scholarly journals NAD+ precursors protect corneal endothelial cells from UVB-induced apoptosis

2020 ◽  
Vol 318 (4) ◽  
pp. C796-C805 ◽  
Author(s):  
Can Zhao ◽  
Wenjing Li ◽  
Haoyun Duan ◽  
Zongyi Li ◽  
Yanni Jia ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cell Apoptosis ◽  
Corneal Endothelium ◽  
Corneal Edema ◽  
Ultraviolet B ◽  
Subconjunctival Injection ◽  
Corneal Endothelial Cells ◽  
Nicotinamide Phosphoribosyltransferase ◽  
Mesenchymal Transition ◽  
Induced Apoptosis

Excessive exposure of the eye to ultraviolet B light (UVB) leads to corneal edema and opacification because of the apoptosis of the corneal endothelium. Our previous study found that nicotinamide (NIC), the precursor of nicotinamide adenine dinucleotide (NAD), could inhibit the endothelial-mesenchymal transition and accelerate healing the wound to the corneal endothelium in the rabbit. Here we hypothesize that NIC may possess the capacity to protect the cornea from UVB-induced endothelial apoptosis. Therefore, a mouse model and a cultured cell model were used to examine the effect of NAD+ precursors, including NIC, nicotinamide mononucleotide (NMN), and NAD, on the UVB-induced apoptosis of corneal endothelial cells (CECs). The results showed that UVB irradiation caused apparent corneal edema and cell apoptosis in mice, accompanied by reduced levels of NAD+ and its key biosynthesis enzyme, nicotinamide phosphoribosyltransferase (NAMPT), in the corneal endothelium. However, the subconjunctival injection of NIC, NMN, or NAD+ effectively prevented UVB-induced tissue damage and endothelial cell apoptosis in the mouse cornea. Moreover, pretreatment using NIC, NMN, and NAD+ increased the survival rate and inhibited the apoptosis of cultured human CECs irradiated by UVB. Mechanistically, pretreatment using nicotinamide (NIC) recovered the AKT activation level and decreased the BAX/BCL-2 ratio. In addition, the capacity of NIC to protect CECs was fully reversed in the presence of the AKT inhibitor LY294002. Therefore, we conclude that NAD+ precursors can effectively prevent the apoptosis of the corneal endothelium through reactivating AKT signaling; this represents a potential therapeutic approach for preventing UVB-induced corneal damage.

scholarly journals Resveratrol attenuates cigarette smoke induced endothelial apoptosis by activating Notch1 signaling mediated autophagy

2020 ◽  
Author(s):  
Dandan Zong ◽  
Xiang-ming Liu ◽  
Jin-hua Li ◽  
Ruo-yun Ouyang ◽  
Ying-jiao Long ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cigarette Smoke ◽  
Cell Apoptosis ◽  
Umbilical Vein ◽  
Chronic Obstructive ◽  
Dependent Manner ◽  
Obstructive Pulmonary Disease ◽  
Endothelial Apoptosis ◽  
Notch1 Signaling ◽  
Induced Apoptosis

Abstract Background Increasing evidences have showed that endothelial apoptosis contributes to cigarette smoke (CS)-induced disease progression, such as chronic obstructive pulmonary disease (COPD). Our previous studies have validated Notch1 as an anti-apoptotic signaling in cigarette smoke (CS)-induced endothelial apoptosis. Resveratrol (RESV) is a naturally occurring polyphenol that exhibits an anti-apoptotic activity in endothelial cells that exposed to many kinds of destructive stimulus. However, the effects of resveratrol on Notch1 signaling in CS-induced endothelial apoptosis have not yet been fully elucidated. Therefore, the aim of this study was to examine whether RESV can protect endothelial cells from cigarette smoke induced apoptosis via regulating Notch1 signaling. Methods Human umbilical vein endothelial cells (HUVECs) were pretreated with RESV for 2 h, followed by cotreatment with 2.5%CSE for 24h to explore the role of RESV in CSE induced endothelial apoptosis. 3-methyladenine (3-MA) or rapamycin was used to alter autophagic levels. Lentivirus Notch1 intracellular domain (LV-N1ICD) or γ-secretase inhibitor (DAPT) were used to change Notch1 expression. The expression of Notch1, autophagic and apoptotic markers were examined by Western blot and the apoptosis rate was detected by Flow cytometry analysis. Results Our results showed that activating autophagy reduced CSE-induced endothelial apoptosis, while blocking autophagy promoted cell apoptosis in HUVECs. RESV pretreatment attenuated the CSE-induced endothelial apoptosis and activated Notch1 signaling. RESV pretreatment also increased LC3b-II and Beclin1 production, decreased p62 and mTOR expression. 3-MA treatment inhibited autophagy and aggravated CSE induced apoptosis, while rapamycin promoted autophagy, led to a decrease in cell apoptosis. LV-N1ICD transfection upregulated autophagy and reduced apoptosis. However, this protective effect was abolished by 3-MA treatment. In cells treated with DAPT, autophagy was decreased, while apoptosis was increased. RESV partly rescued the DAPT induced apoptosis by activating Notch1 signaling. Conclusion In HUVECs, RESV attenuates CSE induced endothelial apoptosis by inducing autophagy in a Notch1-dependent manner.

scholarly journals The Effect of Phacoemulsification on Corneal Endothelial Cells Morphology and Thickness

2020 ◽  
Vol 36 (4) ◽  
Author(s):  
Abd Elaziz Mohamed Elmadina ◽  
Raghda Faisal Abdelfatah ◽  
Saif Hassan Alrasheed ◽  
Mustafa Abdu ◽  
Manzoor Ahmad Qureshi
Keyword(s):  
Endothelial Cells ◽  
Endothelial Cell ◽  
Cell Density ◽  
Corneal Endothelium ◽  
Central Corneal Thickness ◽  
Corneal Thickness ◽  
Endothelial Cell Density ◽  
P Value ◽  
Corneal Endothelial Cells ◽  
Before And After

Purpose:  To compare the corneal endothelial cells morphology and central corneal thickness (CCT) before and after phacoemulsification in Sudanese population. Place and Duration of Study:  Al-Neelain eye hospital, Khartoum, Sudan, from January 2018 to May 2018. Study Design:  Observational longitudinal study. Methods:  One hundred and forty eyes of 140 patients with immature senile cataract were selected by convenient sampling. The age ranged from 40 to 85 years. The patients underwent complete ocular examination including morphology of corneal endothelial cells and CCT using computerized non-contact specular microscope. Inclusion criteria for the study was eyes with normal corneal endothelial cells and cell density more than 1000 cells/mm2. We excluded patients with ocular or systemic diseases, previous history of intraocular surgery, refractive surgery or trauma as well as contact lenses wear. The patients underwent phacoemulsification by a single surgeon. The examination parameters were repeated one month after surgery. Descriptive and comparative statistical analyses were performed using SPSS for Windows Version 21.0. Results:  There was significant reduction in mean endothelial cells density after phacoemulsification compared to baseline with p < 0.001. There was also significant post-operative reduction in mean endothelial cells number as compared to baseline (P value < 0.001). Mean endothelial cells hexagonality was reduced after surgery with P value of 0.003. No significant difference was found between mean coefficient variation of endothelial cells size before and after phacoemulsification (P = 0.55). Central corneal thickness showed significant increase post-operatively, P = 0.003. Conclusion:  Phacoemulsification causes significant damage to corneal endothelium cells, including decrease in corneal endothelial cell density, hexagonality and cell number. Key Words:  Corneal endothelium, Endothelial cell density, Central corneal thickness, Phacoemulsification.

scholarly journals MitoROS due to loss of Slc4a11 in corneal endothelial cells induces ER stress, lysosomal dysfunction and impairs autophagy

2020 ◽  
Author(s):  
Rajalekshmy Shyam ◽  
Diego G. Ogando ◽  
Moonjung Choi ◽  
Joseph A. Bonanno
Keyword(s):  
Endothelial Cells ◽  
Er Stress ◽  
Corneal Edema ◽  
Corneal Endothelial Cells ◽  
Autophagy Flux ◽  
Unfolded Protein ◽  
Stress Markers ◽  
Lysosomal Dysfunction ◽  
Mitochondrial Ros ◽  
Elevated Expression

AbstractRecent studies from Slc4a11 KO mice have identified mitochondrial dysfunction as a major contributor toward oxidative stress and cell death in Congenital Hereditary Endothelial Dystrophy. Here we asked if this stress activated autophagy in the Slc4a11 KO cell line and in KO mouse endothelial tissue. Early indicators of autophagy, phospho-mTOR and LC3-II indicated activation, however P62 was elevated suggesting an impairment of autophagy flux. The activity and the number of lysosomes, the organelle responsible for the final degradation of autophagy substrates, were found to be reduced in the KO. In addition, the expression of the master regulator of lysosomal function and biogenesis, TFEB, was significantly reduced in the KO corneal endothelia. Also, we observed increased Unfolded Protein Response, as well as elevated expression of ER stress markers, BIP and CHOP. To test if lysosomal and ER stress stems from elevated mitochondrial ROS, we treated Slc4a11 KO corneal endothelial cells with the mitochondrial ROS quencher, MitoQ. MitoQ restored lysosomal enzymes as well as TFEB, reduced ER stress, and increased autophagy flux. MitoQ injections of Slc4a11 KO mice decreased corneal edema, the major phenotype associated with CHED. We conclude that mitochondrial ROS causes ER stress and lysosomal dysfunction with impairment of autophagy in Slc4a11 KO corneal endothelium. Our study is the first to identify the presence as well as cause of lysosomal dysfunction and ER stress in an animal model of CHED, and to characterize inter-organelle relationship in a corneal cell type.

scholarly journals Utilização do flap de Gundersen para tratamento de disfunção endotelial em equino – relato de caso

2021 ◽  
Vol 4 (5) ◽  
pp. 32-38
Author(s):  
Cleydianne Rodrigues de Almeida ◽  
◽  
Cleyber José da Trindade de Fátima ◽  
Rômulo Vitelli Rocha Peixoto ◽  
Anderson Farias ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Endothelial Dysfunction ◽  
Corneal Ulcer ◽  
Corneal Edema ◽  
Corneal Endothelial Cells ◽  
Eye Care ◽  
Visual Axis ◽  
Lens Dislocation ◽  
Uveitis Anterior ◽  
Ulcerative Keratitis

Endothelial dysfunction in horses is associated with dystrophy or degeneration of corneal endothelial cells, clinically presented as a diffuse corneal edema unresponsive to conventional treatments. The main causes of such injury are trauma, ulcerative keratitis, recurrent uveitis, anterior lens dislocation and glaucoma. This paper aims to report a case of endothelial dysfunction in a mare, diagnosed with endothelial dysfunction after uveitis, glaucoma and indolent corneal ulcer. For correction, a superficial lamellar keratectomy followed by permanent conjunctival graft, described as a Gundersen flap, was performed. After intensive eye care, he returned to his athletic functions, maintained corneal and visual axis transparency and ocular reflexes.

scholarly journals Resveratrol attenuates cigarette smoke induced endothelial apoptosis by activating Notch1 signaling mediated autophagy

2020 ◽  
Author(s):  
Dandan Zong ◽  
Xiang-ming Liu ◽  
Jin-hua Li ◽  
Ruo-yun Ouyang ◽  
Ying-jiao Long ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Cigarette Smoke ◽  
Cell Apoptosis ◽  
Chronic Obstructive ◽  
Dependent Manner ◽  
Obstructive Pulmonary Disease ◽  
Endothelial Apoptosis ◽  
Notch1 Signaling ◽  
Apoptotic Activity ◽  
Induced Apoptosis

Abstract Background Endothelial apoptosis contributes to the pathogenesis of chronic obstructive pulmonary disease (COPD). Our previous studies have validated Notch1 as an anti-apoptotic signaling in cigarette smoke (CS)-induced endothelial apoptosis. Resveratrol (RESV) is a naturally occurring polyphenol that exhibits an anti-apoptotic activity in endothelial cells that exposed to many kinds of destructive stimulus. However, the effects of resveratrol on Notch1 signaling in CS-induced endothelial apoptosis have not yet been fully elucidated. Therefore, the aim of this study was to examine whether RESV can protect endothelial cells from cigarette smoke induced apoptosis via regulating Notch1 signaling. Methods HUVECs were pretreated with RESV for 2 h, followed by cotreatment with 2.5%CSE for 24h to explore the role of RESV in CSE induced endothelial apoptosis. 3-MA or rapamycin was used to alter autophagic levels. Lentivirus Notch1 intracellular domain (LV-N1ICD) or γ-secretase inhibitor (DAPT) were used to change Notch1 expression. The expression of Notch1, autophagic and apoptotic markers were examined by Western blot and the apoptosis rate was detected by Flow cytometry analysis. Results Our results showed that activating autophagy reduced CSE-induced endothelial apoptosis, while blocking autophagy promoted cell apoptosis in HUVECs. RESV pretreatment attenuated the CSE-induced endothelial apoptosis and activated Notch1 signaling. RESV pretreatment also increased LC3b-II and Beclin1 production, decreased p62 and mTOR expression. 3-MA treatment inhibited autophagy and aggravated CSE induced apoptosis, while rapamycin promoted autophagy, led to a decrease in cell apoptosis. LV-N1ICD transfection upregulated autophagy and reduced apoptosis. However, this protective effect was abolished by 3-MA treatment. In cells treated with DAPT, autophagy was decreased, while apoptosis was increased. RESV partly rescued the DAPT induced apoptosis by activating Notch1 signaling. Conclusion In HUVECs, RESV attenuates CSE induced endothelial apoptosis by inducing autophagy in a Notch1-dependent manner.

scholarly journals Myh11 Lineage Corneal Endothelial Cells and ASCs Populate Corneal Endothelium

2019 ◽  
Vol 60 (15) ◽  
pp. 5095 ◽  
Author(s):  
Bruce A. Corliss ◽  
H. Clifton Ray ◽  
Corbin Mathews ◽  
Kathleen Fitzgerald ◽  
Richard W. Doty ◽  
...  
Keyword(s):  
Endothelial Cells ◽  
Corneal Endothelium ◽  
Corneal Endothelial Cells

scholarly journals Polydatin Prevents Methylglyoxal-Induced Apoptosis through Reducing Oxidative Stress and Improving Mitochondrial Function in Human Umbilical Vein Endothelial Cells

2017 ◽  
Vol 2017 ◽  
pp. 1-9 ◽  
Author(s):  
Ningbo Pang ◽  
Tangting Chen ◽  
Xin Deng ◽  
Ni Chen ◽  
Rong Li ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endothelial Cells ◽  
Mitochondrial Function ◽  
Cell Apoptosis ◽  
Umbilical Vein ◽  
Ros Generation ◽  
Mitochondrial Morphology ◽  
Human Umbilical Vein ◽  
Induced Apoptosis ◽  
Umbilical Vein Endothelial Cells

Methylglyoxal (MGO), an active metabolite of glucose, has been reported to induce vascular cell apoptosis in diabetic complication. Polydatin (PD), a small natural compound from Polygonum cuspidatum, has a number of biological functions, such as antioxidative, anti-inflammatory, and nephroprotective properties. However, the protective effects of PD on MGO-induced apoptosis in endothelial cells remain to be elucidated. In this study, human umbilical vein endothelial cells (HUVECs) were used to explore the effects of PD on MGO-induced cell apoptosis and the possible mechanism involved. HUVECs were pretreated with PD for 2 h, followed by stimulation with MGO. Then cell apoptosis, reactive oxygen species (ROS) generation, mitochondrial membrane potential (MMP) impairment, mitochondrial morphology alterations, and Akt phosphorylation were assessed. The results demonstrated that PD significantly prevented MGO-induced HUVEC apoptosis. PD pretreatment also significantly inhibited MGO-induced ROS production, MMP impairment, mitochondrial morphology changes, and Akt dephosphorylation. These results and the experiments involving N-acetyl cysteine (antioxidant), Cyclosporin A (mitochondrial protector), and LY294002 (Akt inhibitor) suggest that PD prevents MGO-induced HUVEC apoptosis, at least in part, through inhibiting oxidative stress, maintaining mitochondrial function, and activating Akt pathway. All of these data indicate the potential application of PD for the treatment of diabetic vascular complication.

scholarly journals Persimmon Leaves (Diospyros kaki) Extract Enhances the Viability of Human Corneal Endothelial Cells by Improving Na+-K+-ATPase Activity

2022 ◽  
Vol 15 (1) ◽  
pp. 72
Author(s):  
Ramsha Afzal ◽  
Hyung Bin Hwang
Keyword(s):  
Endothelial Cells ◽  
Atpase Activity ◽  
Basolateral Membrane ◽  
Corneal Edema ◽  
Ethanol Extract ◽  
Diospyros Kaki ◽  
Corneal Endothelial Cells ◽  
Human Corneal Endothelial Cells ◽  
Corneal Decompensation

The Na+/K+-ATPase, present in the basolateral membrane of human corneal endothelial cells (HCECs), is known to play an important role for corneal transparency. Na+/K+-ATPase dysfunction is one of the major causes of corneal decompensation. The ethanol extract of Diospyros kaki (EEDK) has been reported to increase corneal cell viability. Thus, we treated HCECs with EEDK and studied its effects on HCECs survival and Na+/K+-ATPase against cytotoxic drugs like staurosporine (ST) and ouabain (OU). Firstly, survival assays, (MTT assay and live dead-imaging) showed that decreased HCECs viability by ST and OU was significantly recovered by EEDK co-treatment. Secondly, Na+/K+-ATPase activity assays revealed that EEDK enhanced Na+/K+-ATPase enzymatic activity (* p < 0.01) with/without ST and OU. Finally, Na+/K+-ATPase expression analysis (Western Blot and confocal microscopy) demonstrated that EEDK treatment with/without ST and OU facilitates Na+/K+-ATPase expression in HCECs. Taken together, our findings led us to the conclusion that EEDK might aid HCECs survival in vitro by increasing the activity and expression of Na+/K+-ATPase enzyme. Since Na+/K+-ATPase activity is important to maintain cellular function of HCECs, we suggest that EEDK can be a potential effective agent against corneal edema and related corneal disorders.

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