Sphere-Derived Multipotent Progenitor Cells Obtained From Human Oral Mucosa Are Enriched in Neural Crest Cells

: Although isolation of oral mucosal stromal stem cells has been previously reported, complex isolation methods are not suitable for clinical application. The neurosphere culture technique is a convenient method for the isolation of neural stem cells and neural crest stem cells (NCSCs); neurosphere generation is a phenotype of NCSCs. However, the molecular details underlying the isolation and characterization of human oral mucosa stromal cells (OMSCs) by neurosphere culture are not understood. The purpose of the present study was to isolate NCSCs from oral mucosa using the neurosphere technique and to establish effective in vivo bone tissue regeneration methods. Human OMSCs were isolated from excised human oral mucosa; these cells formed spheres in neurosphere culture conditions. Oral mucosa sphere-forming cells (OMSFCs) were characterized by biological analyses of stem cells. Additionally, composites of OMSFCs and multiporous polylactic acid scaffolds were implanted subcutaneously into immunocompromised mice. OMSFCs had the capacity for self-renewal and expressed neural crest-related markers (e.g., nestin, CD44, slug, snail, and MSX1). Furthermore, upregulated expression of neural crest-related genes (EDNRA, Hes1, and Sox9) was observed in OMSFCs, which are thought to contain an enriched population of neural crest-derived cells. The expression pattern of α2-integrin (CD49b) in OMSFCs also differed from that in OMSCs. Finally, OMSFCs were capable of differentiating into neural crest lineages in vitro and generating ectopic bone tissues even in the subcutaneous region. The results of the present study suggest that OMSFCs are an ideal source of cells for the neural crest lineage and hard tissue regeneration.

SIGNIFICANCE

The sphere culture technique is a convenient method for isolating stem cells. However, the isolation and characterization of human oral mucosa stromal cells (OMSCs) using the sphere culture system are not fully understood. The present study describes the isolation of neural crest progenitor cells from oral mucosa using this system. Human OMSCs form spheres that exhibit self-renewal capabilities and multipotency, and are enriched with neural crest-derived cells. These oral mucosa sphere-forming cells can generate ectopic bone tissue in vivo. Therefore, the results of the present study show that the sphere culture system can be applied, without the need for complex isolation techniques, to produce multipotent spheres with the properties of neural crest stem cells. Furthermore, a convenient strategy is demonstrated for the isolation and culture of human OMSCs that could have clinical applications.

Volumetric structured illumination microscopy enabled by a tunable-focus lens

We present a mechanical-scan-free method for volumetric imaging of biological tissue. The optical sectioning is provided by structured illumination, and the depth of the imaging plane is varied using an electrically tunable-focus lens. We characterize and evaluate the ability of this axial-scanning mechanism in structured illumination microscopy and demonstrate its ability to perform subcellular resolution imaging in oral mucosa ex vivo. The proposed mechanism can potentially convert any wide-field microscope to a 3D-imaging platform without the need for mechanical scanning of imaging optics and/or sample.

Spectroscopic microscopy can quantify the statistics of subdiffractional refractive-index fluctuations in media with random rough surfaces

We previously established that spectroscopic microscopy can quantify subdiffraction-scale refractive index (RI) fluctuations in a label-free dielectric medium with a smooth surface. However, to study more realistic samples, such as biological cells, the effect of rough surface should be considered. In this Letter, we first report an analytical theory to synthesize microscopic images of a rough surface, validate this theory by finite-difference time-domain (FDTD) solutions of Maxwell's equations, and characterize the spectral properties of light reflected from a rough surface. Then, we report a technique to quantify the RI fluctuations beneath a rough surface and demonstrate its efficacy on FDTD-synthesized spectroscopic microscopy images, as well as experimental data obtained from biological cells.

In vivo determination of aluminum, cobalt, chromium, copper, nickel, titanium and vanadium in oral mucosa cells from orthodontic patients with mini-implants by Inductively coupled plasma-mass spectrometry (ICP-MS)

Miniscrews are used as orthodontic anchorage devices in the dentistry clinical practice but the in vivo metallic release from these structures has been not previously investigated. The aim of this study was to determine the content of Al, Co, Cr, Cu, Ni, Ti and V in oral mucosa cells of control subjects, patients under orthodontic treatment and with both, orthodontic treatment and miniscrew, in order to know the contribution of these mini-implants to the total metallic content. ICP-MS measurements revealed the following ascending order: Cr<Ni<Ti<Cu<Al, and Co and V were practically undetected. Significant differences in comparison to the control group were found for Cu in the orthodontic group, and for Ni in both, orthodontic and orthodontic+miniscrew groups. Potential correlations among metallic elements and with some clinical factors were also explored. These findings suggest that miniscrews do not increase significantly the metal release.

Comparative Assessment of Oral Mesenchymal Stem Cells Isolated from Healthy and Diseased Tissues

The aim of the present study was to isolate human mesenchymal stem cells (MSCs) from palatal connective and periodontal granulation tissues and to comparatively evaluate their properties. MSCs were isolated using the explant culture method. Adherence to plastic, specific antigen makeup, multipotent differentiation potential, functionality, and ultrastructural characteristics were investigated. The frequency of colony-forming unit fibroblasts for palatal-derived mesenchymal stem cells (pMSCs) was significantly higher than that of granulation tissue-derived mesenchymal stem cells (gtMSCs). A significantly higher population doubling time and lower migration potential were recorded for gtMSCs than for pMSCs. Both cell lines were positive for CD105, CD73, CD90, CD44, and CD49f, and negative for CD34, CD45, and HLA-DR, but the level of expression was different. MSCs from both sources were relatively uniform in their ultrastructure. Generally, both cell lines possessed a large, irregular-shaped euchromatic nucleus, and cytoplasm rich in mitochondria, lysosomes, and endoplasmic reticulum. The periphery of the plasma membrane displayed many small filopodia. MSCs from both cell lines were successfully differentiated into osteogenic, adiopogenic, and chondrogenic lineages. Both healthy and diseased tissues may be considered as valuable sources of MSCs for regenerative medicine owing to the high acceptance and fewer complications during harvesting.

Giant Panda (Ailuropoda melanoleuca) Buccal Mucosa Tissue as a Source of Multipotent Progenitor Cells

Since the first mammal was cloned, the idea of using this technique to help endangered species has aroused considerable interest. However, several issues limit this possibility, including the relatively low success rate at every stage of the cloning process, and the dearth of usable tissues from these rare animals. iPS cells have been produced from cells from a number of rare mammalian species and this is the method of choice for strategies to improve cloning efficiency and create new gametes by directed differentiation. Nevertheless information about other stem cell/progenitor capabilities of cells from endangered species could prove important for future conservation approaches and adds to the knowledge base about cellular material that can be extremely limited. Multipotent progenitor cells, termed skin-derived precursor (SKP) cells, can be isolated directly from mammalian skin dermis, and human cheek tissue has also been shown to be a good source of SKP-like cells. Recently we showed that structures identical to SKPs termed m-SKPs could be obtained from monolayer/ two dimensional (2D) skin fibroblast cultures. Here we aimed to isolate m-SKPs from cultured cells of three endangered species; giant panda (Ailuropoda melanoleuca); red panda (Ailurus fulgens); and Asiatic lion (Panthera leo persica). m-SKP-like spheres were formed from the giant panda buccal mucosa fibroblasts; whereas dermal fibroblast (DF) cells cultured from abdominal skin of the other two species were unable to generate spheres. Under specific differentiation culture conditions giant panda spheres expressed neural, Schwann, adipogenic and osteogenic cell markers. Furthermore, these buccal mucosa derived spheres were shown to maintain expression of SKP markers: nestin, versican, fibronectin, and P75 and switch on expression of the stem cell marker ABCG2. These results demonstrate that giant panda cheek skin can be a useful source of m-SKP multipotent progenitors. At present lack of sample numbers means that we can only postulate why we were unable to obtain m-SKPs from the lion and red panda cultures. However the giant panda observations point to the value of archiving cells from rare species, and the possibilities for later progenitor cell derivation.

Oral Mucosal Lamina Propria-Progenitor Cells Exert Antibacterial Properties via the Secretion of Osteoprotegerin and Haptoglobin

The oral cavity possesses a diverse microflora, yet recurrent infections within healthy individuals are rare. Wound healing within the buccal mucosa is preferential, potentially because of the presence of oral mucosal lamina propria-progenitor cells (OMLP-PCs). In addition to their multipotency, OMLP-PCs demonstrate potent immunosuppressive properties. The present study investigated whether OMLP-PCs possess antibacterial properties, directly interacting with microorganisms and contributing to the maintenance of a balanced oral microflora. Gram-positive and -negative bacteria were cocultured with OMLP-PCs, buccal mucosal fibroblasts, or their respective conditioned media (CM). Bacterial growth was significantly inhibited when cocultured with OMLP-PCs or their CM. No antibacterial activity was apparent within the fibroblasts. Analysis of the OMLP-PC CM indicated constitutive secretion of osteoprotegerin (OPG) and haptoglobin (Hp). Exposure of the bacteria to OPG or Hp demonstrated their differential antibacterial properties, with neutralization/blocking studies confirming that the growth of Gram-positive bacteria was partially restored by neutralizing OPG within OMLP-PC CM; blocking Hp restored the growth of Gram-negative bacteria. The present study demonstrates, for the first time, the broad-spectrum antibacterial properties of OMLP-PCs. We report the direct and constitutive antibacterial nature of OMLP-PCs, with retention of this effect within the CM suggesting a role for soluble factors such as OPG and Hp. Knowledge of the immunomodulatory and antibacterial properties of these cells could potentially be exploited in the development of novel cell- or soluble factor-based therapeutics for the treatment of infectious diseases such as pneumonia or ailments such as chronic nonhealing wounds.

SIGNIFICANCE

Oral mucosal lamina propria-progenitor cells (OMLP-PCs) are a cell source with known immunomodulatory properties. The present report demonstrates the novel finding that OMLP-PCs possess potent antibacterial properties, halting the growth of Gram-positive and -negative bacteria through the secretion of soluble factors. OMLP-PCs constitutively secrete osteoprotegerin (OPG) and haptoglobin (Hp) at levels high enough to exert antibacterial action. OPG, a glycoprotein not previously known to be antibacterial, can suppress Gram-positive bacterial growth. Hp is only active against Gram-negative microorganisms. These findings indicate that OMLP-PCs could offer great potential in the development of novel cell- or soluble factor-based therapies for the treatment of infectious illness, such as bacterial pneumonia, through systemic infusion and of chronic wounds through local administration.

Brief Report: Cryopyrin-Associated Periodic Syndrome Caused by a Myeloid-Restricted Somatic NLRP3 Mutation

OBJECTIVE

To identify the cause of disease in an adult patient presenting with recent-onset fevers, chills, urticaria, fatigue, and profound myalgia, who was found to be negative for cryopyrin-associated periodic syndrome (CAPS) NLRP3 mutations by conventional Sanger DNA sequencing.

METHODS

We performed whole-exome sequencing and targeted deep sequencing using DNA from the patient's whole blood to identify a possible NLRP3 somatic mutation. We then screened for this mutation in subcloned NLRP3 amplicons from fibroblasts, buccal cells, granulocytes, negatively selected monocytes, and T and B lymphocytes and further confirmed the somatic mutation by targeted sequencing of exon 3.

RESULTS

We identified a previously reported CAPS-associated mutation, p.Tyr570Cys, with a mutant allele frequency of 15% based on exome data. Targeted sequencing and subcloning of NLRP3 amplicons confirmed the presence of the somatic mutation in whole blood at a ratio similar to the exome data. The mutant allele frequency was in the range of 13.3-16.8% in monocytes and 15.2-18% in granulocytes. Notably, this mutation was either absent or present at a very low frequency in B and T lymphocytes, in buccal cells, and in the patient's cultured fibroblasts.

CONCLUSION

Our findings indicate the possibility of myeloid-restricted somatic mosaicism in the pathogenesis of CAPS, underscoring the emerging role of massively parallel sequencing in clinical diagnosis.

Tracing CD34+ Stromal Fibroblasts in Palatal Mucosa and Periodontal Granulation Tissue as a Possible Cell Reservoir for Periodontal Regeneration

The aim of the present research was to trace CD34+ stromal fibroblastic cells (CD34+ SFCs) in the palatal connective tissue harvested for muco-gingival surgical procedures and in granulation tissues from periodontal pockets using immunohistochemical and transmission electron microscopy. Immunohistochemical analysis targeted the presence of three antigens: CD31, α-smooth muscle actin (α-SMA), and CD34. In the palate, CD31 staining revealed a colored inner ring of the vessels representing the endothelium, α-SMA+ was located in the medial layer of the vasculature, and CD34 was intensely expressed by endothelial cells and artery adventitial cells (considered to be CD34+ SFCs). Granulation tissue showed the same pattern for CD31+ and α-SMA, but a different staining pattern for CD34. Ultrastructural examination of the palatal tissue highlighted perivascular cells with fibroblast-like characteristics and pericytes in close spatial relationship to endothelial cells. The ultrastructural evaluation of granulation tissue sections confirmed the presence of neovasculature and the inflammatory nature of this tissue. The present study traced the presence of CD34+ SFCs and of pericytes in the palatal connective tissue thus highlighting once more its intrinsic regenerative capabilities. The clinical and systemic factors triggering mobilization and influencing the fate of local CD34+SCFs and other progenitors are issues to be further investigated.

Generation and Characterization of Novel Magnetic Field-Responsive Biomaterials

We report the preparation of novel magnetic field-responsive tissue substitutes based on biocompatible multi-domain magnetic particles dispersed in a fibrin-agarose biopolymer scaffold. We characterized our biomaterials with several experimental techniques. First we analyzed their microstructure and found that it was strongly affected by the presence of magnetic particles, especially when a magnetic field was applied at the start of polymer gelation. In these samples we observed parallel stripes consisting of closely packed fibers, separated by more isotropic net-like spaces. We then studied the viability of oral mucosa fibroblasts in the magnetic scaffolds and found no significant differences compared to positive control samples. Finally, we analyzed the magnetic and mechanical properties of the tissue substitutes. Differences in microstructural patterns of the tissue substitutes correlated with their macroscopic mechanical properties. We also found that the mechanical properties of our magnetic tissue substitutes could be reversibly tuned by noncontact magnetic forces. This unique advantage with respect to other biomaterials could be used to match the mechanical properties of the tissue substitutes to those of potential target tissues in tissue engineering applications.

Everything clean? Transfer of DNA traces between textiles in the washtub

Forensic genetic analysis of items possibly handled by a suspect or a victim is frequently inquired by the law enforcement authorities, since DNA left on touched objects can often be linked to an individual. Due to technical improvement, even poor traces, which seemed to be unsuitable for DNA analysis a few years ago, may be amplified successfully today. Yet, DNA can be transferred to a crime scene artificially or unintentionally without any primary contact between the individual and the object found at the crime scene, the so-called secondary transfer or indirect transfer in general. In this study, "secondary transfer" scenarios with cells and DNA of different origins under wet conditions were investigated. Transfer was simulated as either "washing by hand" in a washtub or as "machine laundry" in a washing machine. As expected, major differences were seen between blood stains and epithelial abrasions. DNA from blood donors could be detected clearly both on the donor and on the acceptor textile, regardless of washing method. Regarding epithelial abrasions, simulating worn clothes, after washing by hand, only little residual DNA was found, and partial profiles were displayed on the donor textile, while transfer to the acceptor textile occurred even less and not in noteworthy amount and quality. Single alleles could be found both on donor textiles and acceptor textiles after simulated machine wash, but no reliable DNA profile could be verified after laundry in machine. Therefore, a DNA transfer from one worn cloth (without blood stains) to another textile in the washing machine seems to be extremely unlikely.

Changes in Exfoliative Cell of Oral Mucosa in Kidney Transplant Patients

OBJECTIVES

The aim of this study was to investigate quantitative cytologic changes in oral mucosal smears collected from kidney transplant patients by modern stereologic methods.

METHODS

We enrolled 32 kidney transplant patients. Smears were obtained from the buccal mucosa transplant patients before and 12 months after kidney transplantation. Smears from each individual were stained using the Papanicolaou method and were analyzed using a stereological method.

RESULTS

Statistically, the nuclear volumes and cytoplasmic volumes in the cells of buccal mucosa were markedly higher after kidney transplantation (P < .05). There was a decreased positive cell density in the oral epithelial cells after kidney transplantation compared with before renal transplantation (P < .05).

CONCLUSIONS

These findings suggest that there are alterations in the oral epithelial cells after kidney transplantation, which are detectable by microscopy and cytomorphometry.

Optimization of the Method of Buccal Epithelial Cell Isolation and Culturing on Collagen Substrate for Ophthalmologic Application

We performed morphofunctional analysis of cultured rabbit buccal epithelial cells in the primary culture, during passaging, and upon interaction with collagen substrates. Three different morphological types were identified. It was demonstrated that precursors of rabbit buccal epithelium were characterized by high proliferative activity, retain their biological properties throughout long-term culturing, and adhere to various collagen substrates.

Assessment of DNA damage in floriculturists in southern Brazil

The aim of this study was to assess possible genotoxic effects on floriculturists in a region of the state of Rio Grande do Sul, in the south of Brazil, using the micronucleus test (MN) and comet assay. Thirty-seven floriculturists and 37 individuals not exposed to pesticides participated in the study. The micronucleus test was performed with epithelial cells of the oral mucosa. In the microscopic analysis, 2000 cells were evaluated per subject, verifying the frequency of MN and the frequency of other nuclear abnormalities (nuclear buds, binucleated cells, and karyorrhexis). For the comet assay in the peripheral blood lymphocytes, 100 cells were classified in five classes, according to the migration of DNA fragments, thereby generating the frequency of damaged cells and the damage index. There was no difference between the exposed and control groups in the frequencies of MN and other nuclear abnormalities in the epithelial cells of the oral mucosa. However, the comet assay showed that both the frequency of DNA damaged cells and the damage index were significantly greater in the exposed group. The results therefore indicate that floriculturists are exposed to mixtures of pesticides with genotoxic potential.

[TISSUE-ENGINEERED SUBSTITUTION URETHROPLASTY BASED ON DECELLULARIZED VASCULAR MATRIX AND AUTOLOGOUS CELLS OF THE BUCCAL MUCOSA: THE FIRST EXPERIENCE]

Urethral strictures and anomalies remain a challenging urological problem. Reconstructive plastic surgery has been shown to be the most effective way to treat them. There are two main types of urethroplasty: anastomosis (anastomotic urethroplasty) and expansion of the urethral lumen using of flaps and grafts (substitution urethroplasty). Currently the ideal material for substitution urethroplasty does not exist. Tissue engineering of the urethra seems to be one of the most promising approaches to address this problem. Various tissues-engineering techniques were proposed for substitution urethroplasty. In this study, tissue-engineering design was based on the decellularized cadaveric arterial wall. The study results demonstrated the feasibility of creating stable tissue-engineered structures with autologous cultured epithelial cells of the buccal mucosa and decellularized matrix from human cadaveric arterial wall (DMCAW). There was a complete engraftment of tissue-engineering design based on DMCAW and buccal mucosa cells, used for substitution urethroplasty in a patient with the bulbar urethral stricture. Postoperatively (within 4 months after surgery) no complications and/or adverse events were observed. However, in the late postoperative period (12 months) there was recurrence of urethral stricture in the middle of the tissue-engineering design and the native urethra that warranted another surgery. Tissue-engineering design based on DMCAW and autologous buccal mucosa is safe as a material for substitution urethroplasty. Further research is required to ascertain the effectiveness of the method.

[The Buccal Epithelium as Environmental Indicator]

The use of the buccal mucosa cell micronucleus test for comparison of chemical, radiation, and radiation-chemical environmental pollution has been considered. The combined impact of chemical and radiation factors has been found to cause additive effects, synergism, and inhibition. It has been noted that the cytogenetic characteristics of the buccal epithelium may be used as a "biological dosimeter" of the total level of environmental pollution.

N-acetyl cysteine alleviates inflammatory reaction of oral epithelial cells to poly (methyl methacrylate) extract

OBJECTIVES

The purpose of this in vitro study was to determine whether the cytotoxicity of self-curing polymethyl methacrylate (PMMA) dental resin to oral epithelial cells was eliminated by mixing the antioxidant amino acid derivative, N-acetyl cysteine (NAC) with the material.

MATERIALS AND METHODS

Rat and human oral epithelial cells cultured on polystyrene were incubated in culture medium with or without extract from self-curing PMMA dental resin, with or without pre-mixing with NAC. On day 1, the cultures were evaluated for cellular damage, intracellular formaldehyde invasion, cellular redox status and pro-inflammatory cytokine production. Formaldehyde content and the amount of released NAC in the extract were evaluated.

RESULTS

Rat epithelial cells cultured with PMMA extract showed marked increases in lactate dehydrogenase (LDH) release, intracellular formaldehyde and lysosomal levels and reductions in attached cell number and the amount of E-cadherin compared with those in the culture without the extract; these adverse biological effects were alleviated or prevented by pre-mixing the resin with NAC. In human oral epithelial cells cultured with PMMA extract, the addition of NAC into the resin prevented the intracellular elevation of reactive oxygen species and the reduction in cellular glutathione levels. Human cell cultures with the extract produced higher levels of various pro-inflammatory cytokines than cultures without the extract; this was prevented by mixing the resin with NAC. The extract from PMMA pre-mixed with NAC contained a lower concentration of formaldehyde and a substantial amount of antioxidants.

CONCLUSION

The cytotoxicity of self-curing PMMA dental resin to oral epithelial cells was eliminated by mixing the resin with NAC.

Autologous transplantation of oral mucosal epithelial cell sheets cultured on an amniotic membrane substrate for intraoral mucosal defects

The human amniotic membrane (AM) is a thin intrauterine placental membrane that is highly biocompatible and possesses anti-inflammatory and anti-scarring properties. Using AM, we developed a novel method for cultivating oral mucosal epithelial cell sheets. We investigated the autologous transplantation of oral mucosal epithelial cells cultured on AM in patients undergoing oral surgeries. We obtained specimens of AM from women undergoing cesarean sections. This study included five patients without any history of a medical disorder who underwent autologous cultured oral epithelial transplantation following oral surgical procedures. Using oral mucosal biopsy specimens obtained from these patients, we cultured oral epithelial cells on an AM carrier. We transplanted the resultant cell sheets onto the oral mucosal defects. Patients were followed-up for at least 12 months after transplantation. After 2–3 weeks of being cultured on AM, epithelial cells were well differentiated and had stratified into five to seven layers. Immunohistochemistry revealed that the cultured cells expressed highly specific mucosal epithelial cell markers and basement membrane proteins. After the surgical procedures, no infection, bleeding, rejection, or sheet detachment occurred at the reconstructed sites, at which new oral mucous membranes were evident. No recurrence was observed in the long-term follow-up, and the postoperative course was excellent. Our results suggest that AM-cultured oral mucosal epithelial cell sheets represent a useful biomaterial and feasible method for oral mucosal reconstruction. However, our primary clinical study only evaluated their effects on a limited number of small oral mucosal defects.

[The expression of E-cadherin, vimentin, β-catenin, transforming growth factor-β1 in oral squamous cell carcinomas]

OBJECTIVE

To investigate the expression of E-cadherin, vimentin, β-catenin and transforming growth factor-β1 (TGF-β1) in oral squamous cell carcinomas (OSCC).

METHODS

Eighty-nine cases of OSCC and 20 cases of normal oral mucosa were collected. Then the 89 cases of OSCC were classified as grade I, II, III. The semiquantitative method was used to calculated the positive intensity and positive rate. The relationship between the OSCC differentiation and the four biomarkers was analyzed.

RESULTS

The median of E-cadherin was 9.00 in the normal tissue, 9.00, 6.00 and 6.00 in OSCC I, II and III, respectively. There was significant difference between the normal group and OSCC group (Z=-4.211, P=0.000). The median of vimentin was 0.00 in the normal tissue, 0.00, 0.00 and 4.00 in OSCC I, II and III, respectively. There was significant difference between the normal group and OSCC group (Z=-3.675, P=0.000). The median of β-catenin was 9.00 in the normal tissue, 3.00, 4.00 and 3.00 in OSCC I, II and III, respectively. There was significant difference between the normal group and OSCC group (Z=-6.300, respectively. There was significant difference between the normal group and OSCC group (Z=-3.329, P=0.000). E-cadherin expression was positively correlated to β-catenin expression (r=0.327, P=0.002), negtively correlated to vimentin expression (r=-0.386, P=0.001) and positively correlated to TGF-β1 expression (r=-0.304, P=0.004). Vimentin expression was positively correlated to TGF-β1 expression (r=0.401, P=0.000).

CONCLUSIONS

E-cadherin and β-catenin in OSCC had a down-regulated expression, while the vimentin has an up-regulated expression.

Chromosome damage, apoptosis, and necrosis in exfoliated cells of oral mucosa from androgenic anabolic steroids users

The aim of this study was to evaluate the potential of the androgenic anabolic steroids (AAS) for inducing chromosome damage, apoptosis, and necrosis, using the micronucleus test on exfoliated cells from the oral mucosa of AAS users. The sample consisted of 55 male individuals, practitioners of physical exercise divided into two groups: 25 individuals who were users of AAS and 30 individuals in the control group. Cytological analysis included, in addition to micronuclei, counting of broken eggs and degenerative nuclear changes indicative of apoptosis (karyorrhexis, condensed chromatin, and pyknosis) and necrosis (karyolysis in addition to these changes). The statistical analysis did not show differences in occurrences of micronuclei, karyolysis, and broken eggs between the groups. The occurrence of apoptosis was significantly higher in cells from control subjects. The results obtained showed that inhibition of apoptosis was induced by AAS, suggesting that this may be one of the mechanisms contributing toward the association that has been described between use of AAS and the carcinogenic process.

Extracellular calcium regulates keratinocyte proliferation and HPV 16 E6 RNA expression in vitro

Human papillomaviruses (HPV) are known to immortalize oral keratinocytes in vitro, but the underlying mechanisms causing the following resistance to differentiation remain unclear. We investigated the effect of extracellular calcium on the proliferation of HPV16-positive keratinocytes and on the mRNA expression of the viral E6-oncogene. HPV16-positive hypopharyngeal carcinoma cells (UD-SCC-2), spontaneously immortalized- (HMK) and HPV16 E6/E7-immortalized human gingival keratinocytes (IHGK) were grown for 3, 6 and 9 days in Keratinocyte Serum-free Medium with calcium concentrations ranging from 0 mM to 6 mM. Calcium concentrations up to 0.09 mM increased cellular proliferation, which decreased at higher concentrations. A shift of calcium concentration from 0 to 4 mM increased E6 expression in UD-SCC-2 cells 2.4-fold by day 9. Simultaneously, E2 expression increased. The most significant upregulation of E6 and E2 expressions was observed at day 9, grown in high-calcium media and the increase in E6 expression coincided with an increase in involucrin expression, likely indicating cell differentiation. Despite this, HPV-positive cells continued to proliferate even at high-calcium media in contrast to HPV-negative cells. Overexpression of E6 mRNA may be an important feature of HPV16-positive cells to resist the natural calcium gradient in differentiating keratinocytes allowing cell proliferation.

Maintenance and distribution of epithelial stem/progenitor cells after corneal reconstruction using oral mucosal epithelial cell sheets

We assessed the maintenance and distribution of epithelial stem/progenitor cells after corneal reconstruction using tissue-engineered oral mucosal cell sheets in a rat model. Oral mucosal biopsy specimens were excised from green fluorescent protein (GFP) rats and enzymatically treated with Dispase II. These cells were cultured on inserts with mitomycin C-treated NIH/3T3 cells, and the resulting cell sheets were harvested. These tissue-engineered cell sheets from GFP rats were transplanted onto the eyes of a nude rat limbal stem cell deficiency model. Eight weeks after surgery, ocular surfaces were completely covered by the epithelium with GFP-positive cells. Transplanted corneas expressed p63 in the basal layers and K14 in all epithelial layers. Epithelial cells harvested from the central and peripheral areas of reconstructed corneas were isolated for a colony-forming assay, which showed that the colony-forming efficiency of the peripheral epithelial cells was significantly higher than that of the central epithelial cells 8 weeks after corneal reconstruction. Thus, in this rat model, the peripheral cornea could maintain more stem/progenitor cells than the central cornea after corneal reconstruction using oral mucosal epithelial cell sheets.

Micronuclei and other nuclear anomalies in exfoliated buccal mucosa cells of Mexican women with breast cancer

PURPOSE

Breast cancer (BC) is the most frequently diagnosed form of cancer and the leading cause of cancer-related deaths among females in the world. RESULTS of several studies showed that the genome of primary cancer patients (naive for any treatment) is unstable. The purpose of the present study was to evaluate the genomic instability in BC patients by means of buccal cells micronucleus (MN) cytome assay Methods: The frequencies of nuclear anomalies including MN, binucleates (BN), broken eggs (BE), condensed chromatin (CC), karyorrhexis (KR) and karyolysis (KL) were evaluated in exfoliated buccal mucosa cells of Mexican women with primary BC and healthy women. Buccal cells were collected from 21 BC patients (9 with stage I and 12 with stage II) and from 20 healthy females used as control group.

RESULTS

The results of the evaluation of cells showed that the frequencies of MN, BN, BE, KR and KL were significantly increased in the pooled group of BC patients compared with the control group. However, no one parameter of buccal MN-cytome assay in patients with stage I BC was significant compared with controls and BC patients with stage II.

CONCLUSION

Application of the buccal MN-cytome assay for the study of genomic instability in primary BC patients showed that both genotoxic and cytotoxic effects can be evaluated in such patients.

Spectrally resolved fluorescence lifetime imaging to investigate cell metabolism in malignant and nonmalignant oral mucosa cells

Fluorescence-guided diagnosis of tumor tissue is in many cases insufficient, because false positive results interfere with the outcome. Improvement through observation of cell metabolism might offer the solution, but needs a detailed understanding of the origin of autofluorescence. With respect to this, spectrally resolved multiphoton fluorescence lifetime imaging was investigated to analyze cell metabolism in metabolic phenotypes of malignant and nonmalignant oral mucosa cells. The time-resolved fluorescence characteristics of NADH were measured in cells of different origins. The fluorescence lifetime of bound and free NADH was calculated from biexponential fitting of the fluorescence intensity decay within different spectral regions. The mean lifetime was increased from nonmalignant oral mucosa cells to different squamous carcinoma cells, where the most aggressive cells showed the longest lifetime. In correlation with reports in the literature, the total amount of NADH seemed to be less for the carcinoma cells and the ratio of free/bound NADH was decreased from nonmalignant to squamous carcinoma cells. Moreover for squamous carcinoma cells a high concentration of bound NADH was found in cytoplasmic organelles (mainly mitochondria). This all together indicates that oxidative phosphorylation and a high redox potential play an important role in the energy metabolism of these cells.

[Research progress of cell sheet technology in oral tissue engineering]

OBJECTIVE

Cell sheet technology (CST) demonstrates the innovation and advantage by overcoming some immanent shortcomings of traditional tissue engineering. To review the research progress of CST in oral tissue engineering.

METHODS

The related home and abroad literature about CST and its application in stomatology was extensively reviewed and analyzed.

RESULTS

Compared to the traditional tissue engineering technology, CST has the features of high seeding density, abundant matrix, good biological compatibility, and perfect operability, which can improve the survival rate of cell transplantation and promote functional reconstruction. It is reported that CST has been successfully used in the following fields, repair and reconstruction of periodontium, soft tissues of oral mucosa, and bones in maxillofacial region.

CONCLUSION

With the development of CST and combined with the traditional tissue engineering technologies, it will promote the tissue engineering further progress in stomatology.

Genetic damage in coal miners evaluated by buccal micronucleus cytome assay

During coal mining activities, large quantities of coal dust, ashes, polycyclic aromatic hydrocarbons and metals are released into the environment. This complex mixture presents one of the most important occupational hazards for health of workers. The aim of the present study was to evaluate the genetic damage together with the presence of inorganic elements, in an exposed workers population to coal mining residues of Guajira-Colombia. Thus, 100 exposed workers and 100 non-exposed control individuals were included in this study. To determine genetic damage we assessed the micronucleus (MN) frequencies and nuclear buds in buccal mucosa samples (BMCyt) assay, which were significantly higher in the exposed group than non-exposed control group. In addition, karyorrhectic and karyolytic cells were also significantly higher in the exposed group (cell death). No significant difference was observed between the exposed groups engaged in different mining activities. No correlation between age, alcohol consumption, time of service and MN assay data were found in this study. However, the content of inorganic elements in blood samples analyzed by a Particle-induced X-ray emission technique (PIXE) showed higher values of silicon (Si) and aluminum (Al) in the exposed group. In this study we discuss the possibility of DNA damage observed in the mine workers cells be a consequence of oxidative damage.

The potential of label-free nonlinear optical molecular microscopy to non-invasively characterize the viability of engineered human tissue constructs

Nonlinear optical molecular imaging and quantitative analytic methods were developed to non-invasively assess the viability of tissue-engineered constructs manufactured from primary human cells. Label-free optical measures of local tissue structure and biochemistry characterized morphologic and functional differences between controls and stressed constructs. Rigorous statistical analysis accounted for variability between human patients. Fluorescence intensity-based spatial assessment and metabolic sensing differentiated controls from thermally-stressed and from metabolically-stressed constructs. Fluorescence lifetime-based sensing differentiated controls from thermally-stressed constructs. Unlike traditional histological (found to be generally reliable, but destructive) and biochemical (non-invasive, but found to be unreliable) tissue analyses, label-free optical assessments had the advantages of being both non-invasive and reliable. Thus, such optical measures could serve as reliable manufacturing release criteria for cell-based tissue-engineered constructs prior to human implantation, thereby addressing a critical regulatory need in regenerative medicine.

Panax notoginseng saponins inhibit areca nut extract-induced oral submucous fibrosis in vitro

BACKGROUND

Oral submucous fibrosis (OSF) is a premalignant and fibrosing disease, which is closely associated with the habit of chewing areca nut. Panax notoginseng Buck F. H. Chen is an often used antifibrotic and antitumor agent. To treat areca nut-induced OSF, we have developed a chewable tablet, in which one of the major medicines is total Panax notoginseng saponins (PNS). In this study, we have investigated the antifibrotic effect and mechanism of PNS on areca nut-induced OSF in vitro.

METHODS

Through human procollagen gene promoter luciferase reporter plasmid, hydroxyproline assay, gelatin zymography, qRT-PCR, ELISA, and Western blot, the influences of PNS on areca nut extract (ANE)-induced cell growth, collagen accumulation, procollagen gene transcription, MMP-2/-9 activity, MMP-1/-13 and TIMP-1/-2 expression, cytokine secretion, and the activation of PI3K/AKT, ERK/JNK/p38 MAPK, and TGFβ/Smads pathways were detected.

RESULTS

Panax notoginseng saponins could inhibit the ANE-induced abnormal growth and collagen accumulation of oral mucosal fibroblasts in a concentration-dependent manner. PNS (25 μg/ml) could significantly inhibit the ANE-induced expression of Col1A1 and Col3A1, augment the ANE-induced decrease of MMP-2/-9 activity, inhibit the ANE-induced increase of TIMP-1/-2 expression, and decrease the ANE-induced transcription and release of CTGF, TGFβ1, IL-6, and TNFα. PNS (25 μg/ml) also significantly inhibited the ANE-induced activation of AKT and ERK/JNK/p38 MAPK pathways in oral mucosal fibroblasts and the ANE-induced activation of TGFβ/smad pathway in HaCaT cells.

CONCLUSION

Panax notoginseng saponins possess excellent anti-OSF activity, and its mechanism may be related to its ability to inhibit the ANE-induced activation of PI3K/AKT, ERK/JNK/p38 MAPK, and TGFβ/smad pathways.

Histopathological changes by the use of soft reline materials: a rat model study

Aim

To assess the histopathological changes of rat palatal mucosa exposed to soft reline materials.

Methods

Forty-five adult female Wistar rats with controlled living conditions and fed ad libitum were employed. Palatal appliances of heat-polymerized acrylic resin Lucitone 550 were manufactured and worn by forty animals during 14 days. Five animals did not use the appliances (G1) and were used to control the appliance influence. One experimental group (n = 10) used the appliances without any relining material (G2) to control the material effect. Three experimental groups (n = 10) received the following soft reline materials below appliances: Dentusoft (G3), Dentuflex (G4), and Trusoft (G5). Appliances from half of each experimental group(n = 5) was immersed in water bath at 55°C for 10 min before use. Animals were slaughtered and the palates were fixed in 10% buffered formalin. Hematoxylin and eosin stained sections of 5 µm were analyzed by computerized planimetry. Cellular compartment, keratin and total epithelial thickness, and basement membrane length were measured to histopathological description.Analysis of variance and Tukey post-hoc test were used to data examination(α = 0.05).

Results

For heat-treatment groups, G4 showed less elongated ridges at the basal layer interface (p = 0.037) than G2. When comparing the conditions with and without heat-treatment, only G2 showed a significant decrease in the cellular compartment, keratin layer and total epithelium thickness (p<0.05).

Conclusion

The post-polymerization for Lucitone 550 was an effective method to reduce the changes in the rat palatal mucosa. The soft reline materials tested did not cause significant histopathological changes in the rat palatal mucosa.

Dopaminergic-like neurons derived from oral mucosa stem cells by developmental cues improve symptoms in the hemi-parkinsonian rat model

Achieving safe and readily accessible sources for cell replacement therapy in Parkinson’s disease (PD) is still a challenging unresolved issue. Recently, a primitive neural crest stem cell population (hOMSC) was isolated from the adult human oral mucosa and characterized in vitro and in vivo. In this study we assessed hOMSC ability to differentiate into dopamine-secreting cells with a neuronal-dopaminergic phenotype in vitro in response to dopaminergic developmental cues and tested their therapeutic potential in the hemi-Parkinsonian rat model. We found that hOMSC express constitutively a repertoire of neuronal and dopaminergic markers and pivotal transcription factors. Soluble developmental factors induced a reproducible neuronal-like morphology in the majority of hOMSC, downregulated stem cells markers, upregulated the expression of the neuronal and dopaminergic markers that resulted in dopamine release capabilities. Transplantation of these dopaminergic-induced hOMSC into the striatum of hemi-Parkinsonian rats improved their behavioral deficits as determined by amphetamine-induced rotational behavior, motor asymmetry and motor coordination tests. Human TH expressing cells and increased levels of dopamine in the transplanted hemispheres were observed 10 weeks after transplantation. These results demonstrate for the first time that soluble factors involved in the development of DA neurons, induced a DA phenotype in hOMSC in vitro that significantly improved the motor function of hemiparkinsonian rats. Based on their neural-related origin, their niche accessibility by minimal-invasive procedures and their propensity for DA differentiation, hOMSC emerge as an attractive tool for autologous cell replacement therapy in PD.

Nano-hydroxyapatite and nano-titanium dioxide exhibit different subcellular distribution and apoptotic profile in human oral epithelium

Nanomaterials (NMs) such as titanium dioxide (nano-TiO2) and hydroxyapatite (nano-HA) are widely used in food, personal care, and many household products. Due to their extensive usage, the risk of human exposure is increased and may trigger NMs specific biological outcomes as the NMs interface with the cells. However, the interaction of nano-TiO2 and nano-HA with cells, their uptake and subcellular distribution, and the cytotoxic effects are poorly understood. Herein, we characterized and examined the cellular internalization, inflammatory response and cytotoxic effects of nano-TiO2 and nano-HA using TR146 human oral buccal epithelial cells as an in vitro model. We showed both types of NMs were able to bind to the cellular membrane and passage into the cells in a dose dependent manner. Strikingly, both types of NMs exhibited distinct subcellular distribution profile with nano-HA displaying a higher preference to accumulate near the cell membrane compared to nano-TiO2. Exposure to both types of NMs caused an elevated reactive oxygen species (ROS) level and expression of inflammatory transcripts with increasing NMs concentration. Although cells treated with nano-HA induces minimal apoptosis, nano-TiO2 treated samples displayed approximately 28% early apoptosis after 24 h of NMs exposure. We further showed that nano-TiO2 mediated cell death is independent of the classical p53-Bax apoptosis pathway. Our findings provided insights into the potential cellular fates of human oral epithelial cells as they interface with industrial grade nano-HA and nano-TiO2.

DNA damage in buccal mucosa cells of pre-school children exposed to high levels of urban air pollutants

Air pollution has been recognized as a human carcinogen. Children living in urban areas are a high-risk group, because genetic damage occurring early in life is considered able to increase the risk of carcinogenesis in adulthood. This study aimed to investigate micronuclei (MN) frequency, as a biomarker of DNA damage, in exfoliated buccal cells of pre-school children living in a town with high levels of air pollution. A sample of healthy 3-6-year-old children living in Brescia, Northern Italy, was investigated. A sample of the children's buccal mucosa cells was collected during the winter months in 2012 and 2013. DNA damage was investigated using the MN test. Children's exposure to urban air pollution was evaluated by means of a questionnaire filled in by their parents that included items on various possible sources of indoor and outdoor pollution, and the concentration of fine particulate matter (PM10, PM2.5) and NO2 in the 1-3 weeks preceding biological sample collection. 181 children (mean age ± SD: 4.3 ± 0.9 years) were investigated. The mean ± SD MN frequency was 0.29 ± 0.13%. A weak, though statistically significant, association of MN with concentration of air pollutants (PM10, PM2.5 and NO2) was found, whereas no association was apparent between MN frequency and the indoor and outdoor exposure variables investigated via the questionnaire. This study showed a high MN frequency in children living in a town with heavy air pollution in winter, higher than usually found among children living in areas with low or medium-high levels of air pollution.

Cytogenetic biomonitoring of oral mucosa cells of crack cocaine users

The aim of the present study was to comparatively evaluate genomic damage (micronucleus) and cellular death (pyknosis, karyolysis, and karyorrhexis) in exfoliated oral mucosa cells from crack cocaine users by micronucleus test. A total of 30 crack cocaine users and 30 health controls (non-exposed individuals) were included in this setting. Individuals had epithelial cells from cheek mechanically exfoliated, placed in fixative, and dropped in clean slides, which were checked for the above nuclear phenotypes. The results pointed out significant statistical differences (p < 0.05) of micronucleated oral mucosa cells from crack cocaine users. Exposure to crack cocaine caused an increase of other nuclear alterations closely related to cytotoxicity such as karyolysis in oral cells as well. In summary, these data indicate that crack cocaine is able to induce chromosomal breakage and cellular death in oral mucosa cells of users.

Therapeutic interaction of systemically-administered mesenchymal stem cells with peri-implant mucosa

OBJECTIVES

The objective of this study was to investigate the effect of systemically transplanted mesenchymal stem cells (MSCs) on the peri-implant epithelial sealing around dental implants.

MATERIALS AND METHODS

MSCs were isolated from bone marrow of donor rats and expanded in culture. After recipient rats received experimental titanium dental implants in the bone sockets after extraction of maxillary right first molars, donor rat MSCs were intravenously transplanted into the recipient rats.

RESULTS

The injected MSCs were found in the oral mucosa surrounding the dental implants at 24 hours post-transplantation. MSC transplantation accelerated the formation of the peri-implant epithelium (PIE)-mediated mucosa sealing around the implants at an early stage after implantation. Subsequently, enhanced deposition of laminin-332 was found along the PIE-implant interface at 4 weeks after the replacement. We also observed enhanced attachment and proliferation of oral mucous epithelial cells.

CONCLUSION

Systemically transplanted MSCs might play a critical role in reinforcing the epithelial sealing around dental implants.

[Effect of ribosomal proteins of respiratory bacteria on adhesive properties of buccal epitheliocytes]

AIM

Study the effect of ribosomal proteins of respiratory bacteria composing the basis of the immune-modulating preparation ribomunil on adhesive properties of buccal epithelium of healthy donors, and carry out comparison of this parameter during use of other bacterial products.

MATERIALS AND METHODS

Various amounts of bacterial ribosomal proteins, Escherichia coli (serotype O127:B8) and one-day Staphylococcus aureus (strain 5983) culture supernatant were added to "buccal epitheliocytes--candida" system and incubated. Buccal cells were washed after the incubation from non-bound candida and differentiated microscopically by the amount of cells with various levels of candida adhesion. Separate effect of ribosomal proteins on buccal cells and candida was studied, as well as their impact on the production of secretory products of buccal cells.

RESULTS

Buccal epitheliocytes in control adhered on average 14.6 candidiasis cells. After incubation with bacterial ribosomal proteins the index decreased by 2.3 +/- 0.2 times. During separate addition of ribomunil to buccal cells and candida, ribosomal bacterial proteins were shown to have effect only on epitheliocytes. Activity of ribosomal proteins had a selective character, as shown by the lack of effect under the influence of S. aureus supernatant on buccal cells as well as an increase of adhesion under the influence of lipopolysaccharide on epitheliocytes. Viability of cells in all the cases remained at a level of 90 - 98%. Buccal cells during contact with ribomunil produced a complex of soluble mediators that took part in its blocking effect.

CONCLUSION

The increase of stability of mucosal tract to microbial adhesion is an element of innate immunity and may be one of the components of immune-protecting effect of bacterial ribosomal proteins.

Plasma membrane stretch activates transient receptor potential vanilloid and ankyrin channels in Merkel cells from hamster buccal mucosa

Merkel cells (MCs) have been proposed to form a part of the MC-neurite complex with sensory neurons. Many transient receptor potential (TRP) channels have been identified in mammals; however, the activation properties of these channels in oral mucosal MCs remain to be clarified. We investigated the biophysical and pharmacological properties of TRP vanilloid (TRPV)-1, TRPV2, TRPV4, TRP ankyrin (TRPA)-1, and TRP melastatin (TRPM)-8 channels, which are sensitive to osmotic and mechanical stimuli by measurement of intracellular free Ca(2+) concentration ([Ca(2+)]i) using fura-2. We also analyzed their localization patterns through immunofluorescence. MCs showed immunoreaction for TRPV1, TRPV2, TRPV4, TRPA1, and TRPM8 channels. In the presence of extracellular Ca(2+), the hypotonic test solution evoked Ca(2+) influx. The [Ca(2+)]i increases were inhibited by TRPV1, TRPV2, TRPV4, or TRPA1 channel antagonists, but not by the TRPM8 channel antagonist. Application of TRPV1, TRPV2, TRPV4, TRPA1, or TRPM8 channel selective agonists elicited transient increases in [Ca(2+)]i only in the presence of extracellular Ca(2+). The results indicate that membrane stretching in MCs activates TRPV1, TRPV2, TRPV4, and TRPA1 channels, that it may be involved in synaptic transmission to sensory neurons, and that MCs could contribute to the mechanosensory transduction sequence.

Laser phototherapy accelerates oral keratinocyte migration through the modulation of the mammalian target of rapamycin signaling pathway

Keratinocytes play a central role in wound healing by responding to tissue injury through the activation of cellular proliferation and migration. Current clinical evidence suggests that the laser phototherapy (LPT) accelerates wound healing in a variety of oral diseases; however, the molecular mechanisms involved in response to LPT are not fully understood. Oral keratinocytes (NOK-SI) maintained under nutritional-deficit culture medium (2% fetal bovine serum) were irradiated with InGaAlP laser (660 nm; 40 mW; 0.04  cm2 spot size) in punctual and contact modes. The energy densities used were 4 and 20  J/cm2 corresponding to 4 and 20 s of exposure times and 0.16 and 0.8 J of energy per point, respectively. Three sessions of irradiations were applied with 6-h intervals. Further, the impact of LPT over cellular migration, proliferation, and activation of the mammalian target of rapamycin (mTOR) pathway, known to play a major role in epithelial migration and wound healing, was analyzed. Compared with control cells, the LPT-treated cells showed accelerated cellular migration without any changes in proliferation. Furthermore, LPT resulted in an increase in the phospho-S6 ribosomal protein, indicating activation of the mTOR signaling pathway. Collectively, these findings suggest that the LPT activates mTOR signaling pathway, promotes epithelial cell migration, and accelerates healing of oral mucosa.

Astrocyte-like cells derived from human oral mucosa stem cells provide neuroprotection in vitro and in vivo

Human oral mucosa stem cells (hOMSC) are a recently described neural crest-derived stem cell population. Therapeutic quantities of potent hOMSC can be generated from small biopsies obtained by minimally invasive procedures. Our objective was to evaluate the potential of hOMSC to differentiate into astrocyte-like cells and provide peripheral neuroprotection. We induced hOMSC differentiation into cells showing an astrocyte-like morphology that expressed characteristic astrocyte markers as glial fibrillary acidic protein, S100β, and the excitatory amino acid transporter 1 and secreted neurotrophic factors (NTF) such as brain-derived neurotrophic factor, vascular endothelial growth factor, glial cell line-derived neurotrophic factor, and insulin-like growth factor 1. Conditioned medium of the induced cells rescued motor neurons from hypoxia or oxidative stress in vitro, suggesting a neuroprotective effect mediated by soluble factors. Given the neuronal support (NS) ability of the cells, the differentiated cells were termed hOMSC-NS. Rats subjected to sciatic nerve injury and transplanted with hOMSC-NS showed improved motor function after transplantation. At the graft site we found the transplanted cells, increased levels of NTF, and a significant preservation of functional neuromuscular junctions, as evidenced by colocalization of α-bungarotoxin and synaptophysin. Our findings show for the first time that hOMSC-NS generated from oral mucosa exhibit neuroprotective effects in vitro and in vivo and point to their future therapeutic use in neural disorders.

Nanoparticles strengthen intracellular tension and retard cellular migration

Nanoparticles can have profound effects on cell biology. Here, we show that after TiO2, SiO2, and hydroxyapatite nanoparticles treatment, TR146 epithelial cell sheet displayed slower migration. Cells after exposure to the nanoparticles showed increased cell contractility with significantly impaired wound healing capability however without any apparent cytotoxicity. We showed the mechanism is through nanoparticle-mediated massive disruption of the intracellular microtubule assembly, thereby triggering a positive feedback that promoted stronger substrate adhesions thus leading to limited cell motility.

Investigation of influences of the paraformaldehyde fixation and paraffin embedding removal process on refractive indices and scattering properties of epithelial cells

The scattering properties and refractive indices (RI) of tissue are important parameters in tissue optics. These parameters can be determined from quantitative phase images of thin slices of tissue blocks. However, the changes in RI and structure of cells due to fixation and paraffin embedding might result in inaccuracies in the estimation of the scattering properties of tissue. In this study, three-dimensional RI distributions of cells were measured using digital holographic microtomography to obtain total scattering cross sections (TSCS) of the cells based on the first-order Born approximation. We investigated the slight loss of dry mass and drastic shrinkage of cells due to paraformaldehyde fixation and paraffin embedding removal processes. We propose a method to compensate for the correlated changes in volume and RI of cells. The results demonstrate that the TSCS of live cells can be estimated using restored cells. The percentage deviation of the TSCS between restored cells and live cells was only −8%. Spatially resolved RI and scattering coefficients of unprocessed oral epithelium ranged from 1.35 to 1.39 and from 100 to 450 cm−1, respectively, estimated from paraffinembedded oral epithelial tissue after restoration of RI and volume.

The study of the condition of the oral prosthesis field epithelium in persons wearing dentures of polypropylene and acrylic bases

The goal of the study was to make a comparative assessment of the effect of the partial removable polypropylene and acrylic dentures on the prosthetic bed epithelium. The material of this study was smears-scrapes of the oral mucosa obtained from 316 patients. The results of the investigation of the morphological cell composition of the oral mucosa epithelium obtained from the prosthesis field and after prosthesis show a negative influence of the acrylic denture bases on the epithelium of the oral mucosa. The most optimal was the correlation of epithelial cells in the oral mucosa in the patients with dentures from "Tipplen R 359", processed in plasma of the glow discharge.

Towards a defined, serum- and feeder-free culture of stratified human oral mucosal epithelium for ocular surface reconstruction

PURPOSE

Ocular surface reconstruction with cultivated oral mucosal epithelial transplantation technique is a viable treatment option for severe ocular surface injuries and diseases with limbal stem cell deficiency. Currently, this technique is based on utilization of xenogenic, allogenic or undefined components such as murine 3T3 feeders, serum and amniotic membrane. In this study, we aimed to find a more defined culture method to generate stratified human oral mucosal epithelium.

METHODS

In this study, we have examined the formation of stratified cell sheets from human oral mucosal epithelial cells under serum-free culture environment both in the absence and presence of fibroblast-conditioned culture medium and elevated epidermal growth factor (EGF) concentration.

RESULTS

In all examined culture conditions, the cultivated oral epithelial cells formed a stratified tissue, which was positive for keratins K3/12, K4 and K13. The tissue-engineered oral epithelia also expressed proliferation and progenitor markers Ki67 and p63 in the basal layer of the cell sheets, suggesting that the epithelia still had regenerative capacity. The cultures presented expression of tight junction proteins ZO-1 and occludin and high transepithelial electrical resistance values.

CONCLUSION

In this culture method, we have been able to produce stratified cell sheets successfully without serum, conditioning of the medium or increased EGF concentration. We provide a novel protocol to produce tight multi-layered epithelium with proliferative potential, which can be easily adapted for cultivated oral mucosal epithelial transplantation.

Human epithelial tissue culture study on restorative materials

OBJECTIVES

Health condition of the gingival tissues contacting the surfaces of fixed prostheses is a result of multiple etiologic factors. The aim of the investigation discussed here was to evaluate the attachment and proliferation rate of cultured human epithelial cells on three commonly used restorative materials under in vitro conditions.

METHODS

Morphological and chemical structure of polished lithium-disilicate (IPS e.max Press, Ivoclar Vivadent AG, Germany), yttrium modified zirconium dioxide (5-TEC ICE Zirkon Translucent, Zirkonzahn GmbH Srl, Germany) and cobalt chromium alloy (Remanium star, Dentaurum GmbH & Co. KG, Germany) discs were examined by scanning electron microscopy (SEM), energy dispersive X-ray spectroscopy (EDS) and atomic force microscopy (AFM). Human epithelial cells harvested and cultured from one donor, were applied to investigate cell attachment (24h observation) and proliferation (72h observation) via dimethylthiazol-diphenyl tetrazolium bromide (MTT) and AlamarBlue(®) (AB) assays on control surface (cell-culture plate) and on the restorative materials (n=3×20 specimens/material).

RESULTS

SEM and AFM revealed typical morphology and roughness features for the materials. Zirconia presented significantly higher Ra value. EDS confirmed typical elements on the investigated restorative materials: lithium-disilicate (Si, O); Zirconia (Zi, Y, O); CoCr (Co, Cr, W). All surfaces except CoCr exhibited significant cell proliferation according to MTT and AB assays after 72h compared to 24h. Among the restorative materials, CoCr samples showed the highest cell attachment as indicated by MTT assay. AB results showed that attachment and proliferation of human epithelial cells is supported more on lithium-disilicate. Both assays indicated the lowest value for zirconia.

CONCLUSIONS

The results indicate that the restorative materials examined are equally suitable for subgingival restorations. Lithium-disilicate exhibited the best biocompatibility.

CLINICAL SIGNIFICANCE

The examined materials are indicated for use in restorative procedures, directly contacting the sulcular epithelial tissues. Thus it is essential to monitor the biological acceptibility of these materials in order to better understand their clinical properties. The results indicate that Lithium-disilicate is a suitable material for such purposes.

Distribution changes of epithelial dendritic cells in canine cornea and mucous membranes related to hematopoietic stem cell transplantation

BACKGROUND/AIM

Dendritic cells (DCs) are important immune mediators following allogeneic hematopoietic stem cell transplantation (HSCT). We screened for DC frequency in the cornea and oral mucous membranes after HSCT by confocal laser scanning microscopy (CLSM) in a canine model.

MATERIALS AND METHODS

In vivo CLSM images of the epithelia were taken the day before and on days 28, 56 and 112 following HSCT. Peripheral blood counts and chimerism were determined.

RESULTS

An increase of DCs after HSCT was detected in each animal in both investigated tissue types. Highest DC numbers in the flew and the gingiva were detected on day 28 and in the corneal epithelium on day 56 after HSCT, respectively.

CONCLUSION

Changes of DCs in ocular and non-ocular mucous membranes can be monitored by CLSM in vivo. The DC frequency in the cornea and mucosa changes following HSCT. DC recovery is rapid and their numbers correlate with the development of chimerism of peripheral blood mononuclear cells.

Role of topical drugs in treatment of oral mucosal diseases. A literature review

Few topical formulations have been designed specifically to treat oral mucosal diseases. Local drug delivery may provide a more targeted and efficient option than systemic delivery for diseases of the oral mucosa. The permeability to the topical drugs differs according to the thickness of the epithelium and the extent of keratinization. The loss of the permeability barrier in the oral mucosa, due to ulceration or erosion, leads to rapid diffusion of the drug into tissues as compared to the intact areas of the mucosa. Oral mucosal delivery has the potential to treat many different conditions and diseases, such as oral cancer, mucositis, lichen planus, herpes simplex, candidiasis, recurrent aphthous stomatitis, vesiculo-bullous diseases, neuropathic pain and salivary dysfunction. Each therapy requires distinct penetration and drug retention profiles in order to optimize treatment and minimize side effects. In this paper, topical medications are discussed, as these are advantageous for the treatment of oral mucosal lesions with fewer side effects.

Cytological assessment of Barr bodies using aceto-orcein and papanicolaou stains in buccal mucosal smears and their sex estimation efficacy in an Indian sample

OBJECTIVE

Buccal epithelial cells in saliva traces found at a crime scene can be used for sex determination by examining the presence of Barr bodies in the nucleus. Papanicolaou (PAP) and fluorescent stains, among others, have been used in the past. Aceto-orcein (AO) is a relatively unexplored staining technique for this purpose. This study aims to assess the efficacy of sex determination using AO and PAP stains for the detection of Barr bodies in buccal mucosal scrapes.

STUDY DESIGN

Buccal scrapings were collected from 120 healthy individuals (60 males and 60 females). They were stained with AO and PAP. Fifty cells in each sample were analyzed for identification of Barr bodies. Samples with a presence of Barr bodies ≤5% were recorded as male and those with >5% were recorded as female. The percentage accuracy in determining sex using both stains was evaluated.

RESULTS

The percentage of Barr bodies in AO-stained slides ranged from 5 to 32 among females and from 0 to 8 in males, while with PAP the ranges recorded were 4-20 in females and 0-5 in males (p < 0.001). The sensitivity and specificity of AO for detecting sex accurately was around 98.3 and 95% for PAP.

CONCLUSION

Sex determination using Barr bodies in the buccal cells is a simple method that provides up to 95-98% accuracy; making it a significant accessory for sex determination. AO proved to be a better stain than PAP for visualizing nuclear details, and its staining time was remarkably shorter. It also demonstrated enhanced sex estimation efficacy compared to PAP.

The gustin (CA6) gene polymorphism, rs2274333 (A/G), as a mechanistic link between PROP tasting and fungiform taste papilla density and maintenance

Taste sensitivity to PROP varies greatly among individuals and is associated with polymorphisms in the bitter receptor gene TAS2R38, and with differences in fungiform papilla density on the anterior tongue surface. Recently we showed that the PROP non-taster phenotype is strongly associated with the G variant of polymorphism rs2274333 (A/G) of the gene that controls the salivary trophic factor, gustin. The aims of this study were 1) to investigate the role of gustin gene polymorphism rs2274333 (A/G), in PROP sensitivity and fungiform papilla density and morphology, and 2) to investigate the effect of this gustin gene polymorphism on cell proliferation and metabolic activity. Sixty-four subjects were genotyped for both genes by PCR techniques, their PROP sensitivity was assessed by scaling and threshold methods, and their fungiform papilla density, diameter and morphology were determined. In vitro experiments examined cell proliferation and metabolic activity, following treatment with saliva of individuals with and without the gustin gene mutation, and with isolated protein, in the two iso-forms. Gustin and TAS2R38 genotypes were associated with PROP threshold (p=0.0001 and p=0.0042), but bitterness intensity was mostly determined by TAS2R38 genotypes (p<0.000001). Fungiform papillae densities were associated with both genotypes (p<0.014) (with a stronger effect for gustin; p=0.0006), but papilla morphology was a function of gustin alone (p<0.0012). Treatment of isolated cells with saliva from individuals with the AA form of gustin or direct application of the active iso-form of gustin protein increased cell proliferation and metabolic activity (p<0.0135). These novel findings suggest that the rs2274333 polymorphism of the gustin gene affects PROP sensitivity by acting on fungiform papilla development and maintenance, and could provide the first mechanistic explanation for why PROP super-tasters are more responsive to a broad range of oral stimuli.

IL-17C and its receptor IL-17RA/IL-17RE identify human oral epithelial cell as an inflammatory cell in recurrent aphthous ulcer

BACKGROUND

Recurrent aphthous ulcer (RAU) is an ulcerative disease of non-keratinized oral mucosa. Colon and bronchial epithelial cells produce interleukin-17C (IL-17C) upon stimulation of Toll-like receptor 2 (TLR2), TLR3 and TLR5, which are highly expressed in epithelial cells in RAU lesions. We therefore investigated the eventual presence and function of IL-17C in cultured human oral keratinocytes (HOK) and control biopsies compared to RAU lesions.

METHODS

Expression of IL-17A, IL-17C, IL-17RA and IL-17RE was analysed in cultured HOK cells using quantitative real-time polymerase chain reaction (qRT-PCR). HOK cells were stimulated with IL-17C and analysed for IL-8 and tumour necrosis factor-α (TNF-α) using qRT-PCR. Control mucosa (n = 5) was immunostained for IL-17A, IL-17C, IL-8, TNF-α and mast cell tryptase and compared with RAU lesions (n = 5) using the mean grey scale value.

RESULTS

IL-17C, but no IL-17A, mRNA was found in cultured HOK cells. Components of the heterodimeric IL-17RA/IL-17RE receptor for IL-17C were also highly expressed. Stimulation of HOK with IL-17C increased TNF-α mRNA (P = 0.03; IL-8 increase was not statistically significant). HOK in RAU lesions stained intensively for IL-17C compared to controls (P = 0.006). This was associated with increased epithelial immunostaining of TNF-α (P = 0.04) and IL-8 (P = 0.02). Most of the inflammatory cells which stained for IL-17A in control mucosa and RAU lesions were also mast cell tryptase positive.

CONCLUSION

IL-17C is highly expressed in epithelial cells in RAU lesions, where it seems to stimulate oral keratinocytes via IL-17RA/IL-17RE to produce pro-inflammatory cytokines. Human oral epithelial cells are probably important inflammatory cells in RAU.

Wharton's jelly stem cells: a novel cell source for oral mucosa and skin epithelia regeneration

Perinatal stem cells such as human umbilical cord Wharton's jelly stem cells (HWJSCs) are excellent candidates for tissue engineering because of their proliferation and differentiation capabilities. However, their differentiation potential into epithelial cells at in vitro and in vivo levels has not yet been reported. In this work we have studied the capability of HWJSCs to differentiate in vitro and in vivo to oral mucosa and skin epithelial cells using a bioactive three-dimensional model that mimics the native epithelial-mesenchymal interaction. To achieve this, primary cell cultures of HWJSCs, oral mucosa, and skin fibroblasts were obtained in order to generate a three-dimensional heterotypical model of artificial oral mucosa and skin based on fibrin-agarose biomaterials. Our results showed that the cells were unable to fully differentiate to epithelial cells in vitro. Nevertheless, in vivo grafting of the bioactive three-dimensional models demonstrated that HWJSCs were able to stratify and to express typical markers of epithelial differentiation, such as cytokeratins 1, 4, 8, and 13, plakoglobin, filaggrin, and involucrin, showing specific surface patterns. Electron microscopy analysis confirmed the presence of epithelial cell-like layers and well-formed cell-cell junctions. These results suggest that HWJSCs have the potential to differentiate to oral mucosa and skin epithelial cells in vivo and could be an appropriate novel cell source for the development of human oral mucosa and skin in tissue engineering protocols.