Stressors, emotions, and social support systems among respiratory nurses during the Omicron outbreak in China: a qualitative study.

BACKGROUND: Respiratory nurses faced tremendous challenges when the Omicron variant spread rapidly in China from late 2022 to early 2023. An in-depth understanding of respiratory nurses' experiences during challenging times can help to develop better management and support strategies. The present study was conducted to explore and describe the work experiences of nurses working in the Department of Pulmonary and Critical Care Medicine (PCCM) during the Omicron outbreak in China. METHODS: This study utilized a descriptive phenomenological method. Between January 9 and 22, 2023, semistructured and individual in-depth interviews were conducted with 11 respiratory nurses at a tertiary hospital in Wuhan, Hubei Province. A purposive sampling method was used to select the participants, and the sample size was determined based on data saturation. The data analysis was carried out using Colaizzi's method. RESULTS: Three themes with ten subthemes emerged: (a) multiple stressors (intense workload due to high variability in COVID patients; worry about not having enough ability and energy to care for critically ill patients; fighting for anxious clients, colleagues, and selves); (b) mixed emotions (feelings of loss and responsibility; feelings of frustration and achievement; feelings of nervousness and security); and (c) a perceived social support system (team cohesion; family support; head nurse leadership; and the impact of social media). CONCLUSION: Nursing managers should be attentive to frontline nurses' needs and occupational stress during novel coronavirus disease 2019 (COVID-19) outbreaks. Management should strengthen psychological and social support systems, optimize nursing leadership styles, and proactively consider the application of artificial intelligence (AI) technologies and products in clinical care to improve the ability of nurses to effectively respond to future public health crises.

A novel tri-culture model for neuroinflammation.

Neuroinflammation is believed to play a primary role in the pathogenesis of most neurodegenerative diseases including Alzheimer's disease, Parkinson's disease and schizophrenia. Currently, suitable in vitro neuroinflammation models for studying cellular interactions and inflammatory mechanisms at the neurovascular unit are still scarce. In this study, we established an experimentally flexible tri-culture neuroinflammation model combining murine microglial cells (N11), mouse neuroblastoma Nuro2A cell lines and brain microvascular endothelial MVEC(B3) cells in a transwell co-culture system stimulated with lipopolysaccharides. Neuroinflammation was induced in this tri-culture model as manifested by activated N11 cells via toll-like receptor 4, resulting in increased release of proinflammatory mediators (nitric oxide, interleukin-6 and tumour necrosis factor-α) through the activation of nuclear factor-κB signalling pathway. The released inflammatory cytokines from N11 in turn, damaged the tight junction in microvascular endothelial MVEC(B3) cells, increased permeability of endothelial barrier, and induced tau phosphorylation and up-regulated caspase-3 expression in mouse neuroblastoma Nuro2A cell lines, leading to neuroinflammation injury. In summary, this tri-culture inflammation model mimics the microenvironment, the cellular crosstalk and the molecular events that take place during neuroinflammation. It provides a robust in vitro model for studying neuroinflammation mechanisms and screening for potential therapeutics to treat various neurodegenerative diseases.

Outcomes and prognostic factors for aggressive posterior retinopathy of prematurity following initial treatment with intravitreal ranibizumab.

BACKGROUND: This study sought to identify factors associated with retinal detachment and retreatment of aggressive posterior retinopathy of prematurity (APROP) initially treated with intravitreal ranibizumab (IVR) injection as well as the efficacy of IVR treatment. METHODS: This was a retrospective study. A total of 83 preterm infants (160 eyes) diagnosed with APROP who were primarily treated with IVR were included. The 160 eyes were divided into two groups based on the anatomic outcomes. Group A included 35 eyes that developed retinal detachment, and Group B included 125 eyes without retinal detachment. The following patient factors were retrospectively reviewed: gender, gestational age (GA), birth weight (BW), postmenstrual age (PMA) at first treatment, iris neovascularizations, retinal hemorrhage, neutrophil and lymphocyte counts before the first intravitreal injection, neutrophil-to-lymphocyte ratio (NLR), anatomical outcomes, additional treatment and follow-up time. Three dummy variables were created as dependent variables based on the methods of retreatment. The possible risk factors for APROP were evaluated, and statistical analyses included univariate and multivariate logistic regression. RESULTS: A total of 160 eyes from 83 preterm infants (56 males and 27 females) underwent initial IVR treatment with a follow-up time of 17.17 ± 10.54 months. Thirty-five of the 160 (21.9%) eyes progressed to retinal detachment, and 82 of the 125 (65.6%) non-retinal detachment eyes needed retreatment, with favorable anatomical outcomes. The disease improved approximately 1.5 ± 1.2 weeks after the first IVR treatment. The mean recurrence period of APROP was approximately 7.5 ± 6.9 weeks after the first IVR treatment. Multiple logistic regression analysis revealed postmenstrual age (P < 0.001) and neutrophil count (P = 0.009) as the most significant factors for retinal detachment in APROP. Retinal hemorrhage (P = 0.007) and BW (P = 0.04) were most significantly associated with APROP recurrence and retreatment. CONCLUSIONS: IVR injection is an effective treatment for APROP. In this study, older postmenstrual age and low neutrophil count were identified as risk factors for retinal detachment in APROP. In addition, retinal hemorrhage and low BW were significantly associated with recurrence and retreatment in non-retinal detachment APROP. Thus, patients with a lower BW, older postmenstrual age, low neutrophil count and retinal hemorrhage should be reexamined in a timely and more frequent manner.

The effects of pleiotrophin in proliferative vitreoretinopathy.

PURPOSE: The purpose of our study was to investigate the effects of pleiotrophin (PTN) in proliferative vitreoretinopathy (PVR) both in vitro and in vivo. METHODS: Immunofluorescence was used to observe the PTN expression in periretinal membrane samples from patients with PVR and controls. ARPE-19 cells were exposed to TGF-ß1. The epithelial-to-mesenchymal transition (EMT) of the ARPE-19 cells was confirmed by observed morphological changes and the increased expression of α-SMA and fibronectin at both the mRNA and protein levels. We used specific small interfering (si)RNA to knock down the expression of PTN. The subsequent effects of PTN inhibition were assessed with regard to the EMT, migration, proliferation, cytoskeletal arrangement, TGF-ß signaling, PTN signaling, integral tight junction protein expression (e.g., claudin-1 and occludin), and p38 MAPK and p-p38 MAPK levels. Additionally, a PVR rat model was established by the intravitreal injection of ARPE-19 cells transfected with PTN-siRNA and was evaluated accordingly. RESULTS: PTN was highly expressed in PVR membranes compared to controls. PTN knockdown attenuated the TGF-ß1-induced migration, proliferation, cytoskeletal rearrangement, and expression of EMT markers such as α-SMA and fibronectin in the ARPE-19 cells, and these effects may have been mediated through p38 MAPK signaling pathway activation. PTN silencing inhibited the up-regulation of claudin-1 and occludin stimulated by TGF-ß1, and PTN knockdown inhibited the proliferative aspects of severe PVR in vivo. CONCLUSIONS: PTN is involved in the process of EMT induced by TGF-ß1 in human ARPE-19 cells in vitro, and PTN knockdown attenuated the progression of experimental PVR in vivo. These findings provide new insights into the pathogenesis of PVR.

Effects of p75 neurotrophin receptor on regulating hypoxia-induced angiogenic factors in retinal pigment epithelial cells.

Retinal pigment epithelium (RPE) exerts critical roles in the maintenance of the normal functions of the retina, whereas RPE dysfunction can induce retina neovascularization. p75 neurotrophin receptor (p75(NTR)) has been shown to play essential roles in angiogenesis. However, the function of p75(NTR) in the RPE remains unclear. In the present study, we demonstrated that p75(NTR) was highly expressed in the human choroidal neovascularization membranes. For in vitro study, RPE was exposed to hypoxia, and a knockdown of p75(NTR) was achieved via lentivirus-mediated RNA interference. The results showed that hypoxia induced the expression of p75(NTR) in the RPE, and the knockdown of p75(NTR) rescued RPE proliferation activity and inhibited apoptosis which induced by hypoxia. After the deletion of p75(NTR), RPE-secreted pro-angiogenic factors (vascular endothelial growth factor and platelet-derived growth factor), inflammatory factors [interleukin 1 beta (IL1ß), IL18, and stromal cell-derived factor 1], and matrix metalloproteinases (MMPs) (MMP3 and MMP9) were down-regulated under hypoxic conditions. While the RPE secreted anti-angiogenic factors (pigment epithelium-derived factor) and angiostatin, the tissue inhibitors of metalloproteinases (TIMPs) (TIMP-1 and TIMP-3) were up-regulated after the knockdown of p75(NTR). The human umbilical vein endothelial tube formation ability can be inhibited when it is co-cultured with the supernatant extract from p75(NTR)-knockdown RPE under hypoxic induction. These results suggest that the knockdown of p75(NTR) suppressed pro-angiogenic factors which induced by hypoxia while promoting the anti-angiogenesis-related factors in the RPE. It is indicated that p75(NTR) could be a potential therapeutic target for RPE hypoxia or oxidative stress diseases.

Semaphorin 3A blocks the formation of pathologic choroidal neovascularization induced by transforming growth factor beta.

OBJECTIVE: Choroidal neovascularization (CNV) is a major cause of vision loss in retinal diseases such as age-related macular degeneration (AMD). Previously, we demonstrated that semaphorin3A (Sema3A), which is a chemorepellent guidance molecule, inhibited the formation of retina neovascularization. In the present study, we investigated the antiangiogenic effects of Sema3A on transforming growth factor beta (TGF-ß) in vitro and in vivo. METHODS: Enzyme-linked immunosorbent assays (ELISAs) were used to measure the TGF-ß levels in the vitreous humor of patients with AMD and controls. Human umbilical vein endothelial cells (HUVECs) were used for the in vitro study, and a laser-induced CNV mouse model was prepared for the in vivo study. The HUVECs were incubated with TGF-ß and Sema3A. The proliferation, migration, apoptosis, and tube formation of the cells were then measured using BrdU, Transwell, flow cytometry, and Matrigel assays, respectively, and the SMAD2/3 signaling pathways were analyzed using western blot analysis. The C57BL/6J mouse retina was exposed to a laser to induce choroidal neovascularization (CNV), and Sema3A was injected intravitreously. After 14 days, fundus fluorescein angiography was performed to evaluate the leakage area of the CNV. The vascular endothelial growth factor (VEGF) and TGF-ß concentrations in the retina-choroid complex were measured with ELISA. Components of the p38 mitogen-activated protein kinase (MAPK), extracellular signal-regulated kinase-1/2 (ERK1/2), c-Jun NH2-terminal kinase (JNK), and SMAD2/3 signaling pathways in the Sema3A-treated groups were analyzed using western blotting. RESULTS: In this study, we first verified that the vitreous TGF-ß level was higher in patients with neovascular AMD than in the controls. We also showed that Sema3A inhibited TGF-ß-induced HUVEC proliferation, migration, and tube formation and inhibited the downstream SMAD2/3 signaling pathway. Sema3A also induced TGF-ß-stimulated HUVEC apoptosis and inhibited the response of TGF-ß in vitro. In vivo, the TGF-ß level was increased in the CNV mouse model. Sema3A not only inhibited laser-induced CNV formation but also inhibited the uptake of VEGF and TGF-ß. In the western blot analysis, Sema3A was shown to inhibit the phosphorylation of p38 MAPK, ERK1/2, and JNK and to inhibit the SMAD2/3 signaling pathway after Sema3A treatment in CNV mice. CONCLUSIONS: Sema3A can be applied as a useful, adjunctive therapeutic strategy for preventing CNV formation.

rs4711751 and rs1999930 are not associated with neovascular age-related macular degeneration or polypoidal choroidal vasculopathy in the Chinese population.

PURPOSE: rs1999930 and rs4711751 have recently been identified as novel variants associated with advanced age-related macular degeneration (AMD) in populations of European ancestry. We aimed to investigate whether these two single nucleotide polymorphisms (SNPs) were associated with neovascular AMD (nAMD) or with polypoidal choroidal vasculopathy (PCV), a variant of AMD in Asians, using a Chinese case-control study. METHODS: A total of 900 subjects, including 300 controls, 300 cases with nAMD and 300 cases with PCV, were included in the present study. Genomic DNA was extracted from venous blood leukocytes. The allelic variants of rs1999930 and rs4711751 were determined by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. The differences in allele distribution between cases and controls were tested by a χ(2) test, with additional adjustments for age and gender using logistic regression. The statistical power was also calculated. Values of p < 0.05 were considered statistically significant. RESULTS: No statistically significant association was observed between the two polymorphisms of nAMD or PCV phenotype (p > 0.05 for all comparisons). The difference remained insignificant after correction for age and gender (p > 0.05 for all comparisons). The statistical powers to detect the association between these two SNPs and nAMD or PCV range from 0.05 to 0.36, assuming conventional levels of statistical significance. CONCLUSIONS: In the present study, we could not replicate the reported association of these two SNPs and either nAMD or PCV in a Chinese population, suggesting that they are unlikely to be a major AMD and PCV susceptibility gene locus in the Chinese population. Considering the low power value, a large sample size is required to draw more reliable conclusions.

The effectiveness of a structured educational intervention on disease-related misconception and quality of life in patients with irritable bowel syndrome.

A significant number of patients with irritable bowel syndrome hold misconceptions about their disease and experience more impaired quality of life compared with the general population and people suffering from other chronic diseases. This study was designed to explore the effectiveness of a structured educational intervention on disease-related misconceptions and quality of life in patients with irritable bowel syndrome in Wuhan, China. A convenience sample of 23 patients with irritable bowel syndrome participated in an educational program that consisted of 4 weekly sessions in a group setting. Instruments, including an irritable bowel syndrome-related misconception scale and irritable bowel syndrome quality-of-life scale, were used for evaluation at baseline and 3 months after the sessions. Three months after the structured educational intervention, the score for irritable bowel syndrome-related misconception was significantly decreased (p < .001), and the score for irritable bowel syndrome quality of life was significantly improved (p < .001). We conclude that the structured educational intervention seems to be a proper method to reduce the disease-related misconceptions and improve the quality of life in patients with irritable bowel syndrome. Planning and implementing such clinical education programs will be helpful in decreasing disease-related misconceptions and promoting quality of life in patients with irritable bowel syndrome.

Bioactive Components of Areca Nut: An Overview of Their Positive Impacts Targeting Different Organs.

Areca catechu L. is a widely cultivated tropical crop in Southeast Asia, and its fruit, areca nut, has been consumed as a traditional Chinese medicinal material for more than 10,000 years, although it has recently attracted widespread attention due to potential hazards. Areca nut holds a significant position in traditional medicine in many areas and ranks first among the four southern medicines in China. Numerous bioactive compounds have been identified in areca nuts, including alkaloids, polyphenols, polysaccharides, and fatty acids, which exhibit diverse bioactive functions, such as anti-bacterial, deworming, anti-viral, anti-oxidant, anti-inflammatory, and anti-tumor effects. Furthermore, they also display beneficial impacts targeting the nervous, digestive, and endocrine systems. This review summarizes the pharmacological functions and underlying mechanisms of the bioactive ingredients in areca nut. This helps to ascertain the beneficial components of areca nut, discover its medicinal potential, and guide the utilization of the areca nut.

Endophthalmitis in silicone oil-filled eye: A case report.

BACKGROUND: Endophthalmitis occurring in silicone oil-filled eyes is a very rare occurrence, with reported incidence rates ranging between 0.07% and 0.039%. Traditional methods of management of infectious endophthalmitis include the removal of silicone oil, washout of the vitreous cavity, administration of intravitreal antibiotics, and re-injection of silicone oil. CASE SUMMARY: Herein, we report the case of a 39-year-old man with unilateral endophthalmitis after pars plana vitrectomy and silicone oil tamponade. Intravitreal injections of full-dose antibiotics and anterior chamber washout were used to treat the patient. No signs of retinal toxicity were observed during the follow-up period. CONCLUSION: Intravitreal full-dose antibiotic injections and anterior chamber washout are promising alternatives to traditional therapies for endophthalmitis in silicone oil-filled eyes.

Deubiquitinating Enzyme USP19 Regulates Ferroptosis and Mitochondrial Damage in SH-SY5Y Cells by Targeting the NOX4 Protein.

Background: Ferroptosis is extremely relevant to the progression of neurodegenerative pathologies such as Alzheimer's disease (AD). Ubiquitin-specific proteases (USP) can affect the NADPH oxidase family. Objective: Our study aimed to elucidate the potential role and molecular basis of a certain USP19 in reducing ferroptosis and mitochondrial injury in AD cells by targeting NOX4 stability. Methods: The deubiquitinase USP family gene USP19, which affects the stability of NOX4 protein, was first screened. The cell model of AD was constructed after interfering with SH-SY5Y cells by Aß1-40, and then SH-SY5Y cells were infected with lentiviral vectors to knock down USP19 and overexpress NOX4, respectively. Finally, the groups were tested for cell viability, changes in cellular mitochondrial membrane potential, lipid reactive oxygen species, intracellular iron metabolism, and NOX4, Mf1, Mf2, and Drp1 protein expression. Results: 5 µmol/L Aß1-40 intervened in SH-SY5Y cells for 24 h to construct a cell model of AD. Knockdown of USP19 decreased the expression of NOX4 protein, promoted the expression of mitochondrial fusion proteins Mnf1 and Mnf2, and inhibited the expression of the splitting protein Drp1. Furthermore, USP19 knockdown decreased mitochondrial membrane potential, SOD, MDA, intracellular iron content and increased GSH/GSSG ratio in SH-SY5Y cells. Our study revealed that NOX4 protein interacts with USP19 and knockdown of USP19 enhanced ubiquitination to maintain NOX4 protein stability. Conclusions: USP19 attenuates mitochondrial damage in SH-SY5Y cells by targeting NOX4 protein with Aß1-40.

An interpretable model predicts visual outcomes of no light perception eyes after open globe injury.

BACKGROUND: The visual outcome of open globe injury (OGI)-no light perception (NLP) eyes is unpredictable traditionally. This study aimed to develop a model to predict the visual outcomes of vitrectomy surgery in OGI-NLP eyes using a machine learning algorithm and to provide an interpretable system for the prediction results. METHODS: Clinical data of 459 OGI-NLP eyes were retrospectively collected from 19 medical centres across China to establish a training data set for developing a model, called 'VisionGo', which can predict the visual outcome of the patients involved and compare with the Ocular Trauma Score (OTS). Another 72 cases were retrospectively collected and used for human-machine comparison, and an additional 27 cases were prospectively collected for real-world validation of the model. The SHapley Additive exPlanations method was applied to analyse feature contribution to the model. An online platform was built for real-world application. RESULTS: The area under the receiver operating characteristic curve (AUC) of VisionGo was 0.75 and 0.90 in previtrectomy and intravitrectomy application scenarios, which was much higher than the OTS (AUC=0.49). VisionGo showed better performance than ophthalmologists in both previtrectomy and intravitrectomy application scenarios (AUC=0.73 vs 0.57 and 0.87 vs 0.64). In real-world validation, VisionGo achieved an AUC of 0.60 and 0.91 in previtrectomy and intravitrectomy application scenarios. Feature contribution analysis indicated that wound length-related indicators, vitreous status and retina-related indicators contributed highly to visual outcomes. CONCLUSIONS: VisionGo has achieved an accurate and reliable prediction in visual outcome after vitrectomy for OGI-NLP eyes.

Inhibition of pathological retinal neovascularization by semaphorin 3A.

OBJECTIVE: Pathological retinal angiogenesis is a major cause of vision loss. Semaphorin 3A (Sema3A), a chemorepellent guidance protein, plays crucial roles in neural and vascular patterning. To identify its role in retinal neovascularization, we investigated its antiangiogenic effects. METHODS: Human umbilical vein endothelial cells (HUVECs) were used for the in vitro study, and an oxygen-induced retinopathy (OIR) mouse model was used for the in vivo study. The HUVECs were incubated with Sema3A, and cell proliferation, migration, apoptosis, cell cycle, tube formation, and c-Jun N-terminal kinase (JNK) and p38 mitogen-activated protein kinases (p38 MAPK) signaling pathways were measured using Cell Counting Kit-8, Transwell, flow cytometry, Matrigel assays, and western blot. C57BL/6J mouse pups were exposed to 75% oxygen for 5 days and then brought to room air and injected with Sema3A intravitreously. At postnatal day 18, the retinal nonperfused areas were measured. The in vitro and in vivo vascular endothelial growth factor-165 (VEGF165) secretion was measured using enzyme-linked immunosorbent assay. RESULTS: Sema3A not only inhibited VEGF165-induced proliferation, but also induced cell cycle arrest in a dose-dependent manner. Furthermore, Sema3A inhibited migration and tube formation, both in general and in VEGF165-containing culture medium. Using an enzyme-linked immunosorbent assay, we showed that Sema3A did not affect VEGF165 secretion, but it did impede VEGF165 function. Additionally, Sema3A significantly inhibited the phosphorylation of the JNK and p38MAPK signaling pathways. When administered intravitreously, Sema3A reduced the pathological vascular changes seen in the retinal neovascularization OIR model. CONCLUSIONS: These results suggest that the administration of Sema3A could be a useful therapeutic strategy for preventing hypoxia/ischemic-induced retinal neovascularization.

TOMM40 rs2075650 polymorphism shows no association with neovascular age-related macular degeneration or polypoidal choroidal vasculopathy in a Chinese population.

PURPOSE: Age-related macular degeneration (AMD) and Alzheimer disease (AD) are age-related neurodegenerative diseases that share similar environmental risk factors, cellular pathologies, and genetic backgrounds. Recently, the rs2075650 single nucleotide polymorphism in the translocase of outer mitochondrial membrane 40 homolog (TOMM40) gene was identified as a risk factor for AMD and Alzheimer disease. We aimed to examine the associations between the TOMM40 rs2075650 polymorphism and neovascular age-related macular degeneration (nAMD) and polypoidal choroidal vasculopathy (PCV) in a Chinese population. METHODS: The study consisted of 900 subjects, including 300 controls, 300 cases with nAMD, and 300 cases with PCV. Genomic DNA was extracted from venous blood leukocytes. The allelic variant of rs2075650 was determined with matrix-assisted laser desorption/ionization time-of-flight mass spectrometry. Differences in the observed genotypic distributions between the case and control groups were tested using chi-square tests, with age and gender adjusted using logistic regression analysis. RESULTS: The TOMM40 rs2075650 polymorphism was not statistically significantly associated with the nAMD or PCV phenotype (p>0.05). The difference remained insignificant after correction for age and gender differences based on the logistic regression models (p>0.05). CONCLUSIONS: Our data provide no evidence to support an association of rs2075650 in TOMM40 with nAMD or PCV, suggesting that this gene is unlikely to be a major AMD and PCV susceptibility gene locus in the Chinese population.

Anti-angiogenic effect of KH902 on retinal neovascularization.

PURPOSE: KH902 is a fusion protein derived from the extracellular domains of vascular endothelial growth factor (VEGF) receptors 1 and 2 and the Fc portion of immunoglobulin G1 (IgG1). Retinopathy of prematurity (ROP) is an eye disease that affects premature babies who have received intensive neonatal care, and the disorganization of retinal blood vessels may result in scarring and retinal detachment. This study was designed to examine the inhibitory effects of KH902 on mice with oxygen-induced retinopathy (OIR), one of the animal models of ROP. METHODS: Human umbilical vein endothelial cells (HUVECs) were used for an in vitro study, and the C57BL/6 J OIR mouse model was used for an in vivo study. HUVECs were incubated with KH902 or a VEGF- and KH902-containing medium. Cell proliferation, migration, apoptosis, and tube formation were measured with BrdU incorporation, Transwell, flow cytometry, and Matrigel assays. C57BL/6 J mice were exposed to 75 % oxygen from postnatal day 7 (P7) to P12, after which the mice were brought to room air and intravitreously injected with KH902. At P18, the mice were perfused with fluorescein isothiocyanate (FITC)-dextran and Evans Blue, and flat-mounted retinas were used to measure the non-perfused and leakage areas. The data were analyzed with GraphPad Prism 5.0 software. RESULTS: In vitro, KH902 dose-dependently inhibited HUVEC proliferation in general culture medium and in VEGF165-containing medium at different time points. Moreover, KH902 inhibited HUVEC migration and tube formation and induced HUVEC apoptosis. In vivo, an intravitreous injection of KH902 reduced the retinal non-perfused area from 34 % in the control group to 19 % in the treatment group and significantly reduced the retinal leakage area from 18 % to 9 %. CONCLUSION: KH902 had marked inhibitory effects on angiogenesis both in vitro and in vivo. These data suggest that KH902 could serve as an innovative pharmaceutical agent to prevent retinal neovascularization (NV) and as a strategy for the treatment of ROP.

Targeting of integrin-linked kinase with small interfering RNA inhibits VEGF-induced angiogenesis in retinal endothelial cells.

BACKGROUND: The pathological angiogenesis in the retina is a major cause of vision loss at all ages. Vascular endothelial growth factor (VEGF) has been reported as the most potent inducer of retinal neovascularization. We previously demonstrated that integrin-linked kinase (ILK) regulates retinal vascular endothelial proliferation, migration and tube formation. However, little is known about the existence of cross-talk between ILK and VEGF signaling in retinal vascular endothelial cells and the probable regulatory role of ILK during VEGF-induced retinal endothelial cell migration. The purpose of this work was to investigate the role of ILK in VEGF-induced retinal neovascularization. METHODS: Cultured retinal endothelial cells (RF/6A) were knocked down for ILK using a small interfering RNA (siRNA). For this, cellular ILK expression was quantified by real-time quantitative PCR, Western blot analysis and immunocytochemical assay, and cytotoxicity of transfection was determined by the 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay. ILK siRNA-transfected RF/6A cells were induced by VEGF, and cell proliferation was determined by the MTT assay, cell migration was measured by cell counting in modified Boyden chambers and cell spreading and tube formation assays were performed. Furthermore, the impact of ILK-specific siRNA on VEGF-induced VEGF receptor 2 (VEGFR-2) phosphorylation and activation of downstream signal pathways were tested by Western blot analysis. RESULTS: Both ILK mRNA and protein levels were virtually undetectable after transfection with ILK siRNA, and blocking the expression of ILK by siRNA significantly inhibited VEGF-induced retinal endothelial cell proliferation, attachment, spreading, migration and tube formation. Knockdown of ILK effectively suppressed VEGF-induced p38 mitogen-activated protein kinase (MAPK) and Akt phosphorylation, but had no effects on VEGFR-2, extracellular signal-regulated protein kinase and Jun N terminus kinase phosphorylation. CONCLUSION: We conclude that knockdown of ILK with siRNA effectively inhibited VEGF-induced retinal endothelial cell attachment, spreading, migration and tube formation. p38 MAPK and Akt are downstream signaling pathways of the ILK that regulated VEGF-induced retinal neovascularization. Targeting ILK may be a potentially useful therapeutic approach for treating ocular neovascularization.

KH902, a recombinant human VEGF receptor fusion protein, reduced the level of placental growth factor in alkali burn induced-corneal neovascularization.

AIMS: To investigate the expression of placental growth factor (PIGF) in alkali burn-induced murine corneal neovascularization (NV); to evaluate the effects of KH902, a vascular endothelial growth factor receptor decoy, on prevention and regression of new vessels growths in the cornea; and to determine the influence of KH902 on the levels of vascular endothelial growth factor (VEGF) and PIGF in alkali burn-induced corneal NV. METHODS: Mouse corneal NV was induced by alkali burn. The expression of PIGF was detected by immunohistochemistry and reverse-transcription polymerase chain reaction (RT-PCR). To evaluate the effects of KH902, corneal NV was observed and photographed every 3 days for a total of 28 days after the alkali burn. The percentage of NV area was measured and compared with that of the control group. The VEGF and PIGF levels in the cornea were evaluated by enzyme linked immunosorbent assay (ELISA). RESULTS: PIGF was expressed during the alkali burn-induced corneal neovascularization. On day 3 (D3), day 6 (D6) and day 9 (D9) after chemical cauterization, the length of the longest new vessel and the neovascularization areas in the KH902-treated groups were significantly smaller than those of the PBS-treated group (p < 0.05). The areas of established corneal NV of the KH902-treated groups regressed with time, but the control groups showed no natural regression. The VEGF and PIGF levels of the cornea in the treated groups were significantly decreased compared to those of the control group (p < 0.05). CONCLUSIONS: PIGF may be involved in alkali burn-induced corneal NV. KH902 significantly inhibited new vessel growth and promoted the regression of established vessels in a mouse model of corneal NV, and it also reduced the levels of VEGF and PIGF in the cornea.

Retinal toxicity of long term overdose of sildenafil citrate: A case report.

Purpose: To report a case of eye structure changes in a patient with long-term overdose of sildenafil citrate. Observations: A 28-year-old male presented to our outpatient clinic with flare sensation in both eyes for 1 year after taking sildenafil citrate at a dose of 200 mg daily for two years. mERG and OCT examination revealed persistent damage of retinal photoreceptor cells. The symptoms did not disappear after 3 months off the medication. Conclusions and importance: Long term excessive use of overdose sildenafil citrate can cause serious damage to retinal photoreceptor cells. The retinal side effects of sildenafil citrate still need to be further investigated, and the administration of systemic overdose also needs to be considered by all physicians, not just ophthalmologists.

Effect of Heat Treatment Parameters on the Modification of Nano Residual Austenite of Low-Carbon Medium-Chromium Steel.

The ball milling lining board operates in a harsh environment, and the current materials fail to meet the requirements for large-sized boards due to the lack of synergistic properties between impact toughness and wear resistance. To address this issue, a low-carbon medium-chromium steel with martensite and nano residual austenite phases have been designed for future use. However, the residual austenite network could decrease the properties. Heat treatment, which includes processes like quenching and tempering, has the potential to alter the morphology and quantity of nano-scale residual austenite in the steel. In this study, the influence of heat treatment parameters on the morphologies and properties of steel has been investigated to address the wide-ranging fluctuations in impact toughness affected by nano residual austenite. Furthermore, the effect of cooling transformation on the microstructure has also been examined. The research findings indicate that modifying the quenching temperature of the steel within the range of 950-1100 °C results in a microstructure comprising martensite and nano residual austenite. At all quenching temperatures, the hardness exceeds 45 HRC, and the impact toughness shows a consistent improvement with increasing quenching temperature, indicating a modification of the nano residual austenite phase. The failure mode is primarily dimple fracture, with quasi-dissociation fracture as a secondary mode. The optimal heat treatment parameters are annealing at 930 °C, oil quenching at 1050 °C, and tempering at 250 °C. Under this condition, the steel exhibits a hardness of 51 HRC and impact toughness of 40 J/cm2 and an approximate fourfold increase compared to the untreated sample.

Dendrobium mixture ameliorates type 2 diabetes mellitus with non-alcoholic fatty liver disease through PPAR gamma: An integrated study of bioinformatics analysis and experimental verification.

Dendrobium mixture (DM) is a patented Chinese herbal medicine indicated which has anti-inflammatory and improved glycolipid metabolism. However, its active ingredients, targets of action, and potential mechanisms are still uncertain. Here, we investigate the role of DM as a prospective modulator of protection against non-alcoholic fatty liver disease (NAFLD) induced by type 2 diabetes mellitus (T2DM) and illustrate the molecular mechanisms potentially involved. The network pharmacology and TMT-based quantitative protomics analysis were conducted to identify potential gene targets of the active ingredients in DM against NAFLD and T2DM. DM was administered to the mice of DM group for 4 weeks, and db/m mice (control group) and db/db mice (model group) were gavaged by normal saline. DM was also given to Sprague-Dawley (SD) rats, and the serum was subjected to the palmitic acid-induced HepG2 cells with abnormal lipid metabolism. The mechanism of DM protection against T2DM-NAFLD is to improve liver function and pathological morphology by promoting peroxisome proliferator-activated receptor γ (PPARγ) activation, lowering blood glucose, improving insulin resistance (IR), and reducing inflammatory factors. In db/db mice, DM reduced RBG, body weight, and serum lipids levels, and significantly alleviated histological damage of liver steatosis and inflammation. It upregulated the PPARγ corresponding to the prediction from the bioinformatics analysis. DM significantly reduced inflammation by activating PPARγ in both db/db mice and palmitic acid-induced HepG2 cells.