Kindlin-2 Mediates Lipopolysaccharide-Induced Acute Lung Injury Partially via Pyroptosis in Mice

miRNA-206-3p alleviates LPS-induced acute lung injury via inhibiting inflammation and pyroptosis through modulating TLR4/NF-κB/NLRP3 pathway

Acute lung injury (ALI) is life-threatening. MicroRNAs (miRNAs) are often abnormally expressed in inflammatory diseases and are closely associated with ALI. This study investigates whether miRNA-206-3p attenuates pyroptosis in ALI and elucidates the underlying molecular mechanisms. ALI mouse and cell models were established through lipopolysaccharide (LPS) treatment for 24 h. Subsequently, the models were evaluated based on ultrasonography, the lung tissue wet/dry (W/D) ratio, pathological section assessment, electron microscopy, and western blotting. Pyroptosis in RAW264.7 cells was then assessed via electron microscopy, immunofluorescence, and western blotting. Additionally, the regulatory relationship between miRNA-206-3p and the Toll-like receptor (TLR)4/nuclear factor (NF)-κB/Nod-like receptor protein-3 (NLRP3) pathway was verified. Finally, luciferase reporter gene and RNA pull-down assays were used to verify the targeting relationship between miRNA-206-3p and TLR4. miRNA206-3p levels are significantly decreased in the LPS-induced ALI model. Overexpression of miRNA-206-3p improves ALI, manifested as improved lung ultrasound, improved pathological changes of lung tissue, reduced W/D ratio of lung tissue, release of inflammatory factors in lung tissue, and reduced pyroptosis. Furthermore, overexpression of miRNA-206-3p contributed to reversing the ALI-promoting effect of LPS by hindering TLR4, myeloid differentiation primary response 88 (MyD88), NF-κB, and NLRP3 expression. In fact, miRNA-206-3p binds directly to TLR4. In conclusion, miRNA-206-3p alleviates LPS-induced ALI by inhibiting inflammation and pyroptosis via TLR4/NF-κB/NLRP3 pathway modulation.

Therapeutic potential of curcumin in ARDS and COVID-19

Curcumin is a safe, non-toxic, readily available and naturally occurring compound, an active constituent of Curcuma longa (turmeric). Curcumin could potentially treat diseases, but faces poor physicochemical and pharmacological characteristics. To overcome these limitations, we developed a stable, water-soluble formulation of curcumin called cyclodextrin-complexed curcumin (CDC). We have previously shown that direct delivery of CDC to the lung following lipopolysaccharides exposure reduces acute lung injury (ALI) and effectively reduces lung injury, inflammation and mortality in mice following Klebsiella pneumoniae. Recently, we found that administration of CDC led to a significant reduction in angiotensin-converting enzyme 2 and signal transducer and activator of transcription 3 expression in gene and protein levels following pneumonia, indicating its potential in treating coronavirus disease 2019 (COVID-19). In this review, we consider the clinical features of ALI and acute respiratory distress syndrome (ARDS) and the role of curcumin in modulating the pathogenesis of bacterial/viral-induced ARDS and COVID-19.

Acadesine alleviates acute pancreatitis-related lung injury by mediating the barrier protective function of pulmonary microvascular endothelial cells

Severe acute pancreatitis (SAP) is a condition characterized by highly fatal acute inflammation and is usually associated with multiple organ dysfunction syndrome. Acute lung injury (ALI) is the most common complications of SAP, which is the accelerator of other organ dysfunction caused by SAP and the primary cause of early death due to SAP. Acadesine, an adenosine analog and an AMPK activator, has been discovered to modulate glucose and lipid metabolism, and inhibit the production of pro-inflammatory cytokines and iNOS. However, its role in SAP-ALI and its mechanism remains unclear and need to be explored. Herein, we discovered that acadesine mitigated the generation of reactive oxygen species (ROS) in human pulmonary microvascular endothelial cells (HPMECs), alleviated apoptosis and recovered barrier integrity, thereby contributing to anti-inflammatory effects in vitro and in vivo. Moreover, Nrf2 deficiency partially eliminated the effects of acadesine-induced antioxidant effects and thus weakened the protective effects on cells and Nrf2-knockout (Nrf2^-/-) mice. This study demonstrates that acadesine attenuated SAP-ALI associated inflammation and tissue damage by modulating the Nrf2-dependent antioxidant pathway by triggering AMPK. These findings are of great significance for the treatment of SAP-related lung injury.