LncRNA analysis of lung tissues after hUC-MSCs and FTY720 treatment of lipopolysaccharide-induced acute lung injury in mouse models

The role of lncRNAs in sepsis-induced acute lung injury: Molecular mechanisms and therapeutic potential

Sepsis, a life-threatening syndrome, results from a dysregulated immune and hemostatic response, contributing to acute lung injury (ALI) and its progression into acute respiratory distress syndrome (ARDS). The development of septic ALI is complex, involving excessive inflammatory mediator production that damages endothelial and epithelial cells, leading to vascular leakage, edema, and vasodilation-key factors in ALI pathogenesis. Long noncoding RNAs (lncRNAs), over 200 nucleotides in length, play critical roles in various biological processes, including sepsis regulation. They exhibit both promotive and inhibitory effects, influencing sepsis progression and resolution. Despite their significance, comprehensive reviews detailing lncRNA involvement in sepsis-induced ALI remain limited. This review aims to address this gap by summarizing the diverse functions of lncRNAs in septic ALI, emphasizing their potential in diagnosis and treatment. Furthermore, we will explore the molecular mechanisms underlying lncRNA involvement, particularly their miRNA-dependent regulatory pathways. Understanding these interactions may provide novel insights into therapeutic strategies for sepsis-induced ALI.

Long Noncoding RNA: A Novel Insight into the Pathogenesis of Acute Lung Injury

Acute lung injury (ALI) and its severe form, acute respiratory distress syndrome (ARDS), represent an acute stage of lung inflammation where the alveolar epithelium loses its functionality. ALI has a devastating impact on the population as it not only has a high rate of incidence, but also has high rates of morbidity and mortality. Due to the involvement of multiple factors, the pathogenesis of ALI is complex and is not fully understood yet. Long noncoding RNAs (lncRNAs) are a group of non-protein-coding transcripts longer than 200 nucleotides. Growing evidence has shown that lncRNAs have a decisive role in the pathogenesis of ALI. LncRNAs can either promote or hinder the development of ALI in various cell types in the lungs. Mechanistically, current studies have found that lncRNAs play crucial roles in the pathogenesis of ALI via the regulation of small RNAs (e.g., microRNAs) or downstream proteins. Undoubtedly, lncRNAs not only have the potential to reveal the underlying mechanisms of ALI pathogenesis but also serve as diagnostic and therapeutic targets for the therapy of ALI.

Piper Kadsura Extract Inhibits miR-155 to Protect Lipopolysaccharide-Induced Acute Lung Injury

Acute lung injury (ALI) is a common and critical disease encountered in clinical practice. When the disease progresses to a more serious stage, it is called acute respiratory distress syndrome and is associated with a high mortality rate. However, there is a lack of specific drugs for treating this disease; therefore, it is very important to find safe and effective drugs for treatment. Piper kadsura (P. kadsura), part of the of the vin family Piperaceae, has a capability to dispel wind and dampness and its n-butanol extract can provide protection against inflammatory responses, such as inflammatory infiltration and hyperplasia of synovial tissue of joints. In order to explore the therapeutic effect of P. kadsura extract on ALI, we treated HPAEpiC cells with different doses of its extract. We found that after treatment using low-medium and high-dose P. kadsura extract, the optical density value was decreased in HPAEpiC cells as induced by lipopolysaccharide (LPS). In addition, the following were statistically and significantly decreased in a dose-dependent (P < 0.05): the apoptosis rate, cleaved-caspase3 expression, the expression levels of TNF-α, IL-6, and miR-155. However, procaspase 3 increased the expression of miR-155, which can promote LPS-induced apoptosis and the release of inflammatory factors in HPAEpiC cells. The overexpressed miR-155 can weaken the protection conferred by P. kadsura extract on ALI. These results suggest that P. kadsura extract may play a protective role against ALI induced by LPS by decreasing the expression of miR-155.

The effect of FTY720 at different doses and time-points on LPS-induced acute lung injury in rats

We sought to assess the protective effect of different doses of Fingolimod (FTY720) in a rat model of acute lung injury (ALI) induced by intratracheal instillation of lipopolysaccharide (LPS) and explored the underlying mechanisms. The ALI model was established in rats and different doses of FTY720 (0.1 mg/kg, 0.2 mg/kg, 0.5 mg/kg, 1 mg/kg, or 2 mg/kg) were injected intraperitoneally. Lung computed tomography and blood gas analyses were performed at 6 h, 24 h, and 48 h after intraperitoneal injection, and the lung tissues were extracted to prepare paraffin sections for histopathological examination. The levels of inflammatory cytokines (TNF-α, IL-6, and IL-1β) were detected by ELISA, and the expressions of inflammatory pathway proteins in each group were measured by Western blot analysis. A single intraperitoneal injection of FTY720 inhibited LPS-induced NF-κB activation, reduced the level of inflammatory cytokines, and decreased the infiltration of inflammatory cells. Moreover, it alleviated lung tissue injury, as shown by marked attenuation of pulmonary oedema and improved arterial partial pressure of oxygen (PaO₂) and the general condition of ALI rats. In conclusion, our results demonstrate the protective effect of FTY720 against LPS-induced ALI. The underlying mechanism of the protective effect may involve inhibition of LPS-induced activation of NF-κB and regulation of the inflammatory pathway to alleviate barrier dysfunction of alveolar capillaries.

Long non-coding RNA review and implications in acute lung inflammation

Acute lung inflammatory diseases severely affect the patients' recovery and outcomes worldwide. Unregulated acute inflammatory response is fundamentally central to acute lung inflammation including acute lung injury (ALI) and acute respiratory distress syndrome (ARDS). To limit the potentially deleterious effects of acute lung inflammation, complex transcriptional and posttranscriptional regulatory networks have been explored, which often involves long noncoding RNAs (lncRNA). LncRNAs are RNAs that longer than 200 nucleotides, functioning as scaffolds or decoys in the cytoplasm or nucleus. By now, lncRNAs have been found to join in all major cellular processes including cell proliferation, metabolism, stress response or death. Extensive advance over the last decade furthermore indicated a fundamental role of lncRNAs in acute lung inflammation. This article reviews and summarizes the current knowledge on lncRNA in acute lung inflammatory response.

Silencing of long non-coding RNA MEG3 alleviates lipopolysaccharide-induced acute lung injury by acting as a molecular sponge of microRNA-7b to modulate NLRP3

We aimed to elucidate the roles of the long non-coding RNA (lncRNA) maternally expressed gene 3 (MEG3)/microRNA-7b (miR-7b)/NLR pyrin domain containing 3 (NLRP3) axis in lipopolysaccharide (LPS)-induced acute lung injury (ALI). Mouse alveolar macrophage NR8383 and mice were administrated with LPS to establish ALI models in vitro and in vivo. NLRP3 was silenced while miR-7b was overexpressed in LPS-induced NR8383 cell model of ALI. The interleukin-18 (IL-18) and IL-1β, as well as caspase-1, tumor necrosis factor-α (TNF-α) and IL-6 protein levels were assayed. To further investigate the underlying mechanisms of NLRP3 in ALI, lncRNA MEG3 was silenced and miR-7b was overexpressed in LPS-induced NR8383 cell model of ALI, after which in vivo experiments were performed for further verification. NLRP3 was highly expressed in LPS-induced NR8383 cell model of ALI. Silencing NLRP3 or overexpressing miR-7b inhibited IL-18 and IL-1β, as well as caspase-1, TNF-α and IL-6. LncRNA MEG3 could sponge miR-7b, and lncRNA MEG3 silencing or miR-7b overexpression downregulates NLRP3 expression, thus reducing IL-18 and IL-1β, as well as caspase-1, TNF-α and IL-6 levels. The in vivo experiments further confirmed the aforementioned findings. Silencing lncRNA MEG3 augments miR-7b binding to NLRP3 and downregulates NLRP3 expression, which ultimately improves LPS-induced ALI.

Risiken und Chancen von Immuntherapien in Zeiten der Coronavirus-2019-Pandemie

Immuntherapien stellen die essenzielle Grundlage der Behandlung von neuroinflammatorischen Erkrankungen dar. In Zeiten der Coronavirus-2019 (COVID-19)-Pandemie ergibt sich im klinischen Alltag jedoch zunehmend die Frage, ob eine Immuntherapie bei neurologischen Patienten aufgrund des potenziellen Infektionsrisikos eingeleitet, intensiviert, pausiert oder gar beendet werden sollte. Unsicherheit besteht v. a. deshalb, weil verschiedene nationale und internationale Fachgesellschaften diesbezüglich unterschiedliche Empfehlungen veröffentlichten. In diesem Artikel soll ein Überblick über die Wirkmechanismen von Immuntherapien und den daraus abzuleitenden Infektionsrisiken in Bezug auf COVID-19 (durch den Coronavirus verursachte Erkrankung) gegeben werden. Potenzielle Chancen und vorteilhafte Effekte einzelner Substrate in der Akuttherapie von COVID-19 werden diskutiert.