Activation of the Epac/Rap1 signaling pathway alleviates blood-brain barrier disruption and brain damage following cerebral ischemia/reperfusion injury

Edaravone dexborneol provides neuroprotective benefits by suppressing ferroptosis in experimental intracerebral hemorrhage

Edaravone dexborneol (EDB) is widely recognized for its anti-inflammatory and antioxidant properties and is clinically applied in the treatment of acute cerebral infarction. Ferroptosis is a critical process in the pathophysiology of brain injury following intracerebral hemorrhage (ICH). However, it remains unclear whether EDB can ameliorate ICH through the modulation of ferroptosis. This study aimed to evaluate the function and mechanism of EDB in treatment of ICH. With a male rat ICH model, animal behavior tests, histopathological staining, magnetic resonance imaging and evans blue staining were used to evaluate the neural protective function of EDB on ICH rats. The potential molecular mechanism was investigated using RNA sequencing. With the administration of Fer-1, a range of ferroptosis-related biomarkers, including Fe2+, 4-hydroxynonenal, malondialdehyde, etc., were analyzed to ascertain whether EDB confers neuroprotective effects through the modulation of P53/GPX4 pathways to inhibit ferroptosis. Finally, the findings were further corroborated using an in vitro ICH model with a P53 inhibitor. EDB has the potential to markedly enhance nerve and motor function, mitigate pathological damage, facilitate hematoma clearance, and repair BBB injury in ICH rats. KEGG analysis revealed that the differentially expressed genes were associated with signaling pathways, including P53 and ferroptosis. Both EDB and Fer-1 substantially reduced the concentrations of Fe2+, 4-hydroxynonenal, malondialdehyde, increased the amount of anti-oxidants, decreased the expression of P53, and concurrently upregulated the expression of GPX4. Besides, the P53 inhibitor PFT-α was observed to significantly reduce the levels of 4-HNE and lipid peroxides, while concurrently increasing the expression of GPX4. This investigation has shed light on the crucial neuroprotective role of EDB by regulating ferroptosis in ICH disease, which provided a theoretical basis for the clinical application of EDB in the treatment of ICH.

The effect of anti-CD20 on inflammation and histopathological alternations in rat photothrombotic ischemic stroke model

Ischemic stroke (IS) has remained the main cause of mortality and neurological disabilities worldwide. Anti-CD20 treatments have a potent anti-inflammatory effect. Here, we investigated the effect of anti-CD20 on IS-induced inflammation and histopathologic changes in the rat model. Male Sprague-Dawley rats were divided into three groups: control, sham, and stroke. Rats in the stroke groups underwent photothrombosis-induced IS in the sensorimotor cortex area. They were divided into the following subgroups: treated with anti-CD20 after ischemia and killed after 5 and/or 10 days of IS. Histological changes were assessed by hematoxylin and eosin staining. mRNA levels of inflammation markers (VIM, ANXA3, SLC22 A4, and ADM), and also levels of transcription factors for Th1, Th2, and Th17 subsets (Tbet, GATA3, and ROR-γ, respectively), and also Foxp3 were detected in the peripheral blood mononuclear cells by quantitative real-time PCR. The levels of ADM and SLC22 A4 increased following IS on the 5th and 10th days, while treatment with anti-CD20 reversed their levels. Anti-CD20 therapy attenuated inflammation through down-regulation of VIM and ANXA3 after 10 days. This therapeutic effect was mainly mediated by the downregulation of Th1-Th17-driven inflammatory responses (Tbet and RORγt) and the upregulation of Th2 activities (GATA- 3). In addition, anti-CD20 increased the expression of Foxp3. Anti-CD20 treatment can also reduce brain tissue damage after 10 days. Our data showed that inflammation and histopathological alterations are associated with the photothrombotic model of IS, while treatment with anti-CD20 could reduce inflammation and alleviate histopathological changes.

Forsythiaside A Ameliorates Oxidative Damage Caused by Cerebral Ischemia Through the Nrf2/HO-1 Signaling Pathway

Forsythiaside A (FA) has anti-inflammatory and antioxidant properties. The aim of this study was to explore the antioxidant effects and mechanisms of FA in ischemic stroke (IS). In this work, IS-related genes were obtained through GEO, GeneCards, TTD, CTD, DrugBank, and MalaCards databases. The targets of the FA were obtained from CTD, TargetNet, Super-PRED, TCMIO, and SwissTargetPrediction databases. GO analysis and KEGG pathway enrichment analysis were performed, and a protein-protein interaction (PPI) network was constructed to screen for key pathways. For in vivo assays, a middle cerebral artery occlusion and reperfusion (MCAO/R) model was established in rats, and high and low doses of FA were administered. Neurological impairment score, cerebral infarction, cerebral edema, and tissue morphology were evaluated. The content of reactive oxygen species (ROS), malondialdehyde (MDA) and superoxide dismutase (SOD) were detected. The expressions of cleaved caspase 3, Bax, and bcl-2, and Nrf2/HO-1 pathway-related proteins were detected by Western blot. For in vitro experiments, an oxygen-glucose deprivation/reperfusion (OGD/R) model was constructed in HT22 cells, and CCK-8 and LDH release assays were used to evaluate the effect of FA on OGD/R-induced toxicity of HT22 neurons. The Nrf2 inhibitor ML385 was used for the rescue experiments. Network pharmacology and bioinformatics analysis showed that the role of FA in treating IS was associated with oxidative stress. Topological analysis of the PPI network revealed 11 key genes, which were closely associated with the Nrf2 pathway. FA treatment could significantly reduce cerebral infarction, cerebral edema, neurological function impairment, and neuronal injury of the rats with MCAO/R. FA could also inhibit oxidative stress and neuronal apoptosis, and increase the viability of HT22 cells. In addition, FA promoted the nuclear translocation of Nrf2 and activated the Nrf2/HO-1 pathway, while ML385 weakened the protective effect of FA on neuronal viability and antioxidant capacity. In conclusion, FA attenuates the oxidative damage induced by IS by activating the Nrf2/HO-1 signaling pathway, which is a promising natural drug for IS.

Thyroid Function and Brain Structure: Insight from a Mendelian Randomization Study

INTRODUCTION

Thyroid hormones play a critical role in brain development. However, the precise causal associations between thyroid function and structural changes in specific brain regions remain uncertain.

METHODS

We applied the univariate Mendelian randomization (UVMR) method to assess the causal effects of thyroid function on brain structure. Genome-wide association study (GWAS) data on thyroid-related traits from the ThyroidOmics Consortium including free thyroxine (FT4), free tri-iodothyronine (FT3), thyroid-stimulating hormone (TSH), FT3/FT4 ratio, as well as dichotomized high and low TSH levels were used as exposures. GWAS data on cortical thickness, surface area, and volume of subcortical structures served as outcomes. Inverse variance weighted was the main estimate method. Subsequently, multivariable MR (MVMR) was conducted to validate significant causal associations identified in UVMR.

RESULTS

UVMR analysis demonstrated a statistically significant inverse association between genetically predicted FT4 and putamen volume (β = -71.91 mm3, 95% confidence interval: -112.11 mm3 to -31.71 mm3, p = 4.54 × 10-4). The findings were robust in sensitivity analysis. MVMR analysis further confirmed a persistent causal relationship between FT4 and putamen volume after adjusting for FT3, TSH, and neuropsychiatric disorders. Functional enrichment analyses indicated the pathways by which FT4 influences putamen volume may be related to the thyroid hormone signaling pathway, sodium-independent organic anion transport, and Rap1 signaling pathway.

CONCLUSION

MR analysis provides evidence for causal relationships between thyroid function and brain structural alterations, particularly highlighting the impact of FT4 on putamen volume. Further research is warranted to elucidate the underlying mechanisms by which thyroid hormones modulate brain structure.

Exploring New and Promising Genetic Biomarkers for Evaluating Traumatic Brain Injuries: A Case-Control Study

Traumatic brain injury (TBI) is a common cause of morbidity and death in all age groups, with an estimated 50 million people having brain injury due to trauma each year. Accurate blood-based biomarkers are needed to assist with diagnosis of patients across the spectrum of time and severity. Our objectives were to explore the diagnostic precision of time- and severity- related four blood-based biomarkers: AKT3, GSK-3β, hsa-miR-16-5p, and MALAT-1 for TBI for the purpose of diagnosis, prognosis, and follow-up. 40 samples were recruited as the following: 30 TBI patients and 10 healthy volunteers as controls with matched age and sex. They were divided according to the Glasgow Coma Scale into mild (mTBI), moderate (modTBI), and severe(sTBI) TBI. Blood samples were withdrawn at entry, and after 5 and 30 days, RT-PCR was used for measuring the expression level. The results showed upregulated expression levels of AKT3, hsa-miR-16-5p and significantly downregulated expression levels of GSK-3β in TBI patients compared to controls at all timings measured. mTBI patients showed a higher expression level of hsa-miR-16-5p compared with modTBI, and sTBI patients. MALAT-1 level showed a significant increase in severe cases only. We concluded that AKT3, hsa-miR-16-5p, and GSK-3β are excellent diagnostic biomarkers in TBI patients at initial assessment, as well as at 5 and 30 days following the injury. Moreover, MALAT-1 had good diagnostic value in sTBI patients, and its prognostic value extends to 30 days. GSK-3β was an excellent biomarker for detecting mTBI.

Cyclic adenosine 3', 5'-monophosphate (cAMP) signaling is a crucial therapeutic target for ulcerative colitis

The pathogenesis of ulcerative colitis (UC), a chronic intestine inflammatory disease primarily affecting adolescents, remains uncertain. Contemporary studies suggest that a confluence of elements, including genetic predispositions, environmental catalysts, dysregulated immune responses, and disturbances in the gut microbiome, are instrumental in the initiation and advancement of UC. Among them, inflammatory activation and mucosal barrier damage caused by abnormal immune regulation are essential links in the development of UC. The impairment of the mucosal barrier is intricately linked to the interplay of various cellular mechanisms, including oxidative stress, autophagy, and programmed cell death. An extensive corpus of research has elucidated that level of cyclic adenosine 3',5'-monophosphate (cAMP) undergo modifications in the midst of inflammation and participate in a diverse array of cellular operations that mitigate inflammation and the impairment of the mucosal barrier. Consequently, a plethora of pharmacological agents are currently under development, with some advancing through clinical trials, and are anticipated to garner approval as novel therapeutics. In summary, cAMP exerts a crucial influence on the onset and progression of UC, with fluctuations in its activity being intimately associated with the severity of the disease's manifestation. Significantly, this review unveils the paramount role of cAMP in the advancement of UC, offering a tactical approach for the clinical management of individuals afflicted with UC.

Identification and characterization of extrachromosomal circular DNA in large-artery atherosclerotic stroke

Extrachromosomal circular DNA (eccDNA) is a new biomarker and regulator of diseases. However, the role of eccDNAs in large-artery atherosclerotic (LAA) stroke remains unclear. Through high-throughput circle-sequencing technique, the length distribution, genomic characteristic and motifs feature of plasma eccDNA from healthy controls (CON) and patients with LAA stroke were analysed. Then, the potential functions of the annotated eccDNAs were investigated using GO and KEGG pathway analyses. EccDNAs mapped to the reference genome showed SHN3 and BCL6 were LAA stroke unique transcription factors. The genes of differentially expressed eccDNAs between LAA stroke patients and CON were mainly involved in axon/dendrite/neuron projection development and maintenance of cellular structure via Wnt, Rap1 and MAPK pathways. Moreover, LAA stroke unique eccDNA genes played a role in regulation of coagulation and fibrinolysis, and there were five LAA stroke unique eccDNAs (Chr2:12724406-12724784, Chr4:1867120-186272046, Chr4:186271494-186271696, Chr7:116560296-116560685 and Chr11:57611780-5761192). Additionally, POLR2C and AURKA carried by ecDNAs (eccDNA size >100 kb) of LAA stroke patients were significantly associated with development of LAA stroke. Our data firstly revealed the characteristics of eccDNA in LAA stroke and the functions of LAA stroke unique eccDNAs and eccDNA genes, suggesting eccDNA is a novel biomarker and mechanism of LAA stroke.

EPAC inhibitor suppresses angiogenesis and tumor growth of triple-negative breast cancer

AIMS

Exchange protein directly activated by cAMP 1 (EPAC1), a major isoform of guanine nucleotide exchange factors, is highly expressed in vascular endothelia cells and regulates angiogenesis in the retina. High intratumor microvascular densities (MVD) resulting from angiogenesis is responsible for breast cancer development. Downregulation of EPAC1 in tumor cell reduces triple-negative breast cancer (TNBC)-induced angiogenesis. However, whether Epac1 expressed in vascular endothelial cells contributes to angiogenesis and tumor development of TNBC remains elusive.

MAIN METHODS

We employed NY0123, a previously identified potent EPAC inhibitor, to explore the anti-angiogenic biological role of EPAC1 in vitro and in vivo through vascular endothelial cells, rat aortic ring, Matrigel plug, and chick embryo chorioallantoic membrane (CAM) and yolk sac membrane (YSM) assays, as well as the in vivo xenograft tumor models of TNBC in both chick embryo and mice.

KEY FINDINGS

Inhibiting EPAC1 in vascular endothelial cells by NY0123 significantly suppresses angiogenesis and tumor growth of TNBC. In addition, NY0123 possesses a better inhibitory efficacy than ESI-09, a reported specific EPAC inhibitor tool compound. Importantly, inhibiting EPAC1 in vascular endothelia cells regulates the typical angiogenic signaling network, which is associated with not only vascular endothelial growth factor (VEGF)/vascular endothelial growth factor receptor-2 (VEGFR2) signaling, but also PI3K/AKT, MEK/ERK and Notch pathway.

CONCLUSIONS

Our findings support that EPAC1 may serve as an effective anti-angiogenic therapeutic target of TNBC, and EPAC inhibitor NY0123 has the therapeutic potential to be developed for the treatment of TNBC.

Role of EPAC1 in chronic pain

Chronic pain usually lasts over three months and commonly occurs in chronic diseases (cancer, arthritis, and diabetes), injuries (herniated discs, torn ligaments), and many major pain disorders (neuropathic pain, fibromyalgia, chronic headaches). Unfortunately, there is currently a lack of effective treatments to help people with chronic pain to achieve complete relief. Therefore,it is particularly important to understand the mechanism of chronic pain and find new therapeutic targets. The exchange protein directly activated by cyclic adenosine monophosphate(cAMP) (EPAC) has been recognized for its functions in nerve regeneration, stimulating insulin release, controlling vascular pressure, and controlling other metabolic activities. In recent years, many studies have found that the subtype of EPAC, EPAC1 is involved in the regulation of neuroinflammation and plays a crucial role in the regulation of pain, which is expected to become a new therapeutic target for chronic pain. This article reviews the major contributions of EPAC1 in chronic pain.

Impacts of futile reperfusion and reperfusion injury in acute ischemic stroke

Acute ischemic stroke (AIS) remains to be a challenging cerebrovascular disease. The mainstay of AIS management is endovascular reperfusion therapy, including thrombectomy and thrombolysis. However, ineffective (futile) reperfusion (FR) or reperfusion injury (RI) can be seen in a significant number of patients undergoing reperfusion strategy. In this article, we discuss two clinically relevant concepts known as "time window" and "tissue window" that can impact the clinical outcome of reperfusion therapy. We also explore patient risk factors, leading to FR and RI as well as an emerging concept of "no-reflow phenomenon" seen in ineffective reperfusion. These fundamental concepts provide insight into the clinical management of AIS patients and provide references for future research.