IFT140⁺/K14⁺ cells function as stem/progenitor cells in salivary glands

Abstract

Stem/progenitor cells are important for salivary gland development, homeostasis maintenance, and regeneration following injury. Keratin-14⁺ (K14⁺) cells have been recognized as bona fide salivary gland stem/progenitor cells. However, K14 is also expressed in terminally differentiated myoepithelial cells; therefore, more accurate molecular markers for identifying salivary stem/progenitor cells are required. The intraflagellar transport (IFT) protein IFT140 is a core component of the IFT system that functions in signaling transduction through the primary cilia. It is reportedly expressed in mesenchymal stem cells and plays a role in bone formation. In this study, we demonstrated that IFT140 was intensively expressed in K14⁺ stem/progenitor cells during the developmental period and early regeneration stage following ligation-induced injuries in murine submandibular glands. In addition, we demonstrated that IFT140⁺/ K14⁺ could self-renew and differentiate into granular duct cells at the developmental stage in vivo. The conditional deletion of Ift140 from K14⁺ cells caused abnormal epithelial structure and function during salivary gland development and inhibited regeneration. IFT140 partly coordinated the function of K14⁺ stem/progenitor cells by modulating ciliary membrane trafficking. Our investigation identified a combined marker, IFT140⁺/K14⁺, for salivary gland stem/progenitor cells and elucidated the essential role of IFT140 and cilia in regulating salivary stem/progenitor cell differentiation and gland regeneration.

References

[1] Jensen, S. B., Vissink, A., Limesand, K. H. & Reyland, M. E. Salivary gland hypofunction and xerostomia in head and neck radiation patients. J. Natl. Cancer Inst. Monogr. 2019 https://doi.org/10.1093/jncimonographs/lgz016 (2019).

[2] Sui Y, . Generation of functional salivary gland tissue from human submandibular gland stem/progenitor cells. Stem Cell Res. Ther., 2020, 11: 127.

[3] Emmerson E, Knox SM. Salivary gland stem cells: a review of development, regeneration and cancer. Genesis, 2018, 56: e23211.

[4] Nanduri LS, . Salisphere derived c-Kit+ cell transplantation restores tissue homeostasis in irradiated salivary gland. Radiother. Oncol., 2013, 108: 458-463.

[5] Pringle S, . Human salivary gland stem cells functionally restore radiation damaged salivary glands. Stem Cells, 2016, 34: 640-652.

[6] Schwarz S, . Bone marrow-derived mesenchymal stem cells migrate to healthy and damaged salivary glands following stem cell infusion. Int. J. Oral. Sci., 2014, 6: 154-161.

[7] Ninche, N., Kwak, M. & Ghazizadeh, S. Diverse epithelial cell populations contribute to the regeneration of secretory units in injured salivary glands. Development 147 https://doi.org/10.1242/dev.192807 (2020).

[8] Kwak M, Ghazizadeh S. Analysis of histone H2BGFP retention in mouse submandibular gland reveals actively dividing stem cell populations. Stem Cells Dev., 2015, 24: 565-574.

[9] Kwak M, Alston N, Ghazizadeh S. Identification of stem cells in the secretory complex of salivary glands. J. Dent. Res., 2016, 95: 776-783.

[10] Lombaert IM, . Combined KIT and FGFR2b signaling regulates epithelial progenitor expansion during organogenesis. Stem Cell Rep., 2013, 1: 604-619.

[11] Weng PL, Aure MH, Maruyama T, Ovitt CE. Limited regeneration of adult salivary glands after severe injury involves cellular plasticity. Cell Rep., 2018, 24: 1464-1470.e1463.

[12] Yanardag, S. & Pugacheva, E. N. Primary cilium is involved in stem cell differentiation and renewal through the regulation of multiple signaling pathways. Cells 10 https://doi.org/10.3390/cells10061428 (2021).

[13] Fu W, Wang L, Kim S, Li J, Dynlacht BD. Role for the IFT-A complex in selective transport to the primary cilium. Cell Rep., 2016, 17: 1505-1517.

[14] Anvarian Z, Mykytyn K, Mukhopadhyay S, Pedersen LB, Christensen ST. Cellular signalling by primary cilia in development, organ function and disease. Nat. Rev. Nephrol., 2019, 15: 199-219.

[15] Jordan, M. A. & Pigino, G. The structural basis of intraflagellar transport at a glance. J. Cell Sci. 134 https://doi.org/10.1242/jcs.247163 (2021).

[16] Chen, Y. et al. Lineage tracing of cells expressing the ciliary gene IFT140 during bone development. Dev. Dyn. https://doi.org/10.1002/dvdy.266 (2020).

[17] Li G, . Essential role of IFT140 in promoting dentinogenesis. J. Dent. Res., 2018, 97: 423-431.

[18] Tao D, Xue H, Zhang C, Li G, Sun Y. The role of IFT140 in osteogenesis of adult mice long bone. J. Histochem. Cytochem., 2019, 67: 601-611.

[19] Zhang C, Zhang S, Sun Y. Expression of IFT140 during bone development. J. Histochem. Cytochem., 2019, 67: 723-734.

[20] Perrault I, . Mainzer-Saldino syndrome is a ciliopathy caused by IFT140 mutations. Am. J. Hum. Genet., 2012, 90: 864-870.

[21] Pena-Padilla C, . Compound heterozygous mutations in the IFT140 gene cause Opitz trigonocephaly C syndrome in a patient with typical features of a ciliopathy. Clin. Genet., 2017, 91: 640-646.

[22] Xu M, . Mutations in human IFT140 cause non-syndromic retinal degeneration. Hum. Genet., 2015, 134: 1069-1078.

[23] Wang X, . Novel IFT140 variants cause spermatogenic dysfunction in humans. Mol. Genet. Genom. Med., 2019, 7: e920.

[24] Schmidts M, . Combined NGS approaches identify mutations in the intraflagellar transport gene IFT140 in skeletal ciliopathies with early progressive kidney disease. Hum. Mutat., 2013, 34: 714-724.

[25] Hull S, . Nonsyndromic retinal dystrophy due to bi-Allelic mutations in the ciliary transport gene IFT140. Invest. Ophthalmol. Vis. Sci., 2016, 57: 1053-1062.

[26] Bayat A, Kerr B, Douzgou S. The evolving craniofacial phenotype of a patient with Sensenbrenner syndrome caused by IFT140 compound heterozygous mutations. Clin. Dysmorphol., 2017, 26: 247-251.

[27] Zhang Q, Davenport JR, Croyle MJ, Haycraft CJ, Yoder BK. Disruption of IFT results in both exocrine and endocrine abnormalities in the pancreas of Tg737(orpk) mutant mice. Lab. Invest., 2005, 85: 45-64.

[28] Hosoi, K., Yao, C., Hasegawa, T., Yoshimura, H. & Akamatsu, T. Dynamics of salivary gland AQP5 under normal and pathologic conditions. Int. J. Mol. Sci. 21 https://doi.org/10.3390/ijms21041182 (2020).

[29] Kurabuchi S, Yao C, Chen G, Hosoi K. Reversible conversion among subtypes of salivary gland duct cells as identified by production of a variety of bioactive polypeptides. Acta Histochem. Cytochem., 2019, 52: 59-65.

[30] Frederickson CJ, Perez-Clausell J, Danscher G. Zinc-containing 7S-NGF complex. Evidence from zinc histochemistry for localization in salivary secretory granules. J. Histochem. Cytochem., 1987, 35: 579-583.

[31] Zhang GH, Wu LL, Yu GY. Tight junctions and paracellular fluid and ion transport in salivary glands. Chin. J. Dent. Res., 2013, 16: 13-46.

[32] Shin K, Fogg VC, Margolis B. Tight junctions and cell polarity. Annu. Rev. Cell Dev. Biol., 2006, 22: 207-235.

[33] Picariello, T. et al. A global analysis of IFT-A function reveals specialization for transport of membrane-associated proteins into cilia. J. Cell Sci. 132 https://doi.org/10.1242/jcs.220749 (2019).

[34] Centonze A, . Heterotypic cell-cell communication regulates glandular stem cell multipotency. Nature, 2020, 584: 608-613.

[35] Milenkovic L, . Single-molecule imaging of Hedgehog pathway protein Smoothened in primary cilia reveals binding events regulated by Patched1. Proc. Natl Acad. Sci. USA, 2015, 112: 8320-8325.

[36] Rocchi C, Barazzuol L, Coppes RP. The evolving definition of salivary gland stem cells. NPJ Regen. Med., 2021, 6: 4.

[37] Chatzeli, L. & Simons, B. D. Tracing the dynamics of stem cell fate. Cold Spring Harb. Perspect. Biol. 12 https://doi.org/10.1101/cshperspect.a036202 (2020).

[38] Knox SM, . Parasympathetic stimulation improves epithelial organ regeneration. Nat. Commun., 2013, 4

[39] Nachury MV. The molecular machines that traffic signaling receptors into and out of cilia. Curr. Opin. Cell Biol., 2018, 51: 124-131.

[40] Scheidel N, Blacque OE. Intraflagellar transport complex A genes differentially regulate cilium formation and transition zone gating. Curr. Biol., 2018, 28: 3279-3287 e3272.

[41] Jiang Y, . Defining a critical period in calvarial development for Hedgehog pathway antagonist-induced frontal bone dysplasia in mice. Int. J. Oral. Sci., 2019, 11: 3.

[42] Kuzhandaivel A, Schultz SW, Alkhori L, Alenius M. Cilia-mediated hedgehog signaling in Drosophila. Cell Rep., 2014, 7: 672-680.

[43] Hirano T, Katoh Y, Nakayama K. Intraflagellar transport-A complex mediates ciliary entry and retrograde trafficking of ciliary G protein-coupled receptors. Mol. Biol. Cell, 2017, 28: 429-439.

[44] Hua K, Ferland RJ. Primary cilia proteins: ciliary and extraciliary sites and functions. Cell Mol. Life Sci., 2018, 75: 1521-1540.

Funding

National Natural Science Foundation of China (National Science Foundation of China)(82101035, 81822012, 82061130222, 81771043, 82101035, 81822012, 82061130222, 81771043)

Shanghai Academic Leader of Science and Technology Innovation Action Plan (20XD1424000), and the Shanghai Experimental Animal Research Project of Science and Technology Innovation Action Plan (8191101676, 201409006400).