Combined delivery of dexamethasone and plasmid DNA in an animal model of LPS-induced acute lung injury

Pulmonary delivery of cell membrane-derived nanovesicles carrying anti-miRNA155 oligonucleotides ameliorates LPS-induced acute lung injury

Acute lung injury (ALI) is a devastating inflammatory disease. MicroRNA155 (miR155) in alveolar macrophages and lung epithelial cells enhances inflammatory reactions by inhibiting the suppressor of cytokine signaling 1 (SOCS1) in ALI. Anti-miR155 oligonucleotide (AMO155) have been suggested as a potential therapeutic reagent for ALI. However, a safe and efficient carrier is required for delivery of AMO155 into the lungs for ALI therapy. In this study, cell membrane-derived nanovesicles (CMNVs) were produced from cell membranes of LA4 mouse lung epithelial cells and evaluated as a carrier of AMO155 into the lungs. For preparation of CMNVs, cell membranes were isolated from LA4 cells and CMNVs were produced by extrusion. Cholesterol-conjugated AMO155 (AMO155c) was loaded into CMNVs and extracellular vesicles (EVs) by sonication. The physical characterization indicated that CMNVs with AMO155c (AMO155c/CMNV) were membrane-structured vesicles with a size of ∼120 nm. The delivery efficiency and therapeutic efficacy of CMNVs were compared with those of EVs or polyethylenimine (25 kDa, PEI25k). The delivery efficiency of AMO155c by CMNVs was similar to that by EVs. As a result, the miR155 levels were reduced by AMO155c/CMNV and AMO155c/EV. AMO155c/CMNV were administered intratracheally into the ALI models. The SOCS1 levels were increased more efficiently by AMO155c/CMNV than by the others, suggesting that miR155 effectively was inhibited by AMO155c/CMNV. In addition, the inflammatory cytokines were reduced more effectively by AMO155c/CMNV than they were by AMO155c/EV and AMO155c/PEI25k, reducing inflammation reactions. The results suggest that CMNVs are a useful carrier of AMO155c in the treatment of ALI.

Hybrid biomineralized nanovesicles to enhance inflamed lung biodistribution and reduce side effect of glucocorticoid for ARDS therapy

Acute respiratory distress syndrome (ARDS) is a critical illness characterized by severe lung inflammation. Improving the delivery efficiency and achieving the controlled release of anti-inflammatory drugs at the lung inflammatory site are major challenges in ARDS therapy. Taking advantage of the increased pulmonary vascular permeability and a slightly acidic-inflammatory microenvironment, pH-responsive mineralized nanoparticles based on dexamethasone sodium phosphate (DSP) and Ca2+ were constructed. By further biomimetic modification with M2 macrophage membranes, hybrid mineralized nanovesicles (MM@LCaP) were designed to possess immunomodulatory ability from the membranes and preserve the pH-sensitivity from core nanoparticles for responsive drug release under acidic inflammatory conditions. Compared with healthy mice, the lung/liver accumulation of MM@LCaP in inflammatory mice was increased by around 5.5 times at 48 h after intravenous injection. MM@LCaP promoted the polarization of anti-inflammatory macrophages, calmed inflammatory cytokines, and exhibited a comprehensive therapeutic outcome. Moreover, MM@LCaP improved the safety profile of glucocorticoids. Taken together, the hybrid mineralized nanovesicles-based drug delivery strategy may offer promising ideas for enhancing the efficacy and reducing the toxicity of clinical drugs.

Delivery systems of therapeutic nucleic acids for the treatment of acute lung injury/acute respiratory distress syndrome

Acute lung injury (ALI)/ acute respiratory distress syndrome (ARDS) is a devastating inflammatory lung disease with a high mortality rate. ALI/ARDS is induced by various causes, including sepsis, infections, thoracic trauma, and inhalation of toxic reagents. Corona virus infection disease-19 (COVID-19) is also a major cause of ALI/ARDS. ALI/ARDS is characterized by inflammatory injury and increased vascular permeability, resulting in lung edema and hypoxemia. Currently available treatments for ALI/ARDS are limited, but do include mechanical ventilation for gas exchange and treatments supportive of reduction of severe symptoms. Anti-inflammatory drugs such as corticosteroids have been suggested, but their clinical effects are controversial with possible side-effects. Therefore, novel treatment modalities have been developed for ALI/ARDS, including therapeutic nucleic acids. Two classes of therapeutic nucleic acids are in use. The first constitutes knock-in genes for encoding therapeutic proteins such as heme oxygenase-1 (HO-1) and adiponectin (APN) at the site of disease. The other is oligonucleotides such as small interfering RNAs and antisense oligonucleotides for knock-down expression of target genes. Carriers have been developed for efficient delivery for therapeutic nucleic acids into the lungs based on the characteristics of the nucleic acids, administration routes, and targeting cells. In this review, ALI/ARDS gene therapy is discussed mainly in terms of delivery systems. The pathophysiology of ALI/ARDS, therapeutic genes, and their delivery strategies are presented for development of ALI/ARDS gene therapy. The current progress suggests that selected and appropriate delivery systems of therapeutic nucleic acids into the lungs may be useful for the treatment of ALI/ARDS.

Human umbilical cord mesenchymal stem cell-derived extracellular vesicles loaded with TFCP2 activate Wnt/β-catenin signaling to alleviate preeclampsia

BACKGROUND

Failures in invasive extravillous trophoblasts (EVTs) migration into the maternal uterus have been noticed in preeclampsia (PE). Human umbilical cord mesenchymal stem cell (hUCMSC)-derived extracellular vesicles (EVs) have been highlighted for the role as a potential therapeutic method in PE. This study intends to investigate the mechanistic basis of hUCMSCs-derived EVs loaded with bioinformatically identified TFCP2 in the activities of EVTs of PE.

METHODS

Primary human EVTs were exposed to hypoxic/reoxygenation (H/R) to mimic the environment encountered in PE. The in vivo PE-like phenotypes were induced in mice by reduced uterine perfusion pressure (RUPP) surgery. CCK-8, Transwell and flow cytometry assays were performed to detect proliferation, migration, invasion and apoptosis of H/R-exposed EVTs. More importantly, EVs were extracted from hUCMSCs and transduced with ectopically expressed TFCP2, followed by co-culture with EVTs.

RESULTS

TFCP2 was found to be down-regulated in the preeclamptic placental tissues and in H/R-exposed EVTs. hUCMSCs-EVs loaded with TFCP2 activated the Wnt/β-catenin pathway, thereby promoting the proliferative, migratory, and invasive potential of EVTs. Furthermore, overexpression of TFCP2 alleviated PE-like phenotypes in mice, which was associated with activated Wnt/β-catenin pathway.

CONCLUSION

From our data we conclude that hUCMSCs-EVs overexpressing TFCP2 may be instrumental for the therapeutic targeting and clinical management of PE.

RBC-hitchhiking chitosan nanoparticles loading methylprednisolone for lung-targeting delivery

Hyper-inflammation associated with cytokine storm syndrome causes high mortality in patients with COVID-19. Glucocorticoids, such as methylprednisolone sodium succinate (MPSS), effectively inhibit this inflammatory response. However, frequent and chronic administration of glucocorticoids at high doses leads to hormone dependence and serious side effects. The aim of the present study was to combine nanoparticles with erythrocytes for the targeted delivery of MPSS to the lungs. Chitosan nanoparticles loading MPSS (MPSS-CSNPs) were prepared and adsorbed on the surface of red blood cells (RBC-MPSS-CSNPs) by non-covalent interaction. In vivo pharmacokinetic study indicated that RBC-hitchhiking could significantly reduce the plasma concentration of the drug and prolong the circulation time. The mean residence time (MRT) and area under the curve (AUC) of the RBC-MPSS-CSNPs group were significantly higher than those of the MPSS-CSNPs group and the MPSS injection group. Moreover, in vivo imaging and tissue distribution indicated that RBC-hitchhiking facilitated the accumulation of nanoparticles loading fluorescein in the lung, preventing uptake of these nanoparticles by the liver. Furthermore, compared with the MPSS-CSNPs and MPSS treatment groups, treatment with RBC-MPSS-CSNPs considerably inhibited the production of inflammatory cytokines such as TNF-α and IL-6, and consequently attenuated lung injury induced by lipopolysaccharide in rats. Therefore, RBC-hitchhiking is a potentially effective strategy for the delivery of nanoparticles to the lungs for the treatment of acute lung injury and acute respiratory distress syndrome.

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.

Delivery of MiRNA-92a Inhibitor Using RP1-Linked Peptide Elicits Anti-Inflammatory Effects in an Acute Lung Injury Model

Acute lung injury (ALI) is an inflammatory lung disease. miRNA-92a (miR92a) is induced in the lungs of ALI patients and mediates inflammatory reactions. In this study, a RP1-linked R3V6 (RP1R3V6) peptide was synthesized and evaluated as a carrier of anti-microRNA-92a oligonucleotide (AMO92a) into the lungs of an ALI animal model. In addition to the carrier function, the RP1-linked peptide can have anti-inflammatory effects in the lungs, since RP1 is an antagonist of the receptors for advanced glycation end-products (RAGEs). In a gel retardation assay, the RP1R3V6 peptide formed a spherical complex with AMO92a. In an in vitro delivery assay to L2 rat lung epithelial cells, RP1R3V6 had a lower AMO92a delivery efficiency than R3V6 and polyethyleneimine (PEI25k; 25 kDa). However, RP1R3V6 had an additional anti-inflammatory effect, reducing tumor necrosis factor-α (TNF-α) in lipopolysaccharide-activatedmacrophage cells. With the combined effects of AMO92a and RP1, the RP1R3V6/AMO92a complex reduced the miR92a level more efficiently than did the R3V6/AMO92a and PEI25k/AMO92a complexes. The RP1R3V6/AMO92a complex was administered into the lungs of ALI animals by intratracheal instillation. As a result, the expression of phosphatase and tensin homolog, a target of miR92a, was increased in the lungs. Furthermore, the RP1R3V6/AMO92a complex decreased the TNF-α and interleukin-1β (IL-1β) levels more efficiently than did the PEI25k/AMO92a and R3V6/AMO92a complexes, decreasing the damage in the lungs. These results suggest that RP1R3V6 is a useful carrier of AMO92a and has anti-inflammatory effects in an ALI animal model.

Natural steroid-based cationic copolymers cholesterol/diosgenin-r-PDMAEMAs and their pDNA nanoplexes: impact of steroid structures and hydrophobic/hydrophilic ratios on pDNA delivery

Using natural-based lipids to construct biocompatible, controllable and efficient nanocarriers and elucidating their structure-function relationships, was regarded as an important area for creating sustainable biomaterials. Herein, we utilized two natural steroids: cholesterol and diosgenin (bearing different hydrophobic tails) as the building blocks, to synthesize a series of natural steroid-based cationic random copolymers PMA6Chol-r-PDMAEMA and PMA6Dios-r-PDMAEMA via RAFT polymerization. The results demonstrated that the steroid-r-PDMAEMA copolymers could efficiently bind pDNA (N/P < 3.0) and then form near-spherical shape (142-449 nm) and positively-charged (+11.5 to +19.6 mV) nanoparticles. The in vitro cytotoxicity and gene transfection efficiency greatly depend on the steroid hydrophobic tail structures and steroid/PDMAEMA block ratios. Optimum transfection efficiency of the (Chol-P1/pDNA and Dios-P3/pDNA) nanoplexes could reach to 18.1-31.2% of the PEI-25K/pDNA complex. Moreover, all of the steroid-r-PDMAEMA/Cy3-pDNA nanoplexes have an obvious "lysosome localization" effect, indicating the steroid structures do not remarkably influence the intracellular localization behaviors of these nanoplexes.

Dexamethasone Conjugates: Synthetic Approaches and Medical Prospects

Dexamethasone (DEX) is the most commonly prescribed glucocorticoid (GC) and has a wide spectrum of pharmacological activity. However, steroid drugs like DEX can have severe side effects on non-target organs. One strategy to reduce these side effects is to develop targeted systems with the controlled release by conjugation to polymeric carriers. This review describes the methods available for the synthesis of DEX conjugates (carbodiimide chemistry, solid-phase synthesis, reversible addition fragmentation-chain transfer [RAFT] polymerization, click reactions, and 2-iminothiolane chemistry) and perspectives for their medical application as GC drug or gene delivery systems for anti-tumor therapy. Additionally, the review focuses on the development of DEX conjugates with different physical-chemical properties as successful delivery systems in the target organs such as eye, joint, kidney, and others. Finally, polymer conjugates with improved transfection activity in which DEX is used as a vector for gene delivery in the cell nucleus have been described.

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.

A RAGE-antagonist peptide potentiates polymeric micelle-mediated intracellular delivery of plasmid DNA for acute lung injury gene therapy

Acute lung injury (ALI) is a severe inflammatory lung disease. A high mobility group box-1 (HMGB-1) derived RAGE-antagonist peptide (RAP) was previously developed for anti-inflammatory therapy for ALI. Due to its specific binding to RAGE on the surface of inflammatory cells, the RAP may facilitate polymer-mediated intracellular delivery of plasmid DNA (pDNA) into the inflammatory cells. To evaluate this hypothesis, a pDNA/polymer/RAP ternary-complex was produced and applied for ALI gene therapy. Dexamethasone-conjugated polyamidoamine G2 (PAM-D) was used as a gene carrier, and the adiponectin (APN) gene was employed as a therapeutic gene. First, the ratio of pDNA to PAM-D was optimized in terms of anti-inflammation and low toxicity. Then, the RAP was added to the pDNA/PAM-D complex, producing the pDNA/PAM-D/RAP complex. The transfection efficiency of the luciferase plasmid (pLuc)/PAM-D/RAP reached its maximum at a weight ratio of 1 : 2 : 9. At this weight ratio, pLuc/PAM-D/RAP had a higher transfection efficiency than pLuc/PAM-D or pLuc/RAP. The transfection efficiency of pLuc/PAM-D/RAP decreased due to competition with free RAPs, suggesting the RAGE-mediated endocytosis of the complex. In the LPS-activated ALI mouse models, intratracheal administration of APN plasmid (pAPN)/PAM-D/RAP induced higher APN expression and less pro-inflammatory cytokines in the lungs of ALI animal models than pAPN/PEI25k, pAPN/RAP, and pAPN/PAM-D. Hematoxylin and eosin staining confirmed the higher anti-inflammatory effect of pAPN/PAM-D/RAP than the other complexes in the ALI models. Therefore, RAP-mediated enhanced delivery of pAPN/PAM-D may be useful for the development of a treatment for ALI.

Inhalable Gene Delivery System Using a Cationic RAGE-Antagonist Peptide for Gene Delivery to Inflammatory Lung Cells

Acute lung injury (ALI) is a severe lung inflammatory disease. In ALI, the receptor for advanced glycation end-products (RAGE) is overexpressed in lung epithelial cells and involved in inflammatory reactions. A previous report showed that a RAGE-antagonist peptide (RAP), from high-mobility group box-1, bound to RAGE and reduced inflammatory reactions. RAP has high levels of positive amino acids, which suggests that RAP may form a complex with plasmid DNA (pDNA) by charge interactions. Because the charge density of RAP is lower than polyethylenimine (25 kDa, PEI25k), it may be able to avoid capture by the negatively charged mucus layer more easily and deliver pDNA into RAGE-positive lung cells of ALI animals by RAGE-mediated endocytosis. To prove this hypothesis, RAP was evaluated as a delivery carrier of adiponectin plasmid (pAPN) in lipopolysaccharide (LPS)-induced ALI animal models. In vitro transfection assays showed that RAP had lower transfection efficiency than PEI25k in L2 lung epithelial cells. However, in vivo administration to ALI animal models by inhalation showed that RAP had higher gene delivery efficiency than PEI25k. Particularly, due to a higher expression of RAGE in lung cells of ALI animals, the gene delivery efficiency of RAP was higher in ALI animals than that in normal animals. Delivery of the pAPN/RAP complex had anti-inflammatory effects, reducing pro-inflammatory cytokines. Hematoxylin and eosin staining confirmed that pAPN/RAP decreased inflammation in ALI models. Therefore, the results suggest that RAP may be useful as a carrier of pDNA into the lungs for ALI gene therapy.

Combined delivery of curcumin and the heme oxygenase-1 gene using cholesterol-conjugated polyamidoamine for anti-inflammatory therapy in acute lung injury

BACKGROUND

Acute lung injury (ALI) is an inflammatory lung disease with a high mortality rate. In this study, combined delivery of the anti-inflammatory compound curcumin and the heme-oxygenase-1 (HO-1) gene using cholesterol-conjugated polyamidoamine was evaluated in a mouse model as a therapeutic option for ALI.

METHODS

Curcumin was loaded into cholesterol-conjugated polyamidoamine (PamChol) micelles, and curcumin-loaded PamChol (PamChol-Cur) was then complexed with plasmid DNA (pDNA) through charge interactions. The pDNA/PamChol-Cur complex was physically characterized by dynamic light scattering, gel retardation, and heparin competition assay. Gene delivery efficiency was measured by luciferase assay. The HO-1 expression plasmid (pHO-1)/PamChol-Cur complex was administrated into the ALI model via intratracheal injection. The anti-inflammatory effect of the pDNA/PamChol-Cur complex was evaluated by ELISA, immunohistochemistry, and hematoxylin and eosin staining.

RESULTS

The pDNA/PamChol-Cur complex had a size of approximately 120 nm with a positive surface charge. The in vitro plasmid DNA (pDNA) delivery efficiency of the pDNA/PamChol-Cur complex into L2 lung epithelial cells was higher than that of pDNA/PamChol. In addition, the curcumin in the pDNA/PamChol-Cur complex inhibited the nuclear translocation of NF-κB, suggesting an anti-inflammatory effect of curcumin. In the ALI animal model, the pHO-1/PamChol-Cur complex delivered the pHO-1 gene more efficiently than pHO-1/PamChol. In addition, the pHO-1/PamChol-Cur complex showed greater anti-inflammatory effects by reducing anti-inflammatory cytokine levels more than delivery of pHO-1/PamChol or PamChol-Cur only.

CONCLUSION

The pHO-1/PamChol-Cur complex had a higher pHO-1 gene-delivery efficiency and greater anti-inflammatory effects than the pHO-1/PamChol complex or PamChol-Cur. Therefore, the combined delivery of curcumin and pHO-1 using PamChol-Cur may be useful for treatment of ALI.

The Functional Mechanisms of miR-30b-5p in Acute Lung Injury in Children

Background

Acute lung injury in children is a complicated disease linked to the inflammation response. MicroRNA (miRNA) plays a vital role in acute lung injury. However, the role of miR-30b-5p in the pathogenesis of acute lung injury is not clear. The purpose of our study was to investigate the alteration of miR-30b-5p, suppressor of cytokine signaling 3 (SOCS3), in children with acute lung injury, and also in a mouse model of acute lung injury induced by the endotoxin lipopolysaccharide (LPS).

Material/Methods

The levels of miR-30b-5p, SOCS3, FKN (fractalkine), tumor necrosis factor (TNF)-α, NF-κB (nuclear factor kappa-light-chain-enhancer of activated B), interleukin-6 (IL-6), and IL-8 were detected by ELISA (enzyme-linked immunosorbent assay), western blot, and qRT-PCR (quantitative reverse transcription polymerase chain reaction) assay. The alveolar permeability index and the ratio of wet weight/dry weight (W/D) were measured. Then, we examined the inflammation and apoptosis using hematoxylin and eosin (H&E) staining and TUNEL (terminal deoxynucleotidyl transferase dUTP nick end labeling) assay. Additionally, SOCS3 was investigated as a direct target of miR-30a-5p in RAW264.7 cells by dual-luciferase reporter assays.

Results

Our study indicated that the level of miR-30b-5p was decreased and the levels of SOCS3, FKN, TNF-α, NF-κB, IL-6, and IL-8 were increased in lung tissue, serum, and bronchoalveolar lavage fluid of mice with acute lung injury induced by LPS. In addition, LPS increased alveolar permeability index and the ratio of W/D and induced inflammatory responses, including the activation of the NF-κB pathway in a mouse model. Furthermore, SOCS3 was confirmed to be a target of miR-30a-5p in RAW264.7 cells.

Conclusions

Our data demonstrated an important role for miR-30b-5p in acute lung injury inflammation and suggested that miR-30b-5p might be an important therapy target in children with acute lung injury.

Changes in TNF-α, IL-6, IL-10 and VEGF in rats with ARDS and the effects of dexamethasone

Changes in tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), IL-10 and vascular endothelial growth factor (VEGF) in serum and bronchoalveolar lavage fluid (BALF) in rats with acute respiratory distress syndrome (ARDS) and the intervention effect of dexamethasone were observed to explore the theoretical basis of dexamethasone in the treatment of ARDS. Seventy-two rats were randomly divided into normal control group (group N, n=24), ARDS model group (group L, n=24) and dexamethasone group (group D, n=24). The ARDS rat model was established by jointly injecting oleic acid and lipopolysaccharide via the caudal vein, while rats in group D received intervention with dexamethasone. The wet/dry weight ratios of lung tissues were measured, and the levels of TNF-α, IL-6, IL-10 and VEGF in serum and BALF were measured via enzyme-linked immunosorbent assay. The wet/dry weight ratio of lung tissues of rats in group D was significantly decreased compared with that in group L (P<0.05 or P<0.01). The levels of TNF-α, IL-6 and VEGF in serum and BALF of rats in group L and D were obviously increased compared with those in group N at each time point (P<0.01). The levels of TNF-α, IL-6 and VEGF in serum and BALF of rats in group D were significantly decreased compared with those in group L (P<0.01). In conclusion, there is a serious imbalance between anti-inflammatory response and inflammatory response in rats with ARDS induced by oleic acid combined with lipopolysaccharide of Escherichia coli, whereas dexamethasone can alleviate lung injury through inhibiting expression levels of inflammatory factors and promoting expression levels of anti-inflammatory factors.

Linarin prevents LPS‑induced acute lung injury by suppressing oxidative stress and inflammation via inhibition of TXNIP/NLRP3 and NF‑κB pathways

Acute lung injury (ALI) is an important cause of morbidity and mortality for critically ill patients, and linarin (LR) may be a potential treatment for ALI as it reportedly has antioxidant, anti-inflammatory and apoptotic-regulating activity. In the present study, the authors report that saline and LR (12.5, 25 and 50 mg/kg) were applied to male C57BL/6 mice via gavage. Then, mice were intratracheally injected with either saline or lipopolysaccharide (LPS). LR-pretreatment attenuated LPS-induced ALI and platelet activation and reduced CD41 expression levels and neutrophil platelet aggregates. Additionally, LPS-triggered pulmonary myeloperoxidase activity and neutrophil infiltration in lung tissues, and this was eliminated by LR dose-dependently. Furthermore, LPS-induced oxidative stress and pro-inflammatory cytokine release were downregulated by LR by inhibiting thioredoxin-interacting protein and nuclear factor-κB signaling pathways, including their downstream and upstream signals, such as xanthine oxidase, NLR family WHAT, pyrin domain-containing 3 (NLRP3), apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain (ASC), caspase-1, IκB kinase-α (IKK-α) and IκBα. Moreover, in LPS-induced mice, the mitogen-activated protein kinase pathway was inactivated by LR. In vitro, LR reduced LPS-induced inflammation and oxidative stress, which was linked to reduction of ROS. In conclusion, LR pretreatment may be protective against LPS-induced ALI.

Self-assembled polymeric micelles for combined delivery of anti-inflammatory gene and drug to the lungs by inhalation

Acute lung injury (ALI) is a lung inflammatory disease for which pulmonary delivery of drug and gene could be a useful strategy. In this study, cholesterol-conjugated polyamidoamine (PAM-Chol) was synthesized and characterized as a carrier for combined delivery of anti-inflammatory gene and drug into the lungs by inhalation. The PAM-Chol formed self-assembled micelles in an aqueous solution with a critical micelle concentration of 0.22 mg ml-1. An in vitro transfection assay to L2 lung epithelial cells showed that the PAM-Chol micelle had higher transfection efficiency than lipofectamine and polyethylenimine (25 kDa, PEI25k). As the anti-inflammatory drug, resveratrol was loaded into the cores of the PAM-Chol micelles using the oil-in-water emulsion/solvent evaporation method. In lipopolysaccharide (LPS)-activated macrophage cells, resveratrol-loaded PAM-Chol (PAM-Chol/Res) reduced pro-inflammatory cytokines, confirming the anti-inflammatory effects of resveratrol. In in vitro transfection assays to L2 cells, the PAM-Chol/Res micelles had transfection efficiency similar to that of PAM-Chol. The delivery of resveratrol or the heme oxygenase-1 gene (pHO-1) by inhalation was evaluated in an ALI animal model. Resveratrol delivery using the PAM-Chol/Res micelles inhibited the nuclear translocation of nuclear factor-κB (NF-κB) and reduced pro-inflammatory cytokines in the lungs. pHO-1 delivery using PAM-Chol induced HO-1 expression and reduced pro-inflammatory cytokines. However, the highest anti-inflammatory effects were obtained with combined delivery of pHO-1 and resveratrol using the pHO-1/PAM-Chol/Res complex, as demonstrated in cytokine assays and immunohistochemical studies. Therefore, the PAM-Chol micelle is an efficient carrier of resveratrol and pHO-1 into the lungs and could be useful for the treatment of ALI by inhalation.

Juglanin suppresses fibrosis and inflammation response caused by LPS in acute lung injury

Acute lung injury in children is a complication showing devastating disorders linked to fibrosis progression and inflammation response. Fibrosis and inflammation response are two markers for acute lung injury. Juglanin is a natural product mainly isolated from green walnut husks of Juglans mandshurica, which isconsidered as the functional composition among a series of compounds. It exhibited effective role in various diseases by inhibiting inflammation response. In our study, the protective effects and anti-inflammatory activity of juglanin were investigated in mice and lung cells treated by lipopolysaccharide (LPS) to reveal the possible mechanism by which juglanin attenuates acute lung injury. The mice were separated into four groups. The mouse model was established with 15 mg/kg LPS injection. Juglanin dramatically reduced the inflammation of cell infiltration. Compared to mice only treated with LPS, LPS-treated mice in the presence of juglanin developed less lung fibrosis with lower levels of α-smooth muscle-actin (α-SMA), collagen type I, collagen type III, and transforming growth factor-β1 (TGF-β1). Additionally, juglanin markedly downregulated inflammatory cytokine secretion and phosphorylated nuclear factor-κB (NF-κB) expression via inhibiting IKKα/IκBα signaling pathway. Our results indicate that juglanin has a protective role in LPS-triggered acute lung injury via suppression of fibrosis and inflammation response by NF-κB signaling pathways inactivation. Thus, juglanin may be a potential candidate as dietary supplement for acute lung injury for children in future.

A new combination therapy for asthma using dual-function dexamethasone-conjugated polyethylenimine and vitamin D binding protein siRNA

Asthma is a multifactorial disease that is influenced by the interaction of genetic and environmental factors. Because of its complex nature, there is no cure for asthma currently. Instead, reliever and controller medications are used to treat asthma. Unfortunately, conventional treatments do not work in some severe cases of asthma. In addition, there may be adverse, systemic effects of long-term treatment with high-dose inhaled corticosteroids (ICSs) as a controller medication. Therefore, we attempted to develop a novel combination therapy for asthma. Our regimen included dexamethasone as a controller medication and vitamin D binding protein (VDBP) small interfering RNA (siRNA) as a novel target therapeutic. The dexamethasone moiety of DEXA-PEI (dexamethasone-conjugated polyethylenimine) was used as an ICS, combined with anti-VDBP treatment via delivery of VDBP siRNA, using DEXA-PEI as a siRNA carrier molecule. Treatment with DEXA-PEI/VDBP siRNA effectively reduced the ovalbumin sensitization/challenge-induced enhancement of airway inflammation, goblet cell hyperplasia and expression of interleukin (IL)-4, IL-13 and CCL11. These findings suggest that the DEXA-PEI/VDBP siRNA can be developed as a potent asthma therapeutic by dose-reducing ICSs and using a multitarget therapeutic method.

Anti-Inflammatory Therapeutic Effect of Adiponectin Gene Delivery Using a Polymeric Carrier in an Acute Lung Injury Model

PURPOSE

Adiponectin (APN) is an adipokine with anti-inflammatory and cytoprotective effects. In this study, the therapeutic effect of APN gene delivery using a polymeric carrier was evaluated in an acute lung injury (ALI) model.

METHODS

Polyethylenimine (2 kDa, PEI2K), PEI25K (25 kDa), polyamidoamine (generation 2, PAMG2), dexamethasone-conjugated PEI2k (PEI2K-Dexa), and dexamethasone-conjugated PAMG2 (PAMG2-Dexa) were evaluated in vitro and in vivo as gene carriers. Formation of plasmid DNA (pDNA)/carrier complexes was confirmed by gel retardation and heparin competition assays. Delivery efficiency was measured by a luciferase assay and fluorescence microscopy. In an ALI animal model, pAPN/carrier complexes were delivered by intratracheal administration. Therapeutic effects were evaluated by cytokine assays and hematoxylin and eosin (H&E) staining.

RESULTS

Gel retardation assays showed that PEI2K-Dexa and PAMG2-Dexa formed complexes with pDNA. In L2 lung epithelial cells, PAMG2-Dexa yielded higher transfection efficiency than PEI2K, PAMG2, PEI25K, lipofectamine, and PEI2K-Dexa. In vivo experiments showed that PAMG2-Dexa delivered DNA more efficiently to lung tissue than PEI2K-Dexa and PEI25K. Delivery of pAPN/PAMG2-Dexa complexes upregulated APN expression in the lungs of mice with ALI. As a result, the levels of pro-inflammatory cytokines such as TNF-α and IL-1β were decreased. H&E staining showed that inflammation in the lungs of mice with ALI was reduced by delivery of the APN gene.

CONCLUSION

Delivery of the APN gene using PAMG2-Dexa reduced inflammation in the lungs of mice with ALI. The APN gene could be a useful tool in the development of gene therapy for ALI.

Delivery of Hypoxia-Inducible Heme Oxygenase-1 Gene for Site-Specific Gene Therapy in the Ischemic Stroke Animal Model

PURPOSE

To reduce side effects due to non-specific expression, the heme oxygenase-1 (HO-1) gene under control of a hypoxia-inducible erythropoietin (Epo) enhancer (pEpo-SV-HO-1) was developed for site-specific gene therapy of ischemic stroke.

METHODS

pEpo-SV-HO-1 was constructed by insertion of the Epo enhancer into pSV-HO-1. Dexamethasone-conjugated polyamidoamine (PAMAM-Dexa) was used as a gene carrier. In vitro transfection assays were performed in the Neuro2A cells. In vivo efficacy of pEpo-SV-HO-1 was evaluated in the transient middle cerebral artery occlusion (MCAO) model.

RESULTS

In vitro transfection assay with the PAMAM-Dexa/pEpo-SV-HO-1 complex showed that pEpo-SV-HO-1 had higher HO-1 gene expression than pSV-HO-1 under hypoxia. In addition, pEpo-SV-HO-1 reduced the level of apoptosis more efficiently than pSV-HO-1 in Neuro2A cells under hypoxia. For in vivo evaluation, the PAMAM-Dexa/pEpo-SV-HO-1 complex was injected into the ischemic brain of the transient MCAO model. pEpo-SV-HO-1 increased HO-1 expression and reduced the number of apoptotic cells in the ischemic brain, compared with the pSV-HO-1 injection group. As a result, the infarct volume was more efficiently decreased by pEpo-SV-HO-1 than by pSV-HO-1.

CONCLUSIONS

pEpo-SV-HO-1 induced HO-1 gene expression and therapeutic effect in the ischemic brain. Therefore, pEpo-SV-HO-1 may be useful for site-specific gene therapy of ischemic stroke.

Co-delivery of drugs and plasmid DNA for cancer therapy

Cancer is an extremely complex disease involving multiple signaling pathways that enable tumor cells to evade programmed cell death, thus making cancer treatment extremely challenging. The use of combination therapy involving both gene therapy and chemotherapy has resulted in enhanced anti-cancer effects and has become an increasingly important strategy in medicine. This review will cover important design parameters that are incorporated into delivery systems for the co-administration of drug and plasmid-based nucleic acids (pDNA and shRNA), with particular emphasis on polymers as delivery materials. The unique challenges faced by co-delivery systems and the strategies to overcome such barriers will be discussed. In addition, the advantages and disadvantages of combination therapy using separate carrier systems versus the use of a single carrier will be evaluated. Finally, future perspectives in the design of novel platforms for the combined delivery of drugs and genes will be presented.

Targeted delivery of growth factors in ischemic stroke animal models

INTRODUCTION

Ischemic stroke is caused by reduced blood supply and leads to loss of brain function. The reduced oxygen and nutrient supply stimulates various physiological responses, including induction of growth factors. Growth factors prevent neuronal cell death, promote neovascularization, and induce cell growth. However, the concentration of growth factors is not sufficient to recover brain function after the ischemic damage, suggesting that delivery of growth factors into the ischemic brain may be a useful treatment for ischemic stroke.

AREAS COVERED

In this review, various approaches for the delivery of growth factors to ischemic brain tissue are discussed, including local and targeting delivery systems.

EXPERT OPINION

To develop growth factor therapy for ischemic stroke, important considerations should be taken into account. First, growth factors may have possible side effects. Thus, concentration of growth factors should be restricted to the ischemic tissues by local administration or targeted delivery. Second, the duration of growth factor therapy should be optimized. Growth factor proteins may be degraded too fast to have a high enough therapeutic effect. Therefore, delivery systems for controlled release or gene delivery may be useful. Third, the delivery systems to the brain should be optimized according to the delivery route.

Synthesis, toxicity study and anti-inflammatory effect of MHTP, a new tetrahydroisoquinoline alkaloid

The alkaloid 2-methoxy-4-(7-methoxy-1,2,3,4-tetrahydroisoquinolin-1-yl)phenol (MHTP) was synthesized to prospect new compounds with therapeutic properties. Thus, the goal of this study was to evaluate the MHTP anti-inflammatory effect by in vivo and in vitro assays. The MHTP toxicity was analyzed. We found that MHTP pre-treatment (2.5-10 mg/kg) showed antiedematogenic effect (p < 0.05) in carrageenan-induced paw edema by inhibiting the PGE2 action independently of mast cell degranulation or histamine activity. MHTP also diminished (p < 0.01) total leukocyte migration in 41.5% into peritoneal cavity during carrageenan-induced peritonitis, reducing polymorphonuclear cells (PMNs) (59.6%) and proteins levels (29.4%). MHTP in an experimental model of acute lung injury inhibited (p < 0.001) total inflammatory cell migration into the lungs and PMNs in 58% and 67.5%, respectively. Additionally, MHTP did not present cytotoxicity at concentrations of 10, 25 or 50 μM but decreased (p < 0.001) the NO production in 24%, 47% and 39%, respectively. The alkaloid also reduced (p < 0.001, in lipopolysaccharide (LPS)-stimulated macrophages (1 μg/mL), IL-1β, IL-6 and IL-10 levels in 35.7%, 31.0% and 33.4%, respectively. The results obtained in this study allow us to conclude that the inedited synthetic alkaloid, MHTP has anti-inflammatory effect by inhibiting PGE2 function as well as inhibiting inflammatory cell migration to the inflamed site and attenuated the acute lung injury disease by inhibiting the migration of neutrophil to the lung. However, further studies will be carried out to demonstrate the mechanisms of action of the molecule and explore its potential as a future drug to treat inflammatory processes.

Dexamethasone-Conjugated Polyamidoamine Dendrimer for Delivery of the Heme Oxygenase-1 Gene into the Ischemic Brain

Heme oxygenase-1 (HO-1) has anti-apoptotic and anti-inflammatory effects. In this study, the HO-1 gene was delivered into the brain using dexamethasone-conjugated polyamidoamine generation 2 (PAMAM G2-Dexa) for the treatment of ischemic stroke. PAMAM G2-Dexa formed stable complexes with plasmid DNA (pDNA). The pDNA delivery efficiency of PAMAM G2-Dexa was higher than that of polyethylenimine (PEI25k, 25 kDa), dexamethasone-conjugated PEI (PEI-Dexa), and PAMAM G2 in Neuro2A cells. Therapeutic effect of PAMAM G2-Dexa/pHO-1 complexes was evaluated in a stroke animal model. PAMAM G2-Dexa delivered pHO-1 more efficiently into the ischemic brain than PEI25k and PEI-Dexa with higher therapeutic effect. Therefore, PAMAM G2-Dexa/pHO-1 complexes may be useful for ischemic stroke gene therapy.

In situ DOX-calcium phosphate mineralized CPT-amphiphilic gelatin nanoparticle for intracellular controlled sequential release of multiple drugs

A co-delivery strategy has been developed to achieve the synergistic effect of a hydrophobic drug (camptothecin, CPT) and a hydrophilic drug (doxorubicin, DOX) by utilizing the unique structure of amphiphilic gelatin/camptothecin @calcium phosphate-doxorubicin (AG/CPT@CaP-DOX) nanoparticles as a carriers in order to replace double emulsions while preserving the advantages of inorganic materials. The hydrophobic agent (CPT) was encapsulated via emulsion with an amphiphilic gelatin core, and subsequently mineralized by CaP-hydrophilic drug (DOX) through precipitation to form a CaP shell on the CPT-AG amphiphilic gelatin core so that drug molecules with different characteristics (i.e. hydrophobic and hydrophilic) can be encapsulated in different regions to avoid their interaction. The existence of the CaP shell can protect the DOX against free release and cause an increased transfer of DOX across membranes, overcoming multidrug resistance. Release studies from core-shell carriers showed the possibility of achieving sequential release of more than one type of drug by controlling the pH-sensitive CaP shell and degradable AG core. The highly pH-responsive behavior of the carrier can modulate the dual-drug-release of DOX/CPT, specifically in acidic intracellular pH environments. The AG/CPT@CaP-DOX nanoparticles also exhibited higher drug efficiencies against MCF-7/ADR cells than MCF-7 cells, thanks to a synergistic cell cycle arrest/apoptosis-inducing effect between CPT and DOX. As such, this core-shell system can serve as a general platform for the localized, controlled, sequential delivery of multiple drugs to treat several diseases, especially for multidrug-resistant cancer cells.

Instilled air promotes lipopolysaccharide-induced acute lung injury

Optimization of intratracheal instillation is necessary to establish an ideal animal model of acute lung injury (ALI) in order to further reveal the cellular and molecular pathogenesis of ALI. It is possible that instilling air from a prefilled syringe may promote the delivery of reagents into the alveolar spaces, resulting in different pulmonary responses. In the present study, the influence of instilling air by trans-tracheal intratracheal instillation in a lipopolysaccharide (LPS)-induced mouse model of ALI was investigated. The bronchoalveolar lavage (BAL) fluid biochemical index, BAL fluid differential cell counts, lung wet/dry weight ratio, lung histology and BAL fluid interleukin-8 (IL-8) levels were assessed 24 h subsequent to intratracheal instillation. Instilled air promoted LPS-induced ALI, as indicated by the severity of acute pulmonary inflammation and increased IL-8 release. In conclusion, this study indicates that instilled air may be used to improve the intratracheal instillation procedure and to establish a more reliable animal model of ALI.

Delivery of hypoxia and glioma dual-specific suicide gene using dexamethasone conjugated polyethylenimine for glioblastoma-specific gene therapy

Gene therapy has been considered a promising approach for glioblastoma therapy. To avoid side effects and increase the specificity of gene expression, gene expression should be tightly regulated. In this study, glioma and hypoxia dual-specific plasmids (pEpo-NI2-SV-Luc and pEpo-NI2-SV-HSVtk) were developed by combining the erythropoietin (Epo) enhancer and nestin intron 2 (NI2). In the in vitro studies, pEpo-NI2-SV-Luc showed higher gene expression under hypoxia than normoxia in a glioblastoma-specific manner. The MTT and caspase assays demonstrated that pEpo-NI2-SV-HSVtk specifically induced caspase activity and cell death in hypoxic glioblastoma cells. For in vivo evaluation, subcutaneous and intracranial glioblastoma models were established. Dexamethasone-conjugated-polyethylenimine (PEI-Dexa) was used as a gene carrier, since PEI-Dexa efficiently delivers plasmid to glioblastoma cells and also has an antitumor effect due to the effect of dexamethasone. In the in vivo study in the subcutaneous and intracranial glioblastoma models, the tumor size was reduced more effectively in the pEpo-NI2-SV-HSVtk group than in the control and pSV-HSVtk groups. In addition, higher levels of HSVtk gene expression and TUNEL-positive cells were observed in the pEpo-NI2-SV-HSVtk group compared with the control and pSV-HSVtk groups, suggesting that pEpo-NI2-SV-HSVtk increased the therapeutic efficacy in hypoxic glioblastoma. Therefore, pEpo-NI2-SV-HSVtk/PEI-Dexa complex may be useful for glioblastoma-specific gene therapy.

Potent anti-inflammatory activity of pyrenocine A isolated from the marine-derived fungus Penicillium paxilli Ma(G)K

Very little is known about the immunomodulatory potential of secondary metabolites isolated from marine microorganisms. In the present study, we characterized pyrenocine A, which is produced by the marine-derived fungus Penicillium paxilli Ma(G)K and possesses anti-inflammatory activity. Pyrenocine A was able to suppress, both pretreatment and posttreatment, the LPS-induced activation of macrophages via the inhibition of nitrite production and the synthesis of inflammatory cytokines and PGE2. Pyrenocine A also exhibited anti-inflammatory effects on the expression of receptors directly related to cell migration (Mac-1) as well as costimulatory molecules involved in lymphocyte activation (B7.1). Nitrite production was inhibited by pyrenocine A in macrophages stimulated with CpG but not Poly I:C, suggesting that pyrenocine A acts through the MyD88-dependent intracellular signaling pathway. Moreover, pyrenocine A is also able to inhibit the expression of genes related to NFκB-mediated signal transduction on macrophages stimulated by LPS. Our results indicate that pyrenocine A has promissory anti-inflammatory properties and additional experiments are necessary to confirm this finding in vivo model.

Effects and mechanisms of alveolar type II epithelial cell apoptosis in severe pancreatitis-induced acute lung injury

This study aimed to examine the role of alveolar type II epithelial cell (AEC II) apoptosis in severe pancreatitis-induced acute lung injury (ALI) and the intervening role of Qingyi decoction (QYT). An SAP model was established in male Sprague-Dawley rats. Immunohistochemical analysis was conducted to observe the pathological changes in the pancreas and lung tissue. AEC II apoptosis was detected by flow cytometry and the free Ca²⁺ concentration in AECs II was determined by laser scanning confocal microscopy. A radioimmunoassay was performed to determine serum TNF-α content. Quantitative polymerase chain reaction (qPCR) and immunohistochemical analysis were performed to detect the mRNA and protein expression levels of Bax and caspase-8 in the lung tissue. Hematoxylin and eosin staining of lung tissue sections in the severe acute pancreatitis (SAP) group showed pathological changes from control tissue, consistent with acute lung injury (ALI). Flow cytometry showed that the level of AEC II apoptosis in the SAP group was significantly increased compared with that in the control group (P<0.01). Laser scanning confocal microscopy indicated that the free Ca²⁺ concentration in the AECs II of the SAP group was also significantly increased compared with that in the control (P<0.01). Radioimmunoassay demonstrated that the TNF-α levels were significantly increased in the SAP group compared with those in the control group (P<0.01), and qPCR results showed that the levels of Bax and caspase-8 apoptotic gene expression in the AECs II of the SAP group were significantly elevated (P<0.01). The aforementioned indicators were significantly lower following drug treatment compared with the levels observed in the SAP model group. These results suggest that AEC II apoptosis is involved in the ALI procedure associated with SAP. The mitochondrial pathway and death receptor pathway may have key regulatory roles in AEC II apoptosis. The use of QYT may significantly reduce the extent of lung injury.

Hypoxia/hepatoma dual specific suicide gene expression plasmid delivery using bio-reducible polymer for hepatocellular carcinoma therapy

Gene therapy is suggested as a promising alternative strategy of hepatocellular carcinoma (HCC, also called hepatoma) therapy. To achieve a successful and safe gene therapy, tight regulation of gene expression is required to minimize side-effects in normal tissues. In this study, we developed a novel hypoxia and hepatoma dual specific gene expression vector. The constructed vectors were transfected into various cell lines using bio-reducible polymer, PAM-ABP. First, pAFPS-Luc or pAFPL-Luc vector was constructed with the alpha-fectoprotein (AFP) promoter and enhancer for hepatoma tissue specific gene expression. Then, pEpo-AFPL-Luc was constructed by insertion of the erythropoietin (Epo) enhancer for hypoxic cancer specific gene expression. In vitro transfection assay showed that pEpo-AFPL-Luc transfected hepatoma cell increased gene expression under hypoxic condition. To confirm the therapeutic effect of dual specific vector, herpes simplex virus thymidine kinase (HSV-TK) gene was introduced for cancer cell killing. The pEpo-AFPL-TK was transfected into hepatoma cell lines in the presence of ganciclovir (GCV) pro-drug. Caspase-3/7, MTT and TUNEL assays elucidated that pEpo-AFPL-TK transfected cells showed significant increasing of death rate in hypoxic hepatoma cells compared to controls. Therefore, the hypoxia/hepatoma dual specific gene expression vector with the Epo enhancer and AFP promoter may be useful for hepatoma specific gene therapy.

Stimulation of Rho signaling by pathologic mechanical stretch is a "second hit" to Rho-independent lung injury induced by IL-6

Most patients with acute lung injury (ALI) and acute respiratory distress syndrome of septic and nonseptic nature require assisted ventilation with positive pressure, which at suboptimal range may further exacerbate lung dysfunction. Previous studies described enhancement of agonist-induced Rho GTPase signaling and endothelial cell (EC) permeability in EC cultures exposed to pathologically relevant cyclic stretch (CS) magnitudes. This study examined a role of pathologic CS in modulation of pulmonary EC permeability caused by IL-6, a cytokine increased in sepsis and acting in a Rho-independent manner. IL-6 increased EC permeability, which was associated with activation of Jak/signal transducers and activators of transcription, p38 MAP kinase, and NF-κB signaling and was augmented by EC exposure to 18% CS. Rho kinase inhibitor Y-27632 suppressed the synergistic effect of 18% CS on IL-6-induced EC monolayer disruption but did not alter the IL-6 effects on static EC culture. 18% CS also increased IL-6-induced ICAM-1 expression by pulmonary EC and neutrophil adhesion, which was attenuated by Y-27632. Intratracheal IL-6 administration in C57BL/6J mice increased protein content and cell count in bronchoalveolar lavage fluid. These changes were augmented by high tidal volume mechanical ventilation (HTV; 30 ml/kg, 4 h). Intravenous injection of Y-27632 suppressed IL6/HTV-induced lung injury. In conclusion, this study proposes a novel mechanism contributing to two-hit model of ALI: in addition to synergistic effects on Rho-dependent endothelial hyper-permeability triggered by thrombin, TNFα, LPS, or other agonists, ventilator-induced lung injury-relevant CS may also exacerbate Rho-independent mechanisms of EC permeability induced by other inflammatory mediators such as IL-6 via mechanisms involving Rho activity.