miR-21 Exerts Anti-proliferative and Pro-apoptotic Effects in LPS-induced WI-38 Cells via Directly Targeting TIMP3

MiR-21-5p modulates LPS-induced acute injury in alveolar epithelial cells by targeting SLC16A10

Sepsis is a systemic inflammatory response syndrome resulting from the invasion of the human body by bacteria and other pathogenic microorganisms. One of its most prevalent complications is acute lung injury, which places a significant medical burden on numerous countries and regions due to its high morbidity and mortality rates. MicroRNA (miRNA) plays a critical role in the body's inflammatory response and immune regulation. Recent studies have focused on miR-21-5p in the context of acute lung injury, but its role appears to vary in different models of this condition. In the LPS-induced acute injury model of A549 cells, there is differential expression, but the specific mechanism remains unclear. Therefore, our aim is to investigate the changes in the expression of miR-21-5p and SLC16A10 in a type II alveolar epithelial cell injury model induced by LPS and explore the therapeutic effects of their targeted regulation. A549 cells were directly stimulated with 10 µg/ml of LPS to construct a model of LPS-induced cell injury. Cells were collected at different time points and the expression of interleukin 1 beta (IL-1β), tumor necrosis factor-α (TNF-α) and miR-21-5p were measured by RT-qPCR and western blot. Then miR-21-5p mimic transfection was used to up-regulate the expression of miR-21-5p in A549 cells and the expression of IL-1β and TNF-α in each group of cells was measured by RT-qPCR and western blot. The miRDB, TargetScan, miRWalk, Starbase, Tarbase and miR Tarbase databases were used to predict the miR-21-5p target genes and simultaneously, the DisGeNet database was used to search the sepsis-related gene groups. The intersection of the two groups was taken as the core gene. Luciferase reporter assay further verified SLC16A10 as the core gene with miR-21-5p. The expression of miR-21-5p and SLC16A10 were regulated by transfection or inhibitors in A549 cells with or without LPS stimulation. And then the expression of IL-1β and TNF-α in A549 cells was tested by RT-qPCR and western blot in different groups, clarifying the role of miR-21-5p-SLC16A10 axis in LPS-induced inflammatory injury in A549 cells. (1) IL-1β and TNF-α mRNA and protein expression significantly increased at 6, 12, and 24 h after LPS stimulation as well as the miR-21-5p expression compared with the control group (P < 0.05). (2) After overexpression of miR-21-5p in A549 cells, the expression of IL-1β and TNF-α was significantly reduced after LPS stimulation, suggesting that miR-21-5p has a protection against LPS-induced injury. (3) The core gene set, comprising 51 target genes of miR-21-5p intersecting with the 1448 sepsis-related genes, was identified. This set includes SLC16A10, TNPO1, STAT3, PIK3R1, and FASLG. Following a literature review, SLC16A10 was selected as the ultimate target gene. Dual luciferase assay results confirmed that SLC16A10 is indeed a target gene of miR-21-5p. (4) Knocking down SLC16A10 expression by siRNA significantly reduced the expression of IL-1β and TNF-α in A549 cells after LPS treatment (P < 0.05). (5) miR-21-5p inhibitor increased the expression levels of IL-1β and TNF-α in A549 cells after LPS stimulation (P < 0.05). In comparison to cells solely transfected with miR-21-5p inhibitor, co-transfection of miR-21-5p inhibitor and si-SLC6A10 significantly reduced the expression of IL-1β and TNF-α (P < 0.05). MiR-21-5p plays a protective role in LPS-induced acute inflammatory injury of A549 cells. By targeting SLC16A10, it effectively mitigates the inflammatory response in A549 cells induced by LPS. Furthermore, SLC16A10 holds promise as a potential target for the treatment of acute lung injury.

Sinomenine attenuates lipopolysaccharide-induced inflammation and apoptosis of WI-38 cells by reducing glutathione S-transferase M1 expression

Pediatric pneumonia is an infectious lung disease with high morbidity and mortality. Sinomenine, an alkaloid extracted from Caulis Sinomenii, exerts anti-inflammatory and anti-apoptotic activities. Lipopolysaccharide (LPS) is widely used for the establishment of an inflammatory model. This research aimed to explore the influences of sinomenine on LPS-caused inflammatory injuries in fetal lung WI-38 cells. WI-38 cells were treated with LPS to establish a cellular model of pediatric pneumonia. Cell viability was evaluated using CCK-8 assay. Apoptosis was evaluated using TUNEL staining and caspase-3 activity assays. Inflammatory cytokines and NF-κB p65 phosphorylation levels were measured by Enzyme-Linked Immunosorbent Assay. Glutathione S-transferase M1 (GSTM1) expression was detected by western blotting. Results showed that LPS reduced WI-38 cell viability, and sinomenine protected cells against LPS-induced viability reduction. Sinomenine concentration-dependently attenuated LPS-induced inflammation by reducing TNF-α, IL-1β and MCP-1, and increasing IL-10 levels. Sinomenine mitigated LPS-induced apoptosis. GSTM1 was screened by matching the targets of sinomenine and pediatric pneumonia. GSTM1 was upregulated in LPS-treated WI-38 cells, and this effect was attenuated after sinomenine treatment. GSTM1 was upstream of NF-κB pathway. Overexpression of GSTM1 reversed the suppressive functions of sinomenine on LPS-stimulated inflammation and apoptosis. Overall, sinomenine attenuates inflammation and apoptosis in WI-38 cells stimulated by LPS via inhibiting GSTM1 expression, indicating the therapeutic potential of sinomenine in pediatric pneumonia.

Granulosa cells undergo BPA-induced apoptosis in a miR-21-independent manner

Bisphenol A (BPA) is a harmful endocrine disrupting compound that alters not only classical cellular mechanisms but also epigenetic mechanisms. Evidence suggests that BPA-induced changes in microRNA expression can explain, in part, the changes observed at both the molecular and cellular levels. BPA is toxic to granulosa cells (GCs) as it can activate apoptosis, which is known to contribute to increased follicular atresia. miR-21 is a crucial antiapoptotic regulator in GCs, yet the exact function in a BPA toxicity model remains unclear. BPA was found to induce bovine GC apoptosis through the activation of several intrinsic factors. BPA reduced live cells counts, increased late apoptosis/necrosis, increased apoptotic transcripts (BAX, BAD, BCL-2, CASP-9, HSP70), increased the BAX/Bcl-2 ratio and HSP70 at the protein level, and induced caspase-9 activity at 12 h post-exposure. miR-21 inhibition increased early apoptosis and, while it did not influence transcript levels or caspase-9 activity, it did elevate the BAX/Bcl-2 protein ratio and HSP70 in the same manner as BPA. Overall, this study shows that miR-21 plays a molecular role in regulating intrinsic mitochondrial apoptosis; however, miR-21 inhibition did not make the cells more sensitive to BPA. Therefore, apoptosis induced by BPA in bovine GCs is miR-21 independent.

Role of c-miR-21, c-miR-126, Redox Status, and Inflammatory Conditions as Potential Predictors of Vascular Damage in T2DM Patients

The development of type 2 diabetes mellitus (T2DM) vascular complications (VCs) is associated with oxidative stress and chronic inflammation and can result in endothelial dysfunctions. Circulating microRNAs play an important role in epigenetic regulation of the etiology of T2DM. We studied 30 healthy volunteers, 26 T2DM patients with no complications, and 26 T2DM patients with VCs, to look for new biomarkers indicating a risk of developing VCs in T2DM patients. Peripheral blood samples were used to determine redox state, by measuring the endogenous antioxidant defense system (superoxide dismutase, SOD; catalase, CAT; glutathione reductase, GRd; glutathione peroxidase, GPx; and glucose-6-phosphate dehydrogenase, G6DP) and markers of oxidative damage (advanced oxidation protein products, AOPP; lipid peroxidation, LPO). Additionally, inflammatory marker levels (IL-1, IL-6, IL-18, and TNF-α), c-miR-21, and c-miR-126 expression were analyzed. T2DM patients showed the highest oxidative damage with increased GSSG/GSH ratios, LPO, and AOPP levels. In both diabetic groups, we found that diminished SOD activity was accompanied by increased CAT and decreased GRd and G6PD activities. Diabetic patients presented with increased relative expression of c-miR-21 and decreased relative expression of c-miR-126. Overall, c-miR-21, SOD, CAT, and IL-6 had high predictive values for diabetes diagnoses. Finally, our data demonstrated that IL-6 exhibited predictive value for VC development in the studied population. Moreover, c-miR-21 and c-miR-126, along with GPx and AOPP levels, should be considered possible markers for VC development in future studies.

Ssc-MiR-21-5p and Ssc-MiR-615 Regulates the Proliferation and Apoptosis of Leydig Cells by Targeting SOX5

Leydig cells (LCs) are the predominant cells of androgen production, which plays key roles in spermatogenesis and maintaining male secondary sexual characteristics. Abnormal development of LCs affects androgen levels in vivo, affects fertility and may even lead to infertility. Little is known about the regulation mechanism on LCs’ development and maturation in domestic animals, especially the regulation of non-coding RNAs. In this study, we continued to dig deeper in the previous RNA-seq data of porcine LCs from our group, combined with detecting the expression profiles in different tissues and different types of cells in the testis, to screen out candidate microRNAs (miRNAs) that may affect the regulation of LCs. A total of two miRNAs, ssc-miR-21-5p and ssc-miR-615 (“ssc” is omitted below), were finally determined. After overexpression and interference of miRNAs in vitro, the effects of candidate miRNAs on the proliferation and apoptosis of TM3 (mouse Leydig cell line) were explored. The results showed that miR-21-5p led to a decrease in TM3 cell density and p53 (apoptosis related protein) expression. Meanwhile, miR-21-5p decreased EdU positive cell numbers, but increased TUNEL positive cell numbers, suggesting miR-21-5p could inhibit proliferation and promote apoptosis. Conversely, miR-615 could increase TM3 cell density. Western blot and TUNEL assay indicated miR-615 inhibited apoptosis, but had no effect on proliferation. In addition, Sox5 was identified a potential target gene of these two miRNAs by Dual-Luciferase reporter system assay. Our findings about functions of miRNAs in TM3 and the mapping of miRNAs-target gene regulatory network would provide an important basis for the further elucidation of miRNAs in regulating pig LCs.

The roles of microRNAs played in lung diseases via regulating cell apoptosis

MicroRNAs (miRNAs) are a type of endogenous non-coding short-chain RNA, which plays a crucial role in the regulation of many essential cellular functions, including cellular migration, proliferation, invasion, autophagy, oxidative stress, apoptosis, and differentiation. The lung can be damaged by pathogenic microorganisms, as well as physical or chemical factors. Research has confirmed that miRNAs and lung cell apoptosis can affect the development and progression of several lung diseases. This article reviews the role of miRNAs in the development of lung disease through regulating host cell apoptosis.