miR-200b downregulates Kruppel Like Factor 2 (KLF2) during acute hypoxia in human endothelial cells

Abstract

The role of microRNAs in controlling angiogenesis is recognized as a promising therapeutic target in both cancer and cardiovascular disorders. However, understanding a miRNA’s pleiotropic effects on angiogenesis is a limiting factor for these types of therapeutic approaches. Using genome-wide next-generation sequencing, we examined the role of an antiangiogenic miRNA, miR-200b, in primary human endothelial cells. The results indicate that miR-200b has complex effects on hypoxia-induced angiogenesis in human endothelia and importantly, that many of the reported miR-200b effects using miRNA overexpression may not be representative of the physiological role of this miRNA. We also identified the antiangiogenic KLF2 gene as a novel target of miR-200b. Our studies indicate that the physiological changes in miR-200b levels during acute hypoxia may actually have a proangiogenic effect through Klf2 downregulation and subsequent stabilization of HIF-1 signaling. Moreover, we provide a viable approach for differentiating direct from indirect miRNA effects in order to untangle the complexity of individual miRNA networks.

Primary endothelial cell–specific regulation of hypoxia‐inducible factor (HIF)‐1 and HIF‐2 and their target gene expression profiles during hypoxia

“…Other post-translational mechanisms besides mRNA stability may be required to facilitate the HIF switch. Indeed, numerous factors that selectively modulate HIF-1a and HIF-2a stability have been reported that include spliceosome associated factor 1 (the human homolog of murine hypoxia-associated factor) (56), carboxyl terminus of Hsc70-interacting protein complex (57), the receptor for activated kinase C1, the Kruppel-like factor 2 (22,57), and the heat shock protein 90 (59,60). Furthermore, the HIF-1-dependent induction of PHD3 can also lead to HIF-2a degradation (61).…”

“…The GeneAnalytics webserver (geneanalytics.genecards.org) (35) was used to place HIF-1 and HIF-2 target prediction results into a physiologic context and predict potential HIF effects (22). The scoring algorithm in the pathways category is based on the algorithm used by the GeneDecks Set Distiller tool (36).…”

“…The inability to reduce the HIF-1 levels during prolonged hypoxia leads to cell death (21). Numerous protein factors have been proposed to modulate the HIF transitional switch (22)(23)(24) [reviewed in Serocki et al (21)], and the mechanisms underlying the HIF switch remain poorly understood.…”

miR‐34c‐5p modulates X‐box–binding protein 1 (XBP1) expression during the adaptive phase of the unfolded protein response

“…We used TaqMan One-Step RT-PCR Master Mix Reagents (Thermo Fisher Scientific) as previously described (27,28,30) using the manufacturer's protocol. The relative expressions were calculated using the comparative relative standard curve method (31).…”

Use of Human Umbilical Vein Endothelial Cells (HUVEC) as a Model to Study Cardiovascular Disease: A Review

“…Because the growth of collateral vessels offers an alternative route for irrigation when a coronary artery is blocked, angiogenesis may decrease myocardial damage and improve prognosis [149]. HUVEC models have been used to study the molecular and signaling pathways involved in this process [150][151][152][153][154]. Pro-angiogenic factors are known as potential therapeutic agents to treat ischemic heart disease and protect EC in the arteries [108,[150][151][152][153][154][155][156].…”