Shikonin triggers GSDME-mediated pyroptosis in tumours by regulating autophagy via the ROS-MAPK14/p38α axis.

BACKGROUND: Shikonin (SK), a botanical drug extracted from Lithospermum erythrorhizon, has been shown to inhibit tumour growth through apoptosis and necrosis. However, whether SK induces pyroptosis in cancer cells is still unknown. PURPOSE: This study aims to investigated the mechanisms of SK-induced pyroptosis in tumour cells and mice. METHODS: In vivo and in vitro methods were used in this study. Cell deaths were analysed by LDH and CCK-8 assay and western blotting. To investigated the signalling pathway of SK-induced pyroptosis, various genes expressions were supressed by shRNA or inhibitors. High-sensitivity mass spectrometry assay was used to identified potential factors that regulate GSDME-mediated pyroptosis. Finally, a mouse model was used to investigate the effect of SK administration on tumour growth in vivo. RESULTS: The activation of BAX/caspase-3 signalling was essential for GSDME-mediated pyroptosis by SK. Mechanistically, the intracellular reactive oxygen species (ROS) generation induced by SK treatment initiated GSDME-dependant pyroptosis. SK stimulation induced protective autophagy in a ROS-dependant manner, and repressed autophagy significantly enhanced SK-induced pyroptosis. Moreover, MAPK14/p38α, a ROS sensor, modulated SK-induced autophagy and ultimately affected GSDME-dependant pyroptosis. CONCLUSION: Here, for the first time we demonstrated that SK treatment induced GSDME-dependant pyroptosis in tumour cells. Our results demonstrated that SK initiates ROS signalling to drive pyroptosis in cancer cells.

Low level light therapy/photobiomodulation for diabetic peripheral neuropathy: protocol of a systematic review and meta-analysis.

INTRODUCTION: Diabetic peripheral neuropathy (DPN) is one of the most common complications of diabetes that strongly impact the patients' quality of life and working ability. Evidence indicated that low level light therapy (LLLT)/photobiomodulation might be effective for neuropathy. However, the effect of LLLT for DPN is not clear. The objective of this systematic review and meta-analysis is to determine the effects and safety of LLLT/photobiomodulation for DPN, in comparison with other methods such as sham light, no treatment, other active treatment and LLLT as an additional treatment compared with another treatment alone. METHODS AND ANALYSIS: We will search eight databases from their inception to the date before the review submission. Randomised controlled trials (RCTs) will be included. Two reviewers will independently extract data using a structured data extraction method and assess the risk of bias in the included studies. Data will be synthesised using standardised mean difference or risk ratio with 95% CIs for continuous and dichotomous data, respectively. The primary outcome will be change in pain and secondary outcomes will include global symptom improvement, functional impairment and disability, impairment of sensation, quality of life, nerve conduction, and adverse events. Sensitivity and subgroup analysis will be employed to explore the influence of possible clinical and methodological characteristics. Publication bias will be assessed using funnel plot. We will conduct meta-analysis with RevMan V.5.4 and evaluate quality of the evidence using GRADE approach. ETHICS AND DISSEMINATION: This study does not require ethics approval. Our findings will be disseminated in the peer-reviewed publications. PROSPERO REGISTRATION NUMBER: CRD42021276056.

Clinical and Epidemiological Study of Intracranial Tumors in Children and Identification of Diagnostic Biomarkers for the Most Common Tumor Subtype and Their Relationship with the Immune Microenvironment Through Bioinformatics Analysis.

Brain tumors are the second most common pediatric malignancy and have poor prognosis. Understanding the pathogenesis of tumors at the molecular level is essential for clinical treatment. We conducted a retrospective study on the epidemiology of brain tumors in children based on clinical data obtained from a neurosurgical center. After identifying the most prevalent tumor subtype, we identified new potential diagnostic biomarkers through bioinformatics analysis of the public database. All children (0-15 years) with brain tumors diagnosed histopathologically between 2010 and 2020 at the Department of Neurosurgery, Xijing Hospital, were reviewed retrospectively for age distribution, sex predilection, native location, tumor location, symptoms, and histological grade, and identified the most common tumor subtypes. Two datasets (GSE44971 and GSE44684) were downloaded from the Gene Expression Omnibus database, whereas the GSE44971 dataset was used to screen the differentially expressed genes between normal and tumor samples. Gene ontology, disease ontology, and gene set enrichment analysis enrichment analyses were performed to investigate the underlying mechanisms of differentially expressed genes in the tumor. Combined with methylation data in the GSE44684 dataset, we further analyzed the correlation between methylation and gene expression levels. Two algorithms, LASSO and SVM-RFE, were used to select the hub genes of the tumor. The diagnostic value of the hub genes was assessed using the receiver operating characteristic (ROC) curve. Finally, we further evaluated the relationship between the hub gene and the tumor microenvironment and immune gene sets. Overall, 650 children from 18 provinces in China were included in this study. The male-to-female ratio was 1.41:1, and the number of patients reached a peak in the 10-15-year-old group (41.4%).The most common symptoms we encountered in our institute were headache and dizziness 250 (28.2%), and nausea and vomiting 228 (25.7%). The predominant location is supratentorial, with a supratentorial to infratentorial ratio of 1.74:1. Low-grade tumors (WHO I/II) constituted 60.9% of all cases and were predominant in every age group. According to basic classification, the most common tumor subtype is pilocytic astrocytoma (PA). A total of 3264 differentially expressed genes were identified in the GSE44971 dataset, which are mainly involved in the process of neural signal transduction, immunity, and some diseases. Correlation analysis indicated that the expression of 45 differentially expressed genes was negatively correlated with promoter DNA methylation. Next, we acquired five hub genes (NCKAP1L, GPR37L1, CSPG4, PPFIA4, and C8orf46) from the 45 differentially expressed genes by intersecting the LASSO and SVM-RFE models. The ROC analysis revealed that the five hub genes had good diagnostic value for patients with PA (AUC > 0.99). Furthermore, the expression of NCKAP1L was negatively correlated with immune, stromal, and estimated scores, and positively correlated with immune gene sets. This study, based on the data analysis of intracranial tumors in children in a single center over the past 10 years, reflected the clinical and epidemiological characteristics of intracranial tumors in children in Northwest China to a certain extent. PA is considered the most common subtype of intracranial tumors in children. Through bioinformatics analysis, we suggested that NCKAP1L, GPR37L1, CSPG4, PPFIA4, and C8orf46 are potential biomarkers for the diagnosis of PA.

Molecular mechanism of shikonin inhibiting tumor growth and potential application in cancer treatment.

Shikonin is one of the major bioactive components of Lithospermum erythrorhizon. It has a good killing effect in a variety of tumor cells. Its antitumor effect involves multiple targets and pathways and has received extensive attention and study in recent years. In this review, we systematically review recent progress in determining the antitumor mechanism of shikonin and its derivatives, specifically their induction of reactive oxygen species production, inhibition of EGFR and PI3K/AKT signaling pathway activation, inhibition of angiogenesis and induction of apoptosis and necroptosis. We also discuss the application of nanoparticles loaded with shikonin in the targeted therapy of various cancers. Finally, we suggest new strategies for the clinical application of shikonin and its derivatives.

Opposing and Operated Side Electroacupuncture Generates Similar Analgesic Effects on Pain after Knee Surgery.

The purpose of this study was to investigate whether opposing electroacupuncture (EA) could produce similar analgesic effects as operated side EA after knee surgery in rats. Sprague Dawley rats were randomly divided into the sham surgery group, and three surgery groups: opposing EA, operated side EA, and model. After surgery, compared with the sham surgery group, three kinds of pain behavior test methods (mechanical withdrawal threshold (MWT), cumulative pain score [CPS], and mechanical hypersensitivity of knee) were used to assess the pain behavior of the rats in the surgery groups. After knee surgery, the three surgery groups were intervened for three consecutive days: EA on the nonoperated side in the opposing EA group, EA on the operated side in the operated side EA group, and no intervention in the model group. It was shown that MWT was higher and CPS was lower in the two EA groups than in the model group on the first and second days after surgery. On the third day after surgery, MWT in the two EA groups was the highest among the 3 days, CPS was the lowest among the 3 days, and the number of nonvocalizations in rats also increased compared with the model group. Moreover, the MWT of the nonoperated side increased more in the opposing EA group than in the model and operated side EA groups. This indicated that both opposing EA and operated side EA methods can be used to relieve pain after knee joint surgery.

Identification of key methylation differentially expressed genes in posterior fossa ependymoma based on epigenomic and transcriptome analysis.

BACKGROUND: Posterior fossa ependymoma (EPN-PF) can be classified into Group A posterior fossa ependymoma (EPN-PFA) and Group B posterior fossa ependymoma (EPN-PFB) according to DNA CpG island methylation profile status and gene expression. EPN-PFA usually occurs in children younger than 5 years and has a poor prognosis. METHODS: Using epigenome and transcriptome microarray data, a multi-component weighted gene co-expression network analysis (WGCNA) was used to systematically identify the hub genes of EPN-PF. We downloaded two microarray datasets (GSE66354 and GSE114523) from the Gene Expression Omnibus (GEO) database. The Limma R package was used to identify differentially expressed genes (DEGs), and ChAMP R was used to analyze the differential methylation genes (DMGs) between EPN-PFA and EPN-PFB. GO and KEGG enrichment analyses were performed using the Metascape database. RESULTS: GO analysis showed that enriched genes were significantly enriched in the extracellular matrix organization, adaptive immune response, membrane raft, focal adhesion, NF-kappa B pathway, and axon guidance, as suggested by KEGG analysis. Through WGCNA, we found that MEblue had a significant correlation with EPN-PF (R = 0.69, P = 1 × 10-08) and selected the 180 hub genes in the blue module. By comparing the DEGs, DMGs, and hub genes in the co-expression network, we identified five hypermethylated, lower expressed genes in EPN-PFA (ATP4B, CCDC151, DMKN, SCN4B, and TUBA4B), and three of them were confirmed by IHC. CONCLUSION: ssGSEA and GSVA analysis indicated that these five hub genes could lead to poor prognosis by inducing hypoxia, PI3K-Akt-mTOR, and TNFα-NFKB pathways. Further study of these dysmethylated hub genes in EPN-PF and the pathways they participate in may provides new ideas for EPN-PF treatment.

Molecular mechanism of liver X receptors in cancer therapeutics.

Liver X receptors (LXRs) are receptors that belong to the nuclear receptor superfamily (NRs). It was originally called the "orphan receptor" when it was firstly discovered. Then it was found to be activated by oxysterol and it was officially named LXRs. LXRs are activated by ligands and bind to the retinol X receptor to form a heterodimer and regulate metabolism. Numerous studies have shown that LXRs are involved in regulating immune function and maintaining immune tolerance. Activating LXRs can also inhibit the tumorigenesis and promote apoptosis of tumor cells, which make LXRs as potential targets in cancer treatment. This review will discuss the recent progress of LXRs from the structure and function of LXRs, the signaling pathway of LXRs, the molecular mechanism of LXRs activation in cancers, and the potential targets of LXRs in cancer therapy.

Liver X receptor activation reduces gastric cancer cell proliferation by suppressing Wnt signalling via LXRß relocalization.

Liver X receptors (LXRs) are involved in various diseases associated with lipid disorders, and in regulating cancer cell proliferation. However, the underlying molecular mechanisms, especially those in gastric cancer (GC) remain to be clarified. In this study, immunohistochemistry analysis revealed that LXRß was mainly expressed in GC tissue, with less expression in adjacent normal tissues. The LXRß agonist T0901317 efficiently suppressed the proliferation and colony formation of various GC cell lines. We further showed that LXRß translocated from the cytoplasm to the nucleus when activated by T0901317. LXRß nuclear localization suppressed the activation of Wnt signalling and decreased the expression of target genes such as MYC, BMP4, and MMP7 through binding to their promoters. Moreover, we demonstrated that the LXR agonist efficiently suppressed GC tumour growth in a nude mouse xenograft model. Taken together, these results revealed that LXRß agonist inhibited GC cells proliferation by suppressing Wnt signalling via LXRß relocalization. The results strongly suggest that LXRß could be a promising target in GC therapy.

Immunogenic cell death in anticancer chemotherapy and its impact on clinical studies.

The traditional view holds that apoptosis is non-immunogenic and does not induce an inflammatory response. However, recent studies have suggested that certain chemotherapeutic drugs that induce tumor cell apoptosis can induce immunogenic cell death (ICD) in cancer cells. This process is characterized by not only up-regulation of a series of signaling molecules in cancer cells, including expose of calreticulin (CRT), secretion of adenosine triphosphate (ATP) and release of high mobility group box 1 (HMGB1). In this review, we summarize recent progress in identifying and classifying ICD inducers; concepts and molecular mechanisms of ICD; and the impact and potential applications of ICD in clinical studies. We also discuss the contributions of ICD inducers in combination with other anticancer drugs in clinical applications.

Hepatic Knockdown of Splicing Regulator Slu7 Ameliorates Inflammation and Attenuates Liver Injury in Ethanol-Fed Mice.

Aberrant precursor mRNA splicing plays a pivotal role in liver diseases. However, roles of splicing regulators in alcoholic liver disease are unknown. Herein, we investigated a splicing regulator, Slu7, in the development of alcoholic steatohepatitis. Adenovirus-mediated alteration of hepatic Slu7 expression in mice pair fed either with or without (as control) ethanol in their diet was used. Knockdown of hepatic Slu7 by adenovirus-Slu7shRNA treatment ameliorated inflammation and attenuated liver injury in mice after ethanol administration. Mechanistically, reducing liver Slu7 expression increased the expression of sirtuin 1 (SIRT1) full-length and repressed the splicing of SIRT1 into SIRT1-ΔExon8 isoform in ethanol-fed mice. Knockdown of hepatic Slu7 in the ethanol-fed mice also ameliorated splicing of lipin-1 and serine/arginine-rich splicing factor 3 (Srsf3). In concordance with ameliorated splicing of SIRT1, lipin-1, and Srsf3, knockdown of hepatic Slu7 inhibited the activity of NF-κB, normalized iron and zinc homeostasis, reduced oxidative stress, and attenuated liver damage in ethanol-fed mice. In addition, hepatic Slu7 was significantly elevated in patients with alcoholic steatohepatitis. Our present study illustrates a novel role of Slu7 in alcoholic liver injury and suggests that dysregulated Slu7 may contribute to the pathogenesis of human alcoholic steatohepatitis.

The Detrimental Role Played by Lipocalin-2 in Alcoholic Fatty Liver in Mice.

We have previously shown that the ethanol-mediated elevation of lipocaline-2 (LCN2) is closely associated with the development of alcoholic fatty liver disease (AFLD) in mice. Herein, we aimed to understand the functional significance of LCN2 induction by ethanol and to explore its underlying mechanisms. We evaluated the effects of LCN2 in an in vitro cellular alcoholic steatosis model and in an animal study using wild-type and LCN2 knockout mice fed for 4 weeks with an ethanol-supplemented Lieber-DeCarli diet. In the cellular model of alcoholic steatosis, recombinant LCN2 or overexpression of LCN2 exacerbated ethanol-induced fat accumulation, whereas knocking down LCN2 prevented steatosis in hepatocytes exposed to ethanol. Consistently, removal of LCN2 partially but significantly alleviated alcoholic fatty liver injury in mice. Mechanistically, LCN2 mediates detrimental effects of ethanol in the liver via disrupted multiple signaling pathways, including aberrant nicotinamide phosphoribosyltransferase-sirtuin 1 axis, perturbed endocrine metabolic regulatory fibroblast growth factor 15/19 signaling, and impaired chaperone-mediated autophagy. Finally, compared with healthy human livers, liver samples from patients with AFLD had lower gene expression of several LCN2-regualted molecules. Our study demonstrated a pivotal and causal role of LCN2 in the development of AFLD and suggested that targeting the LCN2 could be of great value for the treatment of human AFLD.

Acupuncture may exert its therapeutic effect through microRNA-339/Sirt2/NFκB/FOXO1 axis.

Recently, we have found that a number of microRNAs (miRNAs) and proteins are involved in the response to acupuncture therapy in hypertensive rats. Our bioinformatics study suggests an association between these miRNAs and proteins, which include miR-339 and sirtuin 2 (Sirt2). In this paper, we aimed to investigate whether Sirt2 was a direct target of miR-339 in neurons. In human SH-SY5Y cells, the luciferase assay implied that Sirt2 was likely a target of miRNA-339. Overexpression of miR-339 downregulated Sirt2 expression, while knockdown of miR-339 upregulated Sirt2 expression in human SH-SY5Y cells and rat PC12 cells. In addition, overexpression of miR-399 increased the acetylation of nuclear factor-κB (NF-κB) and forkhead box protein O1 (FOXO1) in SH-SY5Y cells, which are known targets of Sirt2. Our findings demonstrate that miR-339 regulates Sirt2 in human and rat neurons. Since Sirt2 plays a critical role in multiple important cellular functions, our data imply that acupuncture may act through epigenetic changes and subsequent action on their targets, such as miRNA-339/Sirt2/NF-κB/FOXO1 axis. Some physiological level changes of neurons after altering the miR-339 levels are needed to validate the suggested therapeutic role of miR-339/Sirt2/NF-κB/FOXO1 axis in response to acupuncture therapy in the future work.

Adenosine as a probing tool for the mechanistic study of acupuncture treatment.

To date, acupuncture has been widely used despite a lack of solid clinical evidence in the East and West. However, there are few validated in vitro models for the mechanistic studies of acupuncture. We hypothesized that adenosine could be used as a probing tool in the mechanistic studies of acupuncture because of its critical role in the action of acupuncture. Subsequently, we tested this hypothesis using both in vitro and in vivo experiments. First, we found that adenosine stimulation mimicked the effect of acupuncture on microRNA profiling (including miR-339, miR-145 and miR-451) and protein level (including Sirt2) in nerve growth factor-induced differentiated PC12 cells. These miRNA and proteins have been found to be regulated by acupuncture treatment in the brain of spontaneously hypertensive rats. Next, we found that adenosine stimulation downregulated miR-339 expression through adenosine A1 receptor-mediated pathway. Finally, we showed that the concentration of adenosine was actually decreased in the brain of spontaneously hypertensive rats after acupuncture treatment at Taichong acupoint. Taken together, these findings suggest that adenosine could be used as a useful probing tool for acupuncture mechanistic studies, while more validation studies are certainly warranted.

Evaluation of three tracers for labeling distal cerebrospinal fluid-contacting neurons.

It has been reported that distal cerebrospinal fluid-contacting neurons (dCSF-CNs) can be detected by immunohistochemical assay using cholera toxin subunit B-conjugated horseradish peroxidase (CB-HRP). In the present study, another two methods with CB alone or CB-conjugated FITC (CB-FITC) were used, and the results from the three methods were compared. Adult Sprague-Dawley rats were randomly divided into three groups with CB-HRP, CB or CB-FITC. Tracers were diluted to 30% in artificial cerebrospinal fluid and injected separately (in a volume of 3 µL) into the lateral ventricle. Animals from the CB-HRP and CB groups were perfused 48 h after surgery while animals from the CB-FITC group were perfused 1, 3, 6, 12, 24 or 48 h after surgery. The brain was sectioned (40 µm) for immunofluorescence and five sections with positive neurons were selected from each rat for neuron counting. Three clusters of positive neurons in a 'Y-like' distribution were detected ventral to the cerebral aqueduct of rats from the three groups. No significant difference was observed among the quantitative data. In the CB-FITC group, stable staining was detected even at 6 h after injection. Taken together, lateral ventricle injection of CB/CB-FITC is a useful method for labeling dCSF-CNs in rats. The CB-FITC method makes dCSF-CNs labeling much simpler and more convenient.