DPSC-Derived Extracellular Vesicles Promote Rat Jawbone Regeneration.

Repair and functional reconstruction of large jawbone defects remain one of the challenges in the field of head and neck surgery. The recent progress in tissue engineering technologies and stem cell biology has significantly promoted the development of regenerative reconstruction of jawbone defects. The multiple trophic activities of extracellular vesicles (EVs) produced by mesenchymal stem cells (MSCs) may play a critical role in their therapeutic effects. Accumulating evidence has shown the promise of dental pulp stem cells (DPSCs) in bone regeneration, but less is known about the regenerative effects of DPSC-EVs on jawbone defects. The purpose of this study is to explore the osteogenic effects of DPSC-EVs on jawbone marrow-derived MSCs (JB-MSCs) in vitro and their osteoinductive effects in a mandibular bone defect model in rats. Our results showed that JB-MSCs could efficiently uptake DPSC-EVs, which in turn significantly promoted the expression of osteogenic genes, such as runt-related transcription factor 2 (RUNX2), alkaline phosphatase (ALP), and osteocalcin (OCN), as well as the osteogenic differentiation capability of JB-MSCs. Meanwhile, we found that the pro-osteogenic effect in vitro induced by DPSC-EVs was comparable to that induced by BMP-2 (bone morphogenetic protein 2), currently the only Food and Drug Administration-approved osteoinductive growth factor. In vivo, animals that were locally treated with DPSC-EVs laden with a commercially available collagen membrane exhibited a relatively fast wound closure and increased new bone density at the mandible defects. Our results provide evidence for the osteogenic and osteoinductive effects of DPSC-EVs on jawbone regeneration. Due to the accessibility, rapid proliferation, and osteogenic propensity of DPSCs, DPSC-EVs may represent a safe cell-free therapeutic approach for craniofacial bone regeneration.

Extracellular Vesicles of GMSCs Alleviate Aging-Related Cell Senescence.

Healthy aging is a complex biological process with progressive accumulation of senescent cells characterized by stable cell cycle arrest, resulting in impaired homeostasis, regenerative potential, and gradual functional decline in multiple tissues and organs, whereby the aberrant activation of mammalian target of rapamycin (mTOR) signaling networks plays a central role. Herein, we explored the effects of extracellular vesicles (EVs) released by gingiva-derived mesenchymal stem cells (GMSC-EVs) on oxidative stress-induced cellular senescence in human endothelial cells and skin fibroblasts and their antiaging potentials. Our results showed that GMSC-EVs robustly abrogated oxidative stress-induced upregulation in the expression of cellular senescence-related genes, such as ß-galactosidase, p21, p53, and γH2AX, and mTOR/pS6 signaling pathway, in human umbilical vein endothelial cells (HUVECs) and skin fibroblasts. Meanwhile, GMSC-EVs restored oxidative stress-induced impairment in proliferation and tube formation by HUVECs. Systemic administration of GMSC-EVs attenuated aging-associated elevation in the expression levels of p21, mTOR/pS6, interleukin 6, and tumor necrosis factor α in skin and heart tissues of aged mice. These findings suggest that GMSC-EVs could be a potential alternative source of cell-free product for attenuation of aging-related skin and vascular dysfunctions due to their potent inhibitory effects on oxidative stress-induced cellular senescence in endothelial cells and skin fibroblasts.

Effect of lncRNA MALAT1 on rats with myocardial infarction through regulating ERK/MAPK signaling pathway.

OBJECTIVE: To explore the effect of the long non-coding ribonucleic acid (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) on rats with myocardial infarction (MI) by regulating the extracellular signal-regulated kinase (ERK)/mitogen-activated protein kinase (MAPK) signaling pathway. MATERIALS AND METHODS: The Sprague- Dawley (SD) rat model of MI was established, and lncRNA MALAT1 was overexpressed using pcDNA-MALAT1 plasmids (MALAT1 group, n=10) and silenced using RNA interference technique (siMALAT1 group, n=10). The Sham group (n=10) was also set up. The transfection efficiency of lncRNA MALAT1 in rats was detected via Reverse Transcription-Polymerase Chain Reaction (RT-PCR). 2 weeks after the successful modeling, the cardiac function indexes were measured through magnetic resonance imaging (MRI) and echocardiography (ECG). The myocardial tissue injury was observed via hematoxylin-eosin (HE) staining, and the apoptosis of myocardial tissues was detected via terminal deoxynucleotidyl transferase-mediated dUTP nick end labeling (TUNEL) assay. Moreover, the levels of the serum inflammatory factors were detected via enzyme-linked immunosorbent assay (ELISA), the messenger RNA (mRNA) expressions of Collagen I and III, the apoptosis, the and pathway genes were detected via RT-PCR. The expressions of ERK/MAPK pathway-related proteins in myocardial tissues were detected via Western blotting. RESULTS: The expression of lncRNA MALAT1 was remarkably increased in the MALAT1 group but evidently declined in the siMALAT1 group (p<0.05), indicating the successful transfection. The fractional shortening (FS, %) and ejection fraction (EF, %) were significantly restored in siMALAT1 group (p<0.05), suggesting that the silence of MALAT1 can improve the cardiac function after acute MI. The results of the HE staining and TUNEL assay manifested that siMALAT1 group had milder myocardial injury and decreased apoptosis compared with MALAT1 group. In the MALAT1 group, the mRNA expressions of Collagen I and III, Caspase3, ERK2, and MAPK were remarkably increased (p<0.05), while the mRNA expression of Bcl-2 was remarkably decreased (p<0.05). The above expressions had the opposite trends in siMALAT1 group. Besides, the protein expressions of ERK2 and MAPK in MALAT1 group were significantly increased (p<0.05). CONCLUSIONS: The downregulation of lncRNA MALAT1 can significantly improve the cardiac function after MI in SD rats mainly by inhibiting the ERK/MAPK pathway.

Oral Rehabilitation of Patients Sustaining Orofacial Injuries: The UPenn Initiative.

Tissue injuries in the oral and maxillofacial structures secondary to trauma, warfare, ablative cancer, and benign tumor surgery result in significant losses of speech, masticatory and swallowing functions, aesthetic deformities, and overall psychological stressors and compromise. Optimal oral rehabilitation remains a formidable challenge and an unmet clinical need due to the influence of multiple factors related to the physiologic limitations of tissue repair, the lack of site and function-specific donor tissues and constructs, and an integrated team of multidisciplinary professionals. The advancements in stem cell biology, biomaterial science, and tissue engineering technologies, particularly the 3-dimensional bioprinting technology, together with digital imaging and computer-aided design and manufacturing technologies, have paved the path for personalized/precision regenerative medicine. At the University of Pennsylvania, we have launched the initiative to integrate multidisciplinary health professionals and translational/clinical scientists in medicine, dentistry, stem cell biology, tissue engineering, and regenerative medicine to develop a comprehensive, patient-centered approach for precision and personalized reconstruction, as well as oral rehabilitation of patients sustaining orofacial tissue injuries and defects, especially oral cancer patients.

Induction of Salivary Gland-Like Cells from Dental Follicle Epithelial Cells.

The dental follicle (DF), most often associated with unerupted teeth, is a condensation of ectomesenchymal cells that surrounds the tooth germ in early stages of tooth development. In the present study, we aim to isolate epithelial stem-like cells from the human DF and explore their potential differentiation into salivary gland (SG) cells. We demonstrated the expression of stem cell-related genes in the epithelial components of human DF tissues, and these epithelial progenitor cells could be isolated and ex vivo expanded in a reproducible manner. The human DF-derived epithelial cells possessed clonogenic and sphere-forming capabilities, as well as expressed a panel of epithelial stem cell-related genes, thus conferring stem cell properties (hDF-EpiSCs). When cultured under in vitro 3-dimensional induction conditions, hDF-EpiSCs were capable to differentiate into SG acinar and duct cells. Furthermore, transplantation of hDF-EpiSC-loaded native de-cellularized rat parotid gland scaffolds into the renal capsule of nude mice led to the differentiation of transplanted hDF-EpiSCs into salivary gland-like cells. These findings suggest that hDF-EpiSCs might be a promising source of epithelial stem cells for the development of stem cell-based therapy or bioengineering SG tissues to repair/regenerate SG dysfunction.

Loss of Notch3 Signaling Enhances Osteogenesis of Mesenchymal Stem Cells from Mandibular Torus.

Mandibular torus (MT) is a common intraoral osseous outgrowth located on the lingual surface of the mandible. Histologic features include hyperplastic bone consisting of mature cortical and trabecular bone. Some theories on the etiology of MT have been postulated, such as genetic factors, masticatory hyperfunction, trauma, and continued growth, but the underlying mechanism remains largely unknown. In this study, we investigated the potential role of mesenchymal stem cells (MSCs) derived from human MT in the pathogenesis of bone outgrowth. We demonstrated that MT harbored a distinct subpopulation of MSCs, with enhanced osteogenic and decreased adipogenic differentiation capacities, as compared with their counterparts from normal jaw bone. The increased osteogenic differentiation of mandibular torus MSCs was associated with the suppression of Notch3 signaling and its downstream target genes, Jag1 and Hey1, and a reciprocal increase in the transcriptional activation of ATF4 and NFATc1 genes. Targeted knockdown of Notch3 expression by transient siRNA transfection promoted the expression of osteogenic transcription factors in normal jaw bone MSCs. Our data suggest that the loss of Notch3 signaling may contribute partly to bone outgrowth in MT, as mediated by enhanced MSC-driven osteogenic differentiation in the jaw bone.

PHACTR4 regulates proliferation, migration and invasion of human hepatocellular carcinoma by inhibiting IL-6/Stat3 pathway.

OBJECTIVE: Phosphatase and actin regulator 4 (PHACTR4) is one member of the largely uncharacterized PHACTR family of protein phosphatase 1 (PP1)-and actin-binding proteins. PHACTR4 is significantly deleted or mutant in many tumor subtypes, such as breast, colorectal, lung, neural, ovarian, and renal cancers. However, the role of PHACTR4 in human hepatocellular carcinoma (HCC) is completely unknown. MATERIALS AND METHODS: Ten paired HCC tissues and adjacent non-cancerous tissues were used to detect the expression PHACTR4. Real-time PCR was used to detect the mRNA level of PHACTR4 in clinic samples. The protein level of PHACTR4 was determined by Western blot. Retrovirus-based gene transduction was used to generate Flag-tagged PHACTR4 HepG2 stable cell line. BrdU assay was used to determine the cell growth of HepG2 cells. The cell cycle distribution was detected by flow cytometry assay. In vitro scratch wounding and Matrigel invasion assays were used to test the migration and invasion ability of HepG2 cells. RESULTS: The expression of PHACTR4 was noticeably decreased in clinical HCC tissues, compared to the non-tumoral tissues. Overexpression of PHACTR4 inhibited HCC cells proliferation, colony formation, migration and invasion, and resulted in significant cycle arrest. PHACTR4 attenuated both constitutive and IL-6-induced phosphorylation of signal transducer and activator of transcription 3 (Stat3), and inhibited Stat3 downstream genes expression. CONCLUSIONS: Overall, our results suggest that PHACTR4 is a tumor suppressor in HCC by inhibiting IL-6/ Stat3 pathway.

DPSCs from Inflamed Pulp Modulate Macrophage Function via the TNF-α/IDO Axis.

Human dental pulp stem cells (DPSCs) can be isolated from inflamed pulp derived from carious teeth with symptomatic irreversible pulpitis (I-DPSCs), which possess stemness and multidifferentiation potentials similar to DPSCs from healthy pulp. Since macrophages-essential cell players of the pulpal innate immunity-can regulate pulpal inflammation and repair, the authors investigated the immunomodulatory effects of DPSCs/I-DPSCs on macrophage functions and their underlying mechanisms. Similar to DPSCs, I-DPSCs were capable of colony-forming efficiency and adipogenic and osteo/dentinogenic differentiation under in vitro induction conditions. I-DPSCs also expressed a similar phenotypic profile of mesenchymal stem cell markers, except a relatively higher level of CD146 as compared with DPSCs. Coculture of DPSCs or I-DPSCs with differentiated THP-1 cells, the human monocyte cell line, markedly suppressed tumor necrosis factor α (TNF-α) secretion in response to stimulation with lipopolysaccharides (LPS) and/or nigericin. However, unlike TNF-α, the secreted level of interleukin 1ß was not affected by coculture with DPSCs or I-DPSCs. Furthermore, DPSC/I-DPSC-mediated inhibition of TNF-α secretion by macrophages was abolished by pretreatment with 1-methyl-D-tryptophan, a specific inhibitor of indoleamine-pyrrole 2,3-dioxygenase (IDO), but not by NSC-398, a specific inhibitor of COX-2, suggesting IDO as a mediator. Interestingly, IDO expression was significantly augmented in macrophages and mesenchymal stromal cells in inflamed human pulp tissues. Collectively, these findings show that I-DPSCs, similar to DPSCs, possess stem cell properties and suppress macrophage functions via the TNF-α/IDO axis, thereby providing a physiologically relevant context for their innate immunomodulatory activity in the dental pulp and their capability for pulp repair.

Visible red and infrared light alters gene expression in human marrow stromal fibroblast cells.

OBJECTIVES: This study tested whether or not gene expression in human marrow stromal fibroblast (MSF) cells depends on light wavelength and energy density. MATERIALS AND METHODS: Primary cultures of isolated human bone marrow stem cells (hBMSC) were exposed to visible red (VR, 633 nm) and infrared (IR, 830 nm) radiation wavelengths from a light emitting diode (LED) over a range of energy densities (0.5, 1.0, 1.5, and 2.0 Joules/cm2) Cultured cells were assayed for cell proliferation, osteogenic potential, adipogenesis, mRNA and protein content. mRNA was analyzed by microarray and compared among different wavelengths and energy densities. Mesenchymal and epithelial cell responses were compared to determine whether responses were cell type specific. Protein array analysis was used to further analyze key pathways identified by microarrays. RESULT: Different wavelengths and energy densities produced unique sets of genes identified by microarray analysis. Pathway analysis pointed to TGF-beta 1 in the visible red and Akt 1 in the infrared wavelengths as key pathways to study. TGF-beta protein arrays suggested switching from canonical to non-canonical TGF-beta pathways with increases to longer IR wavelengths. Microarrays suggest RANKL and MMP 10 followed IR energy density dose-response curves. Epithelial and mesenchymal cells respond differently to stimulation by light suggesting cell type-specific response is possible. CONCLUSIONS: These studies demonstrate differential gene expression with different wavelengths, energy densities and cell types. These differences in gene expression have the potential to be exploited for therapeutic purposes and can help explain contradictory results in the literature when wavelengths, energy densities and cell types differ.

Peptides-staple method development and its application in cancer therapy.

α-Helixes are important structural motifs of protein three dimension structures and are largely involved in protein- protein interactions. This review covers the recent advances of the peptide stabilizing methodologies and introduces their applications in cancer research.

Human oral mucosa and gingiva: a unique reservoir for mesenchymal stem cells.

Mesenchymal stem cells (MSCs) represent a heterogeneous population of progenitor cells with self-renewal and multipotent differentiation potential. Aside from their regenerative role, extensive in vitro and in vivo studies have demonstrated that MSCs are capable of potent immunomodulatory effects on a variety of innate and adaptive immune cells. In this article, we will review recent experimental studies on the characterization of a unique population of MSCs derived from human oral mucosa and gingiva, especially their immunomodulatory and anti-inflammatory functions and their application in the treatment of several in vivo models of inflammatory diseases. The ease of isolation, accessible tissue source, and rapid ex vivo expansion, with maintenance of stable stem-cell-like phenotypes, render oral mucosa- and gingiva-derived MSCs a promising alternative cell source for MSC-based therapies.

Valsartan attenuated oxidative stress, decreased MCP-1 and TGF-ß1 expression in glomerular mesangial and epithelial cells induced by high-glucose levels.

Our previous studies revealed that valsartan, an angiotensin II type I receptor blocker, exhibited renoprotective effects through decreasing urine protein excretion levels due to improving glomerular permeability in rats with diabetic nephropathy (DN). In this study, we sought to investigate the underlying mechanisms in perspectives of oxidative stress, transforming growth factor beta-1 (TGF-ß1) and monocyte chemoattractant protein-1 (MCP-1) expressions in glomerular mesangial cells (GMCs) and glomerular epithelial cells (GECs) since their roles are well-established in the development and progression of DN. High-glucose levels significantly increased oxidative stress in GMCs and GECs, as evidenced by enhanced generation of reactive reactive oxygen species (ROS), reduced levels of glutathione (GSH) and antioxidant enzyme superoxide dismutase (SOD), and increased production of malondialdehyde (MDA). Treatment with valsartan significantly restored the levels of those oxidative stress relevant molecules. Furthermore, valsartan obviously diminished the expression of proinflammatory cytokine MCP-1 in GMCs and GECs induced by high-glucose levels both at mRNA and protein levels, as determined by real-time PCR, immunocytochemistry, western blotting, and ELISA. In addition, the increased expressions of TGF-ß1 mRNA and protein induced by high-glucose level were also abrogated by valsartan treatment in GMCs, as evaluated by real-time PCR and ELISA. These results suggest that the renoprotective effects of valsartan may be related to its potential in decreasing oxidative stress and the expressions of MCP-1 and TGF-ß1 in GMCs and GECs.

Clinical outcome of esophageal cancer after distal gastrectomy: a prospective study.

OBJECTIVES: To investigate the clinicopathological characteristics and surgical outcome of thoracic esophageal cancer after gastrectomy, and compare with those without gastrectomy. RESULT: Among 1411 esophageal cancer patients who underwent curative operation, 48 (3.4%) had a history of distal gastrectomy, the interval between gastrectomy and esophagectomy was significantly shorter in those gastrectomized for gastric cancer (11.5+/-8.2 years) than for peptic ulcer (24.6+/-9.2 years), the proportion of lower-third tumors and multiple esophageal cancer was significantly higher compared with that of the non-gastrectomized patients (50.0% vs. 33.1%, P=0.033; 14.6% vs. 5.3%, P=0.006, respectively), this increase was more pronounced after Billroth I vs. Billroth II gastrectomy. Pathologically, the esophageal cancers after gastrectomy frequently showed expansive growth pattern (39.6%), while those without gastrectomy dominantly showed infiltrative growth pattern (40.3%) (P=0.012), the coexisting lesions showed well-differentiated squamous cell carcinoma confined within the superficial mucosal layer. Compared with the non-gastrectomized patients, the operative time (311.2+/-86.0 vs. 263.7+/-84.9 min; P<0.001) was longer and blood loss (4.38+/-1.33 vs. 3.57+/-1.82 IU; P=0.003) was more, the postoperative hospital stay was significantly longer in gastrectomized patients (median 69 days vs. 40 days, P<0.001). The overall 1, 3, 5, 10-year survival of gastrectomized and non-gastrectomized patients were similar, and their cause-specific 5-year survival were 65% vs. 44% (P=0.992). CONCLUSIONS: Gastrectomy (especially the Billroth I) precipitated subsequent chronic gastroesophageal reflux and induced the development of squamous dysplasia and carcinoma at multiple locations in the esophagus. Surgical treatment of the gastrectomized patients should be considered as a reliable therapeutic modality because of favorable prognoses.

Effect of 17beta-oestradiol and ginsenoside on osteoporosis in ovariectomised rats.

To study the anti-osteoporosis effects and mechanism of action of oestradiol (E2) and ginsenoside (tR), we measured the bone mineral densities (BMD) of lumbar vertebra and tibia and analysed the tibia histological morphological data, as well observed the activity and the number of osteoblasts and the activity of alkaline phosphatase (ALP) and the concentration of cAMP. Results showed that E2 (400 microg kg- 1 week- 1) and tR (10, 20, 30 mg kg- 1 day- 1) were able to countervail the decreasing in BMDs of lumbar vertebra and tibia induced by OVX in rats (P<0.05); E2 (0.1 micromol l- 1) and ginsenoside Rg1 (1 micromol l- 1 and 10 micromol l- 1) were able to increase the number of osteoblasts, the activity of ALP and the concentration of intercellular cAMP in cultured osteoblast cells. The present findings suggest that E2 and tR have an anti-osteoporosis effect in ovariectomised rats.

Verapamil, cyproheptadine, and anisodamine antagonized [Ca2+]i elevation induced by TNFalpha in a single endothelial cell.

AIM: To study the effect of tumor necrosis factor alpha (TNFalpha) on intracellular free Ca2+ concentration ([Ca2+]i) and the effects of verapamil (Ver), cyproheptadine (Cyp), and anisodamine (Ani) on TNFalpha-induced [Ca2+]i changes in single endothelial cell, and to explore the mechanisms of TNFalpha-mediated shock and antishock actions of Cyp and Ani. METHODS: Human umbilical vein endothelial cell strains (ECV304) were seeded in 35-mm tissue culture dish with 2 mL DMEM culture medium. The cultured cells were loaded by Fluo-3/AM. The spatial distribution and the dynamic changes of [Ca2+]i in single endothelial cell were determined by laser scanning confocal microscopy. RESULTS: After stimulation with TNFalpha, [Ca2+]i in single endothelial cell rapidly increased in a concentration-dependent manner and arrived at the peak value within 60 s, afterwards, decreased and kept above the basal level. The confocal scanning image showed that [Ca2+]i elevation was more obvious in nuclear than in cytoplasma and decreased slowly. Ver (1, 2 micromol/L), Cyp (30, 60 micromol/L), and Ani (20, 40 micromol/L) markedly inhibited TNFalpha 1.2 nmol/L-induced [Ca2+]i elevation. CONCLUSION: TNFalpha markedly induces elevation of [Ca2+]i in a single endothelial cell, it may be an important mechanism of TNFalpha-induced shock and tissue injury. That Cyp and Ani obviously suppress TNFalpha-induced [Ca2+]i elevation probably is one of the mechanisms of their antishock effects.

[Genetic diagnosis of phenylketonuria. III. Mutations of phenylalanine hydroxylase gene in Orientals].

Phenylketonuria (PKU) is an autosomal recessive disorder caused by lesions in the phenylalanine hydroxylase (PAH) gene. The recent studies on PAH mutations show the genetic drift of PKU alleles among some Oriental populations. Therefore, we searched for PKU mutations among Japanese, Chinese and Taiwanese. Direct sequencing was conducted on DNA fragments amplified by the polymerase chain reaction, using solid-phase technology involving the biotin-streptavidin system. Two new mutations (R241C and G247V) and two of the known mutant alleles (Y204C and R243Q) were found in two Taiwanese and two Chinese PKU patients, and three known mutations (R111X, Y204C and R413P) were recognized in three Japanese; two new mutations were identified in exon 7 of the PAH gene at codon 241 and codon 247, where the single base changes from C to T and from G to T substituted cysteine for arginine and valine for glycine, respectively. Further all the PAH mutations detected are common in Oriental populations as they have been thus far unreported among Caucasians. From these data as well as the clinical phenotype of the patients, we suggest that the R241C and G247V substitutions may interfere with proper enzyme function, although we have not yet performed functional studies. More detailed studies would be needed to clarify the regional distribution of mutant chromosomes in Oriental populations and other unidentified mutations.

Significance of the straight-leg-raising test in the diagnosis and clinical evaluation of lower lumbar intervertebral-disc protrusion.

The cases of 113 patients who had protrusion of a lumbar intervertebral disc were analyzed to determine the relationship between the findings at operation and the location of the pain that resulted from the straight-leg-raising test. The study showed a close relationship between the location of the pain and the position of the protrusion of the disc. The degree of limitation of straight-leg raising was also found to have a direct relationship to the size and position of the protrusion and to its relationship to the spinal nerve. The protrusions were classified into three types according to position in relation to the dura mater and to the pattern of pain that was induced by passive straight-leg raising. On straight-leg raising, central protrusions tended to cause pain in the back, lateral protrusions caused pain in the lower extremity, and intermediate protrusions caused both. On this basis, the distribution of pain on straight-leg raising allowed an accurate prediction of the location of the lesion in 100 (88.5 per cent) of the 113 patients.