Potential New Target for Dry Eye Disease-Oxidative Stress

Dry eye disease (DED) is a multifactorial condition affecting the ocular surface. It is characterized by loss of tear film homeostasis and accompanied by ocular symptoms that may potentially result in damage to the ocular surface and even vision loss. Unmodifiable risk factors for DED mainly include aging, hormonal changes, and lifestyle issues such as reduced sleep duration, increased screen exposure, smoking, and ethanol consumption. As its prevalence continues to rise, DED has garnered considerable attention, prompting the exploration of potential new therapeutic targets. Recent studies have found that when the production of ROS exceeds the capacity of the antioxidant defense system on the ocular surface, oxidative stress ensues, leading to cellular apoptosis and further oxidative damage. These events can exacerbate inflammation and cellular stress responses, further increasing ROS levels and promoting a vicious cycle of oxidative stress in DED. Therefore, given the central role of reactive oxygen species in the vicious cycle of inflammation in DED, strategies involving antioxidants have emerged as a novel approach for its treatment. This review aims to enhance our understanding of the intricate relationship between oxidative stress and DED, thereby providing directions to explore innovative therapeutic approaches for this complex ocular disorder.

Relation Between Corneal Dendritic Cell Density and Tear Film Stability in Patients with Epidemic Keratoconjunctivitis Associated Dry Eye

PURPOSE

To clarify the ocular surface features of patients with recent history of epidemic keratoconjunctivitis (EKC) and the relation between corneal dendritic cells (DCs) and ocular discomfort.

METHODS

Normal controls (NC) and dry eye (DE) patients without EKC were recruited. Patients with recent EKC history (onset >4 weeks, but <20 weeks) were recruited as EKC + DE group (with dry eye) or EKC-DE group (without dry eye). Ocular surface disease index (OSDI) questionnaire, tear film parameters including lipid layer thickness, first tear break-up time (fBUT), average tear break-up time (aBUT), tear meniscus height and Schirmer I test, meibomian gland parameters, and in vivo corneal confocal microscopy were evaluated.

RESULTS

50 subjects in the NC group, 83 patients in the DE group, 76 patients in the EKC + DE group, and 38 patients in the EKC-DE group were included. Compared with the NC, DE, and EKC-DE groups, the EKC + DE group represented higher OSDI, lid margin, and meibum score (p < 0.05). In the EKC + DE group, the tear volume (10.5 ± 3.7 mm) was significantly higher than in the DE group (8.1 ± 2.8 mm, p < 0.001). The DC density in the EKC + DE group (29.98 ± 15.38 cells/image) was significantly higher than in NC, DE, and EKC-DE groups (4.68 ± 4.05 cells/image) (p < 0.001). The DC density was positively correlated with OSDI, lid margin, and meibum score (all p < 0.01) while inversely correlated with fBUT, aBUT (all p < 0.001) in the EKC + DE group.

CONCLUSIONS

Corneal DC density significantly correlates to ocular discomfort and tear film instability in patients with recent EKC history who suffer from DE without aqueous tear deficiency.

Exploration and validation of a combined Hypoxia and m6A/m5C/m1A regulated gene signature for prognosis prediction of liver cancer

BACKGROUND

It is widely acknowledged that hypoxia and m6A/m5C/m1A RNA modifications promote the occurrence and development of tumors by regulating the tumor microenvironment. This study aimed to establish a novel liver cancer risk signature based on hypoxia and m6A/m5C/m1A modifications.

METHODS

We collected data from The Cancer Genome Atlas (TCGA-LIHC), the National Omics Data Encyclopedia (NODE-HCC), the International Cancer Genome Consortium (ICGC), and the Gene Expression Omnibus (GEO) databases for our study (GSE59729, GSE41666). Using Cox regression and least absolute shrinkage and selection operator (LASSO) method, we developed a risk signature for liver cancer based on differentially expressed genes related to hypoxia and genes regulated by m6A/m5C/m1A modifications. We stratified patients into high- and low-risk groups and assessed differences between these groups in terms of gene mutations, copy number variations, pathway enrichment, stemness scores, immune infiltration, and predictive capabilities of the model for immunotherapy and chemotherapy efficacy.

RESULTS

Our analysis revealed a significantly correlated between hypoxia and methylation as well as m6A/m5C/m1A RNA methylation. The three-gene prognosis signature (CEP55, DPH2, SMS) combining hypoxia and m6A/m5C/m1A regulated genes exhibited strong predictive performance in TCGA-LIHC, NODE-HCC, and ICGC-LIHC-JP cohorts. The low-risk group demonstrated a significantly better overall survival compared to the high-risk group (p < 0.0001 in TCGA, p = 0.0043 in NODE, p = 0.0015 in ICGC). The area under the curve (AUC) values for survival at 1, 2, and 3 years are all greater than 0.65 in the three cohorts. Univariate and Multivariate Cox regression analyses of the three datasets indicated that the signature could serve as an independent prognostic predictor (p < 0.001 in the three cohorts). The high-risk group exhibited more genome changes and higher homologous recombination deficiency scores and stemness scores. Analysis of immune infiltration and immune activation confirmed that the signature was associated with various immune microenvironment characteristics. Finally, patients in the high-risk group experienced a more favorable response to immunotherapy, and various common chemotherapy drugs.

CONCLUSION

Our prognostic signature which integrates hypoxia and m6A/m5C/m1A-regulated genes, provides valuable insights for clinical prediction and treatment guidance for liver cancer patients.

Idiopathic Epiretinal Membrane Surgery in Patients Aged Over 80 Years: Efficacy and Safety

Purpose

To evaluate the efficacy and safety of idiopathic epiretinal membrane (ERM) surgery in patients aged over 80 years.

Methods

Consecutive patients who underwent pars plana vitrectomy (PPV) combined with ERM and internal limiting membrane (ILM) peeling with retrobulbar anesthesia were recruited. Based on age, the patients were divided into the elderly group (≥ 80 years of age) and the control group (< 80 years of age). The best-corrected visual acuity (BCVA) and surgical complications were regarded as the main measurement indicators.

Results

This study included 43 eyes from 43 patients aged 80 to 91 years and 86 eyes from 86 patients aged 54 to 79 years. Surgical intervention substantially improved BCVA both in the elderly and control groups (p = 0.005 and p < 0.001, respectively). Statistical analyses showed no significant difference in the incidence of surgical complications between the two groups (p = 0.631). The operations in either group were not delayed or canceled for the reason of complications of retrobulbar anesthesia, severe anxiety, or physical discomfort in the perioperative period. Moreover, no patient required a second operation. Also, no stroke, myocardial infarction, or death occurred during the follow-up period. All the surgical complications were treated satisfactorily.

Conclusion

Our outcomes indicate that PPV combined with ERM and ILM peeling with retrobulbar anesthesia is effective and safe in elderly patients aged 80 years or older. Based on age alone, we believe that advancing age should not be the risk factor for idiopathic ERM surgery.

Limbal Stem Cell Dysfunction Induced by Severe Dry Eye via Activation of the p38 MAPK Signaling Pathway

Severe dry eye (SDE) can cause grievous damage to the ocular surface and result in vision impairment and even blindness. To investigate the fate of limbal stem cells in SDE and the underlying mechanism, the current study established an SDE rat model by removing the extraorbital and infraorbital lacrimal glands and maintaining them in a low-humidity environment. One month after the surgery, aqueous tear secretion was reduced dramatically, blood vessels invaded into the central cornea, and inflammatory cells infiltrated into the limbal stroma. The expressions of keratin 12 and paired box gene 6 were down-regulated dramatically, while those of keratin 10, small proline-rich protein 1b, and mucin 5AC were up-regulated in the corneal epithelium of the SDE rats. Cell proliferation in the limbal epithelium was up-regulated, while the stem/progenitor marker adenosine 5'-triphosphate-binding cassette member 2 and the limbal epithelial colony-forming efficiency were decreased in the SDE condition. Furthermore, the p38 mitogen-activated protein kinase signaling pathway was activated in the limbal corneal epithelium of SDE rats. The abnormal differentiation and stemness loss in the corneal epithelium could be reversed upon treatment with a p38 inhibitor in a SDE in vivo model and in vitro hyperosmolar corneal epithelial culture conditions. These data suggest that SDE can lead to limbal stem cell dysfunction, and p38 mitogen-activated protein kinase signaling pathway activation plays an essential role in this process.

Novel prognostic gene signature for pancreatic ductal adenocarcinoma based on hypoxia

BACKGROUND

Currently, there is lack of marker to accurately assess the prognosis of patients diagnosed with pancreatic ductal adenocarcinoma (PDAC). This study aims to establish a hypoxia-related risk scoring model that can effectively predict the prognosis and chemotherapy outcomes of PDAC patients.

METHODS

Using unsupervised consensus clustering algorithms, we comprehensively analyzed The Cancer Genome Atlas (TCGA) data to identify two distinct hypoxia clusters and used the weighted gene co-expression network analysis (WGCNA) to examine gene sets significantly associated with these hypoxia clusters. Then univariate Cox regression, the least absolute shrinkage and selection operator (LASSO) Cox regression and multivariate Cox regression were used to construct a signature and its efficacy was evaluated using the International Cancer Genome Consortium (ICGC) PDAC cohort. Further, the correlation between the risk scores obtained from the signature and carious clinical, pathological, immunophenotype, and immunoinfiltration factors as well as the differences in immunotherapy potential and response to common chemotherapy drugs between high-risk and low-risk groups were evaluated.

RESULTS

From a total of 8 significantly related modules and 4423 genes, 5 hypoxia-related signature genes were identified to construct a risk model. Further analysis revealed that the overall survival rate (OS) of patients in the low-risk group was significantly higher than the high-risk group. Univariate and multivariate Cox regression analysis showed that the risk scoring signature was an independent factor for prognosis prediction. Analysis of immunocyte infiltration and immunophenotype showed that the immune score and the anticancer immune response in the high-risk were significantly lower than that in the low-risk group.

CONCLUSION

The constructed hypoxia-associated prognostic signature demonstrated could be used as a potential risk classifier for PDAC.

A Novel Pancreatic Cancer Hypoxia Status Related Gene Signature for Prognosis and Therapeutic Responses

Pancreatic cancer (PAC) is a highly fatal and aggressive type of cancer. Hypoxia is a common feature of PAC. The aim of this study was to develop a hypoxia status-related prognostic model for predicting the survival outcomes in PAC. The data sets of PAC from The Cancer Genome Atlas and the International Cancer Genome Consortium were used to construct and validate the signature. A 6 hypoxia status-related differential expression genes prognostic model for predicting the survival outcomes was established. The Kaplan-Meier analysis and Received operating characteristic curve indicated the good performance of the signature at predicting overall survival. Univariate and Multivariate Cox regression revealed that the signature was an independent prognostic factor in PAC. Weighted Gene Co-expression Network Analysis and immune infiltration analysis indicated that Immune-related pathways and immune cell infiltration was mostly enriched in the low-risk group, which presented a better prognosis. We also evaluated the predictive of the signature for immunotherapy and chemoradiotherapy. Risk gene LY6D may be a potential prognostic predictor of PAC. This model can be used as an independent prognostic factor for predicting clinical outcomes and a possible classifier for response to chemotherapy.

NirS-type denitrifying bacteria in aerobic water layers of two drinking water reservoirs: Insights into the abundance, community diversity and co-existence model

The nirS-type denitrifying bacterial community is the main drivers of the nitrogen loss process in drinking water reservoir ecosystems. The temporal patterns in nirS gene abundance and nirS-type denitrifying bacterial community harbored in aerobic water layers of drinking water reservoirs have not been studied well. In this study, quantitative polymerase chain reaction (qPCR) and Illumina Miseq sequencing were employed to explore the nirS gene abundance and denitrifying bacterial community structure in two drinking water reservoirs. The overall results showed that the water quality parameters in two reservoirs had obvious differences. The qPCR results suggested that nirS gene abundance ranged from (2.61 ± 0.12) × 10⁵ to (3.68 ± 0.16) × 10⁵ copies/mL and (3.01 ± 0.12) × 10⁵ to (5.36 ± 0.31) × 10⁵ copies/mL in Jinpen and Lijiahe reservoirs, respectively. The sequencing results revealed that Paracoccus sp., Azoarcus sp., Dechloromonas sp. and Thauera sp. were the dominant genera observed. At species level, Cupriavidus necator, Dechloromonas sp. R-28400, Paracoccus denitrificans and Pseudomonas stutzeri accounted for more proportions in two reservoirs. More importantly, the co-occurrence network analysis demonstrated that Paracoccus sp. R-24615 and Staphylococcus sp. N23 were the keystone species observed in Jinpen and Lijiahe reservoirs, respectively. Redundancy analysis indicated that water quality (particularly turbidity, water temperature, pH and Chlorophyll a) and sampling time had significant influence on the nirS-type denitrifying bacterial community in both reservoirs. These results will shed new lights on exploring the dynamics of nirS-type denitrifying bacteria in aerobic water layers of drinking water reservoirs.

Downregulation of p38 MAPK signaling pathway ameliorates tissue engineered corneal epithelium

Tissue engineered corneal epithelium transplantation is effective treatment for severe limbal stem cell deficiency (LSCD), while epithelial terminal differentiation, tans-differentiation and insufficient stem cell during construction affects the quality of tissue engineered corneal epithelium. In this study, we applied SB203580 in the culture medium to downregulate the P38 MAPK signaling pathway during construction of tissue engineered corneal epithelium. With application of SB203580, tissue engineered corneal epithelium showed enhanced strength and condensed structure. The expression of progenitor cell markers ABCG2, P63, K14, Wnt7a was increased, differentiation markers K12, Pax6, K10, K13, and trans-differentiation markers α-SMA and Snail1 was decreased, while cell junction markers Claudin-1 and E-cadherin was increased in the tissue engineered corneal epithelium. The wnt/β-catenin signaling pathway was upregulated in the epithelium after p38 MAPK inhibition. Transplantation of tissue engineered corneal epithelium treated with SB203580 to rabbit LSCD model showed faster wound healing and improved epithelial quality. We conclude that downregulation of p38 MAPK signaling pathway helps maintain the stemness, prevent terminal differentiation and abnormal differentiation of corneal epithelial cells during epithelium construction process, thus can improve the quality of tissue engineered corneal epithelium.

Ovalbumin-Induced Allergic Inflammation Diminishes Cross-Linked Collagen Structures in an Experimental Rabbit Model of Corneal Cross-Linking

Background

Allergic conjunctivitis (AC) is one of the reported potential risk factors of progression in keratoconus patients after corneal cross-linking surgery; however, the causal relationship is still inconclusive. Recent studies have indicated that various inflammatory cytokines play a vital role in the development of primary keratoconus. It is still unclear whether these inflammatory mediators also trigger CXL failures. This study aimed to investigate the impact of AC on the rabbit corneas after trans-epithelial corneal cross-linking (TCXL).

Methods

A total of six rabbits were kept untreated as the normal control (NC) group. A total of 18 rabbits were treated by TCXL and divided into three groups (six in each group), namely, no treatment (TCXL group); induction of AC (TCXL + AC group); and induction of AC plus topical prednisolone acetate (TCXL + AC + PA group), according to additional treatment. AC was induced by topical application of ovalbumin after intraperitoneal pre-sensitization with ovalbumin. Rabbits were evaluated by slit lamp, in vivo laser scanning confocal microscopy, anterior segment optical coherence tomography, and measurement of corneal biomechanics. The cornea specimens were collected for the transmission electron microscope, the collagenase I digestion test, and PCR assay for TNF-α, IL-6, IL-1β, matrix metalloproteinase 9 (MMP-9), lysyl oxidase (LOX), and tissue inhibitor of metalloproteinases 1 (TIMP-1) on the day (D) 28.

Results

On D28, the TNF-α, IL-6, IL-1β, MMP-9, and LOX levels were significantly increased while the TIMP-1 was decreased in the TCXL + AC group when compared with the TCXL and TCXL + AC + PA groups. In vivo confocal microscopy revealed that at a depth of 150–210 μm, a trabecular patterned hyperdense structure surrounded by elongated needle-like processes could be observed in the TCXL and TCXL + AC + PA groups, but hardly seen in the TCXL + AC group. The demarcation lines were indistinct and blurred in the TCXL + AC group. An electron microscope demonstrated less interlacing fibril lamellae and higher interfibrillar spacing in the TCXL + AC group. The stability of corneal biomechanics and resistance to collagenase were decreased in the TCXL + AC group.

Conclusion

The corneal microstructures induced by TCXL and biomechanical stability were diminished in rabbits with AC but could be maintained by topical anti-inflammatory treatment. Our results supported the causal relationship between altered cytokine profiles and corneal microstructure after primary corneal cross-linking.

Obstructive Sleep Apnea Affects Lacrimal Gland Function

Purpose

To determine the effect of obstructive sleep apnea syndrome (OSA) on lacrimal gland function and its mechanism.

Methods

Male mice aged seven to eight weeks were housed in cages with cyclic intermittent hypoxia to mimic OSA, and the control group was kept in a normal environment. Slit-lamp observation, fluorescein staining, and corneal sensitivity detection are used to assess cornea changes. Tear secretion was detected by phenol red cotton thread, and the pathological changes of lacrimal gland were observed by hematoxylin and eosin staining, oil red O staining, cholesterol and triglyceride kits, immunofluorescence staining, immunohistochemical staining, real-time polymerase chain reaction, transmission electron microscopy, and Western blot.

Results

Studies revealed a decreased tear secretion, corneal epithelial defects and corneal hypersensitivity. Myoepithelial cell damage, abnormal lipid accumulation, reduced cell proliferation, increased apoptosis and inflammatory cell infiltration in the lacrimal gland were also seen. Hifα and NF-κB signaling pathways, moreover, were activated, while Pparα was downregulated, in the lacrimal glands of OSA mice. Fenofibrate treatment significantly alleviated pathological changes of the lacrimal gland induced by OSA.

Conclusion

OSA disturbs the Hifα/Pparα/NF-κB signaling axis, which affects lacrimal gland structure and function and induces dry eye.

Sodium MRI at 7T for Early Response Evaluation of Intracranial Tumors following Stereotactic Radiotherapy Using the CyberKnife

BACKGROUND AND PURPOSE

Conventionally, early treatment response to stereotactic radiotherapy in intracranial tumors is often determined by structural MR imaging. Tissue sodium concentration is altered by cellular integrity and energy status in cells. In this study, we aimed to investigate the feasibility of sodium MR imaging at 7T for the preliminary evaluation of radiotherapeutic efficacy for intracranial tumors.

MATERIALS AND METHODS

Data were collected from 16 patients (12 men and 4 women, 24-75 years of age) with 22 intracranial tumors who were treated with stereotactic radiation therapy using CyberKnife at our institution between December 1, 2016, and August 15, 2019. Sodium MR imaging was performed at 7T before and 48 hours, 1 week, and 1 month after CyberKnife radiation therapy. Tissue sodium concentration (TSC) was calculated and analyzed based on manually labeled regions of tumors.

RESULTS

Ultra-high-field sodium MR imaging clearly showed the intratumoral signal, which is significantly higher than that of normal tissue (t = 5.250, P <.001)., but the edema zone has some influence. The average TSC ratios of tumor to CSF in the 22 tumors, contralateral normal tissues, edema zones, frontal cortex, and frontal white matter were 0.66 (range, 0.23-1.5), 0.30 (range, 0.15-0.43), 0.58 (range, 0.25-1.21), 0.25 (range, 0.17-0.42), and 0.30 (range, 0.19-0.49), respectively. A total of 12 tumors in 8 patients were scanned at 48 hours, 1 week, and 1 month after treatment. The average TSC at 48 hours after treatment was 0.06 higher than that before treatment and began to decrease at 1 week. The TSC ratios of 10 continued to decline and 2 tumors increased at 1 month, respectively. Tumor volume decreased by 2.4%-99% after 3 months.

CONCLUSIONS

Changes in the TSC can be quantified by sodium MR imaging at 7T and used to detect radiobiologic alterations in intracranial tumors at early time points after CyberKnife radiation therapy.

Hyperglycemia Induces Meibomian Gland Dysfunction

Purpose

Patients diagnosed with diabetes are inclined to have abnormalities on stability of tear film and disorder of meibomian gland (MG). This study aims to explore the pathological change of MG induced by diabetes in a rat model.

Methods

Sprague-Dawley (SD) rats were intraperitoneally injected with streptozotocin (STZ) to establish a diabetic animal model. Lipid accumulation in MG was detected by Oil Red O staining and LipidTox staining. Cell proliferation status was determined by Ki67 and P63 immunostaining, whereas cell apoptosis was confirmed by TUNEL assay. Gene expression of inflammatory cytokines and adhesion molecules IL-1α, IL-1β, ELAM1, ICAM1, and VCAM1 were detected by RT-PCR. Activation of ERK, NF-κB, and AMPK signaling pathways was determined by Western Blot analysis. Oxidative stress-related factors NOX4, 4HNE, Nrf2, HO-1, and SOD2 were detected by immunostaining or Western Blot analysis. Tom20 and Tim23 immunostaining and transmission electron microscopy were performed to evaluate the mitochondria functional and structure change.

Results

Four months after STZ injection, there was acini dropout in MG of diabetic rats. Evident infiltration of inflammatory cells, increased expression of inflammatory factors, and adhesion molecules, as well as activated ERK and NF-κB signaling pathways were identified. Oxidative stress of MG was evident in 4-month diabetic rats. Phospho-AMPK was downregulated in MG of 2-month diabetic rats and more prominent in 4-month rats. After metformin treatment, phospho-AMPK was upregulated and the morphology of MG was well maintained. Moreover, inflammation and oxidative stress of MG were alleviated after metformin intervention.

Conclusions

Long-term diabetes may lead to Meibomian gland dysfunction (MGD). AMPK may be a therapeutic target of MGD induced by diabetes.

Effects of hydrogen peroxide on Scenedesmus obliquus: Cell growth, antioxidant enzyme activity and intracellular protein fingerprinting

Hydrogen peroxide (H₂O₂) is an environmental-friendly algicide and it is widely used to control algal blooms in aquatic ecosystems. However, the response of algal cell metabolic characteristics and intracellular protein profile under H₂O₂ stress is still not well understood. In the present study, the green alga Scenedesmus obliquus was exposed to different concentrations of H₂O₂ (0, 2, 6, 8 and 10 mg L^-1) to evaluate the changes in algal morphological, physiological, and proteomic features to H₂O₂ exposure. The results showed that 8 mg L^-1 of H₂O₂ could effectively inhibit the cell growth and photosynthetic activity of S. obliquus including chlorophyll-a content and chlorophyll fluorescence parameters. The increased activities of superoxide dismutase (SOD) and catalase (CAT) observed in this study indicate that cells exposure to H₂O₂ caused oxidative stress. The metabolic activity of S. obliquus was significantly decreased by H₂O₂ treatment. In terms of proteomic analysis, 251 differentially expressed proteins (DEPs) were successfully identified. The Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analysis revealed significant protein enrichment in the metabolic pathways, photosynthesis, ascorbic acid, and alginate metabolism and phenylpropane biosynthesis of S. obliquus. The analysis of protein-protein interaction system shows that the pathways of photosynthesis and metabolic pathways of S. obliquus were essential to resist oxidative stress. Taking together, these results shed new lights on exploring the cell physiological metabolism and intracellular protein mechanisms of H₂O₂ inhibition on algal blooms.

Autophagy positively regulates Wnt signaling in mice with diabetic retinopathy

Diabetic retinopathy (DR) is a microvascular complication of diabetes. Aberrant Wnt signaling activation plays a pathological role in DR. However, the underlying mechanisms of aberrant Wnt signaling in DR remain unknown. Autophagy has been reported to be involved in the pathophysiology of DR. The present study aimed therefore to investigate the regulatory effects of autophagy on Wnt signaling in DR. Wnt signaling was activated in the retina of db/db mice combined with an increase in the expression of the autophagic proteins microtubule-associated protein 1A/1B-light chain 3 and beclin-1 and a decrease in the expression of the autophagic protein P62. Inhibition of autophagy by 3-methyladenin decreased Wnt signaling in diabetic retinas, indicating a potential association between Wnt signaling and autophagy. Rapamycin, an autophagy inducer, upregulated Wnt signaling in the retina of normal C57BL/6J mice. In cultured Müller cells, rapamycin induced autophagy and activated Wnt signaling, while chloroquine, an autophagy inhibitor, inhibited autophagy and downregulated Wnt signaling, suggesting that autophagy could regulate Wnt signaling in mice retina and retinal cells. In summary, this study demonstrated that autophagy may positively regulate Wnt signaling in diabetic retinas, indicating a potential mechanism of Wnt signaling upregulation in DR and a possible novel therapeutic target of DR.

Real-time confocal microscopy imaging of corneal cytoarchitectural changes induced by different stresses

Maintenance of the corneal refractive power and tissue transparency is essential for normal vision. Real-time characterization of changes in corneal cells during suffering stresses or wound healing may provide a way to identify novel targets, whose therapeutic manipulation can improve the outcome of this response induced by injury. Here we describe a novel user friendly and effective confocal real-time confocal microscopy attachment that monitors the effects of anisoosmotic stress on cell morphology and corneal thickness in situ. Corneal epithelial nuclei gradually became highly reflective in the isotonic group and the corneal stroma was slightly thickened as compared with that seen prior to 60 min exposure to a hypotonic solution. After 30 min of exposure to hypertonic stress, the corneal stromal cells became crenate and shriveled. The hyper-reflective area of the corneal stroma in the hypo-osmotic group was significantly larger than that in the other two groups, as demonstrated by 3D reconstruction imaging. The hypotonic fresh chlorinated pool water was observed to cause atrophy of corneal epithelial nuclei, while the isosmotic bee venom solution caused high reflection of the corneal stroma layer and corneal endothelial cell damage. With the microscopic attachment, the inward movement of corneal epithelial cells toward the denuded central region was detected in the serum-treated group. The microscopy attachment is an effective system for obtaining a more detailed understanding of the time dependent losses in the corneal cell structure and tissue architecture of full thickness corneas induced by osmotic stress or cytotoxic agents.

Canonical Wnt Signaling Drives Myopia Development and Can Be Pharmacologically Modulated

Purpose

The purpose of this study was to evaluate the role of the canonical Wnt signaling in the development of the myopia.

Methods

Plasma from adult patients with myopia, myopic animal models including the adenomatous polyposis coli (APC) gene mutation mouse model, and the form deprivation (FD) induced mouse model of myopia were used. Niclosamide, a canonical Wnt pathway inhibitor, was orally administrated in animal models. Plasma levels of DKK-1 were determined by using enzyme-linked immunosorbent assay. Refraction, vitreous chamber depth (VCD), axial length (AL), and other parameters, were measured at the end of the FD treatment. Canonical Wnt signaling changes were evaluated by Western blot analysis and immunostaining analysis.

Results

Plasma level of Wnt inhibitor DKK-1 was markedly decreased in patients with myopia. Meanwhile, the canonical Wnt pathway was progressively activated during myopia development in mice. Moreover, inhibition of canonical Wnt signaling by niclosamide in mouse models markedly reduced lens thickness (LT), VCD, and AL elongation, resulting in myopia inhibition.

Conclusions

Dysregulation of canonical Wnt signaling is a characteristic of myopia and targeting Wnt signaling pathways has potential as a therapeutic strategy for myopia.

Biogeographic distribution patterns of algal community in different urban lakes in China: Insights into the dynamics and co-existence

Urban lake ecosystems are significant for social development, but currently we know little about the geographical distribution of algal community in urban lakes at a large-scale. In this study, we investigated the algal community structure in different areas of urban lakes in China and evaluated the influence of water quality parameters and geographical location on the algal community. The results showed that obvious differences in water quality and algal communities were observed among urban lakes in different geographical areas. Chlorophyta was the dominant phylum, followed by cyanobacteria in all areas. The network analysis indicated that algal community composition in urban lakes of the western and southern area showed more variations than the eastern and northern areas, respectively. Redundancy analysis and structural equation model revealed that nutrients and pH were dominant environmental factors that affected the algal community, and they showed higher influence than that of iron, manganese and COD _Mn concentration. Importantly, algal community and density exhibited longitude and latitude relationship. In general, these results provided an ecological insight into large-scale geographical distributions of algal community in urban lakes, thereby having potential applications for management of the lakes.

Fenofibrate Inhibits Subretinal Fibrosis Through Suppressing TGF-β-Smad2/3 signaling and Wnt signaling in Neovascular Age-Related Macular Degeneration

Subretinal fibrosis is a common pathological change that causes vision loss in neovascular age-related macular degeneration (nAMD). Treatment modalities for subretinal fibrosis are limited. In the present study, the effects of fenofibrate, a specific peroxisome proliferator-activated receptor alpha agonist, on subretinal fibrosis of nAMD were tested, and its molecular mechanisms of action were delineated. Collagen deposition and protein expression of fibrotic markers, such as vimentin, collagen-1, alpha-smooth muscle actin, and fibronectin, were increased in very low-density lipoprotein receptor (VLDLR) knockout mouse, indicating Vldlr ^-/- mice can be used as a model for subretinal fibrosis. Fenofibrate suppressed subretinal fibrosis of Vldlr ^-/- mice by reducing collagen deposition and protein expression of fibrotic markers. Two fibrotic pathways, TGF-β-Smad2/3 signaling and Wnt signaling, were significantly up-regulated, while inhibited by fenofibrate in Vldlr ^-/- retinas. Moreover, fenofibrate significantly reduced the downstream connective tissue growth factor (CTGF) expression of these two pathways. Müller cells were a major source of CTGF in Vldlr ^-/- retinas. Fenofibrate was capable of suppressing Müller cell activation and thus reducing the release of CTGF in Vldlr ^-/- retinas. In cultured Müller cells, fenofibrate reversed TGF-β2-induced up-regulation of Wnt signaling and CTGF expression. These findings suggested that fenofibrate inhibits subretinal fibrosis by suppressing TGF-β-Smad2/3 signaling and Wnt signaling and reducing CTGF expression, and thus, fenofibrate could be a potential treatment for nAMD with subretinal fibrosis.

PPARα-Dependent Effects of Palmitoylethanolamide Against Retinal Neovascularization and Fibrosis

Purpose

Pathological neovascularization and fibrosis are common pathological changes of many retinal diseases, such as proliferative retinopathy (PR) and age-related macular degeneration (AMD). Treatment modalities for these pathological changes are limited. The purpose of the present study was to test the effects of palmitoylethanolamide (PEA), an endocannabinoid mimetic amide, on retinal neovascularization and fibrosis and to determine its molecular mechanism of action.

Methods

A rat Müller cell line (rMC-1), a mouse model of oxygen-induced retinopathy (OIR), and the very-low-density lipoprotein receptor (VLDLR) knockout mouse model were used. PEA was intraperitoneally injected or orally administrated in animal models. Inflammation and profibrotic changes were evaluated by western blot analysis. Glial fibrillary acidic protein (GFAP) and peroxisome proliferator-activated receptor alpha (PPARα) were measured by RT-PCR and western blot analysis.

Results

Profibrotic changes were present in OIR and Vldlr-/- retinas. PEA significantly alleviated inflammation and inhibited neovascularization in OIR and Vldlr-/- retinas and suppressed profibrotic changes in OIR and Vldlr-/- retinas. Moreover, PEA potently suppressed Müller gliosis in these retinas. In rMC-1 cells, PEA suppressed Müller gliosis, reduced inflammatory cytokines, and attenuated profibrotic changes. Further, both mRNA and protein levels of PPARα were elevated in the retina under PEA treatment, and the effects of PEA were abolished in Pparα-/- OIR mice.

Conclusions

PEA reduced retinal neovascularization and fibrotic changes and suppressed Müller gliosis in experimental PR and neovascular AMD by activating PPARα. PEA may be a potential treatment for retinopathies with pathological neovascularization and fibrosis.

Community Compositions of Phytoplankton and Eukaryotes during the Mixing Periods of a Drinking Water Reservoir: Dynamics and Interactions

In deep drinking water reservoir ecosystems, the dynamics and interactions of community compositions of phytoplankton and eukaryotes during the mixing periods are still unclear. Here, morphological characteristics combined with high-throughput DNA sequencing (HTS) were used to investigate the variations of phytoplankton and the eukaryotic community in a large canyon-shaped, stratified reservoir located at the Heihe River in Shaanxi Province for three months. The results showed that Bacillariophyta and Chlorophyta were the dominant taxa of the phytoplankton community, accounting for more than 97% of total phytoplankton abundance, which mainly consisted of Melosira sp., Cyclotella sp., and Chlorella sp., respectively. Illumina Miseq sequencing suggested that the biodiversity of eukaryotes increased over time and thatspecies distribution was more even. Arthropoda (6.63% to 79.19%), Ochrophyta (5.60% to 35.16%), Ciliophora (1.81% to 10.93%) and Cryptomonadales (0.25% to 11.48%) were the keystone taxa in common, contributing over 50% of the total eukaryotic community. Cryptomycota as a unique fungus was observed to possess significant synchronization with algal density, reaching a maximum of 10.70% in December (when the algal density distinctly decreased) and suggesting that it might affect the growth of algae through parasitism. Co-occurrence network patterns revealed the complicated and diverse interactions between eukaryotes and phytoplankton, suggesting that eukaryotes respond to variations in dynamic structure of the phytoplankton community, although there might be antagonistic or mutualistic interactions between them. Redundancy analysis (RDA) results showed that environmental variables collectively explained a 96.7% variance of phytoplankton and 96.3% variance of eukaryotic microorganisms, indicating that the temporal variations of phytoplankton and eukaryotic microorganisms were significantly affected by environmental conditions. This study shows that potential interactions exist between phytoplankton and eukaryotic microorganism communities, andcould improve our understanding of the ecological roles of phytoplankton and eukaryotic microorganisms in changing aquatic ecosystems. However, long-term investigations are necessary in order to obtain comprehensive understandings of their complicated associations.

Geographical Patterns of Algal Communities Associated with Different Urban Lakes in China

Urban lakes play an important role in drainage and water storage, regulating urban microclimate conditions, supplying groundwater, and meeting citizens' recreational needs. However, geographical patterns of algal communities associated with urban lakes from a large scale are still unclear. In the present work, the geographical variation of algal communities and water quality parameters in different urban lakes in China were determined. The water quality parameters were examined in the samples collected from north, central, south, and coastal economic zones in China. The results suggested that significant differences in water quality were observed among different geographical distribution of urban lakes. The highest total phosphorus (TP)(0.21 mg/L) and total nitrogen (TN) (3.84 mg/L) concentrations were found in XinHaiHu (XHH) lake, it also showed highest the nitrate nitrogen (NO3--N) (0.39 mg/L),total organic carbon(TOC) (9.77 mg/L), and COD Mn (9.01 mg/L) concentrations among all samples. Environmental and geographic factors also cause large differences in algal cell concentration in different urban lakes, which ranged from 4,700×104 to 247,800 ×104cell/L. Through light microscopy, 6 phyla were identified, which includes Chlorophyta, Bacillariophyta, Cyanophyta, Dinophyta, Euglenophyta, and Cryptophyta. Meanwhile, the heat map with the total 63 algal community composition at the genus level profile different urban lakes community structures are clearly distinguishable. Further analyses showed that the dominant genera were Limnothrixsp., Synedra sp., Cyclotella sp., Nephrocytium sp., Melosirasp., and Scenedesmussp. among all samples. The integrated network analysis indicated that the highly connected taxa (hub) were Fragilariasp.,Scenedesmus sp., and Stephanodiscus sp. The water quality parameters of NO3--N and NH4+-N had significant impacts on the structural composition of the algal community. Additionally, RDA further revealed distinct algal communities in the different urban lakes, and were influenced by NO2--N, Fe, and algal cell concentrations. In summary, these results demonstrate that the pattern of algal communities are highly correlated with geographic location and water quality on a large scale, and these results also give us further understanding of the complex algal communities and effectively managing eutrophication of urban lakes.

The role of autophagy in the pathogenesis of exposure keratitis

Incomplete tear film spreading and eyelid closure can cause defective renewal of the ocular surface and air exposure-induced epithelial keratopathy (EK). In this study, we characterized the role of autophagy in mediating the ocular surface changes leading to EK. Human corneal epithelial cells (HCECs) and C57BL/6 mice were employed as EK models, respectively. Transmission electron microscopy (TEM) evaluated changes in HCECs after air exposure. Each of these models was treated with either an autophagy inhibitor [chloroquine (CQ) or 3-methyladenine (3-MA)] or activator [Rapamycin (Rapa)]. Immunohistochemistry assessed autophagy-related proteins, LC3 and p62 expression levels. Western blotting confirmed the expression levels of the autophagy-related proteins [Beclin1 and mammalian target of rapamycin (mTOR)], the endoplasmic reticulum (ER) stress-related proteins (PERK, eIF2α and CHOP) and the PI3K/Akt/mTOR signalling pathway-related proteins. Real-time quantitative PCR (qRT-PCR) determined IL-1β, IL-6 and MMP9 gene expression levels. The TUNEL assay detected apoptotic cells. TEM identified autophagic vacuoles in both EK models. Increased LC3 puncta formation and decreased p62 immunofluorescent staining and Western blotting confirmed autophagy induction. CQ treatment increased TUNEL positive staining in HCECs, while Rapa had an opposite effect. Similarly, CQ injection enhanced air exposure-induced apoptosis and inflammation in the mouse corneal epithelium, which was inhibited by Rapa treatment. Furthermore, the phosphorylation status of PERK and eIF2α and CHOP expression increased in both EK models indicating that ER stress-induced autophagy promoted cell survival. Taken together, air exposure-induced autophagy is indispensable for the maintenance of corneal epithelial physiology and cell survival.

SERPINA3K Ameliorates the Corneal Oxidative Injury Induced by 4-Hydroxynonenal

Purpose

We previously demonstrated that SERPINA3K has anti-inflammatory, antiangiogenic, and antioxidant effects in corneas. Here we further investigated the effects of SERPINA3K on the corneal oxidant injury setting recently developed and induced by 4-hydroxynonenal (4-HNE).

Methods

We applied the 4-HNE-induced corneal oxidant stress in cultured human corneal epithelial (HCE) cells in vitro and to the cornea of rats in vivo. The following experiments were conducted: cell counting kit 8 assay to detect cell viability; quantitative real-time PCR assay; Western blotting and immunofluorescent staining to measure gene expressions or protein levels of key reactive oxygen species (ROS)-associated factors (3-nitrotyrosine [3-NT]; nicotinamide adenine dinucleotide phosphate [NADPH]-oxidase 4 [NOX4]; superoxide dismutase [SOD]); catalase and nuclear factor [erythroid-derived 2]-like 2 [NRF2]); as well as main factors of the Wnt/β-catenin signaling pathway (p-LRP6, β-catenin and transcription factor 4 [TCF4]); histologic staining; and TUNEL staining to examine sections of rat corneas.

Results

We found that SERPINA3K concentration dependently protected cell viability, decreased levels of ROS marker 3-NT, suppressed NOX4, and upregulated SOD and catalase. Furthermore, SERPINA3K inhibited the activation of the ROS pathway NRF2 and its downstream factors, NAD(P)H dehydrogenase (quinone) 1 (NQO1) and heme oxygenase 1 (HO1), and also suppressed the activation of the Wnt signaling pathway p-LRP6, β-catenin, and TCF4 in HCE cells treated with 4-HNE. Meanwhile, SERPINA3K ameliorated the oxidant injury of rat corneas induced by 4-HNE and downregulated ROS systems and the Wnt/β-catenin pathway.

Conclusions

Our findings show that SERPINA3K protected the oxidant damage induced by 4-HNE in the cornea and its underlying mechanism was through suppression of the ROS system and inhibition of the activated Wnt/β-catenin signaling pathway.

[Treatment of single one-stage posterior atlantoaxial fixation in Chiari malformation]

Objective: To explore the effects of surgical technique of single one-stage posterior C(1-2) screw rod fixation of Chiari malformation (CM) associated with occipitalization and without atlantoaxial dislocation. Methods: A total of 23 patients with CM treated between January 2014 and October 2015 in Department of Neurosurgery of Chinese People's Liberation Army General Hospital were retrospective reviewed. All of them were diagnosis with CM associated with occipitalization and without atlantoaxial dislocation, including 8 males and 15 females, aging from 11 to 57 years (mean (35.5±10.52) years). Single one-stage posterior C(1-2) screw rod fixation with bone grafting fusion was performed. Operation time and intraoperative blood loss were recorded. Japanese Orthopaedic Association (JOA) scores and Odom rating were used to evaluate the clinical effects at pre- and post-operative. Regression of the cerebellar tonsillar was measured by MRI. The results were analyzed by paired samples t test. Results: Twenty-three patients were implanted screws successfully, the vertebral artery injury and cerebrospinal fluid leakage were not found. The mean operation time was (172.7±19.9) minutes, the intraoperative blood loss was (153.9±49.3) ml. Compared to preoperative, the JOA score increased (13.7±1.6 vs. 11.5±1.4) and the tonsillar herniation decreased ((0.8±0.6)cm vs. (1.9±0.6) cm) in the last follow-up, there were statistical difference (t=13.386, P<0.01; t=17.995, P<0.01). The results of the postoperative Odom grading were as follows: 6 cases were perfect (26.1%), 13 cases were good (56.5%), 4 cases were moderate (17.4%) and no case was poor.No signs of instrument loosen or screw broken was noticed. 100% bony fusion rate was achieved. The follow-up time was 6 to 23 months (mean (10.5±3.2) months). One case developed internal fixator related discomfort, the symptom was relieved by internal fixator removal surgery performed 4 months after the operation when osseous fusion had already been achieved. No new neurologic symptoms were observed in other 22 patients. Conclusions: The results of the study substantiates the effectiveness of single one-stage posterior fixation strategy for CM, which is associated with occipitalization and without atlantoaxial dislocation. This technique could be an alternative choice for this type of CM.

[Copy number variants analysis in whole-genome of patients with lipoma tethered cord syndrome]

Objective: To explore the abnormality of chromosomes of patients with lipoma tethered cord syndrome and the probable association between Copy Number Variations (CNV) and lipoma tethered cord syndrome. Methods: By using the Agilent SurePrint G3 Human CGH 8×60K Microarray Kit, we performed genome-wide screening for CNV on 11 patients with lipoma tethered cord syndrome adopted by the Neurosurgery Department of Chinese PLA General Hospital and their healthy parents from March 2015 to May 2015. We analyze CNVs got by the kit against the gene databases. Unrelated confirmed polymorphisms contained in Database of Genomic Variants (DGV) were discarded. Database of Chromosomal Imbalance and Phenotype in Humans using Ensemble Resources (DECIPHER) helps us with similarity inquiry, and UCSC Genome Browser helps in identification of non-polymorphic CNV. Biological process, cellular component and molecular function enrichment of these genes were conducted to confirm the association between the CNV and lipoma tethered cord syndrome. Results: 17 CNV were discovered by aCGH in 11 patients. Chr8: 39258894-39386158 and Chr15: 20481702-22509254 showed a high frequency of 5/11. Angelman syndrome and Prader-Wolli syndrome were found to be associated with the CNV of Chr15. Gene function enrichment analysis revealed that ADAM5P and ADAM3A contained in CNV obtained from patients with lipoma tethered cord syndrome was also associated with orofacial clefts. Conclusions: CNV in Chr8 and Chr15 of patients with lipoma tethered cord syndrome had a higher frequency than that of common human. It revealed that there is probable association between these two pieces of CNV and lipoma tethered cord syndrome. To explorer related genes or CNV, focusing on certain type of NTDs may increase the research efficiency and get more accurate results.

Erlotinib has tumor inhibitory effect in human retinoblastoma cells

AIM

In this study, we explored the effect of erlotinib on the development of retinoblastoma (RB) cells both in vitro and in vivo.

METHOD

RB cell lines, Y79 and WERI cells were treated with various concentrations of erlotinib in vitro to assess their cytotoxic profiles. In vitro proliferation, cell-cycle transition and migration were compared between RB cells treated with erlotinib and cells without erlotinib treatment. In in vivo tumorigenicity assay, mice were injected with Y79 cells and orally fed with erlotinib for 28days. The effect of erlotinib on in vivo tumor grafts was then assessed. Western blot analysis on EGFR, ERK, AKT proteins and their phosphorylated proteins was also performed to assess molecular signaling pathways of associated with erlotinib in RB cells.

RESULTS

In vitro erlotinib treatment induced cytotoxicity in Y79 and WERI cells in dose-dependent manner. While Y79 and WERI cells were treated with erlotinib close to EC₅₀ concentrations for 3days, RB proliferation, cell-cycle transition and migration were all significantly inhibited. In in vivo tumorigenicity assay, oral induction of erlotinib also dramatically reduced the growth of Y79 tumor grafts. Western blot demonstrated that, in in vitro RB cells, erlotinib did not alter the protein expression levels of EGFR, ERK or AKT, but significantly reduced the expressions of phosphorylated EGFR, ERK and AKT proteins.

CONCLUSION

Erlotinib was shown to have tumor suppressive effect on RB growth in vitro and in vivo, possibly through the inhibition on EGFR, ERG/AKT signaling pathways.

Down-Regulation of MicroRNA-184 Is Associated With Corneal Neovascularization

PURPOSE

Although microRNA-184 (miR-184) is abundantly expressed in the corneas, the role of miR-184 in corneal neovascularization remains unknown. Here we investigated the association between miR-184 expression and corneal neovascularization.

METHODS

Quantitative real-time PCR assay was conducted to detect the expression of miR-184 and its potential target genes in the corneal epithelium of rats with corneal suture-induced neovascularization. MicroRNA-184 was also applied topically to the suture rats. Mimic and inhibitor of miR-184 were transfected into the cultured human umbilical vein endothelial cells (HUVECs), human corneal epithelial (HCE) cells, and simian choroidal endothelial cells (RF/6A). The following experiments were performed to evaluate the effects of miR-184 in these transfected cells: cell proliferation by cell viability assay, cell migration by a scratch wound test, VEGF-induced tube formation, and VEGF and β-catenin levels by Western blot analysis.

RESULTS

The expression of miR-184 was significantly reduced, whereas the gene expression of frizzled-4, a receptor of the Wnt pathway, was up-regulated in the corneal epithelium of corneal suture rats. The corneal neovascularization induced by suture was ameliorated by topical administration of miR-184. In the cells transfected with mimic and inhibitor of miR-184, miR-184 significantly suppressed the cell proliferation and cell migration of HUVECs, miR-184 down-regulated VEGF, and β-catenin expression in HUVECs and HCE cells. Furthermore, miR-184 inhibited the tube formation of RF/6A cells.

CONCLUSIONS

Down-regulation of miR-184 is associated with up-regulation of VEGF and Wnt/β-catenin expression as well as corneal neovascularization, indicating that miR-184 negatively regulates corneal neovascularization.

Synergistic effect of quercetin and 6-gingerol treatment in streptozotocin induced type 2 diabetic rats and poloxamer P-407 induced hyperlipidemia

Ginger and quercetin have been reported to have significant antidiabetic effects.

The oxidant role of 4-hydroxynonenal in corneal epithelium

4-Hydroxynonenal (4-HNE or HNE) is a main endogenous product of cellular lipid peroxidation in tissues and is reported to play pathogenic roles in eye diseases. Here we investigated the association between 4-HNE and oxidative stress in the corneal epithelium. 4-HNE suppressed the cell viability of human corneal epithelial cells (HCE) in a concentration dependent manner. 4-HNE significantly increased the level of 3-Nitrotyrosine (3-NT), a marker of oxidative stress, in HCE cells and corneal epithelium of rats by immunofluorescent staining and Western blot analysis. To its underlying mechanistic on ROS system, 4-HNE elevated the ROS generation enzyme NADPH oxidase 4 (NOX4) and induced the activation of NF-E2–related factor-2 (NRF2) and its downstream effectors: NAD(P)H dehydrogenase (quinone 1) (NQO1) and glutathione S-transferase P (GSTP). Furthermore, N-acetylcysteine (NAC), an antioxidant and ROS scavenger, antagonized the inhibitory and oxidant effects of 4-HNE on the corneal epithelial cells. In conclusion, 4-HNE plays an oxidant role in the corneal epithelium and this work provides a new strategy for the pathogenesis and treatment of corneal diseases.

SERPINA3K plays antioxidant roles in cultured pterygial epithelial cells through regulating ROS system

We recently demonstrated that SERPINA3K, a serine proteinase inhibitor, has antioxidant activity in the cornea. Here we investigated the antioxidant effects of SERPINA3K on the pterygial, which is partially caused by oxidative stress in pathogenesis. The head part of primary pterygial tissue was dissected and then cultured in keratinocyte serum-free defined medium (KSFM). The cultured pterygial epithelial cells (PECs) were treated with SERPINA3K. The cell proliferation and migration of PECs were measured and analyzed. Western blot and quantitative real-time polymerase chain reaction (PCR) assay were performed. It showed that SERPINA3K significantly suppressed the cell proliferation of PECs in a concentration-dependent manner, compared with cultured human conjunctival epithelial cells. SERPINA3K also inhibited the cell migration of PECs. Towards its underlying mechanism, SERPINA3K had antioxidant activities on the PECs by significantly inhibiting NADPH oxidase 4 (NOX4), which is an important enzyme of ROS generation, and by elevating the levels of key antioxidant factors of ROS: such as NAD(P)H dehydrogenase (quinone 1) (NQO1), NF-E2–related factor-2 (NRF2) and superoxide dismutases (SOD2). Meanwhile, SERPINA3K down-regulated the key effectors of Wnt signaling pathway: β-catenin, nonphospho-β-catenin, and low-density lipoprotein receptor-related protein 6 (LRP6). We provided novel evidence that SERPINA3K had inhibitory effects on pterygium and SERPINA3K played antioxidant role via regulating the ROS system and antioxidants.

Serine Proteinase Inhibitor SERPINA3K Suppresses Corneal Neovascularization via Inhibiting Wnt Signaling and VEGF

Purpose: To evaluate the anti-neovascularization effects and investigate the possible mechanisms of SERPINA3K, a member of serine proteinase inhibitor family, using a specific rat model of suture-induced corneal neovascularization. Methods: A rat corneal suture model was set up and SERPINA3K was topically administered three times daily for 7 days. The clinical indications were evaluated on day 2, 5 and 7, including area of neovascularization and inflammation index. The eyeballs were collected after day 7 and the following examinations were performed: histological investigation, immunostaining, western blot and quantitative real-time polymerase chain reaction (PCR) assay. Wnt3a, a Wnt pathway ligand, was added to cultured Human Umbilical Vein Endothelial Cells (HUVEC), followed by detecting cell migration and western blot. Meanwhile, an in vitro VEGF165-stimulated HUVEC model was applied and the following measurements were conducted: cell proliferation, cell migration and tube formation. Results: SERPINA3K significantly suppressed corneal neovascularization and inhibited corneal inflammation. SERPINA3K downregulated the levels of β-catenin, non-pi-β-catenin and transcription factor 4 (TCF4), but upregulated the level of pi-β-catenin of the corneas induced by suture. SERPINA3K also decreased the gene expression and protein level of VEGF. Meanwhile, induction of Wnt3a increased the cell migration, activated the Wnt signaling and upregulated VEGF in cultured HUVEC, which were antagonized by SERPINA3K. In addition, SERPINA3K significantly inhibited VEGF165-induced cell proliferation and migration of HUVEC, SERPINA3K also specifically suppressed the VEGF165-induced tube formation of HUVEC. Conclusions: SERPINA3K has therapeutic potential for corneal neovascularization. The underlying mechanism may be through inhibiting Wnt signaling pathway and VEGF.

Significance of heterogeneous Twist2 expression in human breast cancers

Background

Twist2 (Dermo1) has been shown to mediate the epithelial-mesenchymal transition (EMT) to promote tumor invasion and even metastasis. However, the involvement of EMT in breast cancer progression is highly debated, partially due to clinical observations showing that the majority of human breast carcinoma metastases express E-cadherin and maintain their epithelial morphology. The molecular mechanism by which Twist2 participates in EMT of breast cancer in vivo remains poorly understood.

Methods

We examined Twist2 expression pattern in human breast carcinomas by western blot and tissue microarray, and analyzed Twist2 cellular localization by confocal microscopy, cell fractionation and other approaches.

Results

Twist2 expression was significantly increased in breast cancer. Cytoplasmic Twist2 positive cancer cells expressing E-cadherin on the cellular membrane were mainly located at tumor center of primary carcinomas and lymph metastases, while cancer cells with nuclear Twist2 clearly showed loss of E-cadherin and were detected at the invasive front in ductal breast carcinomas. In addition, ectopically stable-expressed Twist2 was found to localize in the cytoplasm of cancer cells. Collectively, these data indicate that upregulation of cytoplasmic Twist2 is correlated with tumor histological type and tumor metastasis in human breast cancers.

Conclusion

The differential cellular distribution of Twist2 may be associated with tumor progression. The cytoplasmic Twist2 in cancer cells at tumor center of primary carcinomas and lymph metastases contributes to the maintenance of epithelial cancer characteristics expressing E-cadherin in a noninvasive state, while the nuclear Twist2 at the cancer invasion front activates EMT to deprive epithelial property of neoplastic cells, thus facilitating invasion and metastasis. These findings suggest that heterogeneous expression of Twist2 in tumors may have a functional link to tumor progression.

The role of white spot syndrome virus (WSSV) VP466 protein in shrimp antiviral phagocytosis

Widespread evidence indicates that the structural proteins of virus play very important roles in virus-host interactions. However, the effect of viral proteins on host immunity has not been addressed. Our previous studies revealed that the host shrimp Rab6 (termed as PjRab previously), tropomyosin, β-actin and the white spot syndrome virus (WSSV) envelope protein VP466 formed a complex. In this study, the VP466 protein was shown to be able to bind host Rab6 protein and increase its GTPase activity in vivo and vitro. Thus, VP466 could function as a GTPase-activating protein (GAP) of Rab6. In the VP466-Rab-actin pathway, the increase of the Rab6 activity induced rearrangements of the actin cytoskeleton, resulting in the formation of actin stress fibers which promoted the phagocytosis against virus. Therefore our findings revealed that a viral protein could be employed by host to initiate the host immunity, representing a novel molecular mechanism in the virus-host interaction. Our study would help to better understand the molecular events in immune response against virus infection in invertebrates.

Truncated ErbB2 expressed in tumor cell nuclei contributes to acquired therapeutic resistance to ErbB2 kinase inhibitors

ErbB2 tyrosine kinase inhibitors (TKI) block tyrosine autophosphorylation and activation of the full-length transmembrane ErbB2 receptor (p185(ErbB2)). In addition to p185(ErbB2), truncated forms of ErbB2 exist in breast cancer cell lines and clinical tumors. The contribution of these truncated forms, specifically those expressed in tumor cell nuclei, to the development of therapeutic resistance to ErbB2 TKIs has not been previously shown. Here, we show that expression of a 95-kDa tyrosine phosphorylated form of ErbB2, herein referred to as p95L (lapatinib-induced p95) was increased in ErbB2(+) breast cancer cells treated with potent ErbB2 TKIs (lapatinib, GW2974). Expressed in tumor cell nuclei, tyrosine phosphorylation of p95L was resistant to inhibition by ErbB2 TKIs. Furthermore, the expression of p95L was increased in ErbB2(+) breast cancer models of acquired therapeutic resistance to lapatinib that mimic the clinical setting. Pretreatment with proteasome inhibitors blocked p95L induction in response to ErbB2 TKIs, implicating the role of the proteasome in the regulation of p95L expression. In addition, tyrosine phosphorylated C-terminal fragments of ErbB2, generated by alternate initiation of translation and similar in molecular weight to p95L, were expressed in tumor cell nuclei, where they too were resistant to inhibition by ErbB2 TKIs. When expressed in the nuclei of lapatinib-sensitive ErbB2(+) breast cancer cells, truncated ErbB2 rendered cells resistant to lapatinib-induced apoptosis. Elucidating the function of nuclear, truncated forms of ErbB2, and developing therapeutic strategies to block their expression and/or activation may enhance the clinical efficacy of ErbB2 TKIs.

Regulation of phagocytosis against bacterium by Rab GTPase in shrimp Marsupenaeus japonicus

Rab GTPases, members of the Ras superfamily, play important roles in phagosome formation and maturation. However, the involvement of Rab protein in phagocytosis against invading pathogens in crustacean remains unknown. In the present study, the RNAi and mRNA overexpression assays were conducted to elucidate the function of shrimp Rab gene (designated as PjRab) in hemocytic phagocytosis against bacterium. The results indicated that the phagocytic percentage and phagocytic index using FITC-labeled Vibrio parahemolyticus were significantly decreased when the PjRab gene was silenced by sequence-specific siRNA, suggesting that the PjRab protein was essential in hemocytic phagocytosis. On the other hand, the overexpression of PjRab gene leaded to the increase of phagocytic percentage and phagocytic index. The findings indicated that the PjRab protein was involved in the regulation of hemocytic phagocytosis of shrimp. Our report on the regulation of phagocytosis by Rab GTPase would contribute a better clue to realize the still poorly understood molecular events involved in shrimp as well as crustacean immune response.

Antiviral phagocytosis is regulated by a novel Rab-dependent complex in shrimp penaeus japonicus

Rab GTPases are involved in phagosome formation and maturation. However, the role of Rab GTPases in phagocytosis against virus infection remains unknown. In this study, it was found that a Rab gene ( PjRab) from marine shrimp was upregulated in virus-resistant shrimp, suggesting that Rab GTPase was involved in the innate response to virus. The RNAi and mRNA assays revealed that the PjRab protein could regulate shrimp hemocytic phagocytosis through a protein complex consisting of the PjRab, beta-actin, tropomyosin, and envelope protein VP466 of shrimp white spot syndrome virus (WSSV). It was further demonstrated that the PjRab gene silencing by RNAi caused the increase in the number of WSSV copies, indicating that the PjRab might be an intracellular virus recognition protein employed by a host to increase the phagocytic activity. Therefore, our study presents a novel Rab-dependent signaling complex, in which the Rab GTPase might detect virus infection as an intracellular virus recognition protein and trigger downstream phagocytic defense against virus in crustacean for the first time. This discovery would improve our understanding of the still poorly understood molecular events involved in innate immune response against virus infection of invertebrates.

Radiosynthesis of [18F] N-(3-Fluoropropyl)-2-β-Carbomethoxy-3-β-(4-Bromophenyl) Nortropane and the regional brain uptake in non human primate using PET

A synthetic procedure for the preparation of [18F]FPCBT, an imaging agent for the dopamine transporter (DAT), has been developed. The radiosynthesis was carried out in a two step procedure. Even though the yield was low, we were able to prepare 20 to 30 mCi of the product, which was enough for two or three studies. The radiochemical purity was greater than 96%. The in vivo properties of this radiotracer were evaluated using baboon and it showed highest uptake in the striatum. The studies also revealed that the maximum uptake was reached within 7 to 10 minutes post injection. Plasma metabolite analysis indicated that there is only one metabolite and it is less lipophilic than the parent compound. [18F]FPCBT displayed good brain uptake and its high target to non target ratio indicate that it is a potential candidate for DAT imaging.

Synthesis and biological evaluation of a series of novel N- or O-fluoroalkyl derivatives of tropane: potential positron emission tomography (PET) imaging agents for the dopamine transporter

A series of novel fluoroalkyl-containing tropane derivatives was synthesized, and their binding affinities for the dopamine transporter (DAT), serotonin transporter (SERT), and norepinephrine transporter (NET) were determined via competitive binding assays. Among these derivatives, the fluoropropyl ester of beta-CIT (19), the fluoroethyl ester of beta-CIT (20), the N-fluoropropyl derivative of beta-CBT (12), and the fluoropropyl ester of beta-CMT (18) displayed higher affinity and greater selectivity for the DAT versus SERT and NET than FP-CIT, which indicates that they are attractive candidates for the development of (18)F-labeled PET imaging agents for the DAT.

Synthesis and opioid receptor affinity of morphinan and benzomorphan derivatives: mixed kappa agonists and mu agonists/antagonists as potential pharmacotherapeutics for cocaine dependence

This report concerns the synthesis and preliminary pharmacological evaluation of a novel series of kappa agonists related to the morphinan (-)-cyclorphan (3a) and the benzomorphan (-)-cyclazocine (2) as potential agents for the pharmacotherapy of cocaine abuse. Recent evidence suggests that agonists acting at kappa opioid receptors may modulate the activity of dopaminergic neurons and alter the neurochemical and behavioral effects of cocaine. We describe the synthesis and chemical characterization of a series of morphinans 3a-c, structural analogues of cyclorphan [(-)-3-hydroxy-N-cyclopropylmethylmorphinan S(+)-mandelate, 3a], the 10-ketomorphinans 4a,b, and the 8-ketobenzomorphan 1b. Binding experiments demonstrated that the cyclobutyl analogue 3b [(-)-3-hydroxy-N-cyclobutylmethylmorphinan S(+)-mandelate, 3b, MCL-101] of cyclorphan (3a) had a high affinity for mu, delta, and kappa opioid receptors in guinea pig brain membranes. Both 3a,b were approximately 2-fold more selective for the kappa receptor than for the mu receptor. However 3b (the cyclobutyl analogue) was 18-fold more selective for the kappa receptor in comparison to the delta receptor, while cyclorphan (3a) had only 4-fold greater affinity for the kappa receptor in comparison to the delta receptor. These findings were confirmed in the antinociceptive tests (tail-flick and acetic acid writhing) in mice, which demonstrated that cyclorphan (3a) produced antinociception that was mediated by the delta receptor while 3b did not produce agonist or antagonist effects at the delta receptor. Both 3a,b had comparable kappa agonist properties. 3a,b had opposing effects at the mu receptor: 3b was a mu agonist whereas 3a was a mu antagonist.

Local injection of alkylating and nonalkylating dopamine receptor antagonists into rat basal forebrain: autoradiographic assessment of D2-like and D3 sites

N-chloroethyl derivatives of 7-hydroxy-1,2,3,4-tetrahydronaphthalene (7-OH-DPAT), 1-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline (EEDQ), or fluphenazine were microinjected into rat nucleus accumbens (Acc), and receptor binding quantified autoradiographically after 24 h. EEDQ reduced [3H]nemonapride (D2-like receptors) binding in Acc (by 84%) and islands of Calleja (IC; 44%), without affecting [3H](+)-7-OH-DPAT (D3); N-chloroethyl-7-OH-DPATs blocked both radioligands in Acc and IC (30%-70%); fluphenazine had no effect.

[Synthesis and spectroscopic properties of rare earth and p-anisic acid with 1, 10-phenanthroline]

The title complex with the formula EuL3 x phen x H2O (phen=1, 10-phenathroline, HL=p-anisic acid) were synthesized and characterized by elemental analysis, molar conductivity, IR, UV, NMR etc.

Effects of aporphine isomers on rat prolactin

S(+)-aporphines are partial agonists at D2 dopamine receptors. High selectivity of anti-dopaminergic action in limbic vs. extrapyr amidal regions of rat brain and lack of induction of dopaminergic supersensitivity have suggested their potential as atypical antipsychotic drugs. Now, in testing for effects on circulating prolactin, a typical D2 antagonist haloperidol elevated, and potent agonist R(-)-11-hydroxy-N-propylnoraporphine lowered, serum prolactin levels in gentled male rats, while S(+)-N-propylnorapomorphine and its 11-monohydroxy analog had little or no effect, even at high doses. Lack of hyperprolactinemia adds to characteristics of S(+)-aporphines that are desirable in improved antipsychotics.

Receptor affinities of aporphine enantiomers in rat brain tissue

R(-) and S(+) enantiomers of apomorphine, N-n-propylnorapomorphine and 11-hydroxy-N-n-propylnorapomorphine were screened for affinity at over 40 representative sites in rat brain tissue that included amine, purine, amino acid and peptide receptors, transporters, ion channels, and effector components; only dopamine receptors and alpha-adrenoceptors showed appreciable affinity that was quantified further. The aporphines showed R(-) > S(+) isomeric selectivity as well as D2 > D1 selectivity at dopamine receptors. While R(-) isomers preferred alpha 2-adrenoceptors, S(+)-aporphines were alpha 1-selective, with similar affinity at alpha 1-adrenoceptors and dopamine D2 receptors. Interactions of S(+)-aporphines at alpha 1-adrenoceptors as well as dopamine D2 receptors may contribute to their unusual behavioral properties.

Presynaptic inhibition of dopamine synthesis in rat striatal tissue by enantiomeric mono- and dihydroxyaporphines

Presynaptic autoreceptor-mediated modulation of dopamine (DA) synthesis was evaluated as the inhibition of tyrosine hydroxylase activity by enantiomeric mono- and dihydroxyaporphines with minced striatal tissue from rat brain. The isomers of N-n-propylnorapomorphine (NPA) both inhibited tyrosine hydroxylase activity [IC50 = 0.3 and 1.0 microM for (R)-(-)- and (S)-(+)-NPA, respectively; R/S potency = 3.6]. Their effects were fully blocked by the nonselective DA receptor antagonist fluphenazine, as well as by the D2-selective antagonist spiperone, but not by the D1 antagonist SCH-23390. These results suggest a D2-type autoreceptor-mediated inhibition of DA synthesis, with limited enantiomeric selectivity of this catechol-aporphine. The corresponding monohydroxy analogs, (R)-(-)- and (S)-(+)-11-hydroxy-N-n-propylnoraporphine (11-OH-NPa) were about 100 times less potent (IC50 = 42 and 87 microM, respectively) than the NPA isomers in fully inhibiting the enzyme activity in normal tissue but, after depletion of endogenous DA by acute in vivo pretreatment with reserpine (which did not alter the number of D1 or D2 specific binding sites), (R)-(-)-11-OH-NPa was a highly potent but partial agonist (IC25 = 7 nM). Fluphenazine and spiperone fully antagonized the inhibition of tyrosine hydroxylase by (R)-(-)-11-OH-NPa in reserpinized tissue, but SCH-23390 was ineffective. Actions mediated by endogenous DA probably contribute to the effect of high concentrations of (R)-(-)-11-Oh-NPa to evoke a full inhibition of DA synthesis, but its high potency partial agonist effects appear to be mediated by D2-autoreceptors. (S)-(+)-11-OH-NPa was a very weak partial agonist in reserpinized tissue, with an IC25 = 30 microM (essentially the same as normal tissue); thus, (R)-(-)-11-OH-NPa was greater than 4,000 times more potent than its S-(+)-enantiomer in the absence of endogenous DA. These results demonstrate that NPA, which contains a catechol moiety, acts as a full agonist to inhibit striatal DA synthesis via a presynaptic autoreceptor of the D2 type, with only slight stereoselectivity, and that its monohydroxy analog is a very potent but partial D2 autoreceptor agonist, with very high stereoselectivity.