Transcriptome Analysis of Cultured Limbal Epithelial Cells on an Intact Amniotic Membrane following Hypothermic Storage in Optisol-GS

The Evaluation of Debris and Smear Layer Generated by Three Rotary Instruments Neo NiTi, 2Shape and Revo_S: An Ex-vivo Scanning Electron Microscopic Study

Introduction

This study compared the cleaning effectiveness of NeoNiTi, 2Shape and Revo_S rotary instruments.

Materials and Methods

Fifty mandibular molar mesial roots were selected with an angle of curvature less than 20 degrees divided into three groups (n=15). Five samples were selected as negative control group. In all three systems, the final file was 25, 6%. The score of debris and smear layer in three thirds (coronal, middle and apical) of the root canal walls were evaluated using scanning electron microscopic (SEM) magnification. The data were analyzed using the Kruskal Wallis and Mann Whitney U tests for intergroup comparison (P≤0.05) and Freidman and Wilcoxon signed-rank test was employed for intragroup comparison (P≤0.05).

Results

Residual debris of the 2Shape system in the apical region was significantly higher than the other two systems (P=0.039). Revo_S and 2Shape groups had significantly higher quantities of debris in the apical than the coronal region (P=0.029 and P=0.02, respectively). In the 2Shape group, the amount of mid-region debris was significantly higher (P=0.005) than the coronal. In inter-group comparison there was no significant difference in residual smear layer between the systems. In intra-group comparison in all three systems, the amount of smear layer in the coronal third was significantly higher than in the other two areas. (P=0.017, P<0.001 and P=0.032, respectively).

Conclusion

2Shape left the highest amount of debris in the apical region. The amount of debris in Revo_S and 2Shape groups in the apical region was significantly higher than in the coronal. The amount of smear layer in all three groups in the coronal area was higher than the middle and apical areas.

Concise Review: Considering Optimal Temperature for Short-Term Storage of Epithelial Cells

Transplantation of novel tissue-engineered products using cultured epithelial cells is gaining significant interest. While such treatments can readily be provided at centralized medical centers, delivery to patients at geographically remote locations requires the establishment of suitable storage protocols. One important aspect of storage technology is temperature. This paper reviews storage temperature for above-freezing point storage of human epithelial cells for regenerative medicine purposes. The literature search uncovered publications on epidermal cells, retinal pigment epithelial cells, conjunctival epithelial cells, corneal/limbal epithelial cells, oral keratinocytes, and seminiferous epithelial cells. The following general patterns were noted: (1) Several studies across different cell types inclined toward 4 and 16°C being suitable short-term storage temperatures. Correspondingly, almost all studies investigating 37°C concluded that this storage temperature was suboptimal. (2) Cell death typically escalates rapidly following 7–10 days of storage. (3) The importance of the type of storage medium and its composition was highlighted by some of the studies; however, the relative importance of storage medium vs. storage temperature has not been investigated systematically. Although a direct comparison between the included investigations is not reasonable due to differences in cell types, storage media, and storage duration, this review provides an overview, summarizing the work carried out on each cell type during the past two decades.

Functional Annotations of Single-Nucleotide Polymorphism (SNP)-Based and Gene-Based Genome-Wide Association Studies Show Genes Affecting Keratitis Susceptibility

Background

Keratitis is a complex condition in humans and is the second most common cause of legal blindness worldwide.

Material/Methods

To reveal the genomic loci underlying keratitis, we performed functional annotations of SNP-based and gene-based genome-wide association studies of keratitis in the UK Biobank (UKB) cohort with 337 199 subjects of European ancestry.

Results

The publicly available SNP-based association results showed a total of 34 SNPs, from 14 distinct loci, associated with keratitis in the UKB. Gene-based association analysis identified 2 significant genes: IQCF3 (p=2.0×10⁻⁶) and SOD3 (p=2.0×10⁻⁶). Thirty-two candidate genes were then prioritized using information from multiple sources. The overlap of IQCF3 in these 2 analyses resulted in a total of 33 hub genes. Functional annotation of hub genes was performed and transcriptional factors of IQCF3 and SOD3 were predicted.

Conclusions

A total of 34 SNPs from 14 distinct loci were identified as being associated with keratitis, and 32 candidate genes were then prioritized. In addition, IQCF3 and SOD3 were identified by their p values through gene-based tests on the basis of individual SNP-based tests. The functional relationship between these suspect genes and keratitis suggest that IQCF3 and SOD3 are candidate genes underlying keratitis.

Pigmentation Is Associated with Stemness Hierarchy of Progenitor Cells Within Cultured Limbal Epithelial Cells

Ex vivo cultured human limbal epithelial stem/progenitor cells (hLESCs) are the main source for regenerative therapy of limbal stem cell deficiency (LSCD), which is worldwide one of the major causes of corneal blindness. Despite many stemness-associated markers have been identified within the limbal niche, the phenotype of the earliest hLESCs has not been hitherto identified. We sought to confirm or refute the use of tumor protein p63 (p63) and ATP binding cassette subfamily B member 5 (ABCB5) as surrogate markers for hLESCs early within the limbal differentiation hierarchy. Based on a robust fluorescence-activated cell sorting and subsequent RNA isolation protocol, a comprehensive transcriptomic profile was obtained from four subpopulations of cultured hLESCs. The subpopulations were defined by co-expression of two putative stem/progenitor markers, the p63 and ABCB5, and the corneal differentiation marker cytokeratin 3. A comparative transcriptomic analysis yielded novel data that indicated association between pigmentation and differentiation, with the p63 positive populations being the most pigmented and immature of the progenitors. In contrast, ABCB5, either alone or in co-expression patterns, identified more committed progenitor cells with less pigmentation. In conclusion, p63 is superior to ABCB5 as a marker for stemness. Stem Cells 2018;36:1411-1420.