The effect of baicalin on microRNA expression profiles in porcine aortic vascular endothelial cells infected by Haemophilus parasuis

Comparative study of the effects of baicalin and probenecid on microRNA expression profiles in porcine aortic vascular endothelial cells infected by Glaesserella parasuis

BACKGROUND

Glaesserella parasuis elicits severe inflammatory responses and vascular damage, thus resulting in high mortality and morbidity in pigs; consequently, early diagnosis and treatment are critical to controlling economic losses. MicroRNAs (miRNAs) have been demonstrated to be involved in vascular endothelial inflammation. Baicalin is an effective Chinese medicinal herb with anti-microbial, anti-inflammatory, and anti-oxidant activity. Probenecid has activity toward multiple mammalian biological processes. Herein, we compared the effects of baicalin and probenecid on the miRNA expression profiles of porcine aortic vascular endothelial cells (PAVECs) infected with G. parasuis.

RESULTS

We identified 277 known miRNAs and 540 novel miRNAs. Twelve miRNAs were significantly differentially expressed in PAVECs after G. parasuis infection. Both baicalin and probenecid affected the miRNA expression profiles in G. parasuis-infected PAVECs but showed different modulation patterns. Ssc-miR-27b-5p and ssc-miR-1842 were the top differentially expressed miRNAs (DEmiRNAs) in baicalin group comparing to control group. Ssc-miR-9851-3p and ssc-miR-1296-5p were the top DEmiRNAs in probenecid group. And Ssc-miR-127, ssc-miR-1842, and ssc-miR-9810-3p were the top DEmiRNAs between the baicalin group and probenecid group, as validated by qRT-PCR. The target genes of DEmiRNAs between various groups were subjected to KEGG and GO enrichment analyses. Hematopoietic cell lineage, insulin resistance, and AMPK signaling pathway were the top significantly enriched pathways associated with the target genes of DEmiRNAs in G. parasuis-infected PAVECs pretreated with baicalin; in contrast, B cell receptor, T cell receptor, and HIF-1 signaling pathways predominated in G. parasuis-infected PAVECs treated with probenecid. We additionally constructed co-expression and protein-protein interaction networks based on the differentially expressed target genes of miR-127, miR-1842, and miR-9810-3p.

CONCLUSION

Our findings suggested that baicalin and probenecid regulated miRNAs associated with vascular inflammation and damage, but showed different modulation patterns. This report provided the first comparison of the effects of baicalin and probenecid on G. parasuis-infected PAVECs, and might aid in the development of novel biomarkers and therapeutic targets to control G. parasuis infection.

Glaesserella parasuis serotype 5 promotes pyroptosis via degrading Caveolin-1 in 3D4/21 cells

Glaesserella parasuis (G. parasuis) is an important pathogen, which can cause systemic inflammatory response in pigs and bring huge economic losses to the global swine industry. G. parasuis can induce a strong inflammatory response in the lungs under environmental changes and certain stress conditions. However, the underlying mechanism of this adverse response has not been thoroughly studied. In this study we demonstrated that G. parasuis serotype 5 strain (GPS5-SQ) has the potential to induce pyroptosis in 3D4/21 cells. GPS5-SQ could degrade the expression of Cav-1. Knockdown or overexpression of Cav-1 promoted or reduced the occurrence of pyroptosis, respectively. These results suggested that Cav-1 is involved in pyroptosis induced by GPS5-SQ in 3D4/21 cells. In addition, overexpression of Cav-1 suppressed the activation of NLRP3 inflammasome by inhibiting ASC oligomerization, resulted in reducing pyroptosis. In general, we found that GPS5-SQ infection could promote pyroptosis by degrading the expression of Cav-1. The results of the study revealed the new mechanism of inflammation induced by GPS5-SQ in 3D4/21 cells.

The critical role of miRNA in bacterial zoonosis

The public's health and the financial sustainability of international societies remain threatened by bacterial zoonoses, with limited reliable diagnostic and therapeutic options available for bacterial diseases. Bacterial infections influence mammalian miRNA expression in host-pathogen interactions. In order to counteract bacterial infections, miRNAs participate in gene-specific expression and play important regulatory roles that rely on translational inhibition and target gene degradation by binding to the 3' non-coding region of target genes. Intriguingly, according to current studies, that exogenous miRNAs derived from plants could potentially serve as effective medicinal components sourced from traditional Chinese medicine plants. These exogenous miRNAs exhibit stable functionality in mammals and mimic the regulatory roles of endogenous miRNAs, illuminating the molecular processes behind the therapeutic effects of plants. This review details the immune defense mechanisms of inflammation, apoptosis, autophagy and cell cycle disturbance caused by some typical bacterial infections, summarizes the role of some mammalian miRNAs in regulating these mechanisms, and introduces the cGAS-STING signaling pathway in detail. Evidence suggests that this newly discovered immune defense mechanism in mammalian cells can also be affected by miRNAs. Meanwhile, some examples of transboundary regulation of mammalian mRNA and even bacterial diseases by exogenous miRNAs from plants are also summarized. This viewpoint provides fresh understanding of microbial tactics and host mechanisms in the management of bacterial illnesses.

Transcriptome Analysis Reveals Novel Inflammatory Signalings to Glaesserella parasuis Infection

Glaesserella parasuis (GPS) can cause severe systemic inflammation in pigs, resulting in huge economic losses to the pig industry. At present, no effective method is available for the prevention and control of GPS infection. Molecular breeding for disease resistance is imminent, but disease-resistance genes have not been identified. To study the mechanism of systemic acute inflammation caused by GPS, we established three in vitro infection models (3D4/21 cells, PK15 cells, and PAVEC cells) according to its infection path. There was no significant difference in apoptosis among the three kinds of cells after 12 h of continuous GPS stimulation, while inflammatory factors were significantly upregulated. Subsequent transcriptome analysis revealed 1969, 1207, and 3564 differentially expressed genes (DEGs) in 3D4/21 cells, PK15 cells, and PAVEC cells, respectively, after GPS infection. Many of the DEGs were predicted to be associated with inflammatory responses (C3, CD44, etc.); cell proliferation, growth and apoptosis; gene expression; and protein phosphorylation. Key signaling pathways, including S100 family signaling, bacteria and virus recognition, and pathogen-induced cytokine storm signaling, were enriched based on Ingenuity Pathway Analysis (IPA). Furthermore, a total of three putative transmembrane receptors and two putative G-protein-coupled receptors, namely F3, ICAM1, PLAUR, ACKR3, and GPRC5A, were identified by IPA among the three types of cells. ACKR3 and GPRC5A play pivotal roles in bacterial adhesion, invasion, host immune response and inflammatory response through the S100 family signaling pathway. Our findings provide new insights into the pathological mechanisms underlying systemic inflammation caused by GPS infection in pigs, and they lay a foundation for further research on disease-resistance breeding to GPS.

Expression profiles of miRNAs in the lung tissue of piglets infected with Glaesserella parasuis and the roles of ssc-miR-135 and ssc-miR-155-3p in the regulation of inflammation

MicroRNAs (miRNAs) have been shown to play an important regulatory role in the process of pathogenic infection. However, the miRNAs that regulate the pathogenic process of G. parasuis and their functions are still unknown. Here, high-throughput sequencing was used to quantify the expression of miRNA in piglet lung tissue after G. parasuis XX0306 strain infection. A total of 25 differentially expressed microRNAs (DEmiRNAs) were identified. GO and KEGG pathway enrichment analysis showed that many of the functions of genes that may be regulated by DEmiRNA are related to inflammatory response and immune regulation. Further studies found that ssc-miR-135 may promote the expression of inflammatory factors through NF-κB signaling pathway. Whereas, ssc-miR-155-3p inhibited the inflammatory response induced by G. parasuis, and its regulatory mechanism remains to be further investigated. This study provides a valuable reference for revealing the regulatory effects of miRNAs on the pathogenesis of G. parasuis. DATA AVAILABILITY: The datasets generated during the current study are not publicly available due to this study is currently in the ongoing research stage, and some of the data cannot be made public sooner yet, but are available from the corresponding author on reasonable request.

Baicalin attenuates PD-1/PD-L1 axis-induced immunosuppression in piglets challenged with Glaesserella parasuis by inhibiting the PI3K/Akt/mTOR and RAS/MEK/ERK signalling pathways

Infection of piglets with Glaesserella parasuis (G. parasuis) induces host immunosuppression. However, the mechanism underlying the immunosuppression of piglets remains unclear. Activation of the PD-1/PD-L1 axis has been shown to trigger host immunosuppression. Baicalin possesses anti-inflammatory and immunomodulatory functions. However, whether baicalin inhibits PD-1/PD-L1 activation and thus alleviates host immunosuppression has not been investigated. In this study, the effect of baicalin on the attenuation of piglet immunosuppression induced by G. parasuis was evaluated. Seventy piglets were randomly divided into the control group, infection group, levamisole group, BMS-1 group, 25 mg/kg baicalin group, 50 mg/kg baicalin group and 100 mg/kg baicalin group. Following pretreatment with levamisole, BMS-1 or baicalin, the piglets were challenged with 1 × 108 CFU of G. parasuis. Our results showed that baicalin, levamisole and BMS-1 modified routine blood indicators and biochemical parameters; downregulated IL-1β, IL-10, IL-18, TNF-α and IFN-γ mRNA expression; and upregulated IL-2 and IL-8 mRNA expression in blood. Baicalin, levamisole and BMS-1 increased the proportions of CD3+ T cells, CD3+CD4+ T cells, CD3+CD8+ T cells and CD3-CD21+ B cells in the splenocyte population, increased the proportions of CD3+ T cells, CD3+CD4+ T cells and CD3+CD8+ T cells in the blood, and inhibited PD-1/PD-L1 and TIM-3 activation. Baicalin, levamisole and BMS-1 reduced p-PI3K, p-Akt, and p-mTOR expression, the p-MEK1/2/MEK1/2 and p-ERK1/2/ERK1/2 ratios and increased RAS expression. Baicalin, levamisole and BMS-1 provided substantial protection against G. parasuis challenge and relieved tissue histopathological damage. Our findings might provide new strategies for controlling G. parasuis infection and other immunosuppressive diseases.

Transcriptome sequencing reveals non-coding RNAs respond to porcine reproductive and respiratory syndrome virus and Haemophilus parasuis co-infection in Kele piglets

Co-infection with porcine reproductive and respiratory syndrome virus (PRRSV) and Haemophilus parasuis (HPS) has severely restricted the healthy development of pig breeding. Exploring disease resistance of non-coding RNAs in pigs co-infected with PRRSV and HPS is therefore critical to complement and elucidate the molecular mechanisms of disease resistance in Kele piglets and to innovate the use of local pig germplasm resources in China. RNA-seq of lungs from Kele piglets with single-infection of PRRSV or HPS and co-infection of both pathogens was performed. Two hundred and twenty-five differentially expressed long non-coding RNAs (DElncRNAs) and 30 DEmicroRNAs (DEmiRNAs) were identified and characterized in the PRRSV and HPS co-infection (PRRSV-HPS) group. Compared with the single-infection groups, 146 unique DElncRNAs, 17 unique DEmiRNAs, and 206 target differentially expressed genes (DEGs) were identified in the PRRSV-HPS group. The expression patterns of 20 DEmiRNAs and DElncRNAs confirmed by real-time quantitative polymerase chain reaction (RT-qPCR) were consistent with those determined by high-throughput sequencing. In the PRRSV-HPS group, the target DEGs were enriched in eight immune Gene Ontology terms relating to two unique DEmiRNAs and 16 DElncRNAs, and the unique target DEGs participated the host immune response to pathogens infection by affecting 15 immune-related Kyoto Encyclopedia of Genes and Genomes enrichment pathways. Notably, competitive endogenous RNA (ceRNA) networks of different groups were constructed, and the ssc-miR-671-5p miRNA was validated as a potential regulatory factor to regulate DTX4 and AEBP1 genes to achieve innate antiviral effects and inhibit pulmonary fibrosis by dual-luciferase reporter assays. These results provided insight into further study on the molecular mechanisms of resistance to PRRSV and HPS co-infection in Kele piglets.

Baicalin inhibited PANX-1/P2Y6 signaling pathway activation in porcine aortic vascular endothelial cells infected by Glaesserella parasuis

Glaesserella parasuis can induce endothelial barrier damage in piglets, although the mechanism by which this pathogen triggers inflammatory damage remains unclear. Baicalin possesses anti-inflammatory and anti-oxidant activities. However, whether baicalin can relieve endothelial barrier damage caused by Glaesserella parasuis infection has not yet been studied. Hence, we evaluated the ability of baicalin to counteract the changes induced by Glaesserella parasuis in porcine aortic vascular endothelial cells. The results showed that Glaesserella parasuis could upregulate the expression of pannexin 1 channel protein and promote the release of adenosine triphosphate, adenosine diphosphate, adenosine 3'-monophosphate, uridine triphosphate, uridine diphosphate, and uridine monophosphate in porcine aortic vascular endothelial cells. The expression level of purinergic receptor P2Y6 was upregulated in porcine aortic vascular endothelial cells triggered by Glaesserella parasuis. In addition, Glaesserella parasuis could activate phospholipase C-protein kinase C and myosin light chain kinase-myosin light chain signaling pathways in porcine aortic vascular endothelial cells. Baicalin could inhibit pannexin 1 channel protein expression, reduce adenosine triphosphate, adenosine diphosphate, adenosine 3'-monophosphate, uridine triphosphate, uridine diphosphate, and uridine monophosphate release, and attenuate the expression level of P2Y6 in porcine aortic vascular endothelial cells induced by Glaesserella parasuis. Baicalin could also reduce the activation of phospholipase C-protein kinase C and myosin light chain kinase-myosin light chain signaling pathways in porcine aortic vascular endothelial cells triggered by Glaesserella parasuis. Our study report that Glaesserella parasuis could promote pannexin 1 channel protein expression, induce nucleosides substance release, and P2Y6 expression in porcine aortic vascular endothelial cells and baicalin could inhibit the expression levels of pannexin 1, nucleosides substance, and P2Y6 in the porcine aortic vascular endothelial cells induced by Glaesserella parasuis, which might be served as some targets for treatment of inflammation disease caused by Glaesserella parasuis.

Baicalin Inhibits NLRP3 Inflammasome Activity Via the AMPK Signaling Pathway to Alleviate Cerebral Ischemia-Reperfusion Injury

Baicalin has been reported to have ameliorative effects on nerve-induced hypoxic ischemia injury; however, its role in the NLRP3 inflammasome-dependent inflammatory response during cerebral ischemia-reperfusion remains unclear. To investigate the molecular mechanisms involved in baicalin alleviating cerebral ischemia-reperfusion injury, we investigated the AMPK signaling pathway which regulates NLRP3 inflammasome activity. SD rats were treated with baicalin at doses of 100 mg/kg and 200 mg/kg, respectively, after middle cerebral artery occlusion at 2 h and reperfusion for 24 h (MCAO/R). MCAO/R treatment significantly increased cerebral infarct volume, changed the ultrastructure of nerve cells, and activated the NLRP3 inflammasome, manifesting as significantly increased expression of NLRP3, ASC, cleaved caspase-1, IL-1β, and IL-18. Our results demonstrated that baicalin treatment effectively reversed these phenomena in a dose-dependent manner. Additionally, inhibition of NLRP3 expression was found to promote the neuroprotective effects of baicalin on cortical neurons. Furthermore, baicalin remarkably increased the expression of p-AMPK following oxygen glucose deprivation/reperfusion (OGD/R). The expression of the NLRP3 inflammasome was also increased when the AMPK pathway was blocked by compound C. Taken together, our findings reveal that baicalin reduces the activity of the NLRP3 inflammasome and consequently inhibits cerebral ischemia-reperfusion injury through activation of the AMPK signaling pathway.

Effect of Baicalin on Transcriptome Changes in Piglet Vascular Endothelial Cells Induced by a Combination of Glaesserella parasuis and Lipopolysaccharide

Glaesserella parasuis causes porcine Glässer's disease and lipopolysaccharide (LPS) induces acute inflammation and pathological damage. Baicalin has antioxidant, antimicrobial, and anti-inflammatory functions. Long noncoding RNAs (lncRNAs) play key regulatory functions during bacterial infection. However, the role of lncRNAs in the vascular dysfunction induced by a combination of G. parasuis and LPS during systemic inflammation and the effect of baicalin on lncRNA expression induced in porcine aortic vascular endothelial cells (PAVECs) by a combination of G. parasuis and LPS have not been investigated. In this study, we investigated the changes in lncRNA and mRNA expression induced in PAVECs by G. parasuis, LPS, or a combination of G. parasuis and LPS, and the action of baicalin on lncRNA expression induced in PAVECs by the combination of G. parasuis and LPS. Our results showed 133 lncRNAs and 602 genes were differentially expressed when PAVECs were stimulated with the combination of G. parasuis and LPS, whereas 107 lncRNAs and 936 genes were differentially expressed when PAVECs were stimulated with the combination of G. parasuis and LPS after pretreatment with baicalin. The Kyoto Encyclopedia of Genes and Genomes (KEGG) analysis showed the dominant signaling pathways triggered by the combination of G. parasuis and LPS were the tumor necrosis factor signaling pathway, phosphatidylinositol signaling system, and inositol phosphate metabolism. Protein-protein interaction network analysis showed the differentially expressed target genes of the differentially expressed lncRNAs (DELs) were related to each other. A coexpression analysis indicated the expression levels of the DELs were co-regulated with those of their differentially expressed target genes. This is the first study to systematically compare the changes in lncRNAs and mRNAs in PAVECs stimulated with a combination of G. parasuis and LPS. Our data clarified the mechanisms underlying the vascular inflammation and damage triggered by G. parasuis and LPS, and it may provide novel targets for the treatment of LPS-induced systemic inflammation.

Baicalin regulates the development of pediatric asthma via upregulating microRNA-103 and mediating the TLR4/NF-κB pathway

Pediatric asthma seriously endangers the well-being and health of children worldwide. Baicalin (BA) protects against diverse disorders, including asthma. Therefore, this study explored the mechanism of BA in pediatric asthma. The ovalbumin (OVA)-induced asthmatic mouse model was established to evaluate BA efficacy from aspects of oxidative stress, inflammation, blood cells in bronchoalveolar lavage fluid (BALF) and collagen deposition. Differentially expressed microRNAs (miRs) in BA-treated mice were analyzed. Effects of BA on PDGF-BB-induced smooth muscle cells (SMCs) were assessed. miR downstream mRNA and the related pathway were predicted and verified, and their effects on asthmatic mice were evaluated. BA effectively reversed OVA-induced oxidative stress and inflammation, as well as decreased the number of total cells, eosinophils and neutrophils in BALF, and collagen deposition. miR-103 was significantly upregulated after BA treatment. BA inhibited the abnormal proliferation of PDGF-BB-induced SMCs, which was prevented by miR-103 knockdown. miR-103 targeted TLR4 and regulated the extent of NF-κB phosphorylation. In vivo, miR-103 inhibition weakened the alleviating effects of BA on asthma, which was then reversed after silencing of TLR4. We highlighted that BA has the potency to halt the pediatric asthma progression via miR-103 upregulation and the TLR4/NF-κB axis inhibition.