Selective targeting of alveolar type II respiratory epithelial cells by anti-surfactant protein-C antibody-conjugated lipoplexes

Co-Delivery of Astaxanthin and siTGF-β1 via Ionizable Liposome Nanoparticles for Improved Idiopathic Pulmonary Fibrosis Therapy

Alleviating the injury of type II alveolar epithelial cells (AEC 2s) and inhibiting the activation and differentiation of fibroblasts are significant for improving the therapeutic effect of idiopathic pulmonary fibrosis (IPF). To this aim, ionizable liposome nanoparticles (ASNPs) coloaded with antioxidant drug astaxanthin (AST) and small interfering RNA targeting transforming growth factor β1 (siTGF-β1) were developed for enhanced IPF therapy. ASNPs showed high loading and intracellular delivery efficiency for AST and siTGF-β1. After the injection of ASNPs in an IPF mice model, the loaded AST largely scavenged reactive oxygen species (ROS) in the diseased lung to reduce AEC2 apoptosis, thereby ensuring the integrity of the alveolar epithelium. Meanwhile, siTGF-β1, delivered by ASNPs, significantly silenced the expression of TGF-β1 in fibroblasts, inhibiting the differentiation of fibroblasts into myofibroblasts as well as reducing the excessive deposition of extracellular matrix (ECM). The combined use of the two drugs exhibited an excellent synergistic antifibrotic effect and was conducive to minimizing alveolar epithelial damage. This work provides a codelivery strategy of AST and siTGF-β1, which shows great promise for the treatment of IPF by simultaneously reducing alveolar epithelial damage and inhibiting fibroblast activation.

Ferroptotic alveolar epithelial type II cells drive TH2 and TH17 mixed asthma triggered by birch pollen allergen Bet v 1

Asthma is a common allergic disease characterized by airway hypersensitivity and airway remodeling. Ferroptosis is a regulated death marked by iron accumulation and lipid peroxidation. Several environmental pollutants and allergens have been shown to cause ferroptosis in epithelial cells, but the relationship between birch pollinosis and ferroptosis in asthma is poorly defined. Here, for the first time, we have identified ferroptosis of type II alveolar epithelial cells in mice with Bet v 1-induced asthma. Further analysis revealed that treatment with ferrostatin-1 reduced TH2/TH17-related inflammation and alleviated epithelial damage in mice with Bet v 1-induced asthma. In addition, ACSL4-knocked-down A549 cells are more resistant to Bet v 1-induced ferroptosis. Analysis of clinical samples verified higher serum MDA and 4-HNE concentrations compared to healthy individuals. We demonstrate that birch pollen allergen Bet v 1 induces ferroptosis underlaid TH2 and TH17 hybrid asthma. Lipid peroxidation levels can be considered as a biomarker of asthma severity, and treatment with a specific ferroptosis inhibitor could be a novel therapeutic strategy.

Glucocorticoid Nanoparticles Show Full Therapeutic Efficacy in a Mouse Model of Acute Lung Injury and Concomitantly Reduce Adverse Effects

Glucocorticoids (GCs) are widely used to treat inflammatory disorders such as acute lung injury (ALI). Here, we explored inorganic-organic hybrid nanoparticles (IOH-NPs) as a new delivery vehicle for GCs in a mouse model of ALI. Betamethasone (BMZ) encapsulated into IOH-NPs (BNPs) ameliorated the massive infiltration of neutrophils into the airways with a similar efficacy as the free drug. This was accompanied by a potent inhibition of pulmonary gene expression and secretion of pro-inflammatory mediators, whereas the alveolar-capillary barrier integrity was only restored by BMZ in its traditional form. Experiments with genetically engineered mice identified myeloid cells and alveolar type II (AT II) cells as essential targets of BNPs in ALI therapy, confirming their high cell-type specificity. Consequently, adverse effects were reduced when using IOH-NPs for GC delivery. BNPs did not alter T and B cell numbers in the blood and also prevented the induction of muscle atrophy after three days of treatment. Collectively, our data suggest that IOH-NPs target GCs to myeloid and AT II cells, resulting in full therapeutic efficacy in the treatment of ALI while being associated with reduced adverse effects.

Emerging applications and prospects of NFκB decoy oligodeoxynucleotides in managing respiratory diseases

Chronic respiratory diseases like asthma and Chronic Obstructive Pulmonary Disease (COPD) have been a burden to society for an extended period. Currently, there are only preventative treatments in the form of mono- or multiple-drug therapy available to patients who need to utilize it daily. Hence, throughout the years there has been a substantial amount of research in understanding what causes inflammation in the context of these diseases. For example, the transcription factor NFκB has a pivotal role in causing chronic inflammation. Subsequent research has been exploring ways to block the activation of NFκB as a potential therapeutic strategy for many inflammatory diseases. One of the possible ways through which this is probable is the utilisation of decoy oligodeoxynucleotides, which are synthetic, short, single-stranded DNA fragments that mimic the consensus binding site of a targeted transcription factor, thereby functionally inactivating it. However, limitations to the implementation of decoy oligodeoxynucleotides include their rapid degradation by intracellular nucleases and the lack of targeted tissue specificity. An advantageous approach to overcome these limitations involves using nanoparticles as a vessel for drug delivery. In this review, all of those key elements will be explored as to how they come together as an application to treat chronic inflammation in respiratory diseases.

Precise nanodrug delivery systems with cell-specific targeting for ALI/ARDS treatment

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are common acute and critical diseases in clinics and have no effective treatment to date. With the concept of "precision medicine", research into the precise drug delivery of therapeutic and diagnostic drugs has become a frontier in nanomedicine research and has entered the era of design of precise nanodrug delivery systems (NDDSs) with cell-specific targeting. Owing to the distinctive characteristics of ALI/ARDS, designing NDDSs for specific focal sites is an important strategy for changing drug distribution in the body and specifically increasing drug concentration at target sites while decreasing drug concentration at non-target sites. This strategy enhances drug efficacy, reduces adverse reactions, and ensures accurate nano-targeted treatment. On the basis of the characteristics of pathological ALI/ARDS microenvironments, this paper reviews NDDSs targeting vascular endothelial cells, neutrophils, alveolar macrophages, and alveolar epithelial cells to provide reference for designing accurate NDDSs for ALI/ARDS and novel insights into targeted treatments for ALI/ARDS.

miRNAs, from Evolutionary Junk to Possible Prognostic Markers and Therapeutic Targets in COVID-19

The COVID-19 pandemic has been a public health issue around the world in the last few years. Currently, there is no specific antiviral treatment to fight the disease. Thus, it is essential to highlight possible prognostic predictors that could identify patients with a high risk of developing complications. Within this framework, miRNA biomolecules play a vital role in the genetic regulation of various genes, principally, those related to the pathophysiology of the disease. Here, we review the interaction of host and viral microRNAs with molecular and cellular elements that could potentiate the main pulmonary, cardiac, renal, circulatory, and neuronal complications in COVID-19 patients. miR-26a, miR-29b, miR-21, miR-372, and miR-2392, among others, have been associated with exacerbation of the inflammatory process, increasing the risk of a cytokine storm. In addition, increased expression of miR-15b, -199a, and -491 are related to the prognosis of the disease, and miR-192 and miR-323a were identified as clinical predictors of mortality in patients admitted to the intensive care unit. Finally, we address miR-29, miR-122, miR-155, and miR-200, among others, as possible therapeutic targets. However, more studies are required to confirm these findings.

Nanomedicine to advance the treatment of bacteria-induced acute lung injury

Bacteria-induced acute lung injury (ALI) is associated with a high mortality rate due to the lack of an effective treatment. Patients often rely on supportive care such as low tidal volume ventilation to alleviate the symptoms. Nanomedicine has recently received much attention owing to its premium benefits of delivering drugs in a sustainable and controllable manner while minimizing the potential side effects. It can effectively improve the prognosis of bacteria-induced ALI through targeted delivery of drugs, regulation of multiple inflammatory pathways, and combating antibiotic resistance. Hence, in this review, we first discuss the pathogenesis of ALI and its potential therapeutics. In particular, the state-of-the-art nanomedicines for the treatment of bacteria-induced ALI are highlighted, including their administration routes, in vivo distribution, and clearance. Furthermore, the available bacteria-induced ALI animal models are also summarized. In the end, future perspectives of nanomedicine for ALI treatment are proposed.

Protein and peptide delivery to lungs by using advanced targeted drug delivery

The challenges and difficulties associated with conventional drug delivery systems have led to the emergence of novel, advanced targeted drug delivery systems. Therapeutic drug delivery of proteins and peptides to the lungs is complicated owing to the large size and polar characteristics of the latter. Nevertheless, the pulmonary route has attracted great interest today among formulation scientists, as it has evolved into one of the important targeted drug delivery platforms for the delivery of peptides, and related compounds effectively to the lungs, primarily for the management and treatment of chronic lung diseases. In this review, we have discussed and summarized the current scenario and recent developments in targeted delivery of proteins and peptide-based drugs to the lungs. Moreover, we have also highlighted the advantages of pulmonary drug delivery over conventional drug delivery approaches for peptide-based drugs, in terms of efficacy, retention time and other important pharmacokinetic parameters. The review also highlights the future perspectives and the impact of targeted drug delivery on peptide-based drugs in the coming decade.

Nanomedicine for acute respiratory distress syndrome: The latest application, targeting strategy, and rational design

Acute respiratory distress syndrome (ARDS) is characterized by the severe inflammation and destruction of the lung air-blood barrier, leading to irreversible and substantial respiratory function damage. Patients with coronavirus disease 2019 (COVID-19) have been encountered with a high risk of ARDS, underscoring the urgency for exploiting effective therapy. However, proper medications for ARDS are still lacking due to poor pharmacokinetics, non-specific side effects, inability to surmount pulmonary barrier, and inadequate management of heterogeneity. The increased lung permeability in the pathological environment of ARDS may contribute to nanoparticle-mediated passive targeting delivery. Nanomedicine has demonstrated unique advantages in solving the dilemma of ARDS drug therapy, which can address the shortcomings and limitations of traditional anti-inflammatory or antioxidant drug treatment. Through passive, active, or physicochemical targeting, nanocarriers can interact with lung epithelium/endothelium and inflammatory cells to reverse abnormal changes and restore homeostasis of the pulmonary environment, thereby showing good therapeutic activity and reduced toxicity. This article reviews the latest applications of nanomedicine in pre-clinical ARDS therapy, highlights the strategies for targeted treatment of lung inflammation, presents the innovative drug delivery systems, and provides inspiration for strengthening the therapeutic effect of nanomedicine-based treatment.

Hsa_circ_0001361 facilitates the progress of lung adenocarcinoma cells via targeting miR-525-5p/VMA21 axis

Background

Lung adenocarcinoma (LUAD) is a common subtype of lung cancer with high recurrence rate and fatality. Circ_0001361 has been recognized as key regulators in various malignancies, but its roles in LUAD remain ambiguous.

Methods

Circ_0001361, miR-525-5p, and VMA21 levels were assessed by RT-qPCR. The growth and metastasis of LUAD cells were detected by MTT, colony formation, wound scratch, and transwell assays, respectively. The interaction between circ_0001361/VMA21 and miR-525-5p was detected by dual luciferase, RNA immunoprecipitation, and RNA pull-down assays. VMA21 protein level was detected by Western blotting. Nude mouse xenograft model was established to determine the role of circ_0001361 in tumor growth in vivo.

Results

Circ_0001361 was up-regulated, while miR-525-5p was down-regulated in LUAD tissues and cells. Functional experiments demonstrated that circ_0001361 drove LUAD cell growth and metastasis. Mechanistically, circ_0001361 functioned as a sponge of miR-525-5p to up-regulate downstream target VMA21 level. MiR-525-5p/VMA21 axis was involved in circ_0001361-mediated malignant phenotypes of LUAD cells. Finally, inhibition of circ_0001361 restrained in vivo xenograft tumor growth via regulating miR-525-5p/VMA21 axis.

Conclusion

Our findings elucidate that circ_0001361 facilitates the tumorigenesis and development of LUAD through miR-525-5p/VMA21 axis, providing evidence for circ_0001361 as a potential prognosis biomarker and therapeutic target for clinical treatment of LUAD.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12967-021-03045-4.

Chitin-Derived AVR-48 Prevents Experimental Bronchopulmonary Dysplasia (BPD) and BPD-Associated Pulmonary Hypertension in Newborn Mice

Bronchopulmonary dysplasia (BPD) is the most common complication of prematurity and a key contributor to the large health care burden associated with prematurity, longer hospital stays, higher hospital costs, and frequent re-hospitalizations of affected patients through the first year of life and increased resource utilization throughout childhood. This disease is associated with abnormal pulmonary function that may lead to BPD-associated pulmonary hypertension (PH), a major contributor to neonatal mortality and morbidity. In the absence of any definitive treatment options, this life-threatening disease is associated with high resource utilization during and after neonatal intensive care unit (NICU) stay. The goal of this study was to test the safety and efficacy of a small molecule derivative of chitin, AVR-48, as prophylactic therapy for preventing experimental BPD in a mouse model. Two doses of AVR-48 were delivered either intranasally (0.11 mg/kg), intraperitoneally (10 mg/kg), or intravenously (IV) (10 mg/kg) to newborn mouse pups on postnatal day (P)2 and P4. The outcomes were assessed by measuring total inflammatory cells in the broncho-alveolar lavage fluid (BALF), chord length, septal thickness, and radial alveolar counts of the alveoli, Fulton’s Index (for PH), cell proliferation and cell death by immunostaining, and markers of inflammation by Western blotting and ELISA. The bioavailability and safety of the drug were assessed by pharmacokinetic and toxicity studies in both neonatal mice and rat pups (P3-P5). Following AVR-48 treatment, alveolar simplification was improved, as evident from chord length, septal thickness, and radial alveolar counts; total inflammatory cells were decreased in the BALF; Fulton’s Index was decreased and lung inflammation and cell death were decreased, while angiogenesis and cell proliferation were increased. AVR-48 was found to be safe and the no-observed-adverse-effect level (NOAEL) in rat pups was determined to be 100 mg/kg when delivered via IV dosing with a 20-fold safety margin. With no reported toxicity and with a shorter half-life, AVR-48 is able to reverse the worsening cardiopulmonary phenotype of experimental BPD and BPD-PH, compared to controls, thus positioning it as a future drug candidate.

Overcoming barriers by local drug delivery with liposomes

Localized or topical administration of drugs may be considered as a potential approach for overcoming the problems caused by the various biological barriers encountered in drug delivery. The combination of using localized administration routes and delivering drugs in nanoparticulate formulations, such as liposomes, may have additional advantages. Such advantages include prolonged retention of high drug loads at the site of action and controlled release of the drug, ensuring prolonged therapeutic effect; decreased potential for side-effects and toxicity (due to the high topical concentrations of drugs); and increased protection of drugs from possible harsh environments at the site of action. The use of targeted liposomal formulations may further potentiate any acquired therapeutic advantages. In this review we present the most advanced cases of localized delivery of liposomal formulations of drugs, which have been investigated pre-clinically and clinically in the last ten years, together with the reported therapeutic advantages, in each case.

Cell-specific drug targeting in the lung

Non-targeted drug delivery systems have several limitations including the decreased bioavailability of the drug, poor stability and rapid clearance in addition to off-target distribution. Cell-specific targeted delivery approaches promise to overcome some of these limitations and enhance therapeutic selectivity. In this review, we aim to discuss cell-specific targeted approachesin the lung at the biochemical and molecular levels. These approaches include;a) directly administered small molecule drugs with intracellular action; b) targeted biologics and synthetic hybrids with extracellular action; c) site activateddrugs; and d) delivery systems.We discuss the pharmaceutical and biochemical parameters that govern the fate of drug molecules at delivery sites while presenting an overview of relevant literature surrounding this area of research and current advancements.

Nanomedicine-Based Therapeutics to Combat Acute Lung Injury

Acute lung injury (ALI) or its aggravated stage acute respiratory distress syndrome (ARDS) may lead to a life-threatening form of respiratory failure, resulting in high mortality of up to 30-40% in most studies. Although there have been decades of research since ALI was first described in 1967, the clinical therapeutic alternatives for ALI are still in a state of limited availability. Supportive treatment and mechanical ventilation still have priority. Despite some preclinical studies demonstrating the benefit of pharmacological interventions, none of these has been proved completely effective to date. Recent advances in nanotechnology may shed new light on the pharmacotherapy of ALI. Nanomedicine possesses targeting and synergistic therapeutic capability, thus boosting pharmaceutical efficacy and mitigating the side effects. Currently, a variety of nanomedicine with diverse frameworks and functional groups have been elaborately developed, in accordance with their lung targeting ability and the pathophysiology of ALI. The in-depth review of the current literature reveals that liposomes, polymers, inorganic materials, cell membranes, platelets, and other nanomedicine approaches have conferred attractive therapeutic benefits for ALI treatment. In this review, we explore the recent progress in the study of the nanomedicine-based therapy of ALI, presenting various nanomedical approaches, drug choices, therapeutic strategies, and outcomes, thereby providing insight into the trends.

Nanoparticle delivery of microRNA-146a regulates mechanotransduction in lung macrophages and mitigates injury during mechanical ventilation

Mechanical ventilation generates injurious forces that exacerbate lung injury. These forces disrupt lung barrier integrity, trigger proinflammatory mediator release, and differentially regulate genes and non-coding oligonucleotides including microRNAs. In this study, we identify miR-146a as a mechanosensitive microRNA in alveolar macrophages that has therapeutic potential to mitigate lung injury during mechanical ventilation. We use humanized in-vitro systems, mouse models, and biospecimens from patients to elucidate the expression dynamics of miR-146a needed to decrease lung injury during mechanical ventilation. We find that the endogenous increase in miR-146a following injurious ventilation is not sufficient to prevent lung injury. However, when miR-146a is highly overexpressed using a nanoparticle delivery platform it is sufficient to prevent injury. These data indicate that the endogenous increase in microRNA-146a during mechanical ventilation is a compensatory response that partially limits injury and that nanoparticle delivery of miR-146a is an effective strategy for mitigating lung injury during mechanical ventilation.

Strategic advancements and multimodal applications of biofilm therapy

INTRODUCTION

Biofilm is a layer of mucilage consisting of bacterial species like Escherichia coli and Streptococcus aureus adhering to the solid cell surface. Biofilm is an important and novel approach in a delivery system consisting of six elements that includes extracellular DNA, enzymes, proteins, bacteria, exopolysaccharides and water channels. The biofilm formation is based on two mechanisms: extra polymeric substance and quorum sensing. The microbes present in biofilm prevent direct interaction between the cell surface and foreign materials, like allergens, or toxic gases, like carbon-monoxide and chlorofluorocarbon, entering the body.

AREAS COVERED

The authors focus on the novel applications of biofilms such as adhesives, tissue engineering, targeted delivery system, probiotics, nutrients delivery, etc. Moreover, the information of the factors for biofilm formation, techniques useful in biofilm formation, and clinical studies are also covered in this article.

EXPERT OPINION

Many people believe that biofilms have a negative impact on human health, but the expert opinion states that biofilm is a futuristic approach useful in therapeutics for the treatment of tumors and cancer. Biofilms can be combined with novel delivery systems such as nanoparticles, microparticles, etc. for better therapeutic action.

Pulmonary function analysis in cotton rats after respiratory syncytial virus infection

The cotton rat (Sigmodon hispidus) is an excellent small animal model for human respiratory viral infections such as human respiratory syncytial virus (RSV) and human metapneumovirus (HMPV). These respiratory viral infections, as well as other pulmonary inflammatory diseases such as asthma, are associated with lung mechanic disturbances. So far, the pathophysiological effects of viral infection and allergy on cotton rat lungs have not been measured, although this information might be an important tool to determine the efficacy of vaccine and drug candidates. To characterize pulmonary function in the cotton rat, we established forced oscillation technique in uninfected, RSV infected and HDM sensitized cotton rats, and characterized pulmonary inflammation, mucus production, pulmonary edema, and oxygenation. There was a gender difference after RSV infection, with females demonstrating airway hyper-responsiveness while males did not. Female cotton rats 2dpi had a mild increase in pulmonary edema (wet: dry weight ratios). At day 4 post infection, female cotton rats demonstrated mild pulmonary inflammation, no increase in mucus production or reduction in oxygenation. Pulmonary function was not significantly impaired after RSV infection. In contrast, cotton rats sensitized to HDM demonstrated airway hyper-responsiveness with a significant increase in pulmonary inflammation, increase in baseline tissue damping, and a decrease in baseline pulmonary compliance. In summary, we established baseline data for forced oscillation technique and other respiratory measures in the cotton rat and used it to analyze respiratory diseases in cotton rats.

Increased expression of microRNA-155-5p by alveolar type II cells contributes to development of lethal ARDS in H1N1 influenza A virus-infected mice

Alveolar type II (ATII) cells are essential to lung function and a primary site of influenza A virus (IAV) replication. Effects of IAV infection on ATII cell microRNA (miR) expression have not been comprehensively investigated. Infection of C57BL/6 mice with 10,000 or 100 pfu/mouse of IAV A/WSN/33 (H1N1) significantly altered expression of 73 out of 1908 mature murine miRs in ATII cells at 2 days post-infection (d.p.i.) and 253 miRs at 6 d.p.i. miR-155-5p (miR-155) showed the greatest increase in expression within ATII cells at both timepoints and the magnitude of this increase correlated with inoculum size and pulmonary edema severity. Influenza-induced lung injury was attenuated in C57BL/6-congenic miR-155-knockout mice without affecting viral replication. Attenuation of lung injury was dependent on deletion of miR-155 from stromal cells and was recapitulated in ATII cell-specific miR-155-knockout mice. These data suggest that ATII cell miR-155 is a potential therapeutic target for IAV-induced ARDS.

Pulmonary surfactant and drug delivery: Focusing on the role of surfactant proteins

Pulmonary surfactant (PS) has been extensively studied because of its primary role in mammalian breathing. The deposition of this surface-active material at the alveolar air-water interface is essential to lower surface tension, thus avoiding alveolar collapse during expiration. In addition, PS is involved in host defense, facilitating the clearance of potentially harmful particulates. PS has a unique composition, including 92% of lipids and 8% of surfactant proteins (SPs) by mass. Although they constitute the minor fraction, SPs to a large extent orchestrate PS-related functions. PS contains four surfactant proteins (SPs) that can be structurally and functionally divided in two groups, i.e. the large hydrophilic SP-A and SP-D and the smaller hydrophobic SP-B and SP-C. The former belong to the family of collectins and are involved in opsonization processes, thus promoting uptake of pathogens and (nano)particles by phagocytic cell types. The latter SPs regulate interfacial surfactant adsorption dynamics, facilitating (phospho)lipid transfer and membrane fusion processes. In the context of pulmonary drug delivery, the exploitation of PS as a carrier to promote drug spreading along the alveolar interface is gaining interest. In addition, recent studies investigated the interaction of PS with drug-loaded nanoparticles (nanomedicines) following pulmonary administration, which strongly influences their biological fate, drug delivery efficiency and toxicological profile. Interestingly, the specific biophysical mode-of-action of the four SPs affect the drug delivery process of nanomedicines both on the extra-and intracellular level, modulating pulmonary distribution, cell targeting and intracellular delivery. This knowledge can be harnessed to exploit SPs for the design of unique and bio-inspired drug delivery strategies.

Tissue-Clearing Techniques Enable Three-Dimensional Visualization of Aerosolized Model Compound and Lung Structure at the Alveolar Scale

In this study, we examined the usefulness of a tissue-clearing technique for the evaluation of the lung distribution of aerosolized drugs. An aerosol formulation of TexasRed dextran (70 kDa), a model compound of drug carrier for aerosolized drugs, was administered intrapulmonarily to mice using a MicroSprayer, and then DyLight 488-conjugated tomato lectin was administered intravenously to visualize general lung structure via the fluorescent labeling of alveolar and bronchial epithelial cells. Tissue clearing followed by laser scanning confocal microscopy enabled the three-dimensional visualization of intrapulmonary TexasRed dextran and the evaluation of its distribution at the alveolar scale without the preparation of thin tissue sections. These findings suggest that tissue-clearing techniques are useful for the evaluation of intrapulmonary distribution and development of pulmonary drug delivery systems.

Apoptosis and surfactant protein-C expression inhibition induced by lipopolysaccharide in AEC II cell may associate with NF-κB pathway

Lipopolysaccharide (LPS), a Gram-negative bacterial outer membrane component, is one of the major causes of septic shock. Herein we investigate LPS-induced apoptosis of rat alveolar epithelial type II cells (AEC II) and the effects of LPS on surfactant protein-C (SP-C) expression in AEC II, along with the possible molecular mechanisms. LPS exposure impaired cell viability and increased apoptosis of AEC II significantly in concentration-dependent manner embodied in increased caspase-3 expression and the activity of caspase-3. Simultaneously, our results also indicated that LPS inhibited surfactant protein-C (SP-C) expression in AEC II. Mechanistic studies revealed that LPS treatment significantly increased the expression of NF-κB p50, NF-κB p65 and IKKβ proteins as well as induced IκB-α phosphorylation. Moreover, pretreatment with IKK inhibitor IKK-16 or NF-κB inhibitor PDTC ameliorated LPS-caused alterations in cleaved caspase-3 expression, the activity of caspase-3 and SP-C expression. Taken together, these results demonstrate that LPS can induce apoptosis of AEC II and decrease SP-C expression partly through activating the NF-κB pathway.

miRNA nanotherapeutics for cancer

MicroRNAs (miRNAs) are noncoding RNA molecules that regulate gene expression through diverse mechanisms. Increasing evidence suggests that miRNA-based therapies, either restoring or repressing miRNA expression and activity, hold great promise. However, the efficient delivery of miRNAs to target tissues is a major challenge in the transition of miRNA therapy to the clinic. Cationic polymers or viral vectors are efficient delivery agents but their systemic toxicity and immunogenicity limit their clinical usage. Efficient targeting and sustained release of miRNAs/anti-miRNAs using nanoparticles (NPs) conjugated with antibodies and/or peptides could reduce the required therapeutic dosage while minimizing systemic and cellular toxicity. Given their importance in clinical oncology, here we focus on the development of miRNA nanoformulations to achieve enhanced cellular uptake, bioavailability, and accumulation at the tumor site.

Potential and development of inhaled RNAi therapeutics for the treatment of pulmonary tuberculosis

Tuberculosis (TB), caused by the infection of Mycobacterium tuberculosis (Mtb), continues to pose a serious threat to public health, and the situation is worsening with the rapid emergence of multidrug resistant (MDR) TB. Current TB regimens require long duration of treatment, and their toxic side effects often lead to poor adherence and low success rates. There is an urgent need for shorter and more effective treatment for TB. In recent years, RNA interference (RNAi) has become a powerful tool for studying gene function by silencing the target genes. The survival of Mtb in host macrophages involves the attenuation of the antimicrobial responses mounted by the host cells. RNAi technology has helped to improve our understanding of how these bacilli interferes with the bactericidal effect and host immunity during TB infection. It has been suggested that the host-directed intervention by modulation of host pathways can be employed as a novel and effective therapy against TB. This therapeutic approach could be achieved by RNAi, which holds enormous potential beyond a laboratory to the clinic. RNAi therapy targeting TB is being investigated for enhancing host antibacterial capacity or improving drug efficacy on drug resistance strains while minimizing the associated adverse effects. One of the key challenges of RNAi therapeutics arises from the delivery of the RNAi molecules into the target cells, and inhalation could serve as a direct administration route for the treatment of pulmonary TB in a non-invasive manner. However, there are still major obstacles that need to be overcome. This review focuses on the RNAi candidates that are currently explored for the treatment of TB and discusses the major barriers of pulmonary RNAi delivery. From this, we hope to stimulate further studies of local RNAi therapeutics for pulmonary TB treatment.

The toxic effects of microcystin-LR on mouse lungs and alveolar type II epithelial cells

OBJECTIVES

Microcystin-leucine arginine (MC-LR) is produced by cyanobacteria and can accumulate in lungs through blood circulation. However, the effect of MC-LR on lung remains unclear. In this study, we investigated the chronic, low-dose effect of MC-LR on mouse lung tissues and the influence of MC-LR on mouse alveolar type II epithelial cells (ATII cells).

METHODS

MC-LR was orally administered to mice at 0, 1, 10, and 40 μg/L for 6 consecutive months and mouse lungs were obtained for histopathological and immunoblot analysis. ATII cells were cultured in various concentrations of MC-LR (0, 0.5, 5, 50, 500 nmol/L) for indicated time and the cell viability and proteins change were tested.

RESULTS

Our study revealed that the chronic, low-dose MC-LR exposure induced alveolar collapse and lung cell apoptosis as well as the breach of cell junction integrity. Furthermore, following treatment with MC-LR, ATII cells could uptake MC-LR, resulting in apoptosis and disruption of cell junction integrity.

CONCLUSIONS

These data support the toxic potential of low-dose MC-LR in rendering chronic injury to lung tissues.

Non-viral gene therapy: Gains and challenges of non-invasive administration methods

Gene therapy is becoming an influential part of the rapidly increasing armamentarium of biopharmaceuticals for improving health and combating diseases. Currently, three gene therapy treatments are approved by regulatory agencies. While these treatments utilize viral vectors, non-viral alternative technologies are also being developed to improve the safety profile and manufacturability of gene carrier formulations. We present an overview of gene-based therapies focusing on non-viral gene delivery systems and the genetic therapeutic tools that will further revolutionize medical treatment with primary focus on the range and development of non-invasive delivery systems for dermal, transdermal, ocular and pulmonary administrations and perspectives on other administration methods such as intranasal, oral, buccal, vaginal, rectal and otic delivery.