Investigation of Key Genes and Pathways in Inhibition of Oxycodone on Vincristine-Induced Microglia Activation by Using Bioinformatics Analysis

Prevention of Chemotherapy-Induced Peripheral Neuropathy by Inhibiting C-X-C Motif Chemokine Receptor 2

Chemotherapy-induced peripheral neuropathy (CIPN) is a major drawback in the use of chemotherapeutic agents for patients with cancer. Although studies have investigated a broad number of molecules that might be related to CIPN, the differences in the chemokine pathways between various chemotherapeutic agents, such as vincristine and oxaliplatin, which are some of the most widely used treatments, have not been fully elucidated. We confirmed that the administration (intraperitoneal injections for seven days) of vincristine (0.1 mg/kg) and oxaliplatin (3 mg/kg) induced pain by using the von Frey behavioral test. Subsequent applications with vincristine and oxaliplatin led to mechanical allodynia that lasted more than one week from the fifth day. After the induction of mechanical allodynia, the mRNA expression of CXCR2, CXCL1, CXCL3, and CXCL5 was examined in the dorsal root ganglia (DRG) and spinal cord of the CIPN models. As a result, the mRNA expression of CXCR2 robustly increased in the lumbar spinal cord in the oxaliplatin-treated mice. Next, to evaluate the involvement of CXCR2 in CIPN, reparixin, a CXCR1/2 inhibitor, was administered intrathecally or intraperitoneally with vincristine or oxaliplatin and was further verified by treatment with ruxolitinib, which inhibits Janus kinase 2 downstream of the CXCR1/2 pathway. Reparixin and ruxolitinib blocked oxaliplatin-induced allodynia but not vincristine-induced allodynia, which suggests that CXCR2-related pathways are associated with the development of oxaliplatin-induced neuropathy. Together with the above results, this suggests that the prevention of oxaliplatin-induced neuropathy by CXCR2 inhibition can lead to successful chemotherapy, and it is important to provide appropriate countermeasures against CIPN development for each specific chemotherapeutic agent.

Microglial knockdown does not affect acute withdrawal but delays analgesic tolerance from oxycodone in male and female C57BL/6J mice

Opioid Use Disorder (OUD) affects approximately 8%-12% of the population. In dependent individuals, abrupt cessation of opioid taking results in adverse withdrawal symptoms that reinforce drug taking behavior. Considerable unmet clinical need exists for new pharmacotherapies to treat opioid withdrawal as well as improve long-term abstinence. The neuroimmune system has received much scientific attention in recent years as a potential therapeutic target to combat various neurodegenerative and psychiatric disorders including addiction. However, the specific contribution of microglia has not been investigated in oxycodone dependence. Chronic daily treatment with the CSF1R inhibitor Pexidartinib (PLX3397) was administered to knockdown microglia expression and evaluate consequences on analgesia and on naloxone induced withdrawal from oxycodone. In vivo results indicated that an approximately 40% reduction in brain IBA1 staining was achieved in the PLX treatment group, which was associated with a delay in the development of analgesic tolerance to oxycodone and maintained antinociceptive efficacy. Acute withdrawal behavioral symptoms, brain astrocyte expression, and levels of many neuroinflammatory markers were not affected by PLX treatment. KC/GRO (also known as CXCL1) was significantly enhanced in the somatosensory cortex in oxycodone-treated mice receiving PLX. Microglial knock-down did not affect the expression of naloxoneinduced opioid withdrawal but affected antinociceptive responsivity. The consequences of increased KC/GRO expression within the somatosensory cortex due to microglial reduction during opioid dependence are unclear but may be important for neural pathways mediating opioid-induced analgesia.

Kynurenic Acid and Its Analog SZR104 Exhibit Strong Antiinflammatory Effects and Alter the Intracellular Distribution and Methylation Patterns of H3 Histones in Immunochallenged Microglia-Enriched Cultures of Newborn Rat Brains

Kynurenic acid (KYNA) is implicated in antiinflammatory processes in the brain through several cellular and molecular targets, among which microglia-related mechanisms are of paramount importance. In this study, we describe the effects of KYNA and one of its analogs, the brain-penetrable SZR104 (N-(2-(dimethylamino)ethyl)-3-(morpholinomethyl)-4-hydroxyquinoline-2-carboxamide), on the intracellular distribution and methylation patterns of histone H3 in immunochallenged microglia cultures. Microglia-enriched secondary cultures made from newborn rat forebrains were immunochallenged with lipopolysaccharide (LPS). The protein levels of selected inflammatory markers C–X–C motif chemokine ligand 10 (CXCL10) and C–C motif chemokine receptor 1 (CCR1), histone H3, and posttranslational modifications of histone H3 lys methylation sites (H3K9me3 and H3K36me2, marks typically associated with opposite effects on gene expression) were analyzed using quantitative fluorescent immunocytochemistry and western blots in control or LPS-treated cultures with or without KYNA or SZR104. KYNA and SZR104 reduced levels of the inflammatory marker proteins CXCL10 and CCR1 after LPS-treatment. Moreover, KYNA and SZR104 favorably affected histone methylation patterns as H3K9me3 and H3K36me2 immunoreactivities, and histone H3 protein levels returned toward control values after LPS treatment. The cytoplasmic translocation of H3K9me3 from the nucleus indicated inflammatory distress, a process that could be inhibited by KYNA and SZR104. Thus, KYNA signaling and metabolism, and especially brain-penetrable KYNA analogs such as SZR104, could be key targets in the pathway that connects chromatin structure and epigenetic mechanisms with functional consequences that affect neuroinflammation and perhaps neurodegeneration.

Chemotherapy-Induced Peripheral Neuropathy: Epidemiology, Pathomechanisms and Treatment

PURPOSE

This review provides an update on the current clinical, epidemiological and pathophysiological evidence alongside the diagnostic, prevention and treatment approach to chemotherapy-induced peripheral neuropathy (CIPN).

FINDINGS

The incidence of cancer and long-term survival after treatment is increasing. CIPN affects sensory, motor and autonomic nerves and is one of the most common adverse events caused by chemotherapeutic agents, which in severe cases leads to dose reduction or treatment cessation, with increased mortality. The primary classes of chemotherapeutic agents associated with CIPN are platinum-based drugs, taxanes, vinca alkaloids, bortezomib and thalidomide. Platinum agents are the most neurotoxic, with oxaliplatin causing the highest prevalence of CIPN. CIPN can progress from acute to chronic, may deteriorate even after treatment cessation (a phenomenon known as coasting) or only partially attenuate. Different chemotherapeutic agents share both similarities and key differences in pathophysiology and clinical presentation. The diagnosis of CIPN relies heavily on identifying symptoms, with limited objective diagnostic approaches targeting the class of affected nerve fibres. Studies have consistently failed to identify at-risk cohorts, and there are no proven strategies or interventions to prevent or limit the development of CIPN. Furthermore, multiple treatments developed to relieve symptoms and to modify the underlying disease in CIPN have failed.

IMPLICATIONS

The increasing prevalence of CIPN demands an objective approach to identify at-risk patients in order to prevent or limit progression and effectively alleviate the symptoms associated with CIPN. An evidence base for novel targets and both pharmacological and non-pharmacological treatments is beginning to emerge and has been recognised recently in publications by the American Society of Clinical Oncology and analgesic trial design expert groups such as ACTTION.

Sexually dimorphic neuroimmune response to chronic opioid treatment and withdrawal

Opioid use disorder is a leading cause of morbidity and mortality in the United States. Increasing pre-clinical and clinical evidence demonstrates sex differences in opioid use and dependence. However, the underlying molecular mechanisms contributing to these effects, including neuroinflammation, are still obscure. Therefore, in this study, we investigated the effect of oxycodone exposure and withdrawal on sex- and region-specific neuroimmune response. Real-time PCR and multiplex cytokine array analysis demonstrated elevated neuroinflammation with increased pro-inflammatory cytokine levels, and aberrant oligodendroglial response in reward neurocircuitry, following withdrawal from chronic oxycodone treatment. Chronic oxycodone and withdrawal treated male mice had lower mRNA expression of TMEM119 along with elevated protein levels of pro-inflammatory cytokines/chemokines and growth factors (IL-1β, IL-2, IL-7, IL-9, IL-12, IL-15, IL17, M-CSF, VEGF) in the prefrontal cortex (PFC) as compared to their female counterparts. In contrast, reduced levels of pro-inflammatory cytokines/chemokines (IL-1β, IL-6, IL-9, IL-12, CCL11) was observed in the nucleus accumbens (NAc) of oxycodone and withdrawal-treated males as compared to female mice. No treatment specific effects were observed on the mRNA expression of putative microglial activation markers (Iba1, CD68), but an overall sex specific decrease in the mRNA expression of Iba1 and CD68 was found in the PFC and NAc of male mice as compared to females. Moreover, a sex and region-specific increase in the mRNA levels of oligodendrocyte lineage markers (NG2, Sox10) was also observed in oxycodone and withdrawal treated animals. These findings may open a new avenue for the development of sex-specific precision therapeutics for opioid dependence by targeting region-specific neuroimmune signaling.

Co-expression gene modules involved in cisplatin-induced peripheral neuropathy according to sensitivity, status, and severity

Chemotherapy-induced peripheral neuropathy (CIPN) is among the most disabling and frustrating problems for cancer survivors. The neurotoxicity caused by cisplatin varies greatly among patients, and few predictors of appearance, duration of symptoms, susceptibility, or severity are available. A deeper understanding of the mechanisms underlying individual differences in status, severity, or sensitivity in response to cisplatin treatment is therefore required. By analyzing the GSE64174 gene expression profile and constructing a weighted gene co-expression network analysis (WGCNA) network, we screened gene modules and hub genes related to CIPN status, severity and sensitivity. We first identified the transcriptome profile of mouse dorsal root ganglion (DRG) samples and transformed their genes to human DRG counterparts. We then constructed WGCNA gene modules via optimal soft-threshold power-identification and module-preservation analysis. Comprehensive analysis and identification of module hub genes were performed via functional-enrichment analysis and significant common hub genes were identified, including "Cytoscape_cytoHubba," "Cytoscape_MCODE," and "Metascape_MCODE." Brown, green, and blue modules were selected to represent CIPN sensitivity, status, and severity, respectively, via trait-module correlational analysis. Additionally, functional enrichment analysis results indicated that these three modules were associated with some crucial biological functions, such as neutrophil migration, chemokine-mediated signaling pathway, and PI3K-Akt signaling pathway. We then identified seven common hub genes via three methods, including CXCL10, CCL21, CCR2, CXCR4, TLR4, NPY1R, and GALR2, related to CIPN status, severity and sensitivity. Our results provide possible targets and mechanism insights into the development and progress of CIPN, which can guide further transformation and pre-clinical research.

The roles of Qishen granules recipes, Qingre Jiedu, Wenyang Yiqi and Huo Xue, in the treatment of heart failure

ETHNOPHARMACOLOGICAL RELEVANCE

Recipes (Qingre Jiedu (QJ), Wenyang Yiqi (WYYQ) and Huo Xue (HX)) in Qishen granules (QSG) are believed to synergistically exert cardio-protective effects. However, the underlying pattern of each decomposed recipe in QSG and their synergistic effects in the treatment of heart failure (HF) are not clear.

OBJECTIVE

The purpose of this study is to explore the biological contributions of decomposed recipes to therapeutic effects of QSG and reveal the pharmacological mechanism of QSG in treating HF.

MATERIALS AND METHODS

The therapeutic effects of QSG or its recipes on heart failure were examined in wet-lab at both transcription and phenotypic level using HF Sprague-Dawley rats. Sequencing and transcriptome analyses were performed using in silico approaches including identification of differentially expressed genes, pathway enrichment and protein-protein interaction network studies. Specially, an optimized in silico quantitative pathway analysis that maximally extracted gene expression information was developed to reveal differentially expressed pathways (DEPs) among various groups, and is publicly available as R package QPA on GitHub (https://github.com/github-gs/QPA). Finally, the HF-related genes predicted using DEP approach were validated by quantitative real-time polymerase chain reaction and western blot.

RESULTS

Multiple key genes and the associated signaling pathways were shown to be highly relevant for the therapeutic effect of QSG. Decreased expression of Spp1 gene required for inflammatory signaling and profibrotic signaling were observed in failing hearts treated with QJ, WYYQ and HX. Decreased expression of Cx3cr1 gene required for inflammatory signaling was observed in failing hearts treated with WYYQ and HX. Decreased expression of Myc gene required for oxidative stress and Fgfr2 gene required for profibrotic signaling were observed in failing hearts treated with HX and WYYQ, respectively. Increased expression of Adcy1 gene required for cAMP-PKA signaling cascade was observed in failing hearts treated with WYYQ and HX.

CONCLUSIONS

Our study suggests that QJ, WYYQ and HX recipes in QSG achieve synergistic and complementary therapeutic effects through alleviating inflammatory responses, attenuating ventricular remodeling and enhancing myocardial energy supply.