Sequential Isolation of Microplastics and Nanoplastics in Environmental Waters by Membrane Filtration, Followed by Cloud-Point Extraction.

Respective detection of microplastics (MPs) and nanoplastics (NPs) is of great importance for their different environmental behaviors and toxicities. Using spherical polystyrene (PS) and poly(methyl methacrylate) (PMMA) plastics as models, the efficiency for sequential isolation of MPs and NPs by membrane filtration and cloud-point extraction was evaluated. After filtering through a glass membrane (1 µm pore size), over 90.7% of MPs were trapped on the membrane, whereas above 93.0% of NPs remained in the filtrate. The collected MPs together with the glass membrane were frozen in liquid nitrogen, ground, and suspended in water (1 mL) and subjected to pyrolysis-gas chromatography-mass spectrometry (Py-GC/MS) determination. The NPs in the filtrate were concentrated by cloud-point extraction, heated at 190 °C to degrade the extractant, and then determined by Py-GC/MS. For MPs and NPs spiked in pure water, the method detection limits are in the range of 0.05-1.9 µg/L. The proposed method is applied to analyze four real water samples, with the detection of 1.6-7.6 µg/L PS MPs and 0.6 µg/L PMMA MPs in three samples, and spiked recoveries of 75.0-102% for MPs and 67.8-87.2% for NPs. Our method offers a novel sample pretreatment approach for the respective determination of MPs and NPs.

Canonical Wnt Signaling Promotes Neovascularization Through Determination of Endothelial Progenitor Cell Fate via Metabolic Profile Regulation.

Endothelial progenitor cells (EPCs) contribute to blood vessel formation. Canonical Wnt signaling plays an important role in physiological and pathological angiogenesis and EPC fate regulation. However, the mechanism for Wnt signaling to regulate EPC fate in neovascularization (NV) has not been clearly defined. Here, we showed that very low-density lipoprotein receptor knockout (Vldlr -/- ) mice, a model of ocular NV induced by Wnt signaling overactivation, have increased EPC numbers in the bone marrow, blood, and retina, as well as an elevated mitochondrial membrane potential indicating higher mitochondrial function of EPCs in the circulation. Isolated EPCs from Vldlr -/- mice showed overactivated Wnt signaling, correlating with increased mitochondrial function, mass, and DNA copy numbers, compared with WT EPCs. Our results also demonstrated that Wnt signaling upregulated mitochondrial biogenesis and function, while inhibiting glycolysis in EPCs, which further decreased EPC stemness and promoted EPCs to a more active state toward differentiation, which may contribute to pathologic vascular formation. Fenofibric acid, an active metabolite of fenofibrate, inhibited Wnt signaling and mitochondrial function in EPCs and decreased EPC numbers in Vldlr -/- mice. It also decreased mitochondrial biogenesis and reactive oxygen species production in Vldlr -/- EPCs, which may be responsible for its therapeutic effect on diabetic retinopathy. These findings demonstrated that Wnt signaling regulates EPC fate through metabolism, suggesting potential application of the EPC metabolic profile as predictor and therapeutic target for neovascular diseases. Stem Cells 2019;37:1331-1343.

miRNA-451a regulates RPE function through promoting mitochondrial function in proliferative diabetic retinopathy.

The purpose of this study was to explore the role of microRNA-451a (miR-451a) in diabetic retinopathy through activating transcription factor 2 (ATF2). The epiretinal membrane samples from patients with proliferative diabetic retinopathy (PDR) were immunolabeled with an antibody for Ki-67 to identify the proliferative cells. The expression of miR-451a was measured by qRT-PCR in the retina of Akita mice and in RPE cells under diabetic conditions. The potential downstream targets of miR-451a were predicted by bioinformatics and confirmed by dual luciferase assay, qRT-PCR, and Western blotting. Mitochondrial function, cell proliferation, and migration assays were used to detect the functional change after transfection of miR-451a mimic and inhibitor. Proliferative RPE cells were identified in the epiretinal membrane from PDR patients. The expression of miR-451a was downregulated both in the retina of Akita mice and 4-hydroxynonenal (4-HNE)-treated RPE cells. Bioinformatic analysis and luciferase assay identified ATF2 as a potential target of miR-451a. miR-451a inhibited proliferation and migration of RPE cells. The mitochondrial function was enhanced by miR-451a mimic, but suppressed by miR-451a inhibitor. In diabetic conditions, miR-451a showed a protective effect on mitochondrial function. The results of qRT-PCR and Western blotting revealed that overexpression of miR-451a downregulated the expression of ATF2 and its downstream target genes CyclinA1, CyclinD1, and MMP2. In conclusion, miR-451a/ATF2 plays a vital role in the regulation of proliferation and migration in RPE cells through regulation of mitochondrial function, which may provide new perspectives for developing effective therapies for PDR.

Speciation Analysis of the Uptake and Biodistribution of Nanoparticulate and Ionic Silver in Escherichia coli.

A new method was developed to determine the nanoparticulate and ionic silver (Ag) species in bacteria (Escherichia coli, E. coli). By removal of the cell wall with lysozyme, the cell surface-adsorbed Ag species were separated from the intracellular Ag species, which were extracted by tetramethylammonium hydroxide and determined by size-exclusion chromatography coupled with inductively coupled plasma mass spectrometry (SEC-ICP-MS). The detection limit is 3 ng/107 CFU/mL (where CFU is colony-forming unit) for both silver nanoparticles (AgNPs) and ionic Ag(I) species. The cell wall-adsorbed Ag was calculated by subtracting the contents of the intra- and extracellular Ag from the total exposure dose of Ag, and therefore the biodistribution of Ag species was profiled. We then applied this strategy to quantitatively analyze extra- and intracellular Ag species in E. coli after respective exposure to Ag+ and 10 and 30 nm AgNPs at different effective concentrations (EC10, EC50, and EC90). Results showed that the intracellular and cell wall-bound Ag account for 5.98-15.21% and 25.13-64.43% of the exposed dose, respectively, and AgNPs could transform into complexed or free Ag+. Our method opens new avenues for the quantitative analysis of the uptake and biodistribution of nanoparticles and their transformation species in bacteria.

Intracellular Dissolution of Silver Nanoparticles: Evidence from Double Stable Isotope Tracing.

To track transformations of silver nanoparticles (AgNPs) in vivo, HepG2 and A549 cells were cocultured with two enriched stable Ag isotopes (107AgNPs and 109AgNO3) at nontoxic doses. After enzymatic digestion, 107AgNPs, ionic 107Ag+ and 109Ag+ in exposed cells could be separated and quantified by liquid chromatography combined with ICP-MS. We found that ratios of 107Ag+ to total 107Ag and proportions of 107Ag+/ 109Ag+ in cells increased gradually after exposure, proving that the Trojan-horse mechanism occurred, i.e., AgNPs released high contents of Ag+ after internalization. While the presence of 109Ag+ (5 and 100 µg/L) has little influence on the uptake of 107AgNPs (0.1 and 2 mg/L), the presence of 107AgNPs at a high dose (2 mg/L) dramatically increases the ingestion of 109Ag+, even though 107AgNPs at a low dose (100 µg/L) showed negligible effects on the internalization of 109Ag+. Cellular homeostasis may be perturbed under sublethal exposure of 107AgNPs, and thus enhanced uptake of 109Ag+. Our findings suggest that the widely adopted control experiments in toxicology studies, culturing organisms with AgNO3 at the same concentration of Ag+ in the AgNP exposure medium, may underestimate uptake of Ag+ and thus cannot exclude suspected toxic effects of Ag+ at high AgNP exposure doses.

Ocular biometric characteristics of Han ethnicity in Tianjin and Uyghur ethnicity in Xinjiang undergoing cataract surgery.

AIM: To analyze and compare the differences among ocular biometric parameters in Han and Uyghur populations undergoing cataract surgery. METHODS: In this hospital-based prospective study, 410 patients undergoing cataract surgery (226 Han patients in Tianjin and 184 Uyghur patients in Xinjiang) were enrolled. The differences in axial length (AL), anterior chamber depth (ACD), keratometry [steep K (Ks) and flat K (Kf)], and corneal astigmatism (CA) measured using IOL Master 700 were compared between Han and Uyghur patients. RESULTS: The average age of Han patients was higher than that of Uyghur patients (70.22±8.54 vs 63.04±9.56y, P<0.001). After adjusting for age factors, Han patients had longer AL (23.51±1.05 vs 22.86±0.92 mm, P<0.001), deeper ACD (3.06±0.44 vs 2.97±0.37 mm, P=0.001), greater Kf (43.95±1.40 vs 43.42±1.69 D, P=0.001), steeper Ks (45.00±1.47 vs 44.26±1.71 D, P=0.001), and higher CA (1.04±0.68 vs 0.79±0.65, P=0.025) than Uyghur patients. Intra-ethnic male patients had longer AL, deeper ACD, and lower keratometry than female patients; however, CA between the sexes was almost similar. In the correlation analysis, we observed a positive correlation between AL and ACD in patients of both ethnicities (rHan =0.48, rUyghur =0.44, P<0.001), while AL was negatively correlated with Kf (rHan =-0.42, rUyghur =-0.64, P<0.001) and Ks (rHan =-0.38, rUyghur =-0.66, P<0.001). Additionally, Kf was positively correlated with Ks (rHan =0.89, rUyghur =0.93, P<0.001). CONCLUSION: There are differences in ocular biometric parameters between individuals of Han ethnicity in Tianjin and those of Uyghur ethnicity in Xinjiang undergoing cataract surgery. These ethnic variances can enhance our understanding of ocular diseases related to these parameters and provide guidance for surgical procedures.

[Expression and function of microRNA in the eye].

MicroRNA (miRNA), about 22 nt in length, are small single-strand RNA discovered in recent years that universally exist in the genome of creatures. They control physiological and pathological processes through regulation of gene expression at either posttranscriptional or translational level. Hundreds of miRNA have been confirmed to express in ocular tissues, and function as important regulators in physiological processes, including development, differentiation, regeneration after injury, as well as control of circadian rhythms in the eye. On the other hand, miRNA also play a crucial regulatory role in the pathogenesis and development of several ocular diseases, such as neovascularization, autoimmune uveitis, retinitis pigmentosa, glaucoma, and retinoblastoma. The mechanistic study on miRNA and their targets in physiology and pathology of the eye will provide the theoretical basis from which novel molecular therapy to ocular diseases stems.

Role of glycolysis in retinal vascular endothelium, glia, pigment epithelium, and photoreceptor cells and as therapeutic targets for related retinal diseases.

Glycolysis produces large amounts of adenosine triphosphate (ATP) in a short time. The retinal vascular endothelium feeds itself primarily through aerobic glycolysis with less ATP. But when it generates new vessels, aerobic glycolysis provides rapid and abundant ATP support for angiogenesis, and thus inhibition of glycolysis in endothelial cells can be a target for the treatment of neovascularization. Aerobic glycolysis has a protective effect on Müller cells, and it can provide with a target for visual protection and maintenance of the blood-retinal barrier. Under physiological conditions, the mitochondria of RPE can use lactic acid produced by photoreceptor cells as an energy source to provide ATP for survival. In pathological conditions, because RPE cells avoid their oxidative damage by increasing glycolysis, a large number of glycolysis products accumulate, which in turn has a toxic effect on photoreceptor cells. This shows that stabilizing the function of RPE mitochondria may become a target for the treatment of diseases such as retinal degeneration. The decrease of aerobic glycolysis leads to the decline of photoreceptor cell function and impaired vision; therefore, aerobic glycolysis of stable photoreceptor cells provides a reliable target for delaying vision loss. It is of great significance to study the role of glycolysis in various retinal cells for the targeted treatment of ocular fundus diseases.

Follistatin-like protein 1 functions as a potential target of gene therapy in proliferative diabetic retinopathy.

The degree of retinal fibrosis increased in proliferative diabetic retinopathy (PDR) patients after administration of anti-Vascular endothelial growth factor (VEGF) injections. Previous studies showed that the balance between connective tissue growth factor (CTGF) and VEGF plays an important role. Therefore, in a high-glucose state, an anti-VEGF and CTGFshRNA dual-target model was used to simulate clinical dual-target treatment in PDR patients, and RNA sequencing (RNA-Seq) technology was used for whole transcriptome sequencing. A hypoxia model was constructed to verify the sequencing results at the cellular level, and the vitreous humor and proliferative membranes were collected from patients for verification. All sequencing results included Follistatin-like protein 1 (FSTL1) and extracellular matrix (ECM) receptor pathway, indicated that anti-VEGF therapy may upregulate FSTL1 expression, while dual-target treatment downregulated FSTL1. Thus, we further studied the function of FSTL1 on the expression of VEGF and ECM factors by both overexpressing and silencing FSTL1. In conclusion, our results suggested that FSTL1 may be involved in the pathogenesis of PDR and is related to fibrosis caused by the anti-VEGF treatment, thus providing a potential target for gene therapy in PDR.

Protective Effect and Mechanism of Bone Morphogenetic Protein-4 on Apoptosis of Human Lens Epithelium Cells under Oxidative Stress.

Bone morphogenetic proteins (BMPs), a member of the transforming growth factor ß (TGF-ß) superfamily, are abundant in human ocular tissues and play an important role in lens development. Targeted deletion of BMP-4 in mice results in failure of lens placode formation. Following lens maturation, the formation of senile cataracts is demonstrably associated with free radical-related oxidative stress. Previous studies reported that BMPs play an antiapoptotic role in cells under oxidative stress, and the BMP-4 signal is important in inflammation regulation and homeostasis. BMP-4 evidently suppressed the apoptosis of human lens epithelial cells (HLECS) under oxidative stress induced by H2O2. This protective antiapoptotic effect is partly due to a decrease in caspase-3 activity and reactive oxygen species (ROS) level. Furthermore, the expression of activating transcription factor- (ATF-) 6 and Krüppel-like factor- (KLF-) 6 increased under oxidative stress and decreased after BMP-4 treatment.

A Protective Effect of PPARα in Endothelial Progenitor Cells Through Regulating Metabolism.

Deficiency of endothelial progenitor cells, including endothelial colony-forming cells (ECFCs) and circulating angiogenic cells (CACs), plays an important role in retinal vascular degeneration in diabetic retinopathy (DR). Fenofibrate, an agonist of peroxisome proliferator-activated receptor α (PPARα), has shown therapeutic effects on DR in both patients and diabetic animal models. However, the function of PPARα in ECFC/CACs has not been defined. In this study, we determined the regulation of ECFC/CAC by PPARα. As shown by flow cytometry and Seahorse analysis, ECFC/CAC numbers and mitochondrial function were decreased in the bone marrow, circulation, and retina of db/db mice, correlating with PPARα downregulation. Activation of PPARα by fenofibrate normalized ECFC/CAC numbers and mitochondrial function in diabetes. In contrast, PPARα knockout exacerbated ECFC/CAC number decreases and mitochondrial dysfunction in diabetic mice. Primary ECFCs from PPARα -/- mice displayed impaired proliferation, migration, and tube formation. Furthermore, PPARα -/- ECFCs showed reduced mitochondrial oxidation and glycolysis compared with wild type, correlating with decreases of Akt phosphorylation and expression of its downstream genes regulating ECFC fate and metabolism. These findings suggest that PPARα is an endogenous regulator of ECFC/CAC metabolism and cell fate. Diabetes-induced downregulation of PPARα contributes to ECFC/CAC deficiency and retinal vascular degeneration in DR.

Research progress on the role of connective tissue growth factor in fibrosis of diabetic retinopathy.

Diabetic retinopathy (DR) is one of the most important types of diabetic microangiopathy, which is a specific change of fundus lesions and is one of the most serious complications of diabetes. When DR develops to proliferative DR, the main factors of decreasing vision, and even blindness, include retinal detachment and vitreous hemorrhage caused by contraction of blood vessels by fiber membrane. Recent studies reported that the formation of fiber vascular membrane is closely related to retinal fibrosis. The connective tissue growth factor (CTGF) is a cytokine that is closely related to DR fibrosis. However, its mechanism is poorly understood. This paper summarizes the recent studies about CTGF on DR fibrosis for a comprehensive understanding of the role and mechanism of CTGF in PDR.

[Effects of centellaasiatica granule on the expression of Smad 2/3, Smad 7 and collagen â £ in the mesangial cells stably expressed TGF-ß1].

OBJECTIVES: Stably expressed transforming growth factor -beta 1(TGF-ß1)MCs were obtained and the effects of centellaasiatica (CA) granule on the expressions of Smad 2/3, Smad 7 and collagen Ⅳ and the level of Smad 2/3 phosphorylation were observed. METHODS: Lipofectin method was used to transfect TGF-ß1 vector into MC, and the stably expressed TGF-ß1 cell lines were selected by G418. The cells were divided into three groups. Control group:normal MC + RPMI 1640 + 10% normal rat serum; TGF-ß1 group:stably expressed TGF-ß1 MC + RPMI 1640 + 10% normal rat serum; CA group:stably expressed TGF-ß1 MC + RPMI 1640 + 10% rat serum containing high CA. The experiments were repeated for five times. The contents of TGF-ß1 and collagen Ⅳ in the culture medium were detected with ELISA, the expressions of mRNA and protein of TGF-ß1, Smad 2/3, Smad 7 and the level of Smad 2/3 phosphorylation were detected by using real time quantitative polymerase chain reaction and Western blot. RESULTS: The contents of TGF-ß1 and collagen Ⅳ in the culture medium of stably-expressed TGF-ß1 MC were increased significantly, and the CA could reverse the effects of TGF-ß1. The expressions of mRNA and protein of TGF-ß1, Smad 2/3 and the level of Smad 2/3 phosphorylation were increased significantly in TGF-ß1 transfected MC, and CA could dramatically reduce the expressions of mRNA and protein of TGF-ß1, Smad 2/3 and the level of Smad 2/3 phosphorylation. The high expression of TGF-ß1 decreased the expression of Smad 7 mRNA and protein, and the CA could antagonize the effect of mRNA expression. CONCLUSIONS: The MCs stably-expressed TGF-ß1 can activate the TGF-ß1/Smad signal pathway and increase the expression of collagen Ⅳ. CA can decrease the occurrence of diabetic nephropathy(DN) by reducing the production of collagen Ⅳ through inhibiting the TGF-ß1/Smad signal pathway.

[Influence of Dust Events on the Concentration and Size Distribution of Microorganisms in Bioaerosols].

In order to study the influence of dust events on the airborne microbes in atmospheric bioaerosols, bioaerosol samples were continuously collected from March to April 2015 during two dust events using size-fractionated bioaerosol samplers in Lanzhou and Qingdao. The concentration of airborne microbes were measured using an epifluorescence microscope after staining with DAPI (4',6-diamidino-2-phenylindole). The results showed that the concentration of airborne microbes increased significantly during the period of dust (P<0.05). The average concentrations of airborne microbes on sunny days were 5.61×105 cells·m-3 and 2.08×105 cells·m-3 in Lanzhou and Qingdao, respectively, whereas the mean concentrations on dusty days were 14.8 times and 6.42 times those on sunny days, respectively. The concentration of airborne microbes presented a bimodal size distribution on sunny days in Lanzhou and Qingdao, with a peak at>7.0 µm and the lowest values ranging from 4.7 µm to 7.0 µm. However, the second peak appeared at 3.3-4.7 µm and 1.1-2.1 µm in Lanzhou and Qingdao, respectively. The size distribution of airborne microbes changed during the dust period. The size distribution of microbes still presented a bimodal distribution in Lanzhou; however, one peak shifted from>7.0 µm to 1.1-2.1 µm. The size distribution in Qingdao changed from a bimodal distribution to a skewed distribution with the predominant fraction in coarse mode. The background values of microbial load in PM10 before the dust were 2224 cells·µg-1 and 1550 cells·µg-1 in Lanzhou and Qingdao, respectively, and the highest value of such increased significantly to 26442 cells·µg-1 and 10250 cells·µg-1 during the dust events, respectively. This demonstrated that the high concentration of microbes in the dust events resulted not only from increased atmospheric particles but also from dust source and transportation path along with long-range transported dust particles.

Therapeutic effects of mesenchymal stem cells administered at later phase of recurrent experimental autoimmune uveitis.

AIM: To test the therapeutic effects of delayed treatment of mesenchymal stem cells (MSCs) in recurrent experimental autoimmune uveitis (rEAU). METHODS: The efficacy of different regimens of MSC administration in rEAU were tested by evaluation of clinical and pathological intraocular inflammation, as well as retinal structural and functional integrity using optical coherence tomography (OCT) and electroretinogram (ERG). The retinal sections were also immunostained with antibodies to glial fibrillary acidic protein (GFAP) and rhodopsin (RHO). RESULTS: Delayed treatment of MSCs effectively alleviated the severity of intraocular inflammation with relative intact of outer retinal structure and function. Moreover, double therapies with longer interval led to an even better clinical evaluation, as well as a trend of decrease in relapse and amelioration of retinal function. MSC therapies also effectively reduced GFAP expression and increased RHO expression in the retina. CONCLUSION: MSC administration can effectively treat developed diseases of rEAU, and multiple therapies can provide additional therapeutic benefits.

Achromatopsia caused by novel missense mutations in the CNGA3 gene.

AIM: To identify the genetic defects in a Chinese family with achromatopsia. METHODS: A 2.5-year-old boy, who displayed nystagmus, photophobia, and hyperopia since early infancy, was clinically evaluated. To further confirm and localize the causative mutations in this family, targeted region capture and next-generation sequencing of candidate genes, such as CNGA3, CNGB3, GNAT2, PDE6C, and PDE6H were performed using a custom-made capture array. RESULTS: Slit-lamp examination showed no specific findings in the anterior segments. The optic discs and maculae were normal on fundoscopy. The unaffected family members reported no ocular complaints. Clinical signs and symptoms were consistent with a clinical impression of autosomal recessive achromatopsia. The results of sequence analysis revealed two novel missense mutations in CNGA3, c.633T>A (p.D211E) and c.1006G>T (p.V336F), with an autosomal recessive mode of inheritance. CONCLUSION: Genetic analysis of a Chinese family confirmed the clinical diagnosis of achromatopsia. Two novel mutations were identified in CNGA3, which extended the mutation spectrum of this disorder.

Temporal and spatial changes in VEGF, αA- and αB-crystallin expression in a mouse model of oxygen-induced retinopathy.

OBJECTIVE: Retinal neovascularization is an iconic change in retinopathies. Vascular Endothelial Growth Factor (VEGF) and α-crystallins have been identified to mediate the pathogenesis of retinopathy. However, the special and temporal changes in their expression associated with retinal neovascularization have not yet been determined. Therefore, we examined the expression and distribution of VEGF, αA- and αB-crystallins in the retina using a mouse model of oxygen-induced retinopathy (OIR). METHODS: 90 C57/BL mice were randomly divided into the OIR and control groups. The OIR group at postnatal day 7 (P7) were kept at high oxidation state (75 ± 5%) for 5 days before returned to normal environment. Retinal tissue was cut into sections. Oxygen induced retinal neovascularization and vascular structural changes were evaluated using retinal fluorescein angiography. The number of endothelial cell nuclei breaking through the retinal internal limiting membrane was counted after H&E staining. The mRNA expression levels of VEGF, αA- and αB-crystallins in the mouse retina were determined using real-time RT-PCR. The distribution of αA- and αB-crystallins in the retina was detected by fluorescent immunohistochemistry staining. RESULTS: Oxygen induction triggered new blood vessel formation in the retina and impaired the structure of the retinal vascular network. The number of endothelial cell nuclei breaking through the retinal internal limiting membrane was significantly increased in the OIR group compared to the control group at P13, P17 and P21 (P < 0.01), reaching the peak on P17. The expression levels of VEGF, αA- and αB-crystalllins were also significantly different between the OIR and control groups. VEGF expression was highest on P15, αA-crystallin expression was highest on P17, whereas αB-crystallin expression kept increasing during the time frame of our study. Both αA- and αB-crystallins were expressed in the ganglion cell layer and the inner nuclear cell layer. While αA- and αB-crystallins were only located on the cell membrane in the outer ganglion cell layer, they were observed both on the cell membrane and in the cytoplasm in the inner layer of cells. CONCLUSION: Using our mouse model of oxygen-induced retinopathy, we showed that the expression patterns of VEGF, αA- and αB-crystallins during retinal neovascularization in both spatially and temporally manners, providing significant insights into the molecular mechanisms of retinopathy and the associated neovascularization.

Surgical induced astigmatism correlated with corneal pachymetry and intraocular pressure: transconjunctival sutureless 23-gauge versus 20-gauge sutured vitrectomy in diabetes mellitus.

AIM: To determine the difference of surgical induced astigmatism between conventional 20-gauge sutured vitrectomy and 23-gauge transconjunctival sutureless vitrectomy, and the influence of corneal pachymetry and intraocular pressure (IOP) on surgical induced astigmatism in diabetic patients. METHODS: This retrospective, consecutive case series consisted of 40 eyes of 38 diabetic subjects who underwent either 20-gauge or 23-gauge vitrectomy. The corneal curvature and thickness were measured with Scheimpflug imaging before surgery and 1wk; 1, 3mo after surgery. We compared the surgical induced astigmatism (SIA) on the true net power in 23-gauge group with that in 20-gauge group. We determined the correlation between corneal thickness change ratio, IOP and SIA measured by Pentacam. RESULTS: The mean SIAs were 1.082±0.085 D (mean±SEM), 0.689±0.070 D and 0.459±0.063 D at postoperative 1wk; 1, 3mo respectively in diabetic subjects. The vitrectomy induced astigmatisms were declined significantly with time (F 2,36=33.629, P=0.000) postoperatively. The 23-gauge surgery group induced significantly less astigmatism than 20-gauge surgery group (F -1,37=11.046, P=0.020). Corneal thickness in diabetes elevated after surgery (F 3,78=10.532, P=0.000). The linear regression analysis at postoperatively 1wk went as: SIA=-4.519+4.931 change ratio (Port3) +0.026 IOP (R(2)=0.46, P=0.000), whereas the rate of corneal thickness change and IOP showed no correlation with the change of astigmatism at postoperatively 1 and 3mo. CONCLUSION: There are significant serial changes in both 20-gauge and 23-gauge group in diabetic subjects. 23-gauge induce less astigmatism than 20-gauge and become stable more rapidly than 20-gauge. The elevation of corneal thickness and IOP was associated with increased astigmatim at the early postoperative stage both in 23-gauge and 20-gauge surgery group.

Development of retinal pigment epithelium from human parthenogenetic embryonic stem cells and microRNA signature.

PURPOSE: We investigated the potential of human parthenogenetic embryonic stem cells (hPESCs) to differentiate into RPE cells, and identified development-regulating microRNAs (miRNAs). METHODS: RPE cells were derived from hPESCs. The expression of markers and miRNA expression profiles during differentiation were studied by immunocytochemistry, real-time RT-PCR, and miRNA expression array at three time points. Human fetal RPE (hfRPE) cells also were analyzed. The target genes of candidate miRNAs then were validated. RESULTS: hPESC-derived RPE cells exhibited similar morphology and pigmentation to hfRPE cells. The expression of markers during differentiation indicated that the hPESC-derived RPE cells were immature. Most specific miRNAs had a role at some time point during the differentiation and maturation of RPE from hPESCs, except for two miRNAs (miR-204 and the miR-302 family). The miR-204 was upregulated and miR-302 was down-regulated throughout the process. Subsequently, pigmented clusters and RPE signature gene expression increased significantly in the miR-204 overexpression group and miR-302 inhibition group compared to the control groups. CTNNBIP1 and TGFBR2 were confirmed to be the target genes of miR-204 and miR-302, respectively. CONCLUSIONS: hPESCs can develop into RPE-like cells and, thus, can be additional promising sources of RPE cells in cell therapy. The miR-204, miR-302s, and their targets are involved in regulating directed differentiation during the full course, thereby contributing to the search for a new method of improving differentiation efficiency using miRNAs.

MicroRNA-34a targets notch1 and inhibits cell proliferation in glioblastoma multiforme.

Aberrant expression of microRNAs (miRNAs) has been implicated in cancer initiation and progression. In this study, we found that microRNA-34a (miR-34a) is significantly downregulated in glioblastoma multiforme (GBM) specimens compared with normal brain tissues. Growth curve and colony formation assays revealed that miR-34a suppresses proliferation of U373MG and SHG44 glioblastoma cells. Overexpression of miR-34a could induce apoptosis of glioblastoma cells. Also, we identified notch1 as a direct target gene of miR-34a. Knockdown of notch1 showed similar cellular functions as overexpression of miR-34a both in vitro and in vivo. Collectively, our findings show that miR-34a is downregulated in GBM cells and inhibits GBM growth by targeting notch1.