Circ-BICC1 Knockdown Alleviates Lipopolysaccharide (LPS)-Induced WI-38 Cell Injury Through miR-338-3p/MYD88 Axis.

Circular RNAs (circRNAs) play important roles in human diseases, including infantile pneumonia. In this article, we aimed to investigate the functions of circ-BICC1 in lipopolysaccharide (LPS)-induced injury of WI-38 cells. Quantitative real-time polymerase chain reaction (qRT-PCR) assay was performed for the levels of circ-BICC1, BICC1, microRNA-338-3p (miR-338-3p), and myeloid differentiation primary response 88 (MYD88). Cell Counting Kit-8 (CCK-8) assay, 5-ethynyl-2'-deoxyuridine (EdU) assay, and flow cytometry analysis were conducted to evaluate cell viability, proliferation, and apoptosis, respectively. Enzyme-linked immunosorbent assay (ELISA) kits were used for the concentrations of interleukin-1β (IL-1β) and tumor necrosis factor-α (TNF-α). The levels of oxidative stress markers were detected with commercial kits. Dual-luciferase reporter assay was adopted to analyze the interaction between circ-BICC1 and miR-338-3p, as well as MYD88 and miR-338-3p. Western blot assay was employed for the protein level of MYD88. Circ-BICC1 level was increased in pneumonia patients' blood samples and LPS-treated WI-38 cells. LPS treatment suppressed WI-38 cell viability and promoted cell apoptosis, inflammation, and oxidative stress. Circ-BICC1 knockdown reversed the effect of LPS-induced WI-38 cell injury. For mechanism analysis, circ-BICC1 could function as the sponge for miR-338-3p and miR-338-3p inhibition reversed the effect of circ-BICC1 knockdown on LPS-induced WI-38 cell injury. MYD88 was identified as the target of miR-338-3p. MiR-338-3p overexpression relieved LPS-induced injury of WI-38 cells, while the impact was abolished by elevating MYD88. Circ-BICC1 silencing remitted LPS-triggered WI-38 cell damage by adsorbing miR-338-3p and regulating MYD88.

Wang J ，Li G ，Lin S ，Cheng L ... -  《-》

Circ-BNIP3L knockdown alleviates LPS-induced renal tubular epithelial cell injury during sepsis-associated acute kidney injury by miR-370-3p/MYD88 axis.

Sepsis-associated acute kidney injury (SA-AKI) is a frequent complication of the critically ill patient with high morbidity and mortality. Thus, the goal of this study was to investigate the role of circular RNA BCL2 Interacting Protein 3 Like (circ-BNIP3L) in the pathophysiological mechanism of SA-AKI. The SA-AKI cell model was established by using lipopolysaccharide (LPS)-induced HK-2 cells in vitro. Cell survival was analyzed using cell counting kit-8 (CCK-8) assay, EdU (5-ethynyl-2'-deoxyuridine) assay, flow cytometry and Western blot, respectively. Levels of tumor necrosis factor-α (TNF-α) and interleukin-1β (IL-1β) were detected using ELISA analysis. The superoxide dismutase (SOD) activity and malondialdehyde (MDA) level were examined using commercial kits. Levels of genes and proteins were detected by qRT-PCR and Western blot. Dual-luciferase reporter and RNA immunoprecipitation (RIP) assays were used to identify the target relationship between miR-370-3p and circ-BNIP3L or MYD88 (myeloid differentiation primary response 88). Circ-BNIP3L was highly expressed in SA-AKI patients and LPS-induced HK-2 cells. Silencing of circ-BNIP3L attenuated LPS-induced growth inhibition, inflammation, and oxidative stress in HK-2 cells. Mechanistically, circ-BNIP3L competitively bound to miR-370-3p to up-regulate the expression of its target MYD88. Moreover, miR-370-3p inhibition reversed the beneficial effects of circ-BNIP3L knockdown on LPS-stimulated HK-2 cells. Meanwhile, miR-370-3p overexpression abolished LPS-induced injury in HK-2 cells, which was counteracted by MYD88 up-regulation. Circ-BNIP3L knockdown alleviated LPS-induced renal tubular epithelial cell injury by miR-370-3p/MYD88 axis, opening up a completely new avenue for the treatment of sepsis-associated AKI.

Zhou Y ，Qing M ，Xu M 《-》

Downregulation of circ_0035292 Alleviates LPS-Induced WI-38 Cell Injury via Targeting miR-494-3p/TLR4 Pathway in Infantile Pneumonia.

Circular RNAs (circRNAs) have been confirmed to mediate infantile pneumonia development. In this, we investigated the role and new mechanism of circ_0035292 regulating infantile pneumonia progression. Lipopolysaccharide (LPS)-treated WI-38 cells were used to mimic infantile pneumonia cell injury models. Quantitative real-time PCR was used to measure circ_0035292, microRNA (miR)-494-3p and toll-like receptor 4 (TLR4). Cell proliferation and apoptosis were assessed by MTT assay, EdU assay, and flow cytometry. Protein expression was tested using western blot analysis. Inflammation and oxidative stress were evaluated by measuring IL-6, IL-1β, MDA and SOD levels using ELISA assay and corresponding kits. RNA interaction was confirmed by dual-luciferase reporter assay and RIP assay. Circ_0035292 had elevated expression in infantile pneumonia patients and LPS-induced WI-38 cells. Silenced circ_0035292 could enhance WI-38 cell proliferation, while suppress apoptosis, inflammation and oxidative stress under LPS treatment. Mechanically, circ_0035292 targeted miR-494-3p to positively regulate TLR4. The rescue experiments indicated that miR-494-3p inhibitor abolished the function of circ_0035292 knockdown, and TLR4 overexpression reversed the inhibitory effect of miR-494-3p on LPS-induced WI-38 cell injury. Circ_0035292 might be a potential target for infantile pneumonia treatment, which knockdown could relieve LPS-induced cell injury via the regulation of miR-494-3p/TLR4 axis.

Dai Z ，Hu J ，Luo Z ，Xiao J ... -  《-》

Circ_0035292 knockdown alleviates lipopolysaccharide (LPS)-induced WI-38 cell apoptosis and inflammatory injury.

Circular RNAs have emerged as important regulators in the pathogenesis of human diseases, including infantile pneumonia (IP). In this study, we aimed to explore the effects of circ_0035292 on lipopolysaccharide (LPS)-treated Wistsar Institute (WI)-38 cells. Quantitative real-time polymerase chain reaction and western blot were executed to detect the levels of circ_0035292, microRNA-370-3p (miR-370-3p) and transducin β-like 1X related protein 1 (TBL1XR1). Cell counting kit-8, 5-ethynyl-2'-deoxyuridine, and flow cytometry assessed cell proliferation and apoptosis. Concentrations of inflammatory factors were examined with enzyme linked immunosorbent assay kits. Dual-luciferase reporter assay and RNA immunoprecipitation were adopted to analyze binding between miR-370-3p and circ_0035292 or TBL1XR1. Circ_0035292 level was increased in IP patients and LPS-triggered WI-38 cells. Circ_0035292 knockdown rescued LPS-mediated WI-38 cell proliferation suppression and WI-38 cell apoptosis and inflammation promotion. Circ_0035292 interacted with miR-370-3p and miR-370-3p directly targeted TBL1XR1. Moreover, miR-370-3p overexpression alleviated LPS-induced WI-38 cell apoptosis and inflammatory injury, which was abrogated via TBL1XR1 upregulation. Circ_0035292 absence inhibited the NF-κB pathway. Knockdown of circ_0035292 rescued LPS-triggered WI-38 cell injury via miR-370-3p/TBL1XR1 axis and NF-κB pathway.

Guo Y ，Li Z ，Cheng C 《Immunity Inflammation and Disease》

Knockdown of circ_0038467 alleviates lipopolysaccharides-induced 16HBE cell injury by regulating the miR-545-3p/TRAF1 axis in neonatal pneumonia.

Neonatal pneumonia is a common illness in the neonatal period with a high fatality rate. Accumulating proofs have attested to the crucial role of circular RNAs (circRNAs) in pneumonia. This study was intended to expound on the function of circ_0038467 and the underlying mechanism in lipopolysaccharide (LPS)-stimulated 16HBE cell injury in neonatal pneumonia. 16HBE cells were exposed to LPS to establish an in vitro neonatal pneumonia cell model. Quantitative real-time polymerase chain reaction (qRT-PCR) was implemented for detecting the levels of circ_0038467, microRNA-545-3p (miR-545-3p), and tumor necrosis factor receptor-associated factor 1 (TRAF1) in neonatal pneumonia serums and LPS-treated 16HBE cells. Cell Counting Kit-8 (CCK-8), 5-ethynyl-2'-deoxyuridine (EdU) incorporation, and flow cytometry assays were used to examine cell viability, proliferation, and apoptosis, respectively. The protein abundances of proliferation/apoptosis/inflammation-correlated makers and TRAF1 were tested by Western blot. RNase R and Actinomycin D assays were implemented to determine the features of circ_0038467. The mutual effect between miR-545-3p and circ_0038467 or TRAF1 was affirmed by a dual-luciferase reporter and RNA pull-down assay assays. Circ_0038467 was upregulated in neonatal pneumonia serum specimens and LPS-triggered 16HBE cells. LPS administration restrained 16HBE cell proliferation and promoted apoptosis and inflammation, whereas circ_0038467 silence recovered these influences. Meanwhile, miR-545-3p was targeted by circ_0038467, and circ_0038467 could modulate LPS-treated 16HBE cell injury through absorbing miR-545-3p. Furthermore, circ_0038467 controlled TRAF1 level via segregating miR-545-3p. Moreover, TRAF1 overexpression relieved the suppressive impact of circ_0038467 silence in LPS-triggered 16HBE cell detriment. Circ_0038467 knockdown mitigated LPS-exposed 16HBE cell damage through regulating miR-545-3p/PPARA axis.

Xia F ，Yang L ，Zhu X 《-》