Marked Changes in Blood-Brain Barrier Biomarkers After Direct Bypass Surgery for Moyamoya Angiopathy: Preliminary Study

Resistance training modifies of serum levels of matrix metalloproteinase 2 and tissue inhibitor of matrix metalloproteinases in multiple sclerosis women - a randomized controlled trail

The objectives of the present study was to investigate the effects of resistance training (RT) on serum levels of controlling blood-brain barrier (BBB) permeability indices and cognitive performance in MS women (MS-W). In this randomized control trail study (IRCT registration code: IRCT20120912010824N3, 07.09.2023), twenty-five MS-W were randomly divided into sedentary (MS) and resistance exercise (12 weeks/3 times per week/ 60-80% of 1RM) (MS + RT) groups. Fifteen healthy aged-matched women participated as a control group (HCON). The serum level of matrix metalloproteinase-2 (MMP-2), matrix metallopeptidase-9 (MMP-9), tissue metalloproteinase inhibitors-1 (TIMP-1), tissue metalloproteinase inhibitors-2 (TIMP-2), and S100 calcium-binding protein B (S100B) were assessed. In addition, cognitive performance was assessed pre- and post- intervention with the Brief International Cognitive Assessment for MS (BICAMS). A significant reduction in MMP-2, TIMP-2 serum levels, and MMP-2/TIMP-2 ratio were observed in post-test for MS + RT group (p < 0.01) in comparison to the HCON and MS groups; however, no changes were observed in MMP-9, TIMP-1, S100B and MMP-9/TIMP-1 ratio after RT (p > 0.05). The verbal learning was improved in post-test for MS + RT group (p < 0.01), although no change were observed for visuospatial memory and information processing speed (p > 0.05). These findings suggest that resistance training can modify some indices of BBB permeability and improve verbal learning in MS-W. The findings may also be beneficial as a non-pharmacological intervention to reduce inflammation.

Pulsatility index of superficial temporal artery was associated with cerebral infarction after direct bypass surgery for moyamoya disease

OBJECTIVE

Direct bypass surgery by superficial temporal artery (STA) - middle cerebral artery anastomosis is an established procedure for moyamoya disease (MMD). However, some patients may develop cerebral infarction (CI) due to the watershed shift phenomenon after the surgery. This study sought to investigate the correlation between the postoperative changes of STA flow as well as cerebral blood flow (CBF) and the incidence of CI after direct bypass surgery for MMD.

METHODS

We conducted a retrospective study of 62 hemispheres in 50 subjects who underwent direct bypass surgery for MMD. All subjects underwent pre- and post-operative MR imaging, ultrasound evaluation of STA, and single-photon emission computed tomography. The presence of CI was correlated with preoperative CBF, the delta difference of each value of the STA between before and after the surgery, and the postoperative increase ratio of CBF.

RESULTS

All bypass procedures were patent, and CI was observed in 4 cases (6.4%). There was no significant association between the incidence of CI and both pre- and post-operative CBF. However, there was a significant difference in delta pulsatility index (PI) of the STA between cases with or without CI (-0.38±0.22 and -0.87±0.63, respectively, p=0.03). Whereas, other factors did not show any significant differences between those with or without CI.

CONCLUSIONS

A relatively high postoperative PI of the STA was significantly associated with the incidence of CI after direct bypass surgery for MMD. A larger study is needed to confirm these findings.

Physiological and pathophysiological mechanisms of the molecular and cellular biology of angiogenesis and inflammation in moyamoya angiopathy and related vascular diseases

Rationale

The etiology and pathophysiological mechanisms of moyamoya angiopathy (MMA) remain largely unknown. MMA is a progressive, occlusive cerebrovascular disorder characterized by recurrent ischemic and hemorrhagic strokes; with compensatory formation of an abnormal network of perforating blood vessels that creates a collateral circulation; and by aberrant angiogenesis at the base of the brain. Imbalance of angiogenic and vasculogenic mechanisms has been proposed as a potential cause of MMA. Moyamoya vessels suggest that aberrant angiogenic, arteriogenic, and vasculogenic processes may be involved in the pathophysiology of MMA. Circulating endothelial progenitor cells have been hypothesized to contribute to vascular remodeling in MMA. MMA is associated with increased expression of angiogenic factors and proinflammatory molecules. Systemic inflammation may be related to MMA pathogenesis.

Objective

This literature review describes the molecular mechanisms associated with cerebrovascular dysfunction, aberrant angiogenesis, and inflammation in MMA and related cerebrovascular diseases along with treatment strategies and future research perspectives.

Methods and results

References were identified through a systematic computerized search of the medical literature from January 1, 1983, through July 29, 2022, using the PubMed, EMBASE, BIOSIS Previews, CNKI, ISI web of science, and Medline databases and various combinations of the keywords "moyamoya," "angiogenesis," "anastomotic network," "molecular mechanism," "physiology," "pathophysiology," "pathogenesis," "biomarker," "genetics," "signaling pathway," "blood-brain barrier," "endothelial progenitor cells," "endothelial function," "inflammation," "intracranial hemorrhage," and "stroke." Relevant articles and supplemental basic science articles almost exclusively published in English were included. Review of the reference lists of relevant publications for additional sources resulted in 350 publications which met the study inclusion criteria. Detection of growth factors, chemokines, and cytokines in MMA patients suggests the hypothesis of aberrant angiogenesis being involved in MMA pathogenesis. It remains to be ascertained whether these findings are consequences of MMA or are etiological factors of MMA.

Conclusions

MMA is a heterogeneous disorder, comprising various genotypes and phenotypes, with a complex pathophysiology. Additional research may advance our understanding of the pathophysiology involved in aberrant angiogenesis, arterial stenosis, and the formation of moyamoya collaterals and anastomotic networks. Future research will benefit from researching molecular pathophysiologic mechanisms and the correlation of clinical and basic research results.

Paradoxical symptomatic cerebral blood flow decreases after combined revascularization surgery for patients with pediatric moyamoya disease: illustrative case

BACKGROUND

Transient neurological deficits (TNDs) develop after cerebral revascularization in patients with moyamoya disease (MMD). The authors report a rare pediatric MMD case with extensive decreased cerebral blood flow (CBF) and prolonged TNDs after combined revascularization.

OBSERVATIONS

A 9-year-old boy presented with transient left upper limb weakness, and MMD was diagnosed. A right-sided combined surgery was performed. Two years after the surgery, frequent but transient facial (right-sided) and upper limb weakness appeared. The left internal carotid artery terminal stenosis had progressed. Therefore, a left combined revascularization was performed. The patient’s motor aphasia and right upper limb weakness persisted for approximately 10 days after surgery. Magnetic resonance angiography showed that the direct bypass was patent, but extensive decreases in left CBF were observed using single photon emission tomography. With adequate fluid therapy and blood pressure control, the neurological symptoms eventually disappeared, and CBF improved.

LESSONS

The environment of cerebral hemodynamics is heterogeneous after cerebral revascularization for MMD, and the exact mechanism of CBF decreases was not identified. TNDs are significantly associated with the onset of stroke during the early postoperative period. Therefore, appropriate treatment is desired after determining complex cerebral hemodynamics using CBF studies.

Decreased cortical perfusion in areas with blood-brain barrier dysfunction in Moyamoya disease

BACKGROUND

Recently, several studies have focused on the relationship between blood-brain barrier (BBB) impairment and the etiology of Moyamoya disease (MMD). However, in vivo studies investigating about BBB impairment and cortical perfusion in MMD patients were really rare.

METHODS

This study included 16 patients diagnosed with MMD and 9 patients with atherosclerotic cerebrovascular disease (ACVD); all of who were treated with superficial temporal artery-middle cerebral artery (STA-MCA) bypass. Cortical perfusion was assessed using intraoperative indocyanine green (ICG) videoangiography by calculating the blood flow index (BFI). In addition, we used sodium fluorescein (NaFl) to evaluate the permeability of BBB in vivo during operation.

RESULTS

The results showed that BBB impairment in MMD patients was more significant than that in ACVD patients, whereas, the cortical perfusion was comparable between two groups. BFI was significantly improved after STA-MCA bypass both in the MMD group (post-operation vs pre-operation: 109.2 ± 67.7 vs 64.3 ± 35.0, p = 0.004) and the ACVD group (post-operation vs pre-operation: 137.6 ± 89.6 vs 90.8 ± 58.3, p = 0.015). Moreover, BFI was significantly decreased in the cortex with BBB impairment as compared with that in the cortex with intact BBB (impaired BBB vs intact BBB: 55.7 ± 26.5 vs 87.6 ± 55.1, p = 0.025). Following bypass, the cortical perfusion significantly improved in the area of BBB impairment (post-operation vs pre-operation: 93.8 ± 75.2 vs 55.7 ± 26.5, p = 0.004), which was not observed in the BBB intact area (post-operation vs pre-operation: 92.4 ± 50.4 vs 87.6 ± 55.1, p = 0.58).

CONCLUSION

In summary, we observed that BBB impairment in MMD patients was more significant than that in ACVD patients. This study also demonstrated for the first time that cortical perfusion was significantly decreased in the cortex with BBB impairment as compared with that in the cortex with intact BBB in MMD patients. We also observed that After STA-MCA bypass, the cortical perfusion was significantly improved in the cortex with BBB impairment. These results may provide a new insight for BBB impairment and cortical perfusion in the etiology of MMD.

A Panel of Exosome-Derived miRNAs of Cerebrospinal Fluid for the Diagnosis of Moyamoya Disease

Background

Moyamoya disease (MMD) is an important cause of stroke in children and young adults in Asia. To date, diagnosis remains challenging due to varying clinical manifestations and unknown pathogenesis. The study aims to identify cerebrospinal fluid (CSF) exosomal microRNAs (exomiRs) that can serve as a novel diagnostic biomarker for diagnosis and assess its clinical applications.

Methods

CSF samples were taken from 31 MMD patients and 31 healthy controls. Initial screening of miRNA expression was performed on samples pooled from MMD patients and controls using microarray and validated using quantitative reverse transcription polymerase chain reaction (qRT-PCR). The diagnostic accuracy of the potential exosomal miRNAs was evaluated using receiver operating characteristic curve analyses in an independent patient cohort. The potential pathways regulated by the miRNAs was also determined using bioinformatics analysis.

Results

The microarray results demonstrated that six exomiRs were dysregulated in the MMD patients compared to the controls. Using qRT-PCR, we validated four of the miRNAs (miR-3679-5p, miR-6165, miR-6760-5p, and miR-574-5p) as a biomarker for MMD diagnosis. The four exomiRs showed enhanced sensitivity (75%) and specificity (93.75%) in terms of differentiating MMD patients from healthy subjects [area under the curve (AUC) = 0.9453]. Pathway enrichment analysis for potential targets of six exomiRs identified proteins involved in cell adhesion and junction formation in the brain.

Conclusions

We identified a novel and highly sensitive exomiRs signature for MMD detection and explored its potential targets using bioinformatics analysis.