ABSTRACT
Reducing lactate accumulation has always been a goal of the mammalian cell biotechnology industry. When animal cells are cultured in vitro, the accumulation of lactate is mainly the combined result of two metabolic pathways. On one hand, glucose generates lactate under the function of lactate dehydrogenase A (LDHA); on the other hand, lactate can be oxidized to pyruvate by LDHB or LDHC and re-enter the TCA cycle. This study comprehensively evaluated the effects of LDH manipulation on the growth, metabolism and human adenovirus (HAdV) production of human embryonic kidney 293 (HEK-293) cells, providing a theoretical basis for engineering the lactate metabolism in mammalian cells. By knocking out ldha gene and overexpression of ldhb and ldhc genes, the metabolic efficiency of HEK-293 cells was effectively improved, and HAdV production was significantly increased. Compared with the control cell, LDH manipulation promoted cell growth, reduced the accumulation of lactate and ammonia, significantly enhanced the efficiency of substrate and energy metabolism of cells, and significantly increased the HAdV production capacity of HEK-293 cells. Among these LDH manipulation measures, ldhc gene overexpression performed the best, with the maximum cell density increased by about 38.7%. The yield of lactate to glucose and ammonia to glutamine decreased by 33.8% and 63.3%, respectively; and HAdV titer increased by at least 16 times. In addition, the ATP production rate, ATP/O2 ratio, ATP/ADP ratio and NADH content of the modified cell lines were increased to varying degrees, and the energy metabolic efficiency was significantly improved.
Subject(s)
Animals , Humans , L-Lactate Dehydrogenase/genetics , Lactic Acid , Adenoviruses, Human , Ammonia , HEK293 Cells , Glucose/metabolism , Adenosine Triphosphate/metabolism , Kidney/metabolism , Mammals/metabolismABSTRACT
Heart failure (HF) is a global public health problem with high morbidity and mortality. A large number of studies have shown that HF is caused by severe energy metabolism disorders, which result in an insufficient heart energy supply. This deficiency causes cardiac pump dysfunction and systemic energy metabolism failure, which determine the development of HF and recovery of heart. Current HF therapy acts by reducing heart rate and cardiac preload and afterload, treating the HF symptomatically or delaying development of the disease. Drugs aimed at cardiac energy metabolism have not yet been developed. In this review, we outline the main characteristics of cardiac energy metabolism in healthy hearts, changes in metabolism during HF, and related pathways and targets of energy metabolism. Finally, we discuss drugs that improve cardiac function
ABSTRACT
OBJECTIVE: To make a review of nowadays related dissertations about epigenetic modifications (DNA methylation, histone modifications, chromatin remodeling and the non-coding microRNA interruption, etc.) mediating the abnormal expression of drug metabolic enzymes and inactive metabolism of substances in organisms. METHODS: Researches on epigenetic modifications regulating the genes expression or activity change of drug metabolism enzymes were reviewed. RESULTS AND CONCLUSION: The research in this field can provide reference for determining biomarkers in clinical diagnosis and therapies of tumors.