Qi Liu

Alternative splicing of pre-mRNA is a key mechanism for increasing the complexity of proteins in humans, causing a diversity of expression of transcriptomes and proteomes in a tissue-specific manner. Alternative splicing is regulated by a variety of splicing factors. However, the changes and errors of splicing regulation caused by splicing factors are strongly related to many diseases, something which represents one of this study's main interests. Further understanding of alternative splicing regulation mediated by cellular factors is also a prospective choice to develop specific drugs for targeting the dynamic RNA splicing process. In this review, we firstly concluded the basic principle of alternative splicing. Afterwards, we showed how splicing isoforms affect physiological activities through specific disease examples. Finally, the available treatment methods relative to adjusting splicing activities have been summarized.

A gas chromatography-mass spectrometric (GC-MS) method was established for the determination of cyromazine and its metabolite, melamine, in animal-derived food. Chicken and tilapia muscle samples were spiked with (15)N(3)-melamine, extracted with an acidic acetonitrile/water solution, and defatted with dichloromethane. Egg and milk samples were directly extracted with 3% trichloroacetic acid. The extracts were purified using mixed cation-exchange cartridges, derived with N,O-bis(trimethylsilyl)trifluoroacetamide, and detected by GC-MS. Cyromazine and melamine were quantified by external standard methods except for the determination of melamine in animal muscle, which used an internal standard method. Recoveries ranged from 75.0 to 110.0%, and relative standard deviations were <15.0%. In animal muscle the limits of quantification (LOQs) were 20 microg/kg and the limits of detection (LODs) were 10 microg/kg for cyromazine and melamine. In milk and eggs the LOQs were 10 microg/kg and the LODs were 5 microg/kg for both analytes.

In this work, a "two birds with one stone" ruthenium(II) complex probe, Ru-NBD, is proposed as an effective tool for biothiols detection and discrimination in vitro and in vivo. Ru-NBD is nonluminescent due to the quenching of Ru(II) complex emission by photoinduced electron transfer (PET) from Ru(II) center to NBD and the quenching of NBD emission through 4-substitution with "O" ether bond. Ru-NBD is capable of reacting with Cys/Hcy to form long-lived red-emitting Ru-OH and short-lived green-emitting NBD-NR, while reacting with GSH to produce Ru-OH and nonemissive NBD-SR. The long lifetime emission of Ru(II) complex allows elimination of short lifetime background and NBD-NR fluorescence for total biothiols detection ("bird" one) by time-gated luminescence (TGL) analysis, and the remarkable difference in luminescence color response allows discrimination GSH and Cys/Hcy ("bird" two) through steady-state luminescence analysis. Ru-NBD features high sensitivity and selectivity, rapid luminescence response, and low cytotoxicity, which enables it to be used as the probe for luminescence and background-free TGL detection and visualization of biothiols in live cells, zebrafish, and mice. The successful development of this probe is anticipated to contribute to the future biological studies of biothiols roles in various diseases.