Timing is everything: Exercise therapy and remote ischemic conditioning for acute ischemic stroke patients

A New Perspective on Stroke Research: Unraveling the Role of Brain Oxygen Dynamics in Stroke Pathophysiology

Stroke, a leading cause of death and disability, often results from ischemic events that cut off the brain blood flow, leading to neuron death. Despite treatment advancements, survivors frequently endure lasting impairments. A key focus is the ischemic penumbra, the area around the stroke that could potentially recover with prompt oxygenation; yet its monitoring is complex. Recent progress in bioluminescence-based oxygen sensing, particularly through the Green enhanced Nano-lantern (GeNL), offers unprecedented views of oxygen fluctuations in vivo. Utilized in awake mice, GeNL has uncovered hypoxic pockets within the cerebral cortex, revealing the brain's oxygen environment as a dynamic landscape influenced by physiological states and behaviors like locomotion and wakefulness. These findings illuminate the complexity of oxygen dynamics and suggest the potential impact of hypoxic pockets on ischemic injury and recovery, challenging existing paradigms and highlighting the importance of microenvironmental oxygen control in stroke resilience. This review examines the implications of these novel findings for stroke research, emphasizing the criticality of understanding pre-existing oxygen dynamics for addressing brain ischemia. The presence of hypoxic pockets in non-stroke conditions indicates a more intricate hypoxic scenario in ischemic brains, suggesting strategies to alleviate hypoxia could lead to more effective treatments and rehabilitation. By bridging gaps in our knowledge, especially concerning microenvironmental changes post-stroke, and leveraging new technologies like GeNL, we can pave the way for therapeutic innovations that significantly enhance outcomes for stroke survivors, promising a future where an understanding of cerebral oxygenation dynamics profoundly informs stroke therapy.

Long noncoding RNA H19 knockdown promotes angiogenesis via IMP2 after ischemic stroke

AIMS

This study aimed to explore the effects of long noncoding RNA (lncRNA) H19 knockdown on angiogenesis and blood-brain barrier (BBB) integrity following cerebral ischemia/reperfusion (I/R) and elucidate their underlying regulatory mechanisms.

METHODS

A middle cerebral artery occlusion/reperfusion model was used to induce cerebral I/R injury. The cerebral infarct volume and neurological impairment were assessed using 2,3,5-triphenyl-tetrazolium chloride staining and neurobehavioral tests, respectively. Relevant proteins were evaluated using western blotting and immunofluorescence staining. Additionally, a bioinformatics website was used to predict the potential target genes of lncRNA H19. Finally, a rescue experiment was conducted to confirm the potential mechanism.

RESULTS

Silencing of H19 significantly decreased the cerebral infarct volume, enhanced the recovery of neurological function, mitigated BBB damage, and stimulated endothelial cell proliferation following ischemic stroke. Insulin-like growth factor 2 mRNA-binding protein 2 (IMP2) is predicted to be a potential target gene for lncRNA H19. H19 knockdown increased IMP2 protein expression and IMP2 inhibition reversed the protective effects of H19 inhibition.

CONCLUSION

Downregulation of H19 enhances angiogenesis and mitigates BBB damage by regulating IMP2, thereby alleviating cerebral I/R injury.

Remote Ischemic Conditioning in Stroke Recovery

Remote ischemic conditioning (RIC) is a therapeutic strategy to protect a vital organ like the brain from ischemic injury through brief and repeat cycles of ischemia and reperfusion in remote body parts such as arm or leg. RIC has been applied in different aspects of the stroke field and has shown promise. This narrative review will provide an overview of how to implement RIC in stroke patients, summarize the clinical evidence of RIC on stroke recovery, and discuss unresolved questions and future study directions.

Post-stroke dizziness, depression and anxiety

OBJECTIVE

Vestibular and psychiatric disorders are very closely related. Previous research shows that the discomfort and dysfunction caused by dizziness in patients can affect psychological processes, leading to anxiety and depression, and the irritation of anxiety and depression can aggravate the discomfort of dizziness. But the causal relationship between dizziness in the recovery period of stroke and Post-stroke depression (PSD) / Post-stroke anxiety (PSA) is not clear. Identifying the causal relationship between them can enable us to conduct more targeted treatments.

METHODS

We review the epidemiology and relationship of dizziness, anxiety, and depression, along with the related neuroanatomical basis. We also review the pathophysiology of dizziness after stroke, vestibular function of patients experiencing dizziness, and the causes and mechanisms of PSD and PSA. We attempt to explore the possible relationship between post-stroke dizziness and PSD and PSA.

CONCLUSION

The treatment approach for post-stroke dizziness depends on its underlying cause. If the dizziness is a result of PSD and PSA, addressing these psychological factors may alleviate the dizziness. This can be achieved through targeted treatments for PSD and PSA, such as psychotherapy, antidepressants, or anxiolytics, which could indirectly improve dizziness symptoms. Conversely, if PSA and PSD are secondary to vestibular dysfunction caused by stroke, a thorough vestibular function assessment is crucial. Identifying the extent of vestibular impairment allows for tailored interventions. These could include vestibular rehabilitation therapy and medication aimed at vestibular restoration. By improving vestibular function, secondary symptoms like anxiety and depression may also be mitigated.

Environmental Enrichment in Stroke Research: an Update

Environmental enrichment (EE) refers to different forms of stimulation, where the environment is designed to improve the levels of sensory, cognitive, and motor stimuli, inducing stroke recovery in animal models. Stroke is a leading cause of mortality and neurological disability among older adults, hence the importance of developing strategies to improve recovery for such patients. This review provides an update on recent findings, compiling information regarding the parameters affected by EE exposure in both preclinical and clinical studies. During stroke recovery, EE exposure has been shown to improve both the cognitive and locomotor aspects, inducing important neuroplastic alterations, increased angiogenesis and neurogenesis, and modified gene expression, among other effects. There is a need for further research in this field, particularly in those aspects where the evidence is inconclusive. Moreover, it is necessary refine and adapt the EE paradigms for application in human patients.

CircRNA and Stroke: New Insight of Potential Biomarkers and Therapeutic Targets

Stroke, the second-largest cause of death and the leading cause of disability globally, presents significant challenges in terms of prognosis and treatment. Identifying reliable prognosis biomarkers and treatment targets is crucial to address these challenges. Circular RNA (circRNA) has emerged as a promising research biomarkers and therapeutic targets because of its tissue specificity and conservation. However, the potential role of circRNA in stroke prognosis and treatment remains largely unexplored. This review briefly elucidate the mechanism underlying circRNA's involvement in stroke pathophysiology. Additionally, this review summarizes the impact of circRNA on different forms of strokes, including ischemic stroke and hemorrhagic stroke. And, this article discusses the positive effects of circRNA on promoting cerebrovascular repair and regeneration, maintaining the integrity of the blood-brain barrier (BBB), and reducing neuronal injury and immune inflammatory response. In conclusion, the significance of circRNA as a potential prognostic biomarker and a viable therapeutic target was underscored.

No-reflow after stroke reperfusion therapy: An emerging phenomenon to be explored

In the field of stroke thrombectomy, ineffective clinical and angiographic reperfusion after successful recanalization has drawn attention. Partial or complete microcirculatory reperfusion failure after the achievement of full patency of a former obstructed large vessel, known as the "no-reflow phenomenon" or "microvascular obstruction," was first reported in the 1960s and was later detected in both experimental models and patients with stroke. The no-reflow phenomenon (NRP) was reported to result from intraluminal occlusions formed by blood components and extraluminal constriction exerted by the surrounding structures of the vessel wall. More recently, an emerging number of clinical studies have estimated the prevalence of the NRP in stroke patients following reperfusion therapy, ranging from 3.3% to 63% depending on its evaluation methods or study population. Studies also demonstrated its detrimental effects on infarction progress and neurological outcomes. In this review, we discuss the research advances, underlying pathogenesis, diagnostic techniques, and management approaches concerning the no-reflow phenomenon in the stroke population to provide a comprehensive understanding of this phenomenon and offer references for future investigations.

A narrative review of potential neural repair poststroke: Decoction of Chinese angelica and peony in regulating microglia polarization through the neurosteroid pathway

Ischemic stroke is a major global health crisis, characterized by high morbidity and mortality rates. Although there have been significant advancements in treating the acute phase of this condition, there remains a pressing need for effective treatments that can facilitate the recovery of neurological functions. Danggui-Shaoyao-San (DSS), also known as the Decoction of Chinese Angelica and Peony, is a traditional Chinese herbal formula. It has demonstrated promising results in the regulation of microglial polarization and modulation of neurosteroid receptor expression, which may make it a potent strategy for promoting the recovery of neurological functions. Microglia, which plays a crucial role in neuroplasticity and functional reconstruction poststroke, is regulated by neurosteroids. This review posits that DSS could facilitate the recovery of neuronal function poststroke by influencing microglial polarization through the neurosteroid receptor pathway. We will further discuss the potential mechanisms by which DSS could enhance neural function in stroke, including the regulation of microglial activation, neurosteroid regulation, and other potential mechanisms.

A novel stroke rehabilitation strategy and underlying stress granule regulations through inhibition of NLRP3 inflammasome activation

OBJECTIVE

Dynamic changes in ischemic pathology after stroke suggested a "critical window" of enhanced neuroplasticity immediately after stroke onset. Although physical exercise has long been considered a promising strategy of stroke rehabilitation, very early physical exercise may exacerbate brain injury. Since remote ischemic conditioning (RIC) promotes neuroprotection and neuroplasticity, the present study combined RIC with sequential exercise to establish a new rehabilitation strategy for a better rehabilitative outcome.

METHODS

A total of 120 adult male Sprague-Dawley rats were used and divided into five groups: (1) sham, (2) stroke, (3) stroke with exercise, (4) stroke with RIC, and (5) stroke with RIC followed by exercise. Brain damage was evaluated by infarct volume, neurological deficit, cell death, and lactate dehydrogenase (LDH) activity. Long-term functional outcomes were determined by grid walk tests, rotarod tests, beam balance tests, forelimb placing tests, and the Morris water maze. Neuroplasticity was evaluated through measurements of both mRNA and protein levels of synaptogenesis (synaptophysin [SYN], post-synaptic density protein-95 [PSD-95], and brain-derived neurotrophic factor [BDNF]) and angiogenesis (vascular endothelial growth factor [VEGF], angiopoietin-1 [Ang-1], and angiopoietin-2 [Ang-2]). Inflammasome activation was measured by concentrations of interleukin-18 (IL-18) and IL-1β detected by enzyme-linked immunosorbent assay (ELISA) kits, mRNA expressions of NLR pyrin domain containing 3 (NLRP3), apoptosis-associated speck-like protein containing a C-terminal caspase recruitment domain (ASC), IL-18 and IL-1β, and protein quantities of NLRP3, ASC, cleaved-caspase-1, gasdermin D-N (GSDMD-N), and IL-18 and IL-1β. Stress granules (SGs), including GTPase-activating protein-binding protein 1 (G3BP1), T cell-restricted intracellular antigen-1 (TIA1), and DEAD-box RNA helicase 3X (DDX3X) were evaluated at mRNA and protein levels. The interactions between DDX3X with NLRP3 or G3BP1 were determined by immunofluorescence and co-immunoprecipitation.

RESULTS

Early RIC decreased infarct volumes, neurological deficits, cell death, and LDH activity at post-stroke Day 3 (p < 0.05). All treatment groups showed significant improvement in functional outcomes, including sensory, motor, and cognitive functions. RIC and exercise, as compared to RIC or physical exercise alone, had improved functional outcomes after stroke (p < 0.05), as well as synaptogenesis and angiogenesis (p < 0.05). RIC significantly reduced mRNA and protein expressions of NLRP3 (p < 0.05). SGs formation peaked at 0 h after ischemia, then progressively decreased until 24 h postreperfusion, which was reversed by RIC (p < 0.05). The assembly of SGs consumed DDX3X and then inhibited NLRP3 inflammasome activation.

CONCLUSIONS

RIC followed by exercise induced a better rehabilitation in ischemic rats, while early RIC alleviated ischemia-reperfusion injury via stress-granule-mediated inhibition of NLRP3 inflammasome.

Prediction of early neurological deterioration in acute ischemic stroke patients treated with intravenous thrombolysis

A proportion of acute ischemic stroke (AIS) patients suffer from early neurological deterioration (END) within 24 hours following intravenous thrombolysis (IVT), which greatly increases the risk of poor prognosis of these patients. Therefore, we aimed to explore the predictors of early neurological deterioration of ischemic origin (ENDi) in AIS patients after IVT and develop a nomogram prediction model. This study collected 244 AIS patients with post-thrombolysis ENDi as the derivation cohort and 155 patients as the validation cohort. To establish a nomogram prediction model, risk factors were identified by multivariate logistic regression analysis. The results showed that neutrophil to lymphocyte ratio (NLR) (OR 2.616, 95% CI 1.640-4.175, P < 0.001), mean platelet volume (MPV) (OR 3.334, 95% CI 1.351-8.299, P = 0.009), body mass index (BMI) (OR 1.979, 95% CI 1.285-3.048, P = 0.002) and atrial fibrillation (AF) (OR 8.012, 95% CI 1.341-47.873, P = 0.023) were significantly associated with ENDi. The area under the curve of the prediction model constructed from the above four factors was 0.981 (95% CI 0.961-1.000) and the calibration curve was close to the ideal diagonal line. Therefore, this nomogram prediction model exhibited good discrimination and calibration power and might be a reliable and easy-to-use tool to predict post-thrombolysis ENDi in AIS patients.

Remote ischemic conditioning alleviates chronic cerebral hypoperfusion-induced cognitive decline and synaptic dysfunction via the miR-218a-5p/SHANK2 pathway

Vascular cognitive impairment (VCI) due to chronic cerebral hypoperfusion (CCH), is the second leading cause of dementia. Although synaptic impairment plays a critical role in VCI, its exact mechanism remains unknown. Our previous research revealed that remote ischemic conditioning (RIC) could alleviate cognitive decline resulting from CCH, however, its effects on synaptic impairment remain unclear. In this study, we confirmed that RIC alleviated both cognitive decline and its associated synaptic dysfunction caused by CCH. RNA sequencing revealed that CCH increased in miR-218a-5p expression, which was decreased by RIC. Elevated miR-218a-5p levels limited the benefits of RIC, however, inhibiting miR-218a-5p in hippocampal CA1 neurons rescued synaptic dysfunction. Additionally, we found that SHANK2 is a downstream target of miR-218a-5p, and inhibiting SHANK2 expression reduced the alleviation caused by hypoxic conditioning in synaptic impairment in vitro. In conclusion, our results suggested that RIC alleviated synaptic impairment via the miR-218a-5p/SHANK2 pathway, which could be a potential biomarker or therapeutic target for cognitive impairment caused by CCH.

Normobaric Hyperoxia (NBHO): An Adjunctive Therapy to Cerebrovascular Recanalization in Ischemic Stroke

Acute ischemic stroke (AIS) is a serious neurological disease. Normobaric hyperoxia (NBHO) is both a non-invasive and easy method that seems to be able to improve outcomes after cerebral ischemia/reperfusion. In clinical trials, normal low-flow oxygen has been shown to be ineffective, but NBHO has been shown to have a transient brain-protective effect. Today, NBHO combined with recanalization is the best treatment available. NBHO combined with thrombolysis is considered to improve neurological scores and long-term outcomes. Large randomized controlled trials (RCTs), however, are still needed to determine the role they will have in stroke treatment. RCTs of NBHO combined with thrombectomy have both improved infarct volume at 24 hours and the long-term prognosis. These two mechanisms most likely play key roles in the neuroprotective actions of NBHO after recanalization, including the increase in penumbra oxygen supply and the integrity of the blood-brain barrier (BBB). Considering the mechanism of action of NBHO, oxygen should be given as early as possible to increase the duration of oxygen therapy before recanalization is initiated. NBHO can further prolong the existence time of penumbra, so that more patients may benefit from it. Overall, however, recanalization therapy is still essential.

Optimal rehabilitation strategies for early postacute stroke recovery: An ongoing inquiry

Early rehabilitation is crucial in reducing stroke-related disability, but the optimal training model remains unclear. We conducted a trial comparing different initiation timings and intensities of mobilization strategies after stroke. Results showed that early intensive mobilization had favorable outcomes at 3 months post-stroke, while very early intensive mobilization had poorer chances of favorable outcomes. Our investigation into brain injury mechanisms induced by very early exercise within 24 hours of stroke onset aligned with guidelines advising against high-dose very early mobilization. Additionally, we are studying the effects of various exercise intensities and frequencies on early stroke rehabilitation. Integrated rehabilitation models, such as combining remote ischemic conditioning (RIC) with exercise (RICE), hold promise. Our study found RICE to be safe and feasible for early rehabilitation of acute ischemic stroke patients, and further research is underway to determine its efficacy in a larger sample size. Despite extensive research, identifying the most effective early recovery strategies remains a complex challenge, necessitating ongoing work in the field of early rehabilitation after stroke.

Safety and Tolerability of Direct Ischemic Postconditioning Following Thrombectomy for Acute Ischemic Stroke

BACKGROUND

Experimental studies have demonstrated the neuroprotection of ischemic postconditioning (IPostC) in acute ischemic stroke by attenuating ischemia-reperfusion injury. This study aimed to investigate the safety and tolerability of direct IPostC in both a dog model and patients with acute ischemic stroke treated with thrombectomy.

METHODS

The study involved 2 parts. First, IPostC was induced by repeated balloon inflation and deflation in dogs, where a low-pressure balloon was navigated to the anterior spinal artery, and 4 cycles of 5-minute ischemia followed by 5-minute reperfusion were performed. Vascular injuries were assessed using angiography and vascular tissue specimens. Then, a 3+3 dose-escalation trial was conducted in patients with acute ischemic stroke following successful thrombectomy recanalization. Patients received direct IPostC with ischemia and reperfusion durations in progressive increments of 0, 1, 2, 3, 4, and 5 minutes ×4 cycles. Major adverse responses were defined as vessel perforation, rupture, dissection, reocclusion, severe vasospasm, thrombotic events, and rupture of the balloon.

RESULTS

IPostC was investigated in 4 dogs. No vessel perforation or rupture, dissection, or vasospasm was observed under the angiography. Only 1 vessel experienced mild injury between the intima and the internal elastic membrane detected on a histopathologic slide. Then, 18 patients were recruited. The duration of IPostC was progressively escalated with no major response happened. No patient experienced agitation, discomfort, or other tolerability issues. Five patients (27.8%) experienced any intracranial hemorrhage after thrombectomy, and 1 (5.6%) was symptomatic. At 3-month follow-up, no patient died, and 9 patients (50%) achieved functional independence.

CONCLUSIONS

Direct IPostC inducing by 4 cycles of 5-minute ischemia followed by 5-minute reperfusion is safe, feasible, and tolerable in patients with acute ischemic stroke treated with thrombectomy. Further investigations are needed to determine the safety and preliminary efficacy of direct IPostC.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT05153655.

Preceding transient ischemic attack was associated with functional outcome after stroke thrombectomy: A propensity score matching study

Whether preceding transient ischemic attack (TIA) can provide neuroprotective benefits in subsequent acute ischemic stroke (AIS) caused by large vessel occlusion remains unclarified. This study aimed to investigate the association between preceding TIA and functional outcomes in AIS patients with endovascular therapy (EVT). Eligible patients were divided into TIA and non-TIA groups according to whether they experienced TIA within 96 hours prior to stroke. Two groups were balanced using propensity score matching (PSM) analysis at a 1:3 ratio. Onset stroke severity and 3-month functional independence were evaluated. A total of 887 patients were included. After PSM, 73 patients with and 217 patients without preceding TIA were well matched. Onset stroke severity was not different between the groups (p > 0.05). However, the TIA group had a lower systemic immune-inflammation index (SII) (median, 1091 versus 1358, p < 0.05). Preceding TIA was significantly associated with 3-month functional independence (adjusted odds ratio, 2.852; 95% confidence interval [CI], 1.481-5.495; adjusted p < 0.01). The effects of preceding TIA on functional independence were partially mediated by SII (average causal mediation effects 0.02; 95% CI, 0.001-0.06, p < 0.05). In AIS patients treated by EVT, preceding TIA within 96 hours was associated with three-month functional independence but not with reduced onset stroke severity.

Remote Ischemic Conditioning: Challenges and Opportunities

Remote ischemic conditioning (RIC) has been investigated as a promising, safe, and well-tolerated nonpharmacological therapy for cardio-cerebrovascular disease over the past 3 decades; variable results have been found when it is used in cerebrovascular versus cardiovascular disease. For patients with cardiovascular disease, milestone studies suggest that the roles of RIC may be limited. Recently, however, 2 large trials investigating RIC in patients with cerebrovascular disease found promising results, which may reignite the field's research prospects after its setbacks in the cardiovascular field. This perspectives article highlights several important clinical trials of RIC in the cardio-cerebrovascular disease and describes the many challenges of RIC in clinical translation. Finally, based on the available evidence, several promising research directions such as chronic RIC, early initiation in target population, improvement of compliance, better understanding of dosing, and identification of specific biomarkers are proposed and should be investigated before RIC can become applied into clinical practice for patient benefit.

Chronic Remote Ischemic Conditioning on Mild Hypertension in the Absence of Antihypertensive Medication: A Multicenter, Randomized, Double-Blind, Proof-of-Concept Clinical Trial

BACKGROUND

Exploratory studies have shown that remote ischemic conditioning (RIC) has the potential to lower blood pressure (BP). We investigated whether chronic RIC reduces BP for hypertension.

METHODS

This is a multicenter, randomized, double-blind, parallel-controlled trial. Patients with an office BP of 130/80 to 160/100 mm Hg and a 24-hour average BP ≥125/75 mm Hg not on antihypertensive medications were recruited. After a 1-week compliance screening phase, they were randomly assigned in a 1:1 ratio to receive RIC or sham RIC twice daily for 4 weeks. The primary efficacy outcome was the change in 24-hour average systolic BP from baseline to 4 weeks. Safety events were assessed over the study period.

RESULTS

Ninety-five participants were randomly allocated to the RIC (n=49) and sham RIC (n=46) groups. In the intention-to-treat analysis, the reduction in 24-hour average systolic BP was greater in the RIC group than the sham RIC group (-4.6±9.5 versus -0.9±6.8 mm Hg; baseline-adjusted between-group mean difference: -3.6 mm Hg [95% CI, -6.9 to -0.3 mm Hg]; adjusted P=0.035). The per-protocol analysis showed that 24-hour average systolic BP reduced -5.9±8.6 mm Hg in the RIC group and -0.7±6.7 mm Hg in the sham RIC group (baseline-adjusted between-group mean difference: -5.2 mm Hg [95% CI, -8.5 to -1.9 mm Hg]; adjusted P=0.002). No major adverse events were reported in both groups.

CONCLUSIONS

RIC is safe in patients with mild hypertension and may lower BP in the absence of antihypertensive medications. However, the effects of RIC on clinical outcomes in these patients require further investigation.

REGISTRATION

URL: https://www.

CLINICALTRIALS

gov; Unique identifier: NCT04915313.

Intravenous thrombolysis for acute ischemic stroke: From alteplase to tenecteplase

Stroke is one of the primary causes of morbidity and death worldwide. While intravenous (IV) thrombolysis with alteplase has been widely proven to be beneficial for acute ischemic stroke patients, it still has many limitations. Tenecteplase, a revised version of alteplase, is a potential alternative IV thrombolytic agent that has benefits over alteplase. The aim of this mini-review is to summarize the advancements in IV thrombolysis for severe ischemic stroke, specifically the development and transition from alteplase to tenecteplase.

The Implications of Microglial Regulation in Neuroplasticity-Dependent Stroke Recovery

Stroke causes varying degrees of neurological deficits, leading to corresponding dysfunctions. There are different therapeutic principles for each stage of pathological development. Neuroprotection is the main treatment in the acute phase, and functional recovery becomes primary in the subacute and chronic phases. Neuroplasticity is considered the basis of functional restoration and neurological rehabilitation after stroke, including the remodeling of dendrites and dendritic spines, axonal sprouting, myelin regeneration, synapse shaping, and neurogenesis. Spatiotemporal development affects the spontaneous rewiring of neural circuits and brain networks. Microglia are resident immune cells in the brain that contribute to homeostasis under physiological conditions. Microglia are activated immediately after stroke, and phenotypic polarization changes and phagocytic function are crucial for regulating focal and global brain inflammation and neurological recovery. We have previously shown that the development of neuroplasticity is spatiotemporally consistent with microglial activation, suggesting that microglia may have a profound impact on neuroplasticity after stroke and may be a key therapeutic target for post-stroke rehabilitation. In this review, we explore the impact of neuroplasticity on post-stroke restoration as well as the functions and mechanisms of microglial activation, polarization, and phagocytosis. This is followed by a summary of microglia-targeted rehabilitative interventions that influence neuroplasticity and promote stroke recovery.

Remote ischemic conditioning-induced hyperacute and acute responses of plasma proteome in healthy young male adults: a quantitative proteomic analysis

BACKGROUND

Long-term remote ischemic conditioning (RIC) has been proven to be beneficial in multiple diseases, such as cerebral and cardiovascular diseases. However, the hyperacute and acute effects of a single RIC stimulus are still not clear. Quantitative proteomic analyses of plasma proteins following RIC application have been conducted in preclinical and clinical studies but exhibit high heterogeneity in results due to wide variations in experimental setups and sampling procedures. Hence, this study aimed to explore the immediate effects of RIC on plasma proteome in healthy young adults to exclude confounding factors of disease entity, such as medications and gender.

METHODS

Young healthy male participants were enrolled after a systematic physical examination and 6-month lifestyle observation. Individual RIC sessions included five cycles of alternative ischemia and reperfusion, each lasting for 5 min in bilateral forearms. Blood samples were collected at baseline, 5 min after RIC, and 2 h after RIC, and then samples were processed for proteomic analysis using liquid chromatography-tandem mass spectrometry method.

RESULTS

Proteins related to lipid metabolism (e.g., Apolipoprotein F), coagulation factors (hepatocyte growth factor activator preproprotein), members of complement cascades (mannan-binding lectin serine protease 1 isoform 2 precursor), and inflammatory responses (carboxypeptidase N catalytic chain precursor) were differentially altered at their serum levels following the RIC intervention. The most enriched pathways were protein glycosylation and complement/coagulation cascades.

CONCLUSIONS

One-time RIC stimulus may induce instant cellular responses like anti-inflammation, coagulation, and fibrinolysis balancing, and lipid metabolism regulation which are protective in different perspectives. Protective effects of single RIC in hyperacute and acute phases may be exploited in clinical emergency settings due to apparently beneficial alterations in plasma proteome profile. Furthermore, the beneficial effects of long-term (repeated) RIC interventions in preventing chronic cardiovascular diseases among general populations can also be expected based on our study findings.

Remote ischemic conditioning for acute ischemic stroke part 2: Study protocol for a randomized controlled trial

Background

Remote ischemic conditioning (RIC) refers to the application of repeated short periods of ischemia intended to protect remote areas against tissue damage during and after prolonged ischemia.

Aim

We aim to evaluate the efficacy of RIC, determined by the modified Rankin Scale (mRS) score at 90 days after stroke onset.

Design and methods

This study is an investigator-initiated, multicenter, prospective, randomized, open-label, parallel-group clinical trial. The sample size is 400, comprising 200 patients who will receive RIC and 200 controls. The patients will be divided into three groups according to their National Institutes of Health Stroke Scale score at enrollment: 5–9, mild; 10–14, moderate; 15–20, severe. The RIC protocol will be comprised of four cycles, each consisting of 5 min of blood pressure cuff inflation (at 200 mmHg or 50 mmHg above the systolic blood pressure) followed by 5 min of reperfusion, with the cuff placed on the thigh on the unaffected side. The control group will only undergo blood pressure measurements before and after the intervention period. This trial is registered with the UMIN Clinical Trial Registry (https://www.umin.ac.jp/: UMIN000046225).

Study outcome

The primary outcome will be a good functional outcome as determined by the mRS score at 90 days after stroke onset, with a target mRS score of 0–1 in the mild group, 0–2 in the moderate group, and 0–3 in the severe group.

Discussion

This trial may help determine whether RIC should be recommended as a routine clinical strategy for patients with ischemic stroke.

Cerebral Glucose Metabolism and Potential Effects on Endoplasmic Reticulum Stress in Stroke

Ischemic stroke is an extremely common pathology with strikingly high morbidity and mortality rates. The endoplasmic reticulum (ER) is the primary organelle responsible for conducting protein synthesis and trafficking as well as preserving intracellular Ca2⁺ homeostasis. Mounting evidence shows that ER stress contributes to stroke pathophysiology. Moreover, insufficient circulation to the brain after stroke causes suppression of ATP production. Glucose metabolism disorder is an important pathological process after stroke. Here, we discuss the relationship between ER stress and stroke and treatment and intervention of ER stress after stroke. We also discuss the role of glucose metabolism, particularly glycolysis and gluconeogenesis, post-stroke. Based on recent studies, we speculate about the potential relationship and crosstalk between glucose metabolism and ER stress. In conclusion, we describe ER stress, glycolysis, and gluconeogenesis in the context of stroke and explore how the interplay between ER stress and glucose metabolism contributes to the pathophysiology of stroke.