Roles of CSF2 as a modulator of inflammation during retinal degeneration

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.

Glia Modulates Immune Responses in the Retina Through Distinct MHC Pathways

Glia antigen-presenting cells (APCs) are pivotal regulators of immune surveillance within the retina, maintaining tissue homeostasis and promptly responding to insults. However, the intricate mechanisms underlying their local coordination and activation remain unclear. Our study integrates an animal model of retinal injury, retrospective analysis of human retinas, and in vitro experiments to gain insights into the crucial role of antigen presentation in neuroimmunology during retinal degeneration (RD), uncovering the involvement of various glial cells, notably Müller glia and microglia. Glial cells act as sentinels, detecting antigens released during degeneration and interacting with T-cells via MHC molecules, which are essential for immune responses. Microglia function as APCs via the MHC Class II pathway, upregulating key molecules such as Csf1r and cytokines. In contrast, Müller cells act through the MHC Class I pathway, exhibiting upregulated antigen processing genes and promoting a CD8+ T-cell response. Distinct cytokine signaling pathways, including TNF-α and IFN Type I, contribute to the immune balance. Human retinal specimens corroborate these findings, demonstrating glial activation and MHC expression correlating with degenerative changes. In vitro assays also confirmed differential T-cell migration responses to activated microglia and Müller cells, highlighting their role in shaping the immune milieu within the retina. In summary, our study emphasizes the involvement of retinal glial cells in modulating the immune response after insults to the retinal parenchyma. Unraveling the intricacies of glia-mediated antigen presentation in RD is essential for developing precise therapeutic interventions for retinal pathologies.

In vitro and in vivo characterization of oridonin analogs as anti-inflammatory agents that regulate the NF-κB and NLRP3 inflammasome axis

Introduction

A series of oridonin hybrids were synthesized and evaluated for anti-inflammatory potential, focusing on their ability to inhibit NO production in RAW264.7 cells and their therapeutic prospects for NLRP3-driven disorders.

Methods

Anti-inflammatory activity was assessed by measuring NO inhibition in LPS-stimulated RAW264.7 cells. The most active compound, 4c, was further analyzed using ELISA and WB to evaluate its effects on inflammatory proteins (p-NF-κB, p-IκB, NLRP3, IL-6, IL-1β, COX-2, iNOS). In vivo efficacy was tested in a murine acute lung injury model, with RT‒qPCR and WB used to assess inflammatory markers in lung tissues. Molecular docking predicted 4c's binding mode with NLRP3, while RNA-seq and RT‒qPCR identified differentially expressed genes.

Results

Compound 4c significantly inhibited NO production and suppressed key inflammatory proteins in vitro. In vivo, it alleviated acute lung injury, reduced IL-6 and TNF-α mRNA levels, and inhibited NLRP3, p-NF-κB, and IL-6 protein expression. Docking suggested covalent binding to NLRP3. RNA-seq revealed 4c upregulated Trdc, Stfa2, and Gsta2 while downregulating Spib, Csf2, and Nr4a1.

Discussion

Compound 4c demonstrates potent anti-inflammatory effects via NLRP3 pathway inhibition and modulation of inflammatory genes. These findings highlight oridonin hybrids, particularly 4c, as promising candidates for NLRP3-driven inflammatory disorders, warranting further investigation.

The mechanism of multistep progression of the transcriptional cascade in activated microglia as approached by a proteome approach

The ocular cytokine network plays pivotal roles in terms of the initiation and progression of retinal degeneration. Several types of immunocompetent cells such as microglia participate in inflammation, and a temporal transition in the molecular events of inflammation has been hypothesized. We previously found that the Csf2 gene was induced in the early phase of retinal degeneration. CSF2 participates in the transcriptional activation of several cytokines expressed by microglia; however, whether CSF2 is essential in this context is not known. In this work, we approach this question by using anti-CSF2 neutralizing bntibody and the protein synthesis inhibitor cycloheximide (CHX). We first revealed that CSF2 positively regulated the cytokine induction cascade using a CSF2-neutralizing antibody (anti-CSF2) to treat the microglial cell line that were activated by lipopolysaccharide (LPS). LPS or Lipid A stimulation in the presence of the protein synthesis inhibitor cycloheximide (CHX) led to cytokine superinduction, but suppression of the expression of a few cytokines was also noted in MG5 cells. To examine transitions of the molecular events within LPS-activated microglia, we next performed proteome analysis of MG5 cells stimulated with LPS for 0, 4, and 9 h. The Database for Annotation, Visualization, and Integrated Discovery analysis of differentially expressed proteins showed that various mRNA-modifying molecules were induced after LPS stimulation, in addition to molecules involved in inflammation. However, the numbers of common proteins founded in the comparison between the induced proteins of 4 and 9 h were only one-third and one-half of induced proteins at 4 and 9 h, respectively, suggesting dynamic transition of the induced proteins. LPS-induced mRNA-modifying proteins were almost completely suppressed by CHX, as expected, suggesting that transient induction of transcription-editing proteins plays an important role in terms of the phenotype of inflammation that develops in microglia after LPS stimulation.

Therapeutic targets for age-related macular degeneration: proteome-wide Mendelian randomization and colocalization analyses

Background

Currently, effective therapeutic drugs for age-related macular degeneration (AMD) are urgently needed, and it is crucial to explore new treatment targets. The proteome is indispensable for exploring disease targets, so we conducted a Mendelian randomization (MR) of the proteome to identify new targets for AMD and its related subtypes.

Methods

The plasma protein level data used in this study were obtained from two large-scale studies of protein quantitative trait loci (pQTL), comprising 35,559 and 54,219 samples, respectively. The expression quantitative trait loci (eQTL) data were sourced from eQTLGen and GTEx Version 8. The discovery set for AMD data and subtypes was derived from the FinnGen study, consisting of 9,721 AMD cases and 381,339 controls, 5,239 wet AMD cases and 273,920 controls, and 6,651 dry AMD cases and 272,504 controls. The replication set for AMD data was obtained from the study by Winkler TW et al., comprising 14,034 cases and 91,234 controls. Summary Mendelian randomization (SMR) analysis was employed to assess the association between QTL data and AMD and its subtypes, while colocalization analysis was performed to determine whether they share causal variants. Additionally, chemical exploration and molecular docking were utilized to validate potential drugs targeting the identified proteins.

Results

SMR and colocalization analysis jointly identified risk-associated proteins for AMD and its subtypes, including 5 proteins (WARS1, BRD2, IL20RB, TGFB1, TNFRSF10A) associated with AMD, 2 proteins (WARS1, IL20RB) associated with Dry-AMD, and 9 proteins (COL10A1, WARS1, VTN, SDF2, LBP, CD226, TGFB1, TNFRSF10A, CSF2) associated with Wet-AMD. The results revealed potential therapeutic chemicals, and molecular docking indicated a good binding between the chemicals and protein structures.

Conclusion

Proteome-wide MR have identified risk-associated proteins for AMD and its subtypes, suggesting that these proteins may serve as potential therapeutic targets worthy of further clinical investigation.

Loss of 15-Lipoxygenase in Retinodegenerative RCS Rats

Retinitis pigmentosa (RP) is a retinal degenerative disease associated with a diversity of genetic mutations. In a natural progression study (NPS) evaluating the molecular changes in Royal College of Surgeons (RCS) rats using lipidomic profiling, RNA sequencing, and gene expression analyses, changes associated with retinal degeneration from p21 to p60 were evaluated, where reductions in retinal ALOX15 expression corresponded with disease progression. This important enzyme catalyzes the formation of specialized pro-resolving mediators (SPMs) such as lipoxins (LXs), resolvins (RvDs), and docosapentaenoic acid resolvins (DPA RvDs), where reduced ALOX15 corresponded with reduced SPMs. Retinal DPA RvD2 levels were found to correlate with retinal structural and functional decline. Retinal RNA sequencing comparing p21 with p60 showed an upregulation of microglial inflammatory pathways accompanied by impaired damage-associated molecular pattern (DAMP) clearance pathways. This analysis suggests that ALXR/FPR2 activation can ameliorate disease progression, which was supported by treatment with an LXA4 analog, NAP1051, which was able to promote the upregulation of ALOX12 and ALOX15. This study showed that retinal inflammation from activated microglia and dysregulation of lipid metabolism were central to the pathogenesis of retinal degeneration in RP, where ALXR/FPR2 activation was able to preserve retinal structure and function.

Downregulation of VEGF in the retinal pigment epithelium followed by choriocapillaris atrophy after NaIO3 treatment in mice

Sodium iodate (NaIO3) induces retinal pigment epithelium (RPE) dysfunction, which leads to photoreceptor degeneration. Previously, we used electron microscopy to show that the administration of NaIO3 resulted in the accumulation of cell debris in the subretinal space, which was thought to be caused by failed phagocytosis in the outer segment of the photoreceptor due to RPE dysfunction. We further analyzed the pathological changes in the retina and choroid of NaIO3-injected mice, and found that the expression of OTX2, an RPE marker, disappeared from central part of the RPE 1 day after NaIO3 administration. Furthermore, fenestrated capillaries (choriocapillaris, CC) adjacent to the RPE could not be identified only 2 days after NaIO3 administration. An examination of the expression of the CC-specific protein plasmalemma vesicle-associated protein (PLVAP), in sections and flat-mount retina/choroid specimens showed destruction of the CC, and complete disappearance of the PLVAP signal 7 days after NaIO3 administration. In contrast, CD31 flat-mount immunohistochemistry of the retina indicated no difference in retinal vessels between NaIO3-treated mice and controls. Electron microscopy showed that the fenestrated capillaries in the kidney and duodenum were morphologically indistinguishable between control and NaIO3-treated mice. We examined cytokine production in the retina and RPE, and found that the Vegfa transcript level in the RPE decreased starting 1 day after NaIO3 administration. Taken together, these observations show that NaIO3 reduces the CC in the early stages of the pathology, which is accompanied by a rapid decrease in Vegfa expression in the RPE.

Molecular docking and molecular dynamics study Lianhua Qingwen granules (LHQW) treats COVID-19 by inhibiting inflammatory response and regulating cell survival

Purpose

2019 Coronavirus disease (COVID-19) is endangering health of populations worldwide. Latest research has proved that Lianhua Qingwen granules (LHQW) can reduce tissue damage caused by inflammatory reactions and relieve patients' clinical symptoms. However, the mechanism of LHQW treats COVID-19 is currently lacking. Therefore, we employed computer simulations to investigate the mechanism of LHQW treats COVID-19 by modulating inflammatory response.

Methods

We employed bioinformatics to screen active ingredients in LHQW and intersection gene targets. PPI, GO and KEGG was used to analyze relationship of intersection gene targets. Molecular dynamics simulations validated the binding stability of active ingredients and target proteins. Binding free energy, radius of gyration and the solvent accessible surface area were analyzed by supercomputer platform.

Results

COVID-19 had 4628 gene targets, LHQW had 1409 gene targets, intersection gene targets were 415. Bioinformatics analysis showed that intersection targets were closely related to inflammation and immunomodulatory. Molecular docking suggested that active ingredients (including: licopyranocoumarin, Glycyrol and 3-3-Oxopropanoic acid) in LHQW played a role in treating COVID-19 by acting on CSF2, CXCL8, CCR5, NLRP3, IFNG and TNF. Molecular dynamics was used to prove the binding stability of active ingredients and protein targets.

Conclusion

The mechanism of active ingredients in LHQW treats COVID-19 was investigated by computer simulations. We found that active ingredients in LHQW not only reduce cell damage and tissue destruction by inhibiting the inflammatory response through CSF2, CXCL8, CCR5 and IFNG, but also regulate cell survival and growth through NLRP3 and TNF thereby reducing apoptosis.