scholarly journals Constitutive Expression of Functionally Active Protease-Activated Receptors 1 and 2 in Human Conjunctival Epithelial Cells

2006 ◽  
Vol 2006 ◽  
pp. 1-8 ◽  
Author(s):  
Timothy J. Nickel ◽  
Mohammad H. Kabir ◽  
Jaya Talreja ◽  
Daniel J. Stechschulte ◽  
Kottarappat N. Dileepan

Protease-activated receptors (PARs) are G-protein-coupled receptors which initiate inflammatory responses when activated by specific serine proteases. This study was conducted to examine whether human conjunctival epithelial cells (HCECs) express functionally active PAR1 and PAR2 using Chang conjunctival epithelial cells as in vitro model. We performed RT-PCR and immunofluorescence analyses to determine the expression of PAR1 and PAR2, and monitored the production of IL-6 after activating HCECs with PAR1 activating agents (thrombin or TFLLRN) or PAR2 activating agents (tryptase, trypsin, or SLIGKV). The results show that HCECs constitutively express PAR1 and PAR2 mRNA and proteins, and produce significant amounts of IL-6 when incubated with specific PAR-activating enzymes or agonist peptides. Thrombin- and tryptase-induced HCEC activation was blocked by PAR1 and PAR2 neutralizing antibodies, respectively, and by specific enzyme inhibitors. The constitutive expression of PAR1 and PAR2, and their activation by thrombin and tryptase, respectively, may have important implications in ocular inflammation.

2019 ◽  
Vol 86 (2) ◽  
pp. 177-180
Author(s):  
Jacqueline P. Kurz ◽  
Mark P. Richards ◽  
Matthew Garcia ◽  
Zhongde Wang

AbstractThis Research Communication addresses the hypothesis that exogenously administered phospholipase A2 (PLA2) affects the inflammatory responses of bovine mammary epithelial cells (bMEC) in vitro with the aim of providing preliminary justification of investigation into the uses of exogenously administered PLA2 to manage or treat bovine mastitis. Primary bMEC lines from 11 lactating Holstein dairy cows were established and the expression of 14 pro-inflammatory genes compared under unchallenged and lipopolysaccharide (LPS)-challenged conditions, with and without concurrent treatment with bovine pancreatic PLA2G1B, a secreted form of PLA2. No differences in the expression of these genes were noted between PLA2-treated and untreated bMEC under unchallenged conditions. Following LPS challenge, untreated bMEC exhibited significant downregulation of CXCL8, IL1B, CCL20, and CXCL1. In contrast, PLA2-treated bMEC exhibited significant downregulation of IL1B and CCL20 only. These findings indicate that exogenous PLA2 affects the expression of some pro-inflammatory factors in immune-stimulated bMEC, but does not influence the constitutive expression of these factors. Further investigation of the influence of exogenous PLA2 in the bovine mammary gland is justified.


2021 ◽  
Author(s):  
Yan Lin ◽  
Mingjing Wang ◽  
Zhen Xiao ◽  
Zhiyan Jiang

Abstract Adenoid hypertrophy (AH) can cause harmful effects on untreated children, which include mouth breathing, chronic intermittent hypoxia, sleep disordered breathing (SDB), and even some behavioral problems. However, the molecular mechanisms underlying this pathophysiological process have remained poorly understood. In this study, with use of a variety of biochemical approaches including gene silencing and transiently ectopic protein expression, we examined the molecular effectors involved in this process in an in vitro model of human tonsil epithelial cells (HTECs). We found that a hypoxic condition caused a dramatic upregulation of SUMO-1 expression, a member of the ubiquitin-like protein family, which in turn stabilized hypoxia-inducible factor (HIF)-1α by sumoylating this HIF subunit and thus preventing its ubiquitination and degradation in HTECs. We also found that activating HIF-1α promoted permeability of HTEC cells as well as production and secretion of a variety of proinflammatory cytokines including IL-6, IL-8, and TNF-α, and pro-angiogenic growth factor VEGF. Furthermore, our data showed that hypoxia-induced inflammation was markedly inhibited by M2 macrophages that possess potent anti-inflammatory function. Our results suggest that selectively inhibiting the SUMO-1-HIF-1α signaling pathway leads to inflammatory responses in human tonsil epithelial cells, which might be a novel therapeutic approach for managing hypoxia-induced SDB resulting from AH.


Cytokine ◽  
2008 ◽  
Vol 44 (1) ◽  
pp. 160-167 ◽  
Author(s):  
Amalia Enríquez-de-Salamanca ◽  
Virginia Calder ◽  
Jianping Gao ◽  
Grazyna Galatowicz ◽  
Carmen García-Vázquez ◽  
...  

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Shinjini Chakraborty ◽  
Veronika Eva Winkelmann ◽  
Sonja Braumüller ◽  
Annette Palmer ◽  
Anke Schultze ◽  
...  

AbstractSingular blockade of C5a in experimental models of sepsis is known to confer protection by rescuing lethality and decreasing pro-inflammatory responses. However, the role of inhibiting C5a has not been evaluated in the context of sterile systemic inflammatory responses, like polytrauma and hemorrhagic shock (PT + HS). In our presented study, a novel and highly specific C5a L-aptamer, NoxD21, was used to block C5a activity in an experimental murine model of PT + HS. The aim of the study was to assess early modulation of inflammatory responses and lung damage 4 h after PT + HS induction. NoxD21-treated PT + HS mice displayed greater polymorphonuclear cell recruitment in the lung, increased pro-inflammatory cytokine levels in the bronchoalveolar lavage fluids (BALF) and reduced myeloperoxidase levels within the lung tissue. An in vitro model of the alveolar-capillary barrier was established to confirm these in vivo observations. Treatment with a polytrauma cocktail induced barrier damage only after 16 h, and NoxD21 treatment in vitro did not rescue this effect. Furthermore, to test the exact role of both the cognate receptors of C5a (C5aR1 and C5aR2), experimental PT + HS was induced in C5aR1 knockout (C5aR1 KO) and C5aR2 KO mice. Following 4 h of PT + HS, C5aR2 KO mice had significantly reduced IL-6 and IL-17 levels in the BALF without significant lung damage, and both, C5aR1 KO and C5aR2 KO PT + HS animals displayed reduced MPO levels within the lungs. In conclusion, the C5aR2 could be a putative driver of early local inflammatory responses in the lung after PT + HS.


Biomedicines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 631
Author(s):  
Luis Soriano ◽  
Tehreem Khalid ◽  
Fergal J. O'Brien ◽  
Cian O'Leary ◽  
Sally-Ann Cryan

Translation of novel inhalable therapies for respiratory diseases is hampered due to the lack of in vitro cell models that reflect the complexity of native tissue, resulting in many novel drugs and formulations failing to progress beyond preclinical assessments. The development of physiologically-representative tracheobronchial tissue analogues has the potential to improve the translation of new treatments by more accurately reflecting in vivo respiratory pharmacological and toxicological responses. Herein, advanced tissue-engineered collagen hyaluronic acid bilayered scaffolds (CHyA-B) previously developed within our group were used to evaluate bacterial and drug-induced toxicity and inflammation for the first time. Calu-3 bronchial epithelial cells and Wi38 lung fibroblasts were grown on either CHyA-B scaffolds (3D) or Transwell® inserts (2D) under air liquid interface (ALI) conditions. Toxicological and inflammatory responses from epithelial monocultures and co-cultures grown in 2D or 3D were compared, using lipopolysaccharide (LPS) and bleomycin challenges to induce bacterial and drug responses in vitro. The 3D in vitro model exhibited significant epithelial barrier formation that was maintained upon introduction of co-culture conditions. Barrier integrity showed differential recovery in CHyA-B and Transwell® epithelial cultures. Basolateral secretion of pro-inflammatory cytokines to bacterial challenge was found to be higher from cells grown in 3D compared to 2D. In addition, higher cytotoxicity and increased basolateral levels of cytokines were detected when epithelial cultures grown in 3D were challenged with bleomycin. CHyA-B scaffolds support the growth and differentiation of bronchial epithelial cells in a 3D co-culture model with different transepithelial resistance in comparison to the same co-cultures grown on Transwell® inserts. Epithelial cultures in an extracellular matrix like environment show distinct responses in cytokine release and metabolic activity compared to 2D polarised models, which better mimic in vivo response to toxic and inflammatory stimuli offering an innovative in vitro platform for respiratory drug development.


Author(s):  
Alexa N. Lauer ◽  
Rene Scholtysik ◽  
Andreas Beineke ◽  
Christoph Georg Baums ◽  
Kristin Klose ◽  
...  

Streptococcus suis (S. suis) is an important opportunistic pathogen, which can cause septicemia and meningitis in pigs and humans. Previous in vivo observations in S. suis-infected pigs revealed lesions at the choroid plexus (CP). In vitro experiments with primary porcine CP epithelial cells (PCPEC) and human CP epithelial papilloma (HIBCPP) cells demonstrated that S. suis can invade and traverse the CP epithelium, and that the CP contributes to the inflammatory response via cytokine expression. Here, next generation sequencing (RNA-seq) was used to compare global transcriptome profiles of PCPEC and HIBCPP cells challenged with S. suis serotype (ST) 2 infected in vitro, and of pigs infected in vivo. Identified differentially expressed genes (DEGs) were, amongst others, involved in inflammatory responses and hypoxia. The RNA-seq data were validated via quantitative PCR of selected DEGs. Employing Gene Set Enrichment Analysis (GSEA), 18, 28, and 21 enriched hallmark gene sets (GSs) were identified for infected HIBCPP cells, PCPEC, and in the CP of pigs suffering from S. suis ST2 meningitis, respectively, of which eight GSs overlapped between the three different sample sets. The majority of these GSs are involved in cellular signaling and pathways, immune response, and development, including inflammatory response and hypoxia. In contrast, suppressed GSs observed during in vitro and in vivo S. suis ST2 infections included those, which were involved in cellular proliferation and metabolic processes. This study suggests that similar cellular processes occur in infected human and porcine CP epithelial cells, especially in terms of inflammatory response.


2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Diane Frances Lee ◽  
Graham Roger Stewart ◽  
Mark Andrew Chambers

Abstract Bovine tuberculosis (bTB), a zoonosis mainly caused by Mycobacterium bovis has severe socio-economic consequences and impact on animal health. Host–pathogen interactions during M. bovis infection are poorly understood, especially early events which are difficult to follow in vivo. This study describes the utilisation of an in vitro co-culture model, comprising immortalised bovine alveolar type II (BATII) epithelial cells and bovine pulmonary arterial endothelial cells (BPAECs). When cultured at air–liquid interface, it was possible to follow the migration of live M. bovis Bacille Calmette-Guérin (BCG) and to observe interactions with each cell type, alongside cytokine release. Infection with BCG was shown to exert a detrimental effect primarily upon epithelial cells, with corresponding increases in IL8, TNFα, IL22 and IL17a cytokine release, quantified by ELISA. BCG infection increased expression of CD54, MHC Class I and II molecules in endothelial but not epithelial cells, which exhibited constitutive expression. The effect of peripheral blood mononuclear cell conditioned medium from vaccinated cattle upon apical-basolateral migration of BCG was examined by quantifying recovered BCG from the apical, membrane and basolateral fractions over time. The numbers of recovered BCG in each fraction were unaffected by the presence of PBMC conditioned medium, with no observable differences between vaccinated and naïve animals.


2019 ◽  
Vol 48 (1) ◽  
pp. 197-209 ◽  
Author(s):  
Hongyao Xu ◽  
Xiangjie Zou ◽  
Pengcheng Xia ◽  
Mohammad Ahmad Kamal Aboudi ◽  
Ran Chen ◽  
...  

Background: Meniscal injury is very common, and injured meniscal tissue has a limited healing ability because of poor vascularity. Platelets contain both pro- and anti-angiogenic factors, which can be released by platelet selective activation. Hypothesis: Platelets release a high level of vascular endothelial growth factor (VEGF) when they are activated by protease-activated receptor 1 (PAR1), whereas the platelets release endostatin when they are activated by protease-activated receptor 4 (PAR4). The PAR1-treated platelets enhance the proliferation of meniscal cells in vitro and promote in vivo healing of wounded meniscal tissue. Study Design: Controlled laboratory study. Method: Platelets were isolated from human blood and activated with different reagents. The released growth factors from the activated platelets were determined by immunostaining and enzyme-linked immunosorbent assay. The effects of the platelets with different treatments on meniscal cells were tested by an in vitro model of cell culture and an in vivo model of wounded meniscal healing. Results: The results indicated that platelets contained both pro- and antiangiogenic factors including VEGF and endostatin. In unactivated platelets, VEGF and endostatin were contained inside of the platelets. Both VEGF and endostatin were released from the platelets when they were activated by thrombin. However, only VEGF was released from the platelets when they were activated by PAR1, and only endostatin was released from the platelets when they were activated by PAR4. The rat meniscal cells grew much faster in the medium that contained PAR1-activated platelets than in the medium that contained either PAR4-activated platelets or unactivated platelets. The wounds treated with PAR1-activated platelets healed faster than those treated with either PAR4-activated platelets or unactivated platelets. Many blood vessel–like structures were found in the wounded menisci treated with PAR1-activated platelets. Conclusion: The PAR1-activated platelets released high levels of VEGF, which increased the proliferation of rat meniscal cells in vitro, enhanced the vascularization of menisci in vivo, and promoted healing of wounded menisci. Clinical Relevance: Our results suggested that selective activated platelets can be used clinically to enhance healing of wounded meniscal tissue.


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