Matching actions to needs: shifting policy responses to the changing health needs of Chinese children and adolescents.

China is home to the second largest population of children and adolescents in the world. Yet demographic shifts mean that the government must manage the challenge of fewer children with the needs of an ageing population, while considering the delicate tension between economic growth and environmental sustainability. We mapped the health problems and risks of contemporary school-aged children and adolescents in China against current national health policies. We involved multidisciplinary experts, including young people, with the aim of identifying actionable strategies and specific recommendations to promote child and adolescent health and wellbeing. Notwithstanding major improvements in their health over the past few decades, contemporary Chinese children and adolescents face distinct social challenges, including high academic pressures and youth unemployment, and new health concerns including obesity, mental health issues, and sexually transmitted infections. Inequality by gender, geography, and ethnicity remains a feature of health risks and outcomes. We identified a mismatch between current health determinants, risks and outcomes, and government policies. To promote the health of children and adolescents in China, we recommend a set of strategies that target government-led initiatives across the health, education, and community sectors, which aim to build supportive and responsive families, safe communities, and engaging and respectful learning environments. TRANSLATION: For the Chinese translation of the abstract see Supplementary Materials section.

Two new bibenzyl methylglucosides as SIRT3 activators obtained through microbial transformation.

Microbial transformation of dihydroresveratrol (DHRSV) using Beauveria bassiana has produced two new methylglucosylated derivatives of DHRSV (1 and 2), whose structures were characterized as 4'-O-(4″-O-methyl-ß-D-glucopyranosyl)-dihydroresveratrol (4'-O-MG DHRSV, 1) and 3-O-(4″-O-methyl-ß-D-glucopyranosyl)-dihydroresveratrol (3-O-MG DHRSV, 2) on the basis of spectroscopic methods. They showed moderate SIRT3 agonistic activity, and compound 2 exhibited the best deacetylation of 406.63% at 10 µM. The activity of 2 increased by 3.12-fold compared with that of DHRSV, since 2 performed better in molecular docking assay (GScore -8.445).

[Performance of Contrast-enhanced Ultrasound Liver Imaging Reporting and Data System LR-5 in the Diagnosis of Hepatocellular Carcinoma:A Meta-analysis].

Objective To evaluate the performance of contrast-enhanced ultrasound (CEUS) liver imaging reporting and data system (LI-RADS) LR-5 in the diagnosis of hepatocellular carcinoma (HCC). Methods The clinical research reports with the application of CEUS LI-RADS in the diagnosis of HCC were collected from PubMed,Embase,Cochrane Library,CNKI,and Wanfang Data from inception to November 14,2021.Two researchers respectively screened the literature and extracted relevant information.The Quality Assessment of Diagnostic Accuracy Studies (QUADAS) was used to evaluate the quality of all the included articles.RevMan 5.4,Meta disc 1.4,and Stata 16.0 were employed to analyze the diagnostic performance of LR-5 for HCC in high-risk patients. Results Twenty original studies were included,involving a total of 6131 lesions,of which 5142 were HCC.The results of meta-analysis showed that the LR-5 in CEUS LI-RADS for diagnosing HCC in the high-risk population had the overall sensitivity of 0.72 (95%CI=0.66-0.77),the overall specificity of 0.93 (95%CI=0.87-0.96),the overall positive likelihood ratio of 9.89 (95%CI=5.31-18.41),the overall negative likelihood ratio of 0.30 (95%CI=0.25-0.37),and the area under the summary receiver operating characteristic curve of 0.88 (95%CI=0.85-0.91).There was heterogeneity among the included studies (I2=95.31,P<0.001).The funnel plot indicated the existence of publication bias (P=0.04). Conclusion The CEUS LI-RADS can effectively diagnose HCC in high-risk patients based on the LR-5 criteria.

TET2-mediated Cdkn2A DNA hydroxymethylation in midbrain dopaminergic neuron injury of Parkinson's disease.

It has been reported that abnormal epigenetic modification is associated with the occurrence of Parkinson's disease (PD). Here, we found that a ten-eleven translocation 2 (TET2), a staff of the DNA hydroxylases family, was increased in dopaminergic neurons in vitro and in vivo. Genome-wide mapping of DNA 5-hydroxymethylcytosine (5-hmC)-sequencing has revealed an aberrant epigenome 5-hmC landscape in 1-methyl-4-phenylpyridinium iodide (MPP+)-induced SH-SY5Y cells. The TET family of DNA hydroxylases could reverse DNA methylation by oxidization of 5-methylcytosine (5-mC) to 5-hmC. However, the relationship between modification of DNA hydroxymethylation and the pathogenesis of PD is not clear. According to the results of 5-hmC-sequencing studies, 5-hmC was associated with gene-rich regions in the genomes related to cell cycle, especially gene-cyclin-dependent kinase inhibitor 2A (Cdkn2A). Downregulation of TET2 expression could significantly rescue MPP+-stimulated SH-SY5Y cell damage and cell cycle arrest. Meanwhile, knockdown of Tet2 expression in the substantia nigra pars compacta of MPTP-induced PD mice resulted in attenuated MPTP-induced motor deficits and dopaminergic neuronal injury via p16 suppression. In this study, we demonstrated a critical function of TET2 in PD development via the CDKN2A activity-dependent epigenetic pathway, suggesting a potential new strategy for epigenetic therapy.

Chromosome-scale genome assembly of Rhododendron molle provides insights into its evolution and terpenoid biosynthesis.

BACKGROUND: Rhododendron molle (Ericaceae) is a traditional Chinese medicine, which has been used to treat rheumatism and relieve pain since ancient times. The characteristic grayanoids of this plant have been demonstrated to be the chemical basis for the analgesic activity. Moreover, unlike morphine, these diterpenoids are non-addictive. Grayanoids mainly distribute in the leaves, flowers, roots, and fruits of R. molle, with low content. Currently the research on the biosynthesis of grayanoids is hindered, partially due to lack of the genomic information. RESULTS: In the present study, a total of 744 Mb sequences were generated and assembled into 13 chromosomes. An ancient whole-genome duplication event (Ad-ß) was discovered that occurred around 70 million years ago. Tandem and segmental gene duplications led to specific gene expansions in the terpene synthase and cytochrome P450 (CYP450) gene families. Two diterpene synthases were demonstrated to be responsible for the biosynthesis of 16α-hydroxy-ent-kaurane, the key precursor for grayanoids. Phylogenetic analysis revealed a species-specific bloom of the CYP71AU subfamily, which may involve the candidate CYP450s responsible for the biosynthesis of grayanoids. Additionally, three putative terpene biosynthetic gene clusters were found. CONCLUSIONS: We reported the first genome assembly of R. molle and investigated the molecular basis underpinning terpenoids biosynthesis. Our work provides a foundation for elucidating the complete biosynthetic pathway of grayanoids and studying the terpenoids diversity in R. molle.

High-level soluble expression of human Cu,Zn superoxide dismutase with high activity in Escherichia coli.

As the most important member of antioxidant defense system, human Cu,Zn superoxide dismutase (hCu,Zn-SOD) protects cells against the free radicals produced by aerobic metabolism. hCu,Zn-SOD has been widely used in food, cosmetic and medicine industry due to its health benefits and therapeutic potentials. However, a more extensive application of hCu,Zn-SOD is limited by the challenge of expensive and low production of high-activity hCu,Zn-SOD in large scale. In this study, the codon-optimized hCu,Zn-SOD gene was synthesized, cloned into pET-28a( +) and transformed into Escherichia coli BL21(DE3). After induction with IPTG or lactose, hCu,Zn-SOD was highly expressed as soluble form in LB medium with 800 µM Cu2+ and 20 µM Zn2+ at 25 °C. The recombinant hCu,Zn-SOD was efficiently purified by nickel affinity chromatography. Through optimization of fed-batch fermentation conditions, 342 mg purified hCu,Zn-SOD was obtained from 1 L cultures fermented in a 3-L bioreactor. Furthermore, the recombinant hCu,Zn-SOD retained the enzymatic specific activity of 46,541 U/mg. This study has opened up an effective avenue for industrial production of hCu,Zn-SOD through microbial fermentation in the future.

Tetrocarcin Q, a New Spirotetronate with a Unique Glycosyl Group from a Marine-Derived Actinomycete Micromonospora carbonacea LS276.

A new spirotetronate glycoside tetrocarcin Q (1) and six known analogues tetrocarcin A (2), AC6H (3), tetrocarcin N (4), tetrocarcin H (5), arisostatin A (6), and tetrocarcin F1 (7) were isolated from the fermentation broth of the marine-derived actinomycete Micromonospora carbonacea LS276. Their chemical structures were established on the basis of 1D- and 2D-NMR spectroscopy, as well as HR-ESI-MS analysis. The absolute configurations of their stereogenic carbons were determined by circular dichroism (CD) analysis. Compound 1 possesses 2-deoxy-allose, which is a unique sugar type at the C-9 position. This type has not been found in the previously reported spirotetronate glycosides. Compound 1 displayed moderate antibacterial activity against Bacillus subitlis ATCC 63501 with minimum inhibitory concentration (MIC) value of 12.5 µM.

Site-Directed Mutagenesis of a ß-Glycoside Hydrolase from Lentinula Edodes.

The ß-glycoside hydrolases (LXYL-P1-1 and LXYL-P1-2) from Lentinula edodes (strain M95.33) can specifically hydrolyze 7-ß-xylosyl-10-deacetyltaxol (XDT) to form 10-deacetyltaxol for the semi-synthesis of Taxol. Our previous study showed that both the I368T mutation in LXYL-P1-1 and the T368E mutation in LXYL-P1-2 could increase the enzyme activity, which prompted us to investigate the effect of the I368E mutation on LXYL-P1-1 activity. In this study, the ß-xylosidase and ß-glucosidase activities of LXYL-P1-1I368E were 1.5 and 2.2 times higher than those of LXYL-P1-1. Most importantly, combination of I368E and V91S exerted the cumulative effects on the improvement of the enzyme activities and catalytic efficiency. The ß-xylosidase and ß-glucosidase activities of the double mutant LXYL-P1-1V91S/I368E were 3.2 and 1.7-fold higher than those of LXYL-P1-1I368E. Similarly, the catalytic efficiency of LXYL-P1-1V91S/I368E on 7-ß-xylosyl-10-deacetyltaxol was 1.8-fold higher than that of LXYL-P1-1I368E due to the dramatic increase in the substrate affinity. Molecular docking results suggest that the V91S and I368E mutation might positively promote the interaction between enzyme and substrate through altering the loop conformation near XDT and increasing the hydrogen bonds among Ser91, Trp301, and XDT. This study lays the foundation for exploring the relationship between the structure and function of the ß-glycoside hydrolases.

Improving the Catalytic Property of the Glycoside Hydrolase LXYL-P1-2 by Directed Evolution.

The glycoside hydrolase LXYL-P1-2 from Lentinula edodes can specifically hydrolyze 7-ß-xylosyltaxanes to form 7-ß-hydroxyltaxanes for the semi-synthesis of paclitaxel. In order to improve the catalytic properties of the enzyme, we performed error-prone PCR to construct the random mutant library of LXYL-P1-2 and used the methanol-induced plate method to screen the mutants with improved catalytic properties. Two variants, LXYL-P1-2-EP1 (EP1, S91D mutation) and LXYL-P1-2-EP2 (EP2, T368E mutation), were obtained from the library and exhibited 17% and 47% increases in their catalytic efficiencies on 7-ß-xylosyl-10-deacetyltaxol. Meanwhile, compared with LXYL-P1-2, EP1 and EP2 showed elevated stabilities in the range of pH ≥ 6 conditions. After treatment at pH 12 for 48 h, EP1 and EP2 retained 77% and 63% activities, respectively, while the wild-type only retained 33% activity under the same condition. Molecular docking results revealed that the S91D mutation led to a shorter distance between the R-chain and the substrate, while the T368E mutation increased negative charge at the surface of the enzyme, and may introduce alterations of the loop near the active pocket, both of which may result in improved stabilities and catalytic activities of enzymes. This study provides a practical directed evolution method for exploring catalytically improved glycoside hydrolase.

Genetic and environmental influences on the relationship between ADHD symptoms and internalizing problems: A Chinese twin study.

Several twin studies have investigated the overlap between attention deficit hyperactivity disorder (ADHD) and externalizing problems; however, limited information is known regarding the genetic and environmental contribution to the overlap between ADHD and internalizing problems. This study examined the genetic and environmental influences on the variation in and covariation between ADHD symptoms and internalizing problems by using the Child Behavior Checklist (CBCL). We investigated 1,316 child and adolescent twins, including 780 monozygotic twins and 536 dizygotic twins, aged 6 years to 18 years from the Chinese Child and Adolescent Twin Registry. ADHD symptoms and internalizing problems were quantified through parent rating by using the Attention Problems Scale and other three scales, which include Anxious/Depressed, Withdrawn, and Somatic Complaints of CBCL. Genetic and environmental susceptibilities common to ADHD symptoms and internalizing problems were examined through bivariate twin modeling. Results showed that genetic factors substantially influenced the ADHD symptoms with a heritability of 72%. Modest genetic influences and substantial shared environmental influences (20-77%) were observed in the three internalizing problem scales. Common genetic and shared environmental influences were essential for the overlap between ADHD and the three internalizing problems respectively. Approximately one-fifth of the genetic variance of ADHD symptoms was shared with anxiety/depression. In conclusion, substantial genetic and shared environmental influences on ADHD symptoms and internalizing problems were observed in Chinese children and adolescents. Our finding supports a common etiology between ADHD and internalizing problems. This finding can also help explain the co-existence of these behavior problems. © 2015 Wiley Periodicals, Inc.

Cloning and characterization of the glycoside hydrolases that remove xylosyl groups from 7-ß-xylosyl-10-deacetyltaxol and its analogues.

Paclitaxel, a natural antitumor compound, is produced by yew trees at very low concentrations, causing a worldwide shortage of this important anticancer medicine. These plants also produce significant amounts of 7-ß-xylosyl-10-deacetyltaxol, which can be bio-converted into 10-deacetyltaxol for the semi-synthesis of paclitaxel. Some microorganisms can convert 7-ß-xylosyl-10-deacetyltaxol into 10-deacetyltaxol, but the bioconversion yield needs to be drastically improved for industrial applications. In addition, the related ß-xylosidases of these organisms have not yet been defined. We set out to discover an efficient enzyme for 10-deacetyltaxol production. By combining the de novo sequencing of ß-xylosidase isolated from Lentinula edodes with RT-PCR and the rapid amplification of cDNA ends, we cloned two cDNA variants, Lxyl-p1-1 and Lxyl-p1-2, which were previously unknown at the gene and protein levels. Both variants encode a specific bifunctional ß-d-xylosidase/ß-d-glucosidase with an identical ORF length of 2412 bp (97% identity). The enzymes were characterized, and their 3.6-kb genomic DNAs (G-Lxyl-p1-1, G-Lxyl-p1-2), each harboring 18 introns, were also obtained. Putative substrate binding motifs, the catalytic nucleophile, the catalytic acid/base, and potential N-glycosylation sites of the enzymes were predicted. Kinetic analysis of both enzymes showed kcat/Km of up to 1.07 s(-1)mm(-1) against 7-ß-xylosyl-10-deacetyltaxol. Importantly, at substrate concentrations of up to 10 mg/ml (oversaturated), the engineered yeast could still robustly convert 7-ß-xylosyl-10-deacetyltaxol into 10-deacetyltaxol with a conversion rate of over 85% and a highest yield of 8.42 mg/ml within 24 h, which is much higher than those reported previously. Therefore, our discovery might lead to significant progress in the development of new 7-ß-xylosyl-10-deacetyltaxol-converting enzymes for more efficient use of 7-ß-xylosyltaxanes to semi-synthesize paclitaxel and its analogues. This work also might lead to further studies on how these enzymes act on 7-ß-xylosyltaxanes and contribute to the growing database of glycoside hydrolases.

[Effect of obesity intervention with socio-ecological model on anthropometric measurements of children and adolescents].

OBJECTIVE: To study whether the socio-ecological model based on "student-school-family" three-level strategy is effective in obesity prevention. METHODS: A total of 3 175 students aged 7 to 18 from 16 schools (4 urban primary schools, 4 rural primary schools, 4 urban secondary schools and 4 rural secondary schools, of which 2 intervention schools were selected, respectively) were recruited by stratified cluster sampling method. A three-month intervention using "student-school-family" socio-ecological model was conducted through health education and environment improvement. The intervention contents included knowledge on obesity, healthy diet and physical activities. Their anthropometric indexes were recorded. RESULTS: The intervention prevented obesity (OR=1.12, P<0.05), and was effective in waist circumference (WC) and waist-hip ratio (WHR) (adjusted difference=0.63, 0.02, P<0.05). WC and WHR were reduced in girls (adjusted difference=0.52 & 0.02, P<0.05), and obesity was prevented in girls (OR=1.18, P<0.05). WC and WHR were reduced in boys (adjusted difference=0.73, 0.01, P<0.05). WHR were reduced in urban areas (adjusted difference=0.01, P<0.05). WC and WHR were reduced (adjusted difference=1.05, 0.02, P<0.05) and obesity was prevented (OR=1.18, P<0.05) in rural areas. WHR were reduced (adjusted difference=0.01, P<0.05) and obesity was prevented (OR=1.21, P<0.05) in primary schools. WHR were reduced in secondary schools (adjusted difference=0.02, P<0.05).The intervention effect was better in girls than in boys, in rural areas than in urban areas, and in primary schools than in secondary schools. The overweight and obesity prevalence went down after the intervention (χ2=11.01, P<0.01). CONCLUSION: Intervention strategy is effective in central obesity indexes such as WC and WHR, and it can be used widely.

Secular changes of stature in rural children and adolescents in China, 1985-2010.

OBJECTIVE: To analyze and assess secular change in stature in rural children and adolescents in China from 1985 to 2010. METHODS: Data were obtained from the 6 rounds of the Chinese National Survey on Student's Constitution and Health. The subjects enrolled in the study were children and adolescents aged 7-18 years in rural areas of provincial capitals. RESULTS: An overall positive secular trend in stature occurred in rural areas of provincial capitals in China from 1985 to 2010. The overall average increase rates were 3.1 and 2.4 cm/decade for boys and girls, respectively. The total body height increases for grown up boys and girls were 3.6 and 2.3 cm and the increase rates were 1.4 and 0.9 cm/decade, respectively. There were differences in body height increase among eastern, central and western regions. The average body height of the children or adolescents in eastern region was highest, followed by central region and western region. The overall increase rates in central region were highest among the three regions. The difference between eastern/central region and western region was obvious. CONCLUSION: Positive secular trend in stature of children or adolescents has occurred in rural area of China, and rural boys and girls showed a great potential for continuous growth. More attention should be paid to the differences in children's body height between western region and eastern/central region.

Empirical changes in the prevalence of overweight and obesity among Chinese students from 1985 to 2010 and corresponding preventive strategies.

OBJECTIVE: To determine the extent of the obesity epidemic in school-aged Chinese children in 2010 and track the increasing trend in different socioeconomic regions over the preceding 25 years. Strategies for preventing childhood obesity are suggested. METHODS: We used a dataset provided by the Chinese National Survey on Students' Constitution and Health from 1985-2010. Subjects were 7-18-year-old students randomly selected from urban and rural areas in 30 provinces. Eight subgroups were created according to region and socioeconomic status. RESULTS: Increased rates of the epidemic (overweight and obesity combined) were greatest in large coastal cities-32.6% and 19.1% among males and females, respectively. These rates has neared that of developed countries. Similar increases were found in all other regions, including the once poverty-stricken rural west. The epidemic in most of the rural areas began after 2000, but has spread swiftly over the last decade. In 2010, it was estimated that 9.9% of Chinese school-aged children and adolescents were overweight and that an additional 5.1% were obese, representing an estimated 30.43 million individuals. CONCLUSION: The prognosis for China's childhood-obesity epidemic is dire. To prevent childhood obesity, we suggest several strategies, including reasonable dietary intake, increase physical activity, a change in sedentary lifestyles and corresponding behavioral modifications.

Secular change in stature of urban Chinese children and adolescents, 1985-2010.

OBJECTIVE: Research evidence shows a secular trend in Chinese physical growth in recent years. The aim of this study was to analyze and assess changes in stature of children and adolescents during the 25 years from 1985-2010, using national data. METHODS: Data came from successive cycles of the Chinese National Survey on Students' Constitution and Health (CNSSCH). Subjects were 7- to 18-year-old children and adolescents. RESULTS: An overall positive secular trend occurred in urban China during 1985-2010. The overall average rates of increment were 2.4 and 1.7 cm/decade for boys and girls, respectively. Total increases in adult stature for boys and girls were 2.6 and 1.7 cm, yielding rates of 1.0 and 0.7 cm/decade, respectively. Cities with different socioeconomic levels had different characteristic trends. Mean stature increases in big cities were larger than those in moderate and small cities, and boys and girls in moderate and small cities showed greater potential for growth in stature. CONCLUSION: An overall positive secular growth trend was associated with socioeconomic progress and differed with area socioeconomic levels. School policies and strategies should be developed based on increased stature, and should continue narrowing the inequity between different socioeconomic populations.

Secular changes on the distribution of body mass index among Chinese children and adolescents, 1985-2010.

OBJECTIVE: To analyze the change in Body Mass Index (BMI) distribution among Chinese children and adolescents for the development of more effective intervention for childhood obesity. METHODS: Data on the national students' constitution and health survey between 1985 and 2010 was used for this study. Subjects were students aged 7-18 randomly selected from 30 provinces in China. BMI for-age curves were developed by LMS method, and the trend of BMI distribution was determined by comparing the upper BMI percentiles and analyzing the skew shift of distribution between 1985 and 2010. RESULTS: An overall positive swift trend of BMI between 1985 and 2010 was observed among the Chinese school-age children and adolescents. The average median of the BMI increased from 16.8 and 17.0 kg/m2 to 18.2 and 17.9 kg/m2 in 25 years, with increments 0.56 and 0.36 kg/m2 per decade for males and females, respectively. The more obvious increments were found at the high BMI. The total increments of BMI in this period were 4.03 and 2.20 kg/m2 at the 85th, 6.14 and 3.57 kg/m2 at the 95th, and 6.99 and 4.27 kg/m2 at the 97th percentiles, for males and females, respectively. CONCLUSION: Obvious increments were observed at high BMI of the Chinese children and adolescents. More effective interventions should be taken for control and prevention of obesity and its health consequence for these subgroups. It is necessary to establish a risk-complex system consisting of the identification of BMI scope, the screen of the disease risk factors and the assessment of excessive adiposity.

[Comparative study of sexual behaviors of high school students between urban and rural China].

OBJECTIVE: To analyze the situation of sexual behavior in urban and rural Chinese high school students, and to make suggestions for providing appropriate sexual education in the future. METHODS: An anonymous questionnaire survey was conducted in 224 770 high school students selected by using multi-stage stratified cluster sampling method in 28 provincial units of China. RESULTS: Overall, 5.9% high school students reported that they had had sexual intercourses, and the prevalence rate of having had sexual intercourses was higher in the urban students (6.2%) than in the rural (5.2%) students (χ(2)=83.290, P<0.01), and higher in the boys (8.8%) than in the girls (3.3%, χ(2)=2 944.456, P<0.01). Of all the subjects, 44.6% reported that they had forced sex; the prevalence rates were 43.5% and 47.5% in the urban and rural students (χ(2)=16.237, P<0.01), respectively, and lower in the boys (39.7%) than in the girls (55.8%, χ(2)=285.089, P<0.01). Boys, higher grades, vocational schools, living without their parents and in areas of West China were found to be the risk factors to sexual intercourses in the urban and rural students. The pattern of forced sexual intercourses was slightly different between the urban and rural students, however, girls, ordinary schools, living without their parents and in areas of West China were the risk factors. CONCLUSION: Sexual education should be taken as soon as possible by using scientific as well as systematic methods in the occupational school students, and students living without their parents and in areas of West China.

Microbial biotransformation to obtain stilbene methylglucoside with GPR119 agonistic activity.

Introduction: Limitation of pharmaceutical application of resveratrol (RSV) and piceatannol (PIC) continue to exist, there is a need to obtain the superior analogs of two stilbenes with promoted activity, stability, and bioavailability. Microbial transformation has been suggested as a common and efficient strategy to solve the above problems. Methods: In this study, Beauveria bassiana was selected to transform RSV and PIC. LC-MS and NMR spectroscopies were used to analyze the transformed products and identify their structures. The biological activities of these metabolites were evaluated in vitro with GPR119 agonist and insulin secretion assays. Single factor tests were employed to optimize the biotransformation condition. Results: Three new methylglucosylated derivatives of PIC (1-3) and two known RSV methylglucosides (4 and 5) were isolated and characterized from the fermentation broth. Among them, 1 not only showed moderate GPR119 agonistic activity with 65.9%, but also promoted insulin secretion level significantly (12.94 ng/mg protein/hour) at 1 µM. After optimization of fermentation conditions, the yield of 1 reached 45.53%, which was increased by 4.2-fold compared with the control. Discussion: Our work presents that 3-O-MG PIC (1), obtained by microbial transformation, is an effective and safer ligand targeting GPR119, which lays a foundation for the anti-diabetic drug design in the future.

Simulated Gastric Acid Promotes the Horizontal Transfer of Multidrug Resistance Genes across Bacteria in the Gastrointestinal Tract at Elevated pH Levels.

The assessment of factors that can promote the transmission of antibiotic resistance genes (ARGs) across bacteria in the gastrointestinal tract is in great demand to understand the occurrence of infections related to antibiotic-resistant bacteria (ARB) in humans. However, whether acid-resistant enteric bacteria can promote ARG transmission in gastric fluid under high-pH conditions remains unknown. This study assessed the effects of simulated gastric fluid (SGF) at different pH levels on the RP4 plasmid-mediated conjugative transfer of ARGs. Moreover, transcriptomic analysis, measurement of reactive oxygen species (ROS) levels, assessment of cell membrane permeability, and real-time quantitative assessment of the expression of key genes were performed to identify the underlying mechanisms. The frequency of conjugative transfer was the highest in SGF at pH 4.5. Antidepressant consumption and certain dietary factors further negatively impacted this situation, with 5.66-fold and 4.26-fold increases in the conjugative transfer frequency being noted upon the addition of sertraline and 10% glucose, respectively, compared with that in the control group without any additives. The induction of ROS generation, the activation of cellular antioxidant systems, increases in cell membrane permeability, and the promotion of adhesive pilus formation were factors potentially contributing to the increased transfer frequency. These findings indicate that conjugative transfer could be enhanced under certain circumstances in SGF at elevated pH levels, thereby facilitating ARG transmission in the gastrointestinal tract. IMPORTANCE The low pH of gastric acid kills unwanted microorganisms, in turn affecting their inhabitation in the intestine. Hence, studies on the factors that influence antibiotic resistance gene (ARG) propagation in the gastrointestinal tract and on the underlying mechanisms are limited. In this study, we constructed a conjugative transfer model in the presence of simulated gastric fluid (SGF) and found that SGF could promote the dissemination of ARGs under high-pH conditions. Furthermore, antidepressant consumption and certain dietary factors could negatively impact this situation. Transcriptomic analysis and a reactive oxygen species assay revealed the overproduction of reactive oxygen species as a potential mechanism by which SGF could promote conjugative transfer. This finding can help provide a comprehensive understanding of the bloom of antibiotic-resistant bacteria in the body and create awareness regarding the risk of ARG transmission due to certain diseases or an improper diet and the subsequent decrease in gastric acid levels.