Dunaliella salina Alga Protects against Myocardial Ischemia/Reperfusion Injury by Attenuating TLR4 Signaling.

Myocardial ischemia/reperfusion (I/R) injury is marked by rapid increase in inflammation and not only results in myocardial apoptosis but also compromises the myocardial function. Dunaliella salina (D. salina), a halophilic unicellular microalga, has been used as a provitamin A carotenoid supplement and color additive. Several studies have reported that D. salina extract could attenuate lipopolysaccharides-induced inflammatory effects and regulate the virus-induced inflammatory response in macrophages. However, the effects of D. salina on myocardial I/R injury remain unknown. Therefore, we aimed to investigate the cardioprotection of D. salina extract in rats subjected to myocardial I/R injury that was induced by occlusion of the left anterior descending coronary artery for 1 h followed by 3 h of reperfusion. Compared with the vehicle group, the myocardial infarct size significantly decreased in rats that were pre-treated with D. salina. D. salina significantly attenuated the expressions of TLR4, COX-2 and the activity of STAT1, JAK2, IκB, NF-κB. Furthermore, D. salina significantly inhibited the activation of caspase-3 and the levels of Beclin-1, p62, LC3-I/II. This study is the first to report that the cardioprotective effects of D. salina may mediate anti-inflammatory and anti-apoptotic activities and decrease autophagy through the TLR4-mediated signaling pathway to antagonize myocardial I/R injury.

Activation of peripheral TRPM8 mitigates ischemic stroke by topically applied menthol.

BACKGROUND: No reports exist as to neuroprotective effects associated with topical activation of transient receptor potential melastatin 8 (TRPM8), a noted cold receptor. In the present study, we identified whether activating peripheral TRPM8 can be an adjuvant therapy for ischemic stroke. METHODS: Menthol, an agonist of TRPM8, was applied orally or topically to all paws or back of the mouse after middle cerebral artery occlusion (MCAO). We used Trpm8 gene knockout (Trpm8-/-) mice or TRPM8 antagonist and lidocaine to validate the roles of TRPM8 and peripheral nerve conduction in menthol against ischemic stroke. RESULTS: Application of menthol 16% to paw derma attenuated infarct volumes and ameliorated sensorimotor deficits in stroke mice induced by MCAO. The benefits of topically applied menthol were associated with reductions in oxidative stress, neuroinflammation and infiltration of monocytes and macrophages in ischemic brains. Antagonizing TRPM8 or Trpm8 knockout dulls the neuroprotective effects of topically application of menthol against MCAO. Immunohistochemistry analyses revealed significantly higher TRPM8 expression in skin tissue samples obtained from the paws compared with skin from the backs, which was reflected by significantly smaller infarct lesion volumes and better sensorimotor function in mice treated with menthol on the paws compared with the back. Blocking conduction of peripheral nerve in the four paws reversed the neuroprotective effects of topical menthol administrated to paws. On the other hand, oral menthol dosing did not assist with recovery from MCAO in our study. CONCLUSION: Our results suggested that activation of peripheral TRPM8 expressed in the derma tissue of limbs with sufficient concentration of menthol is beneficial to stroke recovery. Topical application of menthol on hands and feet could be a novel and simple-to-use therapeutic strategy for stroke patients.

Postoperative Sore Throat Helps Predict Swallowing Disturbance on Postoperative Day 30 of Anterior Cervical Spine Surgery: A Secondary Exploratory Analysis of a Randomized Clinical Trial of Tracheal Intubation Modes.

Nasotracheal intubation benefits dysphonia recovery after anterior cervical spine surgery (ACSS). The aim of the present study was to investigate the effect of tracheal intubation modes on post-ACSS swallowing function and identify factors associated with deglutition on postoperative day 30 (POD 30). Adult patients were randomized to receive either nasotracheal or orotracheal intubation during surgery. A numerical rating scale (NRS) was used to assess postoperative sore throat, and the Bazaz grading system was used to assess the severity of swallowing disturbance. The primary endpoints were the effect of tracheal intubation modes on postoperative sore throat and deglutition. Thereafter, we further elucidated the predictors of swallowing disturbance on POD 30. Postoperative sore throat and swallowing disturbance did not differ between the nasotracheal and orotracheal intubation groups. A secondary dataset analysis revealed that among 108 patients with complete follow-up until POD 30, 71 (65.7%) presented complete recovery without swallowing disturbance, whereas 37 (34.3%) presented varying degrees of swallowing disturbance. Receiver operating characteristic curve analysis indicated that the NRS score for sore throat predicted a swallowing disturbance-free status on POD 30. The optimal cutoff values were ≤ 4 and ≤ 2 on PODs 1 and 2, respectively. The adjusted odds ratio (OR) for independent predictors was a sore throat NRS score of ≤ 4 on POD 1 (OR 3.2; 95% CI 1.29-7.89; P = 0.012) and score of ≤ 2 on POD 2 (OR 6.67; 95% CI 2.41-18.47; P < 0.001). Therefore, tracheal intubation mode did not affect the incidence of post-ACSS swallowing disturbance, and the severity of sore throat on PODs 1 and 2 could predict a swallowing disturbance-free status on POD 30.The trial was registered at clinicaltrials.gov (Trial No. NCT03240042, date of registration 10/17/2017).

Practice and outcomes of airway management in patients with cervical orthoses.

BACKGROUND/PURPOSE: Increasing evidence indicates an association of video laryngoscopy with the success rate of airway management in patients with neck immobilization. Nevertheless, clinical practice protocols for tracheal intubation in patients immobilized using various types of cervical orthoses and the outcomes remain unclear. METHODS: We retrospectively assessed the tracheal intubation techniques selected for patients immobilized using cervical orthoses from 2015 to 2018. The endpoints were the intubation outcomes of the different techniques and the factors associated with the selection of the technique. RESULTS: We included 218 patients, 118 of whom wore halo vest braces (halo vest group) and 100 wore cervical collars (collar group). GlideScope video laryngoscopy (GVL) and fiberoptic bronchoscopy (FOB) were the initial intubation methods in 98 and 120 patients, respectively. GVL had a higher first-attempt success rate than did FOB in the collar group (p = 0.002) but not in the halo vest group (p = 0.522). GVL was associated with a lower risk of episodes of SaO2< 90% (adjusted relative risk [aRR], 0.11; 95% CI, 0.02-0.67; p = 0.016) and shorter intubation time (aRR, -3.52; 95% CI, -4.79∼-2.25; p < 0.001) in the collar group. However, in the halo vest group, more frequent requirement of a rescue technique (p = 0.002) and necessity of patient awakening (p = 0.001) was noted when GVL was used. Use of the halo vest brace and noting of severe cord compression were independent predictors of the initial selection of FOB. CONCLUSION: Caution should be exercised when using GVL for tracheal intubation in patients immobilized using halo vest braces.

Therapeutic potential of cPLA2 inhibitor to counteract dilated-cardiomyopathy in cholesterol-treated H9C2 cardiomyocyte and MUNO rat.

BACKGROUND AND PURPOSE: The pathogenesis of cardiomyopathy in metabolically unhealthy obesity (MUO) has been well studied. However, the pathogenesis of cardiomyopathy typically associated with high cholesterol levels in metabolically unhealthy nonobesity (MUNO) remains unclear. We investigated whether cholesterol-generated LysoPCs contribute to cardiomyopathy and the role of cytosolic phospholipase A2 (cPLA2) inhibitor in cholesterol-induced MUNO. EXPERIMENTAL APPROACH: Cholesterol diet was performed in Sprague-Dawley rats that were fed either regular chow (C), or high cholesterol chow (HC), or HC diet with 10 % fructose in drinking water (HCF) for 12 weeks. LysoPCs levels were subsequently measured in rats and in MUNO human patients. The effects of cholesterol-mediated LysoPCs on cardiac injury, and the action of cPLA2 inhibitor, AACOCF3, were further assessed in H9C2 cardiomyocytes. KEY RESULTS: HC and HCF rats fed cholesterol diets demonstrated a MUNO-phenotype and cholesterol-induced dilated cardiomyopathy (DCM). Upregulated levels of LysoPCs were found in rat myocardium and the plasma in MUNO human patients. Further testing in H9C2 cardiomyocytes revealed that cholesterol-induced atrophy and death of cardiomyocytes was due to mitochondrial dysfunction and conditions favoring DCM (i.e. reduced mRNA expression of ANF, BNP, DSP, and atrogin-1), and that AACOCF3 counteracted the cholesterol-induced DCM phenotype. CONCLUSION AND IMPLICATIONS: Cholesterol-induced MUNO-DCM phenotype was counteracted by cPLA2 inhibitor, which is potentially useful for the treatment of LysoPCs-associated DCM in MUNO.

Aryl hydrocarbon receptor modulates stroke-induced astrogliosis and neurogenesis in the adult mouse brain.

BACKGROUND: The aryl hydrocarbon receptor (AHR) is a ligand-dependent transcription factor activated by environmental agonists and dietary tryptophan metabolites for the immune response and cell cycle regulation. Emerging evidence suggests that AHR activation after acute stroke may play a role in brain ischemic injury. However, whether AHR activation alters poststroke astrogliosis and neurogenesis remains unknown. METHODS: We adopted conditional knockout of AHR from nestin-expressing neural stem/progenitor cells (AHRcKO) and wild-type (WT) mice in the permanent middle cerebral artery occlusion (MCAO) model. WT mice were treated with either vehicle or the AHR antagonist 6,2',4'-trimethoxyflavone (TMF, 5 mg/kg/day) intraperitoneally. The animals were examined at 2 and 7 days after MCAO. RESULTS: The AHR signaling pathway was significantly upregulated after stroke. Both TMF-treated WT and AHRcKO mice showed significantly decreased infarct volume, improved sensorimotor, and nonspatial working memory functions compared with their respective controls. AHR immunoreactivities were increased predominantly in activated microglia and astrocytes after MCAO compared with the normal WT controls. The TMF-treated WT and AHRcKO mice demonstrated significant amelioration of astrogliosis and microgliosis. Interestingly, these mice also showed augmentation of neural progenitor cell proliferation at the ipsilesional neurogenic subventricular zone (SVZ) and the hippocampal subgranular zone. At the peri-infarct cortex, the ipsilesional SVZ/striatum, and the hippocampus, both the TMF-treated and AHRcKO mice demonstrated downregulated IL-1ß, IL-6, IFN-γ, CXCL1, and S100ß, and concomitantly upregulated Neurogenin 2 and Neurogenin 1. CONCLUSION: Neural cell-specific AHR activation following acute ischemic stroke increased astrogliosis and suppressed neurogenesis in adult mice. AHR inhibition in acute stroke may potentially benefit functional outcomes likely through reducing proinflammatory gliosis and preserving neurogenesis.

Exogenous GDF11 attenuates non-canonical TGF-ß signaling to protect the heart from acute myocardial ischemia-reperfusion injury.

Growth differentiation factor 11 (GDF11) is a member of the transforming growth factor beta 1 (TGF-ß1) superfamily that reverses age-related cardiac hypertrophy, improves muscle regeneration and angiogenesis, and maintains progenitor cells in injured tissue. Recently, targeted myocardial delivery of the GDF11 gene in aged mice was found to reduce heart failure and enhance the proliferation of cardiac progenitor cells after myocardial ischemia-reperfusion (I-R). No investigations have as yet explored the cardioprotective effect of exogenous recombinant GDF11 in acute I-R injury, despite the convenience of its clinical application. We sought to determine whether exogenous recombinant GDF11 protects against acute myocardial I-R injury and investigate the underlying mechanism in Sprague-Dawley rats. We found that GDF11 reduced arrhythmia severity and successfully attenuated myocardial infarction; GDF11 also increased cardiac function after I-R, enhanced HO-1 expression and decreased oxidative damage. GDF11 activated the canonical TGF-ß signaling pathway and inactivated the non-canonical pathways, ERK and JNK signaling pathways. Moreover, administration of GDF11 prior to reperfusion protected the heart from reperfusion damage. Notably, pretreatment with the activin-binding protein, follistatin (FST), inhibited the cardioprotective effects of GDF11 by blocking its activation of Smad2/3 signaling and its inactivation of detrimental TGF-ß signaling. Our data suggest that exogenous GDF11 has cardioprotective effects and may have morphologic and functional recovery in the early stage of myocardial I-R injury. GDF11 may be an innovative therapeutic approach for reducing myocardial I-R injury.

Changes in Sleep Architecture under Sustained Pain in Adult Male Rats Subjected to Neonatal Short-Lasting Local Inflammatory Insult.

Neonatal, short-lasting, local, nociceptive insult by carrageenan can cause long-term alterations in somatosensory and neurohumoral systems. We previously revealed hyporesponsiveness of the autonomic nervous system (ANS) after painful stimulation of adult rats in a neonatal carrageenan-induced pain model. Sleep disturbance has been highly correlated with pain and ANS activity. In the present study, adult rats that had received an intraplantar injection of carrageenan on postnatal day 1 were investigated to determine if there were alterations in their sleep architecture upon the stimulation of pain. Polysomnographic and heart rate variability recordings were carried out, with a wireless transmission of data, for 24 h under baseline conditions and after an intraplantar injection of complete Freund's adjuvant to induce sustained nociception. Increased active awake (AW) and decreased quiet sleep (QS) and paradoxical sleep (PS) times were noted in the control animals. In the carrageenan-treated rats, the AW time increased but with decreased alertness, as revealed by decreases in beta and increases in theta power. The QS time did not decrease. The PS time decreased during the first 12 h, then increased during the following 12 h, suggesting an early rebound of formerly deprived PS time. Sympathetic activation under sustained pain was not apparent in any stage of sleep in carrageenan-treated rats and was even suppressed in AW time. An impaired sympathetic reaction to pain may have contributed to the atypical changes in sleep architecture in these rats. In conclusion, pain in early life has a long-term effect on the cardiovascular-autonomic-electroencephalographic responses to pain later in life. The physiological relevance of these results remains undetermined.

Mechanisms of Acupuncture Therapy in Ischemic Stroke Rehabilitation: A Literature Review of Basic Studies.

Acupuncture is recommended by the World Health Organization (WHO) as an alternative and complementary strategy for stroke treatment and for improving stroke care. Clinical trial and meta-analysis findings have demonstrated the efficacy of acupuncture in improving balance function, reducing spasticity, and increasing muscle strength and general well-being post-stroke. The mechanisms underlying the beneficial effects of acupuncture in stroke rehabilitation remain unclear. The aim of this study was to conduct a literature review, summarize the current known mechanisms in ischemic stroke rehabilitation through acupuncture and electroacupuncture (EA) therapy, and to detail the frequently used acupoints implicated in these effects. The evidence in this review indicates that five major different mechanisms are involved in the beneficial effects of acupuncture/EA on ischemic stroke rehabilitation: (1) Promotion of neurogenesis and cell proliferation in the central nervous system (CNS); (2) Regulation of cerebral blood flow in the ischemic area; (3) Anti-apoptosis in the ischemic area; (4) Regulation of neurochemicals; and, (5) Improvement of impaired long-term potentiation (LTP) and memory after stroke. The most frequently used acupoints in basic studies include Baihui (GV20), Zusanli (ST36), Quchi (LI11), Shuigou (GV26), Dazhui (GV14), and Hegu (LI4). Our findings show that acupuncture exerts a beneficial effect on ischemic stroke through modulation of different mechanisms originating in the CNS.

Lumbrokinase attenuates myocardial ischemia-reperfusion injury by inhibiting TLR4 signaling.

Lumbrokinase, a novel antithrombotic agent, purified from the earthworm Lumbricus rubellus, has been clinically used to treat stroke and cardiovascular diseases. However, inflammatory responses associated with the cardioprotective effect of lumbrokinase remain unknown. In this study, the signaling pathways involved in lumbrokinase-inhibited expressions of inflammation mediators were investigated in rats subjected to myocardial ischemia-reperfusion (I-R) injury. The left main coronary artery of anesthetized rats was subjected to 1h occlusion and 3h reperfusion. The animals were treated with/without lumbrokinase and the severities of I-R-induced arrhythmias and infarction were compared. Lumbrokinase inhibited I-R-induced arrhythmias and reduced mortality, as well as decreased the lactate dehydrogenase levels in carotid blood. Lumbrokinase also inhibited the enhancement of I-R induced expressions of cyclooxygenase (COX)-2, inducible nitric oxide synthase (iNOS), and matrix metalloproteinase (MMP)-9 through toll-like receptor 4 (TLR4) signaling pathway. Moreover, our results demonstrated that stimulation with lumbrokinase decreases the phosphorylation of JNK, IκB, and NF-κB. These findings suggested that lumbrokinase is a potent cardioprotective drug in rats with I-R injury. The cardioprotective effects of lumbrokinase may be correlated with its inhibitory effect on the I-R-induced expressions of COX-2, iNOS and MMP-9, mediated by TLR4 signaling through JNK and NF-κB pathways.

The essential role of endothelial nitric oxide synthase activation in insulin-mediated neuroprotection against ischemic stroke in diabetes.

BACKGROUND: Stroke patients with diabetes have a higher mortality rate, worse neurologic outcome, and more severe disability than those without diabetes. Results from clinical trials comparing the outcomes of stroke seen with intensive glycemic control in diabetic individuals are conflicting. Therefore, the present study was aimed to identify the key factor involved in the neuroprotective action of insulin beyond its hypoglycemic effects in streptozotocin-diabetic rats with ischemic stroke. METHODS: Long-Evans male rats were divided into three groups (control, diabetes, and diabetes treated with insulin) and subjected to focal cerebral ischemia-reperfusion (FC I/R) injury. RESULTS: Hyperglycemia aggravated FC I/R injuries with an increase in cerebral infarction and neurologic deficits, inhibition of glucose uptake and membrane-trafficking activity of glucose transporter 1, and reduction of Akt and endothelial nitric oxide synthase (eNOS) phosphorylation in the cerebrum. Insulin treatment alleviated hyperglycemia and the symptoms of diabetes in streptozotocin-diabetic rats. Insulin administration also significantly decreased cerebral infarction and neurologic deficits and increased phosphorylation of Akt and eNOS protein in the cerebrum of FC I/R-injured diabetic rats. However, the glucose uptake and membrane trafficking activity of glucose transporter 1 in the cerebrum were not restored by insulin treatment. Coadministration of the eNOS inhibitor, N-iminoethyl-L-ornithine, with insulin abrogated beneficial effects of insulin on cerebral infarct volume and neurologic deficits in FC I/R-injured diabetic rats without affecting the hypoglycemic action of insulin. CONCLUSIONS: These results suggest that eNOS activation is required for the neuroprotection of insulin against ischemic stroke in patients with diabetes.

Insulin renders diabetic rats resistant to acute ischemic stroke by arresting nitric oxide reaction with superoxide to form peroxynitrite.

BACKGROUND: The functions of free radicals on the effects of insulin that result in protection against cerebral ischemic insult in diabetes remain undefined. This present study aims to explain the contradiction among nitric oxide (NO)/superoxide/peroxynitrite of insulin in amelioration of focal cerebral ischemia-reperfusion (FC I/R) injury in streptozotocin (STZ)-diabetic rats and to delineate the underlying mechanisms. Long-Evans male rats were divided into three groups (age-matched controls, diabetic, and diabetic treated with insulin) with or without being subjected to FC I/R injury. RESULTS: Hyperglycemia exacerbated microvascular functions, increased cerebral NO production, and aggravated FC I/R-induced cerebral infarction and neurological deficits. Parallel with hypoglycemic effects, insulin improved microvascular functions and attenuated FC I/R injury in STZ-diabetic rats. Diabetes decreased the efficacy of NO and superoxide production, but NO and superoxide easily formed peroxynitrite in diabetic rats after FC I/R injury. Insulin treatment significantly rescued the phenomenon. CONCLUSIONS: These results suggest that insulin renders diabetic rats resistant to acute ischemic stroke by arresting NO reaction with superoxide to form peroxynitrite.

Recovery of neurological function of ischemic stroke by application of conditioned medium of bone marrow mesenchymal stem cells derived from normal and cerebral ischemia rats.

BACKGROUND: Several lines of evidence have demonstrated that bone marrow-derived mesenchymal stem cells (BM-MSC) release bioactive factors and provide neuroprotection for CNS injury. However, it remains elusive whether BM-MSC derived from healthy donors or stroke patients provides equal therapeutic potential. The present work aims to characterize BM-MSC prepared from normal healthy rats (NormBM-MSC) and cerebral ischemia rats (IschBM-MSC), and examine the effects of their conditioned medium (Cm) on ischemic stroke animal model. RESULTS: Isolated NormBM-MSC or IschBM-MSC formed fibroblastic like morphology and expressed CD29, CD90 and CD44 but failed to express the hematopoietic marker CD34. The number of colony formation of BM-MSC was more abundant in IschBM-MSC than in NormBM-MSC. This is in contrast to the amount of Ficoll-fractionated mononuclear cells from normal donor and ischemic rats. The effect of cm of BM-MSC was further examined in cultures and in middle cerebral artery occlusion (MCAo) animal model. Both NormBM-MSC Cm and IschBM-MSC Cm effectively increased neuronal connection and survival in mixed neuron-glial cultures. In vivo, intravenous infusion of NormBM-MSC Cm and IschBM-MSC Cm after stroke onset remarkably improved functional recovery. Furthermore, NormBM-MSC Cm and IschBM-MSC Cm increased neurogenesis and attenuated microglia/ macrophage infiltration in MCAo rat brains. CONCLUSIONS: Our data suggest equal effectiveness of BM-MSC Cm derived from ischemic animals or from a normal population. Our results thus revealed the potential of BM-MSC Cm on treatment of ischemic stroke.

Exogenous endothelin-1 induces cell migration and matrix metalloproteinase expression in U251 human glioblastoma multiforme.

Glioblastoma multiforme (GBM) is the most common and lethal type of primary brain tumor characterized by its rapid infiltration to surrounding tissues during the early stages. The fast spreading of GBM obscures the initiation of the tumor mass making the treatment outcome undesirable. Endothelin-1 is known as a secretory protein presented in various types of brain cells, which has been indicated as a factor for cancer pathology. The aim of the present study was to investigate the molecular mechanism of cell migration in GBM. We found that various malignant glioma cells expressed higher amounts of endothelin-1, ETA, and ETB receptors than nonmalignant human astrocytes. The application of endothelin-1 enhanced the migratory activity in human U251 glioma cells corresponding to increased expression of matrix metalloproteinase (MMP)-9 and MMP-13. The endothelin-1-induced cell migration was attenuated by MMP-9 and MMP-13 inhibitors and inhibitors of mitogen-activated protein (MAP) kinase and PI3 kinase/Akt. Furthermore, the elevated levels of phosphate c-Jun accumulation in the nucleus and activator protein-1 (AP-1)-DNA binding activity were also found in endothelin-1 treated glioma cells. In migration-prone sublines, cells with greater migration ability showed higher endothelin-1, ETB receptor, and MMP expressions. These results indicate that endothelin-1 activates MAP kinase and AP-1 signaling, resulting in enhanced MMP-9 and MMP-13 expressions and cell migration in GBM.

Osthole suppresses the migratory ability of human glioblastoma multiforme cells via inhibition of focal adhesion kinase-mediated matrix metalloproteinase-13 expression.

Glioblastoma multiforme (GBM) is the most common type of primary and malignant tumor occurring in the adult central nervous system. GBM often invades surrounding regions of the brain during its early stages, making successful treatment difficult. Osthole, an active constituent isolated from the dried C. monnieri fruit, has been shown to suppress tumor migration and invasion. However, the effects of osthole in human GBM are largely unknown. Focal adhesion kinase (FAK) is important for the metastasis of cancer cells. Results from this study show that osthole can not only induce cell death but also inhibit phosphorylation of FAK in human GBM cells. Results from this study show that incubating GBM cells with osthole reduces matrix metalloproteinase (MMP)-13 expression and cell motility, as assessed by cell transwell and wound healing assays. This study also provides evidence supporting the potential of osthole in reducing FAK activation, MMP-13 expression, and cell motility in human GBM cells.

Interaction of inflammatory and anti-inflammatory responses in microglia by Staphylococcus aureus-derived lipoteichoic acid.

We investigated the interaction between proinflammatory and inflammatory responses caused by Staphylococcus aureus-derived lipoteichoic acid (LTA) in primary cultured microglial cells and BV-2 microglia. LTA induced inducible nitric oxide synthase (iNOS) and cyclooxygenase-2 (COX-2) protein levels increase in a concentration- and time-dependent manner. Meanwhile, LTA also increased nitric oxide (NO) and PGE2 production in microglia. Administration of TLR2 antagonist effectively inhibited LTA-induced NO, iNOS, and COX-2 expression. Moreover, treatment of cells with LTA caused a time-dependent activation of ERK, p38, JNK, as well as AKT. We also found that LTA-induced iNOS and COX-2 up-regulation were attenuated by p38, JNK, and PI3-kinase inhibitors. On the other hand, LTA-enhanced HO-1 expression was attenuated by p38 and PI3-kinase inhibitors. Treatment of cells with NF-κB and AP-1 inhibitors antagonized LTA-induced iNOS and COX-2 expression. However, only NF-κB inhibitors reduced LTA-induced HO-1 expression in microglia. Furthermore, stimulation of cells with LTA also activated IκBα phosphorylation, p65 phosphorylation at Ser5³6, and c-Jun phosphorylation. Moreover, LTA-induced increases of κB-DNA and AP-1-DNA binding activity were inhibited by p38, JNK, and PI3-kinase inhibitors. HO-1 activator CoPP IX dramatically reversed LTA-induced iNOS expression. Our results provided mechanisms linking LTA and inflammation/anti-inflammation, and indicated that LTA plays a regulatory role in microglia activation.

Leptin modulates electrophysiological characteristics and isoproterenol-induced arrhythmogenesis in atrial myocytes.

BACKGROUND: Obesity is an important risk factor for atrial fibrillation (AF). Leptin is an important adipokine. However, it is not clear whether leptin directly modulates the electrophysiological characteristics of atrial myocytes. RESULTS: Whole cell patch clamp and indo-1 fluorescence were used to record the action potentials (APs) and ionic currents in isolated rabbit left atrial (LA) myocytes incubated with and without (control) leptin (100 nM) for 1 h to investigate the role of leptin on atrial electrophysiology. Leptin-treated LA myocytes (n = 19) had longer 20% of AP duration (28 ± 3 vs. 21 ± 2 ms, p < 0.05), but similar 50% of AP duration (51 ± 4 vs. 50 ± 3 ms, p > 0.05), and 90% of AP duration (89 ± 5 vs. 94 ± 4 ms, p > 0.05), as compared to the control (n = 22). In the presence of isoproterenol (10 nM), leptin-treated LA myocytes (n = 21) showed a lower incidence (19% vs. 54.2%, p < 0.05) of delayed afterdepolarization (DAD) than the control (n = 24). Leptin-treated LA myocytes showed a larger sodium current, but a smaller ultra-rapid delayed rectifier potassium current, and sodium-calcium exchanger current than the control. Leptin-treated and control LA myocytes exhibited a similar late sodium current, inward rectifier potassium current, transient outward current and L-type calcium current. In addition, the leptin-treated LA myocytes (n = 38) exhibited a smaller intracellular Ca2+ transient (0.21 ± 0.01 vs. 0.26 ± 0.01 R410/485, p < 0.05) and sarcoplasmic reticulum Ca2+ content (0.35 ± 0.02 vs. 0.43 ± 0.03 R410/485, p < 0.05) than the control LA myocytes (n = 42). CONCLUSIONS: Leptin regulates the LA electrophysiological characteristics and attenuates isoproterenol-induced arrhythmogenesis.

Chronic intermittent hypoxia worsens brain damage and sensorimotor behavioral abnormalities after ischemic stroke: Effect on autonomic nervous activity and sleep patterns.

OBJECTIVE: Sleep apnea (SA) is characterized by intermittent hypoxia (IH), which increases sympathetic activity and sleep fragmentation, thus increasing the risk of stroke. SA is a highly prevalent disease and can worsen prognosis in patients with stroke. However, the correlation of changes in the cardiac autonomic nervous system and sleep patterns under IH with sensorimotor behavior and cerebral infarction after stroke remains unclear. We hypothesized that dysregulated autonomic activity and unstable sleep patterns induced by IH and correlated with cerebral infarction and abnormal sensorimotor behavior after middle cerebral artery occlusion (MCAO). METHODS: Wistar-Kyoto rats (WKY) were divided into IH (hypoxia: 5 % O2, 8 h/day) and RA group (room air) for 2 weeks and both groups were subjected to MCAO. After MCAO, the IH group was continuously exposed to IH for 1 week. The 24-h physiological signals, blood pressure, and sensorimotor behavior were recorded at baseline (Bas), the first and second weeks during IH (RA/IH1W and RA/IH2W, respectively), and poststroke. RESULTS: Before MCAO, IH caused sympathetic activity during sleep and parasympathetic activity of active waking (AW) to increase. Moreover, IH reduced the accumulated time and duration of paradoxical sleep (PS) and increased the interruption during sleep. After MCAO, IH increased blood pressure, more severe brain damage, and poor sensorimotor performance. Moreover, IH reduced autonomic activity after MCAO and decreased sympathetic activity was associated with poor sensorimotor performance. CONCLUSION: Autonomic activity and sleep patterns affected by IH were correlated with increased cerebral infarction and poor sensorimotor behavior after MCAO.

Intraoperative hypotension in non-emergency decompression surgery for cervical spondylosis: The role of chronic arterial hypertension.

Background: Cervical spondylotic myelopathy and chronic hypertension show a cause-effect relationship. Hypertension increases cardiovascular risk and is associated with intraoperative hypotension. We aimed to evaluate intraoperative hypotension in patients undergoing non-emergency decompression surgery for cervical spondylosis and its association with clinical myelopathy and chronic arterial hypertension. Methods: This retrospective cohort study used healthcare data of adult patients undergoing cervical spine surgeries at Taipei Veterans General Hospital from 2015 to 2019. The primary outcomes were the incidence of intraoperative hypotension and predictive factors, and the secondary outcomes were the association of intraoperative hypotension and postoperative adverse outcomes in the surgical population. Results: Among the 1833 patients analyzed, 795 (43.4%) required vasopressor treatment and 342 (18.7%) showed persistent hypotension. Factors independent associated with hypotension after anesthetic induction were age [odds ratio (OR), 1.15; 95% confidence interval (CI), 1.07-1.23 per 5 years, P < 0.001], male sex (OR, 1.63; 95% CI, 1.21-2.19, P < 0.001), chronic hypertension (OR, 1.77; 95% CI, 1.32-2.38, P < 0.001), upper cervical spine level C0-2 treated (OR, 3.04; 95% CI, 1.92-4.84, P < 0.001 vs. C3-T1), and increased number of spine segments treated (OR, 1.43; 95% CI 1.26-1.63, P < 0.001). Patients who developed intraoperative hypotension experienced more acute postoperative kidney injury (OR, 7.90; 95% CI, 2.34-26.63, P < 0.001), greater need for intensive care (OR, 1.80; 95% CI, 1.24-2.60, P = 0.002), and longer admission after surgery (1.09 days longer, 95% CI 0.06-2.12, P = 0.038). Conclusion: Intraoperative hypotension is common even in non-emergency cervical spine surgery. A history of hypertension independently predicted intraoperative hypotension. Prompt assessments for identifiable features can help ameliorate intraoperative hypotension.

Lumbrokinase regulates endoplasmic reticulum stress to improve neurological deficits in ischemic stroke.

Ischemic stroke is characterized by the loss of cerebral blood flow, which frequently leads to neurological deficits. Tissue plasminogen activator is the only therapeutic agent approved to treat ischemic stroke but increases the risk of intracranial hemorrhage and mortality. The fibrinogen-depleting agent lumbrokinase has been used to improve myocardial perfusion in symptomatic stable angina and to prevent secondary ischemic stroke. Lumbrokinase is highly fibrin-specific and only active in the presence of fibrin. Therefore, lumbrokinase has a low risk of hemorrhage due to excessive fibrinolysis. In this study, we aimed to clarify the neuroprotection of lumbrokinase in mice subjected to permanent middle cerebral artery occlusion. Lumbrokinase significantly attenuated infarct volume and improved neurological dysfunction. Lumbrokinase dramatically decreased the expressions of the endoplasmic reticulum (ER) transmembrane receptor protein inositol-requiring enzyme-1 (IRE1) and its downstream transcription factor, XBP-1, caspase-12, and NF-κB activity, thereby significantly inhibiting apoptosis and autophagy and decreasing the NLRP3 inflammasome. Our evidence indicates that post-stroke treatment with lumbrokinase protects against ischemic stroke, thereby regulating ER stress through the collective inhibitory effect of the IRE1 signaling pathways to decrease apoptosis, autophagy, and inflammatory responses. We suggest that lumbrokinase is potential as an adjuvant treatment for ischemic stroke.