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Background: Asthma remains a common chronic illness in pregnancy with the potential for catastrophic complications. Most women with asthma exacerbation can be treated with medical management and continuation of pregnancy. However, refractory cases may necessitate delivery for fetal or maternal indications.Case: We report a case of status asthmaticus at 33 weeks of gestation with significant maternal respiratory acidosis and difficulty with ventilation necessitating delivery by cesarean delivery in the medical intensive care unit. The patient was unresponsive to standard medical therapies. Delivery resulted in immediate improvement in maternal ventilation parameters.Conclusion: In cases of life-threatening status asthmaticus refractory to standard medical and ventilatory therapies in the third trimester, cesarean delivery should be considered as a final effort to increase tidal volumes and improve maternal gas exchange. [ABSTRACT FROM AUTHOR]

We tested whether surface α7 nicotinic acetylcholine receptor expression is dependent on an endogenous chaperone named Resistance to Inhibitors of Cholinesterase 3 (RIC3) by comparing RIC3 protein in rat GH4C1 and human SH-EP1 cells, which express strikingly different surface receptor levels following α7 transfection. Cloned rat RIC3 exists in at least two isoforms because of an ambiguous splice site between exons 4 and 5. Both rat isoforms permit surface α7 expression in SH-EP1 and human embryonic kidney (HEK) cells measured by α-bungarotoxin binding. Contrary to expectations, endogenous RIC3 protein expression determined by immunoblots did not differ between untransfected GH4C1 or SH-EP1 cells. siRNA against rat RIC3 exon 4 and shRNA against exons 2, 5 and 6 knocked down transfected rat RIC3 expression in SH-EP1 cells and simultaneously blocked toxin binding. However, no RNAi construct blocked binding when co-transfected with α7 into GH4C1 cells. shRNA against rat exons 2 and 5 knocked down rat RIC3 protein transfected into GH4C1 cells with a time course suggesting a protein half-life of a few days. These results suggest GH4C1 cells may possess unknown chaperone(s) allowing high surface α7 expression in the absence of known RIC3 splice variants., (© 2012 International Society for Neurochemistry.)

Exposure of mice to hyperoxia induces alveolar epithelial cell (AEC) injury, acute lung injury and death. Overexpression of granulocyte-macrophage colony-stimulating factor (GM-CSF) in the lung protects against these effects, although the mechanisms are not yet clear. Hyperoxia induces cellular injury via effects on mitochondrial integrity, associated with induction of proapoptotic members of the Bcl-2 family. We hypothesized that GM-CSF protects AEC through effects on mitochondrial integrity. MLE-12 cells (a murine type II cell line) and primary murine type II AEC were subjected to oxidative stress by exposure to 80% oxygen and by exposure to H(2)O(2). Exposure to H(2)O(2) induced cytochrome c release and decreased mitochondrial reductase activity in MLE-12 cells. Incubation with GM-CSF significantly attenuated these effects. Protection induced by GM-CSF was associated with Akt activation. GM-CSF treatment also resulted in increased expression of the antiapoptotic Bcl-2 family member, Mcl-1. Primary murine AEC were significantly more tolerant of oxidative stress than MLE-12 cells. In contrast to MLE-12 cells, primary AEC expressed significant GM-CSF at baseline and demonstrated constitutive activation of Akt and increased baseline expression of Mcl-1. Treatment with exogenous GM-CSF further increased Akt activation and Mcl-1 expression in primary AEC. Conversely, suppression of AEC GM-CSF expression by use of GM-CSF-specific small interfering RNA resulted in decreased tolerance of oxidative stress, Furthermore, silencing of Mcl-1 prevented GM-CSF-induced protection. We conclude that GM-CSF protects alveolar epithelial cells against oxidative stress-induced mitochondrial injury via the Akt pathway and its downstream components, including Mcl-1. Epithelial cell-derived GM-CSF may contribute to intrinsic defense mechanisms limiting lung injury.

Lung cancer is the leading cause of cancer mortality worldwide. A lack of clinical symptoms in early-stage disease frequently leads to diagnosis at a late stage, and a 15% 5-year survival rate in all patients so diagnosed. This has led to significant interest in effective screening methods to detect early-stage cancers, particularly for high-risk groups, such as current or former smokers. Early clinical trials focused on chest radiograph with or without sputum cytology and failed to show an improvement in mortality with screening. A meta-analysis also failed to show a difference in all-cause mortality. Subsequent protocols compared low-dose computed tomography (LDCT) scan with chest radiograph and documented increased detection of early-stage disease; however, they were not designed to prove a reduction in mortality. The most recent trials have focused on LDCT scans, including the National Lung Screening Trial. Data released from the National Lung Screening Trial demonstrated a statistically significant reduction in lung cancer deaths in patients screened with LDCT scans. When data from the study, including cost-effectiveness, are completely analyzed, they may lead to revision of current lung cancer screening recommendations to include LDCT scans in specific populations at high risk of developing lung cancer.

Reduced expression of sarcoplasmic reticulum calcium ATPase (SERCA)2 and other genes in the adult cardiac gene program has raised consideration of an impaired responsiveness to thyroid hormone (T3) that develops in the advanced failing heart. Here, we show that human and murine cardiomyopathy hearts have increased expression of friend of GATA (FOG)-2, a cardiac nuclear hormone receptor corepressor protein. Cardiac-specific overexpression of FOG-2 in transgenic mice led to depressed cardiac function, activation of the fetal gene program, congestive heart failure, and early death. SERCA2 transcript and protein levels were reduced in FOG-2 transgenic hearts, and FOG-2 overexpression impaired T3-mediated SERCA2 expression in cultured cardiomyocytes. FOG-2 physically interacts with thyroid hormone receptor-alpha1 and abrogated even high levels of T3-mediated SERCA2 promoter activity. These results demonstrate that SERCA2 is an important target of FOG-2 and that increased FOG-2 expression may contribute to a decline in cardiac function in end-stage heart failure by impaired T3 signaling.

We previously isolated different isoforms of a new Ets transcription factor family member, NERF/ELF-2, NERF-2, NERF-1a, and NERF-1b. In contrast to the inhibitory isoforms NERF-1a and NERF-1b, NERF-2 acts as a transactivator of the B cell-specific blk promoter. We now report that NERF-2 and NERF-1 physically interact with AML1 (RUNX1), a frequent target for chromosomal translocations in leukemia. NERF-2 bound to AML1 via an interaction site located in a basic region upstream of the Ets domain. This is in contrast to most other Ets factors such as Ets-1 that bind to AML1 via the Ets domain, suggesting that different Ets factors utilize different domains for interaction with AML1. The interaction between AML1 and NERF-2 led to cooperative transactivation of the blk promoter, whereas the interaction between AML1 and NERF-1a led to repression of AML1-mediated transactivation. To delineate the differences in function of the different NERF isoforms, we determined that the transactivation domain of NERF-2 is encoded by the N-terminal 100 amino acids, which have been replaced in NERF-1a by a 19-amino acid transcriptionally inactive sequence. Furthermore, acidic domains A and B, which are conserved in NERF-2 and the related proteins ELF-1 and MEF/ELF-4, but not in NERF-1a, are largely responsible for NERF-2-mediated transactivation. Because translocation of the Ets factor Tel to AML1 is a frequent event in childhood pre-B leukemia, understanding the interaction of Ets factors with AML1 in the context of a B cell-specific promoter might help to determine the function of Ets factors and AML1 in leukemia.

We report here the isolation of Tel-2, a novel member of the Ets transcription factor family, with high homology to Tel/ETV-6. Tel-2 is the second mammalian member of the Tel Ets family subclass whose prototype Tel is involved in various chromosomal translocations in human cancers. Six differentially expressed alternative splice products of Tel-2 were characterized encoding different Tel-2 isoforms which either contain or lack the amino-terminal Pointed domain and also vary at the carboxyl terminus. In contrast to Tel, which is highly expressed in several different cell types and tissues, Tel-2 is only weakly expressed in a variety of tissues and cell types, including placenta, prostate, spleen, liver, and lung. Tel-2 binds to functionally relevant Ets-binding sites of several genes and only the Tel-2 isoform containing the Pointed domain and the DNA-binding domain acts as a strong repressor of transcription. The retinoic acid receptor alpha and bone morphogenetic protein-6B (BMP-6) genes are specifically repressed by Tel-2 indicating a function for Tel-2 as an inhibitor of differentiation. Due to the important involvement of Tel in human cancer and the location of Tel-2 within the MHC cluster region, Tel-2 might be involved in chromosomal translocations in human cancer as well.

We recently isolated a novel member of the Ets transcription factor/oncogene family, ESE-1/ESX/ELF3, with features distinct from any other Ets-related factor. ELF3 is the prototype of a new subclass of Ets factors, contains two DNA-binding domains, and, in contrast to any known Ets factor, is expressed exclusively in epithelial cells. ELF3 expression is induced during differentiation of the epidermis, indicating a role in the regulation of terminal differentiation genes in the epidermis. Due to the important role that other Ets factors play in cellular differentiation, ELF3 is expected to be a critical regulator of epithelial gene expression. We report here the cloning and the structural organization of the human ELF3 gene. The human ELF3 gene contains nine exons, which span approximately 5.8 kb of genomic DNA. Intron/exon borders and number of exons are almost identical to those in the mouse ELF3 gene. Comparison of the immediate promoter regions of the human and mouse ELF3 genes demonstrates the presence of TATA and CCAAT boxes as well as potential binding sites for Ets factors and NF-kappaB. Transfection experiments demonstrate that a 1.5-kb fragment of the 5' upstream region acts as a strong promoter in two epithelial cell lines.

Human CD4, the receptor for the gp120 envelope glycoprotein of HIV-1, is the route for viral entry into CD4+ cells; other cellular factors may cooperate with CD4 to facilitate HIV-1 entry into human cells. Human CD4 expressed on murine cells does not readily mediate HIV-1 entry, which may reflect a functional incompatibility of human CD4 with murine cellular components. We postulated that a HIV-1 gp120-binding mutant murine CD4 (L3T4) possessing a minimal number of human amino acid residues could facilitate HIV-1 entry into rodent cells, unlike human CD4. This hypothesis led us to develop a series of murine L3T4 mutants that bear human CD4 gp120-binding region amino acid residues while retaining most L3T4 epitopes. HeLa cell transfectants expressing gp120-binding mutant L3T4 proteins could be infected with HIV-1. Three mouse cell lines expressing these L3T4 mutant proteins could also be infected with HIV-1 as determined by PCR techniques that detect viral DNA and spliced RNAs. Lectin-stimulated polymorphonuclear leukocytes from transgenic mice (SBL mouse) expressing a gp120-binding L3T4 mutant protein were infected with HIV-1 at the same frequency as lectin-stimulated human peripheral blood lymphocytes as determined by in situ PCR analyses. Supernatant p24gag and reverse transcriptase levels in HIV-infected mouse cell cultures, however, were routinely at background levels, unlike HIV-infected human cell cultures. Thus, gp120-binding mutant L3T4 proteins mediate viral entry in all mouse cells that were tested, but high-level viral replication is absent in these cells.

A murine recombinant Neo(r) retrovirus encoding the SV40 small t antigen was used to infect Balb/c 3T3 CIA31 cells. From analyses of G418-resistant clones containing at least as much intact t as Cos-1 cells, we found that t, alone, had no detectable A31 transforming activity. In contrast, we noted that SV40 large T promoted A31 agar colony formation when present over a 5- to 7.5-fold concentration range. However, at the low end of the spectrum, its transforming effect was manifest inefficiently except in the presence of t. Thus a major role for t in the SV40 transforming mechanism is to enhance directly or indirectly the transforming function of T.