Proteomic profile of carbonylated proteins in rat liver: Discovering possible mechanisms for tetracycline‐induced steatosis

To investigate biochemical mechanisms for the tetracycline‐induced steatosis in rats, targeted proteins of oxidative modification were profiled. The results showed that tetracycline induced lipid accumulation, oxidative stress, and cell viability decline in HepG2 cells only under the circumstances of palmitic acid overload. Tetracycline administration in rats led to significant decrement in blood lipids, while resulted in more than four times increment in intrahepatic triacylglycerol and typical microvesicular steatosis in the livers. The triacylglycerol levels were positively correlated with oxidative stress. Proteomic profiles of carbonylated proteins revealed 26 targeted proteins susceptible to oxidative modification and most of them located in mitochondria. Among them, the long‐chain specific acyl‐CoA dehydrogenase was one of the key enzymes regulating fatty acid β‐oxidation. Oxidative modification of the enzyme in the tetracycline group depressed its enzymatic activity. In conclusion, the increased influx of lipid into the livers is the first hit of tetracycline‐induced microvesicular steatosis. Oxidative stress is an essential part of the second hit, which may arise from the lipid overload and attack a series of functional proteins, aggravating the development of steatosis. The 26 targeted proteins revealed here provide a potential direct link between oxidative stress and tetracycline‐induced steatosis.     

A Novel Glyceraldehyde-3-Phosphate Dehydrogenase (<Emphasis Type="Italic">GAPDH</Emphasis>) Promoter for Expressing Transgenes in the Halotolerant Alga <Emphasis Type="Italic">Dunaliella salina</Emphasis>

A major challenge for efficient transgene expression in Dunaliella salina is to find strong endogenous promoters to drive the transgene expression. In the present study, a novel glyceraldehyde-3-phosphate dehydrogenase (GAPDH) promoter was cloned and used to drive expressions of the bialaphos resistance (bar) gene and of the N-terminal fragment of human canstatin (Can-N). The results showed that the bar gene was transcribed by the GAPDH promoter and integrated into the genome of the transformants of D. salina. Furthermore, the PCR identification, Southern and western blots indicated that Can-N was expressed in transgenic D. salina, demonstrating that the promoter of the D. salina GAPDH gene is suitable for driving expression of heterologous genes in transgenic D. salina.     

Effects of the Notch Signaling Pathway on Secondary Brain Changes Caused by Spinal Cord Injury in Mice

Neurochemical Research - Spinal cord injury (SCI) can cause secondary brain changes, leading to hypomyelination in the dorsolateral prefrontal cortex (dlPFC). Some studies have shown that notch...