Inducible overexpression of endothelial proNGF as a mouse model to study microvascular dysfunction

BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR BASIS OF DISEASE

卷:1864

Article

Mohamed, Riyaz¹  Concha, Maha¹  Elshaer, Sally L.¹  Artham, Sandeep¹  Lemtalsi, Tahira¹  El-Remessy, Azza B.¹ 

[1] Augusta Biomed Res Corp, Charlie Norwood Vet Affairs Med Ctr, Downtown 6B-153, Augusta, GA 30912 USA

关键词: Neurotrophin;    Nerve growth factor;    Diabetic retinopathy;    Acellular capillary;    Apoptosis;    Neurodegeneration;    Inflammation;    Barrier dysfunction;   

DOI  :  10.1016/j.bbadis.2017.12.023

来源: Elsevier

【 摘 要 】

Impaired maturation of nerve growth factor precursor (proNGF) and its accumulation has been reported in several neurodegenerative diseases, myocardial infarction and diabetes. To elucidate the direct impact of proNGF accumulation identified the need to create a transgenic model that can express fully mutated cleavage resistant proNGF. Using Cre-Lox technology, we developed an inducible endothelial-specific proNGF transgenic mouse (proNGF(Loxp)) that overexpresses GFP-conjugated cleavage-resistant proNGF123 when crossed with VE-cadherin-CreERT2 (Cre). Expression of proNGF, inflammatory mediators, NGF and VEGF was evaluated by PCR, Western blot and immunohistochemistry. EC-proNGF overexpression was confirmed using colocalization of anti-proNGF within retinal vasculature. EC-proNGF did not cause retinal neurotoxicity or marked glial activation at 4-weeks. Microvascular preparation from Cre-proNGF mice showed significant imbalance of proNGF/NGF ratio, enhanced expression of TNF-alpha and p75(NTR), and tendency to impair TrkA phosphorylation compared to controls. EC-proNGF overexpression triggered mRNA expression of p75(NTR) and inflammatory mediators in both retina and renal cortex compared to controls. EC-proNGF expression induced vascular permeability including breakdown of BRB and albuminuria in the kidney without affecting VEGF level at 4-weeks. Histopathological changes were assessed after 8-weeks and the results showed that EC-proNGF triggered formation of occluded (acellular) capillaries, hall mark of retinal ischemia. EC-proNGF resulted in glomerular enlargement and kidney fibrosis, hall mark of renal dysfunction. We have successfully created an inducible mouse model that can dissect the contribution of autocrine direct action of cleavage-resistant proNGF on systemic microvascular abnormalities in both retina and kidney, major targets for microvascular complication.

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