The Properties of Circulating Fibrocytes in Severe Asthma

Inflammation associated with asthma mainly affects large airways and is accompanied by extensive structural changes, termed airway remodelling. 5-10% of patients with asthma suffer from severe or refractory asthma which is difficult to control despite receiving high doses of inhaled and sometimes oral corticosteroids (CS). These patients show more prominent characteristics of airway remodelling, specifically sub-epithelial fibrosis and airway smooth muscle (ASM) thickening. My project focuses on one of the cells implicated in airway remodelling, circulating fibrocytes, which are bone marrow-derived peripheral blood mesenchymal progenitors expressing both leukocyte markers, such as CD45, and mesenchymal proteins including collagen I (Col I). Fibrocytes migrate to the sites of disease under the guidance of chemokine receptors such as CC chemokine receptor type 7 (CCR7), and differentiate into α–smooth muscle actin (α-SMA)–expressing myofibroblasts, a process that is facilitated by a variety of pro-inflammatory cytokines and growth factors. Myofibroblasts can promote subepithelial fibrosis as well as contribute to ASM thickening. Indeed, the number of fibrocytes in peripheral blood is correlated with the decline rate of forced expiratory volume in 1s (FEV1) in patients with chronic obstructive asthma. Most importantly, there is increased recruitment of fibrocytes to the airway wall of patients with severe asthma. However, the mechanisms driving the accumulation of fibrocytes in the airways of these patients are currently unclear. I hypothesised that in severe asthma there are increased numbers of circulating fibrocytes that have an increased capacity to differentiate into myofibroblasts and have differential responses to pro-inflammatory mediators and asthma therapeutic agents compared to non-severe asthma. Fibrocytes were isolated from the non-adherent non-T (NANT) cell fraction of peripheral blood mononuclear cells (PBMC) of healthy subjects and patients with non-severe or severe asthma. The number of fibrocytes (Col I+/CD45+ cells) and differentiating fibrocytes (α-SMA+ cells), as well as the expression of CCR7 and glucocorticoid receptor (GR) in fibrocytes were determined by flow cytometry. Apoptosis was determined by Annexin V/propidium iodide staining. Messenger ribonucleic acid (mRNA) expression was quantified by reverse transcription quantitative polymerase chain reaction (RT-qPCR). Fibrocytes were also isolated from the adherent fraction of PBMC. Severe asthmatic patients had a higher number of circulating fibrocytes with a greater capacity to differentiate into myofibroblasts in culture compared to healthy subjects and patients with non-severe asthma. Severe asthmatic fibrocytes did not have a heightened responsiveness to either interleukin (IL)-4, IL-13, nerve growth factor or brain-derived neurotrophic factor. Dexamethasone induced apoptosis in NANT cells, including fibrocytes and differentiating fibrocytes, from healthy subjects and patients with non-severe asthma, but not in the cells from patients with severe asthma. Dexamethasone also reduced CCR7 expression in fibrocytes from patients with non-severe asthma but not in those from patients with severe asthma. The relative CS insensitivity in severe asthmatic fibrocytes may be related to the lower expression of the GR or the heightened c-Jun N-terminal kinase activity. Salmeterol xinafoate, a long-acting β2-adrenoceptor agonist (LABA), reduced the number, myofibroblastic differentiation and CCR7 expression of fibrocytes from healthy subjects and patients with non-severe asthma. Salmeterol did not improve the suppressive effect of dexamethasone, although it was not detrimental to dexamethasone’s effect either. In contrast, tiotropium bromide, a long-acting muscarinic antagonist (LAMA), did reduce the number of fibrocytes and differentiating fibrocytes from patients with severe asthma. Increasing intracellular 3’,5’-cyclic adenosine monophosphate (cAMP), the downstream signalling molecule of β2-adrenoceptor and muscarinic M2 receptor, by phosphodiesterase type IV inhibitor (rolipram) and cAMP analogue (8-bromoadenosine-3’,5’-cyclic monophosphate) could reduce fibrocytes from patients with severe asthma. Patients with severe asthma have elevated numbers of circulating fibrocytes showing enhanced myofibroblastic differentiation and are less responsive to the suppressive effect of CS and LABA, but can be inhibited by LAMA. This study provides insight into a novel target for the treatment of airway remodelling in severe asthma.Open Acces

A combined targeted mutation analysis of IRF6 gene would be useful in the first screening of oral facial clefts

BACKGROUND: Interferon Regulatory Factor 6 (IRF6) is a member of the IRF family of transcription factors. It has been suggested to be an important contributor to orofacial development since mutations of the IRF6 gene has been found in Van der Woude (VWS) and popliteal pterygium syndromes (PPS), two disorders that can present with isolated cleft lip and palate. The association between IRF6 gene and cleft lip and palate has also been independently replicated in many populations. METHODS: We screened a total of 155 Taiwanese patients with cleft lip with or without cleft palate (CL/P); 31 syndromic (including 19 VWS families), 44 non-syndromic families with at least two affected members, and 80 non-syndromic patients through a combined targeted, polymerase chain reaction (PCR)-based mutation analysis for the entire coding regions of IRF6 gene. RESULTS: We found 11 mutations in 57.89% (11/19) of the VWS patients and no IRF6 mutation in 44 of the non-syndromic multiplex families and 80 non-syndromic oral cleft patients. In this IRF6 gene screening, five of these mutations (c.290 A>G, p.Tyr97Cys; c.360-375 16 bp deletion, p.Gln120HisfsX24; c.411_412 insA, p.Glu136fsX3; c.871 A>C, p.Thr291Pro; c.969 G>A, and p.Trp323X) have not been reported in the literature previously. Exon deletion was not detected in this series of IRF6 gene screening. CONCLUSIONS: Our results confirm the crucial role of IRF6 in the VWS patients and further work is needed to explore for its function in the non-syndromic oral cleft with vary clinical features

Efficient quantum cryptography network without entanglement and quantum memory

An efficient quantum cryptography network protocol is proposed with d-dimension polarized photons, without resorting to entanglement and quantum memory. A server on the network, say Alice, provides the service for preparing and measuring single photons whose initial state are |0>. The users code the information on the single photons with some unitary operations. For preventing the untrustworthy server Alice from eavesdropping the quantum lines, a nonorthogonal-coding technique (decoy-photon technique) is used in the process that the quantum signal is transmitted between the users. This protocol does not require the servers and the users to store the quantum state and almost all of the single photons can be used for carrying the information, which makes it more convenient for application than others with present technology. We also discuss the case with a faint laser pulse.Comment: 4 pages, 1 figures. It also presented a way for preparing decoy photons without a sinigle-photon sourc

Predicting the Severity and Prognosis of Trismus after Intensity-Modulated Radiation Therapy for Oral Cancer Patients by Magnetic Resonance Imaging

To develop magnetic resonance imaging (MRI) indicators to predict trismus outcome for post-operative oral cavity cancer patients who received adjuvant intensity-modulated radiation therapy (IMRT), 22 patients with oral cancer treated with IMRT were studied over a two-year period. Signal abnormality scores (SA scores) were computed from Likert-type ratings of the abnormalities of nine masticator structures and compared with the Mann-Whitney U-test and Kruskal–Wallis one-way ANOVA test between groups. Seventeen patients (77.3%) experienced different degrees of trismus during the two-year follow-up period. The SA score correlated with the trismus grade (r = 0.52, p<0.005). Patients having progressive trismus had higher mean doses of radiation to multiple structures, including the masticator and lateral pterygoid muscles, and the parotid gland (p<0.05). In addition, this group also had higher SA-masticator muscle dose product at 6 months and SA scores at 12 months (p<0.05). At the optimum cut-off points of 0.38 for the propensity score, the sensitivity was 100% and the specificity was 93% for predicting the prognosis of the trismus patients. The SA score, as determined using MRI, can reflect the radiation injury and correlate to trismus severity. Together with the radiation dose, it could serve as a useful biomarker to predict the outcome and guide the management of trismus following radiation therapy

TRPC5 channels participate in pressure-sensing in aortic baroreceptors

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