IL-1beta inhibits TGFbeta in the temporomandibular joint

Similarly to humans, healthy, wild-type mice develop osteoarthritis, including of the temporomandibular joint (TMJ), as a result of aging. Pro-inflammatory cytokines, such as IL-1beta, IL-6, and TNFalpha, are known to contribute to the development of osteoarthritis, whereas TGFbeta has been associated with articular regeneration. We hypothesized that a balance between IL-1beta and TGFbeta underlies the development of TMJ osteoarthritis, whereby IL-1beta signaling down-regulates TGFbeta expression as part of disease pathology. Our studies in wild-type mice, as well as the Col1-IL1beta(XAT) mouse model of osteoarthritis, demonstrated an inverse correlation between IL-1beta and TGFbeta expression in the TMJ. IL-1beta etiologically correlated with joint pathology, whereas TGFbeta expression associated with IL-1beta down-regulation and improvement of articular pathology. Better understanding of the underlying inflammatory processes during disease will potentially enable us to harness inflammation for orofacial tissue regeneration.

What can preservation of autobiographic memory after muscarinic blockade tell us about the scopolamine model of dementia?

Autobiographic memory is reported to be impaired in patients with Alzheimer's disease (AD). To determine if cholinergic blockade fully reproduces the amnestic disorder found in dementia, we evaluated aspects of autobiographic and episodic memory in six healthy elderly controls after both scopolamine and placebo administration compared with untreated age- and education-matched patients with AD. The performance of patients with AD was significantly worse than that of controls after both treatment conditions. Scopolamine impaired episodic but not autobiographic memory. Thus, even though the cholinergic system is severely affected in patients with AD, muscarinic blockade alone does not seem to be a good model of this disorder.