Universal and hypoimmunogenic pluripotent stem cells for clinical usage.

It is urgent to prepare and store large numbers of clinical trial grade human pluripotent stem (hPS) cells for off-the-shelf use in stem cell therapies. However, stem cell banks, which store off-the-shelf stem cells, need financial support and large amounts of technicians for daily cell maintenance. Therefore, it is valuable to create "universal" or "hypoimmunogenic" hPS cells with genome editing engineering by knocking in or out immune-related genes. Only a small number of universal or hypoimmunogenic hPS cell lines should be needed to store for off-the-shelf usage and reduce the large amounts of instruments, consumables and technicians. In this article, we consider how to create hypoimmunogenic or universal hPS cells as well as the demerits of the technology. ß2-Microglobulin-knockout hPS cells did not harbor human leukocyte antigen (HLA)-expressing class I cells but led to the activation of natural killer cells. To escape the activities of macrophages and natural killer cells, homozygous hPS cells having a single allele of an HLA class I gene, such as HLA-C, were proposed. Major HLA class Ia molecules were knocked out, and CD47, HLA-G and PD-L1 were knocked in hPS cells utilizing CRISPR/Cas9 genome editing. Finally, some researchers are trying to generate universal hPS cells without genome editing. The cells evaded the activation of not only T cells but also macrophages and natural killer cells. These universal hPS cells have high potential for application in cell therapy.

Identification and functional annotation of differentially expressed long noncoding RNAs in retinoblastoma.

Retinoblastoma (RB), the most common intraocular malignancy, typically occurs in pediatric patients under the age of 6 years. The present study aimed to explore the long noncoding RNA (lncRNA) expression profile in RB and identify novel lncRNA biomarkers to facilitate the investigation of molecular mechanisms of RB and improve clinical therapy. Raw microarray data for the comparison of gene expression between three RB and three adjacent normal tissue samples were downloaded from Gene Expression Omnibus (dataset no. GSE111168). After identification of differentially expressed lncRNAs (DELs) and differentially expressed mRNAs (DEMs) in RB, functional enrichment analyses and a DEL-DEM weighted correlation network analysis were performed. A total of 3,915 DELs (1,774 upregulated and 2,141 downregulated) and 3,715 DEMs (1,492 upregulated and 2,223 downregulated) were identified in RB. The DEL-targeted DEMs were highly enriched by genes involved in hexose transport, muscle tissue morphogenesis, the stereocilium membrane, endothelin B receptor binding and γ-filamin/ABP-L, α-actinin and telethonin binding protein of the Z-disc binding. Furthermore, associations of the DELs and DEMs with several pathways were determined, including PI3K/AKT, Hippo and cancer signaling, as well as extracellular matrix-receptor interaction pathways. Coexpression network analysis revealed that the top three DELs, lnc-DAZ1-161, lnc-HDAC7-21 and lnc-OR52A1-55, formed coexpression modules with 181, 156 and 210 DEMs, respectively. In addition, the top three DEMs, namely EIF1AY, GSTM1 and NLRP11, formed coexpression modules with 33, 50 and 41 DELs, respectively. Validation using reverse transcription-quantitative PCR indicated that the expression of representative lncRNAs (lnc-DAZ1-161 and lnc-HDAC7-21) in RB cells in vitro was consistent with that in RB tissues in the database, while the expression of lnc-OR52A1-55 was not consistent with the database. These results suggested that the aberrant lncRNA expression profile in RB is related to the differential regulation of numerous physiological and pathological processes. The lncRNA and mRNA profiles in RB identified may provide novel targets for the investigation of its molecular mechanisms and thus lead to improvements in clinical therapy for RB.

Poly(vinyl alcohol-co-itaconic acid) hydrogels grafted with several designed peptides for human pluripotent stem cell culture and differentiation into cardiomyocytes.

We developed poly(vinyl alcohol-co-itaconic acid) (PV) hydrogels grafted with laminin-derived peptides that had different joint segments and several specific designs, including dual chain motifs. PV hydrogels grafted with a peptide derived from laminin-ß4 (PMQKMRGDVFSP) containing a joint segment, dual chain motif and cationic amino acid insertion could attach human pluripotent stem (hPS) cells and promoted high expansion folds in long-term culture (over 10 passages) with low differentiation rates, whereas hPS cells attached poorly on PV hydrogels grafted with laminin-α5 peptides that had joint segments with and without a cationic amino acid or on PV hydrogels grafted with laminin-ß4 peptides containing the joint segment only. The inclusion of a cationic amino acid in the laminin-ß4 peptide was critical for hPS cell attachment on PV hydrogels, which contributed to the zeta potential shifting to higher values (3-4 mV enhancement). The novel peptide segment-grafted PV hydrogels developed in this study supported hPS cell proliferation, which induced better hPS cell expansion than recombinant vitronectin-coated dishes (gold standard of hPS cell culture dishes) in xeno-free culture conditions. After long-term culture on peptide-grafted hydrogels, hPS cells could be induced to differentiate into specific lineages of cells, such as cardiomyocytes, with high efficiency.

Comparative Study on the Efficacy and Safety of Tumor Resection in Vitrectomy for Retinal Vasoproliferative Tumors.

PURPOSE: To investigate the efficacy and safety of combined vitrectomy with tumor resection in the treatment of retinal vasoproliferative tumors (RVPT). METHODS: Retrospective study. RVPT patients who underwent vitreous surgery at the Eye Hospital of Wenzhou Medical University from January 2011 to July 2017 were included. The main outcomes included treatment type, tumor activity, and best-corrected visual acuity (BCVA). RESULTS: Altogether, 16 patients with 17 eyes were enrolled with follow-up of no less than 6 months. Eight eyes were in the resection treatment group (Group R) and 9 eyes were in the conservative treatment group (Group C). Female (69%) were more common. The mean age was 50 (49.72 ± 12.92) years. Fifteen patients got unilateral onset and only one patient suffered bilaterally. The common symptoms were decreased visual acuity, floaters, and visual distortion. The preoperative BCVA ranged from hand movement to 20/20, with an average of 0.82 ± 0.75 LogMAR. Patients were all not high myopia, with a mean axial length of 23.27 ± 0.27 mm (21.61 mm to 24.67 mm). Of the retinal diseases, the epiretinal membrane was the most common, followed by vitreous hemorrhage, uveitis, subretinal fluid, and so on. Compared with the baseline BCVA, it improved more at postoperative 6 months and the last visit in Group R than in Group C (P=0.006 and P=0.033). The BCVA-improved 0.2 LogMAR or above in 6 months was 2 eyes in Group C and 7 eyes in Group R. All tumors in Group R were completely resected, whereas three in Group C (33.3%) had definite activity (P=0.008). In all samples, tumors were located on the inner side of the retina and had small vessel wall thickening and hyaline degeneration. The degree of astrocyte proliferation varies widely among different tumors. CONCLUSIONS: RVPT was more likely to occur in nonhigh myopia patients. Epiretinal membrane and vitreous hemorrhage were the main causes for vitreous surgery in RVPT patients. Compared with conservative treatment, surgical resection of the tumor is more beneficial to patients on visual acuity recovery and preventing tumor relapse. It is a safe and effective way to treat RVPT.

EFFECT OF BODY POSITION ON INTRAOCULAR PRESSURE IN SILICONE OIL TAMPONADE EYES.

PURPOSE: To investigate the effect of body position on intraocular pressure (IOP) in silicone oil tamponade eyes. METHODS: This prospective study included 18 eyes from 18 silicone oil tamponade patients and 24 eyes from 24 healthy subjects. Intraocular pressures were measured by Accupen Applanation Tonometer sitting with face forward, sitting with face down, supine, nondependent lateral decubitus, dependent lateral decubitus, and prone positions. The IOPs in each position and the magnitudes of IOP change were compared between the silicone oil and normal groups. RESULTS: In both groups, the IOPs in sitting positions were significantly lower than that of each recumbent position. The IOPs were highest in prone among all positions. No significant difference was found between IOPs of each group in each position. Between both groups, the IOP elevations in each position had no statistical difference compared with sitting with face forward. CONCLUSION: The IOP is lowest in the sitting position and highest in the prone position in both silicone oil and normal groups. Between both groups, the amount of IOP elevations is equivalent in each position compared with sitting with face forward. Ophthalmologists should be aware that IOP is higher in the prone position and that it should be monitored accordingly.