| First Author | Leinonen H | Year | 2016 |
| Journal | Hum Mol Genet | Volume | 25 |
| Issue | 17 | Pages | 3810-3823 |
| PubMed ID | 27466183 | Mgi Jnum | J:237953 |
| Mgi Id | MGI:5817552 | Doi | 10.1093/hmg/ddw228 |
| Citation | Leinonen H, et al. (2016) Lack of P4H-TM in mice results in age-related retinal and renal alterations. Hum Mol Genet 25(17):3810-3823 |
| abstractText | Age-related macular degeneration (AMD), affecting the retinal pigment epithelium (RPE), is the leading cause of blindness in middle-aged and older people in developed countries. Genetic and environmental risk factors have been identified, but no effective cure exists. Using a mouse model we show that a transmembrane prolyl 4-hydroxylase (P4H-TM), which participates in the oxygen-dependent regulation of the hypoxia-inducible factor (HIF), is a potential novel candidate gene for AMD. We show that P4h-tm had its highest expression levels in the mouse RPE and brain, heart, lung, skeletal muscle and kidney. P4h-tm-/- mice were fertile and had a normal life span. Lack of P4h-tm stabilized HIF-1alpha in cortical neurons under normoxia, while in hypoxia it increased the expression of certain HIF target genes in tissues with high endogenous P4h-tm expression levels more than in wild-type mice. Renal erythropoietin levels increased in P4h-tm-/- mice with aging, but the resulting approximately 2-fold increase in erythropoietin serum levels did not lead to erythrocytosis. Instead, accumulation of lipid-containing lamellar bodies in renal tubuli was detected in P4h-tm-/- mice with aging, resulting in inflammation and fibrosis, and later glomerular sclerosis and albuminuria. Lack of P4h-tm was associated with retinal thinning, rosette-like infoldings and drusen-like structure accumulation in RPE with aging, as is characteristic of AMD. Photoreceptor recycling was compromised, and electroretinograms revealed functional impairment of the cone pathway in adult P4h-tm-/- mice and cone and rod deficiency in middle-aged mice. P4H-TM is therefore imperative for normal vision, and potentially a novel candidate for age-induced diseases, such as AMD. |
