Kinetic studies of K-Cl cotransport in cultured rat vascular smooth muscle cells

Vascular Smooth Muscle Cells Phenotypic Switching in Cardiovascular Diseases

Vascular smooth muscle cells (VSMCs), the major cell type in the arterial vessel wall, have a contractile phenotype that maintains the normal vessel structure and function under physiological conditions. In response to stress or vascular injury, contractile VSMCs can switch to a less differentiated state (synthetic phenotype) to acquire the proliferative, migratory, and synthetic capabilities for tissue reparation. Imbalances in VSMCs phenotypic switching can result in a variety of cardiovascular diseases, including atherosclerosis, in-stent restenosis, aortic aneurysms, and vascular calcification. It is very important to identify the molecular mechanisms regulating VSMCs phenotypic switching to prevent and treat cardiovascular diseases with high morbidity and mortality. However, the key molecular mechanisms and signaling pathways participating in VSMCs phenotypic switching have still not been fully elucidated despite long-term efforts by cardiovascular researchers. In this review, we provide an updated summary of the recent studies and systematic knowledge of VSMCs phenotypic switching in atherosclerosis, in-stent restenosis, aortic aneurysms, and vascular calcification, which may help guide future research and provide novel insights into the prevention and treatment of related diseases.

CircZXDC Promotes Vascular Smooth Muscle Cell Transdifferentiation via Regulating miRNA-125a-3p/ABCC6 in Moyamoya Disease

Moyamoya disease (MMD) is an occlusive, chronic cerebrovascular disease affected by genetic mutation and the immune response. Furthermore, vascular smooth muscle cells (VSMCs) and endothelial cells (ECs) participate in the neointima of MMD, but the etiology and pathophysiological changes in MMD vessels remain largely unknown. Therefore, we established the circZXDC (ZXD family zinc finger C)-miR-125a-3p-ABCC6 (ATP-binding cassette subfamily C member 6) axis from public datasets and online tools based on "sponge-like" interaction mechanisms to investigate its possible role in VSMCs. The results from a series of in vitro experiments, such as dual luciferase reporter assays, cell transfection, CCK-8 assays, Transwell assays, and Western blotting, indicate a higher level of circZXDC in the MMD plasma, especially in those MMD patients with the RNF213 mutation. Moreover, circZXDC overexpression results in a VSMC phenotype switching toward a synthetic status, with increased proliferation and migration activity. CircZXDC sponges miR-125a-3p to increase ABCC6 expression, which induces ERS (endoplasmic reticulum stress), and subsequently regulates VSMC transdifferentiation from the contractive phenotype to the synthetic phenotype, contributing to the intima thickness of MMD vessels. Our findings provide insight into the pathophysiological mechanisms of MMD and indicate that the circZXDC-miR-125a-3p-ABCC6 axis plays a pivotal role in the progression of MMD. Furthermore, circZXDC might be a diagnostic biomarker and an ABCC6-specific inhibitor and has the potential to become a promising therapeutic option for MMD.

ClC-3: A Novel Promising Therapeutic Target for Atherosclerosis

Chloride channel 3 (ClC-3), a Cl^-/H⁺ antiporter, has been well established as a member of volume-regulated chloride channels (VRCCs). ClC-3 may be a crucial mediator for activating inflammation-associated signaling pathways by regulating protein phosphorylation. A growing number of studies have indicated that ClC-3 overexpression plays a crucial role in mediating increased plasma low-density lipoprotein levels, vascular endothelium dysfunction, pro-inflammatory activation of macrophages, hyper-proliferation and hyper-migration of vascular smooth muscle cells (VSMCs), as well as oxidative stress and foam cell formation, which are the main factors responsible for atherosclerotic plaque formation in the arterial wall. In the present review, we summarize the molecular structures and classical functions of ClC-3. We further discuss its emerging role in the atherosclerotic process. In conclusion, we explore the potential role of ClC-3 as a therapeutic target for atherosclerosis.

Micro-RNA-338-3p Promotes the Development of Atherosclerosis by Targeting Desmin and Promoting Proliferation

Atherosclerosis (AS) is a dynamic and multi-stage process that involves various cells types, such as vascular smooth muscle cells (VSMCs) and molecules such as microRNAs. In this study, we investigated how miR-338-3p works in the process of AS. To determine how miR-338-3p was expressed in AS, an AS rat model was established and primary rat VSMCs were cultured. Real-time polymerase chain reaction was performed to detect miR-338-3p expression. Markers of different VSMC phenotypes were tested by Western blot. Immunofluorescent staining was employed to observe the morphologic changes of VSMCs transfected with miR-338-3p mimics. A dual luciferase reporter assay system was used to verify that desmin was a target of miR-338-3p. To further identify the role of miR-338-3p in the development of AS, VSMC proliferation and migration were evaluated by EdU incorporation assay, MTT assay, and wound healing assay. miR-338-3p expression was upregulated in the aortic tissues of an AS rat model and in primary rat VSMCs from a later passage. The transfection of miR-338-3p mimics in VSMCs promoted the synthetic cell phenotype. Bioinformatics analysis proposed desmin as a candidate target for miR-338-3p and the dual luciferase reporter assay confirmed in vivo that desmin was a direct target of miR-338-3p. The MTT and EdU incorporation assay revealed increased cell viability when miR-338-3p mimics were transfected. The increased expression of PCNA was a consistent observation, although a positive result was not obtained with respect to VSMC mobility. In AS, miR-338-3p expression was elevated. Elevated miR-338-3p inhibited the expression of desmin, thus promoting the contractile-to-synthetic VSMC phenotypic transition. In addition to morphologic changes, miR-338-3p enhanced the proliferative but not mobile ability of VSMCs. In summary, miR-338-3p promotes the development of AS.

Role of the Cation-Chloride-Cotransporters in Cardiovascular Disease

The SLC12 family of cation-chloride-cotransporters (CCCs) is comprised of potassium chloride cotransporters (KCCs), which mediate Cl- extrusion and sodium-potassium chloride cotransporters (N[K]CCs), which mediate Cl- loading. The CCCs play vital roles in cell volume regulation and ion homeostasis. The functions of CCCs influence a variety of physiological processes, many of which overlap with the pathophysiology of cardiovascular disease. Although not all of the cotransporters have been linked to Mendelian genetic disorders, recent studies have provided new insights into their functional role in vascular and renal cells in addition to their contribution to cardiovascular diseases. Particularly, an imbalance in potassium levels promotes the pathogenesis of atherosclerosis and disturbances in sodium homeostasis are one of the causes of hypertension. Recent findings suggest hypothalamic signaling as a key signaling pathway in the pathophysiology of hypertension. In this review, we summarize and discuss the role of CCCs in cardiovascular disease with particular emphasis on knowledge gained in recent years on NKCCs and KCCs.