Pannexins in the musculoskeletal system: new targets for development and disease progression

Abstract

During cell differentiation, growth, and development, cells can respond to extracellular stimuli through communication channels. Pannexin (Panx) family and connexin (Cx) family are two important types of channel-forming proteins. Panx family contains three members (Panx1-3) and is expressed widely in bone, cartilage and muscle. Although there is no sequence homology between Panx family and Cx family, they exhibit similar configurations and functions. Similar to Cxs, the key roles of Panxs in the maintenance of physiological functions of the musculoskeletal system and disease progression were gradually revealed later. Here, we seek to elucidate the structure of Panxs and their roles in regulating processes such as osteogenesis, chondrogenesis, and muscle growth. We also focus on the comparison between Cx and Panx. As a new key target, Panxs expression imbalance and dysfunction in muscle and the therapeutic potentials of Panxs in joint diseases are also discussed.

References

[1] Allen, M. R. & Burr, D. B. in Basic and Applied Bone Biology (eds David B. Burr & Matthew R. Allen) 75–90 (Academic Press, 2014).

[2] Plotkin LI, Bellido T. Beyond gap junctions: connexin43 and bone cell signaling. Bone, 2013, 52: 157-166

[3] Stains JP, Civitelli R. Gap junctions in skeletal development and function. Biochim. Biophys. Acta, 2005, 1719: 69-81

[4] Bellido, T., Plotkin, L. I. & Bruzzaniti, A. in Basic and Applied Bone Biology (eds David B. Burr & Matthew R. Allen) 27–45 (Academic Press, 2014).

[5] Sáez JC, Cisterna BA, Vargas A, Cardozo CP. Regulation of pannexin and connexin channels and their functional role in skeletal muscles. Cell Mol. Life Sci., 2015, 72: 2929-2935

[6] Tomei EJ, Wolniak SM. Kinesin-2 and kinesin-9 have atypical functions during ciliogenesis in the male gametophyte of Marsilea vestita. BMC Cell Biol., 2016, 17

[7] Bhat EA, Sajjad N. Human Pannexin 1 channel: Insight in structure-function mechanism and its potential physiological roles. Mol. Cell Biochem., 2021, 476: 1529-1540

[8] Pelegrin P, Surprenant A. Pannexin-1 mediates large pore formation and interleukin-1beta release by the ATP-gated P2X7 receptor. EMBO J., 2006, 25: 5071-5082

[9] Scemes E, Suadicani SO, Dahl G, Spray DC. Connexin and pannexin mediated cell-cell communication. Neuron Glia Biol., 2007, 3: 199-208

[10] Alhouayek M, Sorti R, Gilthorpe JD, Fowler CJ. Role of pannexin-1 in the cellular uptake, release and hydrolysis of anandamide by T84 colon cancer cells. Sci. Rep., 2019, 9

[11] Chekeni FB et al. Pannexin 1 channels mediate ‘find-me’ signal release and membrane permeability during apoptosis. Nature, 2010, 467: 863-867

[12] Moorer MC et al. Defective signaling, osteoblastogenesis and bone remodeling in a mouse model of connexin 43 C-terminal truncation. J. Cell Sci., 2017, 130: 531-540

[13] Narahari AK et al. ATP and large signaling metabolites flux through caspase-activated Pannexin 1 channels. Elife, 2021, 10: e64787

[14] Pacheco-Costa R et al. Defective cancellous bone structure and abnormal response to PTH in cortical bone of mice lacking Cx43 cytoplasmic C-terminus domain. Bone, 2015, 81: 632-643

[15] Dubyak GR. Both sides now: multiple interactions of ATP with pannexin-1 hemichannels. Focus on “A permeant regulating its permeation pore: inhibition of pannexin 1 channels by ATP”. Am. J. Physiol. Cell Physiol., 2009, 296: C235-C241

[16] Panchin YV. Evolution of gap junction proteins–the pannexin alternative. J. Exp. Biol., 2005, 208: 1415-1419

[17] Panchin Y et al. A ubiquitous family of putative gap junction molecules. Curr. Biol., 2000, 10: R473-R474

[18] Donahue HJ, Qu RW, Genetos DC. Joint diseases: from connexins to gap junctions. Nat. Rev. Rheumatol., 2017, 14: 42-51

[19] Bond SR et al. Pannexin 3 is a novel target for Runx2, expressed by osteoblasts and mature growth plate chondrocytes. J. Bone Min. Res., 2011, 26: 2911-2922

[20] Penuela S et al. Pannexin 1 and pannexin 3 are glycoproteins that exhibit many distinct characteristics from the connexin family of gap junction proteins. J. Cell Sci., 2007, 120: 3772-3783

[21] Xiao Z et al. Analysis of the extracellular matrix vesicle proteome in mineralizing osteoblasts. J. Cell Physiol., 2007, 210: 325-335

[22] Baranova A et al. The mammalian pannexin family is homologous to the invertebrate innexin gap junction proteins. Genomics, 2004, 83: 706-716

[23] Harber P, McCoy JM. Predicate calculus, artificial intelligence, and workers’ compensation. J. Occup. Med., 1989, 31: 484-489

[24] Riquelme MA et al. The ATP required for potentiation of skeletal muscle contraction is released via pannexin hemichannels. Neuropharmacology, 2013, 75: 594-603

[25] Langlois S et al. Pannexin 1 and pannexin 3 channels regulate skeletal muscle myoblast proliferation and differentiation. J. Biol. Chem., 2014, 289: 30717-30731

[26] Buvinic S et al. ATP released by electrical stimuli elicits calcium transients and gene expression in skeletal muscle. J. Biol. Chem., 2009, 284: 34490-34505

[27] Cea LA et al. De novo expression of connexin hemichannels in denervated fast skeletal muscles leads to atrophy. Proc. Natl. Acad. Sci. USA, 2013, 110: 16229-16234

[28] Kanjanamekanant K, Luckprom P, Pavasant P. P2X7 receptor-Pannexin1 interaction mediates stress-induced interleukin-1 beta expression in human periodontal ligament cells. J. Periodontal. Res., 2014, 49: 595-602

[29] Vogt A, Hormuzdi SG, Monyer H. Pannexin1 and Pannexin2 expression in the developing and mature rat brain. Brain Res. Mol. Brain Res., 2005, 141: 113-120

[30] Ishikawa M et al. Pannexin 3 functions as an ER Ca²⁺ channel, hemichannel, and gap junction to promote osteoblast differentiation. J. Cell Biol., 2011, 193: 1257-1274

[31] Iwamoto T et al. Pannexin 3 regulates proliferation and differentiation of odontoblasts via its hemichannel activities. PLoS One, 2017, 12: e0177557

[32] Le Vasseur M, Lelowski J, Bechberger JF, Sin WC, Naus CC. Pannexin 2 protein expression is not restricted to the CNS. Front. Cell Neurosci., 2014, 8: 392

[33] Pillon NJ et al. Nucleotides released from palmitate-challenged muscle cells through pannexin-3 attract monocytes. Diabetes, 2014, 63: 3815-3826

[34] Deng Z et al. Cryo-EM structures of the ATP release channel pannexin 1. Nat. Struct. Mol. Biol., 2020, 27: 373-381

[35] Jin Q et al. Cryo-EM structures of human pannexin 1 channel. Cell Res., 2020, 30: 449-451

[36] Michalski K et al. The Cryo-EM structure of pannexin 1 reveals unique motifs for ion selection and inhibition. Elife, 2020, 9: e54670

[37] Mou L et al. Structural basis for gating mechanism of Pannexin 1 channel. Cell Res., 2020, 30: 452-454

[38] Qu R et al. Cryo-EM structure of human heptameric Pannexin 1 channel. Cell Res., 2020, 30: 446-448

[39] Ruan Z, Orozco IJ, Du J, Lu W. Structures of human pannexin 1 reveal ion pathways and mechanism of gating. Nature, 2020, 584: 646-651

[40] Ambrosi C et al. Pannexin1 and Pannexin2 channels show quaternary similarities to connexons and different oligomerization numbers from each other. J. Biol. Chem., 2010, 285: 24420-24431

[41] Zhang H et al. Cryo-EM structure of human heptameric pannexin 2 channel. Nat. Commun., 2023, 14

[42] Kawate T, Gouaux E. Fluorescence-detection size-exclusion chromatography for precrystallization screening of integral membrane proteins. Structure, 2006, 14: 673-681

[43] Milks LC, Kumar NM, Houghten R, Unwin N, Gilula NB. Topology of the 32-kd liver gap junction protein determined by site-directed antibody localizations. EMBO J., 1988, 7: 2967-2975

[44] Yeager M, Gilula NB. Membrane topology and quaternary structure of cardiac gap junction ion channels. J. Mol. Biol., 1992, 223: 929-948

[45] Beckmann A, Grissmer A, Krause E, Tschernig T, Meier C. Pannexin-1 channels show distinct morphology and no gap junction characteristics in mammalian cells. Cell Tissue Res., 2016, 363: 751-763

[46] Huang Y, Grinspan JB, Abrams CK, Scherer SS. Pannexin1 is expressed by neurons and glia but does not form functional gap junctions. Glia, 2007, 55: 46-56

[47] Wang N et al. Connexin targeting peptides as inhibitors of voltage- and intracellular Ca²⁺ -triggered Cx43 hemichannel opening. Neuropharmacology, 2013, 75: 506-516

[48] Wang N et al. Paracrine signaling through plasma membrane hemichannels. Biochim. Biophys. Acta, 2013, 1828: 35-50

[49] Weinger JM, Holtrop ME. An ultrastructural study of bone cells: the occurrence of microtubules, microfilaments and tight junctions. Calcif. Tissue Res., 1974, 14: 15-29

[50] Bruzzone R, Hormuzdi SG, Barbe MT, Herb A, Monyer H. Pannexins, a family of gap junction proteins expressed in brain. Proc. Natl. Acad. Sci. USA, 2003, 100: 13644-13649

[51] Ishikawa M et al. Pannexin 3 and connexin 43 modulate skeletal development through their distinct functions and expression patterns. J. Cell Sci., 2016, 129: 1018-1030

[52] Cooreman A et al. Connexin and pannexin (hemi)channels: emerging targets in the treatment of liver disease. Hepatology, 2019, 69: 1317-1323

[53] Vinken M et al. Connexins and their channels in cell growth and cell death. Cell Signal, 2006, 18: 592-600

[54] Flores JA et al. Connexin-46/50 in a dynamic lipid environment resolved by CryoEM at 1.9 A. Nat. Commun., 2020, 11

[55] Lee HJ et al. Cryo-EM structure of human Cx31.3/GJC3 connexin hemichannel. Sci. Adv., 2020, 6: eaba4996

[56] Maeda S et al. Structure of the connexin 26 gap junction channel at 3.5 A resolution. Nature, 2009, 458: 597-602

[57] Myers JB et al. Structure of native lens connexin 46/50 intercellular channels by cryo-EM. Nature, 2018, 564: 372-377

[58] Unger VM, Kumar NM, Gilula NB, Yeager M. Three-dimensional structure of a recombinant gap junction membrane channel. Science, 1999, 283: 1176-1180

[59] Bhaskaracharya A et al. Probenecid blocks human P2X7 receptor-induced dye uptake via a pannexin-1 independent mechanism. PLoS ONE, 2014, 9: e93058

[60] Chiu YH, Schappe MS, Desai BN, Bayliss DA. Revisiting multimodal activation and channel properties of Pannexin 1. J. Gen. Physiol., 2018, 150: 19-39

[61] Iwamoto T et al. Pannexin 3 regulates intracellular ATP/cAMP levels and promotes chondrocyte differentiation. J. Biol. Chem., 2010, 285: 18948-18958

[62] Ma W, Hui H, Pelegrin P, Surprenant A. Pharmacological characterization of pannexin-1 currents expressed in mammalian cells. J. Pharm. Exp. Ther., 2009, 328: 409-418

[63] Li S, Bjelobaba I, Stojilkovic SS. Interactions of Pannexin1 channels with purinergic and NMDA receptor channels. Biochim. Biophys. Acta Biomembr., 2018, 1860: 166-173

[64] Velasquez S, Eugenin EA. Role of Pannexin-1 hemichannels and purinergic receptors in the pathogenesis of human diseases. Front. Physiol., 2014, 5: 96

[65] Silverman WR et al. The pannexin 1 channel activates the inflammasome in neurons and astrocytes. J. Biol. Chem., 2009, 284: 18143-18151

[66] Locovei S, Wang J, Dahl G. Activation of pannexin 1 channels by ATP through P2Y receptors and by cytoplasmic calcium. FEBS Lett., 2006, 580: 239-244

[67] Prochnow N et al. Pannexin1 stabilizes synaptic plasticity and is needed for learning. PLoS One, 2012, 7: e51767

[68] Burboa PC, Puebla M, Gaete PS, Duran WN, Lillo MA. Connexin and pannexin large-pore channels in microcirculation and neurovascular coupling function. Int. J. Mol. Sci., 2022, 23: 7303

[69] Qu Y et al. Pannexin-1 is required for ATP release during apoptosis but not for inflammasome activation. J. Immunol., 2011, 186: 6553-6561

[70] Kanneganti TD et al. Pannexin-1-mediated recognition of bacterial molecules activates the cryopyrin inflammasome independent of Toll-like receptor signaling. Immunity, 2007, 26: 433-443

[71] Seminario-Vidal L et al. Rho signaling regulates pannexin 1-mediated ATP release from airway epithelia. J. Biol. Chem., 2011, 286: 26277-26286

[72] Phelan P. Innexins: members of an evolutionarily conserved family of gap-junction proteins. Biochim. Biophys. Acta, 2005, 1711: 225-245

[73] Berendsen AD, Olsen BR. Bone development. Bone, 2015, 80: 14-18

[74] Yang L, Tsang KY, Tang HC, Chan D, Cheah KS. Hypertrophic chondrocytes can become osteoblasts and osteocytes in endochondral bone formation. Proc. Natl. Acad. Sci. USA, 2014, 111: 12097-12102

[75] Cheung WY et al. Pannexin-1 and P2X7-receptor are required for apoptotic osteocytes in fatigued bone to trigger RANKL production in neighboring bystander osteocytes. J. Bone Min. Res., 2016, 31: 890-899

[76] Caskenette D et al. Global deletion of Panx3 produces multiple phenotypic effects in mouse humeri and femora. J. Anat., 2016, 228: 746-756

[77] Shao Q et al. A germline variant in the PANX1 gene has reduced channel function and is associated with multisystem dysfunction. J. Biol. Chem., 2016, 291: 12432-12443

[78] Ishikawa M, Iwamoto T, Fukumoto S, Yamada Y. Pannexin 3 inhibits proliferation of osteoprogenitor cells by regulating Wnt and p21 signaling. J. Biol. Chem., 2014, 289: 2839-2851

[79] Delgado-Calle J, Bellido T. Osteocytes and skeletal pathophysiology. Curr. Mol. Biol. Rep., 2015, 1: 157-167

[80] Aguirre JI et al. Osteocyte apoptosis is induced by weightlessness in mice and precedes osteoclast recruitment and bone loss. J. Bone Min. Res., 2006, 21: 605-615

[81] Delgado-Calle J, Bellido T. The osteocyte as a signaling cell. Physiol. Rev., 2022, 102: 379-410

[82] Emerton KB et al. Osteocyte apoptosis and control of bone resorption following ovariectomy in mice. Bone, 2010, 46: 577-583

[83] Kennedy OD et al. Activation of resorption in fatigue-loaded bone involves both apoptosis and active pro-osteoclastogenic signaling by distinct osteocyte populations. Bone, 2012, 50: 1115-1122

[84] Kennedy OD, Laudier DM, Majeska RJ, Sun HB, Schaffler MB. Osteocyte apoptosis is required for production of osteoclastogenic signals following bone fatigue in vivo. Bone, 2014, 64: 132-137

[85] Bakker A, Klein-Nulend J, Burger E. Shear stress inhibits while disuse promotes osteocyte apoptosis. Biochem. Biophys. Res. Commun., 2004, 320: 1163-1168

[86] Noble B. Bone microdamage and cell apoptosis. Eur. Cell Mater., 2003, 6: 46-55 discusssion 55

[87] Tomkinson A, Gevers EF, Wit JM, Reeve J, Noble BS. The role of estrogen in the control of rat osteocyte apoptosis. J. Bone Min. Res., 1998, 13: 1243-1250

[88] Verborgt O, Gibson GJ, Schaffler MB. Loss of osteocyte integrity in association with microdamage and bone remodeling after fatigue in vivo. J. Bone Min. Res., 2000, 15: 60-67

[89] McCutcheon S, Majeska RJ, Spray DC, Schaffler MB, Vazquez M. Apoptotic osteocytes induce RANKL production in bystanders via purinergic signaling and activation of pannexin channels. J. Bone Min. Res., 2020, 35: 966-977

[90] Liu W et al. TGF-beta1 facilitates cell-cell communication in osteocytes via connexin43- and pannexin1-dependent gap junctions. Cell Death Discov., 2019, 5: 141

[91] Aguilar-Perez A et al. Age- and sex-dependent role of osteocytic pannexin1 on bone and muscle mass and strength. Sci. Rep., 2019, 9

[92] Courvoisier A, Sailhan F, Laffenetre O, Obert L French Study Group of, B. M. P. i. O. S. Bone morphogenetic protein and orthopaedic surgery: can we legitimate its off-label use? Int. Orthop., 2014, 38: 2601-2605

[93] Kalitina TA. [Survival of Coxsackie viruses of group B 3 and 5 serotypes in sausage meat]. Vopr. Pitan., 1966, 25: 74-77

[94] Song K et al. Identification of a key residue mediating bone morphogenetic protein (BMP)-6 resistance to noggin inhibition allows for engineered BMPs with superior agonist activity. J. Biol. Chem., 2010, 285: 12169-12180

[95] Wang L et al. Bone formation induced by BMP-2 in human osteosarcoma cells. Int. J. Oncol., 2013, 43: 1095-1102

[96] Takeno A, Kanazawa I, Tanaka KI, Notsu M, Sugimoto T. Phloretin suppresses bone morphogenetic protein-2-induced osteoblastogenesis and mineralization via inhibition of phosphatidylinositol 3-kinases/Akt pathway. Int. J. Mol. Sci., 2019, 20: 2481

[97] Ghosh-Choudhury N et al. c-Abl-dependent molecular circuitry involving Smad5 and phosphatidylinositol 3-kinase regulates bone morphogenetic protein-2-induced osteogenesis. J. Biol. Chem., 2013, 288: 24503-24517

[98] Mukherjee A, Wilson EM, Rotwein P. Selective signaling by Akt2 promotes bone morphogenetic protein 2-mediated osteoblast differentiation. Mol. Cell Biol., 2010, 30: 1018-1027

[99] Sun M et al. Effects of matrix stiffness on the morphology, adhesion, proliferation and osteogenic differentiation of mesenchymal stem cells. Int. J. Med. Sci., 2018, 15: 257-268

[100] Afzal F et al. Smad function and intranuclear targeting share a Runx2 motif required for osteogenic lineage induction and BMP2 responsive transcription. J. Cell Physiol., 2005, 204: 63-72

[101] Zaidi SK et al. Integration of Runx and Smad regulatory signals at transcriptionally active subnuclear sites. Proc. Natl. Acad. Sci. USA, 2002, 99: 8048-8053

[102] Lohman AW et al. Expression of pannexin isoforms in the systemic murine arterial network. J. Vasc. Res., 2012, 49: 405-416

[103] Plotkin LI, Stains JP. Connexins and pannexins in the skeleton: gap junctions, hemichannels and more. Cell Mol. Life Sci., 2015, 72: 2853-2867

[104] Rauch A et al. Glucocorticoids suppress bone formation by attenuating osteoblast differentiation via the monomeric glucocorticoid receptor. Cell Metab., 2010, 11: 517-531

[105] Song F, Sun H, Huang L, Fu D, Huang C. The role of Pannexin3-modified human dental pulp-derived mesenchymal stromal cells in repairing rat cranial critical-sized bone defects. Cell Physiol. Biochem., 2017, 44: 2174-2188

[106] Tomita M, Reinhold MI, Molkentin JD, Naski MC. Calcineurin and NFAT4 induce chondrogenesis. J. Biol. Chem., 2002, 277: 42214-42218

[107] Beals CR, Clipstone NA, Ho SN, Crabtree GR. Nuclear localization of NF-ATc by a calcineurin-dependent, cyclosporin-sensitive intramolecular interaction. Genes Dev., 1997, 11: 824-834

[108] Esseltine JL, Laird DW. Next-generation connexin and pannexin cell biology. Trends Cell Biol., 2016, 26: 944-955

[109] Koga T et al. NFAT and osterix cooperatively regulate bone formation. Nat. Med., 2005, 11: 880-885

[110] Nakashima K et al. The novel zinc finger-containing transcription factor osterix is required for osteoblast differentiation and bone formation. Cell, 2002, 108: 17-29

[111] Ishikawa M et al. Pannexin 3 ER Ca²⁺ channel gating is regulated by phosphorylation at the Serine 68 residue in osteoblast differentiation. Sci. Rep., 2019, 9

[112] Boyden LM et al. High bone density due to a mutation in LDL-receptor-related protein 5. N. Engl. J. Med., 2002, 346: 1513-1521

[113] Guntur AR, Rosen CJ. Bone as an endocrine organ. Endocr. Pr., 2012, 18: 758-762

[114] Cheung, W. Y. et al. in Journal Of Bone And Mineral Research. S288-S288 (WILEY-BLACKWELL 111 RIVER ST, HOBOKEN 07030-5774, NJ USA).

[115] Deosthale P et al. Sex-specific differences in direct osteoclastic versus indirect osteoblastic effects underlay the low bone mass of Pannexin1 deletion in TRAP-expressing cells in mice. Bone Rep., 2022, 16: 101164

[116] Oh SK et al. Pannexin 3 is required for normal progression of skeletal development in vertebrates. FASEB J., 2015, 29: 4473-4484

[117] Bond SR, Abramyan J, Fu K, Naus CC, Richman JM. Pannexin 3 is required for late stage bone growth but not for initiation of ossification in avian embryos. Dev. Dyn., 2016, 245: 913-924

[118] Charge SB, Rudnicki MA. Cellular and molecular regulation of muscle regeneration. Physiol. Rev., 2004, 84: 209-238

[119] Riquelme MA et al. Pannexin channels mediate the acquisition of myogenic commitment in C2C12 reserve cells promoted by P2 receptor activation. Front. Cell Dev. Biol., 2015, 3: 25

[120] Jorquera G et al. Cav1.1 controls frequency-dependent events regulating adult skeletal muscle plasticity. J. Cell Sci., 2013, 126: 1189-1198

[121] Rose AJ, Alsted TJ, Kobbero JB, Richter EA. Regulation and function of Ca²⁺ -calmodulin-dependent protein kinase II of fast-twitch rat skeletal muscle. J. Physiol., 2007, 580: 993-1005

[122] Suarez-Berumen K et al. Pannexin 1 regulates skeletal muscle regeneration by promoting bleb-based myoblast migration and fusion through a novel lipid based signaling mechanism. Front. Cell Dev. Biol., 2021, 9: 736813

[123] Freeman E et al. Sex-dependent role of Pannexin 1 in regulating skeletal muscle and satellite cell function. J. Cell Physiol., 2022, 237: 3944-3959

[124] Martel-Pelletier J et al. Osteoarthritis. Nat. Rev. Dis. Prim., 2016, 2: 16072

[125] Glyn-Jones S et al. Osteoarthritis. Lancet, 2015, 386: 376-387

[126] Jiang Y. Osteoarthritis year in review 2021: biology. Osteoarthr. Cartil., 2022, 30: 207-215

[127] Appleton CT, Pitelka V, Henry J, Beier F. Global analyses of gene expression in early experimental osteoarthritis. Arthritis Rheum., 2007, 56: 1854-1868

[128] O’Donnell BL, Penuela S. Pannexin 3 channels in health and disease. Purinergic Signal, 2021, 17: 577-589

[129] Moon PM et al. Deletion of Panx3 prevents the development of surgically induced osteoarthritis. J. Mol. Med., 2015, 93: 845-856

[130] Moon PM et al. Global deletion of Pannexin 3 resulting in accelerated development of aging-induced osteoarthritis in mice. Arthritis Rheumatol., 2021, 73: 1178-1188

[131] Xiao J, Li Y, Zhang J, Xu G, Zhang J. Pannexin 3 activates P2X7 receptor to mediate inflammation and cartilage matrix degradation in temporomandibular joint osteoarthritis. Cell Biol. Int., 2023, 47: 1183-1197

[132] Francisco V et al. A new immunometabolic perspective of intervertebral disc degeneration. Nat. Rev. Rheumatol., 2022, 18: 47-60

[133] Serjeant M et al. The role of Panx3 in age-associated and injury-induced intervertebral disc degeneration. Int. J. Mol. Sci., 2021, 22: 1080

[134] Liu N et al. microRNA-206 promotes skeletal muscle regeneration and delays progression of Duchenne muscular dystrophy in mice. J. Clin. Invest., 2012, 122: 2054-2065

[135] McNally EM, Pytel P. Muscle diseases: the muscular dystrophies. Annu. Rev. Pathol., 2007, 2: 87-109

[136] Arias-Calderon M et al. Characterization of a multiprotein complex involved in excitation-transcription coupling of skeletal muscle. Skelet. Muscle, 2016, 6

[137] Cea LA et al. Fast skeletal myofibers of MDX mouse, model of Duchenne muscular dystrophy, express connexin hemichannels that lead to apoptosis. Cell Mol. Life Sci., 2016, 73: 2583-2599

[138] Valladares D et al. Electrical stimuli are anti-apoptotic in skeletal muscle via extracellular ATP. Alteration of this signal in Mdx mice is a likely cause of dystrophy. PLoS One, 2013, 8: e75340

[139] Pham TL et al. Expression of Pannexin 1 and Pannexin 3 during skeletal muscle development, regeneration, and Duchenne muscular dystrophy. J. Cell Physiol., 2018, 233: 7057-7070

[140] An S et al. Connexin43 in musculoskeletal system: new targets for development and disease progression. Aging Dis., 2022, 13: 1715-1732

[141] Lohman AW, Isakson BE. Differentiating connexin hemichannels and pannexin channels in cellular ATP release. FEBS Lett., 2014, 588: 1379-1388

[142] Brigid Hogan RB. Manipulating the mouse embryo. a laboratory manual, 2nd Edition. Genet. Res., 1994, 66: 296-300

[143] Lecanda F et al. Connexin43 deficiency causes delayed ossification, craniofacial abnormalities, and osteoblast dysfunction. J. Cell Biol., 2000, 151: 931-944

[144] Ishikawa M, Yamada Y. The role of Pannexin 3 in bone biology. J. Dent. Res., 2017, 96: 372-379

[145] Lengner CJ et al. Osteoblast differentiation and skeletal development are regulated by Mdm2-p53 signaling. J. Cell Biol., 2006, 172: 909-921

[146] Uribe P et al. Soluble silica stimulates osteogenic differentiation and gap junction communication in human dental follicle cells. Sci. Rep., 2020, 10

[147] van der Heyden MA et al. Identification of connexin43 as a functional target for Wnt signalling. J. Cell Sci., 1998, 111: 1741-1749

[148] Lohman AW et al. Pannexin 1 channels regulate leukocyte emigration through the venous endothelium during acute inflammation. Nat. Commun., 2015, 6

[149] Wang J, Ma M, Locovei S, Keane RW, Dahl G. Modulation of membrane channel currents by gap junction protein mimetic peptides: size matters. Am. J. Physiol. Cell Physiol., 2007, 293: C1112-C1119

[150] Weilinger NL, Tang PL, Thompson RJ. Anoxia-induced NMDA receptor activation opens pannexin channels via Src family kinases. J. Neurosci., 2012, 32: 12579-12588

[151] Plotkin LI et al. Connexin 43 is required for the anti-apoptotic effect of bisphosphonates on osteocytes and osteoblasts in vivo. J. Bone Min. Res., 2008, 23: 1712-1721

[152] Poornima V, Vallabhaneni S, Mukhopadhyay M, Bera AK. Nitric oxide inhibits the pannexin 1 channel through a cGMP-PKG dependent pathway. Nitric Oxide, 2015, 47: 77-84

[153] Dobrowolski R, Sommershof A, Willecke K. Some oculodentodigital dysplasia-associated Cx43 mutations cause increased hemichannel activity in addition to deficient gap junction channels. J. Membr. Biol., 2007, 219: 9-17

[154] Esseltine JL et al. Connexin43 mutant patient-derived induced pluripotent stem cells exhibit altered differentiation potential. J. Bone Min. Res., 2017, 32: 1368-1385

[155] Katz JN, Arant KR, Loeser RF. Diagnosis and treatment of hip and knee osteoarthritis: a review. JAMA, 2021, 325: 568-578

[156] Hochberg MC. Serious joint-related adverse events in randomized controlled trials of anti-nerve growth factor monoclonal antibodies. Osteoarthr. Cartil., 2015, 23: S18-S21

[157] van der Kraan PM, van den Berg WB. Chondrocyte hypertrophy and osteoarthritis: role in initiation and progression of cartilage degeneration? Osteoarthr. Cartil., 2012, 20: 223-232

[158] Billaud M et al. Pannexin1 regulates alpha1-adrenergic receptor- mediated vasoconstriction. Circ. Res., 2011, 109: 80-85

[159] Masuda T et al. Dorsal horn neurons release extracellular ATP in a VNUT-dependent manner that underlies neuropathic pain. Nat. Commun., 2016, 7

[160] Conesa-Buendia FM et al. Tenofovir causes bone loss via decreased bone formation and increased bone resorption, which can be counteracted by dipyridamole in mice. J. Bone Min. Res., 2019, 34: 923-938

[161] Hirata H et al. Connexin 39.9 protein is necessary for coordinated activation of slow-twitch muscle and normal behavior in zebrafish. J. Biol. Chem., 2012, 287: 1080-1089

[162] Naus CC, Giaume C. Bridging the gap to therapeutic strategies based on connexin/pannexin biology. J. Transl. Med., 2016, 14

[163] Dahl G, Qiu F, Wang J. The bizarre pharmacology of the ATP release channel pannexin1. Neuropharmacology, 2013, 75: 583-593

[164] Bruzzone R, Barbe MT, Jakob NJ, Monyer H. Pharmacological properties of homomeric and heteromeric pannexin hemichannels expressed in Xenopus oocytes. J. Neurochem., 2005, 92: 1033-1043

[165] Molica F et al. Selective inhibition of Panx1 channels decreases hemostasis and thrombosis in vivo. Thromb. Res., 2019, 183: 56-62

[166] Michalski K, Kawate T. Carbenoxolone inhibits Pannexin1 channels through interactions in the first extracellular loop. J. Gen. Physiol., 2016, 147: 165-174

[167] Freeman TJ et al. Inhibition of Pannexin 1 reduces the tumorigenic properties of human melanoma cells. Cancers, 2019, 11: 102

[168] Chen KW, Demarco B, Broz P. Pannexin-1 promotes NLRP3 activation during apoptosis but is dispensable for canonical or noncanonical inflammasome activation. Eur. J. Immunol., 2020, 50: 170-177

[169] Jankowski J et al. Epithelial and endothelial pannexin1 channels mediate AKI. J. Am. Soc. Nephrol., 2018, 29: 1887-1899

[170] Sharma AK et al. Pannexin-1 channels on endothelial cells mediate vascular inflammation during lung ischemia-reperfusion injury. Am. J. Physiol. Lung Cell Mol. Physiol., 2018, 315: L301-L312

[171] Furukawa M, Matsueda M, Takagai Y. Ultrasonic mist generation assist argon-nitrogen mix gas effect on radioactive strontium quantification by online solid-phase extraction with inductively coupled plasma mass spectrometry. Anal. Sci., 2018, 34: 471-476

[172] Feig JL et al. The antiviral drug tenofovir, an inhibitor of Pannexin-1-mediated ATP release, prevents liver and skin fibrosis by downregulating adenosine levels in the liver and skin. PLoS One, 2017, 12: e0188135

[173] Davidson JS, Baumgarten IM. Glycyrrhetinic acid derivatives: a novel class of inhibitors of gap-junctional intercellular communication. Structure-activity relationships. J. Pharm. Exp. Ther., 1988, 246: 1104-1107

[174] Davidson JS, Baumgarten IM, Harley EH. Reversible inhibition of intercellular junctional communication by glycyrrhetinic acid. Biochem. Biophys. Res. Commun., 1986, 134: 29-36

[175] Goldberg GS et al. Evidence that disruption of connexon particle arrangements in gap junction plaques is associated with inhibition of gap junctional communication by a glycyrrhetinic acid derivative. Exp. Cell Res., 1996, 222: 48-53

[176] Guan X, Wilson S, Schlender KK, Ruch RJ. Gap-junction disassembly and connexin 43 dephosphorylation induced by 18 beta-glycyrrhetinic acid. Mol. Carcinog., 1996, 16: 157-164

[177] Armanini D, Karbowiak I, Krozowski Z, Funder JW, Adam WR. The mechanism of mineralocorticoid action of carbenoxolone. Endocrinology, 1982, 111: 1683-1686

[178] Kuzuya M et al. Structures of human pannexin-1 in nanodiscs reveal gating mediated by dynamic movement of the N terminus and phospholipids. Sci. Signal, 2022, 15: eabg6941

[179] Willebrords J, Maes M, Crespo Yanguas S, Vinken M. Inhibitors of connexin and pannexin channels as potential therapeutics. Pharm. Ther., 2017, 180: 144-160

[180] Chen X, Yuan S, Mi L, Long Y, He H. Pannexin1: insight into inflammatory conditions and its potential involvement in multiple organ dysfunction syndrome. Front. Immunol., 2023, 14: 1217366

[181] Grek CL et al. Targeting connexin 43 with alpha-connexin carboxyl-terminal (ACT1) peptide enhances the activity of the targeted inhibitors, tamoxifen and lapatinib, in breast cancer: clinical implication for ACT1. BMC Cancer, 2015, 15

[182] Caufriez A et al. Determination of structural features that underpin the pannexin1 channel inhibitory activity of the peptide ¹⁰Panx1. Bioorg. Chem., 2023, 138: 106612

[183] Zhang Y, Sun Y, Wang Z, Huang L. Fluorescein-5-thiosemicarbazide as a probe for directly imaging of mucin-type O-linked glycoprotein within living cells. Glycoconj. J., 2012, 29: 445-452

[184] Boassa D, Nguyen P, Hu J, Ellisman MH, Sosinsky GE. Pannexin2 oligomers localize in the membranes of endosomal vesicles in mammalian cells while Pannexin1 channels traffic to the plasma membrane. Front. Cell Neurosci., 2014, 8: 468

[185] Hedskog L et al. Modulation of the endoplasmic reticulum-mitochondria interface in Alzheimer’s disease and related models. Proc. Natl. Acad. Sci. USA, 2013, 110: 7916-7921

[186] Yang Y, Wang L, Chen L, Li L. Pannexin-2, a novel mitochondrial-associated membrane protein, may become the new strategy to treat and prevent neurological disorders. Acta Biochim. Biophys. Sin., 2020, 52: 1178-1180

[187] Grimston SK, Watkins MP, Brodt MD, Silva MJ, Civitelli R. Enhanced periosteal and endocortical responses to axial tibial compression loading in conditional connexin43 deficient mice. PLoS One, 2012, 7: e44222

[188] Lecanda F et al. Gap junctional communication modulates gene expression in osteoblastic cells. Mol. Biol. Cell, 1998, 9: 2249-2258

[189] Li Z, Zhou Z, Saunders MM, Donahue HJ. Modulation of connexin43 alters expression of osteoblastic differentiation markers. Am. J. Physiol. Cell Physiol., 2006, 290: C1248-C1255

[190] Schiller PC, Roos BA, Howard GA. Parathyroid hormone up-regulation of connexin 43 gene expression in osteoblasts depends on cell phenotype. J. Bone Min. Res., 1997, 12: 2005-2013

[191] Watkins M et al. Osteoblast connexin43 modulates skeletal architecture by regulating both arms of bone remodeling. Mol. Biol. Cell, 2011, 22: 1240-1251

[192] Hung CT, Allen FD, Mansfield KD, Shapiro IM. Extracellular ATP modulates [Ca2 + ]i in retinoic acid-treated embryonic chondrocytes. Am. J. Physiol., 1997, 272: C1611-C1617

[193] Lima F, Niger C, Hebert C, Stains JP. Connexin43 potentiates osteoblast responsiveness to fibroblast growth factor 2 via a protein kinase C-delta/Runx2-dependent mechanism. Mol. Biol. Cell, 2009, 20: 2697-2708

[194] Niger C et al. ERK acts in parallel to PKCdelta to mediate the connexin43-dependent potentiation of Runx2 activity by FGF2 in MC3T3 osteoblasts. Am. J. Physiol. Cell Physiol., 2012, 302: C1035-C1044

[195] Plotkin LI, Manolagas SC, Bellido T. Transduction of cell survival signals by connexin-43 hemichannels. J. Biol. Chem., 2002, 277: 8648-8657

[196] Stains JP, Civitelli R. Gap junctions regulate extracellular signal-regulated kinase signaling to affect gene transcription. Mol. Biol. Cell, 2005, 16: 64-72

[197] Hashida Y et al. Communication-dependent mineralization of osteoblasts via gap junctions. Bone, 2014, 61: 19-26

[198] Niger C et al. The transcriptional activity of osterix requires the recruitment of Sp1 to the osteocalcin proximal promoter. Bone, 2011, 49: 683-692

[199] Niger C et al. The regulation of runt-related transcription factor 2 by fibroblast growth factor-2 and connexin43 requires the inositol polyphosphate/protein kinase Cdelta cascade. J. Bone Min. Res., 2013, 28: 1468-1477

[200] Stains JP, Lecanda F, Screen J, Towler DA, Civitelli R. Gap junctional communication modulates gene transcription by altering the recruitment of Sp1 and Sp3 to connexin-response elements in osteoblast promoters. J. Biol. Chem., 2003, 278: 24377-24387

[201] Ilvesaro J, Tavi P, Tuukkanen J. Connexin-mimetic peptide Gap 27 decreases osteoclastic activity. BMC Musculoskelet. Disord., 2001, 2

[202] Ilvesaro J, Vaananen K, Tuukkanen J. Bone-resorbing osteoclasts contain gap-junctional connexin-43. J. Bone Min. Res., 2000, 15: 919-926

[203] Jones SJ, Boyde A. Questions of quality and quantity–a morphological view of bone biology. Kaibogaku Zasshi, 1994, 69: 229-243

[204] Zappitelli T et al. The G60S connexin 43 mutation activates the osteoblast lineage and results in a resorption-stimulating bone matrix and abrogation of old-age-related bone loss. J. Bone Min. Res., 2013, 28: 2400-2413

[205] Zhang Y et al. Enhanced osteoclastic resorption and responsiveness to mechanical load in gap junction deficient bone. PLoS One, 2011, 6: e23516

[206] Batra N et al. Mechanical stress-activated integrin alpha5beta1 induces opening of connexin 43 hemichannels. Proc. Natl. Acad. Sci. USA, 2012, 109: 3359-3364

[207] Burra S et al. Dendritic processes of osteocytes are mechanotransducers that induce the opening of hemichannels. Proc. Natl. Acad. Sci. USA, 2010, 107: 13648-13653

[208] Parsons JT, Martin KH, Slack JK, Taylor JM, Weed SA. Focal adhesion kinase: a regulator of focal adhesion dynamics and cell movement. Oncogene, 2000, 19: 5606-5613

[209] Qin L, Liu W, Cao H, Xiao G. Molecular mechanosensors in osteocytes. Bone Res., 2020, 8: 23

[210] Siller-Jackson AJ et al. Adaptation of connexin 43-hemichannel prostaglandin release to mechanical loading. J. Biol. Chem., 2008, 283: 26374-26382

[211] Bivi N et al. Cell autonomous requirement of connexin 43 for osteocyte survival: consequences for endocortical resorption and periosteal bone formation. J. Bone Min. Res., 2012, 27: 374-389

[212] Kar R, Riquelme MA, Werner S, Jiang JX. Connexin 43 channels protect osteocytes against oxidative stress-induced cell death. J. Bone Min. Res., 2013, 28: 1611-1621

[213] Lloyd SA, Loiselle AE, Zhang Y, Donahue HJ. Evidence for the role of connexin 43-mediated intercellular communication in the process of intracortical bone resorption via osteocytic osteolysis. BMC Musculoskelet. Disord., 2014, 15

[214] Hellio Le Graverand MP et al. Formation and phenotype of cell clusters in osteoarthritic meniscus. Arthritis Rheum., 2001, 44: 1808-1818

[215] Kolomytkin OV et al. IL-1beta-induced production of metalloproteinases by synovial cells depends on gap junction conductance. Am. J. Physiol. Cell Physiol., 2002, 282: C1254-C1260

[216] Marino, A. A. et al. Increased intercellular communication through gap junctions may contribute to progression of osteoarthritis. Clin. Orthop. Relat. Res. 224–232, https://doi.org/10.1097/01.blo.0000129346.29945.3b (2004).

[217] Tsuchida S et al. Silencing the expression of connexin 43 decreases inflammation and joint destruction in experimental arthritis. J. Orthop. Res., 2013, 31: 525-530

[218] Gago-Fuentes R et al. The C-terminal domain of connexin43 modulates cartilage structure via chondrocyte phenotypic changes. Oncotarget, 2016, 7: 73055-73067

[219] Chen Q et al. Carcinoma-astrocyte gap junctions promote brain metastasis by cGAMP transfer. Nature, 2016, 533: 493-498

[220] Ormonde S et al. Regulation of connexin43 gap junction protein triggers vascular recovery and healing in human ocular persistent epithelial defect wounds. J. Membr. Biol., 2012, 245: 381-388

[221] Macia E et al. Characterization of gap junction remodeling in epicardial border zone of healing canine infarcts and electrophysiological effects of partial reversal by rotigaptide. Circ. Arrhythm. Electrophysiol., 2011, 4: 344-351

[222] Ghatnekar GS, Grek CL, Armstrong DG, Desai SC, Gourdie RG. The effect of a connexin43-based Peptide on the healing of chronic venous leg ulcers: a multicenter, randomized trial. J. Invest. Dermatol., 2015, 135: 289-298

[223] Jiang J et al. Interaction of alpha Carboxyl Terminus 1 peptide with the connexin 43 carboxyl terminus preserves left ventricular function after ischemia-reperfusion injury. J. Am. Heart Assoc., 2019, 8: e012385

[224] Kim Y et al. Tonabersat prevents inflammatory damage in the central nervous system by blocking Connexin43 hemichannels. Neurotherapeutics, 2017, 14: 1148-1165

[225] O’Carroll SJ, Alkadhi M, Nicholson LF, Green CR. Connexin 43 mimetic peptides reduce swelling, astrogliosis, and neuronal cell death after spinal cord injury. Cell Commun. Adhes., 2008, 15: 27-42

[226] Abudara V et al. The connexin43 mimetic peptide Gap19 inhibits hemichannels without altering gap junctional communication in astrocytes. Front. Cell Neurosci., 2014, 8: 306

[227] Silverman W, Locovei S, Dahl G. Probenecid, a gout remedy, inhibits pannexin 1 channels. Am. J. Physiol. Cell Physiol., 2008, 295: C761-C767

[228] Wang J, Jackson DG, Dahl G. The food dye FD&C Blue No. 1 is a selective inhibitor of the ATP release channel Panx1. J. Gen. Physiol., 2013, 141: 649-656

[229] Locovei S, Scemes E, Qiu F, Spray DC, Dahl G. Pannexin1 is part of the pore forming unit of the P2X(7) receptor death complex. FEBS Lett., 2007, 581: 483-488

[230] Xiao F, Waldrop SL, Khimji AK, Kilic G. Pannexin1 contributes to pathophysiological ATP release in lipoapoptosis induced by saturated free fatty acids in liver cells. Am. J. Physiol. Cell Physiol., 2012, 303: C1034-C1044

[231] Linsdell P. Inhibition of cystic fibrosis transmembrane conductance regulator chloride channel currents by arachidonic acid. Can. J. Physiol. Pharm., 2000, 78: 490-499

[232] Brough D, Pelegrin P, Rothwell NJ. Pannexin-1-dependent caspase-1 activation and secretion of IL-1beta is regulated by zinc. Eur. J. Immunol., 2009, 39: 352-358

Funding

Natural Science Foundation of Hunan Province (Hunan Provincial Natural Science Foundation)(2022JJ70162)

National Natural Science Foundation of China (National Science Foundation of China)(82072506, 92268115)

National Key R&D Program of China (2019YFA0111900) Provincial Natural Science Foundation of Hunan (No. 2022JJ70162)