Integration of Hybridization Chain Reaction and Protein-Binding Amplification for Long-Term Imaging of Intracellular mRNA: Avoiding Signal Fluctuation.

Amplified nanoprobes based on hybridization chain reaction (HCR) have been widely developed for the detection of intracellular low abundance mRNA. However, the formed chain-like assembly decorated with fluorophore would be degraded rapidly by endogenous enzyme, resulting in failure of the long-term fluorescence imaging. To address this issue, herein, a composite signal-amplifying strategy that integrates HCR into protein-binding signal amplification (HPSA) was communicated for the in situ imaging of mRNA by avoiding signal fluctuation. Different from conventional HCR-based nanoprobes (HCR-nanoprobe), the HCR was used as the signal-triggered mode and the amplifying signal generated from in situ fluorophore-protein binding in cells, which can maintain high stability of the signal for a long time. As a proof-of-principle, a nanobeacon based on HPSA (HPSA-nanobeacon) was constructed to detect TK1 mRNA. Taking advantage of the double signal-amplifying mode, the endogenous TK1 mRNA was sensitively detected and the fluorescence signal was maintained for more than 8 h in HepG2 cells. The attempt in this work provides a new option to the current signal-amplifying strategy for sensing nucleic acid targets with high stability, significantly enhancing the acquisition of intracellular molecular information.

Assessment of the anti-diarrhea function of compound Chinese herbal medicine Cangpo Oral Liquid.

BACKGROUND: Diarrhea is a big problem in piglets. Cangpo Oral Liquid (COL) is a compound of Chinese herbal medicine. The preparation was fed to piglets had diarrheal disease in order to determine its anti-diarrhea activity and potential applications in vivo. MATERIALS AND METHODS: The contents of Berberine hydrochloride, Magnolol and Honokiol in COL were performed on HPLC analysis. Organ bath was used to investigate the effect of COL on peristaltic reflexes and peristaltic waves in vitro. And anti-diarrhea activity of COL was evaluated in clinical. RESULTS: Thin layer chromatography (TLC) and HPLC analyses showed that the contents of Berberine hydrochloride, Magnolol and Honokiol in COL were 970µg/mL, 130µg/mL and 300µg/mL, respectively. Administration of the COL to the organ bath caused a concentration-dependent inhibition of intestinal peristalsis. When the COL concentration in the bath was cumulatively increased, the amplitude and frequency of the peristaltic waves was lowered. The result of clinical efficacy of COL was very effective to diarrheic piglets. COL can possibly inhibit the curve of peristaltic waves in vitro; and clinical trial showed a statistically significant therapeutic effect in vivo. CONCLUSION: In conclusion, COL can be used as an effective therapeutic agent. However, the ingredients, pharmacokinetics and specific signaling pathways of COL need to be further studied.