The APOA4 Knockout HT29 Polyclonal Cells are a CRISPR/Cas9-edited polyclonal knockout cell population targeting the APOA4 gene in the HT29 colorectal adenocarcinoma line. This loss-of-function model abolishes APOA4 protein expression, offering a reproducible system for studying APOA4-dependent intestinal epithelial functions. The polyclonal nature captures diverse editing events without clonal bias, ensuring consistent gene disruption.
HT29 cells, derived from a 44-year-old female with colorectal adenocarcinoma, display adherent epithelial morphology and serve as a well-established intestinal epithelial model. Capable of enterocytic differentiation, they express the molecular machinery for lipid absorption and transport, making them ideal for investigating intestinal lipid metabolism, barrier integrity, and lipoprotein assembly.
APOA4 encodes an apolipoprotein that is a structural component of chylomicrons and HDL particles, playing a central role in the absorption, transport, and metabolism of dietary lipids. Mechanistically, APOA4 is transcriptionally induced by nuclear receptors PPAR?? and LXR??, as well as the hepatocyte nuclear factor HNF4??, and is modulated by hormonal cues such as insulin and thyroid hormone. Once expressed, APOA4 directly interacts with APOA1, APOB, and the enzyme LCAT, activating LCAT to esterify cholesterol and modulating CETP-mediated lipid exchange between lipoproteins. These activities are essential for reverse cholesterol transport and the remodeling of lipoprotein particles. In the intestinal epithelial context, APOA4 cooperates with the lipid transporters and enzymes FATP4, DGAT1, MTP, NPC1L1, and ABCA1 to orchestrate chylomicron assembly and secretion.
In HT29 cells, which retain core features of enterocytic lipid metabolism, CRISPR/Cas9-mediated APOA4 disruption directly compromises chylomicron formation and the vectorial transport of dietary fats. This results in reduced triglyceride-rich lipoprotein secretion and disrupted local lipid-signaling networks that normally transduce information about luminal lipid content to neural circuits governing appetite and satiety. The knockout therefore creates a tractable cell-based paradigm to dissect how intestinal APOA4 influences systemic energy homeostasis and to model aspects of hyperlipidemia, cardiovascular disease, and type 2 diabetes. Additionally, the model enables dissection of the intestinal contribution to reverse cholesterol transport and the interplay between dietary lipids and gut barrier function.
These polyclonal knockout cells are suited for a wide range of experimental designs, including mechanistic studies of intestinal lipid absorption, elucidation of the gut-brain axis in satiety control, in vitro modeling of metabolic syndrome, and high-content screening for modulators of dietary fat uptake. Researchers can leverage quantitative assays such as BODIPY-labeled fatty acid uptake kinetics, triglyceride secretion profiling, RT-qPCR and western blot analyses of APOA4 and key lipid transporters (e.g., MTP, FATP4, DGAT1), immunofluorescence visualization of lipid droplets, Transepithelial Electrical Resistance (TEER) measurements to assess barrier integrity, and Oil Red O staining for neutral lipids. Systems-level interrogation can be pursued via RNA-seq to map transcriptional adaptations to APOA4 loss. For product inquiries, technical support, or additional data, please contact Ascent Research.
