Publications by authors named "Chenjun Guo"

Retinoblastoma (RB) is an intraocular malignant tumor originating from primitive retinal stem cells or cone precursor cells, appearing most frequently under the age of three years. EPH receptor B2 (EPHB2) has been found to be involved in RB, but the potential action of EPHB2 in RB remains poorly understood. Real-time quantitative polymerase chain reaction and western blotting detected RNA levels and protein levels.

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CTP synthase (CTPS) is a key enzyme in de novo CTP synthesis, playing a critical role in nucleotide metabolism and cellular proliferation. Human CTPS1 (hCTPS1), one of the two CTPS isoforms, is essential for immune responses and is highly expressed in proliferating cells, making it a promising therapeutic target for immune-related diseases and cancer. Despite its importance, the regulatory mechanisms governing hCTPS1 activity remain poorly understood.

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Fragile X messenger ribonucleoprotein 1 (FMR1) regulates neurodevelopment through mA RNA interactions, yet the domain-specific roles of KH0 and KH1 in RNA binding and disease pathogenesis remain poorly understood. Using mutagenesis and AlphaFold3 structural modeling, we identify KH1 as the primary mA-binding interface, while the KH0 domain (particularly Arg138) modulates liquid-liquid phase separation (LLPS). Pathogenic mutations in KH0 impair RNA binding and promote aberrant LLPS aggregation, whereas mA-modified RNA suppresses LLPS formation at KH0.

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Purpose: Ultraviolet B (UVB) irradiation induces cataract pathogenesis, and Glutaredoxin 2 (Grx2) deficiency causes the early onset of UVB-induced cataracts. Several researchers have shown that, apart from apoptosis and pyroptosis, UVB irradiation also can induce cell ferroptosis. We explored the role of ferroptosis caused by UVB irradiation in human lens epithelial cells (HLECs) and clarified how Grx2 protects against UVB-induced cataracts.

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Purpose: To explore the role of long non-coding RNAs (lncRNAs) and N6-methyladenosine (m6A) in posterior capsule opacification (PCO) and their underlying mechanisms.

Methods: The localization of lncRNAs and proteins was analyzed using fluorescence in situ hybridization and immunofluorescence staining. RNA m6A quantification, RNA immunoprecipitation, co-immunoprecipitation, MeRIP-seq, MeRIP-qPCR, western blotting, wound healing, and Transwell assays were applied to elucidate the underlying mechanisms.

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Purpose: To investigate the role of PTTG1 in thyroid cancer, focusing on its impact on proliferation, migration, and the regulation of p53-related signaling pathways.

Methods: We analyzed PTTG1 expression in thyroid cancer samples by using the TCGA database and validated our findings in tissue samples and cell lines. Functional assays including knockdown experiments using shRNA, CCK-8 assays for proliferation, scratch wound healing and Transwell assays for migration, and in vivo tumorigenesis experiments in mice were conducted.

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Rationale: Macular damage is a rare yet significant ocular complication of coronavirus disease 2019 (COVID-19) infection. This report highlights the clinical features, diagnosis, treatment, and outcomes in 2 cases of COVID-19-associated macular damage, contributing to the understanding of its pathophysiology and management.

Patient Concerns: Both patients presented with a sudden onset of visual impairment and black shadows in their central visual fields shortly after contracting COVID-19.

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Purpose: To highlight the safety and efficacy of tocilizumab (TCZ) in Graves' ophthalmopathy (GO) combined with ocular myasthenia gravis (OMG) patients refractory to steroids and cholinesterase inhibitor (CEI).

Methods: This was retrospective case series. We reviewed the health records of patients with GO combined with OMG, ten of whom were refractory to corticosteroids and CEI treatment and received intravenous injection of TCZ.

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The cytoophidium is a novel type of membraneless organelle, first observed in the ovaries of Drosophila using fluorescence microscopy. In vitro, purified Drosophila melanogaster CTPS (dmCTPS) can form metabolic filaments under the presence of either substrates or products, and their structures that have been analyzed using cryo-electron microscopy (cryo-EM). These dmCTPS filaments are considered the fundamental units of cytoophidia.

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The final step in the de novo synthesis of cytidine 5'-triphosphate (CTP) is catalyzed by CTP synthase (CTPS), which can form cytoophidia in all three domains of life. Recently, we have discovered that CTPS binds to ribonucleotides (NTPs) to form filaments, and have successfully resolved the structures of Drosophila melanogaster CTPS bound with NTPs. Previous biochemical studies have shown that CTPS can bind to deoxyribonucleotides (dNTPs) to produce 2'-deoxycytidine-5'-triphosphate (dCTP).

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Cytidine triphosphate synthase (CTPS) plays a pivotal role in the de novo synthesis of cytidine triphosphate (CTP), a fundamental building block for RNA and DNA that is essential for life. CTPS is capable of directly binding to all four nucleotide triphosphates: adenine triphosphate, uridine triphosphate, CTP, and guanidine triphosphate. Furthermore, CTPS can form cytoophidia in vivo and metabolic filaments in vitro, undergoing regulation at multiple levels.

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In plants, the rapid accumulation of proline is a common response to combat abiotic stress. Delta-1-pyrroline-5-carboxylate synthase (P5CS) is a rate-limiting enzyme in proline synthesis, catalysing the initial two-step conversion from glutamate to proline. Here we determine the first structure of plant P5CS.

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Background: Studies on the factors affecting vault after posterior chamber phakic Implantable Collamer Lens (ICL) have been carried out, but most of them are single-centered and subjective selections of parameters. The present study aimed to systematically analyze the factors for vault.

Methods: A systematic review of case series, case-control, and cohort studies derived from the articles published in PubMed, the Cochrane Library, Embase, Web of Science, CNKI, CBM, Wanfang and VIP, as well as ClinicalTrials, which were conducted to search for studies on factors of vault using four core terms: phakic intraocular lenses, vault, risk factor and observational study, from January 01, 1997, to February 20, 2023.

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The aim of the present study was to compare the performance of the Opel Panorama 200 and Zeiss Clarus 500 (Carl Zeiss AG) systems in diagnosing retinal fractures. Human subjects were selected from 298 fundus examinations (531 eyes) in ophthalmology from February 2021 to June 2021, including 68 patients with retinal fissures (95 eyes). All fundus tests were performed with Opel Panoramic 200.

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To observe the clinical phenomenon of amblyopia vision improvement in patients with monocular amblyopia over 18 years old after non-amblyopia diseases, analyze the conditions and causes of vision improvement, explore the plasticity of the adult optic nerve, and provide a clinical basis for the treatment of adult amblyopia. A total of 74 patients with monocular amblyopia combined with non-amblyopia visual acuity decline from 2018 to 2021 were collected. The patient's age, initial best-corrected visual acuity (BCVA), pattern visual evoked potential examination results, and visual acuity regression were recorded.

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Glutaredoxin 2 (Grx2), a mitochondrial glutathione-dependent oxidoreductase, is crucial for maintaining redox homeostasis and cellular functions in the lens. The oxidative stress-induced epithelial-mesenchymal transition (EMT) of lens epithelial cells (LECs) is related to posterior capsule opacification. In this study, we investigated the effects of Grx2 on oxidative stress-induced EMT in LECs during posterior capsule opacification.

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The nucleotide CTP can be synthesized de novo from UTP via the metabolic enzyme CTP synthase (CTPS). As a textbook enzyme, CTPS has been extensively studied for seven decades. However, it came as a surprise when CTPS was found to form snake-shaped mesoscale cytoophidia in fruit fly cells.

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Background: PRPP synthase (PRPS) transfers the pyrophosphate groups from ATP to ribose-5-phosphate to produce 5-phosphate ribose-1-pyrophosphate (PRPP), a key intermediate in the biosynthesis of several metabolites including nucleotides, dinucleotides and some amino acids. There are three PRPS isoforms encoded in human genome. While human PRPS1 (hPRPS1) and human PRPS2 (hPRPS2) are expressed in most tissues, human PRPS3 (hPRPS3) is exclusively expressed in testis.

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Ultraviolet B (UVB) exposure is reported to cause cataract formation by inducing excessive reactive oxygen species (ROS) and apoptosis in human lens epithelial cells (HLECs). Sodium-dependent Vitamin C transports-2 (SVCT2) is a ascorbic acid (AsA) transporter for that can protect cells and tissues from oxidative stress. Here, we focus on the functional characterization and mechanism analysis of SVCT2 in UVB-treated HLECs.

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Posterior capsule opacification (PCO) is a serious complication after cataract surgery. Diabetes could increase the occurrence of PCO, but the mechanism is still unclear. The purpose of this study is to investigate the role of small extracellular vesicles (sEVs) derived from diabetic aqueous humor in PCO process.

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Objectives: Orbital lymphoma is one of the most common adult orbital malignancies, accounting for approximately 10% of all orbital tumors. This study aimed to analyze the effects of surgical resection and orbital iodine-125 brachytherapy implantation for orbital lymphoma.

Patients And Methods: This was a retrospective study.

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Nondestructive testing and evaluation of composite insulating components of electrical equipment is extremely necessary for assuring the safety of a power system. However, most existing nondestructive testing methods are not applicable for fast and effective live detection due to their time-consuming operation, high cost, and contact or near-field measurement. In this work, the effectiveness of active infrared thermography was investigated for detecting defects in silicone rubber (SIR)-fiber-reinforced plastic (FRP) bonding structures, which have been commonly used in insulating components of power equipment.

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Phosphoribosyl pyrophosphate (PRPP) is a key intermediate in the biosynthesis of purine and pyrimidine nucleotides, histidine, tryptophan, and cofactors NAD and NADP. Abnormal regulation of PRPP synthase (PRPS) is associated with human disorders, including Arts syndrome, retinal dystrophy, and gouty arthritis. Recent studies have demonstrated that PRPS can form filamentous cytoophidia in eukaryotes.

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Cytidine-5'-triphosphate (CTP) synthase (CTPS) is the class I glutamine-dependent amidotransferase (GAT) that catalyzes the last step in the de novo biosynthesis of CTP. Glutamine hydrolysis is catalyzed in the GAT domain and the liberated ammonia is transferred via an intramolecular tunnel to the synthase domain where the ATP-dependent amination of UTP occurs to form CTP. CTPS is unique among the glutamine-dependent amidotransferases, requiring an allosteric effector (GTP) to activate the GAT domain for efficient glutamine hydrolysis.

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