379 results on '"Dong Feng Chen"'
Search Results
2. Optimal transcorneal electrical stimulation parameters for preserving photoreceptors in a mouse model of retinitis pigmentosa
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Sam Enayati, Karen Chang, Anton Lennikov, Menglu Yang, Cherin Lee, Ajay Ashok, Farris Elzaridi, Christina Yen, Kasim Gunes, Jia Xie, Kin-Sang Cho, Tor Paaske Utheim, and Dong Feng Chen
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bipolar cells ,electrical stimulation ,neuroprotection ,photoreceptor degeneration ,retina ,retinal explants ,retinitis pigmentosa ,transcorneal electrical stimulation ,waveform ,Neurology. Diseases of the nervous system ,RC346-429 - Abstract
Retinitis pigmentosa is a hereditary retinal disease that affects rod and cone photoreceptors, leading to progressive photoreceptor loss. Previous research supports the beneficial effect of electrical stimulation on photoreceptor survival. This study aims to identify the most effective electrical stimulation parameters and functional advantages of transcorneal electrical stimulation (tcES) in mice affected by inherited retinal degeneration. Additionally, the study seeked to analyze the electric field that reaches the retina in both eyes in mice and post-mortem humans. In this study, we recorded waveforms and voltages directed to the retina during transcorneal electrical stimulation in C57BL/6J mice using an intraocular needle probe with rectangular, sine, and ramp waveforms. To investigate the functional effects of electrical stimulation on photoreceptors, we used human retinal explant cultures and rhodopsin knockout (Rho–/–) mice, demonstrating progressive photoreceptor degeneration with age. Human retinal explants isolated from the donors’ eyes were then subjected to electrical stimulation and cultured for 48 hours to simulate the neurodegenerative environment in vitro. Photoreceptor density was evaluated by rhodopsin immunolabeling. In vivo Rho–/– mice were subjected to two 5-day series of daily transcorneal electrical stimulation using rectangular and ramp waveforms. Retinal function and visual perception of mice were evaluated by electroretinography and optomotor response (OMR), respectively. Immunolabeling was used to assess the morphological and biochemical changes of the photoreceptor and bipolar cells in mouse retinas. Oscilloscope recordings indicated effective delivery of rectangular, sine, and ramp waveforms to the retina by transcorneal electrical stimulation, of which the ramp waveform required the lowest voltage. Evaluation of the total conductive resistance of the post-mortem human compared to the mouse eyes indicated higher cornea-to-retina resistance in human eyes. The temperature recordings during and after electrical stimulation indicated no significant temperature change in vivo and only a subtle temperature increase in vitro (~0.5–1.5°C). Electrical stimulation increased photoreceptor survival in human retinal explant cultures, particularly at the ramp waveform. Transcorneal electrical stimulation (rectangular + ramp) waveforms significantly improved the survival and function of S and M-cones and enhanced visual acuity based on the optomotor response results. Histology and immunolabeling demonstrated increased photoreceptor survival, improved outer nuclear layer thickness, and increased bipolar cell sprouting in Rho–/– mice. These results indicate that transcorneal electrical stimulation effectively delivers the electrical field to the retina, improves photoreceptor survival in both human and mouse retinas, and increases visual function in Rho–/– mice. Combined rectangular and ramp waveform stimulation can promote photoreceptor survival in a minimally invasive fashion.
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- 2024
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3. Transcorneal but not transpalpebral electrical stimulation disrupts mucin homeostasis of the ocular surface
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Menglu Yang, Anton Lennikov, Karen Chang, Ajay Ashok, Cherin Lee, Kin-Sang Cho, Tor Paaske Utheim, Darlene A. Dartt, and Dong Feng Chen
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Electric stimulation ,Dry eye ,Corneal epithelial damage ,Goblet cells ,Corneal epithelial cells ,Calcium signaling ,Ophthalmology ,RE1-994 - Abstract
Abstract Purpose Transcorneal electrical stimulation (TcES) is increasingly applied as a therapy for preserving and improving vision in retinal neurodegenerative and ischemic disorders. However, a common complaint about TcES is its induction of eye pain and dryness in the clinic, while the mechanisms remain unknown. Method TcES or transpalpebral ES (TpES) was conducted in C57BL6j mice for 14 days. The contralateral eyes were used as non-stimulated controls. Levels of intracellular [Ca2+] ([Ca2+]i) were assessed by Fura-2AM. The conductance resistances of the eye under various ES conditions were measured in vivo by an oscilloscope. Results Although TcES did not affect tear production, it significantly induced damage to the ocular surface, as revealed by corneal fluorescein staining that was accompanied by significantly decreased mucin (MUC) 4 expression compared to the control. Similar effects of ES were detected in cultured primary corneal epithelium cells, showing decreased MUC4 and ZO-1 levels after the ES in vitro. In addition, TcES decreased secretion of MUC5AC from the conjunctiva in vivo, which was also corroborated in goblet cell cultures, where ES significantly attenuated carbachol-induced [Ca2+]i increase. In contrast to TcES, transpalpebral ES (TpES) did not induce corneal fluorescein staining while significantly increasing tear production. Importantly, the conductive resistance from orbital skin to the TpES was significantly smaller than that from the cornea to the retina in TcES. Conclusion TcES, but not TpES, induces corneal epithelial damage in mice by disrupting mucin homeostasis. TpES thus may represent a safer and more effective ES approach for treating retinal neurodegeneration clinically.
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- 2022
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4. Association between Heat Shock Protein-Specific T-Cell Counts and Retinal Nerve Fiber Layer Thickness in Patients with Primary Open-Angle Glaucoma
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Chhavi Saini, MD, Shuhong Jiang, MD, PhD, Julia Devlin, BS, Li Pan, PhD, Yizhen Tang, MD, PhD, Jing Tang, MD, PhD, Jessica A. Sun, BA, Maltish M. Lorenzo, MD, Qingyi Wang, MD, Louis R. Pasquale, MD, Kin-Sang Cho, PhD, Dong Feng Chen, MD, PhD, and Lucy Q. Shen, MD
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Glaucoma ,Heat shock protein ,Primary open-angle glaucoma ,T-cell count ,Retinal nerve fiber layer thickness ,Ophthalmology ,RE1-994 - Abstract
Objective: Previous laboratory reports implicate heat shock protein (HSP)–specific T-cell responses in glaucoma pathogenesis; here, we aimed to provide direct clinical evidence by correlating systemic HSP-specific T-cell levels with glaucoma severity in patients with primary open-angle glaucoma (POAG). Design: Cross-sectional case-control study. Subjects: Thirty-two adult patients with POAG and 38 controls underwent blood draw and optic nerve imaging. Methods: Peripheral blood monocytes (PBMC) were stimulated in culture with HSP27, α-crystallin, a member of the small HSP family, or HSP60. Both interferon-γ (IFN-γ)+ CD4+ T helper type 1 cells (Th1) and transforming growth factor-β1 (TGF-β1)+ CD4+ regulatory T cells (Treg) were quantified by flow cytometry and presented as a percentage of total PBMC counts. Relevant cytokines were measured using enzyme-linked immunosorbent assays. Retinal nerve fiber layer thickness (RNFLT) was measured with OCT. Pearson’s correlation (r) was used to assess correlations. Main Outcome Measures: Correlations of HSP-specific T-cell counts, and serum levels of corresponding cytokine levels with RNFLT. Results: Patients with POAG (visual field mean deviation, –4.7 ± 4.0 dB) and controls were similar in age, gender, and body mass index. Moreover, 46.9% of POAG and 60.0% of control subjects had prior cataract surgery (P = 0.48). Although no significant difference in total nonstimulated CD4+ Th1 or Treg cells was detected, patients with POAG exhibited significantly higher frequencies of Th1 cells specific for HSP27, α-crystallin, or HSP60 than controls (7.3 ± 7.9% vs. 2.6 ± 2.0%, P = 0.004; 5.8 ± 2.7% vs. 1.8 ± 1.3%, P < 0.001; 13.2 ± 13.3 vs. 4.3 ± 5.2, P = 0.01; respectively), but similar Treg specific for the same HSPs compared with controls (P ≥ 0.10 for all). Concordantly, the serum levels of IFN-γ were higher in POAG than in controls (36.2 ± 12.1 pg/ml vs. 10.0 ± 4.3 pg/ml; P < 0.001), but TGF-β1 levels did not differ. Average RNFLT of both eyes negatively correlated with HSP27– and α-crystallin-specific Th1 cell counts, and IFN-γ levels in all subjects after adjusting for age (partial correlation coefficient r = –0.31, P = 0.03; r = –0.52, P = 0.002; r = –0.72, P < 0.001, respectively). Conclusions: Higher levels of HSP-specific Th1 cells are associated with thinner RNFLT in patients with POAG and control subjects. The significant inverse relationship between systemic HSP-specific Th1 cell count and RNFLT supports the role of these T cells in glaucomatous neurodegeneration. Financial Disclosure(s): Proprietary or commercial disclosure may be found in the Footnotes and Disclosures at the end of this article.
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- 2023
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5. IGFBPL1 is a master driver of microglia homeostasis and resolution of neuroinflammation in glaucoma and brain tauopathy
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Li Pan, Kin-Sang Cho, Xin Wei, Fuyi Xu, Anton Lennikov, Guangan Hu, Jing Tang, Shuai Guo, Julie Chen, Emil Kriukov, Robert Kyle, Farris Elzaridi, Shuhong Jiang, Pierre A. Dromel, Michael Young, Petr Baranov, Chi-Wai Do, Robert W. Williams, Jianzhu Chen, Lu Lu, and Dong Feng Chen
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CP: Neuroscience ,CP: Immunology ,Biology (General) ,QH301-705.5 - Abstract
Summary: Microglia shift toward an inflammatory phenotype during aging that is thought to exacerbate age-related neurodegeneration. The molecular and cellular signals that resolve neuroinflammation post-injury are largely undefined. Here, we exploit systems genetics methods based on the extended BXD murine reference family and identify IGFBPL1 as an upstream cis-regulator of microglia-specific genes to switch off inflammation. IGFBPL1 is expressed by mouse and human microglia, and higher levels of its expression resolve lipopolysaccharide-induced neuroinflammation by resetting the transcriptome signature back to a homeostatic state via IGF1R signaling. Conversely, IGFBPL1 deficiency or selective deletion of IGF1R in microglia shifts these cells to an inflammatory landscape and induces early manifestation of brain tauopathy and retinal neurodegeneration. Therapeutic administration of IGFBPL1 drives pro-homeostatic microglia and prevents glaucomatous neurodegeneration and vision loss in mice. These results identify IGFBPL1 as a master driver of the counter-inflammatory microglial modulator that presents an endogenous resolution of neuroinflammation to prevent neurodegeneration in eye and brain.
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- 2023
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6. Direct modulation of microglial function by electrical field
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Anton Lennikov, Menglu Yang, Karen Chang, Li Pan, Madhu Sudhana Saddala, Cherin Lee, Ajay Ashok, Kin-Sang Cho, Tor Paaske Utheim, and Dong Feng Chen
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electric stimulation ,microglia ,bulk RNA sequencing ,cell motility ,inflammation ,phagocytosis ,Biology (General) ,QH301-705.5 - Abstract
Non-invasive electric stimulation (ES) employing a low-intensity electric current presents a potential therapeutic modality that can be applied for treating retinal and brain neurodegenerative disorders. As neurons are known to respond directly to ES, the effects of ES on glia cells are poorly studied. A key question is if ES directly mediates microglial function or modulates their activity merely via neuron-glial signaling. Here, we demonstrated the direct effects of ES on microglia in the BV-2 cells—an immortalized murine microglial cell line. The low current ES in a biphasic ramp waveform, but not that of rectangular or sine waveforms, significantly suppressed the motility and migration of BV-2 microglia in culture without causing cytotoxicity. This was associated with diminished cytoskeleton reorganization and microvilli formation in BV-2 cultures, as demonstrated by immunostaining of cytoskeletal proteins, F-actin and β-tubulin, and scanning electron microscopy. Moreover, ES of a ramp waveform reduced microglial phagocytosis of fluorescent zymosan particles and suppressed lipopolysaccharide (LPS)-induced pro-inflammatory cytokine expression in BV-2 cells as shown by Proteome Profiler Mouse Cytokine Array. The results of quantitative PCR and immunostaining for cyclooxygenase-2, Interleukin 6, and Tumor Necrosis Factor-α corroborated the direct suppression of LPS-induced microglial responses by a ramp ES. Transcriptome profiling further demonstrated that ramp ES effectively suppressed nearly half of the LPS-induced genes, primarily relating to cellular motility, energy metabolism, and calcium signaling. Our results reveal a direct modulatory effect of ES on previously thought electrically “non-responsive” microglia and suggest a new avenue of employing ES for anti-inflammatory therapy.
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- 2022
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7. Metabolomics in Primary Open Angle Glaucoma: A Systematic Review and Meta-Analysis
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Yizhen Tang, Simran Shah, Kin-Sang Cho, Xinghuai Sun, and Dong Feng Chen
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metabolomics ,metabolite profile ,glaucoma ,retinal ganglion cells ,optic neuropathy ,Neurosciences. Biological psychiatry. Neuropsychiatry ,RC321-571 - Abstract
Glaucoma is a leading cause of blindness worldwide. It is suggested that primary open angle glaucoma (POAG), the most common form of glaucoma, may be associated with significant metabolic alternations, but the systemic literature review and meta-analysis in the area have been missing. Altered metabolomic profiles in the aqueous humor and plasma may serve as possible biomarkers for early detection or treatment targets. In this article, we performed a systematic meta-analysis of the current literature surrounding the metabolomics of patients with POAG and metabolites associated with the disease. Results suggest several metabolites found to be specifically altered in patients with POAG, suggesting broad generalizability and pathways for future research.
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- 2022
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8. A comparison of the use of adipose-derived and bone marrow-derived stem cells for peripheral nerve regeneration in vitro and in vivo
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Li Na Zhou, Jia Chuan Wang, Prince Last Mudenda Zilundu, Ya Qiong Wang, Wen Ping Guo, Sai Xia Zhang, Hui Luo, Jian Hong Zhou, Ru Dong Deng, and Dong Feng Chen
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Bone marrow-derived stem cells ,Adipose-derived stem cells ,Schwann cells ,Co-culture ,Chemically extracted acellular nerve allograft ,Peripheral nerve repair ,Medicine (General) ,R5-920 ,Biochemistry ,QD415-436 - Abstract
Abstract Background To date, it has repeatedly been demonstrated that infusing bone marrow-derived stem cells (BMSCs) into acellular nerve scaffolds can promote and support axon regeneration through a peripheral nerve defect. However, harvesting BMSCs is an invasive and painful process fraught with a low cellular yield. Methods In pursuit of alternative stem cell sources, we isolated stem cells from the inguinal subcutaneous adipose tissue of adult Sprague–Dawley rats (adipose-derived stem cells, ADSCs). We used a co-culture system that allows isolated adult mesenchymal stem cells (MSCs) and Schwann cells (SCs) to grow in the same culture medium but without direct cellular contact. We verified SC phenotype in vitro by cell marker analysis and used red fluorescent protein-tagged ADSCs to detect their fate after being injected into a chemically extracted acellular nerve allograft (CEANA). To compare the regenerative effects of CEANA containing either BMSCs or ADSCs with an autograft and CEANA only on the sciatic nerve defect in vivo, we performed histological and functional assessments up to 16 weeks after grafting. Results In vitro, we observed reciprocal beneficial effects of ADSCs and SCs in the ADSC–SC co-culture system. Moreover, ADSCs were able to survive in CEANA for 5 days after in vitro implantation. Sixteen weeks after grafting, all results consistently showed that CEANA infused with BMSCs or ADSCs enhanced injured sciatic nerve repair compared to the acellular CEANA-only treatment. Furthermore, their beneficial effects on sciatic injury regeneration were comparable as histological and functional parameters evaluated showed no statistically significant differences. However, the autograft group was roundly superior to both the BMSC- or ADSC-loaded CEANA groups. Conclusion The results of the present study show that ADSCs are a viable alternative stem cell source for treating sciatic nerve injury in lieu of BMSCs.
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- 2020
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9. Baicalein—A Potent Pro-Homeostatic Regulator of Microglia in Retinal Ischemic Injury
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Li Pan, Ying Hon Sze, Menglu Yang, Jing Tang, Siming Zhao, Irvin Yi, Chi-Ho To, Chuen Lam, Dong Feng Chen, Kin-Sang Cho, and Chi-Wai Do
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baicalein ,neuroinflammation ,microglia ,retinal ischemia ,proteomics ,Th17 cell ,Immunologic diseases. Allergy ,RC581-607 - Abstract
Retinal ischemia is a common cause of many retinal diseases, leading to irreversible vision impairment and blindness. Excessive neuroinflammation, including microglial activation and T-cell responses, has been identified as a critical factor associated with neurodegeneration in retinal ischemia. Baicalein is a natural flavonoid reported to have broad anti-inflammatory and neuroprotective bioactivities. Herein, the effects of baicalein on microglia activation in vitro and in vivo were investigated. We found that baicalein exhibited robust anti-inflammatory effect on cultured human and mouse microglia, as demonstrated by decreased induction of pro-inflammatory cytokines and the phosphorylation of phosphoinositide 3-kinase (PI3K) and nuclear factor kappa B (NFκB). Proteomic analysis further unraveled baicalein’s effect on modulating IL-17 signaling pathways and its upstream regulator IL-1β. Intravitreal administration of baicalein in the mouse model of retinal ischemia/reperfusion (I/R) injury attenuated microglial activation and retinal T-cell infiltration, particularly the T helper 17 cells. Additionally, baicalein was shown to exert neuroprotective effects by significantly reducing the retinal ganglion cell (RGC) loss after I/R injury, leading to an improved retinal function and spatial vision. These results suggest that baicalein, a natural flavonoid, acts as a negative regulator of activated microglia and immune responses both in vitro and in vivo, effectively alleviating neurodegeneration in retinal I/R injury. This finding indicates that baicalein could be a potential therapeutic agent against currently incurable degenerative retinal diseases.
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- 2022
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10. Adaptive Immunity: New Aspects of Pathogenesis Underlying Neurodegeneration in Glaucoma and Optic Neuropathy
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Shuhong Jiang, Marie Kametani, and Dong Feng Chen
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glaucoma ,optic neuropathy ,heat shock proteins ,T cells ,glial response ,neuroinflammation ,Immunologic diseases. Allergy ,RC581-607 - Abstract
Glaucoma is a globally unmet medical challenge and the most prevalent neurodegenerative disease, which permanently damages the optic nerve and retinal ganglion cells (RGCs), leading to irreversible blindness. Present therapies target solely at lowering intraocular ocular pressure (IOP), a major risk factor of the disease; however, elevated IOP is neither necessary nor sufficient to cause glaucoma. Glaucomatous RGC and nerve fiber loss also occur in individuals with normal IOP. Recent studies have provided evidence indicating a link between elevated IOP and T cell-mediated autoimmune responses, particularly that are specific to heat shock proteins (HSPs), underlying the pathogenesis of neurodegeneration in glaucoma. Reactive glial responses and low-grade inflammation may initially represent an adaptive reaction of the retina to primary stress stimuli; whereas, sustained and excessive glial reactions lead to expanded immune responses, including adaptive immunity, that contribute to progressive neural damage in glaucoma. Emerging data suggest a similar mechanism in play in causing neurodegeneration of other forms of optic neuropathy, such as that resulted from acute ischemia and traumatic injuries. These studies may lead to the paradigm shift and offer a new basis for the development of novel mechanism-based diagnosis, therapy, and preventive interventions for glaucoma. As HSPs are induced under various conditions of neural stress and damage in the brain and spinal cord, these findings may have broader implications for our elucidating of the etiology of other neurodegenerative disorders in the central nervous system.
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- 2020
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11. Mouse retinal cell behaviour in space and time using light sheet fluorescence microscopy
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Claudia Prahst, Parham Ashrafzadeh, Thomas Mead, Ana Figueiredo, Karen Chang, Douglas Richardson, Lakshmi Venkaraman, Mark Richards, Ana Martins Russo, Kyle Harrington, Marie Ouarné, Andreia Pena, Dong Feng Chen, Lena Claesson-Welsh, Kin-Sang Cho, Claudio A Franco, and Katie Bentley
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confocal microscopy ,lightsheet microscopy ,mouse retina ,angiogenesis ,retinopathy of prematurity ,neurovascular ,Medicine ,Science ,Biology (General) ,QH301-705.5 - Abstract
As the general population ages, more people are affected by eye diseases, such as retinopathies. It is therefore critical to improve imaging of eye disease mouse models. Here, we demonstrate that 1) rapid, quantitative 3D and 4D (time lapse) imaging of cellular and subcellular processes in the mouse eye is feasible, with and without tissue clearing, using light-sheet fluorescent microscopy (LSFM); 2) flat-mounting retinas for confocal microscopy significantly distorts tissue morphology, confirmed by quantitative correlative LSFM-Confocal imaging of vessels; 3) LSFM readily reveals new features of even well-studied eye disease mouse models, such as the oxygen-induced retinopathy (OIR) model, including a previously unappreciated ‘knotted’ morphology to pathological vascular tufts, abnormal cell motility and altered filopodia dynamics when live-imaged. We conclude that quantitative 3D/4D LSFM imaging and analysis has the potential to advance our understanding of the eye, in particular pathological, neurovascular, degenerative processes.
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- 2020
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12. Non-invasive electrical stimulation as a potential treatment for retinal degenerative diseases
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Karen Chang, Sam Enayati, Kin-Sang Cho, Tor P Utheim, and Dong Feng Chen
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Neurology. Diseases of the nervous system ,RC346-429 - Published
- 2021
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13. Electrical Stimulation Induces Retinal Müller Cell Proliferation and Their Progenitor Cell Potential
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Sam Enayati, Karen Chang, Hamida Achour, Kin-Sang Cho, Fuyi Xu, Shuai Guo, Katarina Z. Enayati, Jia Xie, Eric Zhao, Tytteli Turunen, Amer Sehic, Lu Lu, Tor Paaske Utheim, and Dong Feng Chen
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electrical-stimulation ,retina ,glial cells ,müller cells ,proliferation ,retinitis pigmentosa ,Cytology ,QH573-671 - Abstract
Non-invasive electrical stimulation (ES) is increasingly applied to improve vision in untreatable eye conditions, such as retinitis pigmentosa and age-related macular degeneration. Our previous study suggested that ES promoted retinal function and the proliferation of progenitor-like glial cells in mice with inherited photoreceptor degeneration; however, the underlying mechanism remains obscure. Müller cells (MCs) are thought to be dormant residential progenitor cells that possess a high potential for retinal neuron repair and functional plasticity. Here, we showed that ES with a ramp waveform of 20 Hz and 300 µA of current was effective at inducing mouse MC proliferation and enhancing their expression of progenitor cell markers, such as Crx (cone−rod homeobox) and Wnt7, as well as their production of trophic factors, including ciliary neurotrophic factor. RNA sequencing revealed that calcium signaling pathway activation was a key event, with a false discovery rate of 5.33 × 10−8 (p = 1.78 × 10−10) in ES-mediated gene profiling changes. Moreover, the calcium channel blocker, nifedipine, abolished the observed effects of ES on MC proliferation and progenitor cell gene induction, supporting a central role of ES-induced Ca2+ signaling in the MC changes. Our results suggest that low-current ES may present a convenient tool for manipulating MC behavior toward neuroregeneration and repair.
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- 2020
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14. Ezh2 does not mediate retinal ganglion cell homeostasis or their susceptibility to injury.
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Lin Cheng, Lucy J Wong, Naihong Yan, Richard C Han, Honghua Yu, Chenying Guo, Khulan Batsuuri, Aniket Zinzuwadia, Ryan Guan, Kin-Sang Cho, and Dong Feng Chen
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Medicine ,Science - Abstract
Epigenetic predisposition is thought to critically contribute to adult-onset disorders, such as retinal neurodegeneration. The histone methyltransferase, enhancer of zeste homolog 2 (Ezh2), is transiently expressed in the perinatal retina, particularly enriched in retinal ganglion cells (RGCs). We previously showed that embryonic deletion of Ezh2 from retinal progenitors led to progressive photoreceptor degeneration throughout life, demonstrating a role for embryonic predisposition of Ezh2-mediated repressive mark in maintaining the survival and function of photoreceptors in the adult. Enrichment of Ezh2 in RGCs leads to the question if Ezh2 also mediates gene expression and function in postnatal RGCs, and if its deficiency changes RGC susceptibility to cell death under injury or disease in the adult. To test this, we generated mice carrying targeted deletion of Ezh2 from RGC progenitors driven by Math5-Cre (mKO). mKO mice showed no detectable defect in RGC development, survival, or cell homeostasis as determined by physiological analysis, live imaging, histology, and immunohistochemistry. Moreover, RGCs of Ezh2 deficient mice revealed similar susceptibility against glaucomatous and acute optic nerve trauma-induced neurodegeneration compared to littermate floxed or wild-type control mice. In agreement with the above findings, analysis of RNA sequencing of RGCs purified from Ezh2 deficient mice revealed few gene changes that were related to RGC development, survival and function. These results, together with our previous report, support a cell lineage-specific mechanism of Ezh2-mediated gene repression, especially those critically involved in cellular function and homeostasis.
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- 2018
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15. Emerging roles for insulin-like growth factor binding protein like protein 1
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Yingqian Li, Eric Zhao, and Dong Feng Chen
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Neurology. Diseases of the nervous system ,RC346-429 - Published
- 2019
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16. Induced Pluripotent Stem Cells: Development in the Ophthalmologic Field
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Nan Wu, Marianne Doorenbos, and Dong Feng Chen
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Internal medicine ,RC31-1245 - Abstract
Human induced pluripotent stem cells (iPSCs) are a type of stem cells that can be derived from human somatic cells by introducing certain transcription factors. Induced pluripotent stem cells can divide indefinitely and are able to differentiate into every cell type, which make them viable for transplantation and individual disease modeling. Recently, various ocular cells, including corneal epithelial-like cells, retinal pigment epithelium (RPE) cells displaying functions similar to native RPE, photoreceptors, and retinal ganglion cells, have all been successfully derived from iPSCs. Transplantation of these cells in animal models showed great promise for reversing blindness, and the first clinical trial on humans started in 2013. Despite these promising results, more research is in demand for preventing inadvertent tumor growth, developing precise functionality of the cells, and promoting integration into the host tissue.
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- 2016
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17. Transplantation of Human Neural Progenitor Cells Expressing IGF-1 Enhances Retinal Ganglion Cell Survival.
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Jie Ma, Chenying Guo, Caiwei Guo, Yu Sun, Tiffany Liao, Ursula Beattie, Francisco J López, Dong Feng Chen, and Kameran Lashkari
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Medicine ,Science - Abstract
We have previously characterized human neuronal progenitor cells (hNP) that can adopt a retinal ganglion cell (RGC)-like morphology within the RGC and nerve fiber layers of the retina. In an effort to determine whether hNPs could be used a candidate cells for targeted delivery of neurotrophic factors (NTFs), we evaluated whether hNPs transfected with an vector that expresses IGF-1 in the form of a fusion protein with tdTomato (TD), would increase RGC survival in vitro and confer neuroprotective effects in a mouse model of glaucoma. RGCs co-cultured with hNPIGF-TD cells displayed enhanced survival, and increased neurite extension and branching as compared to hNPTD or untransfected hNP cells. Application of various IGF-1 signaling blockers or IGF-1 receptor antagonists abrogated these effects. In vivo, using a model of glaucoma we showed that IOP elevation led to reductions in retinal RGC count. In this model, evaluation of retinal flatmounts and optic nerve cross sections indicated that only hNPIGF-TD cells effectively reduced RGC death and showed a trend to improve optic nerve axonal loss. RT-PCR analysis of retina lysates over time showed that the neurotrophic effects of IGF-1 were also attributed to down-regulation of inflammatory and to some extent, angiogenic pathways. This study shows that neuronal progenitor cells that hone into the RGC and nerve fiber layers may be used as vehicles for local production and delivery of a desired NTF. Transplantation of hNPIGF-TD cells improves RGC survival in vitro and protects against RGC loss in a rodent model of glaucoma. Our findings have provided experimental evidence and form the basis for applying cell-based strategies for local delivery of NTFs into the retina. Application of cell-based delivery may be extended to other disease conditions beyond glaucoma.
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- 2015
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18. Optimization of Storage Temperature for Cultured ARPE-19 Cells
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Lara Pasovic, Tor Paaske Utheim, Rima Maria, Torstein Lyberg, Edward B. Messelt, Peder Aabel, Dong Feng Chen, Xiangjun Chen, and Jon Roger Eidet
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Ophthalmology ,RE1-994 - Abstract
Purpose. The establishment of future retinal pigment epithelium (RPE) replacement therapy is partly dependent on the availability of tissue-engineered RPE cells, which may be enhanced by the development of suitable storage methods for RPE. This study investigates the effect of different storage temperatures on the viability, morphology, and phenotype of cultured RPE. Methods. ARPE-19 cells were cultured under standard conditions and stored in HEPES-buffered MEM at nine temperatures (4°C, 8°C, 12°C, 16°C, 20°C, 24°C, 28°C, 32°C, and 37°C) for seven days. Viability and phenotype were assessed by a microplate fluorometer and epifluorescence microscopy, while morphology was analyzed by scanning electron microscopy. Results. The percentage of viable cells preserved after storage was highest in the 16°C group (48.7%±9.8%; P
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- 2013
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19. Opposing roles for membrane bound and soluble Fas ligand in glaucoma-associated retinal ganglion cell death.
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Meredith S Gregory, Caroline G Hackett, Emma F Abernathy, Karen S Lee, Rebecca R Saff, Andreas M Hohlbaum, Krishna-Sulayman L Moody, Maura W Hobson, Alexander Jones, Paraskevi Kolovou, Saoussen Karray, Andrea Giani, Simon W M John, Dong Feng Chen, Ann Marshak-Rothstein, and Bruce R Ksander
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Medicine ,Science - Abstract
Glaucoma, the most frequent optic neuropathy, is a leading cause of blindness worldwide. Death of retinal ganglion cells (RGCs) occurs in all forms of glaucoma and accounts for the loss of vision, however the molecular mechanisms that cause RGC loss remain unclear. The pro-apoptotic molecule, Fas ligand, is a transmembrane protein that can be cleaved from the cell surface by metalloproteinases to release a soluble protein with antagonistic activity. Previous studies documented that constitutive ocular expression of FasL maintained immune privilege and prevented neoangeogenesis. We now show that FasL also plays a major role in retinal neurotoxicity. Importantly, in both TNFα triggered RGC death and a spontaneous model of glaucoma, gene-targeted mice that express only full-length FasL exhibit accelerated RGC death. By contrast, FasL-deficiency, or administration of soluble FasL, protected RGCs from cell death. These data identify membrane-bound FasL as a critical effector molecule and potential therapeutic target in glaucoma.
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- 2011
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20. Pilot Allocation Scheme Based on Machine Learning Algorithm and Users' Angle of Arrival in Massive MIMO System.
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Min Yu, Si Yuan Li, and Dong Feng Chen
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- 2020
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21. ZO-1 and IL-1RAP Phosphorylation: Potential Role in Mediated Brain-Gut Axis Dysregulation in Irritable Bowel Syndrome-like Stressed Mice.
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Yu-Qin He, Jian-Ru Zhu, Wen-Jing Sun, Yuan-Yuan Luo, Xiao-Feng Wu, Min Yang, and Dong-Feng Chen
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- 2024
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22. Prevalence and risk factors of covert hepatic encephalopathy in cirrhotic patients: A multicenter study in China
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Xin Zeng, Chuan Yin, Chun Yan Sun, Cui Hua Lu, Shou Song Zhao, Xiao Hong Gao, Dong Feng Chen, Liang Zhi Wen, Shi De Lin, Ping Yang, Qian Hua Zhang, Yu Juan Guan, Yang Zhang, Shu Qin Ren, Da Chuan Cai, Jie Zhang, Lei Li, Cong Ying Chang, Xiao Lin Zhou, Pei Mei Shi, Shi Yao Chen, Yong Lin, and Wei Fen Xie
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Gastroenterology - Published
- 2023
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23. A Study on the Effect of Experience Value and Trust of Hotel Services on Hotel Revisit Intention: Focused on Chinese Hotels
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Mao-Bin Ding, Bing-Sen Zhao, Ni Bi-Yuan, Dong-Feng Chen, Young-Ha Kim, and Hyun-Jee Park
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- 2022
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24. A Study on Service Quality, Emotional Service Value, and Revisit Intention of Chinese Rural Tourism
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Bing-Sen Zhao, Mao-Bin Ding, Dong-Feng Chen, Bi-Yuan Ni, Young-Ha Kim, and Hyun-Jee Park
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- 2022
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25. Berberine blocks inflammasome activation and alleviates diabetic cardiomyopathy via the miR‑18a‑3p/Gsdmd pathway
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Lin Yang, Chun-Feng Cheng, Zhi-Fang Li, Xiao-Jing Huang, Shao-Qing Cai, Shan-Yu Ye, Li-Jun Zhao, Yi Xiong, Dong-Feng Chen, He-Lu Liu, Zhen-Xing Ren, and Hong-Cheng Fang
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Genetics ,General Medicine - Published
- 2023
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26. Aberrant RNA m6A modification in gastrointestinal malignancies: versatile regulators of cancer hallmarks and novel therapeutic opportunities
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Li-Ting Shen, Lin-Rong Che, Zongsheng He, Qian Lu, Dong-Feng Chen, Zhong-yi Qin, and Bin Wang
- Subjects
Cancer Research ,Cellular and Molecular Neuroscience ,Immunology ,Cell Biology - Abstract
Gastrointestinal (GI) cancer is one of the most common malignancies, and a leading cause of cancer-related death worldwide. However, molecular targeted therapies are still lacking, leading to poor treatment efficacies. As an important layer of epigenetic regulation, RNA N6-Methyladenosine (m6A) modification is recently linked to various biological hallmarks of cancer by orchestrating RNA metabolism, including RNA splicing, export, translation, and decay, which is partially involved in a novel biological process termed phase separation. Through these regulatory mechanisms, m6A dictates gene expression in a dynamic and reversible manner and may play oncogenic, tumor suppressive or context-dependent roles in GI tumorigenesis. Therefore, regulators and effectors of m6A, as well as their modified substrates, represent a novel class of molecular targets for cancer treatments. In this review, we comprehensively summarize recent advances in this field and highlight research findings that documented key roles of RNA m6A modification in governing hallmarks of GI cancers. From a historical perspective, milestone findings in m6A machinery are integrated with a timeline of developing m6A targeting compounds. These available chemical compounds, as well as other approaches that target core components of the RNA m6A pathway hold promises for clinical translational to treat human GI cancers. Further investigation on several outstanding issues, e.g. how oncogenic insults may disrupt m6A homeostasis, and how m6A modification impacts on the tumor microenvironment, may dissect novel mechanisms underlying human tumorigenesis and identifies next-generation anti-cancer therapeutics.
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- 2023
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27. Analysis of the Relationship Between Experiential Tourism Motive, Tourism Satisfaction, and Revisit Intention of Visitors to Sichuan Panda National Park: Using Prior Knowledge as a Moderating Variable
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Mao-Bin Ding, Dong-Feng Chen, Bi-Yuan Ni, Bing-Sen Zhao, and Youngha Kim
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- 2022
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28. Investigation of Interfacial Microstructures of TiN/AlN Multilayers by Neutron Reflectometry
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Rong Deng Liu, Yun Tao Liu, Tian Fu Li, Li Zhang, Zi Jun Wang, Kai Sun, and Dong Feng Chen
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Mechanics of Materials ,Mechanical Engineering ,General Materials Science ,Condensed Matter Physics - Abstract
Three alternate TiN/AlN nanostructured multilayers with the TiN layer thicknesses of 60, 70, and 120 Å and the AlN layer thickness of 10 Å were fabricated using dc reactive magnetron sputtering. Microstructural characterizations of the three nano-scale films were performed using nonpolarized specular neutron reflectometry. The results showed that the three TiN/AlN multilayer thin films were typical superlattice films and the thicknesses of the TiN layer and AlN layer in the multilayers were consistent with the design thickness nearly. The interface roughness was asymmetric in all the samples. The interface of AlN growing on TiN was much sharper than that of TiN growing on AlN and the latter was the diffusion interface in the TiN/AlN multilayer films.
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- 2022
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29. The Prevalence of Autoimmune Diseases in Patients with Primary Open-Angle Glaucoma Undergoing Ophthalmic Surgeries
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Kin-Sang Cho, Lucy Q. Shen, Dong Feng Chen, Eleftherios I. Paschalis, Rafaella Nascimento e Silva, Julia Devlin, David Sola-Del Valle, Milica A. Margeta, Maltish M. Lorenzo, Roberto Pineda, Louis R. Pasquale, Sherleen H. Chen, Joseph B. Ciolino, Courtney L. Ondeck, Chhavi Saini, and James Chodosh
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Intraocular pressure ,medicine.medical_specialty ,genetic structures ,business.industry ,medicine.medical_treatment ,Glaucoma ,Subgroup analysis ,General Medicine ,Odds ratio ,Cup-to-disc ratio ,Cataract surgery ,medicine.disease ,eye diseases ,Internal medicine ,Normal tension glaucoma ,Medicine ,sense organs ,business ,Body mass index - Abstract
Purpose To assess the prevalence of autoimmune disease (AiD) in patients with primary open-angle glaucoma (POAG) undergoing ophthalmic surgery. Design Retrospective, cross-sectional study. Participants Patients with POAG undergoing any ophthalmic surgery and control subjects undergoing cataract surgery at the Massachusetts Eye and Ear from March 2019 to April 2020. Methods All available medical records with patient demographics, ocular, and medical conditions were reviewed. Differences in AiD prevalence were assessed and adjusted for covariates using multiple logistic regression. Additionally, a subgroup analysis comparing the POAG patients with and without AiD was performed. Main Outcome Measures To assess the prevalence of AiD based on the American Autoimmune Related Diseases Association list. Results A total of 172 patients with POAG and 179 controls were included. The overall prevalence of AiD was 17.4% in the POAG group and 10.1% in the controls (P = 0.044); 6.4% of POAG patients and 3.4% of controls had more than 1 AiD (P = 0.18). The most prevalent AiDs in POAG group were rheumatoid arthritis (4.6%) and psoriasis (4.1%), which were also the most common in controls (2.8% each). In a fully adjusted multiple logistic regression analysis accounting for steroid use, having an AiD was associated with 2.62-fold increased odds of POAG relative to controls (95% confidence interval, 1.27–5.36, P = 0.009); other risk factors for POAG derived from the analysis included age (odds ratio [OR], 1.04, P = 0.006), diabetes mellitus (OR, 2.31, P = 0.008), and non-White ethnicity (OR, 4.75, P 0.13, for both). Conclusions A higher prevalence of AiD was found in POAG patients compared with control patients undergoing ophthalmic surgery. The presence of AiD was associated with increased risk for POAG after adjusting for covariates. Additional factors may have prevented a difference in RNFL thickness in POAG patients with and without AiD. Autoimmunity should be explored further in the pathogenesis of POAG.
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- 2022
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30. Proteomic profiling identifies CLEC4C expression as a novel biomarker of primary graft dysfunction after heart transplantation
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Carmelo A. Milano, Chetan B. Patel, Christopher L. Holley, Dawn E. Bowles, Lydia Coulter Kwee, Richa Agarwal, Dong-Feng Chen, Adam D. DeVore, Lauren K. Truby, Jacob N. Schroder, Svati H. Shah, and Elizabeth Grass
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Male ,Proteomics ,Pulmonary and Respiratory Medicine ,Oncology ,medicine.medical_specialty ,medicine.medical_treatment ,Primary Graft Dysfunction ,Sensitivity and Specificity ,Article ,chemistry.chemical_compound ,Postoperative Complications ,Internal medicine ,Humans ,Medicine ,Lectins, C-Type ,Receptors, Immunologic ,Aged ,Aged, 80 and over ,Heart transplantation ,Transplantation ,Creatinine ,Membrane Glycoproteins ,business.industry ,Middle Aged ,Pathophysiology ,chemistry ,Heart Transplantation ,Biomarker (medicine) ,Population study ,Female ,Surgery ,Cardiomyopathies ,Cardiology and Cardiovascular Medicine ,Complication ,business ,Biomarkers - Abstract
PURPOSE: Clinical models to identify patients at high risk of primary graft dysfunction (PGD) after heart transplantation (HT) are limited, and the underlying pathophysiology of this common post-transplant complication remains poorly understood. We sought to identify whether pre-transplant levels of circulating proteins reporting on immune activation and inflammation are associated with incident PGD. METHODS: The study population consisted of 219 adult heart transplant recipients identified between 2016 and 2020 at Duke University Medical Center, randomly divided into derivation (n = 131) and validation (n = 88) sets. PGD was defined using modified ISHLT criteria. Proteomic profiling was performed using Olink panels (n = 354 proteins) with serum samples collected immediately prior to transplantation. Association between normalized relative protein expression and PGD was tested using univariate and multivariable (recipient age, creatinine, mechanical circulatory support, and sex; donor age; ischemic time) models. Significant proteins identified in the derivation set (p < 0.05 in univariate models), were then tested in the validation set. Pathway enrichment analysis was used to test candidate biological processes. The predictive performance of proteins was compared to that of the RADIAL score. RESULTS: Nine proteins were associated with PGD in univariate models in the derivation set. Of these, only CLEC4C remained associated with PGD in the validation set after Bonferroni correction (OR [95% CI] = 3.04 [1.74,5.82], p = 2.8×10(−4)). Patterns of association were consistent for CLEC4C in analyses stratified by biventricular/left ventricular and isolated right ventricular PGD. Pathway analysis identified interferon-alpha response and C-type lectin signaling as significantly enriched biologic processes. The RADIAL score was a poor predictor of PGD (AUC = 0.55). CLEC4C alone (AUC = 0.66, p = 0.048) and in combination with the clinical covariates from the multivariable model (AUC = 0.69, p = 0.018) improved discrimination for the primary outcome. CONCLUSIONS: Pre-transplantation circulating levels of CLEC4C, a protein marker of plasmacytoid dendritic cells (pDCs), may identify HT recipients at risk for PGD. Further studies are needed to better understand the potential role pDCs and the innate immune response in PGD.
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- 2021
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31. High-dose dual therapy
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Zhe, Zhao, Pei-Ying, Zou, Na-Yun, Su, Yan, Guo, Xing-Wei, Wang, Jing-Tao, Zhao, Hao, Mei, Qing, Shi, Bin, Wang, Dong-Feng, Chen, and Chun-Hui, Lan
- Abstract
Although the Maastricht VI/Florence consensus report recommended high-dose proton pump inhibitor-amoxicillin dual therapy as possible rescue therapy forTo compare the efficacy, safety, patient compliance, and cost between high-dose dual therapy (HDDT) and culture-based susceptibility-guided therapy (CB-SGT) as a rescue regimen forA single-center, open-label, randomized controlled clinical trial.In all, 146 patients with a history of eradication failure were enrolled and randomly assigned to receive HDDT or CB-SGT. HDDT consisted of esomeprazole 20 mg and amoxicillin 750 mg, both given four times per day (qid). CB-SGT consisted of esomeprazole 20 mg twice daily (bid), amoxicillin 1000 mg bid plus clarithromycin 500 mg bid, metronidazole 400 mg bid, or levofloxacin 500 mg daily (qd) for sensitive patients, in that order. For patients with triple resistance, a bismuth-containing regimen with a high dose of metronidazole was chosen, including esomeprazole 20 mg bid, bismuth 220 mg bid, amoxicillin 1000 mg bid, and metronidazole 400 mg qid. All regimens were given for 14 days.The eradicationHDDT can reach an eradication rate of 85% in treatment-experienced patients ofThis clinical trial was registered at the Chinese Clinical Trail Registry (trail registration number: ChiCTR1900025044).
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- 2022
32. Epigenetic Regulation of Optic Nerve Development, Protection, and Repair
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Ajay Ashok, Sarita Pooranawattanakul, Wai Lydia Tai, Kin-Sang Cho, Tor P. Utheim, Dean M. Cestari, and Dong Feng Chen
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Organic Chemistry ,Optic Nerve ,General Medicine ,Catalysis ,Axons ,Computer Science Applications ,Epigenesis, Genetic ,Nerve Regeneration ,Inorganic Chemistry ,Oligodendroglia ,Physical and Theoretical Chemistry ,Molecular Biology ,Spectroscopy ,Myelin Sheath - Abstract
Epigenetic factors are known to influence tissue development, functionality, and their response to pathophysiology. This review will focus on different types of epigenetic regulators and their associated molecular apparatus that affect the optic nerve. A comprehensive understanding of epigenetic regulation in optic nerve development and homeostasis will help us unravel novel molecular pathways and pave the way to design blueprints for effective therapeutics to address optic nerve protection, repair, and regeneration.
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- 2022
33. Analysis on the Relationships among Characteristics of Choosing Tourism Destination, Image of Tourist Destination, Tourism Satisfaction and Revisit Intention: Focused on Domestic Tourists in China
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Dong-Feng Chen and HyunJee Park
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Business ,Marketing ,Destination image ,China ,Tourism - Published
- 2021
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34. Absence of ephrin-A2/A3 increases retinal regenerative potential for Müller cells in Rhodopsin knockout mice
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Honghua Yu, Ruilin Zhu, Liu Yang, Yuan Fang, Kin-Sang Cho, and Dong Feng Chen
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0301 basic medicine ,Retinal degeneration ,ephrins ,endogenous stem cell ,epha4 ,ephrin-a2 ,ephrin-a3 ,müller cell ,photoreceptor cell regeneration ,retinal degeneration ,retinal regeneration ,retinal stem cell ,EphA4 ,lcsh:RC346-429 ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,Developmental Neuroscience ,medicine ,Progenitor cell ,Outer nuclear layer ,lcsh:Neurology. Diseases of the nervous system ,Retinal regeneration ,Retina ,Müller cell ,Retinal ,medicine.disease ,Molecular biology ,Neural stem cell ,030104 developmental biology ,medicine.anatomical_structure ,chemistry ,Inner nuclear layer ,ephrin-A2 ,sense organs ,ephrin-A3 ,030217 neurology & neurosurgery ,Research Article - Abstract
Muller cells (MC) are considered dormant retinal progenitor cells in mammals. Previous studies demonstrated ephrin-As act as negative regulators of neural progenitor cells in the retina and brain. It remains unclear whether the lack of ephrin-A2/A3 is sufficient to promote the neurogenic potential of MC. Here we investigated whether the MC is the primary retinal cell type expressing ephrin-A2/A3 and their role on the neurogenic potential of Muller cells. In this study, we showed that ephrin-A2/A3 and their receptor EphA4 were expressed in retina and especially enriched in MC. The level of ephrinAs/EphA4 expression increased as the retina matured that is correlated with the reduced proliferative and progenitor cell potential of MC. Next, we investigated the proliferation in primary MC cultures isolated from wild-type and A2-/- A3-/- mice by 5-ethynyl-2'-deoxyuridine (EdU) incorporation. We detected a significant increase of EdU+ cells in MC derived from A2-/- A3-/- mice. Next, we investigated the role of ephrin-A2/A3 in mice undergoing photoreceptor degeneration such as Rhodopsin knockout (Rho-/-) mice. To further evaluate the role of ephrin-A2/A3 in MC proliferation in vivo, EdU was injected intraperitoneally to adult wild-type, A2-/- A3-/- , Rho-/- and Rho-/- A2-/- A3-/- mice and the numbers of EdU+ cells distributed among different layers of the retina. EphrinAs/EphA4 expression was upregulated in the retina of Rho-/- mice compared to the wild-type mice. In addition, cultured MC derived from ephrin-A2-/- A3-/- mice also expressed higher levels of progenitor cell markers and exhibited higher proliferation potential than those from wild-type mice. Interestingly, we detected a significant increase of EdU+ cells in the retinas of adult ephrin-A2-/- A3-/- mice mainly in the inner nuclear layer; and these EdU+ cells were co-localized with MC marker, cellular retinaldehyde-binding protein, suggesting some proliferating cells are from MC. In Rhodopsin knockout mice (Rho-/- A2-/- A3-/- mice), a significantly greater amount of EdU+ cells were located in the ciliary body, retina and RPE than that of Rho-/- mice. Comparing between 6 and 12 weeks old Rho-/- A2-/- A3-/- mice, we recorded more EdU+ cells in the outer nuclear layer in the 12-week-old mice undergoing severe retinal degeneration. Taken together, Ephrin-A2/A3 are negative regulators of the proliferative and neurogenic potentials of MC. Absence of ephrin-A2/A3 promotes the migration of proliferating cells into the outer nuclear layer and may lead to retinal cell regeneration. All experimental procedures were approved by the Animal Care and Use Committee at Schepens Eye Research Institute, USA (approval No. S-353-0715) on October 24, 2012.
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- 2021
35. Research progress in gut-lung axis and lung diseases
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Zhi-Yong Mu, Yan-Ling Wei, Ning Li, Feng-Hua Xu, Guang-Cong Ruan, Zhi-Feng Xiao, Li-Qin Fan, Dong-Feng Chen, and Hong-Li Cui
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lcsh:R5-920 ,gut microbiota ,lcsh:R ,respiratory tract microbiota ,lcsh:Medicine ,lcsh:Medicine (General) ,digestive system ,"gut-lung" axis ,lung diseases - Abstract
There is a huge amount of microbial community in the human intestinal tract, among which the gut microbiota accounts for the largest proportion, which is crucial for maintaining the normal physiological function of human body. Gut microbiota imbalance not only affects gastrointestinal function, but also damages organ functions outside the gastrointestinal tract. Recently, scholars have put forward the doctrines of the "gut-liver" axis and the "gut-brain" axis based on the interrelation and influence between the intestine and other organs. With the deepening of research, the role of gut microbiota in the development and progression of lung diseases has been increasingly concerned, and the theory of "gut-lung" axis has been gradually formed, which is also consistent with the theory described in traditional medicine as "The lung stands in interior-exterior relationship with the large intestine". This paper mainly introduces the research progress of the "gut-lung" axis and lung-related diseases for providing a reference for the treatment of clinical lung diseases. DOI: 10.11855/j.issn.0577-7402.2020.11.12
- Published
- 2020
36. Relationship Analysis of Tourism Social Media Marketing Attributes on Tourism Commitment, Tourism Image, Tourism Satisfaction, Reuse Intention: Targeting Chinese Visitors to Korea
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Dong-Feng Chen and HyunJee Park
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Relationship analysis ,Business ,Reuse ,Marketing ,Tourism ,Social media marketing - Published
- 2020
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37. Increased Calculated Panel Reactive Antigen Is Associated With Increased Waitlist Time and Mortality in Lung Transplantation
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Dong-Feng Chen, Jacob A. Klapper, Mani A. Daneshmand, Michael S. Mulvihill, Matthew G. Hartwig, Yaron D. Barac, Basil S. Nasir, Carmelo A. Milano, Oliver K. Jawitz, and John C. Haney
- Subjects
Pulmonary and Respiratory Medicine ,United Network for Organ Sharing ,medicine.medical_specialty ,business.industry ,medicine.medical_treatment ,Hazard ratio ,030204 cardiovascular system & hematology ,Confidence interval ,Organ transplantation ,Transplantation ,03 medical and health sciences ,Organ procurement ,0302 clinical medicine ,030228 respiratory system ,Antigen ,Internal medicine ,Medicine ,Lung transplantation ,Surgery ,Cardiology and Cardiovascular Medicine ,business - Abstract
Background Sensitized candidates with unacceptable antigens are a group that demands special attention in organ transplantation. Calculated panel reactive antigen (cPRA) is not used to modify allocation priorities in lung transplantation. The impact of cPRA on waiting list time and mortality is unknown. Methods We performed a retrospective review of candidates for lung transplantation listed from May 2005 to 2018. Data from the Organ Procurement and Transplantation Network/United Network for Organ Sharing STAR (Standard Analysis and Research) dataset was paired with additional unacceptable human leukocyte antigen (UA-HLA) data, which were used to calculate the listing cPRA. Candidates were stratified based on the lack of UA-HLAs or cPRA level for candidates with unacceptable antigens reported. Unadjusted competing risks and adjusted subdistribution hazard models were fit. Results A total of 29,085 candidates met inclusion criteria for analysis. Of these, 23,562 (81%) with no UA-HLAs, 3472 (11.9%) with a cPRA less than 50, and 2051 with a cPRA greater than or equal to 50 (7.1%). On adjusted analysis, a cPRA greater than or equal to 50 was independently associated with increased waitlist mortality at 1 year (hazard ratio, 1.71; 95% confidence interval, 1.55-1.88; P Conclusions Further evaluation of organ allocation with consideration of a candidate's cPRA may be warranted in order to optimize equity in access to transplants.
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- 2020
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38. CD4+ T-Cell Responses Mediate Progressive Neurodegeneration in Experimental Ischemic Retinopathy
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Eric F. Thee, Li Pan, Nan Wu, Martine J. Jager, Elisa Arlotti, Thi Hong Khanh Vu, Djoeke Doesburg, Huihui Chen, Kin-Sang Cho, and Dong Feng Chen
- Subjects
0301 basic medicine ,Retina ,Pathology ,medicine.medical_specialty ,business.industry ,Central nervous system ,Ischemia ,Retinal ,medicine.disease ,Pathology and Forensic Medicine ,Pathogenesis ,Optic neuropathy ,03 medical and health sciences ,chemistry.chemical_compound ,030104 developmental biology ,0302 clinical medicine ,medicine.anatomical_structure ,Retinal ganglion cell ,chemistry ,medicine ,Neuron ,business ,030217 neurology & neurosurgery - Abstract
Retinal ischemic events, which result from occlusion of the ocular vasculature share similar causes as those for central nervous system stroke and are among the most common cause of acute and irreversible vision loss in elderly patients. Currently, there is no established treatment, and the condition often leaves patients with seriously impaired vision or blindness. The immune system, particularly T-cell- mediated responses, is thought to be intricately involved, but the exact roles remain elusive. We found that acute ischemia-reperfusion injury to the retina induced a prolonged phase of retinal ganglion cell loss that continued to progress during 8 weeks after the procedure. This phase was accompanied by microglial activation and CD4+ T-cell infiltration into the retina. Adoptive transfer of CD4+ T cells isolated from diseased mice exacerbated retinal ganglion cell loss in mice with retinal reperfusion damage. On the other hand, T-cell deficiency or administration of T-cell or interferon-gamma-neutralizing antibody attenuated retinal ganglion cell degeneration and retinal function loss after injury. These findings demonstrate a crucial role for T-cell-mediated responses in the pathogenesis of neural ischemia. These findings point to novel therapeutic targets of limiting or preventing neuron and function loss for currently untreatable conditions of optic neuropathy and/or central nervous system ischemic stroke.
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- 2020
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39. Transcorneal but not transpalpebral electrical stimulation disrupts mucin homeostasis of the ocular surface
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Menglu, Yang, Anton, Lennikov, Karen, Chang, Ajay, Ashok, Cherin, Lee, Kin-Sang, Cho, Tor Paaske, Utheim, Darlene A, Dartt, and Dong Feng, Chen
- Subjects
Ophthalmology ,General Medicine - Abstract
Purpose Transcorneal electrical stimulation (TcES) is increasingly applied as a therapy for preserving and improving vision in retinal neurodegenerative and ischemic disorders. However, a common complaint about TcES is its induction of eye pain and dryness in the clinic, while the mechanisms remain unknown. Method TcES or transpalpebral ES (TpES) was conducted in C57BL6j mice for 14 days. The contralateral eyes were used as non-stimulated controls. Levels of intracellular [Ca2+] ([Ca2+]i) were assessed by Fura-2AM. The conductance resistances of the eye under various ES conditions were measured in vivo by an oscilloscope. Results Although TcES did not affect tear production, it significantly induced damage to the ocular surface, as revealed by corneal fluorescein staining that was accompanied by significantly decreased mucin (MUC) 4 expression compared to the control. Similar effects of ES were detected in cultured primary corneal epithelium cells, showing decreased MUC4 and ZO-1 levels after the ES in vitro. In addition, TcES decreased secretion of MUC5AC from the conjunctiva in vivo, which was also corroborated in goblet cell cultures, where ES significantly attenuated carbachol-induced [Ca2+]i increase. In contrast to TcES, transpalpebral ES (TpES) did not induce corneal fluorescein staining while significantly increasing tear production. Importantly, the conductive resistance from orbital skin to the TpES was significantly smaller than that from the cornea to the retina in TcES. Conclusion TcES, but not TpES, induces corneal epithelial damage in mice by disrupting mucin homeostasis. TpES thus may represent a safer and more effective ES approach for treating retinal neurodegeneration clinically.
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- 2022
40. Apolipoprotein E4 impairs the response of neurodegenerative retinal microglia and prevents neuronal loss in glaucoma
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Milica A. Margeta, Zhuoran Yin, Charlotte Madore, Kristen M. Pitts, Sophia M. Letcher, Jing Tang, Shuhong Jiang, Christian D. Gauthier, Sebastian R. Silveira, Caitlin M. Schroeder, Eleonora M. Lad, Alan D. Proia, Rudolph E. Tanzi, David M. Holtzman, Susanne Krasemann, Dong Feng Chen, and Oleg Butovsky
- Subjects
Disease Models, Animal ,Mice ,Infectious Diseases ,Apolipoproteins E ,Galectin 3 ,Immunology ,Apolipoprotein E4 ,Immunology and Allergy ,Animals ,Humans ,Glaucoma ,Microglia - Abstract
The apolipoprotein E4 (APOE4) allele is associated with an increased risk of Alzheimer disease and a decreased risk of glaucoma, but the underlying mechanisms remain poorly understood. Here, we found that in two mouse glaucoma models, microglia transitioned to a neurodegenerative phenotype characterized by upregulation of Apoe and Lgals3 (Galectin-3), which were also upregulated in human glaucomatous retinas. Mice with targeted deletion of Apoe in microglia or carrying the human APOE4 allele were protected from retinal ganglion cell (RGC) loss, despite elevated intraocular pressure (IOP). Similarly to Apoe
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- 2021
41. Research progress on adenosine A2B receptor and its role in related diseases
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Yang YANG and Dong-feng CHEN
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lcsh:R5-920 ,lcsh:R ,lcsh:Medicine ,lcsh:Medicine (General) - Abstract
Adenosine is an endogenous nucleoside that modulates many physiological processes. Adenosine is also a chemical mediator that regulates many physiological processes, including inflammation, ischemia and hypoxia. Its actions are mediated by interaction with specific cell membrane receptors. Four subtypes of adenosine receptors have been cloned: A1, A2A, A2B, and A3. Among there receptors, A2B receptor is one of the adenosine receptors with the lowest affinity with adenosine. In recent years, a large number of studies have shown that adenosine A2B receptor is involved in a variety of pathological and physiological processes of diseases. Herein, we try to review the recent advances made in the study of A2B receptor. DOI: 10.11855/j.issn.0577-7402.2019.12.13
- Published
- 2019
42. Layered Co/Ni-free Mn-rich oxide P2-Na2/3Mn0.8Fe0.1Mg0.1O2 as high-performance cathode material for sodium-ion batteries
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Liu Xiaolong, Kai Sun, Dong-Feng Chen, Li Yuqing, Li Meijuan, Wu Meimei, Han Songbai, Linfeng He, Zheng-Yao Li, and Yun-Tao Liu
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Diffraction ,Materials science ,Ionic radius ,General Chemical Engineering ,Sodium ,Doping ,General Engineering ,Oxide ,General Physics and Astronomy ,chemistry.chemical_element ,02 engineering and technology ,Crystal structure ,010402 general chemistry ,021001 nanoscience & nanotechnology ,Electrochemistry ,01 natural sciences ,Energy storage ,0104 chemical sciences ,chemistry.chemical_compound ,chemistry ,Chemical engineering ,General Materials Science ,0210 nano-technology - Abstract
In this work, the Co/Ni-free Na2/3Mn0.8Fe0.1Mg0.1O2 has been synthesized and investigated as low-cost and high–Mn content layered oxide cathode material for sodium-ion batteries by x-ray diffraction and electrochemical techniques. Due to a larger ionic size of Mg2+ than of Fe3+, the lattice parameters a and c both increase and the Mg2+ doping results in an expanded space for sodium-ion diffusion with the improved diffusion coefficient of sodium ion compared with Na2/3Mn0.8Fe0.2O2. Na2/3Mn0.8Fe0.1Mg0.1O2 delivers a high initial discharge capacity of 168 mAh g−1, and great rate capabilities of 102, 80, and 55 mAh g−1 at high rates of 2 C, 5 C, and 10 C. Mg2+ doping also can alleviate the Jahn-Teller effect by Mn3+ and stabilize the crystal structure, thus enhancing the cyclic stability of Na2/3Mn0.8Fe0.1Ti0.1O2 with about 90% capacity retention at 0.1 C. Electrochemical inactive and low-cost Mg-ion doping is an effective approach to improve the layered oxide cathode materials for sodium-ion batteries.
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- 2019
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43. Daratumumab in Sensitized Kidney Transplantation: Potentials and Limitations of Experimental and Clinical Use
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Thibault Damy, Karim Belhadj, Brian Ezekian, Chantal Gautreau, Jaeberm Park, Vincent Audard, David Kheav, Jean Kwun, Marie Matignon, Bradley H. Collins, John S. Yi, Stuart J. Knechtle, Diane Bodez, Janghoon Yoon, Dong-Feng Chen, Alton B. Farris, Elsa Poullot, Philippe Grimbert, Mark D. Stegall, Miriam Manook, Laureline Faivre, Alyssa M. Bilewski, Dehbia Menouch, and Soulef Guendouz
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Adult ,Graft Rejection ,Male ,0301 basic medicine ,Benzylamines ,medicine.medical_specialty ,medicine.drug_class ,Urology ,030230 surgery ,Plasma cell ,CD38 ,Cyclams ,Monoclonal antibody ,T-Lymphocytes, Regulatory ,03 medical and health sciences ,0302 clinical medicine ,HLA Antigens ,Heterocyclic Compounds ,Isoantibodies ,Animals ,Humans ,Medicine ,Kidney transplantation ,biology ,business.industry ,Plerixafor ,Antibody-Dependent Cell Cytotoxicity ,Antibodies, Monoclonal ,Daratumumab ,General Medicine ,medicine.disease ,ADP-ribosyl Cyclase 1 ,Kidney Transplantation ,Macaca mulatta ,Transplantation ,Basic Research ,030104 developmental biology ,medicine.anatomical_structure ,Nephrology ,biology.protein ,Antibody ,business ,medicine.drug - Abstract
BACKGROUND: Donor-specific antibodies are associated with increased risk of antibody-mediated rejection and decreased allograft survival. Therefore, reducing the risk of these antibodies remains a clinical need in transplantation. Plasma cells are a logical target of therapy given their critical role in antibody production. METHODS: To target plasma cells, we treated sensitized rhesus macaques with daratumumab (anti-CD38 mAb). Before transplant, we sensitized eight macaques with two sequential skin grafts from MHC-mismatched donors; four of them were also desensitized with daratumumab and plerixafor (anti-CXCR4). We also treated two patients with daratumumab in the context of transplant. RESULTS: The animals treated with daratumumab had significantly reduced donor-specific antibody levels compared with untreated controls (57.9% versus 13% reduction; P
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- 2019
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44. Analysis of Dimer Impurity in Polyamidoamine Dendrimer Solutions by Small-angle Neutron Scattering
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Han Wenze, Liu Rongdeng, Chunming Yang, Daniel Clemens, Dong-Feng Chen, Uwe Keiderling, Yiyun Cheng, Hui Wang, Wang Zijun, Charl J. Jafta, Yu Wang, Yun-Tao Liu, Tian-Fu Li, and Li Zhang
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Quantitative Biology::Biomolecules ,010407 polymers ,Materials science ,Polymers and Plastics ,Scattering ,General Chemical Engineering ,Dimer ,Organic Chemistry ,Neutron scattering ,01 natural sciences ,Small-angle neutron scattering ,0104 chemical sciences ,Condensed Matter::Soft Condensed Matter ,chemistry.chemical_compound ,Monomer ,chemistry ,Impurity ,Dendrimer ,Indirect Fourier transform ,Physical chemistry ,Condensed Matter::Strongly Correlated Electrons - Abstract
Dimer impurity in the solution of a generation five (G5) polyamidoamine (PAMAM) dendrimer has been investigated by small-angle neutron scattering (SANS). The existence of dimer impurity in dendrimer solution was evidenced by indirect Fourier transform (IFT) analysis of the SANS data, in which the maximum dimension of particles in solution was found to be about twice the diameter of G5 dendrimer. We then developed an analytical model which accounts for the scattering contribution from both dendrimer monomer and dimer. The experimental data were well fitted by using the established model. The results showed that the amount of dimer impurities is significant for the measured three batches of G5 PAMAM dendrimers.
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- 2019
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45. Visual Contrast Sensitivity Correlates to the Retinal Degeneration in Rhodopsin Knockout Mice
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Kin-Sang Cho, Lanbo Yang, Dong Feng Chen, Karen Chang, Zicheng Yu, Muhammed Yasin Adil, Tor Paaske Utheim, and Jiaxin Xiao
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0301 basic medicine ,Retinal degeneration ,medicine.medical_specialty ,Physiology and Pharmacology ,Rhodopsin ,Visual acuity ,genetic structures ,Vision Disorders ,Biology ,Contrast Sensitivity ,03 medical and health sciences ,chemistry.chemical_compound ,Mice ,0302 clinical medicine ,Ophthalmology ,Retinitis pigmentosa ,medicine ,Electroretinography ,Animals ,photoreceptor degeneration ,Mice, Knockout ,Retina ,visual performance ,medicine.diagnostic_test ,Retinal Degeneration ,rhodopsin deficiency mice ,Retinal ,medicine.disease ,eye diseases ,Disease Models, Animal ,030104 developmental biology ,medicine.anatomical_structure ,chemistry ,Optomotor response ,sense organs ,medicine.symptom ,Visual Fields ,Erg ,030217 neurology & neurosurgery - Abstract
Purpose Clinical manifestations of photoreceptor degeneration include gradual thinning of the outer nuclear layer (ONL) and progressive reduction of electroretinogram (ERG) amplitudes and vision loss. Although preclinical evaluations of treatment strategies greatly depend on rodent models, the courses of these changes in mice remain unclear. We thus sought to investigate the temporal correlations in changes of spatial vision, ERG response, and ONL thickness in mice with progressive photoreceptor degeneration. Methods Adult wild-type (WT) mice and mice carrying rhodopsin deficiency (Rho-/-), a frequently used mouse model of human retinitis pigmentosa, were selected for investigation. Mouse spatial vision, including visual acuity (VA) and contrast sensitivity (CS), was determined using optomotor response (OMR) assays; ONL thickness was quantified by spectral-domain optical coherence tomography (SD-OCT), and ERG was performed to evaluate retinal functions. The mice were killed when they were 14 weeks old, and the cone photoreceptors in retinal sections were counted. Results Spatial vision, ONL thickness, and ERG amplitudes remained stable in WT mice at all examined time points. While 6-week-old Rho-/- mice had VA, CS, as well as ERG responses similar to those of WT mice, progressive reductions in the spatial vision and retinal functions were recorded thereafter. Most tested 12-week-old Rho-/- mice had no visual-evoked OMR and ERG responses. Moreover, CS, but not VA, displayed a linear decline that was closely associated with ONL thinning, reduction of ERG amplitudes, and loss of cones. Conclusions We presented a comprehensive study of the relation between the changes of spatial vision, retinal function, and ONL thickness in postnatal week (PW)6 to PW12 Rho-/- mice. CS is a more sensitive indicator of spatial vision compared to VA, although both are required as separate parameters for monitoring the visual changes in retina undergoing photoreceptor degeneration.
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- 2019
46. Non-invasive electrical stimulation as a potential treatment for retinal degenerative diseases
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Sam Enayati, Dong Feng Chen, Tor Paaske Utheim, Karen Chang, and Kin-Sang Cho
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Pathology ,medicine.medical_specialty ,business.industry ,Non invasive ,Retinal ,Stimulation ,lcsh:RC346-429 ,chemistry.chemical_compound ,Developmental Neuroscience ,chemistry ,Perspective ,medicine ,business ,lcsh:Neurology. Diseases of the nervous system - Published
- 2021
47. Pilot Allocation Scheme Based on Machine Learning Algorithm and Users’ Angle of Arrival in Massive MIMO System
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Si Yuan Li, Dong Feng Chen, and Min Yu
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Scheme (programming language) ,Computer science ,business.industry ,05 social sciences ,MIMO ,k-means clustering ,050801 communication & media studies ,Machine learning ,computer.software_genre ,0508 media and communications ,System capacity ,Angle of arrival ,0502 economics and business ,Overhead (computing) ,050211 marketing ,Artificial intelligence ,Antenna (radio) ,business ,computer ,Algorithm ,computer.programming_language - Abstract
Massive MIMO system has attracted attention due to it’s significant improvement in system capacity and spectrum utilization. Pilot pollution greatly limited the performance of Massive MIMO system. To optimize the pilot pollution in Massive MIMO system. In this paper, a pilot allocation scheme based on machine learning algorithm and users’ angle of arrival is proposed. The scheme firstly classified all users according to whether the users’ angle of arrival overlaps with each other. It randomly assigned pilot sequences to users whose angle of arrival do not overlap with each other. Secondly, it used machine learning algorithm to classify users whose angle of arrival overlap with each other into interfering group and non-interfering groups based on users’ location information. We assign orthogonal pilots to users in the interfering group and randomly assign pilot sequences to users in the non-interfering group. Simulation results show that when the number of antenna reached 300, the pilot efficiency can be increased by about 11.67%. The pilot allocation scheme proposed in this paper can effectively suppress the impact of pilot pollution on the performance of Massive MIMO system, improve pilot efficiency and reduce pilot overhead.
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- 2021
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48. Baicalein, Baicalin, and Wogonin: Protective Effects against Ischemia-Induced Neurodegeneration in the Brain and Retina
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Li Pan, Chi Wai Do, Dong Feng Chen, Chi Ho To, Irvin Yi, and Kin-Sang Cho
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Aging ,Ischemia ,Review Article ,Pharmacology ,Biochemistry ,Retina ,chemistry.chemical_compound ,Wogonin ,medicine ,Humans ,Tissue homeostasis ,Flavonoids ,biology ,QH573-671 ,business.industry ,Neurodegeneration ,Neurotoxicity ,Brain ,Cell Biology ,General Medicine ,medicine.disease ,biology.organism_classification ,Baicalein ,Oxidative Stress ,chemistry ,Flavanones ,Scutellaria baicalensis ,business ,Cytology ,Baicalin - Abstract
Ischemia is a common pathological condition present in many neurodegenerative diseases, including ischemic stroke, retinal vascular occlusion, diabetic retinopathy, and glaucoma, threatening the sight and lives of millions of people globally. Ischemia can trigger excessive oxidative stress, inflammation, and vascular dysfunction, leading to the disruption of tissue homeostasis and, ultimately, cell death. Current therapies are very limited and have a narrow time window for effective treatment. Thus, there is an urgent need to develop more effective therapeutic options for ischemia-induced neural injuries. With emerging reports on the pharmacological properties of natural flavonoids, these compounds present potent antioxidative, anti-inflammatory, and antiapoptotic agents for the treatment of ischemic insults. Three major active flavonoids, baicalein, baicalin, and wogonin, have been extracted from Scutellaria baicalensis Georgi (S. baicalensis); all of which are reported to have low cytotoxicity. They have been demonstrated to exert promising pharmacological capabilities in preventing cell and tissue damage. This review focuses on the therapeutic potentials of these flavonoids against ischemia-induced neurotoxicity and damage in the brain and retina. The bioactivity and bioavailability of baicalein, baicalin, and wogonin are also discussed. It is with hope that the therapeutic potential of these flavonoids can be utilized and developed as natural treatments for ischemia-induced injuries of the central nervous system (CNS).
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- 2021
49. Study on Bulk Texture and Mechanical Properties of As-Extruded Wide Mg-Al-Zn Alloy Sheets with Different Al Addition
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Yu-Qing Li, Da-Ye Xu, Min Zha, Dong-Feng Chen, Yun-Tao Liu, Mei-Juan Li, Kai Sun, Gui-Jie Zhu, Si-Qing Wang, Tong Wang, Jian-Bo Gao, and Xiao-Long Liu
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wide magnesium alloy sheets ,extrusion ,microstructure ,bulk texture ,mechanical properties ,General Materials Science - Abstract
The wide Mg alloy sheets produced by hot extrusion usually can easily form an inhomogeneous texture, resulting in anisotropic mechanical properties and poor formability. However, few studies have been carried out on the bulk texture investigation at different areas of as-extruded Mg alloy sheets, especially the Mg alloys with different alloying elements. In this work, the effect of Al on the bulk texture and mechanical properties at different areas for three wide Mg-Al-Zn alloy sheets with different Al contents (Mg-3Al-0.5Zn, Mg-8Al-0.5Zn and Mg-9Al-0.5Zn) are mainly investigated by neutron diffraction. The results showed that a strong and uneven basal texture was formed in the Mg-3Al-0.5Zn sheet. Meanwhile, the intensity of the basal texture was significantly weakened due to the numerous fine precipitates of Mg17Al12 particles, with the Al content increasing, which hinder the grain growth during extrusion, while fine recrystallized grains have a more random orientation. The enhanced tensile properties in Mg-8Al-0.5Zn and Mg-9Al-0.5Zn alloy sheets are ascribed to the cooperation effect of a refined microstructure, precipitates and weakened basal texture. Among the three Mg alloy sheets, the Mg-8Al-0.5Zn alloy sheet has a yield strength of about 270 MPa, an ultimate tensile strength of about 330 MPa and ultimate elongation of about 16% in the extrusion direction, which possesses the most excellent comprehensive mechanical properties.
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- 2022
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50. NF-κB activation in retinal microglia is involved in the inflammatory and neovascularization signaling in laser-induced choroidal neovascularization in mice
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Anton Lennikov, Fumihito Hikage, Hu Huang, Tor Paaske Utheim, Dong Feng Chen, Anthony Mukwaya, Yosuke Ida, Hiroshi Ohguro, and Mieszko Lachota
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0301 basic medicine ,Angiogenesis ,Biology ,Retina ,Article ,Neovascularization ,03 medical and health sciences ,chemistry.chemical_compound ,0302 clinical medicine ,In vivo ,medicine ,Animals ,education ,Inflammation ,education.field_of_study ,Lasers ,NF-kappa B ,Cell Biology ,Molecular biology ,eye diseases ,Choroidal Neovascularization ,Vascular endothelial growth factor ,Mice, Inbred C57BL ,Microglial cell migration ,Disease Models, Animal ,030104 developmental biology ,Choroidal neovascularization ,chemistry ,Gene Expression Regulation ,030220 oncology & carcinogenesis ,Allograft inflammatory factor 1 ,I-kappa B Proteins ,sense organs ,Microglia ,medicine.symptom ,Ex vivo - Abstract
Purpose To evaluate Nuclear Factor NF-κB (NF-κB) signaling on microglia activation, migration, and angiogenesis in laser-induced choroidal neovascularization (CNV). Methods Nine-week-old C57BL/6 male mice were randomly assigned to IMD-0354 treated or untreated groups (5 mice, 10 eyes per group). CNV was induced with a 532-nm laser. Laser spots (power 250 mW, spot size 100 μm, time of exposure 50 ms) were created in each eye using a slit-lamp delivery system. Selective inhibitor of nuclear factor kappa-B kinase subunit beta (IKK2) inhibitor IMD-0354 (10 μg) was delivered subconjunctivally; vehicle-treated mice were the control. The treatment effect on CNV development was assessed at five days post-CNV induction in vivo in C57BL/6 and Cx3cr1gfp/wt mice by fluorescent angiography, fundus imaging, and ex vivo by retinal flatmounts immunostaining and Western blot analysis of RPE/Choroidal/Scleral complexes (RCSC) lysates. In vitro evaluations of IMD-0354 effects were performed in the BV-2 microglial cell line using lipopolysaccharide (LPS) stimulation. Results IMD-0354 caused a significant reduction in the fluorescein leakage and size of the laser spot, as well as a reduction in microglial cell migration and suppression of phospho-IκBα, Vascular endothelial growth factor (VEGF-A), and Prostaglandin-endoperoxide synthase 2 (COX-2). In vivo and ex vivo observations demonstrated reduced lesion size in mice, CD68, and Allograft inflammatory factor 1 (IBA-1) positive microglia cells migration to the laser injury site in IMD-0354 treated eyes. The data further corroborate with GFP-positive cells infiltration of the CNV site in Cx3cr1wt/gfp mice. In vitro IMD-0354 (10–25 ng/ml) treatment reduced NF-κB activation, expression of COX-2, caused decreased Actin-F presence and organization, resulting in reduced BV-2 cells migration capacity. Conclusion The present data indicate that NF-κB activation in microglia and it's migration capacity is involved in the development of laser CNV in mice. Its suppression by NF-κB inhibition might be a promising therapeutic strategy for wet AMD.
- Published
- 2020
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