Dental pulp stem cells-based therapy for the oviduct injury via immunomodulation and angiogenesis in vivo.

OBJECTIVES: As a result of the current limitation of therapeutic strategies, the repair and regeneration of oviduct injuries required an alternative treatment. We present a novel approach to treat oviduct injuries through a dental pulp stem cells (DPSCs)-based therapy. MATERIALS AND METHODS: In vitro and in vivo models have been established. Immunofluorescence staining, flow cytometry and enzyme-linked immunosorbent assay (ELISA) analysis were used to investigate the features and angiogenic properties of DPSCs, as well as their impact on macrophages, in vitro. For the in vivo experiment with female SD rat model, immunohistochemical staining and ELISA analysis were used to assess the effects of DPSCs on the repair and regeneration of damaged oviducts. RESULTS: The present data showed that intraperitoneal injection of DPSCs reduced the expression of IL-6 and TNF-α to inhibit the immunoreaction in injured sites, as well as increased the expression of VEGF to promote the in situ formation of vessel-like structures, thus the repair and recovery process could be initiated. CONCLUSIONS: We concluded that DPSCs-based therapy could be a novel potential technique for restoring the structure and function of damaged oviduct by enhancing immuno-regulated effect and promoting angiogenic property.

Influence of Fluoride-Resistant Streptococcus mutans Within Antagonistic Dual-Species Biofilms Under Fluoride In Vitro.

The widespread application of fluoride, an extremely effective caries prevention agent, induces the generation of fluoride-resistant strains of opportunistic cariogenic bacteria such as fluoride-resistant Streptococcus mutans (S. mutans). However, the influence of this fluoride-resistant strain on oral microecological homeostasis under fluoride remains unknown. In this study, an antagonistic dual-species biofilm model composed of S. mutans and Streptococcus sanguinis (S. sanguinis) was used to investigate the influence of fluoride-resistant S. mutans on dual-species biofilm formation and pre-formed biofilms under fluoride to further elucidate whether fluoride-resistant strains would influence the anti-caries effect of fluoride from the point of biofilm control. The ratio of bacteria within dual-species biofilms was investigated using quantitative real-time PCR and fluorescence in situ hybridization. Cristal violet staining, scanning electron microscopy imaging, and 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyl-2H-tetrazolium bromide assay were used to evaluate biofilm biomass, biofilm structure, and metabolic activity, respectively. Biofilm acidogenicity was determined using lactic acid and pH measurements. The anthrone method and exopolysaccharide (EPS) staining were used to study the EPS production of biofilms. We found that, in biofilm formation, fluoride-resistant S. mutans occupied an overwhelming advantage in dual-species biofilms under fluoride, thus showing more biofilm biomass, more robust biofilm structure, and stronger metabolic activity (except for 0.275 g/L sodium fluoride [NaF]), EPS production, and acidogenicity within dual-species biofilms. However, in pre-formed biofilms, the advantage of fluoride-resistant S. mutans could not be fully highlighted for biofilm formation. Therefore, fluoride-resistant S. mutans could influence the anti-caries effect of fluoride on antagonistic dual-species biofilm formation while being heavily discounted in pre-formed biofilms from the perspective of biofilm control.

Application of thermosensitive-hydrogel combined with dental pulp stem cells on the injured fallopian tube mucosa in an animal model.

Objectives: Fallopian tube (FT) injury is an important factor that can lead to tubal infertility. Stem-cell-based therapy shows great potential for the treatment of injured fallopian tube. However, little research has shown that mesenchymal stem cells (MSCs) can be used to treat fallopian tube damage by in situ injection. In this study, we in situ transplanted PF127 hydrogel encapsulating dental pulp stem cells (DPSCs) into the injured sites to promote the repair and regeneration of fallopian tube injury. Materials and methods: The properties of dental pulp stem cells were evaluated by flow cytometry, immunofluorescence analysis, and multi-differentiation detection. The immunomodulatory and angiogenic characteristics of dental pulp stem cells were analyzed on the basis of the detection of inflammatory factor expression and the formation of capillary-like structures, respectively. The biocompatibility of PF127 hydrogel was evaluated by using Live/Dead and CCK-8 assays. The effects of PF127 hydrogel containing dental pulp stem cells on the repair and regeneration of fallopian tube injury were evaluated by histological analysis [e.g., hematoxylin and eosin (H&E) and Masson's trichrome staining, TUNEL staining, immunofluorescence staining, and immunohistochemistry], Enzyme-linked immunosorbent assay (ELISA), and RT-PCR detections. Results: Dental pulp stem cells had MSC-like characteristics and great immunomodulatory and angiogenic properties. PF127 hydrogel had a thermosensitive feature and great cytocompatibility with dental pulp stem cells. In addition, our results indicated that PF127 hydrogel containing dental pulp stem cells could promote the repair and regeneration of fallopian tube damage by inhibiting cell apoptosis, stimulating the secretion of angiogenic factors, promoting cell proliferation, modulating the secretion of inflammatory factors, and restoring the secretion of epithelial cells. Conclusion: In this study, our results reported that in situ injection of PF127 hydrogel encapsulating dental pulp stem cells into the injured sites could provide an attractive strategy for the future treatment of fallopian tube injury in clinical settings.

Effects and mechanisms of basic fibroblast growth factor on the proliferation and regenerative profiles of cryopreserved dental pulp stem cells.

OBJECTIVES: Various factors could interfere the biological performance of DPSCs during post-thawed process. Yet, little has been known about optimization of the recovery medium for DPSCs. Thus, our study aimed to explore the effects of adding recombinant bFGF on DPSCs after 3-month cryopreservation as well as the underlying mechanisms. MATERIALS AND METHODS: DPSCs were extracted from impacted third molars and purified by MACS. The properties of CD146+ DPSCs (P3) were identified by CCK-8 and flow cytometry. After cryopreservation for 3 months, recovered DPSCs (P4) were immediately supplied with a series of bFGF and analysed cellular proliferation by CCK-8. Then, the optimal dosage of bFGF was determined to further identify apoptosis and TRPC1 channel through Western blot. The succeeding passage (P5) from bFGF pre-treated DPSCs was cultivated in bFGF-free culture medium, cellular proliferation and stemness were verified, and pluripotency was analysed by neurogenic, osteogenic and adipogenic differentiation. RESULTS: It is found that adding 20 ng/mL bFGF in culture medium could significantly promote the proliferation of freshly thawed DPSCs (P4) through suppressing apoptosis, activating ERK pathway and up-regulating TRPC1. Such proliferative superiority could be inherited to the succeeding passage (P5) from bFGF pre-stimulated DPSCs, meanwhile, stemness and pluripotency have not been compromised. CONCLUSIONS: This study illustrated a safe and feasible cell culture technique to rapidly amplify post-thawed DPSCs with robust regenerative potency, which brightening the future of stem cells banking and tissue engineering.

Dental pulp stem cell-derived exosomes alleviate cerebral ischaemia-reperfusion injury through suppressing inflammatory response.

OBJECTIVES: The study aimed to determine whether dental pulp stem cell-derived exosomes (DPSC-Exos) exert protective effects against cerebral ischaemia-reperfusion (I/R) injury and explore its underlying mechanism. MATERIALS AND METHODS: Exosomes were isolated from the culture medium of human DPSC. Adult male C57BL/6 mice were subjected to 2 hours transient middle cerebral artery occlusion (tMCAO) injury followed by 2 hours reperfusion, after which singular injection of DPSC-Exos via tail vein was administrated. Brain oedema, cerebral infarction and neurological impairment were measured on day 7 after exosomes injection. Then, oxygen-glucose deprivation-reperfusion (OGD/R) induced BV2 cells were studied to analyse the therapeutic effects of DPSC-Exos on I/R injury in vitro. Protein levels of TLR4, MyD88, NF-κB p65, HMGB1, IL-6, IL-1ß and TNF-α were determined by western blot or enzyme-linked immunosorbent assay. The cytoplasmic translocation of HMGB1 was detected by immunofluorescence staining. RESULTS: DPSC-Exos alleviated brain oedema, cerebral infarction and neurological impairment in I/R mice. DPSC-Exos inhibited the I/R-mediated expression of TLR4, MyD88 and NF-κB significantly. DPSC-Exos also reduced the protein expression of IL-6, IL-1ß and TNF-α compared with those of the control both in vitro and in vivo. Meanwhile, DPSC-Exos markedly decreased the HMGB1 cytoplasmic translocation induced by I/R damage. CONCLUSIONS: DPSC-Exos can ameliorate I/R-induced cerebral injury in mice. Its anti-inflammatory mechanism might be related with the inhibition of the HMGB1/TLR4/MyD88/NF-κB pathway.

An Evaluation of Norspermidine on Anti-fungal Effect on Mature Candida albicans Biofilms and Angiogenesis Potential of Dental Pulp Stem Cells.

Norspermidine (Nspd) is a kind of polyamine molecule, which is common in eukaryotes and prokaryotes. It has been reported as a potential anti-biofilms agent of bacteria, but its anti-fungal effect remains unclear. Candida albicans (C. albicans) is a common opportunistic pathogen in oral cavity of human beings. C. albicans biofilm is often seen in dental caries. In this work, we aimed to study the effect of Nspd on mature Candida albicans biofilms and to investigate how Nspd would influence human dental pulp stem cells (DPSCs). Our biofilm assays indicated that 111.7 and 55.9 mM Nspd dispersed 48 h mature fungal biofilms and showed significant fungicidal effect. 27.9 and 14.0 mM Nspd showed moderate fungicidal effect. Live/dead staining echoed the fungicidal effect. 111.7-14.0 mM Nspd showed a dose- inhibitory effect on mature fungal biofilm, where 14.0 mM Nspd reduced the metabolic activity by half compared with blank control. Moreover, we demonstrated that 111.7-27.9 mM Nspd restrained the production of hyphae form of C. albicans via SEM. Low dose Nspd (27.9 and 14.0 mM) could significantly reduce virulence related gene expression in C. albicans biofilms. MTT assay displayed a dose effect relation between 2.5-0.08 mM Nspd and DPSCs viability, where 0.63 mM Nspd reduced the viable level of DPSCs to 75% compared with blank control. Live/dead staining of DPSCs did not show distinctive difference between 0.63 mM Nspd and blank control. Vascular differentiation assay showed capillary-like structure of inducted DPSCs culture with and without 0.63 mM Nspd suggesting that it did not significantly affect angiogenic differentiation of DPSCs. Nspd can penetrate remaining dentin at low level, which is confirmed by an in vitro caries model. In conclusion, our study indicated high dosage Nspd (111.7 and 55.9 mM) could effectively disrupt and kill mature fungal biofilms. Low dosage (27.9 and 14.0 mM) showed mild anti-fungal effect on mature C. albicans biofilms. Human DPSCs were tolerate to 0.08-0.63 mM Nspd, where viability was over 75%. 0.63 mM Nspd did not affect the proliferation and angiogenetic differentiation of DPSCs.

Biological Behavioral Alterations of the Post-neural Differentiated Dental Pulp Stem Cells Through an in situ Microenvironment.

Transplantation of undifferentiated dental pulp stem cells (DPSCs) may suffer from tumorigenesis. Neuronal differentiated DPSCs (d-DPSCs) have emerged as an ideal source to treat central nervous system (CNS) disorders. Moreover, different components of culture medium functioned on the characteristics of d-DPSCs in vitro. In this study, d-DPSCs were cultured in three types of medium: Neurobasal®®-A medium supplemented with 2% B27 (the 2% B27 NM group), Neurobasal® -A medium supplemented with 2% B27 and 5% FBS (the 2% B27 + 5% FBS NM group), and α-MEM containing 10% FBS (the 10% FBS α-MEM group). We found that d-DPSCs in the 2% B27 + 5% FBS NM group had lower proliferation and reduced expression of transient receptor potential canonical 1 (TRPC1) and CD146, whereas up-regulated Nestin and microtubule-associated protein-2 (MAP-2). Notably, d-DPSCs in the 10% FBS α-MEM group possessed high proliferative capacity, decreased expression of neuron-like markers and partially restored stemness. It was demonstrated that d-DPSCs cultured in the 2% B27 + 5% FBS NM could maintain their neuron-like characteristics. Besides, d-DPSCs cultivated in the 10% FBS α-MEM could partially recover their stem cells properties, indicating that neural differentiation of DPSCs was reversible and could open novel avenues for exploring the pluripotency of DPSCs.

Current status and future potential of energy derived from Chinese agricultural land: a review.

Energy crisis is receiving attention with regard to the global economy and environmental sustainable development. Developing new energy resources to optimize the energy supply structure has become an important measure to prevent energy shortage as well as achieving energy conservation and emission reduction in China. This study proposed the concept of energy agriculture and constructed an energy agricultural technical support system based on the analysis of energy supply and demand and China's foreign dependence on energy resources, combined with the function of agriculture in the energy field. Manufacturing technology equipment and agricultural and forestry energy, including crop or forestry plants and animal feces, were used in the system. The current status and future potential of China's marginal land resources, energy crop germplasm resources, and agricultural and forestry waste energy-oriented resources were analyzed. Developing the function of traditional agriculture in food production may promote China's social, economic, and environmental sustainable development and achieve energy saving and emission reduction.