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Khairullin AE, Grishin SN, Ziganshin AU. Presynaptic Purinergic Modulation of the Rat Neuro-Muscular Transmission. Curr Issues Mol Biol 2023; 45:8492-8501. [PMID: 37886978 PMCID: PMC10605505 DOI: 10.3390/cimb45100535] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2023] [Revised: 10/08/2023] [Accepted: 10/18/2023] [Indexed: 10/28/2023] Open
Abstract
ATP, being a well-known universal high-energy compound, plays an important role as a signaling molecule and together with its metabolite adenosine they both attenuate the release of acetylcholine in the neuro-muscular synapse acting through membrane P2 and P1 receptors, respectively. In this work, using a mechanomyographic method, we analyzed the presynaptic mechanisms by which ATP and adenosine can modulate the transduction in the rat m. soleus and m. extensor digitorum longus. N-ethylmaleimide, a G-protein antagonist, prevents the modulating effects of both ATP and adenosine. The action of ATP is abolished by chelerythrin, a specific phospholipase C inhibitor, while the inhibitory effect of adenosine is slightly increased by Rp-cAMPS, an inhibitor of protein kinase A, and by nitrendipine, a blocker of L-type Ca2+ channels. The addition of DPCPX, an A1 receptor antagonist, fully prevents the inhibitory action of adenosine in both muscles. Our data indicate that the inhibitory action of ATP involves metabotropic P2Y receptors and is mediated by phospholipase C dependent processes in rat motor neuron terminals. We suggest that the presynaptic effect of adenosine consists of negative and positive actions. The negative action occurs by stimulation of adenosine A1 receptors while the positive action is associated with the stimulation of adenosine A2A receptors, activation of protein kinase A and opening of L-type calcium channels. The combined mechanism of the modulating action of ATP and adenosine provides fine tuning of the synapse to fast changing conditions in the skeletal muscles.
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Affiliation(s)
- Adel E. Khairullin
- Department of Biochemistry, Kazan State Medical University, 420012 Kazan, Russia;
- Research Laboratory of Mechanobiology, Kazan Federal University, 420008 Kazan, Russia
| | - Sergey N. Grishin
- Department of Medicinal Physics, Kazan State Medical University, 420012 Kazan, Russia;
| | - Ayrat U. Ziganshin
- Department of Pharmacology, Kazan State Medical University, 420012 Kazan, Russia
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Lew SY, Mohd Hisam NS, Phang MWL, Syed Abdul Rahman SN, Poh RYY, Lim SH, Kamaruzzaman MA, Chau SC, Tsui KC, Lim LW, Wong KH. Adenosine Improves Mitochondrial Function and Biogenesis in Friedreich's Ataxia Fibroblasts Following L-Buthionine Sulfoximine-Induced Oxidative Stress. BIOLOGY 2023; 12:biology12040559. [PMID: 37106759 PMCID: PMC10136261 DOI: 10.3390/biology12040559] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/20/2023] [Revised: 03/25/2023] [Accepted: 03/30/2023] [Indexed: 04/29/2023]
Abstract
Adenosine is a nucleoside that is widely distributed in the central nervous system and acts as a central excitatory and inhibitory neurotransmitter in the brain. The protective role of adenosine in different pathological conditions and neurodegenerative diseases is mainly mediated by adenosine receptors. However, its potential role in mitigating the deleterious effects of oxidative stress in Friedreich's ataxia (FRDA) remains poorly understood. We aimed to investigate the protective effects of adenosine against mitochondrial dysfunction and impaired mitochondrial biogenesis in L-buthionine sulfoximine (BSO)-induced oxidative stress in dermal fibroblasts derived from an FRDA patient. The FRDA fibroblasts were pre-treated with adenosine for 2 h, followed by 12.50 mM BSO to induce oxidative stress. Cells in medium without any treatments or pre-treated with 5 µM idebenone served as the negative and positive controls, respectively. Cell viability, mitochondrial membrane potential (MMP), aconitase activity, adenosine triphosphate (ATP) level, mitochondrial biogenesis, and associated gene expressions were assessed. We observed disruption of mitochondrial function and biogenesis and alteration in gene expression patterns in BSO-treated FRDA fibroblasts. Pre-treatment with adenosine ranging from 0-600 µM restored MMP, promoted ATP production and mitochondrial biogenesis, and modulated the expression of key metabolic genes, namely nuclear respiratory factor 1 (NRF1), transcription factor A, mitochondrial (TFAM), and NFE2-like bZIP transcription factor 2 (NFE2L2). Our study demonstrated that adenosine targeted mitochondrial defects in FRDA, contributing to improved mitochondrial function and biogenesis, leading to cellular iron homeostasis. Therefore, we suggest a possible therapeutic role for adenosine in FRDA.
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Affiliation(s)
- Sze Yuen Lew
- Department of Anatomy, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | | | - Michael Weng Lok Phang
- Department of Anatomy, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | | | - Rozaida Yuen Ying Poh
- Department of Biomedical Science, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Siew Huah Lim
- Department of Chemistry, Faculty of Science, Universiti Malaya, Kuala Lumpur 50603, Malaysia
| | - Mohd Amir Kamaruzzaman
- Department of Anatomy, Faculty of Medicine, Universiti Kebangsaan Malaysia, Jalan Yaacob Latiff, Cheras, Kuala Lumpur 56000, Malaysia
| | - Sze Chun Chau
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Ka Chun Tsui
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Lee Wei Lim
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
| | - Kah Hui Wong
- Department of Anatomy, Faculty of Medicine, Universiti Malaya, Kuala Lumpur 50603, Malaysia
- School of Biomedical Sciences, Li Ka Shing Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China
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Sousa-Soares C, Noronha-Matos JB, Correia-de-Sá P. Purinergic Tuning of the Tripartite Neuromuscular Synapse. Mol Neurobiol 2023; 60:4084-4104. [PMID: 37016047 DOI: 10.1007/s12035-023-03317-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Accepted: 03/14/2023] [Indexed: 04/06/2023]
Abstract
The vertebrate neuromuscular junction (NMJ) is a specialised chemical synapse involved in the transmission of bioelectric signals between a motor neuron and a skeletal muscle fiber, leading to muscle contraction. Typically, the NMJ is a tripartite synapse comprising (a) a presynaptic region represented by the motor nerve ending, (b) a postsynaptic skeletal motor endplate area, and (c) perisynaptic Schwann cells (PSCs) that shield the motor nerve terminal. Increasing evidence points towards the role of PSCs in the maintenance and control of neuromuscular integrity, transmission, and plasticity. Acetylcholine (ACh) is the main neurotransmitter at the vertebrate skeletal NMJ, and its role is fine-tuned by co-released purinergic neuromodulators, like adenosine 5'-triphosphate (ATP) and its metabolite adenosine (ADO). Adenine nucleotides modulate transmitter release and expression of postsynaptic ACh receptors at motor synapses via the activation of P2Y and P2X receptors. Endogenously generated ADO modulates ACh release by acting via co-localised inhibitory A1 and facilitatory A2A receptors on motor nerve terminals, whose tonic activation depends on the neuronal firing pattern and their interplay with cholinergic receptors and neuropeptides. Thus, the concerted action of adenine nucleotides, ADO, and ACh/neuropeptide co-transmitters is paramount to adapting the neuromuscular transmission to the working load under pathological conditions, like Myasthenia gravis. Unravelling these functional complexities prompted us to review our knowledge about the way purines orchestrate neuromuscular transmission and plasticity in light of the tripartite synapse concept, emphasising the often-forgotten role of PSCs in this context.
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Affiliation(s)
- Carlos Sousa-Soares
- Laboratório de Farmacologia e Neurobiologia, MedInUP, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, R. Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal
- Centro de Investigação Farmacológica e Inovação Medicamentosa (MedInUP), Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal
| | - José Bernardo Noronha-Matos
- Laboratório de Farmacologia e Neurobiologia, MedInUP, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, R. Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal.
- Centro de Investigação Farmacológica e Inovação Medicamentosa (MedInUP), Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal.
| | - Paulo Correia-de-Sá
- Laboratório de Farmacologia e Neurobiologia, MedInUP, Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, R. Jorge Viterbo Ferreira, 228, 4050-313, Porto, Portugal.
- Centro de Investigação Farmacológica e Inovação Medicamentosa (MedInUP), Instituto de Ciências Biomédicas Abel Salazar (ICBAS), Universidade do Porto, Porto, Portugal.
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Todorović J, Dinčić M, Krstić DZ, Čolović MB, Ostojić JN, Kovačević S, Lopičić S, Spasić S, Brkić P, Milovanović A. The simultaneous action of acute paradoxical sleep deprivation and hypothyroidism modulates synaptosomal ATPases and acetylcholinesterase activities in rat brain. Sleep Med 2023; 105:14-20. [PMID: 36940515 DOI: 10.1016/j.sleep.2023.03.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/13/2022] [Revised: 02/22/2023] [Accepted: 03/04/2023] [Indexed: 03/08/2023]
Abstract
BACKGROUND Thyroid dysfunctions as well as sleep abnormalities are usually followed by neurological, psychiatric and/or behavioral disorders. On the other hand, changes in the brain adenosine triphosphatases (ATPases) and acetylcholinesterase (AChE) activities show significant importance in pathogenetic pathways in the evolution of numerous neuropsychiatric diseases. METHODS This study aimed to evaluate the in vivo simultaneous effects of hypothyroidism and paradoxical sleep deprivation for 72 h on synaptosomalATPases and AChE activities of whole rat brains. In order to induce hypothyroidism, 6-n-propyl-2-thiouracil was administrated in drinking water during 21 days. The modified multiple platform method was used to induce paradoxical sleep deprivation. The AChE and ATPases activities were measured using spectrophotometric methods. RESULTS Hypothyroidism significantly increased the activity of Na+/K+-ATPase compared to other groups, while at the same time significantly decreased AChE activity compared to the CT and SD groups. Paradoxical sleep deprivation significantly increased AChE activity compared to other groups. The simultaneous effect of hypothyroidism and sleep deprivation reduced the activity of all three enzymes (for Na+/K+-ATPase between HT/SD and HT group p < 0.0001, SD group p < 0.001,CT group p = 0.013; for ecto-ATPases between HT/SD and HT group p = 0.0034, SD group p = 0.0001, CT group p = 0.0007; for AChE between HT/SD and HT group p < 0.05, SD group p < 0.0001, CT group p < 0.0001). CONCLUSIONS The effect of simultaneous existence of hypothyroidism and paradoxical sleep deprivation reduces the activity of the Na+/K+-ATPase, ecto-ATPases, and AChE, what is different from individual effect of hypothyroidism and paradoxical sleep deprivation itself. This knowledge could help in the choice of appropriate therapy in such condition.
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Affiliation(s)
- Jasna Todorović
- University of Belgrade, Faculty of Medicine, Institute of Pathological Physiology, Serbia.
| | - Marko Dinčić
- University of Belgrade, Faculty of Medicine, Institute of Pathological Physiology, Serbia.
| | - Danijela Z Krstić
- University of Belgrade, Faculty of Medicine, Institute of Medical Chemistry, Serbia.
| | - Mirjana B Čolović
- University of Belgrade, "Vinča" Institute of Nuclear Sciences-National Institute of Thе Republic of Serbia, Department of Physical Chemistry, Serbia.
| | - Jelena Nešović Ostojić
- University of Belgrade, Faculty of Medicine, Institute of Pathological Physiology, Serbia.
| | - Sanjin Kovačević
- University of Belgrade, Faculty of Medicine, Institute of Pathological Physiology, Serbia.
| | - Srđan Lopičić
- University of Belgrade, Faculty of Medicine, Institute of Pathological Physiology, Serbia.
| | - Svetolik Spasić
- University of Belgrade, Faculty of Medicine, Institute of Pathological Physiology, Serbia.
| | - Predrag Brkić
- University of Belgrade, Faculty of Medicine, Institute of Medical Physiology, Serbia.
| | - Aleksandar Milovanović
- University of Belgrade, Faculty of Medicine, Clinical Center of Serbia, Institute of Occupational Health, Serbia.
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P2 Receptor Signaling in Motor Units in Muscular Dystrophy. Int J Mol Sci 2023; 24:ijms24021587. [PMID: 36675094 PMCID: PMC9865441 DOI: 10.3390/ijms24021587] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/04/2023] [Accepted: 01/10/2023] [Indexed: 01/15/2023] Open
Abstract
The purine signaling system is represented by purine and pyrimidine nucleotides and nucleosides that exert their effects through the adenosine, P2X and P2Y receptor families. It is known that, under physiological conditions, P2 receptors play only a minor role in modulating the functions of cells and systems; however, their role significantly increases under some pathophysiological conditions, such as stress, ischemia or hypothermia, when they can play a dominant role as a signaling molecule. The diversity of P2 receptors and their wide distribution in the body make them very attractive as a target for the pharmacological action of drugs with a new mechanism of action. The review is devoted to the involvement of P2 signaling in the development of pathologies associated with a loss of muscle mass. The contribution of adenosine triphosphate (ATP) as a signal molecule in the pathogenesis of a number of muscular dystrophies (Duchenne, Becker and limb girdle muscular dystrophy 2B) is considered. To understand the processes involving the purinergic system, the role of the ATP and P2 receptors in several models associated with skeletal muscle degradation is also discussed.
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Khairullin AE, Grishin SN, Teplov AY, Eremeev AA, Baltina TV, Ziganshin AU. A High Calcium Level-Based Model for Identifying Postsynaptic Effects of ATP. Biophysics (Nagoya-shi) 2022. [DOI: 10.1134/s0006350922050086] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023] Open
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Khairullin AE, Teplov AY, Grishin SN, Ziganshin AU. Purinergic Mechanisms of Adaptation of Different Types of Motor Units under Conditions of Allergic Reorganization. Biophysics (Nagoya-shi) 2022. [DOI: 10.1134/s0006350922050098] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023] Open
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González Sanabria J, Hurtado Paso M, Frontera T, Losavio A. Effect of endogenous purines on electrically evoked ACh release at the mouse neuromuscular junction. J Neurosci Res 2022; 100:1933-1950. [PMID: 35839285 DOI: 10.1002/jnr.25107] [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: 12/17/2021] [Revised: 06/22/2022] [Accepted: 07/04/2022] [Indexed: 11/11/2022]
Abstract
At the mouse neuromuscular junction, adenosine triphosphate (ATP), which is co-released with the neurotransmitter acetylcholine (ACh), and its metabolite adenosine, modulate neurotransmitter release by activating presynaptic inhibitory P2Y13 receptors (a subtype of ATP/adenosine diphosphate [ADP] receptor), inhibitory A1 and A3 adenosine receptors, and excitatory A2A adenosine receptors. To study the effect of endogenous purines, when phrenic-diaphragm preparations are depolarized by different nerve stimulation patterns, we analyzed the effect of the antagonists for P2Y13 , A1 , A3 , and A2A receptors (AR-C69931MX, 8-cyclopentyl-1,3-dipropylxanthine, MRS-1191, and SCH-58261, respectively) on the amplitude of the end-plate potentials of the trains, and contrasted these results with those obtained with the selective agonists of these receptors (2-methylthioadenosine 5'-diphosphate trisodium salt hydrate, 2-chloro-N6 -cyclopentyl-adenosine, inosine, and PSB-0777, respectively). During continuous 0.5-Hz stimulation, the amount of endogenous purines was not enough to activate purinergic receptors, while at continuous 5-Hz stimulation, an incipient action of endogenous purines on P2Y13 , A1 and A3 receptors might be evident just at the end of the trains. During continuous 50-Hz stimulation, the concentration of endogenous ATP/ADP and adenosine exerted an inhibitory action on ACh release after of the initial phase of the train, but when the nerve was stimulated at intermittent 50 Hz (5 bursts), this behavior was not observed. Excitatory A2A receptors were only activated when continuous 100-Hz stimulation was applied. In conclusion, when motor nerve terminals are depolarized by repetitive stimulation of the phrenic nerve, endogenous ATP/ADP and adenosine are able to fine-tune neurosecretion depending on the frequency and pattern of stimulation.
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Affiliation(s)
- Javier González Sanabria
- Laboratorio de Neurofisiología, Instituto de Investigaciones Médicas Alfredo Lanari - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires (UBA), Ciudad Autónoma de Buenos Aires, Argentina
| | - Maximiliano Hurtado Paso
- Laboratorio de Neurofisiología, Instituto de Investigaciones Médicas Alfredo Lanari - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires (UBA), Ciudad Autónoma de Buenos Aires, Argentina
| | - Tamara Frontera
- Laboratorio de Neurofisiología, Instituto de Investigaciones Médicas Alfredo Lanari - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires (UBA), Ciudad Autónoma de Buenos Aires, Argentina
| | - Adriana Losavio
- Laboratorio de Neurofisiología, Instituto de Investigaciones Médicas Alfredo Lanari - Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Universidad de Buenos Aires (UBA), Ciudad Autónoma de Buenos Aires, Argentina
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Khairullin AE, Teplov AY, Grishin SN, Ziganshin AU. Purinergic Mechanisms in the Adaptation of the Mouse Diaphragm to Allergic Disorders. Biophysics (Nagoya-shi) 2022. [DOI: 10.1134/s0006350922030083] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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10
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Grishin SN, Khairullin AE, Teplov AY, Mukhamedyarov MA. Neuromuscular Transmission in a Barium Environment. Biophysics (Nagoya-shi) 2022. [DOI: 10.1134/s000635092203006x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Khairullin AE, Valiullin VV, Teplov AY, Shaihutdinova AR, Kashtanova NM, Grishin SN. The Effect of Cesium Ions on the Inhibitory Action of Purines in the Neuromuscular Synapse. Biophysics (Nagoya-shi) 2021. [DOI: 10.1134/s0006350921060051] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022] Open
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Dissecting the Purinergic Signaling Puzzle. Int J Mol Sci 2021; 22:ijms22168925. [PMID: 34445630 PMCID: PMC8396290 DOI: 10.3390/ijms22168925] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2021] [Revised: 08/15/2021] [Accepted: 08/15/2021] [Indexed: 11/16/2022] Open
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Arkhipov AY, Zhilyakov NV, Malomouzh AI, Samigullin DV. Interaction between the Mechanisms
of Suppression of Acetylcholine Quantal Secretion upon Activation
of Vanilloid (TRPV1) and Purine Receptors in the Mouse Neuromuscular Synapse. J EVOL BIOCHEM PHYS+ 2021. [DOI: 10.1134/s0022093021030182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Khairullin AE, Efimova DV, Markosyan VA, Grishin SN, Teplov AY, Ziganshin AU. The Effect of Acute Unilateral Denervation Injury on Purinergic Signaling in the Cholinergic Synapse. Biophysics (Nagoya-shi) 2021. [DOI: 10.1134/s0006350921030064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Zhang Z, Nam HK, Crouch S, Hatch NE. Tissue Nonspecific Alkaline Phosphatase Function in Bone and Muscle Progenitor Cells: Control of Mitochondrial Respiration and ATP Production. Int J Mol Sci 2021; 22:ijms22031140. [PMID: 33498907 PMCID: PMC7865776 DOI: 10.3390/ijms22031140] [Citation(s) in RCA: 15] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Revised: 01/17/2021] [Accepted: 01/20/2021] [Indexed: 12/23/2022] Open
Abstract
Tissue nonspecific alkaline phosphatase (TNAP/Alpl) is associated with cell stemness; however, the function of TNAP in mesenchymal progenitor cells remains largely unknown. In this study, we aimed to establish an essential role for TNAP in bone and muscle progenitor cells. We investigated the impact of TNAP deficiency on bone formation, mineralization, and differentiation of bone marrow stromal cells. We also pursued studies of proliferation, mitochondrial function and ATP levels in TNAP deficient bone and muscle progenitor cells. We find that TNAP deficiency decreases trabecular bone volume fraction and trabeculation in addition to decreased mineralization. We also find that Alpl−/− mice (global TNAP knockout mice) exhibit muscle and motor coordination deficiencies similar to those found in individuals with hypophosphatasia (TNAP deficiency). Subsequent studies demonstrate diminished proliferation, with mitochondrial hyperfunction and increased ATP levels in TNAP deficient bone and muscle progenitor cells, plus intracellular expression of TNAP in TNAP+ cranial osteoprogenitors, bone marrow stromal cells, and skeletal muscle progenitor cells. Together, our results indicate that TNAP functions inside bone and muscle progenitor cells to influence mitochondrial respiration and ATP production. Future studies are required to establish mechanisms by which TNAP influences mitochondrial function and determine if modulation of TNAP can alter mitochondrial respiration in vivo.
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Affiliation(s)
- Zhi Zhang
- Department of Natural Sciences, University of Michigan-Dearborn, 4901 Evergreen Rd, Dearborn, MI 48128, USA;
| | - Hwa Kyung Nam
- School of Dentistry, University of Michigan-Ann Arbor, 1011 N University Avenue, Ann Arbor, MI 48103, USA; (H.K.N.); (S.C.)
| | - Spencer Crouch
- School of Dentistry, University of Michigan-Ann Arbor, 1011 N University Avenue, Ann Arbor, MI 48103, USA; (H.K.N.); (S.C.)
| | - Nan E. Hatch
- School of Dentistry, University of Michigan-Ann Arbor, 1011 N University Avenue, Ann Arbor, MI 48103, USA; (H.K.N.); (S.C.)
- Correspondence: ; Tel.: +1-734-764-6567
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