Insufficient skeletal repair is the primary threat of health span and lifespan in elders with increasingly vast global burden; yet, to date, the knowledge of resolving this crisis remains limited. In this study, we addressed the specific mechanisms underlying aging-associated poor bone repair, which are driven by the mitochondrial DNA structures mitochondrial G-quadruplex (mtG4). We found that mtG4 is spatiotemporal-wisely accumulated within Pdgfra+ periosteal mesenchymal stromal/stem cells (PPM) both in healthy and premature aging, which substantially increases cellular senescence and the degenerative alterations of PPM. By utilizing transgenic lineage tracking, PPM organoids formation, mitochondrial transgenic mutation, organoids transplantation, and serial cellular molecular investigations, we reveal that mtG4 in PPM restricts vital mitochondrial genes’ transcription to cause mitochondrial dysfunction, which utterly leads to severe mitophagy and cell senescence. These senescent PPM demonstrates impaired stemness and disrupted fate determination, finally phenocopying aging-associated poor bone repair. This study decodes the mitochondrial genomic reasons for insufficient bone repair during aging, which offers insights for developing cell-type- and disease-specific senolytic therapies in the future.
| [1] |
Wu A-M, et al. . Global, regional, and national burden of bone fractures in 204 countries and territories, 1990–2019: a systematic analysis from the Global Burden of Disease Study 2019. Lancet Healthy Longev., 2021, 2: e580-e592
|
| [2] |
Cauley JA. The global burden of fractures. Lancet Healthy Longev., 2021, 2: e535-e536
|
| [3] |
Colón-Emeric CS, McDermott CL, Lee DS, Berry SD. Risk assessment and prevention of falls in older community-dwelling adults: a review. JAMA, 2024, 331: 1397-1406
|
| [4] |
Kim DH, Rockwood K. Frailty in older adults. N. Engl. J. Med., 2024, 391: 538-548
|
| [5] |
Estell EG, Rosen CJ. Emerging insights into the comparative effectiveness of anabolic therapies for osteoporosis. Nat. Rev. Endocrinol., 2021, 17: 31-46
|
| [6] |
Vestergaard P, Rejnmark L, Mosekilde L. Increased mortality in patients with a hip fracture-effect of pre-morbid conditions and post-fracture complications. Osteoporos. Int., 2007, 18: 1583-1593
|
| [7] |
Saul D, Khosla S. Fracture healing in the setting of endocrine diseases, aging, and cellular senescence. Endocr. Rev., 2022, 43: 984-1002
|
| [8] |
Clark D, et al. . Age-related changes to macrophages are detrimental to fracture healing in mice. Aging Cell, 2020, 19 e13112
|
| [9] |
Ambrosi TH, et al. . Aged skeletal stem cells generate an inflammatory degenerative niche. Nature, 2021, 597: 256-262
|
| [10] |
Clark D, Nakamura M, Miclau T, Marcucio R. Effects of aging on fracture healing. Curr. Osteoporos. Rep., 2017, 15: 601-608
|
| [11] |
Xing W, et al. . Itm2a expression marks periosteal skeletal stem cells that contribute to bone fracture healing. J. Clin. Invest., 2024, 134: e176528
|
| [12] |
Liu YL, Tang XT, Shu HS, Zou W, Zhou BO. Fibrous periosteum repairs bone fracture and maintains the healed bone throughout mouse adulthood. Dev. Cell, 2024, 59: 1192-1209.e1196
|
| [13] |
Perrin S, Colnot C. Periosteal skeletal stem and progenitor cells in bone regeneration. Curr. Osteoporos. Rep., 2022, 20: 334-343
|
| [14] |
Maia Ferreira Alencar CH, et al. . Periosteum: an imaging review. Eur. J. Radiol. Open, 2020, 7 100249
|
| [15] |
Bochman ML, Paeschke K, Zakian VA. DNA secondary structures: stability and function of G-quadruplex structures. Nat. Rev. Genet., 2012, 13: 770-780
|
| [16] |
Sahayasheela VJ, Yu Z, Hidaka T, Pandian GN, Sugiyama H. Mitochondria and G-quadruplex evolution: an intertwined relationship. Trends Genet, 2023, 39: 15-30
|
| [17] |
Yang L, et al. . Mitochondrial DNA mutation exacerbates female reproductive aging via impairment of the NADH/NAD+ redox. Aging Cell, 2020, 19 e13206
|
| [18] |
Bharti SK, et al. . DNA sequences proximal to human mitochondrial dna deletion breakpoints prevalent in human disease form g-quadruplexes, a class of dna structures inefficiently unwound by the mitochondrial replicative Twinkle Helicase*. J. Biol. Chem., 2014, 289: 29975-29993
|
| [19] |
Rhodes D, Lipps HJ. G-quadruplexes and their regulatory roles in biology. Nucleic Acids Res, 2015, 43: 8627-8637
|
| [20] |
Micol F, Rafael JF, Johnson FB, Brett AK. Potential roles for g-quadruplexes in mitochondria. Curr. Med Chem., 2019, 26: 2918-2932
|
| [21] |
Varshney D, Spiegel J, Zyner K, Tannahill D, Balasubramanian S. The regulation and functions of DNA and RNA G-quadruplexes. Nat. Rev. Mol. Cell Biol., 2020, 21: 459-474
|
| [22] |
Eshaghian A, et al. . Mitochondrial DNA deletions serve as biomarkers of aging in the skin, but are typically absent in nonmelanoma skin cancers. J. Invest. Dermatol., 2006, 126: 336-344
|
| [23] |
Kraytsberg Y, et al. . Mitochondrial DNA deletions are abundant and cause functional impairment in aged human substantia nigra neurons. Nat. Genet., 2006, 38: 518-520
|
| [24] |
Yu K, Li F, Ye L, Yu F. Accumulation of DNA G-quadruplex in mitochondrial genome hallmarks mesenchymal senescence. Aging Cell, 2024, 23 e14265
|
| [25] |
Trifunovic A, et al. . Premature ageing in mice expressing defective mitochondrial DNA polymerase. Nature, 2004, 429: 417-423
|
| [26] |
Kujoth GC, et al. . Mitochondrial DNA Mutations, Oxidative Stress, and Apoptosis in Mammalian Aging. Science, 2005, 309: 481-484
|
| [27] |
Lim EW, et al. . Progressive alterations in amino acid and lipid metabolism correlate with peripheral neuropathy in PolgD257A mice. Sci. Adv., 2021, 7 eabj4077
|
| [28] |
Zhao H, et al. . Identifying specific functional roles for senescence across cell types. Cell, 2024, 187: 7314-7334.e21
|
| [29] |
Grosse L, et al. . Defined p16High senescent cell types are indispensable for mouse healthspan. Cell Metab., 2020, 32: 87-99.e86
|
| [30] |
Xu J, et al. . PDGFRα reporter activity identifies periosteal progenitor cells critical for bone formation and fracture repair. Bone Res., 2022, 10: 7
|
| [31] |
Branovets J, Soodla K, Vendelin M, Birkedal R. Rat and mouse cardiomyocytes show subtle differences in creatine kinase expression and compartmentalization. PLoS One, 2023, 18: e0294718
|
| [32] |
Paliwal S, Chaudhuri R, Agrawal A, Mohanty S. Human tissue-specific MSCs demonstrate differential mitochondria transfer abilities that may determine their regenerative abilities. Stem Cell Res Ther., 2018, 9: 298
|
| [33] |
Lopez-Otin C, Blasco MA, Partridge L, Serrano M, Kroemer G. Hallmarks of aging: an expanding universe. Cell, 2023, 186: 243-278
|
| [34] |
Chambers VS, et al. . High-throughput sequencing of DNA G-quadruplex structures in the human genome. Nat. Biotechnol., 2015, 33: 877-881
|
| [35] |
Bharti SK, et al. . DNA sequences proximal to human mitochondrial DNA deletion breakpoints prevalent in human disease form G-quadruplexes, a class of DNA structures inefficiently unwound by the mitochondrial replicative Twinkle helicase. J. Biol. Chem., 2014, 289: 29975
|
| [36] |
Snyder RJ, et al. . Guanine quadruplexes mediate mitochondrial RNA polymerase pausing. BMC Biol., 2025, 23 129
|
| [37] |
Bordt EA, et al. . The putative Drp1 inhibitor mdivi-1 Is a reversible mitochondrial complex I inhibitor that modulates reactive oxygen species. Dev. Cell, 2017, 40: 583-594.e586
|
| [38] |
Sanchez-Contreras M, Kennedy SR. The complicated nature of somatic mtDNA mutations in aging. Front. Aging, 2022, 2: 805126
|
| [39] |
Qin T, et al. . Single-cell RNA-seq reveals novel mitochondria-related musculoskeletal cell populations during adult axolotl limb regeneration process. Cell Death Differ., 2021, 28: 1110-1125
|
| [40] |
Chaib S, Tchkonia T, Kirkland JL. Cellular senescence and senolytics: the path to the clinic. Nat. Med, 2022, 28: 1556-1568
|
| [41] |
Safwan-Zaiter H, Wagner N, Wagner K-D. P16INK4A—More Than a Senescence Marker. Life, 2022, 12: 1332
|
| [42] |
Beauséjour CM, et al. . Reversal of human cellular senescence: roles of the p53 and p16 pathways. EMBO J., 2003, 22: 4212-4222
|
| [43] |
Muirhead MR. Epidemiology and control of vaginal discharges in the sow after service. Vet. Rec., 1986, 119: 233-235
|
| [44] |
Bao H, et al. . Biomarkers of aging. Sci. China Life Sci., 2023, 66: 893-1066
|
| [45] |
Debacq-Chainiaux F, Erusalimsky JD, Campisi J, Toussaint O. Protocols to detect senescence-associated beta-galactosidase (SA-βgal) activity, a biomarker of senescent cells in culture and in vivo. Nat. Protoc., 2009, 4: 1798-1806
|
| [46] |
Nilsson Hall G, et al. . Developmentally engineered callus organoid bioassemblies exhibit predictive in vivo long bone healing. Adv. Sci., 2020, 7 1902295
|
| [47] |
Yao L, et al. . Chronological and replicative aging of CD51+/PDGFR-α+ pulp stromal cells. J. Dent. Res, 2023, 102: 929-937
|
| [48] |
Yu F, et al. . Wnt7b-induced Sox11 functions enhance self-renewal and osteogenic commitment of bone marrow mesenchymal stem cells. Stem Cells, 2020, 38: 1020-1033
|
| [49] |
Li X, Zhang Y, Qi G. Evaluation of isolation methods and culture conditions for rat bone marrow mesenchymal stem cells. Cytotechnology, 2013, 65: 323-334
|
Funding
National Natural Science Foundation of China (National Science Foundation of China)(82522021)
Department of Science and Technology of Sichuan Province (Sichuan Provincial Department of Science and Technology)(2024ZYD0172)
RIGHTS & PERMISSIONS
The Author(s)