[Cloning and functional analysis of 3ß-hydroxysteroid dehydrogenase gene involved in biosynthesis of digitoxin].

Digitoxin, an important secondary metabolite of Digitalis purpurea, is a commonly used cardiotonic in clinical practice. 3ß-Hydroxysteroid dehydrogenase(3ßHSD) is a key enzyme involved in the biosynthesis of digitoxin. It belongs to the short-chain dehydrogenase/reductase(SDR) family, playing a role in the biosynthesis of cardiac glycosides by oxidizing and isomerizing the precursor sterol. In this study, two 3ßHSD genes were cloned from D. purpurea. The results showed that the open reading frame(ORF) of Dp3ßHSD1 was 780 bp, encoding 259 amino acid residues. The ORF of Dp3ßHSD2 was 774 bp and encoded 257 residues. Dp3ßHSD1/2 had the cofactor binding site TGxxxA/GxG and the catalytic site YxxxK. In vitro experiments confirmed that Dp3ßHSD1/2 catalyzed the generation of progesterone from pregnenolone, and Dp3ßHSD1 had stronger catalytic capacity than Dp3ßHSD2. The expression level of Dp3ßHSD1 was much higher than that of Dp3ßHSD2 in leaves, and digitoxin was only accumulated in leaves. The results implied that Dp3ßHSD1 played a role in the dehydrogenation of pregnenolone to produce progesterone in the biosynthesis of digitoxin. This study provides a reference for further exploring the biosynthetic pathway of cardiac glycosides in D. purpurea.

[Functional characterization and enzymatic properties of flavonoid glycosyltransferase gene CtUGT49 in Carthamus tinctorius].

Carthami Flos, as a traditional blood-activating and stasis-resolving drug, possesses anti-tumor, anti-inflammatory, and immunomodulatory pharmacological activities. Flavonoid glycosides are the main bioactive components in Carthamus tinctorius. Glycosyltransferase deserves to be studied in depth as a downstream modification enzyme in the biosynthesis of active glycoside compounds. This study reported a flavonoid glycosyltransferase CtUGT49 from C. tinctorius based on the transcriptome data, followed by bioinformatic analysis and the investigation of enzymatic properties. The open reading frame(ORF) of the gene was 1 416 bp, encoding 471 amino acid residues with the molecular weight of about 52 kDa. Phylogenetic analysis showed that CtUGT49 belonged to the UGT73 family. According to in vitro enzymatic results, CtUGT49 could catalyze naringenin chalcone to the prunin and choerospondin, and catalyze phloretin to phlorizin and trilobatin, exhibiting good substrate versatility. After the recombinant protein CtUGT49 was obtained by hetero-logous expression and purification, the enzymatic properties of CtUGT49 catalyzing the formation of prunin from naringenin chalcone were investigated. The results showed that the optimal pH value for CtUGT49 catalysis was 7.0, the optimal temperature was 37 ℃, and the highest substrate conversion rate was achieved after 8 h of reaction. The results of enzymatic kinetic parameters showed that the K_m value was 209.90 µmol·L~(-1) and k_(cat) was 48.36 s~(-1) calculated with the method of Michaelis-Menten plot. The discovery of the novel glycosyltransferase CtUGT49 is important for enriching the library of glycosylation tool enzymes and provides a basis for analyzing the glycosylation process of flavonoid glycosides in C. tinctorius.

New records of powder-post beetles (Coleoptera, Bostrichidae) from China.

Background: The Bostrichidae is a small family of Coleoptera, with up to 600 described species all over the world. Almost 90 species of the family have been recorded in China at present and several new species of powder-post beetles have been described in recent years. Since the 1940s, the family Bostrichidae has become a neglected group in the taxonomy research of the Chinese mainland compared with its extensive territorial and super complex ecological diversity. Thus, there is need for more field specimen collection and in-depth taxonomic study. New information: In this study, two powder-post beetles species Trogoxylonspinifrons (Lesne, 1910) and Mintheabivestita Lesne, 1937, are recorded for the first time from China. New provincial distribution records of another 18 Bostrichidae also listed.

Predicting tall-cell subtype of papillary thyroid carcinomas independently with preoperative multimodal ultrasound.

OBJECTIVES: This study aimed to explore the differences between tall-cell subtype of papillary thyroid carcinoma (TCPTC) and classical papillary thyroid carcinoma (cPTC) using multimodal ultrasound, and identify independent risk factors for TCPTC to compensate the deficiency of preoperative cytological and molecular diagnosis on PTC subtypes. METHODS: Forty-six TCPTC patients and 92 cPTC patients were included. Each patient received grey-scale ultrasound, colour Dopplor flow imaging (CDFI) and shear-wave elastography (SWE) preoperatively. Clinicopathologic information, grey-scale ultrasound features, CDFI features and SWE features of 98 lesions were compared using univariate analysis to find out predictors of TCPTC, based on which, a predictive model was built to differentiate TCPTC from cPTC and validated with 40 patients. RESULTS: Univariate and multivariate analyses identified that extra-thyroidal extension (odds ratio [OR], 15.12; 95% CI, 2.26-115.44), aspect ratio (≥0.91) (OR, 29.34; 95% CI, 1.29-26.23), and maximum diameter ≥14.6 mm (OR, 20.79; 95% CI, 3.87-111.47) were the independent risk factors for TCPTC. Logistic regression equation: P = 1/1+ExpΣ[-5.099 + 3.004 × (if size ≥14.6 mm) + 2.957 × (if aspect ratio ≥ 0.91) + 2.819 × (if extra-thyroidal extension). The prediction model had a good discrimination performance for TCPTC: the area under the receiver-operator-characteristic curve, sensitivity, and specificity were 0.928, 0.848, and 0.954 in cohort 1, and the corresponding values in cohort 2 were 0.943, 0.923, and 0.926, respectively. CONCLUSION: Ultrasound has the potential for differential diagnosis of TCPTC from cPTC. A prediction model based on ultrasound characteristics (extra-thyroidal extension, aspect ratio ≥0.91, and maximum diameter ≥14.6 mm) was useful in predicting TCPTC. ADVANCES IN KNOWLEDGE: Multimodal ultrasound prediction of TCPTC was a supplement to preoperative cytological diagnosis and molecular diagnosis of PTC subtypes.

Low-voltage stimulated denitrification performance of high-salinity wastewater using halotolerant microorganisms.

Nitrate is a common contaminant in high-salinity wastewater, which has adverse effects on both the environment and human health. However, conventional biological treatment exhibits poor denitrification performance due to the high-salinity shock. In this study, an innovative approach using an electrostimulating microbial reactor (EMR) was explored to address this challenge. With a low-voltage input of 1.2 V, the EMR reached nitrate removal kinetic parameter (kNO3-N) of 0.0166-0.0808 h-1 under high-salinities (1.5 %-6.5 %), which was higher than that of the microbial reactor (MR) (0.0125-0.0478 h-1). The mechanisms analysis revealed that low-voltage significantly enhanced microbial salt-in strategy and promoted the secretion of extracellular polymeric substances. Halotolerant denitrification microorganisms (Pseudomonas and Nitratireductor) were also enriched in EMR. Moreover, the EMR achieved a NO3-N removal efficiency of 73.64 % in treating high-salinity wastewater (salinity 4.69 %) over 18-cycles, whereas the MR only reached 54.67 %. In summary, this study offers an innovative solution for denitrification of high-salinity wastewater.

Integrated biogas upgrading and medium-chain fatty acids production for more efficient resource recovery.

The conversion of carbon dioxide (CO2) from biogas into medium-chain fatty acids (MCFAs) represents an eco-friendly resource recovery approach to reduce dependence on fossil fuels and combat global climate change. This study presented the novel concept of integrated resource recovery by coupling biogas upgrading and MCFAs production for the first time. Initially, the impact of different initial ethanol concentrations on chain elongation was examined, determining that an ethanol concentration of 160 mmol/L maximized MCFAs yield at 45.7 mmol/L. Subsequently, using this optimal ethanol supply, the integrated strategy was implemented by connecting two bioreactors in series and maintaining continuous operation for 160-day. The results were noteworthy: upgraded bio-methane purity reached 97.6 %, MCFAs production rate and carbon-flow distribution reached 24.5 mmol/L d-1 and 76.1 %, respectively. In summary, these promising outcomes pioneer a resource recovery approach, enabling the high-value utilization of biogas and the conversion of CO2 into valuable bio-chemicals.

GateView: A Multi-Omics Platform for Gene Feature Analysis of Virus Receptors within Human Normal Tissues and Tumors.

Viruses are obligate intracellular parasites that rely on cell surface receptor molecules to complete the first step of invading host cells. The experimental method for virus receptor screening is time-consuming, and receptor molecules have been identified for less than half of known viruses. This study collected known human viruses and their receptor molecules. Through bioinformatics analysis, common characteristics of virus receptor molecules (including sequence, expression, mutation, etc.) were obtained to study why these membrane proteins are more likely to become virus receptors. An in-depth analysis of the cataloged virus receptors revealed several noteworthy findings. Compared to other membrane proteins, human virus receptors generally exhibited higher expression levels and lower sequence conservation. These receptors were found in multiple tissues, with certain tissues and cell types displaying significantly higher expression levels. While most receptor molecules showed noticeable age-related variations in expression across different tissues, only a limited number of them exhibited gender-related differences in specific tissues. Interestingly, in contrast to normal tissues, virus receptors showed significant dysregulation in various types of tumors, particularly those associated with dsRNA and retrovirus receptors. Finally, GateView, a multi-omics platform, was established to analyze the gene features of virus receptors in human normal tissues and tumors. Serving as a valuable resource, it enables the exploration of common patterns among virus receptors and the investigation of virus tropism across different tissues, population preferences, virus pathogenicity, and oncolytic virus mechanisms.