Recent progress and prospects for anti-cytokine therapy in preclinical and clinical acute lung injury

Host-Directed Adjunctive Therapies in Immunocompromised Patients with Pneumonia

Immunocompromised (IC) hosts represent a unique patient population at risk for not only typical pathogens, but also opportunistic microorganisms. While antimicrobials remain the main treatment, new investigations have demonstrated the importance of host-response to pathogens. In this article, we highlight previously discovered and new areas of investigation for adjunctive host-response treatments for IC host pneumonia.

Plant-derived natural compounds for the treatment of acute lung injury: A systematic review of their anti-inflammatory effects in animal models

BACKGROUNDS AND AIMS

Acute lung injury (ALI) is a complex pulmonary disease characterized by a severe inflammatory response. The management of ALI presents a formidable challenge due to the intricate nature of its inflammatory cascade. Numerous studies have highlighted the potential therapeutic benefits of plant-derived natural compounds (PNCs) in treating inflammatory diseases. Our study aims to provide robust current evidence regarding the anti-inflammatory effects and underlying molecular mechanisms of PNCs for ALI treatment.

MATERIALS AND METHODS

The systematic review was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines, and the protocol was registered in PROSPERO (CRD42024468401). A comprehensive search was conducted in electronic databases including PubMed, Scopus, Web of Science, Embase, China National Knowledge Infrastructure (CNKI), Chinese Scientific Journal database (VIP), Wanfang database, and China biomedical literature service system (SinoMed) up until November 2023. Preclinical studies published in both English and Chinese were included.

RESULTS

Our research encompassed 81 studies, comprising a total of 71 PNCs, including flavonoids, phenylpropanoids, terpenoids, polyphenols, alkaloids, saponins, glycosides, and miscellaneous compounds. This systematic review demonstrated that PNCs played a beneficial role on ALI by regulating the immune response and reducing the release of inflammatory mediators and cytokines. The molecular mechanisms were partially associated with the regulation of Th17/Treg responses, promotion of the polarization of M1-type macrophages to M2-type macrophages, induction of immune cell apoptosis, reversal of microbial dysbiosis in the lungs and the gut, epigenetic modification, and the modulation of inflammatory pathways, including NF-κB, MAPK, TLR4/MyD88, NLRP3/Caspase-1, TGF-β/Smad, Nrf2/HO-1, Rho/ROCK, TLR7/MyD88, and PI3K/AKT, thereby alleviating inflammatory responses and lung damage.

CONCLUSION

The therapeutic effects of PNCs on ALI are mediated through the modulation of immunity and inflammatory pathways. In light of their potential, PNCs represent a promising pharmacological intervention for the treatment of ALI.

Dachengqi decoction dispensing granule ameliorates LPS-induced acute lung injury by inhibiting PANoptosis in vivo and in vitro

ETHNOPHARMACOLOGICAL RELEVANCE

Acute lung injury (ALI) is a serious health-threatening syndrome of intense inflammatory response in the lungs, with progression leading to acute respiratory distress syndrome (ARDS). Dachengqi decoction dispensing granule (DDG) has a pulmonary protective role, but its potential modulatory mechanism to alleviate ALI needs further excavation.

AIM OF THE STUDY

This study aims to investigate the effect and potential mechanism of DDG on lipopolysaccharide (LPS)-induced ALI models in vivo and in vitro.

MATERIALS AND METHODS

LPS-treated Balb/c mice and BEAS-2B cells were used to construct in vivo and in vitro ALI models, respectively. Hematoxylin-eosin (HE), Wet weight/Dry weight (W/D) calculation of lung tissue, and total protein and Lactic dehydrogenase (LDH) assays in BALF were performed to assess the extent of lung tissue injury and pulmonary edema. Enzyme-linked immunosorbent assay (ELISA) was used to detect the levels of tumor necrosis factor-alpha (TNF-α), interleukin-1β (IL-1β), and interleukin-18 (IL-18) in BALF, serum, and cell supernatant. The qRT-PCR was used to detect inflammatory factors, Z-DNA binding protein 1 (ZBP1), and receptor-interacting protein kinase 1 (RIPK1) expression in lung tissues and BEAS-2B cells. Double immunofluorescence staining and co-immunoprecipitation were used to detect the relative expression and co-localization of ZBP1 and RIPK1. The effects of LPS and DDG on BEAS-2B cell activity were detected by Cell Counting Kit-8 (CCK-8). Western blot (WB) was performed to analyze the expression of PANoptosis-related proteins in lung tissues and BEAS-2B cells.

RESULTS

In vivo, DDG pretreatment could dose-dependently improve the pathological changes of lung tissue in ALI mice, and reduce the W/D ratio of lung, total protein concentration, and LDH content in BALF. In vitro, DDG reversed the inhibitory effect of LPS on BEAS-2B cell viability. Meanwhile, DDG significantly reduced the levels of inflammatory factors in vitro and in vivo. In addition, DDG could inhibit the expression levels of PANoptosis-related proteins, especially the upstream key regulatory molecules ZBP1 and RIPK1.

CONCLUSION

DDG could inhibit excessive inflammation and PANoptosis to alleviate LPS-induced ALI, thus possessing good anti-inflammatory and lung-protective effects. This study establishes a theoretical basis for the further development of DDG and provides a new prospect for ALI treatment by targeting PANoptosis.

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.

Alpha B-crystallin Ameliorates Imbalance of Redox Homeostasis, Inflammation and Apoptosis in an Acute Lung Injury Model with Rats

Objective

Ischemia-reperfusion (IR) of the aorta is a significant contributor to the development of postoperative acute lung damage after abdominal aortic surgery. The aim of the present study was to examine the effect of alpha B-crystallin, a small heat shock protein (known as HspB5), on lung injury induced by abdominal aortic IR in rats.

Methods

Male Sprague-Dawley rats were divided into three groups: control, ischemia-reperfusion (IR, 90 min ischemia and 180 min reperfusion), and alpha B-crystallin +IR. Alpha B-crystallin (50 μg/100 g) was intraperitoneally administered 1 h before IR. Lung tissue samples were obtained for histological and biochemical analyses of oxidative stress and cytokine and apoptosis parameters in plasma, lung tissues, and bronchoalveolar lavage (BAL) fluid.

Results

The levels of malondialdehyde, reactive oxygen species, total oxidant status, tumor necrosis factor-alpha (TNF-α), interleukin-1 beta (IL-1β), nuclear factor kappa B (NFKβ), caspase-9 (CASP-9), 8-hydroxy-2'-deoxyguanosine, total antioxidant status, superoxide dismutase, and interleukin-10 levels in lung tissues, plasma, and BAL fluid (p<0.05 versus control) increased in Aortic IR. However, alpha B-crystallin significantly reduced the lung tissue levels of oxidative, inflamatuvar, and apoptotic parameters in the plasma, lung tissues, and BAL fluid (p<0.05 versus aortic IR). Histopathological results showed that alpha B-crystallin ameliorated the morphological changes related to lung injury (p<0.001).

Conclusion

Alpha B-crystallin substantially restored disrupted the redox balance, inflammation, and apoptotic parameters in rats exposed to IR. The cytoprotective effect of alpha B-crystallin on redox balance might be attributed to improved lung injury.

Deficiency and dysfunctional roles of natural killer T cells in patients with ARDS

Objective

Acute respiratory distress syndrome (ARDS) presents a global health challenge, characterized by significant morbidity and mortality. However, the role of natural killer T (NKT) cells in human ARDS remains poorly understood. Therefore, this study explored the numerical and functional status of NKT cells in patients with ARDS, examining their clinical relevance and interactions with macrophages and fibroblasts during various stages of the syndrome.

Methods

Peripheral blood from 40 ARDS patients and 30 healthy controls was analyzed, with paired samples of peripheral blood and bronchoalveolar lavage fluid (BALF) from seven ARDS patients. We measured levels of NKT cells, cytokines, CD69, programmed death-1 (PD-1), and annexin-V using flow cytometry, and extracellular matrix (ECM) protein expression using real-time PCR.

Results

ARDS patients exhibited decreased circulating NKT cells with elevated CD69 expression and enhanced IL-17 production. The reduction in NKT cells correlated with PaO2/FiO2 ratio, albumin, and C-reactive protein levels. Proliferative responses to α-galactosylceramide (α-GalCer) were impaired, and co-culturing NKT cells with monocytes or T cells from ARDS patients resulted in a reduced α-GalCer response. Increased and activated NKT cells in BALF induced proinflammatory cytokine release by macrophages and ECM protein expression in fibroblasts.

Conclusion

ARDS is associated with a numerical deficiency but functional activation of circulating NKT cells, showing impaired responses to α-GalCer and altered interactions with immune cells. The increase in NKT cells within BALF suggests their role in inducing inflammation and remodeling/fibrosis, highlighting the potential of targeting NKT cells as a therapeutic approach for ARDS.

Intratumoral Delivery of Genetically Engineered Anti-IL-6 Trans-signaling Therapeutics

Interleukin-6 (IL-6) is a highly pro-inflammatory cytokine involved in the etiopathology of several inflammatory diseases and cancer. As so, the inhibition of IL-6 signaling pathways has emerged as an attractive therapeutic avenue for the treatment of several chronic diseases. Since IL-6 trans-signaling was described as the pathological branch of IL-6, selective inhibitors were developed. Next-generation variants with increased trans-signaling specificity and potency emerged as great candidates for the treatment of several diseases, with reduced off-target effects. The highly time-consuming and costly processes involving recombinant protein production, however, have hampered the progress of anti-cytokine pharmaceuticals in clinic so far. Herein, we developed gene therapeutic modalities of IL-6-trans-signaling inhibitors as alternatives for sustained recombinant protein secretion. By using an IL-6-dependent lymphoma cell line and xenograft tumor model, we demonstrated the superior inhibitory potential of second-generation anti-IL-6 trans-signaling therapeutic. We compared the efficiency of distinct gene delivery modalities using a bioluminescent biomarker probe and observed consistent protein production via cell-based delivery. When delivered intratumorally, genetically engineered sgp130FlyRFc-secreting cells significantly reduced tumor burden and increased animal survival, representing a promising therapeutic avenue to be explored in clinically relevant gene delivery applications.

A narrative review of chemokine receptors CXCR1 and CXCR2 and their role in acute respiratory distress syndrome

Acute respiratory distress syndrome (ARDS) is a severe form of acute respiratory failure characterised by extensive inflammatory injury to the alveolocapillary barrier leading to alveolar oedema, impaired gas exchange and, ultimately, hypoxaemia necessitating the use of supplemental oxygen combined with some degree of positive airway pressure. Although much heterogeneity exists regarding the aetiology, localisation and endotypic characterisation of ARDS, what remains largely undisputed is the role of the innate immune system, and in particular of neutrophils, in precipitating and propagating lung injury. Activated neutrophils, recruited to the lung through chemokine gradients, promote injury by releasing oxidants, proteases and neutrophil extracellular traps, which ultimately cause platelet aggregation, microvascular thrombosis and cellular death. Among various neutrophilic chemoattractants, interleukin-8/C-X-C motif ligand 8 and related chemokines, collectively called ELR+ chemokines, acting on neutrophils through the G protein-coupled receptors CXCR1 and CXCR2, are pivotal in orchestrating the neutrophil activation status and chemotaxis in the inflamed lung. This allows efficient elimination of infectious agents while at the same time minimising collateral damage to host tissue. Therefore, understanding how CXCR1 and CXCR2 receptors are regulated is important if we hope to effectively target them for therapeutic use in ARDS. In the following narrative review, we provide an overview of the role of ELR+ chemokines in acute lung injury (ALI) and ARDS, we summarise the relevant regulatory pathways of their cognisant receptors CXCR1/2 and highlight current preclinical and clinical evidence on the therapeutic role of CXCR1 and CXCR2 inhibition in animal models of ALI, as well as in ARDS patients.

TM9SF1 offers utility as an efficient predictor of clinical severity and mortality among acute respiratory distress syndrome patients

Introduction

Acute respiratory distress syndrome (ARDS) is a major cause of death among critically ill patients in intensive care settings, underscoring the need to identify biomarkers capable of predicting ARDS patient clinical status and prognosis at an early time point. This study specifically sought to explore the utility and clinical relevance of TM9SF1 as a biomarker for the early prediction of disease severity and prognostic outcomes in patients with ARDS.

Methods

This study enrolled 123 patients with severe ARDS and 116 patients with non-severe ARDS for whom follow-up information was available. The mRNA levels of TM9SF1 and cytokines in peripheral blood mononuclear cells from these patients were evaluated by qPCR. The predictive performance of TM9SF1 and other clinical indicators was evaluated using received operating characteristic (ROC) curves. A predictive nomogram was developed based on TM9SF1 expression and evaluated for its ability in the early prediction of severe disease and mortality in patients with ARDS.

Results

TM9SF1 mRNA expression was found to be significantly increased in patients with severe ARDS relative to those with non-severe disease or healthy controls. ARDS severity increased in correspondence with the level of TM9SF1 expression (odds ratio [OR] = 2.43, 95% confidence interval [CI] = 2.15-3.72, P = 0.005), and high TM9SF1 levels were associated with a greater risk of mortality (hazard ratio [HR] = 2.27, 95% CI = 2.20-4.39, P = 0.001). ROC curves demonstrated that relative to other clinical indicators, TM9SF1 offered superior performance in the prediction of ARDS severity and mortality. A novel nomogram incorporating TM9SF1 expression together with age, D-dimer levels, and C-reactive protein (CRP) levels was developed and was used to predict ARDS severity (AUC = 0.887, 95% CI = 0.715-0.943). A separate model incorporating TM9SF1 expression, age, neutrophil-lymphocyte ratio (NLR), and D-dimer levels (C-index = 0.890, 95% CI = 0.627-0.957) was also developed for predicting mortality.

Conclusion

Increases in ARDS severity and patient mortality were observed with rising levels of TM9SF1 expression. TM9SF1 may thus offer utility as a novel biomarker for the early prediction of ARDS patient disease status and clinical outcomes.

Evaluation of interleukin-1 and interleukin-6 receptor antagonists in a murine model of acute lung injury

The acute exudative phase of acute respiratory distress syndrome (ARDS), a severe form of respiratory failure, is characterized by alveolar damage, pulmonary oedema, and an exacerbated inflammatory response. There is no effective treatment for this condition, but based on the major contribution of inflammation, anti-inflammatory strategies have been evaluated in animal models and clinical trials, with conflicting results. In COVID-19 ARDS patients, interleukin (IL)-1 and IL-6 receptor antagonists (IL-1Ra and IL-6Ra, kineret and tocilizumab, respectively) have shown some efficacy. Moreover, we have previously developed novel peptides modulating IL-1R and IL-6R activity (rytvela and HSJ633, respectively) while preserving immune vigilance and cytoprotective pathways. We aimed to assess the efficacy of these novel IL-1Ra and IL-6Ra, compared to commercially available drugs (kineret, tocilizumab) during the exudative phase (day 7) of bleomycin-induced acute lung injury (ALI) in mice. Our results first showed that none of the IL-1Ra and IL-6Ra compounds attenuated bleomycin-induced weight loss and venousP C O 2 ${P_{{\mathrm{C}}{{\mathrm{O}}_{\mathrm{2}}}}}$ increase. Histological analyses and lung water content measurements also showed that these drugs did not improve lung injury scores or pulmonary oedema, after the bleomycin challenge. Finally, IL-1Ra and IL-6Ra failed to alleviate the inflammatory status of the mice, as indicated by cytokine levels and alveolar neutrophil infiltration. Altogether, these results indicate a lack of beneficial effects of IL-1R and IL-6R antagonists on key parameters of ALI in the bleomycin mouse model.