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Han J, Choi SY, Choi RY, Park KW, Kang KY, Lee MK. Anti-muscle atrophy effect of fermented Tenebrio molitor larvae extract by modulating the PI3K-Akt-mTOR/FoxO3α pathway in mice treated with dexamethasone. Biomed Pharmacother 2024; 178:117266. [PMID: 39137649 DOI: 10.1016/j.biopha.2024.117266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2024] [Revised: 07/29/2024] [Accepted: 08/05/2024] [Indexed: 08/15/2024] Open
Abstract
This study investigated the anti-sarcopenic effect of fermented Tenebrio molitor larvae (mealworms) extract (FME) in both dexamethasone (DEX)-treated C2C12 cells and mice. FME (100 µg/mL) increased the diameter of myotubes and inhibited the gene and protein expression of atrogin-1 compared to DEX- or non-fermented mealworms extract (ME)-treated C2C12 cells. Male C57BL/6N mice were divided into five groups: Normal Control (NC), DEX (10 mg/kg, intraperitoneal), and three groups of DEX+FME (100, 200, or 500 mg FME/kg/day, oral) for two weeks. FME at doses of 200 and 500 mg/kg effectively improved grip strength when compared to the DEX group. Histological analysis of the quadriceps muscle showed a larger muscle fiber size in the DEX+FME groups compared to DEX group. FME (200 and 500 mg/kg) significantly increased cross-sectional area of the muscle fiber compared to DEX group. FME (500 mg/kg) significantly decreased the ubiquitin, atrogin-1 and MuRF-1 protein levels, and increased levels of MHC and MyoG in DEX-treated mice. The puromycin labeling assay revealed that FME increased protein synthesis in DEX-induced muscle atrophy. The FME treatment demonstrated significant upregulation in phosphorylation levels, including mTOR, FoxO3α, Akt, and PI3K compared to DEX group. In conclusion, FME inhibited the increase in proteins associated with muscle atrophy, including, atrogin-1 and MuRF-1, by regulating the PI3K-Akt-FoxO3α pathway. FME improved the PI3K-Akt-mTOR signaling pathway, which was reduced by DEX. This study suggests that FME has the potential for use in sarcopenia therapy, possibly serving as a natural agent that counteracts the negative effects of DEX on muscle tissue.
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Affiliation(s)
- Jisu Han
- Department of Food and Nutrition, Sunchon National University, Suncheon 57922, Republic of Korea
| | - Soo-Young Choi
- Department of Food and Nutrition, Sunchon National University, Suncheon 57922, Republic of Korea
| | - Ra-Yeong Choi
- Department of Agricultural Biology, National Institute of Agricultural Sciences, Rural Development Administration, Wanju 55365, Republic of Korea
| | - Kyung-Wuk Park
- Suncheon Research Center for Bio Health Care, Suncheon 57962, Republic of Korea
| | - Kyung-Yun Kang
- Suncheon Research Center for Bio Health Care, Suncheon 57962, Republic of Korea
| | - Mi-Kyung Lee
- Department of Food and Nutrition, Sunchon National University, Suncheon 57922, Republic of Korea.
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2
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Rodgers BD, Herring SK, Carias DR, Chen J, Rocha AG. Development and validation of a model gene therapy biodistribution assay for AVGN7 using digital droplet polymerase chain reaction. Mol Ther Methods Clin Dev 2023; 29:494-503. [PMID: 37273901 PMCID: PMC10236005 DOI: 10.1016/j.omtm.2023.05.007] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 05/08/2023] [Indexed: 06/06/2023]
Abstract
Biodistribution assays are integral to gene therapy commercialization and have traditionally used real-time qPCR. Droplet digital PCR (ddPCR), however, has distinct advantages including higher sensitivity and absolute quantification but is underused because of lacking regulatory guidance and meaningful examples in the literature. We report a fit-for-purpose model process to validate a good laboratory practice (GLP)-compliant ddPCR assay for AVGN7, a Smad7 gene therapeutic for muscle wasting. Duplexed primer/probe sets for Smad7 and mouse TATA-box binding protein were optimized using gBlock DNA over a dynamic range of 10-80,000 copies/reaction in 250 ng mouse gDNA. Linearized plasmid and mouse gDNA were used for validation, which determined precision, accuracy, ruggedness/robustness, selectivity, recovery, specificity, dilution linearity, and stability. Inter-run precision and accuracy met previously established criteria with bias between -5% and 15%, coefficient of variation (CV) less than 19%, and total error within 8%-35%. The limit of detection was 2.5 copies/reaction, linearity was confirmed at 40-80,000 copies/reaction, specificity was demonstrated by single droplet populations and assay stability was demonstrated for benchtop, refrigerated storage, and repeated freeze-thaw cycles. The procedural road map provided exceeds recently established standards. It is also relevant to many IND-enabling processes, as validated ddPCR assays can be used in biodistribution studies and with vector titering and manufacturing quality control.
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Affiliation(s)
| | | | - Dereck R Carias
- Smithers Pharmaceutical Development Services, Ewing, NJ 08628, USA
| | - Joyce Chen
- Smithers Pharmaceutical Development Services, Ewing, NJ 08628, USA
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3
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Ma J, Chen J, Gan M, Chen L, Zhao Y, Niu L, Zhu Y, Zhang S, Li X, Guo Z, Wang J, Zhu L, Shen L. Comparison of reference gene expression stability in mouse skeletal muscle via five algorithms. PeerJ 2022; 10:e14221. [PMID: 36275473 PMCID: PMC9583855 DOI: 10.7717/peerj.14221] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2022] [Accepted: 09/20/2022] [Indexed: 01/24/2023] Open
Abstract
Real-time quantitative PCR (RT-qPCR) is a widely applied technique for relative quantification of gene expression. In this context, the selection of a suitable reference gene (RG) is an essential step for obtaining reliable and biologically relevant RT-qPCR results. The present study aimed to determine the expression stability of commonly used RGs in mouse skeletal muscle tissue. The expression pattern of eight RGs (ACTB, GAPDH, HPRT, YWHAZ, B2M, PPIA, TUBA and 18S) were evaluated by RT-qPCR in different sample groups classified based on genetic background, muscle tissue type, and growth stage, as well as in a C2C12 myoblast cell line model. Five computational programs were included in the study (comparative ΔCq value, NormFinder, BestKeeper, geNorm, RefFinder) to evaluate the expression stability of RGs. Furthermore, the normalization effects of RGs in soleus (SOL) and gastrocnemius (GAS) muscle tissue were evaluated. Collectively, ACTB, HPRT and YWHAZ were shown to be the most stable RGs, while GADPH and 18S were the least stable. Therefore, the combined use of ACTB, HPRT and YWHAZ is recommended for the normalization of gene expression results in experiments with murine skeletal muscle. The results discussed herein provide a foundation for gene expression analysis by RT-qPCR in mammalian skeletal muscle.
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Affiliation(s)
- Jianfeng Ma
- Department of Animal Science, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China,Key Laboratory of Livestock and Poultry Multiomics, Ministry of Agriculture and Rural Affairs, College of Animal and Technology (Institute of Animal Genetics and Breeding), Sichuan Agricultural University, Chengdu, China,Chongqing Academy of Animal Science, Chongqing, China
| | - Jingyun Chen
- Department of Animal Science, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China,Key Laboratory of Livestock and Poultry Multiomics, Ministry of Agriculture and Rural Affairs, College of Animal and Technology (Institute of Animal Genetics and Breeding), Sichuan Agricultural University, Chengdu, China,Chongqing Academy of Animal Science, Chongqing, China
| | - Mailin Gan
- Department of Animal Science, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China,Key Laboratory of Livestock and Poultry Multiomics, Ministry of Agriculture and Rural Affairs, College of Animal and Technology (Institute of Animal Genetics and Breeding), Sichuan Agricultural University, Chengdu, China
| | - Lei Chen
- Department of Animal Science, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China,Key Laboratory of Livestock and Poultry Multiomics, Ministry of Agriculture and Rural Affairs, College of Animal and Technology (Institute of Animal Genetics and Breeding), Sichuan Agricultural University, Chengdu, China
| | - Ye Zhao
- Department of Animal Science, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China,Key Laboratory of Livestock and Poultry Multiomics, Ministry of Agriculture and Rural Affairs, College of Animal and Technology (Institute of Animal Genetics and Breeding), Sichuan Agricultural University, Chengdu, China
| | - Lili Niu
- Department of Animal Science, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China,Key Laboratory of Livestock and Poultry Multiomics, Ministry of Agriculture and Rural Affairs, College of Animal and Technology (Institute of Animal Genetics and Breeding), Sichuan Agricultural University, Chengdu, China
| | - Yan Zhu
- College of Life Science, China West Normal University, Nanchong, China
| | - Shunhua Zhang
- Department of Animal Science, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China,Key Laboratory of Livestock and Poultry Multiomics, Ministry of Agriculture and Rural Affairs, College of Animal and Technology (Institute of Animal Genetics and Breeding), Sichuan Agricultural University, Chengdu, China
| | - Xuewei Li
- Department of Animal Science, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China,Key Laboratory of Livestock and Poultry Multiomics, Ministry of Agriculture and Rural Affairs, College of Animal and Technology (Institute of Animal Genetics and Breeding), Sichuan Agricultural University, Chengdu, China
| | - Zongyi Guo
- Chongqing Academy of Animal Science, Chongqing, China
| | - Jinyong Wang
- Chongqing Academy of Animal Science, Chongqing, China
| | - Li Zhu
- Department of Animal Science, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China,Key Laboratory of Livestock and Poultry Multiomics, Ministry of Agriculture and Rural Affairs, College of Animal and Technology (Institute of Animal Genetics and Breeding), Sichuan Agricultural University, Chengdu, China
| | - Linyuan Shen
- Department of Animal Science, College of Animal Science and Technology, Sichuan Agricultural University, Chengdu, China,Key Laboratory of Livestock and Poultry Multiomics, Ministry of Agriculture and Rural Affairs, College of Animal and Technology (Institute of Animal Genetics and Breeding), Sichuan Agricultural University, Chengdu, China
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Tran KN, Choi JI. Mimic microgravity effect on muscle transcriptome under ionizing radiation. LIFE SCIENCES IN SPACE RESEARCH 2022; 32:96-104. [PMID: 35065767 DOI: 10.1016/j.lssr.2021.12.002] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Revised: 11/30/2021] [Accepted: 12/08/2021] [Indexed: 06/14/2023]
Abstract
Spaceflight imposes the risk of skeletal muscle atrophy for astronauts. Two main factors of a spaceflight that results in deleterious effects are microgravity and cosmic rays in outer space. To study spaceflight-induced muscle atrophy with ground-based models, we performed two models of microgravity, tail suspension and denervation, in a low dose radiation environment and studied transcriptional changes in rat soleus muscle using microarrays. Soleus muscle from rats in the denervation group had greater expression changes compared to that found in rats from the tail suspension group. However, there was a very similar pattern of expression of differentially expressed genes (DEGs) in both models. In total, we identified 144 differentially expressed genes common in both models. Our study yielded two main findings. First, a large number of genes involved in energy metabolism were transcriptionally suppressed including those involved in fatty acid transport and beta-oxidation, and oxidative phosphorylation. Second, slow-twitch contractile protein encoding genes were down-regulated while there was an up-regulation in the fast-twitch type transcription. These results were consistent with other spaceflight studies on the effects on muscle cells, hence showed the potential of our ground-based models in studying spaceflight effects. The genes that might be involved in spaceflight effects will serve as candidate genes for future studies in understanding the mechanism of spaceflight-induced muscle atrophy and result in the development of effective countermeasures.
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Affiliation(s)
- Kim Ngan Tran
- Department of Biotechnology and Bioengineering, Chonnam National University, Gwangju 61186, Republic of Korea
| | - Jong-Il Choi
- Department of Biotechnology and Bioengineering, Chonnam National University, Gwangju 61186, Republic of Korea.
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Ppia is the most stable housekeeping gene for qRT-PCR normalization in kidneys of three Pkd1-deficient mouse models. Sci Rep 2021; 11:19798. [PMID: 34611276 PMCID: PMC8492864 DOI: 10.1038/s41598-021-99366-x] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2021] [Accepted: 09/13/2021] [Indexed: 01/08/2023] Open
Abstract
Autosomal Dominant Polycystic Kidney Disease (ADPKD) is the most common inherited renal disorder, characterized by renal cyst development leading to end-stage renal disease. Although the appropriate choice of suitable reference is critical for quantitative RNA analysis, no comparison of frequently used “housekeeping” genes is available. Here, we determined the validity of 7 candidate housekeeping genes (Actb, Actg1, B2m, Gapdh, Hprt, Pgam1 and Ppia) in kidney tissues from mouse models orthologous to ADPKD, including a cystic mice (CY) 10–12 weeks old (Pkd1flox/flox:Nestincre/Pkd1flox/−:Nestincre, n = 10) and non-cystic (NC) controls (Pkd1flox/flox/Pkd1flox/-, n = 10), Pkd1-haploinsufficient (HT) mice (Pkd1+/−, n = 6) and wild-type (WT) controls (Pkd1+/+, n = 6) and a severely cystic (SC) mice 15 days old (Pkd1V/V, n = 7) and their controls (CO, n = 5). Gene expression data were analyzed using six distinct statistical softwares. The estimation of the ideal number of genes suggested the use of Ppia alone as sufficient, although not ideal, to analyze groups altogether. Actb, Hprt and Ppia expression profiles were correlated in all samples. Ppia was identified as the most stable housekeeping gene, while Gapdh was the least stable for all kidney samples. Stat3 expression level was consistent with upregulation in SC compared to CO when normalized by Ppia expression. In conclusion, present findings identified Ppia as the best housekeeping gene for CY + NC and SC + CO groups, while Hprt was the best for the HT + WT group.
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Abbadi D, Andrews JJ, Katsara O, Schneider RJ. AUF1 gene transfer increases exercise performance and improves skeletal muscle deficit in adult mice. Mol Ther Methods Clin Dev 2021; 22:222-236. [PMID: 34485607 PMCID: PMC8399044 DOI: 10.1016/j.omtm.2021.07.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2021] [Accepted: 07/09/2021] [Indexed: 11/29/2022]
Abstract
Muscle function and mass begin declining in adults long before evidence of sarcopenia and include reduced mitochondrial function, although much remains to be characterized. We found that mRNA decay factor AU-rich mRNA binding factor 1 (AUF1), which stimulates myogenesis, is strongly reduced in skeletal muscle of adult and older mice in the absence of evidence of sarcopenia. Muscle-specific adeno-associated virus (AAV)8-AUF1 gene therapy increased expression of AUF1, muscle function, and mass. AAV8 AUF1 muscle gene transfer in 12-month-old mice increased the levels of activated muscle stem (satellite) cells, increased muscle mass, reduced markers of muscle atrophy, increased markers of mitochondrial content and muscle fiber oxidative capacity, and enhanced exercise performance to levels of 3-month-old mice. With wild-type and AUF1 knockout mice and cultured myoblasts, AUF1 supplementation of muscle fibers was found to increase expression of Peroxisome Proliferator-activated Receptor Gamma Co-activator 1-alpha (PGC1α), a major effector of skeletal muscle mitochondrial oxidative metabolism. AUF1 stabilized and increased translation of the pgc1α mRNA, which is strongly reduced in adult muscle in the absence of AUF1 supplementation. Skeletal muscle-specific gene transfer of AUF1 therefore restores muscle mass, increases exercise endurance, and may provide a therapeutic strategy for age-related muscle loss.
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Affiliation(s)
- Dounia Abbadi
- Department of Microbiology, New York University School of Medicine, 550 First Avenue, New York, NY 10016, USA
| | - John J. Andrews
- Department of Microbiology, New York University School of Medicine, 550 First Avenue, New York, NY 10016, USA
| | - Olga Katsara
- Department of Microbiology, New York University School of Medicine, 550 First Avenue, New York, NY 10016, USA
| | - Robert J. Schneider
- Department of Microbiology, New York University School of Medicine, 550 First Avenue, New York, NY 10016, USA
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Ehmsen JT, Kawaguchi R, Kaval D, Johnson AE, Nachun D, Coppola G, Höke A. GADD45A is a protective modifier of neurogenic skeletal muscle atrophy. JCI Insight 2021; 6:e149381. [PMID: 34128833 PMCID: PMC8410074 DOI: 10.1172/jci.insight.149381] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/08/2021] [Accepted: 05/26/2021] [Indexed: 12/14/2022] Open
Abstract
Neurogenic muscle atrophy is the loss of skeletal muscle mass and function that occurs with nerve injury and in denervating diseases, such as amyotrophic lateral sclerosis. Aside from prompt restoration of innervation and exercise where feasible, there are currently no effective strategies for maintaining skeletal muscle mass in the setting of denervation. We conducted a longitudinal analysis of gene expression changes occurring in atrophying skeletal muscle and identified growth arrest and DNA damage-inducible A (Gadd45a) as a gene that shows one of the earliest and most sustained increases in expression in skeletal muscle after denervation. We evaluated the role of this induction using genetic mouse models and found that mice lacking GADD45A showed accelerated and exacerbated neurogenic muscle atrophy, as well as loss of fiber type identity. Our genetic analyses demonstrate that, rather than directly contributing to muscle atrophy as proposed in earlier studies, GADD45A induction likely represents a protective negative feedback response to denervation. Establishing the downstream effectors that mediate this protective effect and the pathways they participate in may yield new opportunities to modify the course of muscle atrophy.
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Affiliation(s)
- Jeffrey T Ehmsen
- Neuromuscular Division, Department of Neurology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Riki Kawaguchi
- Department of Neurology and Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - Damlanur Kaval
- Neuromuscular Division, Department of Neurology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Anna E Johnson
- Neuromuscular Division, Department of Neurology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
| | - Daniel Nachun
- Department of Neurology and Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - Giovanni Coppola
- Department of Neurology and Department of Psychiatry and Biobehavioral Sciences, David Geffen School of Medicine, University of California, Los Angeles, Los Angeles, California, USA
| | - Ahmet Höke
- Neuromuscular Division, Department of Neurology, Johns Hopkins School of Medicine, Baltimore, Maryland, USA
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Light Intensity-Dependent Dysregulation of Retinal Reference Genes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020. [PMID: 31884627 DOI: 10.1007/978-3-030-27378-1_48] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register]
Abstract
The degeneration of photoreceptors is a common hallmark of ocular diseases like retinitis pigmentosa (RP) or age-related macular degeneration (AMD). To experimentally induce photoreceptor degeneration, the light damage paradigm is frequently used. In this study we show that the exposure to high amounts of cool white light (10,000 lux, 1 h) resulted in a more than 11-fold higher apoptotic rate in the retina compared to light exposure with 5000 lux for 30 min. Consequently, exposure to intense light resulted in a significant downregulation of retinal mRNA expression levels of the reference genes Gapdh, Gnb2l, Rpl32, Rps9, Actb, Ubc or Tbp compared to untreated controls. Investigators performing light-induced photoreceptor degeneration should be aware of the fact that higher light intensities will result in a dysregulation of reference genes.
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Komiya Y, Kobayashi C, Uchida N, Otsu S, Tanio T, Yokoyama I, Nagasao J, Arihara K. Effect of dietary fish oil intake on ubiquitin ligase expression during muscle atrophy induced by sciatic nerve denervation in mice. Anim Sci J 2019; 90:1018-1025. [PMID: 31132809 DOI: 10.1111/asj.13224] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Revised: 04/03/2019] [Accepted: 04/18/2019] [Indexed: 12/11/2022]
Abstract
Dietary fish oil intake improves muscle atrophy in several atrophy models however the effect on denervation-induced muscle atrophy is not clear. Thus, the aim of this study was to investigate the effects of dietary fish oil intake on muscle atrophy and the expression of muscle atrophy markers induced by sciatic nerve denervation in mice. We performed histological and quantitative mRNA expression analysis of muscle atrophy markers in mice fed with fish oil with sciatic nerve denervation. Histological analysis indicated that dietary fish oil intake slightly prevented the decrease of muscle fiber diameter induced by denervation treatment. In addition, dietary fish oil intake suppressed the MuRF1 (tripartite motif-containing 63) expression up-regulated by denervation treatment, and this was due to decreased tumor necrosis factor-alpha (TNF-α) production in skeletal muscle. We concluded that dietary fish oil intake suppressed MuRF1 expression by decreasing TNF-α production during muscle atrophy induced by sciatic nerve denervation in mice.
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Affiliation(s)
- Yusuke Komiya
- Department of Animal Science, School of Veterinary Medicine, Kitasato University, Towada, Japan
| | - Chiaki Kobayashi
- Department of Animal Science, School of Veterinary Medicine, Kitasato University, Towada, Japan
| | - Naoyasu Uchida
- Department of Animal Science, School of Veterinary Medicine, Kitasato University, Towada, Japan
| | - Shohei Otsu
- Department of Animal Science, School of Veterinary Medicine, Kitasato University, Towada, Japan
| | - Tatsuki Tanio
- Department of Animal Science, School of Veterinary Medicine, Kitasato University, Towada, Japan
| | - Issei Yokoyama
- Department of Animal Science, School of Veterinary Medicine, Kitasato University, Towada, Japan
| | - Jun Nagasao
- Department of Animal Science, School of Veterinary Medicine, Kitasato University, Towada, Japan
| | - Keizo Arihara
- Department of Animal Science, School of Veterinary Medicine, Kitasato University, Towada, Japan
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Identification of qPCR reference genes suitable for normalizing gene expression in the mdx mouse model of Duchenne muscular dystrophy. PLoS One 2019; 14:e0211384. [PMID: 30699165 PMCID: PMC6353192 DOI: 10.1371/journal.pone.0211384] [Citation(s) in RCA: 29] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 01/11/2019] [Indexed: 12/15/2022] Open
Abstract
The mdx mouse is the most widely-used animal model of the human disease Duchenne muscular dystrophy, and quantitative PCR analysis of gene expression in the muscles of this animal plays a key role in the study of pathogenesis and disease progression and in evaluation of potential therapeutic interventions. Normalization to appropriate stably-expressed reference genes is essential for accurate quantitative measurement, but determination of such genes is challenging: healthy and dystrophic muscles present very different transcriptional environments, further altering with disease progression and muscle use, raising the possibility that no single gene or combination of genes may be stable under all experimental comparative scenarios. Despite the pedigree of this animal model, this problem remains unaddressed. The aim of this work was therefore to comprehensively assess reference gene suitability in the muscles of healthy and dystrophic mice, identifying reference genes appropriate for specific experimental comparisons, and determining whether an essentially universally-applicable set of genes exists. Using a large sample collection comprising multiple muscles (including the tibialis anterior, diaphragm and heart muscles) taken from healthy and mdx mice at three disease-relevant ages, and a panel of sixteen candidate reference genes (FBXO38, FBXW2, MON2, ZFP91, HTATSF1, GAPDH, ACTB, 18S, CDC40, SDHA, RPL13a, CSNK2A2, AP3D1, PAK1IP1, B2M and HPRT1), we used the geNorm, BestKeeper and Normfinder algorithms to identify genes that were stable under multiple possible comparative scenarios. We reveal that no single gene is stable under all conditions, but a normalization factor derived from multiple genes (RPL13a, CSNK2A2, AP3D1 and the widely-used ACTB) appears suitable for normalizing gene expression in both healthy and dystrophic mouse muscle regardless of muscle type or animal age. We further show that other popular reference genes, including GAPDH, are markedly disease- or muscle-type correlated. This study demonstrates the importance of empirical reference gene identification, and should serve as a valuable resource for investigators wishing to study gene expression in mdx mice.
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Ohira T, Higashibata A, Seki M, Kurata Y, Kimura Y, Hirano H, Kusakari Y, Minamisawa S, Kudo T, Takahashi S, Ohira Y, Furukawa S. The effects of heat stress on morphological properties and intracellular signaling of denervated and intact soleus muscles in rats. Physiol Rep 2018; 5:5/15/e13350. [PMID: 28784851 PMCID: PMC5555886 DOI: 10.14814/phy2.13350] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2017] [Accepted: 06/20/2017] [Indexed: 12/21/2022] Open
Abstract
The effects of heat stress on the morphological properties and intracellular signaling of innervated and denervated soleus muscles were investigated. Heat stress was applied to rats by immersing their hindlimbs in a warm water bath (42°C, 30 min/day, every other day following unilateral denervation) under anesthesia. During 14 days of experimental period, heat stress for a total of seven times promoted growth‐related hypertrophy in sham‐operated muscles and attenuated atrophy in denervated muscles. In denervated muscles, the transcription of ubiquitin ligase, atrogin‐1/muscle atrophy F‐box (Atrogin‐1), and muscle RING‐finger protein‐1 (MuRF‐1), genes was upregulated and ubiquitination of proteins was also increased. Intermittent heat stress inhibited the upregulation of Atrogin‐1, but not MuRF‐1 transcription. And the denervation‐caused reduction in phosphorylated protein kinase B (Akt), 70‐kDa heat‐shock protein (HSP70), and peroxisome proliferator‐activated receptor γ coactivator‐1α (PGC‐1α), which are negative regulators of Atrogin‐1 and MuRF‐1 transcription, was mitigated. In sham‐operated muscles, repeated application of heat stress did not affect Atrogin‐1 and MuRF‐1 transcription, but increased the level of phosphorylated Akt and HSP70, but not PGC‐1α. Furthermore, the phosphorylation of Akt and ribosomal protein S6, which is known to stimulate protein synthesis, was increased immediately after a single heat stress particularly in the sham‐operated muscles. The effect of a heat stress was suppressed in denervated muscles. These results indicated that the beneficial effects of heat stress on the morphological properties of muscles were brought regardless of innervation. However, the responses of intracellular signaling to heat stress were distinct between the innervated and denervated muscles.
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Affiliation(s)
- Takashi Ohira
- Division of Aerospace Medicine, Department of Cell Physiology, The Jikei University School of Medicine, Tokyo, Japan .,Space Biomedical Research Group, Japan Aerospace Exploration Agency, Tsukuba, Ibaraki, Japan
| | - Akira Higashibata
- Japanese Experiment Module Utilization Center, Japan Aerospace Exploration Agency, Tsukuba, Ibaraki, Japan
| | - Masaya Seki
- Advanced Engineering Services Co. Ltd., Tsukuba, Ibaraki, Japan
| | - Yoichi Kurata
- Advanced Medical Research Center, Yokohama City University, Yokohama, Kanagawa, Japan
| | - Yayoi Kimura
- Advanced Medical Research Center, Yokohama City University, Yokohama, Kanagawa, Japan
| | - Hisashi Hirano
- Advanced Medical Research Center, Yokohama City University, Yokohama, Kanagawa, Japan
| | - Yoichiro Kusakari
- Department of Cell Physiology, The Jikei University School of Medicine, Tokyo, Japan
| | - Susumu Minamisawa
- Department of Cell Physiology, The Jikei University School of Medicine, Tokyo, Japan
| | - Takashi Kudo
- Laboratory Animal Resource Center, Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Satoru Takahashi
- Laboratory Animal Resource Center, Department of Anatomy and Embryology, Faculty of Medicine, University of Tsukuba, Tsukuba, Ibaraki, Japan
| | - Yoshinobu Ohira
- Graduate School of Health and Sports Science, Doshisha University, Kyoto, Japan
| | - Satoshi Furukawa
- Space Biomedical Research Group, Japan Aerospace Exploration Agency, Tsukuba, Ibaraki, Japan
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Choi WH, Jang YJ, Son HJ, Ahn J, Jung CH, Ha TY. Apigenin inhibits sciatic nerve denervation–induced muscle atrophy. Muscle Nerve 2018; 58:314-318. [DOI: 10.1002/mus.26133] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2017] [Revised: 03/15/2018] [Accepted: 03/18/2018] [Indexed: 11/08/2022]
Affiliation(s)
- Won Hee Choi
- Nutrition and Metabolism Research Division, Korea Food Research InstituteWanju‐gun Republic of Korea
| | - Young Jin Jang
- Nutrition and Metabolism Research Division, Korea Food Research InstituteWanju‐gun Republic of Korea
| | - Hyo Jeong Son
- Nutrition and Metabolism Research Division, Korea Food Research InstituteWanju‐gun Republic of Korea
| | - Jiyun Ahn
- Nutrition and Metabolism Research Division, Korea Food Research InstituteWanju‐gun Republic of Korea
| | - Chang Hwa Jung
- Nutrition and Metabolism Research Division, Korea Food Research InstituteWanju‐gun Republic of Korea
| | - Tae Youl Ha
- Nutrition and Metabolism Research Division, Korea Food Research InstituteWanju‐gun Republic of Korea
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Nakao R, Okauchi H, Hashimoto C, Wada N, Oishi K. Determination of reference genes that are independent of feeding rhythms for circadian studies of mouse metabolic tissues. Mol Genet Metab 2017; 121:190-197. [PMID: 28410879 DOI: 10.1016/j.ymgme.2017.04.001] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 04/03/2017] [Accepted: 04/03/2017] [Indexed: 10/19/2022]
Abstract
Real-time reverse transcription-polymerase chain reaction (RT-PCR) analysis is a popular method for the measurement of mRNA expression level and is a critical tool for basic research. The identification of suitable reference genes that are stable and not affected by experimental conditions is a critical step in the accurate normalization of RT-PCR. On the other hand, the levels of numerous transcripts exhibit circadian oscillation in various peripheral tissues and it is thought to be regulated by feeding rhythms in addition to the molecular circadian clock. Here, we investigated the effects of feeding schedule on the temporal expression profiles of 13 common housekeeping genes in metabolic tissues of mice fed during either the sleep or the active phase. The expression of most of these genes fluctuated dependently on feeding rhythms in the liver and WAT, but not in skeletal muscle. Two-way analyses of variance (ANOVA) identified 18S ribosomal RNA (Rn18s) as the only gene that was stably expressed throughout the day independently of feeding schedules in the liver and WAT, although RefFinder software showed that peptidylprolyl isomerase A (Ppia) was the most stably expressed housekeeping gene. Both ANOVA and RefFinder software determined that Actb was the preferred reference gene for skeletal muscle. Furthermore, NormFinder proposed that the optimal pairs of reference genes were beta-2 microglobulin (B2m)-Ppia in the liver, Ppia-TATA box binding protein (Tbp) in WAT, and tyrosine 3-monooxygenase/tryptophan 5-monooxygenase activation protein, zeta polypeptide (Ywhaz)-glyceraldehyde-3-phosphate dehydrogenase (Gapdh) in skeletal muscle, and that their stability value was better than that of a single stable gene. The appropriate reference gene pairs for normalizing genes of interest in mouse circadian studies are B2m-Ppia in the liver, Ppia-Tbp in WAT, and Ywhaz-Gapdh in skeletal muscle.
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Affiliation(s)
- Reiko Nakao
- Biological Clock Research Group, Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan
| | - Hiroki Okauchi
- Biological Clock Research Group, Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan; Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan
| | - Chiaki Hashimoto
- Biological Clock Research Group, Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan; Department of Applied Biological Science, Graduate School of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Naoyuki Wada
- Department of Applied Biological Science, Faculty of Science and Technology, Tokyo University of Science, Noda, Chiba, Japan; Department of Applied Biological Science, Graduate School of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan
| | - Katsutaka Oishi
- Biological Clock Research Group, Biomedical Research Institute, National Institute of Advanced Industrial Science and Technology (AIST), Central 6, 1-1-1 Higashi, Tsukuba, Ibaraki 305-8566, Japan; Department of Applied Biological Science, Graduate School of Science and Technology, Tokyo University of Science, 2641 Yamazaki, Noda, Chiba 278-8510, Japan; Department of Computational and Medical Sciences, Graduate School of Frontier Sciences, The University of Tokyo, 5-1-5 Kashiwa-no-ha, Kashiwa, Chiba 277-8561, Japan.
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14
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Reference genes for quantitative PCR in the adipose tissue of mice with metabolic disease. Biomed Pharmacother 2017; 88:948-955. [DOI: 10.1016/j.biopha.2017.01.091] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Revised: 01/04/2017] [Accepted: 01/15/2017] [Indexed: 12/15/2022] Open
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15
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The Challenge of Stability in High-Throughput Gene Expression Analysis: Comprehensive Selection and Evaluation of Reference Genes for BALB/c Mice Spleen Samples in the Leishmania infantum Infection Model. PLoS One 2016; 11:e0163219. [PMID: 27668434 PMCID: PMC5036817 DOI: 10.1371/journal.pone.0163219] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2016] [Accepted: 09/06/2016] [Indexed: 11/23/2022] Open
Abstract
The interaction of Leishmania with BALB/c mice induces dramatic changes in transcriptome patterns in the parasite, but also in the target organs (spleen, liver…) due to its response against infection. Real-time quantitative PCR (qPCR) is an interesting approach to analyze these changes and understand the immunological pathways that lead to protection or progression of disease. However, qPCR results need to be normalized against one or more reference genes (RG) to correct for non-specific experimental variation. The development of technical platforms for high-throughput qPCR analysis, and powerful software for analysis of qPCR data, have acknowledged the problem that some reference genes widely used due to their known or suspected “housekeeping” roles, should be avoided due to high expression variability across different tissues or experimental conditions. In this paper we evaluated the stability of 112 genes using three different algorithms: geNorm, NormFinder and RefFinder in spleen samples from BALB/c mice under different experimental conditions (control and Leishmania infantum-infected mice). Despite minor discrepancies in the stability ranking shown by the three methods, most genes show very similar performance as RG (either good or poor) across this massive data set. Our results show that some of the genes traditionally used as RG in this model (i.e. B2m, Polr2a and Tbp) are clearly outperformed by others. In particular, the combination of Il2rg + Itgb2 was identified among the best scoring candidate RG for every group of mice and every algorithm used in this experimental model. Finally, we have demonstrated that using “traditional” vs rationally-selected RG for normalization of gene expression data may lead to loss of statistical significance of gene expression changes when using large-scale platforms, and therefore misinterpretation of results. Taken together, our results highlight the need for a comprehensive, high-throughput search for the most stable reference genes in each particular experimental model.
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16
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Kamaludin AA, Smolarchuk C, Bischof JM, Eggert R, Greer JJ, Ren J, Lee JJ, Yokota T, Berry FB, Wevrick R. Muscle dysfunction caused by loss of Magel2 in a mouse model of Prader-Willi and Schaaf-Yang syndromes. Hum Mol Genet 2016; 25:3798-3809. [PMID: 27436578 DOI: 10.1093/hmg/ddw225] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2016] [Revised: 05/31/2016] [Accepted: 07/07/2016] [Indexed: 01/04/2023] Open
Abstract
Prader-Willi syndrome is characterized by severe hypotonia in infancy, with decreased lean mass and increased fat mass in childhood followed by severe hyperphagia and consequent obesity. Scoliosis and other orthopaedic manifestations of hypotonia are common in children with Prader-Willi syndrome and cause significant morbidity. The relationships among hypotonia, reduced muscle mass and scoliosis have been difficult to establish. Inactivating mutations in one Prader-Willi syndrome candidate gene, MAGEL2, cause a Prader-Willi-like syndrome called Schaaf-Yang syndrome, highlighting the importance of loss of MAGEL2 in Prader-Willi syndrome phenotypes. Gene-targeted mice lacking Magel2 have excess fat and decreased muscle, recapitulating altered body composition in Prader-Willi syndrome. We now demonstrate that Magel2 is expressed in the developing musculoskeletal system, and that loss of Magel2 causes muscle-related phenotypes in mice consistent with atrophy caused by altered autophagy. Magel2-null mice serve as a preclinical model for therapies targeting muscle structure and function in children lacking MAGEL2 diagnosed with Prader-Willi or Schaaf-Yang syndrome.
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Affiliation(s)
| | | | | | | | - John J Greer
- Department of Physiology, University of Alberta, Edmonton, AB, Canada
| | - Jun Ren
- Department of Physiology, University of Alberta, Edmonton, AB, Canada
| | | | | | - Fred B Berry
- Department of Medical Genetics
- Department of Surgery and
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17
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Baumann CW, Liu HM, Thompson LV. Denervation-Induced Activation of the Ubiquitin-Proteasome System Reduces Skeletal Muscle Quantity Not Quality. PLoS One 2016; 11:e0160839. [PMID: 27513942 PMCID: PMC4981385 DOI: 10.1371/journal.pone.0160839] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2016] [Accepted: 07/26/2016] [Indexed: 12/20/2022] Open
Abstract
It is well known that the ubiquitin-proteasome system is activated in response to skeletal muscle wasting and functions to degrade contractile proteins. The loss of these proteins inevitably reduces skeletal muscle size (i.e., quantity). However, it is currently unknown whether activation of this pathway also affects function by impairing the muscle’s intrinsic ability to produce force (i.e., quality). Therefore, the purpose of this study was twofold, (1) document how the ubiquitin-proteasome system responds to denervation and (2) identify the physiological consequences of these changes. To induce soleus muscle atrophy, C57BL6 mice underwent tibial nerve transection of the left hindlimb for 7 or 14 days (n = 6–8 per group). At these time points, content of several proteins within the ubiquitin-proteasome system were determined via Western blot, while ex vivo whole muscle contractility was specifically analyzed at day 14. Denervation temporarily increased several key proteins within the ubiquitin-proteasome system, including the E3 ligase MuRF1 and the proteasome subunits 19S, α7 and β5. These changes were accompanied by reductions in absolute peak force and power, which were offset when expressed relative to physiological cross-sectional area. Contrary to peak force, absolute and relative forces at submaximal stimulation frequencies were significantly greater following 14 days of denervation. Taken together, these data represent two keys findings. First, activation of the ubiquitin-proteasome system is associated with reductions in skeletal muscle quantity rather than quality. Second, shortly after denervation, it appears the muscle remodels to compensate for the loss of neural activity via changes in Ca2+ handling.
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Affiliation(s)
- Cory W. Baumann
- Department of Physical Medicine and Rehabilitation, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
| | - Haiming M. Liu
- Department of Physical Medicine and Rehabilitation, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
| | - LaDora V. Thompson
- Department of Physical Medicine and Rehabilitation, University of Minnesota Medical School, Minneapolis, Minnesota, United States of America
- * E-mail:
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Ham DJ, Caldow MK, Chhen V, Chee A, Wang X, Proud CG, Lynch GS, Koopman R. Glycine restores the anabolic response to leucine in a mouse model of acute inflammation. Am J Physiol Endocrinol Metab 2016; 310:E970-81. [PMID: 27094036 DOI: 10.1152/ajpendo.00468.2015] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/30/2015] [Accepted: 04/18/2016] [Indexed: 12/23/2022]
Abstract
Amino acids, especially leucine, potently stimulate protein synthesis and reduce protein breakdown in healthy skeletal muscle and as a result have received considerable attention as potential treatments for muscle wasting. However, the normal anabolic response to amino acids is impaired during muscle-wasting conditions. Although the exact mechanisms of this anabolic resistance are unclear, inflammation and ROS are believed to play a central role. The nonessential amino acid glycine has anti-inflammatory and antioxidant properties and preserves muscle mass in calorie-restricted and tumor-bearing mice. We hypothesized that glycine would restore the normal muscle anabolic response to amino acids under inflammatory conditions. Relative rates of basal and leucine-stimulated protein synthesis were measured using SUnSET methodology 4 h after an injection of 1 mg/kg lipopolysaccharide (LPS). Whereas leucine failed to stimulate muscle protein synthesis in LPS-treated mice pretreated with l-alanine (isonitrogenous control), leucine robustly stimulated protein synthesis (+51%) in mice pretreated with 1 g/kg glycine. The improvement in leucine-stimulated protein synthesis was accompanied by a higher phosphorylation status of mTOR, S6, and 4E-BP1 compared with l-alanine-treated controls. Despite its known anti-inflammatory action in inflammatory cells, glycine did not alter the skeletal muscle inflammatory response to LPS in vivo or in vitro but markedly reduced DHE staining intensity, a marker of oxidative stress, in muscle cross-sections and attenuated LPS-induced wasting in C2C12 myotubes. Our observations in male C57BL/6 mice suggest that glycine may represent a promising nutritional intervention for the attenuation of skeletal muscle wasting.
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Affiliation(s)
- Daniel J Ham
- Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, Melbourne, Victoria, Australia
| | - Marissa K Caldow
- Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, Melbourne, Victoria, Australia
| | - Victoria Chhen
- Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, Melbourne, Victoria, Australia
| | - Annabel Chee
- Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, Melbourne, Victoria, Australia
| | - Xuemin Wang
- Nutrition and Metabolism, South Australian Health and Medical Research Institute, Adelaide, South Austrailia, Australia; and School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Christopher G Proud
- Nutrition and Metabolism, South Australian Health and Medical Research Institute, Adelaide, South Austrailia, Australia; and School of Biological Sciences, University of Adelaide, Adelaide, South Australia, Australia
| | - Gordon S Lynch
- Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, Melbourne, Victoria, Australia
| | - René Koopman
- Basic and Clinical Myology Laboratory, Department of Physiology, University of Melbourne, Melbourne, Victoria, Australia;
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HuR Mediates Changes in the Stability of AChR β-Subunit mRNAs after Skeletal Muscle Denervation. J Neurosci 2015; 35:10949-62. [PMID: 26245959 DOI: 10.1523/jneurosci.1043-15.2015] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Acetylcholine receptors (AChRs) are heteromeric membrane proteins essential for neurotransmission at the neuromuscular junction. Previous work showed that muscle denervation increases expression of AChR mRNAs due to transcriptional activation of AChR subunit genes. However, it remains possible that post-transcriptional mechanisms are also involved in controlling the levels of AChR mRNAs following denervation. We examined whether post-transcriptional events indeed regulate AChR β-subunit mRNAs in response to denervation. First, in vitro stability assays revealed that the half-life of AChR β-subunit mRNAs was increased in the presence of denervated muscle protein extracts. A bioinformatics analysis revealed the existence of a conserved AU-rich element (ARE) in the 3'-untranslated region (UTR) of AChR β-subunit mRNA. Furthermore, denervation of mouse muscle injected with a luciferase reporter construct containing the AChR β-subunit 3'UTR, caused an increase in luciferase activity. By contrast, mutation of this ARE prevented this increase. We also observed that denervation increased expression of the RNA-binding protein human antigen R (HuR) and induced its translocation to the cytoplasm. Importantly, HuR binds to endogenous AChR β-subunit transcripts in cultured myotubes and in vivo, and this binding is increased in denervated versus innervated muscles. Finally, p38 MAPK, a pathway known to activate HuR, was induced following denervation as a result of MKK3/6 activation and a decrease in MKP-1 expression, thereby leading to an increase in the stability of AChR β-subunit transcripts. Together, these results demonstrate the important contribution of post-transcriptional events in regulating AChR β-subunit mRNAs and point toward a central role for HuR in mediating synaptic gene expression. SIGNIFICANCE STATEMENT Muscle denervation is a convenient model to examine expression of genes encoding proteins of the neuromuscular junction, especially acetylcholine receptors (AChRs). Despite the accepted model of AChR regulation, which implicates transcriptional mechanisms, it remains plausible that such events cannot fully account for changes in AChR expression following denervation. We show that denervation increases expression of the RNA-binding protein HuR, which in turn, causes an increase in the stability of AChR β-subunit mRNAs in denervated muscle. Our findings demonstrate for the first time the contribution of post-transcriptional events in controlling AChR expression in skeletal muscle, and points toward a central role for HuR in mediating synaptic development while also paving the way for developing RNA-based therapeutics for neuromuscular diseases.
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Melgar–Rojas P, Alvarado JC, Fuentes–Santamaría V, Gabaldón–Ull MC, Juiz JM. Validation of Reference Genes for RT-qPCR Analysis in Noise-Induced Hearing Loss: A Study in Wistar Rat. PLoS One 2015; 10:e0138027. [PMID: 26366995 PMCID: PMC4569353 DOI: 10.1371/journal.pone.0138027] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 08/24/2015] [Indexed: 12/26/2022] Open
Abstract
The reverse transcriptase–quantitative polymerase chain reaction (RT–qPCR) requires adequate normalization in order to ensure accurate results. The use of reference genes is the most common method to normalize RT–qPCR assays; however, many studies have reported that the expression of frequently used reference genes is more variable than expected, depending on experimental conditions. Consequently, proper validation of the stability of reference genes is an essential step when performing new gene expression studies. Despite the fact that RT–qPCR has been widely used to elucidate molecular correlates of noise–induced hearing loss (NIHL), up to date there are no reports demonstrating validation of reference genes for the evaluation of changes in gene expression after NIHL. Therefore, in this study we evaluated the expression of some commonly used reference genes (Arbp, b–Act, b2m, CyA, Gapdh, Hprt1, Tbp, Tfrc and UbC) and examined their suitability as endogenous control genes for RT–qPCR analysis in the adult Wistar rat in response to NIHL. Four groups of rats were noise–exposed to generate permanent cochlear damage. Cochleae were collected at different time points after noise exposure and the expression level of candidate reference genes was evaluated by RT–qPCR using geNorm, NormFinder and BestKeeper software to determine expression stability. The three independent applications revealed Tbp as the most stably expressed reference gene. We also suggest a group of top–ranked reference genes that can be combined to obtain suitable reference gene pairs for the evaluation of the effects of noise on gene expression in the cochlea. These findings provide essential basis for further RT–qPCR analysis in studies of NIHL using Wistar rats as animal model.
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Affiliation(s)
- Pedro Melgar–Rojas
- Instituto de Investigación en Discapacidades Neurológicas (IDINE), School of Medicine, University of Castilla–La Mancha, Campus in Albacete, Albacete, Spain
- * E-mail:
| | - Juan Carlos Alvarado
- Instituto de Investigación en Discapacidades Neurológicas (IDINE), School of Medicine, University of Castilla–La Mancha, Campus in Albacete, Albacete, Spain
| | - Verónica Fuentes–Santamaría
- Instituto de Investigación en Discapacidades Neurológicas (IDINE), School of Medicine, University of Castilla–La Mancha, Campus in Albacete, Albacete, Spain
| | - María Cruz Gabaldón–Ull
- Instituto de Investigación en Discapacidades Neurológicas (IDINE), School of Medicine, University of Castilla–La Mancha, Campus in Albacete, Albacete, Spain
| | - José M. Juiz
- Instituto de Investigación en Discapacidades Neurológicas (IDINE), School of Medicine, University of Castilla–La Mancha, Campus in Albacete, Albacete, Spain
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Sukhuman W, Supajit S, Ratchadaporn T, Opas B, Duncan RS, Kanokporn T. Validation of a reference gene for transcript analysis in cassava (Manihot esculenta Crantz) and its application in analysis of linamarase and -hydroxynitrile lyase expression at different growth stages. ACTA ACUST UNITED AC 2015. [DOI: 10.5897/ajb2014.14316] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
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