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The scheme of the neurochemical processes in the brain after ischemic stroke leading to necrotic or apoptotic cell death and penumbra formation. The cell signaling system controls all stages of the cerebral tissue responses to ischemic damage
Source publication
Ischemic stroke is the leading cause of human disability and mortality in the world. The main problem in stroke therapy is the search of efficient neuroprotector capable to rescue neurons in the potentially salvageable transition zone (penumbra), which is expanding after brain damage. The data on molecular mechanisms of penumbra formation and expre...
Citations
... Apoptosis signaling transduction is determinant of the fate of neurons in the ischemic brain. Apoptosis signaling molecules, including Bax, Bcl2, Bad and Caspases, change significantly in the ischemic brain [9,10]. It has been reported that AKT regulates multiple biological processes, including cell survival, proliferation, growth, and glycogen metabolism. ...
Prompt reperfusion after cerebral ischemia is important to maintain neuronal survival and reduce permanent disability and death. However, the resupply of blood can induce oxidative stress, inflammatory response and apoptosis, further leading to tissue damage. Here, we report the versatile biological roles of transcript-induced in spermiogenesis 40 (Tisp40) in ischemic stroke. We found that the expression of Tisp40 was upregulated in ischemia/reperfusion-induced brain tissues and oxygen glucose deprivation/returned -stimulated neurons. Tisp40 deficiency increased the infarct size and neurological deficit score, and promoted inflammation and apoptosis. Tisp40 overexpression played the opposite role. In vitro, the oxygen glucose deprivation/returned model was established in Tisp40 knockdown and overexpression primary cultured cortical neurons. Tisp40 knockdown can aggravate the process of inflammation and apoptosis, and Tisp40 overexpression ameliorated the aforementioned processes. Mechanistically, Tisp40 protected against ischemic stroke via activating the AKT signaling pathway. Tisp40 may be a new therapeutic target in brain ischemia/reperfusion injury.
... Calcium dysregulation, increased glutamatergic signaling, oxidative stress, and inflammatory responses are critical factors triggering cell apoptosis in cerebral ischemia [53][54][55]. After an ischemic event, genetic overexpression of the enzyme caspase-3 has been observed [56,57]. Our findings demonstrated that caspase-3 activity decreased in SH-SY5Y cells under OGD/R conditions treated with DDS-CBD, showing a decrease in apoptosis. ...
Oxidative stress and apoptosis cell death are critical secondary damage mechanisms that lead to losing neighboring healthy tissue after cerebral ischemia. This study aims to characterize the type of interaction between dapsone (DDS) and cannabidiol (CBD) and its cytoprotective effect in an in vitro model of oxygen and glucose deprivation for 6 h followed by 24 h of reoxygenation (OGD/R), using the SH-SY5Y cell line. For the combined concentrations, an isobolographic study was designed to determine the optimal concentration–response combinations. Cell viability was evaluated by measuring the lactate dehydrogenase (LDH) release and 3-[4, 5-dimethyl-2-thiazolyl]-2, 5-diphenyl-2H-tetrazolium bromide (MTT) assays. Also, the reactive oxygen species (ROS) and reduced glutathione (GSH) levels were analyzed as oxidative stress markers. Finally, caspase-3 activity was evaluated as a marker cell death by apoptosis. The results showed a decrease in cell viability, an increase in oxidant stress, and the activity of caspase-3 by the effect of OGD/R. Meanwhile, both DDS and CBD demonstrated antioxidant, antiapoptotic, and cytoprotective effects in a concentration–response manner. The isobolographic study indicated that the concentration of 2.5 µM of DDS plus 0.05 µM of CBD presented a synergistic effect so that in treatment, cell death due to OGD/R decreased. The findings indicate that DDS–CBD combined treatment may be a helpful therapy in cerebral ischemia with reperfusion.
... Funding This work was supported by grants from National Natural injury (Nhu et al. 2021;Uzdensky 2019;Choi et al. 2017). The expression of Caspase-3 is strong in the cerebral cortex and hippocampus after cerebral ischemia and is associated with the dynamic change in apoptosis (Velier et al. 1999;Krupinski et al. 2000;Sasaki et al. 2000). ...
Apoptosis is the crucial pathological mechanism following cerebral ischemic injury. Our previous studies demonstrated that clonidine, one agonist of alpha2-adrenergic receptor (α2-AR), could attenuate cerebral ischemic injury in a rat model of middle cerebral artery occlusion/reperfusion (MCAO/R). However, it’s unclear whether clonidine exerts neuroprotective effects by regulating neuronal apoptosis. In this study, we elucidated whether clonidine can exert anti-apoptotic effects in cerebral ischemic injury, and further explored the possible mechanisms. Neurological deficit score was measured to evaluate the neurological function. TTC staining was used for the measurement of brain infarct size. Hematoxylin-Eosin (HE) staining was applied to examine the cell morphology. TUNEL and DAPI fluorescent staining methods were used to analyze the cell apoptosis in brain tissue. Fluorescence quantitative real-time PCR was performed to assess the gene expression of Caspase-3 and P53. Western blotting assay was applied to detect the protein expression of Caspase-3 and P53. The results showed that clonidine improved neurological function, reduced brain infarct size, alleviated neuronal damage, and reduced the ratio of cell apoptosis in the brain with MCAO/R injury. moreover, clonidine down-regulated the gene and protein expression of Caspase-3 and P53 which were over-expressed after MCAO/R injury. Whereas, yohimbine (one selective α2-AR antagonist) mitigated the anti-apoptosis effects of clonidine, accompanied by reversed gene and protein expression changes. The results indicated that clonidine attenuated cerebral MCAO/R injury via suppressing neuronal apoptosis, which may be mediated, at least in part, by activating α2-AR.
... PAR4 blockade additionally reduced apoptotic indices after tMCAO, reflecting our in vitro observations. Caspase-3 is a culprit contributor to early apoptosis in the penumbra (Uzdensky, 2019). Our mice showed high abundance of cleaved caspase-3 in ipsilateral cortical lysates after tMCAO and 6 h of reperfusion, with levels declining thereafter, while TUNEL-positive staining of the penumbra, reflecting later apoptosis, progressively increases over 72 h of reperfusion after tMCAO. ...
Background and Purpose
Thrombo‐inflammation is a key feature of stroke pathophysiology and provides multiple candidate drug targets. Thrombin exerts coagulation‐independent actions via protease‐activated receptors (PAR), of which PAR1 has been implicated in stroke‐associated neuroinflammation. The role of PAR4 in this context is less clear. This study examined if the selective PAR4 antagonist ML354 provides neuroprotection in experimental stroke and explored the underlying mechanisms.
Experimental Approach
Mouse primary cortical neurons were exposed to oxygen–glucose deprivation (OGD) and simulated reperfusion ± ML354. For comparison, functional Ca²⁺‐imaging was performed upon acute stimulation with a PAR4 activating peptide or glutamate. Male mice underwent sham operation or transient middle cerebral artery occlusion (tMCAO), with ML354 or vehicle treatment beginning at recanalization. A subset of mice received a platelet‐depleting antibody. Stroke size and functional outcomes were assessed. Abundance of target genes, proteins, and cell markers was determined in cultured cells and tissues by qPCR, immunoblotting, and immunofluorescence.
Key Results
Stroke up‐regulated PAR4 expression in cortical neurons in vitro and in vivo. OGD augments spontaneous and PAR4‐mediated neuronal activity; ML354 suppresses OGD‐induced neuronal excitotoxicity and apoptosis. ML354 applied in vivo after tMCAO reduced infarct size, apoptotic markers, macrophage accumulation, and interleukin‐1β expression. Platelet depletion did not affect infarct size in mice with tMCAO ± ML354.
Conclusions and Implications
Selective PAR4 inhibition during reperfusion improves infarct size and neurological function after experimental stroke by blunting neuronal excitability, apoptosis, and local inflammation. PAR4 antagonists may provide additional neuroprotective benefits in patients with acute stroke beyond their canonical antiplatelet action.
... Caspase-3 cleaves substrates, inducing apoptotic cell death and energy depletion. Targeting caspase-3 or death receptors reduces post-MCAO cerebral infarct volume [43,44]. Published evidence links caspase-3 to cerebrovascular injuries and its increase is observed in various neurological conditions [45,46]. ...
Ischemic stroke resulting from blockade of brain vessels lacks effective treatments, prompting exploration for potential therapies. Among promising candidates, microRNA-149 (miR-149) has been investigated for its role in alleviating oxidative stress, inflammation, and neurodegeneration associated with ischemic conditions. To evaluate its therapeutic effect, male Wistar rats were categorized into five groups, each consisting of 27 rats: sham, MCAO, lentiviral control, lentiviral miR-149, and miR149-5p mimic. Treatments were microinjected intracerebroventricularly (ICV) (right side), and ischemia was induced using middle cerebral artery occlusion (MCAO) procedure. Post-MCAO, neurological function, histopathological changes, blood-brain barrier (BBB) permeability, cerebral edema, and mRNA levels of Fas ligand (Faslg) and glutamate ionotropic NMDA receptor 1 (GRIN1) were assessed, alongside biochemical assays. MiR-149 administration improved neurological function, reduced brain damage, preserved BBB integrity, and attenuated cerebral edema. Upregulation of miR149-5p decreased Faslg and GRIN1 expression in ischemic brain regions. MiR-149 also reduced oxidative stress, enhanced antioxidant activity, decreased caspase-1 and − 3 activity, and modulated inflammatory factors in ischemic brain regions. Moreover, DNA fragmentation as an index of cell death decreased following miR-149 treatment. In conclusion, the study underscores miR-149 potential as a neuroprotective agent against ischemic stroke, showcasing its efficacy in modulating various mechanisms and supporting its candidacy as a promising therapeutic target for innovative strategies in stroke treatment.
... The morphological features of apoptosis are varied (Kerr et al., 1972). As known, there are many genes and signalling pathways related to apoptosis that are involved in this process (Uzdensky, 2019;Tian et al., 2018). Bcl-2 is an anti-apoptotic protein (Warren et al., 2019). ...
Background
Ischaemic stroke can lead to many complications, but treatment options are limited. Icariin is a traditional Chinese medicine with reported neuroprotective effects against ischaemic cerebral injury; however, the underlying mechanisms by which icariin ameliorates cell apoptosis require further study.
Purpose
This study aimed to investigate the therapeutic potential of icariin after ischaemic stroke and the underlying molecular mechanisms.
Methods
N2a neuronal cells were used to create an in vitro oxygen-glucose deprivation (OGD) model. The effects of icariin on OGD cells were assessed using the CCK-8 kit to detect the survival of cells and based on the concentration, apoptosis markers, inflammation markers, and M2 pyruvate kinase isoenzyme (PKM2) expression were detected using western blotting, RT-qPCR, and flow cytometry. To investigate the underlying molecular mechanisms, we used the PKM2 agonist TEPP-46 and detected apoptosis-related proteins.
Results
We demonstrated that icariin alleviated OGD-induced apoptosis in vitro. The expression levels of the apoptosis marker proteins caspase-3 and Bax were upregulated and Bcl-2 was downregulated. Furthermore, icariin reduced inflammation and downregulated the expression of PKM2. Moreover, activation of the PKM2 by pretreatment with the PKM2 agonist TEPP-46 enhanced the effects on OGD induced cell apoptosis in vitro.
Conclusion
This study elucidated the underlying mechanism of PKM2 in OGD-induced cell apoptosis and highlighted the potential of icariin in the treatment of ischaemic stroke.
... One of the most crucial mechanisms enhancing the brain's tolerance to ischemia is the inhibition of apoptosis in the peri-infarct zone [9,116]. This protective mechanism during the reperfusion period prevents the death of partially damaged neurons in the ischemic zone. ...
... The primary factor determining the cell death mechanism is the level of ATP inside the cell [118]. Additionally, in the context of therapeutic intervention, apoptosis is preferable to necrosis, as it can be blocked by various treatment methods, allowing the preservation of partially damaged tissue [116,119]. In other words, the more damaged cells in the ischemic injury zone that undergo apoptosis (rather than necrosis), the greater the chances of preserving their viability (including through pharmacological neuroprotectants) and reducing the level of inflammatory reaction in the stroke focus. ...
The review introduces the stages of formation and experimental confirmation of the hypothesis regarding the mutual potentiation of neuroprotective effects of hypoxia and hypercapnia during their combined influence (hypercapnic hypoxia). The main focus is on the mechanisms and signaling pathways involved in the formation of ischemic tolerance in the brain during intermittent hypercapnic hypoxia. Importantly, the combined effect of hypoxia and hypercapnia exerts a more pronounced neuroprotective effect compared to their separate application. Some signaling systems are associated with the predominance of the hypoxic stimulus (HIF-1α, A1 receptors), while others (NF-κB, antioxidant activity, inhibition of apoptosis, maintenance of selective blood–brain barrier permeability) are mainly modulated by hypercapnia. Most of the molecular and cellular mechanisms involved in the formation of brain tolerance to ischemia are due to the contribution of both excess carbon dioxide and oxygen deficiency (ATP-dependent potassium channels, chaperones, endoplasmic reticulum stress, mitochondrial metabolism reprogramming). Overall, experimental studies indicate the dominance of hypercapnia in the neuroprotective effect of its combined action with hypoxia. Recent clinical studies have demonstrated the effectiveness of hypercapnic–hypoxic training in the treatment of childhood cerebral palsy and diabetic polyneuropathy in children. Combining hypercapnic hypoxia with pharmacological modulators of neuro/cardio/cytoprotection signaling pathways is likely to be promising for translating experimental research into clinical medicine.
... This process underlies the earlier restoration of blood flow in the stroke area, which contributes to early rehabilitation after a cerebrovascular accident [33]. The decrease in the number of Cas3-positive cells only confirms the role of apoptosis inhibition, namely that AKT phosphorylation is a possible molecular mechanism of neuroprotection by krypton [34,35]. ...
This is the first in vivo study to investigate the neuroprotective effects of krypton on focal cerebral ischemia. The aim of the study was to analyze the effect of 2 h of inhalation of a krypton–oxygen mixture (Kr 70%/O2 30%) on the recovery of neurological functions and the degree of brain damage in rats after photoinduced ischemic stroke (PIS) and to investigate the possible mechanisms responsible for this neuroprotection. Experiments were performed on male Wistar rats weighing 250–300 g (n = 32). Animals were randomized into four groups. Two groups (n = 20) underwent photoinduced ischemic stroke, followed by 2 h of inhalation of krypton–oxygen mixture consisting of Kr 70%/O2 30% or a nitrogen–oxygen breathing mixture consisting of N2 70%/O2 30%, followed by neurological examinations on days 3 and 7. The other two groups (n = 12) received only gas mixtures of the same concentration and exposure duration as in those in the PIS groups, then Western blot analysis of the potential molecular mechanisms was performed. The results of the study show that treatment with the krypton–oxygen mixture consisting of Kr 70%/O2 30% improves the neurological status on day 7 of observation, reduces the lesion volume according to the MRI examination and the number of Iba-1- and caspase-3-positive cells in the damaged area, promotes the activation of neoangiogenesis (an increase in the von Willebrand factor), and reduces the penumbra area and the number of NeuN-positive cells in it on day 14 of observation. Inhalation of the krypton–oxygen mixture also significantly increases the levels of phosphorylated AKT kinase (protein kinase B) and glycogen synthase kinase 3b (pGSK3b) and promotes the expression of transcription factor Nrf2, which was accompanied by the lowered expression of transcription factor NFkB (p50). Thus, we showed pronounced neuroprotection induced by krypton inhalation after stroke and identified the signaling pathways that may be responsible for restoring neurological functions and reducing damage.
... Apoptosis, a process of programmed cell death, is activated during cerebral ischemia (Love, 2003). Caspase-3, a member of the cysteine protease family, plays a crucial role in mediating apoptosis (Uzdensky, 2019). The destruction of the BBB is a significant pathophysiological process in acute ischemic stroke, which can result in destructive malignant brain edema and hemorrhagic transformation (Qiu et al., 2021). ...
Introduction: The objective of this study is to systematically evaluate the effect of ligustrazine on animal models of ischemic stroke and investigate its mechanism of action.
Materials and Methods: The intervention of ligustrazine in ischemic diseases research on stroke model animals was searched in the Chinese National Knowledge Infrastructure (CNKI), Wanfang Database (Wanfang), VIP Database (VIP), Chinese Biomedical Literature Database (CBM), Cochrane Library, PubMed, Web of Science, and Embase databases. The quality of the included literature was evaluated using the Cochrane risk of bias tool. The evaluation included measures such as neurological deficit score (NDS), percentage of cerebral infarction volume, brain water content, inflammation-related factors, oxidative stress-related indicators, apoptosis indicators (caspase-3), and blood-brain barrier (BBB) permeability (Claudin-5).
Results: A total of 32 studies were included in the analysis. The results indicated that ligustrazine significantly improved the neurological function scores of ischemic stroke animals compared to the control group (SMD = −1.84, 95% CI −2.14 to −1.55, P < 0.00001). It also reduced the percentage of cerebral infarction (SMD = −2.97, 95% CI −3.58 to −2.36, P < 0.00001) and brain water content (SMD = −2.37, 95% CI −3.63 to −1.12, P = 0.0002). In addition, ligustrazine can significantly improve various inflammatory factors such as TNF-α (SMD = −7.53, 95% CI −11.34 to −3.72, P = 0.0001), IL-1β (SMD = −2.65, 95% CI −3.87 to −1.44, P < 0.0001), and IL-6 (SMD = −5.55, 95% CI −9.32 to −1.78, P = 0.004). It also positively affects oxidative stress-related indicators including SOD (SMD = 4.60, 95% CI 2.10 to 7.10, P = 0.0003), NOS (SMD = −1.52, 95% CI −2.98 to −0.06, P = 0.04), MDA (SMD = −5.31, 95% CI −8.48 to −2.14, P = 0.001), and NO (SMD = −5.33, 95% CI −8.82 to −1.84, P = 0.003). Furthermore, it shows positive effects on the apoptosis indicator caspase-3 (SMD = −5.21, 95% CI −7.47 to −2.94, P < 0.00001) and the expression level of the sex-related protein Claudin-5, which influences BBB permeability (SMD = 7.38, 95% CI 3.95 to 10.82, P < 0.0001).
Conclusion: Ligustrazine has been shown to have a protective effect in animal models of cerebral ischemic injury. Its mechanism of action is believed to be associated with the reduction of inflammation and oxidative stress, the inhibition of apoptosis, and the repair of BBB permeability. However, further high-quality animal experiments are required to validate these findings.
... According to a previous study, p38MAPK was recognized as a promotor of cell apoptosis. 22 ...
Background
Proprotein convertase subtilisin/kexin type 9 (PCSK9) has been recognized as a novel lipid‐lowing target. Recent clinical studies suggested the value of inhibiting PCSK9 in decreasing the vulnerability of coronary plaques. However, the evidence of PCSK9‐regulated evolution of unstable carotid plaques is unclear, which has limited the use of PCSK9 inhibitor in carotid plaques. This study aimed to determine the effect and molecular mechanisms of PCSK9 on vulnerability of carotid plaques, to provide potential therapeutic targets for stabilizing carotid plaques.
Methods
The expression of PCSK9 in stable and unstable carotid plaques were examined in tissue and plasma. Human aortic vascular smooth muscle cells (VSMCs) and carotid VSMCs were employed to transfect lentivirus for overexpression and knockdown of PCSK9, respectively. Morphological and functional changes of mitochondria were observed by live‐cell imaging. Cell apoptosis was evaluated by propidium iodide staining. RNA‐sequencing and biological examinations were performed to explore and validate the underlying mechanisms. Truncated plasmids were employed to identify the functional domain of PCSK9 in regulation of VSMCs' mitochondrial morphology, function and apoptosis.
Results
Clinically, PCSK9 was closely related with vulnerability of human carotid plaques. Increased expression of PCSK9 in human VSMCs was accompanied by higher level of apoptosis. At subcellular level of VSMCs, the morphology of mitochondria was shifted toward the fission state, followed by mitochondrial dysfunction. Inhibition of p38 MAPK activation partially rescued the above morphological and behavioral changes caused by PCSK9. Furthermore, inhibiting of dynamin‐related protein 1 (DRP1) attenuated PCSK9‐related mitochondrial dysfunction and cell apoptosis. The 1‐149aa domain of PCSK9 protein was essential to achieve functional regulation to VSMCs.
Conclusion
Our findings demonstrated that PCSK9 induced morphology‐related mitochondrial dysfunction and apoptosis of VSMCs, which may be related to increased vulnerability of carotid plaque.
