Conditional expression of human β-hexosaminidase in the neurons of Sandhoff disease rescues mice from neurodegeneration but not neuroinflammation

This study evaluated whether GM(2) ganglioside storage is necessary for neurodegeneration and neuroinflammation by performing β-hexosaminidase rescue experiments in neurons of HexB(−/−) mice. We developed a novel mouse model, whereby the expression of the human HEXB gene was targeted to neurons of HexB(−/−) mice by the Thy1 promoter. Despite β-hexosaminidase restoration in neurons was sufficient in rescuing HexB(−/−) mice from GM(2) neuronal storage and neurodegeneration, brain inflammation persisted, including the presence of large numbers of reactive microglia/macrophages due to persisting GM(2) presence in this cell type. In conclusion, our results suggest that neuroinflammation is not sufficient to elicit neurodegeneration as long as neuronal function is restored

Osteoarthritis accelerates and exacerbates Alzheimer's disease pathology in mice

<p>Abstract</p> <p>Background</p> <p>The purpose of this study was to investigate whether localized peripheral inflammation, such as osteoarthritis, contributes to neuroinflammation and neurodegenerative disease <it>in vivo</it>.</p> <p>Methods</p> <p>We employed the inducible Col1-IL1β^XATmouse model of osteoarthritis, in which induction of osteoarthritis in the knees and temporomandibular joints resulted in astrocyte and microglial activation in the brain, accompanied by upregulation of inflammation-related gene expression. The biological significance of the link between peripheral and brain inflammation was explored in the APP/PS1 mouse model of Alzheimer's disease (AD) whereby osteoarthritis resulted in neuroinflammation as well as exacerbation and acceleration of AD pathology.</p> <p>Results</p> <p>Induction of osteoarthritis exacerbated and accelerated the development of neuroinflammation, as assessed by glial cell activation and quantification of inflammation-related mRNAs, as well as Aβ pathology, assessed by the number and size of amyloid plaques, in the APP/PS1; Col1-IL1β^XATcompound transgenic mouse.</p> <p>Conclusion</p> <p>This work supports a model by which peripheral inflammation triggers the development of neuroinflammation and subsequently the induction of AD pathology. Better understanding of the link between peripheral localized inflammation, whether in the form of osteoarthritis, atherosclerosis or other conditions, and brain inflammation, may prove critical to our understanding of the pathophysiology of disorders such as Alzheimer's, Parkinson's and other neurodegenerative diseases.</p