Exploring the regulatory mechanism of tRNA-derived fragments 36 in acute pancreatitis based on small RNA sequencing and experiments

BACKGROUND Acute pancreatitis(AP)is a disease featuring acute inflammation of the pancreas and histological destruction of acinar cells.Approximately 20%of AP patients progress to moderately severe or severe pancreatitis,with a case fatality rate of up to 30%.However,a single indicator that can serve as the gold standard for prognostic prediction has not been discovered.Therefore,gaining deeper insights into the underlying mechanism of AP progression and the evolution of the disease and exploring effective biomarkers are important for early diagnosis,progression evaluation,and precise treatment of AP.AIM To determine the regulatory mechanisms of tRNA-derived fragments(tRFs)in AP based on small RNA sequencing and experiments.METHODS Small RNA sequencing and functional enrichment analyses were performed to identify key tRFs and the potential mechanisms in AP.Reverse transcription quantitative polymerase chain reaction(RT-qPCR)was conducted to determine tRF expression.AP cell and mouse models were created to investigate the role of tRF36 in AP progression.Lipase,amylase,and cytokine levels were assayed to examine AP progression.Ferritin expression,reactive oxygen species,malondialdehyde,and ferric ion levels were assayed to evaluate cellular ferroptosis.RNA pull down assays and methylated RNA immunoprecipitation were performed to explore the molecular mechanisms.RESULTS RT-qPCR results showed that tRF36 was significantly upregulated in the serum of AP patients,compared to healthy controls.Functional enrichment analysis indicated that target genes of tRF36 were involved in ferroptosisrelated pathways,including the Hippo signaling pathway and ion transport.Moreover,the occurrence of pancreatic cell ferroptosis was detected in AP cells and mouse models.The results of interference experiments and AP cell models suggested that tRF-36 could promote AP progression through the regulation of ferroptosis.Furthermore,ferroptosis gene microarray,database prediction,and immunoprecipitation suggested that tRF-36 accelerated the progression of AP by recruiting insulin-like growth factor 2 mRNA binding protein 3(IGF2BP3)to the p53 mRNA m6A modification site by binding to IGF2BP3,which enhanced p53 mRNA stability and promoted the ferroptosis of pancreatic follicle cells.CONCLUSION In conclusion,regulation of nuclear pre-mRNA domain-containing protein 1B promoted AP development by regulating the ferroptosis of pancreatic cells,thereby acting as a prospective therapeutic target for AP.In addition,this study provided a basis for understanding the regulatory mechanisms of tRFs in AP.

A novel technology to reduce astringency of tea polyphenols extract and its mechanism

Objective:Tea polyphenols are natural extracts used widely throughout the world.However,the severe astringency of tea polyphenols has reduced patient compliance.Based on the analysis of the formation mechanism of astringency,this paper hopes to propose a new method to control the astringency of tea polyphenols and improve patient compliance without changing its effect.Methods:Artificial saliva was used to prepare the tea polyphenols solution with different p H,using bcasein to imitate salivary protein,and preparing 1.2 mg/m L b-casein solution.A fluorescence quenching test was used to study the interaction between tea polyphenols and b-casein,combined with the stability test results of the compound,we can choose the p H with weak binding but good stability as the best p H for masking astringency.The taste-masking tablets were prepared under the best p H conditions,and the Xinnaojian Original Tablets were prepared according to the conventional preparation method.The disintegration time limit and solubility were tested respectively.The astringency of Xinnaojian original tablets and taste-masking tablets was evaluated by visual analogue scale(VAS).Results:The result of the fluorescence quenching test prompted that the combination force was the weakest when the p H was 4.9.Further synchronous fluorescence analysis showed that an increase in p H resulted in a decrease of the binding sites between tea polyphenols and b-casein,and this decrease was closely related to changes in tryptophan residues in b-casein.Both original and taste-masking Xinnaojian Tablets were prepared.Volunteers’VAS scores illustrated that the astringency improved significantly with the masking tablets(P<0.05).Conclusion:This p H-adjusting masking treatment had little effect on the recovery of polyphenols from the tablets or the dissolution of the tablets.This study provides a novel and feasible astringency masking technology for tea polyphenols and its preparation.