Risk factors for the development of airway hyperresponsiveness in patients with allergic rhinitis / 临床耳鼻咽喉头颈外科杂志

Allergic rhinitis（AR） is an independent risk factor for allergic asthma. Some AR patients may have developed airway hyperresponsiveness（AHR） in the absence of asthma symptoms. In this stage, AHR is often neglected due to the absence of typical asthma symptoms. Exploring the clinically relevant risk factors for AHR in patients with AR, as well as the clinical indicators and biomarkers to predict AHR in patients with AR, is of great significance to the prevention of the occurrence of AHR and asthma. This review summarized the risk factors for the development of AHR in AR patients, and gave hints to the prevention of AHR in AR patients.

Involvement and therapeutic implications of airway epithelial barrier dysfunction in type 2 inflammation of asthma / 中华医学杂志(英文版)

Type 2 inflammation is a complex immune response and primary mechanism for several common allergic diseases including allergic rhinitis, allergic asthma, atopic dermatitis, and chronic rhinosinusitis with nasal polyps. It is the predominant type of immune response against helminths to prevent their tissue infiltration and induce their expulsion. Recent studies suggest that epithelial barrier dysfunction contributes to the development of type 2 inflammation in asthma, which may partly explain the increasing prevalence of asthma in China and around the globe. The epithelial barrier hypothesis has recently been proposed and has received great interest from the scientific community. The development of leaky epithelial barriers leads to microbial dysbiosis and the translocation of bacteria to inter- and sub-epithelial areas and the development of epithelial tissue inflammation. Accordingly, preventing the impairment and promoting the restoration of a deteriorated airway epithelial barrier represents a promising strategy for the treatment of asthma. This review introduces the interaction between type 2 inflammation and the airway epithelial barrier in asthma, the structure and molecular composition of the airway epithelial barrier, and the assessment of epithelial barrier integrity. The role of airway epithelial barrier disruption in the pathogenesis of asthma will be discussed. In addition, the possible mechanisms underlying the airway epithelial barrier dysfunction induced by allergens and environmental pollutants, and current treatments to restore the airway epithelial barrier are reviewed.

Expression and function of store-operated calcium channels in human circulating fibrocytes / 中国病理生理杂志

AIM:To investigate the expression and function of store-operated calcium channels ( SOCC) in human circulating fibrocytes.METHODS:Peripheral blood mononuclear cells ( PBMCs) were isolated and cultured in ser-um-free media.After 7 d, the PBMCs differentiated into fibrocytes.RT-PCR and real-time PCR were performed to deter-mine the mRNA expression of ORAI1-3 and STIM1-2 in the fibrocytes.SOCC inhibitor SKF-96365 was used to elucidate the role of SOCC in the differentiation of fibrocytes.RESULTS:The results of real-time PCR showed that the mRNA ex-pression of ORAI1-3 and STIM1-2 was positive in cultured fibrocytes.SKF-96365 (10μmol/L) significantly inhibited the differentiation of fibrocytes.CONCLUSION:SOCC-related proteins ORAI1-3 and STIM1-2 are abundantly expressed in the fibrocytes, and may play an important role in the differentiation of these cells.

Role of protein kinase C in the activation of store-operated Ca(2+) entry in airway smooth muscle cells / 华中科技大学学报（医学）（英德文版）

Store-operated Ca(2+) channels (SOCs) are plasma membrane Ca(2+) permeable channels activated by depletion of intracellular Ca(2+) store. Ca(2+) entry through SOCs is known as store-operated Ca(2+) entry (SOCE), which plays an important role in the functional regulation of airway smooth muscle cells (ASMCs). Protein kinase C (PKC) has been shown to have an activating or inhibiting effect on SOCE, depending on cell types and PKC isoforms that are involved. In ASMCs, the effect of PKC on SOCE has not been elucidated so far. In this study, the role of PKC in the activation of SOCE in rat ASMCs was examined by using Ca(2+) fluorescence imaging technique. The results showed that acute application of PKC activators PMA and PDBu did not affect SOCE induced by the sarcoplasmic reticulum Ca(2+)-ATPase (SERCA) inhibitor thapsigargin. The non-selective PKC inhibitor chelerythrine significantly inhibited thapsigargin- and bradykinin-induced SOCE. RT-PCR assay identified PKCα, δ and ɛ isoforms in rat ASMCs. PKCα-selective inhibitor Gö6976 and PKCɛ-inhibiting peptide Epsilon-V1-2 had no effect on SOCE; by contrast, PKCδ-selective inhibitor rottlerin attenuated SOCE dramatically, suggesting that PKCδ was the major PKC isoform involved in the activation of SOCE in ASMCs. Moreover, PKC down-regulation by extended exposure to high doses of PMA or PDBu also reduced SOCE, confirming the essential role of PKC in the activation of SOCE in ASMCs. In addition, PKC down-regulation did not influence the expression of stromal interaction molecule 1 (STIM1) and Orai1, two elementary molecules in the regulation and activation of SOCs. These results identified PKCδ as an essential PKC isoform involved in the activation of SOCE, and confirmed that PKC regulates the function of ASMCs in a SOCE-dependent manner.

Role of protein kinase C in the activation of store-operated Ca(2+) entry in airway smooth muscle cells / 华中科技大学学报（医学）（英德文版）

Store-operated Ca(2+) channels (SOCs) are plasma membrane Ca(2+) permeable channels activated by depletion of intracellular Ca(2+) store. Ca(2+) entry through SOCs is known as store-operated Ca(2+) entry (SOCE), which plays an important role in the functional regulation of airway smooth muscle cells (ASMCs). Protein kinase C (PKC) has been shown to have an activating or inhibiting effect on SOCE, depending on cell types and PKC isoforms that are involved. In ASMCs, the effect of PKC on SOCE has not been elucidated so far. In this study, the role of PKC in the activation of SOCE in rat ASMCs was examined by using Ca(2+) fluorescence imaging technique. The results showed that acute application of PKC activators PMA and PDBu did not affect SOCE induced by the sarcoplasmic reticulum Ca(2+)-ATPase (SERCA) inhibitor thapsigargin. The non-selective PKC inhibitor chelerythrine significantly inhibited thapsigargin- and bradykinin-induced SOCE. RT-PCR assay identified PKCα, δ and ɛ isoforms in rat ASMCs. PKCα-selective inhibitor Gö6976 and PKCɛ-inhibiting peptide Epsilon-V1-2 had no effect on SOCE; by contrast, PKCδ-selective inhibitor rottlerin attenuated SOCE dramatically, suggesting that PKCδ was the major PKC isoform involved in the activation of SOCE in ASMCs. Moreover, PKC down-regulation by extended exposure to high doses of PMA or PDBu also reduced SOCE, confirming the essential role of PKC in the activation of SOCE in ASMCs. In addition, PKC down-regulation did not influence the expression of stromal interaction molecule 1 (STIM1) and Orai1, two elementary molecules in the regulation and activation of SOCs. These results identified PKCδ as an essential PKC isoform involved in the activation of SOCE, and confirmed that PKC regulates the function of ASMCs in a SOCE-dependent manner.

Effect of nitric oxide on potassium channels of rat airway smooth muscle cells / 华中科技大学学报（医学）（英德文版）

The effect of nitric oxide donor sodium nitroprusside (SNP) on resting membrane potential (Em) and potassium currents of the bronchial smooth muscle cells from rats was investigated. All experiments were conducted in conventional whole-cell configuration. The changes of Em and potassium currents after addition of 0.1 mmol/L SNP were measured under the current-clamp mode and the voltage-clamp mode respectively. Results showed that (1) SNP could decrease the Em from -33.8 +/- 7.4 mV to -43.7 +/- 6.7 mV (n = 10, P < 0.01); (2) SNP could increase the Ca(2+)-activated K+ channel peak currents under ramp protocol from 466.9 +/- 180.1 pA to 597.7 +/- 237.6 pA (n = 7, P < 0.01), and the currents under pulse protocol at mV were increased from 544.2 +/- 145.4 pA to 678.1 +/- 206.2 pA (n = 6, P < 0.05); (3) SNP also could increase voltage-gated K+ channel peak currents under ramp protocol from 389.6 +/- 84.1 pA to 526.7 +/- 98.7 pA (n = 7, P < 0.01), the currents under pulse protocol at mV were increased from 275.7 +/- 85.2 pA to 444.3 +/- 128.5 pA (n = 6, P < 0.01). It was concluded that SNP increases the activities of Ca(2+)-activated K+ channels and voltage-gated K+ channels and leads to K+ efflux and hyperpolarization of the cell membrane, resulting in a decrease of the cell excitement.

Effects of endogenous nitric oxide on potassium channels of bronchial smooth muscle cells from asthmatic rats / 中国病理生理杂志

AIM: To investigate the effects of in vivo application of L - arginine on potassium channels in bronchial smooth muscle cells (BSMC) isolated from asthmatic model rats.METHODS: Male SD rats were randomly divided into control group,asdimatic group and asthmatic rats treated with L-arginine (L-Arg group). Single BSMCs were obtained by acute enzyme separation method. The resting membrane potential (Em), Ca2+ - activated K+ channels (BKca) currents and voltage - dependent K+ channel (Kv) currents in BSMCs were recorded under whole - cell patch clamp technique. RESULTS: (1) The Em of asthmatic group was significantly lower than that in control group ( P 0.05) . (2) The peak current density at + 50 mV of Kca: IKca in asthmatic group [ (43.8?16.5) pA/pF] was significandy lower than that in normal group [ (72.5?19.9) pA/pF] ( P

Effects of down-regulation of protein kinase C on activation of storeoperated Ca~(2+) channels and the proliferation of airway smooth muscle cells / 中国病理生理杂志

AIM:To investigate the effects of down-regulation of protein kinase C (PKC) on the activity of storeoperated Ca2 + channels (SOC) and the proliferation of airway smooth muscle cells (ASMCs). METHODS:Rat bronchial smooth muscle cells were isolated and cultured. Fluo-3 /AM fluorescence was measured by laser confocal microscope to assessing intracellular Ca2 +. Downregulation of PKC activity was achieved by incubation of ASMCs with PKC activator phorbol-12-myristate-13-acetate (PMA,10 ?mol/L) or phorbol 12,13 -dibutyrate (PDBu,1 ?mol/L) for 24 h. The proliferation of ASMCs was assayed by calculating the reduction rates of Alamar blue. RESULTS:Down-regulation of PKC activity by longterm exposure of PMA or PDBu inhibited the proliferation of ASMCs,the similar results were obtained by using PKC inhibitor chelerythrine. Both downregulation of PKC activity and inhibition of PKC activity by chelerythrine reduced Ca2 + entry through SOC channels. Low concentration of PMA (0. 1 ?mol/L) promoted the proliferation of ASMCs,and this effect was inhibited by SOC blocker SKF-96365. CONCLUSION:Inhibition or down -regu-lation of PKC activity results in the inhibition of SOC channels,suggesting that PKC is involved in the activation of these channels. Ca2 + entry through SOC channels might contribute to PKC-promoted proliferation of ASMCs.