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1.
Br J Ophthalmol ; 2024 May 10.
Artículo en Inglés | MEDLINE | ID: mdl-38729765

RESUMEN

BACKGROUND/AIMS: To evaluate the diagnostic accuracy of spectral-domain optical coherence tomography (SD OCT) combined with OCT angiography (OCTA) for myopic myopic macular neovascularisation (MNV) activity. METHODS: Both eyes of patients with myopic MNV diagnosed with fluorescein angiography (FA), SD OCT and OCTA were assessed by unmasked investigators. The images were deidentified and randomised before graded by masked investigators, who determined the presence of active myopic MNV by using SD OCT together with OCTA without FA and by FA alone, respectively. The findings of masked investigators were compared with unmasked investigators. RESULTS: 213 eyes of 110 patients comprising 499 imaging episodes were eligible for grading. For diagnosing new-onset myopic MNV without FA, combined use of SD OCT and OCTA had a sensitivity of 0.94, specificity of 0.84 and area under the curve (AUC) of 0.92. FA had a sensitivity of 0.52 (p<0.01), specificity of 0.80 (p=0.38) and AUC of 0.66 (p<0.01). For recurrent myopic MNV, the combination of SD OCT and OCTA had a sensitivity of 0.98, specificity of 0.78 and AUC of 0.88. FA had a sensitivity of 0.50 (p=0.04), specificity of 0.76 (p=0.85) and AUC of 0.63 (p=0.01). Myopic traction maculopathy was more frequently associated with recurrent myopic MNV (p<0.01). CONCLUSION: SD OCT with dense volumetric scan was highly sensitive for diagnosing myopic MNV. The addition of OCTA improved the diagnostic specificity without FA. Monitoring of the longitudinal changes on SD OCT and judicious use of FA is a reliable surveillance strategy for myopic MNV.

2.
Asia Pac J Ophthalmol (Phila) ; 13(3): 100072, 2024.
Artículo en Inglés | MEDLINE | ID: mdl-38789041

RESUMEN

Retinoblastoma (RB), originating from the developing retina, is an aggressive intraocular malignant neoplasm in childhood. Biallelic loss of RB1 is conventionally considered a prerequisite for initiating RB development in most RB cases. Additional genetic mutations arising from genome instability following RB1 mutations are proposed to be required to promote RB development. Recent advancements in high throughput sequencing technologies allow a deeper and more comprehensive understanding of the etiology of RB that additional genetic alterations following RB1 biallelic loss are rare, yet epigenetic changes driven by RB1 loss emerge as a critical contributor promoting RB tumorigenesis. Multiple epigenetic regulators have been found to be dysregulated and to contribute to RB development, including noncoding RNAs, DNA methylations, RNA modifications, chromatin conformations, and histone modifications. A full understanding of the roles of genetic and epigenetic alterations in RB formation is crucial in facilitating the translation of these findings into effective treatment strategies for RB. In this review, we summarize current knowledge concerning genetic defects and epigenetic dysregulations in RB, aiming to help understand their links and roles in RB tumorigenesis.


Asunto(s)
Epigénesis Genética , Neoplasias de la Retina , Retinoblastoma , Retinoblastoma/genética , Humanos , Neoplasias de la Retina/genética , Epigénesis Genética/genética , Mutación , Metilación de ADN/genética , Proteínas de Unión a Retinoblastoma/genética , Ubiquitina-Proteína Ligasas
3.
Sci Total Environ ; 920: 170943, 2024 Apr 10.
Artículo en Inglés | MEDLINE | ID: mdl-38365029

RESUMEN

Thaliaceans are globally distributed and play an important role in the world's biological carbon pump and marine ecosystems by forming dense swarms with high feeding rates and producing large amounts of fecal pellets and carcasses. The contribution of thaliacean swarms to the downward transport of carbon depends not only on their abundance but also on their body size. However, the key factors influencing the distribution of different-sized thaliaceans remain unstudied. To discriminate thaliacean assemblages and examine the key factors determining the zoogeographical distribution and abundance of different-sized thaliaceans during different monsoon periods, we conducted three cruises in the South China Sea from before the southwest monsoon to the peak of the northeast monsoon. Our results revealed that high thaliacean abundance corresponded to high chlorophyll a concentration, which were associated with hydrodynamic processes, such as upwelling and eddies. Hierarchical partitioning and niche difference analyses demonstrated that current velocity and temperature are key factors that shaped the zoogeographical distribution of different-sized thaliaceans. The global dataset indicated that small-sized thaliacean species tend to occur in coastal areas where the current velocity is generally high, while large-sized species tend to occur in open ocean areas where the current velocity is generally low. The results revealed that global warming-induced changes in surface current velocity and temperature may alter the zoogeographical distribution and abundance of thaliaceans with different sizes, thereby affecting the biological carbon pump and surrounding marine ecosystem. Overall, this study sheds light on the potential responses of pelagic tunicates to global climate change through changes in their hydrodynamic conditions.


Asunto(s)
Cambio Climático , Ecosistema , Temperatura , Clorofila A , Carbono
4.
Appl Environ Microbiol ; 90(1): e0163723, 2024 01 24.
Artículo en Inglés | MEDLINE | ID: mdl-38112726

RESUMEN

Dissolved organic phosphorus (DOP) is an important nutrient for phytoplankton growth in oligotrophic oceans. However, little is known about the impact of DOP on phytoplankton growth in eutrophic waters. In the present study, we conducted field monitoring as well as in situ and laboratory experiments in the Pearl River estuary (PRE). Field observations showed an increase in the nitrogen-to-phosphorus ratio and DOP in recent years in the PRE. The phytoplankton community was dominated by nanophytoplankton Cyclotella in the upper and middle estuary, with high concentrations of DOP and light limitation during the ebb stage of the spring to neap tide in summer. The relative abundance of Cyclotella in natural waters was higher after enrichment with estuarine water with a background of 0.40-0.46 µM DOP, even when dissolved inorganic phosphorus was sufficient (0.55-0.76 µM). In addition, the relative abundance of Cyclotella in natural waters was higher after enrichment with phosphoesters. Laboratory culture results also confirmed that phosphoesters can enhance the growth rate of Cyclotella cryptica. Our study highlights that Cyclotella can become the dominant species in estuaries with increased levels of phosphoesters and low and fluctuating light adaptability and under the joint effect of dynamic processes such as upwelling and tides. Our results provide new insights into the role of Cyclotella in biogeochemical cycles affected by DOP utilization and potential applications in relieving the hypoxia of tropical eutrophic estuaries.IMPORTANCEThis study provides evidence that Cyclotella can become the dominant species in estuaries with increased levels of phosphoesters and low and fluctuating light adaptability and under the joint effect of dynamic processes such as upwelling and tides. Our study provides new insights into the role of Cyclotella in biogeochemical cycles affected by dissolved organic phosphorus utilization, especially affected by anthropogenic inputs and climate change. Potential applications include relieving the hypoxia of tropical eutrophic estuaries.


Asunto(s)
Diatomeas , Materia Orgánica Disuelta , Humanos , Estuarios , Ríos , Fitoplancton , Fósforo/análisis , Hipoxia , Monitoreo del Ambiente
5.
J Innate Immun ; 15(1): 739-750, 2023.
Artículo en Inglés | MEDLINE | ID: mdl-37778330

RESUMEN

Cyclic GMP-AMP (cGAMP) synthase (cGAS), a sensor of cytosolic DNA, recognizes cytoplasmic nucleic acids to activate the innate immune responses via generation of the second messenger cGAMP and subsequent activation of the stimulator of interferon genes (STINGs). The cGAS-STING signaling has multiple immunologic and physiological functions in all human vital organs. It mediates protective innate immune defense against DNA-containing pathogen infection, confers intrinsic antitumor immunity via detecting tumor-derived DNA, and gives rise to autoimmune and inflammatory diseases upon aberrant activation by cytosolic leakage of self-genomic and mitochondrial DNA. Disruptions in these functions are associated with the pathophysiology of various immunologic and neurodegenerative diseases. Recent evidence indicates important roles of the cGAS-STING signaling in mediating inflammatory responses in ocular inflammatory and inflammation-associated diseases, such as keratitis, diabetic retinopathy, age-related macular degeneration, and uveitis. In this review, we summarize the recently emerging evidence of cGAS-STING signaling in mediating ocular inflammatory responses and affecting pathogenesis of these complex eye diseases. We attempt to provide insightful perspectives on future directions of investigating cGAS-STING signaling in ocular inflammation. Understanding how cGAS-STING signaling is modulated to mediate ocular inflammatory responses would allow future development of novel therapeutic strategies to treat ocular inflammation and autoimmunity.


Asunto(s)
Inflamación , Proteínas de la Membrana , Nucleotidiltransferasas , Transducción de Señal , Humanos , ADN , Inmunidad Innata , Nucleotidiltransferasas/metabolismo , Proteínas de la Membrana/metabolismo
6.
Aging (Albany NY) ; 15(13): 6331-6345, 2023 07 06.
Artículo en Inglés | MEDLINE | ID: mdl-37414399

RESUMEN

Cataracts are the leading cause of blindness in the world. Age is a major risk factor for cataracts, and with increasing aging, the burden of cataracts will grow, but the exact details of cataractogenesis remain unclear. A recent study showed that microRNA-34a (MIR34A) is involved in the development of cataracts, but the underlying pathogenesis remains obscure. Here, our results of microRNA target prediction showed that hexokinase 1 (HK1) is one of the genes targeted by MIR34A. Based on this finding, we focused on the function of MIR34A and HK1 in the progress of cataracts, whereby the human lens epithelial cell line SRA01/04 and mouse lens were treated with MIR34A mimics and HK1 siRNA. We found that HK1 mRNA is a direct target of MIR34A, whereby the high expression of MIR34A in the cataract lens suppresses the expression of HK1. In vitro, the upregulation of MIR34A together with the downregulation of HK1 inhibits the proliferation, induces the apoptosis of SRA01/04 cells, and accelerates the opacification of mouse lenses via the HK1/caspase 3 signaling pathway. In summary, our study demonstrates that MIR34A modulates lens epithelial cell (LEC) apoptosis and cataract development through the HK1/caspase 3 signaling pathway.


Asunto(s)
Catarata , MicroARNs , Animales , Ratones , Humanos , Hexoquinasa/metabolismo , Caspasa 3/genética , Caspasa 3/metabolismo , Catarata/patología , MicroARNs/genética , MicroARNs/metabolismo , Apoptosis/genética , Células Epiteliales/metabolismo , Transducción de Señal
7.
Nat Commun ; 14(1): 3298, 2023 06 06.
Artículo en Inglés | MEDLINE | ID: mdl-37280225

RESUMEN

Dysregulation of Th17 cell differentiation and pathogenicity contributes to multiple autoimmune and inflammatory diseases. Previously growth hormone releasing hormone receptor (GHRH-R) deficient mice have been reported to be less susceptible to the induction of experimental autoimmune encephalomyelitis. Here, we show GHRH-R is an important regulator of Th17 cell differentiation in Th17 cell-mediated ocular and neural inflammation. We find that GHRH-R is not expressed in naïve CD4+ T cells, while its expression is induced throughout Th17 cell differentiation in vitro. Mechanistically, GHRH-R activates the JAK-STAT3 pathway, increases the phosphorylation of STAT3, enhances both non-pathogenic and pathogenic Th17 cell differentiation and promotes the gene expression signatures of pathogenic Th17 cells. Enhancing this signaling by GHRH agonist promotes, while inhibiting this signaling by GHRH antagonist or GHRH-R deficiency reduces, Th17 cell differentiation in vitro and Th17 cell-mediated ocular and neural inflammation in vivo. Thus, GHRH-R signaling functions as a critical factor that regulates Th17 cell differentiation and Th17 cell-mediated autoimmune ocular and neural inflammation.


Asunto(s)
Encefalomielitis Autoinmune Experimental , Células Th17 , Ratones , Animales , Transducción de Señal/fisiología , Inflamación/metabolismo , Diferenciación Celular/genética , Hormona Liberadora de Hormona del Crecimiento/genética , Hormona Liberadora de Hormona del Crecimiento/metabolismo , Ratones Endogámicos C57BL
9.
Scand J Immunol ; 98(6): e13319, 2023 Dec.
Artículo en Inglés | MEDLINE | ID: mdl-38441217

RESUMEN

Uveitis is a devastating intraocular inflammatory disease. The secreted leucine-rich repeat protein slit homologue 2 (Slit2) has been found to be an essential regulator of inflammation. This study aimed to analyse the anti-inflammatory effects and the underlying mechanisms of Slit2 in an endotoxin-induced uveitis (EIU) rat model. In this study, rats with EIU pretreated recombinant human Slit2 (rhSlit2) or a control vehicle by intravitreal injection. The clinical scores were graded under a slit lamp. The protein concentrations and total number of cells in the aqueous humour (AqH) were examined, and the retinal expression of various inflammatory mediators was detected. The levels of nuclear factor-kappa B (NF-κB), phosphorylated NF-κB, IkappaB-a (IκB-a), phosphorylated IκB-a, IKK, phosphorylated IKK, PI3Kp85, phosphorylated PI3Kp85, Akt and phosphorylated Akt were evaluated by western blotting. Treatment with rhSlit2 dramatically diminished the clinical scores of EIU, with significant decreases in inflammatory cell infiltration, protein concentrations, cellulose-like exudates, the production of ICAM-1, MCP-1, TNF-α and IL-6 in the AqH; and adhesion of leucocytes. The PI3K/Akt/IKK/NF-κB pathway was found to be activated in EIU. However, the pre-treatment of rhSlit2 significantly inhibited the production of ICAM-1, MCP-1, TNF-α, and IL-6, and inhibited leucocyte adhesion by modulating the PI3K/Akt/IKK/NF-κB pathway. In conclusion, the intravitreal injection of rhSlit2 alleviated EIU-related inflammation in Sprague-Dawley rats by reducing the proinflammatory cytokines and leucocyte adhesion; in particular, rhSlit2 may inhibit LPS-induced inflammation by inhibiting the activation of PI3K/Akt/IKK/NF-κB signalling pathway. Therefore, rhSlit2 shows significant potential for effectively alleviating immune inflammatory responses in vivo.


Asunto(s)
FN-kappa B , Uveítis , Humanos , Animales , Ratas , Ratas Sprague-Dawley , Molécula 1 de Adhesión Intercelular , Fosfatidilinositol 3-Quinasas , Proteínas Proto-Oncogénicas c-akt , Interleucina-6 , Factor de Necrosis Tumoral alfa , Uveítis/inducido químicamente , Uveítis/tratamiento farmacológico , Inflamación
10.
Oxid Med Cell Longev ; 2022: 7435754, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-36406768

RESUMEN

Primary open-angle glaucoma (POAG) is the most common form of glaucoma, for which elevated intraocular pressure (IOP) is a major risk factor. IOP is mainly regulated by dynamic balance of aqueous humor (AH) production and outflow via the conventional trabecular meshwork/Schlemm's canal (TM/SC) pathway. Dysfunctions of TM cells due to endoplasmic reticulum (ER) stress have been demonstrated to increase the resistance of AH outflow, resulting in IOP elevation. Epigallocatechin-3-gallate (EGCG), the most abundant polyphenolic component in green tea, has been shown to alleviate ER stress in several diseases while its potential roles in alleviating ER stress in TM cells have not been determined. In this study, we investigate the mitigation of tunicamycin-induced ER stress in TM cells by EGCG. MTT assay was used to measure the cell viability of human TM (HTM) cells and primary porcine TM (PTM) cells. ER stress levels in both HTM cells and primary PTM cells were detected by quantitative real-time PCR. The primary PTM cells isolated from porcine TM tissues were characterized by immunostaining. We found that 40 µM and 80 µM EGCG pretreatment substantially promoted HTM cell survival under 3 µM tunicamycin-induced ER stress. Pretreatment of 40 µM EGCG markedly reduced the expression of ER stress markers ATF4, HSPA5, and DDIT3, evoked by 3 µM tunicamycin in HTM cells. Furthermore, 40 µM EGCG pretreatment significantly decreased the expressions of ATF4, HSPA5, and DDIT3 at the mRNA level induced by 3 µM tunicamycin and improved cell viability in primary PTM cells. Our results show that EGCG is capable of protecting TM cells from ER stress. EGCG provides a promising therapeutic option for POAG treatment.


Asunto(s)
Glaucoma de Ángulo Abierto , Malla Trabecular , Humanos , Porcinos , Animales , Malla Trabecular/metabolismo , Estrés del Retículo Endoplásmico , Tunicamicina/farmacología , Glaucoma de Ángulo Abierto/tratamiento farmacológico , Glaucoma de Ángulo Abierto/metabolismo
11.
Mar Pollut Bull ; 181: 113908, 2022 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-35810653

RESUMEN

Here we propose a carbon release model that divides fish-released carbon into two sources (ingested food and the fish body), and three forms (dissolved organic carbon (DOC), CO2, and particulate carbon (PC)). We quantified the daily carbon budget of a marine fish Oryzias melastigma by feeding the fish radiocarbon-labeled living rotifer. We found that 91%-92%, 25%-47%, 28%-50%, 20%-31%, and 8%-9% of the ingested food carbon was absorbed, assimilated, and released as DOC, CO2, and PC, respectively. Fish body carbon dissimilated/catabolized and released as 0.053-0.12 d-1 at two daily food rations. DOC, CO2, and PC accounted for 39%-42%, 39%-45%, and 16%-19% of the released fish body carbon, respectively. Our study shows that the fish transformed substantial fractions of their daily ingested food and dissimilated body carbon into DOC, and fish may be an important source of DOC in the ocean.


Asunto(s)
Carbono , Oryzias , Animales , Dióxido de Carbono
12.
J Biomed Sci ; 29(1): 33, 2022 Jun 01.
Artículo en Inglés | MEDLINE | ID: mdl-35650644

RESUMEN

The retinoblastoma protein (pRb) functions as a cell cycle regulator controlling G1 to S phase transition and plays critical roles in tumour suppression. It is frequently inactivated in various tumours. The functions of pRb are tightly regulated, where post-translational modifications (PTMs) play crucial roles, including phosphorylation, ubiquitination, SUMOylation, acetylation and methylation. Most PTMs on pRb are reversible and can be detected in non-cancerous cells, playing an important role in cell cycle regulation, cell survival and differentiation. Conversely, altered PTMs on pRb can give rise to anomalies in cell proliferation and tumourigenesis. In this review, we first summarize recent findings pertinent to how individual PTMs impinge on pRb functions. As many of these PTMs on pRb were published as individual articles, we also provide insights on the coordination, either collaborations and/or competitions, of the same or different types of PTMs on pRb. Having a better understanding of how pRb is post-translationally modulated should pave the way for developing novel and specific therapeutic strategies to treat various human diseases.


Asunto(s)
Procesamiento Proteico-Postraduccional , Proteína de Retinoblastoma , Acetilación , Humanos , Fosforilación , Proteína de Retinoblastoma/genética , Proteína de Retinoblastoma/metabolismo , Ubiquitinación
13.
Ecotoxicol Environ Saf ; 238: 113606, 2022 Jun 15.
Artículo en Inglés | MEDLINE | ID: mdl-35533450

RESUMEN

An outbreak of a macrozooplankton Creseis acicula occurred in the summer of 2020 nearby the Daya Bay Nuclear Power Plant located on the coast of the Daya Bay in the South China Sea. The outbreaks of C. acicula often threaten human health, the marine environment, and other human activities including the safe operation of coastal nuclear power plants. Seawater temperature has been suggested as an important factor influencing such outbreaks. However, the underlying mechanisms through which temperature influences C. acicula remains unknown. Here, we studied the effects of temperature on the ingestion and assimilation of algal food by feeding radiocarbon-labeled algae Chlorella sp. at simulated field temperatures (19-31 °C) to C. acicula collected during the outbreak in the Daya Bay. We also quantified the allocation of the food carbon to dissolved organic carbon (DOC), CO2, and fecal pellets. The results showed that the zooplankton during the same feeding time ingested doubled or tripled algal food at higher temperatures, and it produced and released significantly more DOC, CO2, and fecal pellets with more ingested food carbon. Meanwhile, the assimilation efficiency for the ingested food carbon slightly increased from 48% to 54% with rising temperature. As a result, higher assimilation rates indicating faster growth of C. acicula were observed at higher temperatures. In addition, the high activation energy of 0.908 eV indicated that the assimilation rate was very sensitive to temperature rising. Our results show that relatively rising temperature can enhance C. acicula's ingestion and assimilation rates for algal food, benefit its growth and metabolism, and contribute to its outbreak. This study provides a mechanistic interpretation for the relationship between rising temperature and the outbreaks of C. acicula and suggests that such outbreaks may occur more frequently and widely in the warming ocean.


Asunto(s)
Chlorella , Gastrópodos , Animales , Bahías , Carbono , Dióxido de Carbono , China , Brotes de Enfermedades , Humanos , Plantas de Energía Nuclear , Agua de Mar , Temperatura
14.
Front Med (Lausanne) ; 9: 861371, 2022.
Artículo en Inglés | MEDLINE | ID: mdl-35492354

RESUMEN

Retinitis pigmentosa (RP), characterized by the gradual loss of rod and cone photoreceptors that eventually leads to blindness, is the most common inherited retinal disorder, affecting more than 2.5 million people worldwide. However, the underlying pathogenesis of RP remains unclear and there is no effective cure for RP. Mutations in the Mer receptor tyrosine kinase (MERTK) gene induce the phagocytic dysfunction of retinal pigment epithelium (RPE) cells, leading to RP. Studies have indicated that filamentous actin (F-actin)-which is regulated by chaperonin-containing TCP1 subunit 5 (CCT5)-plays a vital role in phagocytosis in RPE cells. However, whether CCT5/F-actin signaling is involved in MERTK-associated RP remains largely unknown. In the present study, we specifically knocked down MERTK and CCT5 through siRNA transfection and examined the expression of CCT5 and F-actin in human primary RPE (HsRPE) cells. We found that MERTK downregulation inhibited cell proliferation, migration, and phagocytic function; significantly decreased the expression of F-actin; and disrupted the regular arrangement of F-actin. Importantly, our findings firstly indicate that CCT5 interacts with F-actin and is inhibited by MERTK siRNA in HsRPE cells. Upregulating CCT5 using CCT5-specific lentiviral vectors (CCT5-Le) rescued the cell proliferation, migration, and phagocytic function of HsRPE cells under the MERTK knockdown condition by increasing the expression of F-actin and restoring its regular arrangement via the LIMK1/cofilin, but not the SSH1/cofilin, pathway. In conclusion, CCT5 protects against the effect of MERTK knockdown in HsRPE cells and demonstrates the potential for effective treatment of MERTK-associated RP.

15.
Cell Signal ; 88: 110153, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34571190

RESUMEN

Retinal ischemia-reperfusion (I/R) often results in intractable visual impairments, where blood retinal barrier (BRB) homeostasis mediated by retinal pigment epithelium (RPE) and retinal microvascular endothelium (RME) is crucial. However, strategies targeting the BRB are limited. Thus, we investigated the inconclusive effect of lycopene (LYC) in retinal protection under I/R. LYC elevated cellular viability and reversed oxidative stress in aRPE-19 cells/hRME cells under I/R conditions based on oxygen-glucose deprivation (OGD) in vitro. Molecular analysis showed that LYC promoted NRF2 expression and enhanced the downstream factors of the KEAP1/NRF2/ARE pathway: LYC increased the activities of antioxidants, including SOD and CAT, whereas it enhanced the mRNA expression of HO-1 (ho-1) and NQO-1 (nqo-1). The activation resulted in restrained ROS and MDA. On the other hand, LYC ameliorated the damage to retinal function and morphology in a mouse I/R model, which was established by unilateral ligation of the left pterygopalatine artery/external carotid artery and reperfusion. LYC promoted the expression of NRF2 in both the neural retina and the RPE choroid in vivo. This evidence revealed the potential of LYC in retinal protection under I/R, uncovering the pharmacological effect of the KEAP1/NRF2/ARE pathway in BRB targeting. The study generates new insights into scientific practices in retinal research.


Asunto(s)
Factor 2 Relacionado con NF-E2 , Daño por Reperfusión , Animales , Barrera Hematorretinal/metabolismo , Homeostasis , Proteína 1 Asociada A ECH Tipo Kelch/metabolismo , Licopeno/metabolismo , Licopeno/farmacología , Ratones , Factor 2 Relacionado con NF-E2/metabolismo , Estrés Oxidativo , Especies Reactivas de Oxígeno/metabolismo , Retina/metabolismo
16.
Front Cell Dev Biol ; 9: 631413, 2021.
Artículo en Inglés | MEDLINE | ID: mdl-34222224

RESUMEN

Retinal pigment epithelium (RPE), a postmitotic monolayer located between the neuroretina and choroid, supports the retina and is closely associated with vision loss diseases such as age-related macular degeneration (AMD) upon dysfunction. Although environmental stresses are known to play critical roles in AMD pathogenesis and the roles of other stresses have been well investigated, glucose deprivation, which can arise from choriocapillary flow voids, has yet to be fully explored. In this study, we examined the involvement of VEGFR2 in glucose deprivation-mediated cell death and the underlying mechanisms. We found that VEGFR2 levels are a determinant for RPE cell death, a critical factor for dry AMD, under glucose deprivation. RNA sequencing analysis showed that upon VEGFR2 knockdown under glucose starvation, endoplasmic reticulum (ER) stress and unfolded protein response (UPR) are reduced. Consistently, VEGFR2 overexpression increased ER stress under the same condition. Although VEGFR2 was less expressed compared to EGFR1 and c-Met in RPE cells, it could elicit a higher level of ER stress induced by glucose starvation. Finally, downregulated VEGFR2 attenuated the oxidative stress and inflammatory factor expression, two downstream targets of ER stress. Our study, for the first time, has demonstrated a novel role of VEGFR2 in RPE cells under glucose deprivation, thus providing valuable insights into the mechanisms of AMD pathogenesis and suggesting that VEGFR2 might be a potential therapeutic target for AMD prevention, which may impede its progression.

17.
Am J Ophthalmol ; 232: 70-82, 2021 12.
Artículo en Inglés | MEDLINE | ID: mdl-34116008

RESUMEN

PURPOSE: To assess the diagnostic accuracy of optical coherence tomography angiography (OCTA) compared with multimodal imaging for choroidal neovascularization (CNV) in central serous chorioretinopathy (CSC) eyes and to determine the features that predicted CNV. DESIGN: Prospective cross-sectional study. METHODS: Consecutive CSC patients were recruited from retina clinic. The reference standard for CNV was determined by interpretation of multimodal imaging with OCTA, structural OCT line scan, fluorescein angiography (FA), indocyanine green angiography (ICGA), ultra-widefield fundus photography and fundus autofluorescence (FAF). Two independent masked graders examined OCTA without FA and ICGA to diagnose CNV. Univariate and multivariate analyses were performed to evaluate factors associated with CNV. RESULTS: CNV was detected in 69 eyes in 64 out of 277 CSC patients according to reference standard. The two masked graders who examined OCTA had sensitivity of 81.2% (95% Confidence Interval [CI], 71.9%-90.4%) and 78.3% (95% CI, 68.5%-88.0%), specificity of 97.3% (95% CI, 95.9%-98.8%) and 96.2% (95% CI, 94.5%-98.0%), positive predictive values of 82.4% (95% CI, 73.3%-91.4%) and 76.1% (95% CI, 66.1%-86.0%), and negative predictive values of 97.1% (95% CI, 95.6%-98.7%) and 96.7% (95% CI, 95.0%-98.3%). Their mean area under the receiver operating characteristic curve (AUC) was 0.88 with good agreement (Kappa coefficient 0.80 [95% CI, 0.72-0.89]). Flat irregular pigment epithelial detachment on structural OCT, neovascular network on OCTA and ill-defined late leakage on FA significantly correlated with CNV in CSC from multiple regression (P < 0.001, P < 0.001 and P = 0.005, respectively). CONCLUSIONS: There is discordance between OCTA and multimodal imaging in diagnosing CNV in CSC. This study demonstrated the caveats in OCTA interpretation, such as small extrafoveal lesions and retinal pigment epithelial alterations. Comprehensive interpretation of OCTA with dye angiography and structural OCT is recommended.


Asunto(s)
Coriorretinopatía Serosa Central , Neovascularización Coroidal , Coriorretinopatía Serosa Central/diagnóstico , Coroides/diagnóstico por imagen , Neovascularización Coroidal/diagnóstico por imagen , Estudios Transversales , Angiografía con Fluoresceína , Humanos , Verde de Indocianina , Imagen Multimodal , Estudios Prospectivos , Estudios Retrospectivos , Tomografía de Coherencia Óptica
18.
Mar Pollut Bull ; 167: 112331, 2021 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-33862383

RESUMEN

Daya Bay is a eutrophic coastal region with dynamic physico-chemical conditions influenced by terrestrial inputs and seawater intrusion. Zooplankton is a crucial trophic intermediary for energy transfer and fishery resources. In this study, we assessed the distribution and composition of zooplankton in Daya Bay during summer and winter of 2015. We found that zooplankton diversity was the lowest and dominated by small copepods (Acartia spp. and Paracalanus spp.) and gelatinous Oikopleura spp. under terrestrial inputs in the Dan'ao River estuary and Aotou barbour. The highest zooplankton diversity was observed at the bay mouth that influenced by salty intruded seawater, and the dominant oceanic species (such as Euchaeta concinna and Subeucalanus subcrassus invaded into the top of the bay in winter. The dominant species in the estuary shift from Penilia avirostris to Acartia spp. compared with historical researches, indicating the effect of human activities on the succession of dominant species.


Asunto(s)
Bahías , Zooplancton , Animales , China , Monitoreo del Ambiente , Humanos , Océanos y Mares , Estaciones del Año , Agua de Mar
19.
Int J Ophthalmol ; 13(7): 1039-1045, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32685389

RESUMEN

AIM: To identify proangiogenic factors engaged in neovascular age-related macular degeneration (AMD) except vascular endothelial growth factor (VEGF) from human retinal pigment epithelial (hRPE) cells and investigate the underlying mechanisms. METHODS: VEGF receptor 2 (VEGFR2) in ARPE-19 cells was depleted by siRNA transfection or overexpressed through adenovirus infection. The mRNA and the protein levels of interleukin-8 (IL-8) in ARPE-19 cells were measured by quantitative real-time polymerase chain reaction and enzyme-linked immunosorbent assay respectively. The protein levels of AKT, p-AKT, MEK, p-MEK, ERK1/2, p-ERK1/2, JNK, p-JNK, p38 and p-p38 were detected by Western blotting. A selective chemical inhibitor, LY3214996, was employed to inhibit phosphorylation of ERK1/2. Cell viability was determined by MTT assay. RESULTS: Knockdown of VEGFR2 in ARPE-19 cells robustly augmented IL-8 production at both the mRNA and the protein levels. Silencing VEGFR2 substantially enhanced phosphorylation of MEK and ERK1/2 while exerted no effects on phosphorylation of AKT, JNK and p38. Inhibiting ERK1/2 phosphorylation by LY3214996 reversed changes in VEGFR2 knockdown-induced IL-8 upregulation at the mRNA and the protein levels with no effects on cell viability. VEGFR2 overexpression significantly reduced IL-8 generation at the mRNA and the protein levels. CONCLUSION: Blockade of VEGF signaling augments IL-8 secretion via MEK/ERK1/2 axis and overactivation of VEGF pathway decreases IL-8 production in hRPE cells. Upregulated IL-8 expression after VEGF signaling inhibition in hRPE cells may be responsible for being incompletely responsive to anti-VEGF remedy in neovascular AMD, and IL-8 may serve as an alternative therapeutic target for neovascular AMD.

20.
Chemosphere ; 246: 125641, 2020 May.
Artículo en Inglés | MEDLINE | ID: mdl-31901529

RESUMEN

Large amounts of aluminum (Al) enter the ocean through atmospheric dust deposition and river runoffs. However, few studies have reported the effects of Al on marine phytoplankton, especially nitrogen-fixing cyanobacteria. By using the isotope tracer method and quantitative reverse transcription PCR (RT-qPCR), we examined the physiological effect of Al (0.2, 2 and 20 µM) on the unicellular marine nitrogen-fixing cyanobacterium Crocosphaera watsonii in Aquil* medium. We show that Al has an inhibitory physiological effect on C. watsonii, including changes in growth rate, nitrogen fixation rate, carbon fixation rate, cell size, fast rise chlorophyll fluorescence kinetics, cellular photosynthetic pigment and C/N/P content, the same as that of the phosphorus deficient treatment. The ratio of cellular elements C:N:P showed that phosphorus was deficient in the cell of C. watsonii after Al treatment (2 and 20 µM). In addition, Al stimulated the expression of phosphorus-related genes pstS, phoH, phoU, ppK and ppX in C. watsonii. All these results suggest that Al-treated C. watsonii is phosphorus-limited, and that the phosphorus deficiency induced by Al may be one mechanism behind aluminum's toxicity.


Asunto(s)
Aluminio/efectos adversos , Cianobacterias/efectos de los fármacos , Fósforo/deficiencia , Aluminio/metabolismo , Cianobacterias/metabolismo , Fijación del Nitrógeno/efectos de los fármacos , Fósforo/metabolismo , Fotosíntesis/efectos de los fármacos
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