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Progressive fibrosing interstitial lung diseases (PF-ILDs) result in high mortality and lack effective therapies. The pathogenesis of PF-ILDs involves macrophages driving inflammation and irreversible fibrosis. Fc-gamma receptors (FcγRs) regulate macrophages and inflammation, but their roles in PF-ILDs remain unclear. We characterized the expression of FcγRs and found up-regulated FcγRIIB in human and mouse lungs following exposure to silica. FcγRIIB deficiency aggravated lung dysfunction, inflammation and fibrosis in silica-exposed mice. Using single-cell transcriptomics and in vitro experiments, FcγRIIB was found in alveolar macrophages, where it regulated the expression of fibrosis-related genes Spp1 and Ctss. In mice with macrophage-specific over-expression of FcγRIIB, and in mice treated with adenovirus by intra-tracheal instillation to up-regulate FcγRIIB, silica-induced functional and histological changes were ameliorated. Our data from three genetic models and a therapeutic model suggest that FcγRIIB plays a protective role that can be enhanced by adenoviral over-expression, representing a potential therapeutic strategy for PF-ILDs.

A poly(2-hydroxyethyl methacrylate) (pHEMA) hydrogel film was prepared by bulk polymerization. Then, it was surface modified by perfluorooctanoyl chloride to improve the anti-biofouling properties. Attenuated total reflectance-Fourier transform infrared (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), scanning electron microscopy-energy dispersive X-ray spectroscopy (SEM-EDXS), and atomic force microscopy (AFM) analyses demonstrated that the uniform dense fluorinated layer had been successfully grafted onto pHEMA. The water contact angle (WCA) of the modified pHEMA film increased to 135°, while the surface energy decreased to 13.32 mN/m. The protein and bacterial adhesion properties of the modified pHEMA were decreased significantly. The in vitro cytotoxicity showed that the modified pHEMA was noncytotoxic. Thus, the fluorinated modification on the material surface was a convenient and effective method to establish a hydrophobic and anti-biofouling surface.

To understand the mechanism underlying the regression of cardiac hypertrophy, we investigated the pathological changes after isoproterenol (ISO) withdrawal in ISO-induced cardiomyopathy models in rats and neonatal cardiomyocytes. Cardiac hypertrophy was induced in rats by two weeks of ISO administration; however, the hypertrophy did not regress after three weeks of natural maintenance after ISO administration was withdrawn (ISO-wdr group). The remaining hypertrophy in the ISO-wdr group was accompanied by a sustained increase in the level of phosphorylated Ca2+/calmodulin-dependent protein kinase II (p-CaMKII). Additionally, the increased expression levels of histone deacetylase 4 (HDAC4) and the CaV1.2 channel and amounts of CaMKII bound with HDAC4 and CaV1.2 were not recovered in the ISO-wdr group. The results in cardiomyocyte models were similar to those seen in rat models. Losartan, metoprolol or amlodipine neither ameliorated the increase in atrial natriuretic peptide nor inhibited the increase in p-CaMKII and bound CaMKII. In contrast, autocamtide-2-related inhibitor peptide, a CaMKII inhibitor, reduced these increases. This study investigated the phosphorylation status of CaMKII after hypertrophic stimulus was withdrawn for the first time and proposed that CaMKII as well as its complexes with CaV1.2 could be potential targets to achieve effective regression of cardiac hypertrophy.

Intracellular calcium is related to cardiac hypertrophy. The CaV1.2 channel and Ca2+/calmodulin-dependent protein kinase II (CaMKII) and CaM regulate the intracellular calcium content. However, the differences in CaMKII and CaM in cardiac hypertrophy are still conflicting and are worthy of studying as drug targets. Therefore, in this study, we aim to investigate the roles and mechanism of CaM and CaMKII on CaV1.2 in pathological myocardial hypertrophy. The results showed that ISO stimulation caused SD rat heart and cardiomyocyte hypertrophy. In vivo, the HW/BW, LVW/BW, cross-sectional area, fibrosis ratio and ANP expression were all increased. There were no differences in CaV1.2 channel expression in the in vivo model or the in vitro model, but the ISO stimulation induced channel activity, and the [Ca2+]i increased. The protein expression levels of CaMKII and p-CaMKII were all increased in the ISO group, but the CaM expression level decreased. AIP inhibited ANP, CaMKII and p-CaMKII expression, and ISO-induced [Ca2+]i increased. AIP also reduced HDAC4, p-HDAC and MEF2C expression. However, CMZ did not play a cardiac hypertrophy reversal role in vitro. In conclusion, we considered that compared with CaM, CaMKII may be a much more important drug target in cardiac hypertrophy reversal.

In recent years, there are increasing evidences of epidemiology and clinic which indicate that vitamin D deficiency has relationship with cardiovascular disease. It was found the levels of vitamin D were negatively correlated with cardiovascular events such as hypertension, heart failure, atrial fibrillation and coronary heart disease. This article reviews the connection between cardiovascular diseases and vitamin D, and explains the underlying mechanisms including regulating renin-angiotensin system or endothelial function, inhibition of natriuretic peptide expression or the release of parathyroid hormone, effects on inflammation or obesity, bioenergetics, activation of extracellular Ca2+, inhibition of oxidative stress, and so on. These mechanisms provide novel strategy for the treatment of these cardiovascular diseases.

Abdominal aortic aneurysm (AAA) is potentially life-threatening in aging population due to the risk of aortic rupture and a lack of optimal treatment. The roles of different vascular and immune cells in AAA formation and pathogenesis remain to be future characterized. Single-cell RNA sequencing was performed on an angiotensin (Ang) II-induced mouse model of AAA. Macrophages, B cells, T cells, fibroblasts, smooth muscle cells and endothelial cells were identified through bioinformatic analyses. The discovery of multiple subtypes of macrophages, such as the re-polarization of Trem2+Acp5+ osteoclast-like and M2-like macrophages toward the M1 type macrophages, indicates the heterogenous nature of macrophages during AAA development. More interestingly, we defined CD45+COL1+ fibrocytes, which was further validated by flow cytometry and immunostaining in mouse and human AAA tissues. We then reconstituted these fibrocytes into mice with Ang II-induced AAA and found the recruitment of these fibrocytes in mouse AAA. More importantly, the fibrocyte treatment exhibited a protective effect against AAA development, perhaps through modulating extracellular matrix production and thus enhancing aortic stability. Our study reveals the heterogeneity of macrophages and the involvement of a novel cell type, fibrocyte, in AAA. Fibrocyte may represent a potential cell therapy target for AAA.

Silicosis is the most prevalent and fatal occupational disease with no effective therapeutics, and currently used drugs cannot reverse the disease progress. Worse still, there are still challenges to be addressed to fully decipher the intricated pathogenesis. Thus, specifying the essential mechanisms and targets in silicosis progression then exploring anti-silicosis pharmacuticals are desperately needed. In this work, multi-omics atlas was constructed to depict the pivotal abnormalities of silicosis and develop targeted agents. By utilizing an unbiased and time-resolved analysis of the transcriptome, proteome and phosphoproteome of a silicosis mouse model, we have verified the significant differences in transcript, protein, kinase activity and signaling pathway level during silicosis progression, in which the importance of essential biological processes such as macrophage activation, chemotaxis, immune cell recruitment and chronic inflammation were emphasized. Notably, the phosphorylation of EGFR (p-EGFR) and SYK (p-SYK) were identified as potential therapeutic targets in the progression of silicosis. To inhibit and validate these targets, we tested fostamatinib (targeting SYK) and Gefitinib (targeting EGFR), and both drugs effectively ameliorated pulmonary dysfunction and inhibited the progression of inflammation and fibrosis. Overall, our drug discovery with multi-omics approach provides novel and viable therapeutic strategies for the treatment of silicosis.

To solve the biofouling problem of polyvinyl alcohol (PVA) hydrogel as the artificial cornea, glycidyl methacrylate (GMA) and 2-hydroxypropyltrimethyl ammonium chloride chitosan (HACC) were grafted on the surface of PVA hydrogel via a new method of photoinduced electron transfer—reversible addition fragmentation chain transfer (PET-RAFT) polymerization and ring-open reaction. Both attenuated total reflectance Fourier transform infrared spectroscopy (ATR-FTIR), X-ray photoelectron spectroscopy (XPS), atomic force microscopy (AFM), scanning electron microscope (SEM), and thermogravimetric analysis (TGA) confirmed that GMA and HACC were successfully grafted on the surface of PVA hydrogel. A series of experiments to test the hydrophilicity of PVA hydrogel showed that it became hydrophobic due to the introduction of hydrophobic groups after grafting with GMA and HACC. In addition, cytotoxicity in vitro of PVA-g-p(GMA-HACC) hydrogel could be considered as not cytotoxicity according to ISO 10993-5: 2009. The anti-fouling property of hydrogel decreased after grafting with GMA due to the hydrophobic surface, while increased after grafting with HACC due to the steric repulsion of p(GMA-HACC) polymer brush. It’s no doubt that PET-RAFT was a feasible and reliable surface modification method which could be used in many biomolecules due to the excellent advantages.

Bisphenol A (BPA) is an environmental oestrogen or xenoestrogen (XEs). XEs represent a health risk due to their potential for endocrine disruption and ability to mimic estrogenic activity. The effects of BPA on isolated hearts under normal and ischemia/reperfusion (I/R) conditions were investigated for the first time, with a focus on the effects of BPA and 17β-oestradiol (E2) co-administration on I/R injury. Our results indicated that BPA at 10−7 M and 10−5 M did not significantly affect heart rate (HR), coronary flow (CF), lactate dehydrogenase (LDH) or creatine kinase (CK) release in normal or I/R isolated hearts within the 90 min. However, E2 exerted a protective effect against I/R injury, whereas, BPA inhibited the cardio-protective effects of E2 on HR, CF, and LDH and CK release. Furthermore, BPA in combination with E2 aggravated I/R injury by increasing infarct size and causing a more severe ultrastructural disruption as compared to treatment with E2 alone. Based on our results, we conclude that BPA inhibits the cardio-protective effects of E2 on I/R-injured hearts, despite not significantly affecting normal or I/R isolated hearts.

In this study, we grafted brush-like CBMA copolymer brushes onto the surface of PVA hydrogel membrane through photo-induced electron transfer–reversible addition fragmentation chain transfer (PET-RAFT) polymerization. ATR-FTIR, XPS, AFM, UV–Vis absorption spectra and elemental analysis were adopted to characterize the hydrogels, and equilibrium swelling, water contact angle, vitro cytotoxicity assay, protein adsorption and cells adhesion experiments were used to evaluate the related property of hydrogels. The results of ATR-FTIR and XPS showed that pCBMA was successfully grafted onto the surface of PVA hydrogel membrane. The Ra roughness of hydrogel surface in AFM increased slightly from 5.44 nm to 6.12 nm. Transmittance of the PVA-g-pCBMA hydrogel in the visible range (380 nm-780 nm) was remaining at 91.2%–97.0%. The optimal reaction conditions (CPADB: 1.20 mmol/L, Eosin Y: 0.03 mmol/L and CBMA: 358 mmol/L) were confirmed through control experiments. The equilibrium swelling and water contact angle showed that the swelling ratio increased from 2.06 cm3 g−1 to 3.65 cm3 g−1, while the water contact angle decreased from 45.94° to 18.06° with the increase of grafting ratio (23.92%–55.18%). In vitro cytotoxicity assay by CCK-8 showed that the cells relative viability remained at least 90.55%. Anti-protein adsorption experiment illustrated approximately 57.2% improvement of anti-protein capacity at 37 °C, while cells adhesion experiment also showed about 64.57% improvement of anti-cells capacity. These results revealed the applicability of the oxygen tolerant PET-RAFT mechanism on the PVA modification and it was effective, feasible and non-cytotoxic method to prepare the other functional PVA hydrogel membrane.

Poly(zwitterions) polymer brushes were fabricated by surface-initiated atom transfer radical polymerization (SI-ATRP) on PVA substrate. The results of XPS and FTIR proved the successful graft of CBMA and SBMA to PVA. The surface of the PVA films would be rougher after the functionalization. Its hydrophilicity increased dramatically and the water contact angle decreased from 45.2° to 7.2°. The visible light transmittance was above 88%. Mechanical properties decreased slightly after grafting, the tensile strength and tensile strain at break were in 1.23-1.85 MPa and 361.7-471.1%, respectively. The anti-protein adsorption performance of the modified PVA film was significantly enhanced and the lowest adsorption amount was up to 2.25 μg/cm

Intracellular calcium is related to cardiac hypertrophy. The Ca

It is widely accepted that trace elements have been implicated in various metabolic processes. Valproic acid (VPA) is a remarkably safe and effective antiepileptic drug. There is no consensus option regarding the fluctuations in serum zinc (Zn), copper (Cu), and selenium (Se) in epileptic patients treated with VPA. We applied a meta-analysis to systematically assess the effects of VPA on serum ions in these patients. In this study, we performed a meta-analysis of the changes in serum Zn, Cu, and Se levels in human samples of healthy controls, epileptic patients, and patients treated with VPA. Twenty-two published analyzable studies were selected by searching the databases of PubMed, China National Knowledge Infrastructure (CNKI), Google Scholar, Web of Science, EMBASE, WAN FANG and Vip. Serum Se levels in epileptic patients were decreased compared to healthy controls. Serum Zn levels in patients with VPA treatment were significantly lower than those in epileptic patients. The results of this meta-analysis are instructive for the intake of trace elements such as Zn, Cu, and Se in the diet balance of patients with epilepsy treated with VPA. Meanwhile, this study provides a theoretical basis for the combined use of other drugs that affect the intake and absorption of trace elements and VPA.

A novel g-C3N4@InVO4 semiconductor catalyzed surface-initiated photo atom transfer radical polymerization without catalysts residues problem has been developed. This method proceeded in N-methyl pyrrolidone/aqueous under atmospheric conditions. To verify the versatility of this method and enhance the antifouling properties of polyvinyl alcohol (PVA) hydrogel, two types of fluorinated polymer brushes (p6F/p13F) were successfully constructed on PVA hydrogel surface instead of the subsurface. The chemical bonds between PVA matrix and fluorinated polymer brushes (p6F/p13F) enhanced the surface cross link density and resulted in an increase of thermal stability and mechanical properties. All fluorinated PVA hydrogels with excellent antifouling properties was able to tackle the biofouling problem in complex environment of the human body. In addition, all fluorinated PVA hydrogels was no cytotoxicity for L929 and NDHF according to ISO 10993.5:2009. g-C3N4@InVO4 catalyzed SI-photoATRP provides a novel surface modification technology for various biological or medical materials in the industrial-scale application.

An innovative g-C3N4 catalyzed surface-initiated photo atom transfer radical polymerization (SI-photoATRP) has been developed to construct MEDSAH zwitterionic polymer brushes on PVA hydrogel surface. g-C3N4 catalyzed SI-photoATRP is temporal and spatial control. As a heterogeneous reaction system, it can solve the catalyst residues problem. After grafting with MEDSAH, surface chemical composition and morphology of PVA-g-pMEDSAH hydrogel confirmed that MEDSAH was successfully grafted onto PVA hydrogel. Thermal property of PVA-g-pMEDSAH hydrogel decreased and hydrophilicity increased. No statistically significant differences between PVA and PVA-g-pMEDSAH were observed on mechanical properties. Cytotoxicity in vitro of PVA-g-pMEDSAH hydrogel could be considered as no cytotoxicity for L929 and NDHF cells. The antifouling properties of PVA-g-pMEDSAH hydrogel were significantly improved due to the enhancement of the surface hydration and steric repulsion effects caused by pMEDSAH polymer brushes. In addition, g-C3N4 is easier to modify to enhance the photocatalyst property. Thus, the heterogeneous reaction system of g-C3N4 catalyzed SI-photoATRP has huge potential applied in biomaterials surface modification.

A novel near-infrared (NIR) light induced photoinduced electron transfer-reversible addition - fragmentation chain-transfer (PET-RAFT) polymerization was developed and carboxybetaine methacrylate (CBMA) polymer brush was constructed on the PVA hydrogel via this one-spot method to enhance the antifouling properties. PVA-g-pCBMA hydrogel displayed higher hydrophilicity, while the thermal properties decreased due to the lower decomposition properties of pCBMA and the partly destruction of crystal structure inside the PVA hydrogel. The antifouling properties of PVA-g-pCBMA hydrogel was improved significantly because the surface hydration and steric repulsion effect of pCBMA polymer brush. Importantly, PVA-g-pCBMA hydrogel PVA-g-pCBMA hydrogel could be considered as no cytotoxic effect or reduction of proliferation to primary human eyelid fibroblast cells following the guidelines stated by ISO 10993-5:2009 (direct contact test). Considering the excellent penetration ability of NIR, AlPc catalyzed PET-RAFT polymerization provided a new modification approach for various biological or medical materials on industrial scale.

Astragaloside IV (AS-IV) is one of the active ingredients in Astragalus membrananceus (Huangqi), a traditional Chinese medicine. The present study investigated the effects of AS-IV on Ca[Formula: see text] handling in cardiac myocytes to elucidate its possible mechanism in the treatment of cardiac disease. The results showed that AS-IV at 1 and 10[Formula: see text][Formula: see text]M reduced KCl-induced [Ca[Formula: see text]]i increase ([Formula: see text] from 1.33[Formula: see text][Formula: see text][Formula: see text]0.04 (control, [Formula: see text] 28) to 1.22[Formula: see text][Formula: see text][Formula: see text]0.02 ([Formula: see text], [Formula: see text] 29) and 1.22[Formula: see text][Formula: see text][Formula: see text]0.02 ([Formula: see text] 0.01, [Formula: see text]), but it enhanced Ca[Formula: see text] release from SR ([Formula: see text] from 1.04[Formula: see text][Formula: see text][Formula: see text]0.01 (control, [Formula: see text]) to 1.44[Formula: see text][Formula: see text][Formula: see text]0.03 ([Formula: see text], [Formula: see text]) and 1.60[Formula: see text][Formula: see text][Formula: see text]0.04 ([Formula: see text] 0.01, [Formula: see text]0), in H9c2 cells. Similar results were obtained in native cardiomyocytes. AS-IV at 1 and 10[Formula: see text][Formula: see text]M inhibited L-type Ca[Formula: see text] current ([Formula: see text] from [Formula: see text]4.42[Formula: see text][Formula: see text][Formula: see text]0.58 pA/pF of control to [Formula: see text]2.25[Formula: see text][Formula: see text][Formula: see text]0.12 pA/pF ([Formula: see text] 0.01, [Formula: see text] 5) and [Formula: see text]1.78[Formula: see text][Formula: see text][Formula: see text]0.28 pA/pF ([Formula: see text] 0.01, [Formula: see text] 5) respectively, when the interference of [Ca[Formula: see text]]i was eliminated due to the depletion of SR Ca[Formula: see text] store by thapsigargin, an inhibitor of Ca[Formula: see text] ATPase. Moreover, when BAPTA, a rapid Ca[Formula: see text] chelator, was used, CDI (Ca[Formula: see text]-dependent inactivation) of [Formula: see text] was eliminated, and the inhibitory effects of AS-IV on ICaL were significantly reduced at the same time. These results suggest that AS-IV affects Ca[Formula: see text] homeostasis through two opposite pathways: inhibition of Ca[Formula: see text] influx through L-type Ca[Formula: see text] channel, and promotion of Ca[Formula: see text] release from SR.

Design of artificial corneal scaffolds substitute is crucial for replacement of impaired cornea. In this paper, porous polyvinyl alcohol/silk fibroin/nano-hydroxyapatite (PVA/SF/n-HA) composite hydrogel was prepared via the genipin (GP) cross-linking, the pore diameter of the hydrogel ranged from 8.138 nm and 90.269 nm, and the physical and physiological function of hydrogel were investigated. The resulting hydrogel exhibited favourable physical properties. With the GP content increasing, the structural regularity of PVA/SF/n-HA composite hydrogel was enhanced and the thermal stability was improved. The moisture content was slightly decreased and generally maintained at approximately 70%. The tensile strength was heightened up to 0.64 MPa, while the breaking elongation was decreased slightly. Moreover, the biofunction was investigated. The

N-methyl berbamine (N-MB) is a berberine derivative. Its analogue berbamine has been reported to have remarkable antiarrhythmic and ischemic protective effects. However, the pharmacological effects of N-MB are ill-defined. In this study, molecular docking was used to evaluate the binding of N-MB to CaV1.2 Ca2+ and KV11.1 K+ channels, and the effects of N-MB on action potential and ionic currents were observed in the ventricular myocytes of rabbits, HEK293 cells stably transfected with the hCaV1.2 gene and CHO cells stably transfected with hERG (human ether-a-go-go related gene). The results showed that N-MB was able to bind to both CaV1.2 and KV11.1 channels. Following a perfusion with N-MB, the durations of action potentials (APD20, APD50 and APD90) were extended, and the outward tail current, Itail, as well as the hERG current, IhERG, were inhibited, while the amplitude of action potential (APA) was only slightly reduced. N-MB also decreased the peak amplitude of the L-type Ca2+ channel current, ICaL, as well as the CaV1.2 current, ICaV1.2; this may limit the prolongation of APD. In conclusion, N-MB is a potent and natural antiarrhythmic multitarget drug that may elicit its antiarrhythmic effect through blocking both Ca2+ and K+ channel currents. Keywords: N-methyl berbamine, Action potential, Ca2+ current, K+ current, Multitarget

PVA was dissolved in mixed solvent (DMSO and water) and followed by several freeze-thaw cycles in a mold to produce PVA membrane. Surface modification of PVA membranes by HA molecules was investigated to improve the hydrophilicity of the membrane surface thereby reducing adsorption of the proteins onto the membrane. The surface composition, water contact angle, optical and mechanical properties, surface morphology, cell compatibility and protein adhesion were systematically investigated. ATR-FTIR spectra, XPS, SEM and AFM indicated that PVA membranes were successfully modified by grafting of the HA. The modified membranes showed increased hydrophilicity and cytocompatibility, decreased surface roughness and mechanical properties, and suppressed cell and protein adhesion compared to the pristine membrane. In general, the achievement of the HA coating with anti-adhesive property can potentially be widely used on surface modification of artificial cornea and other biomedical implants.

This study aimed to investigate the intracellular Mg(2+) regulation of the L-type Ca(2+) channels in guinea pig ventricular myocytes. By adopting the inside-out configuration of the patch clamp technique, single channel currents of the L-type Ca(2+) channels were recorded at different intracellular Mg(2+) concentrations ([Mg(2+)]i). At free [Mg(2+)]i of 0, 10(-9), 10(-7), 10(-5), 10(-3), and 10(-1) M, 1.4 μM CaM + 3 mM ATP induced channel activities of 44%, 117%, 202%, 181%, 147%, and 20% of the control activity in cell-attached mode, respectively, showing a bell-shaped concentration-response relationship. Moreover, the intracellular Mg(2+) modulated the Ca(2+) channel gating properties, accounting for alterations in channel activities. These results imply that Mg(2+) has a dual effect on the L-type Ca(2+) channels: facilitation and inhibition. Lower [Mg(2+)]i maintains and enhances the basal activity of Ca(2+) channels, whereas higher [Mg(2+)]i inhibits channel activity. Taken together, our data from the application of an [Mg(2+)]i series suggest that the dual effect of Mg(2+) upon the L-type Ca(2+) channels exhibits long open-time dependence.

Calmodulin (CaM) is well known as an activator of calcium/calmodulin-dependent protein kinase II (CaMKII). Voltage-gated sodium channels (VGSCs) are basic signaling molecules in excitable cells and are crucial molecular targets for nervous system agents. However, the way in which Ca2+/CaM/CaMKII cascade modulates NaV1.1 IQ (isoleucine and glutamine) domain of VGSCs remains obscure. In this study, the binding of CaM, its mutants at calcium binding sites (CaM12, CaM34, and CaM1234), and truncated proteins (N-lobe and C-lobe) to NaV1.1 IQ domain were detected by pull-down assay. Our data showed that the binding of Ca2+/CaM to the NaV1.1 IQ was concentration-dependent. ApoCaM (Ca2+-free form of calmodulin) bound to NaV1.1 IQ domain preferentially more than Ca2+/CaM. Additionally, the C-lobe of CaM was the predominant domain involved in apoCaM binding to NaV1.1 IQ domain. By contrast, the N-lobe of CaM was predominant in the binding of Ca2+/CaM to NaV1.1 IQ domain. Moreover, CaMKII-mediated phosphorylation increased the binding of Ca2+/CaM to NaV1.1 IQ domain due to one or several phosphorylation sites in T1909, S1918, and T1934 of NaV1.1 IQ domain. This study provides novel mechanisms for the modulation of NaV1.1 by the Ca2+/CaM/CaMKII axis. For the first time, we uncover the effect of Ca2+, lobe-specificity and CaMKII on CaM binding to NaV1.1.

New Findings What is the central question of this study? Higher levels of positive end-expiratory pressure (PEEP) have recently been used in patients with acute respiratory distress syndrome (ARDS). In normal physiological conditions, the ability of the diaphragm to generate pressure is reduced when the lung volume is elevated beyond its functional residual capacity. It is unknown whether higher levels of PEEP will have a negative impact on diaphragmatic contraction in the presence of the pathophysiology of ARDS. What is the main finding and its importance? Mechanical ventilation with higher levels of PEEP reduced lung injury, improved diaphragmatic contractility and increased the expression of both dihydropyridine receptor and ryanodine receptor in the diaphragms of rats with ARDS. Higher levels of positive end-expiratory pressure (PEEP) have recently been used in patients with acute respiratory distress syndrome (ARDS). In normal physiological conditions, the ability of the diaphragm to generate pressure is reduced when the lung volume is elevated beyond its functional residual capacity. Thus, it is critical to understand whether higher levels of PEEP will have a negative impact on diaphragmatic contraction in the presence of the pathophysiology of ARDS. This study was designed to determine whether higher levels of PEEP reduce diaphragmatic contractility in a rat model of ARDS generated using i.p. lipopolysaccharide. Forty rats were randomly assigned to the following five groups: a control group with no special treatment; an ARDS group with no mechanical ventilation; and three ARDS groups with mechanical ventilation with PEEP at 0, 5 or 10 cmH2O, respectively. We found that mechanical ventilation with PEEP reduced lung injury, improved diaphragmatic contractility and increased the expression of both dihydropyridine receptor and ryanodine receptor in the diaphragms of rats with ARDS. These changes were most significant at a PEEP of 10 cmH2O among all applied levels of PEEP. In conclusion, using a rat ARDS model, this study confirmed that diaphragmatic contractility was preserved by mechanical ventilation with high levels of PEEP.

Nonylphenol (NP) is one of the widely spread xenoestrogens (XEs) and is used in the production of industrial and consumer surfactants. In the present study, we examined the acute effects of NP on myocardial contractility to determine its rapid-response cardiac effects in the isolated heart. We also investigated the mechanism of action of NP by determining its effects on the L-type Ca(2+) channel (LTCC) currents (ICa-L) in ventricular myocytes. Lower concentrations (10(-12)-10(-10)M) of NP increased cardiac contractility while higher concentrations (10(-8)-10(-6)M) exhibited opposite effects. These apparently opposing effects suggest that NP has biphasic concentration-dependent rapid effects on cardiac contractility. These non-monotonic changes in contractility correlated with the effects of NP on ICa-L, indicating that ion channels, as rapidly responding membrane proteins, play a very important role in mediating the rapid-response effects of XEs. Further studies revealed that the G protein coupled receptor 30 (GPR30) mediates the effects of NP on LTCC at lower but not higher concentrations, implying that the differential involvement of GPR30 might be responsible for the non-monotonic effects of NP.

The aim of the present study was to isolate and characterize a complementary DNA (cDNA) clone encoding the calmodulin (CaM; GenBank accession no. {"type":"entrez-nucleotide","attrs":{"text":"FJ012165","term_id":"198448654","term_text":"FJ012165"}}FJ012165) gene from guinea pig hearts. The CaM gene was amplified from cDNA collected from guinea pig hearts and inserted into a pGEM®-T Easy vector. Subsequently, CaM nucleotide and protein sequence similarity analysis was conducted between guinea pigs and other species. In addition, reverse transcription-polymerase chain reaction (RT-PCR) was performed to investigate the CaM 3 expression patterns in different guinea pig tissues. Sequence analysis revealed that the CaM gene isolated from the guinea pig heart had ∼90% sequence identity with the CaM 3 genes in humans, mice and rats. Furthermore, the deduced peptide sequences of CaM 3 in the guinea pig showed 100% homology to the CaM proteins from other species. In addition, the RT-PCR results indicated that CaM 3 was widely and differentially expressed in guinea pigs. In conclusion, the current study provided valuable information with regard to the cloning and expression of CaM 3 in guinea pig hearts. These findings may be helpful for understanding the function of CaM3 and the possible role of CaM3 in cardiovascular diseases.

Recent studies show that colonic vitamin D receptor (VDR) signaling protects the mucosal epithelial barrier and suppresses colonic inflammation, but the underlying molecular mechanism remains to be fully understood. To investigate the implication of colonic VDR downregulation seen in patients with inflammatory bowel disease, we assessed the effect of gut epithelial VDR deletion on colonic inflammatory responses in an experimental colitis model. In a 2,4,6-trinitrobenzenesulfonic acid-induced colitis model, mice carrying VDR deletion in gut epithelial cells [VDRflox/flox (VDRf/f);Villin-Cre or VDRΔIEC] or in colonic epithelial cells (VDRf/f;CDX2-Cre or VDRΔCEC) developed more severe clinical colitis than VDRf/f control mice, characterized by more robust T-helper (TH)1 and TH17 responses, with greater increases in mucosal interferon (IFN)-γ+, interleukin (IL)-17+, and IFN-γ+IL-17+ T cells. Accompanying the severe mucosal inflammation was more profound colonic epithelial cell apoptosis in the mutant mice. Treatment with caspase inhibitor Q-VD-OPh dramatically reduced colitis severity and attenuated TH1 and TH17 responses in VDRΔCEC mice. The blockade of cell apoptosis also prevented the increase in mucosal CD11b+CD103+ dendritic cells (DCs), known to be critical for TH17-cell activation. Moreover, depletion of gut commensal bacteria with antibiotics eliminated the robust TH1 and TH17 responses and CD11b+CD103+ DC induction. Taken together, these observations demonstrate that gut epithelial VDR deletion aggravates epithelial cell apoptosis, resulting in increases in mucosal barrier permeability. Consequently, invading luminal bacteria activate CD11b+CD103+ DCs, which promote mucosal TH1 and TH17 responses. Therefore, gut epithelial VDR signaling controls mucosal inflammation by suppressing epithelial cell apoptosis.

The present study examined the binding of the individual N- and C-lobes of calmodulin (CaM) to Cav1.2 at different Ca(2+) concentration ([Ca(2+)]) from ≈ free to 2mM, and found that they may bind to Cav1.2 Ca(2+)-dependently. In particular, using the patch-clamp technique, we confirmed that the N- or C-lobes can rescue the basal activity of Cav1.2 from run-down, demonstrating the functional relevance of the individual lobes. The data imply that at resting [Ca(2+)], CaM may tether to the channel with its single lobe, leading to multiple CaM molecule binding to increase the grade of Ca(2+)-dependent regulation of Cav1.2.

Cardiac L-type calcium channel (CaV1.2), calmodulin (CaM), and Ca(2+)/calmodulin-dependent protein kinase II (CaMKII) form the CaV1.2/CaM/CaMKII signaling pathway, which plays an important role in maintaining intracellular Ca(2+) homeostasis. The roles of CaM and CaMKII in the regulation of CaV1.2 in Ca(2+)-dependent inactivation and facilitation have been reported; however, alterations in this signaling pathway in the heart after myocardial ischemia (MI) had not been well characterized. In this study, we investigated the dynamic changes in CaV1.2, CaM, and CaMKII mRNA and protein expression levels in the left ventricles of the heart following MI in rats. The MI model was induced by ligating the left anterior descending coronary artery; the rats were divided into the following five groups: the 6 h post-MI group (MI-6h), 24 h post-MI group (MI-24h), 1 week post-MI group (MI-1w), 2 weeks post-MI group (MI-2w), and the sham group. The mRNA levels were measured by quantitative real-time polymerase chain reaction and the protein expression was determined by western blotting and immunohistochemistry. There were no observable differences in the CaV1.2 mRNA and protein levels at the early stages of MI, but these levels decreased at MI-2w. Both the mRNA and protein levels of CaM increased at MI-6h, peaked at MI-24h, and then reduced to normal levels at MI-2w. CaMKII mRNA and protein levels decreased at MI-6h and reached their lowest level at MI-24h. Taken together, these data demonstrate that there are dynamic changes in the CaV1.2/CaM/CaMKII signaling pathway following MI injuries, which suggests that different therapeutic regimens should be used at different time points after MI injuries.

This study examined the bindings of calmodulin (CaM) and its mutants with the C- and N-terminal tails of the voltage-gated Ca(2+) channel CaV1.2 at different CaM and Ca(2+) concentrations ([Ca(2+)]) by using the pull-down assay method to obtain basic information on the binding mode, including its concentration- and Ca(2+)-dependencies. Our data show that more than one CaM molecule could bind to the CaV1.2 C-terminal tail at high [Ca(2+)]. Additionally, the C-lobe of CaM is highly critical in sensing the change of [Ca(2+)] in its binding to the C-terminal tail of CaV1.2, and the binding between CaM and the N-terminal tail of CaV1.2 requires high [Ca(2+)]. Our data provide new details on the interactions between CaM and the CaV1.2 channel.

We have investigated the characteristics of voltage-gated K+ channels and L-type Ca2+ channels in GH3 rat pituitary cells and the effects of the xenoestrogen (XEs) nonylphenol (NP) on these ion channel currents. Our results have shown that the lower concentrations (10−15–10−14 M) of NP decreased the amplitudes of voltage-gated K+ currents (IKv) and activated L-type Ca2+ currents (ICa-L) by reducing half-activation membrane potentials of activation kinetics curves. However, the higher concentrations (10−10–10−9 M) of NP increased the amplitudes of IKv and inhibited ICa-L by reducing the peak values of ICa-L. Thus, NP affects IKv and ICa-L in an opposite and non-monotonic manner.