Primary Epithelium Research Articles

HAGLR, stabilized by m6A modification, triggers PTEN-Akt signaling cascade-mediated RPE cell pyroptosis via sponging miR-106b-5p.

Consistent hyperglycaemia on retinal microvascular tissues is recognized as a vital inducer of diabetic retinopathy (DR) pathogenesis. In view of the essential functionality of long noncoding RNAs (lncRNAs) in multiple human diseases, we aim to figure out the exact role and underlying mechanisms of lncRNA HOXD Cluster Antisense RNA 1 (HAGLR) in DR pathogenesis. Serum specimens from patients with proliferative DR and healthy volunteers were collected for measuring HAGLR levels. Human primary retinal pigment epithelium (HRPE) cells kept in high glucose (HG) condition were applied to simulating hyperglycaemia of DR pathology in vitro. Cell proliferation, apoptosis, either pyroptosis was assess using Cell Counting Kit-8 TUNEL, flow cytometry, and enzyme-linked immunoassay assays. Bioinformatics analysis was subjected to examine the interaction between HAGLR and N6-methyladenosine (m6A)-bind protein IGF2BP2, as determined using RNA immunoprecipitation and RNA pull-down. Luciferase reporter assay was performed to assess the HAGLR-miR-106b-5p-PTEN axis. Levels of pyroptosis-associated biomarkers were detected using western blotting. Aberrantly overexpressed HAGLR was uncovered in the serum samples of DR patients and HG-induced HRPE cells, of which knockdown attenuated HG-induced cytotoxic impacts on cell apoptosis and pyroptosis. Whereas, reinforced HAGLR further aggravated these effects. IGF2BP2 positively regulated HAGLR in a m6A-dependent manner. HAGLR served as a sponge for miR-106b-5p to upregulate PTEN, thereby activating Akt signaling cascade. Rescue assays demonstrated that PTEN overexpression abolished the inhibition of silenced HAGLR on pyroptosis in HRPE cells. HAGLR, epigenetically modified by IGF2BP2 in an m6A-dependent manner, functioned as a sponge for miR-106b-5p, thereby activating PTEN/Akt signaling cascade to accelerate DR pathology.

Origin and development of primary animal epithelia.

Epithelia are the first organized tissues that appear during development. In many animal embryos, early divisions give rise to a polarized monolayer, the primary epithelium, rather than a random aggregate of cells. Here, we review the mechanisms by which cells organize into primary epithelia in various developmental contexts. We discuss how cells acquire polarity while undergoing early divisions. We describe cases where oriented divisions constrain cell arrangement to monolayers including organization on top of yolk surfaces. We finally discuss how epithelia emerge in embryos from animals that branched early during evolution and provide examples of epithelia-like arrangements encountered in single-celled eukaryotes. Although divergent and context-dependent mechanisms give rise to primary epithelia, here we trace the unifyingprinciples underlying their formation.

Distinct phenotype of SARS-CoV-2 Omicron BA.1 in human primary cells but no increased host range in cell lines of putative mammalian reservoir species

SARS-CoV-2′s genetic plasticity has led to several variants of concern (VOCs). Here we studied replicative capacity for seven SARS-CoV-2 isolates (B.1, Alpha, Beta, Gamma, Delta, Zeta, and Omicron BA.1) in primary reconstituted airway epithelia (HAE) and lung-derived cell lines. Furthermore, to investigate the host range of Delta and Omicron compared to ancestral SARS-CoV-2, we assessed replication in 17 cell lines from 11 non-primate mammalian species, including bats, rodents, insectivores and carnivores. Only Omicron's phenotype differed in vitro, with rapid but short replication and efficient production of infectious virus in nasal HAEs, in contrast to other VOCs, but not in lung cell lines. No increased infection efficiency for other species was observed, but Delta and Omicron infection efficiency was increased in A549 cells. Notably replication in A549 and Calu3 cells was lower than in nasal HAE. Our results suggest better adaptation of VOCs towards humans, without an extended host range, and may be relevant to the search for the putative intermediate host and reservoirs prior to the pandemic.

The RNA binding proteins ZFP36L1 and ZFP36L2 are dysregulated in airway epithelium in human and a murine model of asthma.

Introduction: Asthma is the most common chronic inflammatory disease of the airways. The airway epithelium is a key driver of the disease, and numerous studies have established genome-wide differences in mRNA expression between health and asthma. However, the underlying molecular mechanisms for such differences remain poorly understood. The human TTP family is comprised of ZFP36, ZFP36L1 and ZFP36L2, and has essential roles in immune regulation by determining the stability and translation of myriad mRNAs encoding for inflammatory mediators. We investigated the expression and possible role of the tristetraprolin (TTP) family of RNA binding proteins (RBPs), poorly understood in asthma. Methods: We analysed the levels of ZFP36, ZFP36L1 and ZFP36L2 mRNA in several publicly available asthma datasets, including single cell RNA-sequencing. We also interrogated the expression of known targets of these RBPs in asthma. We assessed the lung mRNA expression and cellular localization of Zfp36l1 and Zfp36l2 in precision cut lung slices in murine asthma models. Finally, we determined the expression in airway epithelium of ZFP36L1 and ZFP36L2 in human bronchial biopsies and performed rescue experiments in primary bronchial epithelium from patients with severe asthma. Results: We found ZFP36L1 and ZFP36L2 mRNA levels significantly downregulated in the airway epithelium of patients with very severe asthma in different cohorts (5 healthy vs. 8 severe asthma; 36 moderate asthma vs. 37 severe asthma on inhaled steroids vs. 26 severe asthma on oral corticoids). Integrating several datasets allowed us to infer that mRNAs potentially targeted by these RBPs are increased in severe asthma. Zfp36l1 was downregulated in the lung of a mouse model of asthma, and immunostaining of ex vivo lung slices with a dual antibody demonstrated that Zfp36l1/l2 nuclear localization was increased in the airway epithelium of an acute asthma mouse model, which was further enhanced in a chronic model. Immunostaining of human bronchial biopsies showed that airway epithelial cell staining of ZFP36L1 was decreased in severe asthma as compared with mild, while ZFP36L2 was upregulated. Restoring the levels of ZFP36L1 and ZFP36L2 in primary bronchial epithelial cells from patients with severe asthma decreased the mRNA expression of IL6, IL8 and CSF2. Discussion: We propose that the dysregulation of ZFP36L1/L2 levels as well as their subcellular mislocalization contributes to changes in mRNA expression and cytoplasmic fate in asthma.

47 Novel detection and infection modeling of Aspergillus fumigatus in pyocyanin-stimulated primary airway epithelium and mucus models

47 Novel detection and infection modeling of Aspergillus fumigatus in pyocyanin-stimulated primary airway epithelium and mucus models

204 Mycobacterium abscessus morphotypes affect mucus-producing responses in cystic fibrosis primary respiratory epithelium differentially

204 Mycobacterium abscessus morphotypes affect mucus-producing responses in cystic fibrosis primary respiratory epithelium differentially

A Novel Primary Porcine Retinal Pigment Epithelium Cell Model with Preserved Properties

Purpose To establish an ethical, reliable, and expandable retinal pigment epithelial (RPE) cell model with maintained RPE properties compatible with multifarious assays. Methods RPE cells from abattoir-obtained porcine eyes were cultured under various conditions. Morphology, RPE cell-specific protein markers (RPE-65, CRALBP), and the tight junction marker ZO-1 were analyzed by phase-contrast microscopy, immunocytochemistry, and western blot, and transepithelial electrical resistance (TEER) was determined to assess barrier function. Results The porcine RPE cells (pRPE) were best established using TrypLE Express, 10% fetal bovine serum (FBS) supplemented high-glucose media, and subculturing at semi-confluency. The pRPE cells maintained epithelioid morphology with ZO-1 positive tight junctions at the cell-to-cell borders, the ability to establish proper barrier function (TEERmax: 346/375 Ω⋅cm2 at passage I/passage VI), and expressed CRALBP and RPE-65 for several passages. The RPE characteristics decreased and disappeared with transdifferentiation. Conclusions This work describes, for the first time, a pRPE cell model that exhibits preserved RPE properties for several passages on cell culture plastic plates. Though RPE characteristics were maintained for at least 6 passages, the reduced CRALBP and RPE-65 with passaging emphasize that lower passage cells are advantageous to utilize, and that morphology, barrier function, and ZO-1 localization cannot be solely employed as a quality measure of RPE identity. Pigs are phylogenetically similar to humans, including similar physiology, anatomy and immune system. Therefore, porcine RPE cells constitute a relevant model system for studying human eye diseases, such as AMD.

Toxicity of crude extract of <i>Terminalia superba</i> sawdust to <i>Clarias gariepinus<i/> (Burchell 1822)

The study examined the toxicity of Afara tree (Terminalia superba) sawdust extract to African catfish, Clarias gariepinus. The fish were exposed to four concentrations 55 ml/L, 60 ml/L, 65 ml/L, 70 ml/L and the control for 96 hours. C. gariepinus juveniles exposed to sublethal concentrations of T. superba extract were examined in a static bioassay with reference to behavioural, haematological and histopathological changes. Early observations of fish exposed to T. superba extract showed erratic swimming, loss of equilibrium and respiratory distress. The behavioural response was dose-dependent and decreased with a decrease in concentration. At 24-96 hours of exposure, there were no significant differences in the temperature and pH (p>0.05) while there was a significant difference (p<0.05) in dissolved oxygen at 48-96 hours. The haematological results showed varying degrees of effects of the extracts on blood parameters. The histopathological changes of the gills of fish exposed to T. superba at 65-70 ml/L showed gills distortion, epithelial hyperplasia and disruption of primary lamellar epithelium and that of gills of fish in the control revealed a normal gill filament. Also, the liver of C. gariepinus of the control fish revealed normal structures. Histology of the liver of C. gariepinus in 65 ml/L and 70 ml/L showed varying degrees of space formation, vacuoles in the tissue and increased haemorrhage. The LC50 value of 53.35 ml/L was gotten. It was therefore concluded that sawmill wood waste did not only impact the water quality but also negatively affected the proper functioning of the gills and liver of C. gariepinus.

Utilization of endogenous albumin trafficking pathways in the lungs has potential to modestly increase the lung interstitial access and absorption of drug delivery systems after inhaled administration

ABSTRACT Objectives Drug delivery systems typically show limited access to the lung interstitium and absorption after pulmonary delivery. The aim of this work was to undertake a proof-of-concept investigation into the potential of employing endogenous albumin and albumin absorption mechanisms in the lungs to improve lung interstitial access and absorption of inhaled drug delivery systems that bind albumin. Methods The permeability of human albumin (HSA) through monolayers of primary human alveolar epithelia, small airway epithelia, and microvascular endothelium were investigated. The pulmonary pharmacokinetics of bovine serum albumin (BSA) was also investigated in efferent caudal mediastinal lymph duct-cannulated sheep after inhaled aerosol administration. Results Membrane permeability coefficient values (Papp) of HSA increased in the order alveolar epithelia<small airway epithelia<microvascular endothelium, where the permeability of HSA through small airway and microvascular endothelia were approximately 4- and 28-fold higher than alveolar epithelia, respectively. Only 6.5% of the delivered BSA aerosol dose was absorbed from the lungs of sheep over 5 days, although half of the absorbed dose was absorbed via the lung lymph. Conclusion Drug delivery systems that bind endogenous albumin may show a modest increase in lung permeability and absorption after inhaled delivery compared to systems that do not efficiently bind albumin.

A single-cell atlas of in vitro multiculture systems uncovers the in vivo lineage trajectory and cell state in the human lung

We present an in-depth single-cell atlas of in vitro multiculture systems on human primary airway epithelium derived from normal and diseased lungs of 27 individual donors. Our large-scale single-cell profiling identified new cell states and differentiation trajectories of rare airway epithelial cell types in human distal lungs. By integrating single-cell datasets of human lung tissues, we discovered immune-primed subsets enriched in lungs and organoids derived from patients with chronic respiratory disease. To demonstrate the full potential of our platform, we further illustrate transcriptomic responses to various respiratory virus infections in vitro airway models. Our work constitutes a single-cell roadmap for the cellular and molecular characteristics of human primary lung cells in vitro and their relevance to human tissues in vivo.

Spatiotemporally organized immunomodulatory response to SARS-CoV-2 virus in primary human broncho-alveolar epithelia

The COVID-19 pandemic continues to be a health crisis with major unmet medical needs. The early responses from airway epithelial cells, the first target of the virus regulating the progression toward severe disease, are not fully understood. Primary human air-liquid interface cultures representing the broncho-alveolar epithelia were used to study the kinetics and dynamics of SARS-CoV-2 variants infection. The infection measured by nucleoprotein expression, was a late event appearing between day 4-6 post infection for Wuhan-like virus. Other variants demonstrated increasingly accelerated timelines of infection. All variants triggered similar transcriptional signatures, an "early" inflammatory/immune signature preceding a "late" type I/III IFN, but differences in the quality and kinetics were found, consistent with the timing of nucleoprotein expression. Response to virus was spatially organized: CSF3 expression in basal cells and CCL20 in apical cells. Thus, SARS-CoV-2 virus triggers specific responses modulated over time to engage different arms of immune response.

Expression of targets of the RNA-binding protein AUF-1 in human airway epithelium indicates its role in cellular senescence and inflammation.

The RNA-binding protein AU-rich-element factor-1 (AUF-1) participates to posttranscriptional regulation of genes involved in inflammation and cellular senescence, two pathogenic mechanisms of chronic obstructive pulmonary disease (COPD). Decreased AUF-1 expression was described in bronchiolar epithelium of COPD patients versus controls and in vitro cytokine- and cigarette smoke-challenged human airway epithelial cells, prompting the identification of epithelial AUF-1-targeted transcripts and function, and investigation on the mechanism of its loss. RNA immunoprecipitation-sequencing (RIP-Seq) identified, in the human airway epithelial cell line BEAS-2B, 494 AUF-1-bound mRNAs enriched in their 3'-untranslated regions for a Guanine-Cytosine (GC)-rich binding motif. AUF-1 association with selected transcripts and with a synthetic GC-rich motif were validated by biotin pulldown. AUF-1-targets' steady-state levels were equally affected by partial or near-total AUF-1 loss induced by cytomix (TNFα/IL1β/IFNγ/10 nM each) and siRNA, respectively, with differential transcript decay rates. Cytomix-mediated decrease in AUF-1 levels in BEAS-2B and primary human small-airways epithelium (HSAEC) was replicated by treatment with the senescence- inducer compound etoposide and associated with readouts of cell-cycle arrest, increase in lysosomal damage and senescence-associated secretory phenotype (SASP) factors, and with AUF-1 transfer in extracellular vesicles, detected by transmission electron microscopy and immunoblotting. Extensive in-silico and genome ontology analysis found, consistent with AUF-1 functions, enriched RIP-Seq-derived AUF-1-targets in COPD-related pathways involved in inflammation, senescence, gene regulation and also in the public SASP proteome atlas; AUF-1 target signature was also significantly represented in multiple transcriptomic COPD databases generated from primary HSAEC, from lung tissue and from single-cell RNA-sequencing, displaying a predominant downregulation of expression. Loss of intracellular AUF-1 may alter posttranscriptional regulation of targets particularly relevant for protection of genomic integrity and gene regulation, thus concurring to airway epithelial inflammatory responses related to oxidative stress and accelerated aging. Exosomal-associated AUF-1 may in turn preserve bound RNA targets and sustain their function, participating to spreading of inflammation and senescence to neighbouring cells.

O-019 Decreased Sperm Motility Associated With Bacterial Vaginosis Modeled in a Human Cervix Chip

Abstract Study question What is the underlying cause of infertility associated with bacterial vaginosis (BV)? Summary answer We provide the first evidence to suggest that BV-associated infertility could be the result of sperm dysfunction induced by exposure to poor cervical microbiome. What is known already Infertility is a global health concern, impacting 186 million individuals worldwide. In 25% of infertile couples the underlying cause remains unexplained. The complex interactions between the host mucosal epithelium, microbiome, and other microenvironmental factors play a significant role in health and disease of the reproductive tract. BV affects 30% of reproductive-aged women and is linked to overgrowth of pathogenic Gardnerella vaginalis bacteria. BV has a strong association with infertility, but it is not clear whether the resulting changes in the vaginal microbiome play a causal role, and as such BV screening is not currently included in infertility evaluation or treatment Study design, size, duration Female reproductive tract protective factors such as cervical mucus helps sperm retain their ability to fertilize for days compared to hours in suspension. We previously leveraged human organ-on-a-chip microfluidic culture technology to develop a physiological in vitro model of human cervix (Cervix Chip) that is lined with primary cervical epithelium interfaced with stromal fibroblasts. The epithelium forms a functional tissue barrier and produces mucus with compositional, biophysical, and hormone-responsive properties similar to the living cervix. Participants/materials, setting, methods We used 2D culture of sperm and bacteria as a screening and validated the effect of the identified bacteria on physiological in vitro Cervix Chip. A BV consortium containing E2 and E4 Gardnerella vaginalis bacteria was co-cultured with the Cervix Chip for 48 hours before adding human sperm samples. The motility of fluorescently labeled sperm was non-invasively evaluated in live chips using time-lapse imaging and quantitatively analyzed to obtain the percentage of motile sperm. Main results and the role of chance We initially analyzed the effects of bacterial co-cultur L. crispatus (optimal) or G. vaginalis (suboptimal) bacteria on sperm motility using a conventional 2D culture system. We observed a significant drop in sperm motility within 2 hours when exposed to G. vaginalis compared to L. crispatus or the control condition (no bacteria). We have established sperm staining and live tracking on Cervix Chip. Motile sperm was tracked on Cervix Chip for more than 7 days compared to 12 hours in suspension. We then tested this effect on-chip and observed that co-culture of live sperm with dysbiotic Cervix Chip (infected with G. vaginalis) resulted in a significant reduction in the sperm motility within 24 hours after exposure compared to the sperm exposed to the chips without bacteria. The dysbiotic Cervix Chip also exhibited a disease phenotype with elevated levels of proinflammatory cytokines including IL-1α, IL-1β, IL-6, IL-8, and TNF-α in the effluents of the chip's epithelial channel as well as significantly reduced thickness of the cervical mucus layer that correlated with reduced sperm motility. This finding is consistent with the observation that successful fertility is often associated with the quality of cervical mucus, which can be compromised in the BV dysbiotic condition. Limitations, reasons for caution Primary cervical epithelium cells used in the study were sourced from a single donor. Frozen sperm samples prepared for intrauterine insemination were used in the study Wider implications of the findings Our study suggests that infertility related to BV may be caused by sperm dysfunction, and BV screening should be considered in patients with unexplained infertility. We propose a model that can be used to identify dysbiotic conditions in the female reproductive tract that are unfavorable to sperm motility. Trial registration number N/A

Isolation and Characterization of the Primary Marmoset (Callithrix jacchus) Retinal Pigment Epithelial Cells.

Marmosets have emerged as a valuable primate model in ophthalmic research due to their similarity to the human visual system and their potential for generating transgenic models to advance the development of therapies. In this study, we isolated and cultured primary retinal pigment epithelium (RPE) cells from marmosets to investigate the mechanisms underlying RPE dysfunction in aging and age-related macular degeneration (AMD). We confirmed that our culture conditions and materials supported the formation of RPE monolayers with functional tight junctions that closely resembled the in vivo RPE. Since serum has been shown to induce epithelial-mesenchymal transition (EMT) in RPE cells, we compared the effects of fetal bovine serum (FBS) with serum-free supplements B27 on transepithelial electrical resistance (TER), cell proliferation, and morphological characteristics. Additionally, we assessed the age-related morphological changes of in vivo and primary RPE cells. Our results indicate that primary marmoset RPE cells exhibit in vivo-like characteristics, while cells obtained from an older donor show evidence of aging, including a failure to form a polarized monolayer, low TER, and delayed cell cycle. In conclusion, our primary marmoset RPE cells provide a reliable in vitro model for developing novel therapeutics for visual-threatening disorders such as AMD, which can be used before animal experiments using marmosets.

Crypt-like patterned electrospun nanofibrous membrane and probiotics promote intestinal epithelium models close to tissues.

In vitro intestinal epithelium models have drawn great attention to investigating intestinal biology in recent years. However, the difficulty to maintain the normal physiological status of primary intestinal epithelium in vitro limits the applications. Here, we designed patterned electrospun polylactic acid (PLA) nanofibrous membranes with crypt-like topography and mimic ECM fibrous network to support crypt culture and construct in vitro intestinal epithelium models. The patterned electrospun PLA nanofibrous membranes modified with Matrigels at 0°C showed high biocompatibility and promoted cell growth and proliferation. The constructed duodenum epithelium models and colon epithelium models on the patterned electrospun PLA nanofibrous membranes expressed the typical differentiation markers of intestinal epithelia and the gene expression levels were close to the original tissues, especially with the help of probiotics. The constructed intestinal epithelium models could be used to assess probiotic adhesion and colonization, which were verified to show significant differences with the Caco-2 cell models due to the different cell types. These findings provide new insights and a better understanding of the roles of biophysical, biochemical, and biological signals in the construction of in vitro intestinal epithelium models as well as the potential applications of these models in the study of host-gut microbes interactions. KEY POINTS: • Patterned electrospun scaffold has crypt-like topography and ECM nanofibrous network. • Matrigels at 0°C modify scaffolds more effectively than at 37°C. • Synergy of biomimic scaffold and probiotics makes in vitro model close to tissue.

Efficacy of butterbur in allergic rhinitis: a cell culture study.

The study aims to define butterbur's impact on nasal cells' viability and proliferation. After topically administering butterbur to the nasal epithelial cells, research has been done to see if butterbur has any harmful effect on the nasal cells. Specimens of healthy primary nasal epithelium were collected from the subjects and incubated in cell culture in due course of septoplasty. After implementing 2.5 µM butterbur in cultured cells, cell viability was defined via trypan blue assay, and proliferation was defined via the XTT method. The number of total cells, viability, and proliferation was defined. XTT (2, 3-bis-(2-methoxy-4-nitro-5-sulphophenyl)-2H-tetrazolium-5-carboxanilide) experiments can be used to evaluate cellular toxicity. The findings of the XTT experiment reveal no harm to nasal cells after topical implementation of butterbur. No significant change in the proliferation of the cells, no matter what the doses are. There was no cytotoxic effect on the primary nasal cells at the end of 24 hours of implementation, and no side effects were found. There was no difference in cells' viability between the experimental group with butterbur application and the control group. Cytotoxicity on nasal cells was not observed after the butterbur application. Even if there have been some indications of liver toxicity, butterbur can be suggested as a safe option for seasonal allergic rhinitis. Further studies related to the toxicity of topical butterbur are also recommended, even though this study indicates no cytotoxicity from the topical application on nasal cells.

An IFNT/FOXO1/PTGS2 axis regulates prostaglandin F2α synthesis in goat uterus during early pregnancy

In ruminants, interferon tau (IFNT) regulates the production of prostaglandins (PGs) in the endometrium, which is crucial for conceptus adhesion. However, the related molecular regulatory mechanisms remain unclear. Forkhead box O1 (FOXO1), a member of the FOXO subfamily of transcription factors, is known to be important for mouse implantation and decidualization. In this study, we determined the spatiotemporal expression profile of FOXO1 in goat endometrium during early pregnancy. FOXO1 was highly expressed in the glandular epithelium (GE) since the onset of conceptus adhesion (d 16 of pregnancy). Then, we validated that FOXO1 could bind to the promoter of prostaglandin-endoperoxide synthase 2 (PTGS2) and increase its transcription. And the expression profile of PTGS2 was similar to that of FOXO1 in the peri-implantation uterus. Moreover, IFNT could upregulate the levels of FOXO1 and PTGS2 in goat uterus and primary endometrial epithelium cells (EECs). In EECs, the intracellular content of PGF2α was positively correlated with the levels of IFNT and FOXO1. Altogether, we found an IFNT/FOXO1/PTGS2 axis that controls the synthesis of PGF2α but not PGE2 in goat uterine glands. These findings contribute to better understanding the function of FOXO1 in the reproductive physiology of goats and provide more insights into the implantation of small ruminants.

Is tannic acid a promising option in local treatment of nasal diseases?

We investigated the effects of tannic acid on viability and proliferation of nasal cells after topical application. It was also evaluated whether tannic acid served as an alternative treatment agent. Collected primary nasal epithelium from healthy people who had undergone septoplasty operations were incubated in cell culture. Following the implementation of 2.5 µM tannic acid in cultured cells, both the number of total cells and their viability were measured using the trypan blue assay, while proliferation was assessed through the XTT method. The XTT method, which involves using "2,3-bis-(2-methoxy-4-nitro-5-sulphophenyl)-2H-tetrazolium-5-carboxanilide", is a reliable means of determining cellular toxicity. XTT experiment results showed that there was no harm was detected to nasal cells after tannic acid's topical implementation. There were no significant changes in cell proliferation; moreover, no matter what the doses were. Additionally, no cytotoxic effects were detected on nasal cells' primary culture at "the end of the 24 hours of implementation". There was no side effect of it, either. According to the research, the application of tannic acid topically did not result in any harmful effects on the nasal cell culture. Tannic acid's potential anti-inflammatory properties and its ability to decrease Th2-related cytokines suggest that it may be beneficial for patients with rhinosinusitis or allergic rhinitis, pending confirmation through clinical trials. Additionally, if clinical trials confirm its effectiveness, tannic acid may be useful in healing wounds for patients undergoing septorhinoplasty.

Comparison of Fucoidans from Saccharina latissima Regarding Age-Related Macular Degeneration Relevant Pathomechanisms in Retinal Pigment Epithelium.

Fucoidans from brown algae are described as anti-inflammatory, antioxidative, and antiangiogenic. We tested two Saccharina latissima fucoidans (SL-FRO and SL-NOR) regarding their potential biological effects against age-related macular degeneration (AMD). Primary porcine retinal pigment epithelium (RPE), human RPE cell line ARPE-19, and human uveal melanoma cell line OMM-1 were used. Cell survival was assessed in tetrazolium assay (MTT). Oxidative stress assays were induced with erastin or H2O2. Supernatants were harvested to assess secreted vascular endothelial growth factor A (VEGF-A) in ELISA. Barrier function was assessed by measurement of trans-epithelial electrical resistance (TEER). Protectin (CD59) and retinal pigment epithelium-specific 65 kDa protein (RPE65) were evaluated in western blot. Polymorphonuclear elastase and complement inhibition assays were performed. Phagocytosis of photoreceptor outer segments was tested in a fluorescence assay. Secretion and expression of proinflammatory cytokines were assessed with ELISA and real-time PCR. Fucoidans were chemically analyzed. Neither toxic nor antioxidative effects were detected in ARPE-19 or OMM-1. Interleukin 8 gene expression was slightly reduced by SL-NOR but induced by SL-FRO in RPE. VEGF secretion was reduced in ARPE-19 by SL-FRO and in RPE by both fucoidans. Polyinosinic:polycytidylic acid induced interleukin 6 and interleukin 8 secretion was reduced by both fucoidans in RPE. CD59 expression was positively influenced by fucoidans, and they exhibited a complement and elastase inhibitory effect in cell-free assay. RPE65 expression was reduced by SL-NOR in RPE. Barrier function of RPE was transiently reduced. Phagocytosis ability was slightly reduced by both fucoidans in primary RPE but not in ARPE-19. Fucoidans from Saccharina latissima, especially SL-FRO, are promising agents against AMD, as they reduce angiogenic cytokines and show anti-inflammatory and complement inhibiting properties; however, potential effects on gene expression and RPE functions need to be considered for further research.

Rhinovirus-induced epithelial RIG-I inflammasome suppresses antiviral immunity and promotes inflammation in asthma and COVID-19

Rhinoviruses and allergens, such as house dust mite are major agents responsible for asthma exacerbations. The influence of pre-existing airway inflammation on the infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is largely unknown. We analyse mechanisms of response to viral infection in experimental in vivo rhinovirus infection in healthy controls and patients with asthma, and in in vitro experiments with house dust mite, rhinovirus and SARS-CoV-2 in human primary airway epithelium. Here, we show that rhinovirus infection in patients with asthma leads to an excessive RIG-I inflammasome activation, which diminishes its accessibility for type I/III interferon responses, leading to their early functional impairment, delayed resolution, prolonged viral clearance and unresolved inflammation in vitro and in vivo. Pre-exposure to house dust mite augments this phenomenon by inflammasome priming and auxiliary inhibition of early type I/III interferon responses. Prior infection with rhinovirus followed by SARS-CoV-2 infection augments RIG-I inflammasome activation and epithelial inflammation. Timely inhibition of the epithelial RIG-I inflammasome may lead to more efficient viral clearance and lower the burden of rhinovirus and SARS-CoV-2 infections.