Search Results (96)

Adverse effects in early ontogenesis can have a delayed influence on the functioning of various organs. We hypothesized that acute perinatal hypoxia would worsen the neurological status and functioning of cerebral arteries in adult rats. Two-day-old male Wistar rats underwent normobaric hypoxia for 2 h (8% O₂ content, «Hypoxia» group), while control rats from the same litters were placed in conditions with 21% O₂ content. «Hypoxia» rats exhibited delayed maturation of motor reflexes and reduced learning ability. The levels of key serum biochemical parameters did not differ between the two groups. Contractile responses induced by the thromboxane A₂ receptor agonist U46619 were increased in the basilar arteries of the «Hypoxia» group compared to «Control» rats. Endothelium-dependent relaxations to acetylcholine and arterial sensitivity to exogenous NO did not differ between the two groups. The NO-synthase inhibitor increased arterial contractility to a lesser extent in the «Hypoxia» group compared to the «Control» group, which was associated with decreased eNOS protein content in basilar arteries from «Hypoxia» rats. Thus, acute perinatal hypoxia impairs the neurological status of adult male rats, which may be partly associated with decreased blood supply to the brain as a result of weakened anticontractile influence of NO in basilar artery. Full article

The tree shrew (Tupaia belangeri) is increasingly recognized as an important experimental model for studying human diseases due to its close phylogenetic relationship with humans. Because the basilar artery’s response to endogenous vasoactive mediators varies among species, we investigated the effects of vasoactive substances on isolated tupaia basilar arteries to determine whether this species is suitable as a human model. 5-Hydroxytryptamine (5-HT) and histamine (His) induced contraction, while bradykinin (BK) and acetylcholine (ACh) produced concentration-dependent relaxation. Pharmacological analysis revealed that contractions triggered by 5-HT were regulated through 5-H₁ and 5-HT₂ receptors, while His-induced responses were mediated by H₁ receptors. BK-induced relaxation was inhibited by the B₂ antagonist HOE140 and N^ω-nitro-L-arginine (L-NA), but not by B₁ antagonists or indomethacin, suggesting a B₂ receptor-mediated nitric oxide (NO) pathway. ACh-induced relaxation was markedly reduced in the presence of L-NA and the M₃ antagonist pFHHSiD, indicating M₃ receptor-mediated NO release. At basal tone, L-NA evoked a contractile response, while indomethacin led to relaxation, suggesting basal regulation by NO and prostanoids. These findings demonstrate that 5-HT₁/5-HT₂ and H₁ receptors mediate contraction, while B₂ and M₃ receptors mediate relaxation in the tupaia basilar artery. This study highlights species-specific cerebrovascular regulation and supports the tupaia as a relevant model for investigating human cerebrovascular physiology and pathophysiology. Full article

Background and Objectives: The labyrinthine artery (LA) is a small but surgically important vessel encountered during procedures involving the cerebellopontine angle (CPA). Variations in its number, origin, and relationship to the facial–vestibulocochlear nerve complex may increase the risk of vascular injury during CPA surgery. The aim of this cadaveric microdissection study was to evaluate the number, origin, and course of the LA within the CPA and to characterize its relationship to the anterior inferior cerebellar artery (AICA) and the facial–vestibulocochlear nerve complex. Materials and Methods: Microsurgical dissections were performed bilaterally in 45 formalin-fixed adult cadavers (90 CPAs) using an operating microscope and vascular injection. The number, origin, and course of the LA were analyzed together with its relationship to the AICA and the facial–vestibulocochlear nerve complex. Results: The LA was identified in all specimens. A single LA was observed in 57.8% of CPAs, whereas multiple LAs were identified in 42.2%. The artery most commonly originated from the AICA (65.6%), followed by a common trunk shared with the AICA (21.1%) and direct origin from the basilar artery (13.3%). In specimens with bifurcated AICAs forming double loops, multiple LAs frequently arose from both loops. Considerable variability was observed in the course of the LA relative to the facial–vestibulocochlear nerve complex, including superior, inferior, and interposed courses. Bilateral asymmetry was identified in 15.6% of cadavers. Conclusions: The LA demonstrates substantial anatomical variability within the CPA regarding its number, origin, and neurovascular relationships. Although the artery most commonly arises from the apex or medial aspect of the AICA loop, its subsequent course may vary considerably. Careful microsurgical inspection remains essential during CPA surgery, as the configuration of the AICA alone is insufficient to reliably predict the distal trajectory of the LA. Full article

Objectives: To investigate clinical and imaging predictors of short- and long-term outcomes in patients with posterior circulation stroke (PCS), with particular focus on infarct topography and ischemic burden. Methods: We conducted a retrospective multicenter observational study including 251 consecutive patients with acute PCS. All patients underwent CT angiography within 24 h and follow-up CT/MRI at 48–72 h. Clinical data, vascular risk factors, stroke severity (NIHSS), and functional outcome assessed by modified Rankin Scale (mRS), were collected. Short-term outcome was defined as mRS at discharge and long-term outcome as mRS at 3 months. Favorable outcome was defined as independence, graded as mRS 0–1. Imaging analysis included pc-ASPECTS, collateral scores, and quantitative ischemic volume assessment. Multivariable logistic regression was performed to identify independent predictors of outcome. Results: Among 251 patients, 105 (41.8%) had LVO. Patients with LVO presented with higher NIHSS scores, larger infarct volumes, and more frequent multiregional involvement. Basilar artery occlusion was associated with the most severe clinical and radiological profile. Infarct location, ischemic volume, baseline NIHSS, and pre-stroke mRS were independently associated with short-term outcome. For long-term outcome, age, infarct location, diabetes, and pre-stroke mRS remained significant predictors. LVO status and treatment variables were not independently associated with outcome. Conclusions: In PCS, outcome is primarily influenced by infarct topography and clinical factors rather than LVO status alone. Multiregional involvement and baseline disability are key determinants of prognosis. These findings underscore the need for PCS-specific prognostic models and highlight the importance of detailed imaging assessment beyond vessel occlusion. Full article

Background/Objectives: The renin–angiotensin–aldosterone (RAA) system is a key regulator of cardiovascular homeostasis. Recent evidence suggests that Angiotensin II (Ang II) can trigger ferroptosis, an iron-dependent form of cell death. We previously demonstrated that periodontitis induces neurovascular dysfunction, and our preliminary observations indicate that this oral inflammatory model is associated with elevated blood pressure. However, the mechanism by which Ang II impaired nitrergic vasodilation and triggered ferroptosis in cerebral arteries remains unclear. This study investigates the functional effects of electrical and chemical nerve stimulation in adult spontaneously hypertensive rats (SHR) and Wistar-Kyoto rats (WKY). Methods: Endothelium-denuded basilar arterial (BA) rings from SHRs and WKYs were used to assess the impact of Ang II on neurogenic relaxation via wire myography. Results: Vascular relaxation responses to nicotine and transmural nerve stimulation (TNS) were significantly diminished in SHRs compared to WKYs. This impairment was reversed by both acute preincubation and chronic treatment with losartan (an AT1 receptor antagonist). In WKY BAs, exogenous Ang II pretreatment inhibited relaxation responses to nicotine, TNS, and isoproterenol. Importantly, this inhibition was effectively reversed by marimastat (MMP inhibitor), catalase (antioxidant), and ferrostatin-1 (ferroptosis inhibitor). Conclusions: Our findings indicate that Ang II induces functional alterations in neurovascular signaling patterns by triggering ferroptosis within nerve terminals. This process leads to a functional imbalance between sympathetic and parasympathetic influences, ultimately impairing neurogenic nitrergic dilation in the BAs of SHRs. These results suggest that targeting Ang II-induced ferroptosis may alleviate the neuroinflammation and cognitive decline associated with hypertension-related cerebrovascular dysfunction. Full article

Cerebral aneurysm clipping remains a key surgical approach despite advancements in endovascular techniques. However, training for this procedure is complex due to the variable and fragile nature of aneurysmal tissues. This study evaluates the mechanical behaviour of human basilar arteries during clipping and compares them to 3D-printed models used for neurosurgical training. Mechanical tests were performed on ten cadaveric basilar arteries, distinguishing between healthy and plaque-affected segments. Plaque-affected regions required significantly higher clipping force (1.73 ± 0.22 N) compared to healthy segments (0.45 ± 0.19 N), confirming that atherosclerosis markedly increases arterial stiffness. Six 3D-printed phantom materials were evaluated; none accurately replicated the biomechanical response of real arteries. The Flex Anatomical material showed the highest stiffness (44.51 ± 0.98 N), while Silicone 40A was the most compliant (1.05 ± 0.12 N), yet both deviated substantially from biological performance. These findings underscore the current limitations of anatomical models that lack realistic biomechanical properties. Full article

Background/Objectives: Heart rate variability (HRV) is associated with the risk of vascular events. However, the predictive value of HRV for the presence of intracranial atherosclerosis (ICAS) is unclear. This study aimed to investigate the relationship between daytime HRV measured by 3 min ECG monitoring and ICAS identified by high-resolution magnetic resonance imaging (HR-MRI). Methods: A total of 272 adults (mean age, 63.4 ± 6.8; 43% male) were recruited from November 2022 to December 2024. A series of cardiac function parameters is automatically generated through a 3 min analysis by the electrocardiographic dispersion mapping (ECG-DM) software, including heart rate variability and myocardial ischemic metabolic impairment. HRV was assessed as the standard deviation of normal-to-normal intervals (SDNN), which was categorized into tertiles for data analysis. Myocardial micro-alteration index (MMI, %) was used as an indicator of ischemia, reflecting myocardial abnormalities at the metabolic level. Atrial and ventricular myocardial oxygenation deficits were directly visualized in a color-coded scatter plot, with different colors indicating the severity of pathological changes. On HR-MRI intracranial artery wall scanning, the prevalence of ICAS was assessed in middle cerebral arteries (MCAs), vertebral arteries (VAs), and basilar arteries (BAs), and the associated plaque characteristics (eccentricity, thickening patterns, remodeling index, and surface morphology) were evaluated. Results: Among the subjects, 209 arterial lesions caused by ICAS were detected in 152 subjects (56%), including MCAs (105/544), VAs (68/526), and BAs (36/272). Ninety-four subjects (94/272) with significant HRV deviation had ICAS (p = 0.040). Furthermore, subjects with ICAS were more likely to present with atrial hypoxia (p = 0.030) compared to those without ICAS. In multivariate analyses, lower standard deviation of normal-to-normal intervals (SDNN, odds ratio, OR = 1.55, 95% CI 1.10–2.18, p = 0.012) and atrial deviation (OR = 1.85, 95% CI 1.10–3.14, p = 0.022) were independently associated with the presence of ICAS. Conclusions: Among middle-aged or older adults in a local community, our study suggested that lower HRV and significant atrial hypoxia were independently associated with the presence of ICAS. Full article

Background/Objectives: Despite the reported correlation between white matter hyperintensity (WMH) and intracranial atherosclerosis (ICAS), little is known about the association between intracranial plaque imaging characteristics and the severity of WMH. This study aimed to investigate the relationship between plaque imaging features in the major intracranial large arteries and the severity of WMH by high-resolution magnetic resonance imaging (HR-MRI) in a local community-based cohort. Methods: Stroke-free Chinese aged over 45 years old were recruited. Plaque imaging features of intracranial arteries identified in middle cerebral arteries (MCAs), vertebral arteries (VAs), and basilar arteries (BAs) were analyzed. The plaque characteristics were compared between subjects with or without moderate-to-severe WMH (Fazekas score > 2), and their independent association with the severity of WMH was also assessed using multivariate logistic regression analysis. Results: In the cohort of 272 subjects (mean age, 63.4 ± 6.8 years old; males, n = 118), 24.6% with moderate-to-severe WMH had a significantly higher prevalence of ICAS, eccentric lesions, diffuse thickening pattern, and a heavier plaque burden in the intracranial major arteries compared to those without moderate-to-severe WMH. After adjusting for confounding factors, multivariate logistic regression analysis showed that an eccentric pattern of plaque lesion was independently associated with moderate-to-severe WMH. Conclusions: Eccentric lesions in the major intracranial large arteries, but not diffuse thickening patterns, luminal stenosis, and plaque burden, were independently associated with a greater burden of WMHs among middle-aged or older adults. Eccentricity of major intracranial large artery lesions may be a potential imaging marker to assess WMH burden. Understanding the correlation between atherosclerotic patterns and the severity of WMH would aid in early stratifying the future clinical risk of cerebrovascular events and support the development of individualized treatment strategies. Further studies are warranted to investigate its value in predicting future cerebrovascular events. Full article

Introduction. Cervical artery dissection (CAD) is a rare condition, being one of the leading causes of stroke in patients under the age of 45, with a reported prevalence of up to 20%. The management of CAD remains controversial due to its rarity and the lack of large-scale randomized controlled trials. The aim of this study was to report the long-term outcomes of CAD in a real-world setting. Methods. This retrospective, observational, single-center study included patients diagnosed with CAD between 2010 and 2019 (approval number: 153/2015/U/Oss/AOUBo). Clinical presentation, risk factors, and medical therapies were prospectively analyzed. Management strategies included both medical and interventional approaches. Follow-up consisted of annual clinical visits and carotid duplex ultrasound (DUS), with telephone interviews every six months. The primary endpoint was defined by the overall long-term stroke/death rate and in relation to the type of medical treatment, localization of the dissection and clinical manifestations. Results. A total of 62 patients were included, predominantly male (65%) with a mean age of 58 (±2) years. Thirteen dissections (21%) were trauma-related. CAD locations included the common carotid artery in 6 cases (10%), extracranial internal carotid artery in 29 (46%), intracranial internal carotid artery in 9 (14%), and vertebral artery in 16 (25%). One patient (2%) had dissections in both the extracranial internal carotid and vertebral arteries, and another (2%) in both the vertebral and basilar arteries. Bilateral dissections were observed in 5 patients (8%). Ischemic manifestations occurred in 43 patients (68%): 10 transient ischemic attacks (16%), 17 minor strokes (27%), and 16 major strokes (25%), with ischemic lesions on cerebral CT in 31 cases (72%). Fifty-eight (93%) patients were treated medically (anticoagulants and/or antiplatelets), while 4 patients (7%) underwent surgical or endovascular intervention. The mean follow-up was 81 ± 35 months. During this period, 2 patients (4%) experienced stroke and 15 (24%) died. The estimated 10-year survival rate was 71%, and the 10-year stroke/death-free survival rate was 70%. Among medically treated patients, the 10-year stroke/death-free survival was 86% for those on anticoagulation and 67% for those on antiplatelet therapy (p = 0.1). Patients presenting with ischemic symptoms had a lower estimated 10-year stroke/death-free survival rate compared to those with non-ischemic presentations (61% vs. 69%, p = 0.7). Patients with dissection of the common carotid artery had a significantly lower estimated 10-year stroke/death-free survival rate (25%), compared to dissections in other cervical arteries (p = 0.001). Conclusions. In this real-world, single-center experience, cervical artery dissection was associated with a favorable long-term prognosis in most cases, especially among patients managed conservatively with medical therapy. Stroke and mortality rates were relatively low during extended follow-up. Although no statistically significant difference was observed between anticoagulation and antiplatelet therapy, the trend favored anticoagulation for stroke/death-free survival. Patients with CCA dissections had significantly worse 10-year stroke/death-free survival compared to those with dissections in other cervical arteries. Full article

Background: Intracranial atherosclerosis disease (ICAD) represents a significant etiology of stroke. This study aimed to evaluate correlations between intracranial atherosclerotic burden and risk of ischemic events. Methods: In this prospective observational study, all enrolled patients underwent High-Resolution Magnetic Resonance vessel wall Imaging (HR MR-VMI) within two weeks of onset, or of enrollment. Baseline assessments included modified American Heart Association plaque type, stenosis degree, intra-plaque hemorrhage (IPH), plaque thickness, plaque length, and vessel wall enhancement. Modified Rankin Scale (mRS) was followed with one-year treatment in adherence to the guidelines. Comparative analyses were conducted between symptomatic and asymptomatic groups, culprit versus non-culprit plaques, and favorable versus poor prognosis groups. Results: The study included 129 symptomatic and 42 asymptomatic patients. Hypertension, diabetes, and smoking were more prevalent in patients in the symptomatic group. Vulnerable plaque (97.7% vs. 64.3%, p = 0.003), IPH (17.8% vs. 4.8%, p = 0.022) and higher stenosis degree (χ² = 2.675, p = 0.008) were significantly more prevalent in the symptomatic group. Culprit plaques were predominantly located in the superior wall of the middle cerebral artery (MCA) (χ² = 15.561, p = 0.001) and the left wall of the basilar artery (χ² = 34.138, p = 0.008). Factors associated with poor prognosis included older age (63.63 ± 8.19 vs. 55.63 ± 13.15, p = 0.001), presence of IPH (31.82% vs. 14.29%, p = 0.037), and elevated D-dimer levels (0.77 ± 0.60 vs. 0.40 ± 0.36, p = 0.022). Conclusions: Vulnerable plaque, specific lesion locations, and higher stenosis degree are significantly associated with ischemic events in ICAD. While plaque enhancement and stenosis correlate with stroke occurrence, they show no clear association with prognosis. Neither the length nor the thickness of plaques manifests a significant correlation with either stroke events or the prognostic outcomes. Full article

Background: Intracranial aneurysms of the posterior circulation are of particular clinical significance due to their higher risk of rupture-associated morbidity and mortality compared to anterior circulation aneurysms. Moreover, they exhibit an increased tendency for recurrence, posing challenges for long-term management. The purpose of this study is to identify key risk factors and define criteria for the early detection of high-risk aneurysms with a machine learning-based analysis. Methods: This study employs machine learning (ML), which, unlike traditional statistical methods, can detect complex, previously unrecognized patterns without predefined hypotheses to predict recurrence and rupture in patients with intracranial aneurysms of the posterior circulation. A total of 229 patients were retrospectively screened (2008–2020), and the data set was analyzed using ML algorithms. To avoid bias, a 10-fold cross-validation was employed, and the model performing best in terms of the Area Under the Curve (AUC) was selected. In addition, the sensitivity, specificity, and accuracy of the model were computed as secondary metrics. Results: A total of 229 patients were included, with over 70% being female, older than 50 years, and diagnosed with arterial hypertension. The most significant predictors of aneurysm recurrence identified by the ML model (AUC of 0.74 with a sensitivity of 0.76, a specificity of 0.70, and an accuracy of 0.76) were age, aneurysm size, arterial hypertension, and a history of nicotine consumption. The DeLong test confirmed that the ML model performed significantly better than random classification with an AUC of 0.5 (p < 0.001). Further analysis revealed that the presence of multiple aneurysms and localization at the basilar artery were independent risk factors for early recurrence within six months. For aneurysm rupture, key predictive features included advanced age, basilar artery localization, atherosclerosis, irregular aneurysm morphology, and familial predisposition. Conclusions: ML algorithms identified several risk factors for recurrence and rupture of intracranial aneurysms of the posterior circulation, aligning with previously established risk factors. These findings are intended to serve as a basis for further research in clinical use and prospective studies. Full article

Background/Objectives: The accurate evaluation of stroke etiology in basilar artery occlusion (BAO) remains underexplored. This study aimed to explore a simple and practical method for predicting the in situ atherosclerotic thrombosis (ISAT) subtype of BAO. Methods: We retrospectively analyzed patients diagnosed with BAO at our institution between April 2015 and April 2025. ISAT was characterized by moderate-to-severe stenosis (>50%) at the occlusion site on angiography, while the cardioembolism (CE) subtype was defined as sudden-onset arterial occlusion with evidence of a cardiac source of embolism. The location of BAO was classified based on cerebral angiography findings as proximal, middle, or distal. Clinical and imaging characteristics were compared between CE and ISAT subtypes. Results: Among 33 patients, 8 (24%) were classified as having the ISAT subtype. Multivariable analyses revealed that the presence of atrial fibrillation (AF) (OR 0.03; 95% CI, 0.00–0.56) and a non-proximal occlusion site (i.e., middle or distal) (OR 0.02; 95% CI, 0.00–0.27) were independently associated with ISAT. Patients were stratified into four groups based on the presence or absence of proximal occlusion and AF. CE subtypes predominated in groups with either AF or no proximal occlusion (25/27, 93%), whereas ISAT was present in all patients with both proximal occlusion and absence of AF (6/6, 100%). The area under the curve for this classification was 0.955. The sensitivity, specificity, positive predictive value, and negative predictive value for diagnosing ISAT were 75%, 100%, 100%, and 93%, respectively. Conclusions: A simple classification based on the presence of proximal occlusion and AF status suggested the potential to facilitate preprocedural differentiation of ISAT subtype in BAO. Full article

Introduction: Given the impact of aneurysmal subarachnoid hemorrhage (aSAH) on patients’ health, preclinical research is substantial to understand its pathophysiology and improve treatment strategies, which necessitates reliable and comprehensive animal models. Traditionally, aSAH models utilize iliac or subclavian access for angiography, requiring invasive procedures that are associated with significant risks and animal burden. This pilot study explores a less invasive method of digital subtraction angiography (DSA) by using the auricular artery (AA) as an alternative access point. Our aim was to demonstrate the feasibility of this refined technique, with the intention of reducing procedural risks, providing shorter operation times with enhanced neurological recovery, and simplifying the process for both researchers and animals. Materials and Methods: In this study, six female New Zealand white rabbits (3.2–4.1 kg body weight) underwent experimental induction of aSAH via a subclavian-cisternal shunt. The initial steps of this procedure followed traditional techniques, consisting of subclavian access through microsurgical preparation, followed by DSA to analyze retrograde filling of the basilar artery (BA). To evaluate the alternative method, on day 3 after induction of aSAH, DSA was performed via the AA instead of the traditional subclavian or femoral access. A catheter was placed in the AA to allow retrograde filling of the BA. This approach aimed to simplify the procedure while maintaining comparable imaging quality. Results: All rabbits survived until the study endpoint. Postoperatively, two rabbits showed signs of hemisyndrome, which significantly improved by the time of follow-up. No additional morbidities were observed. Upon euthanasia and necropsy, all animals showed clear subarachnoid bleeding patterns. DSA via the AA produced strong contrasting of the BA comparable to the traditional method. Conclusions: This technical note presents an initial evaluation of AA access as a feasible and potentially advantageous method for DSA in a rabbit model of blood shunt subarachnoid hemorrhage. The method shows promise in reducing invasiveness and procedural complexity, but further studies are required to fully establish its efficacy and safety. Future research should focus on expanding the sample size, refining the anatomical understanding of the AA, and continuing to align with ethical considerations regarding animal welfare. Full article

Backgrounds/Objective: The impact of metabolic disturbances induced by an unbalanced diet on cognitive decline in mid-life is now widely observed, although the mechanisms are not well identified. Here we report that glutamatergic vasoactive pathways are a key feature of high-fat-diet (HFD)-induced neurogliovascular uncoupling in mice. Methods: C57Bl6/J mice are fed either with normal diet (ND) or high-fat diet (HFD) during 6 or 12 months and characterized for metabolic status. Cerebral vascular tree from pial to intraparenchymal arteries, is investigated with Halpern’s arteriography and with differential interference contrast infrared imaging of brain slices. Results: A 70% alteration in the myogenic tone of the basilar artery is observed as early as 6 months (M6) after the HFD. Infrared imaging revealed a 77% reduction in the glutamate-induced vasodilation of intraparenchymal arterioles appearing after 12 months (M12) of the HFD. The respective contributions of enzymes involved in glutamatergic pathways were altered as a function of HFD and time. The decrease in astrocytic COX I observed at M6 was followed by a loss of neuronal COX II and a compensatory action of NOS at M12. Conclusions: This HFD-induced neurogliovascular uncoupling pathway offers therapeutic targets to consider for improving cerebral vasoactive functions while preventing peripheral metabolic disturbances. Full article

This study aims to investigate the mechanism by which the total flavones of Rhododendron (TFR) protect against cerebral ischemic injury through the endothelial-derived H₂S-mediated regulation of RhoA phosphorylation at the Ser188 and Rho kinase 2 (ROCK₂) phosphorylation at Thr436. For experimental design, mouse or rat cerebrovascular endothelial cells (ECs) were cultured with or without neurons and subjected to hypoxia/reoxygenation (H/R) injury. The vasodilation of the cerebral basilar artery was assessed. Cerebral ischemia/reperfusion (I/R) injury was induced in mice by bilateral carotid artery ligation, followed by Morris water maze and open field behavioral assessments. The protein levels of cystathionine-γ-lyase (CSE), 3-mercaptopyruvate sulfurtransferase (3-MST), RhoA, ROCK₂, p-RhoA (RhoA phosphorylated at Ser188), and p-ROCK₂ (ROCK₂ phosphorylated at Thr436) were quantified. Additionally, the activities of RhoA and ROCK₂ were measured. Notably, TFR significantly inhibited H/R-induced H₂S reduction and suppressed the increased expression and activity of RhoA and ROCK₂ in ECs, effects attenuated by CSE or 3-MST knockout. Moreover, TFR-mediated cerebrovascular dilation was reduced by RhoA or ROCK₂ inhibitors, while the protective effect of TFR against cerebral I/R injury in mice was markedly attenuated by the heterozygous knockout of ROCK₂. In the ECs-co-cultured neurons, the inhibition of TFR on H/R-induced neuronal injury and decrease in H₂S level in the co-culture was attenuated by the knockout of CSE or 3-MST in the ECs. TFR notably inhibited the H/R-induced upregulation of neuronal RhoA, ROCK₂, and p-ROCK₂ protein levels, as well as the activities of RhoA and ROCK₂, while reversing the decrease in p-RhoA. However, the knockout of CSE or 3-MST in the ECs significantly attenuated the inhibition of TFR on these increases. Furthermore, 3-MST knockout in ECs attenuated the TFR-mediated suppression of p-RhoA reduction. Additionally, CSE or 3-MST knockout in ECs exacerbated H/R-induced neuronal injury, reduced H₂S level in the co-culture system, and increased RhoA activity and ROCK₂ expression in neurons. In summary, TFR protected against ischemic cerebral injury by endothelial-derived H₂S promoting the phosphorylation of RhoA at Ser188 but inhibited the phosphorylation of ROCK₂ at Thr436 to inhibit the RhoA-ROCK₂ pathway in neurons. Full article