Epithelial Cell Death Research Articles

Rosmarinic acid plus deferasirox inhibits ferroptosis to alleviate crush syndrome-related AKI via Nrf2/Keap1 pathway

BackgroundMyoglobin (Mb) induced death of renal tubular epithelial cells (RTECs) is a major pathological factor in crush syndrome-related acute kidney injury (CS-AKI). It is unclear whether ferroptosis is involved and could be a target for treatment. PurposeThis study aimed to evaluate the potential therapeutic effects of combining the natural small molecule rosemarinic acid (RA) and the iron chelator deferasirox (Dfe) on CS-AKI through inhibition of ferroptosis. MethodsSequencing data were downloaded from the GEO database, and differential expression analysis was performed using the R software limma package. The CS-AKI mouse model was constructed by squeezing the bilateral thighs of mice for 16 h with 1.5 kg weight. TCMK1 and NRK-52E cells were induced with 200 μM Mb and then treated with RA combined with Dfe (Dfe + RA, both were 10 μM). Functional and pathological changes in mouse kidney were evaluated by glomerular filtration rate (GFR) and HE pathology. Immunofluorescence assay was used to detect Mb levels in kidney tissues. The expression levels of ACSL4, GPX4, Keap1, and Nrf2 were analyzed by WB. ResultsWe found that AKI mice in the GSE44925 cohort highly expressed the ferroptosis markers ACSL4 and PTGS2. CS-AKI mice showed a rapid decrease in GFR, up-regulation of ACSL4 expression in kidney tissue, and down-regulation of GPX4 expression, indicating activation of the ferroptosis pathway. Mb was found to deposit in renal tubules, and it has been proven to cause ferroptosis in TCMK1 and NRK-52E cells in vitro. We found that Dfe had a strong iron ion scavenging effect and inhibited ACSL4 expression. RA could disrupt the interaction between Keap1 andNrf2, stabilize Nrf2, and promote its nuclear translocation, thereby exerting antioxidant effects. The combination of Dfe and RA effectively reversed Mb induced ferroptosis in RTECs. ConclusionIn conclusion, we found that RA combined with Dfe attenuated CS-AKI by inhibiting Mb-induced ferroptosis in RTECs via activating the Nrf2/Keap1 pathway.

The artificial sweetener neotame negatively regulates the intestinal epithelium directly through T1R3-signaling and indirectly through pathogenic changes to model gut bacteria.

Recent studies have indicated considerable health risks associated with the consumption of artificial sweeteners. Neotame is a relatively new sweetener in the global market however there is still limited data on the impact of neotame on the intestinal epithelium or the commensal microbiota. In the present study, we use a model of the intestinal epithelium (Caco-2) and microbiota (Escherichia coli and Enterococcus faecalis) to investigate how physiologically-relevant exposure of neotame impacts intestinal epithelial cell function, gut bacterial metabolism and pathogenicity, and gut epithelium-microbiota interactions. Our findings show that neotame causes intestinal epithelial cell apoptosis and death with siRNA knockdown of T1R3 expression significantly attenuating the neotame-induced loss to cell viability. Similarly, neotame exposure results in barrier disruption with enhanced monolayer leak and reduced claudin-3 cell surface expression through a T1R3-dependent pathway. Using the gut bacteria models, E. coli and E. faecalis, neotame significantly increased biofilm formation and metabolites of E. coli, but not E. faecalis, reduced Caco-2 cell viability. In co-culture studies, neotame exposure increased adhesion capacity of E. coli and E. faecalis onto Caco-2 cells and invasion capacity of E. coli. Neotame-induced biofilm formation, E.coli-specific Caco-2 cell death, adhesion and invasion was identified to be meditated through a taste-dependent pathway. Our study identifies novel pathogenic effects of neotame on the intestinal epithelium or bacteria alone, and in co-cultures to mimic the gut microbiome. These findings demonstrate the need to better understand food additives common in the global market and the molecular mechanisms underlying potential negative health impacts.

The role of HPV11 E7 in modulating STING-dependent interferon β response in recurrent respiratory papillomatosis.

Recurrent respiratory papillomatosis (RRP) is a rare benign tumor caused mainly by the infection of the respiratory tract epithelial cells by the human papillomavirus (HPV) type 6/11. However, the specific mechanisms underlying the inhibition of the host's innate immune response by HPV remain unclear. For this purpose, we employed single-cell RNA sequencing to analyze the states of various immune cells in RRP samples post-HPV infection and utilized a cellular model of HPV infection to elucidate the mechanisms by which HPV evades the innate immune system in RRP. The results revealed distinct immune cell heterogeneity in RRP and demonstrated that HPV11 E7 can inhibit the phosphorylation of the stimulator of interferon genes protein, thereby circumventing the body's antiviral response. In vitro co-culture experiments demonstrated that stimulation of macrophages to produce interferon-beta induced the death of HPV-infected epithelial cells, also reducing HPV viral levels. In summary, our study preliminarily identifies the potential mechanisms by which HPV evades the host's antiviral immune response, as well as the latent antiviral functions exhibited by activated macrophages. This research serves as an initial exploration of antiviral immune evasion in RRP, laying a solid foundation for investigating immunotherapeutic approaches for the disease.IMPORTANCESurgical tumor reduction is the most common treatment for recurrent respiratory papillomatosis (RRP). One of the characteristics of RRP is its persistent recurrence, and multiple surgeries are usually required to control the symptoms. Recently, some adjuvant therapies have shown effectiveness, but none of them can completely clear human papillomavirus (HPV) infection, and thus, a localized antiviral immune response is significant for disease control; after all, HPV infection is limited to the epithelium. Inhibition of interferon-beta (IFN-β) secretion by HPV11 E7 viral proteins in epithelial cells by affecting stimulator of interferon genes phosphorylation may account for the persistence of low-risk HPV replication in the RRP. Moreover, suppression of the IFN-I pathway in RRP cell types might provide clues regarding the hyporeactive function of local immune cells. However, activation of macrophage groups to produce IFN-β can still destroy HPV-infected cells.

A novel ESIPT fluorescent probe for early detection and assessment of ferroptosis-mediated acute kidney injury via peroxynitrite fluctuation

BackgroundAcute kidney injury (AKI) poses a severe risk to public health, mostly manifested by damage and death of renal tubular epithelial cells. However, routine blood examination, a conventional approach for clinical detection of AKI, is not available for identifying early-stage AKI. Plenty of reported methods were lack of early biomarkers and real time evaluation tools, which resulted in a vital challenge for early diagnosis of AKI. Therefore, developing novel probes for early detection and assessment of AKI is exceedingly crucial. ResultsBased on ESIPT mechanism, a new fluorescent probe (MEO-NO) with 2-(2′-hydroxyphenyl) benzothiazole (HBT) derivatives as fluorophore has been synthesized for dynamic imaging peroxynitrite (ONOO−) levels in ferroptosis-mediated AKI. Upon the addition of ONOO−, MEO-NO exhibited obvious fluorescence changes, a significant Stokes shift (130 nm) and rapid response (approximately 45 s), and featured exceptional sensitivity (LOD = 7.28 nM) as well as high selectivity from the competitive species at physiological pH. In addition, MEO-NO was conducive to the biological depth imaging ONOO− in cells, zebrafish, and mice. Importantly, MEO-NO could monitor ONOO− levels during sorafenib-induced ferroptosis and CP-induced AKI. With the assistance of MEO-NO, we successfully visualized and tracked ONOO− variations for early detection and assessment of ferroptosis-mediated AKI in cells, zebrafish and mice models. Significance and noveltyBenefiting from the superior performance of MEO-NO, experimental results further demonstrated that the levels of ONOO− was overexpressed during ferroptosis-mediated AKI in cells, zebrafish, and mice models. The developed novel probe MEO-NO provided a strong visualization tool for imagining ONOO−, which might be a potential method for the prevention, diagnosis, and treatment of ferroptosis-mediated AKI.

Artemisinin Confers Cytoprotection toward Hydrogen Peroxide-Induced Cell Apoptosis in Retinal Pigment Epithelial Cells in Correlation with the Increased Acetylation of Histone H4 at Lysine 8.

Increased oxidative stress is one of the critical pathologies inducing age-related macular degeneration (AMD), characterized by retinal pigment epithelial (RPE) cell damage and death. The unbalanced acetylation and deacetylation of histones have been implicated in AMD pathogenesis or hydrogen peroxide (H2O2)-induced cell damage. Therefore, strategies aimed at controlling the balance between acetylation and deacetylation may effectively protect RPE cells from oxidative damage. Artemisinin is an antimalarial lactone drug derived from Artemisia annua, with antioxidant activity known to modulate histone acetylation in the brain, but its effect on the retina is unknown. In this study, we aimed to investigate whether Artemisinin exerts a cytoprotective effect on oxidative stress-induced apoptosis in RPE cells by regulating histone acetylation. We hypothesized that Artemisinin confers cytoprotection toward H2O2-induced apoptosis in RPE cells through this mechanism. In the present study, we found that Artemisinin at a sub-clinic dosage of 20 μM inhibited the H2O2-induced cell viability decrease and B-cell lymphoma 2 (Bcl-2) protein level decrease and attenuated the H2O2-induced decrease in the histone H4 lysine (Lys) 8 acetylation [Acetyl-H4 (Lys 8)] level in the retinal RPE cell line D407. As expected, histone deacetylase inhibitor Trichostatin A at the concentration of 250 nM increased the Acetyl-H4 (Lys 8) level in D407 cells and attenuated the H2O2-induced cell viability decrease and apoptosis. Similar findings were obtained using adult RPE (ARPE)19 cells, another human RPE cell line, and primary human RPE cell cultures. In conclusion, these results confirmed our hypothesis and indicated that Artemisinin attenuated H2O2-induced apoptosis in apparent correlation with the increase in the Acetyl-H4 (Lys 8) level, which is associated with gene transcription and cell survival. By modulating histone acetylation, Artemisinin may restore the balance between acetylation and deacetylation and enhance the resistance and survival of RPE cells under oxidative stress. Our study provides novel mechanistic insights into the effect of Artemisinin on histone acetylation and apoptosis in RPE cells and supports the potential application of Artemisinin in the prevention and/or treatment of AMD.

Global properties of SARS‐CoV‐2 and IAV coinfection model with distributed‐time delays and humoral immunity

Severe acute respiratory syndrome coronavirus 2 (SARS‐CoV‐2) and influenza A virus (IAV) are two respiratory viruses and are similar concerning seasonal occurrence, transmission routes, clinical manifestations, and related immune responses. Recent studies showed that a substantial number of patients infected by SARS‐CoV‐2 were also coinfected with IAV. In this paper, we study the global properties of SARS‐CoV‐2 and IAV coinfection model in vivo. The role of humoral (antibody) immunity in controlling the coinfection is modeled. The model tracks uninfected epithelial cells, latent SARS‐CoV‐2‐infected epithelial cells, latent IAV‐infected epithelial cells, active SARS‐CoV‐2‐infected epithelial cells, active IAV‐infected epithelial cells, free SARS‐CoV‐2 particles, free IAV particles, SARS‐CoV‐2‐specific antibodies and IAV‐specific antibodies. The model includes six distributed‐time delays, two delays for the formation of latent SARS‐CoV‐2‐infected and latent IAV‐infected cells; two delays for the reactivation of latent SARS‐CoV‐2‐infected cells and latent IAV‐infected cells; and two delays for the maturation of new released SARS‐CoV‐2 and IAV virions. The regeneration and death of the uninfected epithelial cells are considered. We first examine the basic qualitative properties of the model, then we calculate all equilibria and prove their global stability. The global stability of equilibria is established using the Lyapunov method. The theoretical findings are demonstrated via numerical simulations. The importance of considering humoral immunity in the coinfection dynamics model is discussed. It is found that without modeling the humoral immunity, the case of IAV and SARS‐CoV‐2 coexistence will not occur. We discuss the effect of time delays on the dynamics of SARS‐CoV‐2 and IAV coinfection. It is noted that increasing the time delay length has similar impact as antiviral therapies.

Bronchoconstriction damages airway epithelia by crowding-induced excess cell extrusion.

Asthma is deemed an inflammatory disease, yet the defining diagnostic feature is mechanical bronchoconstriction. We previously discovered a conserved process called cell extrusion that drives homeostatic epithelial cell death when cells become too crowded. In this work, we show that the pathological crowding of a bronchoconstrictive attack causes so much epithelial cell extrusion that it damages the airways, resulting in inflammation and mucus secretion in both mice and humans. Although relaxing the airways with the rescue treatment albuterol did not affect these responses, inhibiting live cell extrusion signaling during bronchoconstriction prevented all these features. Our findings show that bronchoconstriction causes epithelial damage and inflammation by excess crowding-induced cell extrusion and suggest that blocking epithelial extrusion, instead of the ensuing downstream inflammation, could prevent the feed-forward asthma inflammatory cycle.

Foxq1 Promotes Alveolar Epithelial Cell Death through Tle1-mediated Inhibition of the NFκB Signaling Pathway.

Acute lung injury is a common respiratory disease characterized by diffuse alveolar injury and interstitial edema, as well as a hyperinflammatory response, lung cell damage and oxidative stress. Foxq1, a member of the FOX family of transcription factors, is expressed in various tissues, such as the lungs, liver, and kidneys, and contributes to various biological processes, such as stress, metabolism, cell cycle arrest, and aging-related apoptosis. However, the role of Foxq1 in acute lung injury is unknown. We constructed ex vivo and in vivo acute lung injury models by lipopolysaccharide tracheal perfusion of ICR mice and conditioned medium stimulation of injured MLE-12 cells. Foxq1 expression was increased, and its localization was altered in our acute lung injury model. In normal or injured MLE-12 cells, knockdown of Foxq1 promoted cell survival, and overexpression had the opposite effect. This regulatory effect was likely mediated by Tle1 and the NFκB/Bcl2/Bax signaling pathway. These data suggest a potential link between Foxq1 and acute lung injury, indicating that Foxq1 can be used as a biomarker for the diagnosis of acute lung injury. Targeted inhibition of Foxq1 expression could promote alveolar epithelial cell survival and may provide a strategy for mitigating acute lung injury.

Up-regulation of HSP90α in HDM-induced asthma causes pyroptosis of airway epithelial cells by activating the cGAS-STING-ER stress pathway

Heat Shock protein 90 α (HSP90α), an main subtype of chaperone protein HSP90, involves important biological functions such as DNA damage repair, protein modification, innate immunity. However, the potential role of HSP90α in asthma occurrence and development is still unclear. This study aimed to elucidate the underlying mechanism of HSP90α in asthma by focusing on the cGAS-STING-Endoplasmic Reticulum stress pathway in inflammatory airway epithelial cell death (i.e., pyroptosis; inflammatory cell death). To accomplish that, we modeled allergen exposure in C57/6BL mice and bronchial epithelial cells with house dust mite. Protein technologies and immunofluorescence utilized to study the expression of HSP90α, activation of cGAS-STING pathway and pyroptosis. The effect of inhibitors on HDM-exposed mice detected by histological techniques and examination of bronchoalveolar lavage fluid. Results showed that HSP90α promotes asthma inflammation via pyroptosis and activation of the cGAS-STING-ER stress pathway. Treatment with the HSP90 inhibitor tanespimycin (17-AAG) significantly relieved airway inflammation and abrogated the effect of HSP90α on pyroptosis and cGAS-STING-ER stress in vitro and in vivo models of HDM. Further data indicated that up-regulation of HSP90α stabilized STING through interaction, which increased localization of STING on the ER. Activation of STING triggered ER stress and leaded to pyroptosis-related airway inflammation. The finding showed the potential role of pyroptosis caused by dysregulation of HSP90α on airway epithelial cells in allergic inflammation, suggested that targeting HSP90α in airway epithelial cells might prove to be a potential additional treatment strategy for asthma.

High fructose Corn Syrup recast glucose transporter-5, Wnt, NF-κB signalling and mitochondrial apoptosis in an animal model of oral oncogenesis

BackgroundWnt signalling pathway, is mediated by members of T-cell factor (TCF) transcription factors family, is essential for the control of epithelial cell proliferation and death. Glucose transporter-5 (GLUT5), fructose-specific transporter, is also important in allowing transcellular fructose uptake. The goal of this work to determine how the High fructose Corn Syrup (HFCS) affected Wingless-related integration site (Wnt) and Nuclear factor kappa-light-chain-enhancer of activated B cells (NF-κB) signalling in the 7,12 –dimethylbenzaanthracene (DMBA)-induced hamster buccal pouch carcinogenesis (HBPCs) model. MethodsFour groups of hamsters were created. For 12 weeks, 0.5 % DMBA was applied 3 times/week to the left side buccal pouches of the hamsters in groups (2 & 4). Additionally, the animals in groups (3 & 4) were given through drinking water of HFCS 25 %. The control animals were from group 1. By using western blot analysis, signalling network markers of the GLUT-5, Wnt, TCF-4, GSK-3β and NF-κB as well as mitochondrial apoptotic pathway marker expression B-cell lymphoma protein 2 (Bcl-2)-associated X (Bax) and cyclooxygenase – 2 (COX-2) was assessed. ResultsDrinking water uptake of 25% HFCS encouraged progress of HBP carcinomas by constitutive stimulating of the Wnt pathway via GSK-3β overexpression. HFCS suppressed Wnt signalling which contributed the NF-κB attenuation and changes the signalling markers in apoptotic network. ConclusionsOur hypothesis suggests a mechanically crosstalk between Wnt and NF-κB signalling pathways in HBP carcinomas that is developed by HFCS. HFCS that targets the Wnt pathway and its downstream signalling mediators could be additive reason for cancer development.

Expression of HIF1α in intestinal epithelium restricts arthritis inflammation by inhibiting RIPK3-induced cell death machinery

ObjectivesTo investigate the mechanism by which intestinal epithelial cell (IEC) death induces arthritis.MethodsIEC death was assessed by staining for necroptosis and apoptosis markers and fluorescence in situ hybridisation at different...

TNFRSF1B Signaling Blockade Protects Airway Epithelial Cells from Oxidative Stress.

Progressive respiratory airway destruction due to unresolved inflammation induced by periodic infectious exacerbation episodes is a hallmark of cystic fibrosis (CF) lung pathology. To clear bacteria, neutrophils release high amounts of reactive oxygen species (ROS), which inflict collateral damage to the neighboring epithelial cells causing oxidative stress. A former genome-wide small interfering RNA (siRNA) screening in CF submucosal gland cells, instrumental for mucociliary clearance, proposed tumor necrosis factor receptor superfamily member 1B (TNFRSF1B; TNFR2) as a potential hit involved in oxidative stress susceptibility. Here, we demonstrate the relevance of TNFRSF1B transcript knock-down for epithelial cell protection under strong oxidative stress conditions. Moreover, a blockade of TNFR signaling through its ligand lymphotoxin-α (LTA), overexpressed in airway epithelial cells under oxidative stress conditions, using the anti-tumor necrosis factor (TNF) biologic etanercept significantly increased the viability of these cells from a toxic oxidizing agent. Furthermore, bioinformatic analyses considering our previous RNA interference (RNAi) screening output highlight the relevance of TNFRSF1B and of other genes within the TNF pathway leading to epithelial cell death. Thus, the inhibition of the LTα3-TNFR2 axis could represent a useful therapeutic strategy to protect the respiratory airway epithelial lining from the oxidative stress challenge because of recurrent infection/inflammation cycles faced by CF patients.

Impact of particulate air pollution on airway injury and epithelial plasticity; underlying mechanisms.

Air pollution plays an important role in the mortality and morbidity of chronic airway diseases, such as asthma and chronic obstructive pulmonary disease (COPD). Particulate matter (PM) is a significant fraction of air pollutants, and studies have demonstrated that it can cause airway inflammation and injury. The airway epithelium forms the first barrier of defense against inhaled toxicants, such as PM. Airway epithelial cells clear airways from inhaled irritants and orchestrate the inflammatory response of airways to these irritants by secreting various lipid mediators, growth factors, chemokines, and cytokines. Studies suggest that PM plays an important role in the pathogenesis of chronic airway diseases by impairing mucociliary function, deteriorating epithelial barrier integrity, and inducing the production of inflammatory mediators while modulating the proliferation and death of airway epithelial cells. Furthermore, PM can modulate epithelial plasticity and airway remodeling, which play central roles in asthma and COPD. This review focuses on the effects of PM on airway injury and epithelial plasticity, and the underlying mechanisms involving mucociliary activity, epithelial barrier function, airway inflammation, epithelial-mesenchymal transition, mesenchymal-epithelial transition, and airway remodeling.

IL-13 facilitates ferroptotic death in asthmatic epithelial cells via SOCS1-mediated ubiquitinated degradation of SLC7A11

Th2-high asthma is characterized by elevated levels of type 2 cytokines, such as interleukin 13 (IL-13), and its prevalence has been increasing worldwide. Ferroptosis, a recently discovered type of programmed cell death, is involved in the pathological process of Th2-high asthma; however, the underlying mechanisms remain incompletely understood. In this study, we demonstrated that the serum level of malondialdehyde (MDA), an index of lipid peroxidation, positively correlated with IL-13 level and negatively correlated with the predicted forced expiratory volume in 1 s (FEV1%) in asthmatics. Furthermore, we showed that IL-13 facilitates ferroptosis by upregulating of suppressor of cytokine signaling 1 (SOCS1) through analyzing immortalized airway epithelial cells, human airway organoids, and the ovalbumin (OVA)-challenged asthma model. We identified that signal transducer and activator of transcription 6 (STAT6) promotes the transcription of SOCS1 upon IL-13 stimulation. Moreover, SOCS1, an E3 ubiquitin ligase, was found to bind to solute carrier family 7 member 11 (SLC7A11) and catalyze its ubiquitinated degradation, thereby promoting ferroptosis in airway epithelial cells. Last, we found that inhibiting SOCS1 can decrease ferroptosis in airway epithelial cells and alleviate airway hyperresponsiveness (AHR) in OVA-challenged wide-type mice, while SOCS1 overexpression exacerbated the above in OVA-challenged IL-13-knockout mice. Our findings reveal that the IL-13/STAT6/SOCS1/SLC7A11 pathway is a novel molecular mechanism for ferroptosis in Th2-high asthma, confirming that targeting ferroptosis in airway epithelial cells is a potential therapeutic strategy for Th2-high asthma.

CBA (4-chloro-2-(2-chlorophenoxy)acetamido) benzoic acid) inhibits TMEM206 mediated currents and TMEM206 does not contribute to acid-induced cell death in colorectal cancer cells.

Introduction: Upon activation at low pH, TMEM206 conducts Cl- ions across plasma and vesicular membranes. In a (patho)physiological context, TMEM206 was reported to contribute to acid-induced cell death in neurons, kidney and cervical epithelial cells. We investigated the role of TMEM206 in acid-induced cell death in colorectal cancer cells. In addition, we studied CBA as a new small molecule inhibitor for TMEM206. Methods: The role of TMEM206 in acid-induced cell death was studied with CRISPR/Cas9-mediated knockout and FACS analysis. The pharmacology of TMEM206 was determined with the patch clamp technique. Results: In colorectal cancer cells, TMEM206 is not a critical mediator of acid-induced cell death. CBA is a small molecule inhibitor of TMEM206 (IC50 = 9.55µM) at low pH, at pH 6.0 inhibition is limited. Conclusion: CBA demonstrates effective and specific inhibition of TMEM206; however, its inhibitory efficacy is limited at pH 6.0. Despite this limitation, CBA is a potent inhibitor for functional studies at pH 4.5 and may be a promising scaffold for the development of future TMEM206 inhibitors.

The Role of Ferroptosis in Inflammatory Bowel Disease: Mechanisms and Therapeutic Implications

Inflammatory Bowel Disease (IBD), encompassing Crohn's disease and ulcerative colitis, is characterized by chronic inflammation of the gastrointestinal tract, with an increasing incidence worldwide. Recent advancements in cellular biology have identified ferroptosis, a form of programmed cell death driven by iron-dependent lipid peroxidation, as a critical player in the pathology of IBD. This article reviews the current understanding of ferroptosis and its distinctive mechanisms, including the role of GPx4, Nrf2-HO-1 pathways, and iron metabolism in the context of IBD. It also examines the dual nature of iron in intestinal health and disease, contributing to both physiological functions and pathological processes through oxidative stress and inflammation. The implications of ferroptosis in the intestinal epithelial cell death, barrier function, and immune response are discussed, highlighting its potential as a novel therapeutic target. Despite the promising insights, the article underscores the need for further research to elucidate the complex mechanisms of ferroptosis in IBD and to translate these findings into effective therapeutic strategies. The emerging evidence positions ferroptosis at the crossroads of metabolic, inflammatory, and cell death pathways, offering a unique perspective on the interplay between nutrition, genetics, and immunity in intestinal health and disease.

Vanillic acid restores homeostasis of intestinal epithelium in colitis through inhibiting CA9/STIM1-mediated ferroptosis

The damage of integrated epithelial epithelium is a key pathogenic factor and closely associated with the recurrence of ulcerative colitis (UC). Here, we reported that vanillic acid (VA) exerted potent therapeutic effects on DSS-induced colitis by restoring intestinal epithelium homeostasis via the inhibition of ferroptosis. By the CETSA assay and DARTS assay, we identified carbonic anhydrase IX (CAIX, CA9) as the direct target of VA. The binding of VA to CA9 causes insulin-induced gene-2 (INSIG2) to interact with stromal interaction molecule 1 (STIM1), rather than SREBP cleavage-activating protein (SCAP), leading to the translocation of SCAP-SREBP1 from the endoplasmic reticulum (ER) to the Golgi apparatus for cleavage into mature SREBP1. The activation of SREBP1 induced by VA then significantly facilitated the transcription of stearoyl-CoA desaturase 1 (SCD1) to exert an inhibitory effect on ferroptosis. By inhibiting the excessive death of intestinal epithelial cells caused by ferroptosis, VA effectively preserved the integrity of intestinal barrier and prevented the progression of unresolved inflammation. In conclusion, our study demonstrated that VA could alleviate colitis by restoring intestinal epithelium homeostasis through CA9/STIM1-mediated inhibition of ferroptosis, providing a promising therapeutic candidate for UC.

The Link between Autosomal Dominant Polycystic Kidney Disease and Chromosomal Instability: Exploring the Relationship.

In autosomal dominant polycystic kidney disease (ADPKD) with germline mutations in a PKD1 or PKD2 gene, innumerable cysts develop from tubules, and renal function deteriorates. Second-hit somatic mutations and renal tubular epithelial (RTE) cell death are crucial features of cyst initiation and disease progression. Here, we use established RTE lines and primary ADPKD cells with disease-associated PKD1 mutations to investigate genomic instability and DNA damage responses. We found that ADPKD cells suffer severe chromosome breakage, aneuploidy, heightened susceptibility to DNA damage, and delayed checkpoint activation. Immunohistochemical analyses of human kidneys corroborated observations in cultured cells. DNA damage sensors (ATM/ATR) were activated but did not localize at nuclear sites of damaged DNA and did not properly activate downstream transducers (CHK1/CHK2). ADPKD cells also had the ability to transform, as they achieved high saturation density and formed colonies in soft agar. Our studies indicate that defective DNA damage repair pathways and the somatic mutagenesis they cause contribute fundamentally to the pathogenesis of ADPKD. Acquired mutations may alternatively confer proliferative advantages to the clonally expanded cell populations or lead to apoptosis. Further understanding of the molecular details of aberrant DNA damage responses in ADPKD is ongoing and holds promise for targeted therapies.

The use of salmonid epithelial cells to characterize the toxicity of Tenacibaculum maritimum soluble extracellular products.

This study assessed how the etiological agent of mouth rot in farmed Atlantic salmon, Tenacibaculum maritimum, induces toxicity in host salmonid barrier cells, and determined whether environmental changes are relevant for these effects. Tenacibaculum maritimum soluble extracellular products (ECPs) were collected and used to treat Atlantic salmon and rainbow trout intestinal barrier cell lines as a comparative model of bacterial-salmonid cell interactions. Cellular assays that examine cell membrane integrity, marker expression, and metabolic activity revealed that T. maritimum ECPs induced salmonid epithelial cell death through an apoptosis mechanism. Changes in salinity (25, 29, and 33 ppt) and temperature (12°C, 18°C, and 24°C) within the natural ranges observed in Pacific Northwest aquaculture facilities affected bacterial growth and cytotoxicity of T. maritimum ECPs. Our results suggest epithelial barriers as targets of T. maritimum-mediated toxicity in farmed mouth rot-infected Atlantic salmon. The induction of apoptosis by T. maritimum soluble ECPs may also help to explain the absence of overt inflammation typically reported for these fish.

Tantalum oxide nanoparticles as versatile and high-resolution X-ray contrast agent for intraductal image-guided ablative procedure in rodent models of breast cancer

AbstractThere are limited options for primary prevention of breast cancer (BC). Experimental procedures to locally prevent BC have shown therapeutic efficacy in animal models. To determine the suitability of FDA-approved iodine-containing and various metal-containing (bismuth, gold, iodine, or tantalum) preclinical nanoparticle-based contrast agents for image-guided intraductal (ID) ablative treatment of BC in rodent models, we performed a prospective longitudinal study to determine the imaging performance, local retention and systemic clearance, safety profile, and compatibility with ablative solution of each contrast agent. At least six abdominal mammary glands (>3 female FVB/JN mice and/or Sprague-Dawley rats, 10–11 weeks of age) were intraductally injected with commercially available contrast agents (Omnipaque® 300, Fenestra® VC, MVivoTM Au, MVivoTM BIS) or in-house synthesized tantalum oxide (TaOx) nanoparticles. Contrast agents were administered at stock concentration or diluted in 70% ethanol (EtOH) and up to 1% ethyl cellulose (EC) as gelling agent to assess their compatibility with our image-guided ablative procedure. Mammary glands were serially imaged by microCT for up to 60 days after ID delivery. Imaging data were analyzed by radiologists and deep learning to measure in vivo signal disappearance of contrast agents. Mammary glands and major organs were ultimately collected for histopathological examination. TaOx-containing solutions provided best imaging performance for nitid visualization of ductal tree immediately after infusion, low outward diffusion (<1 day) and high homogeneity. Of all nanoparticles, TaOx had the highest local clearance rate (46% signal decay as stock and 36% as ablative solution 3 days after ID injection) and exhibited low toxicity. TaOx-containing ablative solution with 1% EC caused same percentage of epithelial cell death (88.62% ± 7.70% vs. 76.38% ± 9.99%, p value = 0.089) with similar minimal collateral damage (21.56 ± 5.28% vs. 21.50% ± 7.14%, p value = 0.98) in mouse and rat mammary glands, respectively. In conclusion, TaOx-nanoparticles are a suitable and versatile contrast agent for intraductal imaging and image-guided ablative procedures in rodent models of BC with translational potential to humans.