| First Author | Herskowitz JH | Year | 2013 |
| Journal | J Neurosci | Volume | 33 |
| Issue | 49 | Pages | 19086-98 |
| PubMed ID | 24305806 | Mgi Jnum | J:255339 |
| Mgi Id | MGI:6114922 | Doi | 10.1523/JNEUROSCI.2508-13.2013 |
| Citation | Herskowitz JH, et al. (2013) Pharmacologic inhibition of ROCK2 suppresses amyloid-beta production in an Alzheimer's disease mouse model. J Neurosci 33(49):19086-98 |
| abstractText | Alzheimer''s disease (AD) is the leading cause of dementia and has no cure. Genetic, cell biological, and biochemical studies suggest that reducing amyloid-beta (Abeta) production may serve as a rational therapeutic avenue to delay or prevent AD progression. Inhibition of RhoA, a Rho GTPase family member, is proposed to curb Abeta production. However, a barrier to this hypothesis has been the limited understanding of how the principal downstream effectors of RhoA, Rho-associated, coiled-coil containing protein kinase (ROCK) 1 and ROCK2, modulate Abeta generation. Here, we report that ROCK1 knockdown increased endogenous human Abeta production, whereas ROCK2 knockdown decreased Abeta levels. Inhibition of ROCK2 kinase activity, using an isoform-selective small molecule (SR3677), suppressed beta-site APP cleaving enzyme 1 (BACE1) enzymatic action and diminished production of Abeta in AD mouse brain. Immunofluorescence and confocal microscopy analyses revealed that SR3677 alters BACE1 endocytic distribution and promotes amyloid precursor protein (APP) traffic to lysosomes. Moreover, SR3677 blocked ROCK2 phosphorylation of APP at threonine 654 (T654); in neurons, T654 was critical for APP processing to Abeta. These observations suggest that ROCK2 inhibition reduces Abeta levels through independent mechanisms. Finally, ROCK2 protein levels were increased in asymptomatic AD, mild cognitive impairment, and AD brains, demonstrating that ROCK2 levels change in the earliest stages of AD and remain elevated throughout disease progression. Collectively, these findings highlight ROCK2 as a mechanism-based therapeutic target to combat Abeta production in AD. |
