Systemic FIV vector administration: transduction of CNS immune cells and Purkinje neurons

The Cranial Base in Craniofacial Development: a Gene Therapy Study

The etiology of midface retrusion remains largely unclear. We hypothesized that the cranial base synchondroses play a key role in the development of the craniofacial skeleton in the Sandhoff mouse model. We observed that developmental abnormalities of the cranial base synchondroses involving proliferative chondrocytes are important in craniofacial growth and development. Neonatal restitution of β-hexosaminidase in mutant mice by gene therapy successfully ameliorated the attendant skeletal defects and restored craniofacial morphology in vivo, suggesting this as a critical temporal window in craniofacial development. Analysis of our data implicates parathyroid-related peptide (PTHrP) and cyclo-oxygenase-2 (COX-2) as possible factors underlying the development of the aforementioned skeletal defects. Hence, timely restitution of a genetic deficiency or, alternatively, the restoration of PTHrP or cyclo-oxygenase activity by the administration of PTH and/or non-steroidal anti-inflammatory drugs or COX-2 selective inhibitors to affected individuals may prove beneficial in the management of midface retrusion.

Sequential Down-regulation of E-Cadherin with Squamous Cell Carcinoma Progression: Loss of E-Cadherin via a Prostaglandin E2-EP2–Dependent Posttranslational Mechanism

The incidence of skin cancer is on the rise, with over 1 million new cases yearly. Although it is known that squamous cell cancers (SCC) are caused by UV light, the mechanism(s) involved remains poorly understood. In vitro studies with epithelial cells or reports examining malignant skin lesions suggest that loss of E-cadherin-mediated cell-cell contacts may contribute to SCCs. Other studies show a pivotal role for cyclooxygenase-dependent prostaglandin E2 (PGE2) synthesis in this process. Using chronically UV-irradiated SKH-1 mice, we show a sequential loss of E-cadherin-mediated cell-cell contacts as lesions progress from dysplasia to SCCs. This E-cadherin down-regulation was also evident after acute UV exposure in vivo. In both chronic and acute UV injury, E-cadherin levels declined at a time when epidermal PGE2 synthesis was enhanced. Inhibition of PGE2 synthesis by indomethacin in vitro, targeted deletion of EP2 in primary mouse keratinocyte (PMK) cultures or deletion of the EP2 receptor in vivo abrogated this UV-induced E-cadherin down-regulation. In contrast, addition of PGE2 or the EP2 receptor agonist butaprost to PMK produced a dose- and time-dependent decrease in E-cadherin. We also show that UV irradiation, via the PGE2-EP2 signaling pathway, may initiate tumorigenesis in keratinocytes by down-regulating E-cadherin-mediated cell-cell contacts through its mobilization away from the cell membrane, internalization into the cytoplasm, and shuttling through the lysosome and proteasome degradation pathways. Further understanding of how UV-PGE2-EP2 down-regulates E-cadherin may lead to novel chemopreventative strategies for the treatment of skin and other epithelial cancers.

Intraperitoneal inoculation of Sandhoff mouse neonates with an HIV-1 based lentiviral vector exacerbates the attendant neuroinflammation and disease phenotype

We aimed to evaluate the efficacy of VSV-G pseudotyped, defective HIV-1 based lentiviral vectors for the neonatal transfer of therapeutic genes following systemic administration in Sandhoff mouse pups. Despite transgene expression in mouse brains, these animals presented with significant exacerbation and acceleration of the disease neurological phenotype. We observed an increase and acceleration in the presence of MHC-II and CD45+ cells in their brains, along with neuroinflammation, but not in control heterozygous or wild type littermates that also received the same treatment.

Intraarticular induction of interleukin-1beta expression in the adult mouse, with resultant temporomandibular joint pathologic changes, dysfunction, and pain

OBJECTIVE

To examine the effects of intraarticular induction of interleukin-1beta (IL-1beta) expression in adult mice.

METHODS

We used somatic mosaic analysis in a novel transgenic mouse with an inducible IL-1beta transcription unit. Transgene activation was induced by Cre recombinase in the temporomandibular joints (TMJs) of adult transgenic mice (conditional knockin model). The effects of intraarticular IL-1beta induction were subsequently evaluated at the cellular, histopathologic, and behavioral levels.

RESULTS

We developed transgenic mice capable of germline transmission of a dormant transcription unit consisting of the mature form of human IL-1beta as well as the reporter gene beta-galactosidase driven by the rat procollagen 1A1 promoter. Transgene activation by a feline immunodeficiency virus Cre vector resulted in histopathologic changes, including articular surface fibrillations, cartilage remodeling, and chondrocyte cloning. We also demonstrated up-regulation of genes implicated in arthritis (cyclooxygenase 2, IL-6, matrix metalloproteinase 9). There was a lack of inflammatory cells in these joints. Behavioral changes, including increased orofacial grooming and decreased resistance to mouth opening, were used as measures of nociception and joint dysfunction, respectively. The significant increase in expression of the pain-related neurotransmitter calcitonin gene-related peptide (CGRP) in the sensory ganglia as well as the auxiliary protein CGRP receptor component protein of the calcitonin-like receptor in the brainstem further substantiated the induction of pain.

CONCLUSION

Induction of IL-1beta expression in the TMJs of adult mice led to pathologic development, dysfunction, and related pain in the joints. The somatic mosaic model presented herein may prove useful in the preclinical evaluation of existing and new treatments for the management of joint pathologic changes and pain, such as in osteoarthritis.

β-hexosaminidase lentiviral vectors: transfer into the CNS via systemic administration

Brain inflammation in GM2 gangliosidosis has been recently realized as a key factor in disease development. The aim of this study was to investigate the effects of a FIV beta-hexosaminidase vector in the brain of HexB-deficient (Sandhoff disease) mice following intraperitoneal administration to pups of neonatal age. Since brain inflammation, lysosomal storage and neuromuscular dysfunction are characteristics of HexB deficiency, these parameters were employed as experimental outcomes in our study. The ability of the lentiviral vector FIV(HEX) to infect murine cells was initially demonstrated with success in normal mouse fibroblasts and human Tay-Sachs cells in vitro. Furthermore, systemic transfer of FIV(HEX) to P2 HexB-/- knockout pups lead to transduction of peripheral and central nervous system tissues. Specifically, beta-hexosaminidase expressing cells were immunolocalized in periventricular areas of the cerebrum as well as in the cerebellar cortex. FIV(HEX) neonatal treatment resulted in reduction of GM2 storage along with attenuation of the brain inflammation and amelioration of the attendant neuromuscular deterioration. In conclusion, these results demonstrate the effective transfer of a beta-hexosaminidase lentiviral vector to the brain of Sandhoff mice and resolution of the GM2 gangliosidosis after neonatal intraperitoneal administration.