Abstract 70: KLF14 is a Novel Regulator of Human Metabolism
Human genetic studies have identified DNA variants near the KLF14 gene to be strongly associated with HDL cholesterol levels, triglyceride levels, risk of type 2 diabetes mellitus, and risk of coronary artery disease. Furthermore, the same variants are associated with both the expression level of KLF14 (cis eQTL) and the expression levels of ten other genes related to metabolic traits located on different chromosomes (trans eQTL) in human adipose tissues, suggesting that KLF14 may be a master regulator of gene expression in adipose tissue and a key player in human metabolism. In order to evaluate this hypothesis, we have rapidly and efficiently generated both KLF14 knockout human adipocytes (differentiated from human pluripotent stem cells) and Klf14 knockout mice through the use of clustered regularly interspaced short palindromic repeats (CRISPR)/CRISPR-associated (Cas) systems. We have analyzed the KLF14 knockout adipocytes and the Klf14 knockout mice for metabolic phenotypes at several different levels. At an organismic level, we found Klf14 knockout mice displayed a variety of metabolic phenotypes—increased levels of triglycerides (up 61%), free fatty acids (up 75%), free glycerol (up 43%), and cholesterol levels (up 12%) in the blood. At a tissue level, we found Klf14 knockout adipose showed a broad activation of genes related to lipid synthesis and downregulation of groups of genes involved in muscle function and development, suggesting a switch between muscle (energy usage) and adipose (energy storage) programs. We also confirmed in Klf14 knockout adipose tissue significant changes in several of the ten trans eQTL genes reported in human adipose tissue. At a cellular level, we found in vitro differentiated Klf14 knockout adipocytes had increased adipogenesis with larger lipid droplets and more triglyceride accumulation (increased >50%) compared to wild-type adipocytes. Thus, using novel genome-editing techniques, we were able to rapidly evaluate KLF14 function in mouse and human model systems. Taken together, the obtained data establish that KLF14 is a causal regulator of human metabolism, acting at least in part by modulating adipocyte function. Further studies in other metabolically active tissues such as liver and muscle are underway.
Author Disclosures: Q. Ding: None. R.M. Gupta: None. A. Raghavan: None. K. Musunuru: None.
- © 2014 by American Heart Association, Inc.