Characterization of the Cytochrome P450 CYP716C52 in Celastrol Biosynthesis and Its Applications in Engineered Saccharomyces cerevisiae.

Celastrol is a bioactive pentacyclic triterpenoid with promising therapeutic effects that is mainly distributed in Celastraceae plants. Although some enzymes involved in the celastrol biosynthesis pathway have been reported, many biosynthetic steps remain unknown. Herein, transcriptomics and metabolic profiles of multiple species in Celastraceae were integrated to screen for cytochrome P450s (CYPs) that are closely related to celastrol biosynthesis. The CYP716 enzyme, TwCYP716C52, was found to be able to oxidize the C-2 position of polpunonic acid, a precursor of celastrol, to form the wilforic acid C. RNAi-mediated repression of TwCYP716C52 in Tripterygium wilfordii suspension cells further confirmed its involvement in celastrol biosynthesis. The C-2 catalytic mechanisms of TwCYP716C52 were further explored by using molecular docking and site-directed mutagenesis experiments. Moreover, a modular optimization strategy was used to construct an engineered yeast to produce wilforic acid C at a titer of 5.8 mg·L-1. This study elucidates the celastrol biosynthetic pathway and provides important functional genes and sufficient precursors for further enzyme discovery.

Spatiotemporal expression analysis of jasmonic acid and saponin-related genes uncovers a potential biosynthetic regulation in Panax notoginseng.

BACKGROUND: Sanqi, the root of Panax notoginseng, has long been recognized for its therapeutic effects on cardiovascular diseases. Saponins, including ginsenosides and notoginsenosides, are the main bioactive components of P. notoginseng. The biosynthesis of saponins is closely related to the defense responses orchestrated by endogenous hormones. RESULTS: To provide new insights into the underlying role of phytohormone jasmonic acid (JA) in the synthesis and regulation of saponins, we performed an ultra-performance liquid chromatography analysis of different tissues of P. notoginseng aged 2-4 years. Moreover, by combined evaluation of saponin content and transcriptome profiling of each tissue, the spatial and temporal distribution of saponins was analyzed. N notoginsenoside R1, ginsenoside Rb1 and ginsenoside Rd accumulated in the underground tissues, including the root, tuqi, fibril and rhizome. In agreement with this data, the corresponding genes of the endogenous hormone JAs, especially coronatine insensitive 1 (COI1) and myelocytomatosis proteins 2 (MYC2), were predominantly expressed in the underground tissues. The tissue- and age-specific distribution of saponins was consistent with the expression of genes involved in JA biosynthetic, metabolic and signaling pathways. CONCLUSION: The present study has revealed the temporal and spatial effects of endogenous phtohormones in the synthesis and regulation of notoginsenosides, which will provide a significant impact on improving the ecological planting technology, cultivating new high-quality varieties and protecting the rare resources of medicinal P. notoginseng. © 2024 Society of Chemical Industry.

Probing the functions of friedelane-type triterpene cyclases from four celastrol-producing plants.

Triterpenes are among the most diverse plant natural products, and their diversity is closely related to various triterpene skeletons catalyzed by different 2,3-oxidosqualene cyclases (OSCs). Celastrol, a friedelane-type triterpene with significant bioactivities, is specifically distributed in higher plants, such as Celastraceae species. Friedelin is an important precursor for the biosynthesis of celastrol, and it is synthesized through the cyclization of 2,3-oxidosqualene, with the highest number of rearrangements being catalyzed by friedelane-type triterpene cyclases. However, the molecular mechanisms underlying the catalysis of friedelin production by friedelane-type triterpene cyclases have not yet been fully elucidated. In this study, transcriptome data of four celastrol-producing plants from Celastraceae were used to identify a total of 21 putative OSCs. Through functional characterization, the friedelane-type triterpene cyclases were separately verified in the four plants. Analysis of the selection pressure showed that purifying selection acted on these OSCs, and the friedelane-type triterpene cyclases may undergo weaker selective restriction during evolution. Molecular docking and site-directed mutagenesis revealed that changes in some amino acids that are unique to friedelane-type triterpene cyclases may lead to variations in catalytic specificity or efficiency, thereby affecting the synthesis of friedelin. Our research explored the functional diversity of triterpene synthases from a multispecies perspective. It also provides some references for further research on the relative mechanisms of friedelin biosynthesis.

[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.

Structural and Catalytic Insight into the Unique Pentacyclic Triterpene Synthase TwOSC.

The oxidosqualene cyclase (OSC) catalyzed cyclization of the linear substrate (3S)-2,3-oxidosqualene to form diverse pentacyclic triterpenoid (PT) skeletons is one of the most complex reactions in nature. Friedelin has a unique PT skeleton involving a fascinating nine-step cation shuttle run (CSR) cascade rearrangement reaction, in which the carbocation formed at C2 moves to the other side of the skeleton, runs back to C3 to yield a friedelin cation, which is finally deprotonated. However, as crystal structure data of plant OSCs are lacking, it remains unknown why the CSR cascade reactions occur in friedelin biosynthesis, as does the exact catalytic mechanism of the CSR. In this study, we determined the first cryogenic electron microscopy structure of a plant OSC, friedelin synthase, from Tripterygium wilfordii Hook. f (TwOSC). We also performed quantum mechanics/molecular mechanics simulations to reveal the energy profile for the CSR cascade reaction and identify key residues crucial for PT skeleton formation. Furthermore, we semirationally designed two TwOSC mutants, which significantly improved the yields of friedelin and ß-amyrin, respectively.

Biosynthesis, total synthesis, and pharmacological activities of aryltetralin-type lignan podophyllotoxin and its derivatives.

Covering: up to 2022Podophyllotoxin (PTOX, 1), a kind of aryltetralin-type lignan, was first discovered in the plant Podophyllum peltatum and its structure was clarified by W. Borsche and J. Niemann in 1932. Due to its potent anti-cancer and anti-viral activities, it is considered one of the molecules most likely to be developed into modern drugs. With the increasing market demand and insufficient storage of natural resources, it is crucial to expand the sources of PTOXs. The original extraction method from plants has gradually failed to meet the requirements, and the biosynthesis and total synthesis have become the forward-looking alternatives. As key enzymes in the biosynthetic pathway of PTOXs and their catalytic mechanisms being constantly revealed, it is possible to realize the heterogeneous biosynthesis of PTOXs in the future. Chemical and chemoenzymatic synthesis also provide schemes for strictly controlling the asymmetric configuration of the tetracyclic core. Currently, the pharmacological activities of some PTOX derivatives have been extensively studied, laying the foundation for clinical candidate drugs. This review focuses primarily on the latest research progress in the biosynthesis, total synthesis, and pharmacological activities of PTOX and its derivatives, providing a more comprehensive understanding of these widely used compounds and supporting the future search for clinical applications.

[Research progress in synthetic biology of active compounds in Chinese medicinal plants].

Mecicinal plants boast abundant natural compounds with significant pharmacological activity, and such compounds, featuring diversified and complex structures, can be used for research and development of drugs. At present, these natural compounds are directly extracted from herbs which, however, suffer from damaged wild resources and shortage of planting resources attributing to the increasing demand. Moreover, the low content in medicinal plants and complex structures are another challenge to the research and development of drugs. Heterologous synthesis with synthetic biology methods is a solution that has attracted wide attention. Synthetic bio-logy for the production of natural active compounds in Chinese medicinal plants involves the exploration of key enzymes in compound bio-synthetic pathways from plants, analysis of enzyme functions and mechanisms, and reconstruction and optimization of biosynthetic pathways in microorganisms for efficient synthesis of compounds. This study briefed the development process of synthetic biology and the biosynthetic pathways of terpenoids, alkaloids, and flavonoids, and summarized the related strategies of synthetic biology such as the reconstruction and optimization of metabolic pathways, regulation of fermentation process, and strain improvement, and the latest applications of heterogeneous synthetic biology in the production of natural compounds from Chinese medicinals. This study is expected to serve as a reference for the efficient production of terpenoids, alkaloids, flavonoids, and other active compounds from Chinese medicinal plants with strategies of synthetic biology.

High-throughput sequencing analysis of the rhizosphere arbuscular mycorrhizal fungi (AMF) community composition associated with Ferula sinkiangensis.

BACKGROUND: Ferula sinkiangensis is an increasingly endangered medicinal plant. Arbuscular mycorrhiza fungi (AMF) are symbiotic microorganisms that live in the soil wherein they enhance nutrient uptake, stress resistance, and pathogen defense in host plants. While such AMF have the potential to contribute to the cultivation of Ferula sinkiangensis, the composition of AMF communities associated with Ferula sinkiangensis and the relationship between these fungi and other pertinent abiotic factors still remains to be clarified. RESULTS: Herein, we collected rhizosphere and surrounding soil samples at a range of depths (0-20, 20-40, and 40-60 cm) and a range of slope positions (bottom, middle, top). These samples were then subjected to analyses of soil physicochemical properties and high-throughput sequencing (Illumina MiSeq). We determined that Glomus and Diversispora species were highly enriched in all samples. We further found that AMF diversity and richness varied significantly as a function of slope position, with this variation primarily being tied to differences in relative Glomus and Diversispora abundance. In contrast, no significant relationship was observed between soil depth and overall AMF composition, although some AMF species were found to be sensitive to soil depth. Many factors significantly affected AMF community composition, including organic matter content, total nitrogen, total potassium, ammonium nitrogen, nitrate nitrogen, available potassium, total dissolvable salt levels, pH, soil water content, and slope position. We further determined that Shannon diversity index values in these communities were positively correlated with total phosphorus, nitrate-nitrogen levels, and pH values (P < 0.05), whereas total phosphorus, total dissolvable salt levels, and pH were positively correlated with Chao1 values (P < 0.05). CONCLUSION: In summary, our data revealed that Glomus and Diversispora are key AMF genera found within Ferula sinkiangensis rhizosphere soil. These fungi are closely associated with specific environmental and soil physicochemical properties, and these soil sample properties also differed significantly as a function of slope position (P < 0.05). Together, our results provide new insights regarding the relationship between AMF species and Ferula sinkiangensis, offering a theoretical basis for further studies of their development.

A review of cardiovascular toxicity of TiO2, ZnO and Ag nanoparticles (NPs).

To ensure the safe use of nanoparticles (NPs) in modern society, it is necessary and urgent to assess the potential toxicity of NPs. Cardiovascular system is required for the systemic distribution of NPs entering circulation. Therefore, the adverse cardiovascular effects of NPs have gained extensive research interests. Metal based NPs, such as TiO2, ZnO and Ag NPs, are among the most popular NPs found in commercially available products. They may also have potential applications in biomedicine, which could increase their contact with cardiovascular systems. This review aimed at providing an overview about the adverse cardiovascular effects of TiO2, ZnO and Ag NPs. We discussed about the bio-distribution of NPs following different exposure routes. We also discussed about the cardiovascular toxicity of TiO2, ZnO and Ag NPs as assessed by in vivo and in vitro models. The possible mechanisms and contribution of physicochemical properties of metal based NPs were also discussed.

3-Hydroxyflavone enhances the toxicity of ZnO nanoparticles in vitro.

It is recently shown that flavonoids might reduce the toxicity of nanoparticles (NPs) due to their antioxidative properties. In this study, the influence of 3-hydroxyflavone (H3) on the toxicity of ZnO NPs was investigated. H3 increased hydrodynamic size, polydispersity index and absolute value of the zeta potential of ZnO NPs, which indicated that H3 could influence the colloidal aspects of NPs. Surprisingly, H3 markedly decreased the initial concentration of ZnO NPs required to induce cytotoxicity to Caco-2, HepG2, THP-1 and human umbilical vein endothelial cells, which suggested that H3 could promote the toxicity of ZnO NPs to both cancerous and normal cells. For comparison, 6-hydroxyflavone did not show this effect. H3 remarkably increased cellular Zn elements and intracellular Zn ions in HepG2 cells following ZnO NP exposure, and co-exposure to H3 and NPs induced a relatively higher intracellular reactive oxygen species. Exposure to ZnO NPs at 3 hours induced the expression of endoplasmic reticulum stress markers DDIT3 and XBP-1 s, which was suppressed by H3. The expression of apoptotic genes BAX and CASP3 was significantly induced by ZnO NP exposure after 3 and 5 hours, respectively, and H3 further significantly promoted CASP3 expression at 5 hours. In combination, the results from this study suggested that H3 affected colloidal stability of ZnO NPs, promoted the interactions between NPs and cells, and altered the NP-induced endoplasmic reticulum stress-apoptosis signaling pathway, which finally enhanced the cytotoxicity of ZnO NPs.

Immediate liposuction could shorten the time for endoscopic axillary lymphadenectomy in breast cancer patients.

BACKGROUND: Endoscopic axillary lymphadenectomy (EALND) was introduced to clinical work to reduce side effects of conventional axillary lymphadenectomy, while the lipolysis and liposuction of EALND made the process consume more time. The aim of the study was to determine whether immediate liposuction after tumescent solution injection to the axilla could shorten the total time of EALND. METHODS: Fifty-nine patients were enrolled in the study, 30 of them received EALND with traditional liposuction method (TLM), and the rest 29 patients received EALND with immediate liposuction method (ILM). The operation time, cosmetic result, drainage amount, and hospitalization time of the two groups were compared. RESULTS: The median EALND operation time of TLM group and ILM group were 68 and 46 min, respectively, the difference was significant (P < 0.05); the median cosmetic results of the two groups were 6.6 and 6.4, respectively; the median drainage amount of the two groups were 366 and 385 ml, respectively; the hospitalization time of the two groups were 15 and 16 days, respectively. For the last three measures, no significant difference was confirmed (P > 0.05). CONCLUSIONS: Our work suggests immediate liposuction could shorten the endoscopic axillary lymphadenectomy process, and this method would not compromise the operation results. However, due to the limitations of the research, more work needs to be done to prove the availability and feasibility of immediate liposuction.

The protein arginine methyltransferase PRMT5 regulates Aß-induced toxicity in human cells and Caenorhabditis elegans models of Alzheimer's disease.

The protein arginine methyltransferase 5 (PRMT5) controls cell growth and apoptosis by catalyzing mono and symmetric dimethylation of arginine residues. In human brain tissue, PRMT5 is predominantly expressed in neuronal cells. There is evidence that PRMT5 provides protection against cell death, but the impact of PRMT5 on neuronal apoptosis during the evolution of Alzheimer's disease has not been tested. In the present study, we show that PRMT5 is down-regulated by ß-amyloid (Aß) in primary neurons and SH-SY5Y cells, and this is associated with the up-regulation of the PRMT5 target protein E2F-1. Furthermore, knockdown of PRMT5 in SH-SY5Y cells over-expressing the Swedish mutant form of human amyloid-ß precursor protein caused activation of E2F-1/p53/Bax, NF-κB, and GSK-3ß pathways, which coincided with increased apoptosis. Co-depletion of E2F-1 reduced the activation of p53/Bax, NF-κB, and GSK-3ß, and limited cell apoptosis. In addition, inhibiting NF-κB and GSK-3ß activity by specific inhibitors also attenuated cell apoptosis, suggesting that E2F-1/NF-κB/GSK-3ß pathways mediate for apoptosis induced by PRMT5 depletion. More importantly, knockdown of PRMT5 resulted in more paralysis in a transgenic Caenorhabditis elegans strain CL2006, indicating that PRMT5 provides protection against Aß toxicity in vivo. Collectively, our findings identify PRMT5 as a novel regulator of Aß toxicity and suggest that strategies aimed at activating PRMT5 in the neuron may represent a potential therapeutic approach for the prevention of Alzheimer's disease. We propose the following cascade for protein arginine methyltransferase 5 (PRMT5)-mediated neuronal death: amyloid beta (Aß) deposition decreases PRMT5 expression in neurons, which increases E2F-1 expression - a PRMT5 target protein - and subsequently activates GSK-3ß and NF-κB to induce caspase-3-dependent neuronal apoptosis. These findings might provide a strategy for the treatment of Alzheimer's disease.

Endoscopic axillary lymphadenectomy combined with laparoscopically harvested pedicled omentum for immediate breast reconstruction.

BACKGROUND: To determine the therapeutic and cosmetic outcomes of patients with breast cancer treated with endoscopic axillary lymphadenectomy (EAL) combined with laparoscopically harvested pedicled omentum (LHPO) for immediate breast reconstruction. METHODS: Forty patients with early breast cancer underwent EAL, followed by quadrantectomy and LHPO for immediate breast reconstruction. All patients were evaluated for operating time, blood loss, postoperative hospital stay, complications, etc. The cosmetic outcomes were evaluated 6 months after the surgery, according to the Harris criteria. RESULTS: The average operating time was 308 min, including 39 min for EAL, 63 min for quadrantectomy, and 58 min for LHPO. The average blood loss was 70 ml, and was mainly incurred during breast resection. On average, the patients were discharged 9.5 days after the surgery. Partial graft necrosis and omental fat liquefaction occurred in one patient each. No other complications occurred after the surgery. No local recurrence or distant metastasis was found during the follow-up. The cosmetic results were mostly satisfactory. No size reduction of the reconstructed breast occurred after radiation therapy. Esthetic evaluation of the reconstructed breast showed that the cosmetic outcome was "excellent" in 35 patients, "good" in 4 patients, and "fair" in 1 patient. CONCLUSIONS: EAL combined with LHPO for breast reconstruction is a viable, safe procedure that causes minimal surgical trauma and results in a soft, shapely breast postoperatively.

Exploring the Interplay between Stress Perception and Approach-Avoidance Achievement Goal Orientation among Rural Students in College: A Longitudinal Study in China.

The objective of this study was to examine the relationship between stress perception and achievement goals among rural college students in China. Using a two-wave random intercept cross-lagged model, this study analyzed data from a longitudinal survey conducted at 15 public universities in Beijing. First, there was a significant decline in stress levels among Chinese rural students from their junior to senior years. Second, the achievement goal orientations of these students remained relatively stable during the period. Third, while no significant association was found between approach goals and stress perception, a clear positive reciprocal relationship emerged between avoidance goals and stress perception. These results suggest that educators should focus on alleviating the stress experienced by rural college students through academic, employment, and interpersonal support to break the vicious cycle of stress perception and avoidance goal orientation. Future research should further explore the influence of diverse group characteristics and emotional states on these outcomes.

The Relationship between Stress and Academic Self-Efficacy among Students at Elite Colleges: A Longitudinal Analysis.

Stress and academic self-efficacy are crucial factors in the psychological health of college students. Previous research has shown that stress is associated with academic self-efficacy, but their longitudinal relationships among students at elite colleges remain unclear. This study aimed to explore the longitudinal relationships between stress and academic self-efficacy among students from five elite colleges in China. Descriptive statistics indicated that students experienced a slight reduction in stress accompanied by a marginal increase in academic self-efficacy from the junior year to the senior year. Correlation analysis revealed that stress was negatively correlated with academic self-efficacy. According to cross-lagged models, heightened stress significantly predicted lower levels of academic self-efficacy. However, greater academic self-efficacy did not significantly predict lower stress. In conclusion, stress exhibited a unidirectional negative prediction on academic self-efficacy over time among students at elite colleges. The results of this study suggested that elite colleges should pay more attention to the mental health of students and provide appropriate guidance, such as establishing a positive mental health atmosphere in the educational environment and employing advanced technological means.

CircGPC3 promotes hepatocellular carcinoma progression and metastasis by sponging miR-578 and regulating RAB7A/PSME3 expression.

CircRNAs are a class of highly stable noncoding RNAs that play an important role in the progression of many diseases, especially cancer. In this study, high-throughput sequencing was used to screen for abnormally expressed circRNAs, and we found that circGPC3 was overexpressed in HCC tissues. However, the underlying mechanism of circGPC3 in the development and metastasis of hepatocellular carcinoma (HCC) remains unknown. In our study, we found that circGPC3 was significantly upregulated in HCC tissues and cells and that its overexpression was positively correlated with overall survival, TNM stage and lymph node metastasis. In vivo and in vitro experiments showed that circGPC3 knockdown repressed HCC cell migration, invasion and proliferation and promoted apoptosis. Mechanistically, circGPC3 promoted HCC proliferation and metastasis through the miR-578/RAB7A/PSME3 axis. Our results demonstrate that circGPC3 contributes to the progression of HCC and provides an intervention target for HCC.

CircGNAO1 suppresses hepatocellular carcinoma progression and metastasis via sponging miR-182-5p and regulating FOXO1 expression.

BACKGROUND: Hepatocellular carcinoma (HCC) is an aggressive malignant tumor with poor prognosis. Using high-throughput sequencing, we identified a novel circRNA, circGNAO1, which is downregulated in HCC tissues compared to adjacent tissues. However, the potential functions and mechanisms of circGNAO1 in HCC metastasis remain unclear. METHODS: qRT-PCR was used to detect the expression of circGNAO1, miR-182-5p, and FOXO1 in HCC cells and tissues. Bioinformatics analysis, RNA pull-down assyas, and dual-luciferase reporter assays were employed to verify the interaction between circGNAO1 and miR-182-5p. Functional experiments were conducted using circGNAO1 overexpression and knockdown cell lines, including Transwell, wound healing, and EdU assays. Liver metastasis models and subcutaneous xenograft mouse models were established to analyze the effect of circGNAO1 on HCC metastasis and growth in vivo. RESULTS: High-throughput sequencing and qRT-PCR results showed that the expression of circGNAO1 dramatically decreased in HCC tissues. Functionally, in vivo and in vitro experiments verified that overexpression of circGNAO1 inhibited the proliferation, migration, invasion and EMT of HCC cells, while knockdown of circGNAO1 promoted these behaviors. Mechanistically, we have demonstrated that circGNAO1 functions as a sponge for miR-182-5p to regulate FOXO1 expression, thereby activating the TGF-ß/Smad3 signaling pathway and EMT process. CONCLUSIONS: circGNAO1 suppresses the progression and metastasis of HCC through the miR-182-5p/FOXO1 axis, and circGNAO1 may be an efficient therapeutic target in HCC.

Effects of Liqi Tongbian decoction on gut microbiota, SCFAs production, and 5-HT pathway in STC rats with Qi Stagnation Pattern.

Slow transit constipation (STC) is a common and debilitating condition characterized by delayed colonic transit and difficulty in fecal expulsion, significantly impacting patients' physical and mental wellbeing as well as their overall quality of life. This study investigates the therapeutic potential of Liqi Tongbian Decoction (LTD) in the treatment of STC, especially in cases involving the context of Qi stagnation, through a multifaceted approach involving the modulation of intestinal flora and short-chain fatty acids (SCFAs). We employed a rat model of STC with Qi Stagnation Pattern, established using the "loperamide + tail-clamping provocation method," to explore the effects of LTD on fecal characteristics, intestinal motility, and colonic pathology. Importantly, LTD exhibited the ability to increase the richness, diversity, and homogeneity of intestinal flora while also modulating the composition of microorganisms. It significantly increased the production of SCFAs, especially butyric acid. Moreover, LTD exerted a substantial influence on the synthesis of serotonin (5-HT) by modulating the expression of tryptophan hydroxylase (TPH) and interacting with the 5-HT4 receptor (5-HT4R), resulting in enhanced colonic motility. Correlation analyses revealed a positive correlation between certain bacterial genera, such as Lachnospiraceae_NK4A136 spp. and Clostridiales spp. and the concentrations of butyric acid and 5-HT. These results suggest a mechanistic link between microbiome composition, SCFAs production, and 5-HT synthesis. These findings highlight the potential of LTD to alleviate STC by facilitating a beneficial interplay among intestinal flora, SCFAs production, and 5-HT-mediated colonic motility, providing novel insights into the management of STC with Qi Stagnation Pattern.

Does Subjective Well-Being Improve Self-Rated Health from Undergraduate Studies to Three Years after Graduation in China?

The health status of emerging adults is at risk. Although subjective well-being is one of the factors closely associated with health, their longitudinal relationship is not clear among emerging adults. The study aimed to investigate the prospective relationship between self-rated health and subjective well-being in emerging adults. The study collected longitudinal data from a total of 1021 Chinese college students (537 males and 484 females) for five years, including two years in college and three years after graduation. In the baseline survey, the average age of the sample was 21.57 years old. Descriptive statistics indicated that both self-rated health and subjective well-being significantly decreased from the senior year of college to the year after graduation. Correlation analysis revealed that self-rated health and subjective well-being had a significant positive relationship. In the five-wave random intercept cross-lagged panel model, subjective well-being unidirectionally predicted self-rated health. In other words, the subjective well-being in the previous year could positively predict self-rated health in the following year, but the previous self-rated health could not predict subsequent subjective well-being. Given the significance of emerging adulthood to individual development, more attention and care should be dedicated to improving subjective well-being so as to maintain good health and engagement in work.

Structural and functional investigations of syn-copalyl diphosphate synthase from Oryza sativa.

The large superfamily of labdane-related diterpenoids is defined by the cyclization of linear geranylgeranyl pyrophosphate (GGPP), catalyzed by copalyl diphosphate synthases (CPSs) to form the basic decalin core, the copalyl diphosphates (CPPs). Three stereochemically distinct CPPs have been found in plants, namely (+)-CPP, ent-CPP and syn-CPP. Here, we used X-ray crystallography and cryo-EM methods to describe different oligomeric structures of a syn-copalyl diphosphate synthase from Oryza sativa (OsCyc1), and provided a cryo-EM structure of OsCyc1D367A mutant in complex with the substrate GGPP. Further analysis showed that tetramers are the dominant form of OsCyc1 in solution and are not necessary for enzyme activity in vitro. Through rational design, we identified an OsCyc1 mutant that can generate ent-CPP in addition to syn-CPP. Our work provides a structural and mechanistic basis for comparing different CPSs and paves the way for further enzyme design to obtain diterpene derivatives with specific chirality.