Epigenetic Modifications and Therapy in Uveitis.

Uveitis is a sight-threatening intraocular inflammation, and the exact pathogenesis of uveitis is not yet clear. Recent studies, including multiple genome-wide association studies (GWASs), have identified genetic variations associated with the onset and progression of different types of uveitis, such as Vogt-Koyanagi-Harada (VKH) disease and Behcet's disease (BD). However, epigenetic regulation has been shown to play key roles in the immunoregulation of uveitis, and epigenetic therapies are promising treatments for intraocular inflammation. In this review, we summarize recent advances in identifying epigenetic programs that cooperate with the physiology of intraocular immune responses and the pathology of intraocular inflammation. These attempts to understand the epigenetic mechanisms of uveitis may provide hope for the future development of epigenetic therapies for these devastating intraocular inflammatory conditions.

Tumor Microenvironmental Competitive Endogenous RNA Network and Immune Cells Act as Robust Prognostic Predictor of Acute Myeloid Leukemia.

Acute myeloid leukemia (AML) is malignant hematologic tumors with frequent recurrence and cause high mortality. Its fate is determined by abnormal intracellular competitive endogenous RNA (ceRNA) network and extracellular tumor microenvironment (TME). This study aims to build a ceRNA network related to AML TME to explore new prognostic and therapeutic targets. The RNA expression data of AML were obtained from The Cancer Genome Atlas (TCGA) database. First, we used the ESTIMATE algorithm to calculate the immune cells and stromal cells infiltration scores in the TME and found that all scores were highly correlated with AML's prognostic characteristics. Subsequently, differentially expressed mRNAs and lncRNAs between high and low score groups were identified to construct a TME-related ceRNA network. Further, the Cox-lasso survival model was employed to screen out the hub prognostic ceRNA network composed of two mRNAs (EPB41L3, COL2A1), three miRNAs (hsa-mir-26a-5p, hsa-mir-148b-3p, hsa-mir-148a-3p), and two lncRNAs (CYP1B1-AS1, C9orf106), and construct nomograms. Finally, we used CIBERSORT algorithm and Kaplan-Meier survival analysis to identify the prognostic TME immune cells and found that naive B cells, M2-type macrophages, and helper follicular T cells were related to prognosis, and the hub ceRNAs were highly correlated with immune cell infiltration. This study provided a new perspective to elucidate how TME regulates AML process and put forward the new therapy strategies combining targeting tumor cells with disintegrating TME.

Reconstruction of auto-tissue-engineered lamellar cornea by dynamic culture for transplantation: a rabbit model.

To construct an auto-tissue-engineered lamellar cornea (ATELC) for transplantation, based on acellular porcine corneal stroma and autologous corneal limbal explants, a dynamic culture process, which composed of a submersion culture, a perfusion culture and a dynamic air-liquid interface culture, was performed using appropriate parameters. The results showed that the ATELC-Dynamic possessed histological structure and DNA content that were similar to native lamellar cornea (NLC, p>0.05). Compared to NLC, the protein contents of zonula occludens-1, desmocollin-2 and integrin ß4 in ATELC-Dynamic reached 93%, 89% and 73%, respectively. The basal cells of ATELC-Dynamic showed a better differentiation phenotype (K3-, P63+, ABCG2+) compared with that of ATELC in static air-lift culture (ATELC-Static, K3+, P63-, ABCG2-). Accordingly, the cell-cloning efficiency of ATELC-Dynamic (9.72±3.5%) was significantly higher than that of ATELC-Static (2.13±1.46%, p<0.05). The levels of trans-epithelial electrical resistance, light transmittance and areal modulus variation in ATELC-Dynamic all reached those of NLC (p>0.05). Rabbit lamellar keratoplasty showed that the barrier function of ATELC-Dynamic was intact, and there were no signs of epithelial shedding or neovascularization. Furthermore, the ATELC-Dynamic group had similar optical properties and wound healing processes compared with the NLC group. Thus, the sequential dynamic culture process that was designed according to corneal physiological characteristics could successfully reconstruct an auto-lamellar cornea with favorable morphological characteristics and satisfactory physiological function.

ES micro-environment enhances stemness and inhibits apoptosis in human limbal stem cells via the maintenance of telomerase activity.

Our previous work had found that telomerase rejuvenated in the cytoplasm of corneal epithelial cells cultured in embryonic stem cell-conditioned medium, the functional properties of stem-like corneal epithelial cells can be enhanced by co-culturing with embryonic stem cells (ESCs) via activation of the integrinß1-FAK-PI3K/Akt signaling pathway. The goal of this study was to explore the potential molecular mechanisms of the ES micro-environment that enhance the stem cell-like phenotype and inhibit apoptosis in human limbal stem cells (LSC). The LSC were cultured in different media, either CnT-20 medium or CnT-20 +20% ES culture supernatant (ESC-CM). We observed that LSC cultured in ESC-CM had an increased proliferative capacity, greater serial passage capacity, higher colony-forming efficiency (CFE) and higher levels of stem cell-associated marker than those cultured in CnT-20. Compared with CnT-20, ESC-CM enhanced the undifferentiated status and inhibited apoptosis in the LSC by promoting the maintenance of telomerase activity, which could reduce the generation of reactive oxygen species (ROS), maintain the membrane potential (Δψm) at higher levels and reduce the expression of the p21 protein. Our findings indicated that ESC-CM system induced LSC to maintain a stem cell phenotype and inhibit the process of apoptosis. These effects might partially be achieved via the telomerase-p21-mitochondrial axis and the activation of the FAK/Wnt signaling pathways. This study may have high impact and clinic implication on the expansion of LSC in regenerative medicine, especially for ocular surface reconstruction.

Comparative study of the effects of recombinant human epidermal growth factor and basic fibroblast growth factor on corneal epithelial wound healing and neovascularization in vivo and in vitro.

PURPOSE: This study was undertaken to investigate the effects of recombinant human epidermal growth factor (rhEGF) and basic fibroblast growth factor (bFGF) on corneal wound healing and neovascularization (CNV). METHODS: The positive effects of 10 ng/ml rhEGF and bFGF on the proliferation of corneal epithelial cells (SD-HCEC1s), rabbit keratocyte cells (RKCs) and human umbilical vein endothelial cells (HUVECs) as well as the effects on the migration capacity on HUVECs were observed. An animal central corneal wound and CNV model was established in rabbits. One eye of each group was chosen randomly for topical administration of rhEGF, bFGF or normal saline, and variability in the area of corneal epithelial wound healing and CNV was observed. RESULTS: The optimal concentration of rhEGF and bFGF for the proliferation of corneal epithelial cells was 10 ng/ml. The promotive effect of 10 ng/ml rhEGF on the proliferation of RKCs and HUVECs was less than that of 10 ng/ml bFGF. In the animal experiment, the healing rate of the corneal epithelium in the rhEGF group was better than in the other groups on day 1. On day 3, the healing rates of the 3 groups were nearly equal. The CNV area in the rhEGF group was less than that of the bFGF group. CONCLUSIONS: rhEGF and bFGF both had promotive effects on corneal epithelial wound healing, but rhEGF had a weaker promotive effect on CNV than bFGF. With long-term application of growth factor drugs, rhEGF is suggested for lessening the growth of CNV.

Clinical efficacy of surgical removal of deep corneal plant foreign bodies.

PURPOSE: To describe a technique for removing deep corneal plant foreign bodies. METHODS: Twelve patients (7 males and 5 females, aged 5 to 56 years) with plant foreign bodies embedded in the deep cornea were treated between July 2011 and December 2012. The course of disease ranged from 1 to 11 d. Four of the patients had wooden foreign bodies, 3 had bamboo foreign bodies, and 5 had flower thorns; all underwent surgical removal. During the surgery, a novel suture needle was used to remove the foreign bodies. For injuries with a deep tunnel caused by the foreign bodies, the tunnel was cut open with a keratome. The foreign bodies were then removed and necrotic tissue was thoroughly debrided. Incisions were closed with interrupted sutures. The corneal foreign bodies were collected postoperatively for fungus and bacterial culture and appropriatemedical treatment was provided. RESULTS: Bacteria were identified in 3 cases, fungus in 3 cases, and no bacteria or fungus in 6 cases. All corneal foreign bodies were embedded deep in the corneal stroma without incidence of full-thickness corneal penetration or intraocular infection. CONCLUSION: Plant foreign bodies embedded in the deep cornea should be removed immediately. During the surgery, the foreign bodies and surrounding necrotic corneal stroma should be completely removed. The injured cornea should be cut open to eliminate necrotic tissues when necessary.

[Study on the treatment of dry eye with Loteprednol Etabonate].

OBJECTIVE: To observe the efficacy and safety of 0.5% Loteprednol Etabonate ophthalmic suspension in the treatment of moderate dry eye. METHODS: Totally 34 dry eye patients (68 eyes) in grade 2 or grade 3 (DEWS standard) enrolled in our hospital from March 2009 to September 2010 were randomly divided into two groups: the experimental group (Loteprednol Etabonate Group) and the control group (Cyclosporine A, CsA group). 0.5% Loteprednol Etabonate ophthalmic suspension or 1% CsA eye drops was applied 2 times a day respectively together with 0.2% Liposic eye drops (4 - 6 times/day). Questionnaire was used in these patients before the treatment and repeated every 2 weeks during the treatment till 8 weeks. Slit lamp microscope examination, fluorescent staining, tear break-up time (BUT), Schirmer I test (SIt) and intraocular pressure measurement were carried out at the same time point. The conjunctival impression cytology (IC) was performed before the treatment and 8 weeks after the treatment. The mean of the results were compared by t-tests and χ(2) test. RESULTS: After 2 weeks of the treatment, the mean score of the questionnaire was significantly lower than that before the treatment in each group (t = 5.36, 3.63, P < 0.01). After 4 weeks of the treatment, the inflammation of the ocular surface was relieved obviously in both group and the mean score of the corneal fluorescein staining (FL) was lower than that before the treatment in each group. The average density of the goblet cells before the treatment was (181.2 ± 16.1)/mm(2) and (179.4 ± 17.5)/mm(2) in each group respectively. After 8 weeks of the treatment, this increased to (348.6 ± 22.5)/mm(2) and (360.4 ± 27.8)/mm(2) significantly (t = 16.9, 16.3, P < 0.05). BUT was significantly prolonged in each group after the treatment (P < 0.01). There was no significant change in ST I or NCT in each group (P > 0.05). CONCLUSIONS: Topical 0.5% Loteprednol Etabonate ophthalmic suspension is safe and effective for the treatment of moderate dry eye.

Construction of the recellularized corneal stroma using porous acellular corneal scaffold.

Acellular porcine cornea stroma (APCS) prepared using pancreatic phospholipase A(2) was proven to be promising corneal scaffold. However, its dense ultrastructure provides insufficient space that prevents the seeded cells from organizing into a functional tissue. In this report, freezing dry APCS (FD-APCS) biomaterials containing pores with different sizes were fabricated at different pre-freezing temperatures of -10, -80 or -198°C, and the percentage of large pores (equivalent circle diameter ≥10 µm) was 93.55%, 69.36%, 35.79%, while the small pores (<10 µm) were account for 6.45%, 30.64%, 64.21%, respectively. Both porosity and specific surface area increased in FD-APCS fabricated with decreased pre-freezing temperature, and they were dramatically higher than those in APCS. The three FD-APCS groups displayed higher permeability than APCS, and the -10°C FD-APCS possessed the highest permeability. The keratocytes seeded in the FD-APCS construct survived well in vitro, and maximal cell proliferation was observed in the -10°C FD-APCS. The light transmittance of the FD-APCS-transplanted cornea after interlamellar keratoplasty in rabbit eyes displayed no significant difference from the APCS-transplanted or native cornea. This study indicated that the porous FD-APCS prepared using pancreatic phospholipase A(2) is capable of serving as potential scaffold for constructing tissue-engineered cornea with biological properties.