scholarly journals Effects of Lutein on Hyperosmoticity-Induced Upregulation of IL-6 in Cultured Corneal Epithelial Cells and Its Relevant Signal Pathways

2016 ◽  
Vol 2016 ◽  
pp. 1-7 ◽  
Author(s):  
Shih-Chun Chao ◽  
Chan-Wei Nien ◽  
Codrin Iacob ◽  
Dan-Ning Hu ◽  
Sheng-Chieh Huang ◽  
...  
Keyword(s):  
Dry Eye ◽  
Mtt Assay ◽  
Ocular Surface ◽  
Essential Role ◽  
Signal Pathways ◽  
Corneal Epithelial Cells ◽  
Corneal Epithelial ◽  
Promising Agent ◽  
Nuclear Extracts ◽  
Constitutive Secretion

Dry eye is a common disorder characterized by deficiency of tear. Hyperosmoticity of tear stimulates inflammation and damage of ocular surface tissues and plays an essential role in the pathogenesis of dry eye. Cultured human corneal epithelial (CE) cells were used for the study of effects of lutein and hyperosmoticity on the secretion of IL-6 by CE cells. Cell viability of CE cells was not affected by lutein at 1–10 μM as determined by MTT assay. Hyperosmoticity significantly elevated the secretion of IL-6 by CE cells as measured by ELISA analysis. The constitutive secretion of IL-6 was not affected by lutein. Lutein significantly and dose-dependently inhibited hyperosmoticity-induced secretion of IL-6. Phosphorylated- (p)- p38 MAPK, p-JNK levels in cell lysates and NF-κB levels in cell nuclear extracts were increased by being exposed to hyperosmotic medium. JNK, p38, and NF-κB inhibitors decreased hyperosmoticity-induced secretion of IL-6. Lutein significantly inhibited hyperosmoticity-induced elevation of NF-κB, p38, and p-JNK levels. We demonstrated that lutein inhibited hyperosmoticity-induced secretion of IL-6 in CE cells through the deactivation of p38, JNK, and NF-κB pathways. Lutein may be a promising agent to be explored for the treatment of dry eye.

scholarly journals Antioxidant Effects of the Prenylated Flavonoid, Xanthohumol, on Corneal Epithelial Cells in Experimental Dry Eye Disease

2021 ◽  
Author(s):  
Anita Kirti Ghosh ◽  
Rubina Thapa ◽  
Harsh Nilesh Hariani ◽  
Michael Volyanyuk ◽  
Karoline Anne Orloff ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Epithelial Cells ◽  
Dry Eye ◽  
Ocular Surface ◽  
Dry Eye Disease ◽  
Eye Disease ◽  
Related Factor ◽  
Corneal Epithelial Cells ◽  
Corneal Epithelial

Elevated levels of oxidative stress in the corneal epithelium contribute to the progression of dry eye disease pathology. Previous studies have shown that antioxidant therapeutic intervention is a promising avenue to reduce disease burden and slow disease progression. In this study, we evaluated the pharmacological efficacy of Xanthohumol in preclinical models for dry eye disease. Xanthohumol is a naturally occurring prenylated chalconoid that promotes the transcription of phase II antioxidant enzymes. Xanthohumol exerted a dose-response in preventing tert-butylhydroxide-induced loss of cell viability in human corneal epithelial (HCE-T) cells and resulted in a significant increase in expression of nuclear factor erythroid 2-related factor 2 (Nrf2), the master regulator of the endogenous antioxidant system. Xanthohumol-encapsulating poly(lactic-co-glycolic acid) nanoparticles (PLGA NP) were cytoprotective against oxidative stress in vitro, and significantly reduced corneal fluorescein staining in the mouse desiccating stress/ scopolamine model for dry eye disease in vivo by reducing oxidative stress-associated DNA damage in corneal epithelial cells. PLGA NP represent a safe and efficacious drug delivery vehicle for hydrophobic small molecules to the ocular surface. Optimization of NP-based antioxidant formulations with the goal to minimize instillation frequency may represent future therapeutic options for dry eye disease and related ocular surface disease.

scholarly journals Effects of Lutein and Zeaxanthin on LPS-Induced Secretion of IL-8 by Uveal Melanocytes and Relevant Signal Pathways

2015 ◽  
Vol 2015 ◽  
pp. 1-7 ◽  
Author(s):  
Shih-Chun Chao ◽  
Tommaso Vagaggini ◽  
Chan-Wei Nien ◽  
Sheng-Chieh Huang ◽  
Hung-Yu Lin
Keyword(s):  
P38 Mapk ◽  
Mtt Assay ◽  
Therapeutic Approach ◽  
Inflammatory Diseases ◽  
Signal Pathways ◽  
Dependent Manner ◽  
Nuclear Extracts ◽  
Constitutive Secretion ◽  
Dose Dependent Increase ◽  
Dose Dependent

The effects of lutein and zeaxanthin on lipopolysaccharide- (LPS-) induced secretion of IL-8 by uveal melanocytes (UM) were tested in cultured human UM. MTT assay revealed that LPS (0.01–1 μg/mL) and lutein and zeaxanthin (1–10 μM) did not influence the cell viability of cultured UM. LPS caused a dose-dependent increase of secretion of IL-8 by cultured UM. Lutein and zeaxanthin did not affect the constitutive secretion of IL-8. However, lutein and zeaxanthin decreased LPS-induced secretion of IL-8 in cultured UM in a dose-dependent manner. LPS significantly increased NF-κB levels in cell nuclear extracts and p-JNK levels in the cell lysates from UM, but not p-p38 MAPK and p-ERG. Lutein or zeaxanthin significantly reduced LPS-induced increase of NF-κB and p-JNK levels, but not p38 MAPK and ERG levels. The present study demonstrated that lutein and zeaxanthin inhibited LPS-induced secretion of IL-8 in cultured UM via JNK and NF-κB signal pathways. The anti-inflammatory effects of lutein and zeaxanthin might be explored as a therapeutic approach in the management of uveitis and other inflammatory diseases of the eye.

scholarly journals Poly(lactic-co-glycolic acid) Nanoparticles Encapsulating the Prenylated Flavonoid, Xanthohumol, Protect Corneal Epithelial Cells from Dry Eye Disease-Associated Oxidative Stress

Pharmaceutics ◽  
2021 ◽  
Vol 13 (9) ◽  
pp. 1362
Author(s):  
Anita Kirti Ghosh ◽  
Rubina Thapa ◽  
Harsh Nilesh Hariani ◽  
Michael Volyanyuk ◽  
Sean David Ogle ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Antioxidant Enzymes ◽  
Epithelial Cells ◽  
Dry Eye ◽  
Ocular Surface ◽  
Glycolic Acid ◽  
Dry Eye Disease ◽  
Eye Disease ◽  
Corneal Epithelial Cells ◽  
Corneal Epithelial

Oxidative stress is a known contributor to the progression of dry eye disease pathophysiology, and previous studies have shown that antioxidant intervention is a promising therapeutic approach to reduce the disease burden and slow disease progression. In this study, we evaluated the pharmacological efficacy of the naturally occurring prenylated chalconoid, xanthohumol, in preclinical models for dry eye disease. Xanthohumol acts by promoting the transcription of phase II antioxidant enzymes. In this study, xanthohumol prevented tert-butyl hydroperoxide-induced loss of cell viability in human corneal epithelial (HCE-T) cells in a dose-dependent manner and resulted in a significant increase in expression of the transcription factor nuclear factor erythroid 2-related factor 2 (Nrf2), the master regulator of phase II endogenous antioxidant enzymes. Xanthohumol-encapsulating poly(lactic-co-glycolic acid) nanoparticles (PLGA NP) were cytoprotective against oxidative stress in vitro, and significantly reduced ocular surface damage and oxidative stress-associated DNA damage in corneal epithelial cells in the mouse desiccating stress/scopolamine model for dry eye disease in vivo. PLGA NP represent a safe and efficacious drug delivery vehicle for hydrophobic small molecules to the ocular surface. Optimization of NP-based antioxidant formulations with the goal to minimize instillation frequency may represent future therapeutic options for dry eye disease and related ocular surface disease.

scholarly journals A combination of CMC and α-MSH inhibited ROS activated NLRP3 inflammasome in hyperosmolarity stressed HCECs and scopolamine-induced dry eye rats

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Ying Lv ◽  
Chenchen Chu ◽  
Ke Liu ◽  
Yusha Ru ◽  
Yan Zhang ◽  
...  
Keyword(s):  
Dry Eye ◽  
Nlrp3 Inflammasome ◽  
Ocular Surface ◽  
Combined Treatment ◽  
Underlying Mechanism ◽  
Oxygen Species ◽  
Corneal Epithelial ◽  
Melanocyte Stimulating Hormone ◽  
Human Corneal Epithelial Cells ◽  
Conjunctival Goblet Cells

AbstractAn important mechanism involved in dry eye (DE) is the association between tear hyperosmolarity and inflammation severity. Inflammation in DE might be mediated by the NLRP3 inflammasome, which activated by exposure to reactive oxygen species (ROS). A combination of carboxymethylcellulose (CMC) and α-melanocyte stimulating hormone (α-MSH) may influence DE through this mechanism, thus avoiding defects of signal drug. In this study, we assessed whether treatment comprising CMC combined with α-MSH could ameliorate ocular surface function; we found that it promoted tear secretion, reduced the density of fluorescein sodium staining, enhanced the number of conjunctival goblet cells, and reduced the number of corneal apoptotic cells. Investigation of the underlying mechanism suggested that the synergistic effect of combined treatment alleviated DE inflammation through reduction of ROS level and inhibition of the NLRP3 inflammasome in human corneal epithelial cells. These findings indicate that combined CMC + α-MSH treatment could ameliorate lesions and restore ocular surface function in patients with DE through reduction of ROS level and inhibition of NLRP3 signalling.

scholarly journals The O-GlcNAc modification promotes terminal differentiation of human corneal epithelial cells

Glycobiology ◽  
2020 ◽  
Vol 30 (11) ◽  
pp. 872-880 ◽  
Author(s):  
Nicole M McColgan ◽  
Marissa N Feeley ◽  
Ashley M Woodward ◽  
Damien Guindolet ◽  
Pablo Argüeso
Keyword(s):  
Epithelial Cell ◽  
Epithelial Cells ◽  
Ocular Surface ◽  
Barrier Function ◽  
Terminal Differentiation ◽  
Corneal Epithelial Cell ◽  
Corneal Epithelial Cells ◽  
Corneal Epithelial ◽  
Human Corneal Epithelial Cells ◽  
Glcnac Transferase

Abstract Dynamic modification of nuclear and cytoplasmic proteins with O-linked β-N-acetylglucosamine (O-GlcNAc) plays an important role in orchestrating the transcriptional activity of eukaryotic cells. Here, we report that the O-GlcNAc modification contributes to maintaining ocular surface epithelial homeostasis by promoting mucin biosynthesis and barrier function. We found that induction of human corneal epithelial cell differentiation stimulated the global transfer of O-GlcNAc to both nuclear and cytosolic proteins. Inflammatory conditions, on the other hand, were associated with a reduction in the expression of O-GlcNAc transferase at the ocular surface epithelia. Loss- and gain-of-function studies using small interfering RNA targeting O-GlcNAc transferase, or Thiamet G, a selective inhibitor of O-GlcNAc hydrolase, respectively, revealed that the presence of O-GlcNAc was necessary to promote glycocalyx barrier function. Moreover, we found that Thiamet G triggered a correlative increase in both surface expression of MUC16 and apical epithelial cell area while reducing paracellular permeability. Collectively, these results identify intracellular protein O-glycosylation as a novel pathway responsible for promoting the terminal differentiation of human corneal epithelial cells.

scholarly journals TLR4-Dependent DUOX2 Activation Triggered Oxidative Stress and Promoted HMGB1 Release in Dry Eye

2022 ◽  
Vol 8 ◽  
Author(s):  
Bowen Wang ◽  
Hao Zeng ◽  
Xin Zuo ◽  
Xue Yang ◽  
Xiaoran Wang ◽  
...  
Keyword(s):  
Cell Death ◽  
Western Blot ◽  
Dry Eye ◽  
Ocular Surface ◽  
Cell Counting ◽  
Corneal Epithelial Cell ◽  
Rna Seq ◽  
Corneal Epithelial ◽  
Surface Inflammation ◽  
Ocular Surface Inflammation

Dry eye disease (DED) is one of the most common ocular surface diseases worldwide. DED has been characterized by excessive accumulation of reactive oxygen species (ROS), following significant corneal epithelial cell death and ocular surface inflammation. However, the key regulatory factor remains unclear. In this study, we tended to explore whether DUOX2 contributed to DED development and the underlying mechanism. Human corneal epithelial (HCE) cells were treated with hyperosmolarity, C57BL/6 mice were injected of subcutaneous scopolamine to imitate DED. Expression of mRNA was investigated by RNA sequencing (RNA-seq) and quantitative real-time PCR (qPCR). Protein changes and distribution of DUOX2, high mobility group box 1 (HMGB1), Toll-like receptor 4 (TLR4), and 4-hydroxynonenal (4-HNE) were evaluated by western blot assays and immunofluorescence. Cell death was assessed by Cell Counting Kit-8 (CCK8), lactate dehydrogenase (LDH) release, and propidium iodide (PI) staining. Cellular ROS levels and mitochondrial membrane potential (MMP) were analyzed by flow cytometry. RNA-seq and western blot assay indicated a significant increase of DUOX2 dependent of TLR4 activation in DED both in vitro and in vivo. Immunofluorescence revealed significant translocation of HMGB1 within corneal epithelial cells under hyperosmolar stress. Interestingly, after ablated DUOX2 expression by siRNA, we found a remarkable decrease of ROS level and recovered MMP in HCE cells. Moreover, knockdown of DUOX2 greatly inhibited HMGB1 release, protected cell viability and abolished inflammatory activation. Taken together, our data here suggest that upregulation of DUOX2 plays a crucial role in ROS production, thereafter, induce HMGB1 release and cell death, which triggers ocular surface inflammation in DED.

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