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Tan LX, Oertel FC, Cheng A, Cobigo Y, Keihani A, Bennett DJ, Abdelhak A, Montes SC, Chapman M, Chen RY, Cordano C, Ward ME, Casaletto K, Kramer JH, Rosen HJ, Boxer A, Miller BL, Green AJ, Elahi FM, Lakkaraju A. Targeting complement C3a receptor resolves mitochondrial hyperfusion and subretinal microglial activation in progranulin-deficient frontotemporal dementia. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.05.29.595206. [PMID: 38854134 PMCID: PMC11160746 DOI: 10.1101/2024.05.29.595206] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2024]
Abstract
Mutations in progranulin ( GRN ) cause frontotemporal dementia ( GRN -FTD) due to deficiency of the pleiotropic protein progranulin. GRN -FTD exhibits diverse pathologies including lysosome dysfunction, lipofuscinosis, microgliosis, and neuroinflammation. Yet, how progranulin loss causes disease remains unresolved. Here, we report that non-invasive retinal imaging of GRN -FTD patients revealed deficits in photoreceptors and the retinal pigment epithelium (RPE) that correlate with cognitive decline. Likewise, Grn -/- mice exhibit early RPE dysfunction, microglial activation, and subsequent photoreceptor loss. Super-resolution live imaging and transcriptomic analyses identified RPE mitochondria as an early driver of retinal dysfunction. Loss of mitochondrial fission protein 1 (MTFP1) in Grn -/- RPE causes mitochondrial hyperfusion and bioenergetic defects, leading to NF-kB-mediated activation of complement C3a-C3a receptor signaling, which drives further mitochondrial hyperfusion and retinal inflammation. C3aR antagonism restores RPE mitochondrial integrity and limits subretinal microglial activation. Our study identifies a previously unrecognized mechanism by which progranulin modulates mitochondrial integrity and complement-mediated neuroinflammation.
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Zhang L, Saito H, Higashimoto T, Kaji T, Nakamura A, Iwamori K, Nagano R, Motooka D, Okuzaki D, Uezumi A, Seno S, Fukada SI. Regulation of muscle hypertrophy through granulin: Relayed communication among mesenchymal progenitors, macrophages, and satellite cells. Cell Rep 2024; 43:114052. [PMID: 38573860 DOI: 10.1016/j.celrep.2024.114052] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2023] [Revised: 02/14/2024] [Accepted: 03/19/2024] [Indexed: 04/06/2024] Open
Abstract
Skeletal muscles exert remarkable regenerative or adaptive capacities in response to injuries or mechanical loads. However, the cellular networks underlying muscle adaptation are poorly understood compared to those underlying muscle regeneration. We employed single-cell RNA sequencing to investigate the gene expression patterns and cellular networks activated in overloaded muscles and compared these results with those observed in regenerating muscles. The cellular composition of the 4-day overloaded muscle, when macrophage infiltration peaked, closely resembled that of the 10-day regenerating muscle. In addition to the mesenchymal progenitor-muscle satellite cell (MuSC) axis, interactome analyses or targeted depletion experiments revealed communications between mesenchymal progenitors-macrophages and macrophages-MuSCs. Furthermore, granulin, a macrophage-derived factor, inhibited MuSC differentiation, and Granulin-knockout mice exhibited blunted muscle hypertrophy due to the premature differentiation of overloaded MuSCs. These findings reveal the critical role of granulin through the relayed communications of mesenchymal progenitors, macrophages, and MuSCs in facilitating efficient muscle hypertrophy.
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Affiliation(s)
- Lidan Zhang
- Center for Medical Epigenetics, School of Basic Medical Sciences, Chongqing Medical University, Chongqing 40016, China; Laboratory of Stem Cell Regeneration and Adaptation, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Hayato Saito
- Laboratory of Stem Cell Regeneration and Adaptation, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Tatsuyoshi Higashimoto
- Laboratory of Stem Cell Regeneration and Adaptation, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Takayuki Kaji
- Laboratory of Stem Cell Regeneration and Adaptation, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Ayasa Nakamura
- Laboratory of Stem Cell Regeneration and Adaptation, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Kanako Iwamori
- Laboratory of Stem Cell Regeneration and Adaptation, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka 565-0871, Japan
| | - Ryoko Nagano
- Laboratory of Stem Cell Regeneration and Adaptation, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka 565-0871, Japan; Laboratory of Oral Pathology, Division of Maxillofacial Diagnostic and Surgical Sciences, Faculty of Dental Science, Kyushu University, 3-1-1 Maidashi, Higashi, Fukuoka 812-8582, Japan
| | - Daisuke Motooka
- Genome Information Research Center, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
| | - Daisuke Okuzaki
- Genome Information Research Center, Research Institute for Microbial Diseases, Osaka University, Osaka 565-0871, Japan
| | - Akiyoshi Uezumi
- Division of Cell Heterogeneity, Medical Research Center for High Depth Omics, Medical Institute of Bioregulation, Kyushu University, 3-1-1, Maidashi, Higashi, Fukuoka 812-8582, Japan
| | - Shigeto Seno
- Department of Bioinformatic Engineering, Graduate School of Information Science and Technology, Osaka University, 1-5 Yamadaoka, Suita, Osaka 565-0871, Japan
| | - So-Ichiro Fukada
- Laboratory of Stem Cell Regeneration and Adaptation, Graduate School of Pharmaceutical Sciences, Osaka University, 1-6 Yamada-oka, Suita, Osaka 565-0871, Japan.
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Wang Y, Chen Z, Li J, Wan T, Hu R, Zhang L, Qin L, Zang L, Gu W, Chen R, Liu C, Li R. Gestational exposure to PM 2.5 disrupts fetal development by suppressing placental trophoblast syncytialization via progranulin/mTOR signaling. THE SCIENCE OF THE TOTAL ENVIRONMENT 2024; 921:171101. [PMID: 38387595 DOI: 10.1016/j.scitotenv.2024.171101] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 02/06/2024] [Accepted: 02/18/2024] [Indexed: 02/24/2024]
Abstract
Recent epidemiological and animal studies have indicated that ambient fine particulate matter (PM2.5) exposure during pregnancy is closely associated with intrauterine growth restriction (IUGR). However, the underlying mechanisms remain to be revealed. In this study, we found that gestational exposure to PM2.5 significantly decreased fetal weight and crown-rump length in mice, accompanied by insufficient placental trophoblast syncytialization and increased expression of progranulin (PGRN) in mice placenta. Administering PGRN neutralizing antibody to pregnant mice alleviated growth restriction and insufficient placental trophoblast syncytialization caused by PM2.5, accompanied with suppressed activation of the mTOR signaling pathway. Furthermore, in vitro experiments using human placental BeWo cells showed that 10 μg·mL-1 PM2.5 activated PGRN/mTOR signaling and suppressed forskolin-induced cell fusion, which was blocked by knockdown of PGRN. Taken together, our results demonstrated that PM2.5 exposure during pregnancy inhibited placental trophoblast syncytialization by activating PGRN/mTOR signaling, leading to abnormal placental development and IUGR. This study reveals a novel mechanism underlying the developmental toxicity of PM2.5 exposure during pregnancy.
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Affiliation(s)
- Yirun Wang
- School of Public Health, Zhejiang International Science and Technology Cooperation Base of Air Pollution and Health, Zhejiang Chinese Medical University, Hangzhou, China
| | - Zhuan Chen
- School of Public Health, Zhejiang International Science and Technology Cooperation Base of Air Pollution and Health, Zhejiang Chinese Medical University, Hangzhou, China
| | - Jie Li
- School of Public Health, Zhejiang International Science and Technology Cooperation Base of Air Pollution and Health, Zhejiang Chinese Medical University, Hangzhou, China
| | - Teng Wan
- School of Public Health, Zhejiang International Science and Technology Cooperation Base of Air Pollution and Health, Zhejiang Chinese Medical University, Hangzhou, China
| | - Renjie Hu
- School of Public Health, Zhejiang International Science and Technology Cooperation Base of Air Pollution and Health, Zhejiang Chinese Medical University, Hangzhou, China
| | - Lu Zhang
- School of Public Health, Zhejiang International Science and Technology Cooperation Base of Air Pollution and Health, Zhejiang Chinese Medical University, Hangzhou, China
| | - Li Qin
- School of Public Health, Zhejiang International Science and Technology Cooperation Base of Air Pollution and Health, Zhejiang Chinese Medical University, Hangzhou, China
| | - Lu Zang
- School of Public Health, Zhejiang International Science and Technology Cooperation Base of Air Pollution and Health, Zhejiang Chinese Medical University, Hangzhou, China
| | - Weijia Gu
- School of Public Health, Zhejiang International Science and Technology Cooperation Base of Air Pollution and Health, Zhejiang Chinese Medical University, Hangzhou, China
| | - Rucheng Chen
- School of Public Health, Zhejiang International Science and Technology Cooperation Base of Air Pollution and Health, Zhejiang Chinese Medical University, Hangzhou, China
| | - Cuiqing Liu
- School of Public Health, Zhejiang International Science and Technology Cooperation Base of Air Pollution and Health, Zhejiang Chinese Medical University, Hangzhou, China.
| | - Ran Li
- School of Public Health, Zhejiang International Science and Technology Cooperation Base of Air Pollution and Health, Zhejiang Chinese Medical University, Hangzhou, China.
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Díaz M, Mestres-Arenas A, Lerin C, Cereijo R, López-Bermejo A, de Zegher F, Villarroya F, Ibáñez L. Circulating progranulin in human infants: relation to prenatal growth and early postnatal nutrition. Pediatr Res 2023; 94:1189-1194. [PMID: 37031297 DOI: 10.1038/s41390-023-02595-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 03/04/2023] [Accepted: 03/15/2023] [Indexed: 04/10/2023]
Abstract
BACKGROUND Progranulin (PGRN) displays pleiotropic biological functions and has been proposed as a biomarker for metabolic diseases. We longitudinally assessed PGRN concentrations in infants born appropriate (AGA) or small for gestational age (SGA), the latter being at risk for obesity and type 2 diabetes, especially if they experience an excessive postnatal catch-up in weight and are formula-fed (FF). METHODS The study population consisted of 183 infants who were exclusively breast-fed [(BF), AGA, n = 66; SGA, n = 40], or FF (AGA, n = 31; SGA, n = 46) over the first 4 months. Assessments included auxology, fasting glucose, insulin, IGF-1, high-molecular-weight adiponectin, PGRN and body composition (by DXA), at birth, and at age 4 and 12 months. RESULTS PGRN levels were low at birth and unaffected by prenatal growth. PGRN increased at 4 and 12 months, although to a lesser extent in SGA infants, and was unrelated to the mode of feeding. PGRN correlated with markers of adiposity, inflammation and insulin resistance in both AGA and SGA infants, especially in those FF. CONCLUSIONS The attenuated increase of PGRN levels in SGA infants over the first year of life, along with the association to markers of unhealthy metabolic profile, might point to a role of PGRN in future disease risks. IMPACT Progranulin (PGRN) displays pleiotropic biological functions and has been proposed as a biomarker for metabolic diseases. In healthy infants, PGRN concentrations are low at birth and experience a significant and progressive increase up to age 12 months, which is less marked in infants born small for gestational age (SGA) and is unrelated to the mode of feeding. Circulating PGRN is related to markers of adiposity, inflammation, and insulin sensitivity, especially in formula-fed SGA infants. PGRN may play a role in the metabolic adaptations of SGA infants during early life, potentially contributing to the risk for obesity and type 2 diabetes in this population.
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Affiliation(s)
- Marta Díaz
- Pediatric Research Institute Sant Joan de Déu, University of Barcelona, 08950, Esplugues, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Health Institute Carlos III, Madrid, Spain
| | - Alberto Mestres-Arenas
- Biochemistry and Molecular Biomedicine Department, Biomedicine Institute, University of Barcelona, 08028, Barcelona, Spain
- Network Biomedical Research Center of Physiopathology of Obesity and Nutrition (CIBEROBN), Health Institute Carlos III, 28029, Madrid, Spain
| | - Carles Lerin
- Pediatric Research Institute Sant Joan de Déu, University of Barcelona, 08950, Esplugues, Barcelona, Spain
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Health Institute Carlos III, Madrid, Spain
| | - Rubén Cereijo
- Biochemistry and Molecular Biomedicine Department, Biomedicine Institute, University of Barcelona, 08028, Barcelona, Spain
- Research Institute, Hospital de la Santa Creu i de Sant Pau, Barcelona, Spain
| | - Abel López-Bermejo
- Department of Pediatrics, Dr. Josep Trueta Hospital, 17007, Girona, Spain
- Girona Institute forBiomedical Research, 17007, Girona, Spain
| | | | - Francesc Villarroya
- Biochemistry and Molecular Biomedicine Department, Biomedicine Institute, University of Barcelona, 08028, Barcelona, Spain.
- Network Biomedical Research Center of Physiopathology of Obesity and Nutrition (CIBEROBN), Health Institute Carlos III, 28029, Madrid, Spain.
| | - Lourdes Ibáñez
- Pediatric Research Institute Sant Joan de Déu, University of Barcelona, 08950, Esplugues, Barcelona, Spain.
- Centro de Investigación Biomédica en Red de Diabetes y Enfermedades Metabólicas Asociadas (CIBERDEM), Health Institute Carlos III, Madrid, Spain.
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Astragalus membranaceus Enhances Myotube Hypertrophy through PI3K-Mediated Akt/mTOR Signaling Phosphorylation. Nutrients 2022; 14:nu14081670. [PMID: 35458232 PMCID: PMC9028211 DOI: 10.3390/nu14081670] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2022] [Revised: 04/10/2022] [Accepted: 04/14/2022] [Indexed: 12/14/2022] Open
Abstract
Astragalus membranaceus (AM) is classified as a high-class traditional herbal medicine, which has strengthened vitality and multifunctional pharmacological activities, but limited empirical evidence is available to support its effects in muscular hypertrophy. It evokes skeletal muscle hypertrophy by increasing anabolic pathway, which is essential to prevent sarcopenia in elderly population. In this study, we examined the effects of AM on skeletal muscle hypertrophy by focusing on the molecular mechanism. We employed an in vitro model to investigate whether AM-treated skeletal muscle, as represented by myotube C2C12 cells, was hypertrophic, and to further investigate the efficacy of AM-activated phosphorylation of PI3K/Akt/mTOR signaling that must occur prior to myotube hypertrophy. The results showed that the myotubes formed larger multinucleated myotubes with increased diameter and thickness (1.16-fold relative to control group, p < 0.05). Administration of PI3K and mTOR inhibitors abolished AM-induced muscular hypertrophy. Moreover, AM-induced PI3K-mediated myotube hypertrophy was accompanied by the activation of Akt and mTOR signaling. We concluded that the AM is a nutritional activator to enhance muscular hypertrophy by increasing PI3K/Akt/mTOR signaling phosphorylation. As the AM is effective in myotube hypertrophy, AM and its derivatives may be promising candidates for ergogenic aid to prevent sarcopenia.
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Chiang KY, Li YW, Li YH, Huang SJ, Wu CL, Gong HY, Wu JL. Progranulin A Promotes Compensatory Hepatocyte Proliferation via HGF/c-Met Signaling after Partial Hepatectomy in Zebrafish. Int J Mol Sci 2021; 22:ijms222011217. [PMID: 34681875 PMCID: PMC8538350 DOI: 10.3390/ijms222011217] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2021] [Revised: 10/14/2021] [Accepted: 10/16/2021] [Indexed: 01/11/2023] Open
Abstract
Compensatory hepatocyte proliferation and other liver regenerative processes are activated to sustain normal physiological function after liver injury. A major mitogen for liver regeneration is hepatocyte growth factor (HGF), and a previous study indicated that progranulin could modulate c-met, the receptor for HGF, to initiate hepatic outgrowth from hepatoblasts during embryonic development. However, a role for progranulin in compensatory hepatocyte proliferation has not been shown previously. Therefore, this study was undertaken to clarify whether progranulin plays a regulatory role during liver regeneration. To this end, we established a partial hepatectomy regeneration model in adult zebrafish that express a liver-specific fluorescent reporter. Using this model, we found that loss of progranulin A (GrnA) function by intraperitoneal-injection of a Vivo-Morpholino impaired and delayed liver regeneration after partial hepatectomy. Furthermore, transcriptome analysis and confirmatory quantitative real-time PCR suggested that cell cycle progression and cell proliferation was not as active in the morphants as controls, which may have been the result of comparative downregulation of the HGF/c-met axis by 36 h after partial hepatectomy. Finally, liver-specific overexpression of GrnA in transgenic zebrafish caused more abundant cell proliferation after partial hepatectomy compared to wild types. Thus, we conclude that GrnA positively regulates HGF/c-met signaling to promote hepatocyte proliferation during liver regeneration.
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Affiliation(s)
- Keng-Yu Chiang
- Department of Life Science, National Taiwan University, Taipei 10617, Taiwan;
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan; (Y.-W.L.); (Y.-H.L.); (S.-J.H.)
| | - Ya-Wen Li
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan; (Y.-W.L.); (Y.-H.L.); (S.-J.H.)
| | - Yen-Hsing Li
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan; (Y.-W.L.); (Y.-H.L.); (S.-J.H.)
| | - Shin-Jie Huang
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan; (Y.-W.L.); (Y.-H.L.); (S.-J.H.)
| | - Chih-Lu Wu
- Department of Chemistry and Biochemistry, National Chung Cheng University, Chiayi 62145, Taiwan;
| | - Hong-Yi Gong
- Department of Aquaculture, National Taiwan Ocean University, Keelung 20224, Taiwan;
- Center of Excellence for the Oceans, National Taiwan Ocean University, Keelung 20224, Taiwan
| | - Jen-Leih Wu
- Institute of Cellular and Organismic Biology, Academia Sinica, Taipei 11529, Taiwan; (Y.-W.L.); (Y.-H.L.); (S.-J.H.)
- College of Life Sciences, National Taiwan Ocean University, Keelung 20224, Taiwan
- Correspondence: ; Tel.: +886-2-27899568
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Jing J, Pu Y, Veiga-Lopez A, Lyu L. In Vitro Effects of Emerging Bisphenols on Myocyte Differentiation and Insulin Responsiveness. Toxicol Sci 2021; 178:189-200. [PMID: 32750123 DOI: 10.1093/toxsci/kfaa130] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Bisphenols are endocrine disrupting chemicals to which humans are ubiquitously exposed to. Prenatal bisphenol A exposure can lead to insulin resistance. However, the metabolic effects of other emerging bisphenols, such as bisphenol S (BPS) and bisphenol F (BPF), are less understood. Because the skeletal muscle is the largest of the insulin target tissues, the goal of this study was to evaluate the effects of 2 emerging bisphenols (BPS and BPF) on cytotoxicity, proliferation, myogenic differentiation, and insulin responsiveness in skeletal muscle cells. We tested this using a dose-response approach in C2C12 mouse and L6 rat myoblast cell lines. The results showed that C2C12 mouse myoblasts were more susceptible to bisphenols compared with L6 rat myoblasts. In both cell lines, bisphenol A was more cytotoxic, followed by BPF and BPS. C2C12 myoblast proliferation was higher upon BPF exposure at the 10-4 M dose and the fusion index was increased after exposure to either BPF or BPS at doses over 10-10 M. Exposure to BPS and BPF also reduced baseline expression of p-AKT (Thr) and p-GSK-3β, but not downstream effectors such as mTOR and glucose transporter-4. In conclusion, at noncytotoxic doses, BPS and BPF can alter myoblast cell proliferation, differentiation, and partially modulate early effectors of the insulin receptor signaling pathway. However, BPS or BPF short-term exposure evaluated here does not result in impaired insulin responsiveness.
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Affiliation(s)
- Jiongjie Jing
- College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi 030801, China
| | - Yong Pu
- Department of Animal Science, Michigan State University, East Lansing, Michigan 48824
| | - Almudena Veiga-Lopez
- Department of Animal Science, Michigan State University, East Lansing, Michigan 48824
| | - Lihua Lyu
- College of Animal Science and Veterinary Medicine, Shanxi Agricultural University, Taigu, Shanxi 030801, China
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Narayanan N, Lengemann P, Kim KH, Kuang L, Sobreira T, Hedrick V, Aryal UK, Kuang S, Deng M. Harnessing nerve-muscle cell interactions for biomaterials-based skeletal muscle regeneration. J Biomed Mater Res A 2021; 109:289-299. [PMID: 32490576 DOI: 10.1002/jbm.a.37022] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2019] [Revised: 04/15/2020] [Accepted: 04/27/2020] [Indexed: 12/30/2022]
Abstract
Nerve cells secrete neurotrophic factors that play a critical role in neuronal survival, proliferation, and regeneration. However, their role in regulating myoblast behavior and skeletal muscle repair remains largely unexplored. In the present study, we investigated the effects of PC12 secreted signaling factors in modulating C2C12 myoblast behavior under physiologically relevant conditions. We showed that PC12 conditioned media modulated myoblast proliferation and differentiation in both 2D culture and 3D aligned electrospun fiber scaffold system in a dose-dependent manner. We further developed a biomimetic, tunable hydrogel consisting of hyaluronic acid, chondroitin sulfate, and polyethylene glycol as a 3D matrix encapsulating PC12 cells. The hydrogel-encapsulated PC12 cells promoted survival and proliferation of myoblasts in co-culture. Further proteomics analysis identified a total of 2,088 proteins from the secretome of the encapsulated PC12 cells and revealed the biological role and overlapping functions of nerve-secreted proteins for skeletal muscle regeneration, potentially through regulating myoblast behavior, nerve function, and angiogenesis. These experiments provide insights into the nerve-muscle interactions and pave the way for developing advanced biomaterials strategies incorporating nerve cell secretome for accelerated skeletal muscle regeneration.
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Affiliation(s)
- Naagarajan Narayanan
- Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, Indiana, USA
- Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, USA
| | - Paul Lengemann
- Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, Indiana, USA
- Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, USA
| | - Kun Ho Kim
- Department of Animal Science, Purdue University, West Lafayette, Indiana, USA
| | - Liangju Kuang
- Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, Indiana, USA
- Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, USA
| | - Tiago Sobreira
- Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, USA
| | - Victoria Hedrick
- Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, USA
| | - Uma K Aryal
- Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, USA
- Department of Comparative Pathobiology, Purdue University, West Lafayette, Indiana, USA
| | - Shihuan Kuang
- Department of Animal Science, Purdue University, West Lafayette, Indiana, USA
| | - Meng Deng
- Department of Agricultural and Biological Engineering, Purdue University, West Lafayette, Indiana, USA
- Bindley Bioscience Center, Purdue University, West Lafayette, Indiana, USA
- School of Materials Engineering, Purdue University, West Lafayette, Indiana, USA
- Weldon School of Biomedical Engineering, Purdue University, West Lafayette, Indiana, USA
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Shen X, Tang J, Jiang R, Wang X, Yang Z, Huang Y, Lan X, Lei C, Chen H. CircRILPL1 promotes muscle proliferation and differentiation via binding miR-145 to activate IGF1R/PI3K/AKT pathway. Cell Death Dis 2021; 12:142. [PMID: 33542215 PMCID: PMC7862392 DOI: 10.1038/s41419-021-03419-y] [Citation(s) in RCA: 35] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2020] [Revised: 12/11/2020] [Accepted: 12/17/2020] [Indexed: 12/22/2022]
Abstract
Many novel non-coding RNAs, such as microRNAs (miRNAs) and circular RNAs (circRNAs), are involved in various physiological and pathological processes. The PI3K/AKT signaling pathway is important for its role in regulating skeletal muscle development. In this study, molecular and biochemical assays were used to confirm the role of miRNA-145 (miR-145) in myoblast proliferation and apoptosis. Based on sequencing data and bioinformatics analysis, we identified a new circRILPL1, which acts as a sponge for miR-145. The interactions between circRILPL1 and miR-145 were examined by bioinformatics, a luciferase assay, and RNA immunoprecipitation. Mechanistically, knockdown or exogenous expression of circRILPL1 in the primary myoblasts was performed to prove the functional significance of circRILPL1. We investigated the inhibitory effect of miR-145 on myoblast proliferation by targeting IGF1R to regulate the PI3K/AKT signaling pathway. A novel circRILPL1 was identified that could sponge miR-145 and is related to AKT activation. In addition, circRILPL1 was positively correlated with muscle proliferation and differentiation in vitro and could inhibit cell apoptosis. The newly identified circRILPL1 functions as a miR-145 sponge to regulate the IGF1R gene and rescue the inhibitory effect of miR-145 on the PI3K/AKT signaling pathway, thereby promoting myoblast growth.
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Affiliation(s)
- Xuemei Shen
- Key laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Jia Tang
- Key laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Rui Jiang
- Key laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Xiaogang Wang
- Key laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Zhaoxin Yang
- Key laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Yongzhen Huang
- Key laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Xianyong Lan
- Key laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Chuzhao Lei
- Key laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China
| | - Hong Chen
- Key laboratory of Animal Genetics, Breeding and Reproduction of Shaanxi Province, College of Animal Science and Technology, Northwest A&F University, Yangling, Shaanxi, China.
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10
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Wang M, Yu D, Zheng L, Hong B, Li H, Hu X, Zhang K, Mou Y. Mechanical Stress Affects Circadian Rhythm in Skeletal Muscle (C2C12 Myoblasts) by Reducing Per/Cry Gene Expression and Increasing Bmal1 Gene Expression. Med Sci Monit 2021; 27:e928359. [PMID: 33444293 PMCID: PMC7814509 DOI: 10.12659/msm.928359] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2020] [Accepted: 10/21/2020] [Indexed: 12/21/2022] Open
Abstract
BACKGROUND Circadian rhythm can modulate normal activity of humans in adapting to daily environment changes. Mechanical stress loading affects skeletal muscle development and bio-functions. This study aimed to investigate the effects of mechanical stress loading on circadian rhythm in skeletal muscle (C2C12 cells) and to explore the associated mechanism. MATERIAL AND METHODS C2C12 myoblasts were cultured and treated with mechanical stress loading. After mechanical stress loading for 6 h,12 h, and 24 h, we observed the C2C12 myoblasts and determined gene transcription and protein expression of Clock genes, including Clock, Bmal1, Per, and Cry using RT-PCR and western blot assay. RESULTS Mechanical stress loading triggered C2C12 cells growing by force direction and enhanced the cell proliferation at 6 h, 12 h, and 24 h. Gene transcription and protein expression of the core Clock-associated molecules, Clock and Bmal1, increased from start of loading to 12 h, and decreased from 12 h to 24 h. Gene transcription and protein expression of core Clock-associated molecules, Cry and Per, decreased in the first 12 h (from 6 h to 12 h) and increased in the last 12 h (from 12 h to 24 h). CONCLUSIONS Our study revealed that mechanical stress loading affected circadian rhythm in skeletal muscle (C2C12 myoblasts) through reducing Per/Cry and enhancing Clock/Bmal1 gene expression. This study provides insights for investigating circadian rhythm and associated bio-functions of humans.
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Affiliation(s)
- Mengjia Wang
- Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, P.R. China
| | - Da Yu
- Sir Run Run Hospital, Nanjing Medical University, Nanjing, Jiangsu, P.R. China
| | - Lichun Zheng
- Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, P.R. China
| | - Bing Hong
- Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, P.R. China
| | - Houxuan Li
- Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, P.R. China
| | - Xiaobei Hu
- Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, P.R. China
| | - Kun Zhang
- Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, P.R. China
| | - Yongbin Mou
- Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, Jiangsu, P.R. China
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Serrero G. Progranulin/GP88, A Complex and Multifaceted Player of Tumor Growth by Direct Action and via the Tumor Microenvironment. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2021; 1329:475-498. [PMID: 34664252 DOI: 10.1007/978-3-030-73119-9_22] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Investigation of the role of progranulin/GP88 on the proliferation and survival of a wide variety of cells has been steadily increasing. Several human diseases stem from progranulin dysregulation either through its overexpression in cancer or its absence as in the case of null mutations in some form of frontotemporal dementia. The present review focuses on the role of progranulin/GP88 in cancer development, progression, and drug resistance. Various aspects of progranulin identification, biology, and signaling pathways will be described. Information will be provided about its direct role as an autocrine growth and survival factor and its paracrine effect as a systemic factor as well as via interaction with extracellular matrix proteins and with components of the tumor microenvironment to influence drug resistance, migration, angiogenesis, inflammation, and immune modulation. This chapter will also describe studies examining progranulin/GP88 tumor tissue expression as well as circulating level as a prognostic factor for several cancers. Due to the wealth of publications in progranulin, this review does not attempt to be exhaustive but rather provide a thread to lead the readers toward more in-depth exploration of this fascinating and unique protein.
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12
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Bordbar F, Jensen J, Du M, Abied A, Guo W, Xu L, Gao H, Zhang L, Li J. Identification and validation of a novel candidate gene regulating net meat weight in Simmental beef cattle based on imputed next-generation sequencing. Cell Prolif 2020; 53:e12870. [PMID: 32722873 PMCID: PMC7507581 DOI: 10.1111/cpr.12870] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2020] [Revised: 06/12/2020] [Accepted: 06/13/2020] [Indexed: 12/19/2022] Open
Abstract
Objectives Genome‐wide association studies (GWAS) represent a powerful approach to detecting candidate genes for economically important traits in livestock. Our aim was to identify promising candidate muscle development genes that affect net meat weight (NMW) and validate these candidate genes in cattle. Materials and methods Using a next‐generation sequencing (NGS) dataset, we applied ~ 12 million imputed single nucleotide polymorphisms (SNPs) from 1,252 Simmental cattle to detect genes influencing net meat yield by way of a linear mixed model method. Haplotype and linkage disequilibrium (LD) blocks were employed to augment support for identified genes. To investigate the role of MTPN in bovine muscle development, we isolated myoblasts from the longissimus dorsi of a bovine foetus and treated the cells during proliferation, differentiation and hypertrophy. Results We identified one SNP (rs100670823) that exceeded our stringent significance threshold (P = 8.58 × 10−8) for a putative NMW‐related quantitative trait locus (QTL). We identified a promising candidate gene, myotrophin (MTPN), in the region around this SNP Myotrophin had a stimulatory effect on six muscle‐related markers that regulate differentiation and myoblast fusion. During hypertrophy, myotrophin promoted myotube hypertrophy and increased myotube diameters. Cell viability assay and flow cytometry showed that myotrophin inhibited myoblast proliferation. Conclusions The present experiments showed that myotrophin increases differentiation and hypertrophy of skeletal muscle cells, while inhibiting their proliferation. Our examination of GWAS results with in vitro biological studies provides new information regarding the potential application of myotrophin to increase meat yields in cattle and helpful information for further studies.
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Affiliation(s)
- Farhad Bordbar
- Key Laboratory of Animal Genetics Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Just Jensen
- Center for Quantitative Genetics and Genomics, Aarhus University, Aarhus, Denmark
| | - Min Du
- Department of Animal Sciences, Washington Center for Muscle Biology, Washington State University, Pullman, WA, USA
| | - Adam Abied
- Animal Genetic Breeding and Reproduction, Institute of Animal Science, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Wei Guo
- Meat Science and Muscle Biology, Animal and Diary Science, University of Wisconsin-Madison, Madison, USA
| | - Lingyang Xu
- Key Laboratory of Animal Genetics Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Huijiang Gao
- Key Laboratory of Animal Genetics Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Lupei Zhang
- Key Laboratory of Animal Genetics Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Junya Li
- Key Laboratory of Animal Genetics Breeding and Reproduction, Ministry of Agriculture and Rural Affairs, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
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Da Y, Mou Y, Wang M, Yuan X, Yan F, Lan W, Zhang F. Mechanical stress promotes biological functions of C2C12 myoblasts by activating PI3K/AKT/mTOR signaling pathway. Mol Med Rep 2019; 21:470-477. [PMID: 31746379 DOI: 10.3892/mmr.2019.10808] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2018] [Accepted: 10/17/2019] [Indexed: 11/05/2022] Open
Abstract
The PI3K/AKT signaling pathway regulates cell proliferation and differentiation in multiple types of cells. The present study aimed to investigate the effects of mechanical stress on C2C12 cell proliferation and to explore the associated mechanisms. A cyclic mechanical stress model of C2C12 myoblasts was established. Reverse transcription‑quantitative PCR and western blotting assay were used to examine the PI3K signaling pathways involved in the progress of cell differentiation. Cell counting kit‑8 (CCK‑8) assay was used to evaluate the proliferation of C2C12 cells. Flow cytometry was employed to evaluate apoptosis following mechanical stress. The results demonstrated that mechanical stress activated the PI3K signaling pathway in C2C12 myoblasts. Mechanical stress significantly promoted phosphorylation (p‑) of AKT and expression of mammalian target of rapamycin (mTOR) compared with the normal group. Mechanical stress significantly promoted 4E‑binding protein 1 (4EBP1) expression in C2C12 cells compared with the normal group. The PI3K specific inhibitor LY294002 significantly decreased 4EBP1 expression and reduced p‑AKT and p‑mTOR expression compared with the mechanical stress group. Mechanical stress promoted C2C12 cell proliferation. Apoptosis of C2C12 significantly decreased in the mechanical stress group compared with the normal group. Cyclin D levels significantly increased in the mechanical stress group compared with the normal group. In conclusion, mechanical stress promoted biological functions of C2C12 cells by activating the PI3K/AKT signaling pathway. These results may contribute to a better understanding of the effects of mechanical stress on cells.
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Affiliation(s)
- Yu Da
- Department of Stomatology, Nanjing Tongren Hospital, School of Medicine, Southeast University, Nanjing, Jiangsu 211102, P.R. China
| | - Yongbin Mou
- Department of Implantology, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, Jiangsu 210008, P.R. China
| | - Mengjia Wang
- Department of Implantology, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, Jiangsu 210008, P.R. China
| | - Xiao Yuan
- Department of Orthodontics, The Affiliated Qingdao Municipal Hospital, Qingdao University, Qingdao, Shandong 266000, P.R. China
| | - Fuhua Yan
- Department of Implantology, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, Jiangsu 210008, P.R. China
| | - Weidong Lan
- Department of Implantology, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, Jiangsu 210008, P.R. China
| | - Fang Zhang
- Department of Implantology, Nanjing Stomatological Hospital, Medical School of Nanjing University, Nanjing, Jiangsu 210008, P.R. China
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Liang Y, Wang Y, Xiao M, Hao Y, Zhang Y, Li S. Tumor necrosis factor receptor 2 may promote the proliferation and drug resistance of Kapras299 and L428 lymphoma cells via the AKT and WNT/β-catenin signaling pathways. Oncol Lett 2018; 15:8847-8852. [PMID: 29928327 DOI: 10.3892/ol.2018.8396] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2017] [Accepted: 10/18/2017] [Indexed: 02/06/2023] Open
Abstract
Circulating soluble tumor necrosis factor receptor 2 (sTNFR2) has been associated with a relatively poor prognosis in various types of lymphoma. However, the specific role of TNFR2 expression in lymphoma cells remains uncharacterized. In the present study, TNFR2 expression was quantified in the Hodgkin lymphoma cell line, L428, and the anaplastic large-cell lymphoma cell line, Karpas299, using RT-PCR and western blot analyses. Karpas299 cells exhibited higher TNFR2 expression than L428 cells. Proliferation and drug resistance experiments demonstrated that Karpas299 cells also possessed a greater proliferative ability and resistance to adriamycin (ADM) than L428 cells, with 50% inhibitory concentrations (IC50) of 1.423±0.24 µmol/l for Karpas299 cells, compared with 0.728±0.15 µmol/l for L428 cells (P<0.05). The knockdown of TNFR2 in Karpas299 cells significantly reduced their proliferative ability; when treated with ADM, the cell inhibition rate increased from 49.34±5.42% to 74.13±6.81% (P<0.05). The upregulation of TNFR2 in L428 cells significantly increased their proliferative ability; when treated with ADM, the cell inhibition rate decreased from 47.03±5.25% to 28.71±4.90% (P<0.05). Investigation of the underlying molecular mechanism indicated that the upregulation of TNFR2 expression in L428 cells increased the expression of β-catenin and the phosphorylation of AKT. In L428 cells overexpressing TNFR2, the β-catenin blocker, DKK1, or the AKT inhibitor, LY294002, abrogated the increase in proliferation induced by TNFR2 and increased cell inhibition rate upon treatment with ADM. In summary, the present study demonstrated that TNFR2 promoted the proliferative and drug resistance abilities of lymphoma cells via the AKT and WNT/β-catenin signaling pathways. This may provide the experimental basis for the further study of TNFR2 activity in lymphoma cells and warrant its investigation as a therapeutic target for lymphoma.
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Affiliation(s)
- Yanyan Liang
- Department of Hematology, First People's Hospital of Jining City, Jining, Shandong 257335, P.R. China
| | - Yu Wang
- Department of Medicine 11, People's Hospital of Xintai City, Tai'an, Shandong 271200, P.R. China
| | - Meng Xiao
- Department of Hematology, First People's Hospital of Jining City, Jining, Shandong 257335, P.R. China
| | - Yunliang Hao
- Department of Hematology, First People's Hospital of Jining City, Jining, Shandong 257335, P.R. China
| | - Yongtian Zhang
- Department of Hematology, First People's Hospital of Jining City, Jining, Shandong 257335, P.R. China
| | - Shumei Li
- Department of Hematology, First People's Hospital of Jining City, Jining, Shandong 257335, P.R. China
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Growth factor progranulin promotes tumorigenesis of cervical cancer via PI3K/Akt/mTOR signaling pathway. Oncotarget 2018; 7:58381-58395. [PMID: 27517315 PMCID: PMC5295437 DOI: 10.18632/oncotarget.11126] [Citation(s) in RCA: 45] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 07/26/2016] [Indexed: 11/25/2022] Open
Abstract
Progranulin (PGRN) is an autocrine growth factor with tumorigenic roles in various tumors including cervical cancer. In this study, we investigated mammalian target of rapamycin (mTOR) signaling in response to PGRN induction and the contribution of the PGRN-stimulated PI3K/Akt/mTOR signaling pathway in the transformation and progression of cervical cancer. Here we identified a strong linkage between PGRN and phosphorylated-mTOR in cervical cancer tissues. PGRN promoted the phosphorylation of mTOR and activated mTOR signaling in human cervical mucosa epithelial cells and cervical cancer cells, and TNFR2 was needed for PGRN-stimulated mTOR signaling. Inhibition of mTOR signaling with rapamycin decreased PGRN-stimulated protein synthesis, transformation and proliferation of cervical cells in vitro, and tumor formation and growth in vivo. Thus, our findings update the signal transduction pathways of PGRN by suggesting that mTOR signaling contributes to PGRN-stimulated carcinogenesis of cervical cancer. Inhibition of PGRN/PI3K/Akt/mTOR signaling may be targeted in treatment of cervical cancer.
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16
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Kneppers A, Verdijk L, de Theije C, Corten M, Gielen E, van Loon L, Schols A, Langen R. A novel in vitro model for the assessment of postnatal myonuclear accretion. Skelet Muscle 2018; 8:4. [PMID: 29444710 PMCID: PMC5813369 DOI: 10.1186/s13395-018-0151-4] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2017] [Accepted: 01/26/2018] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Due to the post-mitotic nature of myonuclei, postnatal myogenesis is essential for skeletal muscle growth, repair, and regeneration. This process is facilitated by satellite cells through proliferation, differentiation, and subsequent fusion with a pre-existing muscle fiber (i.e., myonuclear accretion). Current knowledge of myogenesis is primarily based on the in vitro formation of syncytia from myoblasts, which represents aspects of developmental myogenesis, but may incompletely portray postnatal myogenesis. Therefore, we aimed to develop an in vitro model that better reflects postnatal myogenesis, to study the cell intrinsic and extrinsic processes and signaling involved in the regulation of postnatal myogenesis. METHODS Proliferating C2C12 myoblasts were trypsinized and co-cultured for 3 days with 5 days differentiated C2C12 myotubes. Postnatal myonuclear accretion was visually assessed by live cell time-lapse imaging and cell tracing by cell labeling with Vybrant® DiD and DiO. Furthermore, a Cre/LoxP-based cell system was developed to semi-quantitatively assess in vitro postnatal myonuclear accretion by the conditional expression of luciferase upon myoblast-myotube fusion. Luciferase activity was assessed luminometrically and corrected for total protein content. RESULTS Live cell time-lapse imaging, staining-based cell tracing, and recombination-dependent luciferase activity, showed the occurrence of postnatal myonuclear accretion in vitro. Treatment of co-cultures with the myogenic factor IGF-I (p < 0.001) and the cytokines IL-13 (p < 0.05) and IL-4 (p < 0.001) increased postnatal myonuclear accretion, while the myogenic inhibitors cytochalasin D (p < 0.001), myostatin (p < 0.05), and TNFα (p < 0.001) decreased postnatal myonuclear accretion. Furthermore, postnatal myonuclear accretion was increased upon recovery from electrical pulse stimulation-induced fiber damage (p < 0.001) and LY29004-induced atrophy (p < 0.001). Moreover, cell type-specific siRNA-mediated knockdown of myomaker in myoblasts (p < 0.001), but not in myotubes, decreased postnatal myonuclear accretion. CONCLUSIONS We developed a physiologically relevant, sensitive, high-throughput cell system for semi-quantitative assessment of in vitro postnatal myonuclear accretion, which can be used to mimic physiological myogenesis triggers, and can distinguish the cell type-specific roles of signals and responses in the regulation of postnatal myogenesis. As such, this method is suitable for both basal and translational research on the regulation of postnatal myogenesis, and will improve our understanding of muscle pathologies that result from impaired satellite cell number or function.
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Affiliation(s)
- Anita Kneppers
- Department of Respiratory Medicine, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands.
| | - Lex Verdijk
- Department of Human Biology and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Chiel de Theije
- Department of Respiratory Medicine, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Mark Corten
- Department of Respiratory Medicine, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Ellis Gielen
- Department of Respiratory Medicine, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Luc van Loon
- Department of Human Biology and Movement Sciences, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Annemie Schols
- Department of Respiratory Medicine, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
| | - Ramon Langen
- Department of Respiratory Medicine, NUTRIM School of Nutrition and Translational Research in Metabolism, Maastricht University Medical Centre+, Maastricht, The Netherlands
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Sugihara H, Miyaji K, Yamanouchi K, Matsuwaki T, Nishihara M. Progranulin deficiency leads to prolonged persistence of macrophages, accompanied with myofiber hypertrophy in regenerating muscle. J Vet Med Sci 2017; 80:346-353. [PMID: 29249750 PMCID: PMC5836776 DOI: 10.1292/jvms.17-0638] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Skeletal muscle has an ability to regenerate in response to injury due to the presence of satellite cells. Injury in skeletal muscle causes infiltration of pro-inflammatory macrophages (M1 macrophages) to remove necrotic myofibers, followed by their differentiation into anti-inflammatory macrophages (M2 macrophages) to terminate the inflammation. Since both M1 and M2 macrophages play important roles, coordinated regulation of their kinetics is important to complete muscle regeneration successfully. Progranulin (PGRN) is a pluripotent growth factor, having a protective role against the inflamed tissue. In the central nervous system, PGRN regulates inflammation by inhibiting the activation of microglia. Here we used muscle injury model of PGRN-knockout (PGRN-KO) mice to elucidate whether it has a role in the kinetics of macrophages during muscle regeneration. We found the prolonged persistence of macrophages at the late phase of regeneration in PGRN-KO mice, and these macrophages were suggested to be M2 macrophages since this was accompanied with an increased CD206 expression. We also observed muscle hypertrophy in PGRN-KO mice at the late stage of muscle regeneration. Since M2 macrophages are known to have a role in maturation of myofibers, this muscle hypertrophy may be due to the presence of increased number of M2 macrophages. Our results suggest that PGRN plays a role in the regulation of kinetics of macrophages for the systemic progress of muscle regeneration.
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Affiliation(s)
- Hidetoshi Sugihara
- Department of Veterinary Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Kei Miyaji
- Department of Veterinary Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Keitaro Yamanouchi
- Department of Veterinary Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Takashi Matsuwaki
- Department of Veterinary Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
| | - Masugi Nishihara
- Department of Veterinary Physiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo 113-8657, Japan
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Li H, Ma Y, Xu W, Chen H, Day L. MFG-E8 protein promotes C2C12myogenic differentiation by enhancing PI3K/Akt signaling. NEW J CHEM 2017. [DOI: 10.1039/c7nj02216f] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
The effect of MFG-E8 on C2C12cell differentiation was analysed by immunocytochemistry, qRT-PCR and Western blot.
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Affiliation(s)
- He Li
- School of Chemistry and Chemical Engineering
- Harbin Institute of Technology
- Harbin 150090
- P. R. China
| | - Ying Ma
- School of Chemistry and Chemical Engineering
- Harbin Institute of Technology
- Harbin 150090
- P. R. China
| | - Weili Xu
- School of Chemistry and Chemical Engineering
- Harbin Institute of Technology
- Harbin 150090
- P. R. China
| | - Haoran Chen
- School of Chemistry and Chemical Engineering
- Harbin Institute of Technology
- Harbin 150090
- P. R. China
| | - Li Day
- School of Chemistry and Chemical Engineering
- Harbin Institute of Technology
- Harbin 150090
- P. R. China
- AgResearch Limited
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19
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Zhao T, Li H, Liu Z. Tumor necrosis factor receptor 2 promotes growth of colorectal cancer via the PI3K/AKT signaling pathway. Oncol Lett 2016; 13:342-346. [PMID: 28123565 DOI: 10.3892/ol.2016.5403] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 08/02/2016] [Indexed: 02/07/2023] Open
Abstract
Tumor necrosis factor receptor 2 (TNFR2) is the receptor for tumor necrosis factor α (TNF-α). TNFR2 differs from tumor necrosis factor 1 (TNFR1) in various ways and is mainly expressed in hematopoietic and endothelial cells. However, studies about its functions in tumors are limited. The contributions of TNFR2 in colorectal cancer (CRC) remain unknown. In the present study, it was found that TNFR2 was positively associated with Ki67 expression in CRC tissues using immunohistochemistry (IHC), and western blot analysis found that Ki67 was upregulated by overexpressing TNFR2 in SW1116 cells and inhibited by silencing TNFR2 in HT29 cells. Methyl thiazolyl tetrazolium assay found that growth of SW1116 cells overexpressing TNFR2 was significantly increased compared with the control group and that the growth of HT29 cells subsequent to silencing TNFR2 was significantly decreased compared with the control group. Clone formation assay found that more clones were formed in SW1116 cells overexpressing TNFR2 than the control group, and less clones formed in HT29 cells subsequent to silencing TNFR2 than the control group. In addition, western blot analysis found that phosphorylation of protein kinase B (AKT) was activated subsequent to overexpressing TNFR2 in SW1116 cells, and inhibited following silencing of TNFR2 in HT29 cells. Additionally, treatment using LY294002 significantly abrogated the promotion of Ki67 expression, growth and clone formation abilities induced by TNFR2 overexpression in SW1116 cells. All the results suggest that TNFR2 can significantly promote CRC growth via the phosphoinositide 3-kinase/AKT signaling pathway; this provides evidential support for taking TNFR2 as a new target for CRC treatment.
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Affiliation(s)
- Tao Zhao
- Oncology Department, Second People's Hospital of Dongying City, Dongying, Shandong 257335, P.R. China
| | - Huihui Li
- Department of Medical Oncology, Shandong Cancer Hospital and Institute, Jinan, Shandong 250017, P.R. China
| | - Zifeng Liu
- Second Department of Liver Failure, 302 Hospital of PLA, Beijing 100000, P.R. China
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20
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Raina DB, Gupta A, Petersen MM, Hettwer W, McNally M, Tägil M, Zheng MH, Kumar A, Lidgren L. Muscle as an osteoinductive niche for local bone formation with the use of a biphasic calcium sulphate/hydroxyapatite biomaterial. Bone Joint Res 2016; 5:500-511. [PMID: 27784668 PMCID: PMC5108354 DOI: 10.1302/2046-3758.510.bjr-2016-0133.r1] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 07/29/2016] [Indexed: 12/21/2022] Open
Abstract
Objectives We have observed clinical cases where bone is formed in the overlaying muscle covering surgically created bone defects treated with a hydroxyapatite/calcium sulphate biomaterial. Our objective was to investigate the osteoinductive potential of the biomaterial and to determine if growth factors secreted from local bone cells induce osteoblastic differentiation of muscle cells. Materials and Methods We seeded mouse skeletal muscle cells C2C12 on the hydroxyapatite/calcium sulphate biomaterial and the phenotype of the cells was analysed. To mimic surgical conditions with leakage of extra cellular matrix (ECM) proteins and growth factors, we cultured rat bone cells ROS 17/2.8 in a bioreactor and harvested the secreted proteins. The secretome was added to rat muscle cells L6. The phenotype of the muscle cells after treatment with the media was assessed using immunostaining and light microscopy. Results C2C12 cells differentiated into osteoblast-like cells expressing prominent bone markers after seeding on the biomaterial. The conditioned media of the ROS 17/2.8 contained bone morphogenetic protein-2 (BMP-2 8.4 ng/mg, standard deviation (sd) 0.8) and BMP-7 (50.6 ng/mg, sd 2.2). In vitro, this secretome induced differentiation of skeletal muscle cells L6 towards an osteogenic lineage. Conclusion Extra cellular matrix proteins and growth factors leaking from a bone cavity, along with a ceramic biomaterial, can synergistically enhance the process of ectopic ossification. The overlaying muscle acts as an osteoinductive niche, and provides the required cells for bone formation. Cite this article: D. B. Raina, A. Gupta, M. M. Petersen, W. Hettwer, M. McNally, M. Tägil, M-H. Zheng, A. Kumar, L. Lidgren. Muscle as an osteoinductive niche for local bone formation with the use of a biphasic calcium sulphate/hydroxyapatite biomaterial. Bone Joint Res 2016;5:500–511. DOI: 10.1302/2046-3758.510.BJR-2016-0133.R1.
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Affiliation(s)
- D B Raina
- Department of Orthopaedics, Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, 208016, UP, India
| | - A Gupta
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, 208016, UP, India
| | - M M Petersen
- Department of Orthopedic Surgery, Rigshospitalet, University of Copenhagen, Copenhagen, 2100, Denmark
| | - W Hettwer
- Department of Orthopedic Surgery, Rigshospitalet, University of Copenhagen, Copenhagen, 2100, Denmark
| | - M McNally
- Oxford University Hospital, NHS Trust, Nuffield Orthopedic Centre, Headington, Oxford, OX3 7LD, UK
| | - M Tägil
- Department of Orthopedics, Clinical Sciences, University of Western Australia, Crawley, Australia
| | - M-H Zheng
- Centre for Orthopaedic Translational Research, School of Surgery, University of Western Australia, Crawley, Australia
| | - A Kumar
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur, Kanpur, 208016, UP, India
| | - L Lidgren
- Department of Orthopedics, Clinical Sciences, Lund University, Lund, 221 85, Sweden
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21
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Yang WR, Zhu FW, Zhang JJ, Wang Y, Zhang JH, Lu C, Wang XZ. PI3K/Akt Activated by GPR30 and Src Regulates 17β-Estradiol-Induced Cultured Immature Boar Sertoli Cells Proliferation. Reprod Sci 2016; 24:57-66. [DOI: 10.1177/1933719116649696] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Wei-Rong Yang
- College of Animal Science and Technology, Southwest University, Chongqing, China
- Chongqing Key Laboratory of Forage & Herbivore, Chongqing, China
| | - Feng-Wei Zhu
- College of Animal Science and Technology, Southwest University, Chongqing, China
- Chongqing Key Laboratory of Forage & Herbivore, Chongqing, China
| | - Jiao-Jiao Zhang
- College of Animal Science and Technology, Southwest University, Chongqing, China
- Chongqing Key Laboratory of Forage & Herbivore, Chongqing, China
| | - Yi Wang
- College of Animal Science and Technology, Southwest University, Chongqing, China
- Chongqing Key Laboratory of Forage & Herbivore, Chongqing, China
| | - Jia-Hua Zhang
- College of Animal Science and Technology, Southwest University, Chongqing, China
- Chongqing Key Laboratory of Forage & Herbivore, Chongqing, China
| | - Cheng Lu
- State Key Laboratory of Silkworm Genome Biology, Southwest University, Chongqing, China
- Key Laboratory for Sericulture Functional Genomics and Biotechnology of Agricultural Ministry, Southwest University, Chongqing, China
| | - Xian-Zhong Wang
- College of Animal Science and Technology, Southwest University, Chongqing, China
- Chongqing Key Laboratory of Forage & Herbivore, Chongqing, China
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22
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Holler CJ, Taylor G, McEachin ZT, Deng Q, Watkins WJ, Hudson K, Easley CA, Hu WT, Hales CM, Rossoll W, Bassell GJ, Kukar T. Trehalose upregulates progranulin expression in human and mouse models of GRN haploinsufficiency: a novel therapeutic lead to treat frontotemporal dementia. Mol Neurodegener 2016; 11:46. [PMID: 27341800 PMCID: PMC4919863 DOI: 10.1186/s13024-016-0114-3] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2015] [Accepted: 06/20/2016] [Indexed: 01/16/2023] Open
Abstract
BACKGROUND Progranulin (PGRN) is a secreted growth factor important for neuronal survival and may do so, in part, by regulating lysosome homeostasis. Mutations in the PGRN gene (GRN) are a common cause of frontotemporal lobar degeneration (FTLD) and lead to disease through PGRN haploinsufficiency. Additionally, complete loss of PGRN in humans leads to neuronal ceroid lipofuscinosis (NCL), a lysosomal storage disease. Importantly, Grn-/- mouse models recapitulate pathogenic lysosomal features of NCL. Further, GRN variants that decrease PGRN expression increase the risk of developing Alzheimer's disease (AD) and Parkinson's disease (PD). Together these findings demonstrate that insufficient PGRN predisposes neurons to degeneration. Therefore, compounds that increase PGRN levels are potential therapeutics for multiple neurodegenerative diseases. RESULTS Here, we performed a cell-based screen of a library of known autophagy-lysosome modulators and identified multiple novel activators of a human GRN promoter reporter including several common mTOR inhibitors and an mTOR-independent activator of autophagy, trehalose. Secondary cellular screens identified trehalose, a natural disaccharide, as the most promising lead compound because it increased endogenous PGRN in all cell lines tested and has multiple reported neuroprotective properties. Trehalose dose-dependently increased GRN mRNA as well as intracellular and secreted PGRN in both mouse and human cell lines and this effect was independent of the transcription factor EB (TFEB). Moreover, trehalose rescued PGRN deficiency in human fibroblasts and neurons derived from induced pluripotent stem cells (iPSCs) generated from GRN mutation carriers. Finally, oral administration of trehalose to Grn haploinsufficient mice significantly increased PGRN expression in the brain. CONCLUSIONS This work reports several novel autophagy-lysosome modulators that enhance PGRN expression and identifies trehalose as a promising therapeutic for raising PGRN levels to treat multiple neurodegenerative diseases.
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Affiliation(s)
- Christopher J Holler
- Department of Pharmacology, Emory University, School of Medicine, 1510 Clifton Rd, Atlanta, GA, 30322, USA
| | - Georgia Taylor
- Department of Pharmacology, Emory University, School of Medicine, 1510 Clifton Rd, Atlanta, GA, 30322, USA
| | - Zachary T McEachin
- Laboratory of Translational Cell Biology, Emory University, School of Medicine, Atlanta, GA, 30322, USA.,Department of Cell Biology, Emory University, School of Medicine, Atlanta, GA, 30322, USA.,Coulter Department of Biomedical Engineering, Georgia Institute of Technology, 313 Ferst Drive, Atlanta, GA, 30332, USA
| | - Qiudong Deng
- Department of Pharmacology, Emory University, School of Medicine, 1510 Clifton Rd, Atlanta, GA, 30322, USA
| | - William J Watkins
- Department of Pharmacology, Emory University, School of Medicine, 1510 Clifton Rd, Atlanta, GA, 30322, USA
| | - Kathryn Hudson
- Department of Pharmacology, Emory University, School of Medicine, 1510 Clifton Rd, Atlanta, GA, 30322, USA
| | - Charles A Easley
- Laboratory of Translational Cell Biology, Emory University, School of Medicine, Atlanta, GA, 30322, USA.,Department of Cell Biology, Emory University, School of Medicine, Atlanta, GA, 30322, USA
| | - William T Hu
- Center for Neurodegenerative Disease, Emory University, School of Medicine, Atlanta, GA, 30322, USA.,Department of Neurology, Emory University, School of Medicine, Atlanta, GA, 30322, USA
| | - Chadwick M Hales
- Center for Neurodegenerative Disease, Emory University, School of Medicine, Atlanta, GA, 30322, USA.,Department of Neurology, Emory University, School of Medicine, Atlanta, GA, 30322, USA
| | - Wilfried Rossoll
- Laboratory of Translational Cell Biology, Emory University, School of Medicine, Atlanta, GA, 30322, USA.,Department of Cell Biology, Emory University, School of Medicine, Atlanta, GA, 30322, USA.,Coulter Department of Biomedical Engineering, Georgia Institute of Technology, 313 Ferst Drive, Atlanta, GA, 30332, USA.,Center for Neurodegenerative Disease, Emory University, School of Medicine, Atlanta, GA, 30322, USA
| | - Gary J Bassell
- Laboratory of Translational Cell Biology, Emory University, School of Medicine, Atlanta, GA, 30322, USA.,Department of Cell Biology, Emory University, School of Medicine, Atlanta, GA, 30322, USA.,Coulter Department of Biomedical Engineering, Georgia Institute of Technology, 313 Ferst Drive, Atlanta, GA, 30332, USA.,Center for Neurodegenerative Disease, Emory University, School of Medicine, Atlanta, GA, 30322, USA.,Department of Neurology, Emory University, School of Medicine, Atlanta, GA, 30322, USA
| | - Thomas Kukar
- Department of Pharmacology, Emory University, School of Medicine, 1510 Clifton Rd, Atlanta, GA, 30322, USA. .,Center for Neurodegenerative Disease, Emory University, School of Medicine, Atlanta, GA, 30322, USA. .,Department of Neurology, Emory University, School of Medicine, Atlanta, GA, 30322, USA.
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23
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Possible involvement of the cerebellum in motor-function impairment in progranulin-deficient mice. Neuroreport 2016; 26:877-81. [PMID: 26302163 DOI: 10.1097/wnr.0000000000000442] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
Progranulin (PGRN) is a multifunctional growth factor involved in many physiological and pathological processes in the brain such as sexual differentiation, neurogenesis, neuroinflammation, and neurodegeneration. Previously, we showed that PGRN was expressed broadly in the brain and the Purkinje cells in the cerebellum were one of the regions with the highest expression level of PGRN. Thus, in the present study, we investigated the possible roles of PGRN in the cerebellum by comparing wild-type (WT) and PGRN-deficient (KO) mice with immunohistochemical staining for calbindin, a marker of Purkinje cells. The results showed that the density of Purkinje cell dendrites in the molecular layer of the cerebellum was significantly higher in KO mice than in WT mice, although the number of cell bodies was comparable between the genotypes. Subsequently, as the cerebellum is the center of the motor function, we performed a rotarod test and found that KO mice remained on the rotating rod for significantly shorter periods than WT mice. However, KO and WT mice did not differ significantly with respect to the diameter of myofibers in a skeletal muscle. These results suggest that PGRN is involved in the development and/or maturation of neuronal networks comprising Purkinje cells in the cerebellum, which may be a prerequisite to normal motor function.
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24
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Teotia AK, Gupta A, Raina DB, Lidgren L, Kumar A. Gelatin-Modified Bone Substitute with Bioactive Molecules Enhance Cellular Interactions and Bone Regeneration. ACS APPLIED MATERIALS & INTERFACES 2016; 8:10775-10787. [PMID: 27077816 DOI: 10.1021/acsami.6b02145] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/05/2023]
Abstract
In this work, we have synthesized injectable bone cement incorporated with gelatin to enhance cellular interaction. Human osteosarcoma Saos-2 cells derived bone morphogenetic proteins (BMP's) and a bisphosphonate (zoledronic acid (0.2 mM)) were also incorporated to cement. In vitro studies conducted using Saos-2 demonstrated enhanced cell proliferation on gelatin (0.2%w/v) cement. The differentiation of C2C12 mouse myoblast cells into bone forming cells showed 6-fold increase in ALP levels on gelatin cement. Polymerase chain reaction (PCR) for bone biomarkers showed osteoinductive potential of gelatin cement. We investigated efficacy for local delivery of these bioactive molecules in enhancing bone substitution qualities of bone cements by implanting in 3.5 mm critical size defect in tibial metaphysis of wistar rats. The rats were sacrificed after 12 weeks and 16 weeks post implantation. X-ray, micro-CT, histology, and histomorphometry analysis were performed to check bone healing. The cement materials slowly resorbed from the defect site leaving HAP creating porous matrix providing surface for bone formation. The materials showed high biocompatibility and initial bridging was observed in all the animals but maximum bone formation was observed in animals implanted with cement incorporated with zoledronic acid followed by cement with BMP's compared to other groups.
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Affiliation(s)
- Arun Kumar Teotia
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur , Kanpur 208016, India
| | - Ankur Gupta
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur , Kanpur 208016, India
| | - Deepak Bushan Raina
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur , Kanpur 208016, India
- Department of Orthopedics, Clinical Sciences, Lund, Lund University , Lund 221 85, Sweden
| | - Lars Lidgren
- Department of Orthopedics, Clinical Sciences, Lund, Lund University , Lund 221 85, Sweden
| | - Ashok Kumar
- Department of Biological Sciences and Bioengineering, Indian Institute of Technology Kanpur , Kanpur 208016, India
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25
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Luo W, Lin S, Li G, Nie Q, Zhang X. Integrative Analyses of miRNA-mRNA Interactions Reveal let-7b, miR-128 and MAPK Pathway Involvement in Muscle Mass Loss in Sex-Linked Dwarf Chickens. Int J Mol Sci 2016; 17:276. [PMID: 26927061 PMCID: PMC4813140 DOI: 10.3390/ijms17030276] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Revised: 02/17/2016] [Accepted: 02/17/2016] [Indexed: 01/21/2023] Open
Abstract
The sex-linked dwarf (SLD) chicken is an ideal model system for understanding growth hormone (GH)-action and growth hormone receptor (GHR) function because of its recessive mutation in the GHR gene. Skeletal muscle mass is reduced in the SLD chicken with a smaller muscle fiber diameter. Our previous study has presented the mRNA and miRNA expression profiles of the SLD chicken and normal chicken between embryo day 14 and seven weeks of age. However, the molecular mechanism of GHR-deficient induced muscle mass loss is still unclear, and the key molecules and pathways underlying the GHR-deficient induced muscle mass loss also remain to be illustrated. Here, by functional network analysis of the differentially expressed miRNAs and mRNAs between the SLD and normal chickens, we revealed that let-7b, miR-128 and the MAPK pathway might play key roles in the GHR-deficient induced muscle mass loss, and that the reduced cell division and growth are potential cellular processes during the SLD chicken skeletal muscle development. Additionally, we also found some genes and miRNAs involved in chicken skeletal muscle development, through the MAPK, PI3K-Akt, Wnt and Insulin signaling pathways. This study provides new insights into the molecular mechanism underlying muscle mass loss in the SLD chickens, and some regulatory networks that are crucial for chicken skeletal muscle development.
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Affiliation(s)
- Wen Luo
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou 510642, Guangdong, China.
- Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, South China Agricultural University, Guangzhou 510642, Guangdong, China.
- Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, Guangdong, China.
| | - Shumao Lin
- College of Life Science, Foshan University, Foshan 528231, Guangdong, China.
| | - Guihuan Li
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou 510642, Guangdong, China.
- Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, South China Agricultural University, Guangzhou 510642, Guangdong, China.
- Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, Guangdong, China.
| | - Qinghua Nie
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou 510642, Guangdong, China.
- Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, South China Agricultural University, Guangzhou 510642, Guangdong, China.
- Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, Guangdong, China.
| | - Xiquan Zhang
- Department of Animal Genetics, Breeding and Reproduction, College of Animal Science, South China Agricultural University, Guangzhou 510642, Guangdong, China.
- Guangdong Provincial Key Lab of Agro-Animal Genomics and Molecular Breeding, South China Agricultural University, Guangzhou 510642, Guangdong, China.
- Key Lab of Chicken Genetics, Breeding and Reproduction, Ministry of Agriculture, South China Agricultural University, Guangzhou 510642, Guangdong, China.
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Interleukin-6-stimulated progranulin expression contributes to the malignancy of hepatocellular carcinoma cells by activating mTOR signaling. Sci Rep 2016; 6:21260. [PMID: 26879559 PMCID: PMC4754634 DOI: 10.1038/srep21260] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Accepted: 01/20/2016] [Indexed: 12/22/2022] Open
Abstract
This study aimed to determine the expression of progranulin (PGRN) in hepatocellular carcinoma (HCC) cells in response to interleukin 6 (IL-6), a non-cellular component of the tumor microenvironment, and the molecular mechanism of PGRN oncogenic activity in hepatocarcinogenesis. Levels of IL-6 and PGRN were increased and positively correlated in HCC tissues. IL-6 dose- and time-dependently increased PGRN level in HCC cells. IL-6-driven PGRN expression was at least in part mediated by Erk/C/EBPβ signaling, and reduced expression of PGRN impaired IL-6-stimulated proliferation, migration and invasion of HepG2 cells. PGRN activated mammalian target of rapamycin (mTOR) signaling, as evidenced by increased phosphorylation of p70S6K, 4E-BP1, and Akt-Ser473/FoxO1. Inhibition of mTOR signaling with rapamycin, an mTOR signaling inhibitor, disturbed PGRN- or IL-6-mediated proliferation, migration and invasion of HCC cells in vitro. Persistent activation of mTOR signaling by knockdown of TSC2 restored PGRN-knockdown-attenuated pro-proliferation effects of IL-6 in HepG2 cells. In addition, rapamycin treatment in vivo in mice slowed tumor growth stimulated by recombinant human PGRN. Our findings provide a better understanding of the biological activities of the IL-6/PGRN/mTOR cascade in the carcinogenesis of HCC, which may suggest a novel target in the treatment of HCC.
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27
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Liu J, Li H, Zhou B, Xu L, Kang X, Yang W, Wu S, Sun H. PGRN induces impaired insulin sensitivity and defective autophagy in hepatic insulin resistance. Mol Endocrinol 2015; 29:528-41. [PMID: 25664864 DOI: 10.1210/me.2014-1266] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
Progranulin (PGRN) has recently emerged as an important regulator for glucose metabolism and insulin sensitivity. However, the underlying mechanisms of PGRN in the regulation of insulin sensitivity and autophagy remain elusive. In this study, we aimed to address the direct effects of PGRN in vivo and to evaluate the potential interaction of impaired insulin sensitivity and autophagic disorders in hepatic insulin resistance. We found that mice treated with PGRN for 21 days exhibited the impaired glucose tolerance and insulin tolerance and hepatic autophagy imbalance as well as defective insulin signaling. Furthermore, treatment of mice with TNF receptor (TNFR)-1 blocking peptide-Fc, a TNFR1 blocking peptide-Fc fusion protein to competitively block the interaction of PGRN and TNFR1, resulted in the restoration of systemic insulin sensitivity and the recovery of autophagy and insulin signaling in liver. Consistent with these findings in vivo, we also observed that PGRN treatment induced defective autophagy and impaired insulin signaling in hepatocytes, with such effects being drastically nullified by the addition of TNFR1 blocking peptide -Fc or TNFR1-small interference RNA via the TNFR1-nuclear factor-κB-dependent manner, indicating the causative role of PGRN in hepatic insulin resistance. In conclusion, our findings supported the notion that PGRN is a key regulator of hepatic insulin resistance and that PGRN may mediate its effects, at least in part, by inducing defective autophagy via TNFR1/nuclear factor-κB.
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Affiliation(s)
- Jiali Liu
- First Affiliated Hospital of the Medical School of Xi'an Jiaotong University, and Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Medical School of Xi'an Jiaotong University, Xi'an, Shaanxi 710061, China
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28
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de la Encarnación A, Alquézar C, Esteras N, Martín-Requero Á. Progranulin Deficiency Reduces CDK4/6/pRb Activation and Survival of Human Neuroblastoma SH-SY5Y Cells. Mol Neurobiol 2014; 52:1714-1725. [PMID: 25377796 DOI: 10.1007/s12035-014-8965-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/05/2014] [Accepted: 10/24/2014] [Indexed: 11/26/2022]
Abstract
Null mutations in GRN are associated with frontotemporal lobar degeneration with TDP-43 inclusions (FTLD-TDP). However, the influence of progranulin (PGRN) deficiency in neurodegeneration is largely unknown. In neuroblastoma cells, silencing of GRN gene causes significantly reduced cell survival after serum withdrawal. The following observations suggest that alterations of the CDK4/6/retinoblastoma protein (pRb) pathway, secondary to changes in PI3K/Akt and ERK1/2 activation induced by PGRN deficiency, are involved in the control of serum deprivation-induced apoptosis: (i) inhibiting CDK4/6 levels or their associated kinase activity by sodium butyrate or PD332991 sensitized control SH-SY5Y cells to serum deprivation-induced apoptosis without affecting survival of PGRN-deficient cells; (ii) CDK4/6/pRb seems to be downstream of the PI3K/Akt and ERK1/2 signaling pathways since their specific inhibitors, LY294002 and PD98059, were able to decrease CDK6-associated kinase activity and induce death of control SH-SY5Y cells; (iii) PGRN-deficient cells show reduced stimulation of PI3K/Akt, ERK1/2, and CDK4/6 activities compared with control cells in the absence of serum; and (iv) supplementation of recombinant human PGRN was able to rescue survival of PGRN-deficient cells. These observations highlight the important role of PGRN-mediated stimulation of the PI3K/Akt-ERK1/2/CDK4/6/pRb pathway in determining the cell fate survival/death under serum deprivation.
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Affiliation(s)
- Ana de la Encarnación
- Department of Cellular and Molecular Medicine, Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu 9, 28040, Madrid, Spain
| | - Carolina Alquézar
- Department of Cellular and Molecular Medicine, Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu 9, 28040, Madrid, Spain
- CIBER de Enfermedades Raras (CIBERER), Monforte de Lemos 3, 28029, Madrid, Spain
| | - Noemí Esteras
- Department of Cellular and Molecular Medicine, Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu 9, 28040, Madrid, Spain
- Department of Molecular Neuroscience, Institute of Neurology, Queen Square, London, WC1N 3BG, UK
| | - Ángeles Martín-Requero
- Department of Cellular and Molecular Medicine, Centro de Investigaciones Biológicas (CSIC), Ramiro de Maeztu 9, 28040, Madrid, Spain.
- CIBER de Enfermedades Raras (CIBERER), Monforte de Lemos 3, 28029, Madrid, Spain.
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29
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Li H, Zhou B, Xu L, Liu J, Zang W, Wu S, Sun H. Circulating PGRN is significantly associated with systemic insulin sensitivity and autophagic activity in metabolic syndrome. Endocrinology 2014; 155:3493-507. [PMID: 24971611 DOI: 10.1210/en.2014-1058] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
Progranulin (PGRN) is a secreted protein that has recently emerged as an important regulatory adipokine of glucose metabolism and insulin sensitivity. We report here that serum PGRN concentrations were significantly higher in patients with metabolic syndrome (MS) than in subjects without MS and correlated positively with body mass index, waist circumference, fasting insulin, fasting plasma glucose, glycated hemoglobin A1c, triglyceride, and homeostasis model assessment of insulin resistance, and were inversely related to high-density lipoprotein cholesterol and homeostasis model assessment of β cell function. Subgroup analysis in 32 subjects showed that elevated expression levels of PGRN were positively correlated with increased autophagy markers LC3 and Atg7 proteins in omental adipose tissue of subjects with MS. Consistent with these findings, the enhanced PGRN levels were also observed in multiple insulin-resistant cellular models, whereas PGRN-deficient adipocytes were more susceptible to insulin action and refractory to tunicamycin-induced autophagic disorders. PGRN remarkably attenuated insulin sensitivity, increased autophagic activity, and triggered endoplasmic reticulum (ER) stress in cultured human adipocytes, whereas these effects were nullified by reduction of ER stress with phenylbutyric acid chemical chaperone treatment. In addition, PGRN-induced ER stress and impaired insulin sensitivity were improved in TNFR1(-/-) cells, indicating a causative role of TNF receptor in the action of PGRN. Collectively, our findings suggest that circulating PGRN is significantly associated with systemic insulin sensitivity and autophagic activity in adipose tissue and support the notion that PGRN functions as a potential link between chronic inflammation and insulin resistance.
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Affiliation(s)
- Huixia Li
- First Affiliated Hospital of Medical School of Xi'an Jiaotong University, Key Laboratory of Environment and Genes Related to Diseases, Ministry of Education, Medical School of Xi'an Jiaotong University, Xi'an, Shaanxi, 710061, China
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30
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Shaheen F, Grammatopoulos DK, Müller J, Zammit VA, Lehnert H. Extra-nuclear telomerase reverse transcriptase (TERT) regulates glucose transport in skeletal muscle cells. Biochim Biophys Acta Mol Basis Dis 2014; 1842:1762-9. [PMID: 24970747 DOI: 10.1016/j.bbadis.2014.06.018] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2014] [Revised: 05/20/2014] [Accepted: 06/17/2014] [Indexed: 10/25/2022]
Abstract
Telomerase reverse transcriptase (TERT) is a key component of the telomerase complex. By lengthening telomeres in DNA strands, TERT increases senescent cell lifespan. Mice that lack TERT age much faster and exhibit age-related conditions such as osteoporosis, diabetes and neurodegeneration. Accelerated telomere shortening in both human and animal models has been documented in conditions associated with insulin resistance, including T2DM. We investigated the role of TERT, in regulating cellular glucose utilisation by using the myoblastoma cell line C2C12, as well as primary mouse and human skeletal muscle cells. Inhibition of TERT expression or activity by using siRNA (100nM) or specific inhibitors (100nM) reduced basal 2-deoxyglucose uptake by ~50%, in all cell types, without altering insulin responsiveness. In contrast, TERT over-expression increased glucose uptake by 3.25-fold. In C2C12 cells TERT protein was mostly localised intracellularly and stimulation of cells with insulin induced translocation to the plasma membrane. Furthermore, co-immunoprecipitation experiments in C2C12 cells showed that TERT was constitutively associated with glucose transporters (GLUTs) 1, 4 and 12 via an insulin insensitive interaction that also did not require intact PI3-K and mTOR pathways. Collectively, these findings identified a novel extra-nuclear function of TERT that regulates an insulin-insensitive pathway involved in glucose uptake in human and mouse skeletal muscle cells.
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Affiliation(s)
- Fozia Shaheen
- Division of Metabolic and Vascular Health, Warwick Medical School, Clinical Sciences Research Laboratories, University of Warwick, CV2 2DX, UK.
| | - Dimitris K Grammatopoulos
- Division of Metabolic and Vascular Health, Warwick Medical School, Clinical Sciences Research Laboratories, University of Warwick, CV2 2DX, UK.
| | - Jürgen Müller
- Division of Metabolic and Vascular Health, Warwick Medical School, Clinical Sciences Research Laboratories, University of Warwick, CV2 2DX, UK.
| | - Victor A Zammit
- Division of Metabolic and Vascular Health, Warwick Medical School, Clinical Sciences Research Laboratories, University of Warwick, CV2 2DX, UK.
| | - Hendrik Lehnert
- Division of Metabolic and Vascular Health, Warwick Medical School, Clinical Sciences Research Laboratories, University of Warwick, CV2 2DX, UK; First Department of Medicine, University Hospital of Schleswig-Holstein, Campus Lübeck, Ratzeburger Allee 160, 23538 Lübeck, Germany.
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31
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Wei C, Li L, Su H, Xu L, Lu J, Zhang L, Liu W, Ren H, Du L. Identification of the crucial molecular events during the large-scale myoblast fusion in sheep. Physiol Genomics 2014; 46:429-40. [DOI: 10.1152/physiolgenomics.00184.2013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/14/2023] Open
Abstract
It is well known that in sheep most myofibers are formed before birth; however, the crucial myogenic stage and the cellular and molecular mechanisms underpinning phenotypic variation of fetal muscle development remain to be ascertained. We used histological, microarray, and quantitative real-time PCR (qPCR) methods to examine the developmental characteristics of fetal muscle at 70, 85, 100, 120, and 135 days of gestation in sheep. We show that day 100 is an important checkpoint for change in muscle transcriptome and histomorphology in fetal sheep and that the period of 85–100 days is the vital developmental stage for large-scale myoblast fusion. Furthermore, we identified the cis-regulatory motifs for E2F1 or MEF2A in a list of decreasingly or increasingly expressed genes between 85 and 100 days, respectively. Further analysis demonstrated that the mRNA and phosphorylated protein levels of E2F1 and MEF2A significantly declined with myogenic progression in vivo and in vitro. qRT-PCR analysis indicated that PI3K and FST, as targets of E2F1, may be involved in myoblast differentiation and fusion and that downregulation of MEF2A contributes to transition of myofiber types by differential regulation of the target genes involved at the stage of 85–100 days. We clarify for the first time the timing of myofiber proliferation and development during gestation in sheep, which would be beneficial to meat sheep production. Our findings present a repertoire of gene expression in muscle during large-scale myoblast fusion at transcriptome-wide level, which contributes to elucidate the regulatory network of myogenic differentiation.
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Affiliation(s)
- Caihong Wei
- National Center for Molecular Genetics and Breeding of Animal, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Li Li
- National Center for Molecular Genetics and Breeding of Animal, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
- College of Animal Science and Technology, Sichuan Agricultural University, Ya'an, Sichuan, China; and
| | - Hongwei Su
- College of Animal Science and Technology, Shanxi Agricultural University, Taigu, Shanxi, China
| | - Lingyang Xu
- National Center for Molecular Genetics and Breeding of Animal, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Jian Lu
- National Center for Molecular Genetics and Breeding of Animal, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Li Zhang
- National Center for Molecular Genetics and Breeding of Animal, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
| | - Wenzhong Liu
- College of Animal Science and Technology, Shanxi Agricultural University, Taigu, Shanxi, China
| | - Hangxing Ren
- National Center for Molecular Genetics and Breeding of Animal, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
- Chongqing Academy of Animal Sciences, Rongchang, Chongqing, China
| | - Lixin Du
- National Center for Molecular Genetics and Breeding of Animal, Institute of Animal Sciences, Chinese Academy of Agricultural Sciences, Beijing, China
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Konopka J, Richbourgh B, Liu C. The role of PGRN in musculoskeletal development and disease. Front Biosci (Landmark Ed) 2014; 19:662-71. [PMID: 24389211 DOI: 10.2741/4234] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Progranulin (PGRN) is a growth factor that has been implicated in wound healing, inflammation, infection, tumorigenesis, and is most known for its neuroprotective and proliferative properties in neurodegenerative disease. This pleiotropic growth factor has been found to be a key player and regulator of a diverse spectrum of multi-systemic functions. Its critical anti-inflammatory role in rheumatoid arthritis and other inflammatory disease models has allowed for the propulsion of research to establish its significance in musculoskeletal diseases, including inflammatory conditions involving bone and cartilage pathology. In this review, we aim to elaborate on the emerging role of PGRN in the musculoskeletal system, reviewing its particular mechanisms described in various musculoskeletal diseases, with special focus on osteoarthritis and inflammatory joint disease patho-mechanisms and potential therapeutic applications of PGRN and its derivatives in these and other musculoskeletal diseases.
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Affiliation(s)
- Jessica Konopka
- Department of Orthopaedic Surgery, New York University Medical Center, New York, NY, 10003
| | - Brendon Richbourgh
- Department of Orthopaedic Surgery, New York University Medical Center, 301 East 17th Street, New York, NY 10003
| | - Chuanju Liu
- Department of Orthopaedic Surgery, New York University Medical Center, 301 East 17th Street, New York, NY 10003
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Zanou N, Gailly P. Skeletal muscle hypertrophy and regeneration: interplay between the myogenic regulatory factors (MRFs) and insulin-like growth factors (IGFs) pathways. Cell Mol Life Sci 2013; 70:4117-30. [PMID: 23552962 PMCID: PMC11113627 DOI: 10.1007/s00018-013-1330-4] [Citation(s) in RCA: 192] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2013] [Revised: 03/19/2013] [Accepted: 03/19/2013] [Indexed: 10/27/2022]
Abstract
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.
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Affiliation(s)
- Nadège Zanou
- Laboratory of Cell Physiology, Institute of Neuroscience, Université catholique de Louvain, 55 av. Hippocrate, B1.55.12, 1200, Brussels, Belgium,
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Kleinberger G, Capell A, Haass C, Van Broeckhoven C. Mechanisms of granulin deficiency: lessons from cellular and animal models. Mol Neurobiol 2012; 47:337-60. [PMID: 23239020 PMCID: PMC3538123 DOI: 10.1007/s12035-012-8380-8] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 11/14/2012] [Indexed: 12/12/2022]
Abstract
The identification of causative mutations in the (pro)granulin gene (GRN) has been a major breakthrough in the research on frontotemporal dementia (FTD). So far, all FTD-associated GRN mutations are leading to neurodegeneration through a “loss-of-function” mechanism, encouraging researchers to develop a growing number of cellular and animal models for GRN deficiency. GRN is a multifunctional secreted growth factor, and loss of its function can affect different cellular processes. Besides loss-of-function (i.e., mostly premature termination codons) mutations, which cause GRN haploinsufficiency through reduction of GRN expression, FTD-associated GRN missense mutations have also been identified. Several of these missense mutations are predicted to increase the risk of developing neurodegenerative diseases through altering various key biological properties of GRN-like protein secretion, proteolytic processing, and neurite outgrowth. With the use of cellular and animal models for GRN deficiency, the portfolio of GRN functions has recently been extended to include functions in important biological processes like energy and protein homeostasis, inflammation as well as neuronal survival, neurite outgrowth, and branching. Furthermore, GRN-deficient animal models have been established and they are believed to be promising disease models as they show accelerated aging and recapitulate at least some neuropathological features of FTD. In this review, we summarize the current knowledge on the molecular mechanisms leading to GRN deficiency and the lessons we learned from the established cellular and animal models. Furthermore, we discuss how these insights might help in developing therapeutic strategies for GRN-associated FTD.
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Affiliation(s)
- Gernot Kleinberger
- Neurodegenerative Brain Diseases Group, VIB Department of Molecular Genetics, University of Antwerp-CDE, Universiteitsplein 1, Antwerp, 2610, Belgium
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