The Hif1a Knockout TM3 Cell Line is a CRISPR/Cas9-edited knockout cell line derived from the TM3 immortalized mouse Leydig cell line, engineered to disrupt the Hif1a gene encoding hypoxia-inducible factor 1 alpha (HIF1A). This knockout model offers a defined genetic background for investigating HIF1A-dependent signaling and cellular responses to hypoxia without off-target compensation from related family members. The CRISPR/Cas9-mediated gene disruption ablates functional HIF1A protein expression, providing a reliable platform for loss-of-function studies.
The TM3 host cell line is an established, immortalized Leydig cell line originally derived from the testis of a BALB/c mouse. TM3 cells retain key characteristics of primary Leydig cells, including the capacity for steroidogenesis and testosterone biosynthesis, and are widely employed as an in vitro model for studying male reproductive physiology, androgen regulation, and testicular function. Their stable proliferation and well-characterized hormonal responsiveness make them suitable for genetic manipulation and functional assays.
HIF1A functions as a transcriptional master regulator of the cellular and systemic response to hypoxia. Under normoxic conditions, prolyl hydroxylase domain (PHD) enzymes hydroxylate specific proline residues on HIF1A, promoting von Hippel-Lindau (VHL) protein binding, ubiquitination, and proteasomal degradation. Upon oxygen deprivation, PHD activity is inhibited, allowing HIF1A accumulation, dimerization with HIF1B (ARNT), and recruitment of coactivators such as p300/CBP. This complex binds hypoxia response elements (HREs) in promoter regions to activate transcription of target genes including VEGFA, EPO, GLUT1, PDK1, BNIP3, LDHA, and CA9. Upstream regulators such as PI3K, AKT, mTOR, and reactive oxygen species (ROS) modulate HIF1A expression and activity, forming an integrated signaling network that governs angiogenesis, metabolic reprogramming, apoptosis, and cell survival.
In Leydig cells, HIF1A participates in the oxygen-sensitive regulation of steroidogenic enzyme expression and testosterone production. Disruption of Hif1a in the TM3 background permits dissection of hypoxia-dependent versus oxygen-independent pathways that impact Leydig cell function, survival under ischemic stress, and crosstalk with endocrine signaling. This knockout model is particularly valuable for exploring the interplay between hypoxic signaling and reproductive endocrinology, as well as the molecular basis of testicular pathologies where ischemia or altered oxygen homeostasis occurs.
Research applications for the Hif1a Knockout TM3 Cell Line are extensive and encompass hypoxia-mediated signaling studies, cancer metabolism research, Leydig cell steroidogenesis, ischemia-reperfusion injury modeling, and drug screening for HIF pathway inhibitors. The cell line is compatible with a variety of experimental readouts, including Western blot analysis of HIF1A and its hydroxylated forms, RT-qPCR quantification of downstream targets such as VEGFA and GLUT1, luciferase reporter assays driven by HRE sequences, and functional assays under chemically induced hypoxia with CoCl? or within hypoxia chambers. Additional assays include immunofluorescence localization, flow cytometric assessment of cell viability under hypoxic stress, and apoptosis detection. These applications make the cell line a robust tool for both basic and translational research. For further information, please contact Ascent Research.
