Proteomic Analysis of Rat Cerebral Cortex in the Subacute to Long-Term Phases of Focal Cerebral Ischemia-Reperfusion Injury

Dynamics in Redox-Active Molecules Following Ischemic Preconditioning in the Brain

It is well known that the brain is quite vulnerable to oxidative stress, initiating neuronal loss after ischemia-reperfusion (IR) injury. A potent protective mechanism is ischemic preconditioning (IPC), where proteins are among the primary targets. This study explores redox-active proteins' role in preserving energy supply. Adult rats were divided into the control, IR, and IPC groups. Protein profiling was conducted to identify modified proteins and then verified through activity assays, immunoblot, and immunohistochemical analyses. IPC protected cortex mitochondria, as evidenced by a 2.26-fold increase in superoxide dismutase (SOD) activity. Additionally, stable core subunits of respiratory chain complexes ensured sufficient energy production, supported by a 16.6% increase in ATP synthase activity. In hippocampal cells, IPC led to the downregulation of energy-related dehydrogenases, while a significantly higher level of peroxiredoxin 6 (PRX6) was observed. Notably, IPC significantly enhanced glutathione reductase activity to provide sufficient glutathione to maintain PRX6 function. Astrocytes may mobilize PRX6 to protect neurons during initial ischemic events, by decreased PRX6 positivity in astrocytes, accompanied by an increase in neurons following both IR injury and IPC. Maintained redox signaling via astrocyte-neuron communication triggers IPC's protective state. The partnership among PRX6, SOD, and glutathione reductase appears essential in safeguarding and stabilizing the hippocampus.

Chrysin inhibits ferroptosis of cerebral ischemia/reperfusion injury via regulating HIF-1α/CP loop

Chrysin is a natural flavonoid with powerful neuroprotective capacity. Cerebral ischemia/reperfusion injury (CIRI) is associated with oxidative stress and ferroptosis. Hypoxia-inducible factor 1α (HIF-1α) and ceruloplasmin (CP) are the critical targets for oxidation reactions and iron transport. But the regulatory mechanism between them is still unclear. Transient middle cerebral artery occlusion (tMCAO) model in rats and oxygen and glucose deprivation/re-oxygenation (OGD/R) model in PC12 cells were applied. Pathological tissue staining and biochemical kit were used to evaluate the effect of chrysin. The relationship between HIF-1α and CP was verified by transcriptomics, qRT-PCR and Western blot. In CIRI, HIF-1α/CP loop was discovered to be the regulatory pathway of ferroptosis. CIRI led to activation and nuclear translocation of HIF-1α, which promoted CP transcription and translation, and downstream ferroptosis. Inhibition of HIF-1α had opposite effect on CP and ferroptosis regulation. Overexpression of CP increased the expression of HIF-1α, nevertheless, inhibited the nuclear translocation of HIF-1α and alleviated CIRI. Silencing CP promoted HIF-1α elevation in nucleus and aggravated CIRI. Mechanistically, chrysin restrained HIF-1α nuclear translocation, thereby inhibiting CP transcription and translation, which in turn reduced downstream HIF-1α expression and mitigated ferroptosis in CIRI. Our results highlight chrysin restrains ferroptosis in CIRI through HIF-1α/CP loop.

Applying Proteomics and Computational Approaches to Identify Novel Targets in Blast-Associated Post-Traumatic Epilepsy

Traumatic brain injury (TBI) can lead to post-traumatic epilepsy (PTE). Blast TBI (bTBI) found in Veterans presents with several complications, including cognitive and behavioral disturbances and PTE; however, the underlying mechanisms that drive the long-term sequelae are not well understood. Using an unbiased proteomics approach in a mouse model of repeated bTBI (rbTBI), this study addresses this gap in the knowledge. After rbTBI, mice were monitored using continuous, uninterrupted video-EEG for up to four months. Following this period, we collected cortex and hippocampus tissues from three groups of mice: those with post-traumatic epilepsy (PTE+), those without epilepsy (PTE-), and the control group (sham). Hundreds of differentially expressed proteins were identified in the cortex and hippocampus of PTE+ and PTE- relative to sham. Focusing on protein pathways unique to PTE+, pathways related to mitochondrial function, post-translational modifications, and transport were disrupted. Computational metabolic modeling using dysregulated protein expression predicted mitochondrial proton pump dysregulation, suggesting electron transport chain dysregulation in the epileptic tissue relative to PTE-. Finally, data mining enabled the identification of several novel and previously validated TBI and epilepsy biomarkers in our data set, many of which were found to already be targeted by drugs in various phases of clinical testing. These findings highlight novel proteins and protein pathways that may drive the chronic PTE sequelae following rbTBI.

Traditional Chinese Medicine formula, Sanwujiao granule, attenuates ischemic stroke by promoting angiogenesis through early administration

ETHNOPHARMACOLOGICAL RELEVANCE

Ischemic stroke (IS) is one of the most lethal diseases with the insufficient pharmacology therapeutic approach. Sanwujiao granule (SW) is widely used for IS in China with little known about its underlying mechanism.

AIM OF THE STUDY

To investigate the characteristics of therapeutic effects and potential mechanisms of SW against IS.

MATERIALS AND METHODS

The fingerprint of SW was applied by high-performance liquid chromatography-mass spectrometry (HPLC-MS). Three different drug treatment strategies, including prophylactic administration, early administration and delayed administration, were applied in rats' permanent middle cerebral occlusion (pMCAO) model. The Garcia neurological deficit test, adhesive removal test, rotarod test, TTC and TUNEL staining were performed to evaluate the pathological changes. The transcriptomic analysis was used to predict the potential mechanism of SW. The vascular deficiency model of Tg(kdrl:eGFP) zebrafish larvae and oxygen-glucose deprivation model on bEnd.3 cells were used to verify SW's pharmacological effect. qRT-PCR, immunofluorescent staining and Western Blot were applied to detect the expression of genes and proteins. The network pharmacology approach was applied to discover the potential bioactive compounds in SW that contribute to its pharmacological effect.

RESULTS

SW early and delayed administration attenuated cerebral infarction, neurological deficit and cell apoptosis. The transcriptomic analysis revealed that SW activated angiogenesis-associated biological processes specifically by early administration. CD31 immunofluorescent staining further confirmed the microvessel intensity in peri-infarct regions was significantly elevated after SW early treatment. Additionally, on the vascular deficiency model of zebrafish larvae, SW showed the angiogenesis effect. Next, the cell migration and tube formation were also observed in the bEnd.3 cells with the oxygen-glucose deprivation induced cell injury. It's worth noting that both mRNA and protein levels of angiogenesis factor, insulin-like growth factor 1, were significantly elevated in the pMCAO rats' brains treated with SW. The network pharmacology approach was applied and chasmanine, karacoline, talatisamine, etc. were probably the main active compounds of SW in IS treatment as they affected the angiogenesis-associated targets.

CONCLUSIONS

These results demonstrate that SW plays a critical role in anti-IS via promoting angiogenesis through early administration, indicating that SW is a candidate herbal complex for further investigation in treating IS in the clinical.

Multi-Omics Profiling Identifies Microglial Annexin A2 as a Key Mediator of NF-κB Pro-inflammatory Signaling in Ischemic Reperfusion Injury

Cerebral stroke is one of the leading causes of mortality and disability worldwide. Restoring the cerebral circulation following a period of occlusion and subsequent tissue oxygenation leads to reperfusion injury. Cerebral ischemic reperfusion (I/R) injury triggers immune and inflammatory responses, apoptosis, neuronal damage, and even death. However, the cellular function and molecular mechanisms underlying cerebral I/R-induced neuronal injury are incompletely understood. By integrating proteomic, phosphoproteomic, and transcriptomic profiling in mouse hippocampi after cerebral I/R, we revealed that the differentially expressed genes and proteins mainly fall into several immune inflammatory response-related pathways. We identified that Annexin 2 (Anxa2) was exclusively upregulated in microglial cells in response to cerebral I/R in vivo and oxygen-glucose deprivation and reoxygenation (OGD/R) in vitro. RNA-seq analysis revealed a critical role of Anxa2 in the expression of inflammation-related genes in microglia via the NF-κB signaling. Mechanistically, microglial Anxa2 is required for nuclear translocation of the p65 subunit of NF-κB and its transcriptional activity upon OGD/R in BV2 microglial cells. Anxa2 knockdown inhibited the OGD/R-induced microglia activation and markedly reduced the expression of pro-inflammatory factors, including TNF-α, IL-1β, and IL-6. Interestingly, conditional medium derived from Anxa2-depleted BV2 cell cultures with OGD/R treatment alleviated neuronal death in vitro. Altogether, our findings revealed that microglia Anxa2 plays a critical role in I/R injury by regulating NF-κB inflammatory responses in a non-cell-autonomous manner, which might be a potential target for the neuroprotection against cerebral I/R injury.

Post-translational protein lactylation modification in health and diseases: a double-edged sword

As more is learned about lactate, it acts as both a product and a substrate and functions as a shuttle system between different cell populations to provide the energy for sustaining tumor growth and proliferation. Recent discoveries of protein lactylation modification mediated by lactate play an increasingly significant role in human health (e.g., neural and osteogenic differentiation and maturation) and diseases (e.g., tumors, fibrosis and inflammation, etc.). These views are critically significant and first described in detail in this review. Hence, here, we focused on a new target, protein lactylation, which may be a "double-edged sword" of human health and diseases. The main purpose of this review was to describe how protein lactylation acts in multiple physiological and pathological processes and their potential mechanisms through an in-depth summary of preclinical in vitro and in vivo studies. Our work aims to provide new ideas for treating different diseases and accelerate translation from bench to bedside.

Proteomic advance of ischemic stroke: preclinical, clinical, and intervention

Ischemic stroke (IS) is the most common type of stroke and is characterized by high rates of mortality and long-term injury. The prediction and early diagnosis of IS are therefore crucial for optimal clinical intervention. Proteomics has provided important techniques for exploring protein markers associated with IS, but there has been no systematic evaluation and review of research that has used these techniques. Here, we review the differential proteins that have been found in cell- and animal- based studies and clinical trials of IS in the past 10 years; determine the key pathological proteins that have been identified in clinical trials; summarize the target proteins affected by interventions aimed at treating IS, with a focus on traditional Chinese medicine treatments. Overall, we clarify findings and problems that have been identified in recent proteomics research on IS and provide suggestions for improvements in this area. We also suggest areas that could be explored for determining the pathogenesis and developing interventions for IS.

The vascular Na,K-ATPase: clinical implications in stroke, migraine, and hypertension

In the vascular wall, the Na,K-ATPase plays an important role in the control of arterial tone. Through cSrc signaling, it contributes to the modulation of Ca2+ sensitivity in vascular smooth muscle cells. This review focuses on the potential implication of Na,K-ATPase-dependent intracellular signaling pathways in severe vascular disorders; ischemic stroke, familial migraine, and arterial hypertension. We propose similarity in the detrimental Na,K-ATPase-dependent signaling seen in these pathological conditions. The review includes a retrospective proteomics analysis investigating temporal changes after ischemic stroke. The analysis revealed that the expression of Na,K-ATPase α isoforms is down-regulated in the days and weeks following reperfusion, while downstream Na,K-ATPase-dependent cSrc kinase is up-regulated. These results are important since previous studies have linked the Na,K-ATPase-dependent cSrc signaling to futile recanalization and vasospasm after stroke. The review also explores a link between the Na,K-ATPase and migraine with aura, as reduced expression or pharmacological inhibition of the Na,K-ATPase leads to cSrc kinase signaling up-regulation and cerebral hypoperfusion. The review discusses the role of an endogenous cardiotonic steroid-like compound, ouabain, which binds to the Na,K-ATPase and initiates the intracellular cSrc signaling, in the pathophysiology of arterial hypertension. Currently, our understanding of the precise control mechanisms governing the Na,K-ATPase/cSrc kinase regulation in the vascular wall is limited. Understanding the role of vascular Na,K-ATPase signaling is essential for developing targeted treatments for cerebrovascular disorders and hypertension, as the Na,K-ATPase is implicated in the pathogenesis of these conditions and may contribute to their comorbidity.

Long-term iTBS Improves Neural Functional Recovery by Reducing the Inflammatory Response and Inhibiting Neuronal Apoptosis Via miR-34c-5p/p53/Bax Signaling Pathway in Cerebral Ischemic Rats

To investigate intermittent theta-burst stimulation (iTBS) effect on ischemic stroke and the underlying mechanism of neurorehabilitation, we developed an ischemia/reperfusion (I/R) injury model in Sprague-Dawley (SD) rats using the middle cerebral artery occlusion/reperfusion (MCAO/r) method. Next, using different behavioral studies, we compared the improvement of the whole organism with and without iTBS administration for 28 days. We further explored the morphological and molecular biological alterations associated with neuronal apoptosis and neuroinflammation by TTC staining, HE staining, Nissl staining, immunofluorescence staining, ELISA, small RNA sequencing, RT-PCR, and western blot assays. The results showed that iTBS significantly protected against neurological deficits and neurological damage induced by cerebral I/R injury. iTBS also significantly decreased brain infarct volume and increased the number of surviving neurons after 28 days. Additionally, it was observed that iTBS decreased synaptic loss, suppressed activation of astrocytes and M1-polarized microglia, and simultaneously promoted M2-polarized microglial activation. Furthermore, iTBS intervention inhibited neuronal apoptosis and exerted a positive impact on the neuronal microenvironment by reducing neuroinflammation in cerebral I/R injured rats. To further investigate the iTBS mechanism, this study was conducted using small RNA transcriptome sequencing of various groups of peri-infarcted tissues. Bioinformatics analysis and RT-PCR discovered the possible involvement of miR-34c-5p in the mechanism of action. The target genes prediction and detection of dual-luciferase reporter genes confirmed that miR-34c-5p could inhibit neuronal apoptosis in cerebral I/R injured rats by regulating the p53/Bax signaling pathway. We also confirmed by RT-PCR and western blotting that miR-34c-5p inhibited Bax expression. In conclusion, our study supports that iTBS is vital in inhibiting neuronal apoptosis in cerebral I/R injured rats by mediating the miR-34c-5p involvement in regulating the p53/Bax signaling pathway.

Inhibition of the Glycolysis Prevents the Cerebral Infarction Progression Through Decreasing the Lactylation Levels of LCP1

Cerebral infarction (CI), also known as ischemic stroke, has a high incidence rate and mortality rate. The purpose of this study was to investigate the potential effect and mechanism of Lymphocyte cytosolic protein 1 (LCP1) in the CI progression. The middle cerebral artery occlusion (MCAO) treated rats and oxygen–glucose deprivation/reoxygenation (OGD/R) stimulated PC12 cells were used to establish CI model in vivo and in vitro. The cell proliferation and apoptosis was determined by CCK-8 assay and flow cytometry, respectively. Immunoprecipitation and western blot was performed to test the lactylation levels of LCP1. The cells were treated with cycloheximide to determined the protein stability of LCP1. The glucose uptake and lactate production was determined with commercial kits. The extracellular acidification rate were evaluated by Seahorse. The results showed that LCP1 was upregulated in the MCAO rats and OGD/R stimulated PC12 cells. LCP1 knockdown dramatically decreased the neurological score, infarct volume and the brain water content of MCAO rats. Besides, LCP1 knockdown promoted the cell viability while decreased the apoptosis rate of the OGD/R stimulated PC12 cells. Additionally, the global lactylation and lactylation levels of LCP1 was prominently enhanced in vivo and in vitro in cerebral infarction. 2-DG treatment prominently decreased it. In conclusion, inhibiting the glycolysis decreased the lactylation levels of LCP1 and resulted in the degradation of LCP1, which eventually relieved the CI progression.

1DE-MS Profiling for Proteoform-Correlated Proteomic Analysis, by Combining SDS-PAGE, Whole-Gel Slicing, Quantitative LC-MS/MS, and Reconstruction of Gel Distributions of Several Thousands of Proteins

SDS-PAGE has often been used in proteomic analysis, but generally for sample prefractionation although the technique separates proteins by molecular masses (M_ws) and the information would contribute to proteoform-level analysis. Here, we report a method that combines SDS-PAGE, whole-gel slicing, and quantitative LC-MS/MS for establishing gel distributions of several thousand proteins in a proteome. A previously obtained data set on rat cerebral cortex with cerebral ischemia-reperfusion injury¹ was analyzed, and the gel distributions of 5906 proteins were reconstructed. These distributions, referred to as 1DE-MS profiles, revealed that about 30% of the proteins had more than one proteoform detected in the gels. The profiles were categorized into six types by distribution (narrow, dispersed, or broad) and relative deviations between the abundance-peak apparent M_ws and calculated M_ws. Only 56% of the proteins showed narrow distributions and matched M_ws, while the others had rather complex profiles. Bioinformatic analysis on example profiles showed the resolved proteoforms involved alternative splicing, proteolytic processing, glycosylation and ubiquitination, fragmentation, and probably transmembrane structures. Profile-based differential analysis revealed that many of the disease-caused changes were proteoform dependent. This work provided a proteome-scale view of protein distributions in SDS-PAGE gels, and the method would be useful to obtain proteoform-correlated information for in-depth proteomics.

Differential proteomic analysis of mouse cerebrums with high-fat diet (HFD)-induced hyperlipidemia

Hyperlipidemia is a chronic disease characterized by elevated blood cholesterol and triglycerides and there is accumulated evidence that the disease might affect brain functions. Here we report on a proteomic analysis of the brain proteins in hyperlipidemic mice. Hyperlipidemia was successfully induced in mice by a 20 week high-fat diet (HFD) feeding (model group). A control group with a normal diet and a treatment group with HFD-fed mice treated with a lipid-lowering drug simvastatin (SIM) were established accordingly. The proteins were extracted from the left and right cerebrum hemispheres of the mice in the three groups and subjected to shotgun proteomic analysis. A total of 4,422 proteins were detected in at least half of the samples, among which 324 proteins showed significant difference (fold change >1.5 or <0.67, p < 0.05) in at least one of the four types of comparisons (left cerebrum hemispheres of the model group versus the control group, right cerebrums of model versus control, left cerebrums of SIM versus model, right cerebrums of SIM versus model). Biological process analysis revealed many of these proteins were enriched in the processes correlated with lipid metabolism, neurological disorders, synaptic events and nervous system development. For the first time, it has been reported that some of the proteins have been altered in the brain under the conditions of HFD feeding, obesity or hyperlipidemia. Further, 22 brain processes-related proteins showed different expression in the two cerebrum hemispheres, suggesting changes of the brain proteins caused by hyperlipidemia might also be asymmetric. We hope this work will provide useful information to understand the effects of HFD and hyperlipidemia on brain proteins.

Synergy of "Yiqi" and "Huoxue" components of QishenYiqi formula in ischemic stroke protection via lysosomal/inflammatory mechanisms

ETHNOPHARMACOLOGICAL RELEVANCE

Ischemic stroke is one of the leading causes of mortality and long-term disability worldwide. Currently, approved therapies of intravenous thrombolysis and mechanical thrombectomy are limited only to selected patients with rescuable brain tissue. Chinese medicine that benefits Qi (Yiqi, YQ) and activates blood (Huoxue, HX) is widely used in the clinic for treating stroke, but their mechanisms are not well understood yet. We have previously reported that QishenYiqi (QSYQ) formula exerts cerebral protective effect and promotes post-stroke recovery.

AIM OF THE STUDY

This study aimed to explore the chemical basis and molecular mechanism of anti-stroke therapy of QSYQ and its YQ and HX components further.

MATERIALS AND METHODS

Serum pharmacochemistry was performed to identify the bioactive constituents in QSYQ for cerebral protection. The survival rate, mNSS test, open field test, gait analysis, cerebral infarction volume, and blood-brain barrier (BBB) integrity were determined to uncover the synergistic and differential contributions of YQ and HX components in a cerebral ischemia/reperfusion injury (CI/RI) model. Bioinformatic mining of QSYQ proteomics data and experimental validation were executed to access the functional mechanism of YQ and HX components.

RESULTS

Eleven prototype ingredients and six metabolites were successfully identified or tentatively characterized in rat plasma. Therapeutically, YQ and HX components of QSYQ synergistically boosted the survival rate, improved neurological and motor functions, alleviated cerebral infarction as well as protected BBB integrity in CI/RI model in rats. Individually, YQ component contributed more to ameliorating locomotive ability than that of HX component. Mechanistically, HX component played a more prominent role in the modulation of galectin-3 mediated inflammation whereas YQ component regulated lysosomal-autophagy signaling.

CONCLUSIONS

This study identifies major prototype ingredients and metabolites of QSYQ in plasma which may contribute to its cerebral protection. YQ and HX components of QSYQ differentially and synergistically protect the brain from CI/RI by regulating galectin-3-mediated inflammation and lysosomal-autophagy signaling. These findings demonstrate that a maximal stroke protection by a component-based Chinese medicine could be attributed to the combination of its individual components via different mechanisms. It may shed new light on our understanding of the TCM principle of tonifying Qi and activating blood, particularly in a setting of ischemic stroke.

Activated Drp1 regulates p62-mediated autophagic flux and aggravates inflammation in cerebral ischemia-reperfusion via the ROS-RIP1/RIP3-exosome axis

BACKGROUND

Cerebral ischemia-reperfusion injury (CIRI) refers to a secondary brain injury that can occur when the blood supply to the ischemic brain tissue is restored. However, the mechanism underlying such injury remains elusive.

METHODS

The 150 male C57 mice underwent middle cerebral artery occlusion (MCAO) for 1 h and reperfusion for 24 h, Among them, 50 MCAO mice were further treated with Mitochondrial division inhibitor 1 (Mdivi-1) and 50 MCAO mice were further treated with N-acetylcysteine (NAC). SH-SY5Y cells were cultured in a low-glucose culture medium for 4 h under hypoxic conditions and then transferred to normal conditions for 12 h. Then, cerebral blood flow, mitochondrial structure, mitochondrial DNA (mtDNA) copy number, intracellular and mitochondrial reactive oxygen species (ROS), autophagic flux, aggresome and exosome expression profiles, cardiac tissue structure, mitochondrial length and cristae density, mtDNA and ROS content, as well as the expression of Drp1-Ser616/Drp1, RIP1/RIP3, LC3 II/LC3 I, TNF-α, IL-1β, etc., were detected under normal or Drp1 interference conditions.

RESULTS

The mtDNA content, ROS levels, and Drp1-Ser616/Drp1 were elevated by 2.2, 1.7 and 2.7 times after CIRI (P < 0.05). However, the high cytoplasmic LC3 II/I ratio and increased aggregation of p62 could be reversed by 44% and 88% by Drp1 short hairpin RNA (shRNA) (P < 0.05). The low fluorescence intensity of autophagic flux and the increased phosphorylation of RIP3 induced by CIRI could be attenuated by ROS scavenger, NAC (P < 0.05). RIP1/RIP3 inhibitor Necrostatin-1 (Nec-1) restored 75% to a low LC3 II/LC3 I ratio and enhanced 2 times to a high RFP-LC3 after Drp1 activation (P < 0.05). In addition, although CIRI-induced ROS production caused no considerable accumulation of autophagosomes (P > 0.05), it increased the packaging and extracellular secretion of exosomes containing p62 by 4 - 5 times, which could be decreased by Mdivi-1, Drp1 shRNA, and Nec-1 (P < 0.05). Furthermore, TNF-α and IL-1β increased in CIRI-derived exosomes could increase RIP3 phosphorylation in normal or oxygen-glucose deprivation/reoxygenation (OGD/R) conditions (P < 0.05).

CONCLUSIONS

CIRI activated Drp1 and accelerated the p62-mediated formation of autophagosomes while inhibiting the transition of autophagosomes to autolysosomes via the RIP1/RIP3 pathway activation. Undegraded autophagosomes were secreted extracellularly in the form of exosomes, leading to inflammatory cascades that further damaged mitochondria, resulting in excessive ROS generation and the blockage of autophagosome degradation, triggering a vicious cycle.

Phosphoproteome Analysis Identifies a Synaptotagmin-1-Associated Complex Involved in Ischemic Neuron Injury

Cerebral stroke is one of the leading causes of death in adults worldwide. However, the molecular mechanisms of stroke-induced neuron injury are not fully understood. Here, we obtained phosphoproteomic and proteomic profiles of the acute ischemic hippocampus by LC–MS/MS analysis. Quantitative phosphoproteomic analyses revealed that the dysregulated phosphoproteins were involved in synaptic components and neurotransmission. We further demonstrated that phosphorylation of Synaptotagmin-1 (Syt1) at the Thr112 site in cultured hippocampal neurons aggravated oxygen-glucose deprivation–induced neuronal injury. Immature neurons with low expression of Syt1 exhibit slight neuronal injury in a cerebral ischemia model. Administration of the Tat-Syt1^T112A peptide protects neurons against cerebral ischemia-induced injury in vitro and in vivo. Surprisingly, potassium voltage-gated channel subfamily KQT member 2 (Kcnq2) interacted with Syt1 and Annexin A6 (Anxa6) and alleviated Syt1-mediated neuronal injury upon oxygen-glucose deprivation treatment. These results reveal a mechanism underlying neuronal injury and may provide new targets for neuroprotection after acute cerebral ischemia onset.

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Established the phosphoproteome profiles of acute cerebral ischemic hippocampus.

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Phosphoproteomic profile reveals phosphorylation of Syt1 and Kcnq2, which are upregulated.

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Phosphorylation of Syt1 aggravates neuron injury, which is relieved by Tat-Syt1^T112A.

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Kcnq2 interacts with Syt1 and Anxa6 and alleviates Syt1-mediated neuronal injury.

Stroke Proteomics: From Discovery to Diagnostic and Therapeutic Applications

Stroke remains a leading cause of death and disability, with limited therapeutic options and suboptimal tools for diagnosis and prognosis. High throughput technologies such as proteomics generate large volumes of experimental data at once, thus providing an advanced opportunity to improve the status quo by facilitating identification of novel therapeutic targets and molecular biomarkers. Proteomics studies in animals are largely designed to decipher molecular pathways and targets altered in brain tissue after stroke, whereas studies in human patients primarily focus on biomarker discovery in biofluids and, more recently, in thrombi and extracellular vesicles. Here, we offer a comprehensive review of stroke proteomics studies conducted in both animal and human specimen and present our view on limitations, challenges, and future perspectives in the field. In addition, as a unique resource for the scientific community, we provide extensive lists of all proteins identified in proteomic studies as altered by stroke and perform postanalysis of animal data to reveal stroke-related cellular processes and pathways.

How cytosolic compartments play safeguard functions against neuroinflammation and cell death in cerebral ischemia

Ischemic stroke is the second leading cause of mortality and disability globally. Neuronal damage following ischemic stroke is rapid and irreversible, and eventually results in neuronal death. In addition to activation of cell death signaling, neuroinflammation is also considered as another pathogenesis that can occur within hours after cerebral ischemia. Under physiological conditions, subcellular organelles play a substantial role in neuronal functionality and viability. However, their functions can be remarkably perturbed under neurological disorders, particularly cerebral ischemia. Therefore, their biochemical and structural response has a determining role in the sequel of neuronal cells and the progression of disease. However, their effects on cell death and neuroinflammation, as major underlying mechanisms of ischemic stroke, are still not understood. This review aims to provide a comprehensive overview of the contribution of each organelle on these pathological processes after ischemic stroke.

Quantitative proteomics revealed extensive microenvironmental changes after stem cell transplantation in ischemic stroke

The local microenvironment is essential to stem cell-based therapy for ischemic stroke, and spatiotemporal changes of the microenvironment in the pathological process provide vital clues for understanding the therapeutic mechanisms. However, relevant studies on microenvironmental changes were mainly confined in the acute phase of stroke, and long-term changes remain unclear. This study aimed to investigate the microenvironmental changes in the subacute and chronic phases of ischemic stroke after stem cell transplantation. Herein, induced pluripotent stem cells (iPSCs) and neural stem cells (NSCs) were transplanted into the ischemic brain established by middle cerebral artery occlusion surgery. Positron emission tomography imaging and neurological tests were applied to evaluate the metabolic and neurofunctional alterations of rats transplanted with stem cells. Quantitative proteomics was employed to investigate the protein expression profiles in iPSCs-transplanted brain in the subacute and chronic phases of stroke. Compared with NSCs-transplanted rats, significantly increased glucose metabolism and neurofunctional scores were observed in iPSCs-transplanted rats. Subsequent proteomic data of iPSCs-transplanted rats identified a total of 39 differentially expressed proteins in the subacute and chronic phases, which are involved in various ischemic stroke-related biological processes, including neuronal survival, axonal remodeling, antioxidative stress, and mitochondrial function restoration. Taken together, our study indicated that iPSCs have a positive therapeutic effect in ischemic stroke and emphasized the wide-ranging microenvironmental changes in the subacute and chronic phases.

Nephrotoxicity Profile of Cadmium Revealed by Proteomics in Mouse Kidney

Cadmium (Cd) is a highly toxic metal and kidney is its main target. However, the molecular effects and associated potential impacts of Cd-accumulated kidney have not been well investigated. In this study, mouse was used as a model to investigate the Cd-induced proteomic profile change in kidney, and a total of 34 differentially expressed proteins were detected by two-dimensional gel electrophoresis (2-DE) and further identified by matrix-assisted laser desorption/ionization time of flight mass spectrometry (MALDI-TOF-MS). Through Gene Ontology analysis and KEGG pathway annotation, it showed that Cd-regulated kidney metabolism and promoted renal damage and cell migration. By validation of Western blotting and RT-qPCR, metastasis-related proteins LIM and SH3 domain protein 1 (LASP1) and phosphoenolpyruvate carboxykinase/cytosolic [GTP] (PEPCK1) were confirmed to be upregulated; Acyl-CoA synthetase medium-chain family member 3 (ACSM3) was downregulated. Furthermore, carcinoma development-related proteins initiation factor 4A (eIF4A) and pyridoxine-5'-phosphate oxidase (PNPO) were upregulated, and pyridoxal kinase (PK) was downregulated. The downregulation of Na(+)/H(+) exchange regulatory cofactor (NHERF3) might promote renal damage which associated with decrease of transferrin (TRF) in kidney. Taken together, our results revealed proteomic profile of Cd-induced nephrotoxicity and provided data for further insights into the mechanisms of Cd toxicity.

Investigation of brain damage mechanism in middle cerebral artery occlusion/reperfusion rats based on i-TRAQ quantitative proteomics

The objective of this study is to analyze the differential protein expression profile in cerebral cortex of rats with middle cerebral ischemia/reperfusion (MCAO/R), explore the brain damage mechanism of MCAO/R at protein level, and provide experimental foundation for searching specific marker proteins of MCAO/R. Rat model of MCAO/R was established by modified suture-occluded method, and the model was evaluated by the results of brain 2,3,5-triphenyltetrazolium chloride (TTC) and hematoxylin-eosin (HE) staining. Cerebral cortex of rats from sham-operated group (Sham) and MCAO/R groups was used for FASP enzymatic hydrolysis, i-TRAQ quantitative labeling, and reverse-phase liquid chromatography purification and separation. Orbitrap Q Exactive mass spectrometry was used for qualitative and quantitative analyses of total differential protein expression profiles. MCAO/R rats had obvious cerebral infarction lesions, and the relative surface area of cerebral infarction was significantly different compared with sham rats, suggesting that MCAO/R rat model was successfully prepared. There were 199 significant difference proteins (MCAO/R vs Sham, p < 0.05, |fold change|> 1.2), including 104 up-regulated proteins and 95 down-regulated proteins. Gene ontology (GO) enrichment analysis showed that the up-regulated proteins were mainly concentrated in the biological processes of positive regulation of NF-κB transcription and I-κB kinase-NF-κB, etc. Down-regulated proteins were mainly concentrated in long-term synaptic potentiation, cellular response to DNA damage stimulus, etc. KEGG pathway analysis showed that the pathway involved in differential proteins includes oxidative phosphorylation, metabolic pathway, and Ras signaling pathway. Network analysis of differential proteins showed that Alb, ndufb5, ndufs7, ApoB, Cdc42, Ndufa3, Igf1r, P4hb, Mbp, Gc, Nme1, Akt2, and other proteins may play an important role in regulating oxidative stress, apoptosis, and inflammatory response in MCAO/R. Quantitative proteomics based on i-TRAQ labeling reveals the effect of inflammation and apoptosis in brain damage mechanism of MCAO/R. Besides, this research provide some experimental foundation for search and determination of potential therapeutic targets of MCAO/R.

Prevention properties on cerebral ischemia reperfusion of medicine food homologous Dioscorea yam-derived diosgenin based on mediation of potential targets

I/R (cerebral ischemia reperfusion injury) is the secondary complication of ischemic stroke patients that are immediately treated with drug thrombolysis or vascular recanalization in clinic. Diosgenin (DIO) purified from medicine food homologous (MFH) Dioscorea yam source is served as a fatal starting material to synthesize multifarious steroidal anti-inflammatory drugs in medicinal field, and has previously been demonstrated the potential prevention of I/R. However, the detailed mechanisms of neuroprotective effects against I/R remain elusively understood. Here, a global proteomic dynamics of rat right hemisphere brains was executed to investigate the protein expression patterns with a quantitative LC-MSⁿ. In total, 5043 proteins were identified and 418 ones were determined to be significantly dysregulated DEPs (differentially expressed proteins) in comparison of Sham verse I/R and I/R verse DIO after onset stage of I/R, among which 5 DEPs namely BICD2, HNRNPK, CEP41, PPM1K, and ARL2BP, whose biological functions were mainly clustered into the mediation of nervous system, were selected for further validation in vitro and in vivo, and the change tendency expectedly supported the proteomic findings. Additionally, the AUC value of the combined ROC of these 5 DEPs was 0.988 with P < 0.0001, higher than every single one. Collectively, these scientific findings attributed to a typical investigation of dietary Dioscorea-enriched diosgenin in MFH research, suggesting that diosgenin or its derivatives were potential to be developed into food supplements or healthy food products to reveal healthy benefits in natural prevention and reduction risk of I/R. This work also promoted reasonable consumption of Dioscorea yams and contributed to the function of diosgenin-derived products and their applications in food industry.

Therapeutic targets of oxidative/nitrosative stress and neuroinflammation in ischemic stroke: Applications for natural product efficacy with omics and systemic biology

Oxidative/nitrosative stress and neuroinflammation are critical pathological processes in cerebral ischemia-reperfusion injury, and their intimate interactions mediate neuronal damage, blood-brain barrier (BBB) damage and hemorrhagic transformation (HT) during ischemic stroke. We review current progress towards understanding the interactions of oxidative/nitrosative stress and inflammatory responses in ischemic brain injury. The interactions between reactive oxygen species (ROS)/reactive nitrogen species (RNS) and innate immune receptors such as TLR2/4, NOD-like receptor, RAGE, and scavenger receptors are crucial pathological mechanisms that amplify brain damage during cerebral ischemic injury. Furthermore, we review the current progress of omics and systematic biology approaches for studying complex network regulations related to oxidative/nitrosative stress and inflammation in the pathology of ischemic stroke. Targeting oxidative/nitrosative stress and neuroinflammation could be a promising therapeutic strategy for ischemic stroke treatment. We then review recent advances in discovering compounds from medicinal herbs with the bioactivities of simultaneously regulating oxidative/nitrosative stress and pro-inflammatory molecules for minimizing ischemic brain injury. These compounds include sesamin, baicalin, salvianolic acid A, 6-paradol, silymarin, apocynin, 3H-1,2-Dithiole-3-thione, (-)-epicatechin, rutin, Dl-3-N-butylphthalide, and naringin. We finally summarize recent developments of the omics and systematic biology approaches for exploring the molecular mechanisms and active compounds of Traditional Chinese Medicine (TCM) formulae with the properties of antioxidant and anti-inflammation for neuroprotection. The comprehensive omics and systematic biology approaches provide powerful tools for exploring therapeutic principles of TCM formulae and developing precision medicine for stroke treatment.

Integrated analysis of the proteome and transcriptome in a MCAO mouse model revealed the molecular landscape during stroke progression

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DIA proteomics was applied to MCAO mice detection for the first time.

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Proteomics and bioinformatics revealed relationship between stroke process and immunity, especially inflammation.

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C3, Apoa4 and S100a9 were highlighted as a marker or drug targets for stroke.

Strokes usually results in long-term disability and death, and they occur worldwide. Recently, increased research on both on the physiopathological mechanisms and the transcriptome during stroke progression, have highlighted the relationship between stroke progression and immunity, with a special focus on inflammation. Here, we applied proteome analysis to a middle carotid artery occlusion (MCAO) mouse model at 0 h, 6 h, 12 h and 24 h, in which proteome profiling was performed with 23 samples, and 41 differentially expressed proteins (DEPs) were identified. Bioinformatics studies on our data revealed the importance of the immune response and particularly identified the inflammatory response, cytokine- cytokine receptor interactions, the innate immune response and reactive oxygen species (ROS) during stroke progression. In addition, we compared our data with multiple gene expression omnibus (GEO) datasets with and without a time series, in which similar pathways were identified, and three proteins, C3, Apoa4 and S100a9, were highlighted as markers or drug targets for stroke; these three proteins were significantly upregulated in the MCAO model, both in our proteomic data and in the GEO database.