Genetic studies have implicated the evolutionary novel, anthropoid primate-specific gene locus G72/G30 in psychiatric diseases. This gene encodes the protein LG72 that has been discussed to function as a putative activator of the peroxisomal enzyme D-aminoacid-oxidase (DAO) and as a mitochondrial protein. We recently generated 'humanized' bacterial artificial chromosome transgenic mice (G72Tg) expressing G72 transcripts in cells throughout the brain. These mice exhibit several behavioral phenotypes related to psychiatric diseases. Here we show that G72Tg mice have a reduced activity of mitochondrial complex I, with a concomitantly increased production of reactive oxygen species. Affected neurons display deficits in short-term plasticity and an impaired capability to sustain synaptic activity. These deficits lead to an impairment in spatial memory, which can be rescued by pharmacological treatment with the glutathione precursor N-acetyl cysteine. Our results implicate LG72-induced mitochondrial and synaptic defects as a possible pathomechanism of psychiatric disorders.

Dendritic cells (DCs) are pivotal for the development of experimental autoimmune encephalomyelitis (EAE). However, the mechanisms by which they control disease remain to be determined. This study demonstrates that expression of CC chemokine receptor 4 (CCR4) by DCs is required for EAE induction. CCR4 −/− mice presented enhanced resistance to EAE associated with a reduction in IL-23 and GM-CSF expression in the CNS. Restoring CCR4 on myeloid cells in bone marrow chimeras or intracerebral microinjection of CCR4-competent DCs, but not macrophages, restored EAE in CCR4 −/− mice, indicating that CCR4 + DCs are cellular mediators of EAE development. Mechanistically, CCR4 −/− DCs were less efficient in GM-CSF and IL-23 production and also T H -17 maintenance. Intraspinal IL-23 reconstitution restored EAE in CCR4 −/− mice, whereas intracerebral inoculation using IL-23 −/− DCs or GM-CSF −/− DCs failed to induce disease. Thus, CCR4-dependent GM-CSF production in DCs required for IL-23 release in these cells is a major component in the development of EAE. Our study identified a unique role for CCR4 in regulating DC function in EAE, harboring therapeutic potential for the treatment of CNS autoimmunity by targeting CCR4 on this specific cell type.chemokines | neuroinflammation M ultiple sclerosis (MS) is a chronic demyelinating disease of the human CNS (1). Experimental autoimmune encephalomyelitis (EAE), the animal model of MS, is mediated by myelin-specific CD4 + T cells activated by professional antigenpresenting cells (APCs) in peripheral lymphoid tissues (2, 3). In recent studies, both peripherally derived macrophages and DCs have been shown to present myelin antigens to invading autoreactive T cells in the CNS. This presentation initiates the recruitment of a second wave of leukocytes that damage the target organ via demyelination and axonal degeneration (4-8). Understanding the mechanisms responsible for the recruitment of APCs to the CNS and their local function is essential for the development of therapeutic strategies targeting the effector phase and thereby controlling disease progression.Chemokines and their G protein-coupled receptors are key regulators of leukocyte trafficking (9, 10). The CC chemokine receptor 4 (CCR4) is the cognate receptor for the CC chemokines CCL17 and CCL22, and is expressed on functionally distinct subsets of T cells, including activated T cells, T H 2 cells, and Treg cells. CCR4 has also been found on platelets, NK cells, macrophages, and DCs (11-15). DCs are important cellular sources for CCL17 and, in concert with macrophages, produce CCL22 during both homeostasis and inflammation (16,17). Different studies have suggested a critical role for CCR4 in the pathogenesis of EAE and MS. For example, elevated levels of the CCR4 ligands CCL17 or CCL22 have been found in the cerebrospinal fluid of MS patients (18-20). CCL22 protein has been identified in CNS-infiltrating leukocytes and microglia of EAE-induced mice, and CCR4 is expressed by invading leukocyte subsets (21,22). However, it rema...

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Human and animal studies provide evidence for vulnerable periods of brain development for deleterious effects of cannabinoids. We have recently shown that pubertal chronic cannabinoid treatment leads to long-lasting behavioral deficits, whereas a comparable treatment in adult rats did not affect the animals' behavior. In the present study we examined the effects of an identical chronic cannabinoid treatment in juvenile rats, just before the onset of puberty. Treatment with the synthetic cannabinoid agonist WIN 55,212-2 (WIN) (1.2 mg/kg) or vehicle was extended over 25 days throughout the prepubertal period (postnatal days 15-40) in juvenile rats. The rats received a total of 20 injections intraperitoneally. Adult rats were tested for object recognition memory, performance in a progressive ratio (PR) operant behavior task, locomotor activity and prepulse inhibition (PPI) of the acoustic startle response. Juvenile chronic WIN administration had no effect on object recognition memory, PR performance and locomotor activity in adulthood. However, a PPI deficit was observed in WIN-treated rats when tested as adults that could be reversed by the acute administration of the dopamine receptor antagonist haloperidol (0.1 mg/kg). Additionally, juvenile cannabinoid treatment reduced the number of rearings, as well as the time spent in the center of the open field in adult rats, suggesting increased anxiety. Juvenile chronic cannabinoid treatment induced behavioral disturbances in adult rats that are less severe than those observed after pubertal cannabinoid administration. However, based on the observations of sensorimotor gating deficits and increased anxiety, we conclude that the prepubertal developmental phase, in addition to puberty, also represents a vulnerable time period for persistent adverse effects of cannabinoids.