muscle cell (myocyte)-specific mechanism that controls regional organ blood flow and systemic blood pressure. Several different non-selective cation channels contribute to pressure-induced depolarization, but signaling mechanisms involved are unclear. Similarly uncertain is the contribution of anion channels to the myogenic response and physiological functions and mechanisms of regulation of recently discovered transmembrane 16A (TMEM16A) chloride (Cl−) channels in arterial myocytes. Objective Investigate the hypothesis that myocyte TMEM16A channels control membrane potential and contractility and contribute to the myogenic response in cerebral arteries. Methods and Results Cell swelling induced by hyposmotic bath solution stimulated Cl− currents in arterial myocytes that were blocked by TMEM16A channel inhibitory antibodies, RNAi-mediated selective TMEM16A channel knockdown, removal of extracellular calcium (Ca2+), replacement of intracellular EGTA with BAPTA, a fast Ca2+ chelator, and Gd3+ and SKF-96365, non-selective cation channel blockers. In contrast, nimodipine, a voltage-dependent Ca2+ channel inhibitor, or thapsigargin, which depletes intracellular Ca2+ stores, did not alter swelling-activated TMEM16A currents. Pressure (−40 mmHg)-induced membrane stretch activated ion channels in arterial myocyte cell-attached patches that were inhibited by TMEM16A antibodies and were of similar amplitude to recombinant TMEM16A channels. TMEM16A knockdown reduced intravascular pressure-induced depolarization and vasoconstriction, but did not alter depolarization (60 mmol/L K+)-induced vasoconstriction. Conclusions Membrane stretch activates arterial myocyte TMEM16A channels, leading to membrane depolarization and vasoconstriction. Data also provide a mechanism by which a local Ca2+ signal generated by non-selective cation channels stimulates TMEM16A channels to

  14. Effect of caffeine on vestibular evoked myogenic potential: a systematic review with meta-analysis.

    PubMed

    Souza, Maria Eduarda Di Cavalcanti Alves de; Costa, Klinger Vagner Teixeira da; Menezes, Pedro de Lemos

    2017-12-24

    Caffeine can be considered the most consumed drug by adults worldwide, and can be found in several foods, such as chocolate, coffee, tea, soda and others. Overall, caffeine in moderate doses, results in increased physical and intellectual productivity, increases the capacity of concentration and reduces the time of reaction to sensory stimuli. On the other hand, high doses can cause noticeable signs of mental confusion and error induction in intellectual tasks, anxiety, restlessness, muscle tremors, tachycardia, labyrinthine changes, and tinnitus. Considering that the vestibular evoked myogenic potential is a clinical test that evaluates the muscular response of high intensity auditory stimulation, the present systematic review aimed to analyze the effects of caffeine on vestibular evoked myogenic potential. This study consisted of the search of the following databases: MEDLINE, CENTRAL, ScienceDirect, Scopus, Web of Science, LILACS, SciELO and ClinicalTrials.gov. Additionally, the gray literature was also searched. The search strategy included terms related to intervention (caffeine or coffee consumption) and the primary outcome (vestibular evoked myogenic potential). Based on the 253 potentially relevant articles identified through the database search, only two full-text publications were retrieved for further evaluation, which were maintained for qualitative analysis. Analyzing the articles found, caffeine has no effect on vestibular evoked myogenic potential in normal individuals. Copyright © 2017 Associação Brasileira de Otorrinolaringologia e Cirurgia Cérvico-Facial. Published by Elsevier Editora Ltda. All rights reserved.

  15. Redox Signaling via Oxidative Inactivation of PTEN Modulates Pressure-Dependent Myogenic Tone in Rat Middle Cerebral Arteries

    PubMed Central

    Gebremedhin, Debebe; Terashvili, Maia; Wickramasekera, Nadi; Zhang, David X.; Rau, Nicole; Miura, Hiroto; Harder, David R.

    2013-01-01

    The present study examined the level of generation of reactive oxygen species (ROS) and roles of inactivation of the phosphatase PTEN and the PI3K/Akt signaling pathway in response to an increase in intramural pressure-induced myogenic cerebral arterial constriction. Step increases in intraluminal pressure of cannulated cerebral arteries induced myogenic constriction and concomitant formation of superoxide (O2 .−) and its dismutation product hydrogen peroxide (H2O2) as determined by fluorescent HPLC analysis, microscopic analysis of intensity of dihydroethidium fluorescence and attenuation of pressure-induced myogenic constriction by pretreatment with the ROS scavenger 4,hydroxyl-2,2,6,6-tetramethylpiperidine1-oxyl (tempol) or Mito-tempol or MitoQ in the presence or absence of PEG-catalase. An increase in intraluminal pressure induced oxidation of PTEN and activation of Akt. Pharmacological inhibition of endogenous PTEN activity potentiated pressure-dependent myogenic constriction and caused a reduction in NPo of a 238 pS arterial KCa channel current and an increase in [Ca2+]i level in freshly isolated cerebral arterial muscle cells (CAMCs), responses that were attenuated by Inhibition of the PI3K/Akt pathway. These findings demonstrate an increase in intraluminal pressure induced increase in ROS production triggered redox-sensitive signaling mechanism emanating from the cross-talk between oxidative inactivation of PTEN and activation of the PI3K/Akt signaling pathway that involves in the regulation of pressure-dependent myogenic cerebral arterial constriction. PMID:23861911

  16. Redox signaling via oxidative inactivation of PTEN modulates pressure-dependent myogenic tone in rat middle cerebral arteries.

    PubMed

    Gebremedhin, Debebe; Terashvili, Maia; Wickramasekera, Nadi; Zhang, David X; Rau, Nicole; Miura, Hiroto; Harder, David R

    2013-01-01

    The present study examined the level of generation of reactive oxygen species (ROS) and roles of inactivation of the phosphatase PTEN and the PI3K/Akt signaling pathway in response to an increase in intramural pressure-induced myogenic cerebral arterial constriction. Step increases in intraluminal pressure of cannulated cerebral arteries induced myogenic constriction and concomitant formation of superoxide (O2 (.-)) and its dismutation product hydrogen peroxide (H2O2) as determined by fluorescent HPLC analysis, microscopic analysis of intensity of dihydroethidium fluorescence and attenuation of pressure-induced myogenic constriction by pretreatment with the ROS scavenger 4,hydroxyl-2,2,6,6-tetramethylpiperidine1-oxyl (tempol) or Mito-tempol or MitoQ in the presence or absence of PEG-catalase. An increase in intraluminal pressure induced oxidation of PTEN and activation of Akt. Pharmacological inhibition of endogenous PTEN activity potentiated pressure-dependent myogenic constriction and caused a reduction in NPo of a 238 pS arterial KCa channel current and an increase in [Ca(2+)]i level in freshly isolated cerebral arterial muscle cells (CAMCs), responses that were attenuated by Inhibition of the PI3K/Akt pathway. These findings demonstrate an increase in intraluminal pressure induced increase in ROS production triggered redox-sensitive signaling mechanism emanating from the cross-talk between oxidative inactivation of PTEN and activation of the PI3K/Akt signaling pathway that involves in the regulation of pressure-dependent myogenic cerebral arterial constriction.

  17. Myogenic nature of insect heartbeat and intestinal peristalsis, revealed by neuromuscular paralysis caused by the sting of a braconid wasp.

    PubMed

    Sláma, Karel; Lukáš, Jan

    2011-02-01

    Larvae of the greater waxmoth (Galleria mellonella) become paralysed by the venom of the braconid wasp (Habrobracon hebetor) a few minutes after intoxication. The profound neuromuscular paralysis, which may last for several weeks, includes all somatic muscles that are innervated through neuromuscular transmission. The peristaltic contractions of the heart and intestine, which are regulated by the depolarisation potentials of the myocardium or intestinal epithelial muscles, remain unaffected and fully functional. Heartbeat patterns and intestinal pulsations were monitored in the motionless, paralysed larvae by means of advanced electrocardiographic recording methods (contact thermography, pulse-light optocardiography). The records revealed more or less constant cardiac pulsations characterised by 20-25 systolic contractions per minute. The contractions were peristaltically propagated in the forward (anterograde) direction, with a more or less constant speed of 10mm per second (23-25°C). Additional electrocardiographic investigations on larvae immobilised by decapitation revealed the autonomic (brain independent) nature of heartbeat regulation. Sectioning performed in the middle of the heart (4th abdominal segment) seriously impaired the pacemaker rhythmicity and slowed down the rate of heartbeat in the anterior sections. By contrast, the functions of the posterior compartments of the disconnected heart remained unaffected. These results confirmed our previous conclusions about the existence of an autonomic, myogenic, pacemaker nodus in the terminal part of an insect heart. They show an analogy to the similar myogenic, sinoatrial or atrioventricular nodi regulating rhythmicity of the human heart. Peristaltic contractions of the intestine also represent a purely myogenic system, which is fully functional in larvae with complete neuromuscular paralysis. Unlike the constant anterograde direction of the heartbeat, intestinal peristaltic waves periodically reversed

  18. Induction of Skin-Derived Precursor Cells from Human Induced Pluripotent Stem Cells.

    PubMed

    Sugiyama-Nakagiri, Yoriko; Fujimura, Tsutomu; Moriwaki, Shigeru

    2016-01-01

    The generation of full thickness human skin from dissociated cells is an attractive approach not only for treating skin diseases, but also for treating many systemic disorders. However, it is currently not possible to obtain an unlimited number of skin dermal cells. The goal of this study was to develop a procedure to produce skin dermal stem cells from induced pluripotent stem cells (iPSCs). Skin-derived precursor cells (SKPs) were isolated as adult dermal precursors that could differentiate into both neural and mesodermal progenies and could reconstitute the dermis. Thus, we attempted to generate SKPs from iPSCs that could reconstitute the skin dermis. Human iPSCs were initially cultured with recombinant noggin and SB431542, an inhibitor of activin/nodal and TGFβ signaling, to induce neural crest progenitor cells. Those cells were then treated with SKP medium that included CHIR99021, a WNT signal activator. The induction efficacy from neural crest progenitor cells to SKPs was more than 97%. No other modifiers tested were able to induce those cells. Those human iPSC-derived SKPs (hiPSC-SKPs) showed a similar gene expression signature to SKPs isolated from human skin dermis. Human iPSC-SKPs differentiated into neural and mesodermal progenies, including adipocytes, skeletogenic cell types and Schwann cells. Moreover, they could be induced to follicular type keratinization when co-cultured with human epidermal keratinocytes. We here provide a new efficient protocol to create human skin dermal stem cells from hiPSCs that could contribute to the treatment of various skin disorders.

  19. Platelet-Rich Plasma, Especially When Combined with a TGF-β Inhibitor Promotes Proliferation, Viability and Myogenic Differentiation of Myoblasts In Vitro

    PubMed Central

    Kelc, Robi; Trapecar, Martin; Gradisnik, Lidija; Rupnik, Marjan Slak; Vogrin, Matjaz

    2015-01-01

    Regeneration of skeletal muscle after injury is limited by scar formation, slow healing time and a high recurrence rate. A therapy based on platelet-rich plasma (PRP) has become a promising lead for tendon and ligament injuries in recent years, however concerns have been raised that PRP-derived TGF-β could contribute to fibrotic remodelling in skeletal muscle after injury. Due to the lack of scientific grounds for a PRP -based muscle regeneration therapy, we have designed a study using human myogenic progenitors and evaluated the potential of PRP alone and in combination with decorin (a TGF-β inhibitor), to alter myoblast proliferation, metabolic activity, cytokine profile and expression of myogenic regulatory factors (MRFs). Advanced imaging multicolor single-cell analysis enabled us to create a valuable picture on the ratio of quiescent, activated and terminally committed myoblasts in treated versus control cell populations. Finally high-resolution confocal microscopy validated the potential of PRP and decorin to stimulate the formation of polynucleated myotubules. PRP was shown to down-regulate fibrotic cytokines, increase cell viability and proliferation, enhance the expression of MRFs, and contribute to a significant myogenic shift during differentiation. When combined with decorin further synergistc effects were identified. These results suggest that PRP could not only prevent fibrosis but could also stimulate muscle commitment, especially when combined with a TGF-β inhibitor. PMID:25679956

  20. Vestibular evoked myogenic potentials (VEMPs) in central neurological disorders.

    PubMed

    Venhovens, J; Meulstee, J; Verhagen, W I M

    2016-01-01

    Several types of acoustic stimulation (i.e. tone bursts or clicks), bone-conducted vibration, forehead taps, and galvanic stimulation elicit myogenic potentials. These can be recorded in cervical and ocular muscles, the so called vestibular evoked myogenic potentials (VEMPs). The cervical VEMP (cVEMP) resembles the vestibulo-collic reflex and the responses can be recorded from the ipsilateral sternocleidomastoid muscle. The ocular VEMP resembles the vestibulo-ocular reflex and can be recorded from extra-ocular muscles by a surface electrode beneath the contralateral infraorbital margin. Initially, the literature concerning VEMPs was limited to peripheral vestibular disorders, however, the field of VEMP testing is rapidly expanding, with an increasing focus on central neurological disorders. The current literature concerning VEMP abnormalities in central neurological disorders is critically reviewed, especially regarding the methodological aspects in relation to quality as well as the clinical interpretation of the VEMP results. Suggestions for further research are proposed as well as some clinically useful indications. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  1. Enrichment of skin-derived neural precursor cells from dermal cell populations by altering culture conditions.

    PubMed

    Bayati, Vahid; Gazor, Rohoullah; Nejatbakhsh, Reza; Negad Dehbashi, Fereshteh

    2016-01-01

    As stem cells play a critical role in tissue repair, their manipulation for being applied in regenerative medicine is of great importance. Skin-derived precursors (SKPs) may be good candidates for use in cell-based therapy as the only neural stem cells which can be isolated from an accessible tissue, skin. Herein, we presented a simple protocol to enrich neural SKPs by monolayer adherent cultivation to prove the efficacy of this method. To enrich neural SKPs from dermal cell populations, we have found that a monolayer adherent cultivation helps to increase the numbers of neural precursor cells. Indeed, we have cultured dermal cells as monolayer under serum-supplemented (control) and serum-supplemented culture, followed by serum free cultivation (test) and compared. Finally, protein markers of SKPs were assessed and compared in both experimental groups and differentiation potential was evaluated in enriched culture. The cells of enriched culture concurrently expressed fibronectin, vimentin and nestin, an intermediate filament protein expressed in neural and skeletal muscle precursors as compared to control culture. In addition, they possessed a multipotential capacity to differentiate into neurogenic, glial, adipogenic, osteogenic and skeletal myogenic cell lineages. It was concluded that serum-free adherent culture reinforced by growth factors have been shown to be effective on proliferation of skin-derived neural precursor cells (skin-NPCs) and drive their selective and rapid expansion.

  2. Irisin is a pro-myogenic factor that induces skeletal muscle hypertrophy and rescues denervation-induced atrophy.

    PubMed

    Reza, Musarrat Maisha; Subramaniyam, Nathiya; Sim, Chu Ming; Ge, Xiaojia; Sathiakumar, Durgalakshmi; McFarlane, Craig; Sharma, Mridula; Kambadur, Ravi

    2017-10-24

    Exercise induces expression of the myokine irisin, which is known to promote browning of white adipose tissue and has been shown to mediate beneficial effects following exercise. Here we show that irisin induces expression of a number of pro-myogenic and exercise response genes in myotubes. Irisin increases myogenic differentiation and myoblast fusion via activation of IL6 signaling. Injection of irisin in mice induces significant hypertrophy and enhances grip strength of uninjured muscle. Following skeletal muscle injury, irisin injection improves regeneration and induces hypertrophy. The effects of irisin on hypertrophy are due to activation of satellite cells and enhanced protein synthesis. In addition, irisin injection rescues loss of skeletal muscle mass following denervation by enhancing satellite cell activation and reducing protein degradation. These data suggest that irisin functions as a pro-myogenic factor in mice.

  3. Isolation of Primary Human Skeletal Muscle Cells

    PubMed Central

    Spinazzola, Janelle M.; Gussoni, Emanuela

    2017-01-01

    Primary myoblast culture is a valuable tool in research of muscle disease, pathophysiology, and pharmacology. This protocol describes techniques for dissociation of cells from human skeletal muscle biopsies and enrichment for a highly myogenic population by fluorescence-activated cell sorting (FACS). We also describe methods for assessing myogenicity and population expansion for subsequent in vitro study. PMID:29152538

  4. High-resolution Myogenic Lineage Mapping by Single-Cell Mass Cytometry

    PubMed Central

    Porpiglia, Ermelinda; Samusik, Nikolay; Ho, Andrew Tri Van; Cosgrove, Benjamin D.; Mai, Thach; Davis, Kara L.; Jager, Astraea; Nolan, Garry P.; Bendall, Sean C.; Fantl, Wendy J.; Blau, Helen M.

    2017-01-01

    Muscle regeneration is a dynamic process during which cell state and identity change over time. A major roadblock has been a lack of tools to resolve a myogenic progression in vivo. Here we capitalize on a transformative technology, single-cell mass cytometry (CyTOF), to identify in vivo skeletal muscle stem cell and previously unrecognized progenitor populations that precede differentiation. We discovered two cell surface markers, CD9 and CD104, whose combined expression enabled in vivo identification and prospective isolation of stem and progenitor cells. Data analysis using the X-shift algorithm paired with single-cell force directed layout visualization, defined a molecular signature of the activated stem cell state (CD44+/CD98+/MyoD+) and delineated a myogenic trajectory during recovery from acute muscle injury. Our studies uncover the dynamics of skeletal muscle regeneration in vivo and pave the way for the elucidation of the regulatory networks that underlie cell-state transitions in muscle diseases and aging. PMID:28414312

  5. Role of T-type calcium channels in myogenic tone of skeletal muscle resistance arteries.

    PubMed

    VanBavel, Ed; Sorop, Oana; Andreasen, Ditte; Pfaffendorf, Martin; Jensen, Boye L

    2002-12-01

    T-type calcium channels may be involved in the maintenance of myogenic tone. We tested their role in isolated rat cremaster arterioles obtained after CO(2) anesthesia and decapitation. Total RNA was analyzed by RT-PCR and Southern blotting for calcium channel expression. We observed expression of voltage-operated calcium (Ca(V)) channels Ca(V)3.1 (T-type), Ca(V)3.2 (T-type), and Ca(V)1.2 (L-type) in cremaster arterioles (n = 3 rats). Amplification products were observed only in the presence of reverse transcriptase and cDNA. Concentration-response curves of the relatively specific L-type blocker verapamil and the relatively specific T-type blockers mibefradil and nickel were made on cannulated vessels with either myogenic tone (75 mmHg) or a similar level of constriction induced by 30 mM K(+) at 35 mmHg. Mibefradil and nickel were, respectively, 162-fold and 300-fold more potent in inhibiting myogenic tone compared with K(+)-induced constriction [log(IC(50), M): mibefradil, basal -7.3 +/- 0.2 (n = 9) and K(+) -5.1 +/- 0.1 (n = 5); nickel, basal -4.1 +/- 0.2 (n = 5) and K(+) -1.6 +/- 0.5 (n = 5); means +/- SE]. Verapamil had a 17-fold more potent effect [log(IC(50), M): basal -6.6 +/- 0.1 (n = 5); K(+) -5.4 +/- 0.3 (n = 4); all log(IC(50)) P < 0.05, basal vs. K(+)]. These data suggest that T-type calcium channels are expressed and involved in maintenance of myogenic tone in rat cremaster muscle arterioles.

  6. Defining the cellular precursors to human breast cancer

    PubMed Central

    Keller, Patricia J.; Arendt, Lisa M.; Skibinski, Adam; Logvinenko, Tanya; Klebba, Ina; Dong, Shumin; Smith, Avi E.; Prat, Aleix; Perou, Charles M.; Gilmore, Hannah; Schnitt, Stuart; Naber, Stephen P.; Garlick, Jonathan A.; Kuperwasser, Charlotte

    2012-01-01

    Human breast cancers are broadly classified based on their gene-expression profiles into luminal- and basal-type tumors. These two major tumor subtypes express markers corresponding to the major differentiation states of epithelial cells in the breast: luminal (EpCAM+) and basal/myoepithelial (CD10+). However, there are also rare types of breast cancers, such as metaplastic carcinomas, where tumor cells exhibit features of alternate cell types that no longer resemble breast epithelium. Until now, it has been difficult to identify the cell type(s) in the human breast that gives rise to these various forms of breast cancer. Here we report that transformation of EpCAM+ epithelial cells results in the formation of common forms of human breast cancer, including estrogen receptor-positive and estrogen receptor-negative tumors with luminal and basal-like characteristics, respectively, whereas transformation of CD10+ cells results in the development of rare metaplastic tumors reminiscent of the claudin-low subtype. We also demonstrate the existence of CD10+ breast cells with metaplastic traits that can give rise to skin and epidermal tissues. Furthermore, we show that the development of metaplastic breast cancer is attributable, in part, to the transformation of these metaplastic breast epithelial cells. These findings identify normal cellular precursors to human breast cancers and reveal the existence of a population of cells with epidermal progenitor activity within adult human breast tissues. PMID:21940501

  7. Human myostatin negatively regulates human myoblast growth and differentiation

    PubMed Central

    McFarlane, Craig; Hui, Gu Zi; Amanda, Wong Zhi Wei; Lau, Hiu Yeung; Lokireddy, Sudarsanareddy; XiaoJia, Ge; Mouly, Vincent; Butler-Browne, Gillian; Gluckman, Peter D.; Sharma, Mridula

    2011-01-01

    Myostatin, a member of the transforming growth factor-β superfamily, has been implicated in the potent negative regulation of myogenesis in murine models. However, little is known about the mechanism(s) through which human myostatin negatively regulates human skeletal muscle growth. Using human primary myoblasts and recombinant human myostatin protein, we show here that myostatin blocks human myoblast proliferation by regulating cell cycle progression through targeted upregulation of p21. We further show that myostatin regulates myogenic differentiation through the inhibition of key myogenic regulatory factors including MyoD, via canonical Smad signaling. In addition, we have for the first time demonstrated the capability of myostatin to regulate the Notch signaling pathway during inhibition of human myoblast differentiation. Treatment with myostatin results in the upregulation of Hes1, Hes5, and Hey1 expression during differentiation; moreover, when we interfere with Notch signaling, through treatment with the γ-secretase inhibitor L-685,458, we find enhanced myotube formation despite the presence of excess myostatin. Therefore, blockade of the Notch pathway relieves myostatin repression of differentiation, and myostatin upregulates Notch downstream target genes. Immunoprecipitation studies demonstrate that myostatin treatment of myoblasts results in enhanced association of Notch1-intracellular domain with Smad3, providing an additional mechanism through which myostatin targets and represses the activity of the myogenic regulatory factor MyoD. On the basis of these results, we suggest that myostatin function and mechanism of action are very well conserved between species, and that myostatin regulation of postnatal myogenesis involves interactions with numerous downstream signaling mediators, including the Notch pathway. PMID:21508334

  8. Human myostatin negatively regulates human myoblast growth and differentiation.

    PubMed

    McFarlane, Craig; Hui, Gu Zi; Amanda, Wong Zhi Wei; Lau, Hiu Yeung; Lokireddy, Sudarsanareddy; Xiaojia, Ge; Mouly, Vincent; Butler-Browne, Gillian; Gluckman, Peter D; Sharma, Mridula; Kambadur, Ravi

    2011-07-01

    Myostatin, a member of the transforming growth factor-β superfamily, has been implicated in the potent negative regulation of myogenesis in murine models. However, little is known about the mechanism(s) through which human myostatin negatively regulates human skeletal muscle growth. Using human primary myoblasts and recombinant human myostatin protein, we show here that myostatin blocks human myoblast proliferation by regulating cell cycle progression through targeted upregulation of p21. We further show that myostatin regulates myogenic differentiation through the inhibition of key myogenic regulatory factors including MyoD, via canonical Smad signaling. In addition, we have for the first time demonstrated the capability of myostatin to regulate the Notch signaling pathway during inhibition of human myoblast differentiation. Treatment with myostatin results in the upregulation of Hes1, Hes5, and Hey1 expression during differentiation; moreover, when we interfere with Notch signaling, through treatment with the γ-secretase inhibitor L-685,458, we find enhanced myotube formation despite the presence of excess myostatin. Therefore, blockade of the Notch pathway relieves myostatin repression of differentiation, and myostatin upregulates Notch downstream target genes. Immunoprecipitation studies demonstrate that myostatin treatment of myoblasts results in enhanced association of Notch1-intracellular domain with Smad3, providing an additional mechanism through which myostatin targets and represses the activity of the myogenic regulatory factor MyoD. On the basis of these results, we suggest that myostatin function and mechanism of action are very well conserved between species, and that myostatin regulation of postnatal myogenesis involves interactions with numerous downstream signaling mediators, including the Notch pathway.

  9. Reversine-treated fibroblasts acquire myogenic competence in vitro and in regenerating skeletal muscle.

    PubMed

    Anastasia, Luigi; Sampaolesi, Maurilio; Papini, Nadia; Oleari, Diego; Lamorte, Giuseppe; Tringali, Cristina; Monti, Eugenio; Galli, Daniela; Tettamanti, Guido; Cossu, Giulio; Venerando, Bruno

    2006-12-01

    Stem cells hold a great potential for the regeneration of damaged tissues in cardiovascular or musculoskeletal diseases. Unfortunately, problems such as limited availability, control of cell fate, and allograft rejection need to be addressed before therapeutic applications may become feasible. Generation of multipotent progenitors from adult differentiated cells could be a very attractive alternative to the limited in vitro self-renewal of several types of stem cells. In this direction, a recently synthesized unnatural purine, named reversine, has been proposed to induce reversion of adult cells to a multipotent state, which could be then converted into other cell types under appropriate stimuli. Our study suggests that reversine treatment transforms primary murine and human dermal fibroblasts into myogenic-competent cells both in vitro and in vivo. Moreover, this is the first study to demonstrate that plasticity changes arise in primary mouse and human cells following reversine exposure.

  10. Zinc Deficiency Induces Apoptosis via Mitochondrial p53- and Caspase-Dependent Pathways in Human Neuronal Precursor Cells

    ERIC Educational Resources Information Center

    Seth, Rohit; Corniola, Rikki S.; Gower-Winter, Shannon D.; Morgan, Thomas J., Jr.; Bishop, Brian; Levenson, Cathy W.

    2015-01-01

    Previous studies have shown that zinc deficiency leads to apoptosis of neuronal precursor cells in vivo and in vitro. In addition to the role of p53 as a nuclear transcription factor in zinc deficient cultured human neuronal precursors (NT-2), we have now identified the translocation of phosphorylated p53 to the mitochondria and p53-dependent…

  11. Combined ocular and cervical vestibular evoked myogenic potential in individuals with vestibular hyporeflexia and in patients with Ménière's disease.

    PubMed

    Silva, Tatiana Rocha; de Resende, Luciana Macedo; Santos, Marco Aurélio Rocha

    The vestibular evoked myogenic potential is a potential of mean latency that measures the muscle response to auditory stimulation. This potential can be generated from the contraction of the sternocleidomastoid muscle and also from the contraction of extraocular muscles in response to high-intensity sounds. This study presents a combined or simultaneous technique of cervical and ocular vestibular evoked myogenic potential in individuals with changes in the vestibular system, for use in otoneurologic diagnosis. To characterize the records and analyze the results of combined cervical and ocular VEMP in individuals with vestibular hyporeflexia and in those with Ménière's disease. The study included 120 subjects: 30 subjects with vestibular hyporeflexia, 30 with Ménière's disease, and 60 individuals with normal hearing. Data collection was performed by simultaneously recording the cervical and ocular vestibular evoked myogenic potential. There were differences between the study groups (individuals with vestibular hyporeflexia and individuals with Ménière's disease) and the control group for most of wave parameters in combined cervical and ocular vestibular evoked myogenic potential. For cervical vestibular evoked myogenic potential, it was observed that the prolongation of latency of the P13 and N23 waves was the most frequent finding in the group with vestibular hyporeflexia and in the group with Ménière's disease. For ocular vestibular evoked myogenic potential, prolonged latency of N10 and P15 waves was the most frequent finding in the study groups. Combined cervical and ocular vestibular evoked myogenic potential presented relevant results for individuals with vestibular hyporeflexia and for those with Ménière's disease. There were differences between the study groups and the control group for most of the wave parameters in combined cervical and ocular vestibular evoked myogenic potential. Copyright © 2016 Associação Brasileira de Otorrinolaringologia

  12. Ability of human oral microbiota to produce wine odorant aglycones from odourless grape glycosidic aroma precursors.

    PubMed

    Muñoz-González, Carolina; Cueva, Carolina; Ángeles Pozo-Bayón, M; Victoria Moreno-Arribas, M

    2015-11-15

    Grape aroma precursors are odourless glycosides that represent a natural reservoir of potential active odorant molecules in wines. Since the first step of wine consumption starts in the oral cavity, the processing of these compounds in the mouth could be an important factor in influencing aroma perception. Therefore, the objective of this work has been to evaluate the ability of human oral microbiota to produce wine odorant aglycones from odourless grape glycosidic aroma precursors previously isolated from white grapes. To do so, two methodological approaches involving the use of typical oral bacteria or the whole oral microbiota isolated from human saliva were followed. Odorant aglycones released in the culture mediums were isolated and analysed by HS-SPME-GC/MS. Results showed the ability of oral bacteria to hydrolyse grape aroma precursors, releasing different types of odorant molecules (terpenes, benzenic compounds and lipid derivatives). The hydrolytic activity seemed to be bacteria-dependent and was subject to large inter-individual variability. Copyright © 2015 Elsevier Ltd. All rights reserved.

  13. Limit-cycle-based control of the myogenic wingbeat rhythm in the fruit fly Drosophila

    PubMed Central

    Bartussek, Jan; Mutlu, A. Kadir; Zapotocky, Martin; Fry, Steven N.

    2013-01-01

    In many animals, rhythmic motor activity is governed by neural limit cycle oscillations under the control of sensory feedback. In the fruit fly Drosophila melanogaster, the wingbeat rhythm is generated myogenically by stretch-activated muscles and hence independently from direct neural input. In this study, we explored if generation and cycle-by-cycle control of Drosophila's wingbeat are functionally separated, or if the steering muscles instead couple into the myogenic rhythm as a weak forcing of a limit cycle oscillator. We behaviourally tested tethered flying flies for characteristic properties of limit cycle oscillators. To this end, we mechanically stimulated the fly's ‘gyroscopic’ organs, the halteres, and determined the phase relationship between the wing motion and stimulus. The flies synchronized with the stimulus for specific ranges of stimulus amplitude and frequency, revealing the characteristic Arnol'd tongues of a forced limit cycle oscillator. Rapid periodic modulation of the wingbeat frequency prior to locking demonstrates the involvement of the fast steering muscles in the observed control of the wingbeat frequency. We propose that the mechanical forcing of a myogenic limit cycle oscillator permits flies to avoid the comparatively slow control based on a neural central pattern generator. PMID:23282849

  14. Myogenic constriction is increased in mesenteric resistance arteries from rats with chronic heart failure: instantaneous counteraction by acute AT1 receptor blockade

    PubMed Central

    Gschwend, S; Henning, R H; Pinto, Y M; de Zeeuw, D; van Gilst, W H; Buikema, H

    2003-01-01

    Increased vascular resistance in chronic heart failure (CHF) has been attributed to stimulated neurohumoral systems. However, local mechanisms may also importantly contribute to set arterial tone. Our aim, therefore, was to test whether pressure-induced myogenic constriction of resistance arteries in vitro – devoid of acute effects of circulating factors – is increased in CHF and to explore underlying mechanisms. At 12 weeks after coronary ligation-induced myocardial infarction or SHAM-operations in rats, we studied isolated mesenteric arteries for myogenic constriction, determined as the active constriction (% of passive diameter) in response to stepwise increase in intraluminal pressure (20 – 160 mmHg), in the absence and presence of inhibitors of potentially involved modulators of myogenic constriction. We found that myogenic constriction in mesenteric arteries from CHF rats was markedly increased compared to SHAM over the whole pressure range, the difference being most pronounced at 60 mmHg (24±2 versus 4±3%, respectively, P<0.001). Both removal of the endothelium as well as inhibition of NO production (L-NG-monomethylarginine, 100 μM) significantly increased myogenic constriction (+16 and +25%, respectively), the increase being similar in CHF- and SHAM-arteries (P=NS). Neither endothelin type A (ETA)-receptor blockade (BQ123, 1 μM) nor inhibition of perivascular (sympathetic) nerve conduction (tetrodotoxin, 100 nM) affected the myogenic response in either group. Interestingly, increased myogenic constriction in CHF was fully reversed after angiotensin II type I (AT1)-receptor blockade (candesartan, 100 nM; losartan, 10 μM), which was without effect in SHAM. In contrast, neither angiotensin-converting enzyme (ACE) inhibition (lisinopril, 1 μM; captopril, 10 μM) or AT2-receptor blockade (PD123319, 1 μM), nor inhibition of superoxide production (superoxide dismutase, 50 U ml−1), TXA2-receptor blockade (SQ29,548, 1 μM) or inhibition of

  15. Anatomical Location of LPA1 Activation and LPA Phospholipid Precursors in Rodent and Human Brain

    PubMed Central

    González de San Román, E; Manuel, I; Giralt, MT; Chun, J; Estivill-Torrús, G; Rodriguez de Fonseca, F; Santín, LJ; Ferrer, I; Rodriguez-Puertas, R

    2016-01-01

    Lysophosphatidic acid (LPA) is a signaling molecule that binds to six known G protein-coupled receptors (GPCRs): LPA1–LPA6. LPA evokes several responses in the CNS including cortical development and folding, growth of the axonal cone and its retraction process. Those cell processes involve survival, migration, adhesion proliferation, differentiation and myelination. The anatomical localization of LPA1 is incompletely understood, particularly with regard to LPA binding. Therefore, we have used functional [35S]GTPγS autoradiography to verify the anatomical distribution of LPA1 binding sites in adult rodent and human brain. The greatest activity was observed in myelinated areas of the white matter such as corpus callosum, internal capsule and cerebellum. MaLPA1-null mice (a variant of LPA1-null) lack [35S]GTPγS basal binding in white matter areas, where the LPA1 receptor is expressed at high levels, suggesting a relevant role of the activity of this receptor in the most myelinated brain areas. In addition, phospholipid precursors of LPA were localized by MALDI-IMS in both rodent and human brain slices identifying numerous species of phosphatides (PA) and phosphatidylcholines (PC). Both PA and PC species represent potential LPA precursors. The anatomical distribution of these precursors in rodent and human brain may indicate a metabolic relationship between LPA and LPA1 receptors. PMID:25857358

  16. Dnmt1 regulates the myogenic lineage specification of muscle stem cells.

    PubMed

    Liu, Renjing; Kim, Kun-Yong; Jung, Yong-Wook; Park, In-Hyun

    2016-10-18

    DNA methylation is an important epigenetic mark that regulates gene expression. Dnmt1 plays an important role in maintaining DNA methylation patterns on daughter DNA strands. Studies have shed light into the functional role of Dnmt1 regulation in the hematopoietic and epidermal systems. Here we show that Dnmt1 is required for myogenesis. Loss of Dnmt1 results in reduced expression of myogenic genes and defects in myogenic differentiation. We have utilized a conditional knockout mouse approach to examine the functional consequences of Dnmt1 depletion specifically in the developing muscle. These mice were born runted, with smaller body weights, and reduced ability to form myotubes in vitro. We show that expression of Id-1, a negative regulator of myogenesis, is enhanced in Dnmt1-deficient cultures, leading to enhanced transdifferentiation of myoblasts toward the osteogenic lineage. Thus, these studies demonstrate that Dnmt1 influences cellular identity and determines lineage fidelity.

  17. Dnmt1 regulates the myogenic lineage specification of muscle stem cells

    PubMed Central

    Liu, Renjing; Kim, Kun-Yong; Jung, Yong-Wook; Park, In-Hyun

    2016-01-01

    DNA methylation is an important epigenetic mark that regulates gene expression. Dnmt1 plays an important role in maintaining DNA methylation patterns on daughter DNA strands. Studies have shed light into the functional role of Dnmt1 regulation in the hematopoietic and epidermal systems. Here we show that Dnmt1 is required for myogenesis. Loss of Dnmt1 results in reduced expression of myogenic genes and defects in myogenic differentiation. We have utilized a conditional knockout mouse approach to examine the functional consequences of Dnmt1 depletion specifically in the developing muscle. These mice were born runted, with smaller body weights, and reduced ability to form myotubes in vitro. We show that expression of Id-1, a negative regulator of myogenesis, is enhanced in Dnmt1-deficient cultures, leading to enhanced transdifferentiation of myoblasts toward the osteogenic lineage. Thus, these studies demonstrate that Dnmt1 influences cellular identity and determines lineage fidelity. PMID:27752090

  18. Vestibular evoked myogenic potential (Vemp): evaluation of responses in normal subjects.

    PubMed

    Felipe, Lilian; Santos, Marco Aurélio Rocha; Gonçalves, Denise Utsch

    2008-01-01

    the Vestibular Evoked Myogenic Potential (Vemp) is formed by myogenic neurophysiologic responses activated by high-intensity sound stimulation. The response is registered through surface electromyography of the cervical muscles during muscle contraction. The acoustic stimuli activate the saccular macula, the vestibular inferior nerve and the pathways related to the vestibule-spinal descendant nerves. to describe Vemp parameters in a normal population. thirty adults, 13 men and 17 women with no otoneurological complaints were selected. The stimuli were 200 tone burst, with a frequency of 1Hz and intensity of 118 dB Na, band-pass filter ranging from 10Hz to 1500Hz. The first potential biphasic P13-N23 wave was analyzed. no significant difference was observed between the sides of stimulation in terms of latency and amplitude. However, a statistically significant difference was found for amplitude between genders. Vemp demonstrated to be a reliable instrument in the clinical assessment of the vestibular function.

  19. MAPK signaling pathways and HDAC3 activity are disrupted during differentiation of emerin-null myogenic progenitor cells

    PubMed Central

    Collins, Carol M.; Ellis, Joseph A.

    2017-01-01

    ABSTRACT Mutations in the gene encoding emerin cause Emery–Dreifuss muscular dystrophy (EDMD). Emerin is an integral inner nuclear membrane protein and a component of the nuclear lamina. EDMD is characterized by skeletal muscle wasting, cardiac conduction defects and tendon contractures. The failure to regenerate skeletal muscle is predicted to contribute to the skeletal muscle pathology of EDMD. We hypothesize that muscle regeneration defects are caused by impaired muscle stem cell differentiation. Myogenic progenitors derived from emerin-null mice were used to confirm their impaired differentiation and analyze selected myogenic molecular pathways. Emerin-null progenitors were delayed in their cell cycle exit, had decreased myosin heavy chain (MyHC) expression and formed fewer myotubes. Emerin binds to and activates histone deacetylase 3 (HDAC3). Here, we show that theophylline, an HDAC3-specific activator, improved myotube formation in emerin-null cells. Addition of the HDAC3-specific inhibitor RGFP966 blocked myotube formation and MyHC expression in wild-type and emerin-null myogenic progenitors, but did not affect cell cycle exit. Downregulation of emerin was previously shown to affect the p38 MAPK and ERK/MAPK pathways in C2C12 myoblast differentiation. Using a pure population of myogenic progenitors completely lacking emerin expression, we show that these pathways are also disrupted. ERK inhibition improved MyHC expression in emerin-null cells, but failed to rescue myotube formation or cell cycle exit. Inhibition of p38 MAPK prevented differentiation in both wild-type and emerin-null progenitors. These results show that each of these molecular pathways specifically regulates a particular stage of myogenic differentiation in an emerin-dependent manner. Thus, pharmacological targeting of multiple pathways acting at specific differentiation stages may be a better therapeutic approach in the future to rescue muscle regeneration in vivo. PMID:28188262

  20. Low Oxygen Tension Enhances Expression of Myogenic Genes When Human Myoblasts Are Activated from G0 Arrest

    PubMed Central

    Sellathurai, Jeeva; Nielsen, Joachim; Hejbøl, Eva Kildall; Jørgensen, Louise Helskov; Dhawan, Jyotsna; Nielsen, Michael Friberg Bruun; Schrøder, Henrik Daa

    2016-01-01

    Objectives Most cell culture studies have been performed at atmospheric oxygen tension of 21%, however the physiological oxygen tension is much lower and is a factor that may affect skeletal muscle myoblasts. In this study we have compared activation of G0 arrested myoblasts in 21% O2 and in 1% O2 in order to see how oxygen tension affects activation and proliferation of human myoblasts. Materials and Methods Human myoblasts were isolated from skeletal muscle tissue and G0 arrested in vitro followed by reactivation at 21% O2 and 1% O2. The effect was assesses by Real-time RT-PCR, immunocytochemistry and western blot. Results and Conclusions We found an increase in proliferation rate of myoblasts when activated at a low oxygen tension (1% O2) compared to 21% O2. In addition, the gene expression studies showed up regulation of the myogenesis related genes PAX3, PAX7, MYOD, MYOG (myogenin), MET, NCAM, DES (desmin), MEF2A, MEF2C and CDH15 (M-cadherin), however, the fraction of DES and MYOD positive cells was not increased by low oxygen tension, indicating that 1% O2 may not have a functional effect on the myogenic response. Furthermore, the expression of genes involved in the TGFβ, Notch and Wnt signaling pathways were also up regulated in low oxygen tension. The differences in gene expression were most pronounced at day one after activation from G0-arrest, thus the initial activation of myoblasts seemed most sensitive to changes in oxygen tension. Protein expression of HES1 and β-catenin indicated that notch signaling may be induced in 21% O2, while the canonical Wnt signaling may be induced in 1% O2 during activation and proliferation of myoblasts. PMID:27442119

  1. Effects of Maternal Supplementation With Omega-3 Precursors on Human Milk Composition.

    PubMed

    Mazurier, Evelyne; Rigourd, Virginie; Perez, Paul; Buffin, Rachel; Couedelo, Leslie; Vaysse, Carole; Belcadi, Wafae; Sitta, Rémi; Nacka, Fabienne; Lamireau, Delphine; Cambonie, Gilles; Picaud, Jean-Charles; Billeaud, Claude

    2017-05-01

    Long-chain polyunsaturated fatty acids (LC-PUFAs) are important for newborn neurosensory development. Supplementation of breastfeeding mothers' diets with omega-3 PUFAs, such as alpha-linolenic acid (ALA), may increase their concentration in human milk. Research aim: This study aimed to assess human milk composition after 15-day supplementation regimens containing either omega-3 PUFAs or olive oil, which does not provide ALA. A multicenter factorial randomized trial was conducted with four groups of breastfeeding women, with each group containing 19 to 22 women. After a 15-day ALA washout period, three groups received supplementation with omega-3 precursors for 15 days: an enriched margarine (M), a rapeseed oil (R), and a margarine and rapeseed oil (MR). The fourth was unexposed to omega-3 precursors (olive oil control diet, O). After 15 days, blind determination of human milk fatty acid (FA) composition was assessed by gas chromatography, and the FA composition was compared among groups using variance analyses. Alpha-linolenic acid content, expressed as the mean (standard deviation) total human milk FA percentage, was significantly higher after diet supplementation with omega-3 PUFAs, with values of 2.2% (0.7%) (MR), 1.3% (0.5%) (R), 1.1% (0.4%) (M), and 0.8% (0.3%) (O at D30) ( p < .003 for each comparison). The lowest LA-ALA ratio (5.5) was found in the MR group ( p < .001). Docosahexaenoic acid and trans FA concentrations did not differ among groups. In lactating women, omega-3 supplementation via the combination of enriched margarine and rapeseed oil increased the ALA content of human milk and generated the most favorable LA-ALA ratio for LC-PUFA synthesis.

  2. Stretch-activation of angiotensin II type 1a receptors contributes to the myogenic response of mouse mesenteric and renal arteries.

    PubMed

    Schleifenbaum, Johanna; Kassmann, Mario; Szijártó, István András; Hercule, Hantz C; Tano, Jean-Yves; Weinert, Stefanie; Heidenreich, Matthias; Pathan, Asif R; Anistan, Yoland-Marie; Alenina, Natalia; Rusch, Nancy J; Bader, Michael; Jentsch, Thomas J; Gollasch, Maik

    2014-07-07

    Vascular wall stretch is the major stimulus for the myogenic response of small arteries to pressure. The molecular mechanisms are elusive, but recent findings suggest that G protein-coupled receptors can elicit a stretch response. To determine whether angiotensin II type 1 receptors (AT1R) in vascular smooth muscle cells exert mechanosensitivity and identify the downstream ion channel mediators of myogenic vasoconstriction. We used mice deficient in AT1R signaling molecules and putative ion channel targets, namely AT1R, angiotensinogen, transient receptor potential channel 6 (TRPC6) channels, or several subtypes of the voltage-gated K+ (Kv7) gene family (KCNQ3, 4, or 5). We identified a mechanosensing mechanism in isolated mesenteric arteries and in the renal circulation that relies on coupling of the AT1R subtype a to a Gq/11 protein as a critical event to accomplish the myogenic response. Arterial mechanoactivation occurs after pharmacological block of AT1R and in the absence of angiotensinogen or TRPC6 channels. Activation of AT1R subtype a by osmotically induced membrane stretch suppresses an XE991-sensitive Kv channel current in patch-clamped vascular smooth muscle cells, and similar concentrations of XE991 enhance mesenteric and renal myogenic tone. Although XE991-sensitive KCNQ3, 4, and 5 channels are expressed in vascular smooth muscle cells, XE991-sensitive K+ current and myogenic contractions persist in arteries deficient in these channels. Our results provide definitive evidence that myogenic responses of mouse mesenteric and renal arteries rely on ligand-independent, mechanoactivation of AT1R subtype a. The AT1R subtype a signal relies on an ion channel distinct from TRPC6 or KCNQ3, 4, or 5 to enact vascular smooth muscle cell activation and elevated vascular resistance. © 2014 American Heart Association, Inc.

  3. Promotion of Myogenic Maturation by Timely Application of Electric Field Along the Topographical Alignment.

    PubMed

    Ko, Ung Hyun; Park, Sukhee; Bang, Hyunseung; Kim, Mina; Shin, Hyunjun; Shin, Jennifer H

    2018-05-01

    Engineered muscular substitutes can restore the impaired muscle functions when integrated properly into the host tissue. To generate functional muscles with sufficient contractility at the site of transplant, the in vitro construction of fully differentiated muscle fibers would be desired. Many previous reports have identified either topographical alignment or electrical stimulation as an effective tool to promote myogenic differentiation. However, optimization of spatial and temporal arrangement of these two physical cues for better differentiation and maturation of skeletal muscles has not been investigated. In this article, we introduce a novel cell culture system that allows simultaneous application of these two independent directional cues at both orthogonal and parallel arrangements. We then show that the parallel arrangement of the aligned topography and the electric field synergistically facilitates better differentiation and maturation of C2C12, generating myotubes with more fused nuclei. Addition of the electric stimulation at the late stage of myogenic differentiation is found to further improve cell fusion to form multinucleate myotubes through a phosphatidylinositol-3-OH-kinase-dependent pathway. As such, we successfully demonstrated that the combined stimulation of topographical and electrical cues could effectively enhance both myogenic differentiation and maturation in a temporal and orientation-dependent manner, providing the basis for therapeutic strategies for regenerative tissue engineering.

  4. Exercise restores coronary vascular function independent of myogenic tone or hyperglycemic status in db/db mice.

    PubMed

    Moien-Afshari, Farzad; Ghosh, Sanjoy; Elmi, Shahrzad; Khazaei, Majid; Rahman, Mohammad M; Sallam, Nada; Laher, Ismail

    2008-10-01

    Regulation of coronary function in diabetic hearts is an important component in preventing ischemic cardiac events but remains poorly studied. Exercise is recommended in the management of diabetes, but its effects on diabetic coronary function are relatively unknown. We investigated coronary artery myogenic tone and endothelial function, essential elements in maintaining vascular fluid dynamics in the myocardium. We hypothesized that exercise reduces pressure-induced myogenic constriction of coronary arteries while improving endothelial function in db/db mice, a model of type 2 diabetes. We used pressurized mouse coronary arteries isolated from hearts of control and db/db mice that were sedentary or exercised for 1 h/day on a motorized exercise-wheel system (set at 5.2 m/day, 5 days/wk). Exercise caused a approximately 10% weight loss in db/db mice and decreased whole body oxidative stress, as measured by plasma 8-isoprostane levels, but failed to improve hyperglycemia or plasma insulin levels. Exercise did not alter myogenic regulation of arterial diameter stimulated by increased transmural pressure, nor did it alter smooth muscle responses to U-46619 (a thromboxane agonist) or sodium nitroprusside (an endothelium-independent dilator). Moderate levels of exercise restored ACh-simulated, endothelium-dependent coronary artery vasodilation in db/db mice and increased expression of Mn SOD and decreased nitrotyrosine levels in hearts of db/db mice. We conclude that the vascular benefits of moderate levels of exercise were independent of changes in myogenic tone or hyperglycemic status and primarily involved increased nitric oxide bioavailability in the coronary microcirculation.

  5. Inhibition of glycogen synthase kinase-3 enhances the differentiation and reduces the proliferation of adult human olfactory epithelium neural precursors

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Manceur, Aziza P.; Donnelly Centre, University of Toronto, Toronto, Ontario; Tseng, Michael

    2011-09-10

    The olfactory epithelium (OE) contains neural precursor cells which can be easily harvested from a minimally invasive nasal biopsy, making them a valuable cell source to study human neural cell lineages in health and disease. Glycogen synthase kinase-3 (GSK-3) has been implicated in the etiology and treatment of neuropsychiatric disorders and also in the regulation of murine neural precursor cell fate in vitro and in vivo. In this study, we examined the impact of decreased GSK-3 activity on the fate of adult human OE neural precursors in vitro. GSK-3 inhibition was achieved using ATP-competitive (6-bromoindirubin-3'-oxime and CHIR99021) or substrate-competitive (TAT-eIF2B)more » inhibitors to eliminate potential confounding effects on cell fate due to off-target kinase inhibition. GSK-3 inhibitors decreased the number of neural precursor cells in OE cell cultures through a reduction in proliferation. Decreased proliferation was not associated with a reduction in cell survival but was accompanied by a reduction in nestin expression and a substantial increase in the expression of the neuronal differentiation markers MAP1B and neurofilament (NF-M) after 10 days in culture. Taken together, these results suggest that GSK-3 inhibition promotes the early stages of neuronal differentiation in cultures of adult human neural precursors and provide insights into the mechanisms by which alterations in GSK-3 signaling affect adult human neurogenesis, a cellular process strongly suspected to play a role in the etiology of neuropsychiatric disorders.« less

  6. TRPV2 Channels Contribute to Stretch-Activated Cation Currents and Myogenic Constriction in Retinal Arterioles.

    PubMed

    McGahon, Mary K; Fernández, José A; Dash, Durga P; McKee, Jon; Simpson, David A; Zholos, Alex V; McGeown, J Graham; Curtis, Tim M

    2016-10-01

    Activation of the transient receptor potential channels, TRPC6, TRPM4, and TRPP1 (PKD2), has been shown to contribute to the myogenic constriction of cerebral arteries. In the present study we sought to determine the potential role of various mechanosensitive TRP channels to myogenic signaling in arterioles of the rat retina. Rat retinal arterioles were isolated for RT-PCR, Fura-2 Ca2+ microfluorimetry, patch-clamp electrophysiology, and pressure myography studies. In some experiments, confocal immunolabeling of wholemount preparations was used to examine the localization of specific mechanosensitive TRP channels in retinal vascular smooth muscle cells (VSMCs). Reverse transcription-polymerase chain reaction analysis demonstrated mRNA expression for TRPC1, M7, V1, V2, V4, and P1, but not TRPC6 or M4, in isolated retinal arterioles. Immunolabeling revealed plasma membrane, cytosolic and nuclear expression of TRPC1, M7, V1, V2, V4, and P1 in retinal VSMCs. Hypoosmotic stretch-induced Ca2+ influx in retinal VSMCs was reversed by the TRPV2 inhibitor tranilast and the nonselective TRPP1/V2 antagonist amiloride. Inhibitors of TRPC1, M7, V1, and V4 had no effect. Hypoosmotic stretch-activated cation currents were similar in Na+ and Cs+ containing solutions suggesting no contribution by TRPP1 channels. Direct plasma membrane stretch triggered cation current activity that was blocked by tranilast and specific TRPV2 pore-blocking antibodies and mimicked by the TRPV2 activator, Δ9-tetrahydrocannabinol. Preincubation of retinal arterioles with TRPV2 blocking antibodies prevented the development of myogenic tone. Our results suggest that retinal VSMCs express a range of mechanosensitive TRP channels, but only TRPV2 appears to contribute to myogenic signaling in this vascular bed.

  7. Vestibular Evoked Myogenic Potentials in Normal Mice and Phex Mice With Spontaneous Endolymphatic Hydrops

    PubMed Central

    Sheykholeslami, Kianoush; Megerian, Cliff A.; Zheng, Qing Y.

    2010-01-01

    Objective and Background Vestibular evoked myogenic potentials (VEMPs) have been recorded from the neck musculature and the cervical spinal cord in humans and a limited number of laboratory animals in response to loud sound. However, the mouse VEMP has yet to be described. Evaluation of the sacculocollic pathway via VEMPs in mice can set the stage for future evaluations of mutant mice that now play an important role in research regarding human auditory and vestibular dysfunction. Materials and Methods Sound-evoked potentials were recorded from the neck extensor muscles and the cervical spinal cord in normal adult mice and in circling PhexHyp-Duk/y mice with known vestibular abnormalities, including endolymphatic hydrops (ELH). Results Biphasic potentials were recorded from all normal animals. The mean threshold of the VEMP response in normal adult mice was 60 dB normal hearing level with a mean peak latency of 6.25 ± 0.46 and 7.95 ± 0.42 milliseconds for p1 and n1 peaks, respectively. At the maximum sound intensity used (100 dB normal hearing level), 4 of 5 Phex mice did not exhibit VEMP responses, and 1 showed an elevated threshold, but normal response, with regard to peak latency and amplitude. The histologic findings in all of these Phex mice were consistent with distended membranous labyrinth, displaced Reissner membrane, ganglion cell loss, and ELH. Conclusion This is the first report of VEMP recordings in mice and the first report of abnormal VEMPs in a mouse model with ELH. The characteristics of these potentials such as higher response threshold in comparison to auditory brainstem response, myogenic nature of the response, and latency correlation with the cervical recording (accessory nerve nucleus) were similar to those of VEMPs in humans, guinea pigs, cats, and rats, suggesting that the mouse may be used as an animal model in the study of VEMPs. The simplicity and reliability of these recordings make the VEMP a uniquely informative test for assessing

  8. Invited Review: Extrinsic regulation of domestic animal-derived myogenic satellite cells II

    USDA-ARS?s Scientific Manuscript database

    The existence of myogenic satellite cells was reported some forty-seven years ago, and, since that time, satellite cell research has flourished. So much new information is generated (daily) on these cells that it can be difficult for individuals to keep abreast of important issues related to the act...

  9. Contrasting roles for MyoD in organizing myogenic promoter structures during embryonic skeletal muscle development.

    PubMed

    Cho, Ok Hyun; Mallappa, Chandrashekara; Hernández-Hernández, J Manuel; Rivera-Pérez, Jaime A; Imbalzano, Anthony N

    2015-01-01

    Among the complexities of skeletal muscle differentiation is a temporal distinction in the onset of expression of different lineage-specific genes. The lineage-determining factor MyoD is bound to myogenic genes at the onset of differentiation whether gene activation is immediate or delayed. How temporal regulation of differentiation-specific genes is established remains unclear. Using embryonic tissue, we addressed the molecular differences in the organization of the myogenin and muscle creatine kinase (MCK) gene promoters by examining regulatory factor binding as a function of both time and spatial organization during somitogenesis. At the myogenin promoter, binding of the homeodomain factor Pbx1 coincided with H3 hyperacetylation and was followed by binding of co-activators that modulate chromatin structure. MyoD and myogenin binding occurred subsequently, demonstrating that Pbx1 facilitates chromatin remodeling and modification before myogenic regulatory factor binding. At the same time, the MCK promoter was bound by HDAC2 and MyoD, and activating histone marks were largely absent. The association of HDAC2 and MyoD was confirmed by co-immunoprecipitation, proximity ligation assay (PLA), and sequential ChIP. MyoD differentially promotes activated and repressed chromatin structures at myogenic genes early after the onset of skeletal muscle differentiation in the developing mouse embryo. © 2014 Wiley Periodicals, Inc.

  10. Mitophagy is required for mitochondrial biogenesis and myogenic differentiation of C2C12 myoblasts.

    PubMed

    Sin, Jon; Andres, Allen M; Taylor, David J R; Weston, Thomas; Hiraumi, Yoshimi; Stotland, Aleksandr; Kim, Brandon J; Huang, Chengqun; Doran, Kelly S; Gottlieb, Roberta A

    2016-01-01

    Myogenesis is a crucial process governing skeletal muscle development and homeostasis. Differentiation of primitive myoblasts into mature myotubes requires a metabolic switch to support the increased energetic demand of contractile muscle. Skeletal myoblasts specifically shift from a highly glycolytic state to relying predominantly on oxidative phosphorylation (OXPHOS) upon differentiation. We have found that this phenomenon requires dramatic remodeling of the mitochondrial network involving both mitochondrial clearance and biogenesis. During early myogenic differentiation, autophagy is robustly upregulated and this coincides with DNM1L/DRP1 (dynamin 1-like)-mediated fragmentation and subsequent removal of mitochondria via SQSTM1 (sequestosome 1)-mediated mitophagy. Mitochondria are then repopulated via PPARGC1A/PGC-1α (peroxisome proliferator-activated receptor gamma, coactivator 1 alpha)-mediated biogenesis. Mitochondrial fusion protein OPA1 (optic atrophy 1 [autosomal dominant]) is then briskly upregulated, resulting in the reformation of mitochondrial networks. The final product is a myotube replete with new mitochondria. Respirometry reveals that the constituents of these newly established mitochondrial networks are better primed for OXPHOS and are more tightly coupled than those in myoblasts. Additionally, we have found that suppressing autophagy with various inhibitors during differentiation interferes with myogenic differentiation. Together these data highlight the integral role of autophagy and mitophagy in myogenic differentiation.

  11. Chronic Hypoxia Inhibits Sex Steroid Hormone-Mediated Attenuation of Ovine Uterine Arterial Myogenic Tone in Pregnancy

    PubMed Central

    Chang, Katherine; Xiao, DaLiao; Huang, Xiaohui; Xue, Zhice; Yang, Shumei; Longo, Lawrence D.; Zhang, Lubo

    2010-01-01

    Previous studies in ovine uterine arteries have demonstrated that sex steroid hormones upregulate ERK1/2 expression and downregulate PKC signaling pathway, resulting in the attenuated myogenic tone in pregnancy. The present study tested the hypothesis that chronic hypoxia during gesttation inhibits the sex steroid-mediated adaptation of ERK1/2 and PKC signaling pathways and increases the myogenic tone of uterine arteries. Uterine arteries were isolated from nonpregnant and near-term pregnant sheep that had been maintained at sea level (~300 m) or exposed to high altitude (3,801 m) hypoxia for 110 days. In contrast to the previous findings in normoxic animals, 17β-estradiol and progesterone failed to suppress PKC-induced contractions and the pressure-induced myogenic tone in uterine arteries from hypoxic animals. Western analyses showed that the sex steroids lost their effects on ERK1/2 expression and phospho-ERK1/2 levels, as well as the activation of PKC isozymes in uterine arteries of hypoxic ewes. In normoxic animals, pregnancy and the sex steroid treatments significantly increased uterine artery estrogen receptor α and progesterone receptor B expression. Chronic hypoxia selectively downregulated estrogen receptor α expression in uterine arteries of pregnant animals, and eliminated the upregulation of estrogen receptor α in pregnancy or by the steroid treatments observed in normoxic animals. The results demonstrate that in the ovine uterine artery chronic hypoxia in pregnancy inhibits the sex steroid hormone-mediated adaptation of decreased myogenic tone by downregulating estrogen receptor α expression, providing a mechanism linking hypoxia and maladaptation of uteroplacental circulation, and an increased risk of preeclampsia in pregnancy. PMID:20660818

  12. DNA methyltransferase inhibitor CDA-II inhibits myogenic differentiation

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Chen, Zirong; Department of Molecular Genetics and Microbiology, Shands Cancer Center, University of Florida, Gainesville, FL 32610; Jin, Guorong

    2012-06-08

    Highlights: Black-Right-Pointing-Pointer CDA-II inhibits myogenic differentiation in a dose-dependent manner. Black-Right-Pointing-Pointer CDA-II repressed expression of muscle transcription factors and structural proteins. Black-Right-Pointing-Pointer CDA-II inhibited proliferation and migration of C2C12 myoblasts. -- Abstract: CDA-II (cell differentiation agent II), isolated from healthy human urine, is a DNA methyltransferase inhibitor. Previous studies indicated that CDA-II played important roles in the regulation of cell growth and certain differentiation processes. However, it has not been determined whether CDA-II affects skeletal myogenesis. In this study, we investigated effects of CDA-II treatment on skeletal muscle progenitor cell differentiation, migration and proliferation. We found that CDA-II blocked differentiationmore » of murine myoblasts C2C12 in a dose-dependent manner. CDA-II repressed expression of muscle transcription factors, such as Myogenin and Mef2c, and structural proteins, such as myosin heavy chain (Myh3), light chain (Mylpf) and MCK. Moreover, CDA-II inhibited C1C12 cell migration and proliferation. Thus, our data provide the first evidence that CDA-II inhibits growth and differentiation of muscle progenitor cells, suggesting that the use of CDA-II might affect skeletal muscle functions.« less

  13. Effect of CB1 Ligands on Neurogenic and Myogenic Contractile Responses in the Guinea-Pig Ileum.

    PubMed

    Donnerer, Josef; Liebmann, Ingrid

    2018-01-01

    This study aimed at investigating whether the synthetic cannabinoid receptor agonist (+)-WIN 55212-2 has neurogenic and myogenic relaxant effects on the longitudinal muscle-myenteric plexus (LMMP) strip of the guinea-pig ileum. (+)-WIN 55212-2, 1-1,000 nmol/L, concentration-dependently inhibited both the electrical stimulation-induced cholinergic twitch responses as well as the myogenic smooth muscle contractions in the LMMP preparation. SR-141716A (rimonabant) 1-1,000 nmol/L, the cannabinoid CB1 receptor antagonist, being without effect on its own, antagonized the (+)-WIN 55212-2-induced effects. The allyl isothiocyanate (mustard oil, 100 µmol/L) induced a relaxant effect in the guinea-pig ileum, which can be regarded as neurogenic and myogenic, was augmented by (+)-WIN 55212-2, and inhibited by SR-141716A. (+)-WIN 55212-2 only moderately modified the 60 mmol/L KCl-evoked contractions. These results provide functional evidence that the CB1 agonist (+)-WIN 55212-2-induced inhibitory effects in the guinea-pig ileum are exerted both at the neuronal as well as at the intestinal smooth muscle cell level. © 2018 S. Karger AG, Basel.

  14. Human skeletal muscle fibroblasts stimulate in vitro myogenesis and in vivo muscle regeneration.

    PubMed

    Mackey, Abigail L; Magnan, Mélanie; Chazaud, Bénédicte; Kjaer, Michael

    2017-08-01

    Accumulation of skeletal muscle extracellular matrix is an unfavourable characteristic of many muscle diseases, muscle injury and sarcopenia. The extent of cross-talk between fibroblasts, as the source of matrix protein, and satellite cells in humans is unknown. We studied this in human muscle biopsies and cell-culture studies. We observed a strong stimulation of myogenesis by human fibroblasts in cell culture. In biopsies collected 30 days after a muscle injury protocol, fibroblast number increased to four times control levels, where fibroblasts were found to be preferentially located immediately surrounding regenerating muscle fibres. These novel findings indicate an important role for fibroblasts in supporting the regeneration of muscle fibres, potentially through direct stimulation of satellite cell differentiation and fusion, and contribute to understanding of cell-cell cross-talk during physiological and pathological muscle remodelling. Accumulation of skeletal muscle extracellular matrix is an unfavourable characteristic of many muscle diseases, muscle injury and sarcopenia. In addition to the indispensable role satellite cells play in muscle regeneration, there is emerging evidence in rodents for a regulatory influence on fibroblast activity. However, the influence of fibroblasts on satellite cells and muscle regeneration in humans is unknown. The purpose of this study was to investigate this in vitro and during in vivo regeneration in humans. Following a muscle injury protocol in young healthy men (n = 7), the number of fibroblasts (TCF7L2+), satellite cells (Pax7+), differentiating myogenic cells (myogenin+) and regenerating fibres (neonatal/embryonic myosin+) was determined from biopsy cross-sections. Fibroblasts and myogenic precursor cells (MPCs) were also isolated from human skeletal muscle (n = 4) and co-cultured using different cell ratios, with the two cell populations either in direct contact with each other or separated by a permeable

  15. Affordable Precursor Missions to Search for Life and Pave the Way for Human Exploration of Mars

    NASA Astrophysics Data System (ADS)

    Stoker, C. R.

    2017-02-01

    The goal of landing humans on Mars in the 2030s requires a precursor program to assess modern life on Mars and assess the water resource of near surface ground ice. Missions that address these issues are presented.

  16. Kilowatt-Class Fission Power Systems for Science and Human Precursor Missions

    NASA Technical Reports Server (NTRS)

    Mason, Lee S.; Gibson, Marc Andrew; Poston, Dave

    2013-01-01

    Nuclear power provides an enabling capability for NASA missions that might otherwise be constrained by power availability, mission duration, or operational robustness. NASA and the Department of Energy (DOE) are developing fission power technology to serve a wide range of future space uses. Advantages include lower mass, longer life, and greater mission flexibility than competing power system options. Kilowatt-class fission systems, designated "Kilopower," were conceived to address the need for systems to fill the gap above the current 100-W-class radioisotope power systems being developed for science missions and below the typical 100-k We-class reactor power systems being developed for human exploration missions. This paper reviews the current fission technology project and examines some Kilopower concepts that could be used to support future science missions or human precursors.

  17. Kilowatt-Class Fission Power Systems for Science and Human Precursor Missions

    NASA Technical Reports Server (NTRS)

    Mason, Lee; Gibson, Marc; Poston, Dave

    2013-01-01

    Nuclear power provides an enabling capability for NASA missions that might otherwise be constrained by power availability, mission duration, or operational robustness. NASA and the Department of Energy (DOE) are developing fission power technology to serve a wide range of future space uses. Advantages include lower mass, longer life, and greater mission flexibility than competing power system options. Kilowatt-class fission systems, designated "Kilopower," were conceived to address the need for systems to fill the gap above the current 100-Wclass radioisotope power systems being developed for science missions and below the typical 100-kWe-class reactor power systems being developed for human exploration missions. This paper reviews the current fission technology project and examines some Kilopower concepts that could be used to support future science missions or human precursors.

  18. Functional studies of the Ciona intestinalis myogenic regulatory factor reveal conserved features of chordate myogenesis.

    PubMed

    Izzi, Stephanie A; Colantuono, Bonnie J; Sullivan, Kelly; Khare, Parul; Meedel, Thomas H

    2013-04-15

    Ci-MRF is the sole myogenic regulatory factor (MRF) of the ascidian Ciona intestinalis, an invertebrate chordate. In order to investigate its properties we developed a simple in vivo assay based on misexpressing Ci-MRF in the notochord of Ciona embryos. We used this assay to examine the roles of three structural motifs that are conserved among MRFs: an alanine-threonine (Ala-Thr) dipeptide of the basic domain that is known in vertebrates as the myogenic code, a cysteine/histidine-rich (C/H) domain found just N-terminal to the basic domain, and a carboxy-terminal amphipathic α-helix referred to as Helix III. We show that the Ala-Thr dipeptide is necessary for normal Ci-MRF function, and that while eliminating the C/H domain or Helix III individually has no demonstrable effect on Ci-MRF, simultaneous loss of both motifs significantly reduces its activity. Our studies also indicate that direct interaction between CiMRF and an essential E-box of Ciona Troponin I is required for the expression of this muscle-specific gene and that multiple classes of MRF-regulated genes exist in Ciona. These findings are consistent with substantial conservation of MRF-directed myogenesis in chordates and demonstrate for the first time that the Ala/Thr dipeptide of the basic domain of an invertebrate MRF behaves as a myogenic code. Copyright © 2013 Elsevier Inc. All rights reserved.

  19. Engraftment potential of dermal fibroblasts following in vivo myogenic conversion in immunocompetent dystrophic skeletal muscle

    PubMed Central

    Muir, Lindsey A; Nguyen, Quynh G; Hauschka, Stephen D; Chamberlain, Jeffrey S

    2014-01-01

    Autologous dermal fibroblasts (dFbs) are promising candidates for enhancing muscle regeneration in Duchenne muscular dystrophy (DMD) due to their ease of isolation, immunological compatibility, and greater proliferative potential than DMD satellite cells. We previously showed that mouse fibroblasts, after MyoD-mediated myogenic reprogramming in vivo, engraft in skeletal muscle and supply dystrophin. Assessing the therapeutic utility of this system requires optimization of conversion and transplantation conditions and quantitation of engraftment so that these parameters can be correlated with possible functional improvements. Here, we derived dFbs from transgenic mice carrying mini-dystrophin, transduced them by lentivirus carrying tamoxifen-inducible MyoD, and characterized their myogenic and engraftment potential. After cell transplantation into the muscles of immunocompetent dystrophic mdx4cv mice, tamoxifen treatment drove myogenic conversion and fusion into myofibers that expressed high levels of mini-dystrophin. Injecting 50,000 cells/µl (1 × 106 total cells) resulted in a peak of ~600 mini-dystrophin positive myofibers in tibialis anterior muscle single cross-sections. However, extensor digitorum longus muscles with up to 30% regional engraftment showed no functional improvements; similar limitations were obtained with whole muscle mononuclear cells. Despite the current lack of physiological improvement, this study suggests a viable initial strategy for using a patient-accessible dermal cell population to enhance skeletal muscle regeneration in DMD. PMID:25558461

  20. miR-206 represses hypertrophy of myogenic cells but not muscle fibers via inhibition of HDAC4.

    PubMed

    Winbanks, Catherine E; Beyer, Claudia; Hagg, Adam; Qian, Hongwei; Sepulveda, Patricio V; Gregorevic, Paul

    2013-01-01

    microRNAs regulate the development of myogenic progenitors, and the formation of skeletal muscle fibers. However, the role miRNAs play in controlling the growth and adaptation of post-mitotic musculature is less clear. Here, we show that inhibition of the established pro-myogenic regulator miR-206 can promote hypertrophy and increased protein synthesis in post-mitotic cells of the myogenic lineage. We have previously demonstrated that histone deacetylase 4 (HDAC4) is a target of miR-206 in the regulation of myogenic differentiation. We confirmed that inhibition of miR-206 de-repressed HDAC4 accumulation in cultured myotubes. Importantly, inhibition of HDAC4 activity by valproic acid or sodium butyrate prevented hypertrophy of myogenic cells otherwise induced by inhibition of miR-206. To test the significance of miRNA-206 as a regulator of skeletal muscle mass in vivo, we designed recombinant adeno-associated viral vectors (rAAV6 vectors) expressing miR-206, or a miR-206 "sponge," featuring repeats of a validated miR-206 target sequence. We observed that over-expression or inhibition of miR-206 in the muscles of mice decreased or increased endogenous HDAC4 levels respectively, but did not alter muscle mass or myofiber size. We subsequently manipulated miR-206 levels in muscles undergoing follistatin-induced hypertrophy or denervation-induced atrophy (models of muscle adaptation where endogenous miR-206 expression is altered). Vector-mediated manipulation of miR-206 activity in these models of cell growth and wasting did not alter gain or loss of muscle mass respectively. Our data demonstrate that although the miR-206/HDAC4 axis operates in skeletal muscle, the post-natal expression of miR-206 is not a key regulator of basal skeletal muscle mass or specific modes of muscle growth and wasting. These studies support a context-dependent role of miR-206 in regulating hypertrophy that may be dispensable for maintaining or modifying the adult skeletal muscle phenotype

  1. miR-206 Represses Hypertrophy of Myogenic Cells but Not Muscle Fibers via Inhibition of HDAC4

    PubMed Central

    Winbanks, Catherine E.; Beyer, Claudia; Hagg, Adam; Qian, Hongwei; Sepulveda, Patricio V.; Gregorevic, Paul

    2013-01-01

    microRNAs regulate the development of myogenic progenitors, and the formation of skeletal muscle fibers. However, the role miRNAs play in controlling the growth and adaptation of post-mitotic musculature is less clear. Here, we show that inhibition of the established pro-myogenic regulator miR-206 can promote hypertrophy and increased protein synthesis in post-mitotic cells of the myogenic lineage. We have previously demonstrated that histone deacetylase 4 (HDAC4) is a target of miR-206 in the regulation of myogenic differentiation. We confirmed that inhibition of miR-206 de-repressed HDAC4 accumulation in cultured myotubes. Importantly, inhibition of HDAC4 activity by valproic acid or sodium butyrate prevented hypertrophy of myogenic cells otherwise induced by inhibition of miR-206. To test the significance of miRNA-206 as a regulator of skeletal muscle mass in vivo, we designed recombinant adeno-associated viral vectors (rAAV6 vectors) expressing miR-206, or a miR-206 “sponge,” featuring repeats of a validated miR-206 target sequence. We observed that over-expression or inhibition of miR-206 in the muscles of mice decreased or increased endogenous HDAC4 levels respectively, but did not alter muscle mass or myofiber size. We subsequently manipulated miR-206 levels in muscles undergoing follistatin-induced hypertrophy or denervation-induced atrophy (models of muscle adaptation where endogenous miR-206 expression is altered). Vector-mediated manipulation of miR-206 activity in these models of cell growth and wasting did not alter gain or loss of muscle mass respectively. Our data demonstrate that although the miR-206/HDAC4 axis operates in skeletal muscle, the post-natal expression of miR-206 is not a key regulator of basal skeletal muscle mass or specific modes of muscle growth and wasting. These studies support a context-dependent role of miR-206 in regulating hypertrophy that may be dispensable for maintaining or modifying the adult skeletal muscle phenotype

  2. Medulloblastoma with myogenic and/or melanotic differentiation does not align immunohistochemically with the genetically defined molecular subgroups.

    PubMed

    Gupta, Kirti; Jogunoori, Swathi; Satapathy, Ayusman; Salunke, Pravin; Kumar, Narendra; Radotra, Bishan Dass; Vasishta, Rakesh Kumar

    2018-05-01

    The World Health Organization classification of central nervous system neoplasms (2016 update) recognizes 4 histological variants and genetically defined molecular subgroups within medulloblastoma (MB). MB with myogenic differentiation is one of the rare variants, which is usually recognized as a pattern alongside the known histological variants. Because of its rarity, less is known about its molecular landscape and importantly about its placement in the current molecular schema. We aimed to analyze this rare variant for expression of 3 immunohistochemical markers conventionally used in molecular stratification of MB. Demographic profile and imaging details with survival outcome were also analyzed. Sixty-five MB cases were molecularly stratified using immunohistochemical markers (YAP1, GAB1, β-catenin). MB with myogenic differentiation and MB cases showing variable immunoreactivity with the above 3 antibodies were further evaluated for smooth muscle actin, desmin, myogenin, and HMB45. Seven cases were categorized as MB with myogenic and/or melanotic differentiation. Age ranged from 2 to 40 years with a male-to-female ratio of 1:1.3. In 4 cases, myogenic or melanotic differentiation was evident on histology, whereas in 3, differentiation was highlighted only with muscle markers. Interestingly, all 7 cases showed variable immunoreactivity with 3 molecular markers and did not follow the conventionally accepted algorithm used for molecular stratification. Follow-up period ranged from 9 to 57 months. Overall survival revealed a varied pattern, with 3 deaths and 4 patients being alive with no evidence of disease at last follow-up. Our results provide evidence that these variants are distinct and do not align immunohistochemically with the currently recognized genetic subgroups. Copyright © 2018 Elsevier Inc. All rights reserved.

  3. Transcriptome analyses based on genetic screens for Pax3 myogenic targets in the mouse embryo

    PubMed Central

    2010-01-01

    Background Pax3 is a key upstream regulator of the onset of myogenesis, controlling progenitor cell survival and behaviour as well as entry into the myogenic programme. It functions in the dermomyotome of the somite from which skeletal muscle derives and in progenitor cell populations that migrate from the somite such as those of the limbs. Few Pax3 target genes have been identified. Identifying genes that lie genetically downstream of Pax3 is therefore an important endeavour in elucidating the myogenic gene regulatory network. Results We have undertaken a screen in the mouse embryo which employs a Pax3GFP allele that permits isolation of Pax3 expressing cells by flow cytometry and a Pax3PAX3-FKHR allele that encodes PAX3-FKHR in which the DNA binding domain of Pax3 is fused to the strong transcriptional activation domain of FKHR. This constitutes a gain of function allele that rescues the Pax3 mutant phenotype. Microarray comparisons were carried out between Pax3GFP/+ and Pax3GFP/PAX3-FKHR preparations from the hypaxial dermomyotome of somites at E9.5 and forelimb buds at E10.5. A further transcriptome comparison between Pax3-GFP positive and negative cells identified sequences specific to myogenic progenitors in the forelimb buds. Potential Pax3 targets, based on changes in transcript levels on the gain of function genetic background, were validated by analysis on loss or partial loss of function Pax3 mutant backgrounds. Sequences that are up- or down-regulated in the presence of PAX3-FKHR are classified as somite only, somite and limb or limb only. The latter should not contain sequences from Pax3 positive neural crest cells which do not invade the limbs. Verification by whole mount in situ hybridisation distinguishes myogenic markers. Presentation of potential Pax3 target genes focuses on signalling pathways and on transcriptional regulation. Conclusions Pax3 orchestrates many of the signalling pathways implicated in the activation or repression of myogenesis

  4. Alteration in gene expression in Nile tilapia (Oreochromis niloticus) juveniles submitted to fasting and refeeding.

    USDA-ARS?s Scientific Manuscript database

    One of the most important biological processes in living organisms that are affected by environmental fluctuations is growth, and the skeletal muscle growth in fish is dependent on proliferation and differentiation of myogenic precursor cells that are activated by Myogenic Regulatory Factors or inhi...

  5. Factors affecting the structure and maturation of human tissue engineered skeletal muscle.

    PubMed

    Martin, Neil R W; Passey, Samantha L; Player, Darren J; Khodabukus, Alastair; Ferguson, Richard A; Sharples, Adam P; Mudera, Vivek; Baar, Keith; Lewis, Mark P

    2013-07-01

    Tissue engineered skeletal muscle has great utility in experimental studies of physiology, clinical testing and its potential for transplantation to replace damaged tissue. Despite recent work in rodent tissue or cell lines, there is a paucity of literature concerned with the culture of human muscle derived cells (MDCs) in engineered constructs. Here we aimed to tissue engineer for the first time in the literature human skeletal muscle in self-assembling fibrin hydrogels and determine the effect of MDC seeding density and myogenic proportion on the structure and maturation of the constructs. Constructs seeded with 4 × 10(5) MDCs assembled to a greater extent than those at 1 × 10(5) or 2 × 10(5), and immunostaining revealed a higher fusion index and a higher density of myotubes within the constructs, showing greater structural semblance to in vivo tissue. These constructs primarily expressed perinatal and slow type I myosin heavy chain mRNA after 21 days in culture. In subsequent experiments MACS(®) technology was used to separate myogenic and non-myogenic cells from their heterogeneous parent population and these cells were seeded at varying myogenic (desmin +) proportions in fibrin based constructs. Only in the constructs seeded with 75% desmin + cells was there evidence of striations when immunostained for slow myosin heavy chain compared with constructs seeded with 10 or 50% desmin + cells. Overall, this work reveals the importance of cell number and myogenic proportions in tissue engineering human skeletal muscle with structural resemblance to in vivo tissue. Copyright © 2013 Elsevier Ltd. All rights reserved.

  6. Gender differences in myogenic regulation along the vascular tree of the gerbil cochlea.

    PubMed

    Reimann, Katrin; Krishnamoorthy, Gayathri; Wier, Withrow Gil; Wangemann, Philine

    2011-01-01

    Regulation of cochlear blood flow is critical for hearing due to its exquisite sensitivity to ischemia and oxidative stress. Many forms of hearing loss such as sensorineural hearing loss and presbyacusis may involve or be aggravated by blood flow disorders. Animal experiments and clinical outcomes further suggest that there is a gender preference in hearing loss, with males being more susceptible. Autoregulation of cochlear blood flow has been demonstrated in some animal models in vivo, suggesting that similar to the brain, blood vessels supplying the cochlea have the ability to control flow within normal limits, despite variations in systemic blood pressure. Here, we investigated myogenic regulation in the cochlear blood supply of the Mongolian gerbil, a widely used animal model in hearing research. The cochlear blood supply originates at the basilar artery, followed by the anterior inferior cerebellar artery, and inside the inner ear, by the spiral modiolar artery and the radiating arterioles that supply the capillary beds of the spiral ligament and stria vascularis. Arteries from male and female gerbils were isolated and pressurized using a concentric pipette system. Diameter changes in response to increasing luminal pressures were recorded by laser scanning microscopy. Our results show that cochlear vessels from male and female gerbils exhibit myogenic regulation but with important differences. Whereas in male gerbils, both spiral modiolar arteries and radiating arterioles exhibited pressure-dependent tone, in females, only radiating arterioles had this property. Male spiral modiolar arteries responded more to L-NNA than female spiral modiolar arteries, suggesting that NO-dependent mechanisms play a bigger role in the myogenic regulation of male than female gerbil cochlear vessels.

  7. Langerhans cell precursors acquire RANK/CD265 in prenatal human skin

    PubMed Central

    Schöppl, Alice; Botta, Albert; Prior, Marion; Akgün, Johnnie; Schuster, Christopher; Elbe-Bürger, Adelheid

    2015-01-01

    The skin is the first barrier against foreign pathogens and the prenatal formation of a strong network of various innate and adaptive cells is required to protect the newborn from perinatal infections. While many studies about the immune system in healthy and diseased adult human skin exist, our knowledge about the cutaneous prenatal/developing immune system and especially about the phenotype and function of antigen-presenting cells such as epidermal Langerhans cells (LCs) in human skin is still scarce. It has been shown previously that LCs in healthy adult human skin express receptor activator of NF-κB (RANK), an important molecule prolonging their survival. In this study, we investigated at which developmental stage LCs acquire this important molecule. Immunofluorescence double-labeling of cryostat sections revealed that LC precursors in prenatal human skin either do not yet [10–11 weeks of estimated gestational age (EGA)] or only faintly (13–15 weeks EGA) express RANK. LCs express RANK at levels comparable to adult LCs by the end of the second trimester. Comparable with adult skin, dermal antigen-presenting cells at no gestational age express this marker. These findings indicate that epidermal leukocytes gradually acquire RANK during gestation – a phenomenon previously observed also for other markers on LCs in prenatal human skin. PMID:25722033

  8. Clinical application of vestibular evoked myogenic potential (VEMP).

    PubMed

    Murofushi, Toshihisa

    2016-08-01

    The author reviewed clinical aspects of vestibular evoked myogenic potentials (VEMPs). Now two types of VEMPs are available. The first one is cervical VEMP, which is recorded in the sternocleidomastoid muscle and predominantly reflects sacculo-collic reflex. The other is ocular VEMP, which is usually recorded below the lower eye lid and predominantly reflects utriculo-ocular reflex. VEMPs play important roles not only for assessment of common vestibular diseases but also for establishment of new clinical entities. Clinical application in Meniere's disease, vestibular neuritis, benign paroxysmal positional vertigo, vestibular migraine, idiopathic otolithic vertigo, and central vertigo/dizziness was reviewed. Copyright © 2015 Elsevier Ireland Ltd. All rights reserved.

  9. [Effect of acoustic stimulus intensity on air-conducted sound elicited ocular vestibular-evoked myogenic potential and cervical vestibular-evoked myogenic potential].

    PubMed

    Zhang, Rui; Xu, Min; Zhang, Qing; Yang, Yin-Tong; Chen, Yanfei

    2014-06-01

    To observe the effect of acoustic stimulus intensity on air-conducted sound elicited ocular vestibular- evoked myogenic potential (oVEMP) and cervical vestibular-evoked myogenic potential (cVEMP) in normal young Chinese subjects. Thirty-five normal subjects aged 4-40 years (20.80∓8.89 years), including 16 males and 19 females, were recruited for conventional oVEMP and cVEMP examinations. The responses obtained from each side using 500 Hz tone bursts were divided into 6 groups according to different sound intensities (100, 95, 90, 85, 80 and 75dB nHL). The response rate and normal parameters of each stimulus intensity group were calculated. As the acoustic stimulus intensity decreased, the oVEMP response rate decreased from 100% in both 100 dB nHL and 95dB nHL groups to 97.14% (90 dB nHL), 54.29% (85 dB nHL), 14.29% (80 dB nHL), and 2.86% (75 dB nHL), and the response rate of cVEMP, 100% in both 100 dB nHL and 95dB nHL groups, was lowered to 97.14% (90 dB nHL), 84.29% (85 dB nHL), 38.57% (80 dB nHL) and 8.57% (75 dB nHL). The response rate and the parameters were comparable between 100 and 95 dB nHL groups. As the acoustic stimulus intensity decreases, both oVEMP and cVEMP show decreased response rate and amplitude. For Chinese subjects under 40 years of age, we recommend 95dB nHL as the maximum initial stimulus intensity in VEMPs test.

  10. HMC-1 human mast cells synthesize neurotensin (NT) precursor, secrete bioactive NT-like peptide(s) and express NT receptor NTS1.

    PubMed

    Cochrane, David E; Carraway, Robert E; Harrington, Kimberly; Laudano, Melissa; Rawlings, Stephen; Feldberg, Ross S

    2011-12-01

    To determine if mast cells synthesize the inflammatory peptide, neurotensin (NT), secrete immunoreactive and bioactive NT, and express the NT receptor NTS1. HMC-1 cells, pleural mast cells from Sprague-Dawley rats, LAD2 mast cells, and human cord blood mast cells were used. HMC-1 cells were stimulated with NT, C48/80, mastoparan, or PGE(2). For changes in cutaneous vascular permeability, anesthetized rats were injected intravenously with Evans Blue dye and intradermally with saline, NT, histamine, diphenhydramine, and C48/80. RT-PCR was used to identify RNA transcripts. Histamine was measured by fluorometric assay. In vivo cutaneous vascular permeability assays, radio-immunoassays for NT, Western blotting for the NT precursor protein and NTS1 protein from HMC-1 cells and tissues from rats were used. Immunohistochemistry was used to identify NT precursor-like proteins in HMC-1 mast cells. HMC-1 cells express mRNAs for NT precursor, PC5A processing enzyme and NTS1 receptor. Human cord blood mast cells and LAD2 mast cells express mRNA transcripts for NT precursor and NTS1. Western blotting showed NT precursor and NTS1 receptor in HMC1. Rat tissues with high numbers of mast cells contained NT precursor proteins. NT-like peptides from HMC-1 displayed NT-like bioactivity. HMC-1 mast cells synthesize and secrete immunoreactive and bioactive NT-like peptide(s) and express the NT receptor, suggesting that NT from mast cells might serve autocrine and paracrine roles.

  11. Impaired myogenic response and autoregulation of cerebral blood flow is rescued in CYP4A1 transgenic Dahl salt-sensitive rat

    PubMed Central

    Fan, Fan; Geurts, Aron M.; Murphy, Sydney R.; Pabbidi, Mallikarjuna R.; Jacob, Howard J.

    2014-01-01

    We have reported that a reduction in renal production of 20-HETE contributes to development of hypertension in Dahl salt-sensitive (SS) rats. The present study examined whether 20-HETE production is also reduced in the cerebral vasculature of SS rats and whether this impairs the myogenic response and autoregulation of cerebral blood flow (CBF). The production of 20-HETE, the myogenic response of middle cerebral arteries (MCA), and autoregulation of CBF were compared in SS, SS-5BN rats and a newly generated CYP4A1 transgenic rat. 20-HETE production was 6-fold higher in cerebral arteries of CYP4A1 and SS-5BN than in SS rats. The diameter of the MCA decreased to 70 ± 3% to 65 ± 6% in CYP4A1 and SS-5BN rats when pressure was increased from 40 to 140 mmHg. In contrast, the myogenic response of MCA isolated from SS rats did not constrict. Administration of a 20-HETE synthesis inhibitor, HET0016, abolished the myogenic response of MCA in CYP4A1 and SS-5BN rats but had no effect in SS rats. Autoregulation of CBF was impaired in SS rats compared with CYP4A1 and SS-5BN rats. Blood-brain barrier leakage was 5-fold higher in the brain of SS rats than in SS-5BN and SS.CYP4A1 rats. These findings indicate that a genetic deficiency in the formation of 20-HETE contributes to an impaired myogenic response in MCA and autoregulation of CBF in SS rats and this may contribute to vascular remodeling and cerebral injury following the onset of hypertension. PMID:25540098

  12. Induction of multipotential hematopoietic progenitors from human pluripotent stem cells via re-specification of lineage-restricted precursors

    PubMed Central

    Doulatov, Sergei; Vo, Linda T.; Chou, Stephanie S.; Kim, Peter G.; Arora, Natasha; Li, Hu; Hadland, Brandon K.; Bernstein, Irwin D.; Collins, James J.; Zon, Leonard I.; Daley, George Q.

    2013-01-01

    Summary Human pluripotent stem cells (hPSCs) represent a promising source of patient-specific cells for disease modeling, drug screens, and cellular therapies. However, the inability to derive engraftable human hematopoietic stem and progenitor (HSPCs) has limited their characterization to in vitro assays. We report a strategy to re-specify lineage-restricted CD34+CD45+ myeloid precursors derived from hPSCs into multilineage progenitors that can be expanded in vitro and engraft in vivo. HOXA9, ERG, and RORA conferred self-renewal and multilineage potential in vitro and maintained primitive CD34+CD38− cells. Screening cells via transplantation revealed that two additional factors, SOX4 and MYB, were required for engraftment. Progenitors specified with all five factors gave rise to reproducible short-term engraftment with myeloid and erythroid lineages. Erythroid precursors underwent hemoglobin switching in vivo, silencing embryonic and activating adult globin expression. Our combinatorial screening approach establishes a strategy for obtaining transcription factor-mediated engraftment of blood progenitors from human pluripotent cells. PMID:24094326

  13. 17ß-Estradiol increases non-CpG methylation in exon 1 of the rainbow trout (Oncorhynchus mykiss) MyoD gene

    USDA-ARS?s Scientific Manuscript database

    CpH methylations are epigenetic markers enriched in stem cells which are lost during cell differentiation. DNMT3a and DNMT3b are de novo methyltransferases contributing to CpH methylations. MyoD is an important myogenic transcription factor necessary for the differentiation of myogenic precursor cel...

  14. Stabilin-2 modulates the efficiency of myoblast fusion during myogenic differentiation and muscle regeneration

    PubMed Central

    Park, Seung-Yoon; Yun, Youngeun; Lim, Jung-Suk; Kim, Mi-Jin; Kim, Sang-Yeob; Kim, Jung-Eun; Kim, In-San

    2016-01-01

    Myoblast fusion is essential for the formation of skeletal muscle myofibres. Studies have shown that phosphatidylserine is necessary for myoblast fusion, but the underlying mechanism is not known. Here we show that the phosphatidylserine receptor stabilin-2 acts as a membrane protein for myoblast fusion during myogenic differentiation and muscle regeneration. Stabilin-2 expression is induced during myogenic differentiation, and is regulated by calcineurin/NFAT signalling in myoblasts. Forced expression of stabilin-2 in myoblasts is associated with increased myotube formation, whereas deficiency of stabilin-2 results in the formation of small, thin myotubes. Stab2-deficient mice have myofibres with small cross-sectional area and few myonuclei and impaired muscle regeneration after injury. Importantly, myoblasts lacking stabilin-2 have reduced phosphatidylserine-dependent fusion. Collectively, our results show that stabilin-2 contributes to phosphatidylserine-dependent myoblast fusion and provide new insights into the molecular mechanism by which phosphatidylserine mediates myoblast fusion during muscle growth and regeneration. PMID:26972991

  15. The cost-effectiveness of TheraBite® as treatment for acute myogenic temporomandibular disorder.

    PubMed

    Heres Diddens, Andreas; Kraaijenga, Sophie; Coupé, Veerle; Hilgers, Frans; van der Molen, Lisette; Smeele, Ludi; Retèl, Valesca

    2017-09-01

    Temporomandibular disorder (TMD) is a very common and costly pain problem concerning the temporomandibular joint. A previous study has shown that for the treatment of acute myogenic TMD, TheraBite® (TB) offers a faster and greater effect than usual care consisting of physical therapy (PT). This study estimates the cost-effectiveness of TB compared to PT. Differences in costs and quality-adjusted life-years (QALYs) between TB and PT are analyzed using a decision model. The point estimate for the incremental cost-effectiveness ratio is -28,068 EUR (-30,191 USD) per QALY (dominant) for TB versus PT. At the willingness-to-pay ratio of 20,000 EUR (21,513 USD) per QALY, TB has a 97% probability of being cost-effective compared to PT. TB is expected to be cost-effective compared to PT for the treatment of acute myogenic TMD, offering faster recovery of quality of life for patients, at a lower cost to society.

  16. Successful Implantation of Bioengineered, Intrinsically Innervated, Human Internal Anal Sphincter

    PubMed Central

    Raghavan, Shreya; Gilmont, Robert R.; Miyasaka, Eiichi A.; Somara, Sita; Srinivasan, Shanthi; Teitelbaum, Daniel H; Bitar, Khalil N.

    2011-01-01

    Background & Aims To restore fecal continence, the weakened pressure of the internal anal sphincter (IAS) must be increased. We bioengineered intrinsically innervated human IAS, to emulate sphincteric physiology, in vitro. Methods We co-cultured human IAS circular smooth muscle with immortomouse fetal enteric neurons. We investigated the ability of bioengineered innervated human IAS, implanted in RAG1−/− mice, to undergo neovascularization and preserve the physiology of the constituent myogenic and neuronal components. Results The implanted IAS was neovascularized in vivo; numerous blood vessels were observed with no signs of inflammation or infection. Real-time force acquisition from implanted and pre-implant IAS showed distinct characteristics of IAS physiology. Features included the development of spontaneous myogenic basal tone; relaxation of 100% of basal tone in response to inhibitory neurotransmitter vasoactive intestinal peptide (VIP) and direct electrical field stimulation of the intrinsic innervation; inhibition of nitrergic and VIPergic EFS-induced relaxation (by antagonizing nitric oxide synthesis or receptor interaction); contraction in response to cholinergic stimulation with acetylcholine; and intact electromechanical coupling (evidenced by direct response to potassium chloride). Implanted, intrinsically innervated bioengineered human IAS tissue preserved the integrity and physiology of myogenic and neuronal components. Conclusion Intrinsically innervated human IAS bioengineered tissue can be successfully implanted in mice. This approach might be used to treat patients with fecal incontinence. PMID:21463628

  17. [Electromyographic differential diagnosis in cases of abducens nerve paresis with nuclear or distal neurogenic sive myogenic origine (author's transl)].

    PubMed

    Heuser, M

    1979-09-01

    Abducens nerve paresis may be of nuclear, of peripheral distal neurogenic origine, or is simulated by a myogenic weakness of abduction. Polygraphic emg analysis of the oculoauricularphenomenon (oap) permits a differentiation. In the emg, the oap proved to be a physiologic and constant automatic and always bilateral interaction between the hemolateral abducens nerve and both Nn. faciales with corresponding and obligatory coinnervation of the Mm. retroauricularis of the external ear. In case of medullary, nuclear or internuclear lesions, the oap is disturbed, instable, diminished or abolished, whereas in distal neurogenic or myogenic paresis, even in complete paralysis the oap is bilaterally well preserved.

  18. Next Gen NEAR: Near Earth Asteroid Human Robotic Precursor Mission Concept

    NASA Technical Reports Server (NTRS)

    Rivkin, Andrew S.; Kirby, Karen; Cheng, Andrew F.; Gold, Robert; Kelly, Daniel; Reed, Cheryl; Abell, Paul; Garvin, James; Landis, Rob

    2012-01-01

    Asteroids have long held the attention of the planetary science community. In particular, asteroids that evolve into orbits near that of Earth, called near-Earth objects (NEO), are of high interest as potential targets for exploration due to the relative ease (in terms of delta V) to reach them. NASA's Flexible Path calls for missions and experiments to be conducted as intermediate steps towards the eventual goal of human exploration of Mars; piloted missions to NEOs are such example. A human NEO mission is a valuable exploratory step beyond the Earth-Moon system enhancing capabilities that surpass our current experience, while also developing infrastructure for future mars exploration capabilities. To prepare for a human rendezvous with an NEO, NASA is interested in pursuing a responsible program of robotic NEO precursor missions. Next Gen NEAR is such a mission, building on the NEAR Shoemaker mission experience at the JHU/APL Space Department, to provide an affordable, low risk solution with quick data return. Next Gen NEAR proposes to make measurements needed for human exploration to asteroids: to demonstrate proximity operations, to quantify hazards for human exploration and to characterize an environment at a near-Earth asteroid representative of those that may be future human destinations. The Johns Hopkins University Applied Physics Laboratory has demonstrated exploration-driven mission feasibility by developing a versatile spacecraft design concept using conventional technologies that satisfies a set of science, exploration and mission objectives defined by a concept development team in the summer of 2010. We will describe the mission concept and spacecraft architecture in detail. Configuration options were compared with the mission goals and objectives in order to select the spacecraft design concept that provides the lowest cost, lowest implementation risk, simplest operation and the most benefit for the mission implementation. The Next Gen NEAR

  19. Langerhans cell precursors acquire RANK/CD265 in prenatal human skin.

    PubMed

    Schöppl, Alice; Botta, Albert; Prior, Marion; Akgün, Johnnie; Schuster, Christopher; Elbe-Bürger, Adelheid

    2015-01-01

    The skin is the first barrier against foreign pathogens and the prenatal formation of a strong network of various innate and adaptive cells is required to protect the newborn from perinatal infections. While many studies about the immune system in healthy and diseased adult human skin exist, our knowledge about the cutaneous prenatal/developing immune system and especially about the phenotype and function of antigen-presenting cells such as epidermal Langerhans cells (LCs) in human skin is still scarce. It has been shown previously that LCs in healthy adult human skin express receptor activator of NF-κB (RANK), an important molecule prolonging their survival. In this study, we investigated at which developmental stage LCs acquire this important molecule. Immunofluorescence double-labeling of cryostat sections revealed that LC precursors in prenatal human skin either do not yet [10-11 weeks of estimated gestational age (EGA)] or only faintly (13-15 weeks EGA) express RANK. LCs express RANK at levels comparable to adult LCs by the end of the second trimester. Comparable with adult skin, dermal antigen-presenting cells at no gestational age express this marker. These findings indicate that epidermal leukocytes gradually acquire RANK during gestation - a phenomenon previously observed also for other markers on LCs in prenatal human skin. Copyright © 2015 The Authors. Published by Elsevier GmbH.. All rights reserved.

  20. A karyometric note on nucleoli in human early granulocytic precursors.

    PubMed

    Smetana, K; Mikulenková, D; Jirásková, I; Klamová, H

    2006-01-01

    The diameter of nucleoli was measured in human bone marrow early granulocytic precursors after visualization by a simple cytochemical method for demonstration of RNA. Such method facilitated to clearly see nucleolar bodies without perinucleolar chromatin, including those of micronucleoli. The bone marrow of patients suffering from chronic myeloid leukaemia (untreated with cytostatics) provided a satisfactory number of both myeloblasts and promyelocytes for nucleolar measurements because of prevailing granulopoiesis. The direct nucleolar measurement was carried out on digitized and processed images on the screen at magnification 4,300x. It seems to be likely that the nucleolar size is directly related to the number of nucleoli per cell. The largest nucleoli were present in both myeloblasts and promyelocytes that possessed a single nucleolus. In contrast, the nucleolar diameter was significantly smaller in cells with multiple nucleoli. However, in cells with small multiple nucleoli, one of them was always larger and dominant with a large number of AgNORs. Such large nucleoli are possibly visible in specimens stained with panoptic procedures or methods staining nuclear chromatin or DNA. It should also be mentioned that both myeloblasts and promyelocytes mostly possessed two nucleoli with the mean diameter close to 1.5 microm. The incidence of early granulocytic precursors classified according to the nucleolar number and size strongly suggested that the various nucleolar number and nucleolar size in these cells might be related to the different stage of the cell cycle and might also explain their heterogeneity.

  1. Direct Chronic Effect of Steroid Hormones in Attenuating Uterine Arterial Myogenic Tone: Role of PKC/ERK1/2

    PubMed Central

    Xiao, Daliao; Huang, Xiaohui; Yang, Shumei; Zhang, Lubo

    2009-01-01

    Pregnancy is associated with a significant decrease in uterine vascular tone and an increase in uterine blood flow. The present study tested the hypothesis that estrogen and progesterone differentially regulate the ERK1/2 and PKC signaling pathways in vascular smooth muscle resulting in a decrease in uterine vascular myogenic tone in pregnancy. Uterine arteries were isolated from nonpregnant (NPUA) and near-term pregnant (PUA) sheep. Chronic treatment (48 h) of NPUA with 17β-estradiol and progesterone caused a significant decrease in PKC-mediated contractions and pressure-induced myogenic tone. In accordance, treatment of PUA for 48 h with ICI 182,780 and RU 486 significantly increased PKC-induced contractions and myogenic tone. In contrast, acute treatment for 30 min had no effects on uterine artery contractility. An ERK1/2 inhibitor PD098059 restored the chronic effect of steroids on PKC-mediated contractions in NPUA. ERK1/2 protein and mRNA levels were greater in PUA as compared with NPUA. 17β-Estradiol and progesterone increased ERK1/2 protein in NPUA. In agreement, ICI 182,780 and RU 486 caused a significant decrease in ERK1/2 protein in PUA. Western blot showed six PKC isozymes, α, βI, βII, δ, ε and ζ in the uterine arteries. 17β-Estradiol and progesterone decreased the particulate-to-cytosolic ratio of PKCα, ε, and ζ, respectively, in NPUA. ICI 182,780 and RU 486 increased them in PUA. The results indicate a direct chronic effect of the steroid hormones in the up-regulation of ERK1/2 expression and down-regulation of PKC signaling pathway, resulting in attenuated myogenic tone of uterine artery in pregnancy. PMID:19528364

  2. Sonic hedgehog acts cell-autonomously on muscle precursor cells to generate limb muscle diversity

    PubMed Central

    Anderson, Claire; Williams, Victoria C.; Moyon, Benjamin; Daubas, Philippe; Tajbakhsh, Shahragim; Buckingham, Margaret E.; Shiroishi, Toshihiko; Hughes, Simon M.; Borycki, Anne-Gaëlle

    2012-01-01

    How muscle diversity is generated in the vertebrate body is poorly understood. In the limb, dorsal and ventral muscle masses constitute the first myogenic diversification, as each gives rise to distinct muscles. Myogenesis initiates after muscle precursor cells (MPCs) have migrated from the somites to the limb bud and populated the prospective muscle masses. Here, we show that Sonic hedgehog (Shh) from the zone of polarizing activity (ZPA) drives myogenesis specifically within the ventral muscle mass. Shh directly induces ventral MPCs to initiate Myf5 transcription and myogenesis through essential Gli-binding sites located in the Myf5 limb enhancer. In the absence of Shh signaling, myogenesis is delayed, MPCs fail to migrate distally, and ventral paw muscles fail to form. Thus, Shh production in the limb ZPA is essential for the spatiotemporal control of myogenesis and coordinates muscle and skeletal development by acting directly to regulate the formation of specific ventral muscles. PMID:22987640

  3. Bradykinin mediates myogenic differentiation in murine myoblasts through the involvement of SK1/Spns2/S1P2 axis.

    PubMed

    Bruno, Gennaro; Cencetti, Francesca; Bernacchioni, Caterina; Donati, Chiara; Blankenbach, Kira Vanessa; Thomas, Dominique; Meyer Zu Heringdorf, Dagmar; Bruni, Paola

    2018-05-01

    Skeletal muscle tissue retains a remarkable regenerative capacity due to the activation of resident stem cells that in pathological conditions or after tissue damage proliferate and commit themselves into myoblasts. These immature myogenic cells undergo differentiation to generate new myofibers or repair the injured ones, giving a strong contribution to muscle regeneration. Cytokines and growth factors, potently released after tissue injury by leukocytes and macrophages, are not only responsible of the induction of the initial inflammatory response, but can also affect skeletal muscle regeneration. Growth factors exploit sphingosine kinase (SK), the enzyme that catalyzes the production of sphingosine 1-phosphate (S1P), to exert their biological effects in skeletal muscle. In this paper we show for the first time that bradykinin (BK), the leading member of kinin/kallikrein system, is able to induce myogenic differentiation in C2C12 myoblasts. Moreover, evidence is provided that SK1, the specific S1P-transporter spinster homolog 2 (Spns2) and S1P 2 receptor are involved in the action exerted by BK, since pharmacological inhibition/antagonism or specific down-regulation significantly alter BK-induced myogenic differentiation. Moreover, the molecular mechanism initiated by BK involves a rapid translocation of SK1 to plasma membrane, analyzed by time-lapse immunofluorescence analysis. The present study highlights the role of SK1/Spns2/S1P receptor 2 signaling axis in BK-induced myogenic differentiation, thus confirming the crucial involvement of this pathway in skeletal muscle cell biology. Copyright © 2018 Elsevier Inc. All rights reserved.

  4. Increased neuronal beta-amyloid precursor protein expression in human temporal lobe epilepsy: association with interleukin-1 alpha immunoreactivity.

    PubMed

    Sheng, J G; Boop, F A; Mrak, R E; Griffin, W S

    1994-11-01

    Levels of immunoreactive beta-amyloid precursor protein and interleukin-1 alpha were found to be elevated in surgically resected human temporal lobe tissue from patients with intractable epilepsy compared with postmortem tissue from neurologically unaffected patients (controls). In tissue from epileptics, the levels of the 135-kDa beta-amyloid precursor protein isoform were elevated to fourfold (p < 0.05) those of controls and those of the 130-kDa isoform to threefold (p < 0.05), whereas those of the 120-kDa isoform (p > 0.05) were not different from control values. beta-Amyloid precursor protein-immunoreactive neurons were 16 times more numerous, and their cytoplasm and proximal processes were more intensely immunoreactive in tissue sections from epileptics than controls (133 +/- 12 vs. 8 +/- 3/mm2; p < 0.001). However, neither beta-amyloid precursor protein-immunoreactive dystrophic neurites nor beta-amyloid deposits were found in this tissue. Interleukin-1 alpha-immunoreactive cells (microglia) were three times more numerous in epileptics than in controls (80 +/- 8 vs. 25 +/- 5/mm2; p < 0.001), and these cells were often found adjacent to beta-amyloid precursor protein-immunoreactive neuronal cell bodies. Our findings, together with functions established in vitro for interleukin-1, suggest that increased expression of this protein contributes to the increased levels of beta-amyloid precursor protein in epileptics, thus indicating a potential role for both of these proteins in the neuronal dysfunctions, e.g., hyperexcitability, characteristic of epilepsy.

  5. Quantitative comparison of the expression of myogenic regulatory factors in flounder ( Paralichthys olivaceus) embryos and adult tissues

    NASA Astrophysics Data System (ADS)

    Zhang, Yuqing; Tan, Xungang; Xu, Peng; Sun, Wei; Xu, Yongli; Zhang, Peijun

    2010-03-01

    MyoD, Myf5, and myogenin are myogenic regulatory factors that play important roles during myogenesis. It is thought that MyoD and Myf5 are required for myogenic determination, while myogenin is important for terminal differentiation and lineage maintenance. To better understand the function of myogenic regulatory factors in muscle development of flounder, an important economic fish in Asia, real-time quantitative RT-PCR was used to characterize the expression patterns of MyoD, Myf5, and myogenin at early stages of embryo development, and in different tissues of the adult flounder. The results show that, Myf5 is the first gene to be expressed during the early stages of flounder development, followed by MyoD and myogenin. The expressions of Myf5, yoD, and myogenin at the early stages have a common characteristic: expression gradually increased to a peak level, and then gradually decreased to an extremely low level. In the adult flounder, the expression of the three genes in muscle is much higher than that in other tissues, indicating that they are important for muscle growth and maintenance of grown fish. During embryonic stages, the expression level of MyoD might serve an important role in the balance between muscle cell differentiation and proliferation. When the MyoD expression is over 30% of its highest level, the muscle cells enter the differentiation stage.

  6. Precursors and adjuncts of a lunar base

    NASA Technical Reports Server (NTRS)

    Burke, J. D.

    1988-01-01

    The automated, teleoperated, robotic and human-tended subsystems which will precede and accompany a lunar base program are discussed. The information about lunar conditions that can be provided by such precursors and adjuncts is addressed. The use of precursors and adjuncts for communications and navigation, for safety and survival, for lunar archives, and for entertainment and leisure is examined.

  7. The human gastrin precursor. Characterization of phosphorylated forms and fragments.

    PubMed Central

    Varro, A; Desmond, H; Pauwels, S; Gregory, H; Young, J; Dockray, G J

    1988-01-01

    There is a potential phosphorylation site in the C-terminal region of the precursor for the acid-stimulating hormone gastrin, which is immediately adjacent to an important cleavage point. In the present study we have sought to identify, separate, quantify and characterize phosphorylated and unphosphorylated forms of human progastrin and its fragments. Identification was made by two radioimmunoassays: (a) a novel assay employing an antibody raised to intact human progastrin; and (b) an assay using antibody reacting with the C-terminal tryptic fragment of human progastrin, as well as progastrin itself. Two forms of human progastrin isolated from a gastrinoma were separated by ion-exchange h.p.l.c., and had similar elution positions on reverse-phase h.p.l.c. and on gel filtration. The more acidic peptide contained close to equimolar amounts of phosphate. On trypsinization, peptides were released that co-eluted on ion-exchange h.p.l.c. with, and had the immunochemical properties of, naturally occurring C-terminal fragments of progastrin. One of the latter was isolated and shown by Edman degradation after derivatization with ethanethiol to have the sequence Ser (P)-Ala-Glu-Asp-Glu-Asn. Similar peptides occur in antral mucosa resected from ulcer patients. The unphosphorylated forms of progastrin predominated, whereas the phosphorylated forms of the C-terminal fragments were predominant. This distribution could be explained by preferential cleavage of phosphorylated progastrin. We conclude that in human progastrin, Ser-96 can occur in the phosphorylated form; this residue immediately follows a pair of basic residues (Arg-Arg) that are cleaved during synthesis of the biologically active product. PMID:3223964

  8. βENaC acts as a mechanosensor in renal vascular smooth muscle cells that contributes to renal myogenic blood flow regulation, protection from renal injury and hypertension.

    PubMed

    Drummond, Heather A; Stec, David E

    2015-06-01

    Pressure-induced constriction (also known as the "myogenic response") is an important mechanodependent response in small renal arteries and arterioles. The response is initiated by vascular smooth muscle cell (VSMC) stretch due to an increase in intraluminal pressure and leads to vasoconstriction. The myogenic response has two important roles as a mechanism of local blood flow autoregulation and protection against systemic blood pressure-induced microvascular damage. However, the molecular mechanisms underlying initiation of myogenic response are unresolved. Although several molecules have been considered initiators of the response, our laboratory has focused on the role of degenerin proteins because of their strong evolutionary link to mechanosensing in the nematode. Our laboratory has addressed the hypothesis that certain degenerin proteins act as mechanosensors in VSMCs. This article discusses the importance of a specific degenerin protein, β Epithelial Na + Channel (βENaC), in pressure-induced vasoconstriction, renal blood flow and susceptibility to renal injury. We propose that loss of the renal myogenic constrictor response delays the correction of renal blood flow that occurs with fluctuations in systemic pressure, which allows pressure swings to be transmitted to the microvasculature, thus increasing the susceptibility to renal injury and hypertension. The role of βENaC in myogenic regulation is independent of tubular βENaC and thus represents a non-tubular role for βENaC in renal-cardiovascular homeostasis.

  9. Differential muscle regulatory factor gene expression between larval and adult myogenesis in the frog Xenopus laevis: adult myogenic cell-specific myf5 upregulation and its relation to the notochord suppression of adult muscle differentiation.

    PubMed

    Yamane, Hitomi; Nishikawa, Akio

    2013-08-01

    During Xenopus laevis metamorphosis, larval-to-adult muscle conversion depends on the differential responses of adult and larval myogenic cells to thyroid hormone. Essential differences in cell growth, differentiation, and hormone-dependent life-or-death fate have been reported between cultured larval (tail) and adult (hindlimb) myogenic cells. A previous study revealed that tail notochord cells suppress terminal differentiation in adult (but not larval) myogenic cells. However, little is known about the differences in expression patterns of myogenic regulatory factors (MRF) and the satellite cell marker Pax7 between adult and larval myogenic cells. In the present study, we compared mRNA expression of these factors between the two types. At first, reverse transcription polymerase chain reaction analysis of hindlimb buds showed sequential upregulation of myf5, myogenin, myod, and mrf4 during stages 50-54, when limb buds elongate and muscles begin to form. By contrast, in the tail, there was no such increase during the same period. Secondary, these results were duplicated in vitro: adult myogenic cells upregulated myf5, myod, and pax7 in the early culture period, followed by myogenin upregulation and myotube differentiation, while larval myogenic cells did not upregulate these genes and precociously started myotube differentiation. Thirdly, myf5 upregulation and early-phase proliferation in adult myogenic cells were potently inhibited by the presence of notochord cells, suggesting that notochord cells suppress adult myogenesis through inhibiting the transition from Myf5(-) stem cells to Myf5(+) committed myoblasts. All of the data presented here suggest that myf5 upregulation can be a good criterion for the activation of adult myogenesis during X. laevis metamorphosis.

  10. Activation of Pax7-Positive Cells in a Non-Contractile Tissue Contributes to Regeneration of Myogenic Tissues in the Electric Fish S. macrurus

    PubMed Central

    Weber, Christopher M.; Martindale, Mark Q.; Tapscott, Stephen J.; Unguez, Graciela A.

    2012-01-01

    The ability to regenerate tissues is shared across many metazoan taxa, yet the type and extent to which multiple cellular mechanisms come into play can differ across species. For example, urodele amphibians can completely regenerate all lost tissues, including skeletal muscles after limb amputation. This remarkable ability of urodeles to restore entire limbs has been largely linked to a dedifferentiation-dependent mechanism of regeneration. However, whether cell dedifferentiation is the fundamental factor that triggers a robust regeneration capacity, and whether the loss or inhibition of this process explains the limited regeneration potential in other vertebrates is not known. Here, we studied the cellular mechanisms underlying the repetitive regeneration of myogenic tissues in the electric fish S. macrurus. Our in vivo microinjection studies of high molecular weight cell lineage tracers into single identified adult myogenic cells (muscle or noncontractile muscle-derived electrocytes) revealed no fragmentation or cellularization proximal to the amputation plane. In contrast, ultrastructural and immunolabeling studies verified the presence of myogenic stem cells that express the satellite cell marker Pax7 in mature muscle fibers and electrocytes of S. macrurus. These data provide the first example of Pax-7 positive muscle stem cells localized within a non-contractile electrogenic tissue. Moreover, upon amputation, Pax-7 positive cells underwent a robust replication and were detected exclusively in regions that give rise to myogenic cells and dorsal spinal cord components revealing a regeneration process in S. macrurus that is dependent on the activation of myogenic stem cells for the renewal of both skeletal muscle and the muscle-derived electric organ. These data are consistent with the emergent concept in vertebrate regeneration that different tissues provide a distinct progenitor cell population to the regeneration blastema, and these progenitor cells

  11. Differences in the Expression and Distribution of Flotillin-2 in Chick, Mice and Human Muscle Cells

    PubMed Central

    Possidonio, Ana Claudia Batista; Soares, Carolina Pontes; Portilho, Débora Morueco; Midlej, Victor; Benchimol, Marlene; Butler-Browne, Gillian; Costa, Manoel Luis; Mermelstein, Claudia

    2014-01-01

    Myoblasts undergo a series of changes in the composition and dynamics of their plasma membranes during the initial steps of skeletal muscle differentiation. These changes are crucial requirements for myoblast fusion and allow the formation of striated muscle fibers. Membrane microdomains, or lipid rafts, have been implicated in myoblast fusion. Flotillins are scaffold proteins that are essential for the formation and dynamics of lipid rafts. Flotillins have been widely studied over the last few years, but still little is known about their role during skeletal muscle differentiation. In the present study, we analyzed the expression and distribution of flotillin-2 in chick, mice and human muscle cells grown in vitro. Primary cultures of chick myogenic cells showed a decrease in the expression of flotillin-2 during the first 72 hours of muscle differentiation. Interestingly, flotillin-2 was found to be highly expressed in chick myogenic fibroblasts and weakly expressed in chick myoblasts and multinucleated myotubes. Flotillin-2 was distributed in vesicle-like structures within the cytoplasm of chick myogenic fibroblasts, in the mouse C2C12 myogenic cell line, and in neonatal human muscle cells. Cryo-immunogold labeling revealed the presence of flotillin-2 in vesicles and in Golgi stacks in chick myogenic fibroblasts. Further, brefeldin A induced a major reduction in the number of flotillin-2 containing vesicles which correlates to a decrease in myoblast fusion. These results suggest the involvement of flotillin-2 during the initial steps of skeletal myogenesis. PMID:25105415

  12. Differences in the expression and distribution of flotillin-2 in chick, mice and human muscle cells.

    PubMed

    Possidonio, Ana Claudia Batista; Soares, Carolina Pontes; Portilho, Débora Morueco; Midlej, Victor; Benchimol, Marlene; Butler-Browne, Gillian; Costa, Manoel Luis; Mermelstein, Claudia

    2014-01-01

    Myoblasts undergo a series of changes in the composition and dynamics of their plasma membranes during the initial steps of skeletal muscle differentiation. These changes are crucial requirements for myoblast fusion and allow the formation of striated muscle fibers. Membrane microdomains, or lipid rafts, have been implicated in myoblast fusion. Flotillins are scaffold proteins that are essential for the formation and dynamics of lipid rafts. Flotillins have been widely studied over the last few years, but still little is known about their role during skeletal muscle differentiation. In the present study, we analyzed the expression and distribution of flotillin-2 in chick, mice and human muscle cells grown in vitro. Primary cultures of chick myogenic cells showed a decrease in the expression of flotillin-2 during the first 72 hours of muscle differentiation. Interestingly, flotillin-2 was found to be highly expressed in chick myogenic fibroblasts and weakly expressed in chick myoblasts and multinucleated myotubes. Flotillin-2 was distributed in vesicle-like structures within the cytoplasm of chick myogenic fibroblasts, in the mouse C2C12 myogenic cell line, and in neonatal human muscle cells. Cryo-immunogold labeling revealed the presence of flotillin-2 in vesicles and in Golgi stacks in chick myogenic fibroblasts. Further, brefeldin A induced a major reduction in the number of flotillin-2 containing vesicles which correlates to a decrease in myoblast fusion. These results suggest the involvement of flotillin-2 during the initial steps of skeletal myogenesis.

  13. A soluble and active form of Wnt-3a protein is involved in myogenic differentiation after cholesterol depletion.

    PubMed

    Portilho, Débora M; Martins, Eliane R; Costa, Manoel L; Mermelstein, Cláudia S

    2007-12-22

    Cholesterol is one of the major lipids of plasma membranes. Recently, we have shown that cholesterol depletion by methyl-beta-cyclodextrin (M beta CD) induces the activation of the Wnt/beta-catenin pathway and enhances myogenic differentiation. Here, we show that M beta CD-conditioned media accelerates myogenesis in a similar way as M beta CD does, suggesting that the effects induced by M beta CD could be caused by soluble factors present in the culture medium. Soluble Wnt-3 protein is significantly enhanced in M beta CD-conditioned medium. Wnt-3a-enriched media induces myogenesis as much as M beta CD does, whereas Wnt-5a-enriched media inhibits. We suggest that Wnt-3a is involved in the myogenic induction observed after cholesterol depletion.

  14. Heparan sulfates and the decrease of N-glycans promote early adipogenic differentiation rather than myogenesis of murine myogenic progenitor cells.

    PubMed

    Grassot, Vincent; Bouchatal, Amel; Da Silva, Anne; Chantepie, Sandrine; Papy-Garcia, Dulce; Maftah, Abderrahman; Gallet, Paul-François; Petit, Jean-Michel

    In vitro, extracted muscle satellite cells, called myogenic progenitor cells, can differentiate either in myotubes or preadipocytes, depending on environmental factors and the medium. Transcriptomic analyses on glycosylation genes during satellite cells differentiation into myotubes showed that 31 genes present a significant variation of expression at the early stages of murine myogenic progenitor cells (MPC) differentiation. In the present study, we analyzed the expression of 383 glycosylation related genes during murine MPC differentiation into preadipocytes and compared the data to those previously obtained during their differentiation into myotubes. Fifty-six glycosylation related genes are specifically modified in their expression during early adipogenesis. The variations correspond mainly to: a decrease of N-glycans, and of alpha (2,3) and (2,6) linked sialic acids, and to a high level of heparan sulfates. A high amount of TGF-β1 in extracellular media during early adipogenesis was also observed. It seems that the increases of heparan sulfates and TGF-β1 favor pre-adipogenic differentition of MPC and possibly prevent their myogenic differentiation. Copyright © 2016 International Society of Differentiation. Published by Elsevier B.V. All rights reserved.

  15. Nicotinic acid, nicotinamide, and nicotinamide riboside: a molecular evaluation of NAD+ precursor vitamins in human nutrition.

    PubMed

    Bogan, Katrina L; Brenner, Charles

    2008-01-01

    Although baseline requirements for nicotinamide adenine dinucleotide (NAD+) synthesis can be met either with dietary tryptophan or with less than 20 mg of daily niacin, which consists of nicotinic acid and/or nicotinamide, there is growing evidence that substantially greater rates of NAD+ synthesis may be beneficial to protect against neurological degeneration, Candida glabrata infection, and possibly to enhance reverse cholesterol transport. The distinct and tissue-specific biosynthetic and/or ligand activities of tryptophan, nicotinic acid, nicotinamide, and the newly identified NAD+ precursor, nicotinamide riboside, reviewed herein, are responsible for vitamin-specific effects and side effects. Because current data suggest that nicotinamide riboside may be the only vitamin precursor that supports neuronal NAD+ synthesis, we present prospects for human nicotinamide riboside supplementation and propose areas for future research.

  16. Vestibular-evoked myogenic potential (VEMP) to evaluate cervical myelopathy in human T-cell lymphotropic virus type I infection.

    PubMed

    Felipe, Lilian; Gonçalves, Denise Utsch; Santos, Marco Aurélio Rocha; Proietti, Fernando Augusto; Ribas, João Gabriel Ramos; Carneiro-Proietti, Anna Bárbara; Lambertucci, José Roberto

    2008-05-15

    Cross-seccional analysis. To define the clinical usefulness of vestibular-evoked myogenic potential (VEMP) in detecting cervical medullar involvement related to human T-cell lymphotropic virus type 1 (HTLV-1) associated myelopathy/tropical spastic paraparesis (HAM/TSP). VEMP is generated by acoustic or galvanic stimuli, passing through the vestibulo-spinal motor tract, the spinal nerves and recorded by means of surface electrodes on the sternocleidomastoid muscle. HAM/TSP is a progressive inflammatory myelopathy with predominant lesions at the thoracic spinal cord level, although the cervical spine can be affected. VEMP may be of value to investigate cervical myelopathy. Seventy-two individuals were evaluated of whom 30 HTLV-1 were seronegative and 42 HTLV-1 seropositive (22 asymptomatic, 10 with complaints of walking difficulty without definite HAM/TSP and 10 with definite HAM/TSP). VEMP was recorded using monaural delivered short tone burst (linear rise-fall 1 millisecond, plateau 2 milliseconds, 1 KHz) 118 dB NA, stimulation rate of 5 Hz, analysis time of 60 milliseconds, 200 stimuli, band pass filtered between 10 and 1.500 Hz. VEMP was normal in the seronegative group (30 controls). In the seropositive, abnormal VEMP was seen in 11 of 22 (50%) of the HTLV-1 asymptomatic carriers, in 7 of 10 (70%) of those with complaints of walking difficulty and in 8 of 10 (80%) of the HAM/TSP patients. In this last group, the pattern of response was different. No VEMP response was more frequent when compared with the HTLV-1 asymptomatic group (2-tailed P-value = 0.001). VEMP may possibly be useful to identify patients with cervical myelopathy and to distinguish variable degrees of functional damage. Minor injury would be related to latency prolongation and major injury to no potential-evoked response.

  17. CID-miRNA: A web server for prediction of novel miRNA precursors in human genome

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Tyagi, Sonika; Vaz, Candida; Gupta, Vipin

    2008-08-08

    microRNAs (miRNA) are a class of non-protein coding functional RNAs that are thought to regulate expression of target genes by direct interaction with mRNAs. miRNAs have been identified through both experimental and computational methods in a variety of eukaryotic organisms. Though these approaches have been partially successful, there is a need to develop more tools for detection of these RNAs as they are also thought to be present in abundance in many genomes. In this report we describe a tool and a web server, named CID-miRNA, for identification of miRNA precursors in a given DNA sequence, utilising secondary structure-based filteringmore » systems and an algorithm based on stochastic context free grammar trained on human miRNAs. CID-miRNA analyses a given sequence using a web interface, for presence of putative miRNA precursors and the generated output lists all the potential regions that can form miRNA-like structures. It can also scan large genomic sequences for the presence of potential miRNA precursors in its stand-alone form. The web server can be accessed at (http://mirna.jnu.ac.in/cidmirna/)« less

  18. Identifying the myogenic and metabolic components of cerebral autoregulation.

    PubMed

    Payne, S J

    2018-05-14

    Cerebral autoregulation is the term used to describe a number of mechanisms that act together to maintain a near constant cerebral blood flow in response to changes in arterial blood pressure. These mechanisms are complex and known to be affected in a range of cerebrovascular diseases. However, it can be difficult to assign an alteration in cerebral autoregulation to one of the underlying physiological mechanisms without the use of a complex mathematical model. In this paper, we thus set out a new approach that enables these mechanisms to be related to the autoregulation behaviour and hence inferred from experimental measurements. We show that the arteriolar response is a function of just three parameters, which we term the elastic, the myogenic and the metabolic sensitivity coefficients, and that the full vascular response is dependent upon only seven parameters. The ratio of the strengths of the myogenic and the metabolic responses is found to be in the range 2.5 to 5 over a wide range of pressure, indicating that the balance between the two appears to lie within this range. We validate the model with existing experimental data both at the level of an individual vessel and across the whole vasculature, and show that the results are consistent with findings from the literature. We then conduct a sensitivity analysis of the model to demonstrate which parameters are most important in determining the strength of static autoregulation, showing that autoregulation strength is predominantly set by the arteriolar sensitivity coefficients. This new approach could be used in future studies to help to interpret the components of the autoregulation response and how they are affected under different conditions, providing a greater insight into the fundamental processes that govern autoregulation. Copyright © 2018. Published by Elsevier Ltd.

  19. A missense mutation in the vasopressin-neurophysin precursor gene cosegregates with human autosomal dominant neurohypophyseal diabetes insipidus.

    PubMed Central

    Bahnsen, U; Oosting, P; Swaab, D F; Nahke, P; Richter, D; Schmale, H

    1992-01-01

    Familial neurohypophyseal diabetes insipidus in humans is a rare disease transmitted as an autosomal dominant trait. Affected individuals have very low or undetectable levels of circulating vasopressin and suffer from polydipsia and polyuria. An obvious candidate gene for the disease is the vasopressin-neurophysin (AVP-NP) precursor gene on human chromosome 20. The 2 kb gene with three exons encodes a composite precursor protein consisting of the neuropeptide vasopressin and two associated proteins, neurophysin and a glycopeptide. Cloning and nucleotide sequence analysis of both alleles of the AVP-NP gene present in a Dutch ADNDI family reveals a point mutation in one allele of the affected family members. Comparison of the nucleotide sequences shows a G----T transversion within the neurophysin-encoding exon B. This missense mutation converts a highly conserved glycine (Gly17 of neurophysin) to a valine residue. RFLP analysis of six related family members indicates cosegregation of the mutant allele with the DI phenotype. The mutation is not present in 96 chromosomes of an unrelated control group. These data suggest that a single amino acid exchange within a highly conserved domain of the human vasopressin-associated neurophysin is the primary cause of one form of ADNDI. Images PMID:1740104

  20. Differentiated evolutionary relationships among chordates from comparative alignments of multiple sequences of MyoD and MyoG myogenic regulatory factors.

    PubMed

    Oliani, L C; Lidani, K C F; Gabriel, J E

    2015-10-16

    MyoD and MyoG are transcription factors that have essential roles in myogenic lineage determination and muscle differentiation. The purpose of this study was to compare multiple amino acid sequences of myogenic regulatory proteins to infer evolutionary relationships among chordates. Protein sequences from Mus musculus (P10085 and P12979), human Homo sapiens (P15172 and P15173), bovine Bos taurus (Q7YS82 and Q7YS81), wild pig Sus scrofa (P49811 and P49812), quail Coturnix coturnix (P21572 and P34060), chicken Gallus gallus (P16075 and P17920), rat Rattus norvegicus (Q02346 and P20428), domestic water buffalo Bubalus bubalis (D2SP11 and A7L034), and sheep Ovis aries (Q90477 and D3YKV7) were searched from a non-redundant protein sequence database UniProtKB/Swiss-Prot, and subsequently analyzed using the Mega6.0 software. MyoD evolutionary analyses revealed the presence of three main clusters with all mammals branched in one cluster, members of the order Rodentia (mouse and rat) in a second branch linked to the first, and birds of the order Galliformes (chicken and quail) remaining isolated in a third. MyoG evolutionary analyses aligned sequences in two main clusters, all mammalian specimens grouped in different sub-branches, and birds clustered in a second branch. These analyses suggest that the evolution of MyoD and MyoG was driven by different pathways.

  1. Rejuvenation of MPTP-induced human neural precursor cell senescence by activating autophagy

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Zhu, Liang; Dong, Chuanming; Department of Anatomy and Neurobiology, The Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Nantong

    Aging of neural stem cell, which can affect brain homeostasis, may be caused by many cellular mechanisms. Autophagy dysfunction was found in aged and neurodegenerative brains. However, little is known about the relationship between autophagy and human neural stem cell (hNSC) aging. The present study used 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP) to treat neural precursor cells (NPCs) derived from human embryonic stem cell (hESC) line H9 and investigate related molecular mechanisms involved in this process. MPTP-treated NPCs were found to undergo premature senescence [determined by increased senescence-associated-β-galactosidase (SA-β-gal) activity, elevated intracellular reactive oxygen species level, and decreased proliferation] and weremore » associated with impaired autophagy. Additionally, the cellular senescence phenotypes were manifested at the molecular level by a significant increase in p21 and p53 expression, a decrease in SOD2 expression, and a decrease in expression of some key autophagy-related genes such as Atg5, Atg7, Atg12, and Beclin 1. Furthermore, we found that the senescence-like phenotype of MPTP-treated hNPCs was rejuvenated through treatment with a well-known autophagy enhancer rapamycin, which was blocked by suppression of essential autophagy gene Beclin 1. Taken together, these findings reveal the critical role of autophagy in the process of hNSC aging, and this process can be reversed by activating autophagy. - Highlights: • We successfully establish hESC-derived neural precursor cells. • MPTP treatment induced senescence-like state in hESC-derived NPCs. • MPTP treatment induced impaired autophagy of hESC-derived NPCs. • MPTP-induced hESC-derived NPC senescence was rejuvenated by activating autophagy.« less

  2. A canine model of Alzheimer's disease generated by overexpressing a mutated human amyloid precursor protein.

    PubMed

    Lee, Geun-Shik; Jeong, Yeon Woo; Kim, Joung Joo; Park, Sun Woo; Ko, Kyeong Hee; Kang, Mina; Kim, Yu Kyung; Jung, Eui-Man; Moon, Changjong; Hyun, Sang Hwan; Hwang, Kyu-Chan; Kim, Nam-Hyung; Shin, Taeyoung; Jeung, Eui-Bae; Hwang, Woo Suk

    2014-04-01

    Canines are considered the most authentic model for studying multifactorial human diseases, as these animals typically share a common environment with man. Somatic cell nuclear transfer (SCNT) technology along with genetic engineering of nuclear donor cells provides a unique opportunity for examining human diseases using transgenic canines. In the present study, we generated transgenic canines that overexpressed the human amyloid precursor protein (APP) gene containing well-characterized familial Alzheimer's disease (AD) mutations. We successfully obtained five out of six live puppies by SCNT. This was confirmed by observing the expression of green fluorescence protein in the body as a visual transgenic marker and the overexpression of the mutated APP gene in the brain. The transgenic canines developed AD-like symptoms, such as enlarged ventricles, an atrophied hippocampus, and β-amyloid plaques in the brain. Thus, the transgenic canines we created can serve as a novel animal model for studying human AD.

  3. DCEBIO facilitates myogenic differentiation via intermediate conductance Ca2+ activated K+ channel activation in C2C12 myoblasts.

    PubMed

    Tanaka, Shoko; Ono, Yuko; Sakamoto, Kazuho

    2017-04-01

    Membrane hyperpolarization is suggested to be a trigger for skeletal muscle differentiation. We investigated whether DCEBIO, an opener of the small/intermediate conductance Ca 2+ activated K + (SK Ca /IK Ca ) channels, increase myogenic differentiation in C2C12 skeletal myoblasts. DCEBIO significantly increased myotube formation, protein expression level of myosin heavy chain II, and mRNA expression level of myogenin in C2C12 myoblasts cultured in differentiation medium. DCEBIO induced myotube formation and hyperpolarization were reduced by the IK Ca channel blocker TRAM-34, but not by the SK Ca channel blocker apamin. These findings show that DCEBIO increases myogenic differentiation by activating IK Ca channels. Copyright © 2017 The Authors. Production and hosting by Elsevier B.V. All rights reserved.

  4. 5α-Androst-16-en-3α-ol β-D-glucuronide, precursor of 5α-androst-16-en-3α-ol in human sweat.

    PubMed

    Starkenmann, Christian; Mayenzet, Fabienne; Brauchli, Robert; Troccaz, Myriam

    2013-12-01

    5α-Androst-16-en-3α-ol (α-androstenol) is an important contributor to human axilla sweat odor. It is assumed that α-andostenol is excreted from the apocrine glands via a H2 O-soluble conjugate, and this precursor was formally characterized in this study for the first time in human sweat. The possible H2 O-soluble precursors, sulfate and glucuronide derivatives, were synthesized as analytical standards, i.e., α-androstenol, β-androstenol sulfates, 5α-androsta-5,16-dien-3β-ol (β-androstadienol) sulfate, α-androstenol β-glucuronide, α-androstenol α-glucuronide, β-androstadienol β-glucuronide, and α-androstenol β-glucuronide furanose. The occurrence of α-androstenol β-glucuronide was established by ultra performance liquid chromatography (UPLC)/MS (heated electrospray ionization (HESI)) in negative-ion mode in pooled human sweat, containing eccrine and apocrine secretions and collected from 25 female and 24 male underarms. Its concentration was of 79 ng/ml in female secretions and 241 ng/ml in male secretions. The release of α-androstenol was observed after incubation of the sterile human sweat or α-androstenol β-glucuronide with a commercial glucuronidase enzyme, the urine-isolated bacteria Streptococcus agalactiae, and the skin bacteria Staphylococcus warneri DSM 20316, Staphylococcus haemolyticus DSM 20263, and Propionibacterium acnes ATCC 6919, reported to have β-glucuronidase activities. We demonstrated that if α- and β-androstenols and androstadienol sulfates were present in human sweat, their concentrations would be too low to be considered as potential precursors of malodors; therefore, the H2 O-soluble precursor of α-androstenol in apocrine secretion should be a β-glucuronide. Copyright © 2013 Verlag Helvetica Chimica Acta AG, Zürich.

  5. Modulation of CaV1.2 calcium channel by neuropeptide W regulates vascular myogenic tone via G protein-coupled receptor 7.

    PubMed

    Ji, Li; Zhu, Huayuan; Chen, Hong; Fan, Wenyong; Chen, Junjie; Chen, Jing; Zhu, Guoqing; Wang, Juejin

    2015-12-01

    Neuropeptide W (NPW), an endogenous ligand for the G protein-coupled receptor 7 (GPR7), was first found to make important roles in central nerve system. In periphery, NPW was also present and regulated intracellular calcium homeostasis by L-type calcium channels. This study was designed to discover the effects of NPW-GPR7 on the function of CaV1.2 calcium channels in the vascular smooth muscle cells (VSMCs) and vasotone of arterial vessels. By whole-cell patch clamp, we studied the effects of NPW-23, the active form of NPW, on the CaV1.2 channels in the heterologously transfected human embryonic kidney 293 cells and VSMCs isolated from rat. Living system was used to explore the physiological function of NPW-23 in arterial myogenic tone. To investigate the pathological relevance, NPW mRNA level of mesenteric arteries was measured in the hypertensive and normotensive rats. NPW's receptor GPR7 was coexpressed with CaV1.2 channels in arterial smooth muscle. NPW-23 increased the ICa,L in transfected human embryonic kidney 293 cells and VSMCs via GPR7, which could be abrogated by phospholipase C (PLC)/protein kinase C (PKC) inhibitors, not protein kinase A or protein kinase G inhibitor. After NPW-23 application, the expression of pan phospho-PKC was increased; moreover, intracellular diacylglycerol level, the second messenger catalyzed by PLC, was increased 1.5-2-fold. Application with NPW-23 increased pressure-induced vasotone of the rat mesenteric arteries. Importantly, the expression of NPW was decreased in the hypertensive rats. NPW-23 regulates ICa,L via GPR7, which is mediated by PLC/PKC signaling, and such a mechanism plays a role in modulating vascular myogenic tone, which may involve in the development of vascular hypertension.

  6. Anterior midline point stop device (AMPS) in the treatment of myogenous TMDs: comparison with the stabilization splint and control group.

    PubMed

    Al Quran, Firas A M; Kamal, Mudar S

    2006-06-01

    Two occlusal splints, the full-arch stabilization splint and the anterior midline point stop (AMPS) device, were evaluated for their efficiency in relieving myogenous temporomandibular disorders (TMD). One hundred and fourteen patients with myogenous TMD were distributed into 3 groups. The first group was treated with the AMPS device, the second with the stabilization splint, and the third group was the control group. Pain intensity was scored using the visual analogue scale before treatment and 1 month and 3 months after treatment. Statistical Package for the Social Sciences (SPSS, Chicago, Ill) and multiple comparisons tests were used to compare results before and after treatment and to compare the groups. The use of AMPS device in the first group resulted in a significant improvement after 1 month and 3 months (P < or = .001) and showed a 56.66% pain reduction. A significant improvement was also noticed in the second group (P = .001) with a 47.71% pain reduction. Although pain reduction percentage appeared more in the first group, this was not statistically significant. There was a highly significant difference between groups treated with both kinds of splints and the control group. It was concluded that both types of occlusal splints are beneficial to patients with myogenous TMD.

  7. Myogenic Maturation by Optical-Training in Cultured Skeletal Muscle Cells.

    PubMed

    Asano, Toshifumi; Ishizuka, Toru; Yawo, Hiromu

    2017-01-01

    Optogenetic techniques are powerful tools for manipulating biological processes in identified cells using light under high temporal and spatial resolutions. Here, we describe an optogenetic training strategy to promote morphological maturation and functional development of skeletal muscle cells in vitro. Optical stimulation with a rhythmical frequency facilitates specific structural alignment of sarcomeric proteins. Optical stimulation also depolarizes the membrane potential, and induces contractile responses in synchrony with the given pattern of light pulses. These results suggest that optogenetic techniques can be employed to manipulate activity-dependent processes during myogenic development and control contraction of photosensitive skeletal muscle cells with high temporal and special precision.

  8. Cannabidiol Activates Neuronal Precursor Genes in Human Gingival Mesenchymal Stromal Cells.

    PubMed

    Soundara Rajan, Thangavelu; Giacoppo, Sabrina; Scionti, Domenico; Diomede, Francesca; Grassi, Gianpaolo; Pollastro, Federica; Piattelli, Adriano; Bramanti, Placido; Mazzon, Emanuela; Trubiani, Oriana

    2017-06-01

    In the last years, mesenchymal stromal cells (MSCs) from oral tissues have received considerable interest in regenerative medicine since they can be obtained with minimal invasive procedure and exhibit immunomodulatory properties. This study was aimed to investigate whether in vitro pre-treatment of MSCs obtained from human gingiva (hGMSCs) with Cannabidiol (CBD), a cannabinoid component produced by the plant Cannabis sativa, may promote human gingiva derived MSCs to differentiate toward neuronal precursor cells. Specifically, we have treated the hGMSCs with CBD (5 µM) for 24 h in order to evaluate the expression of genes involved in cannabidiol signaling, cell proliferation, self-renewal and multipotency, and neural progenitor cells differentiation. Next generation sequencing (NGS) demonstrated that CBD activates genes associated with G protein coupled receptor signaling in hGMSCs. Genes involved in DNA replication, cell cycle, proliferation, and apoptosis were regulated. Moreover, genes associated with the biological process of neuronal progenitor cells (NCPs) proliferation, neuron differentiation, neurogenesis, and nervous system development were significantly modulated. From our results, we hypothesize that human gingiva-derived MSCs conditioned with CBD could represent a valid method for improving the hGMSCs phenotype and thus might be a potential therapeutic tool in the treatment of neurodegenerative diseases. J. Cell. Biochem. 118: 1531-1546, 2017. © 2016 Wiley Periodicals, Inc. © 2016 Wiley Periodicals, Inc.

  9. An antigen shared by human granulocytes, monocytes, marrow granulocyte precursors and leukemic blasts.

    PubMed

    Shumak, K H; Rachkewich, R A

    1983-01-01

    An antibody to human granulocytes was raised in rabbits by immunization with granulocytes pretreated with rabbit antibody to contaminating antigens. The antibody reacted not only with granulocytes but also with monocytes and bone marrow granulocyte precursors including colony-forming units in culture (CFU-C). In tests with leukemic cells, the antibody reacted with blasts from most (8 of 9) patients with acute myelomonoblastic leukemia and from some patients with acute myeloblastic leukemia, morphologically undifferentiated acute leukemia and chronic myelogenous leukemia in blast crisis. The antibody did not react with blasts from patients with acute lymphoblastic leukemia nor with leukemic cells from patients with chronic lymphocytic leukemia.

  10. p21WAF1 expression induced by MEK/ERK pathway activation or inhibition correlates with growth arrest, myogenic differentiation and onco-phenotype reversal in rhabdomyosarcoma cells

    PubMed Central

    Ciccarelli, Carmela; Marampon, Francesco; Scoglio, Arianna; Mauro, Annunziata; Giacinti, Cristina; De Cesaris, Paola; Zani, Bianca M

    2005-01-01

    Background p21WAF1, implicated in the cell cycle control of both normal and malignant cells, can be induced by p53-dependent and independent mechanisms. In some cells, MEKs/ERKs regulate p21WAF1 transcriptionally, while in others they also affect the post-transcriptional processes. In myogenic differentiation, p21WAF1 expression is also controlled by the myogenic transcription factor MyoD. We have previously demonstrated that the embryonal rhabdomyosarcoma cell line undergoes growth arrest and myogenic differentiation following treatments with TPA and the MEK inhibitor U0126, which respectively activate and inhibit the ERK pathway. In this paper we attempt to clarify the mechanism of ERK-mediated and ERK-independent growth arrest and myogenic differentiation of embryonal and alveolar rhabdomyosarcoma cell lines, particularly as regards the expression of the cell cycle inhibitor p21WAF1. Results p21WAF1 expression and growth arrest are induced in both embryonal (RD) and alveolar (RH30) rhabdomyosarcoma cell lines following TPA or MEK/ERK inhibitor (U0126) treatments, whereas myogenic differentiation is induced in RD cells alone. Furthermore, the TPA-mediated post-transcriptional mechanism of p21WAF1-enhanced expression in RD cells is due to activation of the MEK/ERK pathway, as shown by transfections with constitutively active MEK1 or MEK2, which induces p21WAF1 expression, and with ERK1 and ERK2 siRNA, which prevents p21WAF1 expression. By contrast, U0126-mediated p21WAF1 expression is controlled transcriptionally by the p38 pathway. Similarly, myogenin and MyoD expression is induced both by U0126 and TPA and is prevented by p38 inhibition. Although MyoD and myogenin depletion by siRNA prevents U0126-mediated p21WAF1 expression, the over-expression of these two transcription factors is insufficient to induce p21WAF1. These data suggest that the transcriptional mechanism of p21WAF1 expression in RD cells is rescued when MEK/ERK inhibition relieves the functions of

  11. p21WAF1 expression induced by MEK/ERK pathway activation or inhibition correlates with growth arrest, myogenic differentiation and onco-phenotype reversal in rhabdomyosarcoma cells.

    PubMed

    Ciccarelli, Carmela; Marampon, Francesco; Scoglio, Arianna; Mauro, Annunziata; Giacinti, Cristina; De Cesaris, Paola; Zani, Bianca M

    2005-12-13

    p21WAF1, implicated in the cell cycle control of both normal and malignant cells, can be induced by p53-dependent and independent mechanisms. In some cells, MEKs/ERKs regulate p21WAF1 transcriptionally, while in others they also affect the post-transcriptional processes. In myogenic differentiation, p21WAF1 expression is also controlled by the myogenic transcription factor MyoD. We have previously demonstrated that the embryonal rhabdomyosarcoma cell line undergoes growth arrest and myogenic differentiation following treatments with TPA and the MEK inhibitor U0126, which respectively activate and inhibit the ERK pathway. In this paper we attempt to clarify the mechanism of ERK-mediated and ERK-independent growth arrest and myogenic differentiation of embryonal and alveolar rhabdomyosarcoma cell lines, particularly as regards the expression of the cell cycle inhibitor p21WAF1. p21WAF1 expression and growth arrest are induced in both embryonal (RD) and alveolar (RH30) rhabdomyosarcoma cell lines following TPA or MEK/ERK inhibitor (U0126) treatments, whereas myogenic differentiation is induced in RD cells alone. Furthermore, the TPA-mediated post-transcriptional mechanism of p21WAF1-enhanced expression in RD cells is due to activation of the MEK/ERK pathway, as shown by transfections with constitutively active MEK1 or MEK2, which induces p21WAF1 expression, and with ERK1 and ERK2 siRNA, which prevents p21WAF1 expression. By contrast, U0126-mediated p21WAF1 expression is controlled transcriptionally by the p38 pathway. Similarly, myogenin and MyoD expression is induced both by U0126 and TPA and is prevented by p38 inhibition. Although MyoD and myogenin depletion by siRNA prevents U0126-mediated p21WAF1 expression, the over-expression of these two transcription factors is insufficient to induce p21WAF1. These data suggest that the transcriptional mechanism of p21WAF1 expression in RD cells is rescued when MEK/ERK inhibition relieves the functions of myogenic

  12. Cervical flexion-rotation test and physiological range of motion - A comparative study of patients with myogenic temporomandibular disorder versus healthy subjects.

    PubMed

    Greenbaum, Tzvika; Dvir, Zeevi; Reiter, Shoshana; Winocur, Ephraim

    2017-02-01

    Temporomandibular Disorders (TMD) refer to several common clinical disorders which involve the masticatory muscles, the temporomandibular joint (TMJ) and the adjacent structures. Although neck signs and symptoms are found with higher prevalence in TMD patients compared to the overall population, whether limitation of cervical mobility is an additional positive finding in this cohort is still an open question. To compare the physiological cervical range of motion (CROM) and the extent of rotation during cervical flexion (flexion-rotation test, FRT) in people with TMD (muscular origin) and healthy control subjects. The range of motion of the neck and FRT was measured in 20 women with myogenic TMD and 20 age matched healthy controls. Women with myogenic TMD had significantly lower FRT scores compared to their matched healthy women. No difference was found between groups in CROM in any of the planes of movement. The FRT was positive (less than 32°) in 90% of the TMD participants versus 5% in the healthy control but the findings were not correlated with TMD severity. The results point out a potential involvement of the upper cervical joints (c1-c2) in women with myogenic TMD. Copyright © 2016 Elsevier Ltd. All rights reserved.

  13. Myogenic origin of the hypotension induced by rapid changes in posture in awake dogs following autonomic blockade

    PubMed Central

    Wong, Brett J.; Sheriff, Don D.

    2008-01-01

    The “push-pull” effect denotes the reduced tolerance to +Gz (hypergravity) when +Gz stress is preceded by exposure to hypogravity, i.e., fractional, zero, or negative Gz. The purpose of this study was to test the hypothesis that an exaggerated, myogenically mediated rise in leg vascular conductance contributes to the push-pull effect, using heart level arterial blood pressure as a measure of G tolerance. The approach was to impose control (30 s of 30° head-up tilt) and push-pull (30 s of 30° head-up tilt immediately preceded by 10 s of −15° head-down tilt) gravitational stress after administration of hexamethonium (5 mg/kg) to inhibit autonomic ganglionic neurotransmission in seven dogs. Cardiac output or thigh level arterial pressure (myogenic stimulus) was maintained constant by computer-controlled ventricular pacing. The animals were sedated with acepromazine and lightly restrained in lateral recumbency on a tilt table. Following the onset of head-up tilt, the magnitude of the fall in heart level arterial pressure from baseline was −11.6 ± 2.9 and −17.1 ± 2.2 mmHg for the control and push-pull trials, respectively (P < 0.05), when cardiac output was maintained constant. Over 40% of the exaggerated fall in heart level arterial pressure was attributable to an exaggerated rise in hindlimb vascular conductance (P < 0.05). Maintaining thigh level arterial pressure constant abolished the exaggerated rise in hindlimb blood flow. Thus a push-pull effect largely attributable to a myogenically induced rise in leg vascular conductance occurs when autonomic function is inhibited. PMID:18927267

  14. Differential expression of myogenic regulatory genes and Msx-1 during dedifferentiation and redifferentiation of regenerating amphibian limbs.

    PubMed

    Simon, H G; Nelson, C; Goff, D; Laufer, E; Morgan, B A; Tabin, C

    1995-01-01

    An amputated limb of an adult urodele amphibian is capable of undergoing regeneration. The new structures form from an undifferentiated mass of cells called the regenerative blastema. The cells of the blastema are believed to derive from differentiated tissues of the adult limb. However, the exact source of these cells and the process by which they undergo dedifferentiation are poorly understood. In order to elucidate the molecular and cellular basis for dedifferentiation we isolated a number of genes which are potential regulators of the process. These include Msx-1, which is believed to support the undifferentiated and proliferative state of cells in the embryonic limb bud; and two members of the myogenic regulatory gene family, MRF-4 and Myf-5, which are expressed in differentiated muscle and regulate muscle-specific gene activity. As anticipated, we find that Msx-1 is strongly up-regulated during the initiation of regeneration. It remains expressed throughout regeneration but is not found in the fully regenerated limb. The myogenic gene MRF-4 has the reverse expression pattern. It is expressed in adult limb muscle, is rapidly shut off in early regenerative blastemas, and is only reexpressed at the completion of regeneration. These kinetics are paralleled by those of a muscle-specific Myosin gene. In contrast Myf-5, a second member of the myogenic gene family, continues to be expressed throughout the regenerative process. Thus, MRF-4 and Myf-5 are likely to play distinct roles during regeneration. MRF-4 may directly regulate muscle phenotype and as such its repression may be a key event in dedifferentiation.(ABSTRACT TRUNCATED AT 250 WORDS)

  15. Myogenic regulatory factors during regeneration of skeletal muscle in young, adult, and old rats

    NASA Technical Reports Server (NTRS)

    Marsh, D. R.; Criswell, D. S.; Carson, J. A.; Booth, F. W.

    1997-01-01

    Myogenic factor mRNA expression was examined during muscle regeneration after bupivacaine injection in Fischer 344/Brown Norway F1 rats aged 3, 18, and 31 mo of age (young, adult, and old, respectively). Mass of the tibialis anterior muscle in the young rats had recovered to control values by 21 days postbupivacaine injection but in adult and old rats remained 40% less than that of contralateral controls at 21 and 28 days of recovery. During muscle regeneration, myogenin mRNA was significantly increased in muscles of young, adult, and old rats 5 days after bupivacaine injection. Subsequently, myogenin mRNA levels in young rat muscle decreased to postinjection control values by day 21 but did not return to control values in 28-day regenerating muscles of adult and old rats. The expression of MyoD mRNA was also increased in muscles at day 5 of regeneration in young, adult, and old rats, decreased to control levels by day 14 in young and adult rats, and remained elevated in the old rats for 28 days. In summary, either a diminished ability to downregulate myogenin and MyoD mRNAs in regenerating muscle occurs in old rat muscles, or the continuing myogenic effort includes elevated expression of these mRNAs.

  16. Skeletal muscle hypertrophy and regeneration: interplay between the myogenic regulatory factors (MRFs) and insulin-like growth factors (IGFs) pathways.

    PubMed

    Zanou, Nadège; Gailly, Philippe

    2013-11-01

    Adult skeletal muscle can regenerate in response to muscle damage. This ability is conferred by the presence of myogenic stem cells called satellite cells. In response to stimuli such as injury or exercise, these cells become activated and express myogenic regulatory factors (MRFs), i.e., transcription factors of the myogenic lineage including Myf5, MyoD, myogenin, and Mrf4 to proliferate and differentiate into myofibers. The MRF family of proteins controls the transcription of important muscle-specific proteins such as myosin heavy chain and muscle creatine kinase. Different growth factors are secreted during muscle repair among which insulin-like growth factors (IGFs) are the only ones that promote both muscle cell proliferation and differentiation and that play a key role in muscle regeneration and hypertrophy. Different isoforms of IGFs are expressed during muscle repair: IGF-IEa, IGF-IEb, or IGF-IEc (also known as mechano growth factor, MGF) and IGF-II. MGF is expressed first and is observed in satellite cells and in proliferating myoblasts whereas IGF-Ia and IGF-II expression occurs at the state of muscle fiber formation. Interestingly, several studies report the induction of MRFs in response to IGFs stimulation. Inversely, IGFs expression may also be regulated by MRFs. Various mechanisms are proposed to support these interactions. In this review, we describe the general process of muscle hypertrophy and regeneration and decipher the interactions between the two groups of factors involved in the process.

  17. Relationship between endolymphatic hydrops and vestibular-evoked myogenic potential.

    PubMed

    Katayama, Naomi; Yamamoto, Masako; Teranishi, Masaaki; Naganawa, Shinji; Nakata, Seiichi; Sone, Michihiko; Nakashima, Tsutomu

    2010-08-01

    Vestibular-evoked myogenic potential (VEMP) can be used to examine endolymphatic hydrops, especially in the vestibule. To investigate the relationship between the degree of endolymphatic hydrops revealed by magnetic resonance imaging (MRI) and VEMP. Gadolinium diluted with saline was injected intratympanically in 49 ears (40 patients). One day after the injection, the endolymphatic space in the vestibule and the cochlea was visualized by 3 Tesla MRI. A VEMP test was done, and VEMP was judged as absent when the VEMP was within the noise level. VEMP was present in 21 ears and absent in 28 ears. Endolymphatic hydrops was significantly associated with the disappearance of VEMP. Endolymphatic hydrops in the vestibule had a stronger effect than endolymphatic hydrops in the cochlea. Five patients with extremely large vestibular hydrops showed no response of VEMP.

  18. The functional performance of microencapsulated human pancreatic islet-derived precursor cells.

    PubMed

    Montanucci, Pia; Pennoni, Ilaria; Pescara, Teresa; Blasi, Paolo; Bistoni, Giovanni; Basta, Giuseppe; Calafiore, Riccardo

    2011-12-01

    We have examined long-term cultured, human islet-derived stem/precursor cells (hIPC). Whole human islets (HI) were obtained by multi-enzymatic digestion of cadaveric donor pancreases, plated on tissue flasks, and allowed to adhere and expand for several in vitro passages, in order to obtain hIPC. We detected specific stem cell markers (Oct-4, Sox-2, Nanog, ABCG2, Klf-4, CD117) in both intact HI and hIPC. Moreover, hIPC while retaining the expression of Glut-2, Pdx-1, CK-19, and ICA-512, started re-expressing Ngn3, thereby indicating acquisition of a specific pancreatic islet beta cell-oriented phenotype identity. The intrinsic plasticity of hIPC was documented by their ability to differentiate into various germ layer-derived cell phenotypes (ie, osteocytic, adipocytic and neural), including endocrine cells associated with insulin secretory capacity. To render hIPC suitable for transplantation we have enveloped them within our highly purified, alginate-based microcapsules. Upon intraperitoneal graft in NOD/SCID mice we have observed that the microcapsules acted as three-dimensional niches favouring post-transplant hIPC differentiation and acquisition of beta cell-like functional competence. Copyright © 2011 Elsevier Ltd. All rights reserved.

  19. Increased arterial smooth muscle Ca2+ signaling, vasoconstriction, and myogenic reactivity in Milan hypertensive rats

    PubMed Central

    Linde, Cristina I.; Karashima, Eiji; Raina, Hema; Zulian, Alessandra; Wier, Withrow G.; Hamlyn, John M.; Ferrari, Patrizia; Blaustein, Mordecai P.

    2012-01-01

    The Milan hypertensive strain (MHS) rats are a genetic model of hypertension with adducin gene polymorphisms linked to enhanced renal tubular Na+ reabsorption. Recently we demonstrated that Ca2+ signaling is augmented in freshly isolated mesenteric artery myocytes from MHS rats. This is associated with greatly enhanced expression of Na+/Ca2+ exchanger-1 (NCX1), C-type transient receptor potential (TRPC6) protein, and sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA2) compared with arteries from Milan normotensive strain (MNS) rats. Here, we test the hypothesis that the enhanced Ca2+ signaling in MHS arterial smooth muscle is directly reflected in augmented vasoconstriction [myogenic and phenylephrine (PE)-evoked responses] in isolated mesenteric small arteries. Systolic blood pressure was higher in MHS (145 ± 1 mmHg) than in MNS (112 ± 1 mmHg; P < 0.001; n = 16 each) rats. Pressurized mesenteric resistance arteries from MHS rats had significantly augmented myogenic tone and reactivity and enhanced constriction to low-dose (1–100 nM) PE. Isolated MHS arterial myocytes exhibited approximately twofold increased peak Ca2+ signals in response to 5 μM PE or ATP in the absence and presence of extracellular Ca2+. These augmented responses are consistent with increased vasoconstrictor-evoked sarcoplasmic reticulum (SR) Ca2+ release and increased Ca2+ entry, respectively. The increased SR Ca2+ release correlates with a doubling of inositol 1,4,5-trisphosphate receptor type 1 and tripling of SERCA2 expression. Pressurized MHS arteries also exhibited a ∼70% increase in 100 nM ouabain-induced vasoconstriction compared with MNS arteries. These functional alterations reveal that, in a genetic model of hypertension linked to renal dysfunction, multiple mechanisms within the arterial myocytes contribute to enhanced Ca2+ signaling and myogenic and vasoconstrictor-induced arterial constriction. MHS rats have elevated plasma levels of endogenous ouabain, which may initiate the

  20. Integrin αMβ2 is differently expressed by subsets of human osteoclast precursors and mediates adhesion of classical monocytes to bone

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sprangers, Sara, E-mail: s.l.sprangers@acta.nl; Schoenmaker, Ton, E-mail: t.schoenmaker@acta.nl; Department of Periodontology, Academic Centre for Dentistry Amsterdam

    Bone-degrading osteoclasts are formed through fusion of their monocytic precursors. In the population of human peripheral blood monocytes, three distinct subsets have been identified: classical, intermediate and non-classical monocytes. We have previously shown that when the monocyte subsets are cultured on bone, significantly more osteoclasts are formed from classical monocytes than from intermediate or non-classical monocytes. Considering that this difference does not exist when monocyte subsets are cultured on plastic, we hypothesized that classical monocytes adhere better to the bone surface compared to intermediate and non-classical monocytes. To investigate this, the different monocyte subsets were isolated from human peripheral bloodmore » and cultured on slices of human bone in the presence of the cytokine M-CSF. We found that classical monocytes adhere better to bone due to a higher expression of the integrin αMβ2 and that their ability to attach to bone is significantly decreased when the integrin is blocked. This suggests that integrin αMβ2 mediates attachment of osteoclast precursors to bone and thereby enables the formation of osteoclasts.« less

  1. Genetically engineered mouse models of human B-cell precursor leukemias.

    PubMed

    Hauer, Julia; Borkhardt, Arndt; Sánchez-García, Isidro; Cobaleda, César

    2014-01-01

    B-cell precursor acute lymphoblastic leukemias (pB-ALLs) are the most frequent type of malignancies of the childhood, and also affect an important proportion of adult patients. In spite of their apparent homogeneity, pB-ALL comprises a group of diseases very different both clinically and pathologically, and with very diverse outcomes as a consequence of their biology, and underlying molecular alterations. Their understanding (as a prerequisite for their cure) will require a sustained multidisciplinary effort from professionals coming from many different fields. Among all the available tools for pB-ALL research, the use of animal models stands, as of today, as the most powerful approach, not only for the understanding of the origin and evolution of the disease, but also for the development of new therapies. In this review we go over the most relevant (historically, technically or biologically) genetically engineered mouse models (GEMMs) of human pB-ALLs that have been generated over the last 20 years. Our final aim is to outline the most relevant guidelines that should be followed to generate an "ideal" animal model that could become a standard for the study of human pB-ALL leukemia, and which could be shared among research groups and drug development companies in order to unify criteria for studies like drug testing, analysis of the influence of environmental risk factors, or studying the role of both low-penetrance mutations and cancer susceptibility alterations.

  2. Cervical Vestibular-Evoked Myogenic Potentials: Norms and Protocols

    PubMed Central

    Isaradisaikul, Suwicha; Navacharoen, Niramon; Hanprasertpong, Charuk; Kangsanarak, Jaran

    2012-01-01

    Vestibular-evoked myogenic potential (VEMP) testing is a vestibular function test used for evaluating saccular and inferior vestibular nerve function. Parameters of VEMP testing include VEMP threshold, latencies of p1 and n1, and p1-n1 interamplitude. Less commonly used parameters were p1-n1 interlatency, interaural difference of p1 and n1 latency, and interaural amplitude difference (IAD) ratio. This paper recommends using air-conducted 500 Hz tone burst auditory stimulation presented monoaurally via an inserted ear phone while the subject is turning his head to the contralateral side in the sitting position and recording the responses from the ipsilateral sternocleidomastoid muscle. Normative values of VEMP responses in 50 normal audiovestibular volunteers were presented. VEMP testing protocols and normative values in other literature were reviewed and compared. The study is beneficial to clinicians as a reference guide to set up VEMP testing and interpretation of the VEMP responses. PMID:22577386

  3. Role of PUFAs, the precursors of endocannabinoids, in human obesity and type 2 diabetes.

    PubMed

    Dain, Alejandro; Repossi, Gaston; Das, Undurti N; Eynard, Aldo Renato

    2010-06-01

    Polyunsaturated fatty acids (PUFAs) serve as precursors of the endocannabinoids (ECs) that are bioactive lipids molecules. Recent studies revealed that ECs participate in several physiological and pathological processes including obesity and type 2 diabetes mellitus. Here we review the experimental and clinical aspects of the role of endocannabinoids in obesity and type 2 diabetes mellitus and the modification of the endocannabinoids by exogenously administered PUFAs. Based on these evidences, we propose that the endocannabinoid system (ECS) can be modulated by exogenous manipulation of PUFAs that could help in the prevention and management of human diseases such as obesity, metabolic syndrome and type 2 diabetes mellitus.

  4. Supplementation with IL-6 and Muscle Cell Culture Conditioned Media Enhances Myogenic Differentiation of Adipose Tissue-Derived Stem Cells through STAT3 Activation.

    PubMed

    Seo, Eunhui; Kang, Hwansu; Lim, Oh-Kyung; Jun, Hee-Sook

    2018-05-24

    Mature skeletal muscle cells cannot be expanded in culture systems. Therefore, it is difficult to construct an in vitro model for muscle diseases. To establish an efficient protocol for myogenic differentiation of human adipose tissue-derived stem cells (hADSCs), we investigated whether addition of IL-6 and/or myocyte-conditioned media (CM) to conventional differentiation media can shorten the differentiation period. hADSCs were differentiated to myocytes using the conventional protocol or modified with the addition of 25 pg/mL IL-6 and/or C2C12 CM (25% v / v ). The expression of MyoD and myogenine mRNA was significantly higher at 5⁻6 days after differentiation using the modified protocol than with the conventional protocol. mRNA and protein expression of myosin heavy chain, a marker of myotubes, was significantly upregulated at 28 and 42 days of differentiation using the modified protocol, and the level achieved after a 4-week differentiation period was similar to that achieved at 6 weeks using the conventional protocol. The expression of p-STAT3 was significantly increased when the modified protocol was used. Similarly, addition of colivelin, a STAT3 activator, instead of IL-6 and C2C12 CM, promoted the myogenic differentiation of ADSCs. The modified protocol improved differentiation efficiency and reduced the time required for differentiation of myocytes. It might be helpful to save cost and time when preparing myocytes for cell therapies and drug discovery.

  5. Insulin-like growth factor 1 regulation of proliferation and differentiation of Xenopus laevis myogenic cells in vitro.

    PubMed

    Miyata, Sairi; Yada, Tomotaka; Ishikawa, Natsuko; Taheruzzaman, Kazi; Hara, Ryohei; Matsuzaki, Takashi; Nishikawa, Akio

    2017-03-01

    To understand the mechanism of muscle remodeling during Xenopus laevis metamorphosis, we examined the in vitro effect of insulin-like growth factor 1 (IGF-1) on growth and differentiation of three different-fate myogenic cell populations: tadpole tail, tadpole dorsal, and young adult leg muscle. IGF-1 promoted growth and differentiation of both tail and leg myogenic cells only under conditions where these cells could proliferate. Inhibition of cell proliferation by DNA synthesis inhibitor cytosine arabinoside completely canceled the IGF-1's cell differentiation promotion, suggesting the possibility that IGF-1's differentiation-promotion effect is an indirect effect via IGF-1's cell proliferation promotion. IGF-1 promoted differentiation dose dependently with maximum effect at 100-500 ng/ml. RT-PCR analysis revealed the upregulation (11-fold) of ifg1 mRNA expression in developing limbs, suggesting that IGF-1 plays a role in promoting muscle differentiation during limb development. The combined effect of triiodo-L-thyronine (T 3 ) and IGF-1 was also examined. In adult leg cells, IGF-1 promoted growth and differentiation irrespective of the presence of T 3 . In larval tail cells, cell count was 76% lower in the presence of T 3 , and IGF-1 did not promote proliferation and differentiation in T 3 -containing medium. In larval dorsal cells, cell count was also lower in the presence of T 3 , but IGF-1 enhanced proliferation and differentiation in T 3 -containing medium. This result is likely due to the presence among dorsal cells of both adult and larval types (1:1). Thus, IGF-1 affects only adult-type myogenic cells in the presence of T 3 and helps accelerate dorsal muscle remodeling during metamorphosis.

  6. Human serum and platelet lysate are appropriate xeno-free alternatives for clinical-grade production of human MuStem cell batches.

    PubMed

    Saury, Charlotte; Lardenois, Aurélie; Schleder, Cindy; Leroux, Isabelle; Lieubeau, Blandine; David, Laurent; Charrier, Marine; Guével, Laëtitia; Viau, Sabrina; Delorme, Bruno; Rouger, Karl

    2018-05-02

    Canine MuStem cells have demonstrated regenerative efficacy in a dog model of muscular dystrophy, and the recent characterization of human counterparts (hMuStem) has highlighted the therapeutic potential of this muscle-derived stem cell population. To date, these cells have only been generated in research-grade conditions. However, evaluation of the clinical efficacy of any such therapy will require the production of hMuStem cells in compliance with good manufacturing practices (GMPs). Because the current use of fetal bovine serum (FBS) to isolate and expand hMuStem cells raises several ethical, safety, and supply concerns, we assessed the use of two alternative xeno-free blood derivatives: human serum (HS) and a human platelet lysate (hPL). hMuStem cells were isolated and expanded in vitro in either HS-supplemented or hPL-supplemented media and the proliferation rate, clonogenicity, myogenic commitment potential, and oligopotency compared with that observed in FBS-supplemented medium. Flow cytometry and high-throughput 3'-digital gene expression RNA sequencing were used to characterize the phenotype and global gene expression pattern of hMuStem cells cultured with HS or hPL. HS-supplemented and hPL-supplemented media both supported the isolation and long-term proliferation of hMuStem cells. Compared with FBS-based medium, both supplements enhanced clonogenicity and allowed for a reduction in growth factor supplementation. Neither supplement altered the cell lineage pattern of hMuStem cells. In vitro differentiation assays revealed a decrease in myogenic commitment and in the fusion ability of hMuStem cells when cultured with hPL. In return, this reduction of myogenic potential in hPL-supplemented cultures was rapidly reversed by substitution of hPL with HS or fibrinogen-depleted hPL. Moreover, culture of hMuStem cells in hPL hydrogel and fibrinogen-depleted hPL demonstrated that myogenic differentiation potential is maintained in heparin-free hPL derivatives. Our

  7. Sonic hedgehog is required for survival of both myogenic and chondrogenic somitic lineages.

    PubMed

    Teillet, M; Watanabe, Y; Jeffs, P; Duprez, D; Lapointe, F; Le Douarin, N M

    1998-06-01

    In vertebrates, the medial moieties of the somites give rise to the vertebrae and epaxial muscles, which develop in close relationship with the axial organs, neural tube and notochord. The lateral moieties contribute to the ribs and to limb and body wall muscles (hypaxial muscles) after a phase of lateral and ventral migration. Surgical ablation of the neural tube and notochord in the chick embryo during segmentation and early differentiation of the somites (day 2 of incubation) does not affect primary development of the hypaxial muscles, but leads to a complete absence of epaxial muscles, vertebrae and ribs, due to cell death in the somites. Here we demonstrate that cell death, which occurs within 24 hours of excision of the axial organs, affects both myogenic and chondrogenic cell lineages defined, respectively, by the expression of MyoD and Pax-1 genes. In contrast, Pax-3 transcripts, normally present in cells giving rise to hypaxial muscles, are preserved in the excised embryos. Backgrafting either the ventral neural tube or the notochord allows survival of MyoD- and Pax-1-expressing cells. Similarly, Sonic hedgehog-producing cells grafted in place of axial organs also rescue MyoD- and Pax-1-expressing cells from death and allow epaxial muscles, ribs and vertebrae to undergo organogenesis. These results demonstrate that the ventral neural tube and the notochord promote the survival of both myogenic and chondrogenic cell lineages in the somites and that this action is mediated by Sonic hedgehog.

  8. Differences in initial symptom scores between myogenous TMD patients with high and low temporomandibular opening index.

    PubMed

    Miller, Victor J; Karic, Vesna V; Myers, Sandra L

    2006-01-01

    The temporomandibular opening index (TOI) is a more useful measure of mandibular movement than linear mouth opening, since it is independent of age, gender, ramus length, and gonial angle. It is also useful when categorizing temporomandibular disorder (TMD) patients into diagnostic groups. Two subgroups of myogenous patients have been identified, one with a high and one with a low temporomandibular opening index. This study examined initial symptom severity in these two subgroups. Thirty-three (33) patients with a myogenous temporomandibular disorder were recruited. Twenty-six (26) were female and seven male. Eleven were found to be in the high temporomandibular opening index group and the remaining 22 in the low group. Symptom severity scores were determined prior to the start of treatment. Pain, joint sounds, headache, and neck pain were all rated by patients on a four-point verbal response scale. These symptom scores were compared between the two subgroups using the Wilcoxon two sample test. There appeared to be a significant difference between the two groups (p = 0.0025). TMD patients with high temporomandibular opening index appeared to have more severe signs and symptoms of TMD than patients with a low index.

  9. Melatonin and its precursors in Y79 human retinoblastoma cells - Effect of sodium butyrate

    NASA Technical Reports Server (NTRS)

    Deng, Mei H.; Lopez G.-Coviella, Ignacio; Lynch, Harry J.; Wurtman, Richard J.

    1991-01-01

    We studied the release of melatonin and the production of its precursors, 5-hydroxytryptophan and serotonin, in cultured Y79 human retinoblastoma cells. This biosynthetic capability was found to be dependent on cell differentiation, which was initiated by culturing Y79 cells for 7 days in dishes coated with poly-D-lysine to promote cell adhesion to the surface of the culture dishes. Differentiation was further induced by exposing the cell monolayer to sodium butyrate (3 mM) for three days. This protocol dramatically increased the release of melatonin, and the syntheses of 5-hydroxytryptophan and serotonin in response to forskolin stimulation. Exposure to dopamine or L-DOPA markedly diminished the forskolin-stimulated release of melatonin, as well as the production of 5-hydroxytryptophan and serotonin. These observations indicate that Y79 cells represent a primitive cell line which, following appropriate differentiation can display biochemical characteristics similar to those of the human retina. Moreover, serotonin synthesis and melatonin release appear to be coupled in Y79 ceils.

  10. Asymmetric vestibular evoked myogenic potentials in unilateral Menière patients

    PubMed Central

    Wit, H. P.

    2010-01-01

    Vestibular evoked myogenic potentials (VEMPs) were measured in 22 unilateral Menière patients with monaural and binaural stimulation with 250 and 500 Hz tone bursts. For all measurement situations significantly lower VEMP amplitudes were on average measured at the affected side compared to the unaffected side. Unilateral Menière patients have, in contrast to normal subjects, asymmetric VEMPs, indicating a permanently affected vestibular (most likely otolith) system at the side of hearing loss. The diagnostic value of VEMP amplitude asymmetry measurement in individual patients is low, because of the large overlap of the VEMP amplitude asymmetry range for unilateral Menière patients with that for normal subjects. PMID:20665043

  11. Amyloid precursor protein interaction network in human testis: sentinel proteins for male reproduction.

    PubMed

    Silva, Joana Vieira; Yoon, Sooyeon; Domingues, Sara; Guimarães, Sofia; Goltsev, Alexander V; da Cruz E Silva, Edgar Figueiredo; Mendes, José Fernando F; da Cruz E Silva, Odete Abreu Beirão; Fardilha, Margarida

    2015-01-16

    Amyloid precursor protein (APP) is widely recognized for playing a central role in Alzheimer's disease pathogenesis. Although APP is expressed in several tissues outside the human central nervous system, the functions of APP and its family members in other tissues are still poorly understood. APP is involved in several biological functions which might be potentially important for male fertility, such as cell adhesion, cell motility, signaling, and apoptosis. Furthermore, APP superfamily members are known to be associated with fertility. Knowledge on the protein networks of APP in human testis and spermatozoa will shed light on the function of APP in the male reproductive system. We performed a Yeast Two-Hybrid screen and a database search to study the interaction network of APP in human testis and sperm. To gain insights into the role of APP superfamily members in fertility, the study was extended to APP-like protein 2 (APLP2). We analyzed several topological properties of the APP interaction network and the biological and physiological properties of the proteins in the APP interaction network were also specified by gene ontologyand pathways analyses. We classified significant features related to the human male reproduction for the APP interacting proteins and identified modules of proteins with similar functional roles which may show cooperative behavior for male fertility. The present work provides the first report on the APP interactome in human testis. Our approach allowed the identification of novel interactions and recognition of key APP interacting proteins for male reproduction, particularly in sperm-oocyte interaction.

  12. Effects of muscle contraction on cervical vestibular evoked myogenic potentials in normal subjects.

    PubMed

    Rosengren, Sally M

    2015-11-01

    Cervical vestibular evoked myogenic potentials (cVEMPs) are vestibular-dependent muscle reflexes recorded from the sternocleidomastoid (SCM) muscles in humans. cVEMP amplitude is modulated by stimulus intensity and SCM muscle contraction strength, but the effect of muscle contraction is less well-documented. The effects of intensity and contraction were therefore compared in 25 normal subjects over a wide range of contractions. cVEMPs were recorded at different contraction levels while holding stimulus intensity constant and at different intensities while holding SCM contraction constant. The effect of muscle contraction on cVEMP amplitude was linear for most of the range of muscle contractions in the majority of subjects (mean R(2)=0.93), although there were some nonlinearities when the contraction was either very weak or very strong. Very weak contractions were associated with absent responses, incomplete morphology and prolonged p13 latencies. Normalization of amplitudes, by dividing the p13-n23 amplitude by the muscle contraction estimate, reduced the effect of muscle contraction, but tended to underestimate the amplitude with weak contractions. Minimum contraction levels are required for accurate interpretation of cVEMPs. These data highlight the importance of measuring SCM contraction strength when recording cVEMPs. Copyright © 2015 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  13. Clinical significance of vestibular evoked myogenic potentials in benign paroxysmal positional vertigo.

    PubMed

    Yang, Won Sun; Kim, Sung Huhn; Lee, Jong Dae; Lee, Won-Sang

    2008-12-01

    To investigate the vestibular evoked myogenic potentials (VEMPs) resulting in benign paroxysmal positional vertigo (BPPV) patients and to verify its clinical applications in BPPV. A prospective study. Tertiary referral dizziness center. Forty-one patients with diagnosis of BPPV and 92 healthy volunteers who underwent VEMP testing. Patients were treated by canalith repositioning maneuvers according to the affected canal, and testing of VEMP was performed at diagnosis and after treatment. Testing of VEMP was performed in BPPV patients and in the control group. The number of times the canalith repositioning maneuver was repeated until the patient's report of relief from vertigo and findings of negative positioning test were recorded to find out the relationship between VEMP results and the progress of disease. Vestibular evoked myogenic potential results of BPPV patients showed prolonged p13 and n23 latencies compared with those of the control group, and we could not find any significant difference in VEMP latencies between patients with posterior and horizontal canal type of BPPV. The number of times that the maneuver was repeated did not correlate with the degree of latency prolongation, but in the "no response" group, the number of times was considerably greater than that in the "response" group. We found that VEMP latencies are increased in BPPV patients, which may signify neuronal degenerative changes in the macula of the saccule. When an extensive neuronal damage was suspected by VEMP results such as "no response" in VEMP, the disease progress showed a chronic and resistive course. Therefore, we propose that VEMP could be a useful method to determine a clinical prognosis of patients with BPPV.

  14. Association of 17-β Estradiol with Adipose-Derived Stem Cells: New Strategy to Produce Functional Myogenic Differentiated Cells with a Nano-Scaffold for Tissue Engineering.

    PubMed

    Feng, Chunxiang; Hu, Jinqian; Liu, Chang; Liu, Shiliang; Liao, Guiying; Song, Linjie; Zeng, Xiaoyong

    2016-01-01

    The increased incidence of stress urinary incontinence (SUI) in postmenopausal women has been proposed to be associated with a reduction in the level of 17-β estradiol (E2). E2 has also been shown to enhance the multi-differentiation ability of adipose-derived stem cells (ASCs) in vitro. However, studies on the potential value of E2 for tissue engineering in SUI treatment are rare. In the present study, we successfully fabricated myogenically differentiated ASCs (MD-ASCs), which were seeded onto a Poly(l-lactide)/Poly(e-caprolactone) electrospinning nano-scaffold, and incorporated E2 into the system, with the aim of improving the proliferation and myogenic differentiation of ASCs. ASCs were collected from the inguinal subcutaneous fat of rats. The proliferation and myogenic differentiation of ASCs, as well as the nano-scaffold biocompatibility of MD-ASCs, with or without E2 supplementation, were investigated. We demonstrated that E2 incorporation enhanced the proliferation of ASCs in vitro, and the most optimal concentration was 10-9 M. E2 also led to modulation of the MD-ASCs phenotype toward a concentrated type with smooth muscle-inductive medium. The expression of early (alpha-smooth muscle actin), mid (calponin), and late-stage (myosin heavy chain) contractile markers in MD-ASCs was enhanced by E2 during the different differentiation stages. Furthermore, the nano-scaffold was biocompatible with MD-ASCs, and cell proliferation was significantly enhanced by E2. Taken together, these results demonstrate that E2 can enhance the proliferation and myogenic differentiation of ASCs and can be used to construct a biocompatible cell/nano-scaffold. These scaffolds with desirable differentiation cells show promising applications for tissue engineering.

  15. Ocular Vestibular Evoked Myogenic Potentials in Response to Three Test Positions and Two Frequencies

    PubMed Central

    Todai, Janvi K.; Congdon, Sharon L.; Sangi-Haghpeykar, Haleh; Cohen, Helen S.

    2014-01-01

    Objective To determine how eye closure, test positions, and stimulus frequencies influence ocular vestibular evoked myogenic potentials. Study Design This study used a within-subjects repeated measures design. Methods Twenty asymptomatic subjects were each tested on ocular vestibular evoked myogenic potentials in three head/eye conditions at 500 Hz and 1000 Hz using air-conducted sound: 1) Sitting upright, head erect, eyes open, looking up. 2) Lying supine, neck flexed 30 degrees, eyes open and looking up. 3) Lying supine, neck flexed 30 degrees, eyes closed and relaxed. Four dependent variables measured were n10, p16, amplitude, and threshold. Results The supine position/ eyes open was comparable to sitting/ eyes open and better than supine/ eyes closed. Eyes closed resulted in lower amplitude, higher threshold, and prolonged latency. Significantly fewer subjects provided responses with eyes closed than with eyes open. No significant differences were found between both eyes open conditions. Both n10 and p16 were lower at 1000 Hz than at 500 Hz. Amplitude and threshold were higher at 1000 Hz than at 500 Hz. Conclusion Supine eyes open is a reliable alternative to sitting eyes open in patients who cannot maintain a seated position. Testing at 1000 Hz provides a larger response with a faster onset that fatigues faster than at 500 Hz. The increased variability and decreased response in the eyes closed position suggest that the eyes closed position is not reliable. PMID:24178911

  16. Accuracy of the surface electromyography RMS processing for the diagnosis of myogenous temporomandibular disorder.

    PubMed

    Berni, Kelly Cristina dos Santos; Dibai-Filho, Almir Vieira; Pires, Paulo Fernandes; Rodrigues-Bigaton, Delaine

    2015-08-01

    Due to the multifactor etiology of temporomandibular disorder (TMD), the precise diagnosis remains a matter of debate and validated diagnostic tools are needed. The aim was to determine the accuracy of surface electromyography (sEMG) activity, assessed in the amplitude domain by the root mean square (RMS), in the diagnosis of TMD. One hundred twenty-three volunteers were evaluated using the Research Diagnostic Criteria for Temporomandibular Disorders and distributed into two groups: women with myogenous TMD (n=80) and women without TMD (n=43). The volunteers were then submitted to sEMG evaluation of the anterior temporalis, masseter and suprahyoid muscles at rest and during maximum voluntary teeth clenching (MVC) on parafilm. The accuracy, sensitivity and specificity of the muscle activity were analyzed. Differences between groups were found in all muscles analyzed at rest as well as in the masseter and suprahyoid muscles during MVC on parafilm. Moderate accuracy (AUC: 0.74-0.84) of the RMS sEMG was found in all muscles regarding the diagnosis of TMD at rest and in the suprahyoid muscles during MVC on parafilm. Moreover, sensitivity ranging from 71.3% to 80% and specificity from 60.5% to 76.6%. In contrast, RMS sEMG did not exhibit acceptable degrees of accuracy in the other masticatory muscles during MVC on parafilm. It was concluded that the RMS sEMG is a complementary tool for clinical diagnosis of the myogenous TMD. Copyright © 2015 Elsevier Ltd. All rights reserved.

  17. Crystal structure of human lysyl oxidase-like 2 (hLOXL2) in a precursor state.

    PubMed

    Zhang, Xi; Wang, Qifan; Wu, Jianping; Wang, Jiawei; Shi, Yigong; Liu, Minhao

    2018-04-10

    Lysyl oxidases (LOXs), a type of copper- and lysyl tyrosylquinone (LTQ) -dependent amine oxidase, catalyze the oxidative deamination of lysine residues of extracellular matrix (ECM) proteins such as elastins and collagens and generate aldehyde groups. The oxidative deamination of lysine represents the foundational step for the cross-linking of elastin and collagen and thus is crucial for ECM modeling. Despite their physiological significance, the structure of this important family of enzymes remains elusive. Here we report the crystal structure of human lysyl oxidase-like 2 (hLOXL2) at 2.4-Å resolution. Unexpectedly, the copper-binding site of hLOXL2 is occupied by zinc, which blocks LTQ generation and the enzymatic activity of hLOXL2 in our in vitro assay. Biochemical analysis confirms that copper loading robustly activates hLOXL2 and supports LTQ formation. Furthermore, the LTQ precursor residues in the structure are distanced by 16.6 Å, corroborating the notion that the present structure may represent a precursor state and that pronounced conformational rearrangements would be required for protein activation. The structure presented here establishes an important foundation for understanding the structure-function relationship of LOX proteins and will facilitate LOX-targeting drug discovery. Copyright © 2018 the Author(s). Published by PNAS.

  18. [The role of endothelial cells and endothelial precursor cells in angiogenesis].

    PubMed

    Poreba, Małgorzata; Usnarska-Zubkiewicz, Lidia; Kuliczkowski, Kazimierz

    2006-01-01

    Endothelium plays a key role in maintenance of vascular homeostasis in human organism. According to new data endothelial cells and hematopoietic cells have a common precursor in prenatal life--a hemangioblast, which explains the fact of sharing the same determinants on the surface of both type of cells. Circulating endothelial precursors were identified in adults and this suggests that hemangioblasts may be present not only during embriogenesis. In some clinical situations the increased numbers of endothelial cells and endothelial precursors were noted, and especially in patients with neoplastic diseases, which is probably the result of increased angiogenesis. Endothelial precursors are thought to be the promice for therapeutic purposes in future--to increase local angiogenesis.

  19. Expression and function of heterotypic adhesion molecules during differentiation of human skeletal muscle in culture.

    PubMed Central

    Beauchamp, J. R.; Abraham, D. J.; Bou-Gharios, G.; Partridge, T. A.; Olsen, I.

    1992-01-01

    The infiltration of skeletal muscle by leukocytes occurs in a variety of myopathies and frequently accompanies muscle degeneration and regeneration. The latter involves development of new myofibers from precursor myoblasts, and so infiltrating cells may interact with muscle at all stages of differentiation. The authors have investigated the surface expression of ligands for T-cell adhesion during the differentiation of human skeletal muscle in vitro. Myoblasts expressed low levels of ICAM-1 (CD54), which remained constant during muscle cell differentiation and could be induced by cytokines such as gamma-interferon. It is therefore likely that ICAM-1 is involved in the invasive accumulation of lymphocytes during skeletal muscle inflammation. In contrast, LFA-3 (CD58) was expressed at higher levels than ICAM-1 on myoblasts, decreased significantly during myogenesis, and was unaffected by immune mediators. Both ICAM-1 and LFA-3 were able to mediate T cell binding to myoblasts, whereas adhesion to myotubes was independent of the LFA-3 ligand. Although expressed throughout myogenesis, human leukocyte antigen class I and CD44 did not appear to mediate T cell binding. The expression of ligands that facilitate interaction of myogenic cells with lymphocytes may have important implications for myoblast transplantation. Images Figure 1 Figure 3 Figure 4 PMID:1739132

  20. Pannexin channels mediate the acquisition of myogenic commitment in C2C12 reserve cells promoted by P2 receptor activation

    PubMed Central

    Riquelme, Manuel A.; Cea, Luis A.; Vega, José L.; Puebla, Carlos; Vargas, Aníbal A.; Shoji, Kenji F.; Subiabre, Mario; Sáez, Juan C.

    2015-01-01

    The acquisition of myoblast commitment to the myogenic linage requires rises in intracellular free Ca2+ concentration ([Ca2+]i). Putative cell membrane pathways involved in these [Ca2+]i increments are P2 receptors (P2Rs) as well as connexin (Cx) and/or pannexin (Panx) hemichannels and channels (Cx HChs and Panx Chs), respectively, which are known to permeate Ca2+. Reserve cells (RCs) are uncommitted myoblasts obtained from differentiated C2C12 cell cultures, which acquire commitment upon replating. Regarding these cells, we found that extracellular ATP increases the [Ca2+]i via P2Rs. Moreover, ATP increases the plasma membrane permeability to small molecules and a non-selective membrane current, both of which were inhibited by Cx HCh/Panx1Ch blockers. However, RCs exposed to divalent cation-free saline solution, which is known to activate Cx HChs (but not Panx Chs), did not enhance membrane permeability, thus ruling out the possible involvement of Cx HChs. Moreover, ATP-induced membrane permeability was inhibited with blockers of P2Rs that activate Panx Chs. In addition, exogenous ATP induced the expression of myogenic commitment and increased MyoD levels, which was prevented by the inhibition of P2Rs or knockdown of Panx1 Chs. Similarly, increases in MyoD levels induced by ATP released by RCs were inhibited by Panx Ch/Cx HCh blockers. Myogenic commitment acquisition thus requires a feed-forward mechanism mediated by extracellular ATP, P2Rs, and Panx Chs. PMID:26000275

  1. Loss of myogenic potential and fusion capacity of muscle stem cells isolated from contractured muscle in children with cerebral palsy.

    PubMed

    Domenighetti, Andrea A; Mathewson, Margie A; Pichika, Rajeswari; Sibley, Lydia A; Zhao, Leyna; Chambers, Henry G; Lieber, Richard L

    2018-04-25

    Cerebral palsy (CP) is the most common cause of pediatric neurodevelopmental and physical disability in the United States. It is defined as a group of motor disorders caused by a non-progressive perinatal insult to the brain. While the brain lesion is non-progressive, there is a progressive, lifelong impact on skeletal muscles, which are shorter, spastic, and may develop debilitating contractures. Satellite cells are resident muscle stem cells that are indispensable for postnatal growth and regeneration of skeletal muscles. Here we measured the myogenic potential of satellite cells isolated from contractured muscles in children with CP. When compared to typically developing (TD) children, satellite cell-derived myoblasts from CP differentiated more slowly (Slope: 0.013{plus minus}0.013 CP vs. 0.091{plus minus}0.024 TD over 24 hours, P<0.001) and fused less (Fusion Index: 21.3{plus minus}8.6 CP vs. 81.3{plus minus}7.7 TD after 48 hours, P<0.001) after exposure to low-serum conditions that stimulated myotube formation. This impairment was associated with downregulation of several markers important for myoblast fusion and myotube formation, including DNA methylation-dependent inhibition of pro-myogenic Integrin Beta 1D (ITGB1D) protein expression levels (-50% at 42 hours), and ~25% loss of integrin-mediated FAK kinase phosphorylation. The cytidine analog 5-Azacytidine (5-AZA), a demethylating agent, restored ITGB1D levels and promoted myogenesis in CP cultures. Our data demonstrate that muscle contractures in CP are associated with loss of satellite cell myogenic potential that is dependent on DNA methylation patterns affecting expression of genetic programs associated with muscle stem cell differentiation and muscle fiber formation.

  2. Localization of the putative precursor of Alzheimer's disease-specific amyloid at nuclear envelopes of adult human muscle.

    PubMed Central

    Zimmermann, K; Herget, T; Salbaum, J M; Schubert, W; Hilbich, C; Cramer, M; Masters, C L; Multhaup, G; Kang, J; Lemaire, H G

    1988-01-01

    Cloning and sequence analysis revealed the putative amyloid A4 precursor (pre-A4) of Alzheimer's disease to have characteristics of a membrane-spanning glycoprotein. In addition to brain, pre-A4 mRNA was found in adult human muscle and other tissues. We demonstrate by in situ hybridization that pre-A4 mRNA is present in adult human muscle, in cultured human myoblasts and myotubes. Immunofluorescence with antipeptide antibodies shows the putative pre-A4 protein to be expressed in adult human muscle and associated with some but not all nuclear envelopes. Despite high levels of a single 3.5-kb pre-A4 mRNA species in cultured myoblasts and myotubes, the presence of putative pre-A4 protein could not be detected by immunofluorescence. This suggests that putative pre-A4 protein is stabilized and therefore functioning in the innervated muscle tissue but not in developing, i.e. non-innervated cultured muscle cells. The selective localization of the protein on distinct nuclear envelopes could reflect an interaction with motor endplates. Images PMID:2896589

  3. Vestibular-Evoked Myogenic Potentials in Bilateral Vestibulopathy

    PubMed Central

    Rosengren, Sally M.; Welgampola, Miriam S.; Taylor, Rachael L.

    2018-01-01

    Bilateral vestibulopathy (BVP) is a chronic condition in which patients have a reduction or absence of vestibular function in both ears. BVP is characterized by bilateral reduction of horizontal canal responses; however, there is increasing evidence that otolith function can also be affected. Cervical and ocular vestibular-evoked myogenic potentials (cVEMPs/oVEMPs) are relatively new tests of otolith function that can be used to test the saccule and utricle of both ears independently. Studies to date show that cVEMPs and oVEMPs are often small or absent in BVP but are in the normal range in a significant proportion of patients. The variability in otolith function is partly due to the heterogeneous nature of BVP but is also due to false negative and positive responses that occur because of the large range of normal VEMP amplitudes. Due to their variability, VEMPs are not part of the diagnosis of BVP; however, they are helpful complementary tests that can provide information about the extent of disease within the labyrinth. This article is a review of the use of VEMPs in BVP, summarizing the available data on VEMP abnormalities in patients and discussing the limitations of VEMPs in diagnosing bilateral loss of otolith function. PMID:29719527

  4. Purification of human induced pluripotent stem cell-derived neural precursors using magnetic activated cell sorting.

    PubMed

    Rodrigues, Gonçalo M C; Fernandes, Tiago G; Rodrigues, Carlos A V; Cabral, Joaquim M S; Diogo, Maria Margarida

    2015-01-01

    Neural precursor (NP) cells derived from human induced pluripotent stem cells (hiPSCs), and their neuronal progeny, will play an important role in disease modeling, drug screening tests, central nervous system development studies, and may even become valuable for regenerative medicine treatments. Nonetheless, it is challenging to obtain homogeneous and synchronously differentiated NP populations from hiPSCs, and after neural commitment many pluripotent stem cells remain in the differentiated cultures. Here, we describe an efficient and simple protocol to differentiate hiPSC-derived NPs in 12 days, and we include a final purification stage where Tra-1-60+ pluripotent stem cells (PSCs) are removed using magnetic activated cell sorting (MACS), leaving the NP population nearly free of PSCs.

  5. HIV-1 broadly neutralizing antibody precursor B cells revealed by germline-targeting immunogen

    DOE PAGES

    Jardine, Joseph G.; Kulp, Daniel W.; Havenar-Daughton, Colin; ...

    2016-03-25

    Induction of broadly neutralizing antibodies (bnAbs) is a major HIV vaccine goal. Germline-targeting immunogens aim to initiate bnAb induction by activating bnAb germline precursor B cells. Critical unmet challenges are to determine whether bnAb precursor naïve B cells bind germline-targeting immunogens and occur at sufficient frequency in humans for reliable vaccine responses. We employed deep mutational scanning and multi-target optimization to develop a germline-targeting immunogen (eOD-GT8) for diverse VRC01-class bnAbs. We then used the immunogen to isolate VRC01-class precursor naïve B cells from HIV-uninfected donors. Frequencies of true VRC01-class precursors, their structures, and their eOD-GT8 affinities support this immunogen asmore » a candidate human vaccine prime. Lastly, these methods could be applied to germline targeting for other classes of HIV bnAbs and for Abs to other pathogens.« less

  6. HIV-1 broadly neutralizing antibody precursor B cells revealed by germline-targeting immunogen

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Jardine, Joseph G.; Kulp, Daniel W.; Havenar-Daughton, Colin

    Induction of broadly neutralizing antibodies (bnAbs) is a major HIV vaccine goal. Germline-targeting immunogens aim to initiate bnAb induction by activating bnAb germline precursor B cells. Critical unmet challenges are to determine whether bnAb precursor naïve B cells bind germline-targeting immunogens and occur at sufficient frequency in humans for reliable vaccine responses. We employed deep mutational scanning and multi-target optimization to develop a germline-targeting immunogen (eOD-GT8) for diverse VRC01-class bnAbs. We then used the immunogen to isolate VRC01-class precursor naïve B cells from HIV-uninfected donors. Frequencies of true VRC01-class precursors, their structures, and their eOD-GT8 affinities support this immunogen asmore » a candidate human vaccine prime. Lastly, these methods could be applied to germline targeting for other classes of HIV bnAbs and for Abs to other pathogens.« less

  7. HIV-1 broadly neutralizing antibody precursor B cells revealed by germline-targeting immunogen.

    PubMed

    Jardine, Joseph G; Kulp, Daniel W; Havenar-Daughton, Colin; Sarkar, Anita; Briney, Bryan; Sok, Devin; Sesterhenn, Fabian; Ereño-Orbea, June; Kalyuzhniy, Oleksandr; Deresa, Isaiah; Hu, Xiaozhen; Spencer, Skye; Jones, Meaghan; Georgeson, Erik; Adachi, Yumiko; Kubitz, Michael; deCamp, Allan C; Julien, Jean-Philippe; Wilson, Ian A; Burton, Dennis R; Crotty, Shane; Schief, William R

    2016-03-25

    Induction of broadly neutralizing antibodies (bnAbs) is a major HIV vaccine goal. Germline-targeting immunogens aim to initiate bnAb induction by activating bnAb germline precursor B cells. Critical unmet challenges are to determine whether bnAb precursor naïve B cells bind germline-targeting immunogens and occur at sufficient frequency in humans for reliable vaccine responses. Using deep mutational scanning and multitarget optimization, we developed a germline-targeting immunogen (eOD-GT8) for diverse VRC01-class bnAbs. We then used the immunogen to isolate VRC01-class precursor naïve B cells from HIV-uninfected donors. Frequencies of true VRC01-class precursors, their structures, and their eOD-GT8 affinities support this immunogen as a candidate human vaccine prime. These methods could be applied to germline targeting for other classes of HIV bnAbs and for Abs to other pathogens. Copyright © 2016, American Association for the Advancement of Science.

  8. Vestibular-evoked myogenic potential (VEMP) in the evaluation of schistosomal myeloradiculopathy.

    PubMed

    Felipe, Lilian; Gonçalves, Denise Utsch; Tavares, Maurício Campelo; Sousa-Pereira, Sílvio Roberto; Antunes, Carlos Maurício de Figueiredo; Lambertucci, José Roberto

    2009-10-01

    Schistosomal myeloradiculopathy (SMR) is the most severe and disabling form of schistosomiasis. The diagnosis is based on clinical, laboratory, and image data. Vestibular-evoked myogenic potential (VEMP) is a neurophysiologic test that assesses the vestibulospinal pathway through acoustic or galvanic stimuli. The aim of this study was to evaluate cervical spinal abnormalities in patients with SMR. Fifty-two subjects were evaluated, of whom 29 had SMR and 30 did not (normal control). Normal VEMP was observed in all volunteers without SMR. Abnormal VEMP was recorded in 34% of the group with SMR. After treatment, abnormal VEMP was found in 80% of those with persistent neurologic abnormalities. VEMP is a functional test, and the alteration may precede image abnormalities. This procedure may be useful for early diagnosis of schistosomal cervical spinal cord involvement.

  9. Fibromodulin: a master regulator of myostatin controlling progression of satellite cells through a myogenic program.

    PubMed

    Lee, Eun Ju; Jan, Arif Tasleem; Baig, Mohammad Hassan; Ashraf, Jalaluddin Mohammad; Nahm, Sang-Soep; Kim, Yong-Woon; Park, So-Young; Choi, Inho

    2016-08-01

    Differentiation of muscle satellite cells (MSCs) involves interaction of the proteins present in the extracellular matrix (ECM) with MSCs to regulate their activity, and therefore phenotype. Herein, we report fibromodulin (FMOD), a member of the proteoglycan family participating in the assembly of ECM, as a novel regulator of myostatin (MSTN) during myoblast differentiation. In addition to having a pronounced effect on the expression of myogenic marker genes [myogenin (MYOG) and myosin light chain 2 (MYL2)], FMOD was found to maintain the transcriptional activity of MSTN Moreover, coimmunoprecipitation and in silico studies performed to investigate the interaction of FMOD helped confirm that it antagonizes MSTN function by distorting its folding and preventing its binding to activin receptor type IIB. Furthermore, in vivo studies revealed that FMOD plays an active role in healing by increasing satellite cell recruitment to sites of injury. Together, these findings disclose a hitherto unrecognized regulatory role for FMOD in MSCs and highlight new mechanisms whereby FMOD circumvents the inhibitory effects of MSTN and triggers myoblast differentiation. These findings offer a basis for the design of novel MSTN inhibitors that promote muscle regeneration after injury or for the development of pharmaceutical agents for the treatment of different muscle atrophies.-Lee, E. J., Jan, A. T., Baig, M. H., Ashraf, J. M., Nahm, S.-S., Kim, Y.-W., Park, S.-Y., Choi, I. Fibromodulin: a master regulator of myostatin controlling progression of satellite cells through a myogenic program. © FASEB.

  10. Reduced Osteogenesis of Human Osteogenic Precursors' Cells Cultured in the Random Positioning Machine

    NASA Astrophysics Data System (ADS)

    Gershovich, J. G.; Buravkova, L. B.

    2008-06-01

    Recent studies have shown that simulated microgravity (SMG) results in altered proliferation and differentiation not only osteoblasts but also affects on osteogenic capacity of mesenchymal stem cells (MSCs) from various sources. For present study we used system that simulates effects of microgravity produced by the Random Positioning Machine (RPM). Cultured MCSs from human bone marrow and human osteoblasts (OBs) were exposed to SMG at RPM for 10-40 days. Induced osteogenesis of these progenitor cells was compared with the appropriate static (1g) and dynamic (horizontal shaker) controls. Clinorotated OBs and MSCs showed proliferation rate lower than static and dynamic control groups of cells in the early terms of SMG. Significant reduction of ALP activity was detected after 10 days of clinorotation of MSCs. There was no such dramatic difference in ALP activity of MSCs derived cells between SMG and control groups after 20 days of clinorotation but the expression of ALP was still reduced. However, virtually no matrix mineralization was found in OBs cultured under SMG conditions in the presence of differentiation stimuli. The similar effect was observed when we assayed matrix calcification of MSCs derived cultures. Thus, our results confirm low gravity mediated reduction of osteogenesis of different osteogenic precursors' cells and can clarify the mechanisms of bone loss during spaceflight.

  11. Dynamic changes in copper homeostasis and post-transcriptional regulation of Atp7a during myogenic differentiation.

    PubMed

    Vest, Katherine E; Paskavitz, Amanda L; Lee, Joseph B; Padilla-Benavides, Teresita

    2018-02-21

    Copper (Cu) is an essential metal required for activity of a number of redox active enzymes that participate in critical cellular pathways such as metabolism and cell signaling. Because it is also a toxic metal, Cu must be tightly controlled by a series of transporters and chaperone proteins that regulate Cu homeostasis. The critical nature of Cu is highlighted by the fact that mutations in Cu homeostasis genes cause pathologic conditions such as Menkes and Wilson diseases. While Cu homeostasis in highly affected tissues like the liver and brain is well understood, no study has probed the role of Cu in development of skeletal muscle, another tissue that often shows pathology in these conditions. Here, we found an increase in whole cell Cu content during differentiation of cultured immortalized or primary myoblasts derived from mouse satellite cells. We demonstrate that Cu is required for both proliferation and differentiation of primary myoblasts. We also show that a key Cu homeostasis gene, Atp7a, undergoes dynamic changes in expression during myogenic differentiation. Alternative polyadenylation and stability of Atp7a mRNA fluctuates with differentiation stage of the myoblasts, indicating post-transcriptional regulation of Atp7a that depends on the differentiation state. This is the first report of a requirement for Cu during myogenic differentiation and provides the basis for understanding the network of Cu transport associated with myogenesis.

  12. Genetically distinct leukemic stem cells in human CD34− acute myeloid leukemia are arrested at a hemopoietic precursor-like stage

    PubMed Central

    Quek, Lynn; Garnett, Catherine; Karamitros, Dimitris; Stoilova, Bilyana; Doondeea, Jessica; Kennedy, Alison; Metzner, Marlen; Ivey, Adam; Sternberg, Alexander; Hunter, Hannah; Price, Andrew; Virgo, Paul; Grimwade, David; Freeman, Sylvie; Russell, Nigel; Mead, Adam

    2016-01-01

    Our understanding of the perturbation of normal cellular differentiation hierarchies to create tumor-propagating stem cell populations is incomplete. In human acute myeloid leukemia (AML), current models suggest transformation creates leukemic stem cell (LSC) populations arrested at a progenitor-like stage expressing cell surface CD34. We show that in ∼25% of AML, with a distinct genetic mutation pattern where >98% of cells are CD34−, there are multiple, nonhierarchically arranged CD34+ and CD34− LSC populations. Within CD34− and CD34+ LSC–containing populations, LSC frequencies are similar; there are shared clonal structures and near-identical transcriptional signatures. CD34− LSCs have disordered global transcription profiles, but these profiles are enriched for transcriptional signatures of normal CD34− mature granulocyte–macrophage precursors, downstream of progenitors. But unlike mature precursors, LSCs express multiple normal stem cell transcriptional regulators previously implicated in LSC function. This suggests a new refined model of the relationship between LSCs and normal hemopoiesis in which the nature of genetic/epigenetic changes determines the disordered transcriptional program, resulting in LSC differentiation arrest at stages that are most like either progenitor or precursor stages of hemopoiesis. PMID:27377587

  13. GREG cells, a dysferlin-deficient myogenic mouse cell line

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Humphrey, Glen W.; Mekhedov, Elena; Blank, Paul S.

    2012-01-15

    The dysferlinopathies (e.g. LGMD2b, Myoshi myopathy) are progressive, adult-onset muscle wasting syndromes caused by mutations in the gene coding for dysferlin. Dysferlin is a large ({approx} 200 kDa) membrane-anchored protein, required for maintenance of plasmalemmal integrity in muscle fibers. To facilitate analysis of dysferlin function in muscle cells, we have established a dysferlin-deficient myogenic cell line (GREG cells) from the A/J mouse, a genetic model for dysferlinopathy. GREG cells have no detectable dysferlin expression, but proliferate normally in growth medium and fuse into functional myotubes in differentiation medium. GREG myotubes exhibit deficiencies in plasma membrane repair, as measured by lasermore » wounding in the presence of FM1-43 dye. Under the wounding conditions used, the majority ({approx} 66%) of GREG myotubes lack membrane repair capacity, while no membrane repair deficiency was observed in dysferlin-normal C2C12 myotubes, assayed under the same conditions. We discuss the possibility that the observed heterogeneity in membrane resealing represents genetic compensation for dysferlin deficiency.« less

  14. Behavioral characteristics of capsaicin mediated cutaneous, myogenic, and arthrogenic orofacial nociception in rats.

    PubMed

    Rohrs, Eric L; Neubert, John K; Caudle, Robert M; Allen, Kyle D

    2018-04-30

    To assess changes in orofacial tactile sensitivity and gnawing related to capsaicin-mediated cutaneous, myogenic, and arthrogenic nociception in the rat. After recovery from anesthesia, orofacial tactile sensitivity and gnawing were assessed using operant testing methods following capsaicin application. Twenty female CD-Hairless rats were tested with bilateral capsaicin cream application to the cheek or with isoflurane anesthesia alone. Following several weeks of recovery, animals (n = 20) received either 10 μL unilateral masseter injections of vehicle, or phosphate buffered saline (PBS) to assess injection sensitization. After several weeks, masseter capsaicin (1.0%) injections (10 μL) were assessed compared to vehicle and PBS (n = 13). Weeks later capsaicin TMJ injections were evaluated. Animals (n = 11) received either 10 μL unilateral TMJ injections of capsaicin solution (1%) or vehicle. Capsaicin cream to the skin significantly altered gnawing activity (increased puncture time by 248 s (p = 0.0002)) and tactile sensitivity (decreased tolerated bottle distance by 0.980 cm compared to isoflurane only (p = 0.0001)). Similarly, capsaicin masseter injection increased puncture time (339.6 s, p = 0.07) and decreased tolerated bottle distance (1.04 cm, p = 0.005) compared to vehicle. However, intra-articular capsaicin in the TMJ only modified gnawing (increased puncture time by 133 s), with no changes found in tactile sensitivity compared to vehicle. Application of capsaicin to the skin and masseter had similar behavioral effects; however, intra-articular injections to the TMJ only affected gnawing. These data indicate the behavioral changes in rodent models of myogenic and cutaneous pain may be markedly different than models of arthrogenic pain originating from the TMJ. Copyright © 2018. Published by Elsevier Ltd.

  15. Toxicological effects of three types of silver nanoparticles and their salt precursors acting on human U-937 and HL-60 cells.

    PubMed

    Barbasz, Anna; Oćwieja, Magdalena; Walas, Stanisław

    2017-01-01

    The growing popularity of nanomaterials requires a systematic study of their effects on the human body. Silver nanoparticles (AgNPs), due to their antiseptic properties, are used in almost every area of life. The purpose of the study was to examine whether the precursor used for the synthesis of nanoparticles affects their bio-influence and modifies their impact on cells of the human immune system. To compare the effects of precursor silver salts (AgNO 3 , CH 3 COOAg and AgClO 4 ) and corresponding nanoparticles (TAN TAA and TAC) cytotoxicity study was conducted on two cell lines U-937 and HL-60. For both cell lines, silver salts are more toxic than the corresponding nanoparticles. Cell viability after treatment with the two forms of silver (salt/particle) is dependent on silver dose and degree of cells differentiation. Addition of the silver salt of doses greater than 5 mg/L results in decreased cell viability by over 60%, whereas nanoparticles' addition reduces cell viability on average by 30%. On the basis of the determined LD 50 values it can be stated that for the tested cells the most toxic are AgClO 4 and TAC. Production of nitric oxide, which is a mediator of inflammation, is the greatest after treatment of the cells by TAC. Different interactions of studied nanoparticles with albumin has been found and it was shown that addition of albumin to the cells treated by nanoparticles reduces their toxic effects. Obtained by us highly purified, mono-disperse AgNPs exhibit diverse effects relative to the biological systems, depending on the precursor salt used.

  16. Cancer-associated myositis associated with oesophageal adenocarcinoma arising in Barrett's oesophagus without serum myogenic enzymes elevation: an example suggesting the importance of MRI.

    PubMed

    Sasaki, Yosuke; Shimizu, Hiroshige; Nemoto, Tetsuo; Urita, Yoshihisa

    2016-04-21

    The strong association between myositis and malignancy has been well recognised. Cancer-associated myositis (CAM) is thought to be a cross-reaction to regenerating muscle tissue similar to tumour antigen. We report a case of CAM due to oesophageal adenocarcinoma arising in Barrett's oesophagus without elevation of myogenic enzymes, diagnosed by MRI and repeated endoscopy. Elderly onset, prominent symptoms, lack of interstitial pneumonia, poorer response to immunosuppressive therapies, and the combination of negative conventional myositis-related antibodies and positive anti-p155/140 antibody may help to distinguish CAM from idiopathic inflammatory myopathy. As the prognosis of patients with CAM depends on the malignancy, aggressive diagnosis of CAM and the causative malignancy is required. Our experience underscores the importance of avoiding the over-reliance on serum myogenic enzymes for excluding CAM and recognising MRI as a useful diagnostic tool of myositis. 2016 BMJ Publishing Group Ltd.

  17. Alcohol-Induced Molecular Dysregulation in Human Embryonic Stem Cell-Derived Neural Precursor Cells

    PubMed Central

    Kim, Yi Young; Roubal, Ivan; Lee, Youn Soo; Kim, Jin Seok; Hoang, Michael; Mathiyakom, Nathan; Kim, Yong

    2016-01-01

    Adverse effect of alcohol on neural function has been well documented. Especially, the teratogenic effect of alcohol on neurodevelopment during embryogenesis has been demonstrated in various models, which could be a pathologic basis for fetal alcohol spectrum disorders (FASDs). While the developmental defects from alcohol abuse during gestation have been described, the specific mechanisms by which alcohol mediates these injuries have yet to be determined. Recent studies have shown that alcohol has significant effect on molecular and cellular regulatory mechanisms in embryonic stem cell (ESC) differentiation including genes involved in neural development. To test our hypothesis that alcohol induces molecular alterations during neural differentiation we have derived neural precursor cells from pluripotent human ESCs in the presence or absence of ethanol treatment. Genome-wide transcriptomic profiling identified molecular alterations induced by ethanol exposure during neural differentiation of hESCs into neural rosettes and neural precursor cell populations. The Database for Annotation, Visualization and Integrated Discovery (DAVID) functional analysis on significantly altered genes showed potential ethanol’s effect on JAK-STAT signaling pathway, neuroactive ligand-receptor interaction, Toll-like receptor (TLR) signaling pathway, cytokine-cytokine receptor interaction and regulation of autophagy. We have further quantitatively verified ethanol-induced alterations of selected candidate genes. Among verified genes we further examined the expression of P2RX3, which is associated with nociception, a peripheral pain response. We found ethanol significantly reduced the level of P2RX3 in undifferentiated hESCs, but induced the level of P2RX3 mRNA and protein in hESC-derived NPCs. Our result suggests ethanol-induced dysregulation of P2RX3 along with alterations in molecules involved in neural activity such as neuroactive ligand-receptor interaction may be a molecular event

  18. Plasma glutamine is a minor precursor for the synthesis of citrulline: A multispecies study

    USDA-ARS?s Scientific Manuscript database

    Glutamine is considered the main precursor for citrulline synthesis in many species, including humans. The transfer of 15N from 2[15N]-glutamine to citrulline has been used as evidence for this precursor-product relationship. However, work in mice has shown that nitrogen and carbon tracers follow di...

  19. Nanog reverses the effects of organismal aging on mesenchymal stem cell proliferation and myogenic differentiation potential

    PubMed Central

    Han, Juhee; Mistriotis, Panagiotis; Lei, Pedro; Wang, Dan; Liu, Song; Andreadis, Stelios T.

    2012-01-01

    Although the therapeutic potential of mesenchymal stem cells (MSC) is widely accepted, loss of cell function due to donor aging or culture senescence are major limiting factors hampering their clinical application. Our laboratory recently showed that MSC originating from older donors suffer from limited proliferative capacity and significantly reduced myogenic differentiation potential. This is a major concern, as the patients most likely to suffer from cardiovascular disease are elderly. Here we tested the hypothesis that a single pluripotency associated transcription factor, namely Nanog, may reverse the proliferation and differentiation potential of BM-MSC from adult donors. Microarray analysis showed that adult (a)BM-MSC expressing Nanog clustered close to Nanog-expressing neonatal cells. Nanog markedly upregulated genes involved in cell cycle, DNA replication and DNA damage repair and enhanced the proliferation rate and clonogenic capacity of aBM-MSC. Notably, Nanog reversed the myogenic differentiation potential and restored the contractile function of aBM-MSC to a similar level as that of neonatal (n)BM-MSC. The effect of Nanog on contractility was mediated – at least in part - through activation of the TGF-β pathway by diffusible factors secreted in the conditioned medium of Nanog-expressing BM-MSC. Overall, our results suggest that Nanog may be used to overcome the effects of organismal aging on aBM-MSC, thereby increasing the potential of MSC from aged donors for cellular therapy and tissue regeneration. PMID:22949105

  20. Increased Cardiac Myocyte Progenitors in Failing Human Hearts

    PubMed Central

    Kubo, Hajime; Jaleel, Naser; Kumarapeli, Asangi; Berretta, Remus M.; Bratinov, George; Shan, Xiaoyin; Wang, Hongmei; Houser, Steven R.; Margulies, Kenneth B.

    2009-01-01

    Background Increasing evidence, derived mainly from animal models, supports the existence of endogenous cardiac renewal and repair mechanisms in adult mammalian hearts that could contribute to normal homeostasis and the responses to pathological insults. Methods and Results Translating these results, we isolated small c-kit+ cells from 36 of 37 human hearts using primary cell isolation techniques and magnetic cell sorting techniques. The abundance of these cardiac progenitor cells was increased nearly 4-fold in patients with heart failure requiring transplantation compared with nonfailing controls. Polychromatic flow cytometry of primary cell isolates (<30 μm) without antecedent c-kit enrichment confirmed the increased abundance of c-kit+ cells in failing hearts and demonstrated frequent coexpression of CD45 in these cells. Immunocytochemical characterization of freshly isolated, c-kit–enriched human cardiac progenitor cells confirmed frequent coexpression of c-kit and CD45. Primary cardiac progenitor cells formed new human cardiac myocytes at a relatively high frequency after coculture with neonatal rat ventricular myocytes. These contracting new cardiac myocytes exhibited an immature phenotype and frequent electric coupling with the rat myocytes that induced their myogenic differentiation. Conclusions Despite the increased abundance and cardiac myogenic capacity of cardiac progenitor cells in failing human hearts, the need to replace these organs via transplantation implies that adverse features of the local myocardial environment overwhelm endogenous cardiac repair capacity. Developing strategies to improve the success of endogenous cardiac regenerative processes may permit therapeutic myocardial repair without cell delivery per se. PMID:18645055

  1. TWEAK in inclusion-body myositis muscle: possible pathogenic role of a cytokine inhibiting myogenesis.

    PubMed

    Morosetti, Roberta; Gliubizzi, Carla; Sancricca, Cristina; Broccolini, Aldobrando; Gidaro, Teresa; Lucchini, Matteo; Mirabella, Massimiliano

    2012-04-01

    Tumor necrosis factor-like weak inducer of apoptosis (TWEAK) and its receptor Fn14 exert pleiotropic effects, including regulation of myogenesis. Sporadic inclusion-body myositis (IBM) is the most common muscle disease of the elderly population and leads to severe disability. IBM mesoangioblasts, different from mesoangioblasts in other inflammatory myopathies, display a myogenic differentiation defect. The objective of the present study was to investigate TWEAK-Fn14 expression in IBM and other inflammatory myopathies and explore whether TWEAK modulation affects myogenesis in IBM mesoangioblasts. TWEAK, Fn14, and NF-κB expression was assessed by immunohistochemistry and Western blot in cell samples from both muscle biopsies and primary cultures. Mesoangioblasts isolated from samples of IBM, dermatomyositis, polymyositis, and control muscles were treated with recombinant human TWEAK, Fn14-Fc chimera, and anti-TWEAK antibody. TWEAK-RNA interference was performed in IBM and dermatomyositis mesoangioblasts. TWEAK levels in culture media were determined by enzyme-linked immunosorbent assay. In IBM muscle, we found increased TWEAK-Fn14 expression. Increased levels of TWEAK were found in differentiation medium from IBM mesoangioblasts. Moreover, TWEAK inhibited myogenic differentiation of mesoangioblasts. Consistent with this evidence, TWEAK inhibition by Fn14-Fc chimera or short interfering RNA induced myogenic differentiation of IBM mesoangioblasts. We provide evidence that TWEAK is a negative regulator of human mesoangioblast differentiation. Dysregulation of the TWEAK-Fn14 axis in IBM muscle may induce progressive muscle atrophy and reduce activation and differentiation of muscle precursor cells. Copyright © 2012 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

  2. Vestibular evoked myogenic potential findings in multiple sclerosis.

    PubMed

    Escorihuela García, Vicente; Llópez Carratalá, Ignacio; Orts Alborch, Miguel; Marco Algarra, Jaime

    2013-01-01

    Multiple sclerosis is an inflammatory disease involving the occurrence of demyelinating, chronic neurodegenerative lesions in the central nervous system. We studied vestibular evoked myogenic potentials (VEMPs) in this pathology, to allow us to evaluate the saccule, inferior vestibular nerve and vestibular-spinal pathway non-invasively. There were 23 patients diagnosed with multiple sclerosis who underwent VEMP recordings, comparing our results with a control group consisting of 35 healthy subjects. We registered p13 and n23 wave latencies, interaural amplitude difference and asymmetry ratio between both ears. Subjects also underwent an otoscopy and audiometric examination. The prolongation of p13 and n23 wave latencies was the most notable characteristic, with a mean p13 wave latency of 19.53 milliseconds and a mean latency of 30.06 milliseconds for n23. In contrast, the asymmetry index showed no significant differences with our control group. In case of multiple sclerosis, the prolongation of the p13 and n23 VEMP wave latencies is a feature that has been attributed to slowing of conduction by demyelination of the vestibular-spinal pathway. In this regard, alteration of the response or lack thereof in these potentials has a locator value of injury to the lower brainstem. Copyright © 2013 Elsevier España, S.L. All rights reserved.

  3. The proteolytic processing site of the precursor of lysyl oxidase.

    PubMed Central

    Cronshaw, A D; Fothergill-Gilmore, L A; Hulmes, D J

    1995-01-01

    The precise cleavage site of the N-terminal propeptide region of the precursor of lysyl oxidase has not yet been established, due to N-terminal blocking of the mature protein. Using a combination of peptide fragmentation, amino acid sequencing, time-of-flight m.s. and partial chemical unblocking procedures, it is shown that the mature form of lysyl oxidase begins at residue Asp-169 of the precursor protein (numbered according to the human sequence). The cleavage site is 28 residues to the C-terminal side of the site previously suggested on the basis of apparant molecular mass by SDS/PAGE, with the consequence that the two putative, N-linked glycosylation sites and the position of the Arg/Gln sequence polymorphism are now all in the precursor region. PMID:7864821

  4. Towards an optimal therapy strategy for myogenous TMD, physiotherapy compared with occlusal splint therapy in an RCT with therapy-and-patient-specific treatment durations.

    PubMed

    van Grootel, Robert J; Buchner, Rob; Wismeijer, Daniël; van der Glas, Hilbert W

    2017-02-10

    Temporomandibular Disorders (TMD) may be characterized by pain and restricted jaw movements. In the absence of somatic factors in the temporomandibular joint, mainly myogenous, psychobiological, and psychosocial factors may be involved in the aetiology of myogenous TMD. An occlusal appliance (splint) is commonly used as a basic therapy of the dental practice. Alternatively, a type of physiotherapy which includes, apart from massage of sore muscles, aspects of cognitive-behavioural therapy might be a basic therapy for myogenous TMD. Treatment outcome of physiotherapy (Ph-Tx) was evaluated in comparison to that of splint therapy (Sp-Tx), using the index Treatment Duration Control (TDC) that enabled a randomized controlled trial with, comparable to clinical care, therapy-and-patient-specific treatment durations. Seventy-two patients were randomly assigned to either Ph-Tx or Sp-Tx, with an intended treatment duration between 10 and 21 or 12 and 30 weeks respectively. Using TDC, the clinician controlled treatment duration and the number of visits needed. A blinded assessor recorded anamnestic and clinical data to determine TDC-values following treatment and a 1-year follow-up, yielding success rate (SR) and effectiveness (mean TDC) as treatment outcomes. Cohen's d, was determined for pain intensity. Overall SR for stepped-care was assessed in a theoretical model, i.e. a second of the two studied therapies was applied if the first treatment was unsuccessful, and the effect of therapy sequence and difference in success rates was examined. SR and effectiveness were similar for Ph-Tx and Sp-Tx (long-term SR: 51-60%; TDC: -0.512- -0.575). Cohen's d was 0.86 (Ph-Tx) and 1.39 (Sp-Tx). Treatment duration was shorter for Ph-Tx (on average 10.4 weeks less; p < 0.001). Sp-Tx needed 7.1 less visits (p < 0.001). Physiotherapy may be preferred as initial therapy over occlusal splint therapy in stepped-care of myogenous TMD. With a similar SR and effectiveness, physiotherapy

  5. Isolating RNA from precursor and mature melanocytes from human vitiligo and normal skin using laser capture microdissection.

    PubMed

    Goldstein, Nathaniel B; Koster, Maranke I; Hoaglin, Laura G; Wright, Michael J; Robinson, Steven E; Robinson, William A; Roop, Dennis R; Norris, David A; Birlea, Stanca A

    2016-10-01

    To characterize the gene expression profile of regenerated melanocytes in the narrow band UVB (NBUVB)-treated vitiligo epidermis and their precursors in the hair follicle, we present here a strategy of RNA isolation from in situ melanocytes using human frozen skin. We developed a rapid immunostaining protocol using the NKI-beteb antibody, which labels differentiated and precursor melanocytes, followed by fluorescent laser capture microdissection. This technique enabled the direct isolation, from melanocyte and adjacent keratinocyte populations, of satisfactory quality RNA that was successfully amplified and analysed by qRT-PCR. The melanocyte-specific gene transcripts TYR, DCT, TYRP1 and PMEL were significantly upregulated in our NBUVB-treated melanocyte samples as compared with the keratinocyte samples, while keratinocyte-specific genes (KRT5 and KRT14) were expressed significantly higher in the keratinocyte samples as compared with the melanocyte samples. Furthermore, in both NBUVB-treated vitiligo skin and normal skin, when bulge melanocytes were compared with epidermal melanocytes, we found significantly lower expression of melanocyte-specific genes and significantly higher expression of three melanocytic stem cell genes (SOX9, WIF1 and SFRP1), while ALCAM and ALDH1A1 transcripts did not show significant variation. We found significantly higher expression of melanocyte-specific genes in the epidermis of NBUVB-treated vitiligo, as compared to the normal skin. When comparing bulge melanocyte samples from untreated vitiligo, NBUVB-treated vitiligo and normal skin, we did not find significant differences in the expression of melanocyte-specific genes or melanocytic stem cell genes. These techniques offer valuable opportunities to study melanocytes and their precursors in vitiligo and other pigmentation disorders. © 2016 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  6. Melatonin and its precursors in Y79 human retinoblastoma cells: Effect of sodium butyrate

    NASA Technical Reports Server (NTRS)

    Deng, Mei Hua; Coviella, Ignacio Lopez G.; Lynch, Harry J.; Wurtman, Richard J.

    1991-01-01

    The release of melatonin and the production of its precursors, S-hydroxytryptophan and serotonin, in cultured Y79 human retinoblastoma cells were studied. This biosynthetic capability was found to be dependent on cell differentiation, which was initiated by culturing Y79 cells for 7 days in dishes coated with poly-D-lysine to promote cell adhesion to the surface of the culture dishes. Differentiation was further induced by exposing the cell monolayer to sodium butyrate (3 mM) for 3 days. This protocol dramatically increased the release of melatonin, and the syntheses of 5-hydroxytryptophan and serotonin in response to forskolin stimulation. Exposure to dopamine (10 micro-M) or L-DOPA (100 micro-M) markedly diminished the forskolin-stimulated release of melatonin, as well as the production of 5-hydroxytryptophan and serotonin. These observations indicate that Y79 cells represent a primitive cell line which, following appropriate differentiation (e.g. treatment with sodium butyrate) can display biochemical characteristics similar to those of the human retina. Moreover, serotonin synthesis and melatonin release appear to be coupled in Y79 cells. The inhibition of melatonin release by dopamine supports the hypothesis that in these cells, melatonin and dopamine are components of a retinal feedback loop.

  7. Rotator cuff muscle degeneration and tear severity related to myogenic, adipogenic, and atrophy genes in human muscle.

    PubMed

    Shah, Shivam A; Kormpakis, Ioannis; Cavinatto, Leonardo; Killian, Megan L; Thomopoulos, Stavros; Galatz, Leesa M

    2017-12-01

    Large rotator cuff tear size and advanced muscle degeneration can affect reparability of tears and compromise tendon healing. Clinicians often rely on direct measures of rotator cuff tear size and muscle degeneration from magnetic resonance imaging (MRI) to determine whether the rotator cuff tear is repairable. The objective of this study was to identify the relationship between gene expression changes in rotator cuff muscle degeneration to standard data available to clinicians. Radiographic assessment of preoperative rotator cuff tear severity was completed for 25 patients with varying magnitudes of rotator cuff tears. Tear width and retraction were measured using MRI, and Goutallier grade, tangent (tan) sign, and Thomazeau grade were determined. Expression of myogenic-, adipogenic-, atrophy-, and metabolism-related genes in biopsied muscles were correlated with tear width, tear retraction, Goutallier grade, tan sign, and Thomazeau grade. Tear width positively correlated with Goutallier grade in both the supraspinatus (r = 0.73) and infraspinatus (r = 0.77), along with tan sign (r = 0.71) and Thomazeau grade (r = 0.68). Decreased myogenesis (Myf5), increased adipogenesis (CEBPα, Lep, Wnt10b), and decreased metabolism (PPARα) correlated with radiographic assessments. Gene expression changes suggest that rotator cuff tears lead to a dramatic molecular response in an attempt to maintain normal muscle tissue, increase adipogenesis, and decrease metabolism. Fat accumulation and muscle atrophy appear to stem from endogenous changes rather than from changes mediated by infiltrating cells. Results suggest that chronic unloading of muscle, induced by rotator cuff tear, disrupts muscle homeostasis. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc. J Orthop Res 35:2808-2814, 2017. © 2017 Orthopaedic Research Society. Published by Wiley Periodicals, Inc.

  8. A Python Analytical Pipeline to Identify Prohormone Precursors and Predict Prohormone Cleavage Sites

    PubMed Central

    Southey, Bruce R.; Sweedler, Jonathan V.; Rodriguez-Zas, Sandra L.

    2008-01-01

    Neuropeptides and hormones are signaling molecules that support cell–cell communication in the central nervous system. Experimentally characterizing neuropeptides requires significant efforts because of the complex and variable processing of prohormone precursor proteins into neuropeptides and hormones. We demonstrate the power and flexibility of the Python language to develop components of an bioinformatic analytical pipeline to identify precursors from genomic data and to predict cleavage as these precursors are en route to the final bioactive peptides. We identified 75 precursors in the rhesus genome, predicted cleavage sites using support vector machines and compared the rhesus predictions to putative assignments based on homology to human sequences. The correct classification rate of cleavage using the support vector machines was over 97% for both human and rhesus data sets. The functionality of Python has been important to develop and maintain NeuroPred (http://neuroproteomics.scs.uiuc.edu/neuropred.html), a user-centered web application for the neuroscience community that provides cleavage site prediction from a wide range of models, precision and accuracy statistics, post-translational modifications, and the molecular mass of potential peptides. The combined results illustrate the suitability of the Python language to implement an all-inclusive bioinformatics approach to predict neuropeptides that encompasses a large number of interdependent steps, from scanning genomes for precursor genes to identification of potential bioactive neuropeptides. PMID:19169350

  9. Schwann Cell Precursors from Human Pluripotent Stem Cells as a Potential Therapeutic Target for Myelin Repair.

    PubMed

    Kim, Han-Seop; Lee, Jungwoon; Lee, Da Yong; Kim, Young-Dae; Kim, Jae Yun; Lim, Hyung Jin; Lim, Sungmin; Cho, Yee Sook

    2017-06-06

    Schwann cells play a crucial role in successful nerve repair and regeneration by supporting both axonal growth and myelination. However, the sources of human Schwann cells are limited both for studies of Schwann cell development and biology and for the development of treatments for Schwann cell-associated diseases. Here, we provide a rapid and scalable method to produce self-renewing Schwann cell precursors (SCPs) from human pluripotent stem cells (hPSCs), using combined sequential treatment with inhibitors of the TGF-β and GSK-3 signaling pathways, and with neuregulin-1 for 18 days under chemically defined conditions. Within 1 week, hPSC-derived SCPs could be differentiated into immature Schwann cells that were functionally confirmed by their secretion of neurotrophic factors and their myelination capacity in vitro and in vivo. We propose that hPSC-derived SCPs are a promising, unlimited source of functional Schwann cells for treating demyelination disorders and injuries to the peripheral nervous system. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  10. Prosurvival Factors Improve Functional Engraftment of Myogenically Converted Dermal Cells into Dystrophic Skeletal Muscle

    PubMed Central

    Muir, Lindsey A.; Murry, Charles E.

    2016-01-01

    In Duchenne muscular dystrophy (DMD) and other muscle wasting disorders, cell therapies are a promising route for promoting muscle regeneration by supplying a functional copy of the missing dystrophin gene and contributing new muscle fibers. The clinical application of cell-based therapies is resource intensive, and it will therefore be necessary to address key limitations that reduce cell engraftment into muscle tissue. A pressing issue is poor donor cell survival following transplantation, which in preclinical studies limits the ability to effectively test the impact of cell-based therapy on whole muscle function. We, therefore, sought to improve engraftment and the functional impact of in vivo myogenically converted dermal fibroblasts (dFbs) using a prosurvival cocktail (PSC) that includes heat shock followed by treatment with insulin-like growth factor-1, a caspase inhibitor, a Bcl-XL peptide, a KATP channel opener, basic fibroblast growth factor, Matrigel, and cyclosporine A. Advantages of dFbs include compatibility with the autologous setting, ease of isolation, and greater proliferative potential than DMD satellite cells. dFbs expressed tamoxifen-inducible MyoD and carried a mini-dystrophin gene driven by a muscle-specific promoter. After transplantation into muscles of mdx mice, a 70% reduction in donor cells was observed by day 5, and a 94% reduction by day 28. However, treatment with PSC gave a nearly three-fold increase in donor cells in early engraftment, and greatly increased the number of donor-contributed muscle fibers and total engrafted area in transplanted muscles. Furthermore, dystrophic muscles that received dFbs with PSC displayed reduced injury with eccentric contractions and an increase in maximum isometric force. Thus, enhancing survival of myogenic cells increases engraftment and improves structure and function of dystrophic muscle. PMID:27503462

  11. Prosurvival Factors Improve Functional Engraftment of Myogenically Converted Dermal Cells into Dystrophic Skeletal Muscle.

    PubMed

    Muir, Lindsey A; Murry, Charles E; Chamberlain, Jeffrey S

    2016-09-07

    In Duchenne muscular dystrophy (DMD) and other muscle wasting disorders, cell therapies are a promising route for promoting muscle regeneration by supplying a functional copy of the missing dystrophin gene and contributing new muscle fibers. The clinical application of cell-based therapies is resource intensive, and it will therefore be necessary to address key limitations that reduce cell engraftment into muscle tissue. A pressing issue is poor donor cell survival following transplantation, which in preclinical studies limits the ability to effectively test the impact of cell-based therapy on whole muscle function. We, therefore, sought to improve engraftment and the functional impact of in vivo myogenically converted dermal fibroblasts (dFbs) using a prosurvival cocktail (PSC) that includes heat shock followed by treatment with insulin-like growth factor-1, a caspase inhibitor, a Bcl-XL peptide, a K ATP channel opener, basic fibroblast growth factor, Matrigel, and cyclosporine A. Advantages of dFbs include compatibility with the autologous setting, ease of isolation, and greater proliferative potential than DMD satellite cells. dFbs expressed tamoxifen-inducible MyoD and carried a mini-dystrophin gene driven by a muscle-specific promoter. After transplantation into muscles of mdx mice, a 70% reduction in donor cells was observed by day 5, and a 94% reduction by day 28. However, treatment with PSC gave a nearly three-fold increase in donor cells in early engraftment, and greatly increased the number of donor-contributed muscle fibers and total engrafted area in transplanted muscles. Furthermore, dystrophic muscles that received dFbs with PSC displayed reduced injury with eccentric contractions and an increase in maximum isometric force. Thus, enhancing survival of myogenic cells increases engraftment and improves structure and function of dystrophic muscle.

  12. Low-grade sinonasal sarcoma with neural and myogenic features: a clinicopathologic analysis of 28 cases.

    PubMed

    Lewis, Jason T; Oliveira, Andre M; Nascimento, Antonio G; Schembri-Wismayer, David; Moore, Eric A; Olsen, Kerry D; Garcia, Joaquin G; Lonzo, Melissa L; Lewis, Jean E

    2012-04-01

    Sarcomas of the sinonasal region are rare. We describe a distinct spindle cell sarcoma of the sinonasal region characterized by concomitant neural and myogenic differentiation. Consultation files and surgical cases from Mayo Clinic were reviewed. Twenty-eight cases were identified that met the inclusion criteria. Clinical data were collected from medical records, consultation letters, and referring pathologists. Reverse transcriptase-polymerase chain reaction for synovial sarcoma fusion transcripts was performed on 18 cases. Cytogenetic studies were performed on 2 cases. The 21 female and 7 male patients ranged in age from 24 to 85 years (mean, 52 y). All cases showed a characteristic histology, which included a cellular spindle cell neoplasm with uniform, elongate nuclei and an infiltrative growth pattern. All tumors demonstrated expression of S-100 with actin positivity in 96% of cases tested. Reverse transcriptase-polymerase chain reaction for synovial sarcoma fusion transcripts was negative in all cases tested. Cytogenetic studies conducted on 2 cases demonstrated the chromosomal translocation t(2;4). The nasal cavity (54%) and ethmoid sinus (57%) were the most commonly involved areas, singly or in combination. Follow-up information was available for 57% (16/28) of cases, with a mean of 8.3 years. Of these, 44% (7/16) experienced at least 1 recurrence. No patient has developed metastases or died of disease. We describe a unique tumor with a characteristic morphologic, immunophenotypic, and cytogenetic profile. On the basis of the locally aggressive nature of this lesion we believe it is best considered a low-grade sarcoma and suggest the term low-grade sinonasal sarcoma with neural and myogenic features.

  13. The role of primary myogenic regulatory factors in the developing diaphragmatic muscle in the nitrofen-induced diaphragmatic hernia.

    PubMed

    Dingemann, Jens; Doi, Takashi; Ruttenstock, Elke; Puri, Prem

    2011-06-01

    The nitrofen model of congenital diaphragmatic hernia (CDH) is widely used to investigate the pathogenesis of CDH. However, the exact pathomechanism of the diaphragmatic defect is still unclear. Diaphragmatic muscularization represents the last stage of diaphragmatic development. Myogenic differentiation 1 (MyoD) and myogenic factor 5 (Myf5) play a crucial role in muscularization. MyoD(-/-) : Myf5(+/-) mutant mice show reduced diaphragmatic size, whereas MyoD(+/-) : Myf5(-/-) mutants have normal diaphragms. We designed this study to investigate diaphragmatic gene expression of MyoD and Myf5 in the nitrofen CDH model. Pregnant rats received nitrofen or vehicle on day 9 of gestation (D9), followed by cesarean section on D18 and D21. Fetal diaphragms (n = 40) were micro-dissected and divided into CDH group and controls. MyoD and Myf5 mRNA-expression were determined using Real-time PCR. Immunohistochemistry was performed to evaluate protein expression of MyoD and Myf5. Relative diaphragmatic mRNA expression levels and immunoreactivity of MyoD were decreased in the CDH group on D18 and D21. Myf 5 mRNA and protein expression were not altered in the CDH group. This is the first study showing that MyoD expression is selectively decreased in the diaphragm muscle in the nitrofen model of CDH.

  14. Nuclear localization of foamy virus Gag precursor protein.

    PubMed Central

    Schliephake, A W; Rethwilm, A

    1994-01-01

    All foamy viruses give rise to a strong nuclear staining when infected cells are reacted with sera from infected hosts. This nuclear fluorescence distinguishes foamy viruses from all other retroviruses. The experiments reported here indicate that the foamy virus Gag precursor protein is transiently located in the nuclei of infected cells and this is the likely reason for the typical foamy virus nuclear fluorescence. By using the vaccinia virus expression system, a conserved basic sequence motif in the nucleocapsid domain of foamy virus Gag proteins was identified to be responsible for the nuclear transport of the gag precursor molecule. This motif was also found to be able to direct a heterologous protein, the Gag protein of human immunodeficiency virus, into the nucleus. Images PMID:8035493

  15. Maturation of the myogenic program is induced by postmitotic expression of insulin-like growth factor I.

    PubMed

    Musarò, A; Rosenthal, N

    1999-04-01

    The molecular mechanisms underlying myogenic induction by insulin-like growth factor I (IGF-I) are distinct from its proliferative effects on myoblasts. To determine the postmitotic role of IGF-I on muscle cell differentiation, we derived L6E9 muscle cell lines carrying a stably transfected rat IGF-I gene under the control of a myosin light chain (MLC) promoter-enhancer cassette. Expression of MLC-IGF-I exclusively in differentiated L6E9 myotubes, which express the embryonic form of myosin heavy chain (MyHC) and no endogenous IGF-I, resulted in pronounced myotube hypertrophy, accompanied by activation of the neonatal MyHC isoform. The hypertrophic myotubes dramatically increased expression of myogenin, muscle creatine kinase, beta-enolase, and IGF binding protein 5 and activated the myocyte enhancer factor 2C gene which is normally silent in this cell line. MLC-IGF-I induction in differentiated L6E9 cells also increased the expression of a transiently transfected LacZ reporter driven by the myogenin promoter, demonstrating activation of the differentiation program at the transcriptional level. Nuclear reorganization, accumulation of skeletal actin protein, and an increased expression of beta1D integrin were also observed. Inhibition of the phosphatidyl inositol (PI) 3-kinase intermediate in IGF-I-mediated signal transduction confirmed that the PI 3-kinase pathway is required only at early stages for IGF-I-mediated hypertrophy and neonatal MyHC induction in these cells. Expression of IGF-I in postmitotic muscle may therefore play an important role in the maturation of the myogenic program.

  16. Met-Activating Genetically Improved Chimeric Factor-1 Promotes Angiogenesis and Hypertrophy in Adult Myogenesis.

    PubMed

    Ronzoni, Flavio; Ceccarelli, Gabriele; Perini, Ilaria; Benedetti, Laura; Galli, Daniela; Mulas, Francesca; Balli, Martina; Magenes, Giovanni; Bellazzi, Riccardo; De Angelis, Gabriella C; Sampaolesi, Maurilio

    2017-01-01

    Myogenic progenitor cells (activated satellite cells) are able to express both HGF and its receptor cMet. After muscle injury, HGF-Met stimulation promotes activation and primary division of satellite cells. MAGIC-F1 (Met-Activating Genetically Improved Chimeric Factor-1) is an engineered protein that contains two human Met-binding domains that promotes muscle hypertrophy. MAGIC-F1 protects myogenic precursors against apoptosis and increases their fusion ability enhancing muscle differentiation. Hemizygous and homozygous Magic-F1 transgenic mice displayed constitutive muscle hypertrophy. Here we describe microarray analysis on Magic-F1 myogenic progenitor cells showing an altered gene signatures on muscular hypertrophy and angiogenesis compared to wild-type cells. In addition, we performed a functional analysis on Magic-F1+/+ transgenic mice versus controls using treadmill test. We demonstrated that Magic-F1+/+ mice display an increase in muscle mass and cross-sectional area leading to an improvement in running performance. Moreover, the presence of MAGIC-F1 affected positively the vascular network, increasing the vessel number in fast twitch fibers. Finally, the gene expression profile analysis of Magic-F1+/+ satellite cells evidenced transcriptomic changes in genes involved in the control of muscle growth, development and vascularisation. We showed that MAGIC-F1-induced muscle hypertrophy affects positively vascular network, increasing vessel number in fast twitch fibers. This was due to unique features of mammalian skeletal muscle and its remarkable ability to adapt promptly to different physiological demands by modulating the gene expression profile in myogenic progenitors. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

  17. Human endothelial precursor cells express tumor endothelial marker 1/endosialin/CD248.

    PubMed

    Bagley, Rebecca G; Rouleau, Cecile; St Martin, Thia; Boutin, Paula; Weber, William; Ruzek, Melanie; Honma, Nakayuki; Nacht, Mariana; Shankara, Srinivas; Kataoka, Shiro; Ishida, Isao; Roberts, Bruce L; Teicher, Beverly A

    2008-08-01

    Angiogenesis occurs during normal physiologic processes as well as under pathologic conditions such as tumor growth. Serial analysis of gene expression profiling revealed genes [tumor endothelial markers (TEM)] that are overexpressed in tumor endothelial cells compared with normal adult endothelial cells. Because blood vessel development of malignant tumors under certain conditions may include endothelial precursor cells (EPC) recruited from bone marrow, we investigated TEM expression in EPC. The expression of TEM1 or endosialin (CD248) and other TEM has been discovered in a population of vascular endothelial growth factor receptor 2+/CD31+/CD45-/VE-cadherin+ EPC derived from human CD133+/CD34+ cells. EPC share some properties with fully differentiated endothelial cells from normal tissue, yet reverse transcription-PCR and flow cytometry reveal that EPC express higher levels of endosialin at the molecular and protein levels. The elevated expression of endosialin in EPC versus mature endothelial cells suggests that endosialin is involved in the earlier stages of tumor angiogenesis. Anti-endosialin antibodies inhibited EPC migration and tube formation in vitro. In vivo, immunohistochemistry indicated that human EPC continued to express endosialin protein in a Matrigel plug angiogenesis assay established in nude mice. Anti-endosialin antibodies delivered systemically at 25 mg/kg were also able to inhibit circulating murine EPC in nude mice bearing s.c. SKNAS tumors. EPC and bone marrow-derived cells have been shown previously to incorporate into malignant blood vessels in some instances, yet they remain controversial in the field. The data presented here on endothelial genes that are up-regulated in tumor vasculature and in EPC support the hypothesis that the angiogenesis process in cancer can involve EPC.

  18. Vestibular evoked myogenic potentials in patients with BPPV.

    PubMed

    Korres, Stavros; Gkoritsa, Eleni; Giannakakou-Razelou, Dimitra; Yiotakis, Ioannis; Riga, Maria; Nikolpoulos, Thomas P

    2011-01-01

    The probable cause of Benign Paroxysmal Positional Vertigo (BPPV) is a degeneration of the oto lithic organs (utricle and saccule). The aim of the study is to find possible alterations in Vestibular Evoked Myogenic Potentials (VEMP) recordings in BPPV patients, because the saccule is part of the VEMP pathway. 27 BPPV patients (24 unilateral and 3 bilateral) aged 20 to 70 years and 30 healthy age matched controls. BPPV was diagnosed by the upbeating geotropic nystagmus found in the supine position with the head overextended towards one side. The subjects were investigated with pure tone audiometry, bi-thermal caloric test with electronystagmographic (ENG) recording, and VEMP recording. P1 latency and N1 latency did not present any statistical difference between control ears and affected ears of the BPPV population. The percentage of abnormal VEMP in the BPPV population was statistically higher than in the control ears (p < 0.005). No significant relationship could be shown between the occurrence of Canal Paresis and abnormal VEMP. No relationship was found between the side (right or left ear) where BPPV appeared clinically and the side where abnormal VEMP was registered. BPPV is a clinical entity associated with increased occurrence of abnormal VEMP recordings, possibly due to degeneration of the saccular macula, which is part of the neural VEMP pathway.

  19. Vestibular evoked myogenic potentials in patients with BPPV

    PubMed Central

    Korres, Stavros; Gkoritsa, Eleni; Giannakakou-Razelou, Dimitra; Yiotakis, Ioannis; Riga, Maria; Nikolpoulos, Thomas P.

    2011-01-01

    Summary Background The probable cause of Benign Paroxysmal Positional Vertigo (BPPV) is a degeneration of the oto lithic organs (utricle and saccule). The aim of the study is to find possible alterations in Vestibular Evoked Myogenic Potentials (VEMP) recordings in BPPV patients, because the saccule is part of the VEMP pathway. Material/Methods 27 BPPV patients (24 unilateral and 3 bilateral) aged 20 to 70 years and 30 healthy age matched controls. BPPV was diagnosed by the upbeating geotropic nystagmus found in the supine position with the head overextended towards one side. The subjects were investigated with pure tone audiometry, bi-thermal caloric test with electronystagmographic (ENG) recording, and VEMP recording. Results P1 latency and N1 latency did not present any statistical difference between control ears and affected ears of the BPPV population. The percentage of abnormal VEMP in the BPPV population was statistically higher than in the control ears (p<0.005). No significant relationship could be shown between the occurrence of Canal Paresis and abnormal VEMP. No relationship was found between the side (right or left ear) where BPPV appeared clinically and the side where abnormal VEMP was registered. Conclusions BPPV is a clinical entity associated with increased occurrence of abnormal VEMP recordings, possibly due to degeneration of the saccular macula, which is part of the neural VEMP pathway. PMID:21169909

  20. Cleavage of precursors by the mitochondrial processing peptidase requires a compatible mature protein or an intermediate octapeptide

    PubMed Central

    1991-01-01

    Many precursors of mitochondrial proteins are processed in two successive steps by independent matrix peptidases (MPP and MIP), whereas others are cleaved in a single step by MPP alone. To explain this dichotomy, we have constructed deletions of all or part of the octapeptide characteristic of a twice cleaved precursor (human ornithine transcarbamylase [pOTC]), have exchanged leader peptide sequences between once-cleaved (human methylmalonyl-CoA mutase [pMUT]; yeast F1ATPase beta-subunit [pF1 beta]) and twice-cleaved (pOTC; rat malate dehydrogenase (pMDH); Neurospora ubiquinol-cytochrome c reductase iron-sulfur subunit [pFe/S]) precursors, and have incubated these proteins with purified MPP and MIP. When the octapeptide of pOTC was deleted, or when the entire leader peptide of a once-cleaved precursor (pMUT or pF1 beta) was joined to the mature amino terminus of a twice-cleaved precursor (pOTC or pFe/S), no cleavage was produced by either protease. Cleavage of these constructs by MPP was restored by re- inserting as few as two amino-terminal residues of the octapeptide or of the mature amino terminus of a once-cleaved precursor. We conclude that the mature amino terminus of a twice-cleaved precursor is structurally incompatible with cleavage by MPP; such proteins have evolved octapeptides cleaved by MIP to overcome this incompatibility. PMID:1672532

  1. Differentiation and sarcomere formation in skeletal myocytes directly prepared from human induced pluripotent stem cells using a sphere-based culture.

    PubMed

    Jiwlawat, Saowanee; Lynch, Eileen; Glaser, Jennifer; Smit-Oistad, Ivy; Jeffrey, Jeremy; Van Dyke, Jonathan M; Suzuki, Masatoshi

    Human induced-pluripotent stem cells (iPSCs) are a promising resource for propagation of myogenic progenitors. Our group recently reported a unique protocol for the derivation of myogenic progenitors directly (without genetic modification) from human pluripotent cells using free-floating spherical culture. Here we expand our previous efforts and attempt to determine how differentiation duration, culture surface coatings, and nutrient supplements in the medium influence progenitor differentiation and formation of skeletal myotubes containing sarcomeric structures. A long differentiation period (over 6 weeks) promoted the differentiation of iPSC-derived myogenic progenitors and subsequent myotube formation. These iPSC-derived myotubes contained representative sarcomeric structures, consisting of organized myosin and actin filaments, and could spontaneously contract. We also found that a bioengineering approach using three-dimensional (3D) artificial muscle constructs could facilitate the formation of elongated myotubes. Lastly, we determined how culture surface coating matrices and different supplements would influence terminal differentiation. While both Matrigel and laminin coatings showed comparable effects on muscle differentiation, B27 serum-free supplement in the differentiation medium significantly enhanced myogenesis compared to horse serum. Our findings support the possibility to create an in vitro model of contractile sarcomeric myofibrils for disease modeling and drug screening to study neuromuscular diseases. Copyright © 2017 International Society of Differentiation. Published by Elsevier B.V. All rights reserved.

  2. Leucine and isoleucine reduce protein degradation in rainbow trout (Oncorhynchus mykiss) primary myoblast cultures

    USDA-ARS?s Scientific Manuscript database

    Myogenic precursor cells were isolated from rainbow trout skeletal muscle and incubated in media containing 10% fetal bovine serum for 7 days, thereby differentiating into myoblasts. Rates of protein degradation were determined in response to minimal essential media (MEM) of various amino acid (AA)...

  3. Myogenic progenitors contribute to open but not closed fracture repair.

    PubMed

    Liu, Renjing; Birke, Oliver; Morse, Alyson; Peacock, Lauren; Mikulec, Kathy; Little, David G; Schindeler, Aaron

    2011-12-22

    Bone repair is dependent on the presence of osteocompetent progenitors that are able to differentiate and generate new bone. Muscle is found in close association with orthopaedic injury, however its capacity to make a cellular contribution to bone repair remains ambiguous. We hypothesized that myogenic cells of the MyoD-lineage are able to contribute to bone repair. We employed a MyoD-Cre+:Z/AP+ conditional reporter mouse in which all cells of the MyoD-lineage are permanently labeled with a human alkaline phosphatase (hAP) reporter. We tracked the contribution of MyoD-lineage cells in mouse models of tibial bone healing. In the absence of musculoskeletal trauma, MyoD-expressing cells are limited to skeletal muscle and the presence of reporter-positive cells in non-muscle tissues is negligible. In a closed tibial fracture model, there was no significant contribution of hAP+ cells to the healing callus. In contrast, open tibial fractures featuring periosteal stripping and muscle fenestration had up to 50% of hAP+ cells detected in the open fracture callus. At early stages of repair, many hAP+ cells exhibited a chondrocyte morphology, with lesser numbers of osteoblast-like hAP+ cells present at the later stages. Serial sections stained for hAP and type II and type I collagen showed that MyoD-lineage cells were surrounded by cartilaginous or bony matrix, suggestive of a functional role in the repair process. To exclude the prospect that osteoprogenitors spontaneously express MyoD during bone repair, we created a metaphyseal drill hole defect in the tibia. No hAP+ staining was observed in this model suggesting that the expression of MyoD is not a normal event for endogenous osteoprogenitors. These data document for the first time that muscle cells can play a significant secondary role in bone repair and this knowledge may lead to important translational applications in orthopaedic surgery. Please see related article: http://www.biomedcentral.com/1741-7015/9/136.

  4. Aberrant Splicing Induced by Dysregulated Rbfox2 Produces Enhanced Function of CaV1.2 Calcium Channel and Vascular Myogenic Tone in Hypertension.

    PubMed

    Zhou, Yingying; Fan, Jia; Zhu, Huayuan; Ji, Li; Fan, Wenyong; Kapoor, Isha; Wang, Yue; Wang, Yuan; Zhu, Guoqing; Wang, Juejin

    2017-12-01

    Calcium influx from activated voltage-gated calcium channel Ca V 1.2 in vascular smooth muscle cells is indispensable for maintaining myogenic tone and blood pressure. The function of Ca V 1.2 channel can be optimized by alternative splicing, one of post-transcriptional modification mechanisms. The splicing factor Rbfox2 is known to regulate the Ca V 1.2 pre-mRNA alternative splicing events during neuronal development. However, Rbfox2's roles in modulating the key function of vascular Ca V 1.2 channel and in the pathogenesis of hypertension remain elusive. Here, we report that the proportion of Ca V 1.2 channels with alternative exon 9* is increased by 10.3%, whereas that with alternative exon 33 is decreased by 10.5% in hypertensive arteries. Surprisingly, the expression level of Rbfox2 is increased ≈3-folds, presumably because of the upregulation of a dominant-negative isoform of Rbfox2. In vascular smooth muscle cells, we find that knockdown of Rbfox2 dynamically increases alternative exon 9*, whereas decreases exon 33 inclusion of Ca V 1.2 channels. By patch-clamp studies, we show that diminished Rbfox2-induced alternative splicing shifts the steady-state activation and inactivation curves of vascular Ca V 1.2 calcium channel to hyperpolarization, which makes the window current potential to more negative. Moreover, siRNA-mediated knockdown of Rbfox2 increases the pressure-induced vascular myogenic tone of rat mesenteric artery. Taken together, our data indicate that Rbfox2 modulates the functions of vascular Ca V 1.2 calcium channel by dynamically regulating the expressions of alternative exons 9* and 33, which in turn affects the vascular myogenic tone. Therefore, our work suggests a key role for Rbfox2 in hypertension, which provides a rational basis for designing antihypertensive therapies. © 2017 American Heart Association, Inc.

  5. Consistent latencies of vestibular evoked myogenic potentials.

    PubMed

    Wang, Shou-Jen; Yeh, Te-Huei; Chang, Chun-Hsiang; Young, Yi-Ho

    2008-12-01

    This study investigated the association between neck length and vestibular evoked myogenic potential (VEMP) latencies in healthy children, adolescents, and adults to elucidate when VEMP latencies reach consistent levels. Findings of VEMP tests in 14 healthy children, seven healthy adolescents, and 14 healthy adults were analyzed for correlations with neck length, which was measured as the distance of a line dropping vertically from the mastoid tip to the horizontal plane passing through the clavicle. All healthy children, adolescents, and adults exhibited present VEMP responses. Children, adolescents, and adults significantly differed in p13 latency, n23 latency, and p13-n23 interval. According to receiver operating characteristic curve analysis, the optimal cutoff values of p13 and n23 latencies between children and adults were 12.6 and 19.8 msec, respectively. Because the odds ratio of p13 latency was less than that of n23 latency, n23 latency was used to discriminate VEMP latencies between children and adults. Accordingly, a cutoff value of 15.3 cm for neck length was proposed as a criterion for predicting VEMP latency within the adult range. Consequently, a positive correlation between neck length and VEMP latency was observed when neck length was <15.3 cm, while above which level one need not account for neck length in evaluating VEMP latency. The intra-subject variability of norms can be enhanced if the normative data for VEMP characteristic parameters take structural variance into account. This study suggests that the adult range of VEMP latencies can be anticipated if neck length is >15.3 cm.

  6. Deconvolution of the vestibular evoked myogenic potential.

    PubMed

    Lütkenhöner, Bernd; Basel, Türker

    2012-02-07

    The vestibular evoked myogenic potential (VEMP) and the associated variance modulation can be understood by a convolution model. Two functions of time are incorporated into the model: the motor unit action potential (MUAP) of an average motor unit, and the temporal modulation of the MUAP rate of all contributing motor units, briefly called rate modulation. The latter is the function of interest, whereas the MUAP acts as a filter that distorts the information contained in the measured data. Here, it is shown how to recover the rate modulation by undoing the filtering using a deconvolution approach. The key aspects of our deconvolution algorithm are as follows: (1) the rate modulation is described in terms of just a few parameters; (2) the MUAP is calculated by Wiener deconvolution of the VEMP with the rate modulation; (3) the model parameters are optimized using a figure-of-merit function where the most important term quantifies the difference between measured and model-predicted variance modulation. The effectiveness of the algorithm is demonstrated with simulated data. An analysis of real data confirms the view that there are basically two components, which roughly correspond to the waves p13-n23 and n34-p44 of the VEMP. The rate modulation corresponding to the first, inhibitory component is much stronger than that corresponding to the second, excitatory component. But the latter is more extended so that the two modulations have almost the same equivalent rectangular duration. Copyright © 2011 Elsevier Ltd. All rights reserved.

  7. Neurotoxicity of a Fragment of the Amyloid Precursor Associated with Alzheimer's Disease

    NASA Astrophysics Data System (ADS)

    Yankner, Bruce A.; Dawes, Linda R.; Fisher, Shannon; Villa-Komaroff, Lydia; Oster-Granite, Mary Lou; Neve, Rachael L.

    1989-07-01

    Amyloid deposition in senile plaques and the cerebral vasculature is a marker of Alzheimer's disease. Whether amyloid itself contributes to the neurodegenerative process or is simply a by-product of that process is unknown. Pheochromocytoma (PC12) and fibroblast (NIH 3T3) cell lines were transfected with portions of the gene for the human amyloid precursor protein. Stable PC12 cell transfectants expressing a specific amyloid-containing fragment of the precursor protein gradually degenerated when induced to differentiate into neuronal cells with nerve growth factor. Conditioned medium from these cells was toxic to neurons in primary hippocampal cultures, and the toxic agent could be removed by immunoabsorption with an antibody directed against the amyloid polypeptide. Thus, a peptide derived from the amyloid precursor may be neurotoxic.

  8. Next-Generation Probiotics Targeting Clostridium difficile through Precursor-Directed Antimicrobial Biosynthesis

    PubMed Central

    Auchtung, Jennifer; Brown, Aaron; Boonma, Prapaporn; Oezguen, Numan; Ross, Caná L.; Luna, Ruth Ann; Runge, Jessica; Versalovic, James; Peniche, Alex; Dann, Sara M.; Britton, Robert A.; Haag, Anthony; Savidge, Tor C.

    2017-01-01

    ABSTRACT Integration of antibiotic and probiotic therapy has the potential to lessen the public health burden of antimicrobial-associated diseases. Clostridium difficile infection (CDI) represents an important example where the rational design of next-generation probiotics is being actively pursued to prevent disease recurrence. Because intrinsic resistance to clinically relevant antibiotics used to treat CDI (vancomycin, metronidazole, and fidaxomicin) is a desired trait in such probiotic species, we screened several bacteria and identified Lactobacillus reuteri to be a promising candidate for adjunct therapy. Human-derived L. reuteri bacteria convert glycerol to the broad-spectrum antimicrobial compound reuterin. When supplemented with glycerol, strains carrying the pocR gene locus were potent reuterin producers, with L. reuteri 17938 inhibiting C. difficile growth at a level on par with the level of growth inhibition by vancomycin. Targeted pocR mutations and complementation studies identified reuterin to be the precursor-induced antimicrobial agent. Pathophysiological relevance was demonstrated when the codelivery of L. reuteri with glycerol was effective against C. difficile colonization in complex human fecal microbial communities, whereas treatment with either glycerol or L. reuteri alone was ineffective. A global unbiased microbiome and metabolomics analysis independently confirmed that glycerol precursor delivery with L. reuteri elicited changes in the composition and function of the human microbial community that preferentially targets C. difficile outgrowth and toxicity, a finding consistent with glycerol fermentation and reuterin production. Antimicrobial resistance has thus been successfully exploited in the natural design of human microbiome evasion of C. difficile, and this method may provide a prototypic precursor-directed probiotic approach. Antibiotic resistance and substrate bioavailability may therefore represent critical new determinants of

  9. CCR6 Defines Memory B Cell Precursors in Mouse and Human Germinal Centers, Revealing Light-Zone Location and Predominant Low Antigen Affinity.

    PubMed

    Suan, Dan; Kräutler, Nike J; Maag, Jesper L V; Butt, Danyal; Bourne, Katherine; Hermes, Jana R; Avery, Danielle T; Young, Clara; Statham, Aaron; Elliott, Michael; Dinger, Marcel E; Basten, Antony; Tangye, Stuart G; Brink, Robert

    2017-12-19

    Memory B cells (MBCs) and plasma cells (PCs) constitute the two cellular outputs of germinal center (GC) responses that together facilitate long-term humoral immunity. Although expression of the transcription factor BLIMP-1 identifies cells undergoing PC differentiation, no such marker exists for cells committed to the MBC lineage. Here, we report that the chemokine receptor CCR6 uniquely marks MBC precursors in both mouse and human GCs. CCR6 + GC B cells were highly enriched within the GC light zone (LZ), were the most quiescent of all GC B cells, exhibited a cell-surface phenotype and gene expression signature indicative of an MBC transition, and possessed the augmented response characteristics of MBCs. MBC precursors within the GC LZ predominantly possessed a low affinity for antigen but also included cells from within the high-affinity pool. These data indicate a fundamental dichotomy between the processes that drive MBC and PC differentiation during GC responses. Copyright © 2017 Elsevier Inc. All rights reserved.

  10. Nanolipodendrosome-loaded glatiramer acetate and myogenic differentiation 1 as augmentation therapeutic strategy approaches in muscular dystrophy.

    PubMed

    Afzal, Ehsan; Zakeri, Saba; Keyhanvar, Peyman; Bagheri, Meisam; Mahjoubi, Parvin; Asadian, Mahtab; Omoomi, Nogol; Dehqanian, Mohammad; Ghalandarlaki, Negar; Darvishmohammadi, Tahmineh; Farjadian, Fatemeh; Golvajoee, Mohammad Sadegh; Afzal, Shadi; Ghaffari, Maryam; Cohan, Reza Ahangari; Gravand, Amin; Ardestani, Mehdi Shafiee

    2013-01-01

    [Corrected] Muscular dystrophies consist of a number of juvenile and adult forms of complex disorders which generally cause weakness or efficiency defects affecting skeletal muscles or, in some kinds, other types of tissues in all parts of the body are vastly affected. In previous studies, it was observed that along with muscular dystrophy, immune inflammation was caused by inflammatory cells invasion - like T lymphocyte markers (CD8+/CD4+). Inflammatory processes play a major part in muscular fibrosis in muscular dystrophy patients. Additionally, a significant decrease in amounts of two myogenic recovery factors (myogenic differentation 1 [MyoD] and myogenin) in animal models was observed. The drug glatiramer acetate causes anti-inflammatory cytokines to increase and T helper (Th) cells to induce, in an as yet unknown mechanism. MyoD recovery activity in muscular cells justifies using it alongside this drug. In this study, a nanolipodendrosome carrier as a drug delivery system was designed. The purpose of the system was to maximize the delivery and efficiency of the two drug factors, MyoD and myogenin, and introduce them as novel therapeutic agents in muscular dystrophy phenotypic mice. The generation of new muscular cells was analyzed in SW1 mice. Then, immune system changes and probable side effects after injecting the nanodrug formulations were investigated. The loaded lipodendrimer nanocarrier with the candidate drug, in comparison with the nandrolone control drug, caused a significant increase in muscular mass, a reduction in CD4+/CD8+ inflammation markers, and no significant toxicity was observed. The results support the hypothesis that the nanolipodendrimer containing the two candidate drugs will probably be an efficient means to ameliorate muscular degeneration, and warrants further investigation.

  11. Factor and Rasch analysis of the Fonseca anamnestic index for the diagnosis of myogenous temporomandibular disorder.

    PubMed

    Rodrigues-Bigaton, Delaine; de Castro, Ester M; Pires, Paulo F

    Rasch analysis has been used in recent studies to test the psychometric properties of a questionnaire. The conditions for use of the Rasch model are one-dimensionality (assessed via prior factor analysis) and local independence (the probability of getting a particular item right or wrong should not be conditioned upon success or failure in another). To evaluate the dimensionality and the psychometric properties of the Fonseca anamnestic index (FAI), such as the fit of the data to the model, the degree of difficulty of the items, and the ability to respond in patients with myogenous temporomandibular disorder (TMD). The sample consisted of 94 women with myogenous TMD, diagnosed by the Research Diagnostic Criteria for Temporomandibular Disorders (RDC/TMD), who answered the FAI. For the factor analysis, we applied the Kaiser-Meyer-Olkin test, Bartlett's sphericity, Spearman's correlation, and the determinant of the correlation matrix. For extraction of the factors/dimensions, an eigenvalue >1.0 was used, followed by oblique oblimin rotation. The Rasch analysis was conducted on the dimension that showed the highest proportion of variance explained. Adequate sample "n" and FAI multidimensionality were observed. Dimension 1 (primary) consisted of items 1, 2, 3, 6, and 7. All items of dimension 1 showed adequate fit to the model, being observed according to the degree of difficulty (from most difficult to easiest), respectively, items 2, 1, 3, 6, and 7. The FAI presented multidimensionality with its main dimension consisting of five reliable items with adequate fit to the composition of its structure. Copyright © 2017 Associação Brasileira de Pesquisa e Pós-Graduação em Fisioterapia. Publicado por Elsevier Editora Ltda. All rights reserved.

  12. CEACAM1 in Cervical Cancer and Precursor Lesions: Association With Human Papillomavirus Infection

    PubMed Central

    Albarran-Somoza, Benibelks; Franco-Topete, Ramon; Delgado-Rizo, Vidal; Cerda-Camacho, Felipe; Acosta-Jimenez, Lourdes; Lopez-Botet, Miguel; Daneri-Navarro, Adrian

    2006-01-01

    Carcinoembryonic antigen-related cell adhesion molecule 1 (CEACAM1) is an adhesion molecule expressed in a wide variety of tissues including epithelial cells, leukocytes, and tumors that may establish both homotypic and heterotypic interactions. The aim of this work was to study the protein expression pattern of CEACAM1 in cervical cancer and precursor lesions in the context of human papillomavirus (HPV) infection. We used immunohistochemistry to analyze CEACAM1 expression in formalin-fixed, paraffin-embedded cervical tissues from 15 healthy women, 15 patients with low-grade squamous intraepithelial lesions (SIL), 15 patients with high-grade SIL, and 15 patients with squamous carcinomas. HPV types were identified by PCR. CEACAM1 was either undetectable (13/15) or low (2/15) in normal cervical tissues. By contrast, CEACAM1 expression was increased in high-grade SIL (10 samples staining intermediate/high and 4 samples staining low) as compared with low-grade SIL with undetectable (n=3) or low (n= 12) expression. CEACAM1 expression was undetectable or low in cervical carcinoma. Our results suggest that CEACAM1 may be an interesting progression marker in SIL and cervical cancer, in particular due to reported immunoregulatory properties. PMID:16924126

  13. Overexpression of human virus surface glycoprotein precursors induces cytosolic unfolded protein response in Saccharomyces cerevisiae

    PubMed Central

    2011-01-01

    Background The expression of human virus surface proteins, as well as other mammalian glycoproteins, is much more efficient in cells of higher eukaryotes rather than yeasts. The limitations to high-level expression of active viral surface glycoproteins in yeast are not well understood. To identify possible bottlenecks we performed a detailed study on overexpression of recombinant mumps hemagglutinin-neuraminidase (MuHN) and measles hemagglutinin (MeH) in yeast Saccharomyces cerevisiae, combining the analysis of recombinant proteins with a proteomic approach. Results Overexpressed recombinant MuHN and MeH proteins were present in large aggregates, were inactive and totally insoluble under native conditions. Moreover, the majority of recombinant protein was found in immature form of non-glycosylated precursors. Fractionation of yeast lysates revealed that the core of viral surface protein aggregates consists of MuHN or MeH disulfide-linked multimers involving eukaryotic translation elongation factor 1A (eEF1A) and is closely associated with small heat shock proteins (sHsps) that can be removed only under denaturing conditions. Complexes of large Hsps seem to be bound to aggregate core peripherally as they can be easily removed at high salt concentrations. Proteomic analysis revealed that the accumulation of unglycosylated viral protein precursors results in specific cytosolic unfolded protein response (UPR-Cyto) in yeast cells, characterized by different action and regulation of small Hsps versus large chaperones of Hsp70, Hsp90 and Hsp110 families. In contrast to most environmental stresses, in the response to synthesis of recombinant MuHN and MeH, only the large Hsps were upregulated whereas sHsps were not. Interestingly, the amount of eEF1A was also increased during this stress response. Conclusions Inefficient translocation of MuHN and MeH precursors through ER membrane is a bottleneck for high-level expression in yeast. Overexpression of these recombinant

  14. GBM secretome induces transient transformation of human neural precursor cells.

    PubMed

    Venugopal, Chitra; Wang, X Simon; Manoranjan, Branavan; McFarlane, Nicole; Nolte, Sara; Li, Meredith; Murty, Naresh; Siu, K W Michael; Singh, Sheila K

    2012-09-01

    Glioblastoma (GBM) is the most aggressive primary brain tumor in humans, with a uniformly poor prognosis. The tumor microenvironment is composed of both supportive cellular substrates and exogenous factors. We hypothesize that exogenous factors secreted by brain tumor initiating cells (BTICs) could predispose normal neural precursor cells (NPCs) to transformation. When NPCs are grown in GBM-conditioned media, and designated as "tumor-conditioned NPCs" (tcNPCs), they become highly proliferative and exhibit increased stem cell self-renewal, or the unique ability of stem cells to asymmetrically generate another stem cell and a daughter cell. tcNPCs also show an increased transcript level of stem cell markers such as CD133 and ALDH and growth factor receptors such as VEGFR1, VEGFR2, EGFR and PDGFRα. Media analysis by ELISA of GBM-conditioned media reveals an elevated secretion of growth factors such as EGF, VEGF and PDGF-AA when compared to normal neural stem cell-conditioned media. We also demonstrate that tcNPCs require prolonged or continuous exposure to the GBM secretome in vitro to retain GBM BTIC characteristics. Our in vivo studies reveal that tcNPCs are unable to form tumors, confirming that irreversible transformation events may require sustained or prolonged presence of the GBM secretome. Analysis of GBM-conditioned media by mass spectrometry reveals the presence of secreted proteins Chitinase-3-like 1 (CHI3L1) and H2A histone family member H2AX. Collectively, our data suggest that GBM-secreted factors are capable of transiently altering normal NPCs, although for retention of the transformed phenotype, sustained or prolonged secretome exposure or additional transformation events are likely necessary.

  15. High Fidelity Processing and Activation of the Human α-Defensin HNP1 Precursor by Neutrophil Elastase and Proteinase 3

    PubMed Central

    Tongaonkar, Prasad; Golji, Amir E.; Tran, Patti; Ouellette, André J.; Selsted, Michael E.

    2012-01-01

    The azurophilic granules of human neutrophils contain four α-defensins called human neutrophil peptides (HNPs 1–4). HNPs are tridisulfide-linked antimicrobial peptides involved in the intracellular killing of organisms phagocytosed by neutrophils. The peptides are produced as inactive precursors (proHNPs) which are processed to active microbicides by as yet unidentified convertases. ProHNP1 was expressed in E. coli and the affinity-purified propeptide isolated as two species, one containing mature HNP1 sequence with native disulfide linkages (“folded proHNP1”) and the other containing non-native disulfide linked proHNP1 conformers (misfolded proHNP1). Native HNP1, liberated by CNBr treatment of folded proHNP1, was microbicidal against Staphylococcus aureus, but the peptide derived from misfolded proHNP1 was inactive. We hypothesized that neutrophil elastase (NE), proteinase 3 (PR3) or cathepsin G (CG), serine proteases that co-localize with HNPs in azurophil granules, are proHNP1 activating convertases. Folded proHNP1 was converted to mature HNP1 by both NE and PR3, but CG generated an HNP1 variant with an N-terminal dipeptide extension. NE and PR3 cleaved folded proHNP1 to produce a peptide indistinguishable from native HNP1 purified from neutrophils, and the microbicidal activities of in vitro derived and natural HNP1 peptides were equivalent. In contrast, misfolded proHNP1 conformers were degraded extensively under the same conditions. Thus, NE and PR3 possess proHNP1 convertase activity that requires the presence of the native HNP1 disulfide motif for high fidelity activation of the precursor in vitro. PMID:22448222

  16. High fidelity processing and activation of the human α-defensin HNP1 precursor by neutrophil elastase and proteinase 3.

    PubMed

    Tongaonkar, Prasad; Golji, Amir E; Tran, Patti; Ouellette, André J; Selsted, Michael E

    2012-01-01

    The azurophilic granules of human neutrophils contain four α-defensins called human neutrophil peptides (HNPs 1-4). HNPs are tridisulfide-linked antimicrobial peptides involved in the intracellular killing of organisms phagocytosed by neutrophils. The peptides are produced as inactive precursors (proHNPs) which are processed to active microbicides by as yet unidentified convertases. ProHNP1 was expressed in E. coli and the affinity-purified propeptide isolated as two species, one containing mature HNP1 sequence with native disulfide linkages ("folded proHNP1") and the other containing non-native disulfide linked proHNP1 conformers (misfolded proHNP1). Native HNP1, liberated by CNBr treatment of folded proHNP1, was microbicidal against Staphylococcus aureus, but the peptide derived from misfolded proHNP1 was inactive. We hypothesized that neutrophil elastase (NE), proteinase 3 (PR3) or cathepsin G (CG), serine proteases that co-localize with HNPs in azurophil granules, are proHNP1 activating convertases. Folded proHNP1 was converted to mature HNP1 by both NE and PR3, but CG generated an HNP1 variant with an N-terminal dipeptide extension. NE and PR3 cleaved folded proHNP1 to produce a peptide indistinguishable from native HNP1 purified from neutrophils, and the microbicidal activities of in vitro derived and natural HNP1 peptides were equivalent. In contrast, misfolded proHNP1 conformers were degraded extensively under the same conditions. Thus, NE and PR3 possess proHNP1 convertase activity that requires the presence of the native HNP1 disulfide motif for high fidelity activation of the precursor in vitro.

  17. NASAs Evolvable Mars Campaign: Mars Moons Robotic Precursor

    NASA Technical Reports Server (NTRS)

    Gernhardt, Michael L.; Abercromby, Andrew F. J.; Abell, Paul A.; Love, Stanley G.; Lee, David E.; Chappell, Steven P.; Howe, A. Scott; Friedensen, Victoria

    2015-01-01

    Human exploration missions to the moons of Mars are being considered within NASA's Evolvable Mars Campaign (EMC) as an intermediate step for eventual human exploration and pioneering of the surface of Mars. A range of mission architectures is being evaluated in which human crews would explore one or both moons for as little as 14 days or for as long as 500 days with a variety of orbital and surface habitation and mobility options being considered. Relatively little is known about the orbital, surface, or subsurface characteristics of either moon. This makes them interesting but challenging destinations for human exploration missions during which crewmembers must be able to effectively conduct scientific exploration without being exposed to undue risks due to radiation, dust, micrometeoroids, or other hazards. A robotic precursor mission to one or both moons will be required to provide data necessary for the design and operation of subsequent human systems and for the identification and prioritization of scientific exploration objectives. This paper identifies and discusses considerations for the design of such a precursor mission based on current human mission architectures. Objectives of a Mars' moon precursor in support of human missions are expected to include: 1) identifying hazards on the surface and the orbital environment at up to 50-km distant retrograde orbits; 2) collecting data on physical characteristics for planning of detailed human proximity and surface operations; 3) performing remote sensing and in situ science investigations to refine and focus future human scientific activities; and 4) prospecting for in situ resource utilization. These precursor objectives can be met through a combination or remote sensing (orbital) and in-situ (surface) measurements. Analysis of spacecraft downlink signals using radio science techniques would measure the moon's mass, mass distribution, and gravity field, which will be necessary to enable trajectory planning

  18. JAZF1 promotes proliferation of C2C12 cells, but retards their myogenic differentiation through transcriptional repression of MEF2C and MRF4—Implications for the role of Jazf1 variants in oncogenesis and type 2 diabetes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Yuasa, Katsutoshi; Aoki, Natsumi; Hijikata, Takao, E-mail: hijikata@musashino-u.ac.jp

    Single-nucleotide polymorphisms associated with type 2 diabetes (T2D) have been identified in Jazf1, which is also involved in the oncogenesis of endometrial stromal tumors. To understand how Jazf1 variants confer a risk of tumorigenesis and T2D, we explored the functional roles of JAZF1 and searched for JAZF1 target genes in myogenic C2C12 cells. Consistent with an increase of Jazf1 transcripts during myoblast proliferation and their decrease during myogenic differentiation in regenerating skeletal muscle, JAZF1 overexpression promoted cell proliferation, whereas it retarded myogenic differentiation. Examination of myogenic genes revealed that JAZF1 overexpression transcriptionally repressed MEF2C and MRF4 and their downstream genes.more » AMP deaminase1 (AMPD1) was identified as a candidate for JAZF1 target by gene array analysis. However, promoter assays of Ampd1 demonstrated that mutation of the putative binding site for the TR4/JAZF1 complex did not alleviate the repressive effects of JAZF1 on promoter activity. Instead, JAZF1-mediated repression of Ampd1 occurred through the MEF2-binding site and E-box within the Ampd1 proximal regulatory elements. Consistently, MEF2C and MRF4 expression enhanced Ampd1 promoter activity. AMPD1 overexpression and JAZF1 downregulation impaired AMPK phosphorylation, while JAZF1 overexpression also reduced it. Collectively, these results suggest that aberrant JAZF1 expression contributes to the oncogenesis and T2D pathogenesis. - Highlights: • JAZF1 promotes cell cycle progression and proliferation of myoblasts. • JAZF1 retards myogenic differentiation and hypertrophy of myotubes. • JAZF1 transcriptionally represses Mef2C and Mrf4 expression. • JAZF1 has an impact on the phosphorylation of AMPK.« less

  19. Vestibular evoked myogenic potential testing: Payment policy review for clinicians and payers.

    PubMed

    Fife, Terry D; Satya-Murti, Saty; Burkard, Robert F; Carey, John P

    2018-04-01

    A recent American Academy of Neurology Evidence-Based Practice Guideline on vestibular myogenic evoked potential (VEMP) testing has described superior canal dehiscence syndrome (SCDS) and evaluated the merits of VEMP in its diagnosis. SCDS is an uncommon but now well-recognized cause of dizziness and auditory symptoms. This article familiarizes health care providers with this syndrome and the utility and shortcomings of VEMP as a diagnostic test and also explores payment policies for VEMP. In carefully selected patients with documented history compatible with the SCDS, both high-resolution temporal bone CT scan and VEMP are valuable aids for diagnosis. Payers might be unfamiliar with both this syndrome and VEMP testing. It is important to raise awareness of VEMP and its possible indications and the rationale for coverage of VEMP testing. Payers may not be readily receptive to VEMP coverage if this test is used in an undifferentiated manner for all common vestibular and auditory symptoms.

  20. Wilms tumour histology is determined by distinct types of precursor lesions and not epigenetic changes.

    PubMed

    Fukuzawa, R; Anaka, M R; Heathcott, R W; McNoe, L A; Morison, I M; Perlman, E J; Reeve, A E

    2008-08-01

    Current models of Wilms tumour development propose that histological features of the tumours are programmed by the underlying molecular aberrations. For example, tumours associated with WT1 mutations arise from intralobar nephrogenic rests (ILNR), concur with CTNNB1 mutations and have distinct histology, whereas tumours with IGF2 loss of imprinting (LOI) often arise from perilobar nephrogenic rests (PLNR). Intriguingly, ILNR and PLNR are found simultaneously in Wilms tumours in children with overgrowth who have constitutional IGF2 LOI. We therefore examined whether the precursor lesions or early epigenetic changes are the primary determinant of Wilms tumour histology. We examined the histological features and gene expression profiles of IGF2 LOI tumours and WT1-mutant tumours which are associated with PLNR and/or ILNR. Two distinct types of IGF2 LOI tumours were identified: the first type had a blastemal-predominant histology associated with PLNR, while the second subtype had a myogenic histology, increased expression of mesenchymal lineage genes and an association with ILNR, similar to WT1-mutant tumours. These ILNR-associated IGF2 LOI tumours also showed signatures of activation of the WNT signalling pathway: differential expression of beta-catenin targets (MMP2, RARG, DKK1) and WNT antagonist genes (DKK1, WIF1, SFRP4). Unexpectedly, the majority of these tumours had CTNNB1 mutations, which are normally only seen in WT1-mutant tumours. The absence of WT1 mutations in tumours with IGF2 LOI indicated that CTNNB1 mutations occur predominantly in tumours arising from ILNR independent of the presence or absence of WT1 mutations. Thus, even though these two classes of tumours with IGF2 LOI have the same underlying predisposing epigenetic error, the tumour histology and the gene expression profiles are determined by the nature of the precursor cells within the nephrogenic rests and subsequent CTNNB1 mutations. Copyright (c) 2008 Pathological Society of Great Britain and

  1. Supplementation with tocotrienol-rich fraction alters the plasma levels of Apolipoprotein A-I precursor, Apolipoprotein E precursor, and C-reactive protein precursor from young and old individuals.

    PubMed

    Heng, Eng Chee; Karsani, Saiful Anuar; Abdul Rahman, Mariati; Abdul Hamid, Noor Aini; Hamid, Zalina; Wan Ngah, Wan Zurinah

    2013-10-01

    Tocotrienol possess beneficial effects not exhibited by tocopherol. In vitro studies using animal models have suggested that these effects are caused via modulation of gene and protein expression. However, human supplementation studies using tocotrienol-rich isomers are limited. This study aims to identify plasma proteins that changed in expression following tocotrienol-rich fraction (TRF) supplementation within two different age groups. Subjects were divided into two age groups-32 ± 2 (young) and 52 ± 2 (old) years old. Four subjects from each group were assigned with TRF (78% tocotrienol and 22% tocopherol, 150 mg/day) or placebo capsules for 6 months. Fasting plasma were obtained at 0, 3, and 6 months. Plasma tocopherol and tocotrienol levels were determined. Plasma proteome was resolved by 2DE, and differentially expressed proteins identified by MS. The expressions of three proteins were validated by Western blotting. Six months of TRF supplementation significantly increased plasma levels of tocopherols and tocotrienols. Proteins identified as being differentially expressed were related to cholesterol homeostasis, acute-phase response, protease inhibitor, and immune response. The expressions of Apolipoprotein A-I precursor, Apolipoprotein E precursor, and C-reactive protein precursor were validated. The old groups showed more proteins changing in expression. TRF appears to not only affect plasma levels of tocopherols and tocotrienols, but also the levels of plasma proteins. The identity of these proteins may provide insights into how TRF exerts its beneficial effects. They may also be potentially developed into biomarkers for the study of the effects and effectiveness of TRF supplementation.

  2. Ablation of Prion Protein in Wild Type Human Amyloid Precursor Protein (APP) Transgenic Mice Does Not Alter The Proteolysis of APP, Levels of Amyloid-β or Pathologic Phenotype

    PubMed Central

    Baybutt, Herbert; Diack, Abigail B.; Kellett, Katherine A. B.; Piccardo, Pedro; Manson, Jean C.

    2016-01-01

    The cellular prion protein (PrPC) has been proposed to play an important role in the pathogenesis of Alzheimer’s disease. In cellular models PrPC inhibited the action of the β-secretase BACE1 on wild type amyloid precursor protein resulting in a reduction in amyloid-β (Aβ) peptides. Here we have assessed the effect of genetic ablation of PrPC in transgenic mice expressing human wild type amyloid precursor protein (line I5). Deletion of PrPC had no effect on the α- and β-secretase proteolysis of the amyloid precursor protein (APP) nor on the amount of Aβ38, Aβ40 or Aβ42 in the brains of the mice. In addition, ablation of PrPC did not alter Aβ deposition or histopathology phenotype in this transgenic model. Thus using this transgenic model we could not provide evidence to support the hypothesis that PrPC regulates Aβ production. PMID:27447728

  3. Decreased Migration of Langerhans Precursor-Like Cells in Response to Human Keratinocytes Expressing HPV-16 E6/E7 is Related to Reduced Macrophage Inflammatory Protein-3Alpha Production

    DTIC Science & Technology

    2005-01-01

    high-risk human papillomavirus ( HPV ) types, particularly type 16 and 18, contributes to 90% of cervical cancer cases. HPV infects cutaneous or mucosal...been implicated in cervical/ anogenital cancer and oral squamous cell carcinomas (41). The mucosal lesions caused by HPVs often resolve over time, and a...Decreased Migration of Langerhans Precursor-Like Cells in Response to Human Keratinocytes Expressing HPV -16 E6/E7 is Related to Reduced Macrophage

  4. Vestibular neurolabyrinthitis: a follow-up study with cervical and ocular vestibular evoked myogenic potentials and the video head impulse test.

    PubMed

    Magliulo, Giuseppe; Gagliardi, Silvia; Ciniglio Appiani, Mario; Iannella, Giannicola; Re, Massimo

    2014-03-01

    The aim of this study was to evaluate prospectively, in a group of patients affected by vestibular neurolabyrinthitis (VN), a diagnostic protocol including cervical vestibular evoked myogenic potentials (C-VEMPs), ocular vestibular evoked myogenic potentials (O-VEMPs), and the video head impulse test (vHIT). The diagnosis of VN was based on the patient's clinical history, an absence of associated auditory or neurologic symptoms, and a neuro-otological examination with an evaluation of lateral semicircular canal function by use of the Fitzgerald-Hallpike caloric vestibular test and the ice test. In our series, 55% of the cases were superior and inferior VN, 40% were superior VN, and 5% were inferior VN. These cases, however, comprised different degrees of vestibular involvement, as the individual vestibular end organs have different prognoses. Four patients had only deficits of the horizontal and superior semicircular canals or their ampullary nerves. The implementation of C-VEMPs, O-VEMPs, and the vHIT in a vestibular diagnostic protocol has made it possible to observe patients with ampullary VN in a way that has not been feasible with other types of vestibular examinations. The age of the patient seems to have some impact on recovery from VN. When recovery occurs in the utricular and saccular nerves first and in the ampullary nerves subsequently, it may be reasonable to expect a more favorable outcome.

  5. Low-molecular-weight fucoidan regulates myogenic differentiation through the mitogen-activated protein kinase pathway in C2C12 cells.

    PubMed

    Kim, Kui-Jin; Lee, Ok-Hwan; Lee, Boo-Yong

    2011-12-01

    Low-molecular-weight fucoidan (LMWF) has been broadly studied in recent years due to its numerous biological properties. Nevertheless, there have been no reports about the effects of LMWF on myogenic differentiation (MyoD). The objective of the present study was to demonstrate the impact of LMWF on myogenesis in C2C12 cells. The ultimate aim was to establish whether LMWF regulates myogenesis similar to heparin as a partial regulator of myogenesis. LMWF was prepared at a minimal size by ultra-filtration compared with crude fucoidan. We treated C2C12 cells with LMWF and/or heparin during MyoD. The data from the present study are the first to suggest that LMWF suppresses the expression of the myogenic regulatory factors and the myocyte enhancer factors as well as the morphological changes that occur during differentiation. Additionally, the expression of the mitogen-activated protein kinase (MAPK) family was significantly inhibited by LMWF when compared with controls. The LMWF-treated group showed significantly decreased expression of reactive oxygen species (ROS) enzymes compared with control cells. Heparin was used as a positive control because it has been reported to activate MyoD. Taken together, these results suggest that LMWF might regulate MyoD through the MAPK pathway and by regulating ROS activity in C2C12 cells.

  6. Synthesis of Sol-Gel Precursors for Ceramics from Lunar and Martian Soil Simulars

    NASA Technical Reports Server (NTRS)

    Sibille, L.; Gavira-Gallardo, J. A.; Hourlier-Bahloul, D.

    2004-01-01

    Recent NASA mission plans for the human exploration of our Solar System has set new priorities for research and development of technologies necessary to enable a long-term human presence on the Moon and Mars. The recovery and processing of metals and oxides from mineral sources on other planets is under study to enable use of ceramics, glasses and metals by explorer outposts. We report initial results on the production of sol-gel precursors for ceramic products using mineral resources available in martian or lunar soil. The presence of SO2, TiO2, and Al2O3 in both martian (44 wt.% SiO2, 1 wt.% TiO2, 7 wt.% Al2O3) and lunar (48 wt.% SiO2, 1.5 wt.% TiO2, 16 wt.% Al2O3) soils and the recent developments in chemical processes to solubilize silicates using organic reagents and relatively little energy indicate that such an endeavor is possible. In order to eliminate the risks involved in the use of hydrofluoric acid to dissolve silicates, two distinct chemical routes are investigated to obtain soluble silicon oxide precursors from lunar and martian soil simulars. Clear solutions of sol-gel precursors have been obtained by dissolution of silica from lunar soil similar JSC-1 in basic ethylene glycol (C2H4(OH)2) solutions to form silicon glycolates. Similarly, sol-gel solutions produced from martian soil simulars reveal higher contents of iron oxides. Characterization of the precursor molecules and efforts to further concentrate and hydrolyze the products to obtain gel materials will be presented for evaluation as ceramic precursors.

  7. Synthesis of Sol-Gel Precursors for Ceramics from Lunar and Martian Soil Simulars

    NASA Technical Reports Server (NTRS)

    Sibille, L.; Gavira-Gallardo, J. A.; Hourlier-Bahloul, D.

    2003-01-01

    Recent NASA mission plans for the human exploration of our Solar System has set new priorities for research and development of technologies necessary to enable a long-term human presence on the Moon and Mars. The recovery and processing of metals and oxides from mineral sources on other planets is under study to enable use of ceramics, glasses and metals by explorer outposts. We report initial results on the production of sol-gel precursors for ceramic products using mineral resources available in martian or lunar soil. The presence of SiO2, TiO2, and Al2O3 in both martian (44 wt.% SiO2, 1 wt.% TiO2,7 wt.% Al2O3) and lunar (48 wt.% SiO2, 1.5 wt.% TiO2, 16 wt.% Al2O3) soils and the recent developments in chemical processes to solubilize silicates using organic reagents and relatively little energy indicate that such an endeavor is possible. In order to eliminate the risks involved in the use of hydrofluoric acid to dissolve silicates, two distinct chemical routes are investigated to obtain soluble silicon oxide precursors from lunar and martian soil simulars. Clear solutions of sol-gel precursors have been obtained by dissolution of silica from lunar soil simular in basic ethylene glycol (C2H4(OH)2) solutions to form silicon glycolates. Similarly, sol-gel solutions produced from martian soil simulars reveal higher contents of iron oxides. The elemental composition and structure of the precursor molecules were characterized. Further concentration and hydrolysis of the products was performed to obtain gel materials for evaluation as ceramic precursors.

  8. Vestibular-evoked myogenic potential in patients with unilateral vestibular neuritis: abnormal VEMP and its recovery.

    PubMed

    Ochi, Kentaro; Ohashi, Toru; Watanabe, Shoji

    2003-02-01

    The incidence of inferior vestibular nerve disorders in patients suffering from unilateral vestibular neuritis and the recovery of these disorders were evaluated by monitoring the vestibular-evoked myogenic potential (VEMP). Eight patients ranged from 21 to 73 years that suffered from unilateral vestibular neuritis underwent VEMP and caloric testing. Abnormal VEMP was observed in two of the eight patients with unilateral vestibular neuritis. Two patients were diagnosed as having an inferior vestibular nerve disorder. One of these patients showed recovery of the inferior vestibular nerve function as assessed by the VEMP. Disorders of the inferior vestibular nerve function and their recovery was confirmed by our current results. The time course of recoveries of the superior and inferior vestibular nerve systems were similar in the two patients.

  9. Vestibular evoked myogenic potentials in response to lateral skull taps are dependent on two different mechanisms.

    PubMed

    Brantberg, Krister; Westin, Magnus; Löfqvist, Lennart; Verrecchia, Luca; Tribukait, Arne

    2009-05-01

    To explore the mechanisms for skull tap induced vestibular evoked myogenic potentials (VEMP). The muscular responses were recorded over both sternocleidomastoid (SCM) muscles using skin electrodes. A skull tapper which provided a constant stimulus intensity was used to test cervical vestibular evoked myogenic potentials (VEMP) in response to lateral skull taps in healthy subjects (n=10) and in patients with severe unilateral loss of vestibular function (n=10). Skull taps applied approximately 2 cm above the outer ear canal caused highly reproducible VEMP. There were differences in VEMP in both normals and patients depending on side of tapping. In normals, there was a positive-negative ("normal") VEMP on the side contra-lateral to the skull tapping, but no significant VEMP ipsi-laterally. In patients, skull taps above the lesioned ear caused a contra-lateral positive-negative VEMP (as it did in the normals), in addition there was an ipsi-lateral negative-positive ("inverted") VEMP. When skull taps were presented above the healthy ear there was only a small contra-lateral positive-negative VEMP but, similar to the normals, no VEMP ipsi-laterally. The present data, in conjunction with earlier findings, support a theory that skull-tap VEMP responses are mediated by two different mechanisms. It is suggested that skull tapping causes both a purely ipsi-lateral stimulus side independent SCM response and a bilateral and of opposite polarity SCM response that is stimulus side dependent. Possibly, the skull tap induced VEMP responses are the sum of a stimulation of two species of vestibular receptors, one excited by vibration (which is rather stimulus site independent) and one excited by translation (which is more stimulus site dependent). Skull-tap VEMP probably have two different mechanisms. Separation of the two components might reveal the status of different labyrinthine functions.

  10. Nanolipodendrosome-loaded glatiramer acetate and myogenic differentiation 1 as augmentation therapeutic strategy approaches in muscular dystrophy

    PubMed Central

    Afzal, Ehsan; Zakeri, Saba; Keyhanvar, Peyman; Bagheri, Meisam; Mahjoubi, Parvin; Asadian, Mahtab; Omoomi, Nogol; Dehqanian, Mohammad; Ghalandarlaki, Negar; Darvishmohammadi, Tahmineh; Farjadian, Fatemeh; Golvajoee, Mohammad Sadegh; Afzal, Shadi; Ghaffari, Maryam; Cohan, Reza Ahangari; Gravand, Amin; Ardestani, Mehdi Shafiee

    2013-01-01

    Backgrond Muscular dystrophies consist of a number of juvenile and adult forms of complex disorders which generally cause weakness or efficiency defects affecting skeletal muscles or, in some kinds, other types of tissues in all parts of the body are vastly affected. In previous studies, it was observed that along with muscular dystrophy, immune inflammation was caused by inflammatory cells invasion – like T lymphocyte markers (CD8+/CD4+). Inflammatory processes play a major part in muscular fibrosis in muscular dystrophy patients. Additionally, a significant decrease in amounts of two myogenic recovery factors (myogenic differentation 1 [MyoD] and myogenin) in animal models was observed. The drug glatiramer acetate causes anti-inflammatory cytokines to increase and T helper (Th) cells to induce, in an as yet unknown mechanism. MyoD recovery activity in muscular cells justifies using it alongside this drug. Methods In this study, a nanolipodendrosome carrier as a drug delivery system was designed. The purpose of the system was to maximize the delivery and efficiency of the two drug factors, MyoD and myogenin, and introduce them as novel therapeutic agents in muscular dystrophy phenotypic mice. The generation of new muscular cells was analyzed in SW1 mice. Then, immune system changes and probable side effects after injecting the nanodrug formulations were investigated. Results The loaded lipodendrimer nanocarrier with the candidate drug, in comparison with the nandrolone control drug, caused a significant increase in muscular mass, a reduction in CD4+/CD8+ inflammation markers, and no significant toxicity was observed. The results support the hypothesis that the nanolipodendrimer containing the two candidate drugs will probably be an efficient means to ameliorate muscular degeneration, and warrants further investigation. PMID:23966782

  11. Relationship between organic precursors and N-nitrosodimethylamine (NDMA) formation in tropical water sources.

    PubMed

    Qi, Wang; Fang Yee, Lim; Jiangyong, Hu

    2014-12-01

    The presence of organic compounds in water sources is one of the concerns in water treatment. They are potential precursors of disinfection byproducts (DBPs) and thus induce health problems in humans. Among the emerging DBPs, carcinogenic compound N-nitrosodimethylamine (NDMA) has been receiving attention during the last decade. This study examined the characteristics of organic components in various water sources and investigated their relationships with NDMA formation. Experiments were carried out on selected water samples from both natural water and wastewater. Results showed similar NDMA formation kinetics for both water sources. However, more contribution of NDMA precursors was found to be from the wastewater due to its higher organic nitrogen content. NDMA formation potential (NDMAFP) of secondary effluent ranged from 264 to 530 ng/L. A correlation study between organic compound characteristics and NDMAFP indicated that the majority of NDMA precursors came from dissolved organic nitrogen (DON) compound with small molecular weight (smaller than 500 Da), with correlation R(2) = 0.898. Although secondary treatment removed more than 90% of NDMA precursors, the remaining precursors in secondary effluent would still pose a challenge for water quality.

  12. Prostaglandin E2: from clinical applications to its potential role in bone- muscle crosstalk and myogenic differentiation.

    PubMed

    Mo, Chenglin; Romero-Suarez, Sandra; Bonewald, Lynda; Johnson, Mark; Brotto, Marco

    2012-12-01

    Prostaglandin E(2) (PGE(2)), a prostanoid synthesized from arachidonic acid via the cyclooxygenase pathway, is a modulator of physiological responses including inflammation, fever, and muscle regeneration. Several patents have been filed that are related to PGE(2), one of them being directly related to skeletal muscles. In this report, we first summarize the key patents describing inventions for the utilization of PGE(2) for either diagnostic or therapeutic purposes, including skeletal muscle. In the second part of our work we present new and exciting data that demonstrates that PGE(2) accelerates skeletal muscle myogenic differentiation. Our discovery resulted from our recent and novel concept of bone-muscle crosstalk. Bone and muscle are anatomically intimate endocrine organs and we aimed to determine whether this anatomical intimacy also translates into a biochemical communication from bone cells to muscle cells at the in vitro level. The effects of MLOY4 osteocyte-like cell conditioned medium (CM) and three osteocyte-secreted factors, PGE(2), sclerostin and monocyte chemotactic protein (MCP-3), on C2C12 myogenic differentiation were evaluated using morphological analyses, a customized 96-gene PCR array, and measurements of intracellular calcium levels. MLO-Y4 CM and PGE(2), but not sclerostin and MCP-3, induced acceleration of myogenesis of C2C12 myoblasts that was linked with significant modifications in intracellular calcium homeostasis. This finding should further stimulate the pursuit of new patents to explore the use of PGE(2) and the new concept of bone-muscle crosstalk for the development and application of inventions designed to treat muscle diseases characterized by enhanced muscle wasting, such as sarcopenia.

  13. Large-Scale Expansion of Human iPSC-Derived Skeletal Muscle Cells for Disease Modeling and Cell-Based Therapeutic Strategies.

    PubMed

    van der Wal, Erik; Herrero-Hernandez, Pablo; Wan, Raymond; Broeders, Mike; In 't Groen, Stijn L M; van Gestel, Tom J M; van IJcken, Wilfred F J; Cheung, Tom H; van der Ploeg, Ans T; Schaaf, Gerben J; Pijnappel, W W M Pim

    2018-06-05

    Although skeletal muscle cells can be generated from human induced pluripotent stem cells (iPSCs), transgene-free protocols include only limited options for their purification and expansion. In this study, we found that fluorescence-activated cell sorting-purified myogenic progenitors generated from healthy controls and Pompe disease iPSCs can be robustly expanded as much as 5 × 10 11 -fold. At all steps during expansion, cells could be cryopreserved or differentiated into myotubes with a high fusion index. In vitro, cells were amenable to maturation into striated and contractile myofibers. Insertion of acid α-glucosidase cDNA into the AAVS1 locus in iPSCs using CRISPR/Cas9 prevented glycogen accumulation in myotubes generated from a patient with classic infantile Pompe disease. In vivo, the expression of human-specific nuclear and sarcolemmar antigens indicated that myogenic progenitors engraft into murine muscle to form human myofibers. This protocol is useful for modeling of skeletal muscle disorders and for using patient-derived, gene-corrected cells to develop cell-based strategies. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  14. Association of the macrophage activating factor (MAF) precursor activity with polymorphism in vitamin D-binding protein.

    PubMed

    Nagasawa, Hideko; Sasaki, Hideyuki; Uto, Yoshihiro; Kubo, Shinichi; Hori, Hitoshi

    2004-01-01

    Serum vitamin D-binding protein (Gc protein or DBP) is a highly expressed polymorphic protein, which is a precursor of the inflammation-primed macrophage activating factor, GcMAF, by a cascade of carbohydrate processing reactions. In order to elucidate the relationship between Gc polymorphism and GcMAF precursor activity, we estimated the phagocytic ability of three homotypes of Gc protein, Gc1F-1F, Gc1S-1S and Gc2-2, through processing of their carbohydrate moiety. We performed Gc typing of human serum samples by isoelectric focusing (IEF). Gc protein from human serum was purified by affinity chromatography with 25-hydroxyvitamin D3-sepharose. A phagocytosis assay of Gc proteins, modified using beta-glycosidase and sialidase, was carried out. The Gc1F-1F phenotype was revealed to possess Galbeta1-4GalNAc linkage by the analysis of GcMAF precursor activity using beta1-4 linkage-specific galactosidase from jack bean. The GcMAF precursor activity of the Gc1F-1F phenotype was highest among three Gc homotypes. The Gc polymorphism and carbohydrate diversity of Gc protein are significant for its pleiotropic effects.

  15. Meat flavor precursors and factors influencing flavor precursors--A systematic review.

    PubMed

    Khan, Muhammad Issa; Jo, Cheorun; Tariq, Muhammad Rizwan

    2015-12-01

    Flavor is the sensory impression sensed by taste and smell buds and is a leading factor determining the meat quality and purchasing decision of the consumer. Meat flavor is characteristic of volatiles produced as a result of reactions of non-volatile components that are induced thermally. The water soluble compounds having low molecular weight and meat lipids are important precursors of cooked meat flavor. The Maillard reaction, lipid oxidation, and vitamin degradation are leading reactions during cooking which develop meat flavor from uncooked meat with little aroma and bloody taste. The pre-slaughter and postmortem factors like animal breed, sex, age, feed, aging and cooking conditions contribute to flavor development of cooked meat. The objective of this review is to highlight the flavor chemistry, meat flavor precursors and factors affecting meat flavor precursors. Copyright © 2015 Elsevier Ltd. All rights reserved.

  16. Full-length amyloid precursor protein regulates lipoprotein metabolism and amyloid-β clearance in human astrocytes.

    PubMed

    Fong, Lauren K; Yang, Max M; Dos Santos Chaves, Rodrigo; Reyna, Sol M; Langness, Vanessa F; Woodruff, Grace; Roberts, Elizabeth A; Young, Jessica E; Goldstein, Lawrence S B

    2018-06-01

    Mounting evidence suggests that alterations in cholesterol homeostasis are involved in Alzheimer's disease (AD) pathogenesis. Amyloid precursor protein (APP) or multiple fragments generated by proteolytic processing of APP have previously been implicated in the regulation of cholesterol metabolism. However, the physiological function of APP in regulating lipoprotein homeostasis in astrocytes, which are responsible for de novo cholesterol biosynthesis and regulation in the brain, remains unclear. To address this, here we used CRISPR/Cas9 genome editing to generate isogenic APP-knockout (KO) human induced pluripotent stem cells (hiPSCs) and differentiated them into human astrocytes. We found that APP-KO astrocytes have reduced cholesterol and elevated levels of sterol regulatory element-binding protein (SREBP) target gene transcripts and proteins, which were both downstream consequences of reduced lipoprotein endocytosis. To elucidate which APP fragments regulate cholesterol homeostasis and examine whether familial AD mutations in APP affect lipoprotein metabolism, we analyzed an isogenic allelic series harboring the APP Swedish and APP V717F variants. Only astrocytes homozygous for the APP Swedish (APP Swe/Swe ) mutation, which had reduced full-length APP (FL APP) due to increased β-secretase cleavage, recapitulated the APP-KO phenotypes. Astrocytic internalization of amyloid-β (Aβ), another ligand for low-density lipoprotein (LDL) receptors, was also impaired in APP-KO and APP Swe/Swe astrocytes. Finally, impairing cleavage of FL APP through β-secretase inhibition in APP Swe/Swe astrocytes reversed the LDL and Aβ endocytosis defects. In conclusion, FL APP is involved in the endocytosis of LDL receptor ligands and required for proper cholesterol homeostasis and Aβ clearance in human astrocytes. Published under license by The American Society for Biochemistry and Molecular Biology, Inc.

  17. Human adenovirus serotype 12 virion precursors pMu and pVI are cleaved at amino-terminal and carboxy-terminal sites that conform to the adenovirus 2 endoproteinase cleavage consensus sequence.

    PubMed

    Freimuth, P; Anderson, C W

    1993-03-01

    The sequence of a 1158-base pair fragment of the human adenovirus serotype 12 (Ad12) genome was determined. This segment encodes the precursors for virion components Mu and VI. Both Ad12 precursors contain two sequences that conform to a consensus sequence motif for cleavage by the endoproteinase of adenovirus 2 (Ad2). Analysis of the amino terminus of VI and of the peptide fragments found in Ad12 virions demonstrated that these sites are cleaved during Ad12 maturation. This observation suggests that the recognition motif for adenovirus endoproteinases is highly conserved among human serotypes. The adenovirus 2 endoproteinase polypeptide requires additional co-factors for activity (C. W. Anderson, Protein Expression Purif., 1993, 4, 8-15). Synthetic Ad12 or Ad2 pVI carboxy-terminal peptides each permitted efficient cleavage of an artificial endoproteinase substrate by recombinant Ad2 endoproteinase polypeptide.

  18. Plasma Glutamine Is a Minor Precursor for the Synthesis of Citrulline: A Multispecies Study1234

    PubMed Central

    Marini, Juan C; Agarwal, Umang; Didelija, Inka C; Azamian, Mahshid; Stoll, Barbara; Nagamani, Sandesh CS

    2017-01-01

    Background: Glutamine is considered the main precursor for citrulline synthesis in many species, including humans. The transfer of 15N from 2-[15N]-glutamine to citrulline has been used as evidence for this precursor-product relation. However, work in mice has shown that nitrogen and carbon tracers follow different moieties of glutamine and that glutamine contribution to the synthesis of citrulline is minor. It is unclear whether this small contribution of glutamine is also true in other species. Objective: The objective of the present work was to determine the contribution of glutamine to citrulline production by using nitrogen and carbon skeleton tracers in multiple species. Methods: Humans (n = 4), pigs (n = 5), rats (n = 6), and mice (n = 5) were infused with l-2-[15N]- and l-[2H5]-glutamine and l-5,5-[2H2]-citrulline. The contribution of glutamine to citrulline synthesis was calculated by using different ions and fragments: glutamine M+1 to citrulline M+1, 2-[15N]-glutamine to 2-[15N]-citrulline, and [2H5]-glutamine to [2H5]-citrulline. Results: Species-specific differences in glutamine and citrulline fluxes were found (P < 0.001), with rats having the largest fluxes, followed by mice, pigs, and humans (all P < 0.05). The contribution of glutamine to citrulline as estimated by using glutamine M+1 to citrulline M+1 ranged from 88% in humans to 46% in pigs. However, the use of 2-[15N]-glutamine and 2-[15N]-citrulline as precursor and product yielded values of 48% in humans and 28% in pigs. Furthermore, the use of [2H5]-glutamine to [2H5]-citrulline yielded lower values (P < 0.001), resulting in a contribution of glutamine to the synthesis of citrulline of ∼10% in humans and 3% in pigs. Conclusions: The recycling of the [15N]-glutamine label overestimates the contribution of glutamine to citrulline synthesis compared with a tracer that follows the carbon skeleton of glutamine. Glutamine is a minor precursor for the synthesis of citrulline in humans, pigs, rats

  19. Neuroprotective Properties of Endocannabinoids N-Arachidonoyl Dopamine and N-Docosahexaenoyl Dopamine Examined in Neuronal Precursors Derived from Human Pluripotent Stem Cells.

    PubMed

    Novosadova, E V; Arsenyeva, E L; Manuilova, E S; Khaspekov, L G; Bobrov, M Yu; Bezuglov, V V; Illarioshkin, S N; Grivennikov, I A

    2017-11-01

    Neuroprotective properties of endocannabinoids N-arachidonoyl dopamine (NADA) and N-docosahexaenoyl dopamine (DHDA) were examined in neuronal precursor cells differentiated from human induced pluripotent stem cells and subjected to oxidative stress. Both compounds exerted neuroprotective activity, which was enhanced by elevating the concentration of the endocannabinoids within the 0.1-10 µM range. However, both agents at 10 µM concentration showed a marked toxic effect resulting in death of ~30% of the cells. Finally, antagonists of cannabinoid receptors as well as the receptor of the TRPV1 endovanilloid system did not hamper the neuroprotective effects of these endocannabinoids.

  20. PITX2 Enhances the Regenerative Potential of Dystrophic Skeletal Muscle Stem Cells.

    PubMed

    Vallejo, Daniel; Hernández-Torres, Francisco; Lozano-Velasco, Estefanía; Rodriguez-Outeiriño, Lara; Carvajal, Alejandra; Creus, Carlota; Franco, Diego; Aránega, Amelia Eva

    2018-04-10

    Duchenne muscular dystrophy (DMD), one of the most lethal genetic disorders, involves progressive muscle degeneration resulting from the absence of DYSTROPHIN. Lack of DYSTROPHIN expression in DMD has critical consequences in muscle satellite stem cells including a reduced capacity to generate myogenic precursors. Here, we demonstrate that the c-isoform of PITX2 transcription factor modifies the myogenic potential of dystrophic-deficient satellite cells. We further show that PITX2c enhances the regenerative capability of mouse DYSTROPHIN-deficient satellite cells by increasing cell proliferation and the number of myogenic committed cells, but importantly also increasing dystrophin-positive (revertant) myofibers by regulating miR-31. These PITX2-mediated effects finally lead to improved muscle function in dystrophic (DMD/mdx) mice. Our studies reveal a critical role for PITX2 in skeletal muscle repair and may help to develop therapeutic strategies for muscular disorders. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

  1. The variance modulation associated with the vestibular evoked myogenic potential.

    PubMed

    Lütkenhöner, Bernd; Rudack, Claudia; Basel, Türker

    2011-07-01

    Model considerations suggest that the sound-induced inhibition underlying the vestibular evoked myogenic potential (VEMP) briefly reduces the variance of the electromyogram (EMG) from which the VEMP is derived. Although more difficult to investigate, this inhibitory modulation of the variance promises to be a specific measure of the inhibition, in that respect being superior to the VEMP itself. This study aimed to verify the theoretical predictions. Archived data from 672 clinical VEMP investigations, comprising about 300,000 EMG records altogether, were pooled. Both the complete data pool and subsets of data representing VEMPs of varying degrees of distinctness were analyzed. The data were generally normalized so that the EMG had variance one. Regarding VEMP deflection p13, the data confirm the theoretical predictions. At the latency of deflection n23, however, an additional excitatory component, showing a maximal effect around 30 ms, appears to contribute. Studying the variance modulation may help to identify and characterize different components of the VEMP. In particular, it appears to be possible to distinguish between inhibition and excitation. The variance modulation provides information not being available in the VEMP itself. Thus, studying this measure may significantly contribute to our understanding of the VEMP phenomenon. Copyright © 2010 International Federation of Clinical Neurophysiology. Published by Elsevier Ireland Ltd. All rights reserved.

  2. Precursor processes of human self-initiated action.

    PubMed

    Khalighinejad, Nima; Schurger, Aaron; Desantis, Andrea; Zmigrod, Leor; Haggard, Patrick

    2018-01-15

    A gradual buildup of electrical potential over motor areas precedes self-initiated movements. Recently, such "readiness potentials" (RPs) were attributed to stochastic fluctuations in neural activity. We developed a new experimental paradigm that operationalized self-initiated actions as endogenous 'skip' responses while waiting for target stimuli in a perceptual decision task. We compared these to a block of trials where participants could not choose when to skip, but were instead instructed to skip. Frequency and timing of motor action were therefore balanced across blocks, so that conditions differed only in how the timing of skip decisions was generated. We reasoned that across-trial variability of EEG could carry as much information about the source of skip decisions as the mean RP. EEG variability decreased more markedly prior to self-initiated compared to externally-triggered skip actions. This convergence suggests a consistent preparatory process prior to self-initiated action. A leaky stochastic accumulator model could reproduce this convergence given the additional assumption of a systematic decrease in input noise prior to self-initiated actions. Our results may provide a novel neurophysiological perspective on the topical debate regarding whether self-initiated actions arise from a deterministic neurocognitive process, or from neural stochasticity. We suggest that the key precursor of self-initiated action may manifest as a reduction in neural noise. Copyright © 2017 The Authors. Published by Elsevier Inc. All rights reserved.

  3. Myogenic Progenitor Cells Control Extracellular Matrix Production by Fibroblasts during Skeletal Muscle Hypertrophy.

    PubMed

    Fry, Christopher S; Kirby, Tyler J; Kosmac, Kate; McCarthy, John J; Peterson, Charlotte A

    2017-01-05

    Satellite cells, the predominant stem cell population in adult skeletal muscle, are activated in response to hypertrophic stimuli and give rise to myogenic progenitor cells (MPCs) within the extracellular matrix (ECM) that surrounds myofibers. This ECM is composed largely of collagens secreted by interstitial fibrogenic cells, which influence satellite cell activity and muscle repair during hypertrophy and aging. Here we show that MPCs interact with interstitial fibrogenic cells to ensure proper ECM deposition and optimal muscle remodeling in response to hypertrophic stimuli. MPC-dependent ECM remodeling during the first week of a growth stimulus is sufficient to ensure long-term myofiber hypertrophy. MPCs secrete exosomes containing miR-206, which represses Rrbp1, a master regulator of collagen biosynthesis, in fibrogenic cells to prevent excessive ECM deposition. These findings provide insights into how skeletal stem and progenitor cells interact with other cell types to actively regulate their extracellular environments for tissue maintenance and adaptation. Copyright © 2017 Elsevier Inc. All rights reserved.

  4. Validation of Regression-Based Myogenic Correction Techniques for Scalp and Source-Localized EEG

    PubMed Central

    McMenamin, Brenton W.; Shackman, Alexander J.; Maxwell, Jeffrey S.; Greischar, Lawrence L.; Davidson, Richard J.

    2008-01-01

    EEG and EEG source-estimation are susceptible to electromyographic artifacts (EMG) generated by the cranial muscles. EMG can mask genuine effects or masquerade as a legitimate effect - even in low frequencies, such as alpha (8–13Hz). Although regression-based correction has been used previously, only cursory attempts at validation exist and the utility for source-localized data is unknown. To address this, EEG was recorded from 17 participants while neurogenic and myogenic activity were factorially varied. We assessed the sensitivity and specificity of four regression-based techniques: between-subjects, between-subjects using difference-scores, within-subjects condition-wise, and within-subject epoch-wise on the scalp and in data modeled using the LORETA algorithm. Although within-subject epoch-wise showed superior performance on the scalp, no technique succeeded in the source-space. Aside from validating the novel epoch-wise methods on the scalp, we highlight methods requiring further development. PMID:19298626

  5. The dental literature on occlusion and myogenous orofacial pain: application of critical thinking.

    PubMed

    Solow, Roger Alan

    2016-09-01

    To enhance the reader's critical thinking when reading the dental literature on the relationship of occlusion and myogenous orofacial pain (MOP). Representative journal articles and systematic reviews from the dental literature confirming and denying a relationship of occlusion to MOP were analyzed and reviewed. Studies using computerized occlusal analysis (COA) consistently find a relationship of the occlusion to MOP. Studies that do not confirm this relationship have problems with invalid primary source conclusions, unstated assumptions, bias, and errors in logic that disqualify their conclusion. This review explains four categories of problems with the dental literature that denies occlusion has a relationship with MOP. When the reader understands these examples of flaws in this literature, they can apply this critical thinking to future studies. Correct interpretation of the literature on occlusion and MOP requires a foundation of basic and clinical scientific knowledge as well as an understanding of the details of the primary source articles.

  6. Polyimide Precursor Solid Residuum

    NASA Technical Reports Server (NTRS)

    Weiser, Erik S. (Inventor); St.Clair, Terry L. (Inventor); Echigo, Yoshiaki (Inventor); Kaneshiro, Hisayasu (Inventor)

    2001-01-01

    A polyimide precursor solid residuum is an admixture of an aromatic dianhydride or derivative thereof and an aromatic diamine or derivative thereof plus a complexing agent, which is complexed with the admixture by hydrogen bonding. The polyimide precursor solid residuum is effectively employed in the preparation of polyimide foam and the fabrication of polyimide foam structures.

  7. Vestibular evoked myogenic potential (VEMP) with galvanic stimulation in normal subjects.

    PubMed

    Cunha, Luciana Cristina Matos; Labanca, Ludimila; Tavares, Maurício Campelo; Gonçalves, Denise Utsch

    2014-01-01

    The vestibular evoked myogenic potential (VEMP) generated by galvanic vestibular stimulation (GVS) is related to the vestibulo-spinal pathway. The response recorded from soleus muscle is biphasic with onset of short latency (SL) component around 60 ms and medium latency (ML) component around 100 ms. The first component reflects otolith function (sacule and utricle) and the last deals with semicircular canals. To describe VEMP generated by GVS. In this cross-sectional clinical study, VEMP was generated by 2 mA/400 ms binaural GVS, frequency of 5-6 ms that was recorded from soleus muscles of 13 healthy adults, mean age 56 years. The subjects remained standing, head turned contralateral to the GVS applied to the mastoid. Thirty GVS were applied to the mastoid in the position cathode right anode left, followed by 30 in inverted position. SL and ML were measured. SL and ML components were recorded from both legs of all participants and were similar. The average of SL component was 54 ms and of ML was 112 ms. The components SL and ML of the VEMP response in soleus were reproducible and are useful measures of vestibular-spinal function.

  8. Loss of p19Arf in a Rag1−/− B-cell precursor population initiates acute B-lymphoblastic leukemia

    PubMed Central

    Hauer, Julia; Mullighan, Charles; Morillon, Estelle; Wang, Gary; Bruneau, Julie; Brousse, Nicole; Lelorc'h, Marc; Romana, Serge; Boudil, Amine; Tiedau, Daniela; Kracker, Sven; Bushmann, Frederic D.; Borkhardt, Arndt; Fischer, Alain; Hacein-Bey-Abina, Salima

    2011-01-01

    In human B-acute lymphoblastic leukemia (B-ALL), RAG1-induced genomic alterations are important for disease progression. However, given that biallelic loss of the RAG1 locus is observed in a subset of cases, RAG1's role in the development of B-ALL remains unclear. We chose a p19Arf−/−Rag1−/− mouse model to confirm the previously published results concerning the contribution of CDKN2A (p19ARF /INK4a) and RAG1 copy number alterations in precursor B cells to the initiation and/or progression to B-acute lymphoblastic leukemia (B-ALL). In this murine model, we identified a new, Rag1-independent leukemia-initiating mechanism originating from a Sca1+CD19+ precursor cell population and showed that Notch1 expression accelerates the cells' self-renewal capacity in vitro. In human RAG1-deficient BM, a similar CD34+CD19+ population expressed p19ARF. These findings suggest that combined loss of p19Arf and Rag1 results in B-cell precursor leukemia in mice and may contribute to the progression of precursor B-ALL in humans. PMID:21622646

  9. Total N-nitrosamine Precursor Adsorption with Carbon Nanotubes: Elucidating Controlling Physiochemical Properties and Developing a Size-Resolved Precursor Surrogate

    NASA Astrophysics Data System (ADS)

    Needham, Erin Michelle

    As drinking water sources become increasingly impaired with nutrients and wastewater treatment plant (WWTP) effluent, formation of disinfection byproducts (DBPs)--such as trihalomethanes (THMs), dihaloacetonitriles (DHANs), and N-nitrosamines--during water treatment may also increase. N-nitrosamines may comprise the bulk of the chronic toxicity in treated drinking waters despite forming at low ng/L levels. This research seeks to elucidate physicochemical properties of carbon nanotubes (CNTs) for removal of DBP precursors, with an emphasis on total N-nitrosamines (TONO). Batch experiments with CNTs were completed to assess adsorption of THM, DHAN, and TONO precursors; physiochemical properties of CNTs were quantified through gas adsorption isotherms and x-ray photoelectron spectroscopy. Numerical modeling was used to elucidate characteristics of CNTs controlling DBP precursor adsorption. Multivariate models developed with unmodified CNTs revealed that surface carboxyl groups and, for TONO precursors, cumulative pore volume (CPV), controlled DBP precursor adsorption. Models developed with modified CNTs revealed that specific surface area controlled adsorption of THM and DHAN precursors while CPV and surface oxygen content were significant for adsorption of TONO precursors. While surrogates of THM and DHAN precursors leverage metrics from UV absorbance and fluorescence spectroscopy, a TONO precursor surrogate has proved elusive. This is important as measurements of TONO formation potential (TONOFP) require large sample volumes and long processing times, which impairs development of treatment processes. TONO precursor surrogates were developed using samples that had undergone oxidative or sorption treatments. Precursors were analyzed with asymmetric flow field-flow fractionation (AF4) with inline fluorescence detection (FLD) and whole water fluorescence excitation-emission matrices (EEMs). TONO precursor surrogates were discovered, capable of predicting changes in

  10. Removal of both N-nitrosodimethylamine and trihalomethanes precursors in a single treatment using ion exchange resins.

    PubMed

    Beita-Sandí, Wilson; Karanfil, Tanju

    2017-11-01

    Drinking water utilities are relying more than ever on water sources impacted by wastewater effluents. Disinfection/oxidation of these waters during water treatment may lead to the formation of several disinfection by-products, including the probable human carcinogen N-nitrosodimethylamine (NDMA) and the regulated trihalomethanes (THMs). In this study, the potential of ion exchange resins to control both NDMA and THMs precursors in a single treatment is presented. Two ion exchange resins were examined, a cation exchange resin (Plus) to target NDMA precursors and an anion exchange resin (MIEX) for THMs precursors control. We applied the resins, individually and combined, in the treatment of surface and wastewater effluent samples. The treatment with both resins removed simultaneously NDMA (43-85%) and THMs (39-65%) precursors. However, no removal of NDMA precursors was observed in the surface water with low initial NDMA FP (14 ng/L). The removals of NDMA FP and THMs FP with Plus and MIEX resins applied alone were (49-90%) and (41-69%), respectively. These results suggest no interaction between the resins, and thus the feasibility of effectively controlling NDMA and THMs precursors concomitantly. Additionally, the effects of the wastewater impact and the natural attenuation of precursors were studied. The results showed that neither the wastewater content nor the attenuation of the precursor affected the removals of NDMA and THMs precursors. Finally, experiments using a wastewater effluent sample showed that an increase in the calcium concentration resulted in a reduction in the removal of NDMA precursors of about 50%. Copyright © 2017 Elsevier Ltd. All rights reserved.

  11. Metaplasia in the Stomach—Precursor of Gastric Cancer?

    PubMed Central

    Kinoshita, Hiroto; Koike, Kazuhiko

    2017-01-01

    Despite a significant decrease in the incidence of gastric cancer in Western countries over the past century, gastric cancer is still one of the leading causes of cancer-related deaths worldwide. Most human gastric cancers develop after long-term Helicobacter pylori infection via the Correa pathway: the progression is from gastritis, atrophy, intestinal metaplasia, dysplasia, to cancer. However, it remains unclear whether metaplasia is a direct precursor of gastric cancer or merely a marker of high cancer risk. Here, we review human studies on the relationship between metaplasia and cancer in the stomach, data from mouse models of metaplasia regarding the mechanism of metaplasia development, and the cellular responses induced by H. pylori infection. PMID:28953255

  12. Metaplasia in the Stomach-Precursor of Gastric Cancer?

    PubMed

    Kinoshita, Hiroto; Hayakawa, Yoku; Koike, Kazuhiko

    2017-09-27

    Despite a significant decrease in the incidence of gastric cancer in Western countries over the past century, gastric cancer is still one of the leading causes of cancer-related deaths worldwide. Most human gastric cancers develop after long-term Helicobacter pylori infection via the Correa pathway: the progression is from gastritis, atrophy, intestinal metaplasia, dysplasia, to cancer. However, it remains unclear whether metaplasia is a direct precursor of gastric cancer or merely a marker of high cancer risk. Here, we review human studies on the relationship between metaplasia and cancer in the stomach, data from mouse models of metaplasia regarding the mechanism of metaplasia development, and the cellular responses induced by H. pylori infection.

  13. Mesoangioblasts from facioscapulohumeral muscular dystrophy display in vivo a variable myogenic ability predictable by their in vitro behavior.

    PubMed

    Morosetti, Roberta; Gidaro, Teresa; Broccolini, Aldobrando; Gliubizzi, Carla; Sancricca, Cristina; Tonali, Pietro Attilio; Ricci, Enzo; Mirabella, Massimiliano

    2011-01-01

    Facioscapulohumeral muscular dystrophy (FSHD) is the third most frequent inherited myopathy. We previously demonstrated that mesoangioblasts can be efficiently isolated from FSHD muscles, although their differentiation ability into skeletal muscle was variably impaired. This correlates with overall disease severity and degree of histopathologic abnormalities, since mesoangioblasts from morphologically normal muscles did not show any myogenic differentiation block. The aim of our present study was to verify whether mesoangioblasts from differentially affected FSHD muscles reproduce in vivo the same differentiation ability shown in vitro by studying their capability to form new muscle fibers during muscle regeneration of experimentally damaged muscles. We show that a diverse ability of FSHD mesoangioblasts to engraft and differentiate into skeletal muscle of SCID mice is strictly related to the characteristics of the muscle of origin, closely replicating in vivo what was previously observed in vitro. Moreover, we demonstrate that mesoangioblasts obtained from severely affected muscles scarcely integrate into muscle fibers, remaining mainly localized in the connective tissue. This suggests a defective migration in response to chemoattractants released by damaged fibers, as indicated by cell migration assays in response to HMGB1 and very low levels of RAGE expression, along with a decreased ability to fuse or to appropriately trigger the myogenic program. Our study indicates that FSHD mesoangioblasts from unaffected muscles can be used as selective treatment to halt muscle degeneration in severely affected muscles, and suggests that pharmacological and molecular interventions aimed to ameliorate homing and engraftment of transplanted autologous mesoangioblasts may open the way to cell therapy for FSHD patients, without requiring immunosuppression or genetic correction in vitro.

  14. Stretchable degradable and electroactive shape memory copolymers with tunable recovery temperature enhance myogenic differentiation.

    PubMed

    Deng, Zexing; Guo, Yi; Zhao, Xin; Li, Longchao; Dong, Ruonan; Guo, Baolin; Ma, Peter X

    2016-12-01

    Development of flexible degradable electroactive shape memory polymers (ESMPs) with tunable switching temperature (around body temperature) for tissue engineering is still a challenge. Here we designed and synthesized a series of shape memory copolymers with electroactivity, super stretchability and tunable recovery temperature based on poly(ε-caprolactone) (PCL) with different molecular weight and conductive amino capped aniline trimer, and demonstrated their potential to enhance myogenic differentiation from C2C12 myoblast cells. We characterized the copolymers by Fourier transform infrared spectroscopy (FT-IR), proton nuclear magnetic resonance ( 1 H NMR), cyclic voltammetry (CV), ultraviolet-visible spectroscopy (UV-vis), differential scanning calorimetry (DSC), shape memory test, tensile test and in vitro enzymatic degradation study. The electroactive biodegradable shape memory copolymers showed great elasticity, tunable recovery temperature around 37°C, and good shape memory properties. Furthermore, proliferation and differentiation of C2C12 myoblasts were investigated on electroactive copolymers films, and they greatly enhanced the proliferation, myotube formation and related myogenic differentiation genes expression of C2C12 myoblasts compared to the pure PCL with molecular weight of 80,000. Our study suggests that these electroactive, highly stretchable, biodegradable shape memory polymers with tunable recovery temperature near the body temperature have great potential in skeletal muscle tissue engineering application. Conducting polymers can regulate cell behavior such cell adhesion, proliferation, and differentiation with or without electrical stimulation. Therefore, they have great potential for electrical signal sensitive tissue regeneration. Although conducting biomaterials with degradability have been developed, highly stretchable and electroactive degradable copolymers for soft tissue engineering have been rarely reported. On the other hand, shape

  15. The RNA-binding region of human TRBP interacts with microRNA precursors through two independent domains

    PubMed Central

    Benoit, Matthieu P. M. H.; Imbert, Lionel; Palencia, Andrés; Pérard, Julien; Ebel, Christine; Boisbouvier, Jérôme; Plevin, Michael J.

    2013-01-01

    MicroRNAs (miRNAs) are small non-coding RNAs that regulate gene expression through RNA interference. Human miRNAs are generated through a series of enzymatic processing steps. The precursor miRNA (pre-miRNA) is recognized and cleaved by a complex containing Dicer and several non-catalytic accessory proteins. HIV TAR element binding protein (TRBP) is a constituent of the Dicer complex, which augments complex stability and potentially functions in substrate recognition and product transfer to the RNA-induced silencing complex. Here we have analysed the interaction between the RNA-binding region of TRBP and an oncogenic human miRNA, miR-155, at different stages in the biogenesis pathway. We show that the region of TRBP that binds immature miRNAs comprises two independent double-stranded RNA-binding domains connected by a 60-residue flexible linker. No evidence of contact between the two double-stranded RNA-binding domains was observed either in the apo- or RNA-bound state. We establish that the RNA-binding region of TRBP interacts with both pre-miR-155 and the miR-155/miR-155* duplex through the same binding surfaces and with similar affinities, and that two protein molecules can simultaneously interact with each immature miRNA. These data suggest that TRBP could play a role before and after processing of pre-miRNAs by Dicer. PMID:23435228

  16. Brillouin precursors in Debye media

    NASA Astrophysics Data System (ADS)

    Macke, Bruno; Ségard, Bernard

    2015-05-01

    We theoretically study the formation of Brillouin precursors in Debye media. We point out that the precursors are visible only at propagation distances such that the impulse response of the medium is essentially determined by the frequency dependence of its absorption and is practically Gaussian. By simple convolution, we then obtain explicit analytical expressions of the transmitted waves generated by reference incident waves, distinguishing precursor and main signal by a simple examination of the long-time behavior of the overall signal. These expressions are in good agreement with the signals obtained in numerical or real experiments performed on water in the radio-frequency domain and explain in particular some observed shapes of the precursor. Results are obtained for other remarkable incident waves. In addition, we show quite generally that the shape of the Brillouin precursor appearing alone at sufficiently large propagation distance and the law giving its amplitude as a function of this distance do not depend on the precise form of the incident wave but only on its integral properties. The incidence of a static conductivity of the medium is also examined and explicit analytical results are again given in the limit of weak and strong conductivities.

  17. Muscle satellite cell heterogeneity and self-renewal

    PubMed Central

    Motohashi, Norio; Asakura, Atsushi

    2014-01-01

    Adult skeletal muscle possesses extraordinary regeneration capacities. After muscle injury or exercise, large numbers of newly formed muscle fibers are generated within a week as a result of expansion and differentiation of a self-renewing pool of muscle stem cells termed muscle satellite cells. Normally, satellite cells are mitotically quiescent and reside beneath the basal lamina of muscle fibers. Upon regeneration, satellite cells are activated, and give rise to daughter myogenic precursor cells. After several rounds of proliferation, these myogenic precursor cells contribute to the formation of new muscle fibers. During cell division, a minor population of myogenic precursor cells returns to quiescent satellite cells as a self-renewal process. Currently, accumulating evidence has revealed the essential roles of satellite cells in muscle regeneration and the regulatory mechanisms, while it still remains to be elucidated how satellite cell self-renewal is molecularly regulated and how satellite cells are important in aging and diseased muscle. The number of satellite cells is decreased due to the changing niche during ageing, resulting in attenuation of muscle regeneration capacity. Additionally, in Duchenne muscular dystrophy (DMD) patients, the loss of satellite cell regenerative capacity and decreased satellite cell number due to continuous needs for satellite cells lead to progressive muscle weakness with chronic degeneration. Thus, it is necessary to replenish muscle satellite cells continuously. This review outlines recent findings regarding satellite cell heterogeneity, asymmetric division and molecular mechanisms in satellite cell self-renewal which is crucial for maintenance of satellite cells as a muscle stem cell pool throughout life. In addition, we discuss roles in the stem cell niche for satellite cell maintenance, as well as related cell therapies for approaching treatment of DMD. PMID:25364710

  18. Effects of the antigravitary modification of the myotension of asset (MAGMA) therapy on myogenic cranio-cervical-mandibular dysfunction: a longitudinal surface electromyography analysis.

    PubMed

    D'Attilio, Michele; Di Meo, Silvio; Perinetti, Giuseppe; Filippi, Maria Rita; Tecco, Simona; D'Alconzo, Francesco; Festa, Felice

    2003-01-01

    This study was aimed at evaluating the effects of a novel physiotherapy machine called MAGMA (AntiGravitary Modification of the Myotensions of Asset) on postural and masticatory muscles of subjects with myogenic cranio-cervical-mandibular dysfunction (CMD), by using surface electromyography (sEMG). Fifteen subjects, nine males and six females (mean age 27.6 years), with CMD were included in the study. The bilaterally monitored muscles were: masseter, anterior and posterior temporalis, digastric, posterior cervical, sternocleidomastoid, and upper and lower trapezius. All muscles were monitored at rest, with a second record of maximal voluntary clenching (MVC) for both the masseter and anterior temporalis. Patients were subjected to MAGMA therapy for one session/week of 30 min over ten weeks. The surface EMG activity was recorded twice, at the baseline and at the end of the therapy. After MAGMA therapy, the sEMG activity at rest of the monitored muscles was significantly better when compared to the baseline; the only exception was the anterior and posterior temporalis muscles which did not improve. On the contrary, with the MVC, all the monitored muscles (masseter and anterior temporalis) significantly improved their sEMG activity. Although more investigations are needed, these results indicate that the use of such antigravitary therapy can provide a tool for resolving myogenic CMD.

  19. Duchenne Muscular Dystrophy Gene Expression in Normal and Diseased Human Muscle

    NASA Astrophysics Data System (ADS)

    Oronzi Scott, M.; Sylvester, J. E.; Heiman-Patterson, T.; Shi, Y.-J.; Fieles, W.; Stedman, H.; Burghes, A.; Ray, P.; Worton, R.; Fischbeck, K. H.

    1988-03-01

    A probe for the 5' end of the Duchenne muscular dystrophy (DMD) gene was used to study expression of the gene in normal human muscle, myogenic cell cultures, and muscle from patients with DMD. Expression was found in RNA from normal fetal muscle, adult cardiac and skeletal muscle, and cultured muscle after myoblast fusion. In DMD muscle, expression of this portion of the gene was also revealed by in situ RNA hybridization, particularly in regenerating muscle fibers.

  20. Vestibular evoked myogenic potentials in patients with ankylosing spondylitis.

    PubMed

    Özgür, Abdulkadir; Serdaroğlu Beyazal, Münevver; Terzi, Suat; Coşkun, Zerrin Özergin; Dursun, Engin

    2016-10-01

    Ankylosing spondylitis (AS) is a chronic systemic inflammatory disease with unknown etiology. Although sacroiliac joint involvement is the classic sign along with the formed immune mediators, it may result in immune-mediated inner ear disease and may cause damage to the audiovestibular system. Vestibular evoked myogenic potentials (VEMP) is a clinical reflex test used in the diagnosis of vestibular diseases and is performed by recording and evaluating the muscle potentials resulting from the stimulation of the vestibular system with different stimuli. The aim of this study is to evaluate the cervical VEMP test results in AS patients without vestibular symptoms. Thirty-three patients with AS and a control group of 30 healthy volunteers with similar demographic characteristics were evaluated in the study. VEMP wave latency, P13-N23 wave amplitude, and VEMP asymmetry ratio (VAR) values were compared between the groups. The relationship between clinical and laboratory findings of the AS patients and VEMP data were also investigated. Compared with healthy people, this study shows the response rate of patients with ankylosing spondylitis was reduced in the VEMP test, and P13-N23 wave amplitude showed a decrease in AS patients who had VEMP response (p < 0.001). There was no correlation between the clinical and laboratory findings and VEMP findings in patients with ankylosing spondylitis. The data obtained from this study suggest that AS may lead to decreased sensitivity of the vestibular system.

  1. Preserved vestibular evoked myogenic potentials (VEMP) in some patients with walking-induced oscillopsia due to bilateral vestibulopathy.

    PubMed

    Brantberg, Krister; Löfqvist, Lennart

    2007-01-01

    Bilateral vestibulopathy, i.e. decreased peripheral vestibular function affecting both ears, is characterized by unsteadiness of gait, particularly in darkness and by motion-induced oscillopsia. We have recently seen a few patients with severely impaired semicircular canal function albeit with rather normal vestibular evoked myogenic potentials (VEMP) suggesting normal saccular function. The five young patients, mean age 27 years (range 15-45), 4 males and 1 female, had severely impaired balance in darkness and they all reported walking-induced vertical oscillopsia. Hence, these patients with incomplete vestibular lesions had symptoms that were indistinguishable from the typical patient with bilateral vestibulopathy. Further, the findings in these patients suggest that saccular function probably contributes little to prevent walking-induced vertical oscillopsia.

  2. Applying polarity rapid assessment method and ultrafiltration to characterize NDMA precursors in wastewater effluents.

    PubMed

    Chen, Chao; Leavey, Shannon; Krasner, Stuart W; Mel Suffet, I H

    2014-06-15

    Certain nitrosamines in water are disinfection byproducts that are probable human carcinogens. Nitrosamines have diverse and complex precursors that include effluent organic matter, some anthropogenic chemicals, and natural (likely non-humic) substances. An easy and selective tool was first developed to characterize nitrosamine precursors in treated wastewaters, including different process effluents. This tool takes advantages of the polarity rapid assessment method (PRAM) and ultrafiltration (UF) (molecular weight distribution) to locate the fractions with the strongest contributions to the nitrosamine precursor pool in the effluent organic matter. Strong cation exchange (SCX) and C18 solid-phase extraction cartridges were used for their high selectivity for nitrosamine precursors. The details of PRAM operation, such as cartridge clean-up, capacity, pH influence, and quality control were included in this paper, as well as the main parameters of UF operation. Preliminary testing of the PRAM/UF method with effluents from one wastewater treatment plant gave very informative results. SCX retained 45-90% of the N-nitrosodimethylamine (NDMA) formation potential (FP)-a measure of the precursors-in secondary and tertiary wastewater effluents. These results are consistent with NDMA precursors likely having a positively charged amine group. C18 adsorbed 30-45% of the NDMAFP, which indicates that a substantial portion of these precursors were non-polar. The small molecular weight (MW) (<1 kDa) and large MW (>10 kDa) fractions obtained from UF were the primary contributors to NDMAFP. The combination of PRAM and UF brings important information on the characteristics of nitrosamine precursors in water with easy operation. Copyright © 2014 Elsevier Ltd. All rights reserved.

  3. Sol-Gel Precursors for Ceramics from Minerals Simulating Soils from the Moon and Mars

    NASA Technical Reports Server (NTRS)

    Sibille, Laurent; Gavira-Gallardo, Jose-Antonio; Hourlier-Bahloul, Djamila

    2003-01-01

    Recent NASA mission plans for the human exploration of our Solar System has set new priorities for research and development of technologies necessary to enable a long-term human presence on the Moon and Mars. The recovery and processing of metals and oxides from mineral sources on other planets is under study to enable use of ceramics, glasses and metals by explorer outposts. We report some preliminary results on the production of sol-gel precursors for ceramic products using mineral resources available in Martian or Lunar soil. The presence of SiO2, TiO2, and A12O3 in both Martian (44 wt.% SiO2, 1 wt.% TiO2, 7 wt.% Al2O3) and Lunar (48 wt.% SiO2, 1.5 wt.% TiO2, 16 wt.% Al2O3) soils and the recent developments in chemical processes to solubilize silicates using organic reagents and relatively little energy indicate that such an endeavor is possible. In order to eliminate the risks involved in the use of hydrofluoric acid to dissolve silicates, two distinct chemical routes are investigated to obtain soluble silicon oxide precursors from Lunar and Martian simulant soils. Clear sol-gel precursors have been obtained by dissolution of silica from Lunar simulant soil in basic ethylene glycol (C2H4(OH)2) solutions to form silicon glycolates. Thermogravimetric Analysis and X-ray Photoelectron Spectroscopy were used to characterize the elemental composition and structure of the precursor molecules. Further concentration and hydrolysis of the products was performed to obtain gel materials for evaluation as ceramic precursors. In the second set of experiments, we used the same starting materials to synthesize silicate esters in acidified alcohol mixtures. Preliminary results indicate the presence of silicon alkoxides in the product of distillation.

  4. IGF-1 deficiency impairs cerebral myogenic autoregulation in hypertensive mice.

    PubMed

    Toth, Peter; Tucsek, Zsuzsanna; Tarantini, Stefano; Sosnowska, Danuta; Gautam, Tripti; Mitschelen, Matthew; Koller, Akos; Sonntag, William E; Csiszar, Anna; Ungvari, Zoltan

    2014-12-01

    Aging impairs autoregulatory protection in the brain, exacerbating hypertension-induced cerebromicrovascular injury, neuroinflammation, and development of vascular cognitive impairment. Despite the importance of the age-related decline in circulating insulin-like growth factor-1 (IGF-1) levels in cerebrovascular aging, the effects of IGF-1 deficiency on functional adaptation of cerebral arteries to high blood pressure remain elusive. To determine whether IGF-1 deficiency impairs autoregulatory protection, hypertension was induced in control and IGF-1-deficient mice (Igf1(f/f)+TBG-iCre-AAV8) by chronic infusion of angiotensin-II. In hypertensive control mice, cerebral blood flow (CBF) autoregulation was extended to higher pressure values and the pressure-induced tone of middle cerebral arteries (MCAs) was increased. In hypertensive IGF-1-deficient mice, autoregulation was markedly disrupted, and MCAs did not show adaptive increases in myogenic tone. In control mice, the mechanism of adaptation to hypertension involved upregulation of TRPC channels in MCAs and this mechanism was impaired in hypertensive IGF-1-deficient mice. Likely downstream consequences of cerebrovascular autoregulatory dysfunction in hypertensive IGF-1-deficient mice included exacerbated disruption of the blood-brain barrier and neuroinflammation (microglia activation and upregulation of proinflammatory cytokines and chemokines), which were associated with impaired hippocampal cognitive function. Collectively, IGF-1 deficiency impairs autoregulatory protection in the brain of hypertensive mice, potentially exacerbating cerebromicrovascular injury and neuroinflammation mimicking the aging phenotype.

  5. Preparation of superconductor precursor powders

    DOEpatents

    Bhattacharya, R.

    1998-08-04

    A process for the preparation of a precursor metallic powder composition for use in the subsequent formation of a superconductor. The process comprises the steps of providing an electrodeposition bath comprising an electrolyte medium and a cathode substrate electrode, and providing to the bath one or more soluble salts of one or more respective metals which are capable of exhibiting superconductor properties upon subsequent appropriate treatment. The bath is continually energized to cause the metallic and/or reduced particles formed at the electrode to drop as a powder from the electrode into the bath, and this powder, which is a precursor powder for superconductor production, is recovered from the bath for subsequent treatment. The process permits direct inclusion of all metals in the preparation of the precursor powder, and yields an amorphous product mixed on an atomic scale to thereby impart inherent high reactivity. Superconductors which can be formed from the precursor powder include pellet and powder-in-tube products. 7 figs.

  6. Preparation of superconductor precursor powders

    DOEpatents

    Bhattacharya, Raghunath; Blaugher, Richard D.

    1995-01-01

    A process for the preparation of a precursor metallic powder composition for use in the subsequent formation of a superconductor. The process comprises the steps of providing an electrodeposition bath comprising an electrolyte medium and a cathode substrate electrode, and providing to the bath one or more soluble salts of one or more respective metals, such as nitrate salts of thallium, barium, calcium, and copper, which are capable of exhibiting superconductor properties upon subsequent appropriate treatment. The bath is continually energized to cause the metallic particles formed at the electrode to drop as a powder from the electrode into the bath, and this powder, which is a precursor powder for superconductor production, is recovered from the bath for subsequent treatment. The process permits direct inclusion of thallium in the preparation of the precursor powder, and yields an amorphous product mixed on an atomic scale to thereby impart inherent high reactivity. Superconductors which can be formed from the precursor powder include pellet and powder-in-tube products.

  7. Preparation of superconductor precursor powders

    DOEpatents

    Bhattacharya, Raghunath

    1998-01-01

    A process for the preparation of a precursor metallic powder composition for use in the subsequent formation of a superconductor. The process comprises the steps of providing an electrodeposition bath comprising an electrolyte medium and a cathode substrate electrode, and providing to the bath one or more soluble salts of one or more respective metals which are capable of exhibiting superconductor properties upon subsequent appropriate treatment. The bath is continually energized to cause the metallic and/or reduced particles formed at the electrode to drop as a powder from the electrode into the bath, and this powder, which is a precursor powder for superconductor production, is recovered from the bath for subsequent treatment. The process permits direct inclusion of all metals in the preparation of the precursor powder, and yields an amorphous product mixed on an atomic scale to thereby impart inherent high reactivity. Superconductors which can be formed from the precursor powder include pellet and powder-in-tube products.

  8. 1994 Accident sequence precursor program results

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Belles, R.J.; Cletcher, J.W.; Copinger, D.A.

    1996-01-01

    The Accident Sequence Precursor (ASP) Program involves the systematic review and evaluation of operational events that have occurred at light-water reactors to identify and categorize precursors to potential severe core damage accident sequences. The results of the ASP Program are published in an annual report. The most recent report, which contains the analyses of the precursors for 1994, is NUREG/CR-4674, Vols. 21 and 22, Precursors to Potential Severe Core Damage Accidents: 1994, A Status Report, published in December 1995. This article provides an overview of the ASP review and evaluation process and a summary of the results for 1994. 12more » refs., 2 figs., 4 tabs.« less

  9. Identification of significant precursor gases of secondary organic aerosols from residential wood combustion

    PubMed Central

    Bruns, Emily A.; El Haddad, Imad; Slowik, Jay G.; Kilic, Dogushan; Klein, Felix; Baltensperger, Urs; Prévôt, André S. H.

    2016-01-01

    Organic gases undergoing conversion to form secondary organic aerosol (SOA) during atmospheric aging are largely unidentified, particularly in regions influenced by anthropogenic emissions. SOA dominates the atmospheric organic aerosol burden and this knowledge gap contributes to uncertainties in aerosol effects on climate and human health. Here we characterize primary and aged emissions from residential wood combustion using high resolution mass spectrometry to identify SOA precursors. We determine that SOA precursors traditionally included in models account for only ~3–27% of the observed SOA, whereas for the first time we explain ~84–116% of the SOA by inclusion of non-traditional precursors. Although hundreds of organic gases are emitted during wood combustion, SOA is dominated by the aging products of only 22 compounds. In some cases, oxidation products of phenol, naphthalene and benzene alone comprise up to ~80% of the observed SOA. Identifying the main precursors responsible for SOA formation enables improved model parameterizations and SOA mitigation strategies in regions impacted by residential wood combustion, more productive targets for ambient monitoring programs and future laboratories studies, and links between direct emissions and SOA impacts on climate and health in these regions. PMID:27312480

  10. Vestibular-evoked myogenic potential in response to bone-conducted sound in patients with otosclerosis

    PubMed Central

    Seo, Toru; Fujimori, Kiyoko; Mishiro, Yasuo; Sakagami, Masafumi

    2012-01-01

    Conclusion: Saccular dysfunction is a major cause of balance problems in patients with otosclerosis. Vestibular-evoked myogenic potential in response to bone-conducted sound (BC-VEMP) testing is useful for diagnosis of these patients. Objectives: The purpose of this study was to elucidate the origin of balance problems in patients with otosclerosis using BC-VEMP. Methods: Subjects comprised 25 patients with unoperated otosclerosis (9 men and 16 women). They were divided into two groups depending on type of balance problems. Results of cochleo-vestibular functions including pure-tone audiometry, caloric testing, and BC-VEMP testing were compared between the two groups. Results: Ten patients had complained of dizziness and/or vertigo (disequilibrium group), and the other 15 patients had not (Non-disequilibrium group). Nine patients showed abnormal results on BC-VEMP testing in the disequilibrium group, while one patient had abnormal results in the non-disequilibrium group (p < 0.001). PMID:22830649

  11. Estimating the Benefit per Ton of Reducing PM2.5 Precursors from 17 Sectors

    EPA Pesticide Factsheets

    Technical Support Document (TSD) reporting the human health impact and monetized benefits of reducing emissions of PM2.5 and PM2.5 precursors from 17 sectors. This TSD was updated in 2018 to reflect updated demographic and economic data.

  12. A Dual Mode Pulsed Electro-Magnetic Cell Stimulator Produces Acceleration of Myogenic Differentiation

    PubMed Central

    Leon-Salas, Walter D.; Rizk, Hatem; Mo, Chenglin; Weisleder, Noah; Brotto, Leticia; Abreu, Eduardo; Brotto, Marco

    2013-01-01

    This paper presents the design and test of a dual-mode electric and magnetic biological stimulator (EM-Stim). The stimulator generates pulsing electric and magnetic fields at programmable rates and intensities. While electric and magnetic stimulators have been reported before, this is the first device that combines both modalities. The ability of the dual stimulation to target bone and muscle tissue simultaneously has the potential to improve the therapeutic treatment of osteoporosis and sarcopenia. The device is fully programmable, portable and easy to use, and can run from a battery or a power supply. The device can generate magnetic fields of up to 1.6 mT and output voltages of +/−40 V. The EM-Stim accelerated myogenic differentiation of myoblasts into myotubes as evidenced by morphometric, gene expression, and protein content analyses. Currently, there are many patents concerned with the application of single electrical or magnetic stimulation, but none that combine both simultaneously. However, we applied for and obtained a provisional patent for new device to fully explore its therapeutic potential in pre-clinical models. PMID:23445453

  13. A dual mode pulsed electro-magnetic cell stimulator produces acceleration of myogenic differentiation.

    PubMed

    Leon-Salas, Walter D; Rizk, Hatem; Mo, Chenglin; Weisleder, Noah; Brotto, Leticia; Abreu, Eduardo; Brotto, Marco

    2013-04-01

    This paper presents the design and test of a dual-mode electric and magnetic biological stimulator (EM-Stim). The stimulator generates pulsing electric and magnetic fields at programmable rates and intensities. While electric and magnetic stimulators have been reported before, this is the first device that combines both modalities. The ability of the dual stimulation to target bone and muscle tissue simultaneously has the potential to improve the therapeutic treatment of osteoporosis and sarcopenia. The device is fully programmable, portable and easy to use, and can run from a battery or a power supply. The device can generate magnetic fields of up to 1.6 mT and output voltages of +/- 40 V. The EM-Stim accelerated myogenic differentiation of myoblasts into myotubes as evidenced by morphometric, gene expression, and protein content analyses. Currently, there are many patents concerned with the application of single electrical or magnetic stimulation, but none that combine both simultaneously. However, we applied for and obtained a provisional patent for new device to fully explore its therapeutic potential in pre-clinical models.

  14. Real-time functional imaging for monitoring miR-133 during myogenic differentiation.

    PubMed

    Kato, Yoshio; Miyaki, Shigeru; Yokoyama, Shigetoshi; Omori, Shin; Inoue, Atsushi; Horiuchi, Machiko; Asahara, Hiroshi

    2009-11-01

    MicroRNAs (miRNAs) are a class of non-coding small RNAs that act as negative regulators of gene expression through sequence-specific interactions with the 3' untranslated regions (UTRs) of target mRNA and play various biological roles. miR-133 was identified as a muscle-specific miRNA that enhanced the proliferation of myoblasts during myogenic differentiation, although its activity in myogenesis has not been fully characterized. Here, we developed a novel retroviral vector system for monitoring muscle-specific miRNA in living cells by using a green fluorescent protein (GFP) that is connected to the target sequence of miR-133 via the UTR and a red fluorescent protein for normalization. We demonstrated that the functional promotion of miR-133 during myogenesis is visualized by the reduction of GFP carrying the miR-133 target sequence, suggesting that miR-133 specifically down-regulates its targets during myogenesis in accordance with its expression. Our cell-based miRNA functional assay monitoring miR-133 activity should be a useful tool in elucidating the role of miRNAs in various biological events.

  15. Protocol to Isolate a Large Amount of Functional Oligodendrocyte Precursor Cells from the Cerebral Cortex of Adult Mice and Humans

    PubMed Central

    Medina-Rodríguez, Eva María; Arenzana, Francisco Javier; Bribián, Ana; de Castro, Fernando

    2013-01-01

    During development, oligodendrocytes are generated from oligodendrocyte precursor cells (OPCs), a cell type that is a significant proportion of the total cells (3-8%) in the adult central nervous system (CNS) of both rodents and humans. Adult OPCs are responsible for the spontaneous remyelination that occurs in demyelinating diseases like Multiple Sclerosis (MS) and they constitute an interesting source of cells for regenerative therapy in such conditions. However, there is little data regarding the neurobiology of adult OPCs isolated from mice since an efficient method to isolate them has yet to be established. We have designed a protocol to obtain viable adult OPCs from the cerebral cortex of different mouse strains and we have compared its efficiency with other well-known methods. In addition, we show that this protocol is also useful to isolate functional OPCs from human brain biopsies. Using this method we can isolate primary cortical OPCs in sufficient quantities so as to be able to study their survival, maturation and function, and to facilitate an evaluation of their utility in myelin repair. PMID:24303061

  16. Protocol to isolate a large amount of functional oligodendrocyte precursor cells from the cerebral cortex of adult mice and humans.

    PubMed

    Medina-Rodríguez, Eva María; Arenzana, Francisco Javier; Bribián, Ana; de Castro, Fernando

    2013-01-01

    During development, oligodendrocytes are generated from oligodendrocyte precursor cells (OPCs), a cell type that is a significant proportion of the total cells (3-8%) in the adult central nervous system (CNS) of both rodents and humans. Adult OPCs are responsible for the spontaneous remyelination that occurs in demyelinating diseases like Multiple Sclerosis (MS) and they constitute an interesting source of cells for regenerative therapy in such conditions. However, there is little data regarding the neurobiology of adult OPCs isolated from mice since an efficient method to isolate them has yet to be established. We have designed a protocol to obtain viable adult OPCs from the cerebral cortex of different mouse strains and we have compared its efficiency with other well-known methods. In addition, we show that this protocol is also useful to isolate functional OPCs from human brain biopsies. Using this method we can isolate primary cortical OPCs in sufficient quantities so as to be able to study their survival, maturation and function, and to facilitate an evaluation of their utility in myelin repair.

  17. Using Markov chains of nucleotide sequences as a possible precursor to predict functional roles of human genome: a case study on inactive chromatin regions.

    PubMed

    Lee, K-E; Lee, E-J; Park, H-S

    2016-08-30

    Recent advances in computational epigenetics have provided new opportunities to evaluate n-gram probabilistic language models. In this paper, we describe a systematic genome-wide approach for predicting functional roles in inactive chromatin regions by using a sequence-based Markovian chromatin map of the human genome. We demonstrate that Markov chains of sequences can be used as a precursor to predict functional roles in heterochromatin regions and provide an example comparing two publicly available chromatin annotations of large-scale epigenomics projects: ENCODE project consortium and Roadmap Epigenomics consortium.

  18. Extremely Low-Frequency Electromagnetic Fields Affect Myogenic Processes in C2C12 Myoblasts: Role of Gap-Junction-Mediated Intercellular Communication

    PubMed Central

    Rovetta, Francesca; Boniotti, Jennifer; Mazzoleni, Giovanna

    2017-01-01

    Extremely low-frequency electromagnetic fields (ELF-EMFs) can interact with biological systems. Although they are successfully used as therapeutic agents in physiatrics and rehabilitative practice, they might represent environmental pollutants and pose a risk to human health. Due to the lack of evidence of their mechanism of action, the effects of ELF-EMFs on differentiation processes in skeletal muscle were investigated. C2C12 myoblasts were exposed to ELF-EMFs generated by a solenoid. The effects of ELF-EMFs on cell viability and on growth and differentiation rates were studied using colorimetric and vital dye assays, cytomorphology, and molecular analysis of MyoD and myogenin expression, respectively. The establishment of functional gap junctions was investigated analyzing connexin 43 expression levels and measuring cell permeability, using microinjection/dye-transfer assays. The ELF-EMFs did not affect C2C12 myoblast viability or proliferation rate. Conversely, at ELF-EMF intensity in the mT range, the myogenic process was accelerated, through increased expression of MyoD, myogenin, and connexin 43. The increase in gap-junction function suggests promoting cell fusion and myotube differentiation. These data provide the first evidence of the mechanism through which ELF-EMFs may provide therapeutic benefits and can resolve, at least in part, some conditions of muscle dysfunction. PMID:28607928

  19. The NAD+ precursor nicotinic acid improves genomic integrity in human peripheral blood mononuclear cells after X-irradiation.

    PubMed

    Weidele, Kathrin; Beneke, Sascha; Bürkle, Alexander

    2017-04-01

    NAD + is an essential cofactor for enzymes catalyzing redox-reactions as well as an electron carrier in energy metabolism. Aside from this, NAD + consuming enzymes like poly(ADP-ribose) polymerases and sirtuins are important regulators involved in chromatin-restructuring processes during repair and epigenetics/transcriptional adaption. In order to replenish cellular NAD + levels after cleavage, synthesis starts from precursors such as nicotinamide, nicotinamide riboside or nicotinic acid to match the need for this essential molecule. In the present study, we investigated the impact of supplementation with nicotinic acid on resting and proliferating human mononuclear blood cells with a focus on DNA damage and repair processes. We observed that nicotinic acid supplementation increased NAD + levels as well as DNA repair efficiency and enhanced genomic stability evaluated by micronucleus test after x-ray treatment. Interestingly, resting cells displayed lower basal levels of DNA breaks compared to proliferating cells, but break-induction rates were identical. Despite similar levels of p53 protein upregulation after irradiation, higher NAD + concentrations led to reduced acetylation of this protein, suggesting enhanced SIRT1 activity. Our data reveal that even in normal primary human cells cellular NAD + levels may be limiting under conditions of genotoxic stress and that boosting the NAD + system with nicotinic acid can improve genomic stability. Copyright © 2017 Elsevier B.V. All rights reserved.

  20. The Interrelationships of Mathematical Precursors in Kindergarten

    PubMed Central

    Cirino, Paul T.

    2011-01-01

    This study evaluated the interrelations among cognitive precursors across quantitative, linguistic, and spatial attention domains that have been implicated for math achievement in young children. The dimensionality of the quantity precursors was evaluated in 286 Kindergarteners via latent variable techniques, and the contribution of precursors from each domain was established for small sums addition. Results showed a five factor structure for the quantity precursors with the major distinction between nonsymbolic and symbolic tasks. The overall model demonstrated good fit, and strong predictive power (R2 = 55%) for addition number combinations. Linguistic and spatial attention domains showed indirect relationships with outcomes, with their effects mediated by symbolic quantity measures. These results have implications for the measurement of mathematical precursors, and yield promise for predicting future math performance. PMID:21194711

  1. On the difficulties of detecting PP precursors

    NASA Astrophysics Data System (ADS)

    Lessing, Stephan; Thomas, Christine; Saki, Morvarid; Schmerr, Nicholas; Vanacore, Elizabeth

    2015-06-01

    The PP precursors are seismic waves that form from underside reflections of P waves off discontinuities in the upper mantle transition zone (MTZ). These seismic phases are used to map discontinuity topography, sharpness, and impedance contrasts; the resulting structural variations are then often interpreted as evidence for temperature and/or mineralogy variations within the mantle. The PP precursors as well as other seismic phases have been used to establish the global presence of seismic discontinuities at 410 and 660 km depth. Intriguingly, in more than 80 per cent of PP precursor observations the seismic wave amplitudes are significantly weaker than the amplitudes predicted by seismic reference models. Even more perplexing is the observation that 1-5 per cent of all earthquakes (which are 20-25 per cent of earthquakes with clear PP waveforms) do not show any evidence for the PP precursors from the discontinuities even in the presence of well-developed PP waveforms. Non-detections are found in six different data sets consisting of tens to hundreds of events. We use synthetic modelling to examine a suite of factors that could be responsible for the absence of the PP precursors. The take-off angles for PP and the precursors differ by only 1.2-1.5°; thus source-related complexity would affect PP and the precursors. A PP wave attenuated in the upper mantle would increase the relative amplitude of the PP precursors. Attenuation within the transition zone could reduce precursor amplitudes, but this would be a regional phenomenon restricted to particular source receiver geometries. We also find little evidence for deviations from the theoretical travel path of seismic rays expected for scattered arrivals. Factors that have a strong influence include the stacking procedures used in seismic array techniques in the presence of large, interfering phases, the presence of topography on the discontinuities on the order of tens of kilometres, and 3-D lateral heterogeneity in

  2. Three-dimensional hydrogel scaffolds facilitate in vitro self-renewal of human skin-derived precursors.

    PubMed

    Wang, Xinyue; Liu, Shu; Zhao, Qian; Li, Na; Zhang, Huishan; Zhang, Xudong; Lei, Xiaohua; Zhao, Huashan; Deng, Zhili; Qiao, Jingqiao; Cao, Yujing; Ning, Lina; Liu, Shuang; Duan, Enkui

    2014-07-01

    Skin-derived precursors (SKPs) are multipotent cells with dermal stem cell properties. These easily available cells possess the capacity to reconstitute the skin in vivo, as well as a broader differentiation potential in vitro, which endows them with great prospects in regenerative medicine. However, the present authors' group and others previously found that adult human SKPs (hSKPs) expanded deficiently in vitro, which largely counteracted their research and practical values. Taking the physiological micro-environment of hSKPs into consideration, the authors sought to establish a hydrogel scaffold-based three-dimensional (3-D) culture system for hSKPs in the present study. After comparing their morphology, growth characteristics, signature gene expression and differentiation potential in different hydrogels, the present authors found that a chemically defined hyaluronic acid and denatured collagen-based hydrogel system that mimicked the natural niche of hSKPs in the dermis could alleviate hSKP senescence, support hSKP proliferation as spheres, while largely retaining their properties and potential. This study suggested that recapitulating the in vivo stem cell niche by providing them with 3-D extracellular matrix environments could help them achieve better self-renewal in vitro. In addition, the animal-origin-free and biocompatible 3-D hydrogel system will certainly benefit fundamental research and clinical applications of hSKPs in the near future. Copyright © 2014 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

  3. The role of melatonin in the neurodevelopmental etiology of schizophrenia: A study in human olfactory neuronal precursors.

    PubMed

    Galván-Arrieta, Tania; Trueta, Citlali; Cercós, Montserrat G; Valdés-Tovar, Marcela; Alarcón, Salvador; Oikawa, Julian; Zamudio-Meza, Horacio; Benítez-King, Gloria

    2017-10-01

    Dim light exposure of the mother during pregnancy has been proposed as one of the environmental factors that affect the fetal brain development in schizophrenia. Melatonin circulating levels are regulated by the environmental light/dark cycle. This hormone stimulates neuronal differentiation in the adult brain. However, little is known about its role in the fetal human brain development. Olfactory neuronal precursors (ONPs) are useful for studying the physiopathology of neuropsychiatric diseases because they mimic all the stages of neurodevelopment in culture. Here, we first characterized whether melatonin stimulates neuronal differentiation in cloned ONPs obtained from a healthy control subject (HCS). Then, melatonin effects were evaluated in primary cultures of ONPs derived from a patient diagnosed with schizophrenia (SZ) and an age- and gender-matched HCS. Axonal formation was evidenced morphologically by tau immunostaining and by GSK3β phosphorylated state. Potassium-evoked secretion was assessed as a functional feature of differentiated neurons. As well, we report the expression of MT1/2 receptors in human ONPs for the first time. Melatonin stimulated axonal formation and ramification in cloned ONPs through a receptor-mediated mechanism and enhanced the amount and velocity of axonal and somatic secretion. SZ ONPs displayed reduced axogenesis associated with lower levels of pGSK3β and less expression of melatonergic receptors regarding the HCS ONPs. Melatonin counteracted this reduction in SZ cells. Altogether, our results show that melatonin signaling is crucial for functional differentiation of human ONPs, strongly suggesting that a deficit of this indoleamine may lead to an impaired neurodevelopment which has been associated with the etiology of schizophrenia. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

  4. Robots and Humans in Planetary Exploration: Working Together?

    NASA Technical Reports Server (NTRS)

    Landis, Geoffrey A.; Lyons, Valerie (Technical Monitor)

    2002-01-01

    Today's approach to human-robotic cooperation in planetary exploration focuses on using robotic probes as precursors to human exploration. A large portion of current NASA planetary surface exploration is focussed on Mars, and robotic probes are seen as precursors to human exploration in: Learning about operation and mobility on Mars; Learning about the environment of Mars; Mapping the planet and selecting landing sites for human mission; Demonstration of critical technology; Manufacture fuel before human presence, and emplace elements of human-support infrastructure

  5. Ozone pollution in China: A review of concentrations, meteorological influences, chemical precursors, and effects.

    PubMed

    Wang, Tao; Xue, Likun; Brimblecombe, Peter; Lam, Yun Fat; Li, Li; Zhang, Li

    2017-01-01

    High concentrations of ozone in urban and industrial regions worldwide have long been a major air quality issue. With the rapid increase in fossil fuel consumption in China over the past three decades, the emission of chemical precursors to ozone-nitrogen oxides and volatile organic compounds-has increased sharply, surpassing that of North America and Europe and raising concerns about worsening ozone pollution in China. Historically, research and control have prioritized acid rain, particulate matter, and more recently fine particulate matter (PM 2.5 ). In contrast, less is known about ozone pollution, partly due to a lack of monitoring of atmospheric ozone and its precursors until recently. This review summarizes the main findings from published papers on the characteristics and sources and processes of ozone and ozone precursors in the boundary layer of urban and rural areas of China, including concentration levels, seasonal variation, meteorology conducive to photochemistry and pollution transport, key production and loss processes, ozone dependence on nitrogen oxides and volatile organic compounds, and the effects of ozone on crops and human health. Ozone concentrations exceeding the ambient air quality standard by 100-200% have been observed in China's major urban centers such as Jing-Jin-Ji, the Yangtze River delta, and the Pearl River delta, and limited studies suggest harmful effect of ozone on human health and agricultural corps; key chemical precursors and meteorological conditions conductive to ozone pollution have been investigated, and inter-city/region transport of ozone is significant. Several recommendations are given for future research and policy development on ground-level ozone. Copyright © 2016 Elsevier B.V. All rights reserved.

  6. Functional Analyses and Treatment of Precursor Behavior

    PubMed Central

    Najdowski, Adel C; Wallace, Michele D; Ellsworth, Carrie L; MacAleese, Alicia N; Cleveland, Jackie M

    2008-01-01

    Functional analysis has been demonstrated to be an effective method to identify environmental variables that maintain problem behavior. However, there are cases when conducting functional analyses of severe problem behavior may be contraindicated. The current study applied functional analysis procedures to a class of behavior that preceded severe problem behavior (precursor behavior) and evaluated treatments based on the outcomes of the functional analyses of precursor behavior. Responding for all participants was differentiated during the functional analyses, and individualized treatments eliminated precursor behavior. These results suggest that functional analysis of precursor behavior may offer an alternative, indirect method to assess the operant function of severe problem behavior. PMID:18468282

  7. Regulation of nuclear factor of activated T cells (NFAT) and downstream myogenic proteins during dehydration in the African clawed frog.

    PubMed

    Zhang, Yichi; English, Simon G; Storey, Kenneth B

    2018-06-19

    Xenopus laevis, otherwise known as the African clawed frog, undergoes natural dehydration of up to 30% of its total body water during the dry season in sub-Saharan Africa. To survive under these conditions, a variety of physiological and biochemical changes take place in X. laevis. We were interested in understanding the role that the calcineurin-NFAT pathway plays during dehydration stress response in the skeletal muscles of X. laevis. Immunoblotting was performed to characterize the protein levels of NFATc1-4, calcium signalling proteins, in addition to myogenic proteins (MyoD, MyoG, myomaker). In addition, DNA-protein interaction ELISAs were used to assess the binding of NFATs to their consensus binding sequence, and to identify the effect of urea on NFAT-binding. Our results showed that NFATc1 and c4 protein levels decreased during dehydration, and there were no changes in NFATc2, c3, and calcium signalling proteins. However, MyoG and myomaker both showed increases in protein levels during dehydration, thus indicating that the late myogenic program involving myoblast differentiation, but not satellite cell activation and myoblast proliferation, could be involved in preserving the skeletal muscle of X. laevis during dehydration. In addition, we observed that urea seems to reduce NFATc3-binding to DNA during control, but not during dehydration, possibly indicating that NFATc3 is protected from the denaturing effects of urea as it accumulates during dehydration. These findings expand upon our knowledge of adaptive responses to dehydration, and they identify specific protein targets that could be used to protect the skeletal muscle from damage during stress.

  8. Mesenchymal precursor cells maintain the differentiation and proliferation potentials of breast epithelial cells

    PubMed Central

    2014-01-01

    Introduction Stromal-epithelial interactions play a fundamental role in tissue homeostasis, controlling cell proliferation and differentiation. Not surprisingly, aberrant stromal-epithelial interactions contribute to malignancies. Studies of the cellular and molecular mechanisms underlying these interactions require ex vivo experimental model systems that recapitulate the complexity of human tissue without compromising the differentiation and proliferation potentials of human primary cells. Methods We isolated and characterized human breast epithelial and mesenchymal precursors from reduction mammoplasty tissue and tagged them with lentiviral vectors. We assembled heterotypic co-cultures and compared mesenchymal and epithelial cells to cells in corresponding monocultures by analyzing growth, differentiation potentials, and gene expression profiles. Results We show that heterotypic culture of non-immortalized human primary breast epithelial and mesenchymal precursors maintains their proliferation and differentiation potentials and constrains their growth. We further describe the gene expression profiles of stromal and epithelial cells in co-cultures and monocultures and show increased expression of the tumor growth factor beta (TGFβ) family member inhibin beta A (INHBA) in mesenchymal cells grown as co-cultures compared with monocultures. Notably, overexpression of INHBA in mesenchymal cells increases colony formation potential of epithelial cells, suggesting that it contributes to the dynamic reciprocity between breast mesenchymal and epithelial cells. Conclusions The described heterotypic co-culture system will prove useful for further characterization of the molecular mechanisms mediating interactions between human normal or neoplastic breast epithelial cells and the stroma, and will provide a framework to test the relevance of the ever-increasing number of oncogenomic alterations identified in human breast cancer. PMID:24916766

  9. Functional study of miR-27a in human hepatic stellate cells by proteomic analysis: comprehensive view and a role in myogenic tans-differentiation.

    PubMed

    Ji, Yuhua; Zhang, Jinsheng; Wang, Wenwen; Ji, Juling

    2014-01-01

    We previous reported that miR-27a regulates lipid metabolism and cell proliferation during hepatic stellate cells (HSCs) activation. To further explore the biological function and underlying mechanisms of miR-27a in HSCs, global protein expression affected by overexpression of miR-27a in HSCs was analyzed by a cleavable isotope-coded affinity tags (cICAT) based comparative proteomic approach. In the present study, 1267 non-redundant proteins were identified with unique accession numbers (score ≥1.3, i.e. confidence ≥95%), among which 1171 were quantified and 149 proteins (12.72%) were differentially expressed with a differential expression ratio of 1.5. We found that up-regulated proteins by miR-27a mainly participate in cell proliferation and myogenesis, while down-regulated proteins were the key enzymes involved in de novo lipid synthesis. The expression of a group of six miR-27a regulated proteins was validated and the function of one miR-27a regulated protein was further validated. The results not only delineated the underlying mechanism of miR-27a in modulating fat metabolism and cell proliferation, but also revealed a novel role of miR-27a in promoting myogenic tans-differentiation during HSCs activation. This study also exemplified proteomics strategy as a powerful tool for the functional study of miRNA.

  10. The Psen1-L166P-knock-in mutation leads to amyloid deposition in human wild-type amyloid precursor protein YAC transgenic mice

    PubMed Central

    Vidal, Ruben; Sammeta, Neeraja; Garringer, Holly J.; Sambamurti, Kumar; Miravalle, Leticia; Lamb, Bruce T.; Ghetti, Bernardino

    2012-01-01

    Genetically engineered mice have been generated to model cerebral β-amyloidosis, one of the hallmarks of Alzheimer disease (AD) pathology, based on the overexpression of a mutated cDNA of the amyloid-β precursor protein (AβPP) or by knock-in of the murine Aβpp gene alone or with presenilin1 mutations. Here we describe the generation and initial characterization of a new mouse line based on the presence of 2 copies of the human genomic region encoding the wild-type AβPP and the L166P presenilin 1 mutation. At ∼6 mo of age, double-mutant mice develop amyloid pathology, with signs of neuritic dystrophy, intracellular Aβ accumulation, and glial inflammation, an increase in AβPP C-terminal fragments, and an 8 times increase in Aβ42 levels with a 40% decrease in Aβ40 levels, leading to a significant increase (14 times) of Aβ42/Aβ40 ratios, with minimal effects on presenilin or the Notch1 pathway in the brain. We conclude that in mice, neither mutations in AβPP nor overexpression of an AβPP isoform are a prerequisite for Aβ pathology. This model will allow the study of AD pathogenesis and testing of therapeutic strategies in a more relevant environment without experimental artifacts due to the overexpression of a single-mutant AβPP isoform using exogenous promoters.—Vidal, R., Sammeta, N., Garringer, H. J., Sambamurti, K., Miravalle, L., Lamb B. T., Ghetti, B. The Psen1-L166P-knock-in mutation leads to amyloid deposition in human wild-type amyloid precursor protein YAC transgenic mice. PMID:22459153

  11. Method of texturing a superconductive oxide precursor

    DOEpatents

    DeMoranville, Kenneth L.; Li, Qi; Antaya, Peter D.; Christopherson, Craig J.; Riley, Jr., Gilbert N.; Seuntjens, Jeffrey M.

    1999-01-01

    A method of forming a textured superconductor wire includes constraining an elongated superconductor precursor between two constraining elongated members placed in contact therewith on opposite sides of the superconductor precursor, and passing the superconductor precursor with the two constraining members through flat rolls to form the textured superconductor wire. The method includes selecting desired cross-sectional shape and size constraining members to control the width of the formed superconductor wire. A textured superconductor wire formed by the method of the invention has regular-shaped, curved sides and is free of flashing. A rolling assembly for single-pass rolling of the elongated precursor superconductor includes two rolls, two constraining members, and a fixture for feeding the precursor superconductor and the constraining members between the rolls. In alternate embodiments of the invention, the rolls can have machined regions which will contact only the elongated constraining members and affect the lateral deformation and movement of those members during the rolling process.

  12. Vestibular evoked myogenic potential (VEMP) in patients with auditory neuropathy: Auditory neuropathy or audiovestibular neuropathy?

    PubMed

    Sazgar, Amir Arvin; Yazdani, Nasrin; Rezazadeh, Nima; Yazdi, Alireza Karimi

    2010-10-01

    Our results suggest that isolated auditory or vestibular involvement is unlikely and in fact audiovestibular neuropathy can better explain auditory neuropathy. The purpose of this study was to investigate saccule and related neural pathways in auditory neuropathy patients. Three males and five females diagnosed with auditory neuropathy were included in this prospective study. Patients' ages ranged from 21 to 45 years with a mean age of 28.6 ± 8.1 years and the history of disease was between 4 and 19 years. A group of 30 normal subjects served as the control group. The main outcome measures were the mean peak latency (in ms) of the two early waves (p13 and n23) of the vestibular evoked myogenic potential (VEMP) test in patients and controls. Of the 8 patients (16 ears), normal response was detected in 3 ears (1 in right and 2 in left ears). There were unrepeatable waves in four ears and absent VEMPs in nine ears.

  13. Correlation between caloric and ocular vestibular evoked myogenic potential test results.

    PubMed

    Huang, Chi-Hsuan; Wang, Shou-Jen; Young, Yi-Ho

    2012-02-01

    The ocular vestibular evoked myogenic potential (o-VEMP) test results correlate significantly with caloric test results for patients with acoustic neuroma (AN), but not for patients with Meniere's disease (MD), indicating that the o-VEMP test may replace the caloric test for evaluating the vestibular nerve from which the AN arises. Conversely, the caloric, o-VEMP, and cervical VEMP (c-VEMP) tests should be performed to map lesion sites in the vestibular labyrinth. This study performed caloric, o-VEMP, and c-VEMP tests on patients with central and peripheral vestibular disorders to investigate their relationships. In all, 66 patients comprising 16 with unilateral AN and 50 with unilateral definite MD were enrolled. All patients underwent caloric, o-VEMP, and c-VEMP tests. In the AN group, the caloric test identified canal paresis and caloric areflexia in 10 ears, while the o-VEMP and c-VEMP tests identified abnormal (absent or delayed) responses in 12 and 11 ears, respectively. A significant correlation existed between caloric and o-VEMP test results, but not between caloric and c-VEMP test results, or between o-VEMP and c-VEMP test results. For the MD group, abnormal caloric, o-VEMP, and c-VEMP test results were obtained for 24%, 44%, and 38% of hydropic ears, respectively. No correlation existed between any two test results.

  14. Otoliths - Accelerometer and seismometer; Implications in Vestibular Evoked Myogenic Potential (VEMP).

    PubMed

    Grant, Wally; Curthoys, Ian

    2017-09-01

    Vestibular otolithic organs are recognized as transducers of head acceleration and they function as such up to their corner frequency or undamped natural frequency. It is well recognized that these organs respond to frequencies above their corner frequency up to the 2-3 kHz range (Curthoys et al., 2016). A mechanics model for the transduction of these organs is developed that predicts the response below the undamped natural frequency as an accelerometer and above that frequency as a seismometer. The model is converted to a transfer function using hair cell bundle deflection. Measured threshold acceleration stimuli are used along with threshold deflections for threshold transfer function values. These are compared to model predicted values, both below and above their undamped natural frequency. Threshold deflection values are adjusted to match the model transfer function. The resulting threshold deflection values were well within in measure threshold bundle deflection ranges. Vestibular Evoked Myogenic Potentials (VEMPs) today routinely uses stimulus frequencies of 500 and 1000 Hz, and otoliths have been established incontrovertibly by clinical and neural evidence as the stimulus source. The mechanism for stimulus at these frequencies above the undamped natural frequency of otoliths is presented where otoliths are utilizing a seismometer mode of response for VEMP transduction. Copyright © 2017 Elsevier B.V. All rights reserved.

  15. Soluble Factors from Human Olfactory Neural Stem/Progenitor Cells Influence the Fate Decisions of Hippocampal Neural Precursor Cells.

    PubMed

    Gómez-Virgilio, Laura; Ramírez-Rodríguez, Gerardo Bernabé; Sánchez-Torres, Carmen; Ortiz-López, Leonardo; Meraz-Ríos, Marco Antonio

    2018-03-01

    Neurogenesis plays a significant role during adulthood, and the observation that neural stem cells reside in the central nervous system and the olfactory epithelium has attracted attention due to their importance in neuronal regeneration. In addition, soluble factors (SFs) release by neural stem cells may modulate the neurogenic process. Thus, in this study, we identified the SFs released by olfactory human neural stem/progenitor cells (hNS/PCs-OE). These cells express Ki67, nestin, and βIII-tubulin, indicating their neural lineage. The hNS/PCs-OE also express PSD95 and tau proteins during proliferation, but increased levels are observed after differentiation. Thus, we evaluated the effects of SFs from hNS/PCs-OE on the viability, proliferation, and differentiation potential of adult murine hippocampal neural precursor cells (AHPCs). SFs from hNS/PCs-OE maintain cells in the precursor and proliferative stages and mainly promote the astrocytic differentiation of AHPCs. These effects involved the activation, as measured by phosphorylation, of several proteins (Erk1/2; Akt/PRAS40/GSK3β and JAK/STAT) involved in key events of the neurogenic process. Moreover, according to the results from the antibody-based microarray approach, among the soluble factors, hNS/PCs-OE produce interleukin-6 (IL-6) and neurotrophin 4 (NT4). However, residual epidermal growth factor (EGF) was also detected. These proteins partially reproduced the effects of SFs from hNS/PCs-OE on AHPCs, and the mechanism underlying these effects is mediated by Src proteins, which have been implicated in EGF-induced transactivation of TrkB receptor. The results of the present study suggest the potential use of SFs from hNS/PCs-OE in controlling the differentiation potential of AHPCs. Thus, the potential clinical relevance of hNS/PCs-OE is worth pursuing.

  16. Structural Basis For Antigenic Peptide Precursor Processing by the Endoplasmic Reticulum Aminopeptidase ERAP1

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    T Nguyen; S Chang; I Evnouchidou

    2011-12-31

    ERAP1 trims antigen precursors to fit into MHC class I proteins. To fulfill this function, ERAP1 has unique substrate preferences, trimming long peptides but sparing shorter ones. To identify the structural basis for ERAP1's unusual properties, we determined the X-ray crystal structure of human ERAP1 bound to bestatin. The structure reveals an open conformation with a large interior compartment. An extended groove originating from the enzyme's catalytic center can accommodate long peptides and has features that explain ERAP1's broad specificity for antigenic peptide precursors. Structural and biochemical analyses suggest a mechanism for ERAP1's length-dependent trimming activity, whereby binding of longmore » rather than short substrates induces a conformational change with reorientation of a key catalytic residue toward the active site. ERAP1's unique structural elements suggest how a generic aminopeptidase structure has been adapted for the specialized function of trimming antigenic precursors.« less

  17. Sol-gel precursors and products thereof

    DOEpatents

    Warren, Scott C.; DiSalvo, Jr., Francis J.; Weisner, Ulrich B.

    2017-02-14

    The present invention provides a generalizable single-source sol-gel precursor capable of introducing a wide range of functionalities to metal oxides such as silica. The sol-gel precursor facilitates a one-molecule, one-step approach to the synthesis of metal-silica hybrids with combinations of biological, catalytic, magnetic, and optical functionalities. The single-source precursor also provides a flexible route for simultaneously incorporating functional species of many different types. The ligands employed for functionalizing the metal oxides are derived from a library of amino acids, hydroxy acids, or peptides and a silicon alkoxide, allowing many biological functionalities to be built into silica hybrids. The ligands can coordinate with a wide range of metals via a carboxylic acid, thereby allowing direct incorporation of inorganic functionalities from across the periodic table. Using the single-source precursor a wide range of functionalized nanostructures such as monolith structures, mesostructures, multiple metal gradient mesostructures and Stober-type nanoparticles can be synthesized. ##STR00001##

  18. In vitro genotoxicity assessment of MTES, GPTES and TEOS, three precursors intended for use in food contact coatings.

    PubMed

    Lionti, Krystelle; Séverin, Isabelle; Dahbi, Laurence; Toury, Bérangère; Chagnon, Marie-Christine

    2014-03-01

    Organoalkoxysilanes are precursors that are used increasingly in the synthesis of food contact coatings. To comply with the EU regulation, their potential toxicity must be assessed, and very little information is known. The genotoxicity of three common precursors was studied, namely, tetraethylorthosilicate (TEOS), methyltriethoxysilane (MTES) and 3-glycidyloxypropyltriethoxysilane (GPTES). By the Ames test, MTES and TEOS were not mutagenic for bacteria. A significant positive response was observed with GPTES in the TA100 and TA1535 strains. The mutagenic effect was more pronounced in the presence of the exogenous metabolic activation system with an increase of the induction factor (ten-fold higher for the TA1535 strain). In the micronucleus assay performed with a human hepatoma cell line (HepG2 cells), GPTES gave negative results even in the presence of an exogenous activation system. To ascertain the possibility of using this precursor in food contact material, its migration must be monitored according to the coating formulation because migration might result in hazardous human exposure. Copyright © 2014. Published by Elsevier Ltd.

  19. Detection of Chemical Precursors of Explosives

    NASA Technical Reports Server (NTRS)

    Li, Jing

    2012-01-01

    Certain selected chemicals associated with terrorist activities are too unstable to be prepared in final form. These chemicals are often prepared as precursor components, to be combined at a time immediately preceding the detonation. One example is a liquid explosive, which usually requires an oxidizer, an energy source, and a chemical or physical mechanism to combine the other components. Detection of the oxidizer (e.g. H2O2) or the energy source (e.g., nitromethane) is often possible, but must be performed in a short time interval (e.g., 5 15 seconds) and in an environment with a very small concentration (e.g.,1 100 ppm), because the target chemical(s) is carried in a sealed container. These needs are met by this invention, which provides a system and associated method for detecting one or more chemical precursors (components) of a multi-component explosive compound. Different carbon nanotubes (CNTs) are loaded (by doping, impregnation, coating, or other functionalization process) for detecting of different chemical substances that are the chemical precursors, respectively, if these precursors are present in a gas to which the CNTs are exposed. After exposure to the gas, a measured electrical parameter (e.g. voltage or current that correlate to impedance, conductivity, capacitance, inductance, etc.) changes with time and concentration in a predictable manner if a selected chemical precursor is present, and will approach an asymptotic value promptly after exposure to the precursor. The measured voltage or current are compared with one or more sequences of their reference values for one or more known target precursor molecules, and a most probable concentration value is estimated for each one, two, or more target molecules. An error value is computed, based on differences of voltage or current for the measured and reference values, using the most probable concentration values. Where the error value is less than a threshold, the system concludes that the target

  20. Precursor Mediated Synthesis of Nanostructured Silicas: From Precursor-Surfactant Ion Pairs to Structured Materials.

    PubMed

    Hesemann, Peter; Nguyen, Thy Phung; Hankari, Samir El

    2014-04-11

    The synthesis of nanostructured anionic-surfactant-templated mesoporous silica (AMS) recently appeared as a new strategy for the formation of nanostructured silica based materials. This method is based on the use of anionic surfactants together with a co-structure-directing agent (CSDA), mostly a silylated ammonium precursor. The presence of this CSDA is necessary in order to create ionic interactions between template and silica forming phases and to ensure sufficient affinity between the two phases. This synthetic strategy was for the first time applied in view of the synthesis of surface functionalized silica bearing ammonium groups and was then extended on the formation of materials functionalized with anionic carboxylate and bifunctional amine-carboxylate groups. In the field of silica hybrid materials, the "anionic templating" strategy has recently been applied for the synthesis of silica hybrid materials from cationic precursors. Starting from di- or oligosilylated imidazolium and ammonium precursors, only template directed hydrolysis-polycondensation reactions involving complementary anionic surfactants allowed accessing structured ionosilica hybrid materials. The mechanistic particularity of this approach resides in the formation of precursor-surfactant ion pairs in the hydrolysis-polycondensation mixture. This review gives a systematic overview over the various types of materials accessed from this cooperative ionic templating approach and highlights the high potential of this original strategy for the formation of nanostructured silica based materials which appears as a complementary strategy to conventional soft templating approaches.

  1. Comparison of tone burst versus logon stimulation for vestibular evoked myogenic potentials.

    PubMed

    Ozdek, Ali; Bayır, Omer; Tatar, Emel Cadallı; Korkmaz, Mehmet Hakan

    2012-05-01

    The following study has been carried out to compare the effectiveness of logon and tone burst acoustic stimulation to elicit vestibular evoked myogenic potential (VEMP) responses. The methods and the subjects include 31 healthy adult volunteers (62 ears) who were enrolled in this study. Two different acoustic stimuli, logon (L-VEMP) and tone burst (T-VEMP), were used to elicit VEMP responses in each subject. Bilateral recordings with simultaneous binaural acoustic stimulations were used during VEMP recordings. During the recording period, the subjects were in supine position with their head elevated. The results observed were that the response rate of p1n1 wave was 91.9% for L-VEMP and 88.7% for T-VEMP. The response rate of n2p2 wave was 80.6% for L-VEMP, and 75.8% for T-VEMP. There were no significant differences between the two groups with respect to the latencies of p1, n1, n2 and p2, p1n1 and n2p2 interval, and p1n1 and n2p2 amplitude. The conclusion was that there was no difference between logon and tone burst stimulation with respect to VEMP response rates and VEMP parameters. Therefore, they are not superior to each other.

  2. Earthquakes: hydrogeochemical precursors

    USGS Publications Warehouse

    Ingebritsen, Steven E.; Manga, Michael

    2014-01-01

    Earthquake prediction is a long-sought goal. Changes in groundwater chemistry before earthquakes in Iceland highlight a potential hydrogeochemical precursor, but such signals must be evaluated in the context of long-term, multiparametric data sets.

  3. In-situ resource utilization for the human exploration of Mars : a Bayesian approach to valuation of precursor missions

    NASA Technical Reports Server (NTRS)

    Smith, Jeffrey H.

    2006-01-01

    The need for sufficient quantities of oxygen, water, and fuel resources to support a crew on the surface of Mars presents a critical logistical issue of whether to transport such resources from Earth or manufacture them on Mars. An approach based on the classical Wildcat Drilling Problem of Bayesian decision theory was applied to the problem of finding water in order to compute the expected value of precursor mission sample information. An implicit (required) probability of finding water on Mars was derived from the value of sample information using the expected mass savings of alternative precursor missions.

  4. Signals of Ezh2, Src, and Akt Involve in Myostatin-Pax7 Pathways Regulating the Myogenic Fate Determination during the Sheep Myoblast Proliferation and Differentiation

    PubMed Central

    Li, Li; Liu, Ruizao; Zhang, Li; Zhao, Fuping; Lu, Jian; Zhang, Xiaoning; Du, Lixin

    2015-01-01

    Myostatin and Pax7 have been well documented individually, however, the mechanism by which Myostatin regulates Pax7 is seldom reported. Here, based on muscle transcriptome analysis in Texel (Myostatin mutant) and Ujumqin (wild type) sheep across the five fetal stages, we constructed and examined the Myostatin-Pax7 pathways in muscle. Then we validated the signals by RNAi in the proliferating and differentiating sheep myoblasts in vitro at mRNA, protein, and cell morphological levels. We reveal that Myostatin signals to Pax7 at least through Ezh2, Src, and Akt during the sheep myoblast proliferation and differentiation. Other signals such as p38MAPK, mTOR, Erk1/2, Wnt, Bmp2, Smad, Tgfb1, and p21 are most probably involved in the Myostatin-affected myogenic events. Myostatin knockdown significantly reduces the counts of nucleus and myotube, but not the fusion index of myoblasts during cell differentiation. In addition, findings also indicate that Myostatin is required for normal myogenic differentiation of the sheep myoblasts, which is different from the C2C12 myoblasts. We expand the regulatory network of Myostatin-Pax7 pathways and first illustrate that Myostatin as a global regulator participates in the epigenetic events involved in myogenesis, which contributes to understand the molecular mechanism of Myostatin in regulation of myogenesis. PMID:25811841

  5. Effect of practicing yoga on cervical vestibular evoked myogenic potential.

    PubMed

    Shambhu, Tejaswini; Kumar, Shubhaganga Dhrruva; Prabhu, Prashanth

    2017-10-01

    The present study attempted to determine the effect of practicing yoga on functioning of sacculo-collic pathway using cervical vestibular evoked myogenic potential (cVEMP). cVEMP was recorded from 40 participants (20 who practice yoga regularly and 20 who do not practice yoga regularly). The differences in amplitude of P1, N1, P1-N1 complex, asymmetry ratio and latencies of P1 and N1 of cVEMP were compared between both the groups. The results of the study showed that there was a significant increase (p < 0.05) in the amplitude of P1, N1 and P1-N1 complex and a significant reduction in latency (p < 0.05) for experimental group. The asymmetry ratio in individuals who practice yoga was significantly lower (Mean = 6.73) compared to the control group (Mean = 19.13). Multivariate regression analyses suggested that the number of years of yoga practice significantly predicted the amplitude of P1-N1 complex (β = 0.70, p < 0.01) and amplitude ratio (β = 0.72, p < 0.01). Thus, practicing yoga improves postural control and strengthens the muscles and vestibular system leading to enhanced cVEMP responses. The plastic changes in the vestibular system and increased muscular strength because of constant practicing of yoga could have led to changes in cVEMP responses. However, further studies on a larger group of individuals are essential for better clinical applicability of the results.

  6. Vestibular Evoked Myogenic Potentials (VEMP) Can Detect Asymptomatic Saccular Hydrops

    PubMed Central

    Lin, Ming-Yee; Timmer, Ferdinand C. A.; Oriel, Brad S.; Zhou, Guangwei; Guinan, John J.; Kujawa, Sharon G.; Herrmann, Barbara S.; Merchant, Saumil N.; Rauch, Steven D.

    2009-01-01

    Objective The objective of this study was to explore the useful of vestibular evoked myogenic potential (VEMP) testing for detecting endolymphatic hydrops, especially in the second ear of patients with unilateral Ménière disease (MD). Methods This study was performed at a tertiary care academic medical center. Part I consisted of postmortem temporal bone specimens from the temporal bone collection of the Massachusetts Eye & Ear Infirmary; part II consisted of consecutive consenting adult patients (n = 82) with unilateral MD by American Academy of Otolaryngology–Head and Neck Surgery criteria case histories. Out-come measures consisted of VEMP thresholds in patients and histologic saccular endolymphatic hydrops in postmortem temporal bones. Results Saccular hydrops was observed in the asymptomatic ear in six of 17 (35%) of temporal bones from donors with unilateral MD. Clinic patients with unilateral MD showed elevated mean VEMP thresholds and altered VEMP tuning in their symptomatic ears and, to a lesser degree, in their asymptomatic ears. Specific VEMP frequency and tuning criteria were used to define a “Ménière-like” response. This “Ménière-like” response was seen in 27% of asymptomatic ears of our patients with unilateral MD. Conclusions Bilateral involvement is seen in approximately one third of MD cases. Saccular hydrops appears to precede symptoms in bilateral MD. Changes in VEMP threshold and tuning appear to be sensitive to these structural changes in the saccule. If so, then VEMP may be useful as a detector of asymptomatic saccular hydrops and as a predictor of evolving bilateral MD. PMID:16735912

  7. Vestibular evoked myogenic potentials (VEMP) can detect asymptomatic saccular hydrops.

    PubMed

    Lin, Ming-Yee; Timmer, Ferdinand C A; Oriel, Brad S; Zhou, Guangwei; Guinan, John J; Kujawa, Sharon G; Herrmann, Barbara S; Merchant, Saumil N; Rauch, Steven D

    2006-06-01

    The objective of this study was to explore the useful of vestibular evoked myogenic potential (VEMP) testing for detecting endolymphatic hydrops, especially in the second ear of patients with unilateral Ménière disease (MD). This study was performed at a tertiary care academic medical center. Part I consisted of postmortem temporal bone specimens from the temporal bone collection of the Massachusetts Eye & Ear Infirmary; part II consisted of consecutive consenting adult patients (n = 82) with unilateral MD by American Academy of Otolaryngology-Head and Neck Surgery criteria case histories. Outcome measures consisted of VEMP thresholds in patients and histologic saccular endolymphatic hydrops in postmortem temporal bones. Saccular hydrops was observed in the asymptomatic ear in six of 17 (35%) of temporal bones from donors with unilateral MD. Clinic patients with unilateral MD showed elevated mean VEMP thresholds and altered VEMP tuning in their symptomatic ears and, to a lesser degree, in their asymptomatic ears. Specific VEMP frequency and tuning criteria were used to define a "Ménière-like" response. This "Ménière-like" response was seen in 27% of asymptomatic ears of our patients with unilateral MD. Bilateral involvement is seen in approximately one third of MD cases. Saccular hydrops appears to precede symptoms in bilateral MD. Changes in VEMP threshold and tuning appear to be sensitive to these structural changes in the saccule. If so, then VEMP may be useful as a detector of asymptomatic saccular hydrops and as a predictor of evolving bilateral MD.

  8. Gene expression deregulation in postnatal skeletal muscle of TK2 deficient mice reveals a lower pool of proliferating myogenic progenitor cells.

    PubMed

    Paredes, João A; Zhou, Xiaoshan; Höglund, Stefan; Karlsson, Anna

    2013-01-01

    Loss of thymidine kinase 2 (TK2) causes a heterogeneous myopathic form of mitochondrial DNA (mtDNA) depletion syndrome (MDS) in humans that predominantly affects skeletal muscle tissue. In mice, TK2 deficiency also affects several tissues in addition to skeletal muscle, including brain, heart, adipose tissue, kidneys and causes death about 3 weeks after birth. We analysed skeletal muscle and heart muscle tissues of Tk2 knockout mice at postnatal development phase and observed that TK2 deficient pups grew slower and their skeletal muscles appeared significantly underdeveloped, whereas heart was close to normal in size. Both tissues showed mtDNA depletion and mitochondria with altered ultrastructure, as revealed by transmission electron microscopy. Gene expression microarray analysis showed a strong down-regulation of genes involved in cell cycle and cell proliferation in both tissues, suggesting a lower pool of undifferentiated proliferating cells. Analysis of isolated primary myoblasts from Tk2 knockout mice showed slow proliferation, less ability to differentiate and signs of premature senescence, even in absence of mtDNA depletion. Our data demonstrate that TK2 deficiency disturbs myogenic progenitor cells function in postnatal skeletal muscle and we propose this as one of the causes of underdeveloped phenotype and myopathic characteristic of the TK2 deficient mice, in addition to the progressive mtDNA depletion, mitochondrial damage and respiratory chain deficiency in post-mitotic differentiated tissue.

  9. Gene Expression Deregulation in Postnatal Skeletal Muscle of TK2 Deficient Mice Reveals a Lower Pool of Proliferating Myogenic Progenitor Cells

    PubMed Central

    Paredes, João A.; Zhou, Xiaoshan; Höglund, Stefan; Karlsson, Anna

    2013-01-01

    Loss of thymidine kinase 2 (TK2) causes a heterogeneous myopathic form of mitochondrial DNA (mtDNA) depletion syndrome (MDS) in humans that predominantly affects skeletal muscle tissue. In mice, TK2 deficiency also affects several tissues in addition to skeletal muscle, including brain, heart, adipose tissue, kidneys and causes death about 3 weeks after birth. We analysed skeletal muscle and heart muscle tissues of Tk2 knockout mice at postnatal development phase and observed that TK2 deficient pups grew slower and their skeletal muscles appeared significantly underdeveloped, whereas heart was close to normal in size. Both tissues showed mtDNA depletion and mitochondria with altered ultrastructure, as revealed by transmission electron microscopy. Gene expression microarray analysis showed a strong down-regulation of genes involved in cell cycle and cell proliferation in both tissues, suggesting a lower pool of undifferentiated proliferating cells. Analysis of isolated primary myoblasts from Tk2 knockout mice showed slow proliferation, less ability to differentiate and signs of premature senescence, even in absence of mtDNA depletion. Our data demonstrate that TK2 deficiency disturbs myogenic progenitor cells function in postnatal skeletal muscle and we propose this as one of the causes of underdeveloped phenotype and myopathic characteristic of the TK2 deficient mice, in addition to the progressive mtDNA depletion, mitochondrial damage and respiratory chain deficiency in post-mitotic differentiated tissue. PMID:23341978

  10. In-Situ Cryogenic Propellant Liquefaction and Storage for a Precursor to a Human Mars Mission

    NASA Astrophysics Data System (ADS)

    Mueller, Paul; Durrant, Tom

    The current mission plan for the first human mission to Mars is based on an in-situ propellant production (ISPP) approach to reduce the amount of propellants needed to be taken to Mars and ultimately to reduce mission cost. Recent restructuring of the Mars Robotic Exploration Program has removed ISPP from the early sample return missions. A need still exists to demonstrate ISPP technologies on one or more robotic missions prior to the first human mission. This paper outlines a concept for an ISPP-based precursor mission as a technology demonstration prior to the first human mission. It will also return Martian soil samples to Earth for scientific analysis. The mission will primarily demonstrate cryogenic oxygen and fuel production, liquefaction, and storage for use as propellants for the return trip. Hydrogen will be brought from Earth as a feedstock to produce the hydrocarbon fuel (most likely methane). The analysis used to develop the mission concept includes several different thermal control and liquefaction options for the cryogens. Active cooling and liquefaction devices include Stirling, pulse tube, and Brayton-cycle cryocoolers. Insulation options include multilayer insulation, evacuated microspheres, aerogel blankets, and foam insulation. The cooling capacity and amount of insulation are traded off against each other for a minimum-mass system. In the case of hydrogen feedstock, the amount of hydrogen boiloff allowed during the trip to Mars is also included in the tradeoff. The spacecraft concept includes a Lander (including the propellant production plant) with a Mars Ascent Vehicle (MAV) mounted atop it. An option is explored where the engines on the MAV are also used for descent and landing on the Martian surface at the beginning of the mission. So the MAV propellant tanks would contain oxygen and methane during the trip from Earth. This propellant would be consumed in descent to the Martian surface, resulting in nearly-empty MAV tanks to be filled by the

  11. Descriptive and Experimental Analyses of Potential Precursors to Problem Behavior

    PubMed Central

    Borrero, Carrie S.W; Borrero, John C

    2008-01-01

    We conducted descriptive observations of severe problem behavior for 2 individuals with autism to identify precursors to problem behavior. Several comparative probability analyses were conducted in addition to lag-sequential analyses using the descriptive data. Results of the descriptive analyses showed that the probability of the potential precursor was greater given problem behavior compared to the unconditional probability of the potential precursor. Results of the lag-sequential analyses showed a marked increase in the probability of a potential precursor in the 1-s intervals immediately preceding an instance of problem behavior, and that the probability of problem behavior was highest in the 1-s intervals immediately following an instance of the precursor. We then conducted separate functional analyses of problem behavior and the precursor to identify respective operant functions. Results of the functional analyses showed that both problem behavior and the precursor served the same operant functions. These results replicate prior experimental analyses on the relation between problem behavior and precursors and extend prior research by illustrating a quantitative method to identify precursors to more severe problem behavior. PMID:18468281

  12. Precursor Mediated Synthesis of Nanostructured Silicas: From Precursor-Surfactant Ion Pairs to Structured Materials

    PubMed Central

    Hesemann, Peter; Nguyen, Thy Phung; Hankari, Samir El

    2014-01-01

    The synthesis of nanostructured anionic-surfactant-templated mesoporous silica (AMS) recently appeared as a new strategy for the formation of nanostructured silica based materials. This method is based on the use of anionic surfactants together with a co-structure-directing agent (CSDA), mostly a silylated ammonium precursor. The presence of this CSDA is necessary in order to create ionic interactions between template and silica forming phases and to ensure sufficient affinity between the two phases. This synthetic strategy was for the first time applied in view of the synthesis of surface functionalized silica bearing ammonium groups and was then extended on the formation of materials functionalized with anionic carboxylate and bifunctional amine-carboxylate groups. In the field of silica hybrid materials, the “anionic templating” strategy has recently been applied for the synthesis of silica hybrid materials from cationic precursors. Starting from di- or oligosilylated imidazolium and ammonium precursors, only template directed hydrolysis-polycondensation reactions involving complementary anionic surfactants allowed accessing structured ionosilica hybrid materials. The mechanistic particularity of this approach resides in the formation of precursor-surfactant ion pairs in the hydrolysis-polycondensation mixture. This review gives a systematic overview over the various types of materials accessed from this cooperative ionic templating approach and highlights the high potential of this original strategy for the formation of nanostructured silica based materials which appears as a complementary strategy to conventional soft templating approaches. PMID:28788602

  13. Perfluoroalkyl Acids (PFAAs) and Selected Precursors in the Baltic Sea Environment: Do Precursors Play a Role in Food Web Accumulation of PFAAs?

    PubMed

    Gebbink, Wouter A; Bignert, Anders; Berger, Urs

    2016-06-21

    The present study examined the presence of perfluoroalkyl acids (PFAAs) and selected precursors in the Baltic Sea abiotic environment and guillemot food web, and investigated the relative importance of precursors in food web accumulation of PFAAs. Sediment, water, zooplankton, herring, sprat, and guillemot eggs were analyzed for perfluoroalkane sulfonic acids (PFSAs; C4,6,8,10) and perfluoroalkyl carboxylic acids (PFCAs; C6-15) along with six perfluoro-octane sulfonic acid (PFOS) precursors and 11 polyfluoroalkyl phosphoric acid diesters (diPAPs). FOSA, FOSAA and its methyl and ethyl derivatives (Me- and EtFOSAA), and 6:2/6:2 diPAP were detected in sediment and water. While FOSA and the three FOSAAs were detected in all biota, a total of nine diPAPs were only detected in zooplankton. Concentrations of PFOS precursors and diPAPs exceeded PFOS and PFCA concentrations, respectively, in zooplankton, but not in fish and guillemot eggs. Although PFOS precursors were present at all trophic levels, they appear to play a minor role in food web accumulation of PFOS based on PFOS precursor/PFOS ratios and PFOS and FOSA isomer patterns. The PFCA pattern in fish could not be explained by the intake pattern based on PFCAs and analyzed precursors, that is, diPAPs. Exposure to additional precursors might therefore be a dominant exposure pathway compared to direct PFCA exposure for fish.

  14. Resveratrol and para-coumarate serve as ring precursors for coenzyme Q biosynthesis[S

    PubMed Central

    Xie, Letian X.; Williams, Kevin J.; He, Cuiwen H.; Weng, Emily; Khong, San; Rose, Tristan E.; Kwon, Ohyun; Bensinger, Steven J.; Marbois, Beth N.; Clarke, Catherine F.

    2015-01-01

    Coenzyme Q (Q or ubiquinone) is a redox-active polyisoprenylated benzoquinone lipid essential for electron and proton transport in the mitochondrial respiratory chain. The aromatic ring 4-hydroxybenzoic acid (4HB) is commonly depicted as the sole aromatic ring precursor in Q biosynthesis despite the recent finding that para-aminobenzoic acid (pABA) also serves as a ring precursor in Saccharomyces cerevisiae Q biosynthesis. In this study, we employed aromatic 13C6-ring-labeled compounds including 13C6-4HB, 13C6-pABA, 13C6-resveratrol, and 13C6-coumarate to investigate the role of these small molecules as aromatic ring precursors in Q biosynthesis in Escherichia coli, S. cerevisiae, and human and mouse cells. In contrast to S. cerevisiae, neither E. coli nor the mammalian cells tested were able to form 13C6-Q when cultured in the presence of 13C6-pABA. However, E. coli cells treated with 13C6-pABA generated 13C6-ring-labeled forms of 3-octaprenyl-4-aminobenzoic acid, 2-octaprenyl-aniline, and 3-octaprenyl-2-aminophenol, suggesting UbiA, UbiD, UbiX, and UbiI are capable of using pABA or pABA-derived intermediates as substrates. E. coli, S. cerevisiae, and human and mouse cells cultured in the presence of 13C6-resveratrol or 13C6-coumarate were able to synthesize 13C6-Q. Future evaluation of the physiological and pharmacological responses to dietary polyphenols should consider their metabolism to Q. PMID:25681964

  15. Preparation of boron nitride fiber by organic precursor method

    NASA Astrophysics Data System (ADS)

    Zhou, Yingying; Sun, Runjun; Zhang, Zhaohuan; Fan, Wei; Zhou, Dan; Sheng, Cuihong

    In this paper, boron nitride polymer precursor was made by boric acid, melamine, twelve sodium alkyl sulfate as raw materials and pure water as medium which is heated to 70 °C. Boron nitride precursor polymer was soluble in formic acid solution. The boron nitride precursor can be electrostatically spun at the voltage in 23 kV and the distance between the positive and negative poles is 15 cm. The formed fiber is very uniform. The properties of the precursors were analyzed through electron microscope, infrared spectrum, X-ray and ultraviolet spectrum. The aim of the job is to got the precursor of BN and spun it.

  16. Reactive oxygen species are required for zoledronic acid-induced apoptosis in osteoclast precursors and mature osteoclast-like cells

    PubMed Central

    Tai, Ta-Wei; Chen, Ching-Yu; Su, Fong-Chin; Tu, Yuan-Kun; Tsai, Tsung-Ting; Lin, Chiou-Feng; Jou, I.-Ming

    2017-01-01

    Inhibiting osteoclasts and osteoclast precursors to reduce bone resorption is an important strategy to treat osteoclast-related diseases, such as osteoporosis, inflammatory bone loss, and malignant bone metastasis. However, the mechanism by which apoptosis is induced in the osteoclasts and their precursors are not completely understood. Here, we used nitrogen-containing bisphosphonate zoledronic acid (ZA) to induce cell apoptosis in human and murine osteoclast precursors and mature osteoclast-like cells. Caspase-3-mediated cell apoptosis occurred following the ZA (100 μM) treatment. Reactive oxygen species (ROS) were also generated in a time-dependent manner. Following knock-down of the p47phox expression, which is required for ROS activation, or co-treatment with the ROS inhibitor, N-acetyl-L-cysteine, ZA-induced apoptosis was significantly suppressed in both osteoclast precursors and mature osteoclast-like cells. The ROS-activated mitogen-activated protein kinases pathways did not trigger cell apoptosis. However, a ROS-regulated Mcl-1 decrease simultaneously with glycogen synthase kinase (GSK)-3β promoted cell apoptosis. These findings show that ZA induces apoptosis in osteoclast precursors and mature osteoclast-like cells by triggering ROS- and GSK-3β-mediated Mcl-1 down-regulation. PMID:28281643

  17. SEARCH FOR PRECURSOR ERUPTIONS AMONG TYPE IIB SUPERNOVAE

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Strotjohann, Nora L.; Ofek, Eran O.; Gal-Yam, Avishay

    2015-10-01

    The progenitor stars of several Type IIb supernovae (SNe) show indications of extended hydrogen envelopes. These envelopes might be the outcome of luminous energetic pre-explosion events, so-called precursor eruptions. We use the Palomar Transient Factory (PTF) pre-explosion observations of a sample of 27 nearby SNe IIb to look for such precursors during the final years prior to the SN explosion. No precursors are found when combining the observations in 15-day bins, and we calculate the absolute-magnitude-dependent upper limit on the precursor rate. At the 90% confidence level, SNe IIb have on average <0.86 precursors as bright as an absolute R-bandmore » magnitude of −14 in the final 3.5 years before the explosion and <0.56 events over the final year. In contrast, precursors among SNe IIn have a ≳5 times higher rate. The kinetic energy required to unbind a low-mass stellar envelope is comparable to the radiated energy of a few-weeks-long precursor that would be detectable for the closest SNe in our sample. Therefore, mass ejections, if they are common in such SNe, are radiatively inefficient or have durations longer than months. Indeed, when using 60-day bins, a faint precursor candidate is detected prior to SN 2012cs (∼2% false-alarm probability). We also report the detection of the progenitor of SN 2011dh that does not show detectable variability over the final two years before the explosion. The suggested progenitor of SN 2012P is still present, and hence is likely a compact star cluster or an unrelated object.« less

  18. Stem Cells for Skeletal Muscle Tissue Engineering.

    PubMed

    Pantelic, Molly N; Larkin, Lisa M

    2018-04-19

    Volumetric muscle loss (VML) is a debilitating condition wherein muscle loss overwhelms the body's normal physiological repair mechanism. VML is particularly common among military service members who have sustained war injuries. Because of the high social and medical cost associated with VML and suboptimal current surgical treatments, there is great interest in developing better VML therapies. Skeletal muscle tissue engineering (SMTE) is a promising alternative to traditional VML surgical treatments that use autogenic tissue grafts, and rather uses isolated stem cells with myogenic potential to generate de novo skeletal muscle tissues to treat VML. Satellite cells are the native precursors to skeletal muscle tissue, and are thus the most commonly studied starting source for SMTE. However, satellite cells are difficult to isolate and purify, and it is presently unknown whether they would be a practical source in clinical SMTE applications. Alternative myogenic stem cells, including adipose-derived stem cells, bone marrow-derived mesenchymal stem cells, perivascular stem cells, umbilical cord mesenchymal stem cells, induced pluripotent stem cells, and embryonic stem cells, each have myogenic potential and have been identified as possible starting sources for SMTE, although they have yet to be studied in detail for this purpose. These alternative stem cell varieties offer unique advantages and disadvantages that are worth exploring further to advance the SMTE field toward highly functional, safe, and practical VML treatments. The following review summarizes the current state of satellite cell-based SMTE, details the properties and practical advantages of alternative myogenic stem cells, and offers guidance to tissue engineers on how alternative myogenic stem cells can be incorporated into SMTE research.

  19. The effects of click and tone-burst stimulus parameters on the vestibular evoked myogenic potential (VEMP).

    PubMed

    Akin, Faith Wurm; Murnane, Owen D; Proffitt, Tina M

    2003-11-01

    Vestibular evoked myogenic potentials (VEMP) are short latency electromyograms (EMG) evoked by high-level acoustic stimuli and recorded from surface electrodes over the tonically contracted sternocleidomastoid (SCM) muscle and are presumed to originate in the saccule. The present experiments examined the effects of click and tone-burst level and stimulus frequency on the latency, amplitude, and threshold of the VEMP in subjects with normal hearing sensitivity and no history of vestibular disease. VEMPs were recorded in all subjects using 100 dB nHL click stimuli. Most subjects had VEMPs present at 500, 750, and 1000 Hz, and few subjects had VEMPs present at 2000 Hz. The response amplitude of the VEMP increased with click and tone-burst level, whereas VEMP latency was not influenced by the stimulus level. The largest tone-burst-evoked VEMPs and lowest thresholds were obtained at 500 and 750 Hz. VEMP latency was independent of stimulus frequency when tone-burst duration was held constant.

  20. 40 CFR 766.38 - Reporting on precursor chemical substances.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 31 2011-07-01 2011-07-01 false Reporting on precursor chemical... SUBSTANCES CONTROL ACT DIBENZO-PARA-DIOXINS/DIBENZOFURANS Specific Chemical Testing/Reporting Requirements § 766.38 Reporting on precursor chemical substances. (a) Identification of precursor chemical substances...

  1. 40 CFR 766.38 - Reporting on precursor chemical substances.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 30 2010-07-01 2010-07-01 false Reporting on precursor chemical... SUBSTANCES CONTROL ACT DIBENZO-PARA-DIOXINS/DIBENZOFURANS Specific Chemical Testing/Reporting Requirements § 766.38 Reporting on precursor chemical substances. (a) Identification of precursor chemical substances...

  2. 40 CFR 766.38 - Reporting on precursor chemical substances.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 32 2012-07-01 2012-07-01 false Reporting on precursor chemical... SUBSTANCES CONTROL ACT DIBENZO-PARA-DIOXINS/DIBENZOFURANS Specific Chemical Testing/Reporting Requirements § 766.38 Reporting on precursor chemical substances. (a) Identification of precursor chemical substances...

  3. 40 CFR 766.38 - Reporting on precursor chemical substances.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 31 2014-07-01 2014-07-01 false Reporting on precursor chemical... SUBSTANCES CONTROL ACT DIBENZO-PARA-DIOXINS/DIBENZOFURANS Specific Chemical Testing/Reporting Requirements § 766.38 Reporting on precursor chemical substances. (a) Identification of precursor chemical substances...

  4. 40 CFR 766.38 - Reporting on precursor chemical substances.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 32 2013-07-01 2013-07-01 false Reporting on precursor chemical... SUBSTANCES CONTROL ACT DIBENZO-PARA-DIOXINS/DIBENZOFURANS Specific Chemical Testing/Reporting Requirements § 766.38 Reporting on precursor chemical substances. (a) Identification of precursor chemical substances...

  5. Shape-programmed nanofabrication: understanding the reactivity of dichalcogenide precursors.

    PubMed

    Guo, Yijun; Alvarado, Samuel R; Barclay, Joshua D; Vela, Javier

    2013-04-23

    Dialkyl and diaryl dichalcogenides are highly versatile and modular precursors for the synthesis of colloidal chalcogenide nanocrystals. We have used a series of commercially available dichalcogenide precursors to unveil the molecular basis for the outcome of nanocrystal preparations, more specifically, how precursor molecular structure and reactivity affect the final shape and size of II-VI semiconductor nanocrystals. Dichalcogenide precursors used were diallyl, dibenzyl, di-tert-butyl, diisopropyl, diethyl, dimethyl, and diphenyl disulfides and diethyl, dimethyl, and diphenyl diselenides. We find that the presence of two distinctively reactive C-E and E-E bonds makes the chemistry of these precursors much richer and interesting than that of other conventional precursors such as the more common phosphine chalcogenides. Computational studies (DFT) reveal that the dissociation energy of carbon-chalcogen (C-E) bonds in dichalcogenide precursors (R-E-E-R, E=S or Se) increases in the order (R): diallylprecursor reactivity, leading to progressively slower nucleation and higher selectivity for anisotropic growth, all the way from dots to pods to tetrapods. Under identical experimental conditions, we obtain CdS and CdSe nanocrystals with spherical, elongated, or tetrapodal morphology by simply varying the identity and reactivity of the dichalcogenide precursor. Interestingly, we find that precursors with strong C-E and weak E-E bond dissociation energies such as Ph-S-S-Ph serve as a ready source of thiol radicals that appear to stabilize small CdE nuclei, facilitating anisotropic growth. These CdS and CdSe nanocrystals have been

  6. New Polymeric Precursors of Silicon Carbide

    NASA Technical Reports Server (NTRS)

    Litt, M.; Kumar, K.

    1987-01-01

    Silicon carbide made by pyrolizing polymers. Method conceived for preparation of poly(decamethylcyclohexasilanes) as precursors for preparation of silicon carbide at high yield. Technical potential of polysilanes as precursors of SiC ceramics being explored. Potential limited by intractability of some polysilanes; formation of small, cyclic polycarbosilane fragments during pyrolysis; and overall low char yield and large shrinkage in conversion to ceramics.

  7. Differential and directional estrogenic signaling pathways induced by enterolignans and their precursors

    PubMed Central

    Zhu, Yun; Kawaguchi, Kayoko; Kiyama, Ryoiti

    2017-01-01

    Mammalian lignans or enterolignans are metabolites of plant lignans, an important category of phytochemicals. Although they are known to be associated with estrogenic activity, cell signaling pathways leading to specific cell functions, and especially the differences among lignans, have not been explored. We examined the estrogenic activity of enterolignans and their precursor plant lignans and cell signaling pathways for some cell functions, cell cycle and chemokine secretion. We used DNA microarray-based gene expression profiling in human breast cancer MCF-7 cells to examine the similarities, as well as the differences, among enterolignans, enterolactone and enterodiol, and their precursors, matairesinol, pinoresinol and sesamin. The profiles showed moderate to high levels of correlation (R values: 0.44 to 0.81) with that of estrogen (17β-estradiol or E2). Significant correlations were observed among lignans (R values: 0.77 to 0.97), and the correlations were higher for cell functions related to enzymes, signaling, proliferation and transport. All the enterolignans/precursors examined showed activation of the Erk1/2 and PI3K/Akt pathways, indicating the involvement of rapid signaling through the non-genomic estrogen signaling pathway. However, when their effects on specific cell functions, cell cycle progression and chemokine (MCP-1) secretion were examined, positive effects were observed only for enterolactone, suggesting that signals are given in certain directions at a position closer to cell functions. We hypothesized that, while estrogen signaling is initiated by the enterolignans/precursors examined, their signals are differentially and directionally modulated later in the pathways, resulting in the differences at the cell function level. PMID:28152041

  8. Effects of detergents on ribosomal precursor subunits of Bacillus megaterium.

    PubMed

    Body, A; Brownstein, B H

    1978-01-01

    Cell extracts prepared by osmotic lysis of protoplasts were analyzed by sucrose gradient sedimentation. In the absence of detergents, ribosomal precursor particles were found in a gradient fraction which sedimented faster than mature 50S subunits and in two other fractions coincident with mature 50S and 30S ribosomal subunits. Phospholipid, an indicator of membrane, was shown to be associated with only the fastest-sedimenting ribosomal precursor particle fraction. After the extracts were treated with detergents, all phospholipid was found at the top of the gradients. Brij 58, Triton X-100, and Nonidet P-40 did not cause a change in the sedimentation values of precursors; however, the detergents deoxycholate or LOC (Amway Corp.) disrupted the fastest-sedimenting precursor and converted the ribosomal precursor subunits which sedimented at the 50S and 30S positions to five different classes of more slowly sedimenting particles. Earlier reports on the in vivo assembly of ribosomal subunits have shown that several stages of ribosomal precursor subunits exist, and, in the presence of the detergents deoxycholate and LOC, which had been used to prepare cell extracts, the precursors sedimented more slowly. Our data are consistent with the hypothesis that those detergents selectively modify the structure of ribosomal precursors and lend further support to the hypothesis that the in vivo ribosomal precursor subunits have 50S and 30S sedimentation values. In addition, these data support the idea that the ribosomal precursor particles found in the fast-sedimenting fraction may constitute a unique precursor fraction.

  9. Effects of Detergents on Ribosomal Precursor Subunits of Bacillus megaterium

    PubMed Central

    Body, Barbara A.; Brownstein, Bernard H.

    1978-01-01

    Cell extracts prepared by osmotic lysis of protoplasts were analyzed by sucrose gradient sedimentation. In the absence of detergents, ribosomal precursor particles were found in a gradient fraction which sedimented faster than mature 50S subunits and in two other fractions coincident with mature 50S and 30S ribosomal subunits. Phospholipid, an indicator of membrane, was shown to be associated with only the fastest-sedimenting ribosomal precursor particle fraction. After the extracts were treated with detergents, all phospholipid was found at the top of the gradients. Brij 58, Triton X-100, and Nonidet P-40 did not cause a change in the sedimentation values of precursors; however, the detergents deoxycholate or LOC (Amway Corp.) disrupted the fastest-sedimenting precursor and converted the ribosomal precursor subunits which sedimented at the 50S and 30S positions to five different classes of more slowly sedimenting particles. Earlier reports on the in vivo assembly of ribosomal subunits have shown that several stages of ribosomal precursor subunits exist, and, in the presence of the detergents deoxycholate and LOC, which had been used to prepare cell extracts, the precursors sedimented more slowly. Our data are consistent with the hypothesis that those detergents selectively modify the structure of ribosomal precursors and lend further support to the hypothesis that the in vivo ribosomal precursor subunits have 50S and 30S sedimentation values. In addition, these data support the idea that the ribosomal precursor particles found in the fast-sedimenting fraction may constitute a unique precursor fraction. PMID:412833

  10. Peptide processing and biology in human disease

    PubMed Central

    Kovac, Suzana; Shulkes, Arthur; Baldwin, Graham S.

    2008-01-01

    Purpose of review To describe recent advances in the processing of gastrointestinal hormones, and the consequences for human disease of mutations in the enzymes involved. Recent findings Although gastrointestinal prohormones were long regarded as devoid of biological activity, recent data indicates that the prohormones for both gastrin and gastrin-releasing peptide are bioactive, through different receptors from the mature hormones. Mutations in the family of prohormone convertases responsible for the initial steps in the processing of gastrointestinal hormones are associated with several different pathophysiological conditions in humans. Summary Human mutational studies, when taken together with the phenotypes observed in mice deficient in the prohormone convertases, emphasize the crucial importance of the processing enzymes in mammalian biology. Although the phenotypes may often be ascribed to defective production of a mature hormone or growth factor, the recognition that the precursors are independently bioactive suggests that the increased precursor concentrations may also contribute to the symptoms. The observation that the precursors often act through different receptors from the mature hormones may permit the development of precursor-selective antagonists for therapeutic use. PMID:19104240

  11. Peptide processing and biology in human disease.

    PubMed

    Kovac, Suzana; Shulkes, Arthur; Baldwin, Graham S

    2009-02-01

    To describe recent advances in the processing of gastrointestinal hormones, and the consequences for human disease of mutations in the enzymes involved. Although gastrointestinal prohormones were long regarded as devoid of biological activity, recent data indicate that the prohormones for both gastrin and gastrin-releasing peptide are bioactive, through different receptors from the mature hormones. Mutations in the family of prohormone convertases responsible for the initial steps in the processing of gastrointestinal hormones are associated with several different pathophysiological conditions in humans. Human mutational studies, when taken together with the phenotypes observed in mice deficient in the prohormone convertases, emphasize the crucial importance of the processing enzymes in mammalian biology. Although the phenotypes may often be ascribed to defective production of a mature hormone or growth factor, the recognition that the precursors are independently bioactive suggests that the increased precursor concentrations may also contribute to the symptoms. The observation that the precursors often act through different receptors from the mature hormones may permit the development of precursor-selective antagonists for therapeutic use.

  12. A systematic review of methamphetamine precursor regulations.

    PubMed

    McKetin, Rebecca; Sutherland, Rachel; Bright, David A; Norberg, Melissa M

    2011-11-01

    To assess the effectiveness of methamphetamine precursor regulations in reducing illicit methamphetamine supply and use. A systematic review of 12 databases was used to identify studies that had evaluated the impact of methamphetamine precursor regulations on methamphetamine supply and/or use. The guidelines of the Effective Practice and Organization of Care Group (EPOC) of The Cochrane Collaboration were used to determine which study designs were included and assess their quality. Ten studies met the inclusion criteria. These studies evaluated 15 interventions (13 regulations and two related interdiction efforts), all of which were located in North America. Interventions had consistent impacts across various indicators of methamphetamine supply and use. Seven of the 15 interventions produced reductions in methamphetamine indicators (ranging from 12% to 77%). Two of the largest impacts were seen following interdiction efforts, involving the closure of rogue pharmaceutical companies. There was no evidence of a shift into other types of drug use, or injecting use, although the impact on the synthetic drug market was not examined. Null effects were related largely to the existence of alternative sources of precursor chemicals or the availability of imported methamphetamine. Methamphetamine precursor regulations can reduce indicators of methamphetamine supply and use. Further research is needed to determine whether regulations can be effective outside North America, particularly in developing countries, and what impact they have on the broader synthetic drug market. Improved data on precursor diversion are needed to facilitate the evaluation of precursor regulations. © 2011 The Authors, Addiction © 2011 Society for the Study of Addiction.

  13. The Interrelationships of Mathematical Precursors in Kindergarten

    ERIC Educational Resources Information Center

    Cirino, Paul T.

    2011-01-01

    This study evaluated the interrelations among cognitive precursors across quantitative, linguistic, and spatial attention domains that have been implicated for math achievement in young children. The dimensionality of the quantity precursors was evaluated in 286 kindergarteners via latent variable techniques, and the contribution of precursors…

  14. High-Solids Polyimide Precursor Solutions

    NASA Technical Reports Server (NTRS)

    Chuang, Chun-Hua (Inventor)

    2004-01-01

    The invention is a highly concentrated stable solution of polymide precursors (monometers) having a solids content ranging from about 80 to 98 percent by weight in lower aliphatic alcohols i.e. methyl and/or ethylalcohol. the concentrated polyimide precursos solution comparisons effective amounts of at least one aromatic diamine, at least one aromatic dianhydride, and a monofunctional endcap including monoamines, monoanhydrides and lower alkyl esters of said monoanhydrides. These concentrated polyimide precursor solutions are particularly useful for the preparation of fibrous prepregs and composites for use in structural materials for military and civil applications.

  15. Growth hormone facilitates 5'-azacytidine-induced myogenic but inhibits 5'-azacytidine-induced adipogenic commitment in C3H10T1/2 mesenchymal stem cells.

    PubMed

    Jia, Dan; Zheng, Weijiang; Jiang, Honglin

    2018-06-01

    The C3H10T1/2 cells are considered mesenchymal stem cells (MSCs) because they can be induced to become the progenitor cells for myocytes, adipocytes, osteoblasts, and chondrocytes by the DNA methyltransferase inhibitor 5'-azacytidine. In this study, we determined the effect of growth hormone (GH) on the myogenic and adipogenic lineage commitment in C3H10T1/2 cells. The C3H10T1/2 cells were treated with recombinant bovine GH in the presence or absence of 5'-azacytidine for 4 days. The myogenic commitment in C3H10T1/2 cells was assessed by immunostaining them for MyoD, the marker for myoblasts, and by determining their capacity to differentiate into the multinucleated myotubes. The adipogenic commitment in C3H10T1/2 cells was assessed by determining their ability to differentiate into adipocytes. Myotubes and adipocyteswere identified by immunocytochemistry and Oil Red O staining, respectively. C3H10T1/2 cells treated with 5'-azacytidine and GH for 4 days contained a greater percentage of MyoD-positive cells than those treated with 5'-axacytidine alone (P < 0.05). The former generated more myotubes than the latter upon induced myoblast differentiation (P < 0.05). However, C3H10T1/2 cells treated with GH alone did not form any myotubes. C3H10T1/2 cells treated with 5'-azacytidine formed adipocytes upon adipocyte differentiation induction, whereas C3H10T1/2 cells treated with GH alone did not form any adipocytes. C3H10T1/2 cells treated with both 5'-azacytidine and GH formed fewer adipocytes than those treated with 5'-azacytidine alone (P < 0.05). Both GHR and IGF-I mRNA expression in C3H10T1/2 cells were increased by 5'-azacytidine (P < 0.05), but neither was affected by GH. Overall, this study showed that GH enhanced 5'-azacytidine-induced commitment in C3H10T1/2 cells to myoblasts but inhibited 5'-azacytidine-induced commitment to preadipocytes. These results support the possibility that GH stimulates skeletal muscle growth and inhibits adipose

  16. Persistence of perfluoroalkyl acid precursors in AFFF-impacted groundwater and soil.

    PubMed

    Houtz, Erika F; Higgins, Christopher P; Field, Jennifer A; Sedlak, David L

    2013-08-06

    Several classes of polyfluorinated chemicals that are potential precursors to the perfluorinated carboxylates and sulfonates are present in aqueous film-forming foams (AFFF). To assess the persistence of these AFFF-derived precursors, groundwater, soil, and aquifer solids were obtained in 2011 from an unlined firefighter training area at a U.S. Air Force Base where AFFF was regularly used between 1970 and 1990. To measure the total concentration of perfluorinated carboxylate and sulfonate precursors in archived AFFF formulations and AFFF-impacted environmental samples, a previously developed assay that uses hydroxyl radical to oxidize precursors to perfluorinated carboxylates was adapted for these media. This assay was employed along with direct measurement of 22 precursors found in AFFF and a suite of other poly- and perfluoroalkyl substances (PFASs). On a molar basis, precursors accounted for 41-100% of the total concentration of PFASs in archived AFFF formulations. In the training area, precursors measured by the oxidation assay accounted for an average of 23% and 28% of total PFASs (i.e., precursors and perfluorinated carboxylates and sulfonates) in groundwater and solids samples, respectively. One precursor in AFFF, perfluorohexane sulfonamide amine, was observed on several highly contaminated soil and aquifer solids samples, but no other precursors present in AFFF formulations were detected in any samples at this field site. Suspected intermediate transformation products of precursors in AFFF that were directly measured accounted for approximately half of the total precursor concentration in samples from the training site. The fraction of PFASs consisting of perfluorinated carboxylates and sulfonates was greater in groundwater and solid samples than in any archived AFFF formulations, suggesting that much of the mass of precursors released at the site was converted to perfluorinated carboxylates and sulfonates. The precursors that have persisted at this site

  17. Serrate and Notch specify cell fates in the heart field by suppressing cardiomyogenesis.

    PubMed

    Rones, M S; McLaughlin, K A; Raffin, M; Mercola, M

    2000-09-01

    Notch signaling mediates numerous developmental cell fate decisions in organisms ranging from flies to humans, resulting in the generation of multiple cell types from equipotential precursors. In this paper, we present evidence that activation of Notch by its ligand Serrate apportions myogenic and non-myogenic cell fates within the early Xenopus heart field. The crescent-shaped field of heart mesoderm is specified initially as cardiomyogenic. While the ventral region of the field forms the myocardial tube, the dorsolateral portions lose myogenic potency and form the dorsal mesocardium and pericardial roof (Raffin, M., Leong, L. M., Rones, M. S., Sparrow, D., Mohun, T. and Mercola, M. (2000) Dev. Biol., 218, 326-340). The local interactions that establish or maintain the distinct myocardial and non-myocardial domains have never been described. Here we show that Xenopus Notch1 (Xotch) and Serrate1 are expressed in overlapping patterns in the early heart field. Conditional activation or inhibition of the Notch pathway with inducible dominant negative or active forms of the RBP-J/Suppressor of Hairless [Su(H)] transcription factor indicated that activation of Notch feeds back on Serrate1 gene expression to localize transcripts more dorsolaterally than those of Notch1, with overlap in the region of the developing mesocardium. Moreover, Notch pathway activation decreased myocardial gene expression and increased expression of a marker of the mesocardium and pericardial roof, whereas inhibition of Notch signaling had the opposite effect. Activation or inhibition of Notch also regulated contribution of individual cells to the myocardium. Importantly, expression of Nkx2. 5 and Gata4 remained largely unaffected, indicating that Notch signaling functions downstream of heart field specification. We conclude that Notch signaling through Su(H) suppresses cardiomyogenesis and that this activity is essential for the correct specification of myocardial and non-myocardial cell fates.

  18. Characterization of human myoblast differentiation for tissue-engineering purposes by quantitative gene expression analysis.

    PubMed

    Stern-Straeter, Jens; Bonaterra, Gabriel Alejandro; Kassner, Stefan S; Zügel, Stefanie; Hörmann, Karl; Kinscherf, Ralf; Goessler, Ulrich Reinhart

    2011-08-01

    Tissue engineering of skeletal muscle is an encouraging possibility for the treatment of muscle loss through the creation of functional muscle tissue in vitro from human stem cells. Currently, the preferred stem cells are primary, non-immunogenic satellite cells ( = myoblasts). The objective of this study was to determine the expression patterns of myogenic markers within the human satellite cell population during their differentiation into multinucleated myotubes for an accurate characterization of stem cell behaviour. Satellite cells were incubated (for 1, 4, 8, 12 or 16 days) with a culture medium containing either a low [ = differentiation medium (DM)] or high [ = growth medium (GM)] concentration of growth factors. Furthermore, we performed a quantitative gene expression analysis of well-defined differentiation makers: myogenic factor 5 (MYF5), myogenin (MYOG), skeletal muscle αactin1 (ACTA1), embryonic (MYH3), perinatal (MYH8) and adult skeletal muscle myosin heavy chain (MYH1). Additionally, the fusion indices of forming myotubes of MYH1, MYH8 and ACTA1 were calculated. We show that satellite cells incubated with DM expressed multiple characteriztic features of mature skeletal muscles, verified by time-dependent upregulation of MYOG, MYH1, MYH3, MYH8 and ACTA1. However, satellite cells incubated with GM did not reveal all morphological aspects of muscle differentiation. Immunocytochemical investigations with antibodies directed against the differentiation markers showed correlations between the gene expression and differentiation. Our data provide information about time-dependent gene expression of differentiation markers in human satellite cells, which can be used for maturation analyses in skeletal muscle tissue-engineering applications. Copyright © 2011 John Wiley & Sons, Ltd.

  19. Microfluidic-enhanced 3D bioprinting of aligned myoblast-laden hydrogels leads to functionally organized myofibers in vitro and in vivo.

    PubMed

    Costantini, Marco; Testa, Stefano; Mozetic, Pamela; Barbetta, Andrea; Fuoco, Claudia; Fornetti, Ersilia; Tamiro, Francesco; Bernardini, Sergio; Jaroszewicz, Jakub; Święszkowski, Wojciech; Trombetta, Marcella; Castagnoli, Luisa; Seliktar, Dror; Garstecki, Piotr; Cesareni, Gianni; Cannata, Stefano; Rainer, Alberto; Gargioli, Cesare

    2017-07-01

    We present a new strategy for the fabrication of artificial skeletal muscle tissue with functional morphologies based on an innovative 3D bioprinting approach. The methodology is based on a microfluidic printing head coupled to a co-axial needle extruder for high-resolution 3D bioprinting of hydrogel fibers laden with muscle precursor cells (C2C12). To promote myogenic differentiation, we formulated a tailored bioink with a photocurable semi-synthetic biopolymer (PEG-Fibrinogen) encapsulating cells into 3D constructs composed of aligned hydrogel fibers. After 3-5 days of culture, the encapsulated myoblasts started migrating and fusing, forming multinucleated myotubes within the 3D bioprinted fibers. The obtained myotubes showed high degree of alignment along the direction of hydrogel fiber deposition, further revealing maturation, sarcomerogenesis, and functionality. Following subcutaneous implantation in the back of immunocompromised mice, bioprinted constructs generated organized artificial muscle tissue in vivo. Finally, we demonstrate that our microfluidic printing head allows to design three dimensional multi-cellular assemblies with an exquisite compartmentalization of the encapsulated cells. Our results demonstrate an enhanced myogenic differentiation with the formation of parallel aligned long-range myotubes. The approach that we report here represents a robust and valid candidate for the fabrication of macroscopic artificial muscle to scale up skeletal muscle tissue engineering for human clinical application. Copyright © 2017 The Author(s). Published by Elsevier Ltd.. All rights reserved.

  20. Precursor Lesions of Urologic Malignancies.

    PubMed

    Khani, Francesca; Robinson, Brian D

    2017-12-01

    - Precursor lesions of urologic malignancies are established histopathologic entities, which are important not only to recognize for clinical purposes, but also to further investigate at the molecular level in order to gain a better understanding of the pathogenesis of these malignancies. - To provide a brief overview of precursor lesions to the most common malignancies that develop within the genitourinary tract with a focus on their clinical implications, histologic features, and molecular characteristics. - Literature review from PubMed, urologic pathology textbooks, and the 4th edition of the World Health Organization Classification of Tumours of the Urinary System and Male Genital Organs. All photomicrographs were taken from cases seen at Weill Cornell Medicine or from the authors' personal slide collections. - The clinical importance and histologic criteria are well established for the known precursor lesions of the most common malignancies throughout the genitourinary tract, but further investigation is warranted at the molecular level to better understand the pathogenesis of these lesions. Such investigation may lead to better risk stratification of patients and potentially novel treatments.

  1. Prophylactic vaccination against human papillomaviruses to prevent cervical cancer and its precursors

    PubMed Central

    Arbyn, Marc; Bryant, Andrew; Beutels, Philippe; Martin-Hirsch, Pierre PL; Paraskevaidis, Evangelos; Van Hoof, Elke; Steben, Marc; Qiao, Youlin; Zhao, Fang-Hui; Schneider, Achim; Kaufmann, Andreas; Dillner, Joakim; Markowitz, Lauri; Hildesheim, Allan

    2014-01-01

    This is the protocol for a review and there is no abstract. The objectives are as follows: To evaluate the immunogenicity, clinical efficacy, and safety of prophylactic HPV vaccines in females. The assessment of clinical efficacy will address protection against HPV infection (for homologous and heterologous HPV types), against re-infection, against cervical cancer and its precursors (high-grade CIN (grade 2 or grade 3), adenocarcinoma in situ) in women previously not exposed to HPV infection (negative at enrolment for both HPV DNA and antibodies against the vaccine HPV types). We will assess clinical effectiveness by evaluating outcomes in all women, irrespective of the HPV DNA or serology status at enrolment. Evaluation by fine age and time since sexual debut categories is also planned. PMID:25267916

  2. Thermal Stability of Jet Fuels: Kinetics of Forming Deposit Precursors

    NASA Technical Reports Server (NTRS)

    Naegeli, David W.

    1997-01-01

    The focus of this study was on the autoxidation kinetics of deposit precursor formation in jet fuels. The objectives were: (1) to demonstrate that laser-induced fluorescence is a viable kinetic tool for measuring rates of deposit precursor formation in jet fuels; (2) to determine global rate expressions for the formation of thermal deposit precursors in jet fuels; and (3) to better understand the chemical mechanism of thermal stability. The fuels were isothermally stressed in small glass ampules in the 120 to 180 C range. Concentrations of deposit precursor, hydroperoxide and oxygen consumption were measured over time in the thermally stressed fuels. Deposit precursors were measured using laser-induced fluorescence (LIF), hydroperoxides using a spectrophotometric technique, and oxygen consumption by the pressure loss in the ampule. The expressions, I.P. = 1.278 x 10(exp -11)exp(28,517.9/RT) and R(sub dp) = 2.382 x 10(exp 17)exp(-34,369.2/RT) for the induction period, I.P. and rate of deposit precursor formation R(sub dp), were determined for Jet A fuel. The results of the study support a new theory of deposit formation in jet fuels, which suggest that acid catalyzed ionic reactions compete with free radical reactions to form deposit precursors. The results indicate that deposit precursors form only when aromatics are present in the fuel. Traces of sulfur reduce the rate of autoxidation but increase the yield of deposit precursor. Free radical chemistry is responsible for hydroperoxide formation and the oxidation of sulfur compounds to sulfonic acids. Phenols are then formed by the acid catalyzed decomposition of benzylic hydroperoxides, and deposit precursors are produced by the reaction of phenols with aldehydes, which forms a polymer similar to Bakelite. Deposit precursors appear to have a phenolic resin-like structure because the LIF spectra of the deposit precursors were similar to that of phenolic resin dissolved in TAM.

  3. Experimental analysis of precursors to severe problem behavior.

    PubMed

    Fritz, Jennifer N; Iwata, Brian A; Hammond, Jennifer L; Bloom, Sarah E

    2013-01-01

    Some individuals engage in both mild and severe forms of problem behavior. Research has shown that when mild behaviors precede severe behaviors (i.e., the mild behaviors serve as precursors), they can (a) be maintained by the same source of reinforcement as severe behavior and (b) reduce rates of severe behavior observed during assessment. In Study 1, we developed an objective checklist to identify precursors via videotaped trials for 16 subjects who engaged in problem behavior and identified at least 1 precursor for every subject. In Study 2, we conducted separate functional analyses of precursor and severe problem behaviors for 8 subjects, and obtained correspondence between outcomes in 7 cases. In Study 3, we evaluated noncontingent reinforcement schedule thinning plus differential reinforcement of alternative behavior to reduce precursors, increase appropriate behavior, and maintain low rates of severe behavior during 3 treatment analyses for 2 subjects. Results showed that this treatment strategy was effective for behaviors maintained by positive and negative reinforcement. © Society for the Experimental Analysis of Behavior.

  4. Synthesis and structures of metal chalcogenide precursors

    NASA Technical Reports Server (NTRS)

    Hepp, Aloysius F.; Duraj, Stan A.; Eckles, William E.; Andras, Maria T.

    1990-01-01

    The reactivity of early transition metal sandwich complexes with sulfur-rich molecules such as dithiocarboxylic acids was studied. Researchers recently initiated work on precursors to CuInSe2 and related chalcopyrite semiconductors. Th every high radiation tolerance and the high absorption coefficient of CuInSe2 makes this material extremely attractive for lightweight space solar cells. Their general approach in early transition metal chemistry, the reaction of low-valent metal complexes or metal powders with sulfur and selenium rich compounds, was extended to the synthesis of chalcopyrite precursors. Here, the researchers describe synthesis, structures, and and routes to single molecule precursors to metal chalcogenides.

  5. Demonstrations of Deployable Systems for Robotic Precursor Missions

    NASA Technical Reports Server (NTRS)

    Dervan, J.; Johnson, L.; Lockett, T.; Carr, J.; Boyd, D.

    2017-01-01

    NASA is developing thin-film based, deployable propulsion, power, and communication systems for small spacecraft that serve as enabling technologies for exploration of the solar system. By leveraging recent advancements in thin films, photovoltaics, deployment systems, and miniaturized electronics, new mission-level capabilities will be demonstrated aboard small spacecraft enabling a new generation of frequent, inexpensive, and highly capable robotic precursor missions with goals extensible to future human exploration. Specifically, thin-film technologies are allowing the development and use of solar sails for propulsion, small, lightweight photovoltaics for power, and omnidirectional antennas for communication as demonstrated by recent advances on the Near Earth Asteroid (NEA) Scout and Lightweight Integrated Solar Array and anTenna (LISA-T) projects.

  6. In vitro and in vivo tetracycline-controlled myogenic conversion of NIH-3T3 cells: evidence of programmed cell death after muscle cell transplantation.

    PubMed

    Del Bo, R; Torrente, Y; Corti, S; D'Angelo, M G; Comi, G P; Fagiolari, G; Salani, S; Cova, A; Pisati, F; Moggio, M; Ausenda, C; Scarlato, G; Bresolin, N

    2001-01-01

    Ex vivo gene therapy of Duchenne muscular dystrophy based on autologous transplantation of genetically modified myoblasts is limited by their premature senescence. MyoD-converted fibroblasts represent an alternative source of myogenic cells. In this study the forced MyoD-dependent conversion of murine NIH-3T3 fibroblasts into myoblasts under the control of an inducible promoter silent in the presence of tetracycline was evaluated. After tetracycline withdrawal this promoter drives the transcription of MyoD in the engineered fibroblasts, inducing their myogenesis and giving rise to beta-galactosidase-positive cells. MyoD-expressing fibroblasts withdrew from the cell cycle, but were unable to fuse in vitro into multinucleated myotubes. Five days following implantation of engineered fibroblasts in muscles of C57BL/10J mice we observed a sevenfold increase of beta-galactosidase-positive regenerating myofibers in animals not treated with antibiotic compared with treated animals. After 1 week the number of positive fibers decreased and several apoptotic myonuclei were detected. Three weeks following implantation of MyoD-converted fibroblasts in recipient mice, no positive "blue" fiber was observed. Our results suggest that transactivation by tetracycline of MyoD may drive an in vivo myogenic conversion of NIH-3T3 fibroblasts and that, in this experimental setting, apoptosis plays a relevant role in limiting the efficacy of engineered fibroblast transplantation. This work opens the question whether apoptotic phenomena also play a general role as limiting factors of cell-mediated gene therapy of inherited muscle disorders.

  7. Precursors of chicken flavor. II. Identification of key flavor precursors using sensory methods.

    PubMed

    Aliani, Michel; Farmer, Linda J

    2005-08-10

    Sensory evaluation was used to identify flavor precursors that are critical for flavor development in cooked chicken. Among the potential flavor precursors studied (thiamin, inosine 5'-monophosphate, ribose, ribose-5-phosphate, glucose, and glucose-6-phosphate), ribose appears most important for chicken aroma. An elevated concentration (added or natural) of only 2-4-fold the natural concentration gives an increase in the selected aroma and flavor attributes of cooked chicken meat. Assessment of the volatile odor compounds by gas chromatography-odor assessment and gas chromatography-mass spectrometry showed that ribose increased odors described as "roasted" and "chicken" and that the changes in odor due to additional ribose are probably caused by elevated concentrations of compounds such as 2-furanmethanethiol, 2-methyl-3-furanthiol, and 3-methylthiopropanal.

  8. Production of jet fuel precursor monoterpenoids from engineered Escherichia coli: Production of Jet Fuel Precursor Monoterpenoids

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Mendez-Perez, Daniel; Alonso-Gutierrez, Jorge; Hu, Qijun

    Monoterpenes (C 10 isoprenoids) are the main components of essential oils and are possible precursors for many commodity chemicals and high energy density fuels. Monoterpenes are synthesized from geranyl diphosphate (GPP), which is also the precursor for the biosynthesis of farnesyl diphosphate (FPP). FPP biosynthesis diverts the carbon flux from monoterpene production to C 15 products and quinone biosynthesis. In this study, we tested a chromosomal mutation of Escherichia coli's native FPP synthase (IspA) to improve GPP availability for the production of monoterpenes using a heterologous mevalonate pathway. Monoterpene production at high levels required not only optimization of GPP productionmore » but also a basal level of FPP to maintain growth. The optimized strains produced two jet fuel precursor monoterpenoids 1,8-cineole and linalool at the titer of 653 mg/L and 505 mg/L, respectively, in batch cultures with 1% glucose. The engineered strains developed in this work provide useful resources for the production of high-value monoterpenes.« less

  9. Production of jet fuel precursor monoterpenoids from engineered Escherichia coli: Production of Jet Fuel Precursor Monoterpenoids

    DOE PAGES

    Mendez-Perez, Daniel; Alonso-Gutierrez, Jorge; Hu, Qijun; ...

    2017-05-18

    Monoterpenes (C 10 isoprenoids) are the main components of essential oils and are possible precursors for many commodity chemicals and high energy density fuels. Monoterpenes are synthesized from geranyl diphosphate (GPP), which is also the precursor for the biosynthesis of farnesyl diphosphate (FPP). FPP biosynthesis diverts the carbon flux from monoterpene production to C 15 products and quinone biosynthesis. In this study, we tested a chromosomal mutation of Escherichia coli's native FPP synthase (IspA) to improve GPP availability for the production of monoterpenes using a heterologous mevalonate pathway. Monoterpene production at high levels required not only optimization of GPP productionmore » but also a basal level of FPP to maintain growth. The optimized strains produced two jet fuel precursor monoterpenoids 1,8-cineole and linalool at the titer of 653 mg/L and 505 mg/L, respectively, in batch cultures with 1% glucose. The engineered strains developed in this work provide useful resources for the production of high-value monoterpenes.« less

  10. Biomineralization of a Self-assembled, Soft-Matrix Precursor: Enamel

    NASA Astrophysics Data System (ADS)

    Snead, Malcolm L.

    2015-04-01

    Enamel is the bioceramic covering of teeth, a composite tissue composed of hierarchical organized hydroxyapatite crystallites fabricated by cells under physiologic pH and temperature. Enamel material properties resist wear and fracture to serve a lifetime of chewing. Understanding the cellular and molecular mechanisms for enamel formation may allow a biology-inspired approach to material fabrication based on self-assembling proteins that control form and function. A genetic understanding of human diseases exposes insight from nature's errors by exposing critical fabrication events that can be validated experimentally and duplicated in mice using genetic engineering to phenocopy the human disease so that it can be explored in detail. This approach led to an assessment of amelogenin protein self-assembly that, when altered, disrupts fabrication of the soft enamel protein matrix. A misassembled protein matrix precursor results in loss of cell-to-matrix contacts essential to fabrication and mineralization.

  11. Systems and methods for detection of blowout precursors in combustors

    DOEpatents

    Lieuwen, Tim C.; Nair, Suraj

    2006-08-15

    The present invention comprises systems and methods for detecting flame blowout precursors in combustors. The blowout precursor detection system comprises a combustor, a pressure measuring device, and blowout precursor detection unit. A combustion controller may also be used to control combustor parameters. The methods of the present invention comprise receiving pressure data measured by an acoustic pressure measuring device, performing one or a combination of spectral analysis, statistical analysis, and wavelet analysis on received pressure data, and determining the existence of a blowout precursor based on such analyses. The spectral analysis, statistical analysis, and wavelet analysis further comprise their respective sub-methods to determine the existence of blowout precursors.

  12. Stage of perinatal development regulates skeletal muscle mitochondrial biogenesis and myogenic regulatory factor genes with little impact of growth restriction or cross-fostering.

    PubMed

    Laker, R C; Wadley, G D; McConell, G K; Wlodek, M E

    2012-02-01

    Foetal growth restriction impairs skeletal muscle development and adult muscle mitochondrial biogenesis. We hypothesized that key genes involved in muscle development and mitochondrial biogenesis would be altered following uteroplacental insufficiency in rat pups, and improving postnatal nutrition by cross-fostering would ameliorate these deficits. Bilateral uterine vessel ligation (Restricted) or sham (Control) surgery was performed on day 18 of gestation. Males and females were investigated at day 20 of gestation (E20), 1 (PN1), 7 (PN7) and 35 (PN35) days postnatally. A separate cohort of Control and Restricted pups were cross-fostered onto a different Control or Restricted mother and examined at PN7. In both sexes, peroxisome proliferator-activated receptor (PPAR)-γ coactivator-1α (PGC-1α), cytochrome c oxidase subunits 3 and 4 (COX III and IV) and myogenic regulatory factor 4 expression increased from late gestation to postnatal life, whereas mitochondrial transcription factor A, myogenic differentiation 1 (MyoD), myogenin and insulin-like growth factor I (IGF-I) decreased. Foetal growth restriction increased MyoD mRNA in females at PN7, whereas in males IGF-I mRNA was higher at E20 and PN1. Cross-fostering Restricted pups onto a Control mother significantly increased COX III mRNA in males and COX IV mRNA in both sexes above controls with little effect on other genes. Developmental age appears to be a major factor regulating skeletal muscle mitochondrial and developmental genes, with growth restriction and cross-fostering having only subtle effects. It therefore appears that reductions in adult mitochondrial biogenesis markers likely develop after weaning.

  13. Impact of static magnetic fields on human myoblast cell cultures.

    PubMed

    Stern-Straeter, Jens; Bonaterra, Gabriel Alejandro; Kassner, Stefan S; Faber, Anne; Sauter, Alexander; Schulz, Johannes D; Hörmann, Karl; Kinscherf, Ralf; Goessler, Ulrich Reinhart

    2011-12-01

    Treatment of skeletal muscle loss due to trauma or tumor ablation therapy still lacks a suitable clinical approach. Creation of functional muscle tissue in vitro using the differentiation potential of human satellite cells (myoblasts) is a promising new research field called tissue engineering. Strong differentiation stimuli, which can induce formation of myofibers after cell expansion, have to be identified and evaluated in order to create sufficient amounts of neo-tissue. The objective of this study was to determine the influence of static magnetic fields (SMF) on human satellite cell cultures as one of the preferred stem cell sources in skeletal muscle tissue engineering. Experiments were performed using human satellite cells with and without SMF stimulation after incubation with a culture medium containing low [differentiation medium (DM)] or high [growth medium (GM)] concentrations of growth factors. Proliferation analysis using the alamarBlue assay revealed no significant influence of SMF on cell division. Real-time RT-PCR of the following marker genes was investigated: myogenic factor 5 (MYF5), myogenic differentiation antigen 1 (MYOD1), myogenin (MYOG), skeletal muscle α1 actin (ACTA1), and embryonic (MYH3), perinatal (MYH8) and adult (MYH1) skeletal muscle myosin heavy chain. We detected an influence on marker gene expression by SMF in terms of a down-regulation of the marker genes in cell cultures treated with SMF and DM, but not in cell cultures treated with SMF and GM. Immunocytochemical investigations using antibodies directed against the differentiation markers confirmed the gene expression results and showed an enhancement of maturation after stimulation with GM and SMF. Additional calculation of the fusion index also revealed an increase in myotube formation in cell cultures treated with SMF and GM. Our findings show that the effect of SMF on the process of differentiation depends on the growth factor concentration in the culture medium in human

  14. Sequence-based design of bioactive small molecules that target precursor microRNAs.

    PubMed

    Velagapudi, Sai Pradeep; Gallo, Steven M; Disney, Matthew D

    2014-04-01

    Oligonucleotides are designed to target RNA using base pairing rules, but they can be hampered by poor cellular delivery and nonspecific stimulation of the immune system. Small molecules are preferred as lead drugs or probes but cannot be designed from sequence. Herein, we describe an approach termed Inforna that designs lead small molecules for RNA from solely sequence. Inforna was applied to all human microRNA hairpin precursors, and it identified bioactive small molecules that inhibit biogenesis by binding nuclease-processing sites (44% hit rate). Among 27 lead interactions, the most avid interaction is between a benzimidazole (1) and precursor microRNA-96. Compound 1 selectively inhibits biogenesis of microRNA-96, upregulating a protein target (FOXO1) and inducing apoptosis in cancer cells. Apoptosis is ablated when FOXO1 mRNA expression is knocked down by an siRNA, validating compound selectivity. Markedly, microRNA profiling shows that 1 only affects microRNA-96 biogenesis and is at least as selective as an oligonucleotide.

  15. Sequence-based design of bioactive small molecules that target precursor microRNAs

    PubMed Central

    Velagapudi, Sai Pradeep; Gallo, Steven M.; Disney, Matthew D.

    2014-01-01

    Oligonucleotides are designed to target RNA using base pairing rules, however, they are hampered by poor cellular delivery and non-specific stimulation of the immune system. Small molecules are preferred as lead drugs or probes, but cannot be designed from sequence. Herein, we describe an approach termed Inforna that designs lead small molecules for RNA from solely sequence. Inforna was applied to all human microRNA precursors and identified bioactive small molecules that inhibit biogenesis by binding to nuclease processing sites (41% hit rate). Amongst 29 lead interactions, the most avid interaction is between a benzimidazole (1) and precursor microRNA-96. Compound 1 selectively inhibits biogenesis of microRNA-96, upregulating a protein target (FOXO1) and inducing apoptosis in cancer cells. Apoptosis is ablated when FOXO1 mRNA expression is knocked down by an siRNA, validating compound selectivity. Importantly, microRNA profiling shows that 1 only significantly effects microRNA-96 biogenesis and is more selective than an oligonucleotide. PMID:24509821

  16. Evaluation of Accessory Lacrimal Gland in Muller's Muscle Conjunctival Resection Specimens for Precursor Cell Markers and Biological Markers of Dry Eye Disease.

    PubMed

    Ali, Marwan; Shah, Dhara; Pasha, Zeeshan; Jassim, Sarmad H; Jassim Jaboori, Assraa; Setabutr, Pete; Aakalu, Vinay K

    2017-04-01

    The accessory lacrimal glands (ALGs) are an understudied component of the tear functional unit, even though they are important in the development of dry eye syndrome (DES). To advance our understanding of aging changes, regenerative potential, and histologic correlates to human characteristics, we investigated human ALG tissue from surgical samples to determine the presence or absence of progenitor cell markers and lacrimal epithelial markers and to correlate marker expression to relevant patient characteristics. ALG tissues obtained from Muller's muscle conjunctival resection (MMCR) specimens were created using tissue microarrays (TMAs). Immunofluorescence staining of MMCR sections was performed using primary antibodies specific to cell protein markers. Cell marker localization in TMAs was then assessed by two blinded observers using a standardized scoring system. Patient characteristics including age, race, and status of ocular surface health were then compared against expression of stem cell markers. Human ALG expressed a number of epithelial markers, and in particular, histatin-1 was well correlated with the expression of epithelial markers and was present in most acini. In addition, we noted the presence of precursor cell markers nestin, ABCG2, and CD90 in ALG tissue. There was a decrease in precursor cell marker expression with increasing age. Finally, we noted that a negative association was present between histatin-1 expression and DES. Thus, we report for the first time that human ALG tissues contain precursor marker-positive cells and that this marker expression may decrease with increasing age. Moreover, histatin-1 expression may be decreased in DES. Future studies will be performed to use these cell markers to isolate and culture lacrimal epithelial cells from heterogeneous tissues, determine the relevance of histatin-1 expression to DES, and isolate candidate precursor cells from ALG tissue.

  17. Supramolecular Assembly of Single-Source Metal-Chalcogenide Nanocrystal Precursors.

    PubMed

    Smith, Stephanie C; Bryks, Whitney; Tao, Andrea R

    2018-05-28

    In this Feature Article, we discuss our recent work in the synthesis of novel supramolecular precursors for semiconductor nanocrystals. Metal chalcogenolates that adopt liquid crystalline phases are employed as single-source precursors that template the growth of shaped solid-state nanocrystals. Supramolecular assembly is programmed by both precursor chemical composition and molecular parameters such alkyl chain length, steric bulk, and the intercalation of halide ions. Here, we explore the various design principles that enable the rational synthesis of these single-source precursors, their liquid crystalline phases, and the various semiconductor nanocrystal products that can be generated by thermolysis, ranging from highly anisotropic two-dimensional nanosheets and nanodisks to spheres.

  18. Characterization of the Akt2 Domain Essential for Binding Nuclear p21cip1 to Promote Cell Cycle Arrest during Myogenic Differentiation

    PubMed Central

    Heron-Milhavet, Lisa; Franckhauser, Celine; Fernandez, Anne; Lamb, Ned J.

    2013-01-01

    The binding of the cdk inhibitor p21cip1 to Akt2 in the nucleus is an essential component in determining the specific role of Akt2 in the cell cycle arrest that precedes myogenic differentiation. Here, through a combination of biochemical and cell biology approaches, we have addressed the molecular basis of this binding. Using amino-terminal truncation of Akt2, we show that p21cip1 binds at the carboxy terminal of Akt2 since deletion of the first 400 amino acids did not affect the interaction between Akt2 and p21cip1. Pull down using carboxy terminal-truncated Akt2 protein revealed the importance of the region between amino acids 400 and 445 for the binding to p21cip1. Since Akt2_400–445 and Akt2_420–445 peptides could both bind p21cip1, this refines the binding domain on Akt2 between amino acids 420 and 445. In order to confirm these data in living cells, we developed a protocol to synchronize myoblasts at the cell cycle exit point when p21cip1 expression is induced by MyoD before myogenic differentiation. When a synthetic Akt2 peptide spanning the region (410–437) was microinjected in p21-expressing myoblasts, p21cip1 no longer localized exclusively in the nucleus, instead being redistributed throughout the cell, thus showing that injected peptide 410–437 acts to compete with the binding of endogenous Akt2 to p21cip1. Taken together, our data suggest that this 27 amino acid sequence on Akt2 is necessary and sufficient to bind p21cip1 both in vitro and in living cells. PMID:24194853

  19. Geoelectric precursors to strong earthquakes in China

    NASA Astrophysics Data System (ADS)

    Yulin, Zhao; Fuye, Qian

    1994-05-01

    The main results of searching for electrical precursors to strong earthquakes in China for the last 25 yr are presented. This comprises: the continuous twenty-year resistivity record before and after the great Tangshan earthquake of 1976; spatial and temporal variations in resistivity anomalies observed at more than 6 stations within 150 km of the Tangshan earthquake epicenter; the travel-time curve for the front of the resistivity precursor; and a method of intersection for predicting the epicenter location. These results reveal a number of interesting facts: (1) Resistivity measurements with accuracies of 0.5% or better for over 20 yr show that resistivity decreases of several percent, which began approximately 3 yr prior to the Tangshan earthquake, were larger than the background fluctuations and hence statistically significant. An outstanding example of an intermediate-term resistivity precursor is given. (2) The intermediate-term resistivity precursor decrease before Tangshan earthquake is such a pervasive phenomenon that the mean decrease, in percent, can be contoured on a map of the Beijing-Tianjin-Tangshan region. This shows the maximum decrease centered over the epicenter. (3) The anomalies in resistivity and self-potential, which began 2-0.5 months before the Tangshan main shock, had periods equal to that of the tidal waves M 2 and MS f, respectively, so that the associated anomalies can be identified as impending-earthquake precursors and a modal related to stress-displacement weakening is proposed.

  20. Band limited chirp stimulation in vestibular evoked myogenic potentials.

    PubMed

    Walther, Leif Erik; Cebulla, Mario

    2016-10-01

    Air conducted vestibular evoked myogenic potentials (VEMP) can be elicited by various low frequency and intense sound stimuli, mainly clicks or short tone bursts (STB). Chirp stimuli are increasingly used in diagnostic audiological evaluations as an effective means to obtain acoustically evoked responses in narrowed or extended frequency ranges. We hypothesized in this study that band limited chirp stimulation, which covers the main sensitivity range of sound sensitive otolithic afferents (around 500 Hz), might be useful for application in cervical and ocular VEMP to air conduction. For this purpose we designed a chirp stimulus ranging 250-1000 Hz (up chirp). The chirp stimulus was delivered with a stimulus intensity of 100 dB nHL in normal subjects (n = 10) and patients with otolith involvement (vestibular neuritis) (n = 6). Amplitudes of the designed chirp ("CW-VEMP-chirp, 250-1000 Hz") were compared with amplitudes of VEMPs evoked by click stimuli (0.1 ms) and a short tone burst (STB, 1-2-1, 8 ms, 500 Hz). CVEMPs and oVEMPs were detectable in 9 of 10 normal individuals. Statistical evaluation in healthy patients revealed significantly larger cVEMP and oVEMP amplitudes for CW-VEMP-chirp (250-1000 Hz) stimuli. CVEMP amplitudes evoked by CW-VEMP-chirp (250-1000 Hz) showed a high stability in comparison with click and STB stimulation. CW-VEMP-chirp (250-1000 Hz) showed abnormal cVEMP and oVEMP amplitudes in patients with vestibular neuritis, with the same properties as click and STB stimulated VEMPs. We conclude that the designed CW-VEMP-chirp (250-1000 Hz) is an effective stimulus which can be further used in VEMP diagnostic. Since a chirp stimulus can be easily varied in its properties, in particular with regard to frequency, this might be a promising tool for further investigations.

  1. Mars scientific investigations as a precursor for human exploration.

    PubMed

    Ahlf, P; Cantwell, E; Ostrach, L; Pline, A

    2000-01-01

    In the past two years, NASA has begun to develop and implement plans for investigations on robotic Mars missions which are focused toward returning data critical for planning human missions to Mars. The Mars Surveyor Program 2001 Orbiter and Lander missions will mark the first time that experiments dedicated to preparation for human exploration will be carried out. Investigations on these missions and future missions range from characterization of the physical and chemical environment of Mars, to predicting the response of biology to the Mars environment. Planning for such missions must take into account existing data from previous Mars missions which were not necessarily focused on human exploration preparation. At the same time, plans for near term missions by the international community must be considered to avoid duplication of effort. This paper reviews data requirements for human exploration and applicability of existing data. It will also describe current plans for investigations and place them within the context of related international activities. c 2000 International Astronautical Federation. Published by Elsevier Science Ltd. All rights reserved.

  2. Mars scientific investigations as a precursor for human exploration

    NASA Technical Reports Server (NTRS)

    Ahlf, P.; Cantwell, E.; Ostrach, L.; Pline, A.

    2000-01-01

    In the past two years, NASA has begun to develop and implement plans for investigations on robotic Mars missions which are focused toward returning data critical for planning human missions to Mars. The Mars Surveyor Program 2001 Orbiter and Lander missions will mark the first time that experiments dedicated to preparation for human exploration will be carried out. Investigations on these missions and future missions range from characterization of the physical and chemical environment of Mars, to predicting the response of biology to the Mars environment. Planning for such missions must take into account existing data from previous Mars missions which were not necessarily focused on human exploration preparation. At the same time, plans for near term missions by the international community must be considered to avoid duplication of effort. This paper reviews data requirements for human exploration and applicability of existing data. It will also describe current plans for investigations and place them within the context of related international activities. c 2000 International Astronautical Federation. Published by Elsevier Science Ltd. All rights reserved.

  3. The effect of preterm birth on vestibular evoked myogenic potentials in children.

    PubMed

    Eshaghi, Zahra; Jafari, Zahra; Shaibanizadeh, Abdolreza; Jalaie, Shohreh; Ghaseminejad, Azizeh

    2014-01-01

    Preterm birth is a significant global health problem with serious short- and long-term consequences. This study examined the long term effects of preterm birth on vestibular evoked myogenic potentials (VEMPs) among preschool-aged children. Thirty-one children with preterm and 20 children with term birth histories aged 5.5 to 6.5 years were studied. Each child underwent VEMPs testing using a 500 Hz tone-burst stimulus with a 95 dB nHL (normal hearing level) intensity level. The mean peak latencies of the p13 and n23 waves in the very preterm group were significantly longer than for the full-term group (p≤ 0.041). There was a significant difference between very and mildly preterm children in the latency of peak p13 (p= 0.003). No significant differences existed between groups for p13-n23 amplitude and the interaural amplitude difference ratio. The tested ear and gender did not affect the results of the test. Prolonged VEMPs in very preterm children may reflect neurodevelopmental impairment and incomplete maturity of the vestibulospinal tract (sacculocollic reflex pathway), especially myelination. VEMPs is a non-invasive technique for investigating the vestibular function in young children, and considered to be an appropriate tool for evaluating vestibular impairments at the low brainstem level. It can be used in follow-ups of the long-term effects of preterm birth on the vestibular system.

  4. Saccular function in otosclerosis patients: bone conducted-vestibular evoked myogenic potential analysis.

    PubMed

    Amali, Amin; Mahdi, Parvane; Karimi Yazdi, Alireza; Khorsandi Ashtiyani, Mohammad Taghi; Yazdani, Nasrin; Vakili, Varasteh; Pourbakht, Akram

    2014-01-01

    Vestibular involvements have long been observed in otosclerotic patients. Among vestibular structures saccule has the closest anatomical proximity to the sclerotic foci, so it is the most prone vestibular structure to be affected during the otosclerosis process. The aim of this study was to investigate the saccular function in patients suffering from otosclerosis, by means of Vestibular Evoked Myogenic Potential (VEMP). The material consisted of 30 otosclerosis patients and 20 control subjects. All participants underwent audiometric and VEMP testing. Analysis of tests results revealed that the mean values of Air-Conducted Pure Tone Average (AC-PTA) and Bone-Conducted Pure Tone Average (BC-PTA) in patients were 45.28 ± 15.57 and 19.68 ± 10.91, respectively and calculated 4 frequencies Air Bone Gap (ABG) was 25.64 ± 9.95. The VEMP response was absent in 14 (28.57%) otosclerotic ears. A statistically significant increase in latency of the p13 was found in the affected ears (P=0.004), differences in n23 latency did not reach a statistically significant level (P=0.112). Disparities in amplitude of p13-n23 in between two study groups was statistically meaningful (P=0.009), indicating that the patients with otosclerosis had lower amplitudes. This study tends to suggest that due to the direct biotoxic effect of the materials released from the otosclerosis foci on saccular receptors, there might be a possibility of vestibular dysfunction in otosclerotic patients.

  5. Characteristics of vestibular evoked myogenic potentials in children with enlarged vestibular aqueduct.

    PubMed

    Zhou, Guangwei; Gopen, Quinton

    2011-01-01

    To explore the characteristics of vestibular evoked myogenic potential (VEMP) in children with enlarged vestibular aqueduct (EVA) and to determine the diagnostic value of VEMP testing for this particular inner ear structural anomaly. Retrospective cohort study in a pediatric tertiary care facility. A total of 25 pediatric cases (37 ears) of EVA were identified with complete records, including otologic evaluation, CT scan of the temporal bone, and audiologic assessment. Results of audiometry, tympanometry, and VEMP testing were analyzed. Hearing loss was found in 97% (36/37) of the ears with EVA. Airbone gaps (conductive components) were found in all hearing losses with normal middle ear pressure and mobility. Abnormally low threshold VEMP responses were found in 92% (34/37) of the ears with EVA. VEMP responses were absent unilaterally in three EVA patients who had vestibular complaints. No clear correlation was found between the size of EVA and the audiologic findings. The presence of airbone gaps in children with EVA was found without apparent middle ear pathology. Characteristics of VEMP in EVA were lower thresholds and higher amplitudes despite of the presence of airbone gaps. The abnormally low threshold VEMP responses suggested a "third" window effect in the pathologic condition of EVA. Unilateral absence of VEMP may implicate peripheral vestibular impairment. The findings from our study are helpful in clinical evaluation of young children who usually give limited and ambiguous input regarding their hearing and vestibular problems.

  6. cGMP production of patient-specific iPSCs and photoreceptor precursor cells to treat retinal degenerative blindness

    PubMed Central

    Wiley, Luke A.; Burnight, Erin R.; DeLuca, Adam P.; Anfinson, Kristin R.; Cranston, Cathryn M.; Kaalberg, Emily E.; Penticoff, Jessica A.; Affatigato, Louisa M.; Mullins, Robert F.; Stone, Edwin M.; Tucker, Budd A.

    2016-01-01

    Immunologically-matched, induced pluripotent stem cell (iPSC)-derived photoreceptor precursor cells have the potential to restore vision to patients with retinal degenerative diseases like retinitis pigmentosa. The purpose of this study was to develop clinically-compatible methods for manufacturing photoreceptor precursor cells from adult skin in a non-profit cGMP environment. Biopsies were obtained from 35 adult patients with inherited retinal degeneration and fibroblast lines were established under ISO class 5 cGMP conditions. Patient-specific iPSCs were then generated, clonally expanded and validated. Post-mitotic photoreceptor precursor cells were generated using a stepwise cGMP-compliant 3D differentiation protocol. The recapitulation of the enhanced S-cone phenotype in retinal organoids generated from a patient with NR2E3 mutations demonstrated the fidelity of these protocols. Transplantation into immune compromised animals revealed no evidence of abnormal proliferation or tumor formation. These studies will enable clinical trials to test the safety and efficiency of patient-specific photoreceptor cell replacement in humans. PMID:27471043

  7. Application of Deep Learning to Detect Precursors of Tropical Cyclone

    NASA Astrophysics Data System (ADS)

    Matsuoka, D.; Nakano, M.; Sugiyama, D.; Uchida, S.

    2017-12-01

    Tropical cyclones (TCs) affect significant damage to human society. Predicting TC generation as soon as possible is important issue in both academic and social perspectives. In the present work, we investigate the probability of predicting TCs seven days prior using deep neural networks. The training data is produced from 30-year cloud resolving global atmospheric simulation (NICAM) with 14 km horizontal resolution (Kodama et al., 2015). We employed a TCs tracking algorithm (Sugi et al., 2002; Nakano et al., 2015) to NICAM simulation data in order to generate supervised cloud images (horizontal sizes are 800-1,000km). We generate approximately one million images of "TCs (include their precursors)" and "not TCs (low pressure clouds)". We generate ten types of image classifier based on 2-dimensional convolutional neural network, includes four convolutional layers, three pooling layers and two fully connected layers. The final predicted results are obtained by these ensemble mean values. Generated classifiers are applied to untrained global simulation data (four million test images). As a result, we succeeded in predicting the precursors of TCs seven and five days before their formation with a Recall of 88.6% and 89.6% (Precision is 11.4%), respectively.

  8. Smooth Muscle-Like Cells Generated from Human Mesenchymal Stromal Cells Display Marker Gene Expression and Electrophysiological Competence Comparable to Bladder Smooth Muscle Cells.

    PubMed

    Brun, Juliane; Lutz, Katrin A; Neumayer, Katharina M H; Klein, Gerd; Seeger, Tanja; Uynuk-Ool, Tatiana; Wörgötter, Katharina; Schmid, Sandra; Kraushaar, Udo; Guenther, Elke; Rolauffs, Bernd; Aicher, Wilhelm K; Hart, Melanie L

    2015-01-01

    The use of mesenchymal stromal cells (MSCs) differentiated toward a smooth muscle cell (SMC) phenotype may provide an alternative for investigators interested in regenerating urinary tract organs such as the bladder where autologous smooth muscle cells cannot be used or are unavailable. In this study we measured the effects of good manufacturing practice (GMP)-compliant expansion followed by myogenic differentiation of human MSCs on the expression of a range of contractile (from early to late) myogenic markers in relation to the electrophysiological parameters to assess the functional role of the differentiated MSCs and found that differentiation of MSCs associated with electrophysiological competence comparable to bladder SMCs. Within 1-2 weeks of myogenic differentiation, differentiating MSCs significantly expressed alpha smooth muscle actin (αSMA; ACTA2), transgelin (TAGLN), calponin (CNN1), and smooth muscle myosin heavy chain (SM-MHC; MYH11) according to qRT-PCR and/or immunofluorescence and Western blot. Voltage-gated Na+ current levels also increased within the same time period following myogenic differentiation. In contrast to undifferentiated MSCs, differentiated MSCs and bladder SMCs exhibited elevated cytosolic Ca2+ transients in response to K+-induced depolarization and contracted in response to K+ indicating functional maturation of differentiated MSCs. Depolarization was suppressed by Cd2+, an inhibitor of voltage-gated Ca2+-channels. The expression of Na+-channels was pharmacologically identified as the Nav1.4 subtype, while the K+ and Ca2+ ion channels were identified by gene expression of KCNMA1, CACNA1C and CACNA1H which encode for the large conductance Ca2+-activated K+ channel BKCa channels, Cav1.2 L-type Ca2+ channels and Cav3.2 T-type Ca2+ channels, respectively. This protocol may be used to differentiate adult MSCs into smooth muscle-like cells with an intermediate-to-late SMC contractile phenotype exhibiting voltage-gated ion channel

  9. Hydridosiloxanes as precursors to ceramic products

    DOEpatents

    Blum, Yigal D.; Johnson, Sylvia M.; Gusman, Michael I.

    1997-01-01

    A method is provided for preparing ceramic precursors from hydridosiloxane starting materials and then pyrolyzing these precursors to give rise to silicious ceramic materials. Si--H bonds present in the hydridosiloxane starting materials are catalytically activated, and the activated hydrogen atoms may then be replaced with nonhydrogen substituents. These preceramic materials are pyrolyzed in a selected atmosphere to give the desired ceramic product. Ceramic products which may be prepared by this technique include silica, silicon oxynitride, silicon carbide, metal silicates, and mullite.

  10. Hydridosiloxanes as precursors to ceramic products

    DOEpatents

    Blum, Y.D.; Johnson, S.M.; Gusman, M.I.

    1997-06-03

    A method is provided for preparing ceramic precursors from hydridosiloxane starting materials and then pyrolyzing these precursors to give rise to silicious ceramic materials. Si-H bonds present in the hydridosiloxane starting materials are catalytically activated, and the activated hydrogen atoms may then be replaced with nonhydrogen substituents. These preceramic materials are pyrolyzed in a selected atmosphere to give the desired ceramic product. Ceramic products which may be prepared by this technique include silica, silicon oxynitride, silicon carbide, metal silicates, and mullite.

  11. Kaempferol increases levels of coenzyme Q in kidney cells and serves as a biosynthetic ring precursor.

    PubMed

    Fernández-Del-Río, Lucía; Nag, Anish; Gutiérrez Casado, Elena; Ariza, Julia; Awad, Agape M; Joseph, Akil I; Kwon, Ohyun; Verdin, Eric; de Cabo, Rafael; Schneider, Claus; Torres, Jorge Z; Burón, María I; Clarke, Catherine F; Villalba, José M

    2017-09-01

    Coenzyme Q (Q) is a lipid-soluble antioxidant essential in cellular physiology. Patients with Q deficiencies, with few exceptions, seldom respond to treatment. Current therapies rely on dietary supplementation with Q 10 , but due to its highly lipophilic nature, Q 10 is difficult to absorb by tissues and cells. Plant polyphenols, present in the human diet, are redox active and modulate numerous cellular pathways. In the present study, we tested whether treatment with polyphenols affected the content or biosynthesis of Q. Mouse kidney proximal tubule epithelial (Tkpts) cells and human embryonic kidney cells 293 (HEK 293) were treated with several types of polyphenols, and kaempferol produced the largest increase in Q levels. Experiments with stable isotope 13 C-labeled kaempferol demonstrated a previously unrecognized role of kaempferol as an aromatic ring precursor in Q biosynthesis. Investigations of the structure-function relationship of related flavonols showed the importance of two hydroxyl groups, located at C3 of the C ring and C4' of the B ring, both present in kaempferol, as important determinants of kaempferol as a Q biosynthetic precursor. Concurrently, through a mechanism not related to the enhancement of Q biosynthesis, kaempferol also augmented mitochondrial localization of Sirt3. The role of kaempferol as a precursor that increases Q levels, combined with its ability to upregulate Sirt3, identify kaempferol as a potential candidate in the design of interventions aimed on increasing endogenous Q biosynthesis, particularly in kidney. Copyright © 2017 Elsevier Inc. All rights reserved.

  12. Observation of a Hydrodynamically Driven, Radiative Precursor Shock

    NASA Astrophysics Data System (ADS)

    Keiter, P. A.; Drake, R. P.; Perry, T. S.; Robey, H.; Remington, B. A.; Iglesias, C. A.; Turner, N.; Stone, J.; Knauer, J.

    2001-10-01

    Many astrophysical systems, such as supernova remnants and jets, produce radiative-precursor shock waves. In a radiative-precursor shock, radiation from the shock ionizes and heats the medium ahead of it. The simulation of such systems requires that one treat both the emission and the absorption of the radiation. An important goal of this effort is to produce an experiment that can be modeled by astrophysical codes without implementing laser absorption physics into an astrophysical code. We report here the first measurements of a radiative-precursor shock in such an experiment. The experimental design is based on a past experiment[1,2] that used the Nova laser facility to simulate young supernova remnants. The target consists of a 60 νm CH plastic plug followed by a 150 νm vacuum gap and 2 mm of SiO2 aerogel foam. For the experiment, the density of the components and the laser-irradiation conditions are chosen so that the driven shock will produce an observable radiative precursor. We observed the radiative-precursor by using absorption spectroscopy. By backlighting the silicate aerogel foam with a thulium backlighter, we were able to observe both the 1s-2p and 1s-3p lines. These observations will allow us to determine the temperature profile in the precursor. 1. R.P. Drake, et al, Phys. Rev. Lett. 81, 2068 (1998). 2. R.P. Drake, et al., Phys. Plasmas, 7, 2142 (2000) Work supported by the U.S. Department of Energy both directly and through the Lawrence Livermore National Laboratory

  13. [Effect of the middle ear status on the recording of vestibular evoked myogenic potential--VEMP].

    PubMed

    Kurzyna, Agnieszka; Hassmann-Poznańska, Elzbieta; Topolska, Małgorzata Maria

    2005-01-01

    The aim of this study was to assess the effect of the middle ear status on the recording of air- and bone-conducted vestibular evoked myogenic potential. Forty eight children were included in the study, ranging in age from 4 to 10 years. All of the children underwent otoscopy, pure tone audiometry, tympanometry and air- and bone-conducted VEMP in response to click. There were 3 groups according to the condition of the middle ear: group I--52 ears (type A and C1 tympanogram, pure tone average < or = 20 dB), group II--23 ears (type C2 and B tympanogram, pure tone average < or = 20 dB), group III--21 (type B tympanogram, pure tone average > 20 dB). The threshold, presence of correct waveform morphology of the response and latency was evaluated. The condition of the middle ear has no significant effect on the recording of VEMP and mean level of the response threshold with bone stimulation, based on the performed studies. However, with air stimulation it has effect on the recording of VEMP, increase of the mean threshold response and shortening of latency p13 and n23.

  14. Distinct cortical and sub-cortical neurogenic domains for GABAergic interneuron precursor transcription factors NKX2.1, OLIG2 and COUP-TFII in early fetal human telencephalon.

    PubMed

    Alzu'bi, Ayman; Lindsay, Susan; Kerwin, Janet; Looi, Shi Jie; Khalil, Fareha; Clowry, Gavin J

    2017-07-01

    The extent of similarities and differences between cortical GABAergic interneuron generation in rodent and primate telencephalon remains contentious. We examined expression of three interneuron precursor transcription factors, alongside other markers, using immunohistochemistry on 8-12 post-conceptional weeks (PCW) human telencephalon sections. NKX2.1, OLIG2, and COUP-TFII expression occupied distinct (although overlapping) neurogenic domains which extended into the cortex and revealed three CGE compartments: lateral, medial, and ventral. NKX2.1 expression was very largely confined to the MGE, medial CGE, and ventral septum confirming that, at this developmental stage, interneuron generation from NKX2.1+ precursors closely resembles the process observed in rodents. OLIG2 immunoreactivity was observed in GABAergic cells of the proliferative zones of the MGE and septum, but not necessarily co-expressed with NKX2.1, and OLIG2 expression was also extensively seen in the LGE, CGE, and cortex. At 8 PCW, OLIG2+ cells were only present in the medial and anterior cortical wall suggesting a migratory pathway for interneuron precursors via the septum into the medial cortex. By 12 PCW, OLIG2+ cells were present throughout the cortex and many were actively dividing but without co-expressing cortical progenitor markers. Dividing COUP-TFII+ progenitor cells were localized to ventral CGE as previously described but were also numerous in adjacent ventral cortex; in both the cases, COUP-TFII was co-expressed with PAX6 in proliferative zones and TBR1 or calretinin in post-mitotic cortical neurons. Thus COUP-TFII+ progenitors gave rise to pyramidal cells, but also interneurons which not only migrated posteriorly into the cortex from ventral CGE but also anteriorly via the LGE.

  15. 40 CFR 93.164 - Inter-precursor mitigation measures and offsets.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 40 Protection of Environment 20 2011-07-01 2011-07-01 false Inter-precursor mitigation measures... § 93.164 Inter-precursor mitigation measures and offsets. Federal agencies must reduce the same type of... mitigation measures of different precursors of the same criteria pollutant, if such trades are allowed by a...

  16. 40 CFR 93.164 - Inter-precursor mitigation measures and offsets.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 20 2010-07-01 2010-07-01 false Inter-precursor mitigation measures... § 93.164 Inter-precursor mitigation measures and offsets. Federal agencies must reduce the same type of... mitigation measures of different precursors of the same criteria pollutant, if such trades are allowed by a...

  17. 40 CFR 93.164 - Inter-precursor mitigation measures and offsets.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 21 2012-07-01 2012-07-01 false Inter-precursor mitigation measures... § 93.164 Inter-precursor mitigation measures and offsets. Federal agencies must reduce the same type of... mitigation measures of different precursors of the same criteria pollutant, if such trades are allowed by a...

  18. 40 CFR 93.164 - Inter-precursor mitigation measures and offsets.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 40 Protection of Environment 21 2013-07-01 2013-07-01 false Inter-precursor mitigation measures... § 93.164 Inter-precursor mitigation measures and offsets. Federal agencies must reduce the same type of... mitigation measures of different precursors of the same criteria pollutant, if such trades are allowed by a...

  19. Predicting Solar Cycle 24 Using a Geomagnetic Precursor Pair

    NASA Technical Reports Server (NTRS)

    Pesnell, W. Dean

    2014-01-01

    We describe using Ap and F(10.7) as a geomagnetic-precursor pair to predict the amplitude of Solar Cycle 24. The precursor is created by using F(10.7) to remove the direct solar-activity component of Ap. Four peaks are seen in the precursor function during the decline of Solar Cycle 23. A recurrence index that is generated by a local correlation of Ap is then used to determine which peak is the correct precursor. The earliest peak is the most prominent but coincides with high levels of non-recurrent solar activity associated with the intense solar activity of October and November 2003. The second and third peaks coincide with some recurrent activity on the Sun and show that a weak cycle precursor closely following a period of strong solar activity may be difficult to resolve. A fourth peak, which appears in early 2008 and has recurrent activity similar to precursors of earlier solar cycles, appears to be the "true" precursor peak for Solar Cycle 24 and predicts the smallest amplitude for Solar Cycle 24. To determine the timing of peak activity it is noted that the average time between the precursor peak and the following maximum is approximately equal to 6.4 years. Hence, Solar Cycle 24 would peak during 2014. Several effects contribute to the smaller prediction when compared with other geomagnetic-precursor predictions. During Solar Cycle 23 the correlation between sunspot number and F(10.7) shows that F(10.7) is higher than the equivalent sunspot number over most of the cycle, implying that the sunspot number underestimates the solar-activity component described by F(10.7). During 2003 the correlation between aa and Ap shows that aa is 10 % higher than the value predicted from Ap, leading to an overestimate of the aa precursor for that year. However, the most important difference is the lack of recurrent activity in the first three peaks and the presence of significant recurrent activity in the fourth. While the prediction is for an amplitude of Solar Cycle 24 of

  20. High Tc superconducting films from metallo-organic precursors

    NASA Astrophysics Data System (ADS)

    Davison, W. W.; Shyu, S. G.; Buchanan, R. C.

    High Tc superconducting films of heavy metal soaps (derived from carboxylic acid precursors) have been prepared on Si and other substrates. The precursors were synthesized and mixed in appropriate molar ratios to form the high Tc compound YBa2Cu3O(7-x), using a high boiling point common solvent base. The precursor solution was deposited by a spin casting technique on the substrates. Film thicknesses of 0.1-1.0 micron were achieved after heat treatment at 550-850 C at not longer than 4 hours. Films were analyzed as to orientation, appropriate phase, interfacial reaction, and superconducting properties.

  1. Temporal analysis of reciprocal miRNA-mRNA expression patterns predicts regulatory networks during differentiation in human skeletal muscle cells

    PubMed Central

    Sjögren, Rasmus J. O.; Egan, Brendan; Katayama, Mutsumi; Zierath, Juleen R.

    2014-01-01

    microRNAs (miRNAs) are short noncoding RNAs that regulate gene expression through posttranscriptional repression of target genes. miRNAs exert a fundamental level of control over many developmental processes, but their role in the differentiation and development of skeletal muscle from myogenic progenitor cells in humans remains incompletely understood. Using primary cultures established from human skeletal muscle satellite cells, we performed microarray profiling of miRNA expression during differentiation of myoblasts (day 0) into myotubes at 48 h intervals (day 2, 4, 6, 8, and 10). Based on a time-course analysis, we identified 44 miRNAs with altered expression [false discovery rate (FDR) < 5%, fold change > ±1.2] during differentiation, including the marked upregulation of the canonical myogenic miRNAs miR-1, miR-133a, miR-133b, and miR-206. Microarray profiling of mRNA expression at day 0, 4, and 10 identified 842 and 949 genes differentially expressed (FDR < 10%) at day 4 and 10, respectively. At day 10, 42% of altered transcripts demonstrated reciprocal expression patterns in relation to the directional change of their in silico predicted regulatory miRNAs based on analysis using Ingenuity Pathway Analysis microRNA Target Filter. Bioinformatic analysis predicted networks of regulation during differentiation including myomiRs miR-1/206 and miR-133a/b, miRNAs previously established in differentiation including miR-26 and miR-30, and novel miRNAs regulated during differentiation of human skeletal muscle cells such as miR-138-5p and miR-20a. These reciprocal expression patterns may represent new regulatory nodes in human skeletal muscle cell differentiation. This analysis serves as a reference point for future studies of human skeletal muscle differentiation and development in healthy and disease states. PMID:25547110

  2. Thin HTSC films produced by a polymer metal precursor technique

    NASA Astrophysics Data System (ADS)

    Lampe, L. v.; Zygalsky, F.; Hinrichsen, G.

    In precursors the metal ions are combined with acid groups of polymethacrylic acid (PMAA), polyacrylic acid (PAA) or novolac. Compared to thermal degradation temperature of pure polymers those of precursors are low. Precursors films were patterned by UV lithography. Diffractometric investigations showed that the c-axis oriented epitaxial films of YBa 2Cu 3O x and Bi 2Sr 2CaCu 2O x originated from amorphous metal oxide films, which were received after thermal degradation of the precursor. Transition temperatures and current densities were determined by electric resistivity measurements.

  3. Evaluation of Accessory Lacrimal Gland in Muller’s Muscle Conjunctival Resection Specimens for Precursor Cell Markers and Biological Markers of Dry Eye Disease

    PubMed Central

    Ali, Marwan; Shah, Dhara; Pasha, Zeeshan; Jassim, Sarmad H.; Jaboori, Assraa Jassim; Setabutr, Pete; Aakalu, Vinay K.

    2017-01-01

    Purpose The accessory lacrimal glands (ALG) are an understudied component of the tear functional unit, even though they are important in the development of dry eye syndrome (DES). To advance our understanding of aging changes, regenerative potential and histologic correlates to human characteristics, we investigated human ALG tissue from surgical samples to determine the presence or absence of progenitor cell markers and lacrimal epithelial markers and to correlate marker expression to relevant patient characteristics. Materials and Methods ALG tissues obtained from Muller’s Muscle Conjunctival Resection (MMCR) specimens were created using tissue microarrays (TMAs). Immunofluorescence staining of MMCR sections was performed using primary antibodies specific to cell protein markers. Cell marker localization in TMAs was then assessed by two blinded observers using a standardized scoring system. Patient characteristics including age, race, and status of ocular surface health were then compared against expression of stem cell markers. Results Human ALG expressed a number of epithelial markers, and in particular, histatin-1 was well correlated with the expression of epithelial markers and was present in most acini. In addition, we noted the presence of precursor cell markers nestin, ABCG2 and CD90 in ALG tissue. There was a decrease in precursor cell marker expression with increasing age. Finally, we noted that a negative association was present between histatin-1 expression and DES. Conclusions Thus, we report for the first time that human ALG tissues contain precursor marker positive cells and that this marker expression may decrease with increasing age. Moreover, histatin-1 expression may be decreased in DES. Future studies will be performed to use these cell markers to isolate and culture lacrimal epithelial cells from heterogeneous tissues, determine the relevance of histatin-1 expression to DES and isolate candidate precursor cells from ALG tissue. PMID:27612554

  4. The EM Earthquake Precursor

    NASA Astrophysics Data System (ADS)

    Jones, K. B., II; Saxton, P. T.

    2013-12-01

    Many attempts have been made to determine a sound forecasting method regarding earthquakes and warn the public in turn. Presently, the animal kingdom leads the precursor list alluding to a transmission related source. By applying the animal-based model to an electromagnetic (EM) wave model, various hypotheses were formed, but the most interesting one required the use of a magnetometer with a differing design and geometry. To date, numerous, high-end magnetometers have been in use in close proximity to fault zones for potential earthquake forecasting; however, something is still amiss. The problem still resides with what exactly is forecastable and the investigating direction of EM. After the 1989 Loma Prieta Earthquake, American earthquake investigators predetermined magnetometer use and a minimum earthquake magnitude necessary for EM detection. This action was set in motion, due to the extensive damage incurred and public outrage concerning earthquake forecasting; however, the magnetometers employed, grounded or buried, are completely subject to static and electric fields and have yet to correlate to an identifiable precursor. Secondly, there is neither a networked array for finding any epicentral locations, nor have there been any attempts to find even one. This methodology needs dismissal, because it is overly complicated, subject to continuous change, and provides no response time. As for the minimum magnitude threshold, which was set at M5, this is simply higher than what modern technological advances have gained. Detection can now be achieved at approximately M1, which greatly improves forecasting chances. A propagating precursor has now been detected in both the field and laboratory. Field antenna testing conducted outside the NE Texas town of Timpson in February, 2013, detected three strong EM sources along with numerous weaker signals. The antenna had mobility, and observations were noted for recurrence, duration, and frequency response. Next, two

  5. Notched-noise precursors improve detection of low-frequency amplitude modulationa)

    PubMed Central

    Almishaal, Ali; Bidelman, Gavin M.; Jennings, Skyler G.

    2017-01-01

    Amplitude modulation (AM) detection was measured with a short (50 ms), high-frequency carrier as a function of carrier level (Experiment I) and modulation frequency (Experiment II) for conditions with or without a notched-noise precursor. A longer carrier (500 ms) was also included in Experiment I. When the carrier was preceded by silence (no precursor condition) AM detection thresholds worsened for moderate-level carriers compared to lower- or higher-level carriers, resulting in a “mid-level hump.” AM detection thresholds with a precursor were better than those without a precursor, primarily for moderate-to-high level carriers, thus eliminating the mid-level hump in AM detection. When the carrier was 500 ms, AM thresholds improved by a constant (across all levels) relative to AM thresholds with a precursor, consistent with the longer carrier providing more “looks” to detect the AM signal. Experiment II revealed that improved AM detection with compared to without a precursor is limited to low-modulation frequencies (<60 Hz). These results are consistent with (1) a reduction in cochlear gain over the course of the precursor perhaps via the medial olivocochlear reflex or (2) a form of perceptual enhancement which may be mediated by adaptation of inhibition. PMID:28147582

  6. Inhibitory effects of silodosin on the bladder mechanosensitive afferent activities and their relation with bladder myogenic contractions in male rats with bladder outlet obstruction.

    PubMed

    Aizawa, Naoki; Watanabe, Daiji; Fukuhara, Hiroshi; Fujimura, Tetsuya; Kume, Haruki; Homma, Yukio; Igawa, Yasuhiko

    2018-03-06

    We investigated the effects of silodosin, an α1A-adrenoceptor (AR) antagonist, on bladder function, especially on non-voiding contractions (NVCs), in a male rat model of bladder outlet obstruction (BOO) by evaluating cystometry (CMG) findings and bladder mechanosensitive single-unit afferent activities (SAAs), related with microcontractions, which may be similar with NVCs and to be of myogenic origin, in the rat model. BOO was created by partial ligation of the posterior urethra. At 4 days after surgery for BOO, an osmotic pump filled with silodosin (0.12 mg/kg/day) or its vehicle was subcutaneously implanted. At 10 days after surgery, CMG and SAAs measurements were taken under conscious and urethane-anesthetized conditions, respectively. The SAAs of Aδ- and C-fibers, which were identified by electrical stimulation of the pelvic nerve and by bladder distention, and intravesical pressure were recorded during constant bladder-filling with saline. Microcontractions were divided into three phases: "ascending," "descending," and "stationary." The silodosin-treated group showed a smaller number of NVCs in CMG measurements and lower SAAs of both Aδ- and C-fibers than the vehicle-treated group during bladder-filling. Moreover, in the vehicle-treated groups, the SAAs of both fibers for the ascending phase of microcontractions were significantly higher than those for the other two phases. On the contrary, no significant change was found between any of these three phases in the silodosin-treated group. The present results suggest that silodosin inhibits the SAAs of mechanosensitive Aδ- and C-fibers at least partly due to suppressing myogenic bladder contractions in male BOO rats. © 2018 Wiley Periodicals, Inc.

  7. Osteogenic differentiation capacity of human skeletal muscle-derived progenitor cells.

    PubMed

    Oishi, Teruyo; Uezumi, Akiyoshi; Kanaji, Arihiko; Yamamoto, Naoki; Yamaguchi, Asami; Yamada, Harumoto; Tsuchida, Kunihiro

    2013-01-01

    Heterotopic ossification (HO) is defined as the formation of ectopic bone in soft tissue outside the skeletal tissue. HO is thought to result from aberrant differentiation of osteogenic progenitors within skeletal muscle. However, the precise origin of HO is still unclear. Skeletal muscle contains two kinds of progenitor cells, myogenic progenitors and mesenchymal progenitors. Myogenic and mesenchymal progenitors in human skeletal muscle can be identified as CD56(+) and PDGFRα(+) cells, respectively. The purpose of this study was to investigate the osteogenic differentiation potential of human skeletal muscle-derived progenitors. Both CD56(+) cells and PDGFRα(+) cells showed comparable osteogenic differentiation potential in vitro. However, in an in vivo ectopic bone formation model, PDGFRα(+) cells formed bone-like tissue and showed successful engraftment, while CD56(+) cells did not form bone-like tissue and did not adapt to an osteogenic environment. Immunohistological analysis of human HO sample revealed that many PDGFRα(+) cells were localized in proximity to ectopic bone formed in skeletal muscle. MicroRNAs (miRNAs) are known to regulate many biological processes including osteogenic differentiation. We investigated the participation of miRNAs in the osteogenic differentiation of PDGFRα(+) cells by using microarray. We identified miRNAs that had not been known to be involved in osteogenesis but showed dramatic changes during osteogenic differentiation of PDGFRα(+) cells. Upregulation of miR-146b-5p and -424 and downregulation of miR-7 during osteogenic differentiation of PDGFRα(+) cells were confirmed by quantitative real-time RT-PCR. Inhibition of upregulated miRNAs, miR-146b-5p and -424, resulted in the suppression of osteocyte maturation, suggesting that these two miRNAs have the positive role in the osteogenesis of PDGFRα(+) cells. Our results suggest that PDGFRα(+) cells may be the major source of HO and that the newly identified miRNAs may

  8. Microbial degradation of plant leachate alters lignin phenols and trihalomethane precursors

    USGS Publications Warehouse

    Pellerin, Brian A.; Hernes, Peter J.; Saraceno, John Franco; Spencer, Robert G.M.; Bergamaschi, Brian A.

    2010-01-01

    Although the importance of vascular plant-derived dissolved organic carbon (DOC) in freshwater systems has been studied, the role of leached DOC as precursors of disinfection byproducts (DBPs) during drinking water treatment is not well known. Here we measured the propensity of leachates from four crops and four aquatic macrophytes to form trihalomethanes (THMs)—a regulated class of DBPs—before and after 21 d of microbial degradation. We also measured lignin phenol content and specific UV absorbance (SUVA254) to test the assumption that aromatic compounds from vascular plants are resistant to microbial degradation and readily form DBPs. Leaching solubilized 9 to 26% of total plant carbon, which formed 1.93 to 6.72 mmol THM mol C-1 However, leachate DOC concentrations decreased by 85 to 92% over the 21-d incubation, with a concomitant decrease of 67 to 92% in total THM formation potential. Carbon-normalized THM yields in the residual DOC pool increased by 2.5 times on average, consistent with the preferential uptake of nonprecursor material. Lignin phenol concentrations decreased by 64 to 96% over 21 d, but a lack of correlation between lignin content and THM yields or SUVA254 suggested that lignin-derived compounds are not the source of increased THM precursor yields in the residual DOC pool. Our results indicate that microbial carbon utilization alters THM precursors in ecosystems with direct plant leaching, but more work is needed to identify the specific dissolved organic matter components with a greater propensity to form DBPs and affect watershed management, drinking water quality, and human health.

  9. Early expression of triggering receptors and regulatory role of 2B4 in human natural killer cell precursors undergoing in vitro differentiation

    PubMed Central

    Sivori, Simona; Falco, Michela; Marcenaro, Emanuela; Parolini, Silvia; Biassoni, Roberto; Bottino, Cristina; Moretta, Lorenzo; Moretta, Alessandro

    2002-01-01

    In this study we analyzed the progression of cell surface receptor expression during the in vitro-induced human natural killer (NK) cell maturation from CD34+ Lin− cell precursors. NKp46 and NKp30, two major triggering receptors that play a central role in natural cytotoxicity, were expressed before the HLA class I-specific inhibitory receptors. Moreover, their appearance at the cell surface correlated with the acquisition of cytolytic activity by developing NK cells. Although the early expression of triggering receptors may provide activating signals required for inducing further cell differentiation, it may also affect the self-tolerance of developing NK cells. Our data show that a fail-safe mechanism preventing killing of normal autologous cells may be provided by the 2B4 surface molecule, which, at early stages of NK cell differentiation, functions as an inhibitory rather than as an activating receptor. PMID:11917118

  10. Precursors of Halobenzoquinones and Their Removal During Drinking Water Treatment Processes.

    PubMed

    Wang, Wei; Qian, Yichao; Jmaiff, Lindsay K; Krasner, Stuart W; Hrudey, Steve E; Li, Xing-Fang

    2015-08-18

    Halobenzoquinones (HBQs) widely occur in drinking water treatment plant (DWTP) effluents; however, HBQ precursors and their removal by treatments remain unclear. Thus, we have investigated HBQ precursors in plant influents and their removal by each treatment before chlorination in nine DWTPs. The levels of HBQ precursors were determined using formation potential (FP) tests for 2,6-dichloro-1,4-benzoquinone (DCBQ), 2,3,6-trichloro-1,4-benzoquinone (TCBQ), 2,6-dichloro-3-methyl-1,4-benzoquinone (DCMBQ), and 2,6-dibromo-1,4-benzoquinone (DBBQ). HBQ precursors were present in all plant influents. DCBQ precursors were the most abundant (DCBQ FP up to 205 ng/L). Coagulation removed dissolved organic carbon (DOC) (up to 56%) and HBQ precursors (up to 39% for DCBQ). The level of removal of DOC was significantly greater than the level of removal of HBQ FP, suggesting that organic matter removed by coagulation had a high proportion of non-HBQ-precursor material. Granular activated carbon (GAC) decreased the level of HBQ FPs by 10-20%, where DOC removal was only 0.2-4.7%, suggesting that the GAC was not in the adsorption mode and biodegradation of HBQ precursors may have been occurring. Ozonation destroyed/transformed HBQ FPs by 10-30%, whereas anthracite/sand filtration and UV irradiation appeared to have no impact. The results demonstrated that the combined treatments did not substantially reduce HBQ precursor levels in water.

  11. Natural attenuation of NDMA precursors in an urban, wastewater-dominated wash.

    PubMed

    Woods, Gwen C; Dickenson, Eric R V

    2016-02-01

    N-Nitrosodimethylamine (NDMA) is a disinfection by-product (DBP) that is potentially carcinogenic and has been found to occur in drinking water treatment systems impacted with treated wastewater. A major gap in NDMA research is an understanding of the persistence of wastewater-derived precursors within the natural environment. This research sought to fill this knowledge gap by surveying NDMA precursors across the length of a wastewater effluent-dominated wash. Significant precursor reduction (17%) was found to occur from introduction into the wash to a point 9 h downstream. This reduction translates into a half-life of roughly 32 h for bulk NDMA precursors. Further laboratory experiments examining rates of photolysis, biodegradation and loss to sediments, illustrated that both photolytic and biological degradation were effective removal mechanisms for NDMA precursors. Loss to sediments that were acquired from the wash did not appear to reduce NDMA precursors in the water column, although a control conducted with DI water provided evidence that significant NDMA precursors could be released from autoclaved sediments (suggesting that sorption does occur). Microbial experiments revealed that microbes associated with sediments were much more effective at degrading precursors than microbes within the water column. Overall, this study demonstrated that natural processes are capable of attenuating NDMA precursors relatively quickly within the environment, and that utilities might benefit from maximizing source water residency time in the environment, prior to introduction into treatment plants. Copyright © 2015 Elsevier Ltd. All rights reserved.

  12. Analysis of Precursor Properties of mixed Al/Alumel Cylindrical Wire Arrays*

    NASA Astrophysics Data System (ADS)

    Stafford, A.; Safronova, A. S.; Kantsyrev, V. L.; Esaulov, A. A.; Weller, M. E.; Shrestha, I.; Osborne, G. C.; Shlyaptseva, V. V.; Keim, S. F.; Coverdale, C. A.; Chuvatin, A. S.

    2012-10-01

    Previous studies of mid-Z (Cu and Ni) cylindrical wire arrays (CWAs) on Zebra have found precursors with high electron temperatures of >300 eV. However, past experiments with Al CWAs did not find the same high temperature precursors. New precursor experiments using mixed Al/Alumel (Ni 95%, Si 2%, and Al 2%) cylindrical wire arrays have been performed to understand how the properties of L-shell Ni precursor will change and whether Al precursor will be observed. Time gated spectra and pinholes are used to determine precursor plasma conditions for comparison with previous Alumel precursor experiments. A full diagnostic set which included more than ten different beam-lines was implemented. Future work in this direction is discussed. [4pt] *This work was supported by NNSA under DOE Cooperative Agreements DE-FC52-06NA27588, and in part by DE-FC52-06NA27586, and DE-FC52-06NA27616. Sandia is a multi-program laboratory operated by Sandia Corporation, a Lockheed Martin Company, for the United States Department of Energy under Contract DE-AC04-94AL85000.

  13. Methods for forming particles from single source precursors

    DOEpatents

    Fox, Robert V [Idaho Falls, ID; Rodriguez, Rene G [Pocatello, ID; Pak, Joshua [Pocatello, ID

    2011-08-23

    Single source precursors are subjected to carbon dioxide to form particles of material. The carbon dioxide may be in a supercritical state. Single source precursors also may be subjected to supercritical fluids other than supercritical carbon dioxide to form particles of material. The methods may be used to form nanoparticles. In some embodiments, the methods are used to form chalcopyrite materials. Devices such as, for example, semiconductor devices may be fabricated that include such particles. Methods of forming semiconductor devices include subjecting single source precursors to carbon dioxide to form particles of semiconductor material, and establishing electrical contact between the particles and an electrode.

  14. Subcellular Distribution of Glutathione Precursors in Arabidopsis thaliana

    PubMed Central

    Koffler, Barbara Eva; Maier, Romana; Zechmann, Bernd

    2011-01-01

    Abstract Glutathione is an important antioxidant and has many important functions in plant development, growth and defense. Glutathione synthesis and degradation is highly compartment-specific and relies on the subcellular availability of its precursors, cysteine, glutamate, glycine and γ-glutamylcysteine especially in plastids and the cytosol which are considered as the main centers for glutathione synthesis. The availability of glutathione precursors within these cell compartments is therefore of great importance for successful plant development and defense. The aim of this study was to investigate the compartment-specific importance of glutathione precursors in Arabidopsis thaliana. The subcellular distribution was compared between wild type plants (Col-0), plants with impaired glutathione synthesis (glutathione deficient pad2-1 mutant, wild type plants treated with buthionine sulfoximine), and one complemented line (OE3) with restored glutathione synthesis. Immunocytohistochemistry revealed that the inhibition of glutathione synthesis induced the accumulation of the glutathione precursors cysteine, glutamate and glycine in most cell compartments including plastids and the cytosol. A strong decrease could be observed in γ-glutamylcysteine (γ-EC) contents in these cell compartments. These experiments demonstrated that the inhibition of γ-glutamylcysteine synthetase (GSH1) – the first enzyme of glutathione synthesis – causes a reduction of γ-EC levels and an accumulation of all other glutathione precursors within the cells. PMID:22050910

  15. Isolation of pheromone precursor genes of Magnaporthe grisea.

    PubMed

    Shen, W C; Bobrowicz, P; Ebbole, D J

    1999-01-01

    In heterothallic ascomycetes one mating partner serves as the source of female tissue and is fertilized with spermatia from a partner of the opposite mating type. The role of pheromone signaling in mating is thought to involve recognition of cells of the opposite mating type. We have isolated two putative pheromone precursor genes of Magnaporthe grisea. The genes are present in both mating types of the fungus but they are expressed in a mating type-specific manner. The MF1-1 gene, expressed in Mat1-1 strains, is predicted to encode a 26-amino-acid polypeptide that is processed to produce a lipopeptide pheromone. The MF2-1 gene, expressed in Mat1-2 strains, is predicted to encode a precursor polypeptide that is processed by a Kex2-like protease to yield a pheromone with striking similarity to the predicted pheromone sequence of a close relative, Cryphonectria parasitica. Expression of the M. grisea putative pheromone precursor genes was observed under defined nutritional conditions and in field isolates. This suggests that the requirement for complex media for mating and the poor fertility of field isolates may not be due to limitation of pheromone precursor gene expression. Detection of putative pheromone precursor gene mRNA in conidia suggests that pheromones may be important for the fertility of conidia acting as spermatia. Copyright 1999 Academic Press.

  16. Differential expression of FGF receptors and of myogenic regulatory factors in primary cultures of satellite cells originating from fast (EDL) and slow (Soleus) twitch rat muscles.

    PubMed

    Martelly, I; Soulet, L; Bonnavaud, S; Cebrian, J; Gautron, J; Barritault, D

    2000-11-01

    In the rat, the fast and slow twitch muscles respectively Extensor digitorum longus (EDL) and Soleus present differential characteristics during regeneration. This suggests that their satellite cells responsible for muscle growth and repair represent distinct cellular populations. We have previously shown that satellite cells dissociated from Soleus and grown in vitro proliferate more readily than those isolated from EDL muscle. Fibroblast growth factors (FGFs) are known as regulators of myoblast proliferation and several studies have revealed a relationship between the response of myoblasts to FGF and the expression of myogenic regulatory factors (MRF) of the MyoD family by myoblasts. Therefore, we presently examined the possibility that the satellite cells isolated from EDL and Soleus muscles differ in the expression of FGF receptors (FGF-R) and of MRF expression. FGF-R1 and -R4 were strongly expressed in proliferating cultures whereas FGF-R2 and R3 were not detected in these cultures. In differentiating cultures, only -R1 was present in EDL satellite cells while FGF-R4 was also still expressed in Soleus cells. Interestingly, the unconventional receptor for FGF called cystein rich FGF receptor (CFR), of yet unknown function, was mainly detected in EDL satellite cell cultures. Soleus and EDL satellite cell cultures also differed in the expression MRFs. These results are consistent with the notion that satellite cells from fast and slow twitch muscles belong to different types of myogenic cells and suggest that satellite cells might play distinct roles in the formation and diversification of fast and slow fibres.

  17. Precursors of hexoneogenesis within the human mammary gland

    USDA-ARS?s Scientific Manuscript database

    The human mammary gland is capable of de novo synthesis of glucose and galactose (hexoneogenesis); however, the carbon source is incompletely understood. In this study, we investigated the role of acetate, glutamine, lactate and glycerol as potential carbon sources for hexoneogenesis. Healthy breast...

  18. [Endometrial carcinomas and precursor lesions--new aspects].

    PubMed

    Schmidt, D

    2009-07-01

    Endometrial carcinomas can be separated into two groups which are designated as type I and type II carcinomas today. Both groups of tumors are clearly different with regard to conventional light microscopy, immunohistochemistry, molecular pathology and clinical features. Only type I carcinomas are associated with hyperestrogenism. The group of type I carcinomas consists of endometrioid carcinoma and its variants, and mucinous carcinoma. The prototypes of type II carcinomas are serous and clear cell carcinoma. Not all carcinomas, however, can be assigned to one of the two groups, because there are hybrid tumors and mixed carcinomas, e.g. endometrioid carcinoma with a serous component. The precursor lesions of the endometrioid carcinoma and the serous carcinoma are well characterized morphologically and by molecular pathology. Atypical hyperplasia is the precursor lesion of endometrioid carcinoma, whereas endometrial intraepithelial carcinoma (EIC) is the precursor lesion of serous carcinoma. No precursor lesion has as yet been identified for clear cell carcinoma. Immunohistochemical markers for endometrial carcinoma are CK7 and vimentin, for serous carcinoma markers are p53 and p16. Correct typing is of essential prognostic necessity in endometrial carcinoma. Of utmost importance is the detection of a serous component, because serous carcinoma leads to early tumor spread with the necessity of radical surgery, chemotherapy and radiotherapy.

  19. Strain-induced dimensionality crossover of precursor modulations in Ni2MnGa

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nie, Zhihua; Wang, Yandong; Shang, Shunli

    2015-01-01

    Precursor modulations often occur in functional materials like magnetic shape memory alloys, ferroelectrics, and superconductors. In this letter, we have revealed the underlying mechanism of the precursor modulations in ferromagnetic shape memory alloys Ni2MnGa by combining synchrotron-based x-ray diffraction experiments and first-principles phonon calculations. We discovered the precursor modulations along [011] direction can be eliminated with [001] uniaxial loading, while the precursor modulations or premartensite can be totally suppressed by hydrostatic pressure condition. The TA2 phonon anomaly is sensitive to stress induced lattice strain, and the entire TA2 branch is stabilized along the directions where precursor modulations are eliminated bymore » external stress. Our discovery bridges precursor modulations and phonon anomalies, and sheds light on the microscopic mechanism of the two-step superelasticity in precursor martensite.« less

  20. Mexico's methamphetamine precursor chemical interventions: impacts on drug treatment admissions.

    PubMed

    Cunningham, James K; Bojorquez, Ietza; Campollo, Octavio; Liu, Lon-Mu; Maxwell, Jane Carlisle

    2010-11-01

    To help counter problems related to methamphetamine, Mexico has implemented interventions targeting pseudoephedrine and ephedrine, the precursor chemicals commonly used in the drug's synthesis. This study examines whether the interventions impacted methamphetamine treatment admissions-an indicator of methamphetamine consequences. Quasi-experiment: autoregressive integrated moving average (ARIMA)-based intervention time-series analysis. precursor chemical restrictions implemented beginning November 2005; major rogue precursor chemical company closed (including possibly the largest single drug-cash seizure in history) March 2007; precursor chemicals banned from Mexico (North America's first precursor ban) August 2008. Mexico and Texas (1996-2008). Monthly treatment admissions for methamphetamine (intervention series) and cocaine, heroin and alcohol (quasi-control series). The precursor restriction was associated with temporary methamphetamine admissions decreases of 12% in Mexico and 11% in Texas. The company closure was associated with decreases of 56% in Mexico and 48% in Texas; these decreases generally remained to the end of the study period. Neither intervention was associated with significant changes in the Mexico or Texas quasi-control series. The analysis of Mexico's ban was indeterminate due largely to a short post-ban series. This study, one of the first quasi-experimental analyses of an illicit-drug policy in Mexico, indicates that the country's precursor interventions were associated with positive impacts domestically and in one of the Unites States' most populous states--Texas. These interventions, coupled with previous US and Canadian interventions, amount to a new, relatively cohesive level of methamphetamine precursor control across North America's largest nations, raising the possibility that the impacts found here could continue for an extended period. © 2010 The Authors. Journal compilation © 2010 Society for the Study of Addiction.

  1. Heat shock protein-90 beta is expressed at the surface of multipotential mesenchymal precursor cells: generation of a novel monoclonal antibody, STRO-4, with specificity for mesenchymal precursor cells from human and ovine tissues.

    PubMed

    Gronthos, Stan; McCarty, Rosa; Mrozik, Krzysztof; Fitter, Stephen; Paton, Sharon; Menicanin, Danijela; Itescu, Silviu; Bartold, P Mark; Xian, Cory; Zannettino, Andrew C W

    2009-11-01

    Mesenchymal stromal cells (MSCs) and their precursor cells (MPCs) can proliferate and differentiate into multiple mesodermal and some ectodermal and endodermal tissues. Culture-expanded MSCs are currently being evaluated as a possible cell therapy to replace/repair injured or diseased tissues. While a number of mAb reagents with specificity to human MSCs, including STRO-1, STRO-3 (BLK ALP), CD71 (SH2, SH3), CD106 (VCAM-1), CD166, and CD271, have facilitated the isolation of purified populations of human MSCs from primary tissues, few if any mAb reagents have been described that can be used to isolate equivalent cells from other species. This is of particular relevance when assessing the tissue regenerative efficacy of MSCs in large immunocompetent, preclinical animal models of disease. In light of this, we sought to generate novel monoclonal antibodies (mAb) with specific reactivity against a cell surface molecule that is expressed at high levels by MSCs from different species. Using CD106 (VCAM-1)-selected ovine MSCs as an immunogen, mAb-producing hybridomas were selected for their reactivity to both human and ovine MSCs. One such hybridoma, termed STRO-4, produced an IgG mAb that reacted with <5% of human and ovine bone marrow (BM) mononuclear cells. As a single selection reagent, STRO-4 mAb was able to enrich colony-forming fibroblasts (CFU-F) in both human and ovine BM by 16- and 8-folds, respectively. Cells isolated with STRO-4 exhibited reactivity with markers commonly associated with MSCs isolated by plastic adherence including CD29, CD44, and CD166. Moreover, when placed in inductive culture conditions in vitro, STRO-4(+) MSCs exhibited multilineage differentiation potential and were capable of forming a mineralized matrix, lipid-filled adipocytes, and chondrocytes capable of forming a glycosaminoglycan-rich matrix. Biochemical analysis revealed that STRO-4 identified the beta isoform of heat shock protein-90 (Hsp90beta). In addition to identifying an

  2. Functional Analysis of Precursors for Serious Problem Behavior and Related Intervention

    ERIC Educational Resources Information Center

    Langdon, Nancy A.; Carr, Edward G.; Owen-DeSchryver, Jamie S.

    2008-01-01

    Precursor behaviors are innocuous behaviors that reliably precede the occurrence of problem behavior. Intervention efforts applied to precursors might prevent the occurrence of severe problem behavior. We examined the relationship between precursor behavior and problem behavior in three individuals with developmental disabilities. First, a…

  3. THE CRYSTALLIZATION AND SEROLOGICAL DIFFERENTIATION OF A STREPTOCOCCAL PROTEINASE AND ITS PRECURSOR

    PubMed Central

    Elliott, S. D.

    1950-01-01

    Grown in dialysate broth at a pH between 5.5 and 6.5, some strains of group A streptococci elaborate the precursor of a proteolytic enzyme. Within this range of hydrogen concentration the precursor is also produced when the streptococci are suspended in a peptone dialysate containing glucose and incubated at 37°C. The precursor does not appear to be produced at a neutral or alkaline reaction. Methods are described whereby the precursor and proteinase have been isolated in crystalline form. The precursor crystallizes from half-saturated ammonium sulfate at pH 8.0 and a temperature of 22°C. or higher; the proteinase crystallizes from 0.15 saturated ammonium sulfate at pH 8.0 but does so most readily at refrigerator temperature. The degree of purification achieved by these procedures is discussed. The activity of purified preparations of the precursor and of proteinase has been tested against α-benzoyl-l-arginineamide and, with this as a substrate, the conversion of precursor to proteinase by autocatalysis or by trypsin has been confirmed. Immunological experiments are described, the results of which provide evidence of the distinct antigenic specificity of the precursor and proteinase; the conversion of precursor to proteinase has been followed by means of serological tests. PMID:15436931

  4. Injected Human Muscle Precursor Cells Overexpressing PGC-1α Enhance Functional Muscle Regeneration after Trauma

    PubMed Central

    Haralampieva, Deana; Salemi, Souzan; Betzel, Thomas; Dinulovic, Ivana; Krämer, Stefanie D.; Schibli, Roger; Sulser, Tullio; Ametamey, Simon M.

    2018-01-01

    While many groups demonstrated new muscle tissue formation after muscle precursor cell (MPC) injection, the capacity of these cells to heal muscle damage, for example, sphincter in stress urinary incontinence, in long-term is still limited. Therefore, the first goal of our project was to optimize the functional regenerative potential of hMPC by genetic modification to overexpress human peroxisome proliferator-activated receptor gamma coactivator 1-alpha (hPGC-1α), key regulator of exercise-mediated adaptation. Moreover, we aimed at establishing a feasible methodology for noninvasive PET visualization of implanted cells and their microenvironment in muscle crush injury model. PGC-1α-bioengineered muscles showed enhanced marker expression for myogenesis (α-actinin, MyHC, and Desmin), vascularization (VEGF), neuronal (ACHE), and mitochondrial (COXIV) activity. Consistently, use of hPGC-1α_hMPCs produced significantly increased contractile force one to three weeks postinjury. PET imaging showed distinct differences in radiotracer signals ([18F]Fallypride and [11C]Raclopride (both targeting dopamine 2 receptors (D2R)) and [64Cu]NODAGA-RGD (targeting neovascularization)) between GFP_hMPCs and hD2R_hPGC-1α_hMPCs. After muscle harvesting, inflammation levels were in parallel to radiotracer uptake amount, with significantly lower uptake in hPGC-1α overexpressing samples. In summary, we facilitated early functional muscle tissue regeneration, introducing a novel approach to improve skeletal muscle regeneration. Besides successful tracking of hMPCs in muscle crush injuries, we showed that in high-inflammation areas, the specificity of radioligands might be significantly reduced, addressing a possible bottleneck of neovascularization PET imaging. PMID:29531537

  5. Making Single-Source Precursors of Ternary Semiconductors

    NASA Technical Reports Server (NTRS)

    Hepp, Aloysius; Banger, Kulbindre K.

    2007-01-01

    A synthesis route has been developed for the commercial manufacture of single- source precursors of chalcopyrite semiconductor absorber layers of thin-film solar photovoltaic cells. A closely related class of single-source precursors of these semiconductors, and their synthesis routes, were reported in "Improved Single-Source Precursors for Solar-Cell Absorbers" (LEW-17445-1), NASA Tech Briefs, Vol. 31, No. 6 (June 2007), page 56. The present synthesis route is better suited to commercialization because it is simpler and involves the use of commercially available agents, yet offers the flexibility needed for synthesis of a variety of precursors. A single-source precursor of the type of interest here is denoted by the general formula L2M'(mu-ER)2M(ER)2, where L signifies a Lewis base; M signifies Al, In, or Ga; M' signifies Ag or Cu; R signifies an alkyl, aryl, silyl, or perfluorocarbon group; E signifies O, S, Se, or Te; and mu signifies a bridging ligand. This compound can be synthesized in a "one-pot" procedure from ingredients that are readily available from almost any chemical supplier. In a demonstration, the following synthesis was performed: Under anaerobic conditions, InCl3 was reacted with sodium ethanethiolate in methanol in a 1:4 molar ratio to afford the ionic stable intermediate compound Na+[In(SEt)4]- (where Et signifies ethyl group). After approximately 15 minutes, a heterogeneous solution of CuCl and the Lewis base PPh3 (where Ph signifies phenyl) in a 1:2 ratio in a mixture of CH3CN and CH2Cl2 was added directly to the freshly prepared Na+[In(SEt)4]-. After 24 hours, the reaction was essentially complete. The methanolic solution was concentrated, then the product was extracted with CH2Cl2, then the product was washed with dry ether and pentane. The product in its final form was a creamy white solid. Spectroscopic and elemental analysis confirmed that the product was (PPh3)2Cu(mu-SEt)2In(mu-SEt)2, which is known to be a precursor of the ternary

  6. Non-myogenic Contribution to Muscle Development and Homeostasis: The Role of Connective Tissues

    PubMed Central

    Nassari, Sonya; Duprez, Delphine; Fournier-Thibault, Claire

    2017-01-01

    Skeletal muscles belong to the musculoskeletal system, which is composed of bone, tendon, ligament and irregular connective tissue, and closely associated with motor nerves and blood vessels. The intrinsic molecular signals regulating myogenesis have been extensively investigated. However, muscle development, homeostasis and regeneration require interactions with surrounding tissues and the cellular and molecular aspects of this dialogue have not been completely elucidated. During development and adult life, myogenic cells are closely associated with the different types of connective tissue. Connective tissues are defined as specialized (bone and cartilage), dense regular (tendon and ligament) and dense irregular connective tissue. The role of connective tissue in muscle morphogenesis has been investigated, thanks to the identification of transcription factors that characterize the different types of connective tissues. Here, we review the development of the various connective tissues in the context of the musculoskeletal system and highlight their important role in delivering information necessary for correct muscle morphogenesis, from the early step of myoblast differentiation to the late stage of muscle maturation. Interactions between muscle and connective tissue are also critical in the adult during muscle regeneration, as impairment of the regenerative potential after injury or in neuromuscular diseases results in the progressive replacement of the muscle mass by fibrotic tissue. We conclude that bi-directional communication between muscle and connective tissue is critical for a correct assembly of the musculoskeletal system during development as well as to maintain its homeostasis in the adult. PMID:28386539

  7. Analysis of Saccular Function With Vestibular Evoked Myogenic Potential Test in Meniere's Disease.

    PubMed

    Dabiri, Sasan; Yazdani, Nasrin; Esfahani, Mahdis; Tari, Niloufar; Adil, Susan; Mahvi, Zahra; Rezazadeh, Nima

    2017-02-01

    Meniere's disease is the disorder of inner ear characterized by vertigo, tinnitus and sensorineural hearing loss. The vestibular evoked myogenic potential (VEMP) test could be useful in the analysis of saccular function, and diagnosis of Meniere's disease. In this study, we've analyzed the saccular function, using VEMP test in different groups of Meniere's disease. Patients were categorized as possible, probable or definite Meniere's disease groups according to the guideline of American Academy of Otolaryngology-Head and Neck Surgery. The exclusion criteria were neuromuscular system diseases, diseases of central nervous system, inner ear disorders, conductive hearing loss, a history of ototoxic drug consumption, being a drug abuser and a positive history of inner ear surgery or manipulations. The VEMP test is the recording of positive and negative waves from sternocleidomastoid muscle that is made by an auditory click to the ear. From the total of 100 patients, the waves of VEMP test was seen in 59 patients which 19 patients had abnormal amplitude, and latency and 40 patients were with normally recorded waves. There was a significant relationship between the severity of hearing loss and a VEMP test without any recorded waves. Most of the cases with 'no wave recorded' VEMP test, were patients with severe hearing loss. However, there wasn't any relation between the pattern of hearing loss and 'no wave recorded' VEMP test. VEMP test could be a valuable diagnostic clue especially in patients with definite Meniere's disease.

  8. Non-myogenic Contribution to Muscle Development and Homeostasis: The Role of Connective Tissues.

    PubMed

    Nassari, Sonya; Duprez, Delphine; Fournier-Thibault, Claire

    2017-01-01

    Skeletal muscles belong to the musculoskeletal system, which is composed of bone, tendon, ligament and irregular connective tissue, and closely associated with motor nerves and blood vessels. The intrinsic molecular signals regulating myogenesis have been extensively investigated. However, muscle development, homeostasis and regeneration require interactions with surrounding tissues and the cellular and molecular aspects of this dialogue have not been completely elucidated. During development and adult life, myogenic cells are closely associated with the different types of connective tissue. Connective tissues are defined as specialized (bone and cartilage), dense regular (tendon and ligament) and dense irregular connective tissue. The role of connective tissue in muscle morphogenesis has been investigated, thanks to the identification of transcription factors that characterize the different types of connective tissues. Here, we review the development of the various connective tissues in the context of the musculoskeletal system and highlight their important role in delivering information necessary for correct muscle morphogenesis, from the early step of myoblast differentiation to the late stage of muscle maturation. Interactions between muscle and connective tissue are also critical in the adult during muscle regeneration, as impairment of the regenerative potential after injury or in neuromuscular diseases results in the progressive replacement of the muscle mass by fibrotic tissue. We conclude that bi-directional communication between muscle and connective tissue is critical for a correct assembly of the musculoskeletal system during development as well as to maintain its homeostasis in the adult.

  9. Capacity of Rectified Vestibular Evoked Myogenic Potential in Correcting Asymmetric Muscle Contraction Power

    PubMed Central

    Kim, Kun Woo; Jung, Jae Yun; Lee, Jeong Hyun

    2013-01-01

    Objectives Rectified vestibular evoked myogenic potential (rVEMP) is new method that simultaneously measures the muscle contraction power during VEMP recordings. Although there are a few studies that have evaluated the effect of the rVEMP, there is no study that has evaluated the capacity of rVEMP during asymmetrical muscle contraction. Methods Thirty VEMP measurements were performed among 20 normal subjects (mean age, 28.2±2.1 years; male, 16). VEMP was measured in the supine position. The head was turned to the right side by 0°, 15°, 30°, and 45° and the VEMPs were recorded in each position. The interaural amplitude difference (IAD) ratio was calculated by the conventional non-rectified VEMP (nVEMP) and rVEMP. Results The nVEMP IAD increased significantly according to increasing neck rotation. The IAD in rVEMP was almost similar from 0° to 30°. However, the IAD was significantly larger than the other positions when the neck was rotated 45°. When IAD during 0° was set as a standard, the IAD of the rVEMP was significantly smaller that the nVEMP only during the 30°rotaion. Conclusion Rectified VEMP is capable of correcting asymmetrical muscle contraction power. In contrast, it cannot correct the asymmetry if muscle contraction power asymmetry is 44.8% or larger. Also, it is not necessary if muscle contraction power asymmetry is 22.5% or smaller. PMID:24353859

  10. Multiphoton imaging of myogenic differentiation in gelatin-based hydrogels as tissue engineering scaffolds.

    PubMed

    Kim, Min Jeong; Shin, Yong Cheol; Lee, Jong Ho; Jun, Seung Won; Kim, Chang-Seok; Lee, Yunki; Park, Jong-Chul; Lee, Soo-Hong; Park, Ki Dong; Han, Dong-Wook

    2016-01-01

    Hydrogels can serve as three-dimensional (3D) scaffolds for cell culture and be readily injected into the body. Recent advances in the image technology for 3D scaffolds like hydrogels have attracted considerable attention to overcome the drawbacks of ordinary imaging technologies such as optical and fluorescence microscopy. Multiphoton microscopy (MPM) is an effective method based on the excitation of two-photons. In the present study, C2C12 myoblasts differentiated in 3D gelatin hydroxyphenylpropionic acid (GHPA) hydrogels were imaged by using a custom-built multiphoton excitation fluorescence microscopy to compare the difference in the imaging capacity between conventional microscopy and MPM. The physicochemical properties of GHPA hydrogels were characterized by using scanning electron microscopy and Fourier-transform infrared spectroscopy. In addition, the cell viability and proliferation of C2C12 myoblasts cultured in the GHPA hydrogels were analyzed by using Live/Dead Cell and CCK-8 assays, respectively. It was found that C2C12 cells were well grown and normally proliferated in the hydrogels. Furthermore, the hydrogels were shown to be suitable to facilitate the myogenic differentiation of C2C12 cells incubated in differentiation media, which had been corroborated by MPM. It was very hard to get clear images from a fluorescence microscope. Our findings suggest that the gelatin-based hydrogels can be beneficially utilized as 3D scaffolds for skeletal muscle engineering and that MPM can be effectively applied to imaging technology for tissue regeneration.

  11. Uniaxial cyclic strain enhances adipose-derived stem cell fusion with skeletal myocytes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Andersen, Jens Isak; Juhl, Morten; Nielsen, Thøger

    2014-07-25

    Highlights: • Uniaxial cyclic tensile strain (CTS) applied to ASCs alone or in coculture with myogenic precursors. • CTS promoted the formation of a highly ordered array of parallel ASCs. • Without biochemical supplements, CTS did not support advanced myogenic differentiation of ASCs. • Mechanical stimulation of cocultures boosted fusion of ASCs with skeletal myoblasts. - Abstract: Although adult muscle tissue possesses an exceptional capacity for regeneration, in the case of large defects, the restoration to original state is not possible. A well-known source for the de novo regeneration is the adipose-derived stem cells (ASCs), which can be readily isolatedmore » and have been shown to have a broad differentiation and regenerative potential. In this work, we employed uniaxial cyclic tensile strain (CTS), to mechanically stimulate human ASCs to participate in the formation skeletal myotubes in an in vitro model of myogenesis. The application of CTS for 48 h resulted in the formation of a highly ordered array of parallel ASCs, but failed to support skeletal muscle terminal differentiation. When the same stimulation paradigm was applied to cocultures with mouse skeletal muscle myoblasts, the percentage of ASCs contributing to the formation of myotubes significantly exceeded the levels reported in the literature hitherto. In perspective, the mechanical strain may be used to increase the efficiency of incorporation of ASCs in the skeletal muscles, which could be found useful in diverse traumatic or pathologic scenarios.« less

  12. Methods of making copper selenium precursor compositions with a targeted copper selenide content and precursor compositions and thin films resulting therefrom

    DOEpatents

    Curtis, Calvin J [Lakewood, CO; Miedaner, Alexander [Boulder, CO; van Hest, Marinus Franciscus Antonius Maria; Ginley, David S [Evergreen, CO; Leisch, Jennifer [Denver, CO; Taylor, Matthew [West Simsbury, CT; Stanbery, Billy J [Austin, TX

    2011-09-20

    Precursor compositions containing copper and selenium suitable for deposition on a substrate to form thin films suitable for semi-conductor applications. Methods of forming the precursor compositions using primary amine solvents and methods of forming the thin films wherein the selection of temperature and duration of heating controls the formation of a targeted species of copper selenide.

  13. The Innate Lymphoid Cell Precursor.

    PubMed

    Ishizuka, Isabel E; Constantinides, Michael G; Gudjonson, Herman; Bendelac, Albert

    2016-05-20

    The discovery of tissue-resident innate lymphoid cell populations effecting different forms of type 1, 2, and 3 immunity; tissue repair; and immune regulation has transformed our understanding of mucosal immunity and allergy. The emerging complexity of these populations along with compounding issues of redundancy and plasticity raise intriguing questions about their precise lineage relationship. Here we review advances in mapping the emergence of these lineages from early lymphoid precursors. We discuss the identification of a common innate lymphoid cell precursor characterized by transient expression of the transcription factor PLZF, and the lineage relationships of innate lymphoid cells with conventional natural killer cells and lymphoid tissue inducer cells. We also review the rapidly growing understanding of the network of transcription factors that direct the development of these lineages.

  14. Alternative group V precursors for CVD applications

    NASA Astrophysics Data System (ADS)

    Lum, R. M.; Klingert, J. K.

    1991-01-01

    The chemical vapor deposition (CVD) techniques used to grow III/V semiconductors films, such as metalorganic vapor phase epitaxy (MOVPE), hydride VPE, chemical beam epitaxy (CBE) and gas source molecular beam epitaxy (GS-MBE), all use hydrides (AsH 3 and PH 3) as the Group V source. However, the hydrides are extremely toxic gases which are stored under high pressure (200-2000 psi). To reduce the safety hazards associated with these gases, alternative Group V precursors have been investigated. Organoarsenic and phosphorous compounds have received the most attention as replacements for AsH 3 and PH 3 because they are typically low vapor pressure liquids, and thus present significantly lower exposure risks than the hydrides. For AsH 3 these have included the methyl, ethyl and butyl-based derivatives RnAsH 3- n, with varying degrees ( n = 1-3) of hydrogen atom substitution. In this paper the growth properties, thermochemistry and toxicity of the various alkylarsine precursors are compared with arsine. Data are presented on the impact of the thermochemistry of these compounds on film electrical properties, and on the effects of precursor composition and purity on overall film quality. The suitability of alternative As-precursors for device applications is demonstrated, and selection criteria are presented for the most effective alkylarsine compound for a particular CVD growth process.

  15. Pregnancy causes diminished myogenic tone and outward hypotrophic remodeling of the cerebral vein of Galen.

    PubMed

    van der Wijk, Anne-Eva; Schreurs, Malou P H; Cipolla, Marilyn J

    2013-04-01

    Pregnancy increases the risk of several complications associated with the cerebral veins, including thrombosis and hemorrhage. In contrast to the cerebral arteries and arterioles, few studies have focused on the effect of pregnancy on the cerebral venous side. Here, we investigated for the first time the effect of pregnancy on the function and structure of the cerebral vein of Galen in rats. Our major finding was that cerebral veins from late-pregnant (LP, n=11) rats had larger lumen diameters and thinner walls than veins from nonpregnant (NP, n=13) rats, indicating that pregnancy caused outward hypotrophic remodeling of the vein of Galen. Moreover, veins from NP animals had a small amount of myogenic tone at 10 mm Hg (3.9±1.0%) that was diminished in veins during pregnancy (0.8±0.3%; P<0.01). However, endothelium-dependent and -independent vasodilation of the veins was unchanged during pregnancy. Using immunohistochemistry, we show that the vein of Galen receives perivascular innervation, and that serotonergic innervation of cerebral veins is significantly higher in veins from LP animals. Outward hypotrophic remodeling and diminished tone of cerebral veins during pregnancy may contribute to the development of venous pathology through elevated wall tension and wall stress, and possibly by promoting venous blood stasis.

  16. Chicken ovalbumin upstream promoter-transcription factor II regulates nuclear receptor, myogenic, and metabolic gene expression in skeletal muscle cells.

    PubMed

    Crowther, Lisa M; Wang, Shu-Ching Mary; Eriksson, Natalie A; Myers, Stephen A; Murray, Lauren A; Muscat, George E O

    2011-02-24

    We demonstrate that chicken ovalbumin upstream promoter-transcription factor II (COUP-TFII) mRNA is more abundantly expressed (than COUP-TFI mRNA) in skeletal muscle C2C12 cells and in (type I and II) skeletal muscle tissue from C57BL/10 mice. Consequently, we have utilized the ABI TaqMan Low Density Array (TLDA) platform to analyze gene expression changes specifically attributable to ectopic COUP-TFII (relative to vector only) expression in muscle cells. Utilizing a TLDA-based platform and 5 internal controls, we analyze the entire NR superfamily, 96 critical metabolic genes, and 48 important myogenic regulatory genes on the TLDA platform utilizing 5 internal controls. The low density arrays were analyzed by rigorous statistical analysis (with Genorm normalization, Bioconductor R, and the Empirical Bayes statistic) using the (integromics) statminer software. In addition, we validated the differentially expressed patho-physiologically relevant gene (identified on the TLDA platform) glucose transporter type 4 (Glut4). We demonstrated that COUP-TFII expression increased the steady state levels of Glut4 mRNA and protein, while ectopic expression of truncated COUP-TFII lacking helix 12 (COUP-TFΔH12) reduced Glut4 mRNA expression in C2C12 cells. Moreover, COUP-TFII expression trans-activated the Glut4 promoter (-997/+3), and ChIP analysis identified selective recruitment of COUP-TFII to a region encompassing a highly conserved SP1 binding site (in mouse, rat, and human) at nt positions -131/-118. Mutation of the SpI site ablated COUP-TFII mediated trans-activation of the Glut4 promoter. In conclusion, this study demonstrates that in skeletal muscle cells, COUP-TFII regulates several nuclear hormone receptors, and critical metabolic and muscle specific genes.

  17. Myogenic Potential of Whole Bone Marrow Mesenchymal Stem Cells In Vitro and In Vivo for Usage in Urinary Incontinence

    PubMed Central

    Giammò, Alessandro; Boido, Marina; Rustichelli, Deborah; Mareschi, Katia; Errichiello, Edoardo; Parola, Maurizio; Ferrero, Ivana; Fagioli, Franca; Vercelli, Alessandro; Carone, Roberto

    2012-01-01

    Urinary incontinence, defined as the complaint of any involuntary loss of urine, is a pathological condition, which affects 30% females and 15% males over 60, often following a progressive decrease of rhabdosphincter cells due to increasing age or secondary to damage to the pelvic floor musculature, connective tissue and/or nerves. Recently, stem cell therapy has been proposed as a source for cell replacement and for trophic support to the sphincter. To develop new therapeutic strategies for urinary incontinence, we studied the interaction between mesenchymal stem cells (MSCs) and muscle cells in vitro; thereafter, aiming at a clinical usage, we analyzed the supporting role of MSCs for muscle cells in vitro and in in vivo xenotransplantation. MSCs can express markers of the myogenic cell lineages and give rise, under specific cell culture conditions, to myotube-like structures. Nevertheless, we failed to obtain mixed myotubes both in vitro and in vivo. For in vivo transplantation, we tested a new protocol to collect human MSCs from whole bone marrow, to get larger numbers of cells. MSCs, when transplanted into the pelvic muscles close to the external urethral sphincter, survived for a long time in absence of immunosuppression, and migrated into the muscle among fibers, and towards neuromuscular endplates. Moreover, they showed low levels of cycling cells, and did not infiltrate blood vessels. We never observed formation of cell masses suggestive of tumorigenesis. Those which remained close to the injection site showed an immature phenotype, whereas those in the muscle had more elongated morphologies. Therefore, MSCs are safe and can be easily transplanted without risk of side effects in the pelvic muscles. Further studies are needed to elucidate their integration into muscle fibers, and to promote their muscular transdifferentiation either before or after transplantation. PMID:23029081

  18. Capability of cation exchange technology to remove proven N-nitrosodimethylamine precursors.

    PubMed

    Li, Shixiang; Zhang, Xulan; Bei, Er; Yue, Huihui; Lin, Pengfei; Wang, Jun; Zhang, Xiaojian; Chen, Chao

    2017-08-01

    N-nitrosodimethylamine (NDMA) precursors consist of a positively charged dimethylamine group and a non-polar moiety, which inspired us to develop a targeted cation exchange technology to remove NDMA precursors. In this study, we tested the removal of two representative NDMA precursors, dimethylamine (DMA) and ranitidine (RNTD), by strong acidic cation exchange resin. The results showed that pH greatly affected the exchange efficiency, with high removal (DMA>78% and RNTD>94%) observed at pHprecursor was 4. The exchange order was obtained as follows: Ca 2+ >Mg 2+ >RNTD + >K + >DMA + >NH 4 + >Na + . The partition coefficient of DMA + to Na + was 1.41±0.26, while that of RNTD + to Na + was 12.1±1.9. The pseudo second-order equation fitted the cation exchange kinetics well. Bivalent inorganic cations such as Ca 2+ were found to have a notable effect on NA precursor removal in softening column test. Besides DMA and RNTD, cation exchange process also worked well for removing other 7 model NDMA precursors. Overall, NDMA precursor removal can be an added benefit of making use of cation exchange water softening processes. Copyright © 2017. Published by Elsevier B.V.

  19. Cryopreservation of GABAergic Neuronal Precursors for Cell-Based Therapy

    PubMed Central

    2017-01-01

    Cryopreservation protocols are essential for stem cells storage in order to apply them in the clinic. Here we describe a new standardized cryopreservation protocol for GABAergic neural precursors derived from the medial glanglionic eminence (MGE), a promising source of GABAergic neuronal progenitors for cell therapy against interneuron-related pathologies. We used 10% Me2SO as cryoprotectant and assessed the effects of cell culture amplification and cellular organization, as in toto explants, neurospheres, or individualized cells, on post-thaw cell viability and retrieval. We confirmed that in toto cryopreservation of MGE explants is an optimal preservation system to keep intact the interneuron precursor properties for cell transplantation, together with a high cell viability (>80%) and yield (>70%). Post-thaw proliferation and self-renewal of the cryopreserved precursors were tested in vitro. In addition, their migration capacity, acquisition of mature neuronal morphology, and potency to differentiate into multiple interneuron subtypes were also confirmed in vivo after transplantation. The results show that the cryopreserved precursor features remained intact and were similar to those immediately transplanted after their dissection from the MGE. We hope this protocol will facilitate the generation of biobanks to obtain a permanent and reliable source of GABAergic precursors for clinical application in cell-based therapies against interneuronopathies. PMID:28122047

  20. Gamma-Ray Burst Precursor Activity as Observed with BATSE

    NASA Technical Reports Server (NTRS)

    Koshut, Thomas M.; Kouveliotou, Chryssa; Paciesas, William S.; vanParadijs, Jan; Pendleton, Geoffrey N.; Briggs, Michael S.; Fishman, Gerald J.; Meegan, Charles A.

    1995-01-01

    Gamma-ray burst time histories often consist of multiple episodes of emission with the count rate dropping to the background level between adjacent episodes. We define precursor activity as any case in which the first episode (referred to as the precursor episode) has a lower peak intensity than that of the remaining emission (referred to as the main episode) and is separated from the remaining burst emission by a background interval that is at least as long as the remaining emission. We find that approx. 3% of the bursts observed with the Burst and Transient Source Experiment (BATSE) on Compton Gamma Ray Observatory (CGRO) satisfy this definition. We present the results of a study of the properties of these events. The spatial distribution of these sources is consistent with that of the larger set of all BATSE gamma-ray bursts: inhomogeneous and isotropic. A correlation between the duration of the precursor emission and the duration of the main episode emission is observed at about the 3 sigma confidence level. We find no meaningful significant correlations between or among any of the other characteristics of the precursor or main episode emission. It appears that the characteristics of the main episode emission are independent of the existence of the precursor emission.

  1. Successful transplantation of in vitro expanded human cadaver corneal endothelial precursor cells on to a cadaver bovine's eye using a nanocomposite gel sheet.

    PubMed

    Parikumar, Periyasamy; Haraguchi, Kazutoshi; Ohbayashi, Akira; Senthilkumar, Rajappa; Abraham, Samuel J K

    2014-05-01

    In vitro expansion of human corneal endothelial precursor (HCEP) cells has been reported via production of cell aggregated spheres. However, to translate this procedure in human patients warrants maintaining the position of the eyeballs facing down for 36 h, which is not feasible. In this study, we report a method using a nanocomposite (NC) gel sheet to accomplish the integration of HCEP cells to the endothelium of cadaver bovine's eyes. HCEP cells were isolated from the corneal endothelium of a cadaver human eye and then expanded using a thermoreversible gelation polymer (TGP) as reported earlier. For the study, three cadaver bovine eyes were used. The NC gel sheets were inserted into the bovine eyes', aligned and suture-fixed in position under the host endothelium. HCEP cells previously expanded in the TGP were harvested and injected using a 26-gauge syringe between the endothelium and the NC gel sheet. The eyes were left undisturbed for three hours following which the NC gel sheets were gently removed. The corneas were harvested and subjected to histopathological studies. Histopathological studies showed that all the three corneas used for NC gel sheet implantation showed the presence of engrafted HCEP cells, seen as multi-layered cells over the native endothelium of the bovine cornea. Examination of the NC gel sheets used for implantation showed that only very few corneal endothelial cells remained on the sheets amounting to what could be considered negligible. The use of the NC gel sheet makes HCEP cell transplantation feasible for human patients. Further in vitro basic studies followed by translational studies are necessary to bring this method for clinical application in appropriate indications.

  2. Electron probe X-ray microanalysis of cultured myogenic C2C12 cells with scanning and scanning transmission electron microscopy.

    PubMed

    Tylko, G; Karasiński, J; Wróblewski, R; Roomans, G M; Kilarski, W M

    2000-01-01

    Heterogeneity of the elemental content of myogenic C2C12 cultured cells was studied by electron probe X-ray microanalysis (EPXMA) with scanning (SEM EPXMA) and scanning transmission electron microscopy (STEM EPXMA). The best plastic substrate for growing cells was Thermanox. For STEM EPXMA, a Formvar film coated with carbon was found to be suitable substrate. The cells examined by scanning transmission electron microscopy showed great heterogeneity in their elemental content in comparison with the cells examined in the scanning electron microscope despite of an almost identical preparation procedure for EPXMA. Nevertheless the K/Na ratios obtained from both methods of EPXMA were very close (4.1 and 4.3). We conclude that the observed discrepancy in the elemental content obtained by the two methods may be due to differences in instrumentation and this must be taken into account when planning a comparative study.

  3. Manganite perovskite ceramics, their precursors and methods for forming

    DOEpatents

    Payne, David Alan; Clothier, Brent Allen

    2015-03-10

    Disclosed are a variety of ceramics having the formula Ln.sub.1-xM.sub.xMnO.sub.3, where 0.Itoreq.x.Itoreq.1 and where Ln is La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu or Y; M is Ca, Sr, Ba, Cd, or Pb; manganite precursors for preparing the ceramics; a method for preparing the precursors; and a method for transforming the precursors into uniform, defect-free ceramics having magnetoresistance properties. The manganite precursors contain a sol and are derived from the metal alkoxides: Ln(OR).sub.3, M(OR).sub.2 and Mn(OR).sub.2, where R is C.sub.2 to C.sub.6 alkyl or C.sub.3 to C.sub.9 alkoxyalkyl, or C.sub.6 to C.sub.9 aryl. The preferred ceramics are films prepared by a spin coating method and are particularly suited for incorporation into a device such as an integrated circuit device.

  4. Improved Single-Source Precursors for Solar-Cell Absorbers

    NASA Technical Reports Server (NTRS)

    Banger, Kulbinder K.; Harris, Jerry; Hepp, Aloysius

    2007-01-01

    Improved single-source precursor compounds have been invented for use in spray chemical vapor deposition (spray CVD) of chalcopyrite semiconductor absorber layers of thin-film cells. A "single-source precursor compound" is a single molecular compound that contains all the required elements, which when used under the spray CVD conditions, thermally decomposes to form CuIn(x)Ga(1-x)S(y)Se(2-y).

  5. A Functional Interplay between Human Immunodeficiency Virus Type 1 Protease Residues 77 and 93 Involved in Differential Regulation of Precursor Autoprocessing and Mature Protease Activity

    PubMed Central

    Counts, Christopher J.; Ho, P. Shing; Donlin, Maureen J.; Tavis, John E.; Chen, Chaoping

    2015-01-01

    HIV-1 protease (PR) is a viral enzyme vital to the production of infectious virions. It is initially synthesized as part of the Gag-Pol polyprotein precursor in the infected cell. The free mature PR is liberated as a result of precursor autoprocessing upon virion release. We previously described a model system to examine autoprocessing in transfected mammalian cells. Here, we report that a covariance analysis of miniprecursor (p6*-PR) sequences derived from drug naïve patients identified a series of amino acid pairs that vary together across independent viral isolates. These covariance pairs were used to build the first topology map of the miniprecursor that suggests high levels of interaction between the p6* peptide and the mature PR. Additionally, several PR-PR covariance pairs are located far from each other (>12 Å Cα to Cα) relative to their positions in the mature PR structure. Biochemical characterization of one such covariance pair (77–93) revealed that each residue shows distinct preference for one of three alkyl amino acids (V, I, and L) and that a polar or charged amino acid at either of these two positions abolishes precursor autoprocessing. The most commonly observed 77V is preferred by the most commonly observed 93I, but the 77I variant is preferred by other 93 variances (L, V, or M) in supporting precursor autoprocessing. Furthermore, the 77I93V covariant enhanced precursor autoprocessing and Gag polyprotein processing but decreased the mature PR activity. Therefore, both covariance and biochemical analyses support a functional association between residues 77 and 93, which are spatially distant from each other in the mature PR structure. Our data also suggests that these covariance pairs differentially regulate precursor autoprocessing and the mature protease activity. PMID:25893662

  6. Whole-cell fungal transformation of precursors into dyes

    PubMed Central

    2010-01-01

    Background Chemical methods of producing dyes involve extreme temperatures and unsafe toxic compounds. Application of oxidizing enzymes obtained from fungal species, for example laccase, is an alternative to chemical synthesis of dyes. Laccase can be replaced by fungal biomass acting as a whole-cell biocatalyst with properties comparable to the isolated form of the enzyme. The application of the whole-cell system simplifies the transformation process and reduces the time required for its completion. In the present work, four fungal strains with a well-known ability to produce laccase were tested for oxidation of 17 phenolic and non-phenolic precursors into stable and non-toxic dyes. Results An agar-plate screening test of the organic precursors was carried out using four fungal strains: Trametes versicolor, Fomes fomentarius, Abortiporus biennis, and Cerrena unicolor. Out of 17 precursors, nine were transformed into coloured substances in the presence of actively growing fungal mycelium. The immobilized fungal biomass catalyzed the transformation of 1 mM benzene and naphthalene derivatives in liquid cultures yielding stable and non-toxic products with good dyeing properties. The type of fungal strain had a large influence on the absorbance of the coloured products obtained after 48-hour transformation of the selected precursors, and the most effective was Fomes fomentarius (FF25). Whole-cell transformation of AHBS (3-amino-4-hydroxybenzenesulfonic acid) into a phenoxazinone dye was carried out in four different systems: in aqueous media comprising low amounts of carbon and nitrogen source, in buffer, and in distilled water. Conclusions This study demonstrated the ability of four fungal strains belonging to the ecological type of white rot fungi to transform precursors into dyes. This paper highlights the potential of fungal biomass for replacing isolated enzymes as a cheaper industrial-grade biocatalyst for the synthesis of dyes and other commercially important

  7. Strain-induced dimensionality crossover of precursor modulations in Ni{sub 2}MnGa

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Nie, Zhihua, E-mail: zhihua-nie@yahoo.com, E-mail: ydwang@neu.edu.cn; Wang, Yandong, E-mail: zhihua-nie@yahoo.com, E-mail: ydwang@neu.edu.cn; Shang, Shunli

    2015-01-12

    Precursor modulations often occur in functional materials like magnetic shape memory alloys, ferroelectrics, and superconductors. In this letter, we have revealed the underlying mechanism of the precursor modulations in ferromagnetic shape memory alloys Ni{sub 2}MnGa by combining synchrotron-based x-ray diffraction experiments and first-principles phonon calculations. We discovered the precursor modulations along [011] direction can be eliminated with [001] uniaxial loading, while the precursor modulations or premartensite can be totally suppressed by hydrostatic pressure condition. The TA{sub 2} phonon anomaly is sensitive to stress induced lattice strain, and the entire TA{sub 2} branch is stabilized along the directions where precursor modulationsmore » are eliminated by external stress. Our discovery bridges precursor modulations and phonon anomalies, and sheds light on the microscopic mechanism of the two-step superelasticity in precursor martensite.« less

  8. Identification of a precursor genomic segment that provided a sequence unique to glycophorin B and E genes

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Onda, M.; Kudo, S.; Fukuda, M.

    Human glycophorin A, B, and E (GPA, GPB, and GPE) genes belong to a gene family located at the long arm of chromosome 4. These three genes are homologous from the 5'-flanking sequence to the Alu sequence, which is 1 kb downstream from the exon encoding the transmembrane domain. Analysis of the Alu sequence and flanking direct repeat sequences suggested that the GPA gene most closely resembles the ancestral gene, whereas the GPB and GPE gene arose by homologous recombination within the Alu sequence, acquiring 3' sequences from an unrelated precursor genomic segment. Here the authors describe the identification ofmore » this putative precursor genomic segment. A human genomic library was screened by using the sequence of the 3' region of the GPB gene as a probe. The genomic clones isolated were found to contain an Alu sequence that appeared to be involved in the recombination. Downstream from the Alu sequence, the nucleotide sequence of the precursor genomic segment is almost identical to that of the GPB or GPE gene. In contrast, the upstream sequence of the genomic segment differs entirely from that of the GPA, GPB, and GPE genes. Conservation of the direct repeats flanking the Alu sequence of the genomic segment strongly suggests that the sequence of this genomic segment has been maintained during evolution. This identified genomic segment was found to reside downstream from the GPA gene by both gene mapping and in situ chromosomal localization. The precursor genomic segment was also identified in the orangutan genome, which is known to lack GPB and GPE genes. These results indicate that one of the duplicated ancestral glycophorin genes acquired a unique 3' sequence by unequal crossing-over through its Alu sequence and the further downstream Alu sequence present in the duplicated gene. Further duplication and divergence of this gene yielded the GPB and GPE genes. 37 refs., 5 figs.« less

  9. miRNA Enriched in Human Neuroblast Nuclei Bind the MAZ Transcription Factor and Their Precursors Contain the MAZ Consensus Motif.

    PubMed

    Goldie, Belinda J; Fitzsimmons, Chantel; Weidenhofer, Judith; Atkins, Joshua R; Wang, Dan O; Cairns, Murray J

    2017-01-01

    While the cytoplasmic function of microRNA (miRNA) as post-transcriptional regulators of mRNA has been the subject of significant research effort, their activity in the nucleus is less well characterized. Here we use a human neuronal cell model to show that some mature miRNA are preferentially enriched in the nucleus. These molecules were predominantly primate-specific and contained a sequence motif with homology to the consensus MAZ transcription factor binding element. Precursor miRNA containing this motif were shown to have affinity for MAZ protein in nuclear extract. We then used Ago1/2 RIP-Seq to explore nuclear miRNA-associated mRNA targets. Interestingly, the genes for Ago2-associated transcripts were also significantly enriched with MAZ binding sites and neural function, whereas Ago1-transcripts were associated with general metabolic processes and localized with SC35 spliceosomes. These findings suggest the MAZ transcription factor is associated with miRNA in the nucleus and may influence the regulation of neuronal development through Ago2-associated miRNA induced silencing complexes. The MAZ transcription factor may therefore be important for organizing higher order integration of transcriptional and post-transcriptional processes in primate neurons.

  10. Gene amplification during myogenic differentiation

    PubMed Central

    Fischer, Ulrike; Ludwig, Nicole; Raslan, Abdulrahman; Meier, Carola; Meese, Eckart

    2016-01-01

    Gene amplifications are mostly an attribute of tumor cells and drug resistant cells. Recently, we provided evidence for gene amplifications during differentiation of human and mouse neural progenitor cells. Here, we report gene amplifications in differentiating mouse myoblasts (C2C12 cells) covering a period of 7 days including pre-fusion, fusion and post-fusion stages. After differentiation induction we found an increase in copy numbers of CDK4 gene at day 3, of NUP133 at days 4 and 7, and of MYO18B at day 4. The amplification process was accompanied by gamma-H2AX foci that are indicative of double stand breaks. Amplifications during the differentiating process were also found in primary human myoblasts with the gene CDK4 and NUP133 amplified both in human and mouse myoblasts. Amplifications of NUP133 and CDK4 were also identified in vivo on mouse transversal cryosections at stage E11.5. In the course of myoblast differentiation, we found amplifications in cytoplasm indicative of removal of amplified sequences from the nucleus. The data provide further evidence that amplification is a fundamental mechanism contributing to the differentiation process in mammalians. PMID:26760505

  11. Precursor uptake assays and metabolic analyses in isolated tomato fruit chromoplasts

    PubMed Central

    2012-01-01

    Background Carotenoids are the most widespread group of pigments found in nature. In addition to their role in the physiology of the plant, carotenoids also have nutritional relevance as their incorporation in the human diet provides health benefits. In non-photosynthetic tissues, carotenoids are synthesized and stored in specialized plastids called chromoplasts. At present very little is known about the origin of the metabolic precursors and cofactors required to sustain the high rate of carotenoid biosynthesis in these plastids. Recent proteomic data have revealed a number of biochemical and metabolic processes potentially operating in fruit chromoplasts. However, considering that chloroplast to chromoplast differentiation is a very rapid process during fruit ripening, there is the possibility that some of the proteins identified in the proteomic analysis could represent remnants no longer having a functional role in chromoplasts. Therefore, experimental validation is necessary to prove whether these predicted processes are actually operative in chromoplasts. Results A method has been established for high-yield purification of tomato fruit chromoplasts suitable for metabolic studies. Radiolabeled precursors were efficiently incorporated and further metabolized in isolated chromoplast. Analysis of labeled lipophilic compounds has revealed that lipid biosynthesis is a very efficient process in chromoplasts, while the relatively low incorporation levels found in carotenoids suggest that lipid production may represent a competing pathway for carotenoid biosynthesis. Malate and pyruvate are efficiently converted into acetyl-CoA, in agreement with the active operation of the malic enzyme and the pyruvate dehydrogenase complex in the chromoplast. Our results have also shown that isolated chromoplasts can actively sustain anabolic processes without the exogenous supply of ATP, thus suggesting that these organelles may generate this energetic cofactor in an autonomous way

  12. Precursor uptake assays and metabolic analyses in isolated tomato fruit chromoplasts.

    PubMed

    Angaman, Djédoux Maxime; Petrizzo, Rocco; Hernández-Gras, Francesc; Romero-Segura, Carmen; Pateraki, Irene; Busquets, Montserrat; Boronat, Albert

    2012-01-13

    Carotenoids are the most widespread group of pigments found in nature. In addition to their role in the physiology of the plant, carotenoids also have nutritional relevance as their incorporation in the human diet provides health benefits. In non-photosynthetic tissues, carotenoids are synthesized and stored in specialized plastids called chromoplasts. At present very little is known about the origin of the metabolic precursors and cofactors required to sustain the high rate of carotenoid biosynthesis in these plastids. Recent proteomic data have revealed a number of biochemical and metabolic processes potentially operating in fruit chromoplasts. However, considering that chloroplast to chromoplast differentiation is a very rapid process during fruit ripening, there is the possibility that some of the proteins identified in the proteomic analysis could represent remnants no longer having a functional role in chromoplasts. Therefore, experimental validation is necessary to prove whether these predicted processes are actually operative in chromoplasts. A method has been established for high-yield purification of tomato fruit chromoplasts suitable for metabolic studies. Radiolabeled precursors were efficiently incorporated and further metabolized in isolated chromoplast. Analysis of labeled lipophilic compounds has revealed that lipid biosynthesis is a very efficient process in chromoplasts, while the relatively low incorporation levels found in carotenoids suggest that lipid production may represent a competing pathway for carotenoid biosynthesis. Malate and pyruvate are efficiently converted into acetyl-CoA, in agreement with the active operation of the malic enzyme and the pyruvate dehydrogenase complex in the chromoplast. Our results have also shown that isolated chromoplasts can actively sustain anabolic processes without the exogenous supply of ATP, thus suggesting that these organelles may generate this energetic cofactor in an autonomous way. We have set up a

  13. Amyloid precursor protein and Presenilin 1 interaction studied by FRET in human H4 cells.

    PubMed

    Nizzari, Mario; Venezia, Valentina; Bianchini, Paolo; Caorsi, Valentina; Diaspro, Alberto; Repetto, Emanuela; Thellung, Stefano; Corsaro, Alessandro; Carlo, Pia; Schettini, Gennaro; Florio, Tullio; Russo, Claudio

    2007-01-01

    The mayor pathologic hallmarks of Alzheimer's disease (AD) are senile plaque and neurofibrillary tangles. Senile plaque are primarily made up of deposits of amyloid-beta protein, a proteolytic product derived from the amyloid precursor protein (APP). APP is a transmembrane protein detected into the endoplasmic reticulum, in the Golgi apparatus, at the cell surface, recycled by endocytosis to endosomes, whose physiological function is unclear. Presenilins (PS), are a component of gamma-secretase complex that cleave alpha-CTFs (carboxy-terminal fragment), or beta-CTFs, leaving 40 or 42 amino acids amyloid-beta peptides and 58 or 56 amino acids intracellular domains (AICD). Where the amyloid-beta peptides is generated is not clear. The study of APP-PS interaction in specific cell compartments provides a good opportunity to light upon the molecular mechanisms regulating the activity of the "gamma-secretase complex," and where beta-amyloid is generated. In our study we used a biophysical assay of protein proximity: fluorescence resonance energy transfer (FRET), that can provide information about molecular interactions when two proteins are in the close proximity (<10 nm), to examine the subcellular localization and interaction between APP and PS1 in human neuroglioma cells (H4). Confocal microscopic analysis reveals extensive colocalization in different cells' compartment, and centrosomal or microtubule organizing center (MTOC) localization of APP and PS1, but not necessarily a close molecular interaction. We used FRET to determine if APP and PS1 interact at the cell centrosome. FRET data suggest a close interaction between APP and PS1 in subcellular compartments and at the centrosome of H4 cells. Using this approach we show that APP and PS1 are closely associated in the centrosomes of the H4 cell.

  14. Large-scale expansion of human skin-derived precursor cells (hSKPs) in stirred suspension bioreactors.

    PubMed

    Surrao, Denver C; Boon, Kathryn; Borys, Breanna; Sinha, Sarthak; Kumar, Ranjan; Biernaskie, Jeff; Kallos, Michael S

    2016-12-01

    Human skin-derived precursor cells (hSKPs) are multipotent adult stem cells found in the dermis of human skin. Incorporation of hSKPs into split-thickness skin grafts (STSGs), the current gold standard to treat severe burns or tissue resections, has been proposed as a treatment option to enhance skin wound healing and tissue function. For this approach to be clinically viable substantial quantities of hSKPs are required, which is the rate-limiting step, as only a few thousand hSKPs can be isolated from an autologous skin biopsy without causing donor site morbidity. In order to produce sufficient quantities of clinically viable cells, we have developed a bioprocess capable of expanding hSKPs as aggregates in stirred suspension bioreactors (SSBs). In this study, we found hSKPs from adult donors to expand significantly more (P < 0.05) at 60 rpm in SSBs than in static cultures. Furthermore, the utility of the SSBs, at 60 rpm is demonstrated by serial passaging of hSKPs from a small starting population, which can be isolated from an autologous skin biopsy without causing donor site morbidity. At 60 rpm, aggregates were markedly smaller and did not experience oxygen diffusional limitations, as seen in hSKPs cultured at 40 rpm. While hSKPs also grew at 80 rpm (0.74 Pa) and 100 rpm (1 Pa), they produced smaller aggregates due to high shear stress. The pH of the media in all the SSBs was closer to biological conditions and significantly different (P < 0.05) from static cultures, which recorded acidic pH conditions. The nutrient concentrations of the media in all the SSBs and static cultures did not drop below acceptable limits. Furthermore, there was no significant build-up of waste products to limit hSKP expansion in the SSBs. In addition, hSKP markers were maintained in the 60 rpm SSB as demonstrated by immunocytochemistry. This method of growing hSKPs in a batch culture at 60 rpm in a SSB represents an important first step in developing an

  15. Materials Design Through Chemical Control of Precursors

    DTIC Science & Technology

    2008-08-22

    Ligand Sets,” H. M. El-Kaderi, M.J. Heeg, and C.H. Winter, Polyhedron 2006, 25, 224-234. 7. “Atomic Layer Deposition of Ga2O3 Films from a...poster presentation. 4. “Atomic Layer Deposition (ALD) of High Quality Ga2O3 Thin Films from a Dimeric Dialkylamido-Bridged Gallium Complex,” C. L...growth of Ga2O3 films from a new metalorganic precursor (“Atomic Layer Deposition of Ga2O3 Films from a 4 Dialkylamido-Based Precursor,” C. L

  16. Ribonucleoprotein organization of eukaryotic RNA. XXXII. U2 small nuclear RNA precursors and their accurate 3' processing in vitro as ribonucleoprotein particles.

    PubMed

    Wieben, E D; Nenninger, J M; Pederson, T

    1985-05-05

    Biosynthetic precursors of U2 small nuclear RNA have been identified in cultured human cells by hybrid-selection of pulse-labeled RNA with cloned U2 DNA. These precursor molecules are one to approximately 16 nucleotides longer than mature U2 RNA and contain 2,2,7-trimethylguanosine "caps". The U2 RNA precursors are associated with proteins that react with a monoclonal antibody for antigens characteristic of small nuclear ribonucleoprotein particles. Like previously described precursors of U1 and U4 small nuclear RNAs, the pre-U2 RNAs are recovered in cytoplasmic fractions, although it is not known if this is their location in vivo. The precursors are processed to mature-size U2 RNA when cytoplasmic extracts are incubated in vitro at 37 degrees C. Mg2+ is required but ATP is not. The ribonucleoprotein structure of the pre-U2 RNA is maintained during the processing reaction in vitro, as are the 2,2,7-trimethylguanosine caps. The ribonucleoprotein organization is of major importance, as exogenous, protein-free U2 RNA precursors are degraded rapidly in the in vitro system. Two lines of evidence indicate that the conversion of U2 precursors to mature-size U2 RNA involves a 3' processing reaction. First, the reaction is unaffected by a large excess of mature U2 small nuclear RNP, whose 5' trimethylguanosine caps would be expected to compete for a 5' processing activity. Second, when pre-U2 RNA precursors are first stoichiometrically decorated with an antibody specific for 2,2,7-trimethylguanosine, the extent of subsequent processing in vitro is unaffected. These results provide the first demonstration of a eukaryotic RNA processing reaction in vitro occurring within a ribonucleoprotein particle.

  17. Modeling precursor diffusion and reaction of atomic layer deposition in porous structures

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Keuter, Thomas, E-mail: t.keuter@fz-juelich.de; Menzler, Norbert Heribert; Mauer, Georg

    2015-01-01

    Atomic layer deposition (ALD) is a technique for depositing thin films of materials with a precise thickness control and uniformity using the self-limitation of the underlying reactions. Usually, it is difficult to predict the result of the ALD process for given external parameters, e.g., the precursor exposure time or the size of the precursor molecules. Therefore, a deeper insight into ALD by modeling the process is needed to improve process control and to achieve more economical coatings. In this paper, a detailed, microscopic approach based on the model developed by Yanguas-Gil and Elam is presented and additionally compared with themore » experiment. Precursor diffusion and second-order reaction kinetics are combined to identify the influence of the porous substrate's microstructural parameters and the influence of precursor properties on the coating. The thickness of the deposited film is calculated for different depths inside the porous structure in relation to the precursor exposure time, the precursor vapor pressure, and other parameters. Good agreement with experimental results was obtained for ALD zirconiumdioxide (ZrO{sub 2}) films using the precursors tetrakis(ethylmethylamido)zirconium and O{sub 2}. The derivation can be adjusted to describe other features of ALD processes, e.g., precursor and reactive site losses, different growth modes, pore size reduction, and surface diffusion.« less

  18. Observations of Electron-driven Evaporation in a Flare Precursor

    NASA Astrophysics Data System (ADS)

    Li, Dong; Li, Ying; Su, Wei; Huang, Yu; Ning, Zongjun

    2018-02-01

    We investigate the relationship between the blueshifts of a hot emission line and the nonthermal emissions in microwave and hard X-ray (HXR) wavelengths in the precursor of a solar flare on 2014 October 27. The flare precursor is identified as a small but well-developed peak in the soft X-ray and extreme-ultraviolet passbands before the GOES flare onset, which is accompanied by a pronounced burst in microwave 17 and 34 GHz and in HXR 25–50 keV. The slit of the Interface Region Imaging Spectrograph (IRIS) stays on one ribbon-like transient during the flare precursor phase, which shows visible nonthermal emissions in Nobeyama Radioheliograph and RHESSI images. The IRIS spectroscopic observations show that the hot line of Fe XXI 1354.09 Å (log T ∼ 7.05) displays blueshifts, while the cool line of Si IV 1402.77 Å (log T ∼ 4.8) exhibits redshifts. The blueshifts and redshifts are well correlated with each other, indicative of an explosive chromospheric evaporation during the flare precursor phase combining a high nonthermal energy flux with a short characteristic timescale. In addition, the blueshifts of Fe XXI 1354.09 Å are well correlated with the microwave and HXR emissions, implying that the explosive chromospheric evaporation during the flare precursor phase is driven by nonthermal electrons.

  19. Evolution of Iodoplumbate Complexes in Methylammonium Lead Iodide Perovskite Precursor Solutions

    DOE Office of Scientific and Technical Information (OSTI.GOV)

    Sharenko, Alexander; Mackeen, Cameron; Jewell, Leila

    Here in this study we investigate the local structure present in single-step precursor solutions of methylammonium lead iodide (MAPbI 3) perovskite as a function of organic and inorganic precursor ratio, as well as with hydriodic acid (HI), using X-ray absorption spectroscopy. An excess of organic precursor as well as the use of HI as a processing additive has been shown to lead to the formation of smooth, continuous, pinhole free MAPbI 3 films, whereas films produced from precursor solutions containing molar equivalents of methylammonium iodide (MAI) and PbI 2 lead to the formation of a discontinuous, needlelike morphology. We nowmore » show that as the amount of excess MAI in the precursor solution is increased, the iodide coordination of iodoplumbate complexes present in solution increases. The use of HI results in a similar increase in iodide coordination. We therefore offer insight into how solution chemistry can be used to control MAPbI 3 thin film morphology by revealing a strong correlation between the lead coordination chemistry in precursor solutions and the surface coverage and morphology of the resulting MAPbI 3 film.« less

  20. Evolution of Iodoplumbate Complexes in Methylammonium Lead Iodide Perovskite Precursor Solutions

    DOE PAGES

    Sharenko, Alexander; Mackeen, Cameron; Jewell, Leila; ...

    2017-02-02

    Here in this study we investigate the local structure present in single-step precursor solutions of methylammonium lead iodide (MAPbI 3) perovskite as a function of organic and inorganic precursor ratio, as well as with hydriodic acid (HI), using X-ray absorption spectroscopy. An excess of organic precursor as well as the use of HI as a processing additive has been shown to lead to the formation of smooth, continuous, pinhole free MAPbI 3 films, whereas films produced from precursor solutions containing molar equivalents of methylammonium iodide (MAI) and PbI 2 lead to the formation of a discontinuous, needlelike morphology. We nowmore » show that as the amount of excess MAI in the precursor solution is increased, the iodide coordination of iodoplumbate complexes present in solution increases. The use of HI results in a similar increase in iodide coordination. We therefore offer insight into how solution chemistry can be used to control MAPbI 3 thin film morphology by revealing a strong correlation between the lead coordination chemistry in precursor solutions and the surface coverage and morphology of the resulting MAPbI 3 film.« less