SARS-CoV-2 envelope protein impairs airway epithelial barrier function and exacerbates airway inflammation via increased intracellular Cl- concentration.

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection disrupts the epithelial barrier and triggers airway inflammation. The envelope (E) protein, a core virulence structural component of coronaviruses, may play a role in this process. Pathogens could interfere with transepithelial Cl- transport via impairment of the cystic fibrosis transmembrane conductance regulator (CFTR), which modulates nuclear factor κB (NF-κB) signaling. However, the pathological effects of SARS-CoV-2 E protein on airway epithelial barrier function, Cl- transport and the robust inflammatory response remain to be elucidated. Here, we have demonstrated that E protein down-regulated the expression of tight junctional proteins, leading to the disruption of the airway epithelial barrier. In addition, E protein triggered the activation of Toll-like receptor (TLR) 2/4 and downstream c-Jun N-terminal kinase (JNK) signaling, resulting in an increased intracellular Cl- concentration ([Cl-]i) via up-regulating phosphodiesterase 4D (PDE4D) expression in airway epithelial cells. This elevated [Cl-]i contributed to the heightened airway inflammation through promoting the phosphorylation of serum/glucocorticoid regulated kinase 1 (SGK1). Moreover, blockade of SGK1 or PDE4 alleviated the robust inflammatory response induced by E protein. Overall, these findings provide novel insights into the pathogenic role of SARS-CoV-2 E protein in airway epithelial damage and the ongoing airway inflammation during SARS-CoV-2 infection.

Single-phase ultrathin holey nanoflower Ni5P4 as a bifunctional electrocatalyst for efficient water splitting.

Designing efficient non-precious electrocatalysts to boost water splitting for green energy is a worthy and crucial objective, while it is still an enormous challenge. Herein, single-phase Ni5P4 ultrathin porous nanosheets grown on Ni foam constructed using the three-dimensional single-phase hierarchical nanoflower Ni5P4 (defined as 3D SHF-Ni5P4) were assembled via a simple hydrothermal and phosphating process in an enclosed space. Benefitting from the special structure and morphology of 3D hierarchical porous ultrathin nanosheets, as well as their increasing number of active sites, the 3D SHF-Ni5P4 exhibited outstanding performance with low overpotentials of 180 mV and 106 mV for achieving a current density of 10 mA cm-2 in 1 M KOH toward both the oxygen evolution reaction (OER) and the hydrogen evolution reaction (HER), and the Tafel slopes were 54 mV dec-1 and 79 mV dec-1, respectively. The overall water separation setup, using 3D SHF-Ni5P4 as both the cathode and anode in 1.0 M KOH, achieved a current density of 10 mA cm-2 at a low voltage of 1.47 V, which surpasses that of the commercial Pt C/NF||RuO2/NF (1.52 V). This work highlights an achievable strategy for the controllable fabrication of a 3D single-phase hierarchical nanoflower Ni5P4 electrocatalyst, constructed with ultrathin porous nanosheets containing plenty of active sites. It provided new insights into developing cost-effective single-phase electrocatalysts towards green energy by water splitting.

High aquaporin expression correlates with increased translocation of quinclorac from shoots to roots in resistant Echinochloa crus-galli var. zelayensis.

BACKGROUND: Echinochloa crus-galli var. zelayensis is a troublesome weed in rice fields and can be controlled by using quinclorac. However, over-reliance on quinclorac has resulted in resistant (R) barnyardgrass, which differs significantly in its ability to transport quinclorac compared to susceptible (S) barnyardgrass. This study aimed to investigate the underlying mechanisms for this different translocation between R and S barnyardgrass. RESULTS: Larger amount of quinclorac was transferred from shoots to roots in R compared to S barnyardgrass. After 1 day of quinclorac [300 g active ingredient (a.i.) ha-1 ] foliar treatment, its content in shoots of R was 81.92% of that in S barnyardgrass; correspondingly, in roots of R was 1.17 fold of that in S barnyardgrass. RNA-sequencing and quantitative real-time polymerase chain reaction (qRT-PCR) confirmed the expression levels of PIPs belonging to aquaporins (AQPs) in R were higher than in S barnyardgrass, with or without quinclorac treatment. With co-application of quinclorac and AQPs inhibitors [mercury(II) chloride (HgCl2 )] treatment, even though the expression levels of PIPs and the transport rates of quinclorac were both suppressed in R and S barnyardgrass, this process was less pronounced in R than in S barnyardgrass. CONCLUSION: This report provides clear evidence that higher PIPs expression results in rapid quinclorac translocation from shoots to roots and reduces the quinclorac accumulation in the shoot meristems in R barnyardgrass, thus reducing the control efficacy of quinclorac. © 2022 Society of Chemical Industry.

Toxoplasma gondii infection triggers ongoing inflammation mediated by increased intracellular Cl- concentration in airway epithelium.

Toxoplasma gondii is a widespread parasitic protozoan causing toxoplasmosis including pulmonary toxoplasmosis. As the first line of host defense, airway epithelial cells play critical roles in orchestrating pulmonary innate immunity. However, the mechanism underlying the airway inflammation induced by the T. gondii infection remains largely unclear. This study demonstrated that after infection with T. gondii, the major anion channel located in the apical membranes of airway epithelial cells, cystic fibrosis transmembrane conductance regulator (CFTR), was degraded by the parasite-secreted cysteine proteases. The intracellular Cl- concentration ([Cl-]i) was consequently elevated, leading to activation of nuclear factor-κB (NF-κB) signaling via serum/glucocorticoid regulated kinase 1. Furthermore, the heightened [Cl-]i and activated NF-κB signaling could be sustained in a positive feedback regulatory manner resulting from decreased intracellular cAMP level through NF-κB-mediated up-regulation of phosphodiesterase 4. Conversely, the sulfur-containing compound allicin conferred anti-inflammatory effects on pulmonary toxoplasmosis by decreasing [Cl-]i via activation of CFTR. These results suggest that the intracellular Cl- dynamically modulated by T. gondii mediates sustained airway inflammation, which provides a potential therapeutic target against pulmonary toxoplasmosis.

Bruceine D may affect the phenylpropanoid biosynthesis by acting on ADTs thus inhibiting Bidens pilosa L. seed germination.

Bruceine D is a natural quassinoid, which was successfully isolated in our research group from the residue of Brucea javanica (L.) seeds. Our previous research showed that Bruceine D prevented Bidens pilosa L. seed germination by suppressing the activity of key enzymes and the expression levels of key genes involved in the phenylpropanoid biosynthesis pathway. In this study, integrated analyses of non-targeted metabolomic and transcriptomic were performed. A total of 356 different accumulated metabolites (DAMs) were identified, and KEGG pathway analyses revealed that most of these DAMs were involved in phenylpropanoid biosynthesis. The decreased expression of ADTs and content of L-phenylalanine implicates that Bruceine D may suppress the downstream phenylpropanoid biosynthesis pathway by disrupting primary metabolism, that is, the phenylalanine biosynthesis pathway, thus inhibiting the final products, resulting in the interruption of B. pilosa seed germination. These results suggest that Bruceine D may inhibit the B. pilosa seed germination by suppressing phenylpropanoid biosynthesis through acting on ADTs.

Allicin Facilitates Airway Surface Liquid Hydration by Activation of CFTR.

Airway epithelium plays critical roles in regulating airway surface liquid (ASL), the alteration of which causes mucus stasis symptoms. Allicin is a compound released from garlic and harbors the capacity of lung-protection. However, the potential regulatory effects of allicin on airway epithelium remain elusive. This study aimed to investigate the effects of allicin on ion transport across airway epithelium and evaluate its potential as an expectorant. Application of allicin induced Cl- secretion across airway epithelium in a concentration-dependent manner. Blockade of cystic fibrosis transmembrane conductance regulator (CFTR) or inhibition of adenylate cyclase-cAMP signaling pathway attenuated allicin-induced Cl- secretion in airway epithelial cells. The in vivo study showed that inhaled allicin significantly increased the ASL secretion in mice. These results suggest that allicin induces Cl- and fluid secretion across airway epithelium via activation of CFTR, which might provide therapeutic strategies for the treatment of chronic pulmonary diseases associated with ASL dehydration.

SARS-CoV-2 nucleocapsid protein triggers hyperinflammation via protein-protein interaction-mediated intracellular Cl- accumulation in respiratory epithelium.

SARS-CoV-2, the culprit pathogen of COVID-19, elicits prominent immune responses and cytokine storms. Intracellular Cl- is a crucial regulator of host defense, whereas the role of Cl- signaling pathway in modulating pulmonary inflammation associated with SARS-CoV-2 infection remains unclear. By using human respiratory epithelial cell lines, primary cultured human airway epithelial cells, and murine models of viral structural protein stimulation and SARS-CoV-2 direct challenge, we demonstrated that SARS-CoV-2 nucleocapsid (N) protein could interact with Smad3, which downregulated cystic fibrosis transmembrane conductance regulator (CFTR) expression via microRNA-145. The intracellular Cl- concentration ([Cl-]i) was raised, resulting in phosphorylation of serum glucocorticoid regulated kinase 1 (SGK1) and robust inflammatory responses. Inhibition or knockout of SGK1 abrogated the N protein-elicited airway inflammation. Moreover, N protein promoted a sustained elevation of [Cl-]i by depleting intracellular cAMP via upregulation of phosphodiesterase 4 (PDE4). Rolipram, a selective PDE4 inhibitor, countered airway inflammation by reducing [Cl-]i. Our findings suggested that Cl- acted as the crucial pathological second messenger mediating the inflammatory responses after SARS-CoV-2 infection. Targeting the Cl- signaling pathway might be a novel therapeutic strategy for COVID-19.

G protein-coupled estrogen receptor promotes acrosome reaction via regulation of Ca2+ signaling in mouse sperm†.

G protein-coupled estrogen receptor (GPER), a seven-transmembrane G protein-coupled receptor, mediates the rapid pre-genomic signaling actions of estrogen and derivatives thereof. The expression of GPER is extensive in mammal male reproductive system. However, the functional role of GPER in mouse sperm has not yet been well recognized. This study revealed that GPER was expressed at the acrosome and the mid-flagellum of the mouse sperm. The endogenous GPER ligand 17ß-estradiol and the selective GPER agonist G1 increased intracellular Ca2+ concentration ([Ca2+]i) in mouse sperm, which could be abolished by G15, an antagonist of GPER. In addition, the G1-stimulated Ca2+ response was attenuated by interference with the phospholipase C (PLC) signaling pathways or by blocking the cation channel of sperm (CatSper). Chlortetracycline staining assay showed that the activation of GPER increased the incidence of acrosome-reacted sperm. Conclusively, GPER was located at the acrosome and mid-flagellum of the mouse sperm. Activation of GPER triggered the elevation of [Ca2+]i through PLC-dependent Ca2+ mobilization and CatSper-mediated Ca2+ influx, which promoted the acrosome reaction of mouse sperm.

Cellular mechanism underlying the facilitation of contractile response induced by IL-25 in mouse tracheal smooth muscle.

Asthma is a common heterogeneous respiratory disease characterized by airway inflammation and airway hyperresponsiveness (AHR) which is associated with abnormality in smooth muscle contractility. The epithelial cell-derived cytokine IL-25 is implicated in type 2 immune pathology including asthma, whereas the underlying mechanisms have not been fully elucidated. This study aims to investigate the effects of IL-25 on mouse tracheal smooth muscle contractility and elucidate the cellular mechanisms. Incubation with IL-25 augmented the contraction of mouse tracheal smooth muscles, which could be suppressed by the L-type voltage-dependent Ca2+ channel (L-VDCC) blocker nifedipine. Furthermore, IL-25 enhanced the cytosolic Ca2+ signals and triggered the upregulation of α1C L-VDCC (CaV1.2) in primary cultured mouse tracheal smooth muscle cells. Knocking down IL-17RA/IL-17RB receptors or inhibiting the transforming growth factor-ß-activated kinase 1 (TAK1)-tumor progression locus 2 (TPL2)-MAPK kinase 1/2 (MEK1/2)-ERK1/2-activating protein-1 (AP-1) signaling pathways suppressed the IL-25-elicited upregulation of CaV1.2 and hyperreactivity in tracheal smooth muscles. Moreover, inhibition of TPL2, ERK1/2 or L-VDCC alleviated the AHR symptom induced by IL-25 in a murine model. This study revealed that IL-25 potentiated the contraction of tracheal smooth muscle and evoked AHR via activation of TPL2-ERK1/2-CaV1.2 signaling, providing novel targets for the treatment of asthma with a high-IL-25 phenotype.

Cellular Mechanism Underlying the Facilitation of Contractile Response Induced by Tumor Necrosis Factor-α in Mouse Tracheal Smooth Muscle.

The proinflammatory cytokine tumor necrosis factor-α (TNF-α) augments intracellular Ca2+ signaling and contractile responses of airway smooth muscles, leading to airway hyperresponsiveness. However, the underlying mechanism has not been fully elucidated. This study aimed to investigate the cellular mechanism of the potentiated contraction of mouse tracheal smooth muscle induced by TNF-α. The results showed that TNF-α triggered facilitation of mouse tracheal smooth muscle contraction in an epithelium-independent manner. The TNF-α-induced hypercontractility could be suppressed by the protein kinase C inhibitor GF109203X, the tyrosine kinase inhibitor genistein, the Src inhibitor PP2, or the L-type voltage-dependent Ca2+ channel blocker nifedipine. Following TNF-α incubation, the α1C L-type Ca2+ channel (CaV1.2) was up-regulated in cultured primary mouse tracheal smooth muscle cells. Pronounced phosphotyrosine levels were observed in mouse tracheas. In conclusion, this study shows that TNF-α enhanced airway smooth muscle contraction via protein kinase C-Src-CaV1.2 pathways, which provides novel insights into the pathologic role of proinflammatory cytokines in mediating airway hyperresponsiveness.

Systematic Investigation of Plant-Parasitic Nematodes Associated with Main Subtropical Crops in Guangxi Province, China.

Plant parasitic nematodes (PPNs) are a pathogenic group that causes momentous crop yield loss by retarding plant growth and development through plant parasitization. In this study, the distribution of PPNs based on the main crops in Guangxi Province of China was investigated. A total of 425 samples of soil or roots from sugarcane, rice, maize, and soybean were collected in 68 counties, and a total of 48 order/family/genera of PPNs were identified, of which some genera were found in more than one crop. A total of 31 order/family/genera of PPNs were found in rice, among which Hirschmanniella was the most abundant, accounting for 79.23%, followed by Tylenchorhynchus (34.43%). Forty order/family/genera were observed in maize, of which the dominant genera were Pratylenchus and Tylenchorhynchus at 45.14% and 32.64%, respectively. In addition, 30 order/family/genera of PPNs were detected from sugarcane, and the percentages of Tylenchorhynchus and Helicotylenchus were 70.42% and 39.44%, respectively. The main crop of Eastern ecological regions was rice, with a high frequency of Hirschmanniella. The greatest frequency of Pratylenchus was found in the Western eco-region, which had a large area of maize. In the Northern eco-region, rice and maize were popular, with abundant Hirschmanniella and Helicotylenchus. In the Central eco-region, Pratylenchus was detected on the main crop of sugarcane. Hirschmanniella (72.94%) was dominant in clay, and Tylenchorhynchus (54.17%) showed the highest frequency in loam. The distribution of PPNs varied with different altitudes. The diversity of this phenomenon was closely related to host plants. These results could improve understanding of the distribution of PPNs and provide important information for controlling PPNs.

Trichomonas vaginalis infection impairs anion secretion in vaginal epithelium.

Trichomonas vaginalis is a common protozoan parasite, which causes trichomoniasis associated with severe adverse reproductive outcomes. However, the underlying pathogenesis has not been fully understood. As the first line of defense against invading pathogens, the vaginal epithelial cells are highly responsive to environmental stimuli and contribute to the formation of the optimal luminal fluid microenvironment. The cystic fibrosis transmembrane conductance regulator (CFTR), an anion channel widely distributed at the apical membrane of epithelial cells, plays a crucial role in mediating the secretion of Cl- and HCO3-. In this study, we investigated the effect of T. vaginalis on vaginal epithelial ion transport elicited by prostaglandin E2 (PGE2), a major prostaglandin in the semen. Luminal administration of PGE2 triggered a remarkable and sustained increase of short-circuit current (ISC) in rat vaginal epithelium, which was mainly due to Cl- and HCO3- secretion mediated by the cAMP-activated CFTR. However, T. vaginalis infection significantly abrogated the ISC response evoked by PGE2, indicating impaired transepithelial anion transport via CFTR. Using a primary cell culture system of rat vaginal epithelium and a human vaginal epithelial cell line, we demonstrated that the expression of CFTR was significantly down-regulated after T. vaginalis infection. In addition, defective Cl- transport function of CFTR was observed in T. vaginalis-infected cells by measuring intracellular Cl- signals. Conclusively, T. vaginalis restrained exogenous PGE2-induced anion secretion through down-regulation of CFTR in vaginal epithelium. These results provide novel insights into the intervention of reproductive complications associated with T. vaginalis infection such as infertility and disequilibrium in vaginal fluid microenvironment.

Prostaglandin E2 stimulates anion and fluid secretion triggered by lipopolysaccharide in rat vaginal epithelium.

Prostaglandin E2 (PGE2) is a principal lipid mediator mediating various biological processes including immune responses and fluid secretion. As the first line of host defense against infection, vaginal epithelium plays orchestrated roles in vaginal innate immunity. However, the effect of PGE2 triggered by pro-inflammatory stimuli on vaginal epithelium remains elusive. This study aimed to investigate the regulatory role of PGE2 on vaginal epithelium after lipopolysaccharide (LPS) stimulation. RT-PCR and western blot analysis revealed that E-prostanoid (EP) receptors EP2 and EP4 were expressed in rat vagina. Basolateral application of PGE2 induced anion secretion mediated by cystic fibrosis transmembrane conductance regulator (CFTR) via EP-adenylate cyclase-cAMP signaling pathway in rat vaginal epithelial cells. The in vivo study showed that PGE2 promoted fluid secretion in rat vagina. Moreover, LPS stimulation facilitated cyclooxygenase-dependent PGE2 synthesis and vaginal fluid secretion in vivo. Conclusively, LPS stimulation triggered epithelium-derived PGE2 production in vaginal epithelium, leading to CFTR-mediated anion secretion and luminal flushing. This study provides valuable insights into the physiological role of PGE2 during vaginal bacterial infection.

Cellular mechanism underlying oxytocin-stimulated Cl- secretion in rat cauda epididymal epithelium.

The neurohypophyseal hormone oxytocin (OT) plays critical roles in lactation and parturition, while its function in male reproduction system is largely unknown. This study aims to investigate the effect of OT on regulating transepithelial ion transport in rat cauda epididymal epithelium. With the use of RT-PCR, Western blot, and immunohistochemical analysis, we found that OT receptor (OTR) was expressed and localized at the basal membrane of rat cauda epididymal epithelium. The short-circuit current (Isc) measurement showed that basolateral application of OT to the primary cultured rat cauda epididymal epithelial cells elicited an increase in Isc, which was abrogated by pretreating the epithelial cells with CFTRinh-172, a blocker of cystic fibrosis transmembrane conductance regulator (CFTR). Pretreatment with the prostaglandin H synthase inhibitors indomethacin and piroxicam, or the nonselective antagonists of prostaglandin E2 (PGE2) receptor EP2 or EP4, AH-6809, and AH-23848, significantly attenuated OT-stimulated Isc response. Furthermore, the generation of PGE2 was measured using enzyme-linked immunosorbent assay, demonstrating that OT induced a substantial increase in PGE2 release from primary cultured rat cauda epididymal epithelial cells. In conclusion, activation of OTR by OT triggered PGE2 release, resulting in CFTR-dependent Cl- secretion through paracrine/autocrine pathways in rat cauda epididymal epithelium.

Cellular mechanisms underlying carbon monoxide stimulated anion secretion in rat epididymal epithelium.

Epididymal epithelium possesses active ion transport properties conducive to the maintenance of appropriate epididymal intraluminal microenvironment. The endogenous gasotransmitter carbon monoxide (CO) regulates numerous cellular processes including water and electrolyte transport in various epithelia. However, the functional role of CO in epididymal epithelium is still elusive. This study aims to explore the potential regulatory effect of CO on transepithelial ion transport in rat epididymis. Using qPCR technique, we verified that endogenous CO synthase heme oxygenase 1 was expressed in rat caput, corpus, and cauda epididymis. In addition, endogenous CO was detected in rat cauda epididymis. Ussing chamber experiments showed that CORM-2, a CO donor, induced an increase of the short-circuit current (ISC) in a concentration-dependent manner in rat cauda epididymal epithelium. The ISC response could be abrogated by removing the ambient Cl- or HCO3-. Interfering with the cAMP signaling pathway or blocking cystic fibrosis transmembrane regulator (CFTR) partially suppressed the CO-stimulated ISC response. Moreover, the CO-evoked ISC response was significantly attenuated by blocking Ca2+-activated Cl- channel (CaCC) or chelating intracellular Ca2+. Elevation of intracellular Ca2+ level was also observed after CO stimulation in rat cauda epididymal epithelial cells. Collectively, this study demonstrated that CO stimulated anion secretion via activation of CFTR and CaCC in rat cauda epididymal epithelium, which might contribute to the formation of the appropriate microenvironment essential for sperm storage.

Preparation of Puerarin Chitosan Oral Nanoparticles by Ionic Gelation Method and Its Related Kinetics.

In this paper, as an active ingredient, puerarin chitosan nanoparticles (Pur-CS/TPP-NPs) are prepared by an ionic gelation method. The chitosan (CS) concentration, pH of the CS solution, sodium tripolyphosphate (TPP) concentration, stirring speed, stirring time, ultrasonic power, and dosage are used as single factors for investigation, and the encapsulation efficiency, drug loading capacity, particle size, and polydispersity index (PDI) are used as indicators for investigation. The optimal prescription is determined using the Box-Behnken effect surface design method. The characterization of the best formulation, which is determined via an in vitro release assay and liquid chromatography/tandem mass spectrometry (LC-MS/MS) analysis methods, is used here for pharmacokinetic studies. An in situ single-pass intestinal perfusion model is used to investigate drug absorption in the intestine. After characterization, the morphologies of the nanoparticles are intact. It can be seen from the in vitro release experiments that the equation fitted by the nanoparticles is the Higuchi model, the nanoparticle release process is very stable and without sudden release, indicating that the nanoparticles are well-released in vitro. The pharmacokinetic results and the in situ single-pass intestinal perfusion model study show that the bioavailability and absorption of Pur-CS/TPP-NPs were significantly higher than Pur. Thus, all the results show that the prepared nanoparticles can significantly improve the bioavailability of Pur, and we hope to lay the foundation for the development of new products of Pur.

Weighted gene co-expression network analysis reveals specific modules and hub genes related to neuropathic pain in dorsal root ganglions.

Neuropathic pain is a common, debilitating clinical issue. Here, the weighted gene co-expression network analysis (WGCNA) was used to identify the specific modules and hub genes that are related to neuropathic pain. The microarray dataset of a neuropathic rat model induced by tibial nerve transection (TNT), including dorsal root ganglion (DRG) tissues from TNT model (n=7) and sham (n=8) rats, was downloaded from the ArrayExpress database (E-MTAB-2260). The co-expression network modules were identified by the WGCNA package. The protein-protein interaction (PPI) network was constructed, and the node with highest level of connectivity in the network were identified as the hub gene. A total of 1739 genes and seven modules were identified. The most significant module was the brown module, which contained 215 genes that were primarily associated with the biological process (BP) of the defense response and molecular function of calcium ion binding. Furthermore, C-C motif chemokine ligand 2 (Ccl2), Fos and tissue inhibitor of metalloproteinase 1 (Timp1) which were identified as the hub genes in the PPI network and two subnetworks separately. The in vivo studies validated that mRNA and protein levels of Ccl2, Fos and Timp1 were up-regulated in DRG and spinal cord tissues after TNT. The present study offers novel insights into the molecular mechanisms of neuropathic pain in the context of peripheral nerve injury.

Increased intracellular Cl- concentration mediates Trichomonas vaginalis-induced inflammation in the human vaginal epithelium.

Trichomonas vaginalis is a primary urogenital parasite that causes trichomoniasis, a common sexually transmitted disease. As the first line of host defense, vaginal epithelial cells play critical roles in orchestrating vaginal innate immunity and modulate intracellular Cl- homeostasis via the cystic fibrosis transmembrane conductance regulator (CFTR), an anion channel that plays positive roles in regulating nuclear factor-κB (NF-κB) signalling. However, the association between T. vaginalis infection and intracellular Cl- disequilibrium remains elusive. This study showed that after T. vaginalis infection, CFTR was markedly down-regulated by cysteine proteases in vaginal epithelial cells. The intracellular Cl- concentration ([Cl-]i) was consequently elevated, leading to NF-κB signalling activation via serum- and glucocorticoid-inducible kinase-1. Moreover, heightened [Cl-]i and activated NF-κB signalling could be sustained in a positive feedback regulatory manner resulting from decreased intracellular cAMP through NF-κB-mediated up-regulation of phosphodiesterase 4. The results conclusively revealed that the intracellular Cl- of the human vaginal epithelium could be dynamically modulated by T. vaginalis, which contributed to mediation of epithelial inflammation in the human vagina.

The gasotransmitter hydrogen sulfide inhibits transepithelial anion secretion of pregnant mouse endometrial epithelium.

Endometrial epithelium exhibits a robust ion transport activity required for dynamical regulation of uterine fluid environment and thus embryo implantation. However, there still lacks a thorough understanding of the ion transport processes and regulatory mechanism in peri-implantation endometrial epithelium. As a gaseous signaling molecule or gasotransmitter, hydrogen sulfide (H2S) regulates a myriad of cellular and physiological processes in various tissues, including the modulation of ion transport proteins in epithelium. This study aimed to investigate the effects of H2S on ion transport across mouse endometrial epithelium and its possible role in embryo implantation. The existence of endogenous H2S in pregnant mouse uterus was tested by the detection of two key H2S-generating enzymes and measurement of H2S production rate in tissue homogenates. Transepithelial ion transport processes were electrophysiologically assessed in Ussing chambers on early pregnant mouse endometrial epithelial layers, demonstrating that H2S suppressed the anion secretion by blocking cystic fibrosis transmembrane conductance regulator (CFTR). H2S increased intracellular Cl- concentration ([Cl-]i) in mouse endometrial epithelial cells, which was abolished by pretreatment with the CFTR selective inhibitor CFTRinh-172. The cAMP level in mouse endometrial epithelial cells was not affected by H2S, indicating that H2S blocked CFTR in a cAMP-independent way. In vivo study showed that interference with H2S synthesis impaired embryo implantation. In conclusion, our study demonstrated that H2S inhibits the transepithelial anion secretion of early pregnant mouse endometrial epithelium via blockade of CFTR, contributing to the preparation for embryo implantation.

Differential gene expression profiling of the sciatic nerve in type 1 and type 2 diabetic mice.

Diabetic peripheral neuropathy (DPN) is a common complication of diabetes mellitus (DM). The pathogenic mechanisms of DPN and the therapeutic interventions required may be distinct between type 1 (T1) and type 2 (T2) DM. However, the molecular mechanisms underlying the pathogenesis of DPN in both types of diabetes remain unclear. The aim of the current study was to identify the changes in genes and pathways associated with DPN in sciatic nerves of T1- and T2DM mice using bioinformatics analysis. The microarray profiles of sciatic nerves of T1DM (GSE11343) and T2DM (GSE27382) mouse models were downloaded from the Gene Expression Omnibus database to identify differentially expressed genes (DEGs) in each. DEGs in the two types of DM (with fold change ≥2 and P<0.05) were identified with BRB-ArrayTools. Gene Ontology (GO) term and Kyoto Encyclopedia of Genes and Genomes (KEGG) pathway enrichment analyses were performed using the Database for Annotation, Visualization and Integrated Discovery. A protein-protein interaction (PPI) network was constructed using the Search Tool for the Retrieval of Interacting Genes/Proteins and visualized using Cytoscape. Compared with control samples, 623 and 1,890 DEGs were identified in sciatic nerves of T1- and T2DM mice, respectively. Of these, 75 genes were coordinately dysregulated in the sciatic nerves of both models. Many DEGs unique to T1DM mice were localized to the nucleoplasm and were associated with regulation of transcription processes, while many unique to T2DM mice were localized at cell junctions and were associated with ion transport. In addition, certain DEGs may be associated with the different treatment strategies used for the two types of DM. This analysis provides insight into the functional gene sets and pathways operating in sciatic nerves in T1- and T2DM. The results should improve understanding of the molecular mechanisms underlying the pathophysiology of DPN, and provide information for the development of therapeutic strategies for DPN specific to each type of DM.