BACKGROUND: Amyloid-β soluble oligomers (Aβo) are believed to be the cause of the pathophysiology underlying Alzheimer's disease (AD) and are normally detected some two decades before clinical onset of the disease. Retinal pathology associated with AD pathogenesis has previously been reported, including ganglion cell loss, accumulation of Aβ deposits in the retina, and reduction of nerve fiber layer thickness as well as abnormalities of the microvasculature. OBJECTIVE: This study's aim is to better understand the relationship between brain and retinal Aβo deposition and in particular to quantify levels of the toxic Aβo as a function of age in the retina of a rodent model of AD. METHODS: Retinas and brain tissue from 5×FAD mice were stained with Congo red, Thioflavin-T (Th-T), and Aβ plaque-specific and Aβo-specific antibodies. RESULTS: We show that retinas displayed an age-dependent increase of Th-T-specific amyloid fibrils. Staining with anti-Aβ antibody confirmed the presence of the Aβ plaques in all 5×FAD retinas tested. In contrast, staining with anti-Aβo antibody showed an age-dependent decrease of retinal Aβo. Of note, Aβo was observed mainly in the retinal nuclear layers. Finally, we confirmed the localization of Aβo to neurons, typically accumulating in late endosomes, indicating possible impairment of the endocytic pathway. CONCLUSION: Our results demonstrate the presence of intraneuronal Aβo in the retina and its accumulation inversely correlated with retinal Aβ plaque deposition, indicating an age-related conversion in this animal model. These results support the development of an early AD diagnostic test targeting Aβo in the eye.
BACKGROUND: Amyloid-β soluble oligomers (Aβo) are believed to be the cause of the pathophysiology underlying Alzheimer's disease (AD) and are normally detected some two decades before clinical onset of the disease. Retinal pathology associated with AD pathogenesis has previously been reported, including ganglion cell loss, accumulation of Aβ deposits in the retina, and reduction of nerve fiber layer thickness as well as abnormalities of the microvasculature. OBJECTIVE: This study's aim is to better understand the relationship between brain and retinal Aβo deposition and in particular to quantify levels of the toxic Aβo as a function of age in the retina of a rodent model of AD. METHODS: Retinas and brain tissue from 5×FAD mice were stained with Congo red, Thioflavin-T (Th-T), and Aβ plaque-specific and Aβo-specific antibodies. RESULTS: We show that retinas displayed an age-dependent increase of Th-T-specific amyloid fibrils. Staining with anti-Aβ antibody confirmed the presence of the Aβ plaques in all 5×FAD retinas tested. In contrast, staining with anti-Aβo antibody showed an age-dependent decrease of retinal Aβo. Of note, Aβo was observed mainly in the retinal nuclear layers. Finally, we confirmed the localization of Aβo to neurons, typically accumulating in late endosomes, indicating possible impairment of the endocytic pathway. CONCLUSION: Our results demonstrate the presence of intraneuronal Aβo in the retina and its accumulation inversely correlated with retinal Aβ plaque deposition, indicating an age-related conversion in this animal model. These results support the development of an early AD diagnostic test targeting Aβo in the eye.
Authors: Umma Habiba; Joseph Descallar; Fabian Kreilaus; Utpal K Adhikari; Sachin Kumar; John W Morley; Bang V Bui; Maya Koronyo-Hamaoui; Mourad Tayebi Journal: Alzheimers Dement (Amst) Date: 2021-05-06
Authors: Oana M Dumitrascu; Ryan Rosenberry; Dale S Sherman; Maziyar M Khansari; Julia Sheyn; Tania Torbati; Ayesha Sherzai; Dean Sherzai; Kenneth O Johnson; Alan D Czeszynski; Steven Verdooner; Keith L Black; Sally Frautschy; Patrick D Lyden; Yonggang Shi; Susan Cheng; Yosef Koronyo; Maya Koronyo-Hamaoui Journal: Cells Date: 2021-10-28 Impact factor: 6.600
Authors: Umma Habiba; Makiko Ozawa; James K Chambers; Kazuyuki Uchida; Joseph Descallar; Hiroyuki Nakayama; Brian A Summers; John W Morley; Mourad Tayebi Journal: J Alzheimers Dis Rep Date: 2021-10-06
Authors: Oana M Dumitrascu; Patrick D Lyden; Tania Torbati; Julia Sheyn; Ayesha Sherzai; Dean Sherzai; Dale S Sherman; Ryan Rosenberry; Susan Cheng; Kenneth O Johnson; Alan D Czeszynski; Steven Verdooner; Sally Frautschy; Keith L Black; Yosef Koronyo; Maya Koronyo-Hamaoui Journal: Alzheimers Dement (Amst) Date: 2020-09-28