Objective . The adult spinal cord of mammals contains a certain amount of neural precursor cells, but these endogenous cells have a limited capacity for replacement of lost cells after spinal cord injury. The exogenous stem cells transplantation has become a therapeutic strategy for spinal cord repairing because of their immunomodulatory and differentiation capacity. In addition, dental stem cells originating from the cranial neural crest might be candidate cell sources for neural engineering. Approach . Human dental follicle stem cells (DFSCs), stem cells from apical papilla (SCAPs) and dental pulp stem cells (DPSCs) were isolated and identified in vitro , then green GFP-labeled stem cells with pellets were transplanted into completely transected spinal cord. The functional recovery of rats and multiple neuro-regenerative mechanisms were explored. Main results . The dental stem cells, especially DFSCs, demonstrated the potential in repairing the completely transected spinal cord and promote functional recovery after injury. The major involved mechanisms were speculated below: First, dental stem cells inhibited the expression of interleukin-1 β to reduce the inflammatory response; second, they inhibited the expression of ras homolog gene family member A (RhoA) to promote neurite regeneration; third, they inhibited the sulfonylurea receptor1 (SUR-1) expression to reduce progressive hemorrhagic necrosis; lastly, parts of the transplanted cells survived and differentiated into mature neurons and oligodendrocytes but not astrocyte, which is beneficial for promoting axons growth. Significance . Dental stem cells presented remarkable tissue regenerative capability after spinal cord injury through immunomodulatory, differentiation and protection capacity.

Background: Periodontitis is a common and chronic inflammatory disease characterized by irreversible destruction of the tooth surrounding tissues, especially intrabony defects, which eventually lead to tooth loss. In recent years, stem cell-based therapy for periodontitis has been gradually applied to the clinic, but whether stem cell-based therapy plays a positive role in periodontal regeneration is unclear at present. Methods: The clinical studies related to the evaluation of mesenchymal stem cells for periodontal regeneration in PubMed, Cochrane Central Register of Controlled trials (CENTRAL), Web of Science (WOS), Embase, Scopus, Wanfang and China national knowledge infrastructure (CNKI) databases were searched in June 2023. The inclusion criteria required the studies to compare the efficacy of stem cell-based therapy with stem cell free therapy for the treatment periodontitis, and to have a follow-up for at least six months. Two evaluators searched, screened, and assessed the quality and the risk of bias in the included studies independently. Review Manager 5.4 software was used to perform the meta-analysis, and GRADEpro GDT was used to evaluate the level of the evidence. Results: Five randomized controlled trials (RCTs) including 118 patients were analyzed. The results of this meta-analysis demonstrated that stem cell-based therapy showed better therapeutic effects on clinical attachment level (CAL) (MD = − 1.18, 95% CI = − 1.55, − 0.80, P < 0.00001), pocket probing depth (PPD) (MD = − 0.75, 95% CI = − 1.35, − 0.14, P = 0.020), and linear distance from bone crest to bottom of defect (BC-BD)( MD = − 0.95, 95% CI = − 1.67, − 0.23, P = 0.010) compared with cell-free group. However, stem cell-based therapy presented insignificant effects on gingival recession (P = 0.14), linear distance from cementoenamel junction to bottom of defect (P = 0.05). Conclusion: The results demonstrate that stem cell-based therapy may be beneficial for CAL, PPD and BC-BD. Due to the limited number of studies included, the strength of the results in this analysis was affected to a certain extent. The high‐quality RCTs with large sample size, multi-blind, multi-centric are still required, and the methodological and normative clinical study protocol should be established and executed in the future.

The autoimmune diseases are characterized by overactivation of immune cells, chronic inflammation, and immune response to self-antigens, leading to the damage and dysfunction of multiple organs. Patients still do not receive desired clinical outcomes while suffer from various adverse effects imparted by current therapies. The therapeutic strategies based on mesenchymal stromal cell (MSC) transplantation have become the promising approach for the treatment of autoimmune diseases due to the immunomodulation property of MSCs. MSCs derived from perinatal tissues are collectively known as perinatal MSCs (PMSCs), which can be obtained via painless procedures from donors with lower risk of being contaminated by viruses than those MSCs from adult tissue sources. Therefore, PMSCs may be the ideal cell source for the treatment of autoimmune diseases. This article summarizes recent progress and possible mechanisms of PMSCs in treating autoimmune diseases in animal experiments and clinical studies. This review also presents existing challenges and proposes solutions, which may provide new hints on PMSC transplantation as a therapeutic strategy for the treatment of autoimmune diseases.