Commensal intestinal microbiota interacts with gut epithelial cells in the host by binding to specific host receptors.

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Background The dried fruit of Chaenomeles speciosa, known as Chaenomelis Fructus or Zhoupi Mugua, is a type of traditional Chinese medicine (TCM) that is widely used to treat many diseases. Guangpi Mugua, the dried fruit of the Chaenomeles sinensis, is its most commonly known adulterant. Objective To establish a robust approach for the quality control and identification of Chaenomelis Fructus. Method Thin-layer chromatography (TLC) was optimized and used to discriminate Chaenomelis Fructus from Guangpi Mugua. High-performance liquid chromatography (HPLC) combined with fingerprint analysis and partial least-squares (PLS) discrimination analysis (DA) was employed to study the chemical differences between Chaenomelis Fructus and Guangpi Mugua. The single standard to determine multi-components (SSDMC) method, with credible precision, repeatability, stability, and durability, was developed for quantitative analysis of the abundant markers. Results The developed TLC and HPLC methods were effective in the authentication of Chaenomelis Fructus. Moreover, oleanolic acid, ursolic acid, pomolic acid, corosolic acid, 3-O-acetylpomolic acid, and one unknown compound were identified to be critical markers for the discrimination of Chaenomelis Fructus from Guangpi Mugua. Conclusion Adulteration has always been a challenge in the development of TCM. This study presents useful insights that may help solve the problem of adulteration during the preparation of Chaenomelis Fructus. Highlights The present study provides a systematic method for the quality control of Chaenomelis Fructus. This is therefore the first step towards solving the problem of adulteration to improve the clinical safety and effectiveness of Chaenomelis Fructus.

Extracellular glyceraldehyde-3-phosphate dehydrogenase (GAPDH) has multiple interactions with various gut epithelial components. For instance, GAPDH in Lactobacillus johnsonii MG cells interacts with junctional adhesion molecule-2 (JAM-2) in Caco-2 cells and enhances tight junctions. However, the specificity of GAPDH toward JAM-2 and its role in the tight junctions in Caco-2 cells remain unclear. In the present study, we assessed the effect of GAPDH on tight junction regeneration and explored the GAPDH peptide fragments required for interaction with JAM-2. GAPDH was specifically bound to JAM-2 and rescued H2O2-damaged tight junctions in Caco-2 cells, with various genes being upregulated in the tight junctions. To understand the specific amino acid sequence of GAPDH that interacts with JAM-2, peptides interacting with JAM-2 and L. johnsonii MG cells were purified using HPLC and predicted using TOF–MS analysis. Two peptides, namely 11GRIGRLAF18 at the N-terminus and 323SFTCQMVRTLLKFATL338 at the C-terminus, displayed good interactions and docking with JAM-2. In contrast, the long peptide 52DSTHGTFNHEVSATDDSIVVDGKKYRVYAEPQAQNIPW89 was predicted to bind to the bacterial cell surface. Overall, we revealed a novel role of GAPDH purified from L. johnsonii MG in promoting the regeneration of damaged tight junctions and identified the specific sequences of GAPDH involved in JAM-2 binding and MG cell interaction.

Б а с р е д а к т о р ы х.ғ.д., проф., ҚР ҰҒА академигі М.Ж. Жұрынов Р е д а к ц и я а л қ а с ы: Адекенов С.М. проф., академик (Қазақстан) (бас ред. орынбасары) Величкин В.И. проф., корр.-мүшесі (Ресей) Вольдемар Вуйцик проф. (Польша) Гончарук В.В. проф., академик (Украина) Гордиенко А.И. проф., академик (Белорус) Дука Г. проф., академик (Молдова) Илолов М.И. проф., академик (Тəжікстан), Леска Богуслава проф. (Польша), Локшин В.Н. проф. чл.-корр. (Қазақстан) Нараев В.Н. проф. (Ресей) Неклюдов И.М. проф., академик (Украина) Нур Изура Удзир проф. (Малайзия) Перни Стефано проф. (Ұлыбритания) Потапов В.А. проф. (Украина) Прокопович Полина проф. (Ұлыбритания) Омбаев А.М. проф., корр.-мүшесі (Қазақстан) Өтелбаев М.О. проф., академик (Қазақстан) Садыбеков М.А. проф., корр.-мүшесі (Қазақстан) Сатаев М.И. проф., корр.-мүшесі (Қазақстан) Северский И.В. проф., академик (Қазақстан) Сикорски Марек проф., (Польша) Рамазанов Т.С. проф., академик (Қазақстан) Такибаев Н.Ж. проф., академик (Қазақстан), бас ред. орынбасары Харин С.Н. проф., академик (Қазақстан) Чечин Л.М. проф., корр.-мүшесі (Қазақстан) Харун Парлар проф. (Германия) Энджун Гао проф. (Қытай) Эркебаев А.Э. проф., академик (Қырғыстан) «Қазақстан Республикасы Ұлттық ғылым академиясының баяндамалары»