Ischemia Model Research Articles

Illustrate the metabolic regulatory mechanism of Taohong Siwu decoction in ischemic stroke by mass spectrometry imaging.

Metabolic dysregulation in the ischemic region has been increasingly recognized as a contributing factor to ischemic stroke pathogenesis. Taohong Siwu decoction (THSWD), a traditional Chinese medicine preparation used to enhance blood circulation, is frequently employed in treating ischemic stroke. However, the metabolic regulatory mechanism underlying the therapeutic effects of THSWD in ischemic stroke remains largely unexplored. In this study, we employed desorption electrospray ionization mass spectrometry imaging (DESI-MSI) to investigate the metabolic changes in the brain tissue of ischemic stroke rat model. Our investigation revealed that 30 metabolites exhibited significant dysregulation in the ischemic brain regions, specifically the cortex and striatum, following ischemic injury. Following the treatment of THSWD, almost all the dysregulated metabolites got different degrees of callback. Further pathway analysis indicated that THSWD might exert its therapeutic effects by restoring energy metabolism, improving neurotransmitter metabolism, recovering polyamine metabolism, and so on. DESI-MSI offers a favorable methodology for investigating the alterations in the spatial distribution and level within the ischemic brain region following treatment with THSWD in ischemic stroke. These findings provide a novel perspective on the underlying mechanisms of the efficacy of THSWD in ischemic stroke treatment.

Glial 'omics in ischemia: Acute stroke and chronic cerebral small vessel disease.

Vascular injury and pathologies underlie common diseases including ischemic stroke and cerebral small vessel disease (CSVD). Prior work has identified a key role for glial cells, including microglia, in the multifaceted and temporally evolving neuroimmune response to both stroke and CSVD. Transcriptional profiling has led to important advances including identification of distinct gene expression signatures in ischemia-exposed, flow cytometrically sorted microglia and more recently single cell RNA sequencing-identified microglial subpopulations or clusters. There is a reassuring degree of overlap in the results from these two distinct methodologies with both identifying a proliferative and a separate type I interferon responsive microglial element. Similar patterns were later seen using multimodal and spatial transcriptomal profiling in ischemia-exposed microglia and astrocytes. Methodological advances including enrichment of specific neuroanatomic/functional regions (such as the neurovascular unit) prior to single cell RNA sequencing has led to identification of novel cellular subtypes and generation of new credible hypotheses as to cellular function based on the enhanced cell sub-type specific gene expression patterns. A ribosomal tagging strategy focusing on the cellular translatome analyses carried out in the acute phases post stroke has revealed distinct inflammation-regulating roles for microglia and astrocytes in this setting. Early spatial transcriptomics experiments using cerebral ischemia models have identified regionally distinct microglial cell clusters in ischemic core versus penumbra. There is great potential for combination of these methods for multi-omics approaches to further elucidate glial responses in the context of both acute ischemic stroke and chronic CSVD.

RIP1 inhibition protects retinal ganglion cells in glaucoma models of ocular injury

AbstractReceptor-interacting protein 1 (RIP1, RIPK1) is a critical mediator of multiple signaling pathways that promote inflammatory responses and cell death. The kinase activity of RIP1 contributes to the pathogenesis of a number of inflammatory and neurodegenerative diseases. However, the role of RIP1 in retinopathies remains unclear. This study demonstrates that RIP1 inhibition protects retinal ganglion cells (RGCs) in preclinical glaucoma models. Genetic inactivation of RIP1 improves RGC survival and preserves retinal function in the preclinical glaucoma models of optic nerve crush (ONC) and ischemia–reperfusion injury (IRI). In addition, the involvement of necroptosis in ONC and IRI glaucoma models was examined by utilizing RIP1 kinase-dead (RIP1-KD), RIP3 knockout (RIP3-KO), and MLKL knockout (MLKL-KO) mice. The number of RGCs, retinal thickness, and visual acuity were rescued in RIP1-kinase-dead (RIP1-KD) mice in both models, while wild-type (WT) mice experienced significant retinal thinning, RGC loss, and vision impairment. RIP3-KO and MLKL-KO mice showed moderate protective effects in the IRI model and limited in the ONC model. Furthermore, we confirmed that a glaucoma causative mutation in optineurin, OPTN-E50K, sensitizes cells to RIP1-mediated inflammatory cell death. RIP1 inhibition reduces RGC death and axonal degeneration following IRI in mice expressing OPTN-WT and OPTN-E50K variant mice. We demonstrate that RIP1 inactivation suppressed microglial infiltration in the RGC layer following glaucomatous damage. Finally, this study highlights that human glaucomatous retinas exhibit elevated levels of TNF and RIP3 mRNA and microglia infiltration, thus demonstrating the role of neuroinflammation in glaucoma pathogenesis. Altogether, these data indicate that RIP1 plays an important role in modulating neuroinflammation and that inhibiting RIP1 activity may provide a neuroprotective therapy for glaucoma.

Intracavernosal mesenchymal stem cell therapy in ischaemic priapism: an experimental study.

The most common form of priapism is ischaemic and its prevalence in men has increased in recent years as a result of intracavernosal drug use. Currently, there is no approved specific treatment for ischaemic priapism other than cavernosal aspiration, which can only provide detumescence. This study aims to evaluate the efficacy of intracavernosal mesenchymal stem cell (MSC) therapy in an ischaemic priapism model. Thirty male Wistar albino rats were divided into three groups: sham (n = 6), priapism (n = 12) and priapism + MSC treatment (n = 12). The experimental groups were also divided into 1 and 12h subgroups of ischaemic priapism. The experimental model was created using a vacuum erection device and constrictive tape technique, and intracavernosal MSC were applied immediately after the tape was removed. After 4weeks, intracavernosal pressures (ICPs) and systemic mean arterial pressure (MAP) were measured. Penectomy was then performed to assess histopathological and molecular changes in the rats' penile tissues. In the ischaemic priapism model, MSC therapy showed significant improvements in peak and mean ICPs and mean ICP/MAP ratio. Histopathological analysis showed significant increases in smooth-muscle/collagen ratio and e-NOS and n-NOS expression. Although there was a decrease in fibrosis, it was not significant. At the molecular level, there were significant decreases in TGF-beta and VEGF mRNA expression, whilst NGF and BDNF mRNA-expression levels showed significant increases with MSC therapy. In terms of ICPs, the therapy showed more significant improvements in short-term priapism. However, when looking at histopathological and molecular parameters, the therapy had positive effects on a wider range of parameters in the long-term priapism. MSC treatment improved cavernosal physiology and had positive effects at the histopathological and molecular level in the ischaemic priapism model.

Deciphering heart failure: an integrated proteomic and transcriptomic approach with experimental validation.

This study analyzed transcriptomic and proteomic data to identify molecular changes during heart failure (HF). Additionally,we embarked on an exploration of the prospect of therapeutic intervention through the manipulation of proteins implicated in ferroptosis. Three publicly available microarray datasets (GSE135055, GSE147236, GSE161472) profiling left ventricular samples from HF patients and healthy controls were obtained. Differentially expressed genes were identified in each dataset and cross-analyzed to determine shared gene signatures. Enrichment analysis of Gene Ontology (GO) terms, Kyoto Encyclopedia of Genes and Genomes (KEGG) pathways, and gene set enrichment analysis were performed. Differentially expressed proteins were obtained from published proteomic studies and integrated with the transcriptomic results. To validate findings, a HF mouse model was generated and ferroptosis-related proteins were evaluated. Additionally, the effect of suppression of ferroptosis on hypoxia-induced ischemia model in HL-1 cardiomyocytes was assessed by knocking down Acyl-CoA synthetase long-chain family member 4 (ACSL4) using small interfering RNA (siRNA).Cross-analysis of differentially expressed genes (DEGs) in the GSE135055, GSE147236 and GSE161472 datasets revealed 224 up-regulated and 187 down-regulated potential genes which showed high enrichment in immune, inflammatory and metabolic pathways. Notably, four proteins, among them ACSL4, displayed consistent alterations at both the transcriptional and protein levels. In the HF mouse model, ACSL4 exhibited an elevation, whereas negative regulators of ferroptosis witnessed a decrement. Subsequently, knockdown of ACSL4 in a hypoxia-induced ischemic HL-1 cardiomyocyte cell model upregulated the expression of ferroptosis inhibitory protein and decreased the levels of reactive oxygen species (ROS), malondialdehyde (MDA)., and free iron and increased cell viability. Comprehensive multi-omics analysis revealed that the expression of the molecular target ACSL4 was increased in HF. Targeting ACSL4 to inhibit ferroptosis may represent a novel therapeutic strategy for HF treatment.

Neuroprotective effects of Daphnetin on hippocampal neurons and blood-brain barrier integrity in a mouse model of cerebral ischemia

The purpose of this research was to assess the impact of different doses of Daphnetin (DAP, a natural compound derived from coumarin) on hippocampus neuronal injury, neurobehavioral function, blood-brain barrier (BBB) integrity, expression of claudin-5, brain-derived neurotrophic factor (BDNF), superoxide dismutase (SOD), and inflammatory markers in a mouse model of cerebral ischemia. Cerebral ischemia was induced in mice through 30 minutes of bilateral common carotid occlusion (BCCAO), followed by 48 hours of reperfusion. The viability of hippocampal neurons was assessed using Cresyl violet staining and BBB function was determined by measuring Evans blue (E.B) dye leakage. Spatial memory was tested using the Radial Arm Water Maze (RAWM) task. Claudin-5 and BDNF were measured by immunofluorescence, while SOD, interleukin-1 beta (IL-1β), and nuclear factor-κB (NF-κB) expression were determined through western blotting. Administering DAP significantly increased neuron survival in the hippocampus CA1, CA3, and dentate gyrus (DG) regions and improved spatial memory dose-dependently (P<0.0001). Treatment with DAP (40 mg/kg IP) significantly reduced E.B leakage and brain water content (P<0.001). Furthermore, it increased the claudin-5, BDNF, and SOD levels and diminished NF-κB and IL-1β expression (P<0.0001). The research found that DAP protected neurons in the CA1, CA3, and DG areas of the hippocampus, enhanced behavioral functions, and preserved BBB integrity in a cerebral ischemia model. This positive impact is achieved by increasing the expression of claudin-5, BDNF, and SOD and diminishing neuroinflammation. Further research is required to clarify the mechanisms and possible clinical uses.

Effects of Local Hypothermia on Limb Viability in a Swine Model of Acute Limb Ischemia During Prolonged Damage-Control Resuscitation.

New strategies are needed to mitigate further tissue injury during traumatic limb ischemia in cases requiring damage control resuscitation (DCR). Little is known about the pathophysiology and injury course in acute limb ischemia (ALI) with DCR in polytraumatized casualties. We therefore investigated the effects of therapeutic limb hypothermia in a swine model of ALI and DCR. Fifteen swine underwent a published 6-hour DCR protocol of hemorrhage and then resuscitation. After hemorrhage, animals were randomized to 5oC or 15oC cooling of one hindlimb; the contralateral limb serving as an uncooled control. Physiologic variables, limb temperature, and limb tissue metabolites (glucose, lactate, and pyruvate) were measured throughout the DCR protocol. Muscle and nerve biopsies were obtained after the 6-hour protocol. Lactate and pyruvate levels were significantly lower in the cooled limbs than in the uncooled control limbs but did not differ between the 5oC and 15oC groups. Tissue glucose levels did not differ between the 5oC group, the 15oC group, and controls. Mean histologic muscle score was significantly higher in the 5oC group than in controls (p = 0.03). Mean nerve histology scores did not differ between the 5oC and paired control limbs, or between the mean muscle and nerve histology scores of the 15oC and paired control limbs. Cooling to 15oC significantly reduced local tissue metabolites compared to paired controls, while producing no significant increase in histologic damage, whereas cooling to 5oC increased histologic muscle damage. These results suggest an approach to prevention of ischemic injury through local hypothermia but warrant further functional testing.

PEP-1-PIN1 Promotes Hippocampal Neuronal Cell Survival by Inhibiting Cellular ROS and MAPK Phosphorylation.

Background: The peptidyl-prolyl isomerase (PIN1) plays a vital role in cellular processes, including intracellular signaling and apoptosis. While oxidative stress is considered one of the primary mechanisms of pathogenesis in brain ischemic injury, the precise function of PIN1 in this disease remains to be elucidated. Objective: We constructed a cell-permeable PEP-1-PIN1 fusion protein and investigated PIN1's function in HT-22 hippocampal cells as well as in a brain ischemic injury gerbil model. Methods: Transduction of PEP-1-PIN1 into HT-22 cells and signaling pathways were determined by Western blot analysis. Intracellular reactive oxygen species (ROS) production and DNA damage was confirmed by DCF-DA and TUNEL staining. Cell viability was determined by MTT assay. Protective effects of PEP-1-PIN1 against ischemic injury were examined using immunohistochemistry. Results: PEP-1-PIN1, when transduced into HT-22 hippocampal cells, inhibited cell death in H2O2-treated cells and markedly reduced DNA fragmentation and ROS production. This fusion protein also reduced phosphorylation of mitogen-activated protein kinase (MAPK) and modulated expression levels of apoptosis-signaling proteins in HT-22 cells. Furthermore, PEP-1-PIN1 was distributed in gerbil hippocampus neuronal cells after passing through the blood-brain barrier (BBB) and significantly protected against neuronal cell death and also decreased activation of microglia and astrocytes in an ischemic injury gerbil model. Conclusions: These results indicate that PEP-1-PIN1 can inhibit ischemic brain injury by reducing cellular ROS levels and regulating MAPK and apoptosis-signaling pathways, suggesting that PIN1 plays a protective role in H2O2-treated HT-22 cells and ischemic injury gerbil model.

Effects of Anesthesia with Pentobarbital/Ketamine on Mitochondrial Permeability Transition Pore Opening and Ischemic Brain Damage.

The alteration of mitochondrial functions, especially the opening of the mitochondrial permeability transition pore (mPTP), has been proposed as a key mechanism in the development of lesions in cerebral ischemia, wherefore it is considered as an important target for drugs against ischemic injury. In this study, we aimed to investigate the effects of mitochondrial complex I inhibitors as possible regulators of mPTP using an in vitro brain ischemia model of the pentobarbital/ketamine (PBK)-anesthetized rats. We found that PBK anesthesia itself delayed Ca2+-induced mPTP opening and partially recovered the respiratory functions of mitochondria, isolated from rat brain cortex and cerebellum. In addition, PBK reduced cell death in rat brain slices of cerebral cortex and cerebellum. PBK inhibited the adenosine diphosphate (ADP)-stimulated respiration of isolated cortical and cerebellar mitochondria respiring with complex I-dependent substrates pyruvate and malate. Moreover, pentobarbital alone directly increased the resistance of isolated cortex mitochondria to Ca2+-induced activation of mPTP and inhibited complex I-dependent respiration and mitochondrial complex I activity. In contrast, ketamine had no direct effect on functions of isolated normal cortex and cerebellum mitochondria. Altogether, this suggests that modulation of mitochondrial complex I activity by pentobarbital during PBK anesthesia may increase the resistance of mitochondria to mPTP opening, which is considered the key event in brain cell necrosis during ischemia.

Impaired Endothelium-Dependent Vasodilation and Increased Levels of Soluble Fms-like Tyrosine Kinase-1 Induced by Reduced Uterine Perfusion Pressure in Pregnant Rats: Evidence of Protective Effects with Sodium Nitrite Treatment in Preeclampsia.

Preeclampsia (PE) is a hypertensive disorder of pregnancy and is associated with increases in soluble fms-like tyrosine kinase-1 (sFlt-1) and reductions in nitric oxide (NO) levels. Placental ischemia and hypoxia are hypothesized as initial pathophysiological events of PE. Nitrite (NO metabolite) may be recycled back to NO in ischemic and hypoxic tissues. Therefore, this study examined the sodium nitrite effects in an experimental model of PE. Pregnant rats received saline (Preg group) or sodium nitrite (Preg + Na-Nitrite group). Pregnant rats submitted to the placental ischemia received saline (RUPP group) or sodium nitrite (RUPP + Na-Nitrite group). Blood pressure, placental and fetal weights, and the number of pups were recorded. Plasma levels of NO metabolites and sFlt-1 were also determined. Vascular and endothelial functions were also measured. Blood pressure, placental and fetal weights, the number of pups, NO metabolites, sFlt-1 levels, vascular contraction, and endothelium-dependent vasodilation in the RUPP + Na-Nitrite rats were brought to levels comparable to those in Preg rats. In conclusion, sodium nitrite may counteract the reductions in NO and increases in sFlt-1 levels induced by the placental ischemia model of PE, thus suggesting that increased blood pressure and vascular and endothelial dysfunctions may be attenuated by sodium nitrite-derived NO.

Development and Validation of Prognostic Models for Bleeding and Ischemia in Elderly Patients With Comorbid Acute Coronary Syndrome and Atrial Fibrillation.

Acute coronary syndrome and atrial fibrillation are common cardiovascular diseases in elderly individuals. Patients with comorbidities face increased risks of bleeding and ischemia; however, there is a lack of prognostic models for quantifying these risks in this special population. In this retrospective cohort study, 1851 patients (≥65 years old) with acute coronary syndrome and atrial fibrillation from 2 hospitals in China were included in the development cohort (1252 individuals) and 2 external validation cohorts (284 and 315 individuals). During 1-year follow-up, 96 Bleeding Academic Research Consortium type 3 or 5 bleeding events and 245 thromboembolic events were observed. In the development cohort, the concordance indexes for bleeding at 3, 6, and 12 mo ranged from 0.737 to 0.845 and for ischemia ranged from 0.723 to 0.777. The calibration curve and decision curve analysis indicated adequate calibration and clinical practicability. The concordance indexes varied from 0.679 to 0.809 in the validation cohorts. Subgroup analyses focusing on anticoagulant drugs and antithrombotic therapy were conducted, revealing similar discrimination and calibration. Kaplan-Meier curves demonstrated significant differences (log-rank P<0.001). Additionally, the models outperformed conventional models in concordance indexes, integrated discrimination improvement, and net reclassification improvement. Our study provides 2 robust prognostic models with easily available clinical factors for predicting bleeding and ischemia in elderly patients with acute coronary syndrome and atrial fibrillation. Furthermore, we provide online calculators to facilitate individualized risk evaluation and clinical decision-making. URL: www.chictr.org.cn/. Unique Identifier: ChiCTR2200067185.

Edaravone Dexborneol provides neuroprotective effect by inhibiting neurotoxic activation of astrocytes through inhibiting NF-κB signaling in cortical ischemia

Edaravone Dexborneol (EDB), comprised of edaravone and (+)- bornel, has been demonstrated to have synergistic effects of antioxidant and anti-inflammatory, which makes it to be applied for stroke as a protectant. However, the underlying mechanism of neuroprotection of EDB has not been fully elucidated. Increasing evidence has shown that neurotoxic A1 astrocytes were closely related to neuronal death after cerebral ischemia. However, whether EDB could provide neuroprotection by modulating the activation of astrocytes has not yet been elucidated. The present study aimed to explore whether EDB afforded neuroprotection by modulating A1 polarization of astrocytes and the down-stream signaling after cerebral ischemia. We first validated the neuroprotective effects of EDB in mice suffering focal cerebral ischemia via evaluating behavioral test, infarct volumes and neuronal survival. As for the down-stream signaling, our data further showed that EDB alleviated neuronal death by suppressing activation of neurotoxic A1 astrocytes via inhibition of NF-κB signaling pathway in vitro. Additionally, administration of EDB reduced the number of A1 reactive astrocytes in mice of focal cerebral ischemia. The above findings demonstrated that EDB provided neuroprotective effect by inhibiting neurotoxic activation of A1 astrocytes in animal model of cerebral ischemia, which indicated that EDB-mediated phenotypic regulation of astrocytes is a potential research direction to promote neurological recovery in central nervous system (CNS) diseases.

Identification of 3-methyl-1-(3-methylpyridin-2-yl)-1H-pyrazol-5-ol as promising neuroprotective agent

Pyrazolol derivatives are gaining significant attention for their diverse pharmacological effects, such as analgesic, anti-inflammatory, antioxidant, and anticancer activities. In this study, 20 pyrazolol derivatives were designed and synthesized to develop an anti-ischemic stroke formulation with free radical scavenging activity. Most of these synthesized compounds demonstrated antioxidant capabilities in DPPH, ABTS radical scavenging, and ORACFL assays. The methyl-substituted compound Y12, in particular, showed exceptional antioxidant capacity. Additionally, these compounds showed excellent neurocytoprotective effects in the SH-SY5Y cell injury model subjected to oxygen-glucose deprivation/reoxygenation (OGD/R). Notably, Y12 exhibited significant metal chelating activity with Cu2+. In vivo studies confirmed that compound Y12 has neuroprotective effects and can significantly reduce the infarct area in a mouse model of focal cerebral ischemia induced by transient middle cerebral artery occlusion (tMCAO).

Nattokinase Attenuated Excitatory Amino Acids and Cytokines Release and Restored Cerebral Blood Flow in a Thrombolytic Focal Cerebral Ischemic Rat Model.

Nattokinase (NK), a protease enzyme present in traditional fermented Japanese food, has shown fibrinolytic properties in vitro as well as in cardiac ischemia. In the present study, the Neuroprotective effect of standardized NK was evaluated in the thrombolytic focal cerebral ischemic model. The parameters of behavioural assessment, cerebral blood flow, inflammatory mediators, excitatory amino acids, and immunohistochemistry were measured to support the NK effect. NK was administered at 150 and 300 mg/kg, and its effects were compared with streptokinase (STK) (100μl/rat). Each mg of NK contains 5.5 Units of the enzyme, which can cause lysis of the fibrin. The results indicate that 7 days of treatment of 300 mg NK restored the cerebral blood flow and prevented the release of cytokine and excitatory amino acids. Similarly, neurological scores were reduced, and grip strength increased significantly with NK treatment. The GFAP and synaptophysin staining of the hippocampus (CA1) and cerebrum have shown recovery of neurons from ischemic damage in comparison to vehicle-treated ischemic-reperfused rats. The NK (300 mg/kg) fibrinolytic effect is comparable to STK treatment. To conclude, NK, a serine protease, protects the brain from ischemic degeneration in thrombolytic cerebral ischemia. Consumption of this Japanese food might exhibit prophylactic activity.

Synergistic effect of Hypoxic Conditioning and Cell-Tethering Colloidal Gels enhanced Productivity of MSC Paracrine Factors and Accelerated Vessel Regeneration.

Microporous hydrogels have been widely used for delivering therapeutic cells. However, several critical issues, such as the lack of control over the harsh environment they are subjected to under pathological conditions and rapid egression of cells from the hydrogels, have produced limited therapeutic outcomes. To address these critical challenges, cell-tethering and hypoxic conditioning colloidal hydrogels containing mesenchymal stem cells (MSCs) are introduced to increase the productivity of paracrine factors locally and in a long-term manner. Cell-tethering colloidal hydrogels that are composed of tyramine-conjugated gelatin prevent cells from egressing through on-cell oxidative phenolic crosslinks while providing mechanical stimulation and interconnected microporous networks to allow for host-implant interactions. Oxygenating microparticlesencapsulated in tyramine-conjugated colloidal microgels continuously generated oxygen for 2 weeks with rapid diffusion, resulting in maintaining a mild hypoxic condition while MSCs consumed oxygen under severe hypoxia. Synergistically, local retention of MSCs within the mild hypoxic-conditioned and mechanically robust colloidal hydrogels significantly increased the secretion of various angiogenic cytokines and chemokines. The oxygenating colloidal hydrogels induced anti-inflammatory responses, reduced cellular apoptosis, and promoted numerous large blood vessels in vivo. Finally, mice injected with the MSC-tethered oxygenating colloidal hydrogels significantly improved blood flow restoration and muscle regeneration in a hindlimb ischemia (HLI) model.

Microglia-mediated endothelial protection: the role of SHPL-49 in ischemic stroke

It was previously shown that SHPL-49, a glycoside derivative of salidroside formed through structural modification, exhibited neuroprotective effects in a rat cerebral ischemia model of permanent middle cerebral artery occlusion (pMCAO). Additionally, SHPL-49 enhanced the mRNA expression of vascular endothelial growth factor-a (Vegf-a) in macrophages. Microglia, functioning as resident macrophages within the brain, promptly respond to cerebral ischemia and engage in interactions with the cells of the Glial-Vascular Unit to orchestrate nerve injury responses. We postulated that the neuroprotective effects of SHPL-49 were mediated through microglia-dependent amelioration of endothelial dysfunction following cerebral ischemia. The present study demonstrates that SHPL-49 effectively mitigated microglia-dependent endothelial dysfunction in the pMCAO model by upregulating the expression of VEGF and suppressing the release of MMP-9 from microglia. Further MRI analyses confirmed that SHPL-49 significantly reduced nerve and endothelial function when microglia were depleted in the brains of pMCAO rats. The above phenomenon was also confirmed in the in vitro experiment investigating microglia-mediated brain endothelial cell function. Furthermore, we discovered that SHPL-49 activates the VEGFR2/Akt/eNOS pathways in endothelial cells and suppresses the p38 MAPK/MMP-9 pathways in microglia cells, thereby facilitating brain endothelial cell protection. Altogether, we have demonstrated that SHPL-49 effectively ameliorates endothelial dysfunction induced by cerebral ischemia through a microglia-dependent mechanism, thereby providing more valuable insights and references for the clinical evaluation of SHPL-49 injection for ischemic stroke.

Sex-specific role of RNA-binding protein, pAUF1, on prolonged hypersensitivity after repetitive ischemia with reperfusion injury.

Repetitive ischemia with reperfusion (I/R) injury is a common cause of myalgia. Ischemia with reperfusion injuries occur in many conditions that differentially affect males and females including complex regional pain syndrome and fibromyalgia. Our preclinical studies have indicated that primary afferent sensitization and behavioral hypersensitivity caused by I/R injury may be due to sex-specific gene expression in the dorsal root ganglia (DRG) and distinct upregulation of growth factors and cytokines in the affected muscles. To determine how these unique gene expression programs may be established in a sex-dependent manner in a model that more closely mimics clinical scenarios, we used a developed prolonged ischemic myalgia model in mice whereby animals experience repeated I/R injuries and compared behavioral results with unbiased and targeted screening strategies in male and female DRG. Several distinct proteins were found to be differentially expressed in male and female DRG, including phosphorylated AU-rich element RNA-binding protein (pAUF1), which is known to regulate gene expression. Nerve-specific siRNA-mediated knockdown of AUF1 inhibited prolonged hypersensitivity in females only, whereas overexpression of AUF1 in male DRG neurons increased pain-like responses. AUF1 knockdown was able to specifically inhibit repeated I/R-induced gene expression in females potentially downstream of prolactin receptor signaling. Data suggest RNA-binding proteins such as pAUF1 may underlie the sex-specific effects on DRG gene expression that modulates behavioral hypersensitivity after repeated I/R injury through prolactin signaling. This study may aid in finding distinct receptor differences related to the evolution of acute to chronic ischemic muscle pain development between sexes.

Ozone therapy mitigates parthanatos after ischemic stroke

BackgroundStroke is a leading cause of death worldwide, with oxidative stress and calcium overload playing significant roles in the pathophysiology of the disease. Ozone, renowned for its potent antioxidant properties, is commonly employed as an adjuvant therapy in clinical settings. Nevertheless, it remains unclear whether ozone therapy on parthanatos in cerebral ischemia–reperfusion injury (CIRI). This study aims to investigate the impact of ozone therapy on reducing parthanatos during CIRI and to elucidate the underlying mechanism.MethodsHydrogen peroxide (H2O2) was utilized to mimic the generation of reactive oxygen species (ROS) in SH-SY5Y cell reperfusion injury in vitro, and an in vivo ischemic stroke model was established. Ozone saline was introduced for co-culture or intravenously administered to mice. Apoptosis and oxidative stress were assessed using flow cytometry and immunofluorescence. Western blotting was utilized to examine the expression of parthanatos signature proteins. The mechanism by which ozone inhibits parthanatos was elucidated through inhibiting PPARg or Nrf2 activity. ResultsThe findings demonstrated that ozone mitigated H2O2-induced parthanatos by either upregulating nuclear factor erythroid 2-related factor 2 (Nrf2) or activating peroxisome proliferator-activated receptorg (PPARg). Furthermore, through the use of calcium chelators and ROS inhibitors, it was discovered that ROS directly induced parthanatos and facilitated intracellular calcium elevation. Notably, a malignant feedback loop between ROS and calcium was identified, further amplifying the induction of parthanatos. Ozone therapy exhibited its efficacy by increasing PPARg activity or enhancing the Nrf2 translation, thereby inhibiting ROS production induced by H2O2. Concurrently, our study demonstrated that ozone treatment markedly inhibited parthanatos in stroke-afflicted mice. Additionally, ozone therapy demonstrated significant neuroprotective effects on cortical neurons, effectively suppressing parthanatos.ConclusionsThese findings contribute valuable insights into the potential of ozone therapy as a therapeutic strategy for reducing parthanatos during CIRI, highlighting its impact on key molecular pathways associated with oxidative stress and calcium regulation.

Feasibility of Monitoring Tissue Properties During Microcirculation Disorder Using a Compact Fiber-Based Probe With Sapphire Tip.

One of the urgent tasks of modern medicine is to detect microcirculation disorder during surgery to avoid possible consequences like tissue hypoxia, ischemia, and necrosis. To address this issue, in this article, we propose a compact probe with sapphire tip and optical sensing based on the principle of spatially resolved diffuse reflectance analysis. It allows for intraoperative measurement of tissue effective attenuation coefficient and its alteration during the changes of tissue condition, caused by microcirculation disorder. The results of experimental studies using (1) a tissue-mimicking phantom based on lipid emulsion and hemoglobin and (2) a model of hindlimb ischemia performed in a rat demonstrated the ability to detect rapid changes of tissue attenuation confirming the feasibility of the probe to sense the stressful exposure. Due to a compact design of the probe, it could be useful for rather wide surgical operations and diagnostic purposes as an auxiliary instrument.

Multiple intravenous infusions versus a single infusion of mesenchymal stem cells in a rat model of cerebral ischemia.

Recent randomized clinical trials of a single infusion of mesenchymal stem cells (MSCs) for acute cerebral stroke revealed a limited functional recovery outcome. Conversely, animal studies suggest that multiple MSC infusions may enhance functional recovery by inducing neural plasticity, which indicates that a multiple-infusion approach might be effective for stroke treatment in humans. The objective of this study was to investigate whether multiple infusions of MSCs enhance functional outcomes during the acute phase of cerebral ischemia. Rats subjected to permanent middle cerebral artery occlusion (MCAO) were randomized into four groups: 1) vehicle group (infusion of vehicle only), 2) MSC-1 group (single administration of the standard MSC dose on day 3), 3) high-dose MSC group (single administration of three times the standard MSC dose on day 3), and 4) MSC-3 group (multiple administrations of the standard MSC dose on days 3, 10, and 17). MSCs were administered via the femoral vein. Behavioral performance and ischemic lesion volume were examined using in vivo MRI every 7 days from day 3 to day 45 after MCAO induction. The thickness of the corpus callosum (CC) was determined using Nissl staining, and the area of the CC was measured using ex vivo MRI. Interhemispheric connections within the CC were assessed using ex vivo MRI diffusion tensor imaging. The MSC-3 group exhibited the most significant motor recovery and increased CC thickness and area among all groups. Increased CC thickness and area were correlated with improved behavioral function 45 days after MCAO induction. Neural tracts through interhemispheric connections via the CC were most pronounced in the MSC-3 group, and this anatomical change showed a positive relationship with behavioral function. Multiple infusions of MSCs led to histological changes in the CC and neural tracts within the CC. These results indicate that multiple systemic infusions of MSCs had a greater beneficial effect in the acute phase of MCAO than a single standard or high-dose infusion of MSCs.