Corticosteroids in Acute Lung Injury: The Dilemma Continues

Potential therapeutic and ameliorative effects of ramipril alone and in combination with methylprednisolone for the cytokine releasing syndrome in mice: An in vivo study

Cytokine-releasing syndrome (CRS) is a special form of systemic inflammatory response syndrome provoked by factors like viral infections and certain immunomodulatory drugs like monoclonal antibodies and adoptive T therapy. To elucidate the potential role of ramipril (RM) and its combination with methylprednisolone (MP) against the development and progression of CRS in mice. This experiment consists of two parts: protective and therapeutic interventions. The protective experiment: in the induction group, mice received an intraperitoneal injection (IP) of 5mg/kg lipopolysaccharide (LPS) without intervention. The other groups received various drugs before the induction by three days, then observed for an additional two days (50 mg/kg MP, 3 mg/kg RM, and a combination of 1.5 mg/kg RM with 25 mg/kg MP). The second part of the study involves the therapeutic potential; all groups received similar doses of drugs in the prevention groups, except LPS induction was given first, and after one hour, the mice received daily doses of the drugs for five days. At the end of the experiment, blood and tissue samples were obtained. Mice treated with RM and its combination with MP showed improved serum TNF-α, IL-6, IL-8, IL-1β, INF-γ, MDA, and GSH in both prevention and therapeutic groups. Histopathologically, mice treated with ramipril and its combination with MP ameliorate the tissue damage in both lung and liver tissues following LPS induction. Ramipril showed protective and therapeutic effects in LPS-induced cytokine storms in mice through anti-inflammatory and antioxidant mechanisms.

C1632 protects against LPS-induced acute lung injury by regulating AXL-mediated MAPK/NF-κB signaling pathway

Acute lung injury (ALI), a leading pulmonary inflammatory disorder, is associated with high morbidity and mortality rates. AXL, a member of the TAM family, plays a significant role in the innate immune and inflammatory responses. This study aimed to evaluate the therapeutic potential of C1632 and its mechanisms in the treatment of LPS-induced ALI/ARDS. The results demonstrated that C1632 pretreatment inhibited the transcription, expression, and secretion of LPS-induced inflammatory factors (IL-6, TNF-α) and vascular adhesion molecules (VCAM-1, ICAM-1). Furthermore, it reduced inflammatory cell infiltration in the lungs, thereby alleviating LPS-induced histopathological changes and lung injury in mice. Mechanistically, C1632 suppressed AXL transcription and expression, which inhibited the activation of the MAPK/NF-κB signaling pathway triggered by LPS stimulation. Both in vitro and in vivo studies confirmed that C1632 administration did not exhibit significant cytotoxicity. Additionally, it did not cause functional or structural damage to the liver and kidneys in mice, nor did it induce other acute toxic effects. In summary, these findings suggest that AXL is a novel target for MAPK/NF-κB signaling pathway mediated anti-inflammatory treatment and C1632 is a promising therapeutic agent for ALI/ARDS treatment.

Phosphatidylserine-decorated delivery platform helps alleviate acute lung injury via potentiating macrophage targeting

Acute lung injury (ALI) is a life-threatening inflammatory disease with high morbidity and mortality. It is urgent to develop more effective therapeutic strategies against ALI. Phosphatidylserine (PtdSer) expressed on the surface of apoptotic cells not only allows for macrophage binding and recognition but also drives anti-inflammatory signaling within the macrophage. In this study, we designed an apoptotic cell-mimicry nanoparticle by decorating synthetic PtdSer on the outer face of nanoparticles. The results indicated that PtdSer-decorated poly(lactic-co-glycolic acid) nanoparticles (PSNPs) showed anti-inflammatory properties and increased macrophage phagocytosis in relative to the nondecorated poly(lactic-co-glycolic acid nanoparticles. Dexamethasone-loaded PSNPs exhibited superior anti-inflammatory activity on macrophages in vitro. In vivo studies also showed that PtdSer decoration increased the accumulation of nanoparticles in lung macrophages after pulmonary administration. Accumulation of dexamethasone-loaded PSNPs in lung macrophages effectively reduced inflammation in inflamed lungs and further alleviated ALI syndromes. In conclusion, PtdSer decoration not only endows the anti-inflammatory function to nanocarriers but also potentiates its macrophage targeting in the inflamed microenvironment, which offers an ideal drug delivery platform for ALI therapy.

Kirenol ameliorates endotoxin-induced acute lung injury by inhibiting the ERK and JNK phosphorylation-mediated NFκB pathway in mice

Acute lung injury (ALI) is a pathological condition characterised by varying degrees of lung damage in patients. Kirenol exerts anti-inflammatory, immunosuppressive, and antioxidative effects. We investigated the protective effects of kirenol on lipopolysaccharide-induced ALI in mice. Pretreatment with kirenol significantly ameliorated lung oedema and neutrophil infiltration in ALI mice. Kirenol downregulated the chemokines (MIP-2) expression and the adhesion molecules (ICAM-1 and VCAM-1) secretion. Furthermore, kirenol inhibited the production of the proinflammatory mediators nitric oxide and prostaglandin (PG)E2 through the upstream factors iNOS and cyclooxygenase (COX)-2, respectively. Kirenol suppressed the IKK-IκB-NFκB pathway, which is involved in lipopolysaccharide-induced inflammation. Kirenol inhibited the lipopolysaccharide-induced phosphorylation of ERK and JNK, to a lesser extent, p38 MAPK and Akt. In conclusion, our findings suggest that kirenol exerts ameliorative effects against ALI by suppressing the production of chemokines, adhesion molecules, and proinflammatory mediators and inhibiting the IKK-IκB-NFκB pathway and its upstream factors, phosphorylated ERK and JNK.

Selenium nanoparticles activate selenoproteins to mitigate septic lung injury through miR-20b-mediated RORγt/STAT3/Th17 axis inhibition and enhanced mitochondrial transfer in BMSCs

Sepsis-induced acute lung injury (ALI) remains a critical clinical challenge with complex inflammatory pathogenesis. While bone marrow mesenchymal stem cells (BMSCs) demonstrate therapeutic potential through anti-inflammatory and cytoprotective effects, their age-related functional decline limits clinical utility. This study developed chitosan-functionalized selenium nanoparticles (SeNPs@CS, 100 nm) to rejuvenate BMSCs through miR-20b-mediated selenoprotein biosynthesis. Mechanistic investigations revealed that SeNPs@CS-treated BMSCs exhibited enhanced mitochondrial transfer capacity, delivering functional mitochondria to damaged alveolar epithelial cells (AECII) for cellular repair. Concurrently, miR-20b upregulation suppressed the RORγt/STAT3/Th17 axis, reducing pro-inflammatory Th17 cell differentiation in CD4+ T lymphocytes. The dual-target mechanism integrates immunomodulation via Th17 pathway inhibition with mitochondrial rejuvenation therapy, representing a paradigm-shifting approach for ALI management. These engineered BMSCs mitigated inflammatory markers in murine models, demonstrating superior efficacy to conventional BMSC therapies. Our findings establish SeNPs@CS-modified BMSCs as a novel therapeutic platform combining nanotechnology-enhanced stem cell engineering with precision immunometabolic regulation, providing new avenues for the treatment of sepsis-induced ALI.

Impact of the duration of corticosteroid treatment for postoperative acute lung injury following lung cancer surgery

Background

Acute lung injury (ALI) is one of the most serious pulmonary complications following lung resection. Despite the known beneficial effects of corticosteroid treatment for postoperative ALI, limited data are available regarding corticosteroid treatment duration. This study aimed to evaluate the beneficial effects of a short-course corticosteroid in patients with postoperative ALI following lung resection surgery for lung cancer.

Methods

This retrospective observational study included 91 patients who were treated with corticosteroids for postoperative ALI among 7,317 patients who underwent lung resection surgery for lung cancer between January 2017 and March 2021. Patients were divided into two groups, short (≤14 days, n=31) and long (≥15 days, n=60) courses, on the basis of corticosteroid treatment duration.

Results

While similar baseline characteristics were observed between the two groups, the short-course group had a higher corticosteroid loading dose than the long-course group; however, the cumulative dose in the first 7 days was not different between the two groups. Overall, in-hospital mortality rates were 3.2% and 26.7% in the short- and long-course groups, respectively (P=0.01). Moreover, the long-course group had higher additional intensive care unit (ICU) admission (32.3% vs. 60.0%, P=0.02) and persistent air leakage (0% vs. 13.3%, P=0.09). In the logistic regression analysis, corticosteroid treatment duration was marginally associated with in-hospital mortality [adjusted odds ratio (OR), 9.03; 95% confidence interval (CI): 0.96-84.9, P=0.054].

Conclusions

Short-course corticosteroid treatment was associated with a lower rate of surgical site complications, additional ICU admission, and in-hospital mortality, which suggests the necessity of efforts for reducing the total duration by weighing the benefits and adverse effects of corticosteroid treatment for postoperative ALI.

The Tan-Re-Qing Capsule mitigates acute lung injury by suppressing the NLRP3 inflammasome and MAPK/NF-κB signaling pathways

OBJECTIVE

The Tan-Re-Qing Capsule (TRQC), a traditional Chinese medicine (TCM) preparation, has been historically utilized in treating acute lung injury (ALI) and COVID-19-induced pulmonary diseases. This study aimed to explore the effect and underlying mechanisms of TRQC in lipopolysaccharide (LPS)-induced ALI models.

METHODS

The changes of acute lung injury and inflammatory response were observed after TRQC treatment of the LPS-induced ALI mouse model. Based on active compounds in TRQC and network pharmacology analysis, potential targeting signals were identified. The effects of TRQC on signaling in LPS-stimulated BMDMs were investigated. Additionally, the defecatory status of mice and the mechanism of Cl- secretion in HBE cells and T84 colonic epithelial cells were examined.

RESULTS

TRQC exhibited a notable amelioration of inflammatory injuries in ALI mice. Utilizing a systems-pharmacology approach based on active chemical compounds, TRQC was found to regulate inflammation-related pathways, including NF-κB, NOD-like signaling, and MAPK signaling. In vitro experiments demonstrated that TRQC effectively suppressed LPS-induced activation of macrophages and the assembly of the NLRP3 inflammasome induced by LPS and Nigericin. These effects were attributed to the suppression of NF-κB and NOD-like signaling pathways. Furthermore, TRQC blocked MAPK signaling, thereby mitigating the inhibitory effects of LPS and Nigericin on Ca2+-dependent Cl- efflux across colonic epithelial cells. This mechanism generated a cathartic effect, potentially aiding in the removal of harmful substances and pathogenic bacteria.

CONCLUSION

Our study demonstrates that TRQC significantly mitigates ALI by effectively suppressing the NLRP3 inflammasome and MAPK/NF-κB signaling pathways. These findings suggest that TRQC could serve as a promising therapeutic candidate for inflammatory lung diseases, offering a novel approach to managing conditions like ALI and potentially extending to other inflammatory diseases.

Macrophage‑driven pathogenesis in acute lung injury/acute respiratory disease syndrome: Harnessing natural products for therapeutic interventions (Review)

Acute lung injury (ALI) or acute respiratory distress syndrome (ARDS) is a common respiratory disease characterized by hypoxemia and respiratory distress. It is associated with high morbidity and mortality. Due to the complex pathogenesis of ALI, the clinical management of patients with ALI/ARDS is challenging, resulting in numerous post‑treatment sequelae and compromising the quality of life of patients. Macrophages, as a class of innate immune cells, play an important role in ALI/ARDS. In recent years, the functions and phenotypes of macrophages have been better understood due to the development of flow cytometry, immunofluorescence, single‑cell sequencing and spatial genomics. However, no macrophage‑targeted drugs for the treatment of ALI/ARDS currently exist in clinical practice. Natural products are important for drug development, and it has been shown that numerous natural compounds from herbal medicine can alleviate ALI/ARDS caused by various factors by modulating macrophage abnormalities. In the present review, the natural products from herbal medicine that can modulate macrophage abnormalities in ALI/ARDS to treat ALI/ARDS are introduced, and their mechanisms of action, discovered in the previous five years (2019‑2024), are presented. This will provide novel ideas and directions for further research, to develop new drugs for the treatment of ALI/ARDS.

Reprint of: M1 macrophage-targeted curcumin nanocrystals with l-arginine-modified for acute lung injury by inhalation

Acute Lung Injury/Acute Respiratory Distress Syndrome (ALI/ARDS) with clinical manifestations of respiratory distress and hypoxemia remains a significant cause of respiratory failure, boasting a persistently high incidence and mortality rate. Given the central role of M1 macrophages in the pathogenesis of acute lung injury (ALI), this study utilized the anti-inflammatory agent curcumin as a model drug. l-arginine (L-Arg) was employed as a targeting ligand, and chitosan was initially modified with l-arginine. Subsequently, it was utilized as a surface modifier to prepare inhalable nano-crystals loaded with curcumin (Arg-CS-Cur), aiming for specific targeting of pulmonary M1 macrophages. Compared with unmodified chitosan-curcumin nanocrystals (CS-Cur), Arg-CS-Cur exhibited higher uptake in vitro by M1 macrophages, as evidenced by flow cytometry showing the highest fluorescence intensity in the Arg-CS-Cur group (P < 0.01). In vivo accumulation was greater in inflamed lung tissues, as indicated by small animal imaging demonstrating higher lung fluorescence intensity in the DiR-Arg-CS-Cur group compared to the DiR-CS-Cur group in the rat ALI model (P < 0.05), peaking at 12 h. Moreover, Arg-CS-Cur demonstrated enhanced therapeutic effects in both LPS-induced RAW264.7 cells and ALI rat models. Specifically, treatment with Arg-CS-Cur significantly suppressed NO release and levels of TNF-α and IL-6 in RAW264.7 cells (p < 0.01), while in ALI rat models, expression levels of TNF-α and IL-6 in lung tissues were significantly lower than those in the model group (P < 0.01). Furthermore, lung tissue damage was significantly reduced, with histological scores significantly lower than those in the CS-Cur group (P < 0.01). In conclusion, these findings underscore the targeting potential of l-arginine-modified nanocrystals, which effectively enhance curcumin concentration in inflammatory environments by selectively targeting M1 macrophages. This study thus introduces novel perspectives and theoretical support for the development of targeted therapeutic interventions for acute inflammatory lung diseases, including ALI/ARDS.

Baicalin alleviates acute lung injury in vivo and in vitro

The aim of the present study was to evaluate the effects and mechanisms of Baicalin (BA) on acute lung injury (ALI). ALI model was established by lipopolysaccharide (LPS) and proteomics, immunoprecipitation and F-box/WD repeat containing protein 7 （FBXW7） knockout (KO) mice and FBXW7 silence mouse lung epithelial (MLE-12) cells were used to investigate the mechanisms of BA on acute lung injury ALI. The results showed that 218 differentially expressed proteins were identified in the lung tissue of ALI mice and FBXW7 was one of the changed most proteins and was significantly decreased in in the lung tissue of ALI mice. It was also found that FBXW7 had protective effects on ALI via inhibition of Absent in Melanoma 2 （AIM2） inflammasomes also found that BA mitigated ALI via FBXW7/AIM2 signal pathway. In conclusion, FBXW7 as a key marker was identified in ALI and has a protective effect on ALI and BA regulated FBXW7/AIM2 signal pathway to alleviate ALI. This study provided a new method for treating ALI.

Novel therapeutic effects of rifaximin in combination with methylprednisolone for LPS-induced ‎oxidative stress and inflammation in mice‎: ‎An in vivo study

Cytokine-releasing syndrome (CRS) is a special form of ‎‎systemic inflammatory response syndrome provoked by ‎factors ‎like viral infections and certain immunomodulatory drugs.‎ To elucidate the potential ‎role of rifaximin (RIF) and its combination with methylprednisolone (MP) against the development and ‎progression of CRS in ‎mice.‎ This experiment consists of two parts: protective and therapeutic interventions. The protective experiment: in the induction group, mice received an intraperitoneal injection (IP) of 5 mg/kg lipopolysaccharide (LPS) without intervention. The other group received various drugs before the induction by three days, then observed for an additional two days (50 mg/kg MP, 50 mg/kg RIF, and a combination of 25 mg/kg RIF with 25 mg/kg MP. The second part of the study involves the therapeutic potential; all groups received similar doses of drugs to that received in the prevention groups, except LPS induction was given first, and after one hour, the mice received daily doses of the drugs for five days. At the end of the experiment, blood and tissue samples were obtained. Mice treated with RIF and its combination with MP showed improved serum TNF-α, IL-6, IL-8, IL-1β, INF-γ, MDA, and GSH in both prevention and therapeutic groups. Histopathologically, mice treated with rifaximin and its combination with MP ameliorates the tissue damage in both lung and liver tissues following LPS induction. In conclusion, rifaximin showed protective and therapeutic effects in LPS-induced cytokine storms in mice through anti-inflammatory and antioxidant mechanisms, and its combination with methylprednisolone showed additive/ synergistic action.

Qingfei Huoxue Decoction and Its Active Component Narirutin Alleviate LPS-Induced Acute Lung Injury by Regulating TLR4/NF-κB Pathway Mediated Inflammation

Background

Acute lung injury (ALI) is a life-threatening clinical syndrome with high mortality. Currently, the safe and effective therapies for ALI patients are still limited. Qingfei Huoxue decoction (QFHXD) is a hospital agreement prescription for treating pulmonary diseases and displays a remarkable efficacy. However, the pharmacological effect of QFHXD on preventing lipopolysaccharide (LPS)-induced ALI has yet to be reported, let alone questions of potential molecular mechanisms and anti-ALI active substances.

Methods

To answer the above-mentioned questions, histopathological observation and kit detection were performed to estimate the protective effect of QFHXD pretreatment against LPS-induced ALI. Based on comprehensive chemical profiling of QFHXD, a network pharmacology strategy and experimental validation were integrated to elucidate the underlying functional mechanisms. The potential anti-ALI active components were identified by molecular docking. The anti-ALI activity of narirutin and its anti-inflammatory mechanism were further validated using animal and molecular experiments.

Results

Pretreatment with different doses of QFHXD effectively mitigated histopathological lesions and systemic inflammation caused by LPS stimulation. A detailed analysis of established compound-target-disease network revealed the strong correlation between anti-ALI action of QFHXD and inflammatory mechanisms. Compared with the model group, QFHXD intervention markedly restrained the abnormally increased transcription and protein levels of pro-inflammatory factors (TLR4, NF-κB, IL-6, IL-1β, and TNF-α) in lung tissues of ALI mice. The results of molecular docking highlighted the anti-ALI potential of narirutin targeting to TLR4 and NF-κB p65. In addition to the protective effect of narirutin on suppressing LPS-induced pathological changes, we found that narirutin pretreatment effectively normalized the disordered protein levels of above pro-inflammatory factors of ALI mice.

Conclusion

These interesting findings indicate the beneficial effects of QFHXD and its active component narirutin against ALI partly via regulating TLR4/NF-κB mediated inflammation. This work contributes to the development of novel medications for ALI patients.

Development of a dexamethasone-hyaluronic acid conjugate with selective targeting effect for acute lung injury therapy

Acute lung injury (ALI), a critical complication of COVID-19, is characterized by widespread inflammation and severe pulmonary damage, necessitating intensive care for those affected. Although glucocorticoids (GCs), such as dexamethasone (Dex), have been employed clinically to lower mortality, their nonspecific systemic distribution has led to significant side effects, limiting their use in ALI treatment. In this study, we explored the conjugation of Dex to hyaluronic acid (HA) to achieve targeted delivery to inflamed lung tissues. We achieved a conjugation efficiency exceeding 98 % using a cosolvent system, with subsequent ester bond cleavage releasing the active Dex, as verified by liquid chromatography. Biodistribution and cellular uptake studies indicated the potential of the HA conjugate for cluster of differentiation 44 (CD44)-mediated targeting and accumulation. In a lipopolysaccharide-induced ALI mouse model, intravenous (IV) HA-Dex administration showed superior anti-inflammatory effects compared to free Dex administration. Flow cytometry analysis suggested that the HA conjugate preferentially accumulated in lung macrophages, suggesting the possibility of reducing clinical Dex dosages through this targeted delivery approach.

Network pharmacology-based research into the mechanism of ferulic acid on acute lung injury through enhancing transepithelial sodium transport

ETHNOPHARMACOLOGICAL RELEVANCE

Ferulic acid (FA) has shown potential therapeutic applications in treating lung diseases. However, the underlying mechanisms by which FA ameliorates acute lung injury (ALI) have not been distinctly elucidated.

AIM OF THE STUDY

The project aims to observe the therapeutic effects of FA on lipopolysaccharide-induced ALI and to elucidate its specific mechanisms in regulating epithelial sodium channel (ENaC), which majors in alveolar fluid clearance during ALI.

MATERIALS AND METHODS

In this study, the possible pathways of FA were determined through network pharmacology analyses. The mechanisms of FA in ALI were verified by in vivo mouse model and in vitro studies, including primary alveolar epithelial type 2 cells and three-dimensional alveolar organoid models.

RESULTS

FA ameliorated ALI by improving lung pathological changes, reducing pulmonary edema, and upregulating the α/γ-ENaC expression in C57BL/J male mice. Simultaneously, FA was observed to augment ENaC levels in both three-dimensional alveolar organoid and alveolar epithelial type 2 cells models. Network pharmacology techniques and experimental data from inhibition or knockdown of IkappaB kinase β (IKKβ) proved that FA reduced the phosphorylation of IKKβ/nuclear factor-kappaB (NF-κB) and eliminated the lipopolysaccharide-inhibited expression of ENaC, which could be regulated by nuclear protein NF-κB p65 directly.

CONCLUSIONS

FA could enhance the expression of ENaC at least in part by inhibiting the IKKβ/NF-κB signaling pathway, which may potentially pave the way for promising treatment of ALI.

Tetrastigma hemsleyanum polysaccharide ameliorates cytokine storm syndrome via the IFN-γ-JAK2/STAT pathway

Acute lung injury (ALI)/acute respiratory distress syndrome (ARDS) is an disease characterized by pulmonary edema and widespread inflammation, leading to a notably high mortality rate. The dysregulation of both pro-inflammatory and anti-inflammatory systems, results in cytokine storm (CS), is intricately associated with the development of ALI/ARDS. Tetrastigma hemsleyanum polysaccharide (THP) exerts remarkable anti-inflammatory and immunomodulatory effects against the disease, although its precise role in pathogenesis remains unclear. In the present study, an ALI/ARDS model was established using bacterial lipopolysaccharides. THP administration via aerosol inhalation significantly mitigated lung injury, reduced the number of inflammatory cells, and ameliorated glycerophospholipid metabolism. Furthermore, specific CS-related pathways were investigated by examining the synergy between tumor necrosis factor-α and interferon-γ used to establish CS models. The results indicated that THP effectively decreased inflammatory damage and cell death. The RNA sequencing revealed the involvement of the Janus kinase (JAK) 2-signal transducers and activators of transcription (STAT) signaling pathway in exerting the mentioned effects. Additionally, THP inhibited the activation of the JAK-STAT pathway, thereby alleviating the CS both in vivo and in vitro. Overall, THP exhibited marked therapeutic potential against ALI/ARDS and CS, primarily by targeting the IFN-γ-JAK2/STAT signaling pathway.

M1 Macrophage-Targeted Curcumin Nanocrystals with l-Arginine-Modified for Acute Lung Injury by Inhalation

Acute Lung Injury/Acute Respiratory Distress Syndrome (ALI/ARDS) with clinical manifestations of respiratory distress and hypoxemia remains a significant cause of respiratory failure, boasting a persistently high incidence and mortality rate. Given the central role of M1 macrophages in the pathogenesis of acute lung injury (ALI), this study utilized the anti-inflammatory agent curcumin as a model drug. l-arginine (L-Arg) was employed as a targeting ligand, and chitosan was initially modified with l-arginine. Subsequently, it was utilized as a surface modifier to prepare inhalable nano-crystals loaded with curcumin (Arg-CS-Cur), aiming for specific targeting of pulmonary M1 macrophages. Compared with unmodified chitosan-curcumin nanocrystals (CS-Cur), Arg-CS-Cur exhibited higher uptake in vitro by M1 macrophages, as evidenced by flow cytometry showing the highest fluorescence intensity in the Arg-CS-Cur group (P < 0.01). In vivo accumulation was greater in inflamed lung tissues, as indicated by small animal imaging demonstrating higher lung fluorescence intensity in the DiR-Arg-CS-Cur group compared to the DiR-CS-Cur group in the rat ALI model (P < 0.05), peaking at 12 h. Moreover, Arg-CS-Cur demonstrated enhanced therapeutic effects in both LPS-induced RAW264.7 cells and ALI rat models. Specifically, treatment with Arg-CS-Cur significantly suppressed NO release and levels of TNF-α and IL-6 in RAW264.7 cells (p < 0.01), while in ALI rat models, expression levels of TNF-α and IL-6 in lung tissues were significantly lower than those in the model group (P < 0.01). Furthermore, lung tissue damage was significantly reduced, with histological scores significantly lower than those in the CS-Cur group (P < 0.01). In conclusion, these findings underscore the targeting potential of l-arginine-modified nanocrystals, which effectively enhance curcumin concentration in inflammatory environments by selectively targeting M1 macrophages. This study thus introduces novel perspectives and theoretical support for the development of targeted therapeutic interventions for acute inflammatory lung diseases, including ALI/ARDS.

Mortality associated with SARS-CoV-2 in nondomestic felids

Between September and November 2021, 5 snow leopards (Panthera uncia) and 1 lion (Panthera leo) were naturally infected with severe acute respiratory coronavirus 2 (SARS-CoV-2) and developed progressive respiratory disease that resulted in death. Severe acute respiratory syndrome coronavirus 2 sequencing identified the delta variant in all cases sequenced, which was the predominant human variant at that time. The time between initial clinical signs and death ranged from 3 to 45 days. Gross lesions in all 6 cats included nasal turbinate hyperemia with purulent discharge and marked pulmonary edema. Ulcerative tracheitis and bronchitis were noted in 4 cases. Histologically, there was necrotizing and ulcerative rhinotracheitis and bronchitis with fibrinocellular exudates and fibrinosuppurative to pyogranulomatous bronchopneumonia. The 4 cats that survived longer than 8 days had fungal abscesses. Concurrent bacteria were noted in 4 cases, including those with more acute disease courses. Severe acute respiratory syndrome coronavirus 2 was detected by in situ hybridization using probes against SARS-CoV-2 spike and nucleocapsid genes and by immunohistochemistry. Viral nucleic acid and protein were variably localized to mucosal and glandular epithelial cells, pneumocytes, macrophages, and fibrinocellular debris. Based on established criteria, SARS-CoV-2 was considered a contributing cause of death in all 6 cats. While mild clinical infections are more common, these findings suggest that some SARS-CoV-2 variants may cause more severe disease and that snow leopards may be more severely affected than other felids.

Anti-Inflammatory Potency of Human Wharton's Jelly Mesenchymal Stem Cell-Derived Exosomes on L2 Cell Line Induced by Lipopolysaccharides

Purpose

At present, therapeutic interventions to treat acute lung injury (ALI) remain largely limited to lung-protective strategies, as no real molecular-driven therapeutic intervention has yet become available. The administration of bacterial lipopolysaccharides (LPS) is known as an inflammatory activator, representing a frequently used model of ALI. This study investigated the biological function of normoxic (21% O2 ) vs. hypoxic conditions (5% O2 ) obtained from human Wharton's Jelly mesenchymal stem cells (hWJ-MSCs) and discovered that exosomes have the ability to suppress inflammatory responses by specifically targeting TNF-α, IL-1β, IL-6. and identify the toll-like receptor 4 (TLR4) NF-κβ gene expression.

Methods

Primer culture hWJ-MSCs characterization with trilineage differentiation and CD markers was conducted. To obtain exosomes, hWJ-MSCs were stimulated with two different oxygen levels: 21% (nor-exo) and 5% (hypo-exo). Then, the L2 cell line was induced with LPS 1 µg/mL. Inflamed-L2 was treated with nor-exo, hypo-exo, and dexamethasone as a positive control. The RNA extracted from treated L2 cells was utilized to examine the gene expression profiles of TLR4 and NF-κβ, and the medium was used to measure tumor necrosis factor α (TNF-α), interleukin (IL)-1β, and IL-6 levels using ELISA. Lastly, proteomic analysis of the exosome using LC/MS-MS was conducted.

Results

Nor-exo and hypo-exo can be characterized and can produce higher yields exosomes under hypoxic conditions. The expression of TLR4 and NF-κβ genes and the proinflammatory levels such as IL-6, IL-1β, and TNF-α levels in nor-exo and hypo-exo treatments decreased.

Conclusion

Nor-exo and hypo-exo derived from hWJ-MSCs were proven to have anti-inflammatory activities.

Amplifying protection against acute lung injury: Targeting both inflammasome and cGAS-STING pathway by Lonicerae Japonicae Flos-Forsythiae Fructus drug pair

Objective

Acute lung injury (ALI) is characterized by inflammation and currently lacks an efficacious pharmacological intervention. The medicine combination of Lonicerae Japonicae Flos (LJF) and Forsythiae Fructus (FF) demonstrates combined properties in its anti-infective, anti-inflammatory, and therapeutic effects, particularly in alleviating respiratory symptoms. In previous studies, Chinese medicine has shown promising efficacy in lipopolysaccharides (LPS)-induced ALI. However, there have been no reports of LJF and FF pairing for lung injury. The aim of this study is to compare the efficacy of herb pair Lonicerae Japonicae Flos-Forsythiae Fructus (LF) with LJF or FF alone in the treatment of ALI, and to explore whether LJF and FF have a combined effect in the treatment of lung injury, along with the underlying mechanism involved.

Methods

A total of 36 mice were divided into six groups (control, model, LJF, FF, LF, dexamethasone) based on the treatments they received after undergoing sham-operation/LPS tracheal instillation. H&E staining and pulmonary edema indexes were used to evaluate lung injury severity. Alveolar exudate cells (AECs) were counted based on cell count in bronchoalveolar lavage fluid (BALF), and neutrophil percentage in BALF was measured using flow cytometry. Myeloperoxidase (MPO) activity in BALF was measured using enzyme-linked immunosorbent assay (ELISA), while the production of IL-1β, TNF-α, and IL-6 in the lung and secretion level of them in BALF were detected by quantitative polymerase chain reaction (qPCR) and ELISA. The effect of LJF, FF, and LF on the expression of Caspase-1 and IL-1β proteins in bone marrow derived macrophages (BMDMs) supernatant was assessed using Western blot method under various inflammasome activation conditions. In addition, the concentration of IL-1β and changes in lactatedehydrogenase (LDH) release levels in BMDMs supernatant after LJF, FF, and LF administration, respectively, were measured using ELISA. Furthermore, the effects of LJF, FF and LF on STING and IRF3 phosphorylation in BMDMs were detected by Western blot, and the mRNA changes of IFN-β, TNF-α, IL-6 and CXCL10 in BMDMs were detected by qPCR.

Results

LF significantly attenuated the damage to alveolar structures, pulmonary hemorrhage, and infiltration of inflammatory cells induced by LPS. This was evidenced by a decrease in lung index score and wet/dry weight ratio. Treatment with LF significantly reduced the total number of neutrophil infiltration by 75% as well as MPO activity by 88%. The efficacy of LF in reducing inflammatory factors IL-1β, TNF-α, and IL-6 in the lungs surpasses that of LJF or FF, approaching the effectiveness of dexamethasone. In BMDMs, the co-administration of 0.2 mg/mL of LJF and FF demonstrated superior inhibitory effects on the expression of nigericin-stimulated Caspase-1 and IL-1β, as well as the release levels of LDH, compared to individual treatments. Similarly, the combination of 0.5 mg/mL LJF and FF could better inhibit the phosphorylation levels of STING and IRF3 and the production of IFN-β, TNF-α, IL-6, and CXCL10 in response to ISD stimulation.

Conclusion

The combination of LJF and FF increases the therapeutic effect on LPS-induced ALI, which may be mechanistically related to the combined effect inhibition of cyclic-GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) and NOD-like receptor family protein 3 (NLRP3) inflammasomes pathways by LJF and FF. Our study provides new medicine candidates for the clinical treatment of ALI.

Forsythiaside A alleviates acute lung injury by inhibiting inflammation and epithelial barrier damages in lung and colon through PPAR-γ/RXR-α complex

INTRODUCTION

Acute lung injury (ALI) is a lung disease characterized by inflammation and still requires further drug development. Forsythiaside A as the active compound of Forsythiae Fructus has the therapeutic potential for ALI.

OBJECTIVE

To investigate the mechanism of forsythiaside A in treating ALI through PPAR-γ and its conjugate RXR-α based on gut-lung axis.

METHODS

This study constructed in vitro and in vivo injury models using LPS and TNF-α. Forsythiaside A was used for the drug treatment, and RXR-α inhibitor UVI3003 was used to interfere with PPAR-γ/RXR-α complexes in the cells. HE staining was used for histopathological examination. Serum endotoxin contents were determined using limulus lysate kit. IHC staining and Western blot were conducted to assess the protein expressions. ELISA was applied to examine the content of pro-inflammatory cytokines in the cell supernatants. The protein interactions were analyzed via CO-IP.

RESULTS

In vivo results showed that forsythiaside A regulated PPAR-γ/RXR-α and inhibited TLR4/MAPK/NF-κB and MLCK/MLC2 signal pathways, thus inhibiting inflammation and epithelial barrier damages of lung and colon in ALI mice induced by intratracheal LPS. PPAR-γ/RXR-α were promoted by forsythiaside A in lungs, whereas inhibited by forsythiaside A in colons. Additionally, in vitro results showed that forsythiaside A suppressed inflammation and epithelial barrier damages in macrophages and lung/colon epithelial cells, by manipulating PPAR-γ/RXR-α to suppress the LPS- and TNF-α-induced activation of TLR4/MAPK/NF-κB and NF-κB/MLCK/MLC2 signal pathways. Moreover, further mechanism study indicated that forsythiaside A showed a cell-specific regulatory effect on PPAR-γ/RXR-α complex. Specifically, the PPAR-γ/RXR-α protein interactions were promoted by forsythiaside A in LPS-induced macrophages RAW264.7 and TNF-α-induced lung epithelial cells A549, but inhibited by forsythiaside A in TNF-α-induced colon epithelial cells SW620.

CONCLUSION

In the treatment of ALI, Forsythiaside A inhibited inflammation and epithelial barrier damages of lung and colon through its regulation on PPAR-γ/RXR-α complex.

Nebulized Inhalation of Peptide-Modified DNA Origami To Alleviate Acute Lung Injury

Acute lung injury (ALI) is a severe inflammatory lung disease, with high mortality rates. Early intervention by reactive oxygen species (ROS) scavengers could reduce ROS accumulation, break the inflammation expansion chain in alveolar macrophages (AMs), and avoid irreversible damage to alveolar epithelial and endothelial cells. Here, we reported cell-penetrating R9 peptide-modified triangular DNA origami nanostructures (tDONs-R9) as a novel nebulizable drug that could reach the deep alveolar regions and exhibit an enhanced uptake preference of macrophages. tDONs-R9 suppressed the expression of pro-inflammatory cytokines and drove polarization toward the anti-inflammatory M2 phenotype in macrophages. In the LPS-induced ALI mouse model, treatment with nebulized tDONs-R9 alleviated the overwhelming ROS, pro-inflammatory cytokines, and neutrophil infiltration in the lungs. Our study demonstrates that tDONs-R9 has the potential for ALI treatment, and the programmable DNA origami nanostructures provide a new drug delivery platform for pulmonary disease treatment with high delivery efficiency and biosecurity.

In vitro and in vivo protective potential of quercetin-3-glucuronide against lipopolysaccharide-induced pulmonary injury through dual activation of nuclear factor-erythroid 2 related factor 2 and autophagy

In vitro and in vivo models of lipopolysaccharide (LPS)-induced pulmonary injury, quercetin-3-glucuronide (Q3G) has been previously revealed the lung-protective potential via downregulation of inflammation, pyroptotic, and apoptotic cell death. However, the upstream signals mediating anti-pulmonary injury of Q3G have not yet been clarified. It has been reported that concerted dual activation of nuclear factor-erythroid 2 related factor 2 (Nrf2) and autophagy may prove to be a better treatment strategy in pulmonary injury. In this study, the effect of Q3G on antioxidant and autophagy were further investigated. Noncytotoxic doses of Q3G abolished the LPS-caused cell injury, and reactive oxygen species (ROS) generation with inductions in Nrf2-antioxidant signaling. Moreover, Q3G treatment repressed Nrf2 ubiquitination, and enhanced the association of Keap1 and p62 in the LPS-treated cells. Q3G also showed potential in inducing autophagy, as demonstrated by formation of acidic vesicular organelles (AVOs) and upregulation of autophagy factors. Next, the autolysosomes formation and cell survival were decreased by Q3G under pre-treatment with a lysosome inhibitor, chloroquine (CQ). Furthermore, mechanistic assays indicated that anti-pulmonary injury effects of Q3G might be mediated via Nrf2 signaling, as confirmed by the transfection of Nrf2 siRNA. Finally, Q3G significantly alleviated the development of pulmonary injury in vivo, which may result from inhibiting the LPS-induced lung dysfunction and edema. These findings emphasize a toxicological perspective, providing new insights into the mechanisms of Q3G's protective effects on LPS-induced pulmonary injury and highlighting its role in dual activating Nrf2 and autophagy pathways.

Alpinetin alleviates LPS-induced lung epithelial cell injury by inhibiting p38 and ERK1/2 signaling via aquaporin-1

Alpinetin has been reported to play a protective role in lung diseases, while its special mechanisms remain indistinct. In this study, acute lung injury (ALI) model was constructed by inducing MLE-12 cells with lipopolysaccharide (LPS). Cell activity together with apoptosis was judged employing cell counting kit-8 (CCK-8), flow cytometry along with western blot. Oxidative stress levels were measured by dichloro-dihydro-fluorescein diacetate (DCFH-DA) staining and corresponding kits. In addition, enzyme-linked immunosorbent assay (ELISA) was to examine the levels of inflammatory factors. The protein expressions of aquaporin-1 (AQP1), p38 and extracellular signal-regulated kinase (ERK) 1/2 pathway were estimated utilizing western blot. The data showed that alpinetin increased the viability, reduced the apoptosis, oxidative stress and inflammation and inactivated p38 and ERK1/2 signaling in LPS-induced MLE-12 cells. Moreover, alpinetin also increased AQP1 expression and AQP1 knockdown reversed the impacts of alpinetin on LPS-induced MLE-12 cells. Additionally, AQP1 agonist AqF026 also exerted anti-apoptotic and anti-inflammatory activities in LPS-treated MLE-12 cells. Evidently, alpinetin may exert its protective role in LPS-induced ALI by inactivation of p38 and ERK1/2 signaling through regulating AQP1.

Yemazhui () ameliorates lipopolysaccharide-induced acute lung injury modulation of the toll-like receptor 4/nuclear factor kappa-B/nod-like receptor family pyrin domain-containing 3 protein signaling pathway and intestinal flora in rats

OBJECTIVE

To investigate the impact of Yemazhui (Herba Eupatorii Lindleyani, HEL) against lipopolysaccharide (LPS)-induced acute lung injury (ALI) and explore its underlying mechanism in vivo.

METHODS

The chemical constituents of HEL were analyzed by ultra-high performance liquid chromatography-quadrupole time-of-flight mass spectrometry method. Then, HEL was found to suppress LPS-induced ALI in vivo. Six-week-old male Sprague-Dawley rats were randomly divided into 6 groups: control, LPS, Dexamethasone (Dex), HEL low dose 6 g/kg (HEL-L), HEL medium dose 18 g/kg (HEL-M) and HEL high dose 54 g/kg (HEL-H) groups. The model rats were intratracheally injected with 3 mg/kg LPS to establish an ALI model. Leukocyte counts, lung wet/dry weight ratio, as well as myeloperoxidase (MPO) activity were determined followed by the detection with hematoxylin and eosin staining, enzyme linked immunosorbent assay, quantitative real time polymerase chain reaction, western blotting, immunohistochemistry, and immunofluorescence. Besides, to explore the effect of HEL on ALI-mediated intestinal flora, we performed 16s rRNA sequencing analysis of intestinal contents.

RESULTS

HEL attenuated LPS-induced inflammation in lung tissue and intestinal flora disturbance. Mechanism study indicated that HEL suppressed the lung coefficient and wet/dry weight ratio of LPS-induced ALI in rats, inhibited leukocytes exudation and MPO activity, and improved the pathological injury of lung tissue. In addition, HEL reduced the expression of tumor necrosis factor-alpha, interleukin-1beta (IL-1β) and interleukin-6 (IL-6) in bronchoalveolar lavage fluid and serum, and inhibited nuclear displacement of nuclear factor kappa-B p65 (NF-κBp65). And 18 g/kg HEL also reduced the expression levels of toll-like receptor 4 (TLR4), myeloid differentiation factor 88, NF-κBp65, phosphorylated inhibitor kappa B alpha (phospho-IκBα), nod-like receptor family pyrin domain-containing 3 protein (NLRP3), IL-1β, and interleukin-18 (IL-18) in lung tissue, and regulated intestinal flora disturbance.

CONCLUSIONS

In summary, our findings revealed that HEL has a protective effect on LPS-induced ALI in rats, and its mechanism may be related to inhibiting TLR4/ NF-κB/NLRP3 signaling pathway and improving intestinal flora disturbance.

Modulation of experimental acute lung injury by exosomal miR-7704 from mesenchymal stromal cells acts through M2 macrophage polarization

Acute lung injury (ALI) is a life-threatening condition with limited treatment options. The pathogenesis of ALI involves macrophage-mediated disruption and subsequent repair of the alveolar barriers, which ultimately results in lung damage and regeneration, highlighting the pivotal role of macrophage polarization in ALI. Although exosomes derived from mesenchymal stromal cells have been established as influential modulators of macrophage polarization, the specific role of exosomal microRNAs (miRNAs) remains underexplored. This study aimed to elucidate the role of specific exosomal miRNAs in driving macrophage polarization, thereby providing a reference for developing novel therapeutic interventions for ALI. We found that miR-7704 is the most abundant and efficacious miRNA for promoting the switch to the M2 phenotype in macrophages. Mechanistically, we determined that miR-7704 stimulates M2 polarization by inhibiting the MyD88/STAT1 signaling pathway. Notably, intra-tracheal delivery of miR-7704 alone in a lipopolysaccharide-induced murine ALI model significantly drove M2 polarization in lung macrophages and remarkably restored pulmonary function, thus increasing survival. Our findings highlight miR-7704 as a valuable tool for treating ALI by driving the beneficial M2 polarization of macrophages. Our findings pave the way for deeper exploration into the therapeutic potential of exosomal miRNAs in inflammatory lung diseases.

Function of KvLQT1 potassium channels in a mouse model of bleomycin-induced acute lung injury

Acute respiratory distress syndrome (ARDS) is characterized by an exacerbated inflammatory response, severe damage to the alveolar-capillary barrier and a secondary infiltration of protein-rich fluid into the airspaces, ultimately leading to respiratory failure. Resolution of ARDS depends on the ability of the alveolar epithelium to reabsorb lung fluid through active transepithelial ion transport, to control the inflammatory response, and to restore a cohesive and functional epithelium through effective repair processes. Interestingly, several lines of evidence have demonstrated the important role of potassium (K+) channels in the regulation of epithelial repair processes. Furthermore, these channels have previously been shown to be involved in sodium/fluid absorption across alveolar epithelial cells, and we have recently demonstrated the contribution of KvLQT1 channels to the resolution of thiourea-induced pulmonary edema in vivo. The aim of our study was to investigate the role of the KCNQ1 pore-forming subunit of KvLQT1 channels in the outcome of ARDS parameters in a model of acute lung injury (ALI). We used a molecular approach with KvLQT1-KO mice challenged with bleomycin, a well-established ALI model that mimics the key features of the exudative phase of ARDS on day 7. Our data showed that KvLQT1 deletion exacerbated the negative outcome of bleomycin on lung function (resistance, elastance and compliance). An alteration in the profile of infiltrating immune cells was also observed in KvLQT1-KO mice while histological analysis showed less interstitial and/or alveolar inflammatory response induced by bleomycin in KvLQT1-KO mice. Finally, a reduced repair rate of KvLQT1-KO alveolar cells after injury was observed. This work highlights the complex contribution of KvLQT1 in the development and resolution of ARDS parameters in a model of ALI.

Mortality associated with SARS-CoV-2 in nondomestic felids

Between September and November 2021, 5 snow leopards ( Panthera uncia) and 1 lion ( Panthera leo) were naturally infected with severe acute respiratory coronavirus 2 (SARS-CoV-2) and developed progressive respiratory disease that resulted in death. Severe acute respiratory syndrome coronavirus 2 sequencing identified the delta variant in all cases sequenced, which was the predominant human variant at that time. The time between initial clinical signs and death ranged from 3 to 45 days. Gross lesions in all 6 cats included nasal turbinate hyperemia with purulent discharge and marked pulmonary edema. Ulcerative tracheitis and bronchitis were noted in 4 cases. Histologically, there was necrotizing and ulcerative rhinotracheitis and bronchitis with fibrinocellular exudates and fibrinosuppurative to pyogranulomatous bronchopneumonia. The 4 cats that survived longer than 8 days had fungal abscesses. Concurrent bacteria were noted in 4 cases, including those with more acute disease courses. Severe acute respiratory syndrome coronavirus 2 was detected by in situ hybridization using probes against SARS-CoV-2 spike and nucleocapsid genes and by immunohistochemistry. Viral nucleic acid and protein were variably localized to mucosal and glandular epithelial cells, pneumocytes, macrophages, and fibrinocellular debris. Based on established criteria, SARS-CoV-2 was considered a contributing cause of death in all 6 cats. While mild clinical infections are more common, these findings suggest that some SARS-CoV-2 variants may cause more severe disease and that snow leopards may be more severely affected than other felids.

ICAM-1 targeted and ROS-responsive nanoparticles for the treatment of acute lung injury

Acute lung injury (ALI) is an inflammatory disease caused by multiple factors such as infection, trauma, and chemicals. Without effective intervention during the early stages, it usually quickly progresses to acute respiratory distress syndrome (ARDS). Since ordinary pharmaceutical preparations cannot precisely target the lungs, their clinical application is limited. In response, we constructed a γ3 peptide-decorated and ROS-responsive nanoparticle system encapsulating therapeutic dexamethasone (Dex/PSB-γ3 NPs). In vitro, Dex/PSB-γ3 NPs had rapid H2O2 responsiveness, low cytotoxicity, and strong intracellular ROS removal capacity. In a mouse model of ALI, Dex/PSB-γ3 NPs accumulated at the injured lung rapidly, alleviating pulmonary edema and cytokine levels significantly. The modification of NPs by γ3 peptide achieved highly specific positioning of NPs in the inflammatory area. The ROS-responsive release mechanism ensured the rapid release of therapeutic dexamethasone at the inflammatory site. This combined approach improves treatment accuracy, and drug bioavailability, and effectively inhibits inflammation progression. Our study could effectively reduce the risk of ALI progressing to ARDS and hold potential for the early treatment of ALI.

Jingfang Granules () alleviates bleomycin-induced acute lung injury through regulating PI3K/Akt/mTOR signaling pathway

ETHNOPHARMACOLOGICAL RELEVANCE

Acute lung injury is a kind of clinical emergency severe syndrome which might trigger acute respiratory distress syndrome. Jingfang Granules () is a traditional Chinese medicine which has been proven to improve acute lung injury induced by bleomycin through inhibiting recruitment and overactive of inflammation. However, the potential mechanisms are still not well evaluated.

AIM OF STUDY

The aim of this study was to evaluate the protective function of Jingfang Granules on bleomycin caused acute lung injury and further discuss the potential pharmacological mechanisms.

MATERIALS AND METHODS

C57BL/6J mice were intratracheal injected bleomycin to induce model with acute lung injury. The protective impact of Jingfang Granules on acute lung injury and lung fibrosis triggered by bleomycin were evaluated through detecting mice body weight, lung appearance, lung index, and histopathology. The potential pharmacological mechanism of Jingfang Granules in treating acute lung injury was further elucidated by the methods of network pharmacology, proteomics, metabolomics, as well as western blot. Additionally, the network pharmacology analysis and molecular docking technology were integrated to investigate the targets of Jingfang Granules improving acute lung injury.

RESULTS

Our results indicated that Jingfang Granules effectively protected mice from acute lung injury induced by bleomycin, which was confirmed by higher body weight, lower pulmonary edema and lung index, and improved pathology and fibrosis of lung tissue compared to model group. Proteomics, western blot, and metabolomics were integrated and the results confirmed that Jingfang Granules regulated the Glycolysis/Gluconogenesis and Pyruvate metabolism through downregulating the PI3K/Akt/mTOR signaling pathway. The network pharmacology analysis and molecular docking technology results showed that the targets of Jingfang Granules for treating acute lung injury were enriched in the PI3K/Akt signaling pathway, which included 7 target proteins such as MAPK1, MAPK3, JAK2, HRAS, EGFR, PIK3R1, and PIK3CA.

CONCLUSION

This study indicates that Jingfang Granules displays a markedly protective effect on acute lung injury caused by bleomycin through downregulating PI3K/Akt/mTOR signaling pathway, which in turn regulates Glycolysis/Gluconogenesis and Pyruvate metabolism.

Anti-Inflammatory Effects of Clematis terniflora Leaf on Lipopolysaccharide-Induced Acute Lung Injury

For centuries, natural products are regarded as vital medicines for human survival. Clematis terniflora var. mandshurica (Rupr.) Ohwi is an ingredient of the herbal medicine, Wei Ling Xian, which has been used in Chinese medicine to alleviate pain, fever, and inflammation. In particular, C. terniflora leaves have been used to cure various inflammatory diseases, including tonsillitis, cholelithiasis, and conjunctivitis. Based on these properties, this study aimed to scientifically investigate the anti-inflammatory effect of an ethanol extract of leaves of C. terniflora (EELCT) using activated macrophages that play central roles in inflammatory response. In this study, EELCT inhibited the essential inflammatory mediators, such as nitric oxide, cyclooxygenase-2, tumor necrosis factor-α, interleukin- (IL-) 6, IL-1β, and inducible nitric oxide synthase, by suppressing the nuclear factor-κB and mitogen-activated protein kinase activation in macrophages. Acute lung injury (ALI) is a fatal respiratory disease accompanied by serious inflammation. With high mortality rate, the disease has no effective treatments. Therefore, new therapeutic agents must be developed for ALI. We expected that EELCT can be a promising therapeutic agent for ALI by reducing inflammatory responses and evaluated its action in a lipopolysaccharide- (LPS-) induced ALI model. EELCT alleviated histological changes, immune cell infiltration, inflammatory mediator production, and protein-rich pulmonary edema during ALI. Collectively, our results may explain the traditional usage of C. terniflora in inflammatory diseases and suggest the promising potential of EELCT as therapeutic candidate for ALI.

The effect of budesonide delivered by high-frequency oscillatory ventilation on acute inflammatory response in severe lung injury in adult rabbits

The inflammation present in acute respiratory distress syndrome (ARDS) and thereby associated injury to the alveolar-capillary membrane and pulmonary surfactant can potentiate respiratory failure. Even considering the high mortality rate of severe ARDS, glucocorticoids appear to be a reasonable treatment option along with an appropriate route of delivery to the distal lung. This study aimed to investigate the effect of budesonide therapy delivered intratracheally by high-frequency oscillatory ventilation (HFOV) on lung function and inflammation in severe ARDS. Adult New Zealand rabbits with respiratory failure (P/F<13.3 kPa) induced by intratracheal instillation of hydrochloric acid (HCl, 3 ml/kg, pH 1.5) followed by high tidal ventilation (VT 20 ml/kg) to mimic ventilator-induced lung injury (VILI) were treated with intratracheal bolus of budesonide (0.25 mg/kg, Pulmicort) delivered by HFOV (frequency 8 Hz, MAP 1 kPa, deltaP 0.9 kPa). Saline instead of HCl without VILI with HFOV delivered air bolus instead of therapy served as healthy control. All animals were subjected to lung-protective ventilation for 4 h, and respiratory parameters were monitored regularly. Postmortem, lung injury, wet-to-dry weight ratio, leukocyte shifts, and levels of cytokines in plasma and lung were evaluated. Budesonide therapy improved the lung function (P/F ratio, oxygenation index, and compliance), decreased the cytokine levels, reduced lung edema and neutrophils influx into the lung, and improved lung architecture in interstitial congestion, hyaline membrane, and atelectasis formation compared to untreated animals. This study indicates that HFOV delivered budesonide effectively ameliorated respiratory function, and attenuated acid-induced lung injury in a rabbit model of severe ARDS.

Dihydroquercetin (DHQ) ameliorates LPS-induced acute lung injury by regulating macrophage M2 polarization through IRF4/miR-132-3p/FBXW7 axis

BACKGROUND

Acute lung injury (ALI) is a common complication of sepsis. Dihydroquercetin (DHQ) has been found to attenuate lipopolysaccharide (LPS)-induced inflammation. However, the effect of DHQ on LPS-challenged ALI remains unclear.

METHODS

Pulmonary HE and TUNEL staining and lung wet/dry ratio were detected in LPS-treated Balb/c mice. IL-1β, IL-6 and TNF-α levels were determined utilizing ELISA assay. RAW264.7 cell apoptosis and macrophage markers (CD86, CD206) were tested using flow cytometry. TC-1 viability was analyzed by MTT assay. Western blot measured protein expression of macrophage markers. Interactions of miR-132-3p, IRF4 and FBXW7 were explored utilizing ChIP, RNA pull-down and dual luciferase reporter assays.

RESULTS

DHQ alleviated histopathological change, pulmonary edema and apoptosis in LPS-treated mice. DHQ affected LPS-induced M2 macrophage polarization and TC-1 cell injury-related indicators, such as decreased cell activity, decreased LDH levels, and increased apoptosis. LPS inhibited IRF4 and miR-132-3p expression, activated Notch pathway and increased FBXW7 level, which were overturned by DHQ. IRF4 transcriptionally activated miR-132-3p expression. FBXW7 was a downstream target of miR-132-3p.

CONCLUSION

DHQ alleviated LPS-induced lung injury through promoting macrophage M2 polarization via IRF4/miR-132-3p/FBXW7 axis, which provides a new therapeutic strategy for ALI.

Ginsenosides: a potential natural medicine to protect the lungs from lung cancer and inflammatory lung disease

Lung cancer is the malignancy with the highest morbidity and mortality. Additionally, pulmonary inflammatory diseases, such as pneumonia, acute lung injury, chronic obstructive pulmonary disease (COPD), and pulmonary fibrosis (PF), also have high mortality rates and can promote the development and progression of lung cancer. Unfortunately, available treatments for them are limited, so it is critical to search for effective drugs and treatment strategies to protect the lungs. Ginsenosides, the main active components of ginseng, have been shown to have anti-cancer and anti-inflammatory activities. In this paper, we focus on the beneficial effects of ginsenosides on lung diseases and their molecular mechanisms. Firstly, the molecular mechanism of ginsenosides against lung cancer was summarized in detail, mainly from the points of view of proliferation, apoptosis, autophagy, angiogenesis, metastasis, drug resistance and immunity. In in vivo and in vitro lung cancer models, ginsenosides Rg3, Rh2 and CK were reported to have strong anti-lung cancer effects. Then, in the models of pneumonia and acute lung injury, the protective effect of Rb1 was particularly remarkable, followed by Rg3 and Rg1, and its molecular mechanism was mainly associated with targeting NF-κB, Nrf2, MAPK and PI3K/Akt pathways to alleviate inflammation, oxidative stress and apoptosis. Additionally, ginsenosides may also have a potential health-promoting effect in the improvement of COPD, asthma and PF. Furthermore, to overcome the low bioavailability of CK and Rh2, the development of nanoparticles, micelles, liposomes and other nanomedicine delivery systems can significantly improve the efficacy of targeted lung cancer treatment. To conclude, ginsenosides can be used as both anti-lung cancer and lung protective agents or adjuvants and have great potential for future clinical applications.

Ficolin B secreted by alveolar macrophage exosomes exacerbates bleomycin-induced lung injury via ferroptosis through the cGAS-STING signaling pathway

Pathogenesis exploration and timely intervention of lung injury is quite necessary as it has harmed human health worldwide for years. Ficolin B (Fcn B) is a recognition molecule that can recognize a variety of ligands and play an important role in mediating the cell cycle, immune response, and tissue homeostasis in the lung. However, the role of Fcn B in bleomycin (BLM)-induced lung injury is obscure. This study aims to investigate the sources of Fcn B and its mechanism in BLM-induced lung injury. WT, Fcna-/-, and Fcnb-/- mice were selected to construct the BLM-induced lung injury model. Lung epithelial cells were utilized to construct the BLM-induced cell model. Exosomes that were secreted from alveolar macrophages (AMs) were applied for intervention by transporting Fcn B. Clinical data suggested M-ficolin (homologous of Fcn B) was raised in plasma of interstitial lung disease (ILD) patients. In the mouse model, macrophage-derived Fcn B aggravated BLM-induced lung injury and fibrosis. Fcn B further promoted the development of autophagy and ferroptosis. Remarkably, cell experiment results revealed that Fcn B transported by BLM-induced AMs exosomes accelerated autophagy and ferroptosis in lung epithelial cells through the activation of the cGAS-STING pathway. In contrast, the application of 3-Methyladenine (3-MA) reversed the promotion effect of Fcn B from BLM-induced AMs exosomes on lung epithelial cell damage by inhibiting autophagy-dependent ferroptosis. Meanwhile, in the BLM-induced mice model, the intervention of Fcn B secreted from BLM-induced AMs exosomes facilitated lung injury and fibrosis via ferroptosis. In summary, this study demonstrated that Fcn B transported by exosomes from AMs exacerbated BLM-induced lung injury by promoting lung epithelial cells ferroptosis through the cGAS-STING signaling pathway.

Using the Alluvial diagram to display variable characteristics for COVID-19 patients and research achievements on the topic of COVID-19, epidemiology, pathogenesis, and vaccine (CEPV): Bibliometric analysis

BACKGROUND

An Alluvial diagram illustrates the flow of values from one set to another. Edges (or links/connections) are the connections between nodes (or actors/ vertices). There has been an increase in the use of Alluvial deposits in medical research in recent years. However, there was no illustration of such research on the way to draw the Alluvial for the readers. Our objective was to demonstrate how to draw the Alluvial in Microsoft Excel by using 2 examples, including variable characteristics for COVID-19 patients and research achievements (RAs) on the topic of COVID-19, epidemiology, pathogenesis, and vaccine (CEPV), and provide an easy and friendly method of drawing the Alluvial in MS Excel.

METHODS

Blood samples were collected and analyzed from 485 infected individuals in Wuhan, China. An operational decision tree and 2 Alluvial diagrams were shown to be capable of identifying variable characteristics in COVID-19 patients. A second example is the 100 top-cited articles downloaded from the Web of Science core collection (WoSCC) on the CEPV topic. On the Alluvial diagram, the mean citations (=citations/publications) and x-index were used to identify the top 5 members with the highest RAs in each entity (country, institute, journal, and research area). Two examples (i.e., blood samples taken from 485 infected individuals in Wuhan, China, and 100 top-cited articles on the CEPV topic) were illustrated and compared with traditional visualizations without flow relationships between nodes.

RESULTS

The top members in entities with the x-index are U Arab Emirates (242), Jama-J. Am. Med. Assoc. (27.18), Lancet (58.34), San Francisco Va Med (178), and Chaolin Huang (189) in countries, institutes, departments, and authors, respectively. The most cited article with 1315 citations was written by Huang and his colleagues and published by Lancet in 2021.

CONCLUSION

This study generates several Alluvial diagrams as demonstrations. The tutorial material and MP4 video provided in the Excel module allow readers to draw the Alluvial on their own in an easy and friendly manner.

Remote preconditioning combined with nebulized budesonide alleviate lipopolysaccharide induced acute lung injury via regulating HO-1 and NF-κB in rats

BACKGROUND

Acute lung injury (ALI) may result in severe systemic inflammation and is life-threatening. Remote inflammatory preconditioning (RIPC) has been confirmed to have an endogenous protective effect against ALI. Budesonide (BS) is a potent corticosteroid typically administered through nebulization that reduces inflammation in the lungs. We speculate that the combined use of RIPC and nebulized BS has a stronger protective effect on ALI.

METHODS

48 Sprague-Dawley male rats were used for the experiments. Animals were divided evenly and randomly into three groups, control (NS injection), LPS (LPS injection), and RIPC (LPS injection with RIPC). Each group was then divided into two subgroups with inhalation of nebulized normal saline (NS) or BS. Prior to injection of LPS, RIPC was performed by tying and untying the right hind limb for three cycles of 5 min each. Following LPS injection, animals in each subgroup were placed in a same cage for nebulized inhalation. Animals were sacrificed 6 h after LPS injection. Histological evaluation of ALI and lung wet-to-dry weight ratio were measured. Serum lactate acid, inflammatory cytokines, oxidative stress indicators were detected. The expression of HO-1, NF-κB p65 and p-p65 was measured by western blotting.

RESULTS

RIPC combined with nebulized BS significantly attenuated the LPS-induced ALI in rats. Reduction of MDA, increasing of SOD activity were found significantly improved by the joint strategy. TNF- and IL-1β rise brought on by LPS was reduced, but IL-10 production dramatically enhanced when compared to the LPS group. The expression of HO-1 was significantly increased by RIPC combined with nebulized BS while the expression of NF-κB p65 and p-p65 was decreased when compared with the LPS group.

CONCLUSION

RIPC combined with nebulized budesonide is protective for ALI induced by LPS in rats.

Higher dose corticosteroids in patients admitted to hospital with COVID-19 who are hypoxic but not requiring ventilatory support (RECOVERY): a randomised, controlled, open-label, platform trial

BACKGROUND

Low-dose corticosteroids have been shown to reduce mortality for patients with COVID-19 requiring oxygen or ventilatory support (non-invasive mechanical ventilation, invasive mechanical ventilation, or extracorporeal membrane oxygenation). We evaluated the use of a higher dose of corticosteroids in this patient group.

METHODS

This randomised, controlled, open-label platform trial (Randomised Evaluation of COVID-19 Therapy [RECOVERY]) is assessing multiple possible treatments in patients hospitalised for COVID-19. Eligible and consenting adult patients with clinical evidence of hypoxia (ie, receiving oxygen or with oxygen saturation <92% on room air) were randomly allocated (1:1) to either usual care with higher dose corticosteroids (dexamethasone 20 mg once daily for 5 days followed by 10 mg dexamethasone once daily for 5 days or until discharge if sooner) or usual standard of care alone (which included dexamethasone 6 mg once daily for 10 days or until discharge if sooner). The primary outcome was 28-day mortality among all randomised participants. On May 11, 2022, the independent data monitoring committee recommended stopping recruitment of patients receiving no oxygen or simple oxygen only due to safety concerns. We report the results for these participants only. Recruitment of patients receiving ventilatory support is ongoing. The RECOVERY trial is registered with ISRCTN (50189673) and ClinicalTrials.gov (NCT04381936).

FINDINGS

Between May 25, 2021, and May 13, 2022, 1272 patients with COVID-19 and hypoxia receiving no oxygen (eight [1%]) or simple oxygen only (1264 [99%]) were randomly allocated to receive usual care plus higher dose corticosteroids (659 patients) versus usual care alone (613 patients, of whom 87% received low-dose corticosteroids during the follow-up period). Of those randomly assigned, 745 (59%) were in Asia, 512 (40%) in the UK, and 15 (1%) in Africa. 248 (19%) had diabetes and 769 (60%) were male. Overall, 123 (19%) of 659 patients allocated to higher dose corticosteroids versus 75 (12%) of 613 patients allocated to usual care died within 28 days (rate ratio 1·59 [95% CI 1·20-2·10]; p=0·0012). There was also an excess of pneumonia reported to be due to non-COVID infection (64 cases [10%] vs 37 cases [6%]; absolute difference 3·7% [95% CI 0·7-6·6]) and an increase in hyperglycaemia requiring increased insulin dose (142 [22%] vs 87 [14%]; absolute difference 7·4% [95% CI 3·2-11·5]).

INTERPRETATION

In patients hospitalised for COVID-19 with clinical hypoxia who required either no oxygen or simple oxygen only, higher dose corticosteroids significantly increased the risk of death compared with usual care, which included low-dose corticosteroids. The RECOVERY trial continues to assess the effects of higher dose corticosteroids in patients hospitalised with COVID-19 who require non-invasive ventilation, invasive mechanical ventilation, or extracorporeal membrane oxygenation.

FUNDING

UK Research and Innovation (Medical Research Council), National Institute of Health and Care Research, and Wellcome Trust.

Exosomal Non-Coding RNAs: Novel Regulators of Macrophage-Linked Intercellular Communication in Lung Cancer and Inflammatory Lung Diseases

Macrophages are innate immune cells and often classified as M1 macrophages (pro-inflammatory states) and M2 macrophages (anti-inflammatory states). Exosomes are cell-derived nanovesicles that range in diameter from 30 to 150 nm. Non-coding RNAs (ncRNAs), including microRNAs (miRNAs), long noncoding RNAs (lncRNAs), and circular RNAs (circRNAs), are abundant in exosomes and exosomal ncRNAs influence immune responses. Exosomal ncRNAs control macrophage-linked intercellular communication via their targets or signaling pathways, which can play positive or negative roles in lung cancer and inflammatory lung disorders, including acute lung injury (ALI), asthma, and pulmonary fibrosis. In lung cancer, exosomal ncRNAs mediated intercellular communication between lung tumor cells and tumor-associated macrophages (TAMs), coordinating cancer proliferation, migration, invasion, metastasis, immune evasion, and therapy resistance. In inflammatory lung illnesses, exosomal ncRNAs mediate macrophage activation and inflammation to promote or inhibit lung damage. Furthermore, we also discussed the possible applications of exosomal ncRNA-based therapies for lung disorders.

Treatment of Acute Respiratory Distress Syndrome Caused by COVID-19 with Human Umbilical Cord Mesenchymal Stem Cells

This study aimed to identify the impact of mesenchymal stem cell transplantation on the safety and clinical outcomes of patients with severe COVID-19. This research focused on how lung functional status, miRNA, and cytokine levels changed following mesenchymal stem cell transplantation in patients with severe COVID-19 pneumonia and their correlation with fibrotic changes in the lung. This study involved 15 patients following conventional anti-viral treatment (Control group) and 13 patients after three consecutive doses of combined treatment with MSC transplantation (MCS group). ELISA was used to measure cytokine levels, real-time qPCR for miRNA expression, and lung computed tomography (CT) imaging to grade fibrosis. Data were collected on the day of patient admission (day 0) and on the 7th, 14th, and 28th days of follow-up. A lung CT assay was performed on weeks 2, 8, 24, and 48 after the beginning of hospitalization. The relationship between levels of biomarkers in peripheral blood and lung function parameters was investigated using correlation analysis. We confirmed that triple MSC transplantation in individuals with severe COVID-19 was safe and did not cause severe adverse reactions. The total score of lung CT between patients from the Control and MSC groups did not differ significantly on weeks 2, 8, and 24 after the beginning of hospitalization. However, on week 48, the CT total score was 12 times lower in patients in the MSC group (p ≤ 0.05) compared to the Control group. In the MSC group, this parameter gradually decreased from week 2 to week 48 of observation, whereas in the Control group, a significant drop was observed up to week 24 and remained unchanged afterward. In our study, MSC therapy improved lymphocyte recovery. The percentage of banded neutrophils in the MSC group was significantly lower in comparison with control patients on day 14. Inflammatory markers such as ESR and CRP decreased more rapidly in the MSC group in comparison to the Control group. The plasma levels of surfactant D, a marker of alveocyte type II damage, decreased after MSC transplantation for four weeks in contrast to patients in the Control group, in whom slight elevations were observed. We first showed that MSC transplantation in severe COVID-19 patients led to the elevation of the plasma levels of IP-10, MIP-1α, G-CSF, and IL-10. However, the plasma levels of inflammatory markers such as IL-6, MCP-1, and RAGE did not differ between groups. MSC transplantation had no impact on the relative expression levels of miR-146a, miR-27a, miR-126, miR-221, miR-21, miR-133, miR-92a-3p, miR-124, and miR-424. In vitro, UC-MSC exhibited an immunomodulatory impact on PBMC, increasing neutrophil activation, phagocytosis, and leukocyte movement, activating early T cell markers, and decreasing effector and senescent effector T cell maturation.

The β1 Adrenergic Blocker Nebivolol Ameliorates Development of Endotoxic Acute Lung Injury

Acute lung injury (ALI) is a disease, with no effective treatment, which might result in death. Formations of excessive inflammation and oxidative stress are responsible for the pathophysiology of ALI. Nebivolol (NBL), a third-generation selective β1 adrenoceptor antagonist, has protective pharmacological properties, such as anti-inflammatory, anti-apoptotic, and antioxidant functions. Consequently, we sought to assess the efficacy of NBL on a lipopolysaccharide (LPS)-induced ALI model via intercellular adhesion molecule-1 (ICAM-1) expression and the tissue inhibitor of metalloproteinases-1 (TIMP-1)/matrix metalloproteinases-2 (MMP-2) signaling. Thirty-two rats were split into four categories: control, LPS (5 mg/kg, intraperitoneally [IP], single dose), LPS (5 mg/kg, IP, one dosage 30 min after last NBL treatment), + NBL (10 mg/kg oral gavage for three days), and NBL (10 mg/kg oral gavage for three days). Six hours after the administration of LPS, the lung tissues of the rats were removed for histopathological, biochemical, gene expression, and immunohistochemical analyses. Oxidative stress markers such as total oxidant status and oxidative stress index levels, leukocyte transendothelial migration markers such as MMP-2, TIMP-1, and ICAM-1 expressions in the case of inflammation, and caspase-3 as an apoptotic marker, significantly increased in the LPS group. NBL therapy reversed all these changes. The results of this study suggest that NBL has utility as a potential therapeutic agent to dampen inflammation in other lung and tissue injury models.

Morita-Baylis-Hillman adduct 2-(3-hydroxy-2-oxoindolin-3-yl)acrylonitrile (ISACN) modulates the inflammatory process during LPS-induced acute lung injury

BACKGROUND

Despite its homeostatic role, inflammation is involved in several pathologies, such as acute lung injury. Morita-Ballys-Hilman adducts (MBHA) are a group of synthetic molecules and present a wide range of biological activities, including anti-inflammatory action. Thus, this study aimed to assess whether ISACN, an MBHA, modulates inflammation during acute lung injury induced by lipopolysaccharide (LPS).

METHODS

BALB/c mice were intraperitoneally treated with 24 mg/kg ISACN and challenged with LPS (2.5 mg/kg). On bronchoalveolar lavage fluid (BALF), we assessed the total and differential leukocyte count and measurement of protein leakage, cytokines (IL-1β, IL-6, and TNF-α), and chemokine (CXCL-1). Additionally, lung histopathology was also performed (H&E staining). In vitro studies were conducted with peritoneal macrophages to assess the possible mechanism of action. They were cultured in the presence of ISACN (5 and 10 µM) and stimulated by LPS (1 µg/mL).

RESULTS

ISACN reduced neutrophil migration, protein leakage, and inflammatory cytokines (IL-1β, IL-6, and TNF-α) without interfering with the production of CXCL1. In addition, ISACN caused a decrease in LPS-induced lung injury as evident from histopathological changes. In peritoneal macrophages, ISACN diminishes the nitric oxide and cytokine levels (IL-1β, IL-6, and TNF-α). The treatment with ISACN (10 μM) also reduced LPS-induced TLR4, CD69, iNOS overexpression, and the LPS-induced ERK, JNK, and p38 phosphorylation.

CONCLUSION

Thus, this work showed for the first time the immunomodulatory action of MBHA in LPS-induced acute lung injury and provided new evidence for the mechanisms related to the anti-inflammatory effect of ISACN.

[Prevalence and risk factors of delirium in COVID-19]

OBJECTIVE

To assess the frequency and risk factors of delirium in patients hospitalized with COVID-19.

MATERIAL AND METHODS

Four hundred and forty patients admitted to the Infectious Diseases Hospital of the University Clinical Hospital No.3 of Sechenov University were included in the study. The Patient Health Questionnaire (PHQ-9), the Generalized Anxiety Disorder Screening Questionnaire-7 (GAD-7), the Insomnia Severity Index (ISI), the Delirium severity rating scale (DRS-R-98) were administered.

RESULTS

Delirium was detected in 27.8% of patients. Significant risk factors were age (p=0.002), severity of respiratory failure (p=0.005), concomitant somatic disease (p=0.003), and respiratory therapy (p<0.001). There was an association between severe anxiety (p<0.001) and insomnia (p=0.07) observed at admission with the risk of developing delirium during the hospital stay.

CONCLUSION

The study reveals a high prevalence of delirium in patients with COVID-19. In order to prevent delirium and/or reduce the risk, early diagnosis and identification of preclinical forms are of particular importance.

Inhalation of L-arginine-modified liposomes targeting M1 macrophages to enhance curcumin therapeutic efficacy in ALI

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS), characterized by uncontrolled lung inflammation, is one of the most devastating diseases with high morbidity and mortality. As the first line of defense system, macrophages play a crucial role in the pathogenesis of ALI/ARDS. Therefore, it has great potential to selectively target M1 macrophages to improve the therapeutic effect of anti-inflammatory drugs. l-arginine plays a key role in regulating the immune function of macrophages. The receptors mediating l-arginine uptake are highly expressed on the surface of M1-type macrophages. In this study, we designed an l-arginine-modified liposome for aerosol inhalation to target M1 macrophages in the lung, and the anti-inflammatory drug curcumin was encapsulated in liposomes as model drug. Compared with unmodified curcumin liposome (Cur-Lip), l-arginine functionalized Cur-Lip (Arg-Cur-Lip) exhibited higher uptake by M1 macrophages in vitro and higher accumulation in inflamed lungs in vivo. Furthermore, Arg-Cur-Lip showed more potent therapeutic effects in LPS-induced RAW 264.7 cells and the rat model of ALI. Overall, these findings indicate that l-arginine-modified liposomes have great potential to enhance curcumin treatment of ALI/ARDS by targeting M1 macrophages, which may provide an option for the treatment of acute lung inflammatory diseases such as coronavirus disease 2019 (COVID-19), severe acute respiratory syndrome and middle east respiratory syndrome.

Effects of early dexamethasone treatment on several markers of inflammation and fibrosis in an animal model of lung silicosis in rats – A pilot study

Lung silicosis is primarily caused by inhalation of particles of silicon oxide (silica). Despite a huge progress in understanding the interactions among the pathomechanisms of lung silicosis in the last years, there is a lack of effective therapy. With respect to a wide therapeutic action of corticosteroids, the purpose of this pilot study was to evaluate early effects of dexamethasone on several markers of inflammation and lung fibrosis in a rat model of silicosis. The silicosis model was induced by a single transoral intratracheal instillation of silica (50 mg/ml/animal), while the controls received an equivalent volume of sterile saline. The treatment with intraperitoneal dexamethasone initiated the next day after the silica instillation and was given 2-times a week at a dose of 1 mg/kg, while the controls received an equivalent volume of saline. The animals were euthanized 14 or 28 days after the treatment onset. Total and differential counts of leukocytes in the blood and bronchoalveolar lavage (BAL) fluid were determined. The presence of collagen in the bronchioles and lung vessels was detected by Sirius red staining and a smooth muscle mass was detected by smooth muscle actin. In comparison to saline, the instillation of silica increased the total count of circulating leukocytes after 14 and 28 days of the experiment (both p<0.05), which was associated with higher counts of lymphocytes (p<0.05 after 14 days, p>0.05 after 28 days) and slight but non-significant increases in neutrophils and eosinophils (both p>0.05). Although the total cell count in the BAL fluid did not change significantly, the percentages and absolute counts of neutrophils, eosinophils, and lymphocytes (p<0.05, p<0.01 or p<0.001) elevated after 14 and 28 days of the experiment. Silica induced an accumulation of collagen in the bronchioles (p<0.001 after both 14 and 28 days) and pulmonary vessels (p<0.01 after both 14 and 28 days) and elevated a formation of smooth muscle mass (p<0.05 after 14 days, p<0.01 or p<0.001 after 28 days). Treatment with dexamethasone decreased circulating leukocytes (p<0.01) and lymphocytes (p<0.001) and increased neutrophils (p<0.05), which was associated with a slightly decreased total cell count in BAL (p>0.05), decline in lymphocytes (p<0.01), and slight decreases in neutrophils and eosinophils after 28 days of the treatment. Moreover, dexamethasone reduced the accumulation of collagen (p<0.01 after 14 days and p<0.001 after 28 days) and the formation of smooth muscle mass (p<0.01 for bronchioles and p>0.05 for vessels after 24 days, p<0.001 for both bronchioles and vessels after 28 days). In conclusion, early dexamethasone treatment mitigated silica-induced granulocytic-lymphocytic inflammation and decreased a formation of collagen and smooth muscle mass in the bronchiolar and vascular walls, demonstrating a therapeutic potential of dexamethasone in the lung silicosis.

Immunotherapy strategies and prospects for acute lung injury: Focus on immune cells and cytokines

Acute lung injury/acute respiratory distress syndrome (ALI/ARDS) is a disastrous condition, which can be caused by a wide range of diseases, such as pneumonia, sepsis, traumas, and the most recent, COVID-19. Even though we have gained an improved understanding of acute lung injury/acute respiratory distress syndrome pathogenesis and treatment mechanism, there is still no effective treatment for acute lung injury/acute respiratory distress syndrome, which is partly responsible for the unacceptable mortality rate. In the pathogenesis of acute lung injury, the inflammatory storm is the main pathological feature. More and more evidences show that immune cells and cytokines secreted by immune cells play an irreplaceable role in the pathogenesis of acute lung injury. Therefore, here we mainly reviewed the role of various immune cells in acute lung injury from the perspective of immunotherapy, and elaborated the crosstalk of immune cells and cytokines, aiming to provide novel ideas and targets for the treatment of acute lung injury.

Total terpenoids of Inula japonica activated the Nrf2 receptor to alleviate the inflammation and oxidative stress in LPS-induced acute lung injury

BACKGROUND

Acute lung injury (ALI) is a life-threatening lung disease and characterized by pulmonary edema and atelectasis. Inula japonica Thunb. is a commonly used traditional Chinese medicine for the treatment of lung diseases. However, the potential effect and mechanism of total terpenoids of I. japonica (TTIJ) on ALI remain obscure.

PURPOSE

This study focused on the protective effect of TTIJ on lipopolysaccharide (LPS)-induced ALI in mice and its potential mechanism.

STUDY DESIGN AND METHODS

A mouse model of ALI was established by intratracheal instillation of LPS to investigate the protective effect of TTIJ. RNA-seq and bioinformatics were then performed to reveal the underlying mechanism. Finally, western blot and real-time qPCR were used to verify the effects of TTIJ on the inflammation and oxidative stress.

RESULTS

TTIJ notably attenuated LPS-induced histopathological changes of lung. The RNA-seq result suggested that the protective effect of TTIJ on LPS-induced ALI were associated with the Toll-like receptor 4 (TLR4) and nuclear factor-erythroid 2-related factor 2 (Nrf2) signaling pathways. Pretreatment with TTIJ significantly reduced the inflammation and oxidative stress via regulating levels of pro-inflammatory and anti-oxidative cytokines, such as tumor necrosis factor-α (TNF-α), interleukin-6 (IL-6), superoxide dismutase (SOD), and glutathione (GSH), in LPS-induced ALI mice. TTIJ treatment could suppress the cyclooxygenase-2 (COX-2) expression level and the phosphorylation of p65, p38, ERK, and JNK through the inactivation of the MAPK/NF-κB signaling pathway in a TLR4-independent manner. Meanwhile, TTIJ treatment upregulated expression levels of proteins involved in the Nrf2 signaling pathway, such as heme oxygenase-1 (HO-1), NAD(P)H: quinoneoxidoreductase-1 (NQO-1), glutamate-cysteine ligase catalytic subunit (GCLC), and glutamate-cysteine ligase modifier subunit (GCLM), via activating the Nrf2 receptor, which was confirmed by the luciferase assay.

CONCLUSION

TTIJ could activate the Nrf2 receptor to alleviate the inflammatory response and oxidative stress in LPS-induced ALI mice, which suggested that TTIJ could serve as the potential agent in the treatment of ALI.

Extracellular vesicles in the pathogenesis and treatment of acute lung injury

Acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) are common life-threatening lung diseases associated with acute and severe inflammation. Both have high mortality rates, and despite decades of research on clinical ALI/ARDS, there are no effective therapeutic strategies. Disruption of alveolar-capillary barrier integrity or activation of inflammatory responses leads to lung inflammation and injury. Recently, studies on the role of extracellular vesicles (EVs) in regulating normal and pathophysiologic cell activities, including inflammation and injury responses, have attracted attention. Injured and dysfunctional cells often secrete EVs into serum or bronchoalveolar lavage fluid with altered cargoes, which can be used to diagnose and predict the development of ALI/ARDS. EVs secreted by mesenchymal stem cells can also attenuate inflammatory reactions associated with cell dysfunction and injury to preserve or restore cell function, and thereby promote cell proliferation and tissue regeneration. This review focuses on the roles of EVs in the pathogenesis of pulmonary inflammation, particularly ALI/ARDS.

Focus on long non-coding RNA MALAT1: Insights into acute and chronic lung diseases

Acute lung injury (ALI) is a pulmonary illness with a high burden of morbidity and mortality around the world. Chronic lung diseases also represent life-threatening situations. Metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) is a type of long non-coding RNA (lncRNA) and is highly abundant in lung tissues. MALAT1 can function as a competitive endogenous RNA (ceRNA) to impair the microRNA (miRNA) inhibition on targeted messenger RNAs (mRNAs). In this review, we summarized that MALAT1 mainly participates in pulmonary cell biology and lung inflammation. Therefore, MALAT1 can positively or negatively regulate ALI and chronic lung diseases (e.g., chronic obstructive pulmonary disease (COPD), bronchopulmonary dysplasia (BPD), pulmonary fibrosis, asthma, and pulmonary hypertension (PH)). Besides, we also found a MALAT1-miRNA-mRNA ceRNA regulatory network in acute and chronic lung diseases. Through this review, we hope to cast light on the regulatory mechanisms of MALAT1 in ALI and chronic lung disease and provide a promising approach for lung disease treatment.