CC16 Regulates Inflammation, ROS Generation and Apoptosis in Bronchial Epithelial Cells during Klebsiella pneumoniae Infection

Gram-negative (G-) bacteria are the leading cause of hospital-acquired pneumonia in the United States. The devastating damage caused by G- bacteria results from the imbalance of bactericidal effects and overwhelming inflammation. Despite decades of research, the underlying mechanisms by which runaway inflammation is developed remain incompletely understood. Clara Cell Protein 16 (CC16), also known as uteroglobin, is the major protein secreted by Clara cells and the most abundant protein in bronchoalveolar lavage fluid (BALF). However, the regulation and functions of CC16 during G- bacterial infection are unknown. In this study, we aimed to assess the regulation of CC16 in response to Klebsiella pneumoniae (K. pneu) and to investigate the role of CC16 in bronchial epithelial cells. After K. pneu infection, we found that CC16 mRNA expression was significantly decreased in bronchial epithelial cells. Our data also showed that K. pneu infection upregulated cytokine and chemokine genes, including IL-1β, IL-6, and IL-8 in BEAS-2B cells. Endogenously overexpressed CC16 in BEAS-2B cells provided an anti-inflammatory effect by reducing these markers. We also observed that endogenous CC16 can repress NF-κB reporter activity. In contrast, the recombinant CC16 (rCC16) did not show an anti-inflammatory effect in K. pneu-infected cells or suppression of NF-κB promoter activity. Moreover, the overexpression of CC16 reduced reactive oxygen species (ROS) levels and protected BEAS-2B cells from K. pneu-induced apoptosis.

Biomarkers in Idiopathic Pulmonary Fibrosis

Numerous published papers are investigating the utility of biomarkers in Idiopathic Pulmonary Fibrosis (IPF) diagnosis, treatment, and outcome prediction. This chapter will summarize our current knowledge about biomarkers associated with alveolar epithelial cell damage and dysfunction (Krebs von den Lungen, surfactant proteins, the mucin MUC5B, CA 15-3, CA 125, CA 19-9, defensins, Clara cell protein (CC16), telomere shortening), biomarkers associated with fibrogenesis, fibroproliferation and extracellular matrix (ECM) remodeling (MMPs and their inhibitors, osteopontin, periostin, insulin-like growth factors, fibulin-1, heat shock protein 47, lysyl oxidase-like 2, circulating fibroblasts, extracellular matrix neoepitopes) and biomarkers related to immune dysfunction and inflammation (C-C chemokine ligand-18, C-C chemokine 2, YKL-40, C-X-C motif chemokine 13, S100A4, S100A8/9, S100A12, autoantibodies to heat shock protein 72, toll-like receptor 3, soluble receptor for advanced glycosylated end products, endothelial damage (vascular endothelial growth factor, interleukin 8, endothelin 1). The future directions in incorporating IPF biomarkers into clinical practice will be reviewed.

The Potential of Lung Epithelium Specific Proteins as Biomarkers for COVID-19-Associated Lung Injury

Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) infection was first reported in Wuhan, China, and was declared a pandemic by the World Health Organization (WHO) on 20 March 2020. The respiratory system is the major organ system affected by COVID-19. Numerous studies have found lung abnormalities in patients with COVID-19, including shortness of breath, respiratory failure, and acute respiratory distress syndrome. The identification of lung-specific biomarkers that are easily measurable in serum would be valuable for both clinicians and patients with such conditions. This review is focused on the pneumoproteins and their potential to serve as biomarkers for COVID-19-associated lung injury, including Krebs von den Lungen-6 (KL-6), surfactant proteins (SP-A, SP-B, SP-C, SP-D), and Clara cell secretory protein (CC16). The current findings indicate the aforementioned pneumoproteins may reflect the severity of pulmonary manifestations and could serve as potential biomarkers in COVID-19-related lung injury.

Histo-Morphology Study of the Respiratory Portion of Goat Lung (Capra Hircus) in Baghdad Province

The Histo-mrphology were directed on the pneumonic alveoli of 6 male goats. The respiratory portion is composed of typical cuboidal epithelial cells with Clara cell, however, alveolar ducts are lined by simple squamous epithelium and alveoli were generally circular structures that opened into the alveolar conduits and alveolar sacs or respiratory bronchioles. Alveoli were made out of two kinds of cells for example Type-I pneumocytes and Type-II pneumocytes. Previous framed the mainlining epithelial cells of alveoli which were squamous in sort having noticeable perinuclear territory and central found the core, while the last were cuboidal fit as a fiddle with the midway found core and periodically found among the Sort I cells in the alveolar epithelium. The lung pulmonary parenchyma was enveloped by the mesothelium (squamous epithelium) layer of visceral pleura.

AGO2 promotes tumor progression in KRAS-driven mouse models of non–small cell lung cancer

Lung cancer is the deadliest malignancy in the United States. Non–small cell lung cancer (NSCLC) accounts for 85% of cases and is frequently driven by activating mutations in the gene encoding the KRAS GTPase (e.g., KRASG12D). Our previous work demonstrated that Argonaute 2 (AGO2)—a component of the RNA-induced silencing complex (RISC)—physically interacts with RAS and promotes its downstream signaling. We therefore hypothesized that AGO2 could promote KRASG12D-dependent NSCLC in vivo. To test the hypothesis, we evaluated the impact of Ago2 knockout in the KPC (LSL-KrasG12D/+;p53f/f;Cre) mouse model of NSCLC. In KPC mice, intratracheal delivery of adenoviral Cre drives lung-specific expression of a stop-floxed KRASG12D allele and biallelic ablation of p53. Simultaneous biallelic ablation of floxed Ago2 inhibited KPC lung nodule growth while reducing proliferative index and improving pathological grade. We next applied the KPHetC model, in which the Clara cell–specific CCSP-driven Cre activates KRASG12D and ablates a single p53 allele. In these mice, Ago2 ablation also reduced tumor size and grade. In both models, Ago2 knockout inhibited ERK phosphorylation (pERK) in tumor cells, indicating impaired KRAS signaling. RNA sequencing (RNA-seq) of KPC nodules and nodule-derived organoids demonstrated impaired canonical KRAS signaling with Ago2 ablation. Strikingly, accumulation of pERK in KPC organoids depended on physical interaction of AGO2 and KRAS. Taken together, our data demonstrate a pathogenic role for AGO2 in KRAS-dependent NSCLC. Given the prevalence of this malignancy and current difficulties in therapeutically targeting KRAS signaling, our work may have future translational relevance.

Clara cell 16 KDa protein mitigates house dust mite-induced airway inflammation and damage via regulating airway epithelial cell apoptosis in a manner dependent on HMGB1-mediated signaling inhibition

Background House dust mite (HDM) inhalation can cause airway epithelial damage which is implicated in the process of airway inflammation in asthma. High mobility group box 1 (HMGB1) is critically required for cellular damage and apoptosis as an important endogenous danger signal. Recently, Clara cell 16KDa protein (CC16) has been identified to exert anti-inflammatory and immunomodulatory influence in various injury-related diseases model. However, little is known about its ability to protect against airway epithelial injury in allergic asthma. This study was aimed to clarify the protective roles of CC16 on airway epithelia in HDM-induced asthma and the regulation of HMGB1 by CC16. Methods Mice were sensitized and challenged by HDM extract and administrated intranasally with CC16 (5 μg/g or 10 μg/g) or saline in the challenged period. The BEAS-2B human airway epithelial cell line were cultured with CC16 or the control vehicle and then exposed to HDM. Knockdown or overexpression of HMGB1 was induced by cell transfection or intratracheal injection of recombinant adenovirus. Results CC16 treatment decreased airway inflammation and histological damage of airway epithelium dose-dependently in HDM-induced asthma model. Airway epithelia apoptosis upon HDM stimulation was noticeably abrogated by CC16 in vivo and in vitro. In addition, upregulation of HMGB1 expression and its related signaling were also detected under HDM conditions, while silencing HMGB1 significantly inhibited the apoptosis of BEAS-2B cells. Furthermore, the activity of HMGB1-mediated signaling was restrained after CC16 treatment whereas HMGB1 overexpression abolished the protective effect of CC16 on HDM-induced airway epithelia apoptosis. Conclusions Our data confirm that CC16 attenuates HDM-mediated airway inflammation and damage via suppressing airway epithelial cell apoptosis in a HMGB1-dependent manner, suggesting the role of CC16 as a potential protective option for HDM-induced asthma.

Clara cell 16KDa protein mitigates house dust mite-induced airway inflammation and damage via regulating airway epithelial cell apoptosis in a manner dependent on HMGB1-mediated signaling inhibition.

Background: House dust mite (HDM) inhalation can cause airway epithelial damage which is implicated in the process of airway inflammation in asthma. High mobility group box 1 (HMGB1) is critically required for cellular damage and apoptosis as an important endogenous danger signal. Recently, Clara cell 16KDa protein (CC16) has been identified to exert anti-inflammatory and immunomodulatory influence in various injury-related diseases model. However, little is known about its ability to protect against airway epithelial injury in allergic asthma. This study was aimed to clarify the protective roles of CC16 on airway epithelia in HDM-induced asthma and the regulation of HMGB1 by CC16.Methods: Mice were sensitized and challenged by HDM extract and administrated intranasally with CC16 (5ug/g or 10ug/g) or saline in the challenged period. The BEAS-2B human airway epithelial cell line were cultured with CC16 or the control vehicle and then exposed to HDM. Knockdown or overexpression of HMGB1 was induced by cell transfection or intratracheal injection of recombinant adenovirus.Results: CC16 treatment decreased airway inflammation and histological damage of airway epithelium dose-dependently in HDM-induced asthma model. Airway epithelia apoptosis upon HDM stimulation was noticeably abrogated by CC16 in vivo and in vitro. In addition, upregulation of HMGB1 expression and its related signaling were also detected under HDM conditions, while silencing HMGB1 significantly inhibited the apoptosis of BEAS-2B cells. Furthermore, the activity of HMGB1-mediated signaling was restrained after CC16 treatment whereas HMGB1 overexpression abolished the protective effect of CC16 on HDM-induced airway epithelia apoptosis.Conclusions: Our data confirm that CC16 attenuates HDM-mediated airway inflammation and damage via suppressing airway epithelial cell apoptosis in a HMGB1-dependent manner, suggesting the role of CC16 as a potential protective option for HDM-induced asthma.

Changes in NAD and Lipid Metabolism Drive Acidosis-Induced Acute Kidney Injury

BackgroundThe kidney plays an important role in maintaining normal blood pH. Metabolic acidosis (MA) upregulates the pathway that mitochondria in the proximal tubule (PT) use to produce ammonia and bicarbonate from glutamine, and is associated with AKI. However, the extent to which MA causes AKI, and thus whether treating MA would be beneficial, is unclear.MethodsGavage with ammonium chloride induced acute MA. Multiphoton imaging of mitochondria (NADH/membrane potential) and transport function (dextran/albumin uptake), oxygen consumption rate (OCR) measurements in isolated tubules, histologic analysis, and electron microscopy in fixed tissue, and urinary biomarkers (KIM-1/clara cell 16) assessed tubular cell structure and function in mouse kidney cortex.ResultsMA induces an acute change in NAD redox state (toward oxidation) in PT mitochondria, without changing the mitochondrial energization state. This change is associated with a switch toward complex I activity and decreased maximal OCR, and a major alteration in normal lipid metabolism, resulting in marked lipid accumulation in PTs and the formation of large multilamellar bodies. These changes, in turn, lead to acute tubular damage and a severe defect in solute uptake. Increasing blood pH with intravenous bicarbonate substantially improves tubular function, whereas preinjection with the NAD precursor nicotinamide (NAM) is highly protective.ConclusionsMA induces AKI via changes in PT NAD and lipid metabolism, which can be reversed or prevented by treatment strategies that are viable in humans. These findings might also help to explain why MA accelerates decline in function in CKD.

Clara cell 16KDa protein mitigates house dust mite-induced airway inflammation and damage via regulating airway epithelial cell apoptosis in a manner dependent on HMGB1-mediated signaling inhibition.

Background: House dust mite (HDM) inhalation can cause airway epithelial damage which is implicated in the process of airway inflammation in asthma. High mobility group box 1 (HMGB1) is critically required for cellular damage and apoptosis as an important endogenous danger signal. Recently, Clara cell 16KDa protein (CC16) has been identified to exert anti-inflammatory and immunomodulatory influence in various injury-related diseases model. However, little is known about its ability to protect against airway epithelial injury in allergic asthma. This study was aimed to clarify the protective roles of CC16 on airway epithelia in HDM-induced asthma and the regulation of HMGB1 by CC16.Methods: Mice were sensitized and challenged by HDM extract and administrated intranasally with CC16 (5ug/g or 10ug/g) or saline in the challenged period. The BEAS-2B human airway epithelial cell line were cultured with CC16 or the control vehicle and then exposed to HDM. Knockdown or overexpression of HMGB1 was induced by cell transfection or intratracheal injection of recombinant adenovirus.Results: CC16 treatment decreased airway inflammation and histological damage of airway epithelium dose-dependently in HDM-induced asthma model. Airway epithelia apoptosis upon HDM stimulation was noticeably abrogated by CC16 in vivo and in vitro. In addition, upregulation of HMGB1 expression and its related signaling were also detected under HDM conditions, while silencing HMGB1 significantly inhibited the apoptosis of BEAS-2B cells. Furthermore, the activity of HMGB1-mediated signaling was restrained after CC16 treatment whereas HMGB1 overexpression abolished the protective effect of CC16 on HDM-induced airway epithelia apoptosis.Conclusions: Our data confirm that CC16 attenuates HDM-mediated airway inflammation and damage via suppressing airway epithelial cell apoptosis in a HMGB1-dependent manner, suggesting the role of CC16 as a potential protective option for HDM-induced asthma.