Plausible role of INPP4A dysregulation in idiopathic pulmonary fibrosis.

INPP4A has been shown to be involved in the regulation of cell proliferation and apoptosis of multiple cell types including fibroblasts. Previous reports from our group have demonstrated the role of inositol polyphosphate 4-phosphatase Type I A (INPP4A) in these functions. Though existing evidences suggest a critical role for INPP4A in the maintenance of lung homeostasis, its role in chronic lung diseases is relatively under explored. In the current study, we made an attempt to understand the regulation of INPP4A in idiopathic pulmonary fibrosis (IPF). Through integration of relevant INPP4A gene expression data from public repositories with our results from in vitro experiments and mouse models, we show that INPP4A is altered in IPF. Interestingly, the direction of the change is dependent both on the disease stage and the region of the lung used. INPP4A was found to be upregulated when analyzed in lung sample representative of the whole lung, but was downregulated in the fibrotic regions of the lung. Similarly, INPP4A was found to be high, compared to controls, only in the early stage of the disease. Though the observed increase in INPP4A was found to be negatively correlated to physiological indices, FVC, and DLCO, of lung function, treatment with anti-INPP4A antibody worsened the condition in bleomycin treated mice. These contrasting results taken together are suggestive of a nuanced regulation of INPP4A in IPF which is dependent on the disease stage, cellular state and extent of fibrosis in the lung region being analyzed.

STAT1 Employs Myeloid Cell-Extrinsic Mechanisms to Regulate the Neutrophil Response and Provide Protection against Invasive Klebsiella pneumoniae Lung Infection.

Klebsiella pneumoniae (KP) is an extracellular Gram-negative bacterium that causes infections in the lower respiratory and urinary tracts and the bloodstream. STAT1 is a master transcription factor that acts to maintain T cell quiescence under homeostatic conditions. Although STAT1 helps defend against systemic spread of acute KP intrapulmonary infection, whether STAT1 regulation of T cell homeostasis impacts pulmonary host defense during acute bacterial infection and injury is less clear. Using a clinical KP respiratory isolate and a pneumonia mouse model, we found that STAT1 deficiency led to an early neutrophil-dominant transcriptional profile and neutrophil recruitment in the lung preceding widespread bacterial dissemination and lung injury development. Yet, myeloid cell STAT1 was dispensable for control of KP proliferation and dissemination, because myeloid cell-specific STAT1-deficient (LysMCre/WT;Stat1fl/fl) mice showed bacterial burden in the lung, liver, and kidney similar to that of their wild-type littermates. Surprisingly, IL-17-producing CD4+ T cells infiltrated Stat1-/- murine lungs early during KP infection. The increase in Th17 cells in the lung was not due to preexisting immunity against KP and was consistent with circulating rather than tissue-resident CD4+ T cells. However, blocking global IL-17 signaling with anti-IL-17RC administration led to increased proliferation and dissemination of KP, suggesting that IL-17 provided by other innate immune cells is essential in defense against KP. Contrastingly, depletion of CD4+ T cells reduced Stat1-/- murine lung bacterial burden, indicating that early CD4+ T cell activation in the setting of global STAT1 deficiency is pathogenic. Altogether, our findings suggest that STAT1 employs myeloid cell-extrinsic mechanisms to regulate neutrophil responses and provides protection against invasive KP by restricting nonspecific CD4+ T cell activation and immunopathology in the lung.

MiR-326-mediated overexpression of NFIB offsets TGF-ß induced epithelial to mesenchymal transition and reverses lung fibrosis.

Idiopathic Pulmonary Fibrosis (IPF) is a progressively fatal and incurable disease characterized by the loss of alveolar structures, increased epithelial-mesenchymal transition (EMT), and aberrant tissue repair. In this study, we investigated the role of Nuclear Factor I-B (NFIB), a transcription factor critical for lung development and maturation, in IPF. Using both human lung tissue samples from patients with IPF, and a mouse model of lung fibrosis induced by bleomycin, we showed that there was a significant reduction of NFIB both in the lungs of patients and mice with IPF. Furthermore, our in vitro experiments using cultured human lung cells demonstrated that the loss of NFIB was associated with the induction of EMT by transforming growth factor beta (TGF-ß). Knockdown of NFIB promoted EMT, while overexpression of NFIB suppressed EMT and attenuated the severity of bleomycin-induced lung fibrosis in mice. Mechanistically, we identified post-translational regulation of NFIB by miR-326, a miRNA with anti-fibrotic effects that is diminished in IPF. Specifically, we showed that miR-326 stabilized and increased the expression of NFIB through its 3'UTR target sites for Human antigen R (HuR). Moreover, treatment of mice with either NFIB plasmid or miR-326 reversed airway collagen deposition and fibrosis. In conclusion, our study emphasizes the critical role of NFIB in lung development and maturation, and its reduction in IPF leading to EMT and loss of alveolar structures. Our study highlights the potential of miR-326 as a therapeutic intervention for IPF. The schema shows the role of NFIB in maintaining the normal epithelial cell characteristics in the lungs and how its reduction leads to a shift towards mesenchymal cell-like features and pulmonary fibrosis. A In normal lungs, NFIB is expressed abundantly in the epithelial cells, which helps in maintaining their shape, cell polarity and adhesion molecules. However, when the lungs are exposed to factors that induce pulmonary fibrosis, such as bleomycin, or TGF-ß, the epithelial cells undergo epithelial to mesenchymal transition (EMT), which leads to a decrease in NFIB. B The mesenchymal cells that arise from EMT appear as spindle-shaped with loss of cell junctions, increased cell migration, loss of polarity and expression of markers associated with mesenchymal cells/fibroblasts. C We designed a therapeutic approach that involves exogenous administration of NFIB in the form of overexpression plasmid or microRNA-326. This therapeutic approach decreases the mesenchymal cell phenotype and restores the epithelial cell phenotype, thus preventing the development or progression of pulmonary fibrosis.

Obesity impairs cardiolipin-dependent mitophagy and therapeutic intercellular mitochondrial transfer ability of mesenchymal stem cells.

Mesenchymal stem cell (MSC) transplantation alleviates metabolic defects in diseased recipient cells by intercellular mitochondrial transport (IMT). However, the effect of host metabolic conditions on IMT and thereby on the therapeutic efficacy of MSCs has largely remained unexplored. Here we found impaired mitophagy, and reduced IMT in MSCs derived from high-fat diet (HFD)-induced obese mouse (MSC-Ob). MSC-Ob failed to sequester their damaged mitochondria into LC3-dependent autophagosomes due to decrease in mitochondrial cardiolipin content, which we propose as a putative mitophagy receptor for LC3 in MSCs. Functionally, MSC-Ob exhibited diminished potential to rescue mitochondrial dysfunction and cell death in stress-induced airway epithelial cells. Pharmacological modulation of MSCs enhanced cardiolipin-dependent mitophagy and restored their IMT ability to airway epithelial cells. Therapeutically, these modulated MSCs attenuated features of allergic airway inflammation (AAI) in two independent mouse models by restoring healthy IMT. However, unmodulated MSC-Ob failed to do so. Notably, in human (h)MSCs, induced metabolic stress associated impaired cardiolipin-dependent mitophagy was restored upon pharmacological modulation. In summary, we have provided the first comprehensive molecular understanding of impaired mitophagy in obese-derived MSCs and highlight the importance of pharmacological modulation of these cells for therapeutic intervention. A MSCs obtained from (HFD)-induced obese mice (MSC-Ob) show underlying mitochondrial dysfunction with a concomitant decrease in cardiolipin content. These changes prevent LC3-cardiolipin interaction, thereby reducing dysfunctional mitochondria sequestration into LC3-autophagosomes and thus impaired mitophagy. The impaired mitophagy is associated with reduced intercellular mitochondrial transport (IMT) via tunneling nanotubes (TNTs) between MSC-Ob and epithelial cells in co-culture or in vivo. B Pyrroloquinoline quinone (PQQ) modulation in MSC-Ob restores mitochondrial health, cardiolipin content, and thereby sequestration of depolarized mitochondria into the autophagosomes to alleviate impaired mitophagy. Concomitantly, MSC-Ob shows restoration of mitochondrial health upon PQQ treatment (MSC-ObPQQ). During co-culture with epithelial cells or transplantation in vivo into the mice lungs, MSC-ObPQQ restores IMT and prevents epithelial cell death. C Upon transplantation in two independent allergic airway inflammatory mouse models, MSC-Ob failed to rescue the airway inflammation, hyperactivity, metabolic changes in epithelial cells. D PQQ modulated MSCs restored these metabolic defects and restored lung physiology and airway remodeling parameters.

The matricellular protein thrombospondin-1 in lung inflammation and injury.

Matricellular proteins comprise a diverse group of molecular entities secreted into the extracellular space. They interact with the extracellular matrix (ECM), integrins, and other cell-surface receptors, and can alter matrix strength, cell attachment to the matrix, and cell-cell adhesion. A founding member of this group is thrombospondin-1 (TSP-1), a high molecular-mass homotrimeric glycoprotein. Given the importance of the matrix and ECM remodeling in the lung following injury, TSP-1 has been implicated in a number of lung pathologies. This review examines the role of TSP-1 as a damage controller in the context of lung inflammation, injury resolution, and repair in noninfectious and infectious models. This review also discusses the potential role of TSP-1 in human diseases as it relates to lung inflammation and injury.

Molecular signature of postmortem lung tissue from COVID-19 patients suggests distinct trajectories driving mortality.

To elucidate the molecular mechanisms that manifest lung abnormalities during severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infections, we performed whole-transcriptome sequencing of lung autopsies from 31 patients with severe COVID-19 and ten uninfected controls. Using metatranscriptomics, we identified the existence of two distinct molecular signatures of lethal COVID-19. The dominant 'classical' signature (n=23) showed upregulation of the unfolded protein response, steroid biosynthesis and complement activation, supported by massive metabolic reprogramming leading to characteristic lung damage. The rarer signature (n=8) that potentially represents 'cytokine release syndrome' (CRS) showed upregulation of cytokines such as IL1 and CCL19, but absence of complement activation. We found that a majority of patients cleared SARS-CoV-2 infection, but they suffered from acute dysbiosis with characteristic enrichment of opportunistic pathogens such as Staphylococcus cohnii in 'classical' patients and Pasteurella multocida in CRS patients. Our results suggest two distinct models of lung pathology in severe COVID-19 patients, which can be identified through complement activation, presence of specific cytokines and characteristic microbiome. These findings can be used to design personalized therapy using in silico identified drug molecules or in mitigating specific secondary infections.

Barriers to Access: Global Variability in Implementing Treatment Advances in Lung Cancer.

Globally, lung cancer is the second most-diagnosed cancer and is the leading cause of cancer death. Advances in science and technology have contributed to improvements in primary cancer prevention, cancer diagnosis, and cancer therapy, leading to an increase in survival and improvement in quality of life. Many of these advances have been seen in high-income countries. Accessibility, availability, and affordability are key domains in barriers to access of care between countries and within countries. The impact of these domains, as they relate to molecular testing, radiation therapy, and systemic therapy, are discussed.

ACE2 protein expression in lung tissues of severe COVID-19 infection.

Angiotensin-converting enzyme 2 (ACE2) is a key host protein by which severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2) enters and multiplies within cells. The level of ACE2 expression in the lung is hypothesised to correlate with an increased risk of severe infection and complications in COrona VIrus Disease 2019 (COVID-19). To test this hypothesis, we compared the protein expression status of ACE2 by immunohistochemistry (IHC) in post-mortem lung samples of patients who died of severe COVID-19 and lung samples obtained from non-COVID-19 patients for other indications. IHC for CD61 and CD163 was performed for the assessment of platelet-rich microthrombi and macrophages, respectively. IHC for SARS-CoV-2 viral antigen was also performed. In a total of 55, 44 COVID-19 post-mortem lung samples were tested for ACE2, 36 for CD163, and 26 for CD61, compared to 15 non-covid 19 control lung sections. Quantification of immunostaining, random sampling, and correlation analysis were used to substantiate the morphologic findings. Our results show that ACE2 protein expression was significantly higher in COVID-19 post-mortem lung tissues than in controls, regardless of sample size. Histomorphology in COVID-19 lungs showed diffuse alveolar damage (DAD), acute bronchopneumonia, and acute lung injury with SARS-CoV-2 viral protein detected in a subset of cases. ACE2 expression levels were positively correlated with increased expression levels of CD61 and CD163. In conclusion, our results show significantly higher ACE2 protein expression in severe COVID-19 disease, correlating with increased macrophage infiltration and microthrombi, suggesting a pathobiological role in disease severity.

Transcriptome analysis and connectivity mapping of Cissampelos pareira L. provides molecular links of ESR1 modulation to viral inhibition.

Bioactive fractions obtained from medicinal plants which have been used for the treatment of multiple diseases could exert their effects by targeting common pathways. Prior knowledge of their usage could allow us to identify novel molecular links. In this study, we explored the molecular basis of action of one such herbal formulation Cissampelos pareira L. (Cipa), used for the treatment of female hormone disorders and fever. Transcriptomic studies on MCF7 cell lines treated with Cipa extract carried out using Affymetrix arrays revealed a downregulation of signatures of estrogen response potentially modulated through estrogen receptor α (ERα). Molecular docking analysis identified 38 Cipa constituents that potentially bind (ΔG < - 7.5) with ERα at the same site as estrogen. The expression signatures in the connectivity map ( https://clue.io/; ) revealed high positive scores with translation inhibitors such as emetine (score: 99.61) and knockdown signatures of genes linked to the antiviral response such as ribosomal protein RPL7 (score: 99.92), which is a reported ERα coactivator. Further, gene knockdown experiments revealed that Cipa exhibits antiviral activity in dengue infected MCF7 cells potentially modulated through estrogen receptor 1. This approach reveals a novel pathway involving the ESR1-RPL7 axis which could be a potential target in dengue viral infection.

Adhatoda Vasica attenuates inflammatory and hypoxic responses in preclinical mouse models: potential for repurposing in COVID-19-like conditions.

BACKGROUND: COVID-19 pneumonia has been associated with severe acute hypoxia, sepsis-like states, thrombosis and chronic sequelae including persisting hypoxia and fibrosis. The molecular hypoxia response pathway has been associated with such pathologies and our recent observations on anti-hypoxic and anti-inflammatory effects of whole aqueous extract of Adhatoda Vasica (AV) prompted us to explore its effects on relevant preclinical mouse models. METHODS: In this study, we tested the effect of whole aqueous extract of AV, in murine models of bleomycin induced pulmonary fibrosis, Cecum Ligation and Puncture (CLP) induced sepsis, and siRNA induced hypoxia-thrombosis phenotype. The effect on lung of AV treated naïve mice was also studied at transcriptome level. We also determined if the extract may have any effect on SARS-CoV2 replication. RESULTS: Oral administration AV extract attenuates increased airway inflammation, levels of transforming growth factor-ß1 (TGF-ß1), IL-6, HIF-1α and improves the overall survival rates of mice in the models of pulmonary fibrosis and sepsis and rescues the siRNA induced inflammation and associated blood coagulation phenotypes in mice. We observed downregulation of hypoxia, inflammation, TGF-ß1, and angiogenesis genes and upregulation of adaptive immunity-related genes in the lung transcriptome. AV treatment also reduced the viral load in Vero cells infected with SARS-CoV2. CONCLUSION: Our results provide a scientific rationale for this ayurvedic herbal medicine in ameliorating the hypoxia-hyperinflammation features and highlights the repurposing potential of AV in COVID-19-like conditions.

Adhatoda vasica rescues the hypoxia-dependent severe asthma symptoms and mitochondrial dysfunction.

Severe asthma is a chronic airway disease that exhibits poor response to conventional asthma therapies. Growing evidence suggests that elevated hypoxia increases the severity of asthmatic inflammation among patients and in model systems. In this study, we elucidate the therapeutic effects and mechanistic basis of Adhatoda vasica (AV) aqueous extract on mouse models of acute allergic as well as severe asthma subtypes at physiological, histopathological, and molecular levels. Oral administration of AV extract attenuates the increased airway resistance and inflammation in acute allergic asthmatic mice and alleviates the molecular signatures of steroid (dexamethasone) resistance like IL-17A, KC (murine IL-8 homologue), and HIF-1α (hypoxia-inducible factor-1α) in severe asthmatic mice. AV inhibits HIF-1α levels through restoration of expression of its negative regulator-PHD2 (prolyl hydroxylase domain-2). Alleviation of hypoxic response mediated by AV is further confirmed in the acute and severe asthma model. AV reverses cellular hypoxia-induced mitochondrial dysfunction in human bronchial epithelial cells-evident from bioenergetic profiles and morphological analysis of mitochondria. In silico docking of AV constituents reveal higher negative binding affinity for C and O-glycosides for HIF-1α, IL-6, Janus kinase 1/3, TNF-α, and TGF-ß-key players of hypoxia inflammation. This study for the first time provides a molecular basis of action and effect of AV whole extract that is widely used in Ayurveda practice for diverse respiratory ailments. Further, through its effect on hypoxia-induced mitochondrial dysfunction, the study highlights its potential to treat severe steroid-resistant asthma.

Oral Feeding of Cow Milk Containing A1 Variant of ß Casein Induces Pulmonary Inflammation in Male Balb/c Mice.

Milk is globally consumed as a rich source of protein and calcium. A major protein component of milk is casein, with ß-casein having 2 major variants A1 and A2. Of these, A1 casein variant has been implicated as a potential etiological factor in several pathologies, but direct effect on lungs has not been studied. The objective of the present study was to evaluate the A1and A2 ß casein variants of cow milk as factors causing allergic airway disease in murine model. Mice fed with A1A1 milk exhibited increased airway hyperresponsiveness with increasing concentration of bronchoconstrictor (methacholine), which was not observed in mice fed with A2A2 milk. Significantly elevated levels of IL-4 and IL-5 were found in bronchoalveolar lavage and serum of A1A1 variant fed mice. Increased IgE and IgG levels along with increased infiltration of lymphocytes and eosinophils, leading to peribronchial inflammation was also observed in A1A1 variant fed mice, although, no goblet cell hyperplasia or airway remodeling was observed. In contrast, A2A2 milk fed mice presented phenotype matching the control group, while A1A2 milk fed group presented an intermediate phenotype. In summary, our results show that A1 form of cow milk has a proinflammatory effect on the lung resulting in phenotype closely matching with the typical allergic asthma phenotype.

House dust mite allergen causes certain features of steroid resistant asthma in high fat fed obese mice.

Obesity is a high risk factor for diseases such as cardiovascular, metabolic syndrome and asthma. Obese-asthma is another emerging phenotype in asthma which is typically refractive to steroid treatment due to its non-classical features such as non-eosinophilic cellular inflammation. The overall increased morbidity, mortality and economical burden in asthma is mainly due to steroid resistant asthma. In the present study, we used high fat diet induced obese mice which when sensitized with house dust mite (HDM) showed steroid resistant features. While the steroid, dexamethasone (DEX), treatment to high fat fed naïve mice could not reduce the airway hyperresponsiveness (AHR) induced by high fat, DEX treatment to high fat fed allergic mice could not reduce the HDM allergen induced airway remodeling features though it reduced airway inflammation. Further, these HDM induced high fat fed mice with or without DEX treatment had shown the increased activity and expression of arginase as well as the inducible nitric oxide synthase (iNOS) expression. However, DEX treatment had reduced the expressions of high iNOS and arginase I in control chow diet fed mice. Thus, we speculate that the steroid resistance seen in human obese asthmatics could be stemming from altered NO metabolism and its induced airway remodeling and with further investigations, it would encourage new treatments specific to obese-asthma phenotype.

Linoleic acid metabolite leads to steroid resistant asthma features partially through NF-κB.

Studies have highlighted the role of nutritional and metabolic modulators in asthma pathobiology. Steroid resistance is an important clinical problem in asthma but lacks good experimental models. Linoleic acid, a polyunsaturated fatty acid, has been linked to asthma and glucocorticoid sensitivity. Its 12/15-lipoxygenase metabolite, 13-S-hydroxyoctadecadienoic acid (HODE) induces mitochondrial dysfunction, with severe airway obstruction and neutrophilic airway inflammation. Here we show that HODE administration leads to steroid unresponsiveness in an otherwise steroid responsive model of allergic airway inflammation (AAI). HODE treatment to allergic mice further increased airway hyperresponsiveness and goblet metaplasia. Treatment with dexamethasone was associated with increased neutrophilic inflammation in HODE treated allergic mice; unlike control allergic mice that showed resolution of inflammation. HODE induced loss of steroid sensitivity was associated with increased p-NFkB in mice and reduced GR-α transcript levels in cultured human bronchial epithelia. In summary, HODE modifies typical AAI to recapitulate many of the phenotypic features seen in severe steroid unresponsive asthma. We speculate that since HODE is a natural metabolite, it may be relevant to the increased asthma severity and steroid insensitivity in patients who are obese or consume high fat diets. Further characterization of HODE induced steroid insensitivity may clarify the mechanisms.

Hyperinsulinemia adversely affects lung structure and function.

There is limited knowledge regarding the consequences of hyperinsulinemia on the lung. Given the increasing prevalence of obesity, insulin resistance, and epidemiological associations with asthma, this is a critical lacuna, more so with inhaled insulin on the horizon. Here, we demonstrate that insulin can adversely affect respiratory health. Insulin treatment (1 µg/ml) significantly (P < 0.05) increased the proliferation of primary human airway smooth muscle (ASM) cells and induced collagen release. Additionally, ASM cells showed a significant increase in calcium response and mitochondrial respiration upon insulin exposure. Mice administered intranasal insulin showed increased collagen deposition in the lungs as well as a significant increase in airway hyperresponsiveness. PI3K/Akt mediated activation of ß-catenin, a positive regulator of epithelial-mesenchymal transition and fibrosis, was observed in the lungs of insulin-treated mice and lung cells. Our data suggests that hyperinsulinemia may have adverse effects on airway structure and function. Insulin-induced activation of ß-catenin in lung tissue and the contractile effects on ASM cells may be causally related to the development of asthma-like phenotype.

Combined genetic effects of EGLN1 and VWF modulate thrombotic outcome in hypoxia revealed by Ayurgenomics approach.

BACKGROUND: Extreme constitution "Prakriti" types of Ayurveda exhibit systemic physiological attributes. Our earlier genetic study has revealed differences in EGLN1, key modulator of hypoxia axis between Prakriti types. This was associated with differences in high altitude adaptation and susceptibility to high altitude pulmonary edema (HAPE). In this study we investigate other molecular differences that contribute to systemic attributes of Prakriti that would be relevant in predictive marker discovery. METHODS: Genotyping of 96 individuals of the earlier cohort was carried out in a panel of 2,800 common genic SNPs represented in Indian Genomic Variation Consortium (IGVC) panel from 24 diverse populations. Frequency distribution patterns of Prakriti differentiating variations (FDR correction P < 0.05) was studied in IGVC and 55 global populations (HGDP-CEPH) panels. Genotypic interactions between VWF, identified from the present analysis, and EGLN1 was analyzed using multinomial logistic regression in Prakriti and Indian populations from contrasting altitudes. Spearman's Rank correlation was used to study this genotypic interaction with respect to altitude in HGDP-CEPH panel. Validation of functional link between EGLN1 and VWF was carried out in a mouse model using chemical inhibition and siRNA studies. RESULT: Significant differences in allele frequencies were observed in seven genes (SPTA1, VWF, OLR1, UCP2, OR6K3, LEPR, and OR10Z1) after FDR correction (P < 0.05). A non synonymous variation (C/T, rs1063856) associated with thrombosis/bleeding susceptibility respectively, differed significantly between Kapha (C-allele) and Pitta (T-allele) constitution types. A combination of derived EGLN1 allele (HAPE associated) and ancestral VWF allele (thrombosis associated) was significantly high in Kapha group compared to Pitta (p < 10(-5)). The combination of risk-associated Kapha alleles was nearly absent in natives of high altitude. Inhibition of EGLN1 using (DHB) and an EGLN1 specific siRNA in a mouse model lead to a marked increase in vWF levels as well as pro-thrombotic phenotype viz. reduced bleeding time and enhanced platelet count and activation. CONCLUSION: We demonstrate for the first time a genetic link between EGLN1 and VWF in a constitution specific manner which could modulate thrombosis/bleeding susceptibility and outcomes of hypoxia. Integration of Prakriti in population stratification may help assemble common variations in key physiological axes that confers differences in disease occurrence and patho-phenotypic outcomes.