Induction of human ESC-derived and adult primary multipotent limbal stem cells into retinal pigment epithelial cells and corneal stromal stem cells.

Human embryonic stem cell (hESC)- and human induced pluripotent stem cell (hiPSC)-derived retinal pigment epithelium (RPE) therapies are promising alternatives for the treatment of retinal degenerative diseases caused by RPE degeneration. The generation of autologous RPE cells from human adult donors, which has the advantage of avoiding immune rejection and teratoma formation, is an alternative cell resource to gain mechanistic insight into and test potential therapies for RPE degenerative diseases. Here, we found that limbal stem cells (LSCs) from hESCs and adult primary human limbus have the potential to produce RPE cells and corneal stromal stem cells (CSSCs). We showed that hESC-LSC-derived RPE cells (LSC-RPE) expressed RPE markers, had a phagocytic function, and synthesized tropical factors. Furthermore, during differentiation from LSCs to RPE cells, cells became pigmented, accompanied by a decrease in the level of LSC marker KRT15 and an increase in the level of RPE marker MITF. The Wnt signaling pathway plays a role in LSC-RPE fate transition, promotes MITF expression in the nucleus, and encourages RPE fate transition. In addition, we also showed that primary LSCs (pLSCs) from adult human limbus similar to hESC-LSC could generate RPE cells, which was supported by the co-expression of LSC and RPE cell markers (KRT15/OTX2, KRT15/MITF), suggesting the transition from pLSC to RPE cells, and typical polygonal morphology, melanization, RPE cell marker genes expression (TYR, RPE65), tight junction formation by ZO-1 expression, and the most crucial phagocytotic function. On the other hand, both hESC-LSCs and pLSCs also differentiated into CSSCs (LSC-CSSCs) that expressed stem cell markers (PAX6, NESTIN), presented MSC features, including surface marker expression and trilineage differentiation capability, like those in human CSSCs. Furthermore, the capability of pLSC-CSSC to differentiate into cells expressing keratocyte marker genes (ALDH3A1, PTGDS, PDK4) indicated the potential to induce keratocytes. These results suggest that the adult pLSC is an alternative cell resource, and its application provides a novel potential therapeutic avenue for preventing RPE dysfunction-related retinal degenerative diseases and corneal scarring.

Disrupting Hedgehog signaling in melanocytes by SUFU knockout leads to ocular melanocytosis and anterior segment malformation.

Hedgehog (Hh) signaling is well known for its crucial role during development, but its specific role in individual cell lineages is less well characterized. Here, we disrupted Hh signaling specifically in melanocytes by using Cre-mediated cell-type-specific knockout of the Hh regulator suppressor of fused (Sufu). Interestingly, corresponding mice were fully pigmented and showed no developmental alterations in melanocyte numbers or distribution in skin and hair follicles. However, there were ectopic melanoblasts visible in the anterior chamber of the eye that eventually displayed severe malformation. Choroidal melanocytes remained unaltered. Surprisingly, the abnormal accumulation of anterior uveal melanoblasts was not the result of increased cell proliferation but of increased migration to ectopic locations such as the cornea. In melanoblasts in vitro, Sufu knockdown replicated the increase in cell migration without affecting proliferation and was mediated by an increased level of phosphorylated-ERK brought about by a reduction in the levels of the repressor form of GLI3. These results highlight the developmental divergence of distinct melanocyte subpopulations and may shed light on the pathogenesis of human ocular melanocytosis.

[Comparative study of the condylar positions in different sagittal skeletal facial types with cone-beam computed tomography].

OBJECTIVE: To investigate the differences in the condylar position of subjects with skeletal class I and skeletal class II. To provide a basis of diagnosis and treatment. METHODS: Group A was composed of 50 subjects with skeletal class I (27 males and 26 females; age range = 18 years to 30 years; mean age=26 years). Group B comprised 50 subjects with skeletal class II (24 males and 26 females; age range = 18 years to 28 years; mean age=25 years). The condylar position and the shapes of the condyle and the glenoid fossa were linearly measured on the sagittal and coronal sections by cone-beam computed tomography (CBCT). Data were analyzed by SPSS 19.0. RESULTS: No statistically significant differences were found in the measurements of the condylar position between the sides of each group on the sagittal plane and the coronal plane (P > 0.05). There were significant differences on the anterior space and the posterior space between group A and B (P < 0.05). The A/P joint space ratio of group A was larger than that of group B (P < 0.05). CONCLUSION: The subjects of skeletal class I show an anterior condyle position. The subjects of skeletal class II show a posterior condyle position.

Chloride channels regulate chondrogenesis in chicken mandibular mesenchymal cells.

Voltage gated chloride channels (ClCs) play an important role in the regulation of intracellular pH and cell volume homeostasis. Mutations of these genes result in genetic diseases with abnormal bone deformation and body size, indicating that ClCs may have a role in chondrogenesis. In the present study, we isolated chicken mandibular mesenchymal cells (CMMC) from Hamburg-Hamilton (HH) stage 26 chick embryos and induced chondrocyte maturation by using ascorbic acid and ß-glycerophosphate (AA-BGP). We also determined the effect of the chloride channel inhibitor NPPB [5-nitro-2-(3-phenylpropylamino) benzoic acid] on regulation of growth, differentiation, and gene expression in these cells using MTT and real-time PCR assays. We found that CLCN1 and CLCN3-7 mRNA were expressed in CMMC and NPPB reduced expression of CLCN3, CLCN5, and CLCN7 mRNA in these cells. At the same time, NPPB inhibited the growth of the CMMC, but had no effect on the mRNA level of cyclin D1 and cyclin E (P>0.05) with/without AA-BGP treatment. AA-BGP increased markers for early chondrocyte differentiation including type II collagen, aggrecan (P<0.01) and Sox9 (P<0.05), whilst had no effect on the late chondrocyte differentiation marker type X collagen. NPPB antagonized AA-BGP-induced expression of type II collagen and aggrecan (P<0.05). Furthermore, NPPB downregulated type X collagen (P<0.05) with/without AA-BGP treatment. We conclude that abundant chloride channel genes in CMMC play important roles in regulating chondrocyte proliferation and differentiation. Type X collagen might function as a target of chloride channel inhibitors during the differentiation process.

[Treatment of skeletal Class III adult patients with facemask protraction].

OBJECTIVE: To investigate the clinical effects of facemask protraction on skeletal Class III adult patients. METHODS: Totally 15 skeletal Class III patients (male 7, female 8, aged 18 - 24 years) were included in the study. Removable and fixed appliances were used in the upper or lower arches. Facemask protraction was used at night for about 7 months and Class III elastics were worn during the day. The total treatment time was 24 mouths on average. Cephalometric analysis was carried out before and after treatment. RESULTS: The profile was greatly improved and Class I molar relationship was achieved. SNA angle was increased from (79.6 ± 3.7)° to (81.1 ± 3.8)°. SNB angle was decreased from (83.5 ± 3.3)° to (82.6 ± 3.6)°. ANB angle was increased from (-4.1 ± 2.0)° to (-1.5 ± 1.8)°. CONCLUSIONS: Protraction was effective in the treatment of skeletal Class III adult patients.

Ameloblastoma in children and adolescents.

This study first reviewed the data of 37 patients aged 18 years and younger with ameloblastoma over a 16-year period and then reviewed the literature on this subject from 1970 to 2009. Of 37 patients with ameloblastoma, 23 were male and 14 were female, a ratio of 1.6:1. The mean age was 14.8 years. All lesions were in the mandible. Clinical typing included 28 solid type and 9 unicystic type. Ten cases were recurrent (27.0%). A series of literature review disclosed 233 well-documented cases of ameloblastoma in children and adolescents. The ages ranged from 4 to 20 years with a mean age of 14.5 years. The distribution among males and females were almost identical: 53.6% (125/233) males and 46.4% (108/233) females (1.16:1). The mandible was affected in 225 (96.6%), the maxilla in 8 (3.4%). Histologically, solid type (63.1%) predominated over unicystic type (36.9%). Of 226, 123 (54.4%) patients were treated with radical resection, 103 (45.6%) underwent conservative method. Owing to a high recurrent rate of ameloblastoma, solid type of tumors should be approached with radical surgical treatment, while conservative measure can be applied selectively to unicystic type. Long-term follow-up is important because recurrence may appear years after tumor removal.