Induction of COX-2 expression and enzymatic activity promotes neuronal injury in a number of models of neurological disease. Inhibition of COX-2 activity, either genetically or pharmacologically, has been shown to be neuroprotective in rodent models of stroke, Parkinson's disease, and amyotrophic lateral sclerosis. Inhibition of COX activity with nonsteroidal anti-inflammatory drugs (NSAIDs) reduces inflammation and amyloid accumulation in murine transgenic models of Familial Alzheimer's disease, and the use of NSAIDs decreases the risk of developing Alzheimer's disease in healthy aging populations. COX-mediated neuronal injury is presumed be due to downstream effects of one or more prostaglandin products including PGE2, PGD2, PGF2alpha, PGI2 (prostacylin) and TXA2 (thromboxane) that effect cellular changes through activation of specific prostaglandin receptor subtypes and second messenger systems. In this proceeding, we review recent data demonstrating effects of prostaglandin signaling on neuronal viability that are paradoxically protective, when taken in the context that COX-2 induces neuronal injury in the setting of excitotoxicity. Conversely, in the context of an inflammatory stimulus, the EP2 receptor enhances neuronal injury. These findings argue for an additional level of complexity in the prostaglandin response in neurological disease.

To identify biomarkers of operational tolerance in pediatric and adult liver transplant recipients, transcriptional profiles were examined from 300 samples by microarrays and Q-PCR measurements of blood specimens from pediatric and adult liver transplant recipients and normal tissues. Tolerance-specific genes were validated in independent samples across two different transplant programs and validated by Q-PCR. A minimal set of 13 unique genes, highly expressed in natural killer cells (p = 0.03), were significantly expressed in both pediatric and adult liver tolerance, irrespective of different clinical and demographic confounders. The performance of this gene set by microarray in independent samples was 100% sensitivity and 83% specificity and the AUC was 0.988 for only three genes by Q-PCR. 26% of adults and 64% of children with excellent liver allograft function, on minimal or dual immunosuppression, showed high prediction scores for tolerance. Novel peripheral transcriptional profiles can be identified in operational tolerance in pediatric and adult recipients of liver allografts, suggesting a high incidence of a pro-tolerogenic phenotype in stable patients on chronic immunosuppression. Given the high incidence of viral infections and malignancies in liver transplant recipients, this gene set provides an important monitoring tool that can move the field toward personalized and predictive medicine in organ transplantation.

Objective Boswellic acid is a plant-derived molecule with putative anti-inflammatory effects. This study was performed to determine whether oral or topical administration of boswellic acid can attenuate joint damage in a mouse model of osteoarthritis (OA). Methods Levels of boswellic acid were measured in the blood and synovium of mice treated with oral or topical boswellic acid. OA was generated by surgical destabilization of the medial meniscus (DMM). Therapy with oral or topical boswellic acid was initiated one day after surgery and continued for 12 weeks, when knees were harvested and scored histologically for degree of cartilage loss, osteophyte formation, and synovitis. Microdissected OA synovium was stimulated with IL-1β or lipopolysaccharide (LPS) in the presence or absence of boswellic acid and cytokine production by quantitative polymerase chain reaction (PCR) or multiplex enzyme linked immunoabsorbant assay (ELISA). Results Topical treatment resulted in synovial concentrations of boswellic acid 2–6-fold higher than that measured in plasma. Cartilage loss was significantly reduced in mice treated with oral or topical boswellic acid compared with vehicle control (P < 0.01 for both oral and topical therapies). Likewise, treatment with either oral boswellic acid or boswellic acid ointment reduced of synovitis (P = 0.006 and 0.025, respectively) and osteophyte formation (P = 0.009 and 0.030, respectively). In vitro, boswellic acid was able to inhibit IL-1β and TLR4 mediated induction of several inflammatory mediators from OA synovial explant tissue. Conclusions Significant synovial concentration and therapeutic efficacy can be achieved with topical boswellic acid treatment. These findings suggest that boswellic acid has potential as a disease-modifying agent in OA.