Vascular Collagen Type-IV in Hypertension and Cerebral Small Vessel Disease

The effect of hypertension, obesity, and type 2 diabetes on lacunar stroke: A network Mendelian randomization study

BACKGROUND AND AIMS

Previous studies have reported an association of lacunar stroke with hypertension, obesity, and type 2 diabetes (T2D). The aim of this study was to investigate whether the association was causal and whether body mass index mediated the effect of hypertension on lacunar stroke.

METHODS AND RESULTS

The independence and causal association of hypertension, obesity, and T2D with lacunar stroke were assessed by multivariate Mendelian randomization (MVMR) and network Mendelian randomization (NMR) with inverse variance weighting (IVW). The reliability of the results was increased by sensitivity analyses including MR-Egger, Cochrane's Q test, Mendelian Randomization Pleiotropy RESidual Sum and Outlier (MR-PRESSO), and leave-one-out. MVMR analysis found that genetically predicted hypertension had a 42 % higher lacunar stroke risk (OR: 1.42, 95 % CI: 1.29-1.56, P < 0.001) when adjusted for obesity and T2D, genetically predicted T2D had a 9 % higher lacunar stroke risk (OR: 1.09, 95 % CI: 1.03-1.16, P < 0.004) when adjusted for hypertension and obesity, and genetically predicted obesity had a 15 % lower lacunar stroke risk (OR: 0.85, 95 % CI: 0.77-0.93, P < 0.001) when adjusted for hypertension and T2D. NMR found that 44 % of the association between hypertension and lacunar stroke risk was mediated by obesity.

CONCLUSION

This genetic association study found novel independent genetic associations between hypertension and T2D with high risk of lacunar stroke, whereas obesity attenuated the risk of lacunar stroke. The findings emphasize the importance of individualized lacunar stroke prevention strategies rather than uniform weight management optimize medical care in high-risk populations.

Mesenchymal stem cells attenuate diabetic vascular complication by reducing irregular extracellular matrix production in human blood vessel organoids

Mesenchymal stem cells (MSCs) hold potential for treating diabetic vascular complications, but current models fail to adequately replicate the complexities of diabetic vascular disease, limiting our ability to accurately assess their therapeutic effects. To this end, we developed a co-culture system using a combination of human embryonic stem cell-derived blood vessel organoids (BVOs) and MSCs. This system could accurately replicate key aspects of diabetic pathology, including basement membrane thickening and excessive extracellular matrix (ECM) deposition. The results showed that MSCs were effective in attenuating basement membrane thickening and reducing ECM deposition in BVOs under diabetic conditions. Subsequent transcriptomics demonstrated that the MSC-treated group exhibited a notable normalization of ECM-related gene expression, particularly in collagen IV levels. Furthermore, the inhibition of the NF-κB signaling pathway was identified as a crucial mechanism underlying the therapeutic efficacy of MSCs. This study demonstrates the potential of MSCs to counteract diabetic vascular complications and emphasizes the co-culture system as a more physiologically relevant model to investigate the preventive and therapeutic potential of MSCs in diabetic pathology.

Osteoporosis Is Associated with Cerebral Small Vessel Disease in Stroke-Free Individuals: A Retrospective Observational Study

Objectives: This study aimed to investigate the relationship between osteoporosis and cerebral small vessel disease (CSVD) burden in stroke-free individuals, as well as its specific imaging markers, including lacunes, enlarged perivascular spaces (EPVSs), white matter hyperintensities (WMHs), and brain atrophy (BA). Methods: A total of 684 stroke-free patients who underwent both bone mineral density (BMD) assessments and brain MRI were included. Clinical data, CSVD burden scores, imaging markers of CSVD, and bone density parameters were collected. Logistic regression models were used to evaluate the relationship between BMD and CSVD burden and imaging markers. Results: Osteoporosis, including hip and vertebral osteoporosis, was independently associated with CSVD burden (OR = 2.332, 95%CI: [1.345, 4.039], p = 0.003; OR = 2.598, 95%CI: [1.540, 4.384], p < 0.001; OR = 1.515, 95%CI: [1.010, 2.272], p = 0.044). Increased BMD in the hip and spine correlated with reduced CSVD burden (OR = 0.929, 95%CI: [0.887, 0.972], p = 0.001; OR = 0.952, 95%CI: [0.917, 0.989], p = 0.012). Hip osteoporosis was a risk factor for lacunes (OR = 2.215, 95%CI: [1.197, 4.1], p = 0.011), multiple lacunes (OR = 2.274, 95%CI: [1.039, 4.980], p = 0.04), severe WMH (OR = 2.611, 95%CI: [1.171, 5.823], p = 0.019), and EPVS ≥ 2 (OR = 1.99, 95%CI: [1.133, 3.495], p = 0.017). No significant association was found between osteoporosis and BA (p = 0.928). In sex-stratified analyses, both hip and vertebral osteoporosis were independently associated with a higher CSVD burden in female patients (hip: OR = 2.529, 95%CI: [1.122, 5.703], p = 0.025; vertebral: OR = 3.129, 95%CI: [1.517, 6.455], p = 0.002; general osteoporosis: OR = 1.755, 95%CI: [1.057, 2.912], p = 0.03), whereas no significant association was observed in male patients (all p > 0.05). Conclusions: Osteoporosis was independently associated with an increased burden of CSVD, particularly evident in female patients. These findings suggest that bone health may be important in CSVD management, particularly for women.

Multi-Ancestry Transcriptome-Wide Association Studies of Cognitive Function, White Matter Hyperintensity, and Alzheimer's Disease

Genetic variants increase the risk of neurocognitive disorders in later life, including vascular dementia (VaD) and Alzheimer's disease (AD), but the precise relationships between genetic risk factors and underlying disease etiologies are not well understood. Transcriptome-wide association studies (TWASs) can be leveraged to better characterize the genes and biological pathways underlying genetic influences on disease. To date, almost all existing TWASs on VaD and AD have been conducted using expression studies from individuals of a single genetic ancestry, primarily European. Using the joint likelihood-based inference framework in Multi-ancEstry TRanscriptOme-wide analysis (METRO), we leveraged gene expression data from European ancestry (EA) and African ancestry (AA) samples to identify genes associated with general cognitive function, white matter hyperintensity (WMH), and AD. Regions were fine-mapped using Fine-mapping Of CaUsal gene Sets (FOCUS). We identified 266, 23, 69, and 2 genes associated with general cognitive function, WMH, AD (using EA GWAS summary statistics), and AD (using AA GWAS), respectively (Bonferroni-corrected alpha = p < 2.9 × 10-6), some of which had been previously identified. Enrichment analysis showed that many of the identified genes were in pathways related to innate immunity, vascular dysfunction, and neuroinflammation. Further, the downregulation of ICA1L was associated with a higher WMH and with AD, indicating its potential contribution to overlapping AD and VaD neuropathology. To our knowledge, our study is the first TWAS on cognitive function and neurocognitive disorders that used expression mapping studies for multiple ancestries. This work may expand the benefits of TWASs beyond a single ancestry group and help to identify gene targets for pharmaceuticals or preventative treatments for dementia.

The pathobiology of neurovascular aging

As global life expectancy increases, age-related brain diseases such as stroke and dementia have become leading causes of death and disability. The aging of the neurovasculature is a critical determinant of brain aging and disease risk. Neurovascular cells are particularly vulnerable to aging, which induces significant structural and functional changes in arterial, venous, and lymphatic vessels. Consequently, neurovascular aging impairs oxygen and glucose delivery to active brain regions, disrupts endothelial transport mechanisms essential for blood-brain exchange, compromises proteostasis by reducing the clearance of potentially toxic proteins, weakens immune surveillance and privilege, and deprives the brain of key growth factors required for repair and renewal. In this review, we examine the effects of neurovascular aging on brain function and its role in stroke, vascular cognitive impairment, and Alzheimer's disease. Finally, we discuss key unanswered questions that must be addressed to develop neurovascular strategies aimed at promoting healthy brain aging.

Combined targeting of TCF7L1/2, PTEN, CDK6, and BCCIP by microRNA miR-29c-3p is associated with reduced invasion and proliferation of endometriotic cells

Purpose

Endometriosis is a chronic gynecological disorder associated with pain symptoms and infertility. The expression of microRNA miR-29c-3p is dysregulated in endometriosis. We aimed to identify novel molecular targets of miR-29c-3p functionally linked to proliferation and invasive growth in endometriosis.

Methods

The epithelial endometriotic cell line 12Z and primary endometriotic stromal cells (PESC) were transfected with control miRNA or pre-miR-29c-3p, and subjected to cell cycle analysis, cell viability, wound healing, and Matrigel invasion assays. Expression of bioinformatically predicted miR-29c-3p targets was analyzed by qPCR and western blot. Target gene expression in endometriotic lesions and healthy endometrium was studied in the EndometDB endometriosis database.

Results

miR-29c-3p decreased 12Z and PESC cell viability and the proportion of PESC in the S-phase. 12Z cell invasion, but not migration, was decreased after miR-29c-3p upregulation. miR-29c-3p decreased the mRNA expression of CDK6, BCCIP, TCF7L1, TCF7L2, PTEN, COL4A1, E-Cadherin, and N-Cadherin. A decrease of CDK6 and PTEN and an increase of p21 were confirmed at the protein level. EndometDB database analysis demonstrated dysregulated expression of the selected targets in both deep endometriosis and ovarian endometriosis.

Conclusions

miR-29c-3p effectively curbs endometriotic cell proliferation and invasion by combined inhibition of cell cycle regulators and transcription factors, unveiling a promising therapeutic strategy.

Capillary basal lamina in human brain and spinal cord has fibrillar collagen type I and type III: Ignorance may not be bliss

The capillary basal lamina (BL) located between the endothelial cell, pericyte and perivascular astrocyte plays important roles in normal and diseased central nervous system (CNS). Using immunohistochemistry (IHC), electron microscopy (EM) and post-embedding immunogold EM (IEM), we studied capillary BL in biopsy and autopsy tissues of human CNS from cases with and without significant brain pathology and aged from 4 days to 49 years. In all cases, IHC showed, in the BL of microvessels, immunoreactivity for collagen types I, III, IV, VI and fibronectin. EM revealed fusion of the BL of capillary endothelial cells or pericyte with perivascular astrocyte BL, which was focally split, resulting in expanded spaces bordered by BL and containing striated fibrils. There was no significant thickening of fused or split BL. IEM showed localization of collagen I and III to banded fibrils, and of collagen IV to split and fused BL. These characteristic ultrastructural findings in human capillary BL were not found in normal or transgenic mice. Our observations of fibrillar collagen in young individuals complement previous observations of similar findings in older individuals. This raises the possibility that fibrillar collagen in human vascular BL plays a significant role in CNS capillary physiology and pathophysiology. The species-specific differences in capillary morphology between humans and mice might have relevance to poor correlations between benefits of immunotherapy and drug treatment in mice compared with human.

Application of collagen in bone regeneration

At present, there is a significant population of individuals experiencing bone deficiencies caused by injuries, ailments affecting the bones, congenital abnormalities, and cancer. The management of substantial bone defects a significant global orthopedic challenge due to the intricacies involved in promoting and restoring the growth of fresh osseous tissue. Autografts are widely regarded as the "gold standard" for repairing bone defects because of their superior tissue acceptance and ability to control osteogenesis. However, patients undergoing autografts may encounter various challenges, including but not limited to hernia, bleeding, nerve impairment, tissue death. Therefore, researchers in regenerative medicine are striving to find alternatives. Collagen is the most abundant protein in the human body, and its triple helix structure gives it unique characteristics that contribute to its strength and functionality in various tissues. Collagen is commonly processed into various forms such as scaffolds, sponges, membranes, hydrogels, and composite materials, due to its unique compatibility with the human body, affinity for water, minimal potential for immune reactions, adaptability, and ability to transport nutrients or drugs. As an alternative material in the field of bone regeneration, collagen is becoming increasingly important. The objective of this review is to provide a comprehensive analysis of the primary types and sources of collagen, their processes of synthesis and degradation, as well as the advancements made in bone regeneration research and its potential applications. A comprehensive investigation into the role of collagen in bone regeneration is undertaken, providing valuable points of reference for a more profound comprehension of collagen applications in this field. The concluding section provides a comprehensive overview of the prospective avenues for collagen research, underscoring their promising future and highlighting their significant potential in the field of bone regeneration. The Translational Potential of this Article. The comprehensive exploration into the diverse functions and translational potential of collagen in bone regeneration, as demonstrated in this review, these findings underscore their promising potential as a treatment option with significant clinical implications, thus paving the way for innovative and efficacious therapeutic strategies in this domain.

Single-cell transcriptomic analysis of glioblastoma reveals pericytes contributing to the blood-brain-tumor barrier and tumor progression

The blood-brain barrier is often altered in glioblastoma (GBM) creating a blood-brain-tumor barrier (BBTB) composed of pericytes. The BBTB affects chemotherapy efficacy. However, the expression signatures of BBTB-associated pericytes remain unclear. We aimed to identify BBTB-associated pericytes in single-cell RNA sequencing data of GBM using pericyte markers, a normal brain pericyte expression signature, and functional enrichment. We identified parathyroid hormone receptor-1 (PTH1R) as a potential marker of pericytes associated with BBTB function. These pericytes interact with other cells in GBM mainly through extracellular matrix-integrin signaling pathways. Compared with normal pericytes, pericytes in GBM exhibited upregulation of several ECM genes (including collagen IV and FN1), and high expression levels of these genes were associated with a poor prognosis. Cell line experiments showed that PTH1R knockdown in pericytes increased collagen IV and FN1 expression levels. In mice models, the expression levels of PTH1R, collagen IV, and FN1 were consistent with these trends. Evans Blue leakage and IgG detection in the brain tissue suggested a negative correlation between PTH1R expression levels and blood-brain barrier function. Further, a risk model based on differentially expressed genes in PTH1R+ pericytes had predictive value for GBM, as validated using independent and in-house cohorts.

Benzo(a)pyrene exposure impacts cerebrovascular development in zebrafish embryos and the antagonistic effect of berberine

Polycyclic aromatic hydrocarbons (PAHs) widely present in the environment, but their effect on cerebrovascular development has been rarely reported. In this study, dechorionated zebrafish embryos at 24 hpf were exposed to benzo(a)pyrene (BaP) at 0.5, 5 and 50 nM for 48 h, cerebrovascular density showed a significant reduction in the 5 and 50 nM groups. The expression of aryl hydrocarbon receptor (AhR) was significantly increased. Transcriptomic analysis showed that the pathway of positive regulation of vascular development was down-regulated and the pathway of inflammation response was up-regulated. The transcription of main genes related to vascular development, such as vegf, bmper, cdh5, f3b, itgb1 and prkd1, was down-regulated. Addition of AhR-specific inhibitor CH233191 in the 50 nM BaP group rescued cerebrovascular developmental defects and down-regulation of relative genes, suggesting that BaP-induced cerebrovascular defects was AhR-dependent. The cerebrovascular defects were persistent into adult fish raised in clean water, showing that the relative area of vascular network, the length of vessels per unit area and the number of vascular junctions per unit area were significantly decreased in the 50 nM group. Supplementation of berberine (BBR), a naturally derived medicine from a Chinese medicinal herb, alleviated BaP-induced cerebrovascular defects, accompanied by the restoration of altered expression of AhR and relative genes, which might be due to that BBR promoted BaP elimination via enhancing detoxification enzyme activities, suggesting that BBR could be a potential agent in the prevention of cerebrovascular developmental defects caused by PAHs.

Collagen IV deficiency causes hypertrophic remodeling and endothelium-dependent hyperpolarization in small vessel disease with intracerebral hemorrhage

BACKGROUND

Genetic variants in COL4A1 and COL4A2 (encoding collagen IV alpha chain 1/2) occur in genetic and sporadic forms of cerebral small vessel disease (CSVD), a leading cause of stroke, dementia and intracerebral haemorrhage (ICH). However, the molecular mechanisms of CSVD with ICH and COL4A1/COL4A2 variants remain obscure.

METHODS

Vascular function and molecular investigations in mice with a Col4a1 missense mutation and heterozygous Col4a2 knock-out mice were combined with analysis of human brain endothelial cells harboring COL4A1/COL4A2 mutations, and brain tissue of patients with sporadic CSVD with ICH.

FINDINGS

Col4a1 missense mutations cause early-onset CSVD independent of hypertension, with enhanced vasodilation of small arteries due to endothelial dysfunction, vascular wall thickening and reduced stiffness. Mechanistically, the early-onset dysregulated endothelium-dependent hyperpolarization (EDH) is due to reduced collagen IV levels with elevated activity and levels of endothelial Ca2+-sensitive K+ channels. This results in vasodilation via the Na/K pump in vascular smooth muscle cells. Our data support this endothelial dysfunction preceding development of CSVD-associated ICH is due to increased cytoplasmic Ca2+ levels in endothelial cells. Moreover, cerebral blood vessels of patients with sporadic CSVD show genotype-dependent mechanisms with wall thickening and lower collagen IV levels in those harboring common non-coding COL4A1/COL4A2 risk alleles.

INTERPRETATION

COL4A1/COL4A2 variants act in genetic and sporadic CSVD with ICH via dysregulated EDH, and altered vascular wall thickness and biomechanics due to lower collagen IV levels and/or mutant collagen IV secretion. These data highlight EDH and collagen IV levels as potential treatment targets.

FUNDING

MRC, Wellcome Trust, BHF.

Methylome analysis of endothelial cells suggests new insights on sporadic brain arteriovenous malformation

Arteriovenous malformation of the brain (bAVM) is a vascular phenotype related to brain defective angiogenesis. Involved vessels show impaired expression of vascular differentiation markers resulting in the arteriolar to venule direct shunt. In order to clarify aberrant gene expression occurring in bAVM, here we describe results obtained by methylome analysis performed on endothelial cells (ECs) isolated from bAVM specimens, compared to human cerebral microvascular ECs. Results were validated by quantitative methylation-specific PCR and quantitative realtime-PCR. Differential methylation events occur in genes already linked to bAVM onset, as RBPJ and KRAS. However, among differentially methylated genes, we identified EPHB1 and several other loci involved in EC adhesion as well as in EC/vascular smooth muscle cell (VSMC) crosstalk, suggesting that only endothelial dysfunction might not be sufficient to trigger the bAVM phenotype. Moreover, aberrant methylation pattern was reported for many lncRNA genes targeting transcription factors expressed during neurovascular development. Among these, the YBX1 that was recently shown to target the arteridin coding gene. Finally, in addition to the conventional CpG methylation, we further considered the role of impaired CHG methylation, mainly occurring in brain at embryo stage. We showed as differentially CHG methylated genes are clustered in pathways related to EC homeostasis, as well as to VSMC-EC crosstalk, suggesting as impairment of this interaction plays a prominent role in loss of vascular differentiation, in bAVM phenotype.

Correlation analysis between cerebral microangiopathy and autonomic nervous dysfunction

OBJECTIVE

Our study was conducted aimed at investigating the potential correlation between cerebral microangiopathy and autonomic nervous dysfunction.

METHODS

We initially included 164 hospitalized patients with cerebral microangiopathy at our hospital from November 2019 to January 2021. Based on the inclusion and exclusion criteria, a final total of 162 patients with cerebral microangiopathy were selected. According to the patient's Autonomic Symptom Profile (ASP) score, patients with a score greater than 22 were categorized into a group with concomitant autonomic dysfunction (71 cases, combined group), while those with a score below 22 were categorized into a group of isolated cerebral microangiopathy (83 cases, cerebral microangiopathy group). The general data and laboratory examination results of the two groups were analyzed, and Pearson correlation analysis was performed to evaluate the correlation between cerebral microangiopathy and autonomic dysfunction, as well as the influencing factors of cerebral microangiopathy patients combined with autonomic dysfunction.

RESULTS

There were no significant differences between the two groups in terms of sex, BMI, smoking, drinking, family dementia history, diabetes, hypothyroidism, carotid atherosclerosis, obstructive sleep apnea hypopnea syndrome, hyperuricemia, hyperlipidemia, chronic obstructive pulmonary disease, Hamilton Anxiety Scale score, Hamilton Depression Scale score, 24-h mean systolic blood pressure (SBP), 24-h mean diastolic blood pressure DBP, daytime mean systolic blood pressure (dSBP), daytime mean diastolic blood pressure, nighttime mean systolic blood pressure (nSBP), nighttime mean diastolic blood pressure, 24-h systolic blood pressure standard deviation (SBPSD), 24-h diastolic blood pressure standard deviation, daytime diastolic blood pressure standard deviation, nighttime diastolic blood pressure standard deviation (nDBPSD), nDBPSD (p > .05). However, significant differences were observed between the two groups regarding age, history of coronary heart disease, hypertension, leukoaraiosis, cognitive function, ASP score, SSR, 24-h SBPSD, daytime systolic blood pressure standard deviation (dSBPSD), nighttime systolic blood pressure standard deviation (nSBPSD), standard deviation of RR interval (SDNN), root mean square value of successive RR interval difference (RMSSD), high-frequency component (HF), and low-frequency component (LF) (p < .05). Moreover, the levels of TG, TC, HDL-C, and LDL-C did not show significant differences between the two groups (p > .05), but there were significant differences in blood uric acid and homocysteine (Hcy) levels (p < .05). Age, history of leukoaraiosis, cognitive function assessment, blood uric acid, Hcy levels, 24-h SBPSD, dSBPSD, and nSBPSD showed positive correlations with ASP scores and SSR in patients with cerebral microangiopathy (p < .001). In contrast, hypertension, SDNN, RMSSD, HF, and LF showed negative correlations with ASP scores and SSR (p < .001). Moreover, coronary heart disease was negatively correlated with ASP scores but positively correlated with SSR (p < .001). The independent variables included age, history of leukoaraiosis, cognitive function assessment, ASP score, SSR, blood uric acid, Hcy, bradykinin, coronary heart disease, hypertension, 24-h SBPSD, dSBPSD, nSBPSD, SDNN, RMSSD, HF, and LF, which were indicators with differences in general data and laboratory indicators. The dependent variable was patients with cerebral microangiopathy combined with autonomic nervous dysfunction. The analysis results showed that age, history of leukoaraiosis, ASP score, SSR, 24-h SBPSD, dSBPSD, nSBPSD, SDNN, RMSSD, HF, and LF were the influencing factors of patients with cerebral microangiopathy complicated with autonomic nervous dysfunction.

CONCLUSION

We demonstrates that age, history of leukoaraiosis, cognitive function assessment, blood uric acid, Hcy level, 24-h SBPSD, dSBPSD, nSBPSD, blood pressure, SDNN, RMSSD, HF, LF, and coronary heart disease were highly associated with cerebral microangiopathy with autonomic dysfunction. Furthermore, the influencing factors of cerebral microangiopathy with autonomic dysfunction are age, history of leukoaraiosis, ASP score, SSR, blood pressure variability, and HRV.

Cerebral Small Vessel Disease, Hypertension, and Vascular Contributions to Cognitive Impairment and Dementia

Hypertension-associated cerebral small vessel disease is a common finding in older people. Strongly associated with age and hypertension, small vessel disease is found at autopsy in over 50% of people aged ≥65 years, with a spectrum of clinical manifestations. It is the main cause of lacunar stroke and a major source of vascular contributions to cognitive impairment and dementia. The brain areas affected are subcortical and periventricular white matter and deep gray nuclei. Neuropathological sequelae are diffuse white matter lesions (seen as white matter hyperintensities on T2-weighted magnetic resonance imaging), small ischemic foci (lacunes or microinfarcts), and less commonly, subcortical microhemorrhages. The most common form of cerebral small vessel disease is concentric, fibrotic thickening of small penetrating arteries (up to 300 microns outer diameter) termed arteriolosclerosis. Less common forms are small artery atheroma and lipohyalinosis (the lesions described by C. Miller Fisher adjacent to lacunes). Other microvascular lesions that are not reviewed here include cerebral amyloid angiopathy and venous collagenosis. Here, we review the epidemiology, neuropathology, clinical management, genetics, preclinical models, and pathogenesis of hypertensive small vessel disease. Knowledge gaps include initiating factors, molecular pathogenesis, relationships between arterial pathology and tissue damage, possible reversibility, pharmacological targets, and molecular biomarkers. Progress is anticipated from multicell transcriptomic and proteomic profiling, novel experimental models and further target-finding and interventional clinical studies.

Intratracheally Administered Peptide-Modified Lipid Admixture Containing Fasudil and/or DETA NONOate Ameliorates Various Pathologies of Pulmonary Arterial Hypertension

This study examined the therapeutic potential of a combination therapy using fasudil, a Rho-kinase inhibitor, and DETA NONOate (DN), a nitric oxide donor, delivered as a lipid admixture modified with a cyclic homing peptide known as CAR (CAR-lipid mixture) for the treatment of pulmonary arterial hypertension (PAH). CAR-lipid mixtures were initially prepared via a thin-film hydration method and then combined with fasudil, DN, or a mixture of both. The therapeutic efficacy of this drug-laden lipid mixture was evaluated in a Sugen/Hypoxia (Su/Hx) rat model of PAH by measuring RV systolic pressure (RVSP), mean pulmonary arterial pressure (mPAP), Fulton indices, and assessing right ventricular (RV) functions, as well as evaluating pulmonary vascular morphology. Rats that received no treatment exhibited increases in RVSP, mPAP, Fulton indices, and changes in RV functional parameters. However, the treatment with the CAR-lipid mixture containing either fasudil or DN or a combination of both led to a decline in mPAP, RVSP, and Fulton indices compared to saline-treated rats. Similarly, rats that received these treatments showed concurrent improvement in various echocardiographic parameters such as pulmonary acceleration time (PAT), tricuspid annular plane systolic excursion (TAPSE), and ventricular free wall thickness (RVFWT). A significant decrease in the wall thickness of pulmonary arteries larger than 100 µm was observed with the combination therapy. The findings reveal that fasudil, DN, and their combination in a CAR-modified lipid mixture improved pulmonary hemodynamics, RV functions, and pathological alterations in the pulmonary vasculature. This study underscores the potential of combination therapy and targeted drug delivery in PAH treatment, laying the groundwork for future investigations into the optimization of these treatments, their long-term safety and efficacy, and the underlying mechanism of action of the proposed therapy.

Progressive mechanical and structural changes in anterior cerebral arteries with Alzheimer's disease

Alzheimer's disease (AD) is a neurodegenerative disease and the main cause for dementia. The irreversible neurodegeneration leads to a gradual loss of brain function characterized predominantly by memory loss. Cerebrovascular changes are common neuropathologic findings in aged subjects with dementia. Cerebrovascular integrity is critical for proper metabolism and perfusion of the brain, as cerebrovascular remodeling may render the brain more susceptible to pulse pressure and may be associated with poorer cognitive performance and greater risk of cerebrovascular events. The objective of this study is to provide understanding of cerebrovascular remodeling with AD progression. Anterior cerebral arteries (ACAs) from a total of 19 brain donor participants from controls and pathologically diagnosed AD groups (early-Braak stages I-II; intermediate-Braak stages III-IV; and advanced-Braak stages V-VI) were included in this study. Mechanical testing, histology, advanced optical imaging, and mass spectrometry were performed to study the progressive structural and functional changes of ACAs with AD progression. Biaxial extension-inflation tests showed that ACAs became progressively less compliant, and the longitudinal stress in the intermediate and advanced AD groups was significantly higher than that from the control group. With pathological AD development, the inner and outer diameters of the ACAs remained almost unchanged; however, histology study revealed progressive smooth muscle cell atrophy and loss of elastic fibers which led to compromised structural integrity of the arterial wall. Multiphoton imaging demonstrated elastin degradation at the media-adventitia interface, which led to the formation of an empty band of 21.0 ± 15.4 μm and 32.8 ± 9.24 μm in width for the intermediate and advanced AD groups, respectively. Furthermore, quantitative birefringence microscopy showed disorganized adventitial collagen with AD development. Mass spectrometry analysis provided further evidence of altered collagen content and other extracellular matrix (ECM) molecule and smooth muscle cell changes that were consistent with the mechanical and structural alterations. Collectively, our study provides understanding of the mechanical and structural cerebrovascular deterioration in cerebral arteries with AD, which may be related to neurodegenration and pathology in the brain.

Progressive Mechanical and Structural Changes in Anterior Cerebral Arteries with Alzheimer's Disease

Alzheimer disease (AD) is a neurodegenerative disease and the main cause for dementia. The irreversible neurodegeneration leads to a gradual loss of brain function characterized predominantly by memory loss. Cerebrovascular changes are common neuropathologic findings in aged subjects with dementia. Cerebrovascular integrity is critical for proper metabolism and perfusion of the brain, as cerebrovascular remodeling may render the brain more susceptible to pulse pressure and may be associated with poorer cognitive performance and greater risk of cerebrovascular events. The objective of this study is to provide understanding of cerebrovascular remodeling with AD progression. A total of 28 brain donor participants with human anterior cerebral artery (ACA) from controls and pathologically diagnosed AD groups (early - Braak stages I-II; intermediate - Braak stages III-IV; and advanced - Braak stages V-VI) were included in this study. Mechanical testing, histology, advanced optical imaging, and mass spectrometry were performed to study the progressive structural and functional changes of ACAs with AD progression. Biaxial extension-inflation tests showed that ACAs became progressively less compliant, and the longitudinal stress in the intermediate& advanced AD groups was significantly higher than that from the control group. With pathological AD development, the inner and outer diameter of ACA remained almost unchanged; however, histology study revealed progressive smooth muscle cell atrophy and loss of elastic fibers which led to compromised structural integrity of the arterial wall. Multiphoton imaging demonstrated elastin degradation at the media-adventitia interface, which led to the formation of an empty band of 21.0 ± 15.4 μm and 32.8 ± 9.24 μm in width for the intermediate& advanced AD groups, respectively. Furthermore, quantitative birefringence microscopy showed disorganized adventitial collagen with AD development. Mass spectrometry analysis provided further evidence of altered collagen content and other extracellular matrix (ECM) molecule and smooth muscle cell changes that were consistent with the mechanical and structural alterations. Collectively, our study provides understanding of the mechanical and structural cerebrovascular deterioration in cerebral arteries with AD, which may be related to neurodegenration and pathology in the brain.

ER stress induced immunopathology involving complement in CADASIL: implications for therapeutics

Cerebral autosomal-dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL) is caused by NOTCH3 mutations. Typical CADASIL is characterised by subcortical ischemic strokes due to severe arteriopathy and fibrotic thickening of small arteries. Arteriolar vascular smooth muscle cells (VSMCs) are the key target in CADASIL, but the potential mechanisms involved in their degeneration are still unclear. Focusing on cerebral microvessels in the frontal and anterior temporal lobes and the basal ganglia, we used advanced proteomic and immunohistochemical methods to explore the extent of inflammatory and immune responses in CADASIL subjects compared to similar age normal and other disease controls. There was variable loss of VSMC in medial layers of arteries in white matter as well as the cortex, that could not be distinguished whether NOTCH3 mutations were in the epidermal growth factor (EGFr) domains 1-6 or EGFr7-34. Proteomics of isolated cerebral microvessels showed alterations in several proteins, many associated with endoplasmic reticulum (ER) stress including heat shock proteins. Cerebral vessels with sparsely populated VSMCs also attracted robust accrual of perivascular microglia/macrophages in order CD45+ > CD163+ > CD68+cells, with > 60% of vessel walls exhibiting intercellular adhesion molecule-1 (ICAM-1) immunoreactivity. Functional VSMC cultures bearing the NOTCH3 Arg133Cys mutation showed increased gene expression of the pro-inflammatory cytokine interleukin 6 and ICAM-1 by 16- and 50-fold, respectively. We further found evidence for activation of the alternative pathway of complement. Immunolocalisation of complement Factor B, C3d and C5-9 terminal complex but not C1q was apparent in ~ 70% of cerebral vessels. Increased complement expression was corroborated in > 70% of cultured VSMCs bearing the Arg133Cys mutation independent of N3ECD immunoreactivity. Our observations suggest that ER stress and other cellular features associated with arteriolar VSMC damage instigate robust localized inflammatory and immune responses in CADASIL. Our study has important implications for immunomodulation approaches to counter the characteristic arteriopathy of CADASIL.

Implication of heart rate variability on cerebral small vessel disease: A potential therapeutic target

OBJECTIVE

This study aimed to investigate the relationships of heart rate variability (HRV) with the presence, severity, and individual neuroimaging markers of cerebral small vessel disease (CSVD).

METHOD

A total of 4676 participants from the Third China National Stroke Registry (CNSR-III) study were included in this cross-sectional analysis. CSVD and its markers, including white matter hyperintensity (WMH), lacunes, enlarged perivascular spaces (EPVS), cerebral microbleeds (CMBs), and brain atrophy (BA), were evaluated. Two common HRV parameters, including the square root of the mean of the sum of the squares of differences between adjacent N-N intervals (RMSSD) and the standard deviation of all N-N intervals (SDNN), were used to evaluate the function of the autonomic nervous system (ANS). Binary or ordinal logistic regression analyses were performed to investigate the association between HRV and CSVD. In addition, two-sample mendelian randomization (MR) analyses were performed to investigate the causality of HRV with CSVD.

RESULTS

RMSSD was significantly associated with total burden of CSVD (Wardlaw's scale, common odds ratio [cOR] 0.80, 95% confidence interval [CI] 0.67-0.96, p = 0.02; Rothwell's scale, cOR 0.75, 95% CI 0.60-0.93, p = 0.008) and the presence of CSVD (Rothwell, OR 0.75, 95% CI 0.60-0.93, p = 0.008). However, no significant associations between SDNN and the presence or total burden of CSVD were observed. Moreover, RMSSD was related to WMH burden (OR 0.80, 95% CI 0.66-0.96, p = 0.02), modified WMH burden (cOR 0.82, 95% CI 0.69-0.97, p = 0.02), and Deep-WMH (OR 0.75, 95% CI 0.62-0.91, p = 0.003), while SDNN was related to Deep-WMH (OR 0.80, 95% CI 0.66-0.96, p = 0.02) and BA (cOR 0.80, 95% CI 0.68-0.95, p = 0.009). Furthermore, adding HRV to the conventional model based on vascualr risk factors enhanced the predictive performance for CSVD, as validated by the integrated discrimination index (p < 0.05). In addition, no causality between HRV and CSVD was observed in two-sample MR analyses.

CONCLUSION

Decreased HRV may be a potential risk factor of CSVD, implying the possible role of the ANS in the pathogenesis of CSVD.