miR-221-3p targets Ang-2 to inhibit the transformation of HCMECs to tip cells

The Involvement of miR-221/222 in Vascular Pathophysiology: Implications for Stenting

MicroRNAs (miRNAs) are pivotal regulatory molecules involved in numerous cellular processes, including apoptosis, differentiation, proliferation, and migration. Recent research highlights specific miRNAs, such as the miR-221/222 cluster, which modulate key signaling pathways related to vascular smooth muscle cell (VSMC) proliferation, inflammation, and endothelial function. This function of miR-221/222 is accompanied by influencing the expression of certain proteins implicated in VSMCs and endothelial cells regulatory processes. miRNAs have been increasingly recognized for their roles in cardiovascular diseases, particularly in the mechanisms underlying in-stent restenosis and stent thrombosis. Elevated levels of miR-221/222 have been reported to be associated with severe adverse events following stenting and affect VSMC behavior and inflammatory responses. This image makes them promising candidates for new therapeutic strategies to address the most complex inferences of stenting, in-stent restenosis/stent thrombosis. Therefore, a discussion over the involvement of miR-221/222 in vascular pathophysiology could lead to finding possible signaling pathways and better stent designing for improving outcomes in patients undergoing stenting. Emerging therapeutic approaches, such as anti-miR oligonucleotides, offer the potential for translating these findings into clinical practice. This review article systematically investigates the biogenesis and functions of the miR-221/222 cluster along with its contributions to angiogenesis, vascular calcification, and neointimal formation. It aims to provide readers and researchers with insights into the signaling pathways that underpin vascular pathology linked to the miR-221 and miR-222 involvement.

Survival strategies: How tumor hypoxia microenvironment orchestrates angiogenesis

During tumor development, the tumor itself must continuously generate new blood vessels to meet their growth needs while also allowing for tumor invasion and metastasis. One of the most common features of tumors is hypoxia, which drives the process of tumor angiogenesis by regulating the tumor microenvironment, thus adversely affecting the prognosis of patients. In addition, to overcome unsuitable environments for growth, such as hypoxia, nutrient deficiency, hyperacidity, and immunosuppression, the tumor microenvironment (TME) coordinates angiogenesis in several ways to restore the supply of oxygen and nutrients and to remove metabolic wastes. A growing body of research suggests that tumor angiogenesis and hypoxia interact through a complex interplay of crosstalk, which is inextricably linked to the TME. Here, we review the TME's positive contribution to angiogenesis from an angiogenesis-centric perspective while considering the objective impact of hypoxic phenotypes and the status and limitations of current angiogenic therapies.

Regulation of the HIF switch in human endothelial and cancer cells

Hypoxia-inducible factors (HIFs) are transcription factors that reprogram the transcriptome for cells to survive hypoxic insults and oxidative stress. They are important during embryonic development and reprogram the cells to utilize glycolysis when the oxygen levels are extremely low. This metabolic change facilitates normal cell survival as well as cancer cell survival. The key feature in survival is the transition between acute hypoxia and chronic hypoxia, and this is regulated by the transition between HIF-1 expression and HIF-2/HIF-3 expression. This transition is observed in many human cancers and endothelial cells and referred to as the HIF Switch. Here we discuss the mechanisms involved in the HIF Switch in human endothelial and cancer cells which include mRNA and protein levels of the alpha chains of the HIFs. A major continuing effort in this field is directed towards determining the differences between normal and tumor cell utilization of this important pathway, and how this could lead to potential therapeutic approaches.