Adenosine Deaminase-2-Induced Hyperpermeability in Human Retinal Vascular Endothelial Cells Is Suppressed by MicroRNA-146b-3p.
We recently demonstrated that adenosine deaminase-2 (ADA2) contributes to diabetic retinopathy (DR) via up-regulating the production of inflammatory cytokines in macrophages. Also, microRNA (miR)-146b-3p has the ability to inhibit ADA2. The goal of this study was to investigate the potential role of ADA2 and therapeutic benefit of miR-146b-3p in retinal inflammation and endothelial barrier dysfunction during diabetes.



Adenosine deaminase-2 activity was determined by colorimetric method in diabetic human vitreous. Human monocyte cell line U937 was differentiated into macrophages and then treated with amadori glycated albumin (AGA), and conditioned medium (CM) was used to assess the changes in ADA2 activity and TNF-α and IL-6 levels by ELISA. Also, macrophages were transfected with miR-146b-3p before treatment with AGA. Permeability of human retinal endothelial cells (hRECs) was assessed by electric cell-substrate impedance sensing (ECIS) after treatment with macrophage CM. Zonula occludens (ZO)-1 was examined by immuno-fluorescence in hRECs. Leukocyte adhesion was assessed in hRECs by measuring myeloperoxidase (MPO) activity and intercellular adhesion molecule-1 (ICAM-1) expression.



Adenosine deaminase-2 activity was significantly increased in diabetic human vitreous. ADA2 activity and TNF-α and IL-6 levels were significantly increased in human macrophages by AGA treatment. Amadori glycated albumin-treated macrophage CM significantly increased hREC permeability, disrupted ZO-1 pattern, and increased leukocyte adhesion to hRECs through up-regulating ICAM-1. All these changes were reversed by miR-146b-3p.



Adenosine deaminase-2 is implicated in breakdown of the blood-retinal barrier (BRB) in DR through macrophages-derived cytokines. Therefore, inhibition of ADA2 by miR-146b-3p might be a useful tool to preserve BRB function in DR.
Department of Biochemistry, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt 2Department of Ophthalmology and The Culver Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, Georgia, United States.
Yara A
YA
Samra
Department of Oral Biology/Anatomy, Dental College of Georgia, Augusta University, Augusta, Georgia, United States.
Heba M
HM
Saleh
Department of Oral Biology/Anatomy, Dental College of Georgia, Augusta University, Augusta, Georgia, United States 4Department of Oral Medicine and Surgery, Oral and Dental Research Division, National Research Centre, Cairo, Egypt.
Khaled A
KA
Hussein
Department of Biochemistry, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt 3Department of Oral Biology/Anatomy, Dental College of Georgia, Augusta University, Augusta, Georgia, United States 5Department of Pharmaceutical Chemistry, Faculty of Pharmacy, University of Tabuk, Tabuk, Saudi Arabia.
Nehal M
NM
Elsherbiny
Department of Biochemistry, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt 3Department of Oral Biology/Anatomy, Dental College of Georgia, Augusta University, Augusta, Georgia, United States.
Ahmed S
AS
Ibrahim
Department of Oral Biology/Anatomy, Dental College of Georgia, Augusta University, Augusta, Georgia, United States 6Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia, United States 7Department of Anatomy, Faculty of Medicine, Mansoura University, Egypt.
Khaled
K
Elmasry
Department of Orthopedics, Medical College of Georgia, Augusta University, Augusta, Georgia, United States.
Sadanand
S
Fulzele
Department of Biochemistry, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt.
Mamdouh M
MM
El-Shishtawy
Department of Biochemistry, Faculty of Pharmacy, Mansoura University, Mansoura, Egypt.
Laila A
LA
Eissa
Department of Ophthalmology and The Culver Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, Georgia, United States 3Department of Oral Biology/Anatomy, Dental College of Georgia, Augusta University, Augusta, Georgia, United States 6Department of Cellular Biology and Anatomy, Medical College of Georgia, Augusta University, Augusta, Georgia, United States 7Department of Anatomy, Faculty of Medicine, Mansoura University, Egypt.
Mohamed
M
Al-Shabrawey
Department of Ophthalmology and The Culver Vision Discovery Institute, Medical College of Georgia, Augusta University, Augusta, Georgia, United States.
Gregory I
GI
Liou
D000243:Adenosine Deaminase / Q000187:drug effects / Q000378:metabolism*; D015153:Blotting, Western; D002199:Capillary Permeability / Q000187:drug effects*; D002460:Cell Line; D016207:Cytokines / Q000378:metabolism; D003930:Diabetic Retinopathy / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D042783:Endothelial Cells / Q000187:drug effects / Q000378:metabolism*; D004797:Enzyme-Linked Immunosorbent Assay; D017127:Glycation End Products, Advanced; D006801:Humans; D035683:MicroRNAs / Q000494:pharmacology*; D012160:Retina / Q000378:metabolism* / Q000473:pathology; D012171:Retinal Vessels / Q000187:drug effects / Q000378:metabolism*; D012709:Serum Albumin / Q000494:pharmacology; D019108:Tight Junctions / Q000378:metabolism; D000093423:Glycated Serum Albumin
D016207:Cytokines; D017127:Glycation End Products, Advanced; C542542:MIRN146 microRNA, human; D035683:MicroRNAs; D012709:Serum Albumin; D000243:Adenosine Deaminase; D000093423:Glycated Serum Albumin