Full-length and N-terminally truncated chicken intestinal diazepam-binding inhibitor. Purification, structural characterization and influence on insulin release

A neurochemical basis for an epigenetic vision of psychiatric disorders (1994-2009)

In 1996, Dr. Costa was invited by Prof. Boris Astrachan, Chairman of the Department of Psychiatry at the University of Illinois at Chicago, to direct the research of the "Psychiatric Institute, Department of Psychiatry, School of Medicine, at the University of Illinois at Chicago." He was asked to develop a seminal research program on psychiatric disorders. Viewed in retrospect, Dr. Costa met and surpassed the challenge, as was usual for him. To elucidate the molecular mechanisms whereby nurture (epigenetic factors) and nature (genetic factors) interact to cause major psychiatric disorders was at the center of Dr. Costa's mission for the last 15 years of his research at the Psychiatric Institute. The challenge for Dr. Costa and his colleagues (Auta, Caruncho, Davis, Grayson, Guidotti, Impagnatiello, Kiedrowski, Larson, Manev, Pappas, Pesold, Pinna, Sharma, Smalheiser, Sugaya, Tueting, Veldic [1-111]) had always been to find new ways to prevent and treat psychiatric disorders with pharmacological agents that failed to have major unwanted side effects. In this list, we have quoted the first authors of the papers pertaining to the field of research highlighted in the title. As you know, Dr. Costa was an eclectic scientist and in his 15 years of studies at UIC, he touched many other aspects of neuroscience research that are not discussed in this overview.

A legacy of discovery: from monoamines to GABA

Seldom does a single individual have such a profound effect on the development of a scientific discipline as Erminio Costa had on neuropharmacology. During nearly sixty years of research, Costa and his collaborators helped established many of the basic principles of the pharmacodynamic actions of psychotherapeutics. His contributions range from defining basic neurochemical, physiological and behavioral properties of neurotransmitters and their receptors, to the development of novel theories for drug discovery. Outlined in this report is a portion of his work relating to the involvement of monoamines and GABA in mediating the symptoms of neuropsychiatric disorders and as targets for drug therapies. These studies were selected for review because of their influence on my own work and as an illustration of his logical and insightful approach to research and his clever use of techniques and technologies. Given the significance of his work, the legions of scientist who collaborated with him, and those inspired by his reports, his research will continue to have an impact as long as there is a search for new therapeutics to alleviate the pain and suffering associated with neurological and psychiatric disorders. This article is part of a Special Issue entitled 'Trends in neuropharmacology: in memory of Erminio Costa'.

Acyl-CoA binding protein gene ablation induces pre-implantation embryonic lethality in mice

Unique among the intracellular lipid binding proteins, acyl-CoA binding protein (ACBP) exclusively binds long-chain fatty acyl-CoAs (LCFA-CoAs). To test if ACBP is an essential protein in mammals, the ACBP gene was ablated by homologous recombination in mice. While ACBP heterozygotes appeared phenotypically normal, intercrossing of the heterozygotes did not produce any live homozygous deficient (null) ACBP((-/-)) pups. Heterozygous and wild type embryos were detected at all post-implantation stages, but no homozygous ACBP-null embryos were obtained-suggesting that an embryonic lethality occurred at a pre-implantation stage of development, or that embryos never formed. While ACBP-null embryos were not detected at any blastocyst stage, ACBP-null embryos were detected at the morula (8-cell), cleavage (2-cell), and zygote (1-cell) pre-implantation stages. Two other LCFA-CoA binding proteins, sterol carrier protein-2 (SCP-2) and sterol carrier protein-x (SCP-x) were significantly upregulated at these stages. These findings demonstrate for the first time that ACBP is an essential protein required for embryonic development and its loss of function may be initially compensated by concomitant upregulation of two other LCFA-CoA binding proteins, but only at the earliest pre-implantation stages. The fact that ACBP is the first known intracellular lipid binding protein whose deletion results in embryonic lethality suggests its vital importance in mammals.

How does cholecystokinin stimulate exocrine pancreatic secretion? From birds, rodents, to humans

The field of cholecystokinin (CCK) stimulation of exocrine pancreatic secretion has experienced major changes in the recent past. This review attempts to summarize the present status of the field. CCK production in the intestinal I cells, the molecular forms of CCK produced and subsequently circulated in the blood, the presence or absence of CCK receptors on the isolated pancreatic acinar cells and the associated signaling for acinar cell secretion, and the actual circuits and sites of action for CCK regulation of exocrine pancreatic secretion in vivo are reviewed in different animal species with an emphasis on birds, rodents, and humans. Clear differences in the relative importance of neural and direct modes of CCK action on pancreatic acinar cells were identified. Rodents seem to be endowed with both modes of action, whereas in humans the neural mode may predominate. In birds, such as duck, the direct mode needs further assistance from pituitary adenylate cyclase-activating peptide/VIP receptors. However, much further work needs to be directed to the neural mode to map out all sites of CCK action and details of the full circuits, and we foresee a major revival for this field of research in the near future.

The mitochondrial benzodiazepine receptor and avoidance learning in the day-old chick

The specific mitochondrial benzodiazepine receptor (MBR) agonist, FGIN 1-27, and antagonist, PK 11195, were used to investigate whether this receptor was involved in passive avoidance memory formation in the day-old chick. PK 11195 at a concentration of 1-10 microM was found to be amnesic when injected directly into the lobus parolfactorius (LPO) 5 h after training (P<.01). Unilateral injections of PK 11195 further showed that memory was only disrupted with injections into the right hemisphere (P<.01). Since the MBR is considered to be involved in the production of a neurosteroid that modulates GABAergic transmission, we injected bicuculline and muscimol, specific inhibitor and agonist, respectively, of the GABA(A) receptor, to see if either disrupted memory formation. The results of bilateral injections into the LPO at 5 h post-training indicated that enhanced GABAergic transmission was involved in memory formation since the inhibitor, bicuculline, caused amnesia (P<.01) and unilateral injections also showed that this effect was confined to the right hemisphere (P<.05). Since memory for passive avoidance learning is thought to involve both cytosolic and mitochondrial protein synthesis at this 5-h time point [Freeman FM, Young IG. Chloramphenicol-induced amnesia for passive avoidance training in the day-old chick. Neurobiol Learn Mem 1999;71:80-93.], we studied the effect of unilateral injections of chloramphenicol (CAP) and anisomycin (ANI) during this second wave of protein synthesis and found that CAP only disrupted memory when injected into the right LPO 5 h post-training (P<.05). This lateralization to the right hemisphere was also seen when ANI was injected 4 h post-training (P<.05) but at 5 h, only bilateral injections of ANI could disrupt memory (P<.05). The results suggest a role for mitochondria and the GABAergic system in the retention of passive avoidance learning in the day-old chick.

Benzodiazepine receptors and avian macrophage activity: diazepam decreases spreading and phagocytosis

The complex interrelations between the nervous system and the immune system have led to the creation of a new research area denoted neuroimmunology. The effects of stress on the immune response have long been observed in chickens. Since benzodiazepine receptors are involved in the stress reaction, we proposed to assess the importance of these receptors in the activity of chick peritoneal macrophages. We used 420 viable embryonated eggs of the commercial Hubbard broiler line treated through the chorioallantoid membrane on the 11th day of incubation: falsely manipulated (Sham group), with 40% propyleneglycol (PG) in simple Ringer solution (Vehicle group), and treated with diazepam (DZ), 8 mg/kg (DZ group). After hatching, the chicks were housed in metal rearing cages of the "battery" type for 5 weeks. At 36 days of age, 24 chicks from each treated group were divided at random into two groups of 12 animals each which were treated with DZ (2 mg/kg) or with 40% PPG in an equal volume once a day by the oral route for 4 days. Peritoneal macrophages were collected and submitted to the spreading an phagocytosis tests. Data were analyzed statistically using the SAS software (p < 0.05). Administration of DZ in ovo did not cause a significant decrease in egg hatchability, birth weight or performance parameters during the 5 weeks of assessment. However, the rate of macrophage spreading and phagocytosis was reduced. When administered at 40 days of age, DZ did not change the spreading rate but reduced the phagocytosis rate. There was no interaction between treatments. These results indicate that benzodiazepine receptors seem to be important for macrophage activity also in birds, as previously observed in rodents and primates. Since benzodiazepine receptors are involved in the response to stress, it is possible that the effects of stress on avian immunity may be mediated in part by these receptors.