Human Vascular Diseases Research Articles

Research Progress in the Construction and Application of In Vitro Vascular Models

The vascular system maintains cellular homeostasis by transporting oxygen, nutrients, and metabolic waste products. The vascular system is involved in a variety of fundamental physiological phenomena and is closely associated with human vascular diseases. Additionally, the stability of drugs in the vasculature affects their efficacy. Therefore, researchers have used vascular models to study vascular diseases, assess drug stability, and screen drugs. However, there are many shortcomings in the animal models and in vitro two-dimensional vascular models that have been extensively developed. In this paper, we specifically review the construction methods of in vitro vascular models and classify the specific methods into photolithography, soft lithography, self-assembly, template, 3D bioprinting, and laser degradation/cavitation. The first two are microfluidics-based methods and the last three are non-microfluidics-based methods. The vascular model construction methods reviewed in this paper overcome the shortcomings of traditional models—which cannot accurately reproduce the human vascular microenvironment—and can assist in the construction of in vitro 3D vascular models and tissue engineering vascularization. These models can be reused by perfusion devices, and the cells within the channels reside on biocompatible materials that are used to simulate the microenvironment and 3D cellular organization of the vasculature in vivo. In addition, these models are reproducible in shape and length, allowing experiments to be repeated, which is difficult to do with natural vessels. In vitro vascular models are widely used in research and drug screening for diseases associated with endothelial dysfunction, cancer, and other vascular abnormalities.

Stable, Conductive, Adhesive Polymer Patterning Inside a Microfluidic Chamber for Endothelial Cell Alignment

AbstractEndothelial cells (ECs) line the inner walls of blood vessels, respond to shear stress by elongating in the direction of flow. Engineering aligned ECs in vitro is essential for modeling human vascular diseases and for drug testing. Current microfluidic approaches mainly rely on unidirectional laminar flow, uniform coating of surfaces to improve cellular adhesion or alteration of the surface topography. Challenges persist due to shear stress‐induced changes in cellular behavior, especially in complex multicellular environments and the time needed for the cells to align and polarize inside the microfluidic conduits. Generally, protein coating processes and physical treatments are also not compatible with the steps required for the assembly of microfluidic devices. This approach employs aerosol jet printing (AJP) to precisely pattern poly(3,4‐ethylenedioxythiophene) polystyrene sulphonate (PEDOT:PSS) within microfluidic chambers in a single step. It is shown that the PEDOT:PSS is biocompatible and facilitates EC adhesion, patterning, elongation, and alignment. Under capillary flow, the cells retain their pattern‐induced morphology over 7 d, confirming the efficacy of the approach in promoting cellular organization, eliminating the need for external pumps. Furthermore, it is demonstrated that the PEDOT:PSS pattern retains structural integrity and electrical stability following oxygen plasma treatment, required for assembling of fully enclosed microfluidic devices.

Abstract 3077: Identifying Regulators Of Human Adventitial Fibroblast Activation Through A Genome-wide CRISPR Screen

Background: Vascular diseases, including atherosclerosis, are the leading cause of death in the US and world-wide. A quiescent population of fibroblasts that reside in the adventitia (AdvFib) activates and expands upon different vascular insults and contribute to the progression of vascular diseases. However, what regulates AdvFib’s activation remains unknown. We designed a genome-wide CRISPRi screen on human AdvFib to identify these regulators. Methods: We generated an immortalized human coronary AdvFib line that stably expresses dCas9-KRAB, which effectively silences any genes of interest. These cells were infected with a pool of lentivirus carrying guide RNAs (gRNA) covering the entire transcriptome at 200X coverage and allowed to expand freely. Frequency of gRNAs was assessed at different cell passages to identify those that influence AdvFib activation and was followed by experimental validation. Lastly, bioinformatic analysis was performed to determine regulatory pathways and gene networks involved in AdvFib activation. Results: Comparing relative gRNA abundances from early to late passages revealed several hundred putative regulators of AdvFib activation. GO biological process analysis of the top 250 enriched gRNA targets demonstrated disproportionate representation of cyclin inhibitors, validating the effectiveness of our screening. Molecular signatures for adipogenesis and key regulators of tissue mineralization including IBSP and ENPP1 were notably enriched in our screen. Human disease association using PhenGenI revealed a significant association with atherosclerosis. Indeed, numerous coronary artery disease GWAS genes including TCF21 , ZEB2 , CDKN1A , and CDKN2A were enriched in our screen, providing additional support for AdvFib’s importance in atherosclerosis. These hits were subsequently validated individually in vitro. Conclusion: A genome-wide CRISPRi screen of AdvFib activation modulators identified numerous potential regulator genes, many of which have known genetic and observational association with human vascular diseases. This study affirms the potentially important role of AdvFib in human vascular disease and may pave the way to future therapeutics targeting this often neglected cell population.

Analysis of periodic pulsating blood flow of fractional Maxwell power-law fluid in carotid artery with elastic vessel wall

Hemodynamic analysis reveals a highly significant effect on the prevention, diagnosis, and treatment of human vascular diseases. This article goes deeply into the periodic pulsatile blood flow in the carotid artery with an elastic vessel wall. In view of blood rheological experimental data, the constitutive equation of fractional Maxwell power-law fluid with yield stress, which can describe the four characteristics of yield stress, viscoelasticity, shear thinning, and thixotropy is established. Meanwhile, drawing support from the data of pulsatile flow, the finite Fourier series of pressure gradient with a period of 1 s has been proposed. Leading into Hooke’s law can build the fluid-structure coupling boundary condition of blood flow and elastic vessel wall. The numerical solutions are got hold of finite difference method integrated with the newly developed L1-algorithm, and their convergence and stability of which are verified. The axial velocities of blood under different constitutive relationships are compared. The results throw light that other constitutive relationships underestimate the velocity of blood. Furthermore, the flow rate and wall shear stress on different fluid are calculated. It can be concluded that compared with Bingham fluid, the maximum and minimum flow rate/wall shear stress of fractional Maxwell power-law fluid with yield stress increases by 19% and 32%, respectively. The flow rate lags behind the pressure gradient and has time delay effect, on the contrary, the velocity of blood vessel wall is keeping pace with the pressure gradient. The effects of relevant physical parameters on velocity are discussed. In addition, the spatiotemporal distribution of blood flow in cerebral artery and femoral artery are analyzed.

Release of 6-nitrodopamine from human popliteal artery and vein

6-Nitrodopamine (6-ND) is a novel catecholamine that is released from human umbilical cord vessels, and it causes vascular relaxation by acting as a dopamine D2-receptor antagonist. Here it was investigated whether human peripheral vessels obtained from patients who have undergone surgery for leg amputation release 6-ND, and its action in these tissues. Popliteal artery and vein strips present basal release of 6-ND, as measured by liquid chromatography coupled to tandem mass spectrometry. The release was significantly reduced when the tissues were pre-treated with the nitric oxide synthase inhibitor L-NAME (100 μM), or when the endothelium was mechanically removed. In U-46619 (3 nM) pre-contracted rings, 6-ND induced concentration-dependent relaxations (pEC50 8.18 ± 0.05 and 8.40 ± 0.08, in artery and vein rings, respectively). The concentration-dependent relaxations induced by 6-ND were unaffected in tissues pre-treated with L-NAME, but significantly reduced in tissues where the endothelium has been mechanically removed. In U-46619 (3 nM) pre-contracted rings, the selective dopamine D2 receptor antagonist L-741,626 also caused concentration-dependent relaxations (pEC50 8.92 ± 0.22 and 8.79 ± 0.19, in artery and vein rings, respectively). The concentration-dependent relaxations induced by L-741,626 were unaffected in tissues pre-treated with L-NAME, but significantly reduced in tissues where the endothelium has been mechanically removed. This is the first demonstration that 6-nitrodopamine is released from human peripheral artery and vein rings. The results also indicate that endothelium-derived dopamine is a major contractile agent in the popliteal artery and vein, and that selective dopamine D2-receptor antagonists such as 6-ND, may have therapeutic potential in the treatment of human peripheral vascular diseases.

Atomic Force Microscopy-Based Measurements of Retinal Microvessel Stiffness in Mice with Endothelial-Specific Deletion of CCN1.

Vascular stiffness is an independent predictor of human vascular diseases and is linked to ischemia, diabetes, high blood pressure, hyperlipidemia, and/or aging. Blood vessel stiffening increases owing to changes in the microscale architecture and/or content of extracellular, cytoskeletal, and nuclear matrix proteins. These alterations, while best appreciated in large blood vessels, also gradually occur in the microvasculature and play an important role in the initiation and progression of numerous microangiopathies including diabetic retinopathy. Although macroscopic measurements of arterial stiffness by pulse wave velocity are often used for clinical diagnosis, stiffness changes of intact microvessels and their causative factors have not been characterized. Herein, we describe the use of atomic force microscopy (AFM) to determine stiffness of mouse retinal capillaries and assess its regulation by the cellular communication network (CCN) 1, a stiffness-sensitive gene-encoded matricellular protein. AFM yields reproducible measurements of retinal capillary stiffness in lightly fixed freshly isolated retinal flat mounts. AFM measurements also show significant changes in compliance properties of the retinal microvasculature of mice with endothelial-specific deletion of CCN1, indicating that CCN1 expression, or lack thereof, affects the mechanical properties of microvascular cells in vivo. Thus, AFM has the force sensitivity and the spatial resolution necessary to measure the local modulus of retinal capillaries in situ and eventually to investigate microvascular compliance heterogeneities as key components of disease pathogenesis.

Abstract P3006: A Human Arterial Cell Atlas

Background: Human vascular diseases are the worldwide leading causes of morbidity and mortality. Nearly all human vascular diseases have arterial segment-specific tropisms despite identical exposures to genetic and environmental risk factors. Understanding the cellular and transcriptomic determinants of arterial identities may hold the key to identifying novel pathophysiology and potential therapies. Methods: To specifically determine arterial site-specific differences independent of inter-individual variation, we have generated a human arterial cellular atlas by simultaneously collecting and analyzing up to 8 arterial sites from multiple healthy transplant donors. We performed single cell transcriptomic analysis on arterial segments to determine the differences in cellular composition and transcriptomic programs. We subsequently integrated human genetic data with cell-type specific transcriptomic differences across vascular beds to identify probable causal cells and causal genes associated with human vascular phenotypes. Results/Conclusions: Single cell transcriptomic analysis of >150,000 cells sequenced at >50,000 reads per cell revealed that the dominant cellular drivers of transcriptomic differences between distinct arterial segments, i.e. determinants of arterial identity, are fibroblasts and smooth muscle cells, not endothelial cells or macrophages. Adult vascular cells transcriptomes from different segments are most influenced by their embryonic origins but not by anatomical proximity. Differentially regulated genes in fibroblast across different vascular beds were particularly enriched for vascular disease associated genetic signals, suggesting a prominent role for these cells in human disease. While the majority of endothelial cells were transcriptionally similar across vascular beds, a rare, previously undescribed, cluster of endothelial cells were identified who expressed segment-specific transcriptomic signatures. Differentially expressed genes in these cells were enriched for vascular disease signals, suggesting a possible role of these rare cells in human disease.

Abstract 107: A Human Arterial Cell Atlas

Background: Human vascular diseases are the worldwide leading causes of morbidity and mortality. Nearly all human vascular diseases have arterial segment-specific tropisms despite identical exposures to genetic and environmental risk factors. Understanding the cellular and transcriptomic determinants of arterial identities may hold the key to identifying novel pathophysiology and potential therapies. Methods: To specifically determine arterial site-specific differences independent of inter-individual variation, we have generated a human arterial cellular atlas by simultaneously collecting and analyzing up to 8 arterial sites from multiple healthy transplant donors. We performed single cell transcriptomic analysis on arterial segments to determine the differences in cellular composition and transcriptomic programs. We subsequently integrated human genetic data with cell-type specific transcriptomic differences across vascular beds to identify probable causal cells and causal genes associated with human vascular phenotypes. Results/Conclusions: Single cell transcriptomic analysis of > 150,000 cells sequenced at > 50,000 reads per cell revealed that the dominant cellular drivers of transcriptomic differences between distinct arterial segments, i.e. determinants of arterial identity, are fibroblasts and smooth muscle cells, not endothelial cells or macrophages. Adult vascular cells from different segments clustered not by anatomical proximity but by embryonic origin. Differentially regulated genes in fibroblast across different vascular beds were particularly enriched for vascular disease associated genetic signals, suggesting a prominent role for these cells in human disease. While the majority of endothelial cells were transcriptionally similar across vascular beds, a rare, previously undescribed, cluster of endothelial cells were identified who expressed segment-specific transcriptomic signatures. Differentially expressed genes in these cells were enriched for vascular disease signals, suggesting a possible role of these rare cells in human disease.

Circ_CHFR regulates ox-LDL-mediated cell proliferation, apoptosis, and EndoMT by miR-15a-5p/EGFR axis in human brain microvessel endothelial cells.

Oxidized low-density lipoprotein (ox-LDL) is a significant risk factor for various brain vascular diseases. Circular RNA (circRNA) is involved in the pathogenesis of brain vascular diseases. This study revealed the roles of circ_CHFR in ox-LDL-mediated cell proliferation, apoptosis, and endothelial-to-mesenchymal transition (EndoMT). Our results showed that circ_CHFR and EGFR expressions were dramatically upregulated, while miR-15a-5p expression was downregulated in ox-LDL-induced human brain microvessel endothelial cells (HBMECs) relative to control groups. circ_CHFR knockdown hindered the effects of ox-LDL exposure on cell proliferation, cell cycle, apoptosis, and EndoMT in HBMECs, whereas these impacts were abolished by miR-15a-5p inhibitor. In addition, circ_CHFR functioned as a sponge of miR-15a-5p and miR-15a-5p bound to EGFR. Thus, we concluded that circ_CHFR silencing hindered ox-LDL-mediated cell proliferation, apoptosis, and EndoMT by downregulating EGFR expression through sponging miR-15a-5p in HBMECs. Our findings provide a new mechanism for studying circRNA-directed therapy in ox-LDL-induced human brain vascular diseases.

MiR‑125a‑5p and miR‑7 inhibits the proliferation, migration and invasion of vascular smooth muscle cell by targeting EGFR.

The ectopic proliferation, migration and invasion of vascular smooth muscle cells (VSMCs) contributes to the progression of various human vascular diseases. Accumulating evidence has demonstrated that microRNAs (miRs) exert vital functions in the proliferation and invasion of VSMCs. The current study aimed to elucidate the functions of miR-125a-5p and miR-7 in VSMCs and investigate the associated molecular mechanisms. The results of EdU and reverse transcription-quantitative PCR assays revealed that platelet-derived growth factor (PDGF)-BB enhanced the proliferation of VSMCs and significantly reduced the expression of miR-125a-5p and miR-7. miR-125a-5p or miR-7 overexpression significantly ameliorated PDGF-BB-induced proliferation, migration and invasion of VSMCs. Furthermore, the results demonstrated that epidermal growth factor receptor (EGFR) may be a target mRNA of miR-125a-5p and miR-7 in VSMCs. The results of western blot analysis indicated that co-transfection of miR-125a-5p mimics or miR-7 mimics distinctly decreased the protein expression of EGFR in EGFR-overexpressed VSMCs. Moreover, rescue experiments indicated that EGFR overexpression alleviated the suppressive impact of the miR-125a-5p and miR-7 s on the growth, migration and invasion of VSMCs. In conclusion, the current study identified that miR-125a-5p and miR-7 repressed the growth, migration and invasion of PDGF-BB-stimulated VSMCs by, at least partially, targeting EGFR. The current study verified that miR-125a-5p and miR-7 may be used as feasible therapeutic targets for cardiovascular diseases.

Endothelial Cells Differentiated from Porcine Epiblast Stem Cells.

Pluripotent stem cells (PSCs) have the ability of self-renewal that can retain the characteristics of the mother cell, and of pluripotency that can differentiate into several body types. PSCs typically include embryonic stem cells (ESCs) derived from the inner cell mass of the preimplantation embryo, and epiblast stem cells (EpiSCs) derived from the epiblast of postimplantation embryo. Although PSCs are able to be used by differentiation into endothelial cells as a potential treatment for vascular diseases, human ESCs and induced PSCs (iPSCs) are followed by ethical and safety issues. Pigs are anatomically and physiologically similar to humans. Therefore, the goal of this study was to establish an efficient protocol that differentiates porcine EpiSCs (pEpiSCs) into the endothelial cells for applying the treatment of human vascular diseases. As a result, alkaline phosphatase (AP)-negative (-) pEpiSCs cultured in endothelial cell growth basal medium-2 (EBM-2) differentiation medium in association with 50 ng/mL of vascular endothelial growth factor (VEGF) for 8 days were changed morphologically like the feature of endothelial cells, and expression of pluripotency-associated markers (OCT-3/4, NANOG, SOX2, and C-MYC) in porcine differentiated cells was significantly decreased (p < 0.05). Additionally, when pEpiSCs were cultured in EBM-2 + 50 ng/mL of VEGF, porcine differentiated cells represented a common endothelial cell marker positive (CD31+) but monocytes and lymphocytes marker negative (CD45-). Therefore, these results indicated that pEpiSCs cultured in EBM-2 + 50 ng/mL of VEGF culture condition were efficiently differentiated into endothelial cells for the treatment of blood vessel diseases.

Sensitive imaging of intact microvessels in vivo with synchrotron radiation.

Early stages of diseases, including stroke, hypertension, angiogenesis of tumours, spinal cord injuries, etc., are closely associated with the lesions of microvasculature. Rodent models of human vascular diseases are extensively used for the preclinical investigation of the disease evolution and therapy with synchrotron radiation. Therefore, non-invasive and in vivo X-ray imaging with high sensitivity and clarity is desperately needed to visualize the microvessels in live-animal models. Contrast agent is essential for the in vivo X-ray imaging of vessels and angiomatous tissue. Because of the non-rigid motion of adjacent tissues, the short circulation time and the intermittent flow of contrast agents in vessels, it is a great challenge for the traditional X-ray imaging methods to achieve well defined images of microvessels in vivo. In this article, move contrast X-ray imaging (MCXI) based on high-brightness synchrotron radiation is developed to overcome the intrinsic defects in conventional methods. Experiments with live rodents demonstrate the practicability of the MCXI method for sensitive and intact imaging of microvessels in vivo.

Isolation and characterization of endothelial progenitor cells from canine bone marrow

ABSTRACT Endothelial progenitor cells (EPC) are located predominantly in the bone marrow. These cells are useful for treating human vascular diseases; they also are a possible target for restricting blood vessel growth for tumors. Little is known about canine EPC. We investigated a bone marrow EPC isolation method that combines the whole bone marrow culture method and the differential adherent speed method using stillborn canines. MTT proliferation, flow cytometry detection, Dil-ac-LDL uptake, FITC-UEA-1 binding and matrigel assays were used to identify and characterize EPC. We isolated two types of EPC: early EPC and late EPC. We found that isolated cells produced typical colony and cobblestone morphology, and were positive for CD31, CD34, CD133 and VEGFR-2. Significant differences were observed in the intensity of expression between early and late EPC, which suggests their different roles during angiogenesis and vasculogenesis. Both early and late EPC were positive for Dil-ac-LDL and FITC-UEA-1, and displayed tube formation when re-suspended in matrigel, both of which are important functional criteria for identifying EPC. Our method is a novel, effective and efficient way to produce enriched EPC.

Revealing Interfacial Lipid Hydrolysis Catalyzed by Phospholipase A1 at Molecular Level via Sum Frequency Generation Vibrational Spectroscopy and Fluorescence Microscopy.

The interfacial hydrolysis of phospholipids catalyzed by phospholipase A1 (PLA1) was studied via sum frequency generation (SFG) vibrational spectroscopy and fluorescence microscopy. Both monolayer and bilayer setups were used to confirm the hydrolysis mechanism. During the hydrolysis, lysophospholipids, one of the hydrolysis products, were desorbed from the interface into the solution, while the other products, fatty acids, self-organized and accumulated with PLA1 at the interface to form the PLA1-induced regions, which can serve as nonspecific binding domains for proteins and thus lead to human vascular diseases. This experimental study provides the essential information on revealing the interfacial biochemical process related to the metabolism of the lipids, which is one of the basic building blocks for cells.

Circ_Lrp6, a Circular RNA Enriched in Vascular Smooth Muscle Cells, Acts as a Sponge Regulating miRNA-145 Function.

microRNAs (miRNAs) modulate gene expression by repressing translation of targeted genes. Previous work has established a role for miRNAs in regulating vascular smooth muscle cell (VSMC) activity. Whether circular RNAs are involved in the modulation of miRNA activity in VSMCs is unknown. We aimed to identify circular RNAs interacting with miRNAs enriched in VSMCs and modulating the cells' activity. RNA sequencing and bioinformatics identified several circular RNAs enriched in VSMCs; however, only one, possessing multiple putative binding sites for miR-145, was highly conserved between mouse and man. This circular RNA gemmed from alternative splicing of Lrp6 (lipoprotein receptor 6), a gene highly expressed in vessels and implicated in vascular pathologies and was thus named circ_Lrp6. Its role as a miR-145 sponge was confirmed by determining reciprocal interaction through RNA immunoprecipitation, stimulated emission depletion microscopy, and competitive luciferase assays; functional inhibition of miR-145 was assessed by measuring expression of the target genes ITGβ8 (integrin-β8), FASCIN (fascin actin-bundling protein 1), KLF4 (Kruppel-like factor 4), Yes1 (YES proto-oncogene 1), and Lox (lysyl oxidase). The interaction was preferentially localized to P-bodies, sites of mRNA degradation. Using loss- and gain-of-function approaches, we found that circ_Lrp6 hindered miR-145-mediated regulation of VSMC migration, proliferation, and differentiation. Differential expression of miR-145 and circ_Lrp6 in murine and human vascular diseases suggests that the ratio of circ_Lrp6 bound to miR-145 versus unbound could play a role in vascular pathogenesis. Viral delivery of circ_Lrp6 shRNA prevented intimal hyperplasia in mouse carotids. circ_Lrp6 is an intracellular modulator and a natural sponge for miR-145, counterbalancing the functions of the miRNA in VSMCs.

THE GENETIC SUSCEPTIBILITY TO ATHEROSCLEROSIS

Atherosclerosis is a complex multifocal arterial disease involving interactions of multiple genetic and environmental factors. Atherosclerosis is the main cause of death and disability in developed countries, while in developing countries the incidence of this pathology is growing rapidly. Advances in techniques of molecular genetics have revealed that genetic polymorphisms significantly influence susceptibility to atherosclerotic vascular diseases. A large number of candidate genes, genetic polymorphisms and susceptibility loci associated with atherosclerotic diseases have been identified in recent years and their number is rapidly increasing. In recent years, there is significant interest in identifying additional factors of genetic risk for atherosclerosis. In recent years, a large number of genetic studies have been carried out to prove the genetic effect on the atherosclerotic process. Rapid progress in the sequencing of the human genome and molecular genetic methods have helped in the definition of susceptibility loci and associated candidate genes with atherosclerosis and concomitant diseases. The association of a large number of susceptibility genes with atherosclerosis reflects the enormous complexity of the disease. Multiple factors, including endothelial dysfunction, lipid metabolism defects, inflammation and immune responses, oxidative stress, cell proliferation, tissue remodeling and hemostatic defects are involved in the pathogenesis of atherosclerosis. In this review we focus and discuss on some of the major candidate genes and genetic polymorphisms associated with human atherosclerotic vascular diseases.

Emerging trends in multiscale modeling of vascular pathophysiology: Organ-on-a-chip and 3D printing

Most biomedical and pharmaceutical research of the human vascular system aims to unravel the complex mechanisms that drive disease progression from molecular to organ levels. The knowledge gained can then be used to innovate diagnostic and treatment strategies which can ultimately be determined precisely for patients. Despite major advancements, current modeling strategies are often limited at identifying, quantifying, and dissecting specific cellular and molecular targets that regulate human vascular diseases. Therefore, development of multiscale modeling approaches are needed that can advance our knowledge and facilitate the design of next-generation therapeutic approaches in vascular diseases. This article critically reviews animal models, static in vitro systems, and dynamic in vitro culture systems currently used to model vascular diseases. A leading emphasis on the potential of emerging approaches, specifically organ-on-a-chip and three-dimensional (3D) printing, to recapitulate the innate human vascular physiology and anatomy is described. The applications of these approaches and future outlook in designing and screening novel therapeutics are also presented.

A comfortability and signal quality study of conductive weave electrodes in long-term collection of human electrocardiographs

Long-term electrocardiogram (ECG) recording can reveal some vital cardiovascular disorders and provide warning of human sudden cerebral or vascular diseases in advance. This requires high-quality ECG skin electrodes. Gel (Ag/AgCl) electrodes were reported to have good signal quality in ECG acquisition, but easily caused human skin irritation or allergy. Consequently, textile electrodes have attracted more attention for long-term ECG acquisition. In this paper, eight woven fabrics with diverse yarns and weft densities were fabricated in plain and honeycomb structures. The fabrics were investigated in terms of comfortability, fabric–skin contact impedance and acquired bio-signal quality. Honeycomb weave electrodes were measured with a high comfort level from subjective and objective views, including pleasant tactile comfort, high visual acceptance, good air permeability and good heat transfer. Weave electrodes made of all conductive filaments in high density had low skin contact impedance and high-quality ECG signals. An increase of compression load on weave electrodes resulted in a decrease of contact impedance with a high signal quality. A conductive honeycomb weave with unit repeat of 6*6 warps*wefts presented the highest score of acquired ECG signals of all studied electrodes based on the qualities of the QRS complex, P and T waves, R peak amplitude and variation and signal-to-noise ratio. This study contributes to the future design and fabrication of textile electrodes using honeycomb weave in long-term and real-time collection of human ECGs.

Recent insights into vascular development from studies in zebrafish.

Zebrafish has provided a powerful platform to study vascular biology over the past 25 years, owing to their distinct advantages for imaging and genetic manipulation. In this review, we summarize recent progress in vascular biology with particular emphasis on vascular development in zebrafish. The advent of transcription activator-like effector nuclease and clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated protein 9 genome-editing technologies has dramatically facilitated reverse genetic approaches in zebrafish, as in other models. Here, we highlight recent studies on vascular development in zebrafish which mainly employed forward or reverse genetics combined with high-resolution imaging. These studies have advanced our understanding of diverse areas in vascular biology, including transcriptional regulation of endothelial cell differentiation, endothelial cell signaling during angiogenesis and lymphangiogenesis, vascular bed-specific developmental mechanisms, and perivascular cell recruitment. The unique attributes of the zebrafish model have allowed critical cellular and molecular insights into fundamental mechanisms of vascular development. Knowledge acquired through recent zebrafish work further advances our understanding of basic mechanisms underlying vascular morphogenesis, maintenance, and homeostasis. Ultimately, insights provided by the zebrafish model will help to understand the genetic, cellular, and molecular underpinnings of human vascular malformations and diseases.

Long noncoding RNA MALAT1 contributes to inflammatory response of microglia following spinal cord injury via the modulation of a miR-199b/IKKβ/NF-κB signaling pathway.

Long noncoding RNA (lncRNA) metastasis-associated lung adenocarcinoma transcript 1 (MALAT1) was widely recognized to be implicated in human cancer, vascular diseases, and neurological disorders. This study was to explore the role and underlying mechanism of MALAT1 in acute spinal cord injury (ASCI). ASCI models in adult rats were established and demonstrated by a numerical decrease in BBB scores. Expression profile of MALAT1 and miR-199b following ASCI in rats and in vitro was determined using quantitative real-time PCR. RNA pull-down assays combined with RIP assays were performed to explore the interaction between MALAT1 and miR-199b. In the present study, MALAT1 expression was significantly increased (2.4-fold that of control) in the spinal cord of the rat contusion epicenter accompanied by activation of IKKβ/NF-κB signaling pathway and an increase in the level of proinflammatory cytokines TNF-α and IL-1β. Upon treatment with LPS, MALAT1 expression dramatically increased in the microglia in vitro, but knockdown of MALAT1 attenuated LPS-induced activation of MGs and TNF-α and IL-1β production. Next, we confirmed that LPS-induced MALAT1 activated IKKβ/NF-κB signaling pathway and promoted the production of proinflammatory cytokines TNF-α and IL-1β through downregulating miR-199b. More importantly, MALAT1 knockdown gradually improved the hindlimb locomotor activity of ASCI rats as well as inhibited TNF-α, IL-1β levels, and Iba-1 protein, the marker of activated microglia in injured spinal cords. Our study demonstrated that MALAT1 was dysregulated in ASCI rats and in LPS-activated MGs, and MALAT1 knockdown was expected to attenuate ASCI through repressing inflammatory response of MGs.