Gang He

Umami is a fundamental taste sensation, often described as a delicious and pleasant flavor perception. To enhance or complement the original flavor and meet the tastes of diverse regions, umami dipeptides have been extensively utilized in global food manufacturing. Currently, the application and purification techniques of dipeptides are relatively mature, while their umami mechanisms and molecular modification are both scarce. In this work, the 3D structure of the umami dipeptide target T1R1/T1R3 was first obtained through sequence alignment and homology modeling, then followed by the successful construction of a database containing 400 samples of dipeptides. Subsequently, the complex models of T1R1/T1R3, respectively, with DG (Asp-Gly) and EK (Glu-Lys) (i.e., T1R1_DG/T1R3, T1R1/T1R3_DG, T1R1_EK/T1R3, and T1R1/T1R3_EK) were obtained via molecular docking and virtual screening. Finally, based on comparative molecular dynamics (MD) simulation trajectories, the binding free energy was calculated to investigate receptor–ligand recognition and conformational changes, providing some implications for potential modifications of umami dipeptides. T1R1 tends to bind relatively small umami dipeptides, whereas T1R3 does the opposite, both of which favor the recognition of acidic and hydrophilic dipeptides. By comparing strategies such as hydroxyl introduction and chain length alteration, electrostatic effects may be more important than non-polar effects in molecular design. This work not only explores the recognition mechanism of umami dipeptides with the receptor T1R1/T1R3 showing certain theoretical significance, but also provides feasible suggestions for dipeptide screening and modification having certain application value.

Introduction: Prostate cancer (PCa) often progresses to castration-resistant prostate cancer (CRPC), which is linked to higher treatment resistance and recurrence rates. This highlights the urgent need for new therapeutic options. Natural products, especially flavonoids, have shown promise in reducing drug resistance and possess both antioxidant and anticancer effects. Developing drugs that specifically target CRPC could offer significant therapeutic advantages. Methods: Chrysosplenetin B (CspB) was extracted and purified from the herb Laggera pterodonta (DC.) Benth. using traditional flavonoid extraction techniques, followed by high-performance liquid chromatography (HPLC) for purity assessment and nuclear magnetic resonance (NMR) for structural identification. The effect of CspB on the viability of PCa cells was evaluated using the Cell Counting Kit-8 assay. Subsequently, transcriptome analysis was conducted, and cell cycle progression was assessed through flow cytometry in conjunction with propidium iodide (PI) staining. Additionally, western blotting and quantitative real-time polymerase chain reaction (qRT-PCR) were employed to confirm the expression levels of relevant proteins and genes. Results: CspB was found to inhibit the proliferation of PC3, DU145, and LNCaP cells in a dose-dependent manner, with a stronger effect noted in PC3 and DU145 cells. Transcriptomic analysis revealed that CspB treatment led to cell cycle arrest, particularly in PC3 cells. Flow cytometry with PI staining confirmed that CspB caused G1 phase cell cycle arrest in PC3 cells. Moreover, CspB treatment significantly increased the expression of essential members of the Cip/Kip family, including CIP1/P21 and KIP1/P27, as well as CDKN2B (P15) and CDKN2D (P19) from the INK4 family. Additionally, CspB exposure notably raised the expression of the G1 phase-negative regulatory gene CDKN1C, while key cell cycle regulators like CDK6 and E2F1 were significantly downregulated at the protein level. Conclusion: Our findings indicate that CspB effectively inhibits the proliferation of CRPC cells by reducing the activity of cell cycle proteins and cyclin-dependent kinase (CDK) complexes while upregulating the expression of P21 and P27 and inducing G1 phase cell cycle arrest. These results highlight the potential of CspB as a promising candidate for developing therapeutic agents aimed at targeting CRPC.

The pectin methyl esterase gene from Populus trichocarpa (PtPME) was successfully cloned through PCR amplification and subsequently inserted into the expressing vector pMAL-c5e for successful expression in Escherichia coli BL21 (DE3). Initially, we determined the primary enzymatic properties of PtPME, a pectin methyl esterase derived from Populus trichocarpa. Notably, this enzyme exhibits a higher affinity towards citrus pectin, with an esterification degree exceeding 60%. Furthermore, this enzyme’s optimal reaction temperature and pH were found to be 30 °C and 8, respectively. Importantly, its exceptional stability under neutral conditions highlights its potential application in the industrial production of low-ester pectin.

Introduction: Fatty acid binding protein 5 (FABP5) exhibits heightened expression levels in triple-negative breast cancer. The inhibitor of FABP5, Stony Brook fatty acid‐binding protein inhibitor 26 (SBFI-26), has demonstrated the capacity to suppress cell proliferation, migration, and invasion. This study delves into the functional mechanism and impact of combining SBFI-26 with docetaxel in treating MDA-MB-231 cells of triple-negative breast cancer. Methods: Various concentrations of docetaxel and SBFI-26 were chosen for individual or combined treatments. The effects of SBFI-26, docetaxel, or their combination on cell cycle arrest and apoptosis were assessed using flow cytometry. Western blotting was utilised to detect the expression of apoptosis-related proteins, namely cysteinyl aspartate-specific proteases 3 (Caspase3), B cell leukemia/lymphoma 2 (Bcl-2), and Bcl-2 associated X (Bax), while intracellular reactive oxygen species (ROS) levels were determined using a fluorescence spectrophotometer. Results: The IC50 values for SBFI-26 and docetaxel in inhibiting MDA-MB-231 cells were determined to be 106.1 μM and 86.14 nM, respectively. Significantly, the combination treatment augmented the proportion of G1 phase (apoptotic) cells by 3.67-fold compared to the control group (P < 0.0001). Furthermore, the apoptosis rate in the combination group was 2.59-fold higher than that in the docetaxel group (P < 0.0001) and demonstrated a significant increase of 1.82-fold compared with the SBFI-26 group (P < 0.001). Analyses revealed a decrease in the protein expression of Bcl-2, while Bax and Caspase3 exhibited an increase in the combination group for MDA-MB-231 cells. Moreover, the combined treatment group demonstrated a 2.97-fold increase (P < 0.0001) in ROS fluorescence intensity compared to the control group, a noteworthy 1.39-fold increase (P < 0.01) compared to the SBFI-26 treatment group, and a substantial 1.70-fold increase (P < 0.0001) compared to the docetaxel treatment group. Conclusion: These findings suggest that the co-administration of SBFI-26 with docetaxel effectively enhances apoptosis in triple-negative breast cancer MDA-MB-231 cells by elevating intracellular ROS levels.

SBFI26, an inhibitor of FABP5, has been shown to suppress the proliferation and metastasis of tumour cells. However, the underlying mechanism by which SBFI26 induces ferroptosis in breast cancer cells remains largely unknown. Three breast cancer cell lines were treated with SBFI26 and CCK‐8 assessed cytotoxicity. Transcriptome was performed on the Illumina platform and verified by qPCR. Western blot evaluated protein levels. Malondialdehyde (MDA), total superoxide dismutase (T‐SOD), Fe, glutathione (GSH) and oxidized glutathione (GSSG) were measured. SBFI26 induced cell death time‐ and dose‐dependent, with a more significant inhibitory effect on MDA‐MB‐231 cells. Fer‐1, GSH and Vitamin C attenuated the effects but not erastin. RNA‐Seq analysis revealed that SBFI26 treatment significantly enriched differentially expressed genes related to ferroptosis. Furthermore, SBFI26 increased intracellular MDA, iron ion, and GSSG levels while decreasing T‐SOD, total glutathione (T‐GSH), and GSH levels.SBFI26 dose‐dependently up‐regulates the expression of HMOX1 and ALOX12 at both gene and protein levels, promoting ferroptosis. Similarly, it significantly increases the expression of SAT1, ALOX5, ALOX15, ALOXE3 and CHAC1 that, promoting ferroptosis while downregulating the NFE2L2 gene and protein that inhibit ferroptosis. SBFI26 leads to cellular accumulation of fatty acids, which triggers excess ferrous ions and subsequent lipid peroxidation for inducing ferroptosis.

Polysaccharides derived from Auricularia auricula exhibit diverse biological activities and hold significant potential for commercial utilization as functional food ingredients. In this investigation, polysaccharides from A. auricula were obtained using six extraction techniques (ammonium oxalate solution extraction, sodium hydroxide solution extraction, hot water extraction, pectinase and cellulase-assisted extraction, ultrasonic-assisted extraction, and microwave-assisted extraction). Subsequently, a comprehensive comparison was conducted to evaluate their physicochemical properties and biological functionalities. The ammonium oxalate solution extraction method yielded a higher extraction rate (11.76%) and polysaccharide content (84.12%), as well as a higher uronic acid content (10.13%). Although the six Auricularia polysaccharides had different molecular weight distributions, monosaccharide molar ratios, similar monosaccharide compositions, and characteristic functional groups of polysaccharides, they exhibited different surface morphology. In vitro assays showed that polysaccharides extracted by ammonium oxalate solution possessed good scavenging ability against DPPH free radical, hydroxyl free radical and superoxide anion free radical as well as reduction power of iron ion. At the same time, both polysaccharides extracted by ammonium oxalate solution and sodium hydroxide solution promoted NO production in mouse macrophages along with the secretion of cytokines TNF-α, IL-1β, and IL-6. These results indicated significant differences in the structure and characteristics among Auricularia polysaccharides prepared by various extraction methods, which may be related to the variety or origin of A. auricula; furthermore, their bioactivities varied accordingly in vitro assays where the ammonium oxalate solution extraction method was found more beneficial for obtaining high-quality bioactive Auricularia polysaccharides.

It has been shown that Tibetan tea (TT) inhibits obesity and controls lipid metabolism. The fundamental processes by which TT prevents obesity are yet entirely unknown. Consequently, this research aimed to ascertain if TT may prevent obesity by modifying the gut flora. Our research demonstrated that TT prevented mice from gaining weight and accumulating fat due to the high‐fat diet (HFD), decreased levels of blood total cholesterol (TC), triglycerides (TG), and low‐density lipoprotein cholesterol (LDL‐C), and raised levels of high‐density lipoprotein cholesterol (HDL‐C). Adipogenesis‐related genes such as acetyl‐Coenzyme A carboxylase 1 (ACC1, LOC107476), fatty acid synthase (Fas, LOC14104), sterol regulatory element‐binding protein‐1c (SREBP‐1c, LOC20787), CCAAT/enhancer‐binding protein α (C/EBPα, LOC12606), stearoyl‐CoA desaturase 1 (SCD1, LOC20249), and peroxisome proliferator‐activated receptor γ (PPARγ, LOC19016) had their expression downregulated by lowering the Firmicutes/Bacteroidetes (F/B) ratio and controlling the number of certain gut bacteria. TT also alleviated HFD‐induced abnormalities of the gut microbiota. The Muribaculaceae, Lachnospiraceae NK4A136_group, Alistipes, and Odoribacter families were identified as the major beneficial gut microorganisms using Spearman's correlation analysis. Fecal microbiota transplantation (FMT) demonstrated that TT's anti‐obesity and gut microbiota‐modulating benefits might be transmitted to mice on an HFD, demonstrating that one of TT's targets for preventing obesity is the gut microbiota. TT also increased the amount of short‐chain fatty acids (SCFAs) in the feces, including acetic, propionic, and butyric acids. These results indicate the possible development of TT as a prebiotic to combat obesity and associated disorders. These results suggest that TT may act as a prebiotic against obesity and its associated diseases.

Enzalutamide is a drug used to treat PC. Docetaxel is a drug for chemotherapy for different cancers including prostate cancer (PC). The effectiveness of these drugs in treating castration-resistant prostate cancer (CRPC) is not consistent and thus, CRPC is still an incurable disease. Recent evidence showed that the bio-inhibitor of FABP5, dmrFABP5, suppressed the tumorigenicity and metastasis of the CRPC cells. In this work, we studied the possible synergic effect of dmrFABP5 combined with either Enzalutamide or Docetaxel on suppressing tumorigenicity of the PC cells. A highly significant synergic effect was observed when dmrFABP5 was used in combination with Enzalutamide on the androgen-responsive PC cells 22RV1. A highly significant synergic effect was also observed when dmrFABP5 was combined with Docetaxel on 22RV1 cells and on the highly malignant, androgen-receptor (AR)-negative DU145 cells. These combined applications exhibited a highly significant inhibitory action on the viability, migration, invasion and colony formation abilities of both 22RV1and DU145 cells. However, dmrFABP5 did not produce any suppression effect when used on FABP5-negative cell line LNCaP, although Enzalutamide can significantly suppress LNCaP cells as a single agent. Further investigations suggested that these synergistic effects were produced by interrupting the FABP5-related signal transduction pathway in PC cells.