Cannabinoid CB2 receptors regulate central sensitization and pain responses associated with osteoarthritis of the knee joint.

Osteoarthritis (OA) of the joint is a prevalent disease accompanied by chronic, debilitating pain. Recent clinical evidence has demonstrated that central sensitization contributes to OA pain. An improved understanding of how OA joint pathology impacts upon the central processing of pain is crucial for the identification of novel analgesic targets/new therapeutic strategies. Inhibitory cannabinoid 2 (CB2) receptors attenuate peripheral immune cell function and modulate central neuro-immune responses in models of neurodegeneration. Systemic administration of the CB2 receptor agonist JWH133 attenuated OA-induced pain behaviour, and the changes in circulating pro- and anti-inflammatory cytokines exhibited in this model. Electrophysiological studies revealed that spinal administration of JWH133 inhibited noxious-evoked responses of spinal neurones in the model of OA pain, but not in control rats, indicating a novel spinal role of this target. We further demonstrate dynamic changes in spinal CB2 receptor mRNA and protein expression in an OA pain model. The expression of CB2 receptor protein by both neurones and microglia in the spinal cord was significantly increased in the model of OA. Hallmarks of central sensitization, significant spinal astrogliosis and increases in activity of metalloproteases MMP-2 and MMP-9 in the spinal cord were evident in the model of OA pain. Systemic administration of JWH133 attenuated these markers of central sensitization, providing a neurobiological basis for analgesic effects of the CB2 receptor in this model of OA pain. Analysis of human spinal cord revealed a negative correlation between spinal cord CB2 receptor mRNA and macroscopic knee chondropathy. These data provide new clinically relevant evidence that joint damage and spinal CB2 receptor expression are correlated combined with converging pre-clinical evidence that activation of CB2 receptors inhibits central sensitization and its contribution to the manifestation of chronic OA pain. These findings suggest that targeting CB2 receptors may have therapeutic potential for treating OA pain.

Management of ductal carcinoma in situ according to Van Nuys Prognostic Index in Australia and New Zealand.

INTRODUCTION: Clinicians often use the Van Nuys Prognostic Index (VNPI) to determine management of ductal carcinoma in situ (DCIS). The VNPI uses age, extent of DCIS, pathological grade and resection margins to stratify patients into three groups pertaining to risk of local recurrence: low-risk (where breast-conserving surgery - BCS - alone appears adequate), intermediate-risk (where BCS plus radiotherapy is recommended) and high-risk (where mastectomy may be the safest option). The purpose of this study was to determine patterns of management of DCIS in Australia and New Zealand according to the VNPI. METHODS: Using the National Breast Cancer Audit for the period 2004-2009, 4578 cases of DCIS were identified where complete data were available. Patterns of management according to the VNPI were determined. The chi-squared test was used for statistical analysis. RESULTS: In VNPI group 1, 77% of patients were treated with BCS compared with 63% in group 2 and 32% in group 3. Of patients in group 1 who underwent BCS, 58% also received adjuvant radiotherapy, compared with 80% in group 2. In group 3, 68% were treated with mastectomy, and of those who underwent BCS, 86% received radiotherapy. Overall, 23% of DCIS cases did not conform to best practice according to individual VNPI prognostic groupings. CONCLUSIONS: Significant differences in the management of DCIS according to VNPI groups were observed. The results suggest the possibility that some patients in the low-risk group were over-treated, while a proportion of patients in the intermediate- and high-risk groups were under-treated.

A regulatory toolbox of MiniPromoters to drive selective expression in the brain.

The Pleiades Promoter Project integrates genomewide bioinformatics with large-scale knockin mouse production and histological examination of expression patterns to develop MiniPromoters and related tools designed to study and treat the brain by directed gene expression. Genes with brain expression patterns of interest are subjected to bioinformatic analysis to delineate candidate regulatory regions, which are then incorporated into a panel of compact human MiniPromoters to drive expression to brain regions and cell types of interest. Using single-copy, homologous-recombination "knockins" in embryonic stem cells, each MiniPromoter reporter is integrated immediately 5' of the Hprt locus in the mouse genome. MiniPromoter expression profiles are characterized in differentiation assays of the transgenic cells or in mouse brains following transgenic mouse production. Histological examination of adult brains, eyes, and spinal cords for reporter gene activity is coupled to costaining with cell-type-specific markers to define expression. The publicly available Pleiades MiniPromoter Project is a key resource to facilitate research on brain development and therapies.

TWIST family of basic helix-loop-helix transcription factors mediate human mesenchymal stem cell growth and commitment.

The TWIST family of basic helix-loop-helix transcription factors, Twist-1 and Dermo-1 are known mediators of mesodermal tissue development and contribute to correct patterning of the skeleton. In this study, we demonstrate that freshly purified human bone marrow-derived mesenchymal stromal/stem cells (MSC) express high levels of Twist-1 and Dermo-1 which are downregulated following ex vivo expansion. Enforced expression of Twist-1 or Dermo-1 in human MSC cultures increased expression of the MSC marker, STRO-1, and the early osteogenic transcription factors, Runx2 and Msx2. Conversely, overexpression of Twist-1 and Dermo-1 was associated with a decrease in the gene expression of osteoblast-associated markers, bone morphogenic protein-2, bone sialoprotein, osteopontin, alkaline phosphatase and osteocalcin. High expressing Twist-1 or Dermo-1 MSC lines exhibited an enhanced proliferative potential of approximately 2.5-fold compared with control MSC populations that were associated with elevated levels of Id-1 and Id-2 gene expression. Functional studies demonstrated that high expressing Twist-1 and Dermo-1 MSC displayed a decreased capacity for osteo/chondrogenic differentiation and an enhanced capacity to undergo adipogenesis. These findings implicate the TWIST gene family members as potential mediators of MSC self-renewal and lineage commitment in postnatal skeletal tissues by exerting their effects on genes involved in the early stages of bone development.