Review Article

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

Table 1

Summary of the included studies investigating the effect of dental MSCs’ secretome/conditioned medium on neurogenic regeneration.

Authors, yearCell origin-contributing factorScaffoldStudy modelFactors contained in dental MSC-CMFactors promoted by dental MSC-CMOutcome

Neural regeneration and treating neural disorders
SHED-CM
Sakai et al., 2012 [109]Human SHED-CM
Human dental pulp MSC-CM
-In vivo spinal cord injury.
In vitro.
--Promoted neural regeneration.
Inoue et al., 2013 [114]Human SHED-CM-In vivo rat with cerebral ischemia.DCX, NF, NeuN, & RECA1.-Promoted neuronal progenitor cells migration, differentiation, and vasculogenesis.
Yamagata et al., 2013 [113]Human SHED-CM-In vivo hypoxic ischemic brain injury mouse.IL-1β & TNF-α.-Improved neurological function, inhibited apoptosis, and decreased tissue loss.
Fujii et al., 2015 [119]Human SHED-CM-In vivo Parkinson's disease model.
In vitro
--Promoted neurite outgrowth of neurons and inhibited neuron apoptosis.
Jarmalaviciute et al., 2015 [120]Human SHED-EXs and MVs-In vitro Parkinson’s disease.--Stimulated neurite outgrowth of neurons and inhibited neuron apoptosis.
Matsubara et al., 2015 [112]Human SHED-CM-In vivo rat with spinal cord injury.M2 markers (IL-10, CD206) & M2-like macrophage inducers: MCP-1, Siglec-9, & IL-6.-Regenerated neurons suppressed inflammation which promoted functional recovery.
Mita et al., 2015 [117]Human SHED-CM-In vivo Alzheimer’s disease.
In vitro.
Ym-1, Arginase-1, & Fizz1. IL-10, mRNA of BDNF, NGF, & IGF.-Protected against neurodegeneration, improved cognitive functions, and inhibited neuroblastoma cell apoptosis.
Sugimura-Wakayama et al., 2015 [110]Human SHED-CM-In vivo sciatic nerve defect.
In vitro
NGF, BDNF, NT-3, GDNF, CNTF, VEGF, & HGF.NGF, BDNF, NT-3, CNTF, GDNF, VEGF, laminin, fibronectin, & collagen type IV.Promoted axon regeneration, remyelination, and motor functional recovery. Increased Schwann cell proliferation, migration, and activation.
Shimojima et al., 2016 [118]Human SHED-CM-In vivo multiple sclerosis mouse model.ED–Siglec-9 & HGF.mRNAs of Arginase-1 & CD206.
↓ mRNA of iNOS.
Reduced axon injury, demyelination, and reduced inflammation.
Kano et al., 2017 [111]Human SHED-CMCollagen spongeIn vitro & in vivo peripheral nerve injury.MCP-1 & sSiglec-9.mRNAs of Arginase-1, Cd206, & Il-10.Mediated neurological regeneration. Schwann cell proliferation, migration, and differentiation.
Li et al., 2017 [115]Human SHED-EXs-In vivo rat with traumatic brain injury.
In vitro
CD9, CD63, & CD81.↓ TNF-α, IL-6, CD11b, CD68, mRNA of CD11b, CD86, CD16, MHCII, iNOS, CD206, IL-10, & Arginase-1.Improved motor functional recovery and reduced neuroinflammation.
Asadi-Golshan et al., 2018 [116]Human SHED-CMCollagen hydrogelIn vivo rat spinal cord injury.--Enhanced neurological functional recovery.
Tsuruta et al., 2018 [122]Human SHED-CM-In vivo superior laryngeal nerve injury dysphagia in rat.Arginase-1, IL-10, Lif, Ccl2, NGF, BDNF, NTN, and mRNA VEGF.
↓ iNOS & IL-1β.
Promoted axonal regeneration and enhanced angiogenesis.
Narbute et al., 2019 [121]Human SHED-EVs-In vivo rat with Parkinson’s disease.--Suppression of gait impairments and normalization of tyrosine hydroxylase expression.
Dental pulp MSC-CM
Ishizaka et al., 2013 [106]Porcine dental pulp MSC-CM-In vitro--Triggered antiapoptotic activity on fibroblast and promoted neurite outgrowth of human neuroblastoma cell line.
Mead et al., 2014 [66]Human dental pulp MSC-CM-In vitro retinal nerve damage.NGF, BDNF, & VEGF.-Showed the presence of different neurotrophic factors.
Ahmed et al., 2016 [148]Human dental pulp MSC-CM-In vitro Alzheimer’s disease.VEGF, RANTES, fractalkine, FLT-3, GM-CSF, MCP-1, & neprilysin.Bcl-2 & Bax.Inhibited apoptosis in neuroblastoma cell line and increased its viability.
Yamamoto et al., 2016 [147]Human dental pulp MSC-CM-In vitro nerve section.--Induced proliferation, differentiation, and migration of Schwann cells and inhibited their apoptosis.
Gervois et al., 2017 [146]Human dental pulp MSC-CM-In vitro--Induced recruitment, neuronal maturation, and neuritogenesis of human neuroblastoma cells.
Song et al., 2017 [69]Human dental pulp MSC-CMEndothelial cell medium gelIn vitro model of ischemia.--Increased the number and total length of tubular structures in HUVECs.
Chen et al., 2019 [151]Rat dental pulp MSC-CM-In vivo rat with aneurysmal subarachnoid hemorrhage.IGF-1, TGF-β, TIMP1, & 2.-Improvement of microcirculation and neuroinflammation.
Makino et al., 2019 [150]Rat dental pulp MSC-CM-In vivo rat with diabetic polyneuropathy.
In vitro
--Exhibited neuroprotective, anti-inflammatory, and angiogenic actions.
Increased proliferation of HUVEC in vitro.
Wang et al., 2019 [149]Human dental pulp MSC-CM-In vivo mouse with amyotrophic lateral sclerosis.--Improved neuromuscular junction innervation and motor neuron survival.
Gingival MSC-CM
Rajan et al., 2017 [170]Human gingival MSC-CM-In vitro neuron degenerative diseases.NGF, NT-3, IL-10, & TGF-β.Bcl-2, IL-10, BDNF, & NT-3. ↓ SOD-1, iNOS, COX-2; TNF-α, cleaved caspase-3, & Bax.Suppression of neural cell apoptosis, oxidative stress, and inflammation.
Mao et al., 2019 [168]Human gingival MSC-EVs
Human gingival MSC-CM
-In vivo mouse with sciatic nerve injury.
In vitro
-Postsynaptic AChR clusters in NMJ, β-tubulin III, S100β, GFAP, c-JUN, Notch1, SOX-2, EGR2/KROX-20, PCNA, BrdU.Promoted proliferation, migration of Schwann cells, axonal regeneration, and functional recovery.
Rao et al., 2019 [169]Human gingival MSC-EXs-In vivo rat with sciatic nerve injury.
In vitro
-Neurofilament 200, S100, & CCK8.Promoted increase in number of nerve fibers, myelin formation, recovery of muscle and nerve function, Schwann cell proliferation, and cell axon growth.
Zhang et al., 2019 [173]Human gingival MSC-EXsSIS-ECMIn vivo critical-sized tongue defect in rats.-CK14, CK8, NTPdase 2, PLC-β2, AADC, UCH-L1/PGP9.5, BDNF, P2X3, & Shh.Promoted tongue lingual papillae recovery and taste bud regeneration and re-innervation.
Periodontal ligament MSC-CM
Rajan et al., 2016 [175]Multiple sclerosis human periodontal ligament MSC-CM
Multiple sclerosis human periodontal ligament MSC-EVMs
Human periodontal ligament MSC-CM
Human periodontal ligament MSC-EVMs.
-In vivo mouse with multiple sclerosis.-IL-10, TGF-β
↓ IL-4, IL-17, IFN-γ, TNF-α, IL-6, IL-1β, STAT1, p53, caspase-3, & Bax.
Promoted anti-inflammatory, immunosuppressive effects and downregulated apoptosis-related genes.
Giacoppo et al., 2017 [176]Hypoxia—human periodontal ligament MSC-CM-In vivo mouse with multiple sclerosis.
In vitro
NT-3, IL-10, & TGF-βIL-37, caspase-1, IL-10, BDNF, NT-3, Bcl-2; Beclin-1, LC3; phosphorylation of PI3K, Akt, & mTOR.
↓ IL-17, IFN-γ, JNK, TNF-α, iNOS, COX-2, cleaved caspase- 3, & Bax.
Clinical and histologic features of the disease were diminished via modulation of inflammation, oxidative stress, and apoptotic pathways.
Rajan et al., 2017 [192]Multiple sclerosis human periodontal ligament MSC-CM
Multiple sclerosis human periodontal ligament MSC-EMVs
-In vivo mouse with multiple sclerosis.Substantial level of IL-10, TGF-β, & SDF-1α
Less amount of IL-15, MCP-1, and MIP-1α.
↓ NALP3, cleaved caspase-1, IL-1β, IL-18, TLR-4, & NF-κB.Promoted anti-inflammatory and immunosuppressive effects.
Dental follicle MSC-CM & MSCs from apical papilla-CM
Kumar et al., 2017 [65]Human dental pulp MSC-CM
Human dental follicle MSC-CM
Human MSCs from apical papilla-CM
-In vitroGM-CSF, IFN-γ, TGF-β, NGF, BDNF, NT-3MFI, MAP-2, β-tubulin III, nestin, and SOX-1Enhanced neural differentiation.

AADC: aromatic l-amino acid decarboxylas; AChR: acetylcholine receptor; Akt: protein kinase B; Bax: Bcl-2-associated X protein; Bcl-2: B-cell lymphoma 2; BDNF: brain-derived neurotrophic factor; BrdU: bromodeoxyuridine; CCK8: Cell Count Kit-8; Ccl2: chemokine C-C motif ligand; CD: cluster of differentiation; CM: conditioned medium; CNTF: ciliary neurotrophic factor; COX-2: cyclooxygenase 2; DCX: doublecortin; ED-Siglec-9: ectodomain of sialic acid-binding Ig-like lectin-9; EGR2/KROX: early growth response gene; EVs: extracellular vesicles; EXs: exosomes; Fizz 1: resistin-like molecule alpha 1; FLT-3: Fms-related tyrosine kinase 3; GDN: glial cell line-derived neurotrophic factor; GFAP: glial fibrillary acidic protein; GM-CSF: granulocyte-macrophage colony-stimulating factor; MSCs: mesenchymal stem cells; HGF: hepatocyte growth factor; HUVECs: human umbilical vascular endothelial cells; IGF: insulin-like growth factor; IL: interleukin; iNOS: inducible nitric oxide synthase; JNK: c-Jun N terminal kinases; Lif: leukemia inhibitory factor; MAP-2: microtubule associated protein 2; MCP-1: monocyte chemoattractant protein-1; MHC: major histocompatibility complex; MIP-1α: macrophage inflammatory protein-1α; mTOR: mammalian target of rapamycin; MVs: microvesicles; NALP3: NACHT domain-, leucine-rich repeat-, and PYD-containing protein 3; NeuN: hexaribonucleotide binding protein 3; NF: nuclear factor; NF-κB: nuclear factor, kappa light chain enhancer of activated B-cells; NGF: nerve growth factor; Notch 1: neurogenic locus notch homolog protein; NT-3: neurotrophin 3; NTN: neurturin; NTPdase 2: ectonucleotidases; P2X3: purinergic receptor P2X3; p53: tumor protein p53; PCNA: proliferating cell nuclear antigen; MSCs: stem cells; PI3K: phosphoinositide 3- kinases; PLC-β2: phospholipase c β2; RANTES: chemokine (c-c motif) ligand 5 (CCL5); RECA1: homolog of bacteria RecA; S100β: S 100 calcium-binding protein β; SDF-1α: stromal cell-derived factor 1α; Shh: sonic hedgehog; Siglrc-9: sialic acid-binding immunoglobulin type lectins-9; SOD-1: superoxide dismutase; SOX: sex-determining region Y-box; STAT1: signal transducer and activator of transcription 1; TLR: Toll-like receptor; TNF: tumor necrosis factor; UCH-L1/PGP9.5: ubiquitin carboxyterminal hydrolase isozyme 1; VEGF: vascular endothelial growth factor.