Inhibitory Effect of Gualou Guizhi Decoction on Microglial Inflammation and Neuron Injury by Promoting Anti-Inflammation via Targeting mmu-miR-155

Exploring the potential molecular mechanism of Gualou Guizhi decoction in the treatment of rheumatoid arthritis based on network pharmacology and molecular docking

BACKGROUND

Traditional Chinese medicine (TCM) has been used in China for a long time and is gradually gaining more and more recognition worldwide. Gualou Guizhi Decoction (GGD) has long been used as a folk medicine for the treatment of rheumatic diseases, but its bioactive components and therapeutic mechanisms are still unclear.

METHODS

An integrated approach using network pharmacology and molecular docking and using methotrexate as a positive control drug.

RESULTS

We obtained 157 active ingredients of GGD, 7542 RA disease targets and 49 intersecting targets. GO and KEGG enrichment analysis revealed that their functions were mainly related to cytokine active metal ion binding, enzyme binding and DNA binding, and enriched in TNF signaling pathway, T cell receptor signaling pathway, Toll-like receptor signaling pathway, RA pathway and other signaling pathways that are closely related to RA. The molecular docking results show that the effector components of GGD bind better to the core targets of RA, and some are even better than methotrexate.

CONCLUSION

The therapeutic effect of GGD for RA is achieved by affecting the core targets such as VEGFA, IL-1β, IL6, CXCL8, CCL2, and JUN, which together interfere with the tumor necrosis factor signaling pathway and RA pathway to treat RA. The above study provides new ideas for further exploration of this classic formula in the future.

Neuroinflammatory Biomarkers in the Brain, Cerebrospinal Fluid, and Blood After Ischemic Stroke

The most frequent type of stroke, known as ischemic stroke (IS), is a significant global public health issue. The pathological process of IS and post-IS episodes has not yet been fully explored, but neuroinflammation has been identified as one of the key processes. Biomarkers are objective indicators used to assess normal or pathological processes, evaluate responses to treatment, and predict outcomes, and some biomarkers can also be used as therapeutic targets. After IS, various molecules are produced by different cell types, such as microglia, astrocytes, infiltrating leukocytes, endothelial cells, and damaged neurons, that participate in the neuroinflammatory response within the ischemic brain region. These molecules may either promote or inhibit neuroinflammation and may be released into extracellular spaces, including cerebrospinal fluid (CSF) and blood, due to reasons such as BBB damage. These neuroinflammatory molecules should be valued as biomarkers to monitor whether their expression levels in the blood, CSF, and brain correlate with the diagnosis and prognosis of IS patients or whether they have potential as therapeutic targets. In addition, although some molecules do not directly participate in the process of neuroinflammation, they have been reported to have potential diagnostic or therapeutic value against post-IS neuroinflammation, and these molecules will also be listed. In this review, we summarize the neuroinflammatory biomarkers in the brain, CSF, and blood after an IS episode and the potential value of these biomarkers for the diagnosis, treatment, and prognosis of IS patients.

Protective effects of baicalin against L-glutamate-induced oxidative damage in HT-22 cells by inhibiting NLRP3 inflammasome activation via Nrf2/HO-1 signaling

Objectives

To explore the ability and underlying molecular mechanisms involved in the protective effects of Baicalin (BA) against L-Glutamate-induced mouse hippocampal neuron cell line HT-22.

Materials and Methods

The cell injury model of HT-22 cells was induced by L-glutamate, and cell viability and damage were detected by CCK-8 and LDH assays. Generation of intracellular reactive oxygen species (ROS) was measured by DCFH-DA in situ fluorescence method. The SOD activity and MDA concentration in the supernatants were determined by WST-8 and colorimetric method, respectively. Furthermore, Western blot and real-time qPCR analysis were utilized to detect the expression levels of the Nrf2/HO-1 signaling pathway and NLRP3 inflammasome proteins and genes.

Results

L-Glutamate exposure induced cell injuries in HT-22 cells, and the concentration of 5 mM L-Glutamate was chosen to be the modeling condition. Co-treatment with BA significantly promoted cell viability and reduced LDH release in a dose-dependent manner. In addition, BA attenuated the L-Glutamate-induced injuries by decreasing the ROS production and MDA concentration, while increasing the SOD activity. Moreover, we also found that BA treatment up-regulated the gene and protein expression of Nrf2 and HO-1, and then inhibited the expression of NLRP3.

Conclusion

Our study found that BA could relieve oxidative stress damage of HT-22 cells induced by L-Glutamate, and the mechanism might be related to the activation of Nrf2/HO-1 and inhibition of NLRP3 inflammasome.

Gualou Guizhi Decoction Improves Glucose Metabolism and Alleviates Microglia-Associated Inflammation after Cerebral Ischemia

Background

The classical prescription Gualou Guizhi decoction (GL), a mixture of Radix Trichosanthis, Ramulus Cinnamomi, Radix Paeoniae Alba, Radix Glycyrrhizae, Zingiberis Rhizoma Recens, and Fructus Ziziphus Jujuba, was clinically used in the treatment of limb spasms after stroke and has achieved remarkable therapeutic effects. However, the underlying mechanism still needs to be further explored.

Methods

Cerebral ischemia/reperfusion (CI/R) in Sprague-Dawley rats was induced by middle cerebral artery occlusion followed by filament removal. GL was intragastrically administered once daily for 7 or 14 consecutive days. The effect of GL on neurobehavioral impairment was evaluated. ¹⁸F-FDG micro-PET imaging was used to detect the effects of GL on glucose utilization in neural cells after CI/R. Immunohistochemical staining of glucose transporter 1 (Glut-1), glial fibrillary acidic protein (GFAP), and ionized calcium-binding adaptor molecule-1 (Iba-1) was further performed to show the effects of GL on cerebral glucose transport and the activation of inflammatory-related glial cells. Markers related to the microglial subtype were also assessed to investigate the effects of GL on microglia polarization.

Results

Neurological deficits induced by CI/R were significantly improved by GL administration. GL restored the glucose uptake in the ischemic hemisphere. Glut-1, the major glucose transporter in the brain, was significantly increased after GL treatment. Moreover, GL mitigated the activation of astrocytes and microglia after CI/R. Furthermore, GL significantly decreased proinflammatory M1-type microglial markers TNF-α and iNOS, while increasing anti-inflammatory M2 microglial markers CD206 and Arg-1.

Conclusion

GL enhanced the uptake and utilization of glucose in neural cells after CI/R. It exerted significant anti-inflammatory effects by regulating the polarization of microglia. These results provided further evidence supporting the clinical application of GL in the treatment of cerebral ischemic stroke.

MiR-155: An Important Regulator of Neuroinflammation

MicroRNAs (miRNAs) are small non-coding RNA molecules that regulate gene expression at the post-transcriptional level and that play an important role in many cellular processes, including modulation of inflammation. MiRNAs are present in high concentrations in the central nervous system (CNS) and are spatially and temporally expressed in a specific way. Therefore, an imbalance in the expression pattern of these small molecules can be involved in the development of neurological diseases. Generally, CNS responds to damage or disease through the activation of an inflammatory response, but many neurological disorders are characterized by uncontrolled neuroinflammation. Many studies support the involvement of miRNAs in the activation or inhibition of inflammatory signaling and in the promotion of uncontrolled neuroinflammation with pathological consequences. MiR-155 is a pro-inflammatory mediator of the CNS and plays an important regulatory role. The purpose of this review is to summarize how miR-155 is regulated and the pathological consequences of its deregulation during neuroinflammatory disorders, including multiple sclerosis, Alzheimer's disease and other neuroinflammatory disorders. Modulation of miRNAs' expression could be used as a therapeutic strategy in the treatment of pathological neuroinflammation.