The effect of coculture with human smooth muscle cells on the proliferation, the IL-1 beta secretion, the PDGF production and tube formation of human aortic endothelial cells

Emerging Roles of Extracellular Non-Coding RNAs in Vascular Diseases

Extracellular vesicles (EVs) are secreted by cells and carry diverse components, including proteins, lipids, nucleic acids, and metabolites. EVs could be found in blood and other biofluids. They vary greatly in size, function, cargo, and cellular origin. Accumulating evidence shows that extracellular non-coding RNAs, the dominant extracellular RNAs encapsulated into EVs, function as critical mediators of cell-cell communication and play critical roles in human health and disease. Blood vessels form a dense network that nourishes all of the body's tissues. These vascular networks' dysregulated functions contribute to vascular diseases, such as pulmonary arterial hypertension (PAH), hypertension, atherosclerosis, and aneurysm. With the increase in unhealthy lifestyle-associated obesity and metabolic disorders, vascular diseases are becoming serious medical and public health issues with a profound global economic burden. The present review summarizes the latest advances on extracellular non-coding RNAs in pathological vascular remodeling-associated diseases, briefly describing vessel-associated extracellular non-coding RNAs and their mechanisms of action.

Altered pulmonary artery endothelial-smooth muscle cell interactions in experimental congenital diaphragmatic hernia

BACKGROUND

Pulmonary hypertension (PH) secondary to vascular remodeling contributes to poor outcomes in congenital diaphragmatic hernia (CDH), however mechanisms responsible are unknown. We hypothesized that pulmonary artery endothelial cell (PAEC) dysfunction contributes to smooth muscle cell (SMC) hyperplasia in experimental CDH.

METHODS

PAEC and SMC were isolated from fetal sheep with experimental CDH and controls. SMC growth was assessed alone and with SOD plus catalase and during coculture with control or CDH PAEC with and without ET-1 siRNA transfection. ET-1 protein was measured in PAEC and SMC lysates and supernatant. ROS production was measured in normal and CDH PAECs with and without ET-1 siRNA. PAEC growth and tube formation were measured with SOD plus catalase.

RESULTS

CDH SMC growth was decreased and increased with coculture with CDH PAEC more than control PAEC. Treatment of CDH PAEC with SOD plus catalase or ET-1 siRNA prevented the increase in SMC growth seen with coculture. ET-1 protein was increased in CDH PAEC and SMC. ROS production was increased in CDH PAEC and decreased with ET-1 SiRNA. SOD plus catalase restored CDH PAEC growth and tube formation.

CONCLUSION

PAEC dysfunction in experimental CDH increases SMC proliferation via ET-1 induced ROS production by PAEC.

Explants of porcine coronary artery in culture: A paradigm for studying the influence of heparin on vascular wall cell proliferation

Explant cultures of porcine coronary artery provided a coculture model, used as a paradigm of arterial wall in contact with vascular prosthesis which allowed the study of spatial and temporal changes in cell phenotype. First cells emerging from the explant had an endothelial phenotype monitored by cytoimmunostaining. Percentages of anti-smooth muscle alpha-actin labelled cells were assessed at early and late phase by flow cytofluorometric analysis to control the effect of heparin. At 100 mug ml(-1), no effect on alpha-actin labelled cell growth has been detected. This result contrasted with the inhibition of monolayer cell cultures. At 500 mug ml(-1), the proliferation of smooth muscle cells was reduced. This explant system should be useful for testing drugs susceptible to interfere with restenosis.

Endothelial cells and pulmonary arterial hypertension: apoptosis, proliferation, interaction and transdifferentiation

Severe pulmonary arterial hypertension, whether idiopathic or secondary, is characterized by structural alterations of microscopically small pulmonary arterioles. The vascular lesions in this group of pulmonary hypertensive diseases show actively proliferating endothelial cells without evidence of apoptosis. In this article, we review pathogenetic concepts of severe pulmonary arterial hypertension and explain the term "complex vascular lesion ", commonly named "plexiform lesion", with endothelial cell dysfunction, i.e., apoptosis, proliferation, interaction with smooth muscle cells and transdifferentiation.

Vascular cells contribute to atherosclerosis by cytokine- and innate-immunity-related inflammatory mechanisms

Cardiovascular diseases are the human diseases with the highest death rate and atherosclerosis is one of the major underlying causes of cardiovascular diseases. Inflammatory and innate immune mechanisms, employing monocytes, innate receptors, innate cytokines, or chemokines are suggested to be involved in atherogenesis. Among the inflammatory pathways the cytokines are central players. Plasma levels of cytokines and related proteins, such as CRP, have been investigated in cardiovascular patients, tissue mRNA expression was analyzed and correlations to vascular diseases established. Consistent with these findings the generation of cytokine-deficient animals has provided direct evidence for a role of cytokines in atherosclerosis. In vitro cell culture experiments further support the suggestion that cytokines and other innate mechanisms contribute to atherogenesis. Among the initiation pathways of atherogenesis are innate mechanisms, such as toll-like-receptors (TLRs), including the endotoxin receptor TLR4. On the other hand, innate cytokines, such as IL-1 or TNF, or even autoimmune triggers may activate the cells. Cytokines potently activate multiple functions relevant to maintain or spoil homeostasis within the vessel wall. Vascular cells, not least smooth muscle cells, can actively contribute to the inflammatory cytokine-dependent network in the blood vessel wall by: (i) production of cytokines; (ii) response to these potent cell activators; and (iii) cytokine-mediated interaction with invading cells, such as monocytes, T-cells, or mast cells. Activation of these pathways results in accumulation of cells and increased LDL- and ECM-deposition which may serve as an 'immunovascular memory' resulting in an ever-growing response to subsequent invasions. Thus, vascular cells may potently contribute to the inflammatory pathways involved in development and acceleration of atherosclerosis.

Neutrophils, lymphocytes, and monocytes exhibit diverse behaviors in transendothelial and subendothelial migrations under coculture with smooth muscle cells in disturbed flow

Atherosclerosis develops at regions of the arterial tree exposed to disturbed flow. The early stage of atherogenesis involves the adhesion of leukocytes (white blood cells [WBCs]) to and their transmigration across endothelial cells (ECs), which are located in close proximity to smooth muscle cells (SMCs). We investigated the effects of EC/SMC coculture and disturbed flow on the adhesion and transmigration of 3 types of WBCs (neutrophils, peripheral blood lymphocytes [PBLs], and monocytes) using our vertical-step flow (VSF) chamber, in which ECs were cocultured with SMCs in collagen gels. Such coculture significantly increased the adhesion and transmigration of neutrophils, PBLs, and monocytes under VSF, particularly in the reattachment area, where the rolling velocity of WBCs and their transmigration time were decreased, as compared with the other areas. Neutrophils, PBLs, and monocytes showed different subendothelial migration patterns under VSF. Their movements were more random and shorter in distance in the reattachment area. Coculture of ECs and SMCs induced their expressions of adhesion molecules and chemokines, which contributed to the increased WBC adhesion and transmigration. Our findings provide insights into the mechanisms of WBC interaction with the vessel wall (composed of ECs and SMCs) under the complex flow environments found in regions of prevalence for atherogenesis.

Microscale multilayer cocultures for biomimetic blood vessels

Living tissues have complex and well-organized microstructures. Although microtechnology has been used to create in vivo-like cell microstructures in vitro, most available microscale systems are two-dimensional, and few three-dimensional (3D) systems have been explored. This article demonstrates a 3D hierarchical biomimetic multilayer microsystem created by a generally applicable technique. The technique employs layer-by-layer microfluidics to build layers of cells and biopolymers in microchannels, allowing controlled patterning of cells and their microenvironments in the x, y, and z-dimension. As a prototype, a multilayer system was created using three vascular cell types within heterogeneous types of biopolymers to mimic the structure and composition of a blood vessel wall. The effects of matrix composition and multilayer configurations on 3D cell-cell interactions and cell biology were revealed. Cell migration in the z-dimension, matrix remodeling, intercellular adhesion molecule expression and actin organization were examined under different 3D coculture conditions. A more biomimetic coculture was found to reproduce a more stable structure and in vivo-like function. This approach provides a method to fabricate microscale hierarchical "neotissues" with 3D configurations of matrix materials and multiple cell types, and an in vitro cell coculture model to understand 3D processes of cell-cell and cell-matrix interactions.