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Acute respiratory distress syndrome (ARDS) is a severe lung condition without targeted therapy that is characterized by the disruption of epithelial and endothelial barriers. The role of the tight junction protein occludin in the pathogenesis of this disease is unknown, although it has previously been deemed redundant in some tissues. The aim of the present study is to determine whether occludin is required for lung function by controlling alveolar barrier integrity in mouse models. Immunofluorescence staining of lungs from ARDS patients revealed a significant decrease in occludin expression compared to controls. Gene delivery of shRNA against occludin in the mouse lung reduced occludin levels and induced lung injury, as assessed by wet-to-dry-ratio, histology, and cellularity and protein content of bronchial alveolar lavage fluid. Conversely, gene delivery of an occludin-expressing plasmid increased occludin expression and dampened endotoxin-induced lung injury. In primary rat alveolar epithelial cells, occludin levels were positively correlated with barrier integrity, as well as membrane localization of claudin-18, another tight junction protein. Collectively, our data demonstrate that occludin plays a significant role in alveolar barrier function and that targeting occludin may provide a new therapeutic approach for ARDS.

Purpose: To identify the number and timing of audiology encounters for adult oncology patients in a tertiary care setting in Australia., Setting (population): A retrospective case review was completed for 149 patients who received Cisplatin chemotherapy (CT) at a large, publicly funded tertiary hospital in Brisbane, Queensland, Australia between 1st January and 31st December 2019. Patient data was extracted from the Queensland Oncology Repository (QOR) provided by Cancer Alliance Queensland (CAQ)., Results: The number of audiology encounters was low overall with a median of 0 and interquartile range (IQR) of 0-1. Of the entire patient cohort, there was a mean of 1.2 encounters with 56% of patients not engaging with audiology. Where audiology did occur, encounters were most likely before or early in the CT treatment period., Conclusions: This study has demonstrated engagement with audiology services for patients undergoing CT treatment was limited with the few audiology engagements occurring before or early in the CT treatment period. Further research is needed to identify the barriers and facilitators to accessing audiological ototoxic monitoring (OtoM) during chemotherapy treatment in hospitals in Australia., Implications for Cancer Survivors: Early identification of ototoxic hearing loss offers the opportunity to minimise further exposure to the ototoxic agent, minimise functional and communication impacts for the patient and provide early opportunity for discussion, education and counselling with patients, carers and their treating team. This, in turn, is expected to improve health related quality of life., (© 2024. The Author(s).)

Objective: The effectiveness of audiological monitoring for detecting early hearing changes in patients receiving ototoxic medication could be limited by the lack of adequate audiological ototoxicity monitoring (OtoM) guidelines. This study aimed to evaluate existing OtoM guidelines using the AGREE II tool for guideline evaluation., Design: Guideline Review., Study Sample: Three audiological OtoM guidelines., Results: An online search identified three audiological OtoM guidelines published by the American Speech-Language and Hearing Association (ASHA), the American Academy of Audiology (AAA) and the Health Professionals Council of South Africa (HPCSA). Evaluation using the Appraisal of Guidelines for Research and Evaluation (AGREE) II tool found the HPCSA audiological OtoM guideline scored higher than the ASHA and AAA guidelines in five of the six tool domains. All guidelines received average domain ratings of less than 50% with each reviewer recommending all three guidelines for use following modification., Conclusion: The findings of this study could partly explain the poor uptake of audiological OtoM practices internationally, further investigation is needed to identify the specific factors limiting the implementation of audiological OtoM in clinical practice.

Acute Lung Injury/Acute Respiratory Distress Syndrome (ALI/ARDS) is characterized by diffuse alveolar damage and significant edema accumulation, which is associated with impaired alveolar fluid clearance (AFC) and alveolar-capillary barrier disruption, leading to acute respiratory failure. Our previous data showed that electroporation-mediated gene delivery of the Na + , K + -ATPase β1 subunit not only increased AFC, but also restored alveolar barrier function through upregulation of tight junction proteins, leading to treatment of LPS-induced ALI in mice. More importantly, our recent publication showed that gene delivery of MRCKα, the downstream effector of β1 subunit-mediated signaling towards upregulation of adhesive junctions and epithelial and endothelial barrier integrity, also provided therapeutic potential for ARDS treatment in vivo but without necessarily accelerating AFC, indicating that for ARDS treatment, improving alveolar capillary barrier function may be of more benefit than improving fluid clearance. In the present study, we investigated the therapeutical potential of β2 and β3 subunits, the other two β isoforms of Na + , K + -ATPase, for LPS-induced ALI. We found that gene transfer of either the β1, β2, or β3 subunits significantly increased AFC compared to the basal level in naïve animals and each gave similar increased AFC to each other. However, unlike that of the β1 subunit, gene transfer of the β2 or β3 subunit into pre-injured animal lungs failed to show the beneficial effects of attenuated histological damage, neutrophil infiltration, overall lung edema, or increased lung permeability, indicating that β2 or β3 gene delivery could not treat LPS induced lung injury. Further, while β1 gene transfer increased levels of key tight junction proteins in the lungs of injured mice, that of either the β2 or β3 subunit had no effect on levels of tight junction proteins. Taken together, this strongly suggests that restoration of alveolar-capillary barrier function alone may be of equal or even more benefit than improving AFC for ALI/ARDS treatment., (© 2023. The Author(s).)

Exogenous electric fields are currently used in human therapy in a number of contexts. Interestingly, electric fields have also been shown to alter migration and function of immune cells, suggesting the potential for electric field-based immune therapy. Little is known as to the effect of electric field treatment (EFT) on the lung. To determine if EFT associates with changes in lung immune cell infiltration, we used a mouse model with varying methods of EFT application and measured cells and soluble mediators using flow cytometry and cytokine/chemokine multiplex. EFT was associated with a transient increase in lung neutrophils and decrease in eosinophils in naïve mice within 2 h of treatment, accompanied by an increase in IL-6 levels. In order to test whether EFT could alter eosinophil/neutrophil recruitment in a relevant disease model, a mouse model of allergic airway inflammation was used. Four EFT doses in allergen-sensitized mice resulted in increased neutrophil and reduced eosinophil infiltrates following allergen challenge, suggesting a durable change in inflammation by EFT. Mice with allergic inflammation were analyzed by flexiVent for measures of lung function. EFT-treated mice had increased inspiratory capacity and other measures of lung function were not diminished. These data suggest EFT may be used to manipulate immune cell infiltration in the lung without affecting lung function.

Background: Alveolar capillary dysplasia with misalignment of the pulmonary veins (ACDMPV) is a lethal disorder of lung development. ACDMPV is associated with haploinsufficiency of the transcription factor FOXF1 , which plays an important role in the development of the lung and intestine. CNVs upstream of the FOXF1 gene have also been associated with an ACDMPV phenotype, but mechanism(s) by which these deletions disrupt lung development are not well understood. The objective of our study is to gain insights into the mechanisms by which CNVs contribute to an ACDMPV phenotype., Methods: We analysed primary lung tissue from an infant with classic clinical and histological findings of ACDMPV and harboured a 340 kb deletion on chromosome 16q24.1 located 250 kb upstream of FOXF1 ., Results: In RNA generated from paraffin-fixed lung sections, our patient had lower expression of FOXF1 than age-matched controls. He also had an abnormal pattern of FOXF1 protein expression, with a dramatic loss of FOXF1 expression in the lung. To gain insights into the mechanisms underlying these changes, we assessed the epigenetic landscape using chromatin immunoprecipitation, which demonstrated loss of histone H3 lysine 27 acetylation (H3K27Ac), an epigenetic mark of active enhancers, in the region of the deletion., Conclusions: Together, these data suggest that the deletion disrupts an enhancer responsible for directing FOXF1 expression in the developing lung and provide novel insights into the mechanisms underlying a fatal developmental lung disorder., Competing Interests: Competing interests: None declared., (© Author(s) (or their employer(s)) 2020. No commercial re-use. See rights and permissions. Published by BMJ.)

A major barrier to curing HIV-1 is the long-lived latent reservoir that supports re-emergence of HIV-1 upon treatment interruption. Targeting this reservoir will require mechanistic insights into the establishment and maintenance of HIV-1 latency. Whether T cell signaling at the time of HIV-1 infection influences productive replication or latency is not fully understood. We used a panel of chimeric antigen receptors (CARs) with different ligand binding affinities to induce a range of signaling strengths to model differential T cell receptor signaling at the time of HIV-1 infection. Stimulation of T cell lines or primary CD4+ T cells expressing chimeric antigen receptors supported HIV-1 infection regardless of affinity for ligand; however, only signaling by the highest affinity receptor facilitated HIV-1 expression. Activation of chimeric antigen receptors that had intermediate and low binding affinities did not support provirus transcription, suggesting that a minimal signal is required for optimal HIV-1 expression. In addition, strong signaling at the time of infection produced a latent population that was readily inducible, whereas latent cells generated in response to weaker signals were not easily reversed. Chromatin immunoprecipitation showed HIV-1 transcription was limited by transcriptional elongation and that robust signaling decreased the presence of negative elongation factor, a pausing factor, by more than 80%. These studies demonstrate that T cell signaling influences HIV-1 infection and the establishment of different subsets of latently infected cells, which may have implications for targeting the HIV-1 reservoir., Competing Interests: The authors have declared that no competing interests exist.

Despite advances in antiretroviral therapy, HIV-1 infection remains incurable in patients and continues to present a significant public health burden worldwide. While a number of factors contribute to persistent HIV-1 infection in patients, the presence of a stable, long-lived reservoir of latent provirus represents a significant hurdle in realizing an effective cure. One potential strategy to eliminate HIV-1 reservoirs in patients is reactivation of latent provirus with latency reversing agents in combination with antiretroviral therapy, a strategy termed "shock and kill". This strategy has shown limited clinical effectiveness thus far, potentially due to limitations of the few therapeutics currently available. We have identified a novel class of benzazole compounds effective at inducing HIV-1 expression in several cellular models. These compounds do not act via histone deacetylase inhibition or T cell activation, and show specificity in activating HIV-1 in vitro. Initial exploration of structure-activity relationships and pharmaceutical properties indicates that these compounds represent a potential scaffold for development of more potent HIV-1 latency reversing agents.

Since HIV-1 has a propensity to integrate into actively expressed genes, transcriptional interference from neighboring host promoters has been proposed to contribute to the establishment and maintenance HIV-1 latency. To gain insights into how endogenous promoters influence HIV-1 transcription we utilized a set of inducible T cell lines and characterized whether there were correlations between expression of endogenous genes, provirus and long terminal repeat architecture. We show that neighboring promoters are active but have minimal impact on HIV-1 transcription, in particular, expression of the endogenous gene did not prevent expression of HIV-1 following induction of latent provirus. We also demonstrate that releasing paused RNAP II by diminishing negative elongation factor (NELF) is sufficient to reactivate transcriptionally repressed HIV-1 provirus regardless of the integration site and orientation of the provirus suggesting that NELF-mediated RNAP II pausing is a common mechanism of maintaining HIV-1 latency., (Copyright © 2015 Elsevier Inc. All rights reserved.)

A barrier to eradicating HIV infection is targeting and eliminating latently infected cells. Events that contribute to HIV transcriptional latency include repressive chromatin structure, transcriptional interference, the inability of Tat to recruit positive transcription factor b, and poor processivity of RNA polymerase II (RNAP II). In this study, we investigated mechanisms by which negative elongation factor (NELF) establishes and maintains HIV latency. Negative elongation factor (NELF) induces RNAP II promoter proximal pausing and limits provirus expression in HIV-infected primary CD4(+) T cells. Decreasing NELF expression overcomes RNAP II pausing to enhance HIV transcription elongation in infected primary T cells, demonstrating the importance of pausing in repressing HIV transcription. We also show that RNAP II pausing is coupled to premature transcription termination and chromatin remodeling. NELF interacts with Pcf11, a transcription termination factor, and diminishing Pcf11 in primary CD4(+) T cells induces HIV transcription elongation. In addition, we identify NCoR1-GPS2-HDAC3 as a NELF-interacting corepressor complex that is associated with repressed HIV long terminal repeats. We propose a model in which NELF recruits Pcf11 and NCoR1-GPS2-HDAC3 to paused RNAP II, reinforcing repression of HIV transcription and establishing a critical checkpoint for HIV transcription and latency.

Interleukin 2-inducible T cell kinase (ITK) influences T cell signaling by coordinating actin polymerization and polarization as well as recruitment of kinases and adapter proteins. ITK regulates multiple steps of HIV-1 replication, including virion assembly and release. Fluorescent microscopy was used to examine the functional interactions between ITK and HIV-1 Gag during viral particle release. ITK and Gag colocalized at the plasma membrane and were concentrated at sites of F-actin accumulation and membrane lipid rafts in HIV-1 infected T cells. There was polarized staining of ITK, Gag, and actin towards sites of T cell conjugates. Small molecule inhibitors of ITK disrupted F-actin capping, perturbed Gag-ITK colocalization, inhibited virus like particle release, and reduced HIV replication in primary human CD4+ T cells. These data provide insight as to how ITK influences HIV-1 replication and suggest that targeting host factors that regulate HIV-1 egress provides an innovative strategy for controlling HIV infection., (Copyright © 2012 Elsevier Inc. All rights reserved.)

Long-lived latent HIV-infected cells lead to the rebound of virus replication following antiretroviral treatment interruption and present a major barrier to eliminating HIV infection. These latent reservoirs, which include quiescent memory T cells and tissue-resident macrophages, represent a subset of cells with decreased or inactive proviral transcription. HIV proviral transcription is regulated at multiple levels including transcription initiation, polymerase recruitment, transcription elongation, and chromatin organization. How these biochemical processes are coordinated and their potential role in repressing HIV transcription along with establishing and maintaining latency are reviewed.