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

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.

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.