Expression, purification, characterization and crystallization of Panax quinquefolius ginsenoside glycosyltransferase Pq3-O-UGT2.

Pq3-O-UGT2, derived from Panax quinquefolius, functions as a ginsenoside glucosyltransferase, utilizing UDP-glucose (UDPG) as the sugar donor to catalyze the glycosylation of Rh2 and F2. An essential step in comprehending its catalytic mechanism involves structural analysis. In preparation for structural analysis, we expressed Pq3-O-UGT2 in the Escherichia coli (E. coli) strain Rosetta (DE3). The recombinant Pq3-O-UGT2 was purified through Ni-NTA affinity purification, a two-step ion exchange chromatography, and subsequently size-exclusion chromatography (SEC). Notably, the purified Pq3-O-UGT2 showed substantial activity toward Rh2 and F2, catalyzing the formation of Rg3 and Rd, respectively. This activity was discernible within a pH range of 4.0-9.0 and temperature range of 30-55 °C, with optimal conditions observed at pH 7.0-8.0 and 37 °C. The catalytic efficiency of Pq3-O-UGT2 toward Rh2 and F2 was 31.43 s-1 mΜ-1 and 169.31 s-1 mΜ-1, respectively. We further crystalized Pq3-O-UGT2 in both its apo form and co-crystalized forms with UDPG, Rh2 and F2, respectively. High-quality crystals were obtained and X-ray diffraction data was collected for all co-crystalized samples. Analysis of the diffraction data revealed that the crystal of Pq3-O-UGT2 co-crystalized with UDP-Glc belonged to space group P1, while the other two crystals belonged to space group P212121. Together, this study has laid a robust foundation for subsequent structural analysis of Pq3-O-UGT2.

Cut-off values of haemoglobin and clinical outcomes in incident peritoneal dialysis: the PDTAP study.

BACKGROUND: To explore the cut-off values of haemoglobin (Hb) on adverse clinical outcomes in incident peritoneal dialysis (PD) patients based on a national-level database. METHODS: The observational cohort study was from the Peritoneal Dialysis Telemedicine-assisted Platform (PDTAP) dataset. The primary outcomes were all-cause mortality, major adverse cardiovascular events (MACE) and modified MACE (MACE+). The secondary outcomes were the occurrences of hospitalization, first-episode peritonitis and permanent transfer to haemodialysis (HD). RESULTS: A total of 2591 PD patients were enrolled between June 2016 and April 2019 and followed up until December 2020. Baseline and time-averaged Hb <100 g/l were associated with all-cause mortality, MACE, MACE+ and hospitalizations. After multivariable adjustments, only time-averaged Hb <100 g/l significantly predicted a higher risk for all-cause mortality {hazard ratio [HR] 1.83 [95% confidence interval (CI) 1.19-281], P = .006}, MACE [HR 1.99 (95% CI 1.16-3.40), P = .012] and MACE+ [HR 1.77 (95% CI 1.15-2.73), P = .010] in the total cohort. No associations between Hb and hospitalizations, transfer to HD and first-episode peritonitis were observed. Among patients with Hb ≥100 g/l at baseline, younger age, female, use of iron supplementation, lower values of serum albumin and renal Kt/V independently predicted the incidence of Hb <100 g/l during the follow-up. CONCLUSION: This study provided real-world evidence on the cut-off value of Hb for predicting poorer outcomes through a nation-level prospective PD cohort.

Engineering of triterpene metabolism and overexpression of the lignin biosynthesis gene PAL promotes ginsenoside Rg3 accumulation in ginseng plant chassis.

The ginsenoside Rg3 found in Panax species has extensive pharmacological properties, in particular anti-cancer effects. However, its natural yield in Panax plants is limited. Here, we report a multi-modular strategy to improve yields of Rg3 in a Panax ginseng chassis, combining engineering of triterpene metabolism and overexpression of a lignin biosynthesis gene, phenylalanine ammonia lyase (PAL). We first performed semi-rational design and site mutagenesis to improve the enzymatic efficiency of Pq3-O-UGT2, a glycosyltransferase that directly catalyzes the biosynthesis of Rg3 from Rh2 . Next, we used clustered regularly interspaced palindromic repeats (CRISPR)/CRISPR-associated protein 9 (Cas9) gene editing to knock down the branch pathway of protopanaxatriol-type ginsenoside biosynthesis to enhance the metabolic flux of the protopanaxadiol-type ginsenoside Rg3 . Overexpression of PAL accelerated the formation of the xylem structure, significantly improving ginsenoside Rg3 accumulation (to 6.19-fold higher than in the control). We combined overexpression of the ginsenoside aglycon synthetic genes squalene epoxidase, Pq3-O-UGT2, and PAL with CRISPR/Cas9-based knockdown of CYP716A53v2 to improve ginsenoside Rg3 accumulation. Finally, we produced ginsenoside Rg3 at a yield of 83.6 mg/L in a shake flask (7.0 mg/g dry weight, 21.12-fold higher than with wild-type cultures). The high-production system established in this study could be a potential platform to produce the ginsenoside Rg3 commercially for pharmaceutical use.

Protective Effect of Ganshuang Granules () on Liver Cirrhosis by Suppressing Regulatory T Cells in Mouse Model.

OBJECTIVE: To investigate the potential antifibrotic mechanisms of Chinese medicine Ganshuang Granules (, GSG) and to provide clinical therapeutic evidence of its effects. METHODS: A cirrhotic mouse model was established by intraperitoneally injecting a mixture of CCl4 (40%) and oil (60%) at 0.2 mL per 100 g of body weight twice a week for 12 weeks. After 12-week modeling, GSG was intragastric administrated to the mice for 2 weeks, and the mice were divided into low-, medium- and high-dose groups at doses of 1, 2 and 4 g/(kg·day), respectively. Liver morphology changes were observed using Masson's trichrome staining and B-ultrasound. The levels of alanine aminotransferase (ALT), aspartate aminotransferase (AST) and hyaluronic acid (HA) in serum were detected using an automatic biochemistry analyzer. The expressions of desmin, smooth muscle actin (SMA) and Foxp3 in liver were detected by immunoflfluorescence. The regulatory T cell (Treg) frequency was determined through flflow cytometry analysis. Collagen-I, SMA, IL-6, tumor necrosis factor α (TNF-α), interleukin (IL)-1ß and transforming growth factor ß1 (TGF-ß1) expression levels were measured using quantitative polymerase chain reaction (qPCR). RESULTS: Masson's staining result showed fewer pseudolobule structures and fibrous connective tissue in the GSG-treatment groups than in the spontaneous recovery group. Ultrasonography showed that GSG treatment reduced the number of punctate hyperechoic lesions in mice cirrhotic livers. The serum ALT, AST, HA levels were significantly ameliorated by GSG treatment (ALT: F=8.104, P=0.000; AST: F=7.078, P=0.002; and HA: F=7.621, P=0.001). The expression levels of collagen-I and SMA in the cirrhotic livers were also attenuated by GSG treatment (collagen-I: F=3.938, P=0.011; SMA: F=4.115, P=0.009). Tregs, which were elevated in the fibrotic livers, were suppressed by GSG treatment (F=8.268, P=0.001). The expressions of IL-6, TNF-α and IL-1ß increased, and TGF-ß levels decreased in the cirrhotic livers after GSG treatment (IL-6: F=5.457, P=0.004; TNF-α: F=6.023, P=0.002; IL-1ß: F=6.658, P=0.001; and TGF-ß1: F=11.239, P=0.000). CONCLUSIONS: GSG promoted the resolution/regression of cirrhosis and restored liver functions in part by suppressing Treg cell differentiation, which may be mediated by hepatic stellate cells.

[Cross-sectional survey of characteristics of reaction point Jingtong in balance acupuncture].

OBJECTIVE: To explore the performance patterns of reaction point Jingtong in balance acupuncture through multi-center and big-sample clinical investigation. Methods The Jingtong points of balance acupuncture on healthy side and affected side were observed among 230 cases of cervical spondylosis and scores of self-discomfort in reaction point, color of skin, changes of skin, morphology of subcutaneous tissue and abnormal pressing pain were recorded. The software SPSS 15.0 was applied to statistically analyze the recorded scores. RESULTS: Among 230 cases, the reaction point appeared in 226 cases, accounting for 98. 3%. Among the 226 cases who had reaction point, the total score of symptom and sign was (1.08+/-1.09) on the healthy side and (0. 84+/-1. 36) on the affected side, which had statistical significance (P<0. 01); score of self-discomfort in reaction point was (0. 76 +/-0. 83) on the healthy side and (0. 40+/-0.80) on the affected side, which had statistical significance (P<0.01); the score of skin color was (0.10+/-0.36) on the healthy side and (0. 03+/- 0. 19) on the affected side, which had statistical significance (P<0. 05); the score of abnormal pressing pain was (2. 47+/-2. 46) on the healthy side and (1. 39+/-2. 37) on the affected side, which had statistical significance (P<0. 01). CONCLUSION: The total score of symptom and sign of reaction point Jingtong on the healthy side is higher than that on the affected side, indicating positive reaction of Jingtong on the healthy side has specificity for cervical spondylosis. When patient has cervical spondylosis on either side of neck, the other side will have anomaly in Jingtong.