Aging of craniofacial skeleton significantly impairs the repair and regeneration of trauma-induced bony defects, and complicates dental treatment outcomes. Age-related alveolar bone loss could be attributed to decreased progenitor pool through senescence, imbalance in bone metabolism and bone-fat ratio. Mesenchymal stem cells isolated from oral bones (OMSCs) have distinct lineage propensities and characteristics compared to MSCs from long bones, and are more suited for craniofacial regeneration. However, the effect of epigenetic modifications regulating OMSC differentiation and senescence in aging has not yet been investigated. In this study, we found that the histone demethylase KDM4B plays an essential role in regulating the osteogenesis of OMSCs and oral bone aging. Loss of KDM4B in OMSCs leads to inhibition of osteogenesis. Moreover, KDM4B loss promoted adipogenesis and OMSC senescence which further impairs bone-fat balance in the mandible. Together, our data suggest that KDM4B may underpin the molecular mechanisms of OMSC fate determination and alveolar bone homeostasis in skeletal aging, and present as a promising therapeutic target for addressing craniofacial skeletal defects associated with age-related deteriorations.
Aging ; Cell Differentiation ; Facial Bones/physiology* ; Humans ; Jumonji Domain-Containing Histone Demethylases/genetics* ; Mesenchymal Stem Cells/cytology* ; Osteogenesis ; Osteoporosis

Combined radiation-wound injury (CRWI) is characterized by blood vessel damage and pro-inflammatory cytokine deficiency. Studies have identified that the direct application of leptin plays a significant role in angiogenesis and inflammation. We established a sustained and stable leptin expression system to study the mechanism. A lentivirus method was employed to explore the angiogenic potential and peripheral inflammation of irradiated human umbilical vein endothelial cells (HUVECs). Leptin was transfected into human placenta-derived mesenchymal stem cells (HPMSCs) with lentiviral vectors. HUVECs were irradiated by X-ray at a single dose of 20 Gy. Transwell migration assay was performed to assess the migration of irradiated HUVECs. Based on the Transwell systems, co-culture systems of HPMSCs and irradiated HUVECs were established. Cell proliferation was measured by cell counting kit-8 (CCK-8) assay. The secretion of pro-inflammatory cytokines (human granulocyte macrophage-colony stimulating factor (GM-CSF), interleukin (IL)-1α, IL-6, and IL-8) was detected by enzyme-linked immunosorbent assay (ELISA). The expression of pro-angiogenic factors (vascular endothelial growth factor (VEGF) and basic fibroblast growth factor (bFGF)) mRNA was detected by real-time quantitative polymerase chain reaction (RT-qPCR) assay. Relevant molecules of the nuclear factor-κB (NF-κB) and Janus kinase (JAK)/signal transducer and activator of transcription (STAT) signaling pathways were detected by western blot assay. Results showed that leptin-modified HPMSCs (HPMSCs/ leptin) exhibited better cell proliferation, migration, and angiogenic potential (expressed more VEGF and bFGF). In both the single HPMSCs/leptin and the co-culture systems of HPMSCs/leptin and irradiated HUVECs, the increased secretion of pro-inflammatory cytokines (human GM-CSF, IL-1α, and IL-6) was associated with the interaction of the NF-κB and JAK/STAT signaling pathways. We conclude that HPMSCs/leptin could promote angiogenic potential and peripheral inflammation of HUVECs after X-ray radiation.
Cell Proliferation ; Cells, Cultured ; Cytokines/biosynthesis* ; Female ; Human Umbilical Vein Endothelial Cells/radiation effects* ; Humans ; Inflammation/etiology* ; Leptin/pharmacology* ; Mesenchymal Stem Cells/physiology* ; Neovascularization, Physiologic/physiology* ; Placenta/cytology* ; Pregnancy ; STAT3 Transcription Factor/genetics* ; Transcription Factor RelA/genetics* ; X-Rays

OBJECTIVE: To investigate the effects of autophagy on osteogenic differentiation of stem cells from the apical papilla (SCAPs) in the presence of tumor necrosis factor- (TNF-) stimulation . METHODS: SCAPs treated with TNF- (0, 5, and 10 ng/mL) with or without 5 mmol/L 3-MA were examined for the expression of autophagy marker LC3-Ⅱ using Western blotting. The cells were transfected with GFP-LC3 plasmid and fluorescence microscopy was used for quantitative analysis of intracellular GFP-LC3; AO staining was used to detect the acidic vesicles in the cells. The cell viability was assessed with CCK-8 assays and the cell apoptosis rate was analyzed using flow cytometry. The cells treated with TNF- or with TNF- and 3-MA were cultured in osteogenic differentiation medium for 3 to 14 days, and real- time PCR was used to detect the mRNA expressions of osteogenesis-related genes (ALP, BSP, and OCN) for evaluating the cell differentiation. RESULTS: TNF- induced activation of autophagy in cultured SCAPs. Pharmacological inhibition of TNF--induced autophagy by 3-MA significantly decreased the cell viability and increased the apoptosis rate of SCAPs ( < 0.05). Compared with the cells treated with TNF- alone, the cells treated with both TNF- and 3-MA exhibited decreased expressions of the ALP and BSP mRNA on days 3, 7 and 14 during osteogenic induction ( < 0.05) and decreased expression of OCN mRNA on days 3 and 7 during the induction ( < 0.05). CONCLUSIONS Autophagy may play an important role during the osteogenic differentiation of SCAPs in the presence of TNF- stimulation.
Autophagy ; drug effects ; physiology ; Cell Differentiation ; drug effects ; physiology ; Cell Survival ; drug effects ; Cells, Cultured ; Dental Papilla ; cytology ; Green Fluorescent Proteins ; Humans ; Osteogenesis ; physiology ; Stem Cells ; drug effects ; physiology ; Transfection ; Tumor Necrosis Factor-alpha ; administration & dosage ; antagonists & inhibitors ; pharmacology

Antigens, CD34 ; metabolism ; Biomarkers ; metabolism ; Cell Differentiation ; physiology ; Hair Follicle ; cytology ; Humans ; Intramolecular Oxidoreductases ; metabolism ; Keratinocytes ; metabolism ; Melanins ; metabolism ; Melanocytes ; metabolism ; PAX3 Transcription Factor ; metabolism ; Stem Cells ; metabolism

BACKGROUND: Several patients experience persistent otorrhea after a flawless surgical procedure because of insufficient epithelial healing. Several efforts, such as autologous tissue allograft and xenograft, have been made to halt otorrhea. However, a stable technology to induce temporal epithelial repair is yet to be established. Therefore, this study aims to investigate whether implantation of seeding adipose-derived mesenchymal stem cell (ADMSC) aggregates on extracellular matrix (ECM; herein, ADMSC aggregate-ECM) into damaged skin wound promotes skin regeneration. METHODS: ADMSC aggregate-ECM was prepared using a previously described procedure that isolated ADMSCs from rabbits and applied to the auricle and auditory meatus wound beds of New Zealand white rabbits. Wound healing was assessed by general observation and hematoxylin and eosin (H&E) staining. Secretion of growth factor of the tissue was evaluated by western blotting. Two other groups, namely, ECM and control, were used. Comparisons of three groups were conducted by one-way analysis of variance analysis. RESULTS: ADMSCs adhered tightly to the ECM and quickly formed cell sheets. At 2 weeks, general observation and H&E staining indicated that the wound healing rates in the ADMSC aggregate-ECM (69.02 ± 6.36%) and ECM (59.32 ± 4.10%) groups were higher than that in the control group (43.74 ± 12.15%; P = 0.005, P < 0.001, respectively) in ear auricle excisional wounds. At 7 weeks, The scar elevation index was evidently reduced in the ADMSC aggregate-ECM (2.08 ± 0.87) and ECM (2.31 ± 0.33) groups compared with the control group (4.06 ± 0.45; P < 0.001, P < 0.001, respectively). In addition, the scar elevation index of the ADMSC aggregate-ECM group reached the lowest rate 4 weeks in advance. In auditory meatus excisional wounds, the ADMSC aggregate-ECM group had the largest range of normal skin-like structure at 4 weeks. The ADMSC aggregate-ECM and ECM groups secreted increased amounts of growth factors that contributed to skin regeneration at weeks 1 and 2, respectively. CONCLUSIONS ADMSC aggregate-ECM and ECM are effective repair materials for wound healing, especially ADMSC aggregate-ECM. This approach will provide a meaningful experimental basis for mastoid epithelium repair in subsequent clinical trials.
Adipose Tissue ; cytology ; Animals ; Cell Differentiation ; physiology ; Cell Proliferation ; physiology ; Cells, Cultured ; Ear Auricle ; cytology ; Extracellular Matrix ; chemistry ; Flow Cytometry ; Mesenchymal Stem Cell Transplantation ; methods ; Mesenchymal Stem Cells ; cytology ; Microscopy, Electron, Scanning ; Osteogenesis ; physiology ; Rabbits ; Real-Time Polymerase Chain Reaction

At present, it is generally believed that the paracrine effect of stem cells in the repair of myocardial injury is one of the important ways for stem cell therapy. Exosomes are phospholipid bilayer-enclosed nanovesicles that secreted by cells under physiological and pathological conditions. Cargo loaded into exosomes including protein, lipids and nucleic acids can be delivered to recipient cells. Therefore, exosomes are recognized as important mediators for intercellular communication. It has been suggested that exosomes from stem cells (eg. embryonic stem cells, induced pluripotent stem cells, cardiac progenitor cells, mesenchymal stem cells and cardiosphere-derived cells) have protective effects against heart injury. In this review, we summarized recent research progresses on stem cell-derived exosomes in myocardial injury, including the therapeutic effects and mechanism.
Cell Communication ; Exosomes ; physiology ; Heart Injuries ; Humans ; Induced Pluripotent Stem Cells ; cytology ; Mesenchymal Stem Cells ; cytology

The teeth are highly differentiated chewing organs formed by the development of tooth germ tissue located in the jaw and consist of the enamel, dentin, cementum, pulp, and periodontal tissue. Moreover, the teeth have a complicated regulatory mechanism, special histologic origin, diverse structure, and important function in mastication, articulation, and aesthetics. These characteristics, to a certain extent, greatly complicate the research in tooth regeneration. Recently, new ideas for tooth and tissue regeneration have begun to appear with rapid developments in the theories and technologies in tissue engineering. Numerous types of stem cells have been isolated from dental tissue, such as dental pulp stem cells (DPSCs), stem cells isolated from human pulp of exfoliated deciduous teeth (SHED), periodontal ligament stem cells (PDLSCs), stem cells from apical papilla (SCAPs), and dental follicle cells (DFCs). All these cells can regenerate the tissue of tooth. This review outlines the cell types and strategies of stem cell therapy applied in tooth regeneration, in order to provide theoretical basis for clinical treatments.
Adult Stem Cells ; physiology ; Animals ; Cell Differentiation ; Humans ; Stem Cell Transplantation ; Tissue Engineering ; Tooth ; cytology ; growth & development ; physiology ; Wound Healing

ObjectiveTo investigate the protective effect of human urine-derived stem cells (USCs) on erectile function and cavernous structure in rats with cavernous nerve injury (CNI).

METHODSSixty adult male SD rats with normal sexual function were randomly divided into four groups of equal number: sham operation, bilateral CNI (BCNI) model control, phosphate buffered saline (PBS), and USC. The BCNI model was established in the latter three groups of rats by clamping the bilateral cavernous nerves. After modeling, the rats in the PBS and USC groups were treated by intracavernous injection of PBS at 200 μl and USCs at 1×106/200 μl PBS respectively for 28 days. Then, the maximum intracavernous pressure (mICP) and the ratio of mICP to mean arterial pressure (mICP/MAP) of the rats were calculated by electrical stimulation of the major pelvic ganglions, the proportion of nNOS- or NF200-positive nerve fibers in the total area of penile dorsal nerves determined by immunohistochemical staining, the levels of endothelial cell marker eNOS, smooth muscle marker α-SMA and collagen I detected by Western blot, and the smooth muscle to collagen ratio and the cell apoptosis rate in the corpus cavernosum measured by Masson staining and TUNEL, respectively.

RESULTSAfter 28 days of treatment, the rats in the USC group, as compared with those in the PBS and BCNI model control groups, showed significant increases in the mICP (［81 ± 9.9］ vs ［31 ± 8.3］ and ［33 ± 4.2］ mmHg, P <0.05), mICP/MAP ratio (0.72 ± 0.05 vs 0.36 ± 0.03 and 0.35 ± 0.04, P <0.05), the proportions of nNOS-positive nerve fibers (［11.31 ± 4.22］% vs ［6.86 ± 3.08］% and ［7.29 ± 4.84］% , P <0.05) and NF200-positive nerve fibers in the total area of penile dorsal nerves (［27.31 ± 3.12］% vs ［17.38 ± 2.87］% and ［19.49 ± 4.92］%, P <0.05), the eNOS/GAPDH ratio (0.52 ± 0.08 vs 0.31 ± 0.06 and 0.33 ± 0.07, P <0.05), and the α-SMA/GAPDH ratio (1.01 ± 0.09 vs 0.36 ± 0.05 and 0.38 ± 0.04, P <0.05), but a remarkable decrease in the collagen I/GAPDH ratio (0.28 ± 0.06 vs 0.68 ± 0.04 and 0.70 ± 0.10, P <0.05). The ratio of smooth muscle to collagen in the corpus cavernosum was significantly higher in the USC than in the PBS and BCNI model control groups (17.91 ± 2.86 vs 7.70 ± 3.12 and 8.21 ± 3.83, P <0.05) while the rate of cell apoptosis markedly lower in the former than in the latter two (3.31 ± 0.83 vs 9.82 ± 0.76, P <0.01; 3.31 ± 0.83 vs 9.75 ± 0.91, P <0.05).

CONCLUSIONSIntracavernous injection of USCs can protect the erectile function of the rat with cavernous nerve injury by protecting the nerves, improving the endothelial function, alleviating fibrosis and inhibiting cell apoptosis in the cavernous tissue.

Actins ; analysis ; Animals ; Arterial Pressure ; Collagen ; analysis ; Disease Models, Animal ; Erectile Dysfunction ; prevention & control ; Male ; Nitric Oxide Synthase Type I ; analysis ; Nitric Oxide Synthase Type III ; analysis ; Penile Erection ; physiology ; Penis ; innervation ; Pudendal Nerve ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Saline Solution ; administration & dosage ; Stem Cell Transplantation ; methods ; Stem Cells ; Urine ; cytology

OBJECTIVE: To investigate the effect of Piwil2-induced cancer stem-like cell (Piwil2-iCSC)-derived exosomes on the proliferation,migration and invasion of human umbilical cord blood-derived mesenchymal stem cells (hucMSCs). METHODS: Piwil2-iCSC-derived exosomes were isolated by ultracentrifugation and identified using transmission electron microscopy,nanoparticle tracking analysis and Western blotting.Exosome uptake assay was used to identify the pathway that Piwil2-iCSCderived exosomes utilized.HucMSCs were divided into control group,PBS intervention group and exosome intervention group,and CCK-8 assay,wound healing assay,Transwell assay,Western blotting and cell karyotype analysis were used to observe the proliferation,migration,invasion,expression levels of MMP2 and MMP9 proteins,and chromosome structure of hucMSCs. RESULTS: The diameter of Piwil2-iCSC-derived exosomes ranged from 50 nm to 100 nm,and most of them were oval or spherical capsules rich in CD9,CD63 and Piwil2 proteins.Exosomal uptake assay showed that the exosomes executed theirs functions after entering the cells.Compared with the control cells and PBS-treated cells,hucMSCs treated with the exosomes showed significantly increased number of proliferating cells (<0.05) with accelerated healing rate (<0.05 at 24 h;<0.01 at 48 h),increased invasive cells (<0.01),enhanced protein expressions of MMP2(<0.05 PBS group;<0.01 control group) and MMP9(<0.05),but their karyotype still remained 46XY without any abnormalities. CONCLUSIONS Piwil2-iCSC-derived exosomes can promote the proliferation,migration and invasion but does not cause cancer-like heterogeneity changes in hucMSCs.
Argonaute Proteins ; Cell Movement ; physiology ; Cell Proliferation ; physiology ; Exosomes ; physiology ; Fetal Blood ; cytology ; Humans ; Karyotyping ; Mesenchymal Stem Cells ; pathology ; Neoplasm Invasiveness ; Neoplastic Stem Cells ; Umbilical Cord ; Wound Healing

Axon regeneration is crucial for recovery from neurological diseases. Numerous studies have identified several genes, microRNAs (miRNAs), and transcription factors (TFs) that influence axon regeneration. However, the regulatory networks involved have not been fully elucidated. In the present study, we analyzed a regulatory network of 51 miRNAs, 27 TFs, and 59 target genes, which is involved in axon regeneration. We identified 359 pairs of feed-forward loops (FFLs), seven important genes (Nap1l1, Arhgef12, Sema6d, Akt3, Trim2, Rab11fip2, and Rps6ka3), six important miRNAs (hsa-miR-204-5p, hsa-miR-124-3p, hsa-miR-26a-5p, hsa-miR-16-5p, hsa-miR-17-5p, and hsa-miR-15b-5p), and eight important TFs (Smada2, Fli1, Wt1, Sp6, Sp3, Smad4, Smad5, and Creb1), which appear to play an important role in axon regeneration. Functional enrichment analysis revealed that axon-associated genes are involved mainly in the regulation of cellular component organization, axonogenesis, and cell morphogenesis during neuronal differentiation. However, these findings need to be validated by further studies.
Axons/physiology* ; Cell Differentiation ; Cluster Analysis ; Embryonic Stem Cells/cytology* ; Gene Expression Profiling ; Gene Expression Regulation ; Gene Regulatory Networks ; Humans ; MicroRNAs/metabolism* ; Nerve Regeneration ; Neurons/metabolism* ; Software ; Transcription Factors/metabolism*