Inhibition of neuroinflammation by MIF inhibitor 3-({[4-(4-methoxyphenyl)-6-methyl-2-pyrimidinyl]thio}1methyl)benzoic acid (Z-312)

Polo-like kinase 2 promotes microglial activation via regulation of the HSP90α/IKKβ pathway

Polo-like kinase 2 (PLK2) is a serine/threonine protein kinase associated with the regulation of synaptic plasticity and centriole duplication. We identify PLK2 as a crucial early-response gene in lipopolysaccharide (LPS)-stimulated microglial cells. Knockdown or inhibition of PLK2 remarkably attenuates LPS-induced expression of proinflammatory factors in microglial cells by suppressing the inhibitor of nuclear factor kappa B kinase subunit beta (IKKβ)-nuclear factor (NF)-κB signaling pathway. We identify heat shock protein 90 alpha (HSP90α), a regulator of IKKβ activity, as a novel PLK2 substrate. Knockdown or pharmacological inhibition of HSP90α abolishes PLK2-mediated activation of NF-κB transcriptional activity and microglial inflammatory activation. Furthermore, phosphoproteomic analysis pinpoints Ser252 and Ser263 on HSP90α as novel phosphorylation targets of PLK2. Lastly, conditional knockout of PLK2 in microglial cells dramatically ameliorates neuroinflammation and subsequent dopaminergic neuron loss in an intracranial LPS-induced mouse Parkinson's disease (PD) model. The present study reveals that PLK2 promotes microglial activation through the phosphorylation of HSP90α and subsequent activation of the IKKβ-NF-κB signaling pathway.

Macrophage migration inhibitor factor (MIF): Potential role in cognitive impairment disorders

Macrophage migration inhibitory factor (MIF) is a cytokine in the immune system, participated in both innate and adaptive immune responses. Except from immune cells, MIF is also secreted by a variety of non-immune cells, including hematopoietic cells, endothelial cells (ECs), and neurons. MIF plays a crucial role in various diseases, such as sepsis, rheumatoid arthritis, acute kidney injury, and neurodegenerative diseases. The role of MIF in the neuropathogenesis of cognitive impairment disorders is emphasized, as it recruits multiple inflammatory mediators, leading to activating microglia or astrocyte-derived neuroinflammation. Furthermore, it contributes to the cell death of neurons and ECs with the binding of apoptosis-inducing factor (AIF) through parthanatos-associated apoptosis-inducing factor nuclease (PAAN) / MIF pathway. This review comprehensively delves into the relationship between MIF and the neuropathogenesis of cognitive impairment disorders, providing a series of emerging MIF-targeted pharmaceuticals as potential treatments for cognitive impairment disorders.

Clinical Efficacy and Mechanistic Insights of Anshen Dingzhi Prescription on Breast Cancer-Related PTSD Through Network Pharmacology and Molecular Docking

Anshen Dingzhi prescription (ADP) is a classic prescription of traditional Chinese medicine, which has been used in the treatment of neuropsychiatric diseases. However, its treatment of breast cancer-related post-traumatic stress disorder (BC-PTSD) lacks clinical research evidence and its mechanism is not clear. The present study investigated the efficacy and action mechanism of ADP against BC-PTSD. The results of the clinical trial showed that after 4 weeks of treatment, both groups showed reduced post-traumatic stress disorder checklist-civilian version (PCL-C), Pittsburgh sleep quality index (PSQI), self-rating depression scale (SDS) and self-rating anxiety scale (SAS) scores, and increased functional assessment of cancer therapy-breast (FACT-B) scores. The serum cortisol (CORT), tumor necrosis factor-alpha (TNF-α) and interleukin-1 beta (IL-1β) levels were decreased and brain-derived neurotrophic factor (BDNF) level were increased, and the improvement of serum TNF-α, IL-1β, and BDNF in treatment group was better than that of the control group. The overall treatment efficacy in the treatment group (43.90%) was superior to that in the control group (23.81%), and the overall incidence of adverse effects was lower than that in the control group. The results of network analysis and molecular docking showed that ADP blood components could act on IL1B, TNF, and BDNF. ADP contributes to the treatment of BC-PTSD symptoms, with a mechanism possibly related to its regulatory effect on TNF-α, IL-1β, and BDNF levels.Trial registration: Chinese Clinical Trial Registry, http://www.chictr.org.cn,ChiCTR2300077801.

Hypothesizing mechanistic links between microbes and disease using knowledge graphs

Knowledge graphs have found broad biomedical applications, providing useful representations of complex knowledge. Although plentiful evidence exists linking the gut microbiome to disease, mechanistic understanding of those relationships remains generally elusive. Here we demonstrate the potential of knowledge graphs to hypothesize plausible mechanistic accounts of host-microbe interactions in disease. To do so, we constructed a knowledge graph of linked microbes, genes and metabolites called MGMLink. Using a semantically constrained shortest path search through the graph and a novel path prioritization methodology based on cosine similarity, we show that this knowledge supports inference of mechanistic hypotheses that explain observed relationships between microbes and disease phenotypes. We discuss specific applications of this methodology in inflammatory bowel disease and Parkinson's disease. This approach enables mechanistic hypotheses surrounding the complex interactions between gut microbes and disease to be generated in a scalable and comprehensive manner.

Single-Cell Sequencing Reveals the Optimal Time Window for Anti-Inflammatory Treatment in Spinal Cord Injury

Though the occurrence of neuroinflammation after spinal cord injury (SCI) is essential for antigen clearance and tissue repair, excessive inflammation results in cell death and axon dieback. The effect of anti-inflammatory medicine used in clinical treatment remains debatable owing to the inappropriate therapeutic schedule that does not align with the biological process of immune reaction. A better understanding of the immunity process is critical to promote effective anti-inflammatory therapeutics. However, cellular heterogeneity, which results in complex cellular functions, is a major challenge. This study performs single-cell RNA sequencing by profiling the tissue proximity to the injury site at different time points after SCI. Depending on the analysis of single-cell data and histochemistry observation, an appropriate time window for anti-inflammatory medicine treatment is proposed. This work also verifies the mechanism of typical anti-inflammatory medicine methylprednisolone sodium succinate (MPSS), which is found attributable to the activation inhibition of cells with pro-inflammatory phenotype through the downregulation of pathways such as TNF, IL2, and MIF. These pathways can also be provided as targets for anti-inflammatory treatment. Collectively, this work provides a therapeutic schedule of 1-3 dpi (days post injury) to argue against classical early pulse therapy and provides some pathways for target therapy in the future.

Dualistic roles and mechanistic insights of macrophage migration inhibitory factor in brain injury and neurodegenerative diseases

Macrophage migration inhibitory factor (MIF) is involved in various immune-mediated pathologies and regulates both innate and adaptive immune reactions, thus being related to several acute and chronic inflammatory diseases such as rheumatoid arthritis, septic shock, and atherosclerosis. Its role in acute and chronic brain pathologies, such as stroke and neurodegenerative diseases, has attracted increasing attention in recent years. In response to stimuli like hypoxia, inflammation or infection, different cell types can rapidly release MIF, including immune cells, endothelial cells, and neuron cells. Notably, clinical data from past decades also suggested a possible link between serum MIF levels and the severity of stroke and the evolving of neurodegenerative diseases. In this review, we summarize the major and recent findings focusing on the mechanisms of MIF modulating functions in brain injury and neurodegenerative diseases, which may provide important therapeutic targets meriting further investigation.