scholarly journals Comparative gene expression and phenotype analyses of skeletal muscle from aged wild-type and PAPP-A-deficient mice

2016 ◽  
Vol 80 ◽  
pp. 36-42 ◽  
Author(s):  
Cheryl A. Conover ◽  
Laurie K. Bale ◽  
K. Sreekumaran Nair
2005 ◽  
Vol 22 (2) ◽  
pp. 204-212 ◽  
Author(s):  
M. Thabet ◽  
T. Miki ◽  
S. Seino ◽  
J.-M. Renaud

Although it has been suggested that the ATP-sensitive K+ (KATP) channel protects muscle against function impairment, most studies have so far given little evidence for significant perturbation in the integrity and function of skeletal muscle fibers from inactive mice that lack KATP channel activity in their cell membrane. The objective was, therefore, to test the hypothesis that KATP channel-deficient skeletal muscle fibers become damaged when mice are subjected to stress. Wild-type and KATP channel-deficient mice (Kir6.2−/− mice) were subjected to 4–5 wk of treadmill running at either 20 m/min with 0° inclination or at 24 m/min with 20° uphill inclination. Muscles of all wild-type mice and of nonexercised Kir6.2−/− mice had very few fibers with internal nuclei. After 4–5 wk of treadmill running, there was little evidence for connective tissues and mononucleated cells in Kir6.2−/− hindlimb muscles, whereas the number of fibers with internal nuclei, which appear when damaged fibers are regenerated by satellite cells, was significantly higher in Kir6.2−/− than wild-type mice. Between 5% and 25% of the total number of fibers in Kir6.2−/− extensor digitum longus, plantaris, and tibialis muscles had internal nuclei, and most of such fibers were type IIB fibers. Contrary to hindlimb muscles, diaphragms of Kir6.2−/− mice that had run at 24 m/min had few fibers with internal nuclei, but mild to severe fiber damage was observed. In conclusion, the study provides for the first time evidence 1) that the KATP channels of skeletal muscle are essential to prevent fiber damage, and thus muscle dysfunction; and 2) that the extent of fiber damage is greater and the capacity of fiber regeneration is less in Kir6.2−/− diaphragm muscles compared with hindlimb muscles.


Blood ◽  
2001 ◽  
Vol 97 (6) ◽  
pp. 1703-1711 ◽  
Author(s):  
Frederic Lluı́s ◽  
Josep Roma ◽  
Mònica Suelves ◽  
Maribel Parra ◽  
Gloria Aniorte ◽  
...  

Plasminogen activators urokinase-type plasminogen activator (uPA) and tissue-type plasminogen activator (tPA) are extracellular proteases involved in various tissue remodeling processes. A requirement for uPA activity in skeletal myogenesis was recently demonstrated in vitro. The role of plasminogen activators in skeletal muscle regeneration in vivo in wild-type, uPA-deficient, and tPA-deficient mice is investigated here. Wild-type and tPA−/− mice completely repaired experimentally damaged skeletal muscle. In contrast, uPA−/− mice had a severe regeneration defect, with decreased recruitment of blood-derived monocytes to the site of injury and with persistent myotube degeneration. In addition, uPA-deficient mice accumulated fibrin in the degenerating muscle fibers; however, the defibrinogenation of uPA-deficient mice resulted in a correction of the muscle regeneration defect. A similar severe regeneration deficit with persistent fibrin deposition was also reproducible in plasminogen-deficient mice after injury, suggesting that fibrinolysis by uPA-mediated plasminogen activation plays a fundamental role in skeletal muscle regeneration. In conclusion, the uPA-plasmin system is identified as a critical component of the mammalian skeletal muscle regeneration process, possibly because it prevents intramuscular fibrin accumulation and contributes to the adequate inflammatory response after injury. These studies demonstrate the requirement of an extracellular proteolytic cascade during muscle regeneration in vivo.


2011 ◽  
Vol 34 (3) ◽  
pp. 386-395 ◽  
Author(s):  
Yan Jiao ◽  
Jifei Zhang ◽  
Jian Yan ◽  
John Stuart ◽  
Griffin Gibson ◽  
...  

1999 ◽  
Vol 277 (6) ◽  
pp. C1263-C1268 ◽  
Author(s):  
Constantinos Kyriakides ◽  
William Austen ◽  
Yong Wang ◽  
Joanne Favuzza ◽  
Lester Kobzik ◽  
...  

The relative inflammatory roles of neutrophils, selectins, and terminal complement components are investigated in this study of skeletal muscle reperfusion injury. Mice underwent 2 h of hindlimb ischemia followed by 3 h of reperfusion. The role of neutrophils was defined by immunodepletion, which reduced injury by 38%, as did anti-selectin therapy with recombinant soluble P-selectin glycoprotein ligand-immunoglobulin (Ig) fusion protein. Injury in C5-deficient and soluble complement receptor type 1-treated wild-type mice was 48% less than that of untreated wild-type animals. Injury was restored in C5-deficient mice reconstituted with wild-type serum, indicating the effector role of C5–9. Neutropenic C5-deficient animals showed additive reduction in injuries (71%), which was lower than C5-deficient neutrophil-replete mice, indicating neutrophil activity without C5a. Hindlimb histological injury was worse in ischemic wild-type and C5-deficient animals reconstituted with wild-type serum. In conclusion, the membrane attack complex and neutrophils act additively to mediate skeletal muscle reperfusion injury. Neutrophil activity is independent of C5a but is dependent on selectin-mediated adhesion.


PLoS ONE ◽  
2014 ◽  
Vol 9 (4) ◽  
pp. e94356 ◽  
Author(s):  
Heather K. Smith ◽  
Kenneth G. Matthews ◽  
Jenny M. Oldham ◽  
Ferenc Jeanplong ◽  
Shelley J. Falconer ◽  
...  

Blood ◽  
2002 ◽  
Vol 99 (8) ◽  
pp. 2835-2844 ◽  
Author(s):  
Mònica Suelves ◽  
Roser López-Alemany ◽  
Frederic Lluı́s ◽  
Gloria Aniorte ◽  
Erika Serrano ◽  
...  

Abstract Plasmin, the primary fibrinolytic enzyme, has a broad substrate spectrum and is implicated in biologic processes dependent upon proteolytic activity, such as tissue remodeling and cell migration. Active plasmin is generated from proteolytic cleavage of the zymogen plasminogen (Plg) by urokinase-type plasminogen activator (uPA) and tissue-type plasminogen activator (tPA). Here, we have investigated the role of plasmin in C2C12 myoblast fusion and differentiation in vitro, as well as in skeletal muscle regeneration in vivo, in wild-type and Plg-deficient mice. Wild-type mice completely repaired experimentally damaged skeletal muscle. In contrast, Plg−/− mice presented a severe regeneration defect with decreased recruitment of blood-derived monocytes and lymphocytes to the site of injury and persistent myotube degeneration. In addition, Plg-deficient mice accumulated fibrin in the degenerating muscle fibers; however, fibrinogen depletion of Plg-deficient mice resulted in a correction of the muscular regeneration defect. Because we found that uPA, but not tPA, was induced in skeletal muscle regeneration, and persistent fibrin deposition was also reproducible in uPA-deficient mice following injury, we propose that fibrinolysis by uPA-dependent plasmin activity plays a fundamental role in skeletal muscle regeneration. In summary, we identify plasmin as a critical component of the mammalian skeletal muscle regeneration process, possibly by preventing intramuscular fibrin accumulation and by contributing to the adequate inflammatory response after injury. Finally, we found that inhibition of plasmin activity with α2-antiplasmin resulted in decreased myoblast fusion and differentiation in vitro. Altogether, these studies demonstrate the requirement of plasmin during myogenesis in vitro and muscle regeneration in vivo.


2006 ◽  
Vol 169 (2) ◽  
pp. 212-219 ◽  
Author(s):  
Tarmo Areda ◽  
Sirli Raud ◽  
Mari-Anne Philips ◽  
Jürgen Innos ◽  
Toshimitsu Matsui ◽  
...  

Blood ◽  
2016 ◽  
Vol 128 (22) ◽  
pp. 1051-1051
Author(s):  
Vikas Madan ◽  
Lin Han ◽  
Norimichi Hattori ◽  
Anand Mayakonda ◽  
Qiao-Yang Sun ◽  
...  

Abstract Chromosomal translocation t(8;21) (q22;q22) leading to generation of oncogenic RUNX1-RUNX1T1 fusion is a cytogenetic abnormality observed in about 10% of acute myelogenous leukemia (AML). Studies in animal models and recent next generation sequencing approaches have suggested cooperativity of secondary genetic lesions with t(8;21) in inducing leukemogenesis. In this study, we used targeted and whole exome sequencing of 93 cases (including 30 with matched relapse samples) to profile the mutational landscape of t(8;21) AML at initial diagnosis and post-therapy relapse. We identified recurrent mutations of KIT, TET2, MGA, FLT3, NRAS, DHX15, ASXL1 and KMT2Dgenes in this subtype of AML. In addition, high frequency of truncating alterations in ASXL2 gene (19%) also occurred in our cohort. ASXL2 is a member of mammalian ASXL family involved in epigenetic regulation through recruitment of polycomb or trithorax complexes. Unlike its closely related homolog ASXL1, which is mutated in several hematological malignancies including AML, MDS, MPN and others; mutations of ASXL2 occur specifically in t(8;21) AML. We observed that lentiviral shRNA-mediated silencing of ASXL2 impaired in vitro differentiation of t(8;21) AML cell line, Kasumi-1, and enhanced its colony forming ability. Gene expression analysis uncovered dysregulated expression of several key hematopoiesis genes such as IKZF2, JAG1, TAL1 and ARID5B in ASXL2 knockdown Kasumi-1 cells. Further, to investigate implications of loss of ASXL2 in vivo, we examined hematopoiesis in Asxl2 deficient mice. We observed an age-dependent increase in white blood cell count in the peripheral blood of Asxl2 KO mice. Myeloid progenitors from Asxl2 deficient mice possessed higher re-plating ability and displayed altered differentiation potential in vitro. Flow cytometric analysis of >1 year old mice revealed increased proportion of Lin-Sca1+Kit+ (LSK) cells in the bone marrow of Asxl2 deficient mice, while the overall bone marrow cellularity was significantly reduced. In vivo 5-bromo-2'-deoxyuridine incorporation assay showed increased cycling of LSK cells in mice lacking Asxl2. Asxl2 deficiency also led to perturbed maturation of myeloid and erythroid precursors in the bone marrow, which resulted in altered proportions of mature myeloid populations in spleen and peripheral blood. Further, splenomegaly was observed in old ASXL2 KO mice and histological and flow cytometric examination of ASXL2 deficient spleens demonstrated increased extramedullary hematopoiesis and myeloproliferation compared with the wild-type controls. Surprisingly, loss of ASXL2 also led to impaired T cell development as indicated by severe block in maturation of CD4-CD8- double negative (DN) population in mice >1 year old. These findings established a critical role of Asxl2 in maintaining steady state hematopoiesis. To gain mechanistic insights into its role during hematopoietic differentiation, we investigated changes in histone marks and gene expression affected by loss of Asxl2. Whole transcriptome sequencing of LSK population revealed dysregulated expression of key myeloid-specific genes including Mpo, Ltf, Ngp Ctsg, Camp and Csf1rin cells lacking Asxl2 compared to wild-type control. Asxl2 deficiency also caused changes in histone modifications, specifically H3K27 trimethylation levels were decreased and H2AK119 ubiquitination levels were increased in Asxl2 KO bone marrow cells. Global changes in histone marks in control and Asxl2 deficient mice are being investigated using ChIP-Sequencing. Finally, to examine cooperativity between the loss of Asxl2 and RUNX1-RUNX1T1 in leukemogenesis, KO and wild-type fetal liver cells were transduced with retrovirus expressing AML1-ETO 9a oncogene and transplanted into irradiated recipient mice, the results of this ongoing study will be discussed. Overall, our sequencing studies have identified ASXL2 as a gene frequently altered in t(8;21) AML. Functional studies in mouse model reveal that loss of ASXL2 causes defects in hematopoietic differentiation and leads to myeloproliferation, suggesting an essential role of ASXL2 in normal and malignant hematopoiesis. *LH and NH contributed equally Disclosures Ogawa: Takeda Pharmaceuticals: Consultancy, Research Funding; Sumitomo Dainippon Pharma: Research Funding; Kan research institute: Consultancy, Research Funding.


Sign in / Sign up

Export Citation Format

Share Document