Current and future perspectives on the treatment of cerebral ischemia

Inhibition of Long non-coding RNA zinc finger antisense 1 improves functional recovery and angiogenesis after focal cerebral ischemia via microRNA-144-5p/fibroblast growth factor 7 axis

Long non-coding RNA zinc finger antisense 1 (ZFAS1) has been probed in cerebral ischemia, while the regulatory mechanism of ZFAS1 in focal cerebral ischemia (FCI) via binding to microRNA (miR)-144-5p remains rarely explored. This study aims to decipher the function of ZFAS1 on FCI via sponging miR-144-5p to modulate fibroblast growth factor 7 (FGF7). The focal cerebral ischemia rat model was established by occlusion of the middle cerebral artery (MCAO) Lentivirus vectors altering ZFAS1, miR-144-5p or FGF7 expression were injected into rats before MCAO. Then, ZFAS1, miR-144-5p, and FGF7 levels were detected, the inflammatory factor level, oxidative stress level, angiogenesis, neurological function injury and neuronal apoptosis were assessed. The binding relations among ZFAS1, miR-144-5p and FGF7 were validated. ZFAS1 and FGF7 expression was elevated, while miR-144-5p expression was reduced in FCI rats. Decreased ZFAS1 or FGF7 or enriched miR-144-5p repressed the inflammatory response, oxidative stress, neuronal apoptosis, while it improved angiogenesis, and neurological function recovery; while up-regulated ZFAS1 exerted opposite effects. The augmented miR-144-5p or silenced FGF7 reversed the effects of enriched ZFAS1. ZFAS1 sponged miR-144-5p that targeted FGF7. Inhibition of lncRNA ZFAS1 improves functional recovery and angiogenesis after FCI via miR-144-5p/FGF7 axis. This study provides novel therapeutic targets for FCI treatment.

Biotechnology-based therapeutics for management of cerebral stroke

Cerebral stroke, commonly caused due to hindrance in blood flow, is broadly classified into two categories-ischemic and haemorrhagic strokes. The onset of stroke triggers multiple mechanisms causing inflammation, generation of free radicals and protein damage leading to apoptosis of neuronal cells. The current therapies available for cerebral strokes involve use of complex surgical treatments and tissue plasminogen activator which increases the risk of internal bleeding, brain edema and cerebral damage, thereby restricting their use in clinical setting. The alarming need to develop safe, effective, target specific systems which, promote neuronal growth and reduce cerebral inflammation can be accomplished with use of biotechnological approaches. The article gives an insight to biotechnology-based advancements for tissue plasminogen activators, cell penetrating peptides, growth factors, ribonucleic acid systems and monoclonal antibodies for cerebral stroke. We also emphasis on challenges and future perspective of biotechnology-based therapeutics for better management of stroke.

PARP inhibitor PJ34 ameliorates cognitive impairments induced by transient cerebral ischemia/reperfusion through its anti-inflammatory effects in a rat model

Cerebral ischemia is a major health threat to humankind around the world, and the reperfusion methods may provoke irreversible damages to brain tissues, causing impairment of neurological function. The goal of this study is to investigate the potential neurological protective effect of PJ34, a well-characterized poly (ADP-ribose) polymerase 1 (PARP-1) inhibitor, on cerebral ischemia-reperfusion (I/R)-induced injury of the rat model. The cerebral I/R rats were received (3, 6, or 12 mg/kg) injections of PJ34 or saline at 24 h, 6 h before middle cerebral artery occlusion (MCAO) and 1 h, 24 h, and 48 h after MCAO. All rats were subject to the neurological behavior tests by open field test and Morris water maze test. The expression of pro-inflammatory cytokines, Cyclooxygenase 2 (COX-2) and inducible nitric oxide synthase (iNOS) in cerebral tissues was also determined. Our results demonstrated that the administration of PJ34 dose-dependently ameliorated cerebral I/R-induced injury and improved neurological performance of cerebral I/R rats. We also revealed that PJ34 treatment effectively reduced COX2, iNOS, and pro-inflammatory cytokine levels in the I/R-induced injury tissues. Our finding further supports that inhibition of PARP-1 activity is beneficial for reducing post-I/R-induced brain damage via targeting inflammatory response.

Histone Deacetylases and Their Isoform-Specific Inhibitors in Ischemic Stroke

Cerebral ischemia is the second leading cause of death in the world and multimodal stroke therapy is needed. The ischemic stroke generally reduces the gene expression due to suppression of acetylation of histones H3 and H4. Histone deacetylases inhibitors have been shown to be effective in protecting the brain from ischemic damage. Histone deacetylases inhibitors induce neurogenesis and angiogenesis in damaged brain areas promoting functional recovery after cerebral ischemia. However, the role of different histone deacetylases isoforms in the survival and death of brain cells after stroke is still controversial. This review aims to analyze the data on the neuroprotective activity of nonspecific and selective histone deacetylase inhibitors in ischemic stroke.

Electromagnetic Field as a Treatment for Cerebral Ischemic Stroke

Cerebral stroke is a leading cause of death and adult-acquired disability worldwide. To this date, treatment options are limited; hence, the search for new therapeutic approaches continues. Electromagnetic fields (EMFs) affect a wide variety of biological processes and accumulating evidence shows their potential as a treatment for ischemic stroke. Based on their characteristics, they can be divided into stationary, pulsed, and sinusoidal EMF. The aim of this review is to provide an extensive literature overview ranging from in vitro to even clinical studies within the field of ischemic stroke of all EMF types. A thorough comparison between EMF types and their effects is provided, as well as an overview of the signal pathways activated in cell types relevant for ischemic stroke such as neurons, microglia, astrocytes, and endothelial cells. We also discuss which steps have to be taken to improve their therapeutic efficacy in the frame of the clinical translation of this promising therapy.

Inhibition of autophagy by CRMP2-derived peptide ST2-104 (R9-CBD3) via a CaMKKβ/AMPK/mTOR pathway contributes to ischemic postconditioning-induced neuroprotection against cerebral ischemia-reperfusion injury

Cerebral ischemia, a common cerebrovascular disease, is characterized by functional deficits and apoptotic cell death. Autophagy, a type of programmed cell death, plays critical roles in controlling neuronal damage and metabolic homeostasis, and has been inextricably linked to cerebral ischemia. We previously identified a short peptide aptamer from collapsin response mediator protein 2 (CRMP2), designated the Ca2+ channel-binding domain 3 (CBD3) peptide, that conferred protection against excitotoxicity and traumatic brain injury. ST2-104, a nona-arginine (R9)-fused CBD3 peptide, exerted beneficial effects on neuropathic pain and was neuroprotective in a model of Alzheimer's disease; however, the effect of ST2-104 on cerebral ischemia and its mechanism of action have not been studied. In this study, we modeled cerebral ischemia-reperfusion injury in rats with the middle cerebral artery occlusion (MCAO) as well as challenged SH-SY5Y neuroblastoma cells with glutamate to induce toxicity to interrogate the effects of ST2-104 on autophagy following ischemic/excitotoxic insults. ST2-104 reduced the infarct volume and improved the neurological score of rats subjected to MCAO. ST2-104 protected SH-SY5Y cells from death following glutamate exposure via blunting apoptosis and autophagy as well as limiting excessive calcium entry. 3-Methyladenine (3-MA), an inhibitor of autophagy, promoted the effects of ST2-104 in inhibiting apoptosis triggered by glutamate while rapamycin, an activator of autophagy, failed to do so. ST2-104 peptide reversed glutamate-induced apoptosis via inhibiting Ca2+/CaM-dependent protein kinase kinase β (CaMKKβ)-mediated autophagy, which was partly enhanced by STO-609 (an inhibitor of CaMKKβ). ST2-104 attenuated neuronal apoptosis by inhibiting autophagy through CaMKKβ/AMPK/mTOR pathway. Our results suggest that the neuroprotective effect of ST2-104 are due to actions on the crosstalk between apoptosis and autophagy via the CaMKKβ/AMPK/mTOR signaling pathway. The findings present novel insights into the potential neuroprotection of ST2-104 in cerebral ischemia.

Neuroprotective effects of zonisamide on cerebral ischemia injury via inhibition of neuronal apoptosis

It is known that neuronal apoptosis contributes to pathology of cerebral ischemia injury. Zonisamide (ZNS) has shown anti-apoptosis effects in recent studies. The present study investigated whether the anti-apoptotic effect can account for the neuroprotective action of ZNS on cerebral ischemia. Neuronal cells were maintained under oxygen-glucose deprivation conditions to simulate cerebral ischemia and treated with ZNS simultaneously. The apoptosis of the cells and expression of apoptosis-related proteins were investigated by flow cytometry and western blot analysis, respectively. A cerebral ischemia mouse model was created via middle cerebral artery occlusion, and the mice were treated with ZNS. Neurological deficit scores and infarct volumes of the cerebral ischemia mice were measured. The apoptosis status of the neuronal cells was evaluated by TUNEL staining. In vitro, the ZNS treatment inhibited both the apoptosis of the neuronal cells and apoptosis-related protein expression (caspase-3, caspase-8, and calpain-1) induced by the oxygen-glucose deprivation. The anti-apoptosis effect of ZNS could occur through the blocking of reactive oxygen species. Moreover, ZNS treatment significantly ameliorated neurological deficits and reduced infarct volumes in the cerebral ischemia mice model. In this study, ZNS exerted neuroprotective effects by inhibition of apoptosis in neuronal cells in cerebral ischemia. Therefore, ZNS might be a promising therapy for cerebral ischemia.

Preventing and Treating Neurological Disorders with the Flavonol Fisetin

Neurological disorders, including neurodegenerative diseases, have a significant negative impact on both patients and society at large. Since the prevalence of most of these disorders increases with age, the consequences for our aging population are only going to grow. It is now acknowledged that neurological disorders are multi-factorial involving disruptions in multiple cellular systems. While each disorder has specific initiating mechanisms and pathologies, certain common pathways appear to be involved in most, if not all, neurological disorders. Thus, it is becoming increasingly important to identify compounds that can modulate the multiple pathways that contribute to disease development or progression. One of these compounds is the flavonol fisetin. Fisetin has now been shown in preclinical models to be effective at preventing the development and/or progression of multiple neurological disorders including Alzheimer’s disease, Parkinson’s disease, Huntington’s disease, amyotrophic lateral sclerosis, stroke (both ischemic and hemorrhagic) and traumatic brain injury as well as to reduce age-associated changes in the brain. These beneficial effects stem from its actions on multiple pathways associated with the different neurological disorders. These actions include its well characterized anti-inflammatory and anti-oxidant effects as well as more recently described effects on the regulated cell death oxytosis/ferroptosis pathway, the gut microbiome and its senolytic activity. Therefore, the growing body of pre-clinical data, along with fisetin’s ability to modulate a large number of pathways associated with brain dysfunction, strongly suggest that it would be worthwhile to pursue its therapeutic effects in humans.

A Step further-The Role of Trigeminocardiac Reflex in Therapeutic Implications: Hypothesis, Evidence, and Experimental Models

The trigeminocardiac reflex (TCR) is a well-recognized brainstem reflex that represents a unique interaction between the brain and the heart through the Vth and Xth cranial nerves and brainstem nuclei. The TCR has mainly been reported as an intraoperative phenomenon causing cardiovascular changes during skull-base surgeries. However, it is now appreciated that the TCR is implicated during non-neurosurgical procedures and in nonsurgical conditions, and its complex reflex pathways have been explored as potential therapeutic options in various neurological and cardiovascular diseases. This narrative review presents an in-depth overview of hypothetical and experimental models of the TCR phenomenon in relation to the Vth and Xth cranial nerves. In addition, primitive interactions between these 2 cranial nerves and their significance are highlighted. Finally, therapeutic models of the complex interactions of the TCR and areas for further research will be considered.

Pharmacological management of cerebral ischemia in the elderly

Introduction: For elderly adults in the United States, stroke is the fifth leading cause of death of which ischemic strokes comprise a vast majority. Optimal pharmacological management of elderly ischemic stroke patients involves both reperfusion and supportive care. Recent research into pharmacological management has focused on vascular, immunomodulatory, cytoprotective, and alternative agents, some of which have shown limited success in clinical trials. However, no treatments have been established as a reliable mode for management of cerebral ischemia for elderly adults beyond acute thrombolysis.Areas covered: The authors conducted a literature search for ischemic stroke management in the elderly and a search for human drug studies for managing ischemic stroke on clinicaltrials.gov. Here, they describe recent progress in the pharmacological management of cerebral ischemia in the elderly.Expert opinion: Many drug classes (antihypertensive, cytoprotective and immunomodulatory, and alternative agents) have been explored with limited success in managing ischemic stroke, though some have shown preventative benefits. We generally observed a broad gap in evidence on elderly patients from studies across all drug classes, necessitating further studies to gain an understanding of effective management of ischemic stroke in this large demographic of patients.

A high-fat diet rich in corn oil exaggerates the infarct size and memory impairment in rats with cerebral ischemia and is associated with suppressing osteopontin and Akt, and activating GS3Kβ, iNOS, and NF-κB

The increase in osteopontin (OPN) levels after stroke induces neural protection by activating Akt signaling and inhibiting GS3Kβ, iNOS, and NF-κB. This study investigated the effect of a high-fat diet rich in corn oil (CO-HFD) on infarct size and memory function in rats after induction of cerebral ischemia in rats and investigated its effect on the expression of OPN/Akt/iNOS/NF-κB signaling pathways. Rats were initially fed a standard diet (STD, 3.82 kcal/g; 9.4%, from fat) or a CO-HFD (5.4 kcal/g, 40% from fat) for 12 weeks. Then, both groups were further subdivided into either sham group or group exposed to cerebral ischemia by the middle cerebral artery occlusion (MCAO) protocol. Compared with sham-operated rats fed STD diet, neurological scores and both short- and long-term memory functions were significantly impaired in sham-operated CO-HFD-fed rats. In addition, brains collected from CO-HFD-fed rats showed lower protein levels of OPN, p-Akt (Thr³⁰⁸), p-GS3Kβ (Ser⁹), and Bcl-2 and had higher protein levels of iNOS, cleaved caspase-3, nuclear NF-κB p65, and cytoplasmic cytochrome C. However, once exposed to MCAO surgery, similar but more profound alterations of all these biochemical parameters with more severe impairment in short- and long-term memory functions and larger infarct size were noticed in the brains of CO-HFD-fed rats as compared with STD-fed rats exposed to MCAO. In conclusion, chronic consumption of CO-HFD induces memory impairments and worsens memory function recovery and infarct size after cerebral ischemia in rats by reducing levels of OPN, inhibiting the activation of Akt and activating iNOS and NF-κB.

Dexmedetomidine Attenuates Glutamate-Induced Cytotoxicity by Inhibiting the Mitochondrial-Mediated Apoptotic Pathway

Background

Glutamate (GLU) is the most excitatory amino acid in the central nervous system and plays an important role in maintaining the normal function of the nervous system. During cerebral ischemia, massive release of GLU leads to neuronal necrosis and apoptosis. It has been reported that dexmedetomidine (DEX) possesses anti-oxidant and anti-apoptotic properties. The objective of this study was to investigate the effects of DEX on GLU-induced neurotoxicity in PC12 cells.

Material/Methods

PC12 cells were treated with 20 mM GLU to establish an ischemia-induced injury model. Cell viability was accessed by MTT assay. MDA content and SOD activity were analyzed by assay kits. Apoptosis rate, ROS production, intracellular Ca²⁺ concentration, and MMP were evaluated by flow cytometry. Western blot analysis was performed to analyze expressions of caspase-3, caspase-9, cyt-c, bax, and bcl-2.

Results

PC12 cells treated with GLU exhibited reduced cell viability and increased apoptosis rates, which were ameliorated by pretreatment with DEX. DEX significantly increased SOD activity, reduced content of MDA, and decreased production of ROS in PC12 cells. In addition, DEX clearly reduced the level of intracellular Ca²⁺ and attenuated the decline of MMP. Moreover, DEX notably reduced expressions of caspase-3, caspase-9, cyt-c, and bax and increased expression of bcl-2.

Conclusions

Our findings suggest that DEX can protect PC12 cells against GLU-induced cytotoxicity, which may be attributed to its anti-oxidative property and reduction of intracellular calcium overload, as well as its ability to inhibit the mitochondria-mediated apoptotic pathway.

Neuroprotective Effect of Danhong Injection on Cerebral Ischemia-Reperfusion Injury in Rats by Activation of the PI3K-Akt Pathway

Many traditional Chinese medicines, including Danhong injection (DHI), can be used to treat cerebral ischemia-reperfusion injury and have neuroprotective effects on the brain; however, few studies have explored the mechanism by which this effect is generated. In this study, we investigated the neuroprotective effect of DHI against cerebral ischemia-reperfusion injury mediated via the PI3K-Akt signaling pathway. After establishing the model of middle cerebral artery occlusion (MCAO), 60 male Sprague–Dawley rats were allocated to six groups as follows: sham, MCAO, DHI (MCAO + DHI), LY294002 (MCAO + LY294002 [PI3K-Akt pathway specific inhibitor]), DHI + LY294002 (MCAO + DHI + LY294002), and NMDP + LY294002 (MCAO + NMDP [nimodipine] + LY294002). Hematoxylin and eosin (HE) and terminal deoxynucleotidyl transferase dUTP nick-end labeling (TUNEL) staining were used to evaluate the pathological changes of brain tissue and the degree of neuronal apoptosis. Real-time quantitative polymerase chain reaction (qRT-PCR), western blot analysis and enzyme-linked immunosorbent assays were used to measure the expression of Bad, Bax, Bcl-2, Bim, P53, MDM2, Akt, PI3K, p-Akt, p-PI3K, and Cyt-C. Compared with the MCAO group, brain tissue cell apoptosis was significantly reduced in the DHI group, and the brain function score was significantly improved. In addition, the expression of pro-apoptotic factors (Bad, Bax, and Bim) was significantly downregulated in the DHI group, while expression of the anti-apoptotic factor Bcl-2 was significantly upregulated, and expression of the apoptotic gene p53 was also significantly attenuated. Moreover, this neuroprotective effect was attenuated by the PI3K-Akt signaling pathway inhibitor (LY294002). Thus, our results confirmed the neuroprotective effects of DHI in rats with ischemia-reperfusion injury and indicate that these effects on the brain are partly generated by activation of the PI3K-Akt signaling pathway.

Hydroxysafflor Yellow A Confers Neuroprotection from Focal Cerebral Ischemia by Modulating the Crosstalk Between JAK2/STAT3 and SOCS3 Signaling Pathways

Natural bioactive compounds have increasingly proved to be promising in evidence- or target-directed treatment or modification of a spectrum of diseases including cerebral ischemic stroke. Hydroxysafflor yellow A (HSYA), a major active component of the safflower plant, has drawn more interests in recent year for its multiple pharmacological actions in the treatment of cerebrovascular and cardiovascular diseases. Although the Janus kinase signaling, such as JAK2/STAT3 pathway, has been implicated in the modulation of the disease, the inhibition or activation of the pathway that contributed to the neuronal prevention from ischemic damages remains controversial. In this study, a series of experiments were performed to examine the dose- and therapeutic time window-related pharmacological efficacies of HSYA with emphasis on the HSYA-modulated interaction of JAK2/STAT3 and SOCS3 signaling in the MCAO rats. We found that HSYA treatment significantly rescued the neurological and functional deficits in a dose-dependent manner in the MCAO rats within 3 h after ischemia. HSYA treatment with a dosage of 8 mg/kg or higher markedly downregulated the expression of the JAK2-mediated signaling that was activated in response to ischemic insult, while it also promoted the expression of SOCS3 coordinately. In the subsequent experiments with the use of the JAK2 inhibitor WP1066, we found that the treatment of WP1066 alone or combination of WP1066/HSYA all exhibited inhibitory effects on JAK2-mediated signaling, while there was no influence on the SOCS3 activity of corresponding efficacious data in the MCAO rats, suggesting that excessive activation of JAK2/STAT3 might be necessary for HSYA to provoke SOCS3-negative feedback signaling. Taking together, our study demonstrates that HSYA might modulate the crosstalk between JAK2/STAT3 and SOCS3 signaling pathways that eventually contributed to its therapeutic roles against cerebral ischemic stroke.

Ozone alleviates ischemia/reperfusion injury by inhibiting mitochondrion-mediated apoptosis pathway in SH-SY5Y cells

Cerebral ischemia/reperfusion (I/R) injuries are common and often cause severe complications. Ozone has been applied for protecting I/R injury in animal models of several organs including cerebra, but the detailed mechanism remains unclear. 3-(4,5-Dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and lactate dehydrogenase measurement were used to determine the influence of ozone on cell activity and damage of SH-SY5Y cells. Some redox items such as catalase (CAT), malondialdehyde (MDA), glutathione peroxidase (GSH-Px), and superoxide dismutase (SOD) were measured by enzyme-linked immunosorbent assay. The mitochondrial membrane potential (ΔΨ_m ) was determined by JC-1 assay. Cytochrome-c (cyt-c) level in the cytoplasm and mitochondrion was measured by western blotting. Apoptosis was determined by flow cytometry, and some apoptosis-related molecules were detected by quantitative real-time polymerase chain reaction and western blotting. Ozone alleviated oxidative damage by increasing GSH-Px, SOD, CAT, and decreasing MDA. Ozone decreased mitochondrial damage caused by I/R injury and inhibited the release of cyt-c from mitochondrion to cytoplasm in SH-SY5Y cells. The cell apoptosis caused by I/R was inhibited by ozone, and ozone could decrease apoptosis by increasing the ratio of Bcl-2/Bax and inhibiting caspase signaling pathway in SH-SY5Y cells. Ozone has the ability of maintaining redox homeostasis, decreasing mitochondrion damage, and inhibiting neurocytes apoptosis induced by I/R. Therefore, ozone may be a promising protective strategy against cerebral I/R injury.

Pramipexole prevents ischemic cell death via mitochondrial pathways in ischemic stroke

A dopamine D2 receptor agonist, pramipexole, has been found to elicit neuroprotection in patients with Parkinson's disease and restless leg syndrome. Recent evidence has shown that pramipexole mediates its neuroprotection through mitochondria. Considering this, we examined the possible mitochondrial role of pramipexole in promoting neuroprotection following an ischemic stroke of rat. Male Wistar rats underwent transient middle cerebral artery occlusion (tMCAO) and then received pramipexole (0.25 mg and 1 mg/kg body weight) at 1, 6, 12 and 18 h post-occlusion. A panel of neurological tests and 2,3,5-triphenyl tetrazolium chloride (TTC) staining were performed at 24 h after the surgery. Flow cytometry was used to detect the mitochondrial membrane potential, and mitochondrial levels of reactive oxygen species (ROS) and Ca²⁺, respectively. Mitochondrial oxidative phosphorylation was analyzed by oxygraph (oxygen electrode). Western blotting was used to analyze the expression of various proteins such as Bax, Bcl-2 and cytochrome c Pramipexole promoted the neurological recovery as shown by the panel of neurobehavioral tests and TTC staining. Post-stroke treatment with pramipexole reduced levels of mitochondrial ROS and Ca²⁺ after ischemia. Pramipexole elevated the mitochondrial membrane potential and mitochondrial oxidative phosphorylation. Western blotting showed that pramipexole inhibited the transfer of cytochrome c from mitochondria to cytosol, and hence inhibited the mitochondrial permeability transition pore. Thus, our results have demonstrated that post-stroke administration of pramipexole induces the neurological recovery through mitochondrial pathways in ischemia/reperfusion injury.

Long noncoding RNA-MEG3 contributes to myocardial ischemia-reperfusion injury through suppression of miR-7-5p expression

Long noncoding RNA (lncRNA) maternally expressed gene 3 (MEG3) plays an important role in protection of ischemia–reperfusion (I/R) injury in brain and liver. However, role of MEG3 in myocardial I/R injury remains unclear. Here, the role of MEG3 in protection of myocardial I/R injury and its association with microRNA-7-5p (miR-7-5p) was investigated using rat cardiac I/R model and myocardial I/R cell model. Our results showed that MEG3 was significantly up-regulated and miR-7-5p was significantly down-regulated after I/R. Following I/R, the levels of intact PARP and intact caspase-3 were reduced, while the cleaved fragments of PARP and caspase-3 were increased. TUNEL assay showed an increase in cardiomyocyte apoptosis after I/R. The levels of I/R-induced creatine kinase (CK) and lactate dehydrogenase (LDH) were inhibited by knockdown of MEG3 (siMEG3). SiMEG3 increased cell proliferation and inhibited cell apoptosis after I/R. In contrast, overexpression of MEG3 increased the I/R-induced CK and LDH activities and cell apoptosis and decreased cell proliferation. The dual-luciferase reporter system showed a direct binding of MEG3 to miR-7-5p. The level of miR-7-5p was negatively associated with the change in levels of MEG3 in H9c2 cells. The levels of intact RARP1 and caspase-3 were significantly increased by knockdown of MEG3. Co-transfection of miR-7-5p inhibitor with siMEG3 activates CK and LDH, significantly decreased cell proliferation, increased cell apoptosis, and decreased intact poly(ADP-ribose) polymerase 1 (PARP1) and caspase-3. In summary, down-regulation of MEG3 protects myocardial cells against I/R-induced apoptosis through miR-7-5p/PARP1 pathway, which might provide a new therapeutic target for treatment of myocardial I/R injury.

Dose-response, therapeutic time-window and tPA-combinatorial efficacy of compound 21: A randomized, blinded preclinical trial in a rat model of thromboembolic stroke

The aim of this translational, randomized, controlled, blinded preclinical trial was to determine the effect of compound 21 (C21) in embolic stroke. Rats were subjected to embolic-middle cerebral artery occlusion (eMCAO). They received C21 (0.01, 0.03 and 0.06 mg/kg/d) or saline (orally) for five days, with the first-dose given IV at 3 h post-eMCAO. For the time-window study, the optimal-dose of C21 was initiated at 3, 6 or 24 h post-eMCAO and continued for five days. For the combinatorial study, animals received IV-tissue plasminogen activator (tPA) at either 2 or 4 h, with IV-C21 (0.01 mg/kg) or saline at 3 h post-eMCAO and daily thereafter for five days. After performing the behavior tests, brains were collected for analyses. The dose-response study showed significant motor improvements with the lowest-dose (0.01 mg/kg) of C21. In the time-window study, this same dose resulted in improvements when given 6 h and 24 h post-eMCAO. Moreover, C21-treated animals performed better on the novel object recognition test. Neither the single treatment with C21 or tPA (4 h) nor the combination therapy was effective in reducing the hemorrhage or infarct size, although C21 alone lowered sensorimotor deficit scores post-eMCAO. Future studies should focus on the long-term cognitive benefits of C21, rather than acute neuroprotection.

Neuroprotection of cordycepin in NMDA-induced excitotoxicity by modulating adenosine A1 receptors

Cerebral ischemia impairs physiological form of synaptic plasticity such as long-term potentiation (LTP). Clinical symptoms of cognitive dysfunction resulting from cerebral ischemia are associated with neuron loss and synaptic function impairment in hippocampus. It has been widely reported that cordycepin displays neuroprotective effect on ameliorating cognitive dysfunction induced by cerebral ischemia. Therefore, it is necessary to study whether cordycepin recovers cognitive function after brain ischemia through improving LTP induction. However, there has been very little discussion about the effects of cordycepin on LTP of cerebral ischemia so far. In the present study, we investigated the effects of cordycepin on LTP impairment and neuron loss induced by cerebral ischemia and excitotoxicity, using electrophysiological recording and Nissl staining techniques. The models were obtained by bilateral common carotid artery occlusion (BCCAO) and intrahippocampal NMDA microinjection. We also explored whether adenosine A₁ receptors involve in the neuroprotection of cordycepin by using western blot. We found that cordycepin remarkably alleviated LTP impairment and protected pyramidal cell of hippocampal CA1 region against cerebral ischemia and excitotoxicity. Meanwhile, cordycepin prevented the reduction on adenosine A₁ receptor level caused by ischemia but did not alter the adenosine A_2A receptor level in hippocampal CA1 area. The improvement of LTP in the excitotoxic rats after cordycepin treatment could be blocked by DPCPX, a selective antagonist of adenosine A₁ receptor. In summary, our findings provided new insights into the mechanisms of cordycepin neuroprotection in excitotoxic diseases, which is through regulating adenosine A₁ receptor to improve LTP formation and neuronal survival.

Systems Pharmacology-Based Approach to Comparatively Study the Independent and Synergistic Mechanisms of Danhong Injection and Naoxintong Capsule in Ischemic Stroke Treatment

To provide evidence for the better clinical use of traditional Chinese medicine preparations (TCMPs), comparison of the pharmacological mechanisms between TCMPs with similar therapeutic effect is necessary. However, methodology for dealing with this issue is still scarce. Danhong injection (DHI) and Naoxintong capsule (NXT) are representative TCMPs for ischemic stroke (IS) treatment, which are also frequently used in combination. Here they were employed as research objects to demonstrate the feasibility of systems pharmacology approach in elucidation of the independent and combined effect of TCMPs. By incorporating chemical screening, target prediction, and network construction, a feasible systems pharmacology model has been established to systematically uncover the underlying action mechanisms of DHI, NXT, or their pair in IS treatment. Systematic analysis of the created TCMP-Compound-Target-Disease network revealed that DHI and NXT shared common targets such as PTGS2, F2, ADRB1, IL6, ALDH2, and CCL2, which were involved in the vasomotor system regulation, blood-brain barrier disruption, redox imbalance, neurotrophin activity, and brain inflammation. In comparative mechanism study, the merged DHI/NXT-IS PPI network and pathway enrichment analysis indicated that DHI and NXT exerted the therapeutic effects mainly through immune system and VEGF signaling pathways. Meanwhile, they had their own unique pathways, e.g., calcium signaling pathway for DHI and gap junction for NXT. While for their synergistic mechanism, DHI and NXT participated in chemokine signaling pathway, T cell receptor signaling pathway, VEGF signaling pathway, gap junction, and so on. Our study provided an optimized strategy for dissecting the different and combined effect of TCMPs with similar actions.

2D:4D Ratio Differs in Ischemic Stroke: A Single Center Experience

Background

The index to ring finger length (2D:4D) ratio is a proxy biomarker for prenatal exposure of sex hormones. Sex hormones are associated with the pathogenesis of ischemic stroke. The purpose of the study was to demonstrate the association between 2D:4D and ischemic stroke.

Methodology

This study retrospectively reviewed the data of 100 patients with first ever ischemic stroke between September, 2016 and June, 2017. The lengths of index finger and ring finger of both hands were measured using electronic calipers and calculated for 2D:4D ratios. Receive operating characteristic (ROC) mode was used to detect predicting performance of 2D:4D ratios for ischemic stroke.

Results

2D:4D ratios in ischemic stroke patients were higher than controls in both hands (P < 0.05), except right 2D:4D ratio in females. The ROC analyses showed that the area under the curve (AUC) were 0.635 (95%CI: 0.527-0.743) for left 2D:4D ratio, and 0.647 for right (95%CI: 0.539-0.755) (P < 0.05). The AUC of left and right 2D:4D ratio in male were 0.667 (95%CI: 0.514-0.820) and 0.670 (95%CI: 0.519-0.822) (P < 0.05). In female, no significance were found in ROC analysis. And there were no correlation between 2D:4D value and stroke severity (P > 0.05).

Conclusions

The current study indicated that the diagnostic value of 2D:4D ratio was limited in ischemic stroke. Further research is required to explore the role of it in screening ischemic stroke.

Small Peptides as Modulators of Serine Proteases

Serine proteases play critical roles in many physiological and pathological processes, and are proven diagnostic and therapeutic targets in a number of clinical indications. Suppression of the aberrant proteolytic activities of these proteases has been clinically used for the treatments of relevant diseases. Polypeptides with 10-20 residues are of great interests as medicinal modulators of serine proteases, because these peptides demonstrate the characteristics of both small molecule drugs and macromolecular drugs. In this review, we summarized the recent development of peptide-based inhibitors against serine proteases with potent inhibitory and high specificity comparable to monoclonal antibodies. In addition, we also discussed the strategies of enhancing plasma half-life and bioavailability of peptides in vivo, which is the main hurdle that limits the clinical translation of peptide-based drugs. This review advocates new avenue for the development of effective serine protease inhibitors and highlights the prospect of the medicinal use of these inhibitors.

Hydroxysafflor Yellow A (HSYA) Improves Learning and Memory in Cerebral Ischemia Reperfusion-Injured Rats via Recovering Synaptic Plasticity in the Hippocampus

Hydroxysafflor yellow A (HSYA) is the major active chemical component of the safflower plant flower, which is widely used in Chinese medicine for cerebrovascular and cardiovascular disease treatment. Recent studies have demonstrated that HSYA exerts neuroprotective effect on cerebral ischemia, such as neuronal anti-apoptosis, antioxidant activity and oxygen free radical-scavenging. However, whether and how HSYA has a protective effect on cognitive impairment induced by cerebral ischemia reperfusion remains elusive. In the present study, by using the middle cerebral artery occlusion (MCAO) model, we found that 8 mg/kg and 16 mg/kg HSYA administration by common carotid artery (CCA) injection improved impaired cognitive function in Morris water maze (MWM) and passive avoidance tasks, but not 4 mg/kg HSYA treatment, suggesting that HSYA treatment in a certain concentration can improve cognitive impairment in MCAO rats. Furthermore, we found that 8 mg/kg HSYA treatment rescued the impaired long-term potentiation (LTP) in hippocampus of MCAO rats. Taken together, these results for the first time demonstrate that HSYA has the capacity to protect cognitive function and synaptic plasticity against cerebral ischemia-reperfusion injury, and provide a new insight that HSYA may be a promising alternative for recovery of cognitive dysfunction after brain ischemic injury.

Protective effect of Danhong Injection combined with Naoxintong Capsule on cerebral ischemia-reperfusion injury in rats

ETHNOPHARMACOLOGICAL RELEVANCE

Danhong Injection (DHI) and Naoxintong Capsule (NXT) are renowned traditional Chinese medicine in China. The drug combination of DHI and NXT is frequently applied for the treatment of cardiovascular and cerebrovascular diseases in clinic. However, there had been no pharmacological experiment studies of interaction between DHI and NXT. Due to the drug interactions, exploring their interaction profile is of great importance.

MATERIAL AND METHODS

In this study, focal cerebral I/R injury in adult male Sprague-Dawley rats were induced by transient middle cerebral artery occlusion (tMCAO) for 1h followed by reperfusion. Rats were divided into 5 groups: sham group, ischemia reperfusion untreated group (IRU), DHI group (DHI 10mL/kg/d), NXT group (NXT 0.5g/kg/d), DHI plus NXT group (DHI-NXT, DHI 10mL/kg/d plus NXT 0.5g/kg/d). All drug-treated groups were respectively successive administrated for 7 days after ischemia/ reperfusion (I/R) injury. The effects on rat neurological function were estimated by neurological defect scores. Brain infarct volumes were determined based on 2, 3, 5-triphenyltetrazolium chloride (TTC) staining. Pathological changes in brain tissues were observed using hematoxylin and eosin (H&E) staining and transmission electron microscope (TEM). Levels of nitric oxide (NO), granulocyte colony-stimulating factor (G-CSF) and granulocyte macrophage colony-stimulating factor (GM-CSF) in serum were determined with enzyme-linked immunosorbent assay (ELISA). Immunohisto-chemistry and Western blot were used to detect the expressions of basic fibroblast growth factor (bFGF), von Willebrand factor-microvessel vascular density (vWF-MVD), vascular endothelial cell growth factor (VEGF), transforming growth factor-β1 (TGF-β1), angiogenin-1 (Ang-1), angiogenin-2 (Ang-2) and platelet derived growth factor (PDGF) at day 7 after ischemia/reperfusion (I/R) injury.

RESULTS

Compared with IRU group and mono-therapy group (DHI group or NXT group), Danhong Injection combined with Naoxintong Capsule (DHI-NXT) group significantly ameliorated neurological deficits scores, infarct volume and pathological change, significantly decreased the overexpression of NO and the level of Ang-1, significantly increased the expressions of VEGF, Ang-2, G-CSF, GM-CSF, bFGF, PDGF, vWF, TGF-β1.

CONCLUSION

The protective benefits on rat brain against I/R injury were clearly produced when DHI and NXT were used in combination, which provided rational guidance for clinical combined application of DHI and NXT, and this protection maybe associated with the up-regulation expressions of the related chemokines and growth factors of angiogenesis.

Elevated Factor VIII and von Willebrand Factor Levels Predict Unfavorable Outcome in Stroke Patients Treated with Intravenous Thrombolysis

Introduction

Plasma factor VIII (FVIII) and von Willebrand factor (VWF) levels have been associated with the rate and severity of arterial thrombus formation and have been linked to outcomes following thrombolytic therapy in acute myocardial infarction patients. Here, we aimed to investigate FVIII and VWF levels during the course of thrombolysis in acute ischemic stroke (AIS) patients and to find out whether they predict long-term outcomes.

Materials and methods

Study population included 131 consecutive AIS patients (median age: 69 years, 60.3% men) who underwent i.v. thrombolysis with recombinant tissue plasminogen activator (rt-PA). Blood samples were taken on admission, 1 and 24 h after rt-PA administration to measure FVIII activity and VWF antigen levels. Neurological deficit of patients was determined according to the National Institutes of Health Stroke Scale (NIHSS). ASPECT scores were assessed using computer tomography images taken before and 24 h after thrombolysis. Intracranial hemorrhage was classified according to the European Cooperative Acute Stroke Study (ECASS) II criteria. Long-term functional outcome was determined at 90 days after the event by the modified Rankin scale (mRS).

Results

VWF levels on admission were significantly elevated in case of more severe AIS [median and IQR values: NIHSS <6:189.6% (151.9-233.2%); NIHSS 6-16: 199.6% (176.4-250.8%); NIHSS >16: 247.8% (199.9-353.8%), p = 0.013]; similar, but non-significant trend was observed for FVIII levels. FVIII and VWF levels correlated well on admission (r = 0.748, p < 0.001) but no significant correlation was found immediately after thrombolysis (r = 0.093, p = 0.299), most probably due to plasmin-mediated FVIII degradation. VWF levels at all investigated occasions and FVIII activity before and 24 h after thrombolysis were associated with worse 24 h post-lysis ASPECT scores. In a binary backward logistic regression analysis including age, gender, high-sensitivity C-reactive protein, active smoking, diabetes, and NIHSS >5 on admission, elevated FVIII and VWF levels after thrombolysis were independently associated with poor functional outcomes (mRS ≥ 3) at 90 days (immediately after thrombolysis: FVIII: OR: 7.10, 95% CI: 1.77-28.38, p = 0.006, VWF: OR: 6.31, 95% CI: 1.83-21.73, p = 0.003; 24 h after thrombolysis: FVIII: OR: 4.67, 95% CI: 1.42-15.38, p = 0.011, VWF: OR: 19.02, 95% CI: 1.94-186.99, p = 0.012).

Conclusion

Elevated FVIII activity and VWF antigen levels immediately after lysis and at 24 h post-therapy were shown to have independent prognostic values regarding poor functional outcomes at 90 days.