An analysis of fear inhibition and fear extinction in a sample of veterans with obstructive sleep apnea (OSA): Implications for co-morbidity with post-traumatic stress disorder (PTSD).

Obstructive sleep apnea (OSA) is a respiratory condition characterized by interrupted sleep due to repeated, temporary collapse of the soft tissue of the upper airway that can lead to a cascade of physiological and psychological adverse health outcomes. The most common therapeutic interventions for OSA patients include the application of continuous positive airway pressure (CPAP) which acts to keep the airway open and, as such, provides less interrupted and more restorative sleep. Improved sleep has been linked to more efficacious treatments for psychiatric conditions most notably those that include cognitive-behavioral elements, new learning, and memory consolidation. In the current study, we investigated the acquisition, inhibition, and extinction of conditioned fear in OSA patients, before and after CPAP therapy, using an established fear-potentiated startle paradigm. Patients with OSA displayed an intact ability to acquire, inhibit, and extinguish fear prior to CPAP treatment and this ability was significantly enhanced following CPAP usage. In addition, those patients with more severe OSA, as measured by apnea-hypopnea index (AHI), were more likely to show improved fear inhibition and extinction. Lastly, we observed impairments in discrimination between reinforced and nonreinforced conditioned stimuli, in the inhibition of fear, and in fear extinction in a subset of patients with OSA and co-morbid posttraumatic stress disorder (PTSD). These data suggest that evolving treatment algorithms for PTSD should address disrupted sleep problems prior to initiation of inhibition/extinction-based exposure therapies.

Macrophage colony-stimulating factor expression in retrovirally transduced cells is dependent upon both the adherence status of the target cells and its 5' flanking untranslated region.

Numerous cell types retrovirally transduced with macrophage colony-stimulating factor (M-CSF) using LXSN-based vectors showed a variable expression of the transgene. Expression of M-CSF correlated with the cells' adherent status. Transduced adherent cells produced the M-CSF, whereas the non-adherent cells synthesized little M-CSF. Studies showed that the 5'-UTR of the M-CSF gene regulated transgenic M-CSF gene expression. Ligation of this 5'-UTR to the enhanced green fluorescent protein gene (EGFP) caused the expression of EGFP to show the same dichotomy as previously seen with the M-CSF. Transgenic M-CSF was expressed within non-adherent cells when the 5'-UTR was removed from the LXSN vector. Quantitative real-time polymerase chain reaction analysis confirmed that lesser production of M-CSF mRNA occurred within the non-adherent cells than in the adherent cells. This difference was eliminated when the 5'-UTR was removed from the retroviral vector. Our work suggests that this 5'-UTR of the M-CSF gene could be an important way to get transgenic expression within adherent cells, but not in non-adherent cells.

Antiangiogenic drugs synergize with a membrane macrophage colony-stimulating factor-based tumor vaccine to therapeutically treat rats with an established malignant intracranial glioma.

Combining a T9/9L glioma vaccine, expressing the membrane form of M-CSF, with a systemic antiangiogenic drug-based therapy theoretically targeted toward growth factor receptors within the tumor's vasculature successfully treated >90% of the rats bearing 7-day-old intracranial T9/9L gliomas. The antiangiogenic drugs included (Z)-3-[4-(dimethylamino)benzylidenyl]indolin-2-one (a platelet-derived growth factor receptor beta and a fibroblast growth factor receptor 1 kinase inhibitor) and oxindole (a vascular endothelial growth factor receptor 2 kinase inhibitor). A total of 20-40% of the animals treated with the antiangiogenic drugs alone survived, while all nontreated controls and tumor vaccine-treated rats died within 40 days. In vitro, these drugs inhibited endothelial cells from proliferating in response to the angiogenic factors produced by T9/9L glioma cells and prevented endothelial cell tubulogenesis. FITC-labeled tomato lectin staining demonstrated fewer and constricted blood vessels within the intracranial tumor after drug therapy. Magnetic resonance imaging demonstrated that the intracranial T9 glioma grew much slower in the presence of these antiangiogenic drugs. These drugs did not affect in vitro glioma cell growth nor T cell mitogenesis. Histological analysis revealed that the tumor destruction occurred at the margins of the tumor, where there was a heavy lymphocytic infiltrate. Real-time PCR showed more IL-2-specific mRNA was present within the gliomas in the vaccinated rats treated with the drugs. Animals that rejected the established T9/9L glioma by the combination therapy proved immune against an intracranial rechallenge by T9/9L glioma, but showed no resistance to an unrelated MADB106 breast cancer.