The Hif1a Knockout RAW 264.7 Cell Line is a CRISPR/Cas9-edited knockout cell line derived from the murine RAW 264.7 macrophage cell line, featuring targeted disruption of the Hif1a gene (Mus musculus). This loss-of-function model eliminates expression of hypoxia-inducible factor 1-alpha (HIF-1??), a master transcriptional regulator of the adaptive response to hypoxia. The cell line serves as a robust and genetically defined tool for interrogating HIF-1??-dependent molecular mechanisms, circumventing the need for acute pharmacological modulation or variable hypoxic culture conditions. Engineered via CRISPR/Cas9-mediated gene disruption, this model provides a stable, homogenous genetic background for reproducible experimentation.
The parental RAW 264.7 cell line is a widely utilized BALB/c mouse-derived leukemic macrophage cell line, originally induced by the Abelson murine leukemia virus. These cells exhibit characteristic macrophage functions, including robust phagocytic activity, cytokine secretion, and responsiveness to inflammatory stimuli, making them a principal model for studies of macrophage biology and innate immunity. RAW 264.7 cells retain many features of primary macrophages, such as expression of surface markers F4/80 and CD11b, and the capacity for polarization toward pro- or anti-inflammatory phenotypes. This genetic knockout in the RAW 264.7 background enables dissection of HIF-1????s role specifically within the macrophage lineage under physiologically relevant hypoxic conditions.
Hif1a encodes HIF-1??, which is constitutively synthesized but rapidly degraded under normoxia via hydroxylation by prolyl hydroxylases (PHD1, PHD2, PHD3) and subsequent von Hippel-Lindau (VHL)-mediated ubiquitination. Under low oxygen tension, HIF-1?? stabilizes, translocates to the nucleus, and heterodimerizes with ARNT/HIF-1?? to form a functional transcription factor that binds hypoxia-response elements (HREs). This complex activates a wide array of target genes, including VEGF, erythropoietin (EPO), GLUT1, lactate dehydrogenase A (LDHA), BNIP3, NOS2, PDK1, and CA9, thereby orchestrating angiogenesis, metabolic reprogramming toward glycolysis, and cell survival. HIF-1?? activity is also modulated by growth factors (IGF, EGF) via PI3K/AKT/mTOR signaling, and by inflammatory cytokines such as TNF-?? and IL-1??, which can stabilize HIF-1?? even under normoxia. Key interacting cofactors include p300/CBP, which are recruited for transcriptional activation, and MDM2, which can modulate protein stability.
In the RAW 264.7 macrophage context, HIF-1?? is a pivotal regulator of the cellular response to hypoxia, a condition commonly encountered in inflamed or tumor microenvironments. Knockout of Hif1a abrogates hypoxia-induced expression of target genes, impairing the metabolic switch to glycolysis and altering macrophage effector functions such as phagocytosis, cytokine production, and migration. This deficiency enables researchers to delineate HIF-1??-dependent versus -independent pathways in macrophage activation, particularly in inflammatory models where HIF-1?? contributes to the pathogenesis of diseases like rheumatoid arthritis and tumor-associated macrophage reprogramming. The loss of HIF-1?? also affects the expression of downstream effectors like NOS2 and VEGF, which are critical for vasodilation and angiogenesis, respectively.
This Hif1a Knockout RAW 264.7 Cell Line is a versatile platform for diverse biomedical research applications. It is particularly suited for investigating macrophage function under hypoxia, including drug screening assays targeting the HIF-1 pathway for cancer or ischemic diseases, and studies of metabolic reprogramming in immune cells. Experimental approaches such as western blotting for HIF-1?? protein levels, RT-qPCR for target gene expression, luciferase reporter assays driven by HREs, flow cytometry for surface markers, and functional assays like phagocytosis or migration/invasion can be employed. Additionally, ChIP-qPCR can be used to assess HIF-1?? binding to chromatin in control versus knockout cells. Researchers may culture these cells under normoxic or controlled hypoxic conditions to probe pathway activation, and co-culture systems with tumor cells can model the tumor microenvironment. For additional technical information, product specifications, or experimental guidance, please contact Ascent Research.
