SIS-ECM Laden with GMSC-Derived Exosomes Promote Taste Bud Regeneration

Abstract

Oral cancer has a high annual incidence rate all over the world, and the tongue is the most frequently affected anatomic structure. The current standard care is ablative surgery of malignant neoplasm, followed by tongue reconstruction with free flap. However, such reconstructive modalities with postsurgery radiotherapy or chemotherapy can hardly support the functional recovery of the tongue—particularly, functional taste bud regeneration—in reconstructed areas, thus seriously affecting patients’ prognosis and life quality. Using a critical-sized tongue defect model in rats, we show that combinatory transplantation of small intestinal submucosa–extracellular matrix (SIS-ECM) with gingival mesenchymal stem cells (GMSCs) or their derivative exosomes promoted tongue lingual papillae recovery and taste bud regeneration as evidenced by increased expression of CK14, CK8, and markers for type I, II, and III taste bud cells (NTPdase 2, PLC-β2, and AADC, respectively). In addition, our results indicate that GMSCs or their derivative exosomes could increase BDNF expression, a growth factor that plays an important role in the proliferation and differentiation of epithelial basal progenitor cells into taste bud cells. Meanwhile, we showed an elevated expression level of Shh—which is essential for development, homeostasis, and maintenance of the taste bud organ—in wounded areas of the tongue among animals treated with GMSC/SIS-ECM or exosome/SIS-ECM as compared with SIS-ECM control. Moreover, our data show that GMSCs or their derivative exosomes promoted innervation of regenerated taste buds, as evidenced by elevated expressions of neurofilament and P2X3 at the injury areas. Together, our findings indicate that GMSC/SIS-ECM and exosome/SIS-ECM constructs can facilitate taste bud regeneration and reinnervation with promising potential application in postsurgery tongue reconstruction of patients with tongue cancer.

Dental Stem Cell-Derived Secretome/Conditioned Medium: The Future for Regenerative Therapeutic Applications

“…Although neurodegenerative diseases and other neural insults represent a major challenge as they currently do not have an effective treatment, dental MSC-CM opened the way for treating these challenging conditions. Several studies supported the neuroregenerative effects of dental MSC-CM [66,69,109,110,112,116,[168][169][170]173]. The key role of dental MSC-CM as a modulator of the neurogenic microenvironment is through the release of multiple growth factors promoting neural growth and differentiation like NGF [65,66,110,117]; BDNF [65, 66, 110, 117, 168-170, 173, 176]; NT-3 [65, 110, 168-170, 173, 176]; CNTF, GDNF, and HGF [110]; IGF [117,151]; MFI, MAP-2, β-tubulin III, nestin, and SOX-1 [65], besides Neurofilament 200 and S100 [168][169][170]173].…”

“…In critical-sized tongue defect model in rats, involving the combinative transplantation of small intestinal submucosaextracellular matrix with gingival MSCs or their derivative, EXs proved to regenerate tongue lingual papillae and taste buds, with an increasing expression of CK14 + (basal epithelial progenitor cells' marker); CK8 + (intragemmal cells' marker); type I, II, and III taste bud cells' markers (NTPdase 2, PLC-β2, and AADC, respectively), in addition to nerve fiber markers (UCH-L1/PGP9.5 and P2X 3 receptor). Moreover, the expression of two key trophic factors (BDNF and Shh), with remarkable roles in the proliferation and differentiation of basal epithelial progenitor cells into taste bud cells and the reconstruction of submucosal connective tissues [173], was promoted. The faster wound healing rate in the gingiva was primarily attributed to the gingival MSCs and their unique secretory mechanism through the Fas/Fasassociated phosphatase-1 (Fap-1)/caveolin-1 (Cav-1) complex that triggers SNARE-mediated membrane fusion to secrete a large quantity of IL-1 receptor antagonist-(IL-1RA-) expressing EVs, inhibiting the proinflammatory cytokine IL-1β [174].…”

“…This finding represents an auspicious application potential for tongue reconstruction in patients suffering from tongue cancer. All these studies propose gingival MSCs' secretome/CM as a simple and autologous therapeutic tool to repair/regenerate nerve injuries, mainly through increasing the expression of anti-inflammatory cytokines (IL-10), antiapoptotic cytokine (Bcl2) [170], and markers denoting neural growth (BDGF, NT-3, Neurofilament 200, S100) [168][169][170]173], as well as enhancing proliferation and regeneration of nerve cells detected by PCNA [168], CCK-8 [169], and Shh [173] aside from a suppression of proinflammatory cytokine TNF-α [170], IL-17, IFN-γ [175,176], and proapoptotic (Bax and cleaved caspase-3) and oxidative stress markers (SOD-1, iNOS, COX-2) [170]. (Table 2).…”

A Role for Exosomes in Craniofacial Tissue Engineering and Regeneration

“…Exosomes have also been isolated from gingival MSCs and their administration to tongue wounds increased BDNF expression and associated taste bud regeneration with neurofilament expression reflecting re-innervation (Zhang Y. et al, 2018). Gingival MSCs isolated from gingival lamina propria were used in a diabetes-induced wound closure assay to facilitated recalcitrant healing.…”

Stemness Potency of Human Gingival Cells—Application in Anticancer Therapies and Clinical Trials

“…After the treatment, the deposition and remodeling of collagen and re-epithelialization occurred, and the microvessel and nerve density were increased compared to the control group [93]. In another study, GMSCs-derived exosomes were combined with small intestinal submucosa-extracellular matrix and transplanted into rats with a critical-sized tongue defect model, to examine the influence on taste bud regeneration [94]. Such therapy resulted in an increased expression of Shh, BDNF, CK14, CK8, and markers for type I, II, and II taste bud cells as compared to the controls, therefore facilitating taste bud regeneration and reinnervation, suggesting a possible application in tongue reconstruction [94].…”