A- and B-type wheat starch granules: The multiscale structural evolution during digestion and the distinct digestion mechanisms.

The digestive characteristics of wheat starch are closely related to human health. However, the digestive mechanisms of distinct wheat starch granules are not well understood. To address this problem, A- and B-type wheat starch granules (AWS and BWS, respectively) were digested in vitro and the structural evolution of the digestive remnants was compared. After stomach-intestinal digestion of AWS, its crystallinity decreased from 12.75 % to 6.65 %, its fractal dimension decreased from 3.12 to 2.35, and the median particle size decreased from 20.613 to 10.135 µm. Additionally, the number of short chains (polymerization degree<14) and thermodynamic stability decreased after digestion. For BWS, Fourier transform infrared ratio of 1047/1022 cm-1 and 995/1022 cm-1 increased from 0.665 and 0.725 to 0.990 and 0.800, respectively. The median particle size decreased from 5.480 to 4.769 µm. An enzyme-resistant scattering peak was observed in the 1.35 nm-1 lamellar structure. Additionally, the number of B2 and B3 chains and the thermodynamic stability increased after digestion. Our study confirmed that BWS is more likely than AWS to form enzyme-resistant structures during digestion. These findings provide insights into the distinct digestion mechanisms of AWS and BWS, and serve as a foundation for modifying wheat starch to increase its nutritional value.

Novel Strategies for Angiogenesis in Tissue Injury: Therapeutic Effects of iPSCs-Derived Exosomes.

Regeneration after tissue injury is a dynamic and complex process, and angiogenesis is necessary for normal physiological activities and tissue repair. Induced pluripotent stem cells are a new approach in regenerative medicine, which provides good model for the study of difficult-to-obtain human tissues, patient-specific therapy, and tissue repair. As an innovative cell-free therapeutic strategy, the main advantages of the treatment of induced pluripotent stem cells (iPSCs)-derived exosomes are low in tumorigenicity and immunogenicity, which become an important pathway for tissue injury. This review focuses on the mechanism of the angiogenic effect of iPSCs-derived exosomes on wound repair in tissue injury and their potential therapeutic targets, with a view to providing a theoretical basis for the use of iPSCs-derived exosomes in clinical therapy.

CircADSS contributes to hepatocellular carcinoma development by regulating miR-431-5p/TOP2A.

CircRNAs participated in regulating hepatocellular carcinoma (HCC), and the regulation function of circRNA adenylosuccinate synthase (circADSS) on HCC development is not clear. RT-qPCR and western blot were performed to detect RNA expression. Cell proliferation was analysed by CCK-8 and EdU assay. Cell cycle distribution was analysed by flow cytometry assay. Cell migration and invasion were measured by transwell assay. Mechanism assays were employed to examine the interaction between miR-431-5p and circADSS, or TOP2A. Xenograft mouse model was constructed for in vivo assay. CircADSS and TOP2A expression were boosted, while miR-431-5p was limited in tumour tissues and cells. CircADSS silencing decreased HCC cell proliferation, cell cycle progression, migration, invasion, as well as EMT. MiR-431-5p inhibitors or ectopic TOP2A expression could restore the effect of circADSS knockdown on HCC progression. There was target relationship between miR-431-5p and circADSS, or TOP2A. Knockdown of circADSS suppressed tumour growth in vivo. CircADSS could regulate HCC cell malignancy by miR-431-5p/TOP2A axis.

Circular RNA hsa_circ_0005397 promotes hepatocellular carcinoma progression by regulating the miR-326/PDK2 axis.

INTRODUCTION: Circular RNAs (circRNAs) are associated with the initiation and progression of cancer. However, the biological functions and underlying mechanism of hsa_circ_0005397 in hepatocellular carcinoma (HCC) have not been fully elucidated. METHODS: Hemotoxylin and eosin staining was used to assess histological changes. The expression levels of hsa_circ_0005397, miR-326 and pyruvate dehydrogenase kinase 2 (PDK2) were measured by a quantitative real-time polymerase chain reaction. Cell proliferation was evaluated by cell counting kit-8 and colony formation assays. Cell cycle distribution and apoptosis were detected by flow cytometry analysis. Caspase-3 activity was determined by a caspase-3 activity kit. Wound healing and transwell assays were used to evaluate cell migration and invasion. A western blot assay was performed to measure the expression of cyclin D1, p21, matrix metalloproteinase (MMP)2, MMP9, PDK2 and PCNA. The interaction between miR-326 and hsa_circ_0005397 or PDK2 was confirmed by dual-luciferase reporter, RNA immunoprecipitation and RNA pull-down assays. Xenograft tumor models were established to confirm the role of hsa_circ_0005397 in vivo. RESULTS: Hsa_circ_0005397 and PDK2 were up-regulated, whereas miR-326 was down-regulated in HCC tissues and cells. Hsa_circ_0005397 knockdown inhibited cell proliferation and metastasis, and promoted apoptosis. miR-326 was a direct target of hsa_circ_0005397, and inhibition of miR-326 reversed the inhibitory effect of hsa_circ_0005397 silencing on HCC progression. Moreover, PDK2 was a direct target of miR-326 and PDK2 overexpression abated the anti-cancer roles of miR-326 in HCC. Additionally, hsa_circ_0005397 regulated PDK2 expression by sponging miR-326. Furthermore, hsa_circ_0005397 down-regulation suppressed tumor growth by up-regulating miR-326 and down-regulating PDK2. CONCLUSIONS: Hsa_circ_0005397 facilitates HCC progression by regulating the miR-326/PDK2 axis, providing a promising circRNA-targeted therapy for HCC.

Fluorescence Sensing of Caffeine in Tea Beverages with 3,5-diaminobenzoic Acid.

A rapid, selective and sensitive method for the detection of caffeine in tea infusion and tea beverages are proposed by using 3,5-diaminobenzoic acid as a fluorescent probe. The 3,5-diaminobenzoic acid emits strong fluorescence around 410 nm under the excitation of light at 280 nm. Both the molecular electrostatic potential analysis and fluorescent lifetime measurement proved that the existence of caffeine can quench the fluorescence of 3,5-diaminobenzoic acid. Under the optimal experimental parameters, the 3,5-diaminobenzoic acid was used as a fluorescent probe to detect the caffeine aqueous solution. There exists a good linear relationship between the fluorescence quenching of the fluorescent probe and the concentration of caffeine in the range of 0.1-100 µM, with recovery within 96.0 to 106.2%, while the limit of detection of caffeine is 0.03 µM. This method shows a high selectivity for caffeine. The caffeine content in different tea infusions and tea beverages has been determined and compared with the results from HPLC measurement.