T17 cells and corticosteroid insensitivity in severe asthma.

Asthma is classically described as having either a type 2 (T2) eosinophilic phenotype or a non-T2 neutrophilic phenotype. T2 asthma usually responds to classical bronchodilation therapy and corticosteroid treatment. Non-T2 neutrophilic asthma is often more severe.

Airway relaxation mechanisms and structural basis of osthole for improving lung function in asthma.

Overuse of β2-adrenoceptor agonist bronchodilators evokes receptor desensitization, decreased efficacy, and an increased risk of death in asthma patients. Bronchodilators that do not target β2-adrenoceptors represent a critical unmet need for asthma management. Here, we characterize the utility of osthole, a coumarin derived from a traditional Chinese medicine, in preclinical models of asthma.

TGF-β1-induced miR-424 promotes pulmonary myofibroblast differentiation by targeting Slit2 protein expression.

Idiopathic pulmonary fibrosis (IPF) is a devastating interstitial lung disease with irreversible loss of lung tissue and function. Myofibroblasts in the lung are key cellular mediators of IPF progression. Transforming growth factor (TGF)-β1, a major profibrogenic cytokine, induces pulmonary myofibroblast differentiation, and emerging evidence has established the importance of microRNAs (miRs) in the development of IPF.

Progressive cardiorespiratory dysfunction in Kv1.1 knockout mice may provide temporal biomarkers of pending sudden unexpected death in epilepsy (SUDEP): The contribution of orexin.

Objective: Immediately preceding sudden unexpected death in epilepsy (SUDEP), patients experienced a final generalized tonic-clonic seizure (GTCS), rapid ventilation, apnea, bradycardia, terminal apnea, and asystole. Whether a progressive pathophysiology develops and increases risk of SUDEP remains unknown. Here, we determined (a) heart rate, respiratory rate, and blood oxygen saturation (SaO ) in low-risk and high-risk knockout (KO) mice; and (b) whether blocking receptors for orexin, a cardiorespiratory neuromodulator, influences cardiorespiratory function mice or longevity in high-risk KO mice.

Transforming growth factor (TGF)-β1-induced miR-133a inhibits myofibroblast differentiation and pulmonary fibrosis.

Transforming growth factor (TGF)-β1, a main profibrogenic cytokine in the progression of idiopathic pulmonary fibrosis (IPF), induces differentiation of pulmonary fibroblasts to myofibroblasts that produce high levels of collagen, leading to concomitantly loss of lung elasticity and function. Recent studies implicate the importance of microRNAs (miRNAs) in IPF but their regulation and individual pathological roles remain largely unknown. We used both RNA sequencing and quantitative RT-PCR strategies to systematically study TGF-β1-induced alternations of miRNAs in human lung fibroblasts (HFL).

Up-regulated miR-133a orchestrates epithelial-mesenchymal transition of airway epithelial cells.

Dysregulation of microRNAs (miRNAs) contributes to epithelial-mesenchymal transition (EMT) of cancer, but the pathological roles of miRNAs in airway EMT of lung diseases remains largely unknown. We performed sequencing and real-time PCR analysis of the miRNA expression profile of human airway epithelial cells undergoing EMT, and revealed miR-133a to be one of the most common up-regulated miRNAs. MiR-133a was previously reported to be persistently up-regulated in airway epithelial cells of smokers.

Respiratory dysfunction progresses with age in Kcna1-null mice, a model of sudden unexpected death in epilepsy.

Objective: Increased breathing rate, apnea, and respiratory failure are associated with sudden unexpected death in epilepsy (SUDEP). We recently demonstrated the progressive nature of epilepsy and mortality in Kcna1 mice, a model of temporal lobe epilepsy and SUDEP. Here we tested the hypothesis that respiratory dysfunction progresses with age in Kcna1 mice, thereby increasing risk of respiratory failure and sudden death (SD).

Upregulation of RGS2: a new mechanism for pirfenidone amelioration of pulmonary fibrosis.

Background: Pirfenidone was recently approved for treatment of idiopathic pulmonary fibrosis. However, the therapeutic dose of pirfenidone is very high, causing side effects that limit its doses and therapeutic effectiveness. Understanding the molecular mechanisms of action of pirfenidone could improve its safety and efficacy.

Regulator of G-protein signaling 2 repression exacerbates airway hyper-responsiveness and remodeling in asthma.

G protein-coupled receptors (GPCRs) are important regulators of cell functions in asthma. We recently reported that regulator of G-protein signaling (RGS) 2, a selective modulator of Gq-coupled GPCRs, is a key regulator of airway hyper-responsiveness (AHR), the pathophysiologic hallmark of asthma. Because RGS2 protein levels in airway cells were significantly lower in patients with asthma compared with patients without asthma, we further investigated the potential pathological importance of RGS2 repression in asthma.

An Efficient Synthesis of 4(5)-Benzyl-L-Histidines Employing Catalytic Transfer Hydrogenolysis at Elevated Temperatures.

An efficient two-step synthesis of 4(5)-benzyl-L-histidine from L-histidine was developed. A Pictet-Spengler reaction between L-histidine and benzaldehyde in the presence of excess strong base yielded 4-phenylspinacine within one hour. Catalytic transfer hydrogenolysis in methanol at reflux using ammonium formate rapidly converted 4-L-phenylspinacine to 4(5)-benzyl-L-histidine within five minutes.

Identification of upregulated phosphoinositide 3-kinase γ as a target to suppress breast cancer cell migration and invasion.

Metastasis is the major cause of breast cancer mortality. We recently reported that aberrant G-protein coupled receptor (GPCR) signaling promotes breast cancer metastasis by enhancing cancer cell migration and invasion. Phosphatidylinositol 3-kinase γ (PI3Kγ) is specifically activated by GPCRs.

α-Adrenoceptor assays.

α-Adrenoceptors mediate responses to activation of both peripheral sympathetic nerves and central noradrenergic neurons. They also serve as autoreceptors that modulate the release of norepinephrine (NE) and other neurotransmitters. There are two major classes of α-adrenoceptors, the α(1)- and α(2).

Regulator of G protein signaling 2 is a key modulator of airway hyperresponsiveness.

Background: Drugs targeting individual G protein-coupled receptors are used as asthma therapies, but this strategy is limited because of G protein-coupled receptor signal redundancy. Regulator of G protein signaling 2 (RGS2), an intracellular selective inhibitor of multiple bronchoconstrictor receptors, may play a central role in the pathophysiology and treatment of asthma.

Objective: We defined functions and mechanisms of RGS2 in regulating airway hyperresponsiveness (AHR), the pathophysiologic hallmark of asthma.

Targeting phosphoinositide 3-kinase γ in airway smooth muscle cells to suppress interleukin-13-induced mouse airway hyperresponsiveness.

We recently reported that phosphoinositide 3-kinase γ (PI3Kγ) directly regulates airway smooth muscle (ASM) contraction by modulating Ca(2+) oscillations. Because ASM contraction plays a critical role in airway hyperresponsiveness (AHR) of asthma, the aim of the present study was to determine whether targeting PI3Kγ in ASM cells could suppress AHR in vitro and in vivo. Intranasal administration into mice of interleukin-13 (IL-13; 10 μg per mouse), a key pathophysiologic cytokine in asthma, induced AHR after 48 h, as assessed by invasive tracheostomy.

Epigenetic regulation of phosphatidylinositol 3,4,5-triphosphate-dependent Rac exchanger 1 gene expression in prostate cancer cells.

Aberrant up-regulation of P-Rex1 expression plays important roles in cancer progression and metastasis. The present study investigated the regulatory mechanism underlying P-Rex1 gene expression in prostate cancer cells. We showed that P-Rex1 expression was much higher in metastatic prostate cancer cells than in prostate epithelial cells and non-metastatic prostate cancer cells.

Epigenetic repression of regulator of G-protein signaling 2 promotes androgen-independent prostate cancer cell growth.

G-protein-coupled receptor (GPCR)-stimulated androgen-independent activation of androgen receptor (AR) contributes to acquisition of a hormone-refractory phenotype by prostate cancer. We previously reported that regulator of G-protein signaling (RGS) 2, an inhibitor of GPCRs, inhibits androgen-independent AR activation (Cao et al., Oncogene 2006;25:3719-34).

DHHC protein-dependent palmitoylation protects regulator of G-protein signaling 4 from proteasome degradation.

Regulator of G-protein signaling 4 (RGS4), an intracellular modulator of G-protein coupled receptor (GPCR)-mediated signaling, is regulated by multiple processes including palmitoylation and proteasome degradation. We found that co-expression of DHHC acyltransferases (DHHC3 or DHHC7), but not their acyltransferase-inactive mutants, increased expression levels of RGS4 but not its Cys2 to Ser mutant (RGS4C2S). DHHC3 interacts with and palmitoylates RGS4 but not RGS4C2S in vivo.

Phosphoinositide 3-kinase gamma regulates airway smooth muscle contraction by modulating calcium oscillations.

Phosphoinositide 3-kinase gamma (PI3Kgamma) has been implicated in the pathogenesis of asthma, but its mechanism has been considered indirect, through release of inflammatory cell mediators. Because airway smooth muscle (ASM) contractile hyper-responsiveness plays a critical role in asthma, the aim of the present study was to determine whether PI3Kgamma can directly regulate contractility of ASM. Immunohistochemistry staining indicated expression of PI3Kgamma protein in ASM cells of mouse trachea and lung, which was confirmed by Western blot analysis in isolated mouse tracheal ASM cells.

Gbetagamma signaling promotes breast cancer cell migration and invasion.

Signaling through G protein-coupled receptors (GPCRs) promotes breast cancer metastasis. G proteins convey GPCR signals by dissociating into Galpha and Gbetagamma subunits. The aim of the present study was to determine whether blockade of Gbetagamma signaling suppresses breast cancer cell migration and invasion, which are critical components of metastasis.

Breast cancer migration and invasion depend on proteasome degradation of regulator of G-protein signaling 4.

Aberrant signaling through G-protein coupled receptors promotes metastasis, the major cause of breast cancer death. We identified regulator of G-protein signaling 4 (RGS4) as a novel suppressor of breast cancer migration and invasion, important steps of metastatic cascades. By blocking signals initiated through G(i)-coupled receptors, such as protease-activated receptor 1 and CXC chemokine receptor 4, RGS4 disrupted Rac1-dependent lamellipodia formation, a key step involved in cancer migration and invasion.

The role of voltage-gated potassium channels in the regulation of mouse uterine contractility.

Background: Uterine smooth muscle cells exhibit ionic currents that appear to be important in the control of uterine contractility, but how these currents might produce the changes in contractile activity seen in pregnant myometrium has not been established. There are conflicting reports concerning the role of voltage-gated potassium (Kv) channels and large-conductance, calcium-activated potassium (BK) channels in the regulation of uterine contractility. In this study we provide molecular and functional evidence for a role for Kv channels in the regulation of spontaneous contractile activity in mouse myometrium, and also demonstrate a change in Kv channel regulation of contractility in pregnant mouse myometrium.

Characterization of the alpha1-adrenoceptor subtype activating extracellular signal-regulated kinase in submandibular gland acinar cells.

Alpha(1)-Adrenoceptors and extracellular signal-regulated kinases 1 and 2 (ERK1/2) regulate salivary secretion. However, whether alpha(1)-adrenoceptors couple to ERK1/2 activation and the specific alpha(1)-adrenoceptor subtypes involved in salivary glands is unknown. Western blotting of ERK1/2 phosphorylation showed phenylephrine activated ERK1/2 by 2-3-fold in submandibular gland slices and 3-4-fold in submandibular acinar (SMG-C10) cells with an EC(50) of 2.