Creation of Genetically Modified Adipocytes for Tissue Engineering: Creatine Kinase B Overexpression Leads to Stimulated Glucose Uptake and Mitochondrial Potential Growth, but Lowered Lipid Synthesis

Background: The global burden of obesity and type 2 diabetes mellitus is a significant contributor to mortality and disability in the modern world. In this regard, the modification of adipocyte metabolism has been identified as a promising approach to develop new genetic and cellular engineering therapeutics. In this study, we activate the expression of creatine kinase B (CKB), a key enzyme of a non-canonical futile cycle and the regulator of energy storage, to promote catabolic processes in mature adipocytes. Methods: The protein-coding sequence of CKB was amplified by PCR from Mus musculus brain mRNA. Lentiviral transduction was used to transfer the CKB sequence into mature adipocytes. Adipocyte metabolism was analyzed by radioisotope monitoring of labeled [3H]-2-deoxyglucose and [14C]-glucose. Confocal microscopy was applied to estimate lipid droplets morphology (BODIPY493/503 dye), mitochondrial membrane potential (JC-1 dye), and thermogenesis (ERthermAC dye). Results: After lentiviral delivery of the CKB-coding sequence, CKB mRNA level increased 75-fold and protein expression fivefold. CKB overexpression does not cause significant changes in lipid droplet morphology. Despite this, enhanced glucose uptake and reduced lipid synthesis under adrenergic stimulation are detected during CKB overexpression. CKB causes an increase in mitochondrial potential with no effect on thermogenesis in adipocytes. Conclusions: In this study, we have shown that CKB overexpression in mature adipocytes allows us to obtain adipocytes with high glucose uptake, potency of ATP synthesis, and suppressed lipogenesis. These genetically modified cells may potentially exhibit a favorable metabolic effect in the context of excessive nutrient utilization.