AAV gene therapy vectors in the TMJ.

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.

Conditional ablation of E-cadherin in the oral epithelium progeny results in tooth anomalies.

Objectives: The objective of this study is to confirm the developmental origin of the enamel organ and evaluate the role of E-cadherin in tooth development by conditional deletion in the oral epithelium and its enamel organ progeny. K5-Cre;ROSA26 compound mice were included in this study in order to confirm the oral epithelial origin of the enamel organ, as well as of the action of the K5-Cre transgene in ablating E-cadherin in the enamel organ. K5-Cre;Ecad knockout mice were included to evaluate the effects of the conditional E-cadherin ablation onto tooth development.

Calcitonin gene-related peptide: An intra-articular therapeutic target for TMJ disorders.

Objectives: The goal of this project was to evaluate the role of calcitonin gene-related peptide (CGRP) in the development of arthritis.

Methods: Herein, we employed somatic mosaic analysis in two different joints by FIV(CGRP) intra-articular inoculation in the knees or temporomandibular joints (TMJ) of young adult male C57/BL6 mice. FIV(CGRP) is a feline immunodeficiency virus over-expressing full-length CGRP.

Partial epithelial-mesenchymal transition during enamel development.

Objectives: We set out to investigate whether a hybrid stem-like p-EMT phenotype develops during murine molar enamel development in vivo.

Setting And Sample Population: Histology specimens incorporating molar tooth buds harvested from mice at post-natal day 4 (P4) were included in our studies.

Materials And Methods: We employed double immunofluorescence staining to analyze the simultaneous expression of the epithelial marker E-cadherin and the mesenchymal marker N-cadherin in histology specimens with tooth buds harvested from P4 mice.

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.

Serotonin contributes to the in vitro production of a biomimetic enamel-like material from reprogrammed oral epithelial keratinocytes.

Objectives: To evaluate the role of serotonin in the development of a biomimetic enamel-like material in vitro.

Setting And Sample Population: Immortalized murine oral keratinocytes raised from adult mouse mucosa were cultured in vitro. In addition, specimens incorporating molar tooth buds harvested from mice were included in our studies.

Effects of vascular endothelial growth factor on osteoblasts and osteoclasts.

Introduction: Bone remodeling is crucial to the success of many dental procedures and is tightly regulated. Vascular endothelial growth factor (VEGF), a key cytokine for angiogenesis, is also an important regulator of bone remodeling. We aimed to examine the mechanisms by which VEGF induces bone remodeling by studying its effects on cultured osteoblasts and osteoclasts.

Neurologic Regulation and Orthodontic Tooth Movement.

Pain and discomfort are prevalent symptoms among the vast majority of patients with fixed orthodontic appliances and is the most disliked aspect of treatment. The periodontium is a highly innervated structure that also provides the necessary trophic factors, such as nerve growth factor, which promote neuronal survival, maintenance and axonal growth, via interaction with specific nerve surface receptors, such as TrkA. Various types of nerves are found in the periodontium, including thinly myelinated and unmyelinated sensory fibers that express the neuropeptides substance P and calcitonin gene-related peptide among others.

Differential modulation of methamphetamine-mediated behavioral sensitization by overexpression of Mu opioid receptors in nucleus accumbens and ventral tegmental area.

Rationale: Repeated administration of methamphetamine (Meth) induces behavioral sensitization which is characterized by a progressive increase in locomotor response after each injection. Previous studies have shown that Mu opioid receptors (MORs) can regulate Meth-mediated behavioral sensitization. However, the reported interactions are controversial; systemic activation of MORs either enhanced or suppressed Meth sensitization.

Accelerated orthodontic tooth movement: molecular mechanisms.

Accelerating orthodontic tooth movement can significantly reduce treatment duration and risks of side effects. The rate of orthodontic tooth movement is chiefly determined by the remodeling of tissues surrounding the roots; this in turn is under the control of molecular mechanisms regulating cellular behaviors in the alveolar bone and periodontal ligament. This review summarizes the current knowledge on the molecular mechanisms underlying accelerated orthodontic tooth movement, and the clinical and experimental methods that accelerate orthodontic tooth movement with possible molecular mechanisms.

Ectodomain-specific E-cadherin antibody suppresses skin SCC growth and reduces tumor grade: a multitargeted therapy modulating RTKs and the PTEN-p53-MDM2 axis.

Tumor cell survival consists of an intricate balance between cell growth and cell death pathways involving receptor tyrosine kinases [RTK; i.e., HER1-4, insulin-like growth factor-1 receptor (IGF-1R), etc.

Soluble-E-cadherin activates HER and IAP family members in HER2+ and TNBC human breast cancers.

Recent literature suggests that sEcad exerts pro-oncogenic effects, possibly acting as a ligand for the human epidermal growth factor family. Here we show that sEcad is a novel candidate protein for drug targeting since it is increased in human and mouse HER2-positive (HER2+) breast tumors, MMTV-PyMT bodily fluids and human cell culture systems. Mechanistically, we show that endogenous sEcad, and to a lesser extent membrane-bound E-cadherin, associates with HER1, HER2, and HER3 in human and MMTV-PyMT mouse HER2+ tumors and with HER1 in triple negative breast cancer (TNBC) specimens.

Monoclonal antibody against the ectodomain of E-cadherin (DECMA-1) suppresses breast carcinogenesis: involvement of the HER/PI3K/Akt/mTOR and IAP pathways.

Purpose: Although targeted therapies against HER2 have been one of the most successful therapeutic strategies for breast cancer, patients eventually developed acquired resistance from compensatory upregulation of alternate HERs and mitogen-activated protein kinase-phosphoinositide 3-kinase (PI3K)/Akt/mTOR signaling. As we and others have shown that the soluble ectodomain fragment of E-cadherin exerts prooncogenic effects via HER1/2-mediated binding and activation of downstream prosurvival pathways, we explored whether targeting this ectodomain [DECMA-1 monoclonal antibody (mAb)] was effective in the treatment of HER2-positive (HER2(+)) breast cancers.

Experimental Design: MMTV-PyMT transgenic mice and HER2(+)/E-cadherin-positive MCF-7 and BT474 trastuzumab-resistant (TtzmR) cells were treated with the DECMA-1 mAb.

Sustained interleukin-1β overexpression exacerbates tau pathology despite reduced amyloid burden in an Alzheimer's mouse model.

Neuroinflammation is an important component of Alzheimer's disease (AD) pathogenesis and has been implicated in neurodegeneration. Interleukin-1 (IL-1), a potent inflammatory cytokine in the CNS, is chronically upregulated in human AD and believed to serve as part of a vicious inflammatory cycle that drives AD pathology. To further understand the role of IL-1β in AD pathogenesis, we used an inducible model of sustained IL-1β overexpression (IL-1β(XAT)) developed in our laboratory.

Autosomal dominant mesomandibular fibro-osseous dysplasia: a self-resolving inherited fibro-osseous lesion of the jaws.

A hereditary congenital condition characterized by a fibro-osseous lesion sharing some features with fibrous dysplasia and affecting the middle aspect of the mandible is presented. The condition was initially described as congenital monostotic fibrous dysplasia in two siblings, a male and a female. However, there is sufficient evidence that the disorder is autosomal dominant since it has been encountered in two of four children, both males, of the female propositus and one child, a boy, of the male propositus.

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.

Chronic IL-1β-mediated neuroinflammation mitigates amyloid pathology in a mouse model of Alzheimer's disease without inducing overt neurodegeneration.

Neuroinflammation is a local tissue response to injurious stimuli in the central nervous system (CNS) and is characterized by glial reactivity, induction of cytokines and chemokines, and vascular permeability. The cytokine interleukin (IL)-1β is rapidly induced following CNS insult, and is chronically expressed in neurodegenerative disorders such as Alzheimer's disease (AD). We recently developed a novel method of sustained IL-1β production in the brain to study the link between IL-1β and AD pathogenesis.

Osteoarthritis accelerates and exacerbates Alzheimer's disease pathology in mice.

Background: The purpose of this study was to investigate whether localized peripheral inflammation, such as osteoarthritis, contributes to neuroinflammation and neurodegenerative disease in vivo.

Methods: We employed the inducible Col1-IL1βXAT mouse 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.

Cyclooxygenase-1 mediates prostaglandin E(2) elevation and contextual memory impairment in a model of sustained hippocampal interleukin-1beta expression.

Interleukin (IL)-1beta is a proinflammatory cytokine implicated in several neurodegenerative disorders. Downstream actions of IL-1beta include production of prostaglandin (PG) E(2) by increasing expression of cyclooxygenase (COX) enzymes and prostaglandin E synthase (PGES) isoforms. We recently developed a transgenic mouse carrying a dormant human IL-1beta eXcisional Activation Transgene (XAT) for conditional and chronic up-regulation of IL-1beta in selected brain regions.

The trigeminal retrograde transfer pathway in the treatment of neurodegeneration.

The trigeminal sensory system was evaluated for the retrograde transfer of gene therapy vectors into the CNS. The feline immunodeficiency viral vector, FIV(HEXB), encoding for the human HEXB gene, was injected intra-articularly in the temporomandibular joint of 12 week-old HexB(-/-) mice displaying clinical and histopathological signs of Sandhoff disease. This treatment regiment reduced GM(2) storage and ameliorated neuroinflammation in the brain of HexB(-/-) mice, as well as attenuated behavioral deficits.

Spinal interleukin-1beta in a mouse model of arthritis and joint pain.

Objective: Pain from arthritis has been associated with peripheral sensitization of primary sensory afferents and the development of inflammation at the dorsal horns. This study was undertaken to determine whether the role of spinal interleukin-1beta (IL-1beta) in central processing of pain is important in the development of arthritis.

Methods: Col1-IL-1betaXAT mice and GFAP-IL-1betaXAT mice were injected with the feline immunodeficiency virus (FIV) (Cre) vector in the right and left temporomandibular joints (TMJs), or in the cisterna magna, respectively, to induce IL-1beta expression in the dorsal horns of the spinal horn.

Peripheral blood mononuclear cell infiltration and neuroinflammation in the HexB-/- mouse model of neurodegeneration.

Myeloid-derived immune cells, including microglia, macrophages and monocytes, have been previously implicated in neurodegeneration. We investigated the role of infiltrating peripheral blood mononuclear cells (PBMC) in neuroinflammation and neurodegeneration in the HexB-/- mouse model of Sandhoff disease. Ablation of the chemokine receptor CCR2 in the HexB-/- mouse resulted in significant inhibition of PBMC infiltration into the brain, decrease in TNFalpha and MHC-II mRNA abundance and retardation in clinical disease development.

Chronic interleukin-1beta expression in mouse brain leads to leukocyte infiltration and neutrophil-independent blood brain barrier permeability without overt neurodegeneration.

The proinflammatory cytokine interleukin-1beta (IL-1beta) plays a significant role in leukocyte recruitment to the CNS. Although acute effects of IL-1beta signaling in the mouse brain have been well described, studies elucidating the downstream effects of sustained upregulation have been lacking. Using the recently described IL-1beta(XAT) transgenic mouse model, we triggered sustained unilateral hippocampal overexpression of IL-1beta.