Contribution of dipeptidyl peptidase 4 to non-typeable Haemophilus influenzae-induced lung inflammation in COPD.

Dipeptidyl peptidase 4 (DPP4) expression is increased in the lungs of chronic obstructive pulmonary disease (COPD). DPP4 is known to be associated with inflammation in various organs, including LPS-induced acute lung inflammation. Since non-typeable Haemophilus influenzae (NTHi) causes acute exacerbations in COPD patients, we examined the contribution of DPP4 in NTHi-induced lung inflammation in COPD. Pulmonary macrophages isolated from COPD patients showed higher expression of DPP4 than the macrophages isolated from normal subjects. In response to NTHi infection, COPD, but not normal macrophages show a further increase in the expression of DPP4. COPD macrophages also showed higher expression of IL-1ß, and CCL3 responses to NTHi than normal, and treatment with DPP4 inhibitor, diprotin A attenuated this response. To examine the contribution of DPP4 in NTHi-induced lung inflammation, COPD mice were infected with NTHi, treated with diprotin A or PBS intraperitoneally, and examined for DPP4 expression, lung inflammation, and cytokine expression. Mice with COPD phenotype showed increased expression of DPP4, which increased further following NTHi infection. DPP4 expression was primarily observed in the infiltrated inflammatory cells. NTHi-infected COPD mice also showed sustained neutrophilic lung inflammation and expression of CCL3, and this was inhibited by DPP4 inhibitor. These observations indicate that enhanced expression of DPP4 in pulmonary macrophages may contribute to sustained lung inflammation in COPD following NTHi infection. Therefore, inhibition of DPP4 may reduce the severity of NTHi-induced lung inflammation in COPD.

Smoking and COVID-19: Adding Fuel to the Flame.

The coronavirus disease 2019 (COVID-19) pandemic, an infection caused by the severe acute respiratory syndrome coronavirus (SARS-CoV-2), has led to more than 771,000 deaths worldwide. Tobacco smoking is a major known risk factor for severe illness and even death from many respiratory infections. The effects of smoking on COVID-19 are currently controversial. Here, we provide an overview of the current knowledge on the effects of smoking on the clinical manifestations, disease progression, inflammatory responses, immunopathogenesis, racial ethnic disparities, and incidence of COVID-19. This review also documents future directions of smoking related research in COVID-19. The current epidemiological finding suggests that active smoking is associated with an increased severity of disease and death in hospitalized COVID-19 patients. Smoking can upregulate the angiotensin-converting enzyme-2 (ACE-2) receptor utilized by SARS-CoV-2 to enter the host cell and activate a 'cytokine storm' which can lead to worsen outcomes in COVID-19 patients. This receptor can also act as a potential therapeutic target for COVID-19 and other infectious diseases. The COVID-19 pandemic sheds light on a legacy of inequalities regarding gender, racial, and ethnic health disparities associated with active smoking, thus, smoking cessation may help in improving outcomes. In addition, to flatten the COVID-19 curve, staying indoors, avoiding unnecessary social contact, and bolstering the immune defense system by maintaining a healthy diet/living are highly desirable.

Rhinovirus-induces progression of lung disease in a mouse model of COPD via IL-33/ST2 signaling axis.

Rhinovirus (RV), which is associated with acute exacerbations, also causes persistent lung inflammation in patients with chronic obstructive pulmonary disease (COPD), but the underlying mechanisms are not well-known. Recently, we demonstrated that RV causes persistent lung inflammation with accumulation of a subset of macrophages (CD11b+/CD11c+), and CD8+ T cells, and progression of emphysema. In the present study, we examined the mechanisms underlying the RV-induced persistent inflammation and progression of emphysema in mice with COPD phenotype. Our results demonstrate that at 14 days post-RV infection, in addition to sustained increase in CCL3, CXCL-10 and IFN-γ expression as previously observed, levels of interleukin-33 (IL-33), a ligand for ST2 receptor, and matrix metalloproteinase (MMP)12 are also elevated in mice with COPD phenotype, but not in normal mice. Further, MMP12 was primarily expressed in CD11b+/CD11c+ macrophages. Neutralization of ST2, reduced the expression of CXCL-10 and IFN-γ and attenuated accumulation of CD11b+/CD11c+ macrophages, neutrophils and CD8+ T cells in COPD mice. Neutralization of IFN-γ, or ST2 attenuated MMP12 expression and prevented progression of emphysema in these mice. Taken together, our results indicate that RV may stimulate expression of CXCL-10 and IFN-γ via activation of ST2/IL-33 signaling axis, which in turn promote accumulation of CD11b+/CD11c+ macrophages and CD8+ T cells. Furthermore, RV-induced IFN-γ stimulates MMP12 expression particularly in CD11b+/CD11c+ macrophages, which may degrade alveolar walls thus leading to progression of emphysema in these mice. In conclusion, our data suggest an important role for ST2/IL-33 signaling axis in RV-induced pathological changes in COPD mice.

rHuKGF ameliorates protease/anti-protease imbalance in emphysematous mice.

We attempted to elucidate the beneficial role of rHuKGF supplementation in the amelioration of protease/antiprotease imbalance and TGF-ß1 signaling pathway leading to alveolar tissue maintenance in elastase induced emphysematous mice. Thirty two male C57BL mice were divided into four groups i.e. control, emphysema, therapy and rHuKGF only and were oropharyngeally instilled with saline/porcine pancreatic elastase/rHuKGF. Subsequently, lungs from mice were collected for histopathology and molecular biology studies. rHuKGF supplementation significantly ameliorated the mRNA expressions of CRP, TNF-α, MMP-2, MMP-7, MMP-8, MMP-9, MMP-12, A1AT, TIMP1, TIMP2, PCNA, Ki67, SPB, SPC and PdPn. MMP-2 and TIMP-1 enzyme activity was resolved due to rHuKGF. Likewise, due to rHuKGF supplementation the protein expressions of CRP, MMP2, MMP7, MMP8 & CTSE, SERPINE1, SERPINA1, TIMP4, GSTA1, HDAC3, PCNA, CDH1, SP-B & SP-C were ameliorated. Moreover, the mRNA expressions of overall TGFß-1 pathway was also significantly ameliorated due to rHuKGF supplementation. Lung histopathology represents recovery of lost alveolar septa due to rHuKGF supplementation. Moreover, positive DAB staining of PCNA, SP-B & SP-C was observed due to rHuKGF supplementation at tissue level. rHuKGF is therapeutically potent in maintaining pulmonary tissue integrity by amelioration of protease/antiprotease imbalance and TGFß-1 pathway in emphysema.

Recombinant human keratinocyte growth factor attenuates apoptosis in elastase induced emphysematous mice lungs.

Alveolar cell apoptosis is one of the potential factors involved in the pathogenesis of emphysema. Recently, exogenous recombinant human keratinocyte growth factor (rHuKGF) has been reported to induce the regeneration of gas exchange structures. Therefore, the rationale of the present study was to investigate the potential effect of rHuKGF in ameliorating tissue destruction in the emphysematous mice lungs. Four experimental groups (i.e. control-, emphysema-, therapy- and therapy control-group) were prepared. Subsequently, lungs from each mouse were collected for comet assay, elastase activity assay, antioxidant activity assay and real-time PCR based analyses. Comet assay analysis demonstrated the reduced tail DNA % and olive tail moment in therapy group. rHuKGF supplementation in emphysematous mice caused a significant reduction in the elastase activity levels along with reduction in activity of CAT, SOD and GPx. Furthermore, based on mRNA expression studies, the supplementation of rHuKGF ameliorated the induced apoptosis pathway in emphysematous mice lungs. Moreover, due to rHuKGF supplementation, TNF-α and p53 expression and production were markedly decreased in emphysematous mice lungs. Thus, therapeutic supplementation of rHuKGF might have reversed the alveolar cell loss in elastase induced emphysematous mice lungs by reducing DNA damage and maintaining antioxidant activities.

Effect of recombinant human keratinocyte growth factor in inducing Ras-Raf-Erk pathway-mediated cell proliferation in emphysematous mice lung.

CONTEXT: Pulmonary emphysema is resulted due to destruction of the structure of the alveoli. Recently, exogenous recombinant human Keratinocyte growth factor (rHuKGF) has been reported to induce the regeneration of gas exchange structures. However, the molecular mechanisms governing this process are so far unknown. OBJECTIVE: The objective of this study was to investigate the effect of rHuKGF in the lungs of emphysema-challenged mice on Ras-Raf-Erk (Erk, extracellular signal-regulated kinase) mediated signaling pathway that regulates alveolar epithelial cell proliferation. METHODS: Three experimental groups (i.e. emphysema, therapy and control group) were prepared. Lungs of mice were therapeutically treated at three occasions by oropharyngeal instillation of 10 mg rHuKGF per kg body weight after induction of emphysema by porcine pancreatic elastase (PPE). Subsequently, lung tissues from each mouse were collected for histopathology and molecular biology studies. RESULTS AND DISCUSSION: Histopathology photomicrographs and Destructive Index analysis have shown that elastase induced airspace enlargement and loss of alveoli were recovered in therapy group. Moreover, proliferating cell nuclear antigen (PCNA) at mRNA and protein expression level was markedly increased in therapy group than emphysema group. Upon validation at mRNA level, expressions of FGF-7, FGF-R, Ras, c-Raf, Erk-1, Erk-2, c-Myc and were significantly increased, whereas Elk-1 was notably decreased in therapy group when compared with emphysema group and were well comparable with the control group. CONCLUSION: Therapeutic supplementation of rHuKGF rectifies the deregulated Ras-Raf-Erk pathway in emphysema condition, resulting in alveolar epithelium regeneration. Hence, rHuKGF may prove to be a potential drug in the treatment of emphysema.

CEACAM7 expression contributes to early events of pancreatic cancer.

BACKGROUND: The trends of pancreatic cancer (PanCa) incidence and mortality are on rising pattern, and it will be a second leading cause of cancer related deaths by 2030. Pancreatic ductal adenocarcinoma (PDAC), major form of PanCa, exhibits a grim prognosis as mortality rate is very close to the incidence rate, due to lack of early detection methods and effective therapeutic regimen. Considering this alarming unmet clinic need, our team has identified a novel oncogenic protein, carcinoembryonic antigen-related cell adhesion molecule 7 (CEACAM7), that can be useful for spotting early events of PDAC. METHODOLOGY: This study includes bioinformatics pre-screening using publicly available cancer databases followed by molecular biology techniques in PDAC progressive cell line panel and human tissues to evaluate CEACAM7 expression in early events of pancreatic cancer. RESULTS: PanCa gene and protein expression analysis demonstrated the significantly higher expression of CEACAM7 in PDAC, compared to other cancers and normal pancreas. Overall survival analysis demonstrated an association between the higher expression of CEACAM7 and poor patients' prognosis with high hazard ratio. Additionally, in a performance comparison analysis CEACAM7 outperformed S100A4 in relation to PDAC. We also observed an increase of CEACAM7 in PDAC cell line panel model. However, poorly differentiated, and normal cell lines did not show any expression. Human tissue analysis also strengthened our data by showing strong and positive IHC staining in early-stage tumors. CONCLUSION: Our observations clearly cite that CEACAM7 can serve as a potential early diagnostic and/or prognostic marker of PDAC and may also potentiate the sensitivity of the existing biomarker panel of PDAC. However, further studies are warranted to determine its clinical significance.

Neuroinflammatory Responses and Blood-Brain Barrier Injury in Chronic Alcohol Exposure: Role of Purinergic P2X7 Receptor Signaling.

Alcohol consumption leads to neuroinflammation and blood-brain barrier (BBB) damage, resulting in neurological impairment. We previously demonstrated that ethanol-induced disruption of barrier function in human brain endothelial cells was associated with mitochondrial injury, increased ATP and extracellular vesicle (EV) release, and purinergic receptor P2X7R activation. Therefore, we aimed to evaluate the effect of P2X7r blockade on peripheral and neuro-inflammation in EtOH-exposed mice. In a chronic intermittent ethanol (CIE)-exposed mouse model, P2X7R was inhibited by two different methods: Brilliant Blue G (BBG) or gene knockout. We assessed blood ethanol concentration (BEC), plasma P2X7R and P-gp, number of extra-cellular vesicles (EV), serum ATP and EV-ATP levels. Brain microvessel gene expression and EV mtDNA copy numbers were measured by RT2 PCR array and digital PCR, respectively. A RT2 PCR array of brain microvessels revealed significant upregulation of proinflammatory genes involved in apoptosis, vasodilation, and platelet activation in CIE-exposed animals, which were decreased 15-50-fold in BBG-treated CIE-exposed animals. Plasma P-gp levels and serum P2X7R shedding were significantly increased in CIE-exposed animals. Pharmacological or genetic suppression of P2X7R decreased P2X7R shedding to levels equivalent to those in control group. The increase in EV number and EV-ATP content in the CIE-exposed mice was significantly reduced by P2X7R inhibition. CIE mice showed augmented EV-mtDNA copy numbers which were reduced in EVs after P2X7R inhibition or receptor knockout. These observations suggested that P2X7R signaling plays a critical role in ethanol-induced brain injury. Increased eATP, EV-ATP, EV numbers, and EV-mtDNA copy numbers highlight a new mechanism of brain injury during alcohol exposure via P2X7R and biomarkers of such damage. In this study, for the first time, we report the in vivo involvement of P2X7R signaling in CIE-induced brain injury.

A Systems Biology Approach Unveils a Critical Role of DPP4 in Upper Gastrointestinal Cancer Patient Outcomes.

Gastrointestinal (GI) cancers comprise of cancers that affect the digestive system and its accessory organs. The late detection and poor prognosis of GI cancer emphasizes the importance of identifying reliable and precise biomarkers for early diagnosis and prediction of prognosis. The membrane-bound glycoprotein dipeptidyl-peptidase 4 (DPP4), also known as CD26, is ubiquitously expressed and has a wide spectrum of biological roles. The role of DPP4/CD26 in tumor progression in different types of cancers remains elusive. However, the link between DPP4 and tumor-infiltrating cells, as well as its prognostic significance in malignancies, still require further investigation. This study was intended to elucidate the correlation of DPP4 expression and survival along with prognosis, followed by its associated enriched molecular pathways and immune cell marker levels in upper GI cancers. Results demonstrated a strong correlation between increased DPP4 expression and a worse prognosis in esophageal and gastric cancer and the co-expressed common genes with DPP4 were associated with crucial molecular pathways involved in tumorigenesis. Additionally, DPP4 was shown to be significantly linked to several immune infiltrating cell marker genes, including Macrophages (M1, M2 and Tumor Associated Macrophages), neutrophils, Treg, T-cell exhaustion, Th1 and Th2. Overall, our findings suggest that DPP4 may serve as a substantial prognostic biomarker, a possible therapeutic target, as well as it can play a critical role in the regulation of immune cell invasion in patients with gastroesophageal (esophageal, gastroesophageal junction and gastric) cancer. KEY WORDS: DPP4, integrated analysis, GI cancer, gastroesophageal cancer, gastroesophageal junction, prognosis.

Therapeutic potential of growth factors in pulmonary emphysematous condition.

Pulmonary emphysema is a major manifestation of chronic obstructive pulmonary disease (COPD), which is characterized by progressive destruction of alveolar parenchyma with persistent inflammation of the small airways. Such destruction in the distal respiratory tract is irreversible and irreparable. All-trans-retinoic acid was suggested as a novel therapy for regeneration of lost alveoli in emphysema. However, profound discrepancies were evident between studies. At present, no effective therapeutic options are available that allow for the regeneration of lost alveoli in emphysematous human lungs. Recently, some reports on rodent's models have suggested the beneficial effects of various growth factors toward alveolar maintenance and repair processes.

Glutathione-Responsive Tannic Acid-Assisted FRET Nanomedicine for Cancer Therapy.

In cancer combination therapy, a multimodal delivery vector is used to improve the bioavailability of multiple anti-cancer hydrophobic drugs. Further, targeted delivery of therapeutics along with simultaneous monitoring of the drug release at the tumor site without normal organ toxicity is an emerging and effective strategy for cancer treatment. However, the lack of a smart nano-delivery system limits the application of this therapeutic strategy. To overcome this issue, a PEGylated dual drug, conjugated amphiphilic polymer (CPT-S-S-PEG-CUR), has been successfully synthesized by conjugating two hydrophobic fluorescent anti-cancer drugs, curcumin (CUR) and camptothecin (CPT), through an ester and a redox-sensitive disulfide (-S-S-) linkage, respectively, with a PEG chain via in situ two-step reactions. CPT-S-S-PEG-CUR is spontaneously self-assembled in the presence of tannic acid (TA, a physical crosslinker) into anionic, comparatively smaller-sized (~100 nm), stable nano-assemblies in water in comparison to only polymer due to stronger H-bond formation between polymer and TA. Further, due to the spectral overlap between CPT and CUR and a stable, smaller nano-assembly formation by the pro-drug polymer in water in presence of TA, a successful Fluorescence Resonance Energy Transfer (FRET) signal was generated between the conjugated CPT (FRET donor) and conjugated CUR (FRET acceptor). Interestingly, these stable nano-assemblies showed a preferential breakdown and release of CPT in a tumor-relevant redox environment (in the presence of 50 mM glutathione), leading to the disappearance of the FRET signal. These nano-assemblies exhibited a successful cellular uptake by the cancer cells and an enhanced antiproliferative effect in comparison to the individual drugs in cancer cells (AsPC1 and SW480). Such promising in vitro results with a novel redox-responsive, dual-drug conjugated, FRET pair-based nanosized multimodal delivery vector can be highly useful as an advanced theranostic system towards effective cancer treatment.

Boosting Mitochondrial Potential: An Imperative Therapeutic Intervention in Amyotrophic Lateral Sclerosis.

BACKGROUND: Amyotrophic Lateral Sclerosis (ALS) is a progressive and terminal neurodegenerative disorder. Mitochondrial dysfunction, imbalance of cellular bioenergetics, electron chain transportation and calcium homeostasis are deeply associated with the progression of this disease. Impaired mitochondrial functions are crucial in rapid neurodegeneration. The mitochondria of ALS patients are associated with deregulated Ca2+ homeostasis and elevated levels of reactive oxygen species (ROS), leading to oxidative stress. Overload of mitochondrial calcium and ROS production leads to glutamatereceptor mediated neurotoxicity. This implies mitochondria are an attractive therapeutic target. OBJECTIVE: The aim of this review is to brief the latest developments in the understanding of mitochondrial pathogenesis in ALS and emphasize the restorative capacity of therapeutic candidates. RESULTS: In ALS, mitochondrial dysfunction is a well-known phenomenon. Various therapies targeted towards mitochondrial dysfunction aim at decreasing ROS generation, increasing mitochondrial biogenesis, and inhibiting apoptotic pathways. Some of the therapies briefed in this review may be categorized as synthetic, natural compounds, genetic materials, and cellular therapies. CONCLUSION: The overarching goals of mitochondrial therapies in ALS are to benefit ALS patients by slowing down the disease progression and prolonging overall survival. Despite various therapeutic approaches, there are many hurdles in the development of a successful therapy due to the multifaceted nature of mitochondrial dysfunction and ALS progression. Intensive research is required to precisely elucidate the molecular pathways involved in the progression of mitochondrial dysfunctions that ultimately lead to ALS. Because of the multifactorial nature of ALS, a combination therapy approach may hold the key to cure and treat ALS in the future.

In silico CD4 + T-cell multiepitope prediction and HLA distribution analysis for Marburg Virus-A strategy for vaccine designing.

Marburg, a RNA virus (MRV), is responsible for causing hemorrhagic fever that affects humans and non-human primates. World Health Organization (WHO), National Institutes of Health (NIH) and Centre of Disease Control and Prevention (CDC) considered this as an extremely dangerous virus, thus categorised as risk group 4, category A priority pathogen and category "A" bioterrorism agent, respectively. Despite of all these alarming concerns, no prophylaxis arrangements are available against this virus till date. In fact, the construction of immunogenic vaccine candidates by traditional molecular immunology methods is time consuming and very expensive. Considering these concerns, herein, we have designed CD4 + T Cell multiepitopes against MRV using in silico approach. The pin-point criteria of the screening and selection of potential epitopes are, non-mutagenic, antigenic, large HLAs coverage, non-toxic and high world population coverage. This kind of methodology and investigations can precisely reduce the expenditure and valuable time for experimental planning in development of vaccines in laboratories. In current scenario, researchers are frequently using in silico approaches to speed up their vaccine-based lab studies. The computational studies are highly valuable for the screening of large epitope dataset into smaller one prior to in vitro and in vivo confirmatory analyses.

A topography of immunotherapies against gastrointestinal malignancies.

Gastrointestinal (GI) cancers are one of the leading causes of death worldwide. Although various approaches are implemented to improve the health condition of GI patients, none of the treatment protocols promise for eradicating cancer. However, a treatment mechanism against any kind of disease condition is already existing executing inside the human body. The 'immune system' is highly efficient to detect and destroy the unfavorable events of the body including tumor cells. The immune system can restrict the growth and proliferation of cancer. Cancer cells behave much smarter and adopt new mechanisms for hiding from the immune cells. Thus, cancer immunotherapy might play a decisive role to train the immune system against cancer. In this review, we have discussed the immunotherapy permitted for the treatment of GI cancers. We have discussed various methods and mechanisms, periodic development of cancer immunotherapies, approved biologicals, completed and ongoing clinical trials, role of various biopharmaceuticals, and epigenetic factors involved in GI cancer immunotherapies.

A bird eye view on cystic fibrosis: An underestimated multifaceted chronic disorder.

Cystic fibrosis (CF) is an autosomal recessive disease which involves the mutations in the cystic fibrosis transmembrane conductance regulator (CFTR) gene. CF involves in the inflammatory processes and is considered as a multisystem disorder that is not confined to lungs, but it also affects other vital organs that leads to numerous co-morbidities. The respiratory disorder in the CF results in mortality and morbidity which is characterized by series of serious events involving mucus hypersecretion, microbial infections, airways obstruction, inflammation, destruction of epithelium, tissue remodeling and terminal lung diseases. Mucins are the high molecular weight glycoproteins important for the viscoelastic properties of the mucus, play a significant role in the disease mechanisms. Determining the functional association between the CFTR and mucins might help to identify the putative target for specific therapeutic approach. In fact, furin enzyme which helps in the entry of novel COVID-19 virus into the cell, is upregulated in CF and this can also serve as a potential target for CF treatment. Moreover, the use of nano-formulations for CF treatment is an area of research being widely studied as they have also demonstrated promising outcomes. The in-depth knowledge of non-coding RNAs like miRNAs and lncRNAs and their functional association with CFTR gene expression and mutation can provide a different range of opportunity to identify the promising therapeutic approaches for CF.

Neutralization of SARS-CoV-2 Spike Protein via Natural Compounds: A Multilayered High Throughput Virtual Screening Approach.

BACKGROUND: Previously human society has faced various unprecedented pandemics in the history and viruses have majorly held the responsibilities of those outbreaks. Furthermore, due to amplified global connection and speedy modernization, epidemic outbreaks caused by novel and re-emerging viruses signify potential risk to community health. Despite great advancements in immunization and drug discovery processes, various viruses still lack prophylactic vaccines and efficient antiviral therapies. Although, vaccine is a prophylaxes option, but it cannot be applied to infected patients, hence therapeutic interventions are urgently needed to control the ongoing global SARS- CoV-2 pandemic condition. To spot the novel antiviral therapy is of decisive importance and Mother Nature is an excellent source for such discoveries. METHODOLOGY: In this article, prompt high through-put virtual screening for vetting the best possible drug candidates from natural compounds' databases has been implemented. Herein, time tested rigorous multi-layered drug screening process to narrow down 66,969 natural compounds for the identification of potential lead(s) is implemented. Druggability parameters, different docking approaches and neutralization tendency of the natural products were employed in this study to screen the best possible natural compounds from the digital libraries. CONCLUSION: The results of this study conclude that compounds PALA and HMCA are potential inhibitors of SARS-CoV-2 spike protein and can be further explored for experimental validation. Overall, the methodological approach reported in this article can be suitably used to find the potential drug candidates against SARS-CoV2 in the burning situation of COVID-19 with less expenditure and a concise span of time.

Microarray analysis identifies defects in regenerative and immune response pathways in COPD airway basal cells.

BACKGROUND: Airway basal cells are specialised stem cells and regenerate airway epithelium. Airway basal cells isolated from patients with COPD regenerate airway epithelium with an abnormal phenotype. We performed gene expression analysis to gain insights into the defective regenerative programme in COPD basal cells. METHODS: We conducted microarray analysis and compared COPD versus normal basal cells to identify differentially regulated genes (DEGs) and the enriched biological pathways. We determined the correlation of DEGs with cell polarisation and markers of ciliated and goblet cells. HOXB2 was knocked down in 16HBE14o- cells and monitored for polarisation of cells. HOXB2 expression in the lung sections was determined by immunofluorescence. RESULTS: Comparison of normal and COPD basal cell transcriptomic profiles highlighted downregulation of genes associated with tissue development, epithelial cell differentiation and antimicrobial humoral response. Expression of one of the tissue development genes, HOXB2 showed strong correlation with transepithelial resistance and this gene was downregulated in COPD basal cells. Knockdown of HOXB2, abrogated polarisation of epithelial cells in normal cells. Finally, HOXB2 expression was substantially reduced in the bronchial epithelium of COPD patients. CONCLUSIONS: Defect in gene signatures involved in tissue development and epithelial differentiation were implicated in COPD basal cells. One of the tissue developmental genes, HOXB2, is substantially reduced in bronchial epithelium of COPD patients. Since HOXB2 contributes to airway epithelial cell polarisation, we speculate that reduced expression of HOXB2 in COPD may contribute to abnormal airway epithelial regeneration in COPD.

FOXO3a regulates rhinovirus-induced innate immune responses in airway epithelial cells.

Forkhead transcription factor class O (FOXO)3a, which plays a critical role in a wide variety of cellular processes, was also found to regulate cell-type-specific antiviral responses. Airway epithelial cells express FOXO3a and play an important role in clearing rhinovirus (RV) by mounting antiviral type I and type III interferon (IFN) responses. To elucidate the role of FOXO3a in regulating antiviral responses, we generated airway epithelial cell-specific Foxo3a knockout (Scga1b1-Foxo3a-/-) mice and a stable FOXO3a knockout human airway epithelial cell line. Compared to wild-type, Scga1b1-Foxo3a-/- mice show reduced IFN-α, IFN-ß, IFN-λ2/3 in response to challenge with RV or double-stranded (ds)RNA mimic, Poly Inosinic-polycytidylic acid (Poly I:C) indicating defective dsRNA receptor signaling. RV-infected Scga1b1-Foxo3a-/- mice also show viral persistence, enhanced lung inflammation and elevated pro-inflammatory cytokine levels. FOXO3a K/O airway epithelial cells show attenuated IFN responses to RV infection and this was associated with conformational change in mitochondrial antiviral signaling protein (MAVS) but not with a reduction in the expression of dsRNA receptors under unstimulated conditions. Pretreatment with MitoTEMPO, a mitochondrial-specific antioxidant corrects MAVS conformation and restores antiviral IFN responses to subsequent RV infection in FOXO3a K/O cells. Inhibition of oxidative stress also reduces pro-inflammatory cytokine responses to RV in FOXO3a K/O cells. Together, our results indicate that FOXO3a plays a critical role in regulating antiviral responses as well as limiting pro-inflammatory cytokine expression. Based on these results, we conclude that FOXO3a contributes to optimal viral clearance and prevents excessive lung inflammation following RV infection.

Recombinant Human Keratinocyte Growth Factor Induces Akt Mediated Cell Survival Progression in Emphysematous Mice.

INTRODUCTION: Emphysema has been associated with decreased VEGF and VEGFR-2 expression and the presence of high numbers of apoptotic alveolar cells. Keratinocyte growth factor stimulates VEGF synthesis which in turn confers normal lung structure maintenance via the Akt pathway. In this study the potential role of rHuKGF in the improvement of deregulated Akt mediated cell survival pathway in emphysematous mice was investigated. METHODS: Three experimental groups, i.e., emphysema, treatment and control groups, were prepared. Lungs of mice were treated on 3 occasions by oropharyngeal instillation of 10mg rHuKGF per kg body weight after induction of emphysema with porcine pancreatic elastase. Subsequently, lung tissues from mice were collected for histopathology and molecular biology studies. RESULTS AND DISCUSSION: Histopathology photomicrographs and destructive index analysis have shown that elastase-induced airspace enlargement and loss of alveoli recovered in the treatment group. rHuKGF stimulates VEGF production which in turn induces the Akt mediated cell survival pathway in emphysematous lungs. mRNA expression of VEGF, VEGFR, PI3K and Akt was significantly increased while Pten, Caspase-9 and Bad was notably decreased in treatment group when compared with emphysema group, being comparable with the control group. Moreover, VEGF protein expression was in accordance with that found for mRNA. CONCLUSION: Therapeutic rHuKGF supplementation improves the deregulated Akt pathway in emphysema, resulting in alveolar cell survival through activation of the endogenous VEGF-dependent cell survival pathway. Hence rHuKGF may prove to be a potential drug in the treatment of emphysema.