Cystic fibrosis (CF) is due to mutations in the CFTR gene and is characterized by hypersecretion of the proinflammatory chemokine IL-8 into the airway lumen. Consequently, this induces the highly inflammatory cellular phenotype typical of CF. Our initial studies revealed that IL-8 mRNA is relatively stable in CF cells compared with those that had been repaired with [WT]CFTR (wild-type CFTR). Relevantly, the 3′-UTR of IL-8 mRNA contains AU-rich sequences (AREs) that have been shown to mediate posttranscriptional regulation of proinflammatory genes upon binding to ARE-binding proteins including Tristetraprolin (TTP). We therefore hypothesized that very low endogenous levels of TTP in CF cells might be responsible for the relative stability of IL-8 mRNA. As predicted, increased expression of TTP in CF cells resulted in reduced stability of IL-8 mRNA. An in vitro analysis of IL-8 mRNA stability in CF cells also revealed a TTP-induced enhancement of deadenylation causing reduction of IL-8 mRNA stability. We conclude that enhanced stability of IL-8 mRNA in TTP-deficient CF lung epithelial cells serve to drive the proinflammatory cellular phenotype in the CF lung.

Without timely pharmacological treatment, nerve agent exposure can cause a large number of casualties, as occurred in the recent sarin attack in Syria. Nerve agent-induced seizures are initiated due to inhibition of acetylcholinesterase, but they become quickly refractory to muscarinic antagonists, and their suppression by benzodiazepines can be only temporary. Therefore, novel treatments are necessary to stop seizures and prevent brain damage and the resulting long-term behavioral deficits. We have previously shown that LY293558, a GluK1/AMPA receptor antagonist, is a very effective anticonvulsant and neuroprotectant against nerve agent exposure. In the present study, we examined whether the protection against nerve agent-induced seizures and neuropathology conferred by LY293558 translates into protection against pathophysiological alterations in the basolateral amygdala (BLA) and the development of anxiety, which is the most prevalent behavioral deficit resulting from exposure. LY293558 (15 mg/kg) was administered to rats along with atropine and the oxime HI-6, at 20 min after exposure to soman (1.2 x LD50). At 24 h, 7 days, and 30 days after exposure, soman-exposed rats that did not receive LY293558 had reduced but prolonged evoked field potentials in the BLA, as well as increased paired-pulse ratio, suggesting neuronal damage and impaired synaptic inhibition. In contrast, soman-exposed rats that received LY293558 did not differ from controls in these parameters. Similarly, long-term potentiation of synaptic transmission was impaired at 7 days after exposure in the soman-exposed rats that did not receive anticonvulsant treatment, while this impairment was not present in the LY293558-treated rats. Anxiety-like behavior assessed by the open field and acoustic startle response tests was increased in the soman-exposed rats at 30 and 90 days after exposure, while soman-exposed rats treated with LY293558 did not differ from controls. Along with our previous findings, the present data demonstrate the remarkable efficacy of LY293558 in counteracting nerve agent-induced seizures, neuropathology, pathophysiological alterations in the BLA, and anxiety-related behavioral deficits.

After surgery requiring general anesthesia, patients often experience emotional disturbances, but it is unclear if this is due to anesthetic exposure. In the present study, we examined whether isoflurane anesthesia produces long-term pathophysiological alterations in the basolateral amygdala (BLA), a brain region that plays a central role in emotional behavior. Ten-week-old, male rats were administered either a single, 1 h long isoflurane (1.5%) anesthesia or three, 1 h long isoflurane exposures, separated by 48 h. Long-term potentiation (LTP) and spontaneous GABAergic activity in the BLA were studied 1 day, 1 week, and 1 month later. Single isoflurane anesthesia had no significant effect on the magnitude of LTP. In contrast, after repeated isoflurane exposures, LTP was dramatically impaired at both 1 day and 1 week after the last exposure but was restored by 1 month after the exposures. Spontaneous GABAA receptor-mediated IPSCs were increased at 1 day and 1 week after repeated exposures but had returned to control levels by 1 month after exposure. Thus, repeated exposures to isoflurane cause a long-lasting—but not permanent—impairment of synaptic plasticity in the BLA, which could be due to increased basal GABAergic activity. These pathophysiological alterations may produce emotional disturbances and impaired fear-related learning.