The Effect of S-Allyl L-Cysteine on Retinal Ischemia: The Contributions of MCP-1 and PKM2 in the Underlying Medicinal Properties.

Retinal ischemia plays a vital role in vision-threatening retinal ischemic disorders, such as diabetic retinopathy, age-related macular degeneration, glaucoma, etc. The aim of this study was to investigate the effects of S-allyl L-cysteine (SAC) and its associated therapeutic mechanism. Oxidative stress was induced by administration of 500 µM H2O2 for 24 h; SAC demonstrated a dose-dependent neuroprotective effect with significant cell viability effects at 100 µM, and it concurrently downregulated angiogenesis factor PKM2 and inflammatory biomarker MCP-1. In a Wistar rat model of high intraocular pressure (HIOP)-induced retinal ischemia and reperfusion (I/R), post-administration of 100 µM SAC counteracted the ischemic-associated reduction of ERG b-wave amplitude and fluorogold-labeled RGC reduction. This study supports that SAC could protect against retinal ischemia through its anti-oxidative, anti-angiogenic, anti-inflammatory, and neuroprotective properties.

Evaluation of post-stroke spasticity from the subacute to chronic stages: A clinical and neurophysiologic study of motoneuron pool excitability.

Spasticity measured using clinical scales, such as the modified Ashworth scale (MAS), may not sufficiently evaluate the effectiveness of therapeutic interventions and predict prognosis. This study aimed to compare changes in H-reflex excitability in the spastic and unimpaired upper and lower limbs of patients with acute and chronic stroke. We also investigated the relationship between the degree of spasticity as assessed by the MAS and motor neuron pool excitability with by analyzing H-reflex excitability. Sixty adult patients with a first-ever stroke were recruited for this study. MAS scores were recorded in the post-stroke upper and lower limb muscles. H-reflexes and M-responses of the bilateral flexor carpi radialis and soleus were tested by stimulating the median and tibial nerves. The results showed that both the ratio of the maximal size of the H-reflex (Hmax) to the maximal size of the M-response (Mmax) and the ratio of the developmental slope of H-reflex (Hslp) to that of the M-responses (Mslp) were significantly higher on the spastic side than on the unimpaired side for the upper and lower limbs. In contrast, the ratio of the threshold of the H-reflex (Hth) to the threshold of the M-response (Mth) only showed significant differences between the two sides in the upper limbs. The Hslp/Mslp paretic/non-paretic ratio was increased in patients with MAS scores of 2 or 3 compared to MAS scores of 1 for both the upper and lower limbs, whereas the Hmax/Mmax paretic/non-paretic ratio showed significant differences between MAS scores of 2 or 3 and 1 only in the upper limbs. Moreover, in either the spastic or unimpaired sides, there were no significant differences in any of the three motoneuron pool excitability parameters, Hmax/Mmax, Hslp/Mslp, and Hth/Mth, between the shorter chronicity (time post-stroke ≤6 months) and longer chronicity groups (time post-stroke >6 months) for both the upper and lower limbs. These results suggest that Hslp/Mslp could be a potential neurophysiological indicator for evaluating the degree of spasticity in both the upper and lower limbs of patients with hemiplegia. The MAS and Hslp/Mslp characterize clinical and neurophysiologic spasticity, respectively, and could be used as an integrated approach to evaluate and follow up post-stroke spasticity.

Increased GABAergic inhibitory function against ischemic long-term potentiation in the CA1 region of the hippocampus.

Potentiation of N-methyl-D-aspartate receptor (NMDAR)-mediated excitatory synaptic plasticity around 1 h after brief exposure to anoxia/aglycemia is called ischemic long-term potentiation (iLTP), which is considered a pathological form of synaptic response during the early phase of ischemic stroke. It is known that GABAergic inhibitory transmission is also an important molecular process involved in synaptic plasticity and learning memory. However, whether GABAergic transmission is involved in iLTP and early-phase plasticity in ischemic stroke remains unknown. In this study, iLTP was found to be induced in the hippocampal Schaffer-collateral pathway by exposure to oxygen glucose deprivation (OGD). Western blot analysis was conducted to analyze excitatory synaptic receptors and inhibitory synaptic receptors following OGD. The ß3 subunit of the GABAA receptor (GABAAR) was markedly reduced, whereas the GluN2B subunit of the NMDAR was increased in the hippocampal area in the OGD group. Using extracellular recording, we demonstrated that application of GABAAR agonist midazolam could abolish the hippocampal iLTP. Moreover, midazolam had no significant effect on the increase in NMDAR subunit GluN2B, but ameliorated the reduction in the ß3 subunit of GABAAR after OGD. In summary, our results indicated that hippocampal GABAAR reduction promoted synaptic potentiation after OGD. Activation of GABAergic inhibitory transmission function could inhibit iLTP; thus, modulation of GABAergic function is a protective treatment method in the acute phase of synaptic plasticity in ischemic stroke.

Astaxanthin Ameliorates Ischemic-Hypoxic-Induced Neurotrophin Receptor p75 Upregulation in the Endothelial Cells of Neonatal Mouse Brains.

Ischemic stroke is a leading cause of human death in present times. Two phases of pathological impact occur during an ischemic stroke, namely, ischemia and reperfusion. Both periods include individual characteristic effects on cell injury and apoptosis. Moreover, these conditions can cause severe cell defects and harm the blood-brain barrier (BBB). Also, the BBB components are the major targets in ischemia-reperfusion injury. The BBB owes its enhanced protective roles to capillary endothelial cells, which maintain BBB permeability. One of the nerve growth factor (NGF) receptors initiating cell signaling, once activated, is the p75 neurotrophin receptor (p75NTR). This receptor is involved in both the survival and apoptosis of neurons. Although many studies have attempted to explain the role of p75NTR in neurons, the mechanisms in endothelial cells remain unclear. Endothelial cells are the first cells to encounter p75NTR stimuli. In this study, we found the upregulated p75NTR expression and reductive expression of tight junction proteins after in vivo and in vitro ischemia-reperfusion injury. Moreover, astaxanthin (AXT), an antioxidant drug, was utilized and was found to reduce p75NTR expression and the number of apoptotic cells. This study verified that p75NTR plays a prominent role in endothelial cell death and provides a novel downstream target for AXT.

Regulation of Cigarette Smoke Induction of IL-8 in Macrophages by AMP-activated Protein Kinase Signaling.

Inhaled cigarette smoke (CS) causes persistent lung inflammation in smokers. Interleukin 8 (IL-8) released from macrophages is a key chemokine during initiation and progression of CS-induced lung inflammation, yet its regulation is largely unknown. AMP-activated protein kinase (AMPK), a crucial energy homeostasis regulator, may modulate inflammation. Here we report that CS extract (CSE) increased the level of intracellular reactive oxygen species (ROS), activating AMPK, mitogen-activated protein kinases (MAPKs), and NF-κB, as well as inducing IL-8, in human macrophages. N-acetyl-cysteine (ROS scavenger) or hexamethonium [nicotinic acetylcholine receptor (nAChR) antagonist] attenuated the CSE-induced increase in intracellular ROS, activation of AMPK and NF-κB, as well as IL-8 induction, which suggests that nAChRs and ROS are important. Prevention of AMPK activation by compound C or AMPK siRNA reduced CSE-induced IL-8 production, confirming the role of AMPK. Compound C or AMPK siRNA also inhibited the activation of MAPKs and NF-κB by CSE, which suggests that these molecules are downstream of AMPK. Additionally, exposure of human macrophages to nicotine activated AMPK and induced IL-8 and that these effects were lessened by hexamethonium or compound C, implying that nicotine in CS may be causative. Furthermore, chronic CS exposure in mice promoted AMPK phosphorylation and expression of MIP-2 (an IL-8 homolog) in infiltrated macrophages and in lung tissues, as well as induced lung inflammation, all of which were reduced by compound C treatment. Thus, we identified a novel nAChRs-dependent, ROS-sensitive, AMPK/MAPKs/NF-κB signaling pathway, which seems to be important to CS-induced macrophage IL-8 production and possibly to lung inflammation.

Paeonol attenuates cigarette smoke-induced lung inflammation by inhibiting ROS-sensitive inflammatory signaling.

Cigarette smoking causes persistent lung inflammation that is mainly regulated by redox-sensitive pathways. We have previously reported that cigarette smoke (CS) activates reactive oxygen species- (ROS-) sensitive mitogen-activated protein kinases (MAPKs)/nuclear factor-κB (NF-κB) signaling leading to induction of lung inflammation. Paeonol, the main phenolic compound present in the Chinese herb Paeonia suffruticosa, has antioxidant and anti-inflammatory properties. However, whether paeonol has similar beneficial effects against CS-induced lung inflammation remains unclear. Using a murine model, we showed that chronic CS exposure for 4 weeks caused pulmonary inflammatory infiltration, increased lung vascular permeability, elevated lung levels of chemokines, cytokines, and 4-hydroxynonenal (an oxidative stress biomarker), and induced lung inflammation; all of these CS-induced events were suppressed by chronic treatment with paeonol. Using human bronchial epithelial cells (HBECs), we demonstrated that cigarette smoke extract (CSE) sequentially increased extracellular and intracellular levels of ROS, activated the MAPKs/NF-κB signaling, and induced interleukin-8 (IL-8); all these CSE-induced events were inhibited by paeonol pretreatment. Our findings suggest a novel role for paeonol in alleviating the oxidative stress and lung inflammation induced by chronic CS exposure in vivo and in suppressing CSE-induced IL-8 in vitro via its antioxidant function and an inhibition of the MAPKs/NF-κB signaling.

Transient receptor potential vanilloid 1 inhibition reduces brain damage by suppressing neuronal apoptosis after intracerebral hemorrhage.

Intracerebral hemorrhage (ICH) induces a complex sequence of apoptotic cascades and inflammatory responses, leading to neurological impairment. Transient receptor potential vanilloid 1 (TRPV1), a nonselective cation channel with high calcium permeability, has been implicated in neuronal apoptosis and inflammatory responses. This study used a mouse ICH model and neuronal cultures to examine whether TRPV1 activation exacerbates brain damage and neurological deficits by promoting neuronal apoptosis and neuroinflammation. ICH was induced by injecting collagenase in both wild-type (WT) C57BL/6 mice and TRPV1-/- mice. Capsaicin (CAP; a TRPV1 agonist) or capsazepine (a TRPV1 antagonist) was administered by intracerebroventricular injection 30 min before ICH induction in WT mice. The effects of genetic deletion or pharmacological inhibition of TRPV1 using CAP or capsazepine on motor deficits, histological damage, apoptotic responses, blood-brain barrier (BBB) permeability, and neuroinflammatory reactions were explored. The antiapoptotic mechanisms and calcium influx induced by TRPV1 inactivation were investigated in cultured hemin-stimulated neurons. TRPV1 expression was upregulated in the hemorrhagic brain, and TRPV1 was expressed in neurons, microglia, and astrocytes after ICH. Genetic deletion of TRPV1 significantly attenuated motor deficits and brain atrophy for up to 28 days. Deletion of TRPV1 also reduced brain damage, neurodegeneration, microglial activation, cytokine expression, and cell apoptosis at 1 day post-ICH. Similarly, the administration of CAP ameliorated brain damage, neurodegeneration, brain edema, BBB permeability, and cytokine expression at 1 day post-ICH. In primary neuronal cultures, pharmacological inactivation of TRPV1 by CAP attenuated neuronal vulnerability to hemin-induced injury, suppressed apoptosis, and preserved mitochondrial integrity in vitro. Mechanistically, CAP reduced hemin-stimulated calcium influx and prevented the phosphorylation of CaMKII in cultured neurons, which was associated with reduced activation of P38 and c-Jun NH2 -terminal kinase mitogen-activated protein kinase signaling. Our results suggest that TRPV1 inhibition may be a potential therapy for ICH by suppressing mitochondria-related neuronal apoptosis.

The development and impact of an app for a smart drug interaction reminder system.

BACKGROUND: Improved access to media and medical knowledge has elicited stronger public health awareness. OBJECTIVE: This study developed a smart drug interaction reminder system for patients to increase knowledge and reduce nurse workload. METHODS: This study used a single-group pre-test/post-test design and applied mining techniques to analyze the weight and probability of interaction among various medicines. Data were collected from 258 participants at a teaching hospital in northern Taiwan using convenience sampling. An app was used to give patients real-time feedback to obtain access to information and remind them of their health issues. In addition to guiding the patients on medications, this app measured the nurses' work satisfaction and patients' knowledge of drug interaction. RESULTS: The results indicate that using information technology products to assist the app's real-time feedback system promoted nurses' work satisfaction, improved their health education skills, and helped patients to better understand drug interactions. CONCLUSION: Using information technology to provide patients with real-time inquiring functions has a significant effect on nurses' load reduction. Thus, smart drug interaction reminder system apps can be considered suitable nursing health education tools and the SDINRS app can be integrated into quantitative structure-activity relationship intelligence in the future.

Caveolin-1 deletion reduces early brain injury after experimental intracerebral hemorrhage.

Intracerebral hemorrhage (ICH) is a subtype of stroke with high rates of morbidity and mortality. Caveolin-1 (Cav-1) is the main structural protein of caveolae and is involved in regulating signal transduction and cholesterol trafficking in cells. Although a recent study suggests a protective role of Cav-1 in cerebral ischemia, its function in ICH remains unknown. In this study, we examined the role of Cav-1 and in a model of collagenase-induced ICH and in neuronal cultures. Our results indicate that Cav-1 was up-regulated in the perihematomal area predominantly in endothelial cells. Cav-1 knockout mice had smaller injury volumes, milder neurologic deficits, less brain edema, and neuronal death 1 day after ICH than wild-type mice. The protective mechanism in Cav-1 knockout mice was associated with marked reduction in leukocyte infiltration, decreased expression of inflammatory mediators, including macrophage inflammatory protein (MIP)-2 and cyclooxygenase (COX)-2, and reduced matrix metalloproteinase-9 activity. Deletion of Cav-1 also suppressed heme oxygenase-1 expression and attenuated reactive oxygen species production after ICH. Moreover, deletion or knockdown of Cav-1 decreased neuronal vulnerability to hemin-induced toxicity and reduced heme oxygenase (HO)-1 induction in vitro. These data suggest that Cav-1 plays a deleterious role in early brain injury after ICH. Inhibition of Cav-1 may provide a novel therapeutic approach for the treatment of hemorrhagic stroke.

Inhibition of phosphorylated STAT3 by cucurbitacin I enhances chemoradiosensitivity in medulloblastoma-derived cancer stem cells.

INTRODUCTION: CD133 (PROM1) is a potential marker for cancer stem cells (CSCs), including those found in brain tumors. Recently, medulloblastoma (MB)-derived CD133-positive cells were found to have CSC-like properties and were proposed to be important contributors to tumorigenicity, cancer progression, and chemoradioresistance. However, the biomolecular pathways and therapeutic targets specific to MB-derived CSCs remain unresolved. MATERIALS AND METHODS: In the present study, we isolated CD133(+) cells from MB cell lines and determined that they showed increased tumorigenicity, radioresistance, and higher expression of both embryonic stem cell-related and drug resistance-related genes compared to CD133(-) cells. Bioinformatics analysis suggested that the STAT3 pathway might be important in MB and CD133(+) cells. To evaluate the effects of inhibiting the STAT3 pathway, MB-derived CD133(+/-) cells were treated with the potent STAT3 inhibitor, cucurbitacin I. Treatment with cucurbitacin I significantly suppressed the CSC-like properties and stemness gene signature of MB-derived CD133(+) cells. Furthermore, cucurbitacin I treatment increased the apoptotic sensitivity of MB-derived CD133(+) cells to radiation and chemotherapeutic drugs. Notably, cucurbitacin I demonstrated synergistic effects with ionizing radiation to inhibit tumorigenicity in MB-CD133(+)-inoculated mice. RESULTS: These results indicate that the STAT3 pathway plays a key role in mediating CSC properties in MB-derived CD133(+) cells. Targeting STAT3 with cucurbitacin I may therefore represent a novel therapeutic approach for treating malignant brain tumors.

A Preclinical Controlled Cortical Impact Model for Traumatic Hemorrhage Contusion and Neuroinflammation.

Cerebral contusion is a severe medical problem affecting millions of people worldwide each year. There is an urgent need to understand the pathophysiological mechanism and to develop effective therapeutic strategy for this devastating neurological disorder. Intraparenchymal hemorrhage and post-traumatic inflammatory response induced by initial physical impact can aggravate microglia/macrophage activation and neuroinflammation which subsequently worsen brain pathology. We provide here a controlled cortical impact (CCI) protocol that can reproduce experimental cortical contusion in mice by using a pneumatic impactor system to deliver mechanical force with controllable magnitude and velocity onto the dural surface. This preclinical model allows researchers to induce moderately severe focal cerebral contusion in mice and to investigate a wide range of post-traumatic pathological progressions including hemorrhage contusion, microglia/macrophage activation, iron toxicity, axonal injury, as well as short-term and long-term neurobehavioral deficits. The present protocol can be useful for exploring the long-term effects of and potential interventions for cerebral contusion.

Acute Kahweol Treatment Attenuates Traumatic Brain Injury Neuroinflammation and Functional Deficits.

Traumatic brain injury (TBI) affects millions worldwide with devastating long-term effects on health and cognition. Emerging data suggest that targeting the immune response may offer promising strategies to alleviate TBI outcomes; kahweol, an anti-inflammatory diterpene that remains in unfiltered coffee, has been shown to be beneficial in neuronal recovery. Here, we examined whether kahweol could alleviate brain trauma-induced injury in a mouse model of TBI and its underlying mechanisms. TBI was induced by controlled cortical impact (CCI) and various doses of kahweol were intraperitoneally administered following injury. Contusion volume, brain edema, neurobehavioral deficits, and protein expression and activity were evaluated in both short-term and long-term recovery. We found that kahweol treatments significantly reduced secondary brain injury and improved neurobehavioral outcomes in TBI mice. These changes were accompanied by the attenuation of proinflammatory cytokine secretion, decreased microglia/macrophage activation, and reduction of neutrophil and leukocyte infiltration. In addition, continuous kahweol treatment further improved short-term TBI outcomes compared to single-dosage. Collectively, our data showed that kahweol protects against TBI by reducing immune responses and may serve as a potential therapeutic intervention for TBI patients.

Menthol suppresses laryngeal C-fiber hypersensitivity to cigarette smoke in a rat model of gastroesophageal reflux disease: the role of TRPM8.

Patients with gastroesophageal reflux disease (GERD) display enhanced laryngeal reflex reactivity to stimuli that may be due to sensitization of the laryngeal C-fibers by acid and pepsin. Menthol, a ligand of transient receptor potential melastatin-8 (TRPM8), relieves throat irritation. However, the possibility that GERD induces laryngeal C-fiber hypersensitivity to cigarette smoke (CS) and that menthol suppresses this event has not been investigated. We delivered CS into functionally isolated larynxes of 160 anesthetized rats. Laryngeal pH 5-pepsin treatment, but not pH 5-denatured pepsin, augmented the apneic response to CS, which was blocked by denervation or perineural capsaicin treatment (a procedure that blocks the conduction of C fibers) of the superior laryngeal nerves. This augmented apnea was partially attenuated by capsazepine [an transient receptor potential vanilloid 1 (TRPV1) antagonist], SB-366791 (a TRPV1 antagonist), and HC030031 [a transient receptor potential ankyrin 1 (TRPA1) antagonist] and was completely prevented by a combination of TRPV1 and TRPA1 antagonists. Local application of menthol significantly suppressed the augmented apnea and this effect was reversed by pretreatment with AMTB (a TRPM8 antagonist). Our electrophysiological studies consistently revealed that laryngeal pH 5-pepsin treatment increased the sensitivity of laryngeal C-fibers to CS. Likewise, menthol suppressed this laryngeal C-fiber hypersensitivity and its effect could be reversed by pretreatment with AMTB. Our results suggest that laryngeal pH 5-pepsin treatment increases sensitivity to CS of both TRPV1 and TRPA1, which are presumably located at the terminals of laryngeal C-fibers. This sensory sensitization leads to enhanced laryngeal reflex reactivity and augmentation of the laryngeal C-fiber responses to CS, which can be suppressed by menthol acting via TRPM8.

Anti-inflammatory and neuroprotective effects of triptolide on traumatic brain injury in rats.

Traumatic brain injury (TBI) is characterized by neuroinflammation, brain edema, and cerebral damage leading to impairment of neurobehavioral function. Triptolide (PG-490), a diterpenoid component from Tripterygium wilfordii Hook F., has anti-inflammatory properties. Whether triptolide has neuroprotective functions when treating TBI is unclear. To investigate this possibility, Sprague-Dawley rats were treated with triptolide immediately after TBI had been induced by a controlled cortical impact procedure or after a sham procedure. TBI produced neuroinflammation when measured on day 1 after TBI, induced cerebral damage when measured on day 1 and day 3, and impaired neurobehavioral functioning over a 28-day observation period. Triptolide suppressed TBI-induced increases in contusion volume, cell apoptosis, edema and the levels of various pro-inflammatory mediators in the brain. Thriptolide reversed the TBI-induced decrease in brain levels of anti-inflammatory cytokine interleukin-10. Importantly, triptolide improved neurobehavioral outcomes regarding motor, sensory, reflex and balance function. We conclude that triptolide confers neuroprotection against TBI, at least in part, via its anti-inflammatory activity.