Endothelin-1 mediated vasoconstriction leads to memory impairment and synaptic dysfunction

Development of therapeutic supplement using roasted-cashew-nut to protect cerebral vasoconstriction injury triggered by mixture of petroleum hydrocarbons in the hypothalamus and hippocampus of rat model

Petroleum-related activities have been a health global risk concern, particularly in the limbic disorders. The study aims to investigate the neuroprotection of roasted cashew nuts (RCN) on brain vasoconstriction injury induced by a mixture of petroleum hydrocarbons (MFPP). Seventy Male Wistar rats ranging 160 ± 10 g were randomized into seven groups. Group I was given distilled water. Group II was exposed to 0.2 ml MFPP. Group III, IV and V were exposed to 0.2 ml MFPP followed by treatment with 50 mg/kg atenolol, 10 % RCN and 20 % RCN, respectively. Group VI and VII were treated with 10 % RCN and 20 % RCN, respectively. The regimen period was 28 days. Cell pathological evaluation was done using hematoxylin and eosin staining and visualized under the microscope. Biochemical and molecular markers of brain vasoconstriction injury (BVI) were evaluated using spectrophotometer and RT-PCR analyzer, respectively. Student-T-test and one-way analysis of variance (ANOVA) were used to analyze the results. Sub-chronic exposure to MFPP induced BVI as evident in neuroinflammation and derangements in the histology of the hippocampus and hypothalamus coupled with momentous alterations in the neurons. Post treatment with RCN supplement remarkably modulated the effects by depleting the inflammatory mediators including HIF-1, p53 and MCP-1. Also, adenosinergic, purigenic and cholinergic of the hypothalamus and hippocampus were normalized by the supplement. It is pertinent to conclude that treatment with RCN inhibited BVI in rats via the NO-cAMP-PKA signaling pathway by reversing neuroinflammation, normalizing the purinergic and cholinergic neurotransmission in the hypothalamus and hippocampus, and stabilizing NO level coupled with brain histology improvement.

Antithrombotic macrocyclic sesquiterpene pyridine alkaloids from Tripterygium hypoglaucum

Six previously undescribed macrocyclic sesquiterpene pyridine alkaloids (SPAs) derivatives, named triptocumines A-F (1-6), as well as eighteen known analogs, were isolated from Tripterygium hypoglaucum. The structures were assigned based on analysis of spectroscopic data and electron circular dichroism calculations. Furthermore, compounds 1-6, 8, and 24 could effectively inhibit adenosine diphosphate-induced platelet aggregation, alleviate thrombosis and oxidative stress in zebrafish, reduce endothelin-1 level, protect endothelial cells from oxidative damage, and promote the formation of lumen structure.

Insight into cerebral microvessel endothelial regulation of cognitive impairment: A systematic review of the causes and consequences

Research on cognitive impairment (CI) has increasingly focused on the central nervous system, identifying numerous neuronal targets and circuits of relevance for CI pathogenesis and treatment. Brain microvascular endothelial cells (BMECs) form a barrier between the peripheral and central nervous systems, constituting the primary component of the blood-brain barrier (BBB) and playing a vital role in maintaining neural homeostasis. Stemming from the recognition of the close link between vascular dysfunction and CI, in recent years intense research has been devoted to characterize the pathological changes and molecular mechanisms underlying BMEC dysfunction both during normal aging and in disorders of cognition such as Alzheimer's disease and vascular dementia. In this review, keywords such as "dementia", "cognitive impairment", and "endothelium" were used to search PubMed and Web of Science. Based on the literature thus retrieved, we first review some common triggers of CI, i.e., amyloid beta and tau deposition, chronic cerebral hypoperfusion, hyperglycemia, viral infections, and neuroinflammation, and describe the specific mechanisms responsible for endothelial damage. Second, we review molecular aspects of endothelial damage leading to BBB disruption, neuronal injury, and myelin degeneration, which are crucial events underlying CI. Finally, we summarize the potential targets of endothelial damage in the development of cognitive dysfunction associated with Alzheimer's disease, vascular dementia, type 2 diabetes mellitus, and physiological aging. A thorough understanding of the induction mechanism and potential outcomes of microvascular endothelial damage is of great significance for the study of CI, to guide both diagnostic and therapeutic approaches for its prevention and treatment.

Recurrent endothelin-1 mediated vascular insult leads to cognitive impairment protected by trophic factor pleiotrophin

Vascular dementia (VaD) is a complex neurodegenerative condition, with cerebral small vessel dysfunctions as the central role in its pathogenesis. Given the lack of suitable animal models to study the disease pathogenesis, we developed a mouse model to closely emulate the clinical scenarios of recurrent transient ischemic attacks (TIAs) leading to VaD using vasoconstricting peptide Endothelin-1(ET-1). We observed that administration of ET-1 led to blood-brain barrier (BBB) disruption and detrimental changes in its components, such as endothelial cells and pericytes, along with neuronal loss and synaptic dysfunction, resulting in irreversible memory loss. Further, in our pursuit of understanding potential interventions, we co-administered pleiotrophin (PTN) alongside ET-1 injections. PTN exhibited remarkable efficacy in preserving vital components of the BBB, including endothelial cells and pericytes, thereby restoring BBB integrity, preventing neuronal loss, and enhancing memory function. Our findings give a valuable framework for understanding the detrimental effects of multiple TIAs on brain health and provide a useful animal model to explore VaD's underlying mechanisms further and pave the way for promising therapies.

Stroke studies in large animals: Prospects of mitochondrial transplantation and enhancing efficiency using hydrogels and nanoparticle-assisted delivery

One of the most frequent reasons for mortality and disability today is acute ischemic stroke, which occurs by an abrupt disruption of cerebral circulation. The intricate damage mechanism involves several factors, such as inflammatory response, disturbance of ion balance, loss of energy production, excessive reactive oxygen species and glutamate release, and finally, neuronal death. Stroke research is now carried out using several experimental models and potential therapeutics. Furthermore, studies are being conducted to address the shortcomings of clinical care. A great deal of research is being done on novel pharmacological drugs, mitochondria targeting compounds, and different approaches including brain cooling and new technologies. Still, there are many unanswered questions about disease modeling and treatment strategies. Before these new approaches may be used in therapeutic settings, they must first be tested on large animals, as most of them have been done on rodents. However, there are several limitations to large animal stroke models used for research. In this review, the damage mechanisms in acute ischemic stroke and experimental acute ischemic stroke models are addressed. The current treatment approaches and promising experimental methods such as mitochondrial transplantation, hydrogel-based interventions, and strategies like mitochondria encapsulation and chemical modification, are also examined in this work.

Neuropsychological aspects of reversible cerebral vasoconstriction syndrome

Despite the increasing knowledge in the past years, only minimal attention has been directed to the neuropsychological aspects and the prevalence of cognitive impairment associated with reversible cerebral vasoconstriction syndrome (RCVS).

Objective

To describe the frequency and expand the understanding of cognitive dysfunction in RCVS.

Methods

The neuropsychological evaluation was performed using a battery consisting of specific neuropsychological instruments that were administered to patients diagnosed with RCVS. A triage was conducted to exclude other potential causes of cognitive impairment. Performance on the tests was treated as a categorical variable, and a cutoff of -1.5 Z-score was adopted to indicate impaired performance.

Results

Seven patients diagnosed with RCVS were evaluated, all of whom had a bachelor's degree and normal score in the Mini-Mental State Examination. The average time between diagnosis and neuropsychological evaluation was 1.8 years. Among the patients, 85.6% (n=6) exhibited performance below that of the normal population in at least two of the administered tests. Specifically, 71.4% (n=5) showed alterations in tests from the Psychological Battery for Attention Assessment, with impairment observed in concentrated (n=1), divided (n=3), or alternating (n=4) attention. Furthermore, 28.6% (n=2) demonstrated impairments in the Phonological Verbal Fluency Task, another 28.6% (n=2) exhibited difficulties copying elements of the Rey Complex Figure, and 14.3% (n=1) displayed lower performance in the Five-Digit test, all indicating executive dysfunction.

Conclusion

This study provides evidence that cognitive impairment associated with RCVS is more prevalent than previously believed and has not received sufficient attention. Specifically, attention and executive functions are the cognitive domains most significantly impacted by RCVS.

Aspirin Caused Intestinal Damage through FXR and ET-1 Signaling Pathways

Aspirin is a non-steroidal, anti-inflammatory drug often used long term. However, long-term or large doses will cause gastrointestinal adverse reactions. To explore the mechanism of intestinal damage, we used non-targeted metabolomics; farnesoid X receptor (FXR) knockout mice, which were compared with wild-type mice; FXR agonists obeticholic acid (OCA) and chenodeoxycholic acid (CDCA); and endothelin-producing inhibitor estradiol to explore the mechanisms of acute and chronic intestinal injuries induced by aspirin from the perspective of molecular biology. Changes were found in the bile acids taurocholate acid (TCA) and tauro-β-muricholic acid (T-β-MCA) in the duodenum, and we detected a significant inhibition of FXR target genes. After additional administration of the FXR agonists OCA and CDCA, duodenal villus damage and inflammation were effectively improved. The results in the FXR knockout mice and wild-type mice showed that the overexpression of endothelin 1 (ET-1) was independent of FXR regulation after aspirin exposure, whereas CDCA was able to restore the activation of ET-1, which was induced by aspirin in wild-type mice in an FXR-dependent manner. The inhibition of ET-1 production could also effectively protect against small bowel damage. Therefore, the study revealed the key roles of the FXR and ET-1 pathways in acute and chronic aspirin-induced intestinal injuries, as well as strategies on alleviating aspirin-induced gastrointestinal injury by activating FXR and inhibiting ET-1 overexpression.

Neurovascular glial unit: A target of phytotherapy for cognitive impairments

BACKGROUND

Neurovascular glial unit (NVGU) dysfunction has been reported to be an early and critical event in the pathophysiology of Alzheimer's disease (AD) and vascular dementia (VD). Although herbal medicines, with their favorable safety profiles and low adverse effects, have been suggested to be useful for the treatment of cognitive impairment, the potential role of the NVGU as the target of the effects of herbal medicines is still unclear.

PURPOSE

This review aimed to retrieve evidence from experimental studies of phytopharmaceuticals targeting the NVGU for the treatment of cognitive impairment in AD and VD, and discussed the potential of phytopharmaceuticals to improve cognitive impairment from the perspective of the NVGU.

STUDY DESIGN AND METHODS

We systematically searched PubMed, Google Scholar, Web of Science, and CNKI. The keywords used for searching information on the NVGU in the treatment of cognitive impairments included "Alzheimer's disease," "Vascular dementia," "Herbal medicines," "Natural products," "Neurovascular," "Adverse reaction," and "Toxicity, etc." We selected studies on the basis of predefined eligibility criteria.

RESULTS

NVGU mainly consists of endothelial cells, pericytes, astrocytes, microglia, oligodendrocytes, and neurons, and damage to these cells can induce cognitive impairment by impairing the blood-brain barrier (BBB) and cerebral blood flow (CBF) as well as neuronal function. The active components of herbal medicines, including Ginkgo biloba L., Ginseng Radix et Rhizoma, Epimedium Folium, Chuanxiong Rhizoma, Carthami flos, and Acorus tatarinowii Schott, as well as traditional Chinese medicine prescriptions have shown the potential to improve BBB function and increase CBF to prevent cognitive impairment by inhibiting astrocyte and microglia activation, protecting oligodendrocyte myelin function, reducing neuronal apoptosis, and promoting angiogenesis.

CONCLUSIONS

Herbal medicines demonstrate great potential to prevent cognitive impairment. Multiple components from herbal medicines may function through different signaling pathways to target the NVGU. Future studies using novel drug-carrier or delivery systems targeting the NVGU will certainly facilitate the development of phytopharmaceuticals for AD and VD.

A Scoping Review on Biomarkers of Endothelial Dysfunction in Small Vessel Disease: Molecular Insights from Human Studies

Small vessel disease (SVD) is a highly prevalent disorder of the brain's microvessels and a common cause of dementia as well as ischaemic and haemorrhagic strokes. Though much about the underlying pathophysiology of SVD remains poorly understood, a wealth of recently published evidence strongly suggests a key role of microvessel endothelial dysfunction and a compromised blood-brain barrier (BBB) in the development and progression of the disease. Understanding the causes and downstream consequences associated with endothelial dysfunction in this pathological context could aid in the development of effective diagnostic and prognostic tools and provide promising avenues for potential therapeutic interventions. In this scoping review, we aim to summarise the findings from clinical studies examining the role of the molecular mechanisms underlying endothelial dysfunction in SVD, focussing on biochemical markers of endothelial dysfunction detectable in biofluids, including cell adhesion molecules, BBB transporters, cytokines/chemokines, inflammatory markers, coagulation factors, growth factors, and markers involved in the nitric oxide cascade.

A clinical randomized controlled trial: moxibustion at Laogong interval with Panax notoginseng promoted the maturation of arteriovenous fistulae

BACKGROUND

We aim to study the clinical effect of moxibustion at Laogong interval with Panax notoginseng on the short-term maturation and long-term patency of arteriovenous fistula.

METHODS

Seventy-four pre-dialysis uremic patients who received distal forearm radial-cephalic fistula creations were enrolled in this study and randomly assigned to the control group and experimental group. After arteriovenous fistula creations, the control group underwent handgrip exercise, and the experimental group received moxibustion at Laogong acupoint interval with Panax notoginseng. Both groups received a 12-week treatment and were followed up for 24 weeks in all at the following time points: before creations and 2, 4, 8, 12, 24 weeks after creations. The diameter of anastomosis, the diameter and outflow of draining-veins 5 cm above anastomosis, the diameter and outflow of brachial arteries evaluated the maturation and patency of arteriovenous fistula. Enzyme linked immunosorbent assay determined serum levels of endothelin and nitric oxide.

RESULTS

The maturity rate in the experimental group was significantly higher than that in the control group at 4 weeks after arteriovenous fistula creations (P = 0.048). The diameter of anastomosis, the diameter of draining veins, and the blood flow of draining veins increased in both groups during the whole 24 weeks. The diameter and blood flow of brachial arteries ascended in both groups during the previous 12 weeks. Compared with the control group, moxibustion at Laogong interval with Panax notoginseng significantly improved the value of the diameter of draining-veins (P = 0.016), the blood flow of draining-veins (P = 0.015), the diameter of brachial arteries (P < 0.001), and the blood flow of brachial arteries (P = 0. 012) at 2 weeks, and enhanced the blood flow of draining-veins (P = 0.029) and brachial arteries (P < 0.001) at 12 weeks. Serum levels of endothelin were significantly lower (P = 0.047), and serum levels of nitric oxide were markedly higher (P < 0.001) in the experimental group than that in the control group at 2 weeks after creations.

CONCLUSIONS

Moxibustion at Laogong interval with Panax notoginseng was non-invasive and promoted the maturation of arteriovenous fistula at 4 weeks after creations. However, its long-term beneficial effect on patency at 24 weeks after creations was not significant. Trial registration Chinese Clinical Trial Registry, No. ChiCTR1900024042. Registered, http://www.chictr.org.cn/index.aspx.

Vasoactive neuropeptides and Alzheimer's disease: a systematic review focusing on calcitonin gene-related peptide

Vasoactive peptides constitute a heterogenous family of mediators exerting various physiological functions, mostly studied for their vasotropic effects and role as peripheral neurotransmitters/neuromodulators, mainly involved in nociceptive transmission modulation. They have been divided into vasodilatory or vasoconstrictive peptides, according to their predominant effects on vascular tone. Recent research has shown in the Central Nervous System effects as transmitters and "growth factor-like" signals. Therefore, deregulation of their signaling systems has been thought to play a role in neural cell death and in the pathogenesis of neurodegenerative disorders, including Alzheimer's disease, since these peptides can regulate neuronal stress signaling, survival cascades, synaptic plasticity. This review considers evidence about the implication of neuropeptide systems in Alzheimer's disease while focusing mainly on calcitonin gene-related peptide-alpha. In vitro and in vivo studies have shown potential implications in its pathogenesis. It has been possibly proposed as a neuroprotective agent, considering not only its pleiotropic actions on blood vessels, neurovascular coupling, energy metabolism, but also its potential actions on neuronal, glial, and immune system stress signaling, which might also derive from its structural homology to amylin. Amylin signaling is thought to be disrupted in Alzheimer's disease, and amylin itself takes part in the composition of senile plaques. Calcitonin gene-related peptide-containing systems seem more closely related to Alzheimer's disease pathogenesis than other neuropeptidergic systems, and their regulation might represent an interesting mechanism in developing novel therapeutic approaches.

PTSD as an Endothelial Disease: Insights From COVID-19

SARS-CoV-2 virus, the etiologic agent of COVID-19, has affected almost every aspect of human life, precipitating stress-related pathology in vulnerable individuals. As the prevalence rate of posttraumatic stress disorder in pandemic survivors exceeds that of the general and special populations, the virus may predispose to this disorder by directly interfering with the stress-processing pathways. The SARS-CoV-2 interactome has identified several antigens that may disrupt the blood-brain-barrier by inducing premature senescence in many cell types, including the cerebral endothelial cells. This enables the stress molecules, including angiotensin II, endothelin-1 and plasminogen activator inhibitor 1, to aberrantly activate the amygdala, hippocampus, and medial prefrontal cortex, increasing the vulnerability to stress related disorders. This is supported by observing the beneficial effects of angiotensin receptor blockers and angiotensin converting enzyme inhibitors in both posttraumatic stress disorder and SARS-CoV-2 critical illness. In this narrative review, we take a closer look at the virus-host dialog and its impact on the renin-angiotensin system, mitochondrial fitness, and brain-derived neurotrophic factor. We discuss the role of furin cleaving site, the fibrinolytic system, and Sigma-1 receptor in the pathogenesis of psychological trauma. In other words, learning from the virus, clarify the molecular underpinnings of stress related disorders, and design better therapies for these conditions. In this context, we emphasize new potential treatments, including furin and bromodomains inhibitors.