The novel tellurium immunomodulator AS101 inhibits interleukin-10 production and p38 MAPK expression in atopic dermatitis.

The immunomodulator, AS101, inhibits production of IL-10, IL-4 and expression of p38 MAPK, while increasing production of IFNgamma and IL-2. Together with its excellent clinical safety profile in humans, suggests a potential therapeutic use for AD.

Multifunctional tellurium molecule protects and restores dopaminergic neurons in Parkinson's disease models.

In Parkinson's disease (PD) dopaminergic neurons in the substantia nigra (SN) become dysfunctional and many ultimately die. We report that the tellurium immunomodulating compound ammonium trichloro(dioxoethylene-O,O'-)tellurate (AS101) protects dopaminergic neurons and improves motor function in animal models of PD. It is effective when administered systemically or by direct infusion into the brain. Multifunctional activities of AS101 were identified in this study. These were mainly due to the peculiar Tellur(IV)-thiol chemistry of the compound, which enabled the compound to interact with cysteine residues on both inflammatory and apoptotic caspases, resulting in their inactivation. Conversely, its interaction with a key cysteine residue on p21(ras), led to its activation, an obligatory activity for AS101-induced neuronal differentiation. Furthermore, AS101 inhibited IL-10, resulting in up-regulation of GDNF in the SN. This was associated with activation of the neuroprotective kinases Akt and mitogen-activated protein kinases, and up-regulation of the antiapoptotic protein Bcl-2. Inhibition of caspase-1 and caspase-3 activities were associated with decreased neuronal death and inhibition of IL-1beta. We suggest that, because multiple mechanisms are involved in the dysfunction and death of neurons in PD, use of a multifunctional compound, exerting antiapoptotic, anti-inflammatory, and neurotrophic-inducing capabilities may be potentially efficacious for the treatment of PD.

TH1/TH2 cytokines in the central nervous system.

For the past 20 years it has become increasingly evident that cytokines play an important role in both the normal development of the brain, acting as neurotrophic factors, and in brain injuries. Although cytokines and their receptors are synthesized and expressed in the brain (normally at low levels), increased cytokine production levels are now associated with various neurological disorders. T lymphocytes are the cells responsible for coordinating the immune response and a major source of cytokines. Different cytokines induce different subsets of T cells or have different effects on proliferation within a particular subset. Recent studies suggest that the immune response is in fact regulated by the balance between Th1 and Th2 cytokines. These two pathways are often mutually exclusive, the one resulting in protection and the other in progression of disease. Various studies describe the function and production of proinflammatory cytokines in the central nervous system (CNS) and their role in health and disease. Inflammation is upregulated following activation of Th1 cells, whereas Th2 cells may play a significant role in downregulating Th1 proinflammatory responses in those instances in which there is overproduction of Th2 cytokines. Although both Th1 and Th2 cytokines may influence CNS functioning, most studies have so far dealt with proinflammatory cytokines, probably because they directly affect CNS cells and are thought to be implicated in CNS pathology. It is of interest that endogenous glucocorticoids also control Th1-Th2 balance, favoring Th2 cell development. This review presents the evidence that cytokines have important functions in the CNS, both during development and as a part of brain pathology. In particular, the author highlighted recent work that supports a major role for the so-called inflammatory cytokines, Th1, and the anti-inflammatory Th2 cytokines.