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Li S, Mu R, Zhu Y, Zhao F, Qiu Q, Si H, Wright ADG, Li Z. Shifts in the microbial community and metabolome in rumen ecological niches during antler growth. Comput Struct Biotechnol J 2024; 23:1608-1618. [PMID: 38680874 PMCID: PMC11047195 DOI: 10.1016/j.csbj.2024.04.018] [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: 01/15/2024] [Revised: 03/29/2024] [Accepted: 04/07/2024] [Indexed: 05/01/2024] Open
Abstract
Antlers are hallmark organ of deer, exhibiting a relatively high growth rate among mammals, and requiring large amounts of nutrients to meet its development. The rumen microbiota plays key roles in nutrient metabolism. However, changes in the microbiota and metabolome in the rumen during antler growth are largely unknown. We investigated rumen microbiota (liquid, solid, ventral epithelium, and dorsal epithelium) and metabolic profiles of sika deer at the early (EG), metaphase (MG) and fast growth (FG) stages. Our data showed greater concentrations of acetate and propionate in the rumens of sika deer from the MG and FG groups than in those of the EG group. However, microbial diversity decreased during antler growth, and was negatively correlated with short-chain fatty acid (SCFA) levels. Prevotella, Ruminococcus, Schaedlerella and Stenotrophomonas were the dominant bacteria in the liquid, solid, ventral epithelium, and dorsal epithelium fractions. The proportions of Stomatobaculum, Succiniclasticum, Comamonas and Anaerotruncus increased significantly in the liquid or dorsal epithelium fractions. Untargeted metabolomics analysis revealed that the metabolites also changed significantly, revealing 237 significantly different metabolites, among which the concentrations of γ-aminobutyrate and creatine increased during antler growth. Arginine and proline metabolism and alanine, aspartate and glutamate metabolism were enhanced. The co-occurrence network results showed that the associations between the rumen microbiota and metabolites different among the three groups. Our results revealed that the different rumen ecological niches were characterized by distinct microbiota compositions, and the production of SCFAs and the metabolism of specific amino acids were significantly changed during antler growth.
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Affiliation(s)
- Songze Li
- Joint International Research Laboratory of Modern Agricultural Technology, Ministry of Education, Jilin Agricultural University, Changchun 130118, China
- College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Ruina Mu
- College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Yuhang Zhu
- College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Fei Zhao
- College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
| | - Qiang Qiu
- School of Ecology and Environment, Northwestern Polytechnical University, Xi’an 710100, China
| | - Huazhe Si
- College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
- Key Lab of Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun 130118, China
- Jilin Provincial Engineering Research Center for Efficient Breeding and Product Development of Sika Deer, Jilin Agricultural University, Changchun 130118, China
| | | | - Zhipeng Li
- Joint International Research Laboratory of Modern Agricultural Technology, Ministry of Education, Jilin Agricultural University, Changchun 130118, China
- College of Animal Science and Technology, Jilin Agricultural University, Changchun 130118, China
- Key Lab of Animal Production, Product Quality and Security, Ministry of Education, Jilin Agricultural University, Changchun 130118, China
- Jilin Provincial Engineering Research Center for Efficient Breeding and Product Development of Sika Deer, Jilin Agricultural University, Changchun 130118, China
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Teng L, Qin Q, Zhou Z, Zhou F, Cao C, Yang J, Ding J. Glutamate secretion by embryonic stem cells as an autocrine signal to promote proliferation. Sci Rep 2023; 13:19069. [PMID: 37925518 PMCID: PMC10625544 DOI: 10.1038/s41598-023-46477-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2023] [Accepted: 11/01/2023] [Indexed: 11/06/2023] Open
Abstract
Glutamate, the major excitatory neurotransmitter in the central nervous system, has also been found to play a role in embryonic stem (ES) cells. However, the exact mechanism and function of glutamatergic signaling in ES cells remain poorly understood. In this study, we identified a glutamatergic transmission circuit in ES cells that operates through an autocrine mechanism and regulates cell proliferation. We performed biological analyses to identify the key components involved in glutamate biosynthesis, packaging for secretion, reaction, and reuptake in ES cells, including glutaminase, vesicular glutamate transporter, glutamate N-methyl-D-aspartate (NMDA) receptor, and cell membrane excitatory amino-acid transporter (EAAT). We directly quantified the released glutamate signal using microdialysis-high performance liquid chromatography-tandem mass spectrometry (MD-HPLC-MS-MS). Pharmacological inhibition of endogenous glutamate release and the resulting tonic activation of NMDA receptors significantly affected ES cell proliferation, suggesting that ES cells establish a glutamatergic autocrine niche via releasing and responding to the transmitter for their own regulation.
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Affiliation(s)
- Lin Teng
- Department of Cardiology, Yichang Central People's Hospital/The First College of Clinical Medical Sciences, China Three Gorges University, No. 183 Yiling Road, Yichang, 443003, Hubei, China
- Institute of Cardiovascular Disease, China Three Gorges University, Yichang, 443003, Hubei, China
- College of Basic Medical Sciences, Hubei Key Laboratory of Tumor Microencironment and Immunotherapy, China Three Gorges University, Yichang, 443000, Hubei, China
| | - Qin Qin
- Department of Cardiology, Yichang Central People's Hospital/The First College of Clinical Medical Sciences, China Three Gorges University, No. 183 Yiling Road, Yichang, 443003, Hubei, China
- Institute of Cardiovascular Disease, China Three Gorges University, Yichang, 443003, Hubei, China
| | - Ziyi Zhou
- Department of Cardiology, Yichang Central People's Hospital/The First College of Clinical Medical Sciences, China Three Gorges University, No. 183 Yiling Road, Yichang, 443003, Hubei, China
- Institute of Cardiovascular Disease, China Three Gorges University, Yichang, 443003, Hubei, China
| | - Fei Zhou
- Department of Cardiology, Yichang Central People's Hospital/The First College of Clinical Medical Sciences, China Three Gorges University, No. 183 Yiling Road, Yichang, 443003, Hubei, China
- Institute of Cardiovascular Disease, China Three Gorges University, Yichang, 443003, Hubei, China
| | - Chunyu Cao
- College of Basic Medical Sciences, Hubei Key Laboratory of Tumor Microencironment and Immunotherapy, China Three Gorges University, Yichang, 443000, Hubei, China
| | - Jian Yang
- Department of Cardiology, Yichang Central People's Hospital/The First College of Clinical Medical Sciences, China Three Gorges University, No. 183 Yiling Road, Yichang, 443003, Hubei, China
- Institute of Cardiovascular Disease, China Three Gorges University, Yichang, 443003, Hubei, China
| | - Jiawang Ding
- Department of Cardiology, Yichang Central People's Hospital/The First College of Clinical Medical Sciences, China Three Gorges University, No. 183 Yiling Road, Yichang, 443003, Hubei, China.
- Institute of Cardiovascular Disease, China Three Gorges University, Yichang, 443003, Hubei, China.
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Londzin P, Cegieła U, Trawczyński M, Czuba ZP, Folwarczna J. Unfavorable effects of memantine on the skeletal system in female rats. Biomed Pharmacother 2023; 164:114921. [PMID: 37229803 DOI: 10.1016/j.biopha.2023.114921] [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: 04/06/2023] [Revised: 05/15/2023] [Accepted: 05/19/2023] [Indexed: 05/27/2023] Open
Abstract
Memantine is an N-methyl-D-aspartate (NMDA) receptor antagonist used in the treatment of Alzheimer's disease (AD). NMDA receptors are expressed on bone cells. The aim of the present study was to investigate the effects of memantine on the rat musculoskeletal system. Taking into account that most of female AD patients are postmenopausal, the study was carried out on intact and ovariectomized (estrogen-deficient) rats. Mature Wistar rats were divided into following groups: non-ovariectomized (NOVX) control rats, NOVX rats treated with memantine, ovariectomized (OVX) control rats, and OVX rats treated with memantine. Memantine (2 mg/kg p.o.) was administered once daily for four weeks, starting one week after ovariectomy. The serum bone turnover marker and cytokine levels, bone density, mass, mineralization, mechanical properties, histomorphometric parameters of compact and cancellous bone, skeletal muscle mass and grip strength were determined. In NOVX rats, memantine slightly decreased the strength of compact bone of the femoral diaphysis (parameters in the yield point) and unfavorably affected histomorphometric parameters of cancellous bone (the femoral epiphysis and metaphysis). In OVX rats, in which estrogen deficiency induced osteoporotic changes, memantine increased the phosphorus content in the femoral bone mineral. No other effects on bone were observed in the memantine-treated OVX rats. In conclusion, the results of the present study indicated slight damaging skeletal effects of memantine in rats with normal estrogen levels.
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Affiliation(s)
- Piotr Londzin
- Department of Pharmacology, Faculty of Pharmaceutical Sciences in Sosnowiec, Medical University of Silesia, Katowice, Jagiellońska 4, 41-200 Sosnowiec, Poland.
| | - Urszula Cegieła
- Department of Pharmacology, Faculty of Pharmaceutical Sciences in Sosnowiec, Medical University of Silesia, Katowice, Jagiellońska 4, 41-200 Sosnowiec, Poland.
| | - Marcin Trawczyński
- Department of Pharmacology, Faculty of Pharmaceutical Sciences in Sosnowiec, Medical University of Silesia, Katowice, Jagiellońska 4, 41-200 Sosnowiec, Poland.
| | - Zenon P Czuba
- Department of Microbiology and Immunology, Faculty of Medical Sciences in Zabrze, Medical University of Silesia, Katowice, Jordana 19, 41-808 Zabrze, Poland.
| | - Joanna Folwarczna
- Department of Pharmacology, Faculty of Pharmaceutical Sciences in Sosnowiec, Medical University of Silesia, Katowice, Jagiellońska 4, 41-200 Sosnowiec, Poland.
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Elsayyad NME, Gomaa I, Salem MA, Amer R, El-Laithy HM. Efficient lung-targeted delivery of risedronate sodium/vitamin D3 conjugated PAMAM-G5 dendrimers for managing osteoporosis: Pharmacodynamics, molecular pathways and metabolomics considerations. Life Sci 2022; 309:121001. [PMID: 36174709 DOI: 10.1016/j.lfs.2022.121001] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2022] [Revised: 09/18/2022] [Accepted: 09/22/2022] [Indexed: 10/31/2022]
Abstract
AIMS This study aims at formulating combined delivery of Risedronate sodium (RIS) and Vitamin D3 (VITD3) for augmented therapeutic outcome against osteoporosis (OP) using deep lung targeted PAMAM-G5-NH2 dendrimers to minimize RIS gastrointestinal side effects and enhance both drugs bioavailability through absorption from the alveoli directly to the blood. METHODS RIS-PAMAM-G5-NH2, VITD3-PAMAM-G5-NH2, and RIS/VITD3-PAMAM-G5-NH2 were prepared and evaluated in vitro for particle size (PS), zeta potential (ZP), %loading efficiency (%LE), morphology and FTIR. The efficacy of the RIS/VITD3-PAMAM-G5-NH2 compared to oral RIS was evaluated in OP-induced rats by comparing serum calcium, phosphorus, and computed bone mineral density (BMD) pre- and post-treatment. Additionally, a comprehensive metabolomics and molecular pathways approach was applied to find serum potential biomarkers for diagnosis and to evaluate the efficacy of inhaled RIS/VITD3-PAMAM-G5-NH2. KEY FINDINGS RIS/VITD3-PAMAM-G5-NH2 was successfully prepared with a %LE of 92.4 ± 6.7 % (RIS) and 83.2 ± 4.4 % (VIT-D3) and a PS of 252.8 ± 34.1 adequate deep lung delivery. RIS/VITD3-PAMAM-G5-NH2 inhalation therapy was able to restore serum calcium, phosphorus, and BMD close to normal levels after 21 days of treatment in OP-induced rats. The WNT-signalling pathway and changes in the metabolite levels recovered to approximately normal levels upon treatment. Moreover, histone acetylation of the WNT-1 gene and miR-148a-3p interference proved to play a role in the regulation of the WNT-signalling pathway during OP progression and treatment. SIGNIFICANCE Pulmonary delivery of RIS/VITD3-PAMAM-G5-NH2 offers superior treatment for OP treatment compared to the oral route. Molecular and Metabolic pathways offer a key indicator of OP diagnosis and progression.
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Affiliation(s)
- Nihal Mohamed Elmahdy Elsayyad
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, October University for Modern Sciences and Arts (MSA) University, 6th of October, Giza 12451, Egypt.
| | - Iman Gomaa
- Department of Biological Sciences, Faculty of Science, Galala University (GU), New Galala City 43511, Egypt
| | - Mohamed A Salem
- Department of Pharmacognosy and Natural Products, Faculty of Pharmacy, Menoufia University, Gamal Abd El Nasr st., Shibin Elkom, 32511 Menoufia, Egypt
| | - Reham Amer
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, October University for Modern Sciences and Arts (MSA) University, 6th of October, Giza 12451, Egypt; Department of Pharmaceutics and Pharmaceutical Technology, Faculty of Pharmacy, Al-Azhar University, Youssef Abbas St. of Mostafa Elnahas, 6th District, Nasr City, Cairo 11751, Egypt
| | - Hanan M El-Laithy
- Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, October University for Modern Sciences and Arts (MSA) University, 6th of October, Giza 12451, Egypt; Department of Pharmaceutics and Industrial Pharmacy, Faculty of Pharmacy, Cairo University, Kasr El-Aini street, Cairo 11562, Egypt
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Ribet ABP, Ng PY, Pavlos NJ. Membrane Transport Proteins in Osteoclasts: The Ins and Outs. Front Cell Dev Biol 2021; 9:644986. [PMID: 33718388 PMCID: PMC7952445 DOI: 10.3389/fcell.2021.644986] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 02/09/2021] [Indexed: 12/12/2022] Open
Abstract
During bone resorption, the osteoclast must sustain an extraordinarily low pH environment, withstand immense ionic pressures, and coordinate nutrient and waste exchange across its membrane to sustain its unique structural and functional polarity. To achieve this, osteoclasts are equipped with an elaborate set of membrane transport proteins (pumps, transporters and channels) that serve as molecular ‘gatekeepers’ to regulate the bilateral exchange of ions, amino acids, metabolites and macromolecules across the ruffled border and basolateral domains. Whereas the importance of the vacuolar-ATPase proton pump and chloride voltage-gated channel 7 in osteoclasts has long been established, comparatively little is known about the contributions of other membrane transport proteins, including those categorized as secondary active transporters. In this Special Issue review, we provide a contemporary update on the ‘ins and outs’ of membrane transport proteins implicated in osteoclast differentiation, function and bone homeostasis and discuss their therapeutic potential for the treatment of metabolic bone diseases.
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Affiliation(s)
- Amy B P Ribet
- Bone Biology and Disease Laboratory, School of Biomedical Sciences, The University of Western Australia, Nedlands, WA, Australia
| | - Pei Ying Ng
- Bone Biology and Disease Laboratory, School of Biomedical Sciences, The University of Western Australia, Nedlands, WA, Australia
| | - Nathan J Pavlos
- Bone Biology and Disease Laboratory, School of Biomedical Sciences, The University of Western Australia, Nedlands, WA, Australia
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Matta C, Juhász T, Fodor J, Hajdú T, Katona É, Szűcs-Somogyi C, Takács R, Vágó J, Oláh T, Bartók Á, Varga Z, Panyi G, Csernoch L, Zákány R. N-methyl-D-aspartate (NMDA) receptor expression and function is required for early chondrogenesis. Cell Commun Signal 2019; 17:166. [PMID: 31842918 PMCID: PMC6915923 DOI: 10.1186/s12964-019-0487-3] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2019] [Accepted: 11/26/2019] [Indexed: 12/19/2022] Open
Abstract
Background In vitro chondrogenesis depends on the concerted action of numerous signalling pathways, many of which are sensitive to the changes of intracellular Ca2+ concentration. N-methyl-D-aspartate (NMDA) glutamate receptor is a cation channel with high permeability for Ca2+. Whilst there is now accumulating evidence for the expression and function of NMDA receptors in non-neural tissues including mature cartilage and bone, the contribution of glutamate signalling to the regulation of chondrogenesis is yet to be elucidated. Methods We studied the role of glutamatergic signalling during the course of in vitro chondrogenesis in high density chondrifying cell cultures using single cell fluorescent calcium imaging, patch clamp, transient gene silencing, and western blotting. Results Here we show that key components of the glutamatergic signalling pathways are functional during in vitro chondrogenesis in a primary chicken chondrogenic model system. We also present the full glutamate receptor subunit mRNA and protein expression profile of these cultures. This is the first study to report that NMDA-mediated signalling may act as a key factor in embryonic limb bud-derived chondrogenic cultures as it evokes intracellular Ca2+ transients, which are abolished by the GluN2B subunit-specific inhibitor ifenprodil. The function of NMDARs is essential for chondrogenesis as their functional knock-down using either ifenprodil or GRIN1 siRNA temporarily blocks the differentiation of chondroprogenitor cells. Cartilage formation was fully restored with the re-expression of the GluN1 protein. Conclusions We propose a key role for NMDARs during the transition of chondroprogenitor cells to cartilage matrix-producing chondroblasts.
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Affiliation(s)
- Csaba Matta
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.
| | - Tamás Juhász
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - János Fodor
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Tibor Hajdú
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Éva Katona
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Csilla Szűcs-Somogyi
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Roland Takács
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Judit Vágó
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Tamás Oláh
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,Center of Experimental Orthopaedics, Saarland University, Homburg, Germany
| | - Ádám Bartók
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.,Department of Medical Biochemistry, Semmelweis University, Budapest, Hungary
| | - Zoltan Varga
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Gyorgy Panyi
- Department of Biophysics and Cell Biology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - László Csernoch
- Department of Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Róza Zákány
- Department of Anatomy, Histology and Embryology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary.
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7
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Zhao Q, Shen H, Su KJ, Zhang JG, Tian Q, Zhao LJ, Qiu C, Zhang Q, Garrett TJ, Liu J, Deng HW. Metabolomic profiles associated with bone mineral density in US Caucasian women. Nutr Metab (Lond) 2018; 15:57. [PMID: 30116286 PMCID: PMC6086033 DOI: 10.1186/s12986-018-0296-5] [Citation(s) in RCA: 44] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2018] [Accepted: 07/30/2018] [Indexed: 02/08/2023] Open
Abstract
Background Individuals’ peak bone mineral density (BMD) achieved and maintained at ages 20–40 years is the most powerful predictor of low bone mass and osteoporotic fractures later in life. The aim of this study was to identify metabolomic factors associated with peak BMD variation in US Caucasian women. Methods A total of 136 women aged 20–40 years, including 65 subjects with low and 71 with high hip BMD, were enrolled. The serum metabolites were assessed using a liquid chromatography-mass spectrometry (LC-MS) method. The partial least-squares discriminant analysis (PLS-DA) method and logistic regression models were used, respectively, to examine the associations of metabolomic profiles and individual metabolites with BMD. Results The low and high BMD groups could be differentiated by the detected serum metabolites using PLS-DA (Ppermutation = 0.008). A total of 14 metabolites, including seven amino acids and amino acid derivatives, five lipids (including three bile acids), and two organic acids, were significantly associated with the risk for low BMD. Most of these metabolites are novel in that they have never been linked with BMD in humans earlier. The prediction model including the newly identified metabolites significantly improved the classification of the groups with low and high BMD. The area under the receiver operating characteristic curve without and with metabolites were 0.88 (95% CI: 0.83–0.94) and 0.97 (95% CI: 0.94–0.99), respectively (P for the difference = 0.0004). Conclusion Metabolomic profiling may improve the risk prediction of osteoporosis among Caucasian women. Our findings also suggest the potential importance of the metabolism of amino acids and bile acids in bone health.
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Affiliation(s)
- Qi Zhao
- 1Department of Preventive Medicine, College of Medicine, University of Tennessee Health Science Center, 66 N, Memphis, TN 38163 USA
| | - Hui Shen
- 2Tulane Center of Bioinformatics and Genomics, Department of Global Biostatistics and Data Science, Tulane University School of Public Health and Tropical Medicine, 1440 Canal St., RM 1619F, New Orleans, LA 70112 USA
| | - Kuan-Jui Su
- 2Tulane Center of Bioinformatics and Genomics, Department of Global Biostatistics and Data Science, Tulane University School of Public Health and Tropical Medicine, 1440 Canal St., RM 1619F, New Orleans, LA 70112 USA
| | - Ji-Gang Zhang
- 2Tulane Center of Bioinformatics and Genomics, Department of Global Biostatistics and Data Science, Tulane University School of Public Health and Tropical Medicine, 1440 Canal St., RM 1619F, New Orleans, LA 70112 USA
| | - Qing Tian
- 2Tulane Center of Bioinformatics and Genomics, Department of Global Biostatistics and Data Science, Tulane University School of Public Health and Tropical Medicine, 1440 Canal St., RM 1619F, New Orleans, LA 70112 USA
| | - Lan-Juan Zhao
- 2Tulane Center of Bioinformatics and Genomics, Department of Global Biostatistics and Data Science, Tulane University School of Public Health and Tropical Medicine, 1440 Canal St., RM 1619F, New Orleans, LA 70112 USA
| | - Chuan Qiu
- 2Tulane Center of Bioinformatics and Genomics, Department of Global Biostatistics and Data Science, Tulane University School of Public Health and Tropical Medicine, 1440 Canal St., RM 1619F, New Orleans, LA 70112 USA
| | - Qiang Zhang
- 2Tulane Center of Bioinformatics and Genomics, Department of Global Biostatistics and Data Science, Tulane University School of Public Health and Tropical Medicine, 1440 Canal St., RM 1619F, New Orleans, LA 70112 USA
| | - Timothy J Garrett
- 3Southeast Center for Integrated Metabolomics Core, University of Florida, Gainesville, FL 32610 USA
| | - Jiawang Liu
- 4Medicinal Chemistry Core, Office of Research, University of Tennessee Health Science Center, Memphis, TN 38163 USA.,5Department of Pharmaceutical Science, College of Pharmacy, University of Tennessee Health Science Center, Memphis, TN 38163 USA
| | - Hong-Wen Deng
- 2Tulane Center of Bioinformatics and Genomics, Department of Global Biostatistics and Data Science, Tulane University School of Public Health and Tropical Medicine, 1440 Canal St., RM 1619F, New Orleans, LA 70112 USA.,6School of Basic Medical Science, Central South University, Changsha, 410013 Hunan China.,7National Clinical Research Center for Geriatric Diseases, Xiangya Hospital, Central South University, Changsha, 410078 Hunan China
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Abstract
OBJECTIVES The efficacy of ketamine in relieving complex regional pain syndrome (CRPS) lacks predictive factors. The value of three-phase bone scintigraphy (TPBS) was assessed for this purpose. MATERIALS AND METHODS TPBS was performed in 105 patients with unilateral, focal CRPS of type 1 before 5 days of ketamine infusions. Tracer uptake was measured in the region of interest concerned by CRPS and the contralateral homologous region. For the 3 scintigraphic phases (vascular, tissular, and bone phases), an asymmetry ratio of fixation was calculated between the affected and the unaffected sides (vascular phase [VPr], tissular phase [TPr], and bone phase [BPr]). Ketamine efficacy was assessed on pain intensity scores. RESULTS Ketamine-induced pain relief did not correlate with VPr, TPr, and BPr, but with the ratios of these ratios: BPr/TPr (r=0.32, P=0.009), BPr/VPr (r=0.34, P=0.005), and TPr/VPr (r=0.23, P=0.02). The optimum cut-off value for predicting the response to ketamine therapy was >1.125 for BPr/TPr, >1.075 for BPr/VPr, and >0.935 for TPr/VPr. The combination of increased values of BPr/TPr, BPr/VPr, and TPr/VPr was highly significantly associated with ketamine therapy outcome. CONCLUSIONS The relative hyperfixation of the radioactive tracer in the limb region concerned by CRPS in phases 2 and 3 versus phase 1 of TPBS correlated positively to the analgesic efficacy of ketamine. This study shows for the first time the potential predictive value of TPBS regarding ketamine therapy outcome. In addition, these results suggest that the analgesic action of ketamine is not restricted to "central" mechanisms, but may also involve "peripheral" mechanisms related to tissue inflammation and bone remodeling.
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Corrado A, Sanpaolo ER, Di Bello S, Cantatore FP. Osteoblast as a target of anti-osteoporotic treatment. Postgrad Med 2017; 129:858-865. [PMID: 28770650 DOI: 10.1080/00325481.2017.1362312] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Abstract
Osteoblasts are mesenchymal cells that play a key role in maintaining bone homeostasis; they are responsible for the production of extracellular matrix proteins, regulation of matrix mineralization, control of bone remodeling and regulate osteoclast differentiation. Osteoblasts have an essential role in the pathogenesis of many bone diseases, particularly osteoporosis. For many decades, the main current available treatments for osteoporosis have been represented by anti-resorptive drugs, such as bisphosphonates, which act mainly by inhibiting osteoclasts maturation, proliferation and activity; nevertheless, in recent years much attention has been paid on anabolic aspects of osteoporosis treatment. Many experimental evidences support the hypothesis of direct effects of the classical anti-resorptive drugs also on osteoblasts, and recent progress in understanding bone physiology have led to the development of new pharmacological agents such as anti-sclerostin antibodies and teriparatide which directly target osteoblasts, inducing anabolic effects and promoting bone formation.
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Affiliation(s)
- Addolorata Corrado
- a Rheumatology Clinic Department of Medical and Surgical Sciences , University of Foggia , Foggia , Italy
| | - Eliana Rita Sanpaolo
- a Rheumatology Clinic Department of Medical and Surgical Sciences , University of Foggia , Foggia , Italy
| | - Silvana Di Bello
- a Rheumatology Clinic Department of Medical and Surgical Sciences , University of Foggia , Foggia , Italy
| | - Francesco Paolo Cantatore
- a Rheumatology Clinic Department of Medical and Surgical Sciences , University of Foggia , Foggia , Italy
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Genetic architecture of bone quality variation in layer chickens revealed by a genome-wide association study. Sci Rep 2017; 7:45317. [PMID: 28383518 PMCID: PMC5382839 DOI: 10.1038/srep45317] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2016] [Accepted: 02/23/2017] [Indexed: 11/15/2022] Open
Abstract
Skeletal problems in layer chickens are gaining attention due to animal welfare and economic losses in the egg industry. The genetic improvement of bone traits has been proposed as a potential solution to these issues; however, genetic architecture is not well understood. We conducted a genome-wide association study (GWAS) on bone quality using a sample of 1534 hens genotyped with a 600 K Chicken Genotyping Array. Using a linear mixed model approach, a novel locus close to GSG1L, associated with femur bone mineral density (BMD), was uncovered in this study. In addition, nine SNPs in genes were associated with bone quality. Three of these genes, RANKL, ADAMTS and SOST, were known to be associated with osteoporosis in humans, which makes them good candidate genes for osteoporosis in chickens. Genomic partitioning analysis supports the fact that common variants contribute to the variations of bone quality. We have identified several strong candidate genes and genomic regions associated with bone traits measured in end-of-lay cage layers, which accounted for 1.3–7.7% of the phenotypic variance. These SNPs could provide the relevant information to help elucidate which genes affect bone quality in chicken.
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11
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Antunes JC, Pereira CL, Teixeira GQ, Silva RV, Caldeira J, Grad S, Gonçalves RM, Barbosa MA. Poly(γ-glutamic acid) and poly(γ-glutamic acid)-based nanocomplexes enhance type II collagen production in intervertebral disc. JOURNAL OF MATERIALS SCIENCE. MATERIALS IN MEDICINE 2017; 28:6. [PMID: 27885573 DOI: 10.1007/s10856-016-5787-1] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/08/2015] [Accepted: 01/12/2016] [Indexed: 06/06/2023]
Abstract
Intervertebral disc (IVD) degeneration often leads to low back pain, which is one of the major causes of disability worldwide, affecting more than 80% of the population. Although available treatments for degenerated IVD decrease symptoms' progression, they fail to address the underlying causes and to restore native IVD properties. Poly(γ-glutamic acid) (γ-PGA) has recently been shown to support the production of chondrogenic matrix by mesenchymal stem/stromal cells. γ-PGA/chitosan (Ch) nanocomplexes (NCs) have been proposed for several biomedical applications, showing advantages compared with either polymer alone. Hence, this study explores the potential of γ-PGA and γ-PGA/Ch NCs for IVD regeneration. Nucleotomised bovine IVDs were cultured ex vivo upon injection of γ-PGA (pH 7.4) and γ-PGA/Ch NCs (pH 5.0 and pH 7.4). Tissue metabolic activity and nucleus pulposus DNA content were significantly reduced when NCs were injected in acidic-buffered solution (pH 5.0). However, at pH 7.4, both γ-PGA and NCs promoted sulphated glycosaminoglycan production and significant type II collagen synthesis, as determined at the protein level. This study is a first proof of concept that γ-PGA and γ-PGA/Ch NCs promote recovery of IVD native matrix, opening new perspectives on the development of alternative therapeutic approaches for IVD degeneration.
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Affiliation(s)
- Joana C Antunes
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal
- INEB-Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal
- Faculdade de Engenharia, Universidade do Porto, Rua Dr. Roberto Frias s/n, Porto, 4200-465, Portugal
| | - Catarina Leite Pereira
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal
- INEB-Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal
- ICBAS-Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, Porto, 4050-313, Portugal
| | - Graciosa Q Teixeira
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal
- INEB-Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal
- ICBAS-Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, Porto, 4050-313, Portugal
| | - Ricardo V Silva
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal
- INEB-Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal
| | - Joana Caldeira
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal
- INEB-Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal
- Instituto de Patologia e Imunologia Molecular da Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal
| | - Sibylle Grad
- AO Research Institute, Davos, Clavadelerstrasse 8, Davos, 7270, Switzerland
| | - Raquel M Gonçalves
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal
- INEB-Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal
| | - Mário A Barbosa
- Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal.
- INEB-Instituto de Engenharia Biomédica, Universidade do Porto, Rua Alfredo Allen, 208, Porto, 4200-135, Portugal.
- ICBAS-Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Rua de Jorge Viterbo Ferreira 228, Porto, 4050-313, Portugal.
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12
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Wu N, Yang M, Gaur U, Xu H, Yao Y, Li D. Alpha-Ketoglutarate: Physiological Functions and Applications. Biomol Ther (Seoul) 2016; 24:1-8. [PMID: 26759695 PMCID: PMC4703346 DOI: 10.4062/biomolther.2015.078] [Citation(s) in RCA: 164] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2015] [Revised: 08/21/2015] [Accepted: 08/28/2015] [Indexed: 11/05/2022] Open
Abstract
Alpha-ketoglutarate (AKG) is a key molecule in the Krebs cycle determining the overall rate of the citric acid cycle of the organism. It is a nitrogen scavenger and a source of glutamate and glutamine that stimulates protein synthesis and inhibits protein degradation in muscles. AKG as a precursor of glutamate and glutamine is a central metabolic fuel for cells of the gastrointestinal tract as well. AKG can decrease protein catabolism and increase protein synthesis to enhance bone tissue formation in the skeletal muscles and can be used in clinical applications. In addition to these health benefits, a recent study has shown that AKG can extend the lifespan of adult Caenorhabditis elegans by inhibiting ATP synthase and TOR. AKG not only extends lifespan, but also delays age-related disease. In this review, we will summarize the advances in AKG research field, in the content of its physiological functions and applications.
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Affiliation(s)
- Nan Wu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, P.R. China
| | - Mingyao Yang
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, P.R. China
| | - Uma Gaur
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, P.R. China
| | - Huailiang Xu
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, P.R. China
| | - Yongfang Yao
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, P.R. China
| | - Diyan Li
- Farm Animal Genetic Resources Exploration and Innovation Key Laboratory of Sichuan Province, Sichuan Agricultural University, Chengdu 611130, P.R. China
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13
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Wang S, Wei X, Chen B, Zhao M, Song G, Zhang Z, Li N. Expression of metabotropic glutamate receptor 4 in osteosarcoma. Mol Clin Oncol 2015; 4:65-69. [PMID: 26870360 DOI: 10.3892/mco.2015.661] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2015] [Accepted: 10/13/2015] [Indexed: 01/08/2023] Open
Abstract
Metabotropic glutamate receptor 4 (mGluR4) has been associated with the pathogenesis of osteosarcoma. The aim of this study was to investigate mGluR4 expression and its clinical significance in osteosarcoma patients. mGluR4 expression was investigated using immunohistochemistry (IHC) in 58 osteosarcomas and 32 giant-cell tumors of bone. The correlations between mGluR4 expression and clinicopathological characteristics were analyzed with the Chi-squared test and survival curves were generated using the Kaplan-Meier method. The IHC results demonstrated that 20.69% (12/58) of the osteosarcomas and 43.75% (14/32) of the giant-cell tumors were mGluR4-positive. The statistical analysis revealed that mGluR4 expression was correlated with gender, age, Enneking stage and tumor volume in osteosarcomas (P<0.05). In the multivariate stepwise Cox regression analysis, Enneking stage was found to be statistically significantly associated with survival (P<0.05) and the survival analysis demonstrated that the survival probability was significantly higher in patients with higher mGluR4 expression compared with those with lower expression (P<0.05). Therefore, mGluR4 expression may be used to estimate the prognosis of osteosarcoma patients.
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Affiliation(s)
- Shuo Wang
- Department of Orthopedic Oncology, the First Affiliated Hospital of Chinese People's Liberation Army General Hospital, Beijing 100048, P.R. China
| | - Xing Wei
- Department of Orthopedic Oncology, the First Affiliated Hospital of Chinese People's Liberation Army General Hospital, Beijing 100048, P.R. China
| | - Bingyao Chen
- Department of Orthopedic Oncology, the First Affiliated Hospital of Chinese People's Liberation Army General Hospital, Beijing 100048, P.R. China
| | - Min Zhao
- Department of Pathology, the First Affiliated Hospital of Chinese People's Liberation Army General Hospital, Beijing 100048, P.R. China
| | - Guangze Song
- Department of Orthopedic Oncology, the First Affiliated Hospital of Chinese People's Liberation Army General Hospital, Beijing 100048, P.R. China
| | - Zengliang Zhang
- Department of Orthopedic Oncology, the First Affiliated Hospital of Chinese People's Liberation Army General Hospital, Beijing 100048, P.R. China
| | - Nan Li
- Department of Orthopedic Oncology, the First Affiliated Hospital of Chinese People's Liberation Army General Hospital, Beijing 100048, P.R. China
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14
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Antunes JC, Tsaryk R, Gonçalves RM, Pereira CL, Landes C, Brochhausen C, Ghanaati S, Barbosa MA, Kirkpatrick CJ. Poly(γ-Glutamic Acid) as an Exogenous Promoter of Chondrogenic Differentiation of Human Mesenchymal Stem/Stromal Cells. Tissue Eng Part A 2015; 21:1869-85. [PMID: 25760236 DOI: 10.1089/ten.tea.2014.0386] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
Cartilage damage and/or aging effects can cause constant pain, which limits the patient's quality of life. Although different strategies have been proposed to enhance the limited regenerative capacity of cartilage tissue, the full production of native and functional cartilaginous extracellular matrix (ECM) has not yet been achieved. Poly(γ-glutamic acid) (γ-PGA), a naturally occurring polyamino acid, biodegradable into glutamate residues, has been explored for tissue regeneration. In this work, γ-PGA's ability to support the production of cartilaginous ECM by human bone marrow mesenchymal stem/stromal cells (MSCs) and nasal chondrocytes (NCs) was investigated. MSC and NC pellets were cultured in basal medium (BM), chondrogenic medium (CM), and CM-γ-PGA-supplemented medium (CM+γ-PGA) over a period of 21 days. Pellet size/shape was monitored with time. At 14 and 21 days of culture, the presence of sulfated glycosaminoglycans (sGAGs), type II collagen (Col II), Sox-9, aggrecan, type XI collagen (Col XI), type X collagen (Col X), calcium deposits, and type I collagen (Col I) was analyzed. After excluding γ-PGA's cytotoxicity, earlier cell condensation, higher sGAG content, Col II, Sox-9 (day 14), aggrecan, and Col X (day 14) production was observed in γ-PGA-supplemented MSC cultures, with no signs of mineralization or Col I. These effects were not evident with NCs. However, Sox-9 (at day 14) and Col X (at days 14 and 21) were increased, decreased, or absent, respectively. Overall, γ-PGA improved chondrogenic differentiation of MSCs, increasing ECM production earlier in culture. It is proposed that γ-PGA incorporation in novel biomaterials has a beneficial impact on future approaches for cartilage regeneration.
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Affiliation(s)
- Joana C Antunes
- 1Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,2INEB-Instituto de Engenharia Biomédica, Universidade do Porto, Porto, Portugal.,3Faculdade de Engenharia, Universidade do Porto, Porto, Portugal
| | - Roman Tsaryk
- 3Faculdade de Engenharia, Universidade do Porto, Porto, Portugal.,4Max Planck Institute for Molecular Biomedicine, Münster, Germany
| | - Raquel M Gonçalves
- 1Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,2INEB-Instituto de Engenharia Biomédica, Universidade do Porto, Porto, Portugal
| | - Catarina Leite Pereira
- 1Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,2INEB-Instituto de Engenharia Biomédica, Universidade do Porto, Porto, Portugal.,5ICBAS-Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | - Constantin Landes
- 6Department of Oral, Cranio-Maxillofacial and Facial Plastic Surgery, University Medical Center of the Goethe University, Frankfurt am Main, Germany.,7Sana Hospital Offenbach, Offenbach, Germany
| | - Christoph Brochhausen
- 8REPAIR Lab, Institute of Pathology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Shahram Ghanaati
- 6Department of Oral, Cranio-Maxillofacial and Facial Plastic Surgery, University Medical Center of the Goethe University, Frankfurt am Main, Germany.,7Sana Hospital Offenbach, Offenbach, Germany.,8REPAIR Lab, Institute of Pathology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
| | - Mário A Barbosa
- 1Instituto de Investigação e Inovação em Saúde, Universidade do Porto, Porto, Portugal.,2INEB-Instituto de Engenharia Biomédica, Universidade do Porto, Porto, Portugal.,5ICBAS-Instituto de Ciências Biomédicas Abel Salazar, Universidade do Porto, Porto, Portugal
| | - C James Kirkpatrick
- 8REPAIR Lab, Institute of Pathology, University Medical Center of the Johannes Gutenberg University, Mainz, Germany
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15
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Gonzalez J, Jurado-Coronel JC, Ávila MF, Sabogal A, Capani F, Barreto GE. NMDARs in neurological diseases: a potential therapeutic target. Int J Neurosci 2014; 125:315-27. [PMID: 25051426 DOI: 10.3109/00207454.2014.940941] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
N-methyl-D-aspartate ionotropic glutamate receptor (NMDARs) is a ligand-gated ion channel that plays a critical role in excitatory neurotransmission, brain development, synaptic plasticity associated with memory formation, central sensitization during persistent pain, excitotoxicity and neurodegenerative diseases in the central nervous system (CNS). Within iGluRs, NMDA receptors have been the most actively investigated for their role in neurological diseases, especially neurodegenerative pathologies such as Alzheimer's and Parkinson's diseases. It has been demonstrated that excessive activation of NMDA receptors (NMDARs) plays a key role in mediating some aspects of synaptic dysfunction in several CNS disorders, so extensive research has been directed on the discovery of compounds that are able to reduce NMDARs activity. This review discusses the role of NMDARs on neurological pathologies and the possible therapeutic use of agents that target this receptor. Additionally, we delve into the role of NMDARs in Alzheimer's and Parkinson's diseases and the receptor antagonists that have been tested on in vivo models of these pathologies. Finally, we put into consideration the importance of antioxidants to counteract oxidative capacity of the signaling cascade in which NMDARs are involved.
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Affiliation(s)
- Janneth Gonzalez
- 1Departamento de Nutrición y Bioquímica, Facultad de Ciencias, Pontificia Universidad Javeriana, Bogotá D.C., Colombia
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16
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Kim KT, Kim J, Han YJ, Kim JH, Lee JS, Chung JH. Assessment of NMDA receptor genes (GRIN2A, GRIN2B and GRIN2C) as candidate genes in the development of degenerative lumbar scoliosis. Exp Ther Med 2013; 5:977-981. [PMID: 23408766 PMCID: PMC3570245 DOI: 10.3892/etm.2013.910] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 01/16/2013] [Indexed: 11/17/2022] Open
Abstract
Degenerative lumbar scoliosis (DLS) progresses with aging after 50–60 years. The genetic association of DLS remains largely unclear. In this study, the genetic association between glutamate receptor, ionotropic, N-methyl D-aspartate (NMDA, GRIN) receptor genes and DLS was investigated. A total of 9 coding single nucleotide polymorphisms (cSNPs) in NMDA receptor genes [GRIN2A (rs8049651, Leu425Leu; rs9806806, Tyr730Tyr); GRIN2B (rs7301328, Pro122Pro; rs35025065, Asp447Asp; rs1805522, Ile602Ile; rs1806201, Thr888Thr; rs1805247, His1399His); and GRIN2C (rs689730, Ala33Ala; rs3744215, Arg1209Ser)] were selected and genotyped using direct sequencing in 70 patients with DLS and 141 healthy controls. Multiple logistic models (codominant, dominant and recessive) were calculated for the odds ratio (OR), 95% confidence interval (CI) and corresponding P-values. The SNPStats, SNPAnalyzer and HelixTree programs were used for the evaluation of the genetic data. Among the SNPs examined, no significant associations were observed between the NMDA receptor genes and DLS. When the patients were divided into two groups according to clinical characteristics based on Cobb’s angle (<20° or ≥20°) and lateral listhesis (<6 mm or ≥6 mm), associations were observed between rs689730 of GRIN2C and Cobb’s angle (codominant, P=0.038; dominant, P=0.022) and between rs7301328 of GRIN2B and lateral listhesis (codominant, P=0.003; dominant, P=0.015; recessive, P=0.015). These results indicate that the GRIN2A, GRIN2B and GRIN2C genes do not affect the development of DLS. However, the GRIN2C gene may be associated with Cobb’s angle, while the GRIN2B gene may be associated with lateral listhesis.
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Affiliation(s)
- Ki-Tack Kim
- Department of Orthopedic Surgery, Spine Center, School of Medicine, Kyung Hee University Hospital at Gangdong, Seoul 134-727
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17
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Radzki RP, Bienko M, Pierzynowski SG. Anti-osteopenic effect of alpha-ketoglutarate sodium salt in ovariectomized rats. J Bone Miner Metab 2012; 30:651-9. [PMID: 22864414 DOI: 10.1007/s00774-012-0377-x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/23/2011] [Accepted: 06/26/2012] [Indexed: 12/11/2022]
Abstract
The purpose of the study was to determine the effect of alpha-ketoglutarate sodium salt (AKG) treatment on the mineralization of the tibia in female rats during the development of osteopenia (Experiment-1) and in the condition of established osteopenia (Experiment-2). Thirty-two female rats were ovariectomized (OVX) to induce osteopenia and osteoporosis and another 32 female rats were sham-operated (SHO) and then randomly divided between the two experiments. In Experiment-1, the treatment with AKG started after a 7-day period of convalescence, whereas in Experiment-2 the rats were subjected to a 60-day period of osteopenia fixation, after which the actual experimental protocol commenced. AKG was administered in the experimental solution for drinking at a concentration of 1.0 mol/l and a placebo (PLC) was used as a control solution. After 60 days of experimental treatment the rats in both experiements were sacrificed, the body weight recorded, and blood serum and isolated tibia were stored for further analysis. The bones were analyzed using tomography and densitometry, and for estimation of mechanical properties the 3-point bending test was used. Serum concentrations of osteocalcin and collagen type I crosslinked C-telopeptide were measured. The anabolic effects of AKG on bone during osteopenia development in Experiment-1 not only stopped the degradation of bone tissue, but also stimulated its mineralization. The usage of AKG in animals with established osteopenia (Experiment-2) was not able to prevent bone atrophy, but markedly reduced its intensity. The stimulation of tibia mineralization after AKG treatment has been also argued in healthy SHO animals. The results obtained prove the effectiveness of AKG usage in the prophylaxis and therapy of osteopenia and osteoporosis, induced by bilateral gonadectomy. Additionally, the results clearly prove that treatment with AKG improves the mineralization of bone tissue in healthy animals.
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Affiliation(s)
- Radoslaw Piotr Radzki
- Department of Biochemistry and Animal Physiology, University of Life Sciences in Lublin, Lublin, Poland.
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18
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Cowan RW, Seidlitz EP, Singh G. Glutamate signaling in healthy and diseased bone. Front Endocrinol (Lausanne) 2012; 3:89. [PMID: 22833735 PMCID: PMC3400067 DOI: 10.3389/fendo.2012.00089] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2012] [Accepted: 06/30/2012] [Indexed: 01/22/2023] Open
Abstract
Bone relies on multiple extracellular signaling systems to maintain homeostasis of its normal structure and functions. The amino acid glutamate is a fundamental extracellular messenger molecule in many tissues, and is used in bone for both neural and non-neural signaling. This review focuses on the non-neural interactions, and examines the evolutionarily ancient glutamate signaling system in the context of its application to normal bone functioning and discusses recent findings on the role of glutamate signaling as they pertain to maintaining healthy bone structure. The underlying mechanisms of glutamate signaling and the many roles glutamate plays in modulating bone physiology are featured, including those involved in osteoclast and osteoblast differentiation and mature cell functions. Moreover, the relevance of glutamate signaling systems in diseases that affect bone, such as cancer and rheumatoid arthritis, is discussed, and will highlight how the glutamate system may be exploited as a viable therapeutic target. We will identify novel areas of research where knowledge of glutamate communication mechanisms may aid in our understanding of the complex nature of bone homeostasis. By uncovering the contributions of glutamate in maintaining healthy bone, the reader will discover how this complex molecular signaling system may advance our capacity to treat bone pathologies.
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Affiliation(s)
- Robert W. Cowan
- Department of Pathology and Molecular Medicine, McMaster UniversityHamilton, ON, Canada
| | - Eric P. Seidlitz
- Department of Pathology and Molecular Medicine, McMaster UniversityHamilton, ON, Canada
| | - Gurmit Singh
- Department of Pathology and Molecular Medicine, McMaster UniversityHamilton, ON, Canada
- *Correspondence: Gurmit Singh, Juravinski Cancer Centre, Room 4-225, 699 Concession Street, Hamilton, ON, Canada L8V 5C2. e-mail:
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Haas HS, Linecker A, Pfragner R, Sadjak A. Peripheral glutamate signaling in head and neck areas. Head Neck 2011; 32:1554-72. [PMID: 20848447 DOI: 10.1002/hed.21438] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
The major excitatory neurotransmitter glutamate is also found in the periphery in an increasing number of nonexcitable cells. In line with this it became apparent that glutamate can regulate a broad array of peripheral biological responses, as well. Of particular interest is the discovery that glutamate receptor reactive reagents can influence tumor biology. However, the knowledge of glutamate signaling in peripheral tissues is still incomplete and, in the case of head and neck areas, is almost lacking. The roles of glutamate signaling pathways in these regions are manifold and include orofacial pain, periodontal bone production, skin and airway inflammation, as well as salivation. Furthermore, the interrelations between glutamate and cancers in the oral cavity, thyroid gland, and other regions are discussed. In summary, this review shall strengthen the view that glutamate receptor reagents may also be promising targets for novel therapeutic concepts suitable for a number of diseases in peripheral tissues. The contents of this review cover the following sections: Introduction; The "Glutamate System"; The Taste of Glutamate; Glutamate Signaling in Dental Regions; Glutamate Signaling in Head and Neck Areas; Glutamate Signaling in Head and Neck Cancer; A Brief Overview of Glutamate Signaling in Other Cancers; and Conclusion.
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Affiliation(s)
- Helga Susanne Haas
- Department of Pathophysiology and Immunology, Center of Molecular Medicine, Medical University of Graz, Graz, Austria.
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20
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Manske SL, Boyd SK, Zernicke RF. Muscle changes can account for bone loss after botulinum toxin injection. Calcif Tissue Int 2010; 87:541-9. [PMID: 20967431 DOI: 10.1007/s00223-010-9428-2] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/20/2010] [Accepted: 09/29/2010] [Indexed: 10/18/2022]
Abstract
Studies to date have assumed that botulinum toxin type A (BTX) affects bone indirectly, through its action on muscle. We hypothesized that BTX has no discernable effect on bone morphometry, independent of its effect on muscle. Therefore, we investigated whether BTX had an additional effect on bone when combined with tenotomy compared to tenotomy in isolation. Female BALB/c mice (n = 73) underwent one of the following procedures in the left leg: BTX injection and Achilles tenotomy (BTX-TEN), BTX injection and sham surgery (BTX-sham), Achilles tenotomy (TEN), or sham surgery (sham). BTX groups were injected with 20 μL of BTX (1 U/100 g) in the posterior lower hindlimb. At 4 weeks, muscle cross-sectional area (MCSA) and tibial bone morphometry were assessed using micro-CT. Each treatment, other than sham, resulted in significant muscle and bone loss (P < 0.05). BTX-TEN experienced the greatest muscle loss (23-45% lower than other groups) and bone loss (20-30% lower bone volume fraction than other groups). BTX-sham had significantly lower MCSA and bone volume fraction than TEN and sham. After adjusting for differences in MCSA, there were no significant between-group differences in bone properties. We found that BTX injection resulted in more adverse muscle and bone effects than tenotomy and that effects were amplified when the procedures were combined. However, between-group differences in bone could be accounted for by MCSA. We conclude that any independent effect of BTX on bone morphometry is likely small or negligible compared with the effect on muscle.
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Affiliation(s)
- Sarah L Manske
- Faculty of Kinesiology, University of Calgary, Calgary, Canada
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21
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Featherstone DE. Intercellular glutamate signaling in the nervous system and beyond. ACS Chem Neurosci 2010; 1:4-12. [PMID: 22778802 DOI: 10.1021/cn900006n] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2009] [Revised: 09/25/2009] [Indexed: 01/22/2023] Open
Abstract
Most intercellular glutamate signaling in the nervous system occurs at synapses. Some intercellular glutamate signaling occurs outside synapses, however, and even outside the nervous system where high ambient extracellular glutamate might be expected to preclude the effectiveness of glutamate as an intercellular signal. Here, I briefly review the types of intercellular glutamate signaling in the nervous system and beyond, with emphasis on the diversity of signaling mechanisms and fundamental unanswered questions.
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Affiliation(s)
- David E. Featherstone
- Department of Biological Sciences, University of Illinois at Chicago, Chicago, Illinois 60607
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22
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Hajati AK, Alstergren P, Näsström K, Bratt J, Kopp S. Endogenous glutamate in association with inflammatory and hormonal factors modulates bone tissue resorption of the temporomandibular joint in patients with early rheumatoid arthritis. J Oral Maxillofac Surg 2009; 67:1895-903. [PMID: 19686927 DOI: 10.1016/j.joms.2009.04.056] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2008] [Revised: 03/27/2009] [Accepted: 04/21/2009] [Indexed: 11/26/2022]
Abstract
PURPOSE The aim of this study was to investigate the relation between plasma level of glutamate and extent of radiographic bone erosion of the temporomandibular joint (TMJ) in patients with early rheumatoid arthritis (RA) in relation to inflammatory disease activity as well as estradiol and testosterone. MATERIALS AND METHODS A total of 47 patients (29 women and 18 men) of whom 24 were seropositive were included shortly after being diagnosed with RA. Radiographic signs of bone tissue resorption (erosions) in the TMJ were recorded by cone-beam CT images, and an erosion score (0 to 24) was calculated for each patient. Venous blood was analyzed for rheumatoid factor, C-reactive protein, erythrocyte sedimentation rate, leukocyte particle count, glutamate, estradiol, and testosterone. Nonparametric statistical methods were used in the analysis. RESULTS Resorptive changes of the TMJ were found in a major part of the patients. There was a significant positive correlation between plasma level of glutamate and extension of radiographic erosions that was strongest in the patients with low levels of C-reactive protein, estradiol, or testosterone. By contrast, erosions were correlated with C-reactive protein in patients with high levels of estradiol. The highest levels of glutamate were found in patients with low levels of C-reactive protein and estradiol. CONCLUSIONS This study shows that a majority of patients with early RA presents radiographic signs of bone tissue resorption of the TMJ and that circulating glutamate is associated with the extent of these changes. The relationship between glutamate and bone resorption seems to be influenced by systemic inflammatory activity as well as estradiol and testosterone levels.
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Affiliation(s)
- Anna-Kari Hajati
- Department of Clinical Oral Physiology, Institute of Odontology, Karolinska Institutet, Huddinge, Sweden.
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Giardino L, Armelloni S, Corbelli A, Mattinzoli D, Zennaro C, Guerrot D, Tourrel F, Ikehata M, Li M, Berra S, Carraro M, Messa P, Rastaldi MP. Podocyte glutamatergic signaling contributes to the function of the glomerular filtration barrier. J Am Soc Nephrol 2009; 20:1929-40. [PMID: 19578006 DOI: 10.1681/asn.2008121286] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022] Open
Abstract
Podocytes possess the complete machinery for glutamatergic signaling, raising the possibility that neuron-like signaling contributes to glomerular function. To test this, we studied mice and cells lacking Rab3A, a small GTPase that regulates glutamate exocytosis. In addition, we blocked the glutamate ionotropic N-methyl-d-aspartate receptor (NMDAR) with specific antagonists. In mice, the absence of Rab3A and blockade of NMDAR both associated with an increased urinary albumin/creatinine ratio. In humans, NMDAR blockade, obtained by addition of ketamine to general anesthesia, also had an albuminuric effect. In vitro, Rab3A-null podocytes displayed a dysregulated release of glutamate with higher rates of spontaneous exocytosis, explained by a reduction in Rab3A effectors resulting in freedom of vesicles from the actin cytoskeleton. In addition, NMDAR antagonism led to profound cytoskeletal remodeling and redistribution of nephrin in cultured podocytes; the addition of the agonist NMDA reversed these changes. In summary, these results suggest that glutamatergic signaling driven by podocytes contributes to the integrity of the glomerular filtration barrier and that derangements in this signaling may lead to proteinuric renal diseases.
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Affiliation(s)
- Laura Giardino
- Renal Research Laboratory, Fondazione IRCCS Ospedale Maggiore Policlinico, Mangiagalli e Regina Elena and Fondazione D'Amico per la Ricerca sulle Malattie Renali, Milan, Italy
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24
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Yu JH, Lee SP, Kim TI, Jang JH. Identification of N-Methyl-D-Aspartate Receptor Subunit in Human Periodontal Ligament Fibroblasts: Potential Role in Regulating Differentiation. J Periodontol 2009; 80:338-46. [DOI: 10.1902/jop.2009.080407] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
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25
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Bellesini LS, Beloti MM, Crippa GE, Bombonato-Prado KF, Junta CM, Marques MM, Passos GA, Rosa AL. The effect of TAK-778 on gene expression of osteoblastic cells is mediated through estrogen receptor. Exp Biol Med (Maywood) 2008; 234:190-9. [PMID: 19064943 DOI: 10.3181/0808-rm-246] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/04/2023] Open
Abstract
This study evaluated the effect of TAK-778 [(2R, 4S)-(-)-N-(4-diethoxyphosphorylmethylphenyl)-1,2,4,5-tetrahydro-4-methyl-7,8-methylenedioxy-5-oxo-3-benzothiepin-2-carboxamide)] on in vitro osteogenic events and on gene expression of osteoblastic cells derived from human alveolar bone and the participation of estrogen receptors (ERs) on such effect. Osteoblastic cells were subcultured, with or without TAK-778 (10(-5) M), to evaluate cell growth and viability, total protein content, and alkaline phosphatase (ALP) activity at 7, 14, and 21 days; bone-like formation at 21 days; and gene expression, using cDNA microarray, at 7 days. Also, osteoblastic cells were exposed to TAK-778 (10(-5) M) combined to ICI182,780, a nonspecific ER antagonist (10(-6) M), and gene expression was evaluated by real-time polymerase chain reaction (PCR) at 7 days. TAK-778 induced a reduction in culture growth and an increase in cell synthesis, ALP activity, and bone-like formation. The cDNA microarray showed genes associated with cell adhesion and differentiation, skeletal development, ossification, and transforming growth factor-beta receptor signaling pathway, with a tendency to be higher expressed in cells exposed to TAK-778. The gene expression of ALP, osteocalcin, Msh homeobox 2, receptor activator of NF-kappa B ligand, and intercellular adhesion molecule 1 was increased by TAK-778 as demonstrated by real-time PCR, and this effect was antagonized by ICI182,780. The present results demonstrated that TAK-778 acts at a transcriptional level to enhance the in vitro osteogenic process and that its effect on gene expression of osteoblastic cells is mediated, at least partially, through ERs. Based on these findings, TAK-778 could be considered in the treatment of bone metabolic disorders.
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Affiliation(s)
- Larissa S Bellesini
- Cell Culture Laboratory, Molecular Immunogenetics Group, Department of Genetics, School of Dentistry of Ribeirao Preto, University of Sao Paulo, Av do Cafe, s/n, 14040-904-Ribeirao Preto, SP, Brazil
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26
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Jean YH, Wen ZH, Chang YC, Hsieh SP, Lin JD, Tang CC, Chen WF, Chou AK, Wong CS. Increase in excitatory amino acid concentration and transporters expression in osteoarthritic knees of anterior cruciate ligament transected rabbits. Osteoarthritis Cartilage 2008; 16:1442-9. [PMID: 18524638 DOI: 10.1016/j.joca.2008.04.008] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2007] [Accepted: 04/19/2008] [Indexed: 02/06/2023]
Abstract
OBJECTIVE The present study aimed to determine the role of excitatory amino acids (EAAs) and EAA transporters (EAATs) in an osteoarthritis (OA) model of rabbit knees. METHODS OA was induced in New Zealand white male rabbits by anterior cruciate ligament transection (ACLT) in one knee of one hind limb; the other knee left unoperated. Rabbits that received ACLT of knee were assigned to the ACLT group (n=6), while a sham-operated group (n=6) underwent arthrotomy with no ACLT. Six naïve rabbits that received no surgery were used as normal control. The width of the knee joint was measured to determine the severity of joint inflammation. Before operation and at 10, 20, and 30 weeks after operation, knee joint dialysates were collected by microdialysis and assayed for EAAs by high-performance liquid chromatography. Gross morphology and histopathology and EAATs glutamate/aspartate transporter (GLAST) and glutamate transporter-1 (GLT-1) expression in the articular cartilage of the knees were evaluated by immunohistochemistry and western blot analysis. RESULTS In the ACLT knees, a significant increase in the joint width was observed (5.3+/-0.9 mm, P<0.05) at 30 weeks after operation, while the sham-operated and naïve knees showed no difference as compared with the basal values. The concentrations (microM) of aspartate and glutamate in knee dialysates at 30 weeks after ACLT in naïve, sham, and ACLT were 0.36+/-0.07 and 4.5+/-1.10; 0.38+/-0.09 and 4.61+/-1.11; 0.67+/-0.18 and 9.71+/-2.89, respectively. Levels of glutamate and aspartate in the dialysates obtained from the ACLT knees increased by 213.3+/-29.6% and 187.5+/-33.8% (P<0.05) when compared to those in the sham-operated knees. Both naïve and ACLT chondrocytes were positively stained by antibodies against GLAST and GLT-1. GLAST and GLT-1 protein expressions were significantly increased in the ACLT knees (P<0.05). CONCLUSION Our findings indicate an involvement of EAAs and EAATs in the pathogenesis of OA in ACLT rabbits.
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Affiliation(s)
- Y-H Jean
- Section of Orthopedic Surgery, Pingtung Christian Hospital, Pingtung, Taiwan
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27
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Arana-Chavez VE, Bradaschia-Correa V. Clastic cells: mineralized tissue resorption in health and disease. Int J Biochem Cell Biol 2008; 41:446-50. [PMID: 18840541 DOI: 10.1016/j.biocel.2008.09.007] [Citation(s) in RCA: 36] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2008] [Revised: 08/28/2008] [Accepted: 09/08/2008] [Indexed: 10/21/2022]
Abstract
Clastic cells are responsible for mineralized tissue resorption. Bone resorbing cells are called osteoclasts; however, they are able to resorb mineralized dental tissues or calcified cartilage and then they are called odontoclasts and chondroclasts, respectively. They derive from mononuclear precursors of the monocyte-macrophage lineage from hemopoietic tissue, reach target mineralized tissues and degrade them under many different physiologic or pathologic stimuli. Clastic cells play a key role in calcium homeostasis, and participate in skeletal growth, tooth movement, and other physiological and pathological events. They interact tightly with forming cells in bone and dental hard tissues; their unbalance may result in disturbed resorptive activity thus, causing local or systemic diseases.
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Affiliation(s)
- Victor E Arana-Chavez
- Laboratory of Mineralized Tissue Biology, Department of Cell and Developmental Biology, Institute of Biomedical Sciences, University of São Paulo, 05508-900 São Paulo, SP, Brazil.
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28
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Olkku A, Mahonen A. Wnt and steroid pathways control glutamate signalling by regulating glutamine synthetase activity in osteoblastic cells. Bone 2008; 43:483-93. [PMID: 18555765 DOI: 10.1016/j.bone.2008.04.016] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/30/2007] [Revised: 03/06/2008] [Accepted: 04/20/2008] [Indexed: 10/22/2022]
Abstract
Glutamate signalling has recently been found functional also outside the central nervous system, especially in bone. Glutamate is converted to glutamine by glutamine synthetase (GS), which is therefore able to regulate intracellular concentrations of glutamate. We previously characterized the induction of GS expression by glucocorticoids (GCs) in human osteoblast-like cells. Besides this observation, the mechanisms controlling GS in bone are unknown. Therefore, the aim of our present study was to investigate further the regulation of GS in osteoblastic cells. We observed that vitamin D inhibited basal and, even more efficiently, GC-stimulated GS activity by affecting both the mRNA and protein levels of the enzyme in human MG-63 osteoblast-like cells. In osteoblasts derived from rat bone marrow stem cells (rMSCs), GS activity was induced accordingly by the osteogenic culture conditions including GCs. Also in these primary cells, vitamin D clearly inhibited GS activity. In addition, the canonical Wnt signalling pathway was characterized as a negative regulator of GS activity. All these changes in GS activity were reflected on the intracellular glutamate concentration. Our results provide novel evidence that GS activity and expression are regulated by several different signalling pathways in osteoblastic cells. Therefore, GS is a strategic enzyme in controlling glutamate concentration in bone environment: GCs decreased the amount of this signalling molecule while vitamin D and Wnt signalling pathway increased it. Interestingly, GS activity and expression declined rapidly when the rMSC derived osteoblasts began to mineralize. Due to its downregulation during osteoblast mineralization, GS could be held as a marker for osteoblast development. Further supporting this, GS activity was stimulated and intracellular glutamate concentration maintained by the N-methyl-d-aspartate (NMDA) type glutamate receptor antagonist MK801, which inhibited osteogenic differentiation of the rMSCs. GS, a novel target for both steroidal and Wnt pathways in bone, might be a central player in the regulation of osteoblastogenesis and/or intercellular signal transmission. Therefore, the proper understanding of the interplay of these three signalling cascades, i.e., steroidal, Wnt, and glutamate signalling, gives vital information on how bone cells communicate together aiming to keep bone healthy.
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Affiliation(s)
- Anu Olkku
- Institute of Biomedicine, Medical Biochemistry, University of Kuopio, Kuopio, Finland
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