Atorvastatin improved ulcerative colitis in association with gut microbiota-derived tryptophan metabolism.

AIMS: Atorvastatin is a commonly used cholesterol-lowering drug that possesses non-canonical anti-inflammatory properties. However, the precise mechanism underlying its anti-inflammatory effects remains unclear. MATERIALS AND METHODS: The acute phase of ulcerative colitis (UC) was induced using a 5 % dextran sulfate sodium (DSS) solution for 7 consecutive days and administrated with atorvastatin (10 mg/kg) from day 3 to day 7. mRNA-seq, histological pathology, and inflammatory response were determined. Intestinal microbiota alteration, tryptophan, and its metabolites were analyzed through 16S rRNA sequencing and untargeted metabolomics. KEY FINDINGS: Atorvastatin relieved the DSS-induced UC in mice, as evidenced by colon length, body weight, disease activity index score and pathological staining. Atorvastatin treatment reduced the level of pro-inflammatory cytokines interleukin-6 (IL-6) and tumor necrosis factor alpha (TNF-α). Atorvastatin also relieved the intestinal microbiota disorder caused by UC and decreased the proliferation of pernicious microbiota such as Akkermansia and Bacteroides. Atorvastatin dramatically altered tryptophan metabolism and increased the fecal contents of tryptophan, indolelactic acid (ILA), and indole-3-acetic acid (IAA). Furthermore, atorvastatin enhanced the expression level of aryl hydrocarbon receptor (AhR) and interleukin-22 (IL-22) and further promoted the expression level of intestinal tight junction proteins, such as ZO-1 and occludin, in colitis mice. SIGNIFICANCE: These findings indicated that atorvastatin could alleviate UC by regulating intestinal flora disorders, promoting microbial tryptophan metabolism, and repairing the intestinal barrier.

Susceptibility to Hepatotoxic Drug-Induced Liver Injury Increased After Traumatic Brain Injury in Mice.

The early stages of brain injury can induce acute liver injury, which can be recovered in the short term. Continued medication treatment during hospitalization for brain injury alleviates the prognosis and contributes to a high incidence of drug-induced liver injury (DILI). We hypothesize that there is an interaction between changes in the hepatic environment after brain injury and liver injury produced by intensive drug administration, leading to an upregulation of the organism's sensitivity to DILI. In this study, mice models of TBI were established by controlled cortical impact (CCI) and models of DILI were constructed by acetaminophen (APAP). All mice were divided into four groups: Sham, TBI, APAP, and TBI+APAP, and related liver injury indicators in liver and serum were detected by Western blot, Quantitative real-time PCR (qRT-PCR), and immunohistochemical staining. The results suggested that liver injury induced in the early stages of brain injury recovered in 3 days, but this state could still significantly aggravate DILI, represented by higher liver enzymes (aspartate aminotransferase [AST] and alanine aminotransferase [ALT]), oxidative stress (increase in malondialdehyde [MDA] concentration and deregulation of glutathione [GSH] and superoxide dismutase [SOD] activities), inflammatory response (activation of the HMGB1/TLR4/NF-κB signaling pathway, and increased messenger RNA [mRNA] and protein levels of pro-inflammatory cytokines including tumor necrosis factor alpha [TNF-α], interleukin [IL]-6, and IL-1ß), and apoptosis (TUNEL assay, upregulation of Bax protein and deregulation of Bcl-2 protein). In summary, our results suggested that TBI is a potential susceptibility factor for DILI and exacerbates DILI.

A deep learning-based interpretable decision tool for predicting high risk of chemotherapy-induced nausea and vomiting in cancer patients prescribed highly emetogenic chemotherapy.

OBJECTIVE: This study aims to develop a risk prediction model for chemotherapy-induced nausea and vomiting (CINV) in cancer patients receiving highly emetogenic chemotherapy (HEC) and identify the variables that have the most significant impact on prediction. METHODS: Data from Tianjin Medical University General Hospital were collected and subjected to stepwise data preprocessing. Deep learning algorithms, including deep forest, and typical machine learning algorithms such as support vector machine (SVM), categorical boosting (CatBoost), random forest, decision tree, and neural network were used to develop the prediction model. After training the model and conducting hyperparameter optimization (HPO) through cross-validation in the training set, the performance was evaluated using the test set. Shapley additive explanations (SHAP), partial dependence plot (PDP), and Local Interpretable Model-Agnostic Explanations (LIME) techniques were employed to explain the optimal model. Model performance was assessed using AUC, F1 score, accuracy, specificity, sensitivity, and Brier score. RESULTS: The deep forest model exhibited good discrimination, outperforming typical machine learning models, with an AUC of 0.850 (95%CI, 0.780-0.919), an F1 score of 0.757, an accuracy of 0.852, a specificity of 0.863, a sensitivity of 0.784, and a Brier score of 0.082. The top five important features in the model were creatinine clearance (Ccr), age, gender, anticipatory nausea and vomiting, and antiemetic regimen. Among these, Ccr had the most significant predictive value. The risk of CINV decreased with increased Ccr and age, while it was higher in the presence of anticipatory nausea and vomiting, female gender, and non-standard antiemetic regimen. CONCLUSION: The deep forest model demonstrated good discrimination in predicting the risk of CINV in cancer patients prescribed HEC. Kidney function, as represented by Ccr, played a crucial role in the model's prediction. The clinical application of this predictive tool can help assess individual risks and improve patient care by proactively optimizing the use of antiemetics in cancer patients receiving HEC.

Transcription factors in megakaryocytes and platelets.

Transcription factors bind promoter or regulatory sequences of a gene to regulate its rate of transcription. However, they are also detected in anucleated platelets. The transcription factors RUNX1, GATA1, STAT3, NFκB, and PPAR have been widely reported to play key roles in the pathophysiology of platelet hyper-reactivity, thrombosis, and atherosclerosis. These non-transcriptional activities are independent of gene transcription or protein synthesis but their underlying mechanisms of action remain poorly defined. Genetic and acquired defects in these transcription factors are associated with the production of platelet microvesicles that are known to initiate and propagate coagulation and to promote thrombosis. In this review, we summarize recent developments in the study of transcription factors in platelet generation, reactivity, and production of microvesicles, with a focus on non-transcriptional activities of selected transcription factors.

Construction and Comprehensive Analysis of ceRNA Networks and Tumor-Infiltrating Immune Cells in Hepatocellular Carcinoma With Vascular Invasion.

Background: Hepatocellular carcinoma (HCC) is a common malignant cancer. Metastasis plays a critical role in tumor progression, and vascular invasion is considered one of the most crucial factors for HCC metastasis. However, comprehensive analysis focusing on competitive endogenous RNA (ceRNA) and immune infiltration in the vascular invasion of HCC is lacking. Methods: The gene expression profiles of 321 samples, including 210 primary HCC cases and 111 HCC cases with vascular invasion, were downloaded from The Cancer Genome Atlas-Liver Hepatocellular Carcinoma project, and used in identifying significant differentially expressed lncRNAs (DElncRNAs), miRNAs (DEmiRNAs), and mRNAs (DEmRNAs). The RNAs associated with vascular invasion were used in constructing a ceRNA network. A multigene-based risk signature was constructed using the least absolute shrinkage and selection operator algorithm. We detected the fractions of 28 immune cell types in HCC through single-sample gene set enrichment analysis (ssGSEA). Finally, the relationship between the ceRNA network and immune cells was determined through correlation analysis and used in clarifying the potential mechanism involved in vascular invasion. Results: Overall, 413 DElncRNAs, 27 DEmiRNAs, and 397 DEmRNAs were recognized in HCC. A specific ceRNA network based on the interaction among 3 lncRNA-miRNA pairs and 24 miRNA-mRNA pairs were established. A ceRNA-based prognostic signature was constructed and used in dividing samples into high- and low-risk subgroups. The signature showed significant efficacy; its 3- and 5-year areas under the receiver operating characteristic curves were 0.712 and 0.653, respectively. ceRNA and ssGSEA integration analysis demonstrated that PART1 (p = 0, R = -0.33) and CDK5R2 (p = 0.01, R = -0.15) were negatively correlated to natural killer cells. Conclusion: This study demonstrated that vascular invasion in HCC might be related to PART1, and its role in regulating CDK5R2 and NK cells. A nomogram was developed to predict the prognosis of patients with HCC and demonstrated the value of the ceRNA network and tumor-infiltrating immune cells value in improving personalized management.

MicroRNA alteration in cerebrospinal fluid from comatose patients with traumatic brain injury after right median nerve stimulation.

Electrical stimulation of the right median nerve can aid coma arousal after traumatic brain injury (TBI). This study aimed to confirm the efficacy further and explore possible mechanisms of right median nerve electrical stimulation (RMNS). Five comatose patients after severe TBI from May to September 2020 in the Tianjin Medical University General Hospital received RMNS for 2 weeks besides standard management. After the 2-week treatment, the mean Glasgow Coma Scale (GCS) and neurophysiological examination were used. We then investigated the alterations in microRNA (miRNA) expression in cerebrospinal fluid (CSF) by high-throughput whole transcriptome sequencing, analyzed the data by Gene Ontology (GO) and pathway analysis, and constructed the miRNA-target gene network. Patient awareness and brain function showed a more rapid increase after treatment. We also found 38 differently expressed miRNAs, 34 of which were upregulated and 4 downregulated. GO analysis showed a relation of these differentially expressed miRNAs with neuronal growth, repair, and neural signal transmission. The most highly correlated pathways were primarily associated with the tumor necrosis factor (TNF) signaling pathway and dopaminergic synapse. The application of RMNS effectively promoted early awakening in comatose patients with severe TBI. Moreover, differentially expressed miRNAs might reduce neuronal apoptosis and increase dopamine levels by regulating target gene expression, thus participating in the specific biological process after arousal therapy. Our study provided novel targets for further research on the molecular mechanisms of RMNS arousal treatment and a new way to treat neurotraumatic diseases.

Development, validation, and clinical application of a rapid UPLC-MS/MS method for detection of colchicine in human whole blood and urine.

A rapid, simple, and economical method has been developed to determine colchicine in both human whole blood and urine using UPLC-MS/MS. Colchicine and isotope-labeled internal standard were extracted from the matrix by liquid-liquid extraction with saturated borax and ethyl acetate, and separated by a reversed-phase chromatography C18 column. Gradient elution was carried out using acetonitrile and water spiked with 0.01% formic acid. Multiple reaction monitoring was performed at positive ion mode. The quantitative transitions were m/z 400.27 → 310.28 for colchicine and m/z 406.16 → 313.18 for colchicine-D6. The method has good linearity in the range of 0.5-200 ng/mL for blood and 2-2000 ng/mL for urine. The sensitivity, accuracy, and matrix effect were all in line with the guidelines of Food and Drug Administration and European Medicines Agency. The extraction recovery was above 63.94%. The samples were stable under various storage conditions. Six deuterium-substituted isotopic internal standard was used to demonstrate a different mode of colchicine cleavage from the existing literature. This method has been successfully used in the diagnosis of patients with colchicine poisoning. Blood is recommended as the optimal sample compared with urine.

Process analysis of anthracycline adverse reactions in breast cancer patients with postoperative chemotherapy.

This study aimed to explore the clinical adverse effects of anthracyclines on patients undergoing chemotherapy after breast cancer surgery. A total of 118 patients who received anthracycline chemotherapy after breast cancer surgery were selected as the research object, and the changes of echocardiogram, ECG, myocardial enzymes and blood biochemical indices before, during and after chemotherapy were studied. SPSS V.20 was used to conduct statistical analysis. The differences in heart rate, ST-segment abnormalities, creatine kinase, lactate dehydrogenase, hemoglobin, albumin, triglycerides and high-density lipoprotein were statistically significant. Heart rate and triglycerides increased significantly in the early stage of chemotherapy; ST-segment abnormality increased during the entire chemotherapy period; creatine kinase and lactate dehydrogenase increased significantly in the late stage of chemotherapy; hemoglobin and albumin decreased in the early stage of chemotherapy. The magnitude is large; high-density lipoprotein decreases throughout the chemotherapy period. In anthracycline chemotherapy regimens, bone marrow suppression and dyslipidemia occur in the early stage of chemotherapy, and the risk of cardiotoxicity is higher in the late stage of chemotherapy.

Alterations of microRNAs expression profiles in small extracellular vesicle after traumatic brain injury in mice.

Traumatic brain injury (TBI) is one of the leading causes of mortality and morbidity worldwide. Tools available for diagnosis and therapy are limited. Small extracellular vesicle (sEV) microRNAs (miRNAs) play an important role in TBI disease progression. This study aimed to investigate the alterations in sEV miRNAs expression in the mouse brain extracellular space after TBI. Twenty-four C57BL/6J mice were randomly divided into two groups (12/group). The TBI group was subjected to all surgical procedures and fluid percussion injury (FPI). The sham group only underwent surgery. Brain specimens were collected 3 h after TBI/sham. The brain sEV were isolated. Differentially expressed miRNAs were identified. A total of 50 miRNAs were observed to be differentially expressed (fold change ≥1.5 and P<0.05) after TBI, including 5 upregulated and 45 downregulated. The major enriched Gene Ontology terms were metabolic processes, cell, intracellular, organelle, cytoplasm, axon, binding, protein kinase activity, protein binding, and protein dimerization activity. The KEGG pathway analysis predicted that the pathways affected by the variation of miRNAs in sEVs after TBI included the Wnt signaling pathway and NF-κB signaling pathway. The changes in five miRNAs were confirmed by qRT-PCR. In conclusion, this study demonstrated the differential expression of a series of miRNAs in brain sEV after TBI, which might be correlated with post-TBI physiological and pathological processes. The findings might also provide novel targets for further investigating the molecular mechanisms underlying TBI and potential therapeutic interventions.

Role of the Aryl Hydrocarbon Receptor and Gut Microbiota-Derived Metabolites Indole-3-Acetic Acid in Sulforaphane Alleviates Hepatic Steatosis in Mice.

Scope: Gut microbiome-derived metabolites are the major mediators of diet-induced host-microbial interactions. Aryl hydrocarbon receptor (AHR) plays a crucial role in glucose, lipid, and cholesterol metabolism in the liver. In this study, we aimed to investigate the role of indole-3-acetic acid (IAA) and AHR in sulforaphane (SFN) alleviates hepatic steatosis in mice fed on a high-fat diet (HFD). Methods and Results: The HFD-fed male C57BL/6 mice were intervened with SFN for 6 weeks. HFD-mice showed classical pathophysiological characteristics of hepatic steatosis. The results showed that SFN significantly reduced body weight, liver inflammation and hepatic steatosis in HFD-fed mice. SFN reduced hepatic lipogenesis by activating AHR/SREBP-1C pathway, which was confirmed in HepG2 cell experiments. Moreover, SFN increased hepatic antioxidant activity by modulating Nrf-2/NQO1 expression. SFN increased serum and liver IAA level in HFD mice. Notably, SFN manipulated the gut microbiota, resulting in reducing Deferribacteres and proportions of the phylum Firmicutes/Bacteroidetes and increasing the abundance of specific bacteria that produce IAA. Furthermore, SFN upregulated Ahr expression and decreased the expression of inflammatory cytokines in Raw264.7 cells. Conclusions: SFN ameliorated hepatic steatosis not only by modulating lipid metabolism via AHR/SREBP-1C pathway but regulating IAA and gut microbiota in HFD-induced NAFLD mice.

Dexamethasone enhances the efficacy of atorvastatin in inhibiting excessively inflammation-induced abnormal angiogenesis by regulating macrophages.

BACKGROUND: We have recently showed that atorvastatin (ATO) combined with low dose of dexamethasone (DEX) was more efficacious in treating patients with chronic subdural haematoma (CSDH) than ATO monotherapy. This study was designed to investigate the underlying mechanisms of the improved efficacy of this combined therapy. METHODS: Mass spectrometry was performed to quantitatively detect drugs in haematoma fluids and serum samples from CSDH patients and also in cultured macrophages after treatment with either ATO alone or in combination with DEX. The differentiation and apoptosis of macrophages were evaluated using flow cytometry. The expression of cytokines, chemokines and angiogenesis-related proteins was evaluated using proteome profile arrays, immunoblots and ELISA, respectively. RESULTS: ATO was detected in haematoma fluids and serum samples, whose levels were increased significantly in samples collected from patients treated with both ATO and DEX. ATO was also increased in cultured macrophages treated with ATO and DEX. The numbers of M1-polarized macrophages were higher than the M2 phenotype in the haematoma fluids of patients. Cultured macrophages treated with ATO and DEX had reduced numbers of M1-polarized macrophages, increased numbers of M2-polarized macrophages as compared to monotherapies, and decreased rate of apoptosis induced by high-dose DEX. DEX enhanced the anti-inflammatory and anti-angiogenic activity of ATO by suppressing VEGFA and other inflammatory angiogenic factors. Consistent with the finding, patients responded well to the drug treatments had lower serum levels of VEGFA. CONCLUSIONS: We have shown for the first time that ATO given orally was detected in CSDH haematoma fluids. DEX enhances the anti-inflammatory and anti-angiogenic effects of ATO, primarily by increasing the presence of ATO in haematoma and macrophages and by regulating the functions of macrophages.

Low-temperature laminar flow ward for the treatment of multidrug resistance Acinetobacter baumannii pneumonia.

This study was designed to investigate the effect of low-temperature laminar flow ward (LTLFW) on the Acinetobacter baumannii pneumonia (MDR-ABP) in neurosurgical intensive care unit (NICU) patients. We evaluated whether patients in a LTLFW had significantly improved clinical outcomes as compared to those in nonconstant-temperature NICU (room temperature). The association of temperature with the prevalence of ABP and A. baumannii isolates (ABI) found in NICU patients was specifically investigated. In vitro microbiological experiments were conducted to measure the proliferation, antibiotic sensitivity, and genomic profiles of A. baumannii (AB) that grew in variable temperatures. MDR-ABP patients in LTLFW had significantly improved outcomes than those in the room temperature NICU. In addition, the numbers of ABI were positively associated with mean ambient outdoor temperatures (P = 0.002), with the incidence of ABP and average numbers of ABI among NICU patients being substantially lower in the winter as compared to other seasons. However, there were no significant seasonal variations in the other strains of the top five bacteria. Consistent with these clinical observations, AB growing at 20°C and 25°C had significantly reduced viability and antibiotic resistance compared to those growing at 35°C. The expression of genes related to AB survival ability, drug resistance, and virulence also differed between AB growing at 20°C and those at 35°C. LTLFW is effective in promoting the recovery of MDR-ABP patients because low temperatures reduced the density and virulence of AB and enhanced the efficacy of antibiotics, likely at the genetic level.

Extracellular mitochondria released from traumatized brains induced platelet procoagulant activity.

Coagulopathy often develops soon after acute traumatic brain injury and its cause remains poorly understood. We have shown that injured brains release cellular microvesicles that disrupt the endothelial barrier and induce consumptive coagulopathy. Morphologically intact extracellular mitochondria accounted for 55.2% of these microvesicles, leading to the hypothesis that these extracellular mitochondria are metabolically active and serve as a source of oxidative stress that activates platelets and renders them procoagulant. In testing this hypothesis experimentally, we found that the extracellular mitochondria purified from brain trauma mice and those released from brains subjected to freeze-thaw injury remained metabolically active and produced reactive oxygen species. These extracellular mitochondria bound platelets through the phospholipid-CD36 interaction and induced α-granule secretion, microvesiculation, and procoagulant activity in an oxidant-dependent manner, but failed to induce aggregation. These results define an extracellular mitochondria-induced and redox-dependent intermediate phenotype of platelets that contribute to the pathogenesis of traumatic brain injury-induced coagulopathy and inflammation.

Physical proximity and functional cooperation of glycoprotein 130 and glycoprotein VI in platelet membrane lipid rafts.

OBJECTIVE: Clinical and laboratory studies have demonstrated that platelets become hyperactive and prothrombotic in conditions of inflammation. We have previously shown that the proinflammatory cytokine interleukin (IL)-6 forms a complex with soluble IL-6 receptor α (sIL-6Rα) to prime platelets for activation by subthreshold concentrations of collagen. Upon being stimulated with collagen, the transcription factor signal transducer and activator of transcription (STAT) 3 in platelets is phosphorylated and dimerized to act as a protein scaffold to facilitate the catalytic action between the kinase Syk and the substrate phospholipase Cγ2 (PLCγ2) in collagen-induced signaling. However, it remains unknown how collagen induces phosphorylation and dimerization of STAT3. METHODS AND RESULTS: We conducted complementary in vitro experiments to show that the IL-6 receptor subunit glycoprotein 130 (GP130) was in physical proximity to the collagen receptor glycoprotein VI (GPVI in membrane lipid rafts of platelets. This proximity allows collagen to induce STAT3 activation and dimerization, and the IL-6-sIL-6Rα complex to activate the kinase Syk and the substrate PLCγ2 in the GPVI signal pathway, resulting in an enhanced platelet response to collagen. Disrupting lipid rafts or blocking GP130-Janus tyrosine kinase (JAK)-STAT3 signaling abolished the cross-activation and reduced platelet reactivity to collagen. CONCLUSION: These results demonstrate cross-talk between collagen and IL-6 signal pathways. This cross-talk could potentially provide a novel mechanism for inflammation-induced platelet hyperactivity, so the IL-6-GP130-JAK-STAT3 pathway has been identified as a potential target to block this hyperactivity.

Circular Ribonucleic Acid Expression Alteration in Exosomes from the Brain Extracellular Space after Traumatic Brain Injury in Mice.

Traumatic brain injury (TBI) has high morbidity and mortality rates. The mechanisms underlying TBI are unclear and may include the change in biological material in exosomes. Circular ribonucleic acids (circRNAs) are enriched and stable in exosomes, which can function as microRNA (miRNA) sponges to regulate gene expression levels. Therefore, we speculated that circRNAs in exosomes might play an important role in regulating gene expression after TBI and then regulate specific signaling pathways, which may protect the brain. We first isolated exosomes from the brain extracellular space in mice with TBI by digestion. We then investigated the alterations in circRNA expression in exosomes by high-throughput whole transcriptome sequencing, analyzed the data by gene ontology (GO) and pathway analysis, and constructed the circRNA-miRNA network. In this study, we identified 231 significantly and differentially expressed circRNAs, including 155 that were upregulated and 76 that were downregulated. GO analysis showed that these differentially expressed circRNAs might be related to the growth and repair of neurons, the development of the nervous system, and the transmission of nerve signals. The most highly correlated pathways that we identified were involved primarily with glutamatergic synapse and the cyclic guanosine monophosphate-protein kinase G signaling pathway. The circRNA-miRNA network predicted the potential roles of these differentially expressed circRNAs and the interaction of circRNAs with miRNAs. Our study broadens the horizon of research on gene regulation in exosomes from the brain extracellular space after TBI and provides novel targets for further research on both the molecular mechanisms of TBI and the potential intervention therapy targets.

Antidepressant-like effect of the saponins part of ethanol extract from SHF.

ETHNOPHARMACOLOGICAL RELEVANCE: Suanzaorenhehuan Formula (SHF) has been used for treating depression-like disorders for many years in China. The saponins part of the SHF (SSHF) extract was the antidepressant effective component. AIM OF STUDY: To investigate the antidepressant-like effect of SSHF and its possible mechanisms. MATERIALS AND METHODS: Experimental approaches including the forced swim test (FST), the tail suspension test (TST) and unpredictable chronic mild stress (UCMS) were used to evaluate the effects of SSHF. The possible mechanisms were explored by measuring monoamine neurotransmitter in mice frontal cortex and hippocampus, testing monoamine oxidase enzyme (MAO) activities, antioxidant enzyme activities and free radicals levels in the brains of UCMS-exposed mice. RESULTS: The results showed that SSHF (10, 20, 40mg/kg) significantly decreased the immobility period in FST and TST in mice after two-week treatment. Whereas, SSHF had no significant effect on locomotor activity in mice. It was also found that the serotonin (5-HT) and noradrenaline (NE) levels in the hippocampus and frontal cortex were significantly increased only in 40mg/kg SSHF treated mice. In addition, SSHF (10, 20, 40mg/kg) significantly inhibited monoamine oxidase-A (MAO-A) and monoamine oxidase-B (MAO-B) after 21-day UCMS exposure. SSHF (10, 20, 40mg/kg) significantly decreased the nitrous oxide (NO) levels, and increased the activities of total antioxidant capability (T-AOC), glutathione peroxidase (GSH-PX), and catalase (CAT) in different degrees in the brains of UCMS-exposed mice. CONCLUSIONS: Our results suggested that SSHF may effectively produce an antidepressant-like effect, which appeared to involve the serotonergic, noradrenergic, monoamine oxidase enzyme and antioxidant systems.

Piperlongumine Blocks JAK2-STAT3 to Inhibit Collagen-Induced Platelet Reactivity Independent of Reactive Oxygen Species.

BACKGROUND: Piperlongumine (PL) is a compound isolated from the piper longum plant. It possesses anti-cancer activities through blocking the transcription factor STAT3 and by inducing reactive oxygen species (ROS) in cancer, but not normal cells. It also inhibits platelet aggregation induced by collagen, but the underlying mechanism is not known. OBJECTIVE: We conducted in vitro experiments to test the hypothesis that PL regulates a non-transcriptional activity of STAT3 to specifically reduce the reactivity of human platelets to collagen. RESULTS: PL dose-dependently blocked collagen-induced platelet aggregation, calcium influx, CD62p expression and thrombus formation on collagen with a maximal inhibition at 100 µM. It reduced platelet microvesiculation induced by collagen. PL blocked the activation of JAK2 and STAT3 in collagen-stimulated platelets. This inhibitory effect was significantly reduced in platelets pretreated with a STAT3 inhibitor. Although PL induced ROS production in platelets; quenching ROS using excessive reducing agents: 20 µM GSH and 0.5 mM L-Cysteine, did not block the inhibitory effects. The NADPH oxidase inhibitor Apocynin also had no effect. CONCLUSIONS: PL inhibited collagen-induced platelet reactivity by targeting the JAK2-STAT3 pathway. We also provide experimental evidence that PL and collagen induce different oxidants that have differential effects on platelets. Studying these differential effects may uncover new mechanisms of regulating platelet functions by oxidants in redox signals.

Brain-derived microparticles induce systemic coagulation in a murine model of traumatic brain injury.

Traumatic brain injury (TBI) is associated with coagulopathy, although it often lacks 2 key risk factors: severe bleeding and significant fluid resuscitation associated with hemorrhagic shock. The pathogenesis of TBI-associated coagulopathy remains poorly understood. We tested the hypothesis that brain-derived microparticles (BDMPs) released from an injured brain induce a hypercoagulable state that rapidly turns into consumptive coagulopathy. Here, we report that mice subjected to fluid percussion injury (1.9 ± 0.1 atm) developed a BDMP-dependent hypercoagulable state, with peak levels of plasma glial cell and neuronal BDMPs reaching 17 496 ± 4833/µL and 18 388 ± 3657/µL 3 hours after TBI, respectively. Uninjured mice injected with BDMPs developed a dose-dependent hyper-turned hypocoagulable state measured by a progressively prolonged clotting time, fibrinogen depletion, and microvascular fibrin deposition in multiple organs. The BDMPs were 50 to 300 nm with intact membranes, expressing neuronal or glial cell markers and procoagulant phosphatidylserine and tissue factor. Their procoagulant activity was greater than platelet microparticles and was dose-dependently blocked by lactadherin. Microparticles were produced from injured hippocampal cells, transmigrated through the disrupted endothelial barrier in a platelet-dependent manner, and activated platelets. These data define a novel mechanism of TBI-associated coagulopathy in mice, identify early predictive markers, and provide alternative therapeutic targets.

Noninvasive delayed limb ischemic preconditioning in rats increases antioxidant activities in cerebral tissue during severe ischemia-reperfusion injury.

BACKGROUND: To study the protection offered by noninvasive delayed limb ischemic preconditioning (NDLIP) against cerebral ischemia reperfusion (I/R) injury in rats. MATERIALS AND METHODS: Healthy male Wistar rats were randomly divided into four groups. The delayed protection offered by NDLIP was estimated in light of changes in the neural behavior marker and cerebral tissue antioxidative ability. Neurological functions were studied by observing neural behavior. Total superoxide dismutase (T-SOD), manganese-superoxide dismutase (Mn-SOD), glutathione peroxidase (GSH-PX), and xanthine oxidase (XOD) activity in cerebral tissue and malonaldehyde (MDA) content were detected using a spectrophotometer. Mn-SOD mRNA was measured by the reverse transcription polymerase chain reaction method. RESULTS: Cerebral infarct size was diminished in the early cerebral ischemia preconditioning (ECIP)+I/R and NDLIP+I/R groups compared with the I/R group (P < 0.05). The cortical and hippocampal antioxidant enzyme activity and Mn-SOD expression were increased in the ECIP+I/R and NDLIP+I/R groups. In contrast, the cortical and hippocampal XOD activity and MDA content decreased in the ECIP+I/R and NDLIP+I/R groups. CONCLUSIONS: NDLIP decreased cerebral infarct size, increased cerebral antioxidative ability after I/R injury, and decreased peroxidative damage. The antioxidative protection offered by NDLIP was as effective as that offered by ECIP.