Bioinspired therapeutic platform based on extracellular vesicles for prevention of arterial wall remodeling in hypertension

Supplementation of Clostridium butyricum Alleviates Vascular Inflammation in Diabetic Mice

BACKGRUOUND

Gut microbiota is closely related to the occurrence and development of diabetes and affects the prognosis of diabetic complications, and the underlying mechanisms are only partially understood. We aimed to explore the possible link between the gut microbiota and vascular inflammation of diabetic mice.

METHODS

The db/db diabetic and wild-type (WT) mice were used in this study. We profiled gut microbiota and examined the and vascular function in both db/db group and WT group. Gut microbiota was analyzed by 16s rRNA sequencing. Vascular function was examined by ultrasonographic hemodynamics and histological staining. Clostridium butyricum (CB) was orally administered to diabetic mice by intragastric gavage every 2 days for 2 consecutive months. Reactive oxygen species (ROS) and expression of nuclear factor erythroid-derived 2-related factor 2 (Nrf2) and heme oxygenase-1 (HO-1) were detected by fluorescence microscopy. The mRNA expression of inflammatory cytokines was tested by quantitative polymerase chain reaction.

RESULTS

Compared with WT mice, CB abundance was significantly decreased in the gut of db/db mice, together with compromised vascular function and activated inflammation in the arterial tissue. Meanwhile, ROS in the vascular tissue of db/db mice was also significantly increased. Oral administration of CB restored the protective microbiota, and protected the vascular function in the db/db mice via activating the Nrf2/HO-1 pathway.

CONCLUSION

This study identified the potential link between decreased CB abundance in gut microbiota and vascular inflammation in diabetes. Therapeutic delivery of CB by gut transplantation alleviates the vascular lesions of diabetes mellitus by activating the Nrf2/HO-1 pathway.

Insight into extracellular vesicles in vascular diseases: intercellular communication role and clinical application potential

BACKGROUND

Cells have been increasingly known to release extracellular vesicles (EVs) to the extracellular environment under physiological and pathological conditions. A plethora of studies have revealed that EVs contain cell-derived biomolecules and are found in circulation, thereby implicating them in molecular trafficking between cells. Furthermore, EVs have an effect on physiological function and disease development and serve as disease biomarkers.

MAIN BODY

Given the close association  between EV circulation and vascular disease, this review aims to provide a brief introduction to EVs, with a specific focus on the EV cargoes participating in pathological mechanisms, diagnosis, engineering, and clinical potential, to highlight the emerging evidence suggesting promising targets in vascular diseases. Despite the expansion of research in this field, some noticeable limitations remain for clinical translational research.

CONCLUSION

This review makes a novel contribution to a summary of recent advances and a perspective on the future of EVs in vascular diseases. Video Abstract.

Targeted elimination of senescent cells by engineered extracellular vesicles attenuates atherosclerosis in ApoE-/- mice with minimal side effects

Senescent cells in plaques emerge as a detrimental factor for atherosclerosis (AS), for which targeted senolysis might be a promising therapeutic strategy. The development of safe and efficient senolytics for senescent cell eradication by targeted delivery is greatly needed. Methods: Pro-apoptotic intelligent Bax (iBax)-overexpressing plasmid was constructed by molecular cloning, in which Bax CDS was fused to miR-122 recognition sites. Extracellular vesicle-based senolytics (EViTx) were developed to be conjugated with magnetic nanoparticles on the surface, iBax mRNA encapsulated inside, and BAX activator BTSA1 incorporated into the membrane. EViTx was characterized, and in vivo distribution was tracked via fluorescence imaging. The therapeutic effects of EViTx on AS and its systemic side effects were analyzed in ApoE-/- mice. Results: Magnetic nanoparticles, iBax mRNA and BAX activator BTSA1 were efficiently loaded into/onto EViTx. With external magnetic field navigation, EViTx was delivered into atherosclerotic plaques and induced significant apoptosis in senescent cells regardless of origins. Repeated delivery of EViTx via tail vein injection has achieved high therapeutic efficacy in ApoE-/- mice. Notably, EViTx is inevitably accumulated in liver cells, while the iBax mRNA was translationally repressed by miR-122, an endogenous miRNA highly expressed in hepatocytes, and thus the liver cells are protected from the potential toxicity of Bax mRNA. Conclusion: Our work demonstrated that magnetic EV-based delivery of iBax mRNA and the BAX activator BTSA1, efficiently induced apoptosis in recipient senescent cells in atherosclerotic plaques. This strategy represents a promising treatment approach for AS and other age-related diseases.

Extracellular vesicles: a rising star for therapeutics and drug delivery

Extracellular vesicles (EVs) are nano-sized, natural, cell-derived vesicles that contain the same nucleic acids, proteins, and lipids as their source cells. Thus, they can serve as natural carriers for therapeutic agents and drugs, and have many advantages over conventional nanocarriers, including their low immunogenicity, good biocompatibility, natural blood-brain barrier penetration, and capacity for gene delivery. This review first introduces the classification of EVs and then discusses several currently popular methods for isolating and purifying EVs, EVs-mediated drug delivery, and the functionalization of EVs as carriers. Thereby, it provides new avenues for the development of EVs-based therapeutic strategies in different fields of medicine. Finally, it highlights some challenges and future perspectives with regard to the clinical application of EVs.

In Vivo Deep-Brain 3- and 4-Photon Fluorescence Imaging of Subcortical Structures Labeled by Quantum Dots Excited at the 2200 nm Window

Multiphoton microscopy (MPM) is an enabling technology for visualizing deep-brain structures at high spatial resolution in vivo. Within the low tissue absorption window, shifting to longer excitation wavelengths reduces tissue scattering and boosts penetration depth. Recently, the 2200 nm excitation window has emerged as the last and longest window suitable for deep-brain MPM. However, multiphoton fluorescence imaging at this window has not been demonstrated, due to the lack of characterization of multiphoton properties of fluorescent labels. Here we demonstrate technologies for measuring both the multiphoton excitation and emission properties of fluorescent labels at the 2200 nm window, using (1) 3-photon (ησ₃) and 4-photon action cross sections (ησ₄) and (2) 3-photon and 4-photon emission spectra both ex vivo and in vivo of quantum dots. Our results show that quantum dots have exceptionally large ησ₃ and ησ₄ for efficient generation of multiphoton fluorescence. Besides, the 3-photon and 4-photon emission spectra of quantum dots are essentially identical to those of one-photon emission, which change negligibly subject to the local environment of circulating blood. Based on these characterization results, we further demonstrate deep-brain vasculature imaging in vivo. Due to the superb multiphoton properties of quantum dots, 3-photon and 4-photon fluorescence imaging reaches a maximum brain imaging depth of 1060 and 940 μm below the surface of a mouse brain, respectively, which enables the imaging of subcortical structures. We thus fill the last gap in multiphoton fluorescence imaging in terms of wavelength selection.

Multiplexed strategies toward clinical translation of extracellular vesicles

Extracellular vesicles (EVs), of which exosomes are a representative subgroup, are naturally secreted nanoparticles with a variety of payloads. With the intrinsic merits of stability, biocompatibility, low immunogenicity, and large capacity, EVs are widely regarded as effective carriers of drug delivery. However, disadvantages, such as low yield, complicated isolation procedures, and low loading efficiency, hinder its clinical translation. In this review, we systematically summarize the advances in EV (especially exosomes) engineering for clinical application, focusing on strategies toward high yield, facile isolation, efficient cargo loading, improved delivery, and optimized manufacturing, which might unleash the infinite power of EVs in clinical translation.

An overview of substrate stiffness guided cellular response and its applications in tissue regeneration

Cell-matrix interactions play a critical role in tissue repair and regeneration. With gradual uncovering of substrate mechanical characteristics that can affect cell-matrix interactions, much progress has been made to unravel substrate stiffness-mediated cellular response as well as its underlying mechanisms. Yet, as a part of cell-matrix interaction biology, this field remains in its infancy, and the detailed molecular mechanisms are still elusive regarding scaffold-modulated tissue regeneration. This review provides an overview of recent progress in the area of the substrate stiffness-mediated cellular responses, including 1) the physical determination of substrate stiffness on cell fate and tissue development; 2) the current exploited approaches to manipulate the stiffness of scaffolds; 3) the progress of recent researches to reveal the role of substrate stiffness in cellular responses in some representative tissue-engineered regeneration varying from stiff tissue to soft tissue. This article aims to provide an up-to-date overview of cell mechanobiology research in substrate stiffness mediated cellular response and tissue regeneration with insightful information to facilitate interdisciplinary knowledge transfer and enable the establishment of prognostic markers for the design of suitable biomaterials.

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Substrate stiffness physically determines cell fate and tissue development.

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Rational design of scaffolds requires the understanding of cell-matrix interactions.

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Substrate stiffness depends on scaffold molecular-constituent-structure interaction.

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Substrate stiffness-mediated cellular responses vary in different tissues.

Mechanisms and Clinical Implications of Endothelial Dysfunction in Arterial Hypertension

The endothelium is composed of a monolayer of endothelial cells, lining the interior surface of blood and lymphatic vessels. Endothelial cells display important homeostatic functions, since they are able to respond to humoral and hemodynamic stimuli. Thus, endothelial dysfunction has been proposed as a key and early pathogenic mechanism in many clinical conditions. Given the relevant repercussions on cardiovascular risk, the complex interplay between endothelial dysfunction and systemic arterial hypertension has been a matter of study in recent years. Numerous articles have been published on this issue, all of which contribute to providing an interesting insight into the molecular mechanisms of endothelial dysfunction in arterial hypertension and its role as a biomarker of inflammation, oxidative stress, and vascular disease. The prognostic and therapeutic implications of endothelial dysfunction have also been analyzed in this clinical setting, with interesting new findings and potential applications in clinical practice and future research. The aim of this review is to summarize the pathophysiology of the relationship between endothelial dysfunction and systemic arterial hypertension, with a focus on the personalized pharmacological and rehabilitation strategies targeting endothelial dysfunction while treating hypertension and cardiovascular comorbidities.

The Contribution of Gut Microbiota and Endothelial Dysfunction in the Development of Arterial Hypertension in Animal Models and in Humans

The maintenance of the physiological values of blood pressure is closely related to unchangeable factors (genetic predisposition or pathological alterations) but also to modifiable factors (dietary fat and salt, sedentary lifestyle, overweight, inappropriate combinations of drugs, alcohol abuse, smoking and use of psychogenic substances). Hypertension is usually characterized by the presence of a chronic increase in systemic blood pressure above the threshold value and is an important risk factor for cardiovascular disease, including myocardial infarction, stroke, micro- and macro-vascular diseases. Hypertension is closely related to functional changes in the endothelium, such as an altered production of vasoconstrictive and vasodilator substances, which lead to an increase in vascular resistance. These alterations make the endothelial tissue unresponsive to autocrine and paracrine stimuli, initially determining an adaptive response, which over time lead to an increase in risk or disease. The gut microbiota is composed of a highly diverse bacterial population of approximately 10¹⁴ bacteria. A balanced intestinal microbiota preserves the digestive and absorbent functions of the intestine, protecting from pathogens and toxic metabolites in the circulation and reducing the onset of various diseases. The gut microbiota has been shown to produce unique metabolites potentially important in the generation of hypertension and endothelial dysfunction. This review highlights the close connection between hypertension, endothelial dysfunction and gut microbiota.

Endothelial MicroRNA-483-3p Is Hypertension-Protective

Hypertension is a high-risk factor for developing coronary heart disease and stroke. Endothelial dysfunction and arterial remodeling can lead to increased vascular wall thickness and arterial stiffness. Previous studies showed that microRNA-483 (miR-483) enhances endothelial cell (EC) function. Here, we investigated the protective role of miR-483 in hypertension. Data collected from two patient cohorts showed that the serum miR-483-3p level was associated with the progression of hypertension and positively correlated with vascular function. In cultured ECs, miR-483 targets a number of endothelial dysfunction-related genes, such as transforming growth factor-β (TGF-β), connective tissue growth factor (CTGF), angiotensin-converting enzyme 1 (ACE1), and endothelin-1 (ET-1). Overexpression of miR-483-3p in ECs inhibited Ang II-induced endothelial dysfunction, revealed by the decreased expression of TGF-β, CTGF, ACE1, and ET-1. Furthermore, miR-483-3p secreted from ECs was taken up by smooth muscle cells (SMCs) via the exosome pathway, which also decreased these genes in SMCs. Additionally, telmisartan could increase the aortic and serum levels of miR-483-3p in hypertension patients and spontaneous hypertension rats (SHR). These findings suggest that miR-483-3p exerts a protective effect on EC function during the onset of hypertension and thus may be considered a potential therapeutic target for hypertension-related cardiovascular diseases.

Prevalence and predictive risk factors of hypertension in patients hospitalized in Kamenge Military hospital and Kamenge University teaching hospital in 2019: A fixed effect modelling study in Burundi

INTRODUCTION

Hypertension is a major threat to public health globally. Especially in sub-Saharan African countries, this coexists with high burden of other infectious diseases, creating a complex public health situation which is difficult to address. Tackling this will require targeted public health intervention based on evidence that well defines the at risk population. In this study, using retrospective data from two referral hospitals in Burundi, we model the risk factors of hypertension in Burundi.

MATERIALS AND METHODS

Retrospective data of a sample of 353 randomly selected from a population of 4,380 patients admitted in 2019 in two referral hospitals in Burundi: Military and University teaching hospital of Kamenge. The predictive risk factors were carried out by fixed effect logistic regression. Model performance was assessed with Area under Curve (AUC) method. Model was internally validated using bootstrapping method with 2000 replications. Both data processing and data analysis were done using R software.

RESULTS

Overall, 16.7% of the patients were found to be hypertensive. This study didn't showed any significant difference of hypertension's prevalences among women (16%) and men (17.7%). After adjustment of the model for cofounding covariates, associated risk factors found were advanced age (40-59 years) and above 60 years, high education level, chronic kidney failure, high body mass index, familial history of hypertension. In absence of these highlighted risk factors, the risk of hypertension occurrence was about 2 per 1000 persons. This probability is more than 90% in patients with more than three risk factors.

CONCLUSION

The relatively high prevalence and associated risk factors of hypertension in Burundi raises a call for concern especially in this context where there exist an equally high burden of infectious diseases, other chronic diseases including chronic malnutrition. Targeting interventions based on these identified risk factors will allow judicious channel of resources and effective public health planning.