MiR-124-3p targeting PDE4B attenuates LPS-induced ALI through the TLR4/NF-κB signaling pathway

Catalpol antagonizes LPS-mediated inflammation and promotes osteoblast differentiation through the miR-124-3p/DNMT3b/TRAF6 axis

BACKGROUND

Dysregulated inflammation and osteoblast differentiation are implicated in osteoporosis. Exploring the activity of catalpol in inflammation and osteoblast differentiation deepens the understanding of osteoporosis pathogenesis.

METHODS

LPS was used to treated hFOB1.19 cells to induce inflammation and repress osteoblast differentiation. FOB1.19 cells were induced in osteoblast differentiation medium and treated with LPS and catalpol. Cell viability was assessed using CCK-8. ALP and Alizarin red S staining were conducted for analyzing osteoblast differentiation. The levels of IL-1β, TNF-α and IL-6 were examined by ELISA. The methylation of TRAF6 promoter was examined through MS-PCR. The binding of miR-124-3p to DNMT3b and DNMT3b to TRAF6 promoter was determined with dual luciferase reporter and ChIP assays.

RESULTS

LPS enhanced secretion of inflammatory cytokines and suppressed osteoblast differentiation. MiR-124-3p and TRAF6 were upregulated and DNMT3b was downregulated in LPS-induced hFOB1.19 cells. Catalpol protected hFOB1.19 cells against LPS via inhibiting inflammation and promoting osteoblast differentiation. MiR-124-3p targeted DNMT3b, and its overexpression abrogated catalpol-mediated protection in LPS-treated hFOB1.19 cells. In addition, DNMT3b methylated TRAF6 promoter to restrain its expression. Catalpol exerted protective effects through suppression of the miR-124-3p/DNMT3b/TRAF6 axis in hFOB1.19 cells.

CONCLUSION

Catalpol antagonizes LPS-mediated inflammation and suppressive osteoblast differentiation via controlling the miR-124-3p/DNMT3b/TRAF6 axis.

Qinhuo Shanggan oral solution resolves acute lung injury by down-regulating TLR4/NF-κB signaling cascade and inhibiting NLRP3 inflammasome activation

Acute lung injury (ALI) is a common condition, particularly in the COVID-19 pandemic, which is distinguished by sudden onset of respiratory insufficiency with tachypnea, oxygen-refractory cyanosis, reduced lung compliance and diffuse infiltration of pulmonary alveoli. It is well-established that increasing activity of toll-like receptor 4 (TLR4)/nuclear factor kappa-B (NF-κB) signaling axis and the NOD-, LRR- and pyrin domain-containing protein 3 (NLRP3) inflammasome activation are associated with the pathogenesis of ALI. Since ALI poses a huge challenge to human health, it is urgent to tackle this affliction with therapeutic intervention. Qinhuo Shanggan oral solution (QHSG), a traditional Chinese herbal formula, is clinically used for effective medication of various lung diseases including ALI, with the action mechanism obscure. In the present study, with the rat model of lipopolysaccharide (LPS)-induced ALI, QHSG was unveiled to ameliorate ALI by alleviating the pathological features, reversing the alteration in white blood cell profile and impeding the production of inflammatory cytokines through down-regulation of TLR4/NF-κB signaling cascade and inhibition of NLRP3 inflammasome activation. In LPS-stimulated RAW264.7 mouse macrophages, QHSG was discovered to hinder the generation of inflammatory cytokines by lessening TLR4/NF-κB signaling pathway activity and weakening NLRP3 inflammasome activation. Taken together, QHSG may resolve acute lung injury, attributed to its anti-inflammation and immunoregulation by attenuation of TLR4/NF-κB signaling cascade and inhibition of NLRP3 inflammasome activation. Our findings provide a novel insight into the action mechanism of QHSG and lay a mechanistic foundation for therapeutic intervention in acute lung injury with QHSG in clinical practice.

Rgl-exomiR-7972, a novel plant exosomal microRNA derived from fresh Rehmanniae Radix, ameliorated lipopolysaccharide-induced acute lung injury and gut dysbiosis

Plant-derived exosome-like nanoparticles (ELNs) have been proposed as a novel therapeutic tool for preventing human diseases. However, the number of well-verified plant ELNs remains limited. In this study, the microRNAs in ELNs derived from fresh Rehmanniae Radix, a well-known traditional Chinese herb for treating inflammatory and metabolic diseases, were determined by using microRNA sequencing to investigate the active components in the ELNs and the protection against lipopolysaccharide (LPS)-induced acute lung inflammation in vivo and in vitro. The results showed that rgl-miR-7972 (miR-7972) was the main ingredient in ELNs. It exerted stronger protective activities against LPS-induced acute lung inflammation than catalpol and acteoside, which are two well-known chemical markers in this herb. Moreover, miR-7972 decreased the production of pro-inflammatory cytokines (IL-1β, IL-6, and TNF-α), reactive oxygen species (ROS) and nitric oxide (NO) in LPS-exposed RAW264.7 cells, thereby facilitating M2 macrophage polarization. Mechanically, miR-7972 downregulated the expression of G protein-coupled receptor 161 (GPR161), activating the Hedgehog pathway, and inhibited the biofilm form of Escherichia coli via targeting virulence gene sxt2. Therefore, miR-7972 derived from fresh R. Radix alleviated LPS-induced lung inflammation by targeting the GPR161-mediated Hedgehog pathway, recovering gut microbiota dysbiosis. It also provided a new direction for gaining novel bioactivity nucleic acid drugs and broadening the knowledge on cross-kingdom physiological regulation through miRNAs.

Bioinformatics gene analysis of potential biomarkers and therapeutic targets of osteoarthritis associated myelodysplastic syndrome

Objective: Osteoarthritis (OA) and Myelodysplastic syndrome (MDS) are diseases caused by the same immune disorder with unclear etiology and many similarities in clinical manifestations; however, the specific mechanisms between osteoarthritis and myelodysplastic syndrome are unclear.

Methods: The expression profile microarrays of osteoarthritis and myelodysplastic syndrome were searched in the GEO database, the intersection of their differential genes was taken, Venn diagrams were constructed to find common pathogenic genes, bioinformatics analysis signaling pathway analysis was performed on the obtained genes, and protein-protein interaction networks were constructed to find hub genes in order to establish diagnostic models for each disease and explore the immune infiltration of hub genes.

Results: 52 co-pathogenic genes were screened for association with immune regulation, immune response, and inflammation. The mean area under the receiver operating characteristic (ROC) for all 10 genes used for co-causal diagnosis ranged from 0.71–0.81. Immune cell infiltration analysis in the myelodysplastic syndrome subgroup showed that the relative numbers of Macrophages M1, B cells memory, and T cells CD4 memory resting in the myelodysplastic syndrome group were significantly different from the normal group, however, in the osteoarthritis subgroup the relative numbers of Mast cells resting in the osteoarthritis subgroup was significantly different from the normal group.

Conclusion: There are common pathogenic genes in osteoarthritis and myelodysplastic syndrome, which in turn mediate differential alterations in related signaling pathways and immune cells, affecting the high prevalence of osteoarthritis and myelodysplastic syndrome and the two disease phenomena.

Recent advances of Phosphodiesterase 4B in cancer

INTRODUCTION

Phosphodiesterase 4B (PDE4B) is a crucial enzyme in the phosphodiesterases (PDEs), acting as a regulator of cyclic adenosine monophosphate (cAMP). It is involved in cancer process through PDE4B/cAMP signaling pathway. Cancer occurs and develops with the regulation of PDE4B in the body, suggesting that PDE4B is a promising therapeutic target.

AREAS COVERED

This review covereed the function and mechanism of PDE4B in cancer. We summarized the possible clinical applications of PDE4B, and highlighted the possible ways to develop clinical applications of PDE4B inhibitors. We also discussed some common PDEs inhibitors, and expected the development of combined targeting PDE4B and other PDEs drugs in the future.

EXPERT OPINION

The existing research and clinical data can strongly prove the role of PDE4B in cancer. PDE4B inhibition can effectively increase cell apoptosis, inhibit cell proliferation, transformation, migration, etc., indicating that PDE4B inhibition can effectively inhibit the development of cancer. Other PDEs may antagonize or coordinate this effect. As for the further study on the relationship between PDE4B and other PDEs in cancer, it is still a challenge to develop multi-targeted PDEs inhibitors.

Anti-inflammatory effect of chlorogenic acid in Klebsiella pneumoniae-induced pneumonia by inactivating the p38MAPK pathway

INTRODUCTION

Pneumonia is an inflammation-related respiratory infection and chlorogenic acid (CGA) possesses a wide variety of bioactive properties, such as anti-inflammation and anti-bacteria.

AIM

This study explored the anti-inflammatory mechanism of CGA in Klebsiella pneumoniae (Kp)-induced rats with severe pneumonia.

METHODS

The pneumonia rat models were established by infection with Kp and treated with CGA. Survival rates, bacterial load, lung water content, and cell numbers in the bronchoalveolar lavage fluid were recorded, lung pathological changes were scored, and levels of inflammatory cytokines were determined by enzyme-linked immunosorbent assay. RLE6TN cells were infected with Kp and treated with CGA. The expression levels of microRNA (miR)-124-3p, p38, and mitogen-activated protein kinase (MAPK)-activated protein kinase 2 (MK2) in lung tissues and RLE6TN cells were quantified by real-time quantitative polymerase chain reaction or Western blotting. The binding of miR-124-3p to p38 was validated by the dual-luciferase and RNA pull-down assays. In vitro, the functional rescue experiments were performed using miR-124-3p inhibitor or p38 agonist.

RESULTS

Kp-induced pneumonia rats presented high mortality, increased lung inflammatory infiltration and the release of inflammatory cytokines, and enhanced bacterial load, while CGA treatment improved rat survival rates and the above situations. CGA increased miR-124-3p expression, and miR-124-3p inhibited p38 expression and inactivated the p38MAPK pathway. Inhibition of miR-124-3p or activation of the p38MAPK pathway reversed the alleviative effect of CGA on pneumonia in vitro.

CONCLUSION

CGA upregulated miR-124-3p expression and inactivated the p38MAPK pathway to downregulate inflammatory levels, facilitating the recovery of Kp-induced pneumonia rats.

Increased miR-124-3p alleviates type 2 inflammatory response in allergic rhinitis via IL-4Rα

Background and objectives

miRNAs play a crucial role in regulating immune responses. However, the effect of miR-124-3p on type 2 inflammation in allergic rhinitis (AR) is unclear. We aimed to study the immune regulation of miR-124-3p in AR and the mechanisms involved.

Methods

The direct interaction between miR-124-3p and IL-4Rα was confirmed through a dual-luciferase reporter assay. In vitro splenic lymphocytes from mice and peripheral blood mononuclear cells (PBMCs) from healthy individuals were cultured and treated with miR-124-3p mimic/inhibitor. Twenty-four female C57BL/C mice were divided into four groups: control, AR model, miR-124-3p agomir, and miR-124-3p antagomir groups (n = 6 per group). The allergic responses were evaluated based on the number of sneezing and nasal scratching, the serum HDM-specific IgE (sIgE) levels, and the degree of nasal mucosa eosinophil infiltration. The expression of IL-4Rα, p-STAT6, and type 2 inflammatory cytokines (IL-4, IL-5 and IL-13) in lymphocytes or nasal mucosa was determined by qPCR, western blotting, flow cytometry, immunohistochemistry and immunofluorescence.

Results

miR-124-3p directly targets the 3'UTR of IL-4Rα. The miR-124-3p mimic lowered the IL-4Rα, p-STAT6, IL-4, IL-5, and IL-13 expression levels in both mouse splenic lymphocytes and human PBMCs in vitro, and the miR-124-3p inhibitor rescued these changes. Furthermore, the miR-124-3p agomir decreased the levels of IL-4Rα and IL-4 in nasal mucosa, Th2 differentiation in spleen, and allergic response in AR mice. Moreover, the miR-124-3p antagonist increased the IL-4Rα and IL-4 levels and further aggravated the allergic responses.

Conclusions

miR-124-3p might attenuate type 2 inflammation in AR by regulating IL-4Rα signaling, and miR-124-3p may be a promising new target in AR treatment.

Supplementary Information

The online version contains supplementary material available at 10.1007/s00011-022-01614-x.