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Hunt LC, Upadhyay A, Jazayeri JA, Tudor EM, White JD. Caspase-3, myogenic transcription factors and cell cycle inhibitors are regulated by leukemia inhibitory factor to mediate inhibition of myogenic differentiation. Skelet Muscle 2011; 1:17. [PMID: 21798094 PMCID: PMC3156640 DOI: 10.1186/2044-5040-1-17] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2010] [Accepted: 04/07/2011] [Indexed: 11/13/2022] Open
Abstract
BACKGROUND Leukemia inhibitory factor (LIF) is known to inhibit myogenic differentiation as well as to inhibit apoptosis and caspase-3 activation in non-differentiating myoblasts. In addition caspase-3 activity is required for myogenic differentiation. Therefore the aim of this study was to further investigate mechanisms of the differentiation suppressing effect of LIF in particular the possibility of a caspase-3 mediated inhibition of differentiation. RESULTS LIF dependent inhibition of differentiation appeared to involve several mechanisms. Differentiating myoblasts that were exposed to LIF displayed increased transcripts for c-fos. Transcripts for the cell cycle inhibitor p21 as well as muscle regulatory factors myoD and myogenin were decreased with LIF exposure. However, LIF did not directly induce a proliferative effect under differentiation conditions, but did prevent the proportion of myoblasts that were proliferating from decreasing as differentiation proceeded. LIF stimulation decreased the percentage of cells positive for active caspase-3 occurring during differentiation. Both the effect of LIF inhibiting caspase-3 activation and differentiation appeared dependent on mitogen activated protein kinase and extracellular signal regulated kinase kinase (MEK) signalling. The role of LIF in myogenic differentiation was further refined to demonstrate that myoblasts are unlikely to secrete LIF endogenously. CONCLUSIONS Altogether this study provides a more comprehensive view of the role of LIF in myogenic differentiation including LIF and receptor regulation in myoblasts and myotubes, mechanisms of inhibition of differentiation and the link between caspase-3 activation, apoptosis and myogenic differentiation.
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Affiliation(s)
- Liam C Hunt
- Faculty of Veterinary Science, University of Melbourne, Flemington Road, Parkville, Victoria 3010, Australia
- Murdoch Childrens Research Institute, Royal Children's Hospital, Flemington Road, Parkville, Victoria 3052, Australia
| | - Aradhana Upadhyay
- Medicinal Chemistry and Drug Action, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus), 381 Royal Parade, Parkville, Victoria 3052, Melbourne, Australia
| | - Jalal A Jazayeri
- Medicinal Chemistry and Drug Action, Monash Institute of Pharmaceutical Sciences, Monash University (Parkville Campus), 381 Royal Parade, Parkville, Victoria 3052, Melbourne, Australia
| | - Elizabeth M Tudor
- Faculty of Veterinary Science, University of Melbourne, Flemington Road, Parkville, Victoria 3010, Australia
| | - Jason D White
- Faculty of Veterinary Science, University of Melbourne, Flemington Road, Parkville, Victoria 3010, Australia
- Murdoch Childrens Research Institute, Royal Children's Hospital, Flemington Road, Parkville, Victoria 3052, Australia
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2
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A defined long-term in vitro tissue engineered model of neuromuscular junctions. Biomaterials 2010; 31:4880-8. [PMID: 20346499 DOI: 10.1016/j.biomaterials.2010.02.055] [Citation(s) in RCA: 68] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2010] [Accepted: 02/21/2010] [Indexed: 01/08/2023]
Abstract
Neuromuscular junction (NMJ) formation, occurring between motoneurons and skeletal muscle, is a complex multistep process involving a variety of signaling molecules and pathways. In vitro motoneuron-muscle co-cultures are powerful tools to study the role of different growth factors, hormones and cellular structures involved in NMJ formation. In this study, a serum-free culture system utilizing defined temporal growth factor application and a non-biological substrate resulted in the formation of robust NMJs. The system resulted in long-term survival of the co-culture and selective expression of neonatal myosin heavy chain, a marker of myotube maturation. NMJ formation was verified by colocalization of dense clusters of acetylcholine receptors visualized using alpha-bungarotoxin and synaptophysin containing vesicles present in motoneuron axonal terminals. This model will find applications in basic NMJ research and tissue engineering applications such as bio-hybrid device development for limb prosthesis and regenerative medicine as well as for high-throughput drug and toxin screening applications.
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Das M, Rumsey JW, Bhargava N, Stancescu M, Hickman JJ. Skeletal muscle tissue engineering: a maturation model promoting long-term survival of myotubes, structural development of the excitation-contraction coupling apparatus and neonatal myosin heavy chain expression. Biomaterials 2009; 30:5392-402. [PMID: 19625080 DOI: 10.1016/j.biomaterials.2009.05.081] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2009] [Accepted: 05/25/2009] [Indexed: 01/17/2023]
Abstract
The use of defined in vitro systems to study the developmental and physiological characteristics of a variety of cell types is increasing, due in large part to their ease of integration with tissue engineering, regenerative medicine, and high-throughput screening applications. In this study, myotubes derived from fetal rat hind limbs were induced to develop several aspects of mature muscle including: sarcomere assembly, development of the excitation-contraction coupling apparatus and myosin heavy chain (MHC) class switching. Utilizing immunocytochemical analysis, anisotropic and isotropic band formation (striations) within the myotubes was established, indicative of sarcomere formation. In addition, clusters of ryanodine receptors were colocalized with dihydropyridine complex proteins which signaled development of the excitation-contraction coupling apparatus and transverse tubule biogenesis. The myotubes also exhibited MHC class switching from embryonic to neonatal MHC. Lastly, the myotubes survived significantly longer in culture (70-90 days) than myotubes from our previously developed system (20-25 days). These results were achieved by modifying the culture timeline as well as the development of a new medium formulation. This defined model system for skeletal muscle maturation supports the goal of developing physiologically relevant muscle constructs for use in tissue engineering and regenerative medicine as well as for high-throughput screening applications.
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Affiliation(s)
- Mainak Das
- Hybrid Systems Lab, NanoScience Technology Center, University of Central Florida, Suite 402, Research Pavilion, 12424 Research Parkway, Orlando, FL 32826, USA
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4
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Trenerry MK, Carey KA, Ward AC, Farnfield MM, Cameron-Smith D. Exercise-induced activation of STAT3 signaling is increased with age. Rejuvenation Res 2008; 11:717-24. [PMID: 18729804 DOI: 10.1089/rej.2007.0643] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Activation of the transcription factor signal transducers and activators of transcription (STAT) 3 is common to many inflammatory cytokines and growth factors, with recent evidence of involvement in skeletal muscle regeneration. The purpose of this study was to determine whether STAT3 signaling activation is regulated differentially, at rest and following intense resistance exercise, in aged human skeletal muscle. Skeletal muscle biopsies were harvested from healthy younger (n = 11, 20.4 +/- 0.8 years) and older men (n = 10, 67.4 +/- 1.3 years) under resting conditions and 2 h after the completion of resistance exercise. No differences were evident at rest, whereas the phosphorylation of STAT3 was significantly increased in old (23-fold) compared to young (5-fold) subjects after exercise. This correlated with significantly higher induction of the STAT3 target genes including; interleukin-6 (IL-6), JUNB, c-MYC, and suppressor of cytokine signaling (SOCS) 3 mRNA in older subjects following exercise. Despite increased SOCS3 mRNA, cellular protein abundance was suppressed. SOCS3 protein is an important negative regulator of STAT3 activation and cytokine signaling. Thus, in aged human muscle, elevated responsiveness of the STAT3 signaling pathway and suppressed SOCS3 protein are evident following resistance exercise. These data suggest that enhanced STAT3 signaling responsiveness to proinflammatory factors may impact on mechanisms of muscle repair and regeneration.
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Affiliation(s)
- Marissa K Trenerry
- School of Exercise and Nutrition Science, Deakin University, 221 Burwood Highway, Burwood, Victoria 3125, Australia
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5
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Sarig R, Baruchi Z, Fuchs O, Nudel U, Yaffe D. Regeneration and transdifferentiation potential of muscle-derived stem cells propagated as myospheres. Stem Cells 2006; 24:1769-78. [PMID: 16574751 DOI: 10.1634/stemcells.2005-0547] [Citation(s) in RCA: 68] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
We have isolated from mouse skeletal muscle a subpopulation of slow adherent myogenic cells that can proliferate for at least several months as suspended clusters of cells (myospheres). In the appropriate conditions, the myospheres adhere to the plate, spread out, and form a monolayer of MyoD(+) cells. Unlike previously described myogenic cell lines, most of the myosphere cells differentiate, without cell fusion, into thin mononucleated contractile fibers, which express myogenin and skeletal muscle myosin heavy chain. The presence of Pax-7 in a significant proportion of these cells suggests that they originate from satellite cells. The addition of leukemia inhibitory factor to the growth medium of the myospheres enhances proliferation and dramatically increases the proportion of cells expressing Sca-1, which is expressed by several types of stem cells. The capacity of myosphere cells to transdifferentiate to other mesodermal cell lineages was examined. Exposure of cloned myosphere cells to bone morphogenetic protein resulted in suppression of myogenic differentiation and induction of osteogenic markers such as alkaline phosphatase and osteocalcin. These cells also sporadically differentiated to adipocytes. Myosphere cells could not, so far, be induced to transdifferentiate to hematopoietic cells. When inoculated into injured muscle, myosphere-derived cells participated in regeneration, forming multinucleated cross-striated mature fibers. This suggests a potential medical application.
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Affiliation(s)
- Rachel Sarig
- Department of Molecular Cell Biology, The Weizmann Institute of Science, Rehovot, Israel.
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6
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Jo C, Kim H, Jo I, Choi I, Jung SC, Kim J, Kim SS, Jo SA. Leukemia inhibitory factor blocks early differentiation of skeletal muscle cells by activating ERK. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2005; 1743:187-97. [PMID: 15843032 DOI: 10.1016/j.bbamcr.2004.11.002] [Citation(s) in RCA: 53] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2003] [Revised: 10/13/2004] [Accepted: 11/05/2004] [Indexed: 01/18/2023]
Abstract
Leukemia inhibitory factor (LIF) is a multifunctional cytokine belonging to the interleukin-6 family and has been shown to stimulate regeneration of injured skeletal muscle. Although LIF has been shown to stimulate muscle cell proliferation, its precise role in differentiation is unclear. Thus, we examined the effect of LIF on the differentiation of cultured C2C12 myoblast cells. In this study, we used both non-glycosylated LIF expressed in bacteria and glycosylated LIF secreted from NIH3T3 cells infected with Ad-LIF. Both non-glycosylated and glycosylated LIF blocked differentiation of myoblasts as measured by expression of myosin heavy chain and myotube formation. Treatment of myoblasts with LIF induced phosphorylation of ERK, and the LIF-induced inhibitory effect on myogenesis was blocked by pretreatment with U0126, a specific MEK inhibitor, and transient transfection with dominant negative (DN)-MEK1. In contrast, although LIF activated STAT3, the LIF-induced repression of the MCK transcriptional activity was not reversed by pretreatment with AG490, a specific Jak kinase inhibitor or transient transfection with DN-STAT3. Additionally, LIF exhibited its inhibitory effect on myogenesis only when cells were treated at earlier than 12 h after inducing differentiation. Taken together, these results suggest that LIF strongly inhibited early myogenic differentiation though activation of the ERK signaling pathway and its effect is irrespective of glycosylation.
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Affiliation(s)
- Chulman Jo
- Department of Biomedical Sciences, National Institute of Health, Seoul, South Korea
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7
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Natsu K, Ochi M, Mochizuki Y, Hachisuka H, Yanada S, Yasunaga Y. Allogeneic Bone Marrow-Derived Mesenchymal Stromal Cells Promote the Regeneration of Injured Skeletal Muscle without Differentiation into Myofibers. ACTA ACUST UNITED AC 2004; 10:1093-112. [PMID: 15363167 DOI: 10.1089/ten.2004.10.1093] [Citation(s) in RCA: 90] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023]
Abstract
Half-stratum laceration was performed on the tibialis anterior muscle of Sprague-Dawley (SD) rats as a skeletal muscle injury model. Bone marrow-derived mesenchymal stromal cells (BMMSCs), which were derived from enhanced green fluorescent protein (GFP) transgenic SD rats, were transplanted into the injured site. Tensile strength produced by nerve stimulation was measured for functional evaluation before sacrifice. Specimens of the tibialis anterior muscles were stained with hematoxylin and eosin, and immunohistochemically stained for histological evaluation. Our results showed that transplanted BMMSCs promoted maturation of myofibers histologically and made the injured muscle acquire almost normal muscle power functionally by 1 month after transplantation. However, the results of immunohistochemical staining could not prove that transplanted BMMSCs differentiated into or fused to skeletal myofibers, although it showed that transplanted BMMSCs seemed to differentiate into muscle precursor cells. Therefore, our results indicated that BMMSCs contributed to the regeneration of skeletal muscle by mechanisms other than fusion to myofibers after differentiation.
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MESH Headings
- Animals
- Bone Marrow Cells/pathology
- Bone Marrow Transplantation/methods
- Bone Marrow Transplantation/pathology
- Cell Differentiation
- Cells, Cultured
- Male
- Mesenchymal Stem Cell Transplantation/methods
- Mesenchymal Stem Cells/pathology
- Muscle Contraction
- Muscle Fibers, Skeletal/pathology
- Muscle, Skeletal/injuries
- Muscle, Skeletal/pathology
- Muscle, Skeletal/physiopathology
- Muscle, Skeletal/surgery
- Rats
- Rats, Sprague-Dawley
- Regeneration/physiology
- Stromal Cells/pathology
- Stromal Cells/transplantation
- Transplantation, Homologous
- Wound Healing/physiology
- Wounds, Penetrating/pathology
- Wounds, Penetrating/physiopathology
- Wounds, Penetrating/surgery
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Affiliation(s)
- Koji Natsu
- Department of Orthopaedic Surgery, Programs for Applied Biomedicine, Division of Clinical Medical Science, Graduate School of Biomedical Sciences, Hiroshima University, Hiroshima 734-8551, Japan.
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8
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Jasmin L, Ohara PT. Anatomical identification of neurons responsive to nociceptive stimuli. METHODS IN MOLECULAR MEDICINE 2004; 99:167-88. [PMID: 15131337 DOI: 10.1385/1-59259-770-x:167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/29/2023]
Abstract
We describe methods for labeling and identifying neurons within the central nervous system involved in the transmission of nociceptive stimuli. The most reliable methods are physiological identification followed by intracellular injection or immunocytochemical detection of stimulus-induced markers such as Fos. These latter strategies are used with appropriate controls to distinguish neurons activated secondarily (e.g., motor response or inhibitory neurons) by the nociceptive stimuli. Other methods include location and morphology as determined by standard cytological and tracing methods and/or the presence of specific neurochemical markers such as substance P determined by immunocytochemistry.
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Affiliation(s)
- Luc Jasmin
- Department of Neurological Surgery, University of California San Francisco, USA
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9
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Abstract
Under normal circumstances, mammalian adult skeletal muscle is a stable tissue with very little turnover of nuclei. However, upon injury, skeletal muscle has the remarkable ability to initiate a rapid and extensive repair process preventing the loss of muscle mass. Skeletal muscle repair is a highly synchronized process involving the activation of various cellular responses. The initial phase of muscle repair is characterized by necrosis of the damaged tissue and activation of an inflammatory response. This phase is rapidly followed by activation of myogenic cells to proliferate, differentiate, and fuse leading to new myofiber formation and reconstitution of a functional contractile apparatus. Activation of adult muscle satellite cells is a key element in this process. Muscle satellite cell activation resembles embryonic myogenesis in several ways including the de novo induction of the myogenic regulatory factors. Signaling factors released during the regenerating process have been identified, but their functions remain to be fully defined. In addition, recent evidence supports the possible contribution of adult stem cells in the muscle regeneration process. In particular, bone marrow-derived and muscle-derived stem cells contribute to new myofiber formation and to the satellite cell pool after injury.
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10
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White JD, Davies M, McGeachie J, Grounds MD. An evaluation of leukaemia inhibitory factor as a potential therapeutic agent in the treatment of muscle disease. Neuromuscul Disord 2002; 12:909-16. [PMID: 12467745 DOI: 10.1016/s0960-8966(02)00117-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
The exogenous delivery of growth factors and cytokines is a potential therapeutic strategy to alleviate the degenerative effects of primary inherited myopathies such as Duchenne muscular dystrophy. The mdx mouse diaphragm is a model for examining the progressive degeneration of dystrophic muscle. We have delivered leukaemia inhibitory factor to the mdx diaphragm using slow release alginate gels. Previous studies have reported an improvement in the histology of mdx diaphragms after delivery of leukaemia inhibitory factor in a similar manner, but little attention has been paid to the mechanism by which leukaemia inhibitory factor acts. We have used autoradiography to examine cell proliferation, Evans Blue Dye to examine myofibre damage, and morphometric analysis to examine histology in leukaemia-inhibitory-factor-treated diaphragms and compared them with untreated mdx and normal C57Bl10/ScSn diaphragms. Autoradiography showed that although myoblast proliferation was significantly increased in leukaemia inhibitory factor-treated mdx diaphragms, leukaemia inhibitory factor did not reduce myofibre damage and no histological improvement was observed. The data presented here, while demonstrating a role for leukaemia inhibitory factor in myoblast proliferation, do not support a strong and consistent benefit of leukaemia inhibitory factor on dystrophic muscle in vivo as a means of alleviating the effects of chronic dystrophic muscle degeneration.
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Affiliation(s)
- Jason D White
- Department of Anatomy and Human Biology, University of Western Australia, Stirling Hwy, Western Australia, 6009, Crawley, Australia.
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11
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Kami K, Senba E. In vivo activation of STAT3 signaling in satellite cells and myofibers in regenerating rat skeletal muscles. J Histochem Cytochem 2002; 50:1579-89. [PMID: 12486080 DOI: 10.1177/002215540205001202] [Citation(s) in RCA: 75] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022] Open
Abstract
Although growth factors and cytokines play critical roles in skeletal muscle regeneration, intracellular signaling molecules that are activated by these factors in regenerating muscles have been not elucidated. Several lines of evidence suggest that leukemia inhibitory factor (LIF) is an important cytokine for the proliferation and survival of myoblasts in vitro and acceleration of skeletal muscle regeneration. To elucidate the role of LIF signaling in regenerative responses of skeletal muscles, we examined the spatial and temporal activation patterns of an LIF-associated signaling molecule, the signal transducer and activator transcription 3 (STAT3) proteins in regenerating rat skeletal muscles induced by crush injury. At the early stage of regeneration, activated STAT3 proteins were first detected in the nuclei of activated satellite cells and then continued to be activated in proliferating myoblasts expressing both PCNA and MyoD proteins. When muscle regeneration progressed, STAT3 signaling was no longer activated in differentiated myoblasts and myotubes. In addition, activation of STAT3 was also detected in myonuclei within intact sarcolemmas of surviving myofibers that did not show signs of necrosis. These findings suggest that activation of STAT3 signaling is an important molecular event that induces the successful regeneration of injured skeletal muscles.
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Affiliation(s)
- Katsuya Kami
- Department of Health Science, Osaka University of Health and Sport Sciences, Wakayama, Japan.
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12
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Wang F, Trial J, Diwan A, Gao F, Birdsall H, Entman M, Hornsby P, Sivasubramaniam N, Mann D. Regulation of cardiac fibroblast cellular function by leukemia inhibitory factor. J Mol Cell Cardiol 2002; 34:1309-16. [PMID: 12392991 DOI: 10.1006/jmcc.2002.2059] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
BACKGROUND Previous studies have shown that leukemia inhibitory factor (LIF) provokes hypertrophic and cytoprotective effects in cardiac myocytes. However, the effects of LIF in cardiac fibroblasts are not known. Given that the cardiac fibroblast is the most abundant cell type in the heart, we sought to examine the functional effects of LIF on cardiac fibroblasts in vitro. RESULTS Short-term LIF stimulation (24h) had no effect on fibroblast proliferation and/or cell differentiation. However, longer-term LIF stimulation (48-72h) increased fibroblast proliferation, and significantly inhibited cardiac fibroblast differentiation into myofibroblasts. Moreover, 72h of LIF stimulation significantly reduced collagen content in cardiac fibroblasts cultures, as well as decreased MMP activity in fibroblast culture supernatants. CONCLUSION The results of this study suggest that LIF stimulation down-regulates several key components of the remodeling process, including collagen content and matrix metalloproteinase (MMP) activation, and thus suggest that LIF may play an important autocrine/paracrine role in preventing excessive extracellular matrix remodeling following acute myocardial injury.
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Affiliation(s)
- Feng Wang
- Winters Center for Heart Failure Research, Baylor College of Medicine, 6565 Fannin Street, Houston, TX 77030, USA
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13
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Dowsing BJ, Hayes A, Bennett TM, Morrison WA, Messina A. Effects of LIF dose and laminin plus fibronectin on axotomized sciatic nerves. Muscle Nerve 2000; 23:1356-64. [PMID: 10951438 DOI: 10.1002/1097-4598(200009)23:9<1356::aid-mus6>3.0.co;2-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
Leukemia inhibitory factor (LIF), a cytokine which has neurotrophic and myotrophic activities, has been shown to enhance nerve regeneration and consequent return of muscle function in the entubulation model of sciatic nerve repair. Fibronectin (FN) and laminin (LN) are two extracellular matrix (ECM) components that, when combined, promote axon growth in the entubulation model. The aim of this study was to determine the optimal LIF dose and the efficacy of FN plus LN administered either alone or simultaneously with the optimal LIF dose. We found that at 12 weeks following nerve repair, a single 10 ng LIF dose produced the largest medial gastrocnemius (MG) muscle mass (P < 0.0001) and maximum force contraction (P < 0.001). The diameter of the axons in the FN plus LN group were significantly greater than for saline (P < 0.001) and the LIF dose groups (P < 0.01). When 10 ng LIF was combined with FN plus LN, the MG muscle mass was significantly greater than the optimal LIF dose (P < 0.05), suggesting an additive effect. Our findings support the view that combinations of factors, which perhaps act on complementary mechanisms for nerve regeneration, will be required to maximally potentiate nerve regeneration and return of muscle function after nerve injury.
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Affiliation(s)
- B J Dowsing
- Bernard O'Brien Institute of Microsurgery, St. Vincent's Hospital, Fitzroy, Victoria, Australia.
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14
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Abstract
1. Leukaemia inhibitory factor (LIF) is a 180 amino acid single-chain protein, named after its effect on haematopoietic cells. Leukaemia inhibitory factor belongs to a group of cytokines that includes ciliary neurotrophic factor, interleukin (IL)-6, IL-11, cardiotrophin-1 and oncostatin M. All group members use the gp130 signal transducing subunit for intracellular signalling, but show differences in biological effect. 2. Research over the past 6-8 years has shown LIF to have potent neuromuscular activity. In vitro and in vivo studies on axotomy and nerve crush models demonstrate a powerful effect of LIF in enhancing the survival of both motor and sensory neurons, while reducing denervation-induced muscle atrophy. In models of both axotomy induced neuronal death and in the wobbler mouse, LIF is active at doses as low as 1 microgram/kg delivered systemically. 3. In muscle, LIF will increase the rate of muscle regeneration in vivo when applied exogenously after injury and will stimulate intrinsic muscle repair following its targeted release to dystrophic muscle in the mdx mouse. Leukaemia inhibitory factor may also have a role as an adjunct to myoblast transfer therapy, with studies showing that the transplantation of genetically competent myoblasts into mdx mouse muscle is enhanced when cells are injected with LIF. 4. Distribution and pharmacokinetic studies have been conducted in primates with doses of 20 micrograms/kg recombinant human LIF given subcutaneously over 2 weeks tolerated without major side effects. 5. A pharmaceutical form of recombinant human LIF (AM424; AMRAD Operations, Richmond, Victoria, Australia) entered human clinical trials during 1997 and a phase I clinical trial in healthy volunteers has been completed. A phase I repeat dose study has also been completed in cancer patients undergoing chemotherapy. The primary indication for a phase II study is the treatment of chemotherapy induced peripheral neuropathy. Other potential indications include muscle wasting diseases, acute nerve trauma and motor neuron disease. 6. The role of LIF in modulating nerve loss should make it an ideal candidate for the treatment of a number of neurological conditions. The phase I study represents the first trial in a programme for the clinical development of AM424.
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Affiliation(s)
- J Kurek
- AMRAD Operations Pty Ltd, Richmond, Victoria, Australia.
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15
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Maes M, Libbrecht I, Van Hunsel F, Lin AH, De Clerck L, Stevens W, Kenis G, de Jongh R, Bosmans E, Neels H. The immune-inflammatory pathophysiology of fibromyalgia: increased serum soluble gp130, the common signal transducer protein of various neurotrophic cytokines. Psychoneuroendocrinology 1999; 24:371-83. [PMID: 10341365 DOI: 10.1016/s0306-4530(98)00087-0] [Citation(s) in RCA: 72] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
Abstract
Fibromyalgia is a chronic, painful musculoskeletal disorder characterized by widespread pain, pressure hyperalgesia, morning stiffness and by an increased incidence of depressive symptoms. The etiology, however, has remained elusive. The aim of the present study was to examine the inflammatory response system (IRS) in fibromyalgia. Serum interleukin-6 (IL-6), soluble IL-6 receptor (sIL-6R), sgp130, sIL-1R antagonist (IL-1RA) and sCD8 were determined in 33 healthy volunteers and in 21 fibromyalgia patients, classified according to the American College of Rheumatology criteria. Severity of illness was measured with several pain scales, dolorimetry and the Hamilton Depression Rating Scale (HDRS). Serum sgp130 was significantly higher and serum sCD8 significantly lower in fibromyalgia patients than in healthy volunteers. Serum sIL-6R and sIL-1RA were significantly higher in fibromyalgia patients with an increased HDRS score (> or = 16) than in normal volunteers and fibromyalgia patients with a HDRS score < 16. In fibromyalgia patients, an important part of the variance in sCD8 (50.3%) and IL-1RA (19.3%) could be explained by the HDRS score; 74.3% of the variance in sIL-6R was explained by the combined effects of pain symptoms and the HDRS score; and 25.9% of the variance in serum sgp130 was explained by stiffness. The results support the contention that pain and stiffness in fibromyalgia may be accompanied by a suppression of some aspects of the IRS and that the presence of clinically significant depressive symptoms in fibromyalgia is associated with some signs of IRS activation.
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Affiliation(s)
- M Maes
- University Department of Psychiatry, Clinical Research Center for Mental Health (CRC-MH), Antwerp, Belgium.
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16
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Bennett TM, Dowsing BJ, Austin L, Messina A, Nicola NA, Morrison WA. Anterograde transport of leukemia inhibitory factor within transected sciatic nerves. Muscle Nerve 1999; 22:78-87. [PMID: 9883860 DOI: 10.1002/(sici)1097-4598(199901)22:1<78::aid-mus12>3.0.co;2-i] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
Disappointing functional recovery following peripheral nerve repair can be improved by neurotrophic growth factors. Leukemia inhibitory factor (LIF) is unique in that it has independent neurotrophic and myotrophic actions. The aim of this study was to explain this finding by establishing the existence of anterograde axonal transport of LIF from the site of nerve division to denervated muscles. Using 125I LIF, administered topically via an entubulation repair of divided rat sciatic nerve, we monitored its subsequent distribution by measuring the radioactivity associated with nerve segments and denervated muscles. We established that LIF preferentially accumulated in denervated muscles, a process we could reduce by 70% after tightly ligating the intervening nerve, confirming the presence of anterograde axonal transport. This was most likely an active mode of transport that ceased approximately 24 h after nerve division, establishing a narrow clinical time frame within which the myotrophic action of LIF could be optimized following nerve repair.
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Affiliation(s)
- T M Bennett
- Bernard O'Brien Institute of Microsurgery, St. Vincent's Hospital, Victoria, Australia
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17
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Kurek JB, Radford AJ, Crump DE, Bower JJ, Feeney SJ, Austin L, Byrne E. LIF (AM424), a promising growth factor for the treatment of ALS. J Neurol Sci 1998; 160 Suppl 1:S106-13. [PMID: 9851659 DOI: 10.1016/s0022-510x(98)00208-1] [Citation(s) in RCA: 36] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Growth factors are theoretically promising agents for ALS therapy, but have been disappointing in subcutaneous delivery due to either toxicity or lack of major efficacy. Leukaemia inhibitory factor (LIF), was named after its effect on haemopoietic cells, and belongs to a group of cytokines which includes CNTF, IL-6, CT-1, OM and IL-11. All group members use the gp130 signal transducing subunit for intracellular signalling, but show differences in biological effect. In vitro and in vivo studies on axotomy and nerve crush models demonstrate a powerful effect of LIF in the survival of both motor and sensory neurones, while reducing denervation induced muscle atrophy. Its effects in muscle also include stimulating myoblast proliferation in vitro, and up-regulation after muscle injury. LIF will also stimulate muscle regeneration in vivo when applied exogenously after injury. In published studies of both axotomy induced neuronal death and in the Wobbler mouse models LIF is active at doses of 10 microg/kg delivered systemically, well below the expected maximum tolerated dose suggested by primate safety studies. LIF is expressed in low levels by spinal cord neurones with significant up-regulation when the neurones are damaged by BOAA toxin, an excitatory amino acid associated with a form of ALS. This augments other evidence suggesting LIF is a trauma factor playing a role in the injury response of adult neuronal tissue, and may be more effective than related growth factors. Taken together, the data suggests LIF is a physiologically relevant trophic factor with implications in clinical medicine as a therapy for ALS, and a human recombinant form (AM424), entered human clinical trials during 1998.
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Affiliation(s)
- J B Kurek
- AMRAD Corporation Ltd, Melbourne, Australia.
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Kurek JB, Bower JJ, Romanella M, Koentgen F, Murphy M, Austin L. The role of leukemia inhibitory factor in skeletal muscle regeneration. Muscle Nerve 1997; 20:815-22. [PMID: 9179153 DOI: 10.1002/(sici)1097-4598(199707)20:7<815::aid-mus5>3.0.co;2-a] [Citation(s) in RCA: 103] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
Although a number of cytokines have been implicated in tissue regeneration, it is unknown which ones actually function in vivo. Here, we use mice with a targeted mutation in the leukemia inhibitory factor (LIF) gene to examine the role of LIF in muscle regeneration. Using a muscle crush model, we show that muscle regeneration in LIF knockout mice is significantly, reduced compared to control littermates. Further, targeted infusion of LIF in both normal and LIF knockout animals stimulated muscle regeneration, but the stimulation observed was much greater in the mutant animals than in controls. In contrast, interleukin-6 and transforming growth factor-alpha, which also stimulate myoblast proliferation in vitro, had no effect on regeneration. These findings demonstrate directly that LIF is involved in regeneration of injured muscle and points to the use of LIF as a therapeutic agent in the treatment of neuromuscular disease.
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Affiliation(s)
- J B Kurek
- Melbourne Neuromuscular Research Centre, St. Vincent's Hospital, Fitzroy, Melbourne, Australia
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