Reprogramming Oral Epithelial Keratinocytes into a Pluripotent Phenotype for Tissue Regeneration

OBJECTIVES: We set out to reprogram adult somatic oral epithelial keratinocytes into pluripotent cells for regenerative dentistry. SETTING AND SAMPLE POPULATION: Immortalized murine oral keratinocyte cell (IMOK) line raised from adult mouse mucosa were cultured in vitro in our studies. MATERIALS AND METHODS: Adult murine oral epithelial keratinocytes were chronically treated with TGF-β1 in vitro, and the expression of Oct4, Nanog, Sox2 and Nestin, as well as specific homeobox Gata and Pax gene family members were investigated. RESULTS: We documented the induction of stem factors linked with pluripotency and/or the maintenance and regulation of stem-cell self-renewal in oral epithelial keratinocytes by TGFβ1. Moreover, we discovered that this TGF-β1-induced increase in Oct4, Nanog, Sox2 and Nestin was inhibited by SB431542, suggesting that TGF-β1 signals via the TGF-βRI receptor to induce pluripotency and stemness. CONCLUSIONS: Adult oral epithelial keratinocytes treated chronically with TGF-β1 acquired phenotypic characteristics consistent with pluripotent stem cells, highlighting the facileness of reprogramming adult oral keratinocytes into an unlimited supply of pluripotent stem cells

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

AAV gene therapy vectors in the TMJ

Abstract Objectives The goal of this project was to evaluate the use of two adeno‐associated viral vector serotypes, adeno‐associated viral vectors (AAV)‐2 and AAV‐6, approved for and used for gene therapy in humans, for the delivery of therapeutic genes to the temporomandibular joint (TMJ) and the attendant sensory nerves. Methods Young adult wild‐type C57BL/6 mice were intra‐articularly inoculated with AAV‐2 and AAV‐6 encoding the reporter gene gfp, the expression of which was assessed in the TMJ as well as along nerves innervating the TMJ. Results AAV‐2 and AAV‐6 serotypes were characterized by varying levels of tissue tropism demonstrating different efficacy of infection for articular chondrocytes, meniscal fibroblasts, and trigeminal neurons. Specifically, AAV‐2 infected both neurons and articular chondrocytes/meniscal fibroblasts, whereas AAV‐6 showed selectivity primarily for neurons. Conclusions The results of this study are clinically significant in the successful application of gene therapy vectors for TMJ disorders, as this new knowledge will allow for appropriate targeting of specific therapeutic genes to selective tissues (neurons vs. chondrocytes/fibroblasts) as needed by using specific viral vector serotypes

Effects of Continuous-Wave (670-nm) Red Light on Wound Healing

BACKGROUND Recent work suggests that injuries can heal faster if treated by lasers emitting 670-nm red light. LED lights emitting 670-nm light are now available. This suggests that inexpensive and easyto-use 670-nm LED lights might help accelerate cutaneous wound healing