Ibrutinib ameliorates cerebral ischemia/reperfusion injury through autophagy activation and PI3K/Akt/mTOR signaling pathway in diabetic mice

PU.1 induces tumor-associated macrophages promoting glioma progression through BTK-mediated Akt/mTOR pathway activation

Glioma, the most common primary malignant brain tumor, is characterized by infiltrating immune cells that contribute to tumor progression and therapeutic resistance. Tumor-associated macrophages (TAMs) constitute a significant proportion of these infiltrating immune cells and have been implicated in glioma progression. However, the underlying molecular mechanisms by which TAMs promote glioma progression remain elusive. In this study, we investigated the role of PU.1, a crucial transcription factor involved in myeloid cell development, in glioma-associated macrophage polarization and activation. First, bioinformatics and analysis of clinical glioma samples demonstrated a positive correlation between PU.1 expression in TAMs and disease severity. Further experiments using in vitro coculture systems revealed that the expression of PU.1 is increased in glioma cells vs. control cells. Importantly, PU.1-overexpressing macrophages exhibited a protumorigenic phenotype characterized by enhanced migration, invasion, and proliferation. Mechanistically, we found that PU.1-induced activation of the Bruton tyrosine kinase (BTK) signaling pathway led to Akt/mTOR pathway activation in macrophages, which further enhanced their protumorigenic functions. Furthermore, pharmacological inhibition of the BTK or Akt/mTOR pathway reversed the protumorigenic effects of macrophages in vitro and impaired their ability to promote glioma progression in vivo. In conclusion, our study elucidates a novel mechanism by which PU.1 induces the polarization and activation of TAMs in the glioma microenvironment. We highlight the significance of BTK-mediated Akt/mTOR pathway activation in driving the protumorigenic functions of TAMs. Targeting PU.1 and its downstream signaling pathways in TAMs may provide a promising therapeutic strategy to suppress glioma progression and improve patient outcomes.

Role of NLRP3 Inflammasome in Stroke Pathobiology: Current Therapeutic Avenues and Future Perspective

Neuroinflammation is a key pathophysiological feature of stroke-associated brain injury. A local innate immune response triggers neuroinflammation following a stroke via activating inflammasomes. The nucleotide-binding oligomerization domain leucine-rich repeat and pyrin domain-containing protein 3 (NLRP3) inflammasome has been heavily implicated in stroke pathobiology. Following a stroke, several stimuli have been suggested to trigger the assembly of the NLRP3 inflammasome. Recent studies have advanced the understanding and revealed several new players regulating NLRP3 inflammasome-mediated neuroinflammation. This article discussed recent advancements in NLRP3 assembly and highlighted stroke-induced mitochondrial dysfunction as a major checkpoint to regulating NLRP3 activation. The NLRP3 inflammasome activation leads to caspase-1-dependent maturation and release of IL-1β, IL-18, and gasdermin D. In addition, genetic or pharmacological inhibition of the NLRP3 inflammasome activation and downstream signaling has been shown to attenuate brain infarction and improve the neurological outcome in experimental models of stroke. Several drug-like small molecules targeting the NLRP3 inflammasome are in different phases of development as novel therapeutics for various inflammatory conditions, including stroke. Understanding how these molecules interfere with NLRP3 inflammasome assembly is paramount for their better optimization and/or development of newer NLRP3 inhibitors. In this review, we summarized the assembly of the NLRP3 inflammasome and discussed the recent advances in understanding the upstream regulators of NLRP3 inflammasome-mediated neuroinflammation following stroke. Additionally, we critically examined the role of the NLRP3 inflammasome-mediated signaling in stroke pathophysiology and the development of therapeutic modalities to target the NLRP3 inflammasome-related signaling for stroke treatment.

Exploration of the molecular mechanism of insulin resistance in adipose tissue of patients with type 2 diabetes mellitus through a bioinformatic analysis

BACKGROUND

We aimed to determine the cis-expression Quantitative Trait Loci (cis-eQTL) and trans-eQTL of differentially expressed genes (DEGs) in insulin resistance (IR) related pathways.

METHODS

The expression profile data for insulin sensitivity (IS) and IR in the adipose tissue of patients with type 2 diabetes mellitus (T2DM) were acquired from the Gene Expression Omnibus databases. Then, the Gene set enrichment analysis (GSEA) and Gene set variation analysis (GSVA) methods were performed to identify the significant enrichment of potential Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways between IS and IR groups, and the Wilcoxon rank sum test was carried out to identify the DEGs related to KEGG pathways. Finally, the cis-eQTLs and trans-eQTLs that can affect the expression of DEGs were screened from the eQTLGen database.

RESULTS

The GSEA and GSVA analysis indicated that the mTOR signaling pathway, insulin signaling pathway and T2DM had a strong correlation with the pathological process of T2DM. Furthermore, six genes (ACACA, GYS2, PCK1, PRKAR1A, SLC2A4, and VEGFA) were found to be significantly differentially expressed in IR-related pathways. Finally, we have identified a total of 1073 cis-eQTLs and 24 trans-eQTLs.

CONCLUSIONS

We screened out six genes that were significantly differentially expressed in IR-related pathways, including ACACA, GYS2, PCK1, PRKAR1A, SLC2A4, and VEGFA. Moreover, we discovered that these six genes were affected by 1073 cis-eQTLs and 24 trans-eQTLs.

Unsupervised cluster analysis of clinical and metabolite characteristics in patients with chronic complications of T2DM: an observational study of real data

Introduction

The aim of this study was to cluster patients with chronic complications of type 2 diabetes mellitus (T2DM) by cluster analysis in Dalian, China, and examine the variance in risk of different chronic complications and metabolic levels among the various subclusters.

Methods

2267 hospitalized patients were included in the K-means cluster analysis based on 11 variables [Body Mass Index (BMI), Systolic Blood Pressure (SBP), Diastolic Blood Pressure (DBP), Glucose, Triglycerides (TG), Total Cholesterol (TC), Uric Acid (UA), microalbuminuria (mAlb), Insulin, Insulin Sensitivity Index (ISI) and Homa Insulin-Resistance (Homa-IR)]. The risk of various chronic complications of T2DM in different subclusters was analyzed by multivariate logistic regression, and the Kruskal-Wallis H test and the Nemenyi test examined the differences in metabolites among different subclusters.

Results

Four subclusters were identified by clustering analysis, and each subcluster had significant features and was labeled with a different level of risk. Cluster 1 contained 1112 inpatients (49.05%), labeled as "Low-Risk"; cluster 2 included 859 (37.89%) inpatients, the label characteristics as "Medium-Low-Risk"; cluster 3 included 134 (5.91%) inpatients, labeled "Medium-Risk"; cluster 4 included 162 (7.15%) inpatients, and the label feature was "High-Risk". Additionally, in different subclusters, the proportion of patients with multiple chronic complications was different, and the risk of the same chronic complication also had significant differences. Compared to the "Low-Risk" cluster, the other three clusters exhibit a higher risk of microangiopathy. After additional adjustment for 20 covariates, the odds ratios (ORs) and 95% confidence intervals (95%CI) of the "Medium-Low-Risk" cluster, the "Medium-Risk" cluster, and the"High-Risk" cluster are 1.369 (1.042, 1.799), 2.188 (1.496, 3.201), and 9.644 (5.851, 15.896) (all p<0.05). Representatively, the "High-Risk" cluster had the highest risk of DN [OR (95%CI): 11.510(7.139,18.557), (p<0.05)] and DR [OR (95%CI): 3.917(2.526,6.075), (p<0.05)] after 20 variables adjusted. Four metabolites with statistically significant distribution differences when compared with other subclusters [Threonine (Thr), Tyrosine (Tyr), Glutaryl carnitine (C5DC), and Butyryl carnitine (C4)].

Conclusion

Patients with chronic complications of T2DM had significant clustering characteristics, and the risk of target organ damage in different subclusters was significantly different, as were the levels of metabolites. Which may become a new idea for the prevention and treatment of chronic complications of T2DM.

Dexmedetomidine alleviates cerebral ischemia-reperfusion injury via inhibiting autophagy through PI3K/Akt/mTOR pathway

Dexmedetomidine has been shown to protect against cerebral ischemia-reperfusion injury (CIRI). Nevertheless, the precise mechanism is obscure. In order to explore the effect of dexmedetomidine pre-conditioning on autophagy against CIRI in rats, middle cerebral artery occlusion (MCAO) was conducted to establish cerebral ischemia-reperfusion (I/R) model in male SD rats with 2 h ischemia and 24 h reperfusion. Dexmedetomidine was delivered to rats at 10, 50 and 100 µg/kg doses respectively, and LY294002, a PI3K/Akt/mTOR pathway inhibitor, was administered at 10 mg/kg intraperitoneally 30 min before MCAO. Neurological deficit score was assessed and cerebral infarct size was detected by TTC staining. Morris water maze (MWM) was performed to estimate spatial learning and memory ability. Furthermore, to detect activity of PI3K/Akt/mTOR pathway and autophagy, p-Akt, p-mTOR, Beclin-1 and LC3 were measured by western blot. Our findings revealed that 50 and 100 µg/kg of dexmedetomidine pretreatment could improve the neurological deficit score and reduce cerebral infarct size after CIRI, while these effects were markedly suppressed by LY294002. In MWM test, dexmedetomidine was confirmed to shorten escape latency and increase times across platform after CIRI. Nevertheless, LY294002 pretreatment eliminated the improvement of dexmedetomidine on spatial learning and memory ability. Furthermore, dexmedetomidine pretreatment reduced ratios of Beclin-1 and LC3II/LC3I and elevated p-Akt/Akt and p-mTOR/mTOR after CIRI. However, above effects of dexmedetomidine were partly reversed by LY294002. Overall, dexmedetomidine pretreatment exerted neuroprotection against CIRI in rats by attenuating autophagy via the PI3K/Akt/mTOR pathway.

Acupuncture for autophagy in animal models of middle cerebral artery occlusion: A systematic review and meta-analysis protocol

INTRODUCTION

Ischemic stroke has high morbidity, disability and mortality rates. The effective treatments recommended by guideline have considerable limitations due to their strict range of adaptation and narrow time window. Acupuncture is an effective and safe treatment for ischemic stroke, and the mechanism may be related to autophagy. In this systematic review, we aim to summarize and evaluate the evidence of autophagy in acupuncture therapy for animal models of middle cerebral artery occlusion (MCAO).

METHODS

Publications will be retrieved from the MEDLINE, Embase, Cochrane Library, Web of Science, CNKI, CBM, CVIP and Wanfang databases. We will include animal experimental studies of acupuncture for MCAO, and the control group will receive placebo/sham acupuncture or no treatment after model establishment. Outcome measures must include autophagy and will include neurologic scores and/or infarct size. The Systematic Review Center for Laboratory animal Experimentation (SYRCLE) risk of bias tool will be used to assess the risk of bias. A meta-analysis will be performed if the included studies are sufficiently homogenous. Subgroup analyses will be conducted according to different intervention types and different types of outcomes. Sensitivity analyses will also performed to explore the heterogeneity and to assess the stability of the results. Publication bias will be assessed by funnel plots. The Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) system will be applied to evaluate the quality of evidence in this systematic review.

DISCUSSION

The results of this study may help to explain autophagy in acupuncture therapy for ischemic stroke. The limitation of this review is that all included studies will be retrieved from Chinese or English medical databases due to language barriers.

REGISTRATION

We registered in PROSPERO on May 31, 2022. (https://www.crd.york.ac.uk/PROSPERO/display_record.php?RecordID=329917) (CRD42022329917).

FDA-Approved Kinase Inhibitors in Preclinical and Clinical Trials for Neurological Disorders

Cancers and neurological disorders are two major types of diseases. We previously developed a new concept termed "Aberrant Cell Cycle Diseases" (ACCD), revealing that these two diseases share a common mechanism of aberrant cell cycle re-entry. The aberrant cell cycle re-entry is manifested as kinase/oncogene activation and tumor suppressor inactivation, which are hallmarks of both tumor growth in cancers and neuronal death in neurological disorders. Therefore, some cancer therapies (e.g., kinase inhibition, tumor suppressor elevation) can be leveraged for neurological treatments. The United States Food and Drug Administration (US FDA) has so far approved 74 kinase inhibitors, with numerous other kinase inhibitors in clinical trials, mostly for the treatment of cancers. In contrast, there are dire unmet needs of FDA-approved drugs for neurological treatments, such as Alzheimer's disease (AD), intracerebral hemorrhage (ICH), ischemic stroke (IS), traumatic brain injury (TBI), and others. In this review, we list these 74 FDA-approved kinase-targeted drugs and identify those that have been reported in preclinical and/or clinical trials for neurological disorders, with a purpose of discussing the feasibility and applicability of leveraging these cancer drugs (FDA-approved kinase inhibitors) for neurological treatments.

A New Therapeutic Trend: Natural Medicine for Ameliorating Ischemic Stroke via PI3K/Akt Signaling Pathway

Ischemic stroke (IS) is an acute cerebrovascular disease caused by sudden arterial occlusion, which is characterized by a high morbidity, mortality, and disability rate. It is one of the most important causes of nervous system morbidity and mortality in the world. In recent years, the search for new medicine for the treatment of IS has become an attractive research focus. Due to the extremely limited time window of traditional medicine treatment, some side effects may occur, and accompanied by the occurrence of adverse reactions, the frequency of exploration with natural medicine is significantly increased. Phosphatidylinositol-3-kinase/Protein kinase B (PI3K/Akt) signaling pathway is a classical pathway for cell metabolism, growth, apoptosis, and other physiological activities. There is considerable research on medicine that treats various diseases through this pathway. This review focuses on how natural medicines (including herbs and insects) regulate important pathophysiological processes such as inflammation, oxidative stress, apoptosis, and autophagy through the PI3K/Akt signaling pathway, and the role it plays in improving IS. We found that many kinds of herbal medicine and insect medicine can alleviate the damage caused by IS through the PI3K/Akt signaling pathway. Moreover, the prescription after their combination can also achieve certain results. Therefore, this review provides a new candidate category for medicine development in the treatment of IS.

EGCG protects the mouse brain against cerebral ischemia/reperfusion injury by suppressing autophagy via the AKT/AMPK/mTOR phosphorylation pathway

Stroke remains one of the leading reasons of mortality and physical disability worldwide. The treatment of cerebral ischemic stroke faces challenges, partly due to a lack of effective treatments. In this study, we demonstrated that autophagy was stimulated by transient middle cerebral artery occlusion/reperfusion (MCAO/R) and oxygen-glucose deprivation/reoxygenation (OGD/R). Treatment with (−)-epigallocatechin-3-gallate (EGCG), a bioactive ingredient in green tea, was able to mitigate cerebral ischemia/reperfusion injury (CIRI), given the evidence that EGCG administration could reduce the infarct volume and protect poststroke neuronal loss in MCAO/R mice in vivo and attenuate cell loss in OGD/R-challenged HT22 cells in vitro through suppressing autophagy activity. Mechanistically, EGCG inhibited autophagy via modulating the AKT/AMPK/mTOR phosphorylation pathway both in vivo and in vitro models of stroke, which was further confirmed by the results that the administration of GSK690693, an AKT/AMPK inhibitor, and rapamycin, an inhibitor of mTOR, reversed aforementioned changes in autophagy and AKT/AMPK/mTOR signaling pathway. Overall, the application of EGCG relieved CIRI by suppressing autophagy via the AKT/AMPK/mTOR phosphorylation pathway.

CircRNA CTNNB1 (circCTNNB1) ameliorates cerebral ischemia/reperfusion injury by sponging miR-96-5p to up-regulate scavenger receptor class B type 1 (SRB1) expression

Emerging studies show that circRNA catenin beta 1 (circCTNNB1) plays a critical role in cancer. However, the expression and function of circCTNNB1 in cerebral ischemia/reperfusion injury (IRI) have not been reported. The present study discovered that circCTNNB1 and scavenger receptor class B type 1 (SRB1) expression levels were significantly down-regulated in mouse astrocytes (mAS) treated with oxygen glucose deprivation and reperfusion (OGD/R), and similar results were observed in a mouse middle cerebral artery occlusion model. Overexpression of circCTNNB1 alleviated cell apoptosis, oxidative stress and the inflammatory response induced by OGD/R in vitro. Up-regulation of circCTNNB1 increased SRB1 expression levels to protect mAS cells from OGD/R-induced damage. CircCTNNB1 and SRB1 interacted with miR-96-5p, and the overexpression of miR-96-5p efficiently reversed the function of circCTNNB1 in OGD/R-treated mAS cells. CircCTNNB1 protected against cerebral ischemia-reperfusion injury by up-regulating SRB1 in vivo. In conclusion, our findings suggest that circCTNNB1 acts as a competitive endogenous RNA for miR-96-5p to alleviate cerebral IRI, which provides novel evidence that circCTNNB1 and SRB1 may be biomarkers and therapeutic targets for cerebral IRI.