ESM1 enhances fatty acid synthesis and vascular mimicry in ovarian cancer by utilizing the PKM2-dependent warburg effect within the hypoxic tumor microenvironment.

BACKGROUND: The hypoxic tumor microenvironment is a key factor that promotes metabolic reprogramming and vascular mimicry (VM) in ovarian cancer (OC) patients. ESM1, a secreted protein, plays an important role in promoting proliferation and angiogenesis in OC. However, the role of ESM1 in metabolic reprogramming and VM in the hypoxic microenvironment in OC patients has not been determined. METHODS: Liquid chromatography coupled with tandem MS was used to analyze CAOV3 and OV90 cells. Interactions between ESM1, PKM2, UBA2, and SUMO1 were detected by GST pull-down, Co-IP, and molecular docking. The effects of the ESM1-PKM2 axis on cell glucose metabolism were analyzed based on an ECAR experiment. The biological effects of the signaling axis on OC cells were detected by tubule formation, transwell assay, RT‒PCR, Western blot, immunofluorescence, and in vivo xenograft tumor experiments. RESULTS: Our findings demonstrated that hypoxia induces the upregulation of ESM1 expression through the transcription of HIF-1α. ESM1 serves as a crucial mediator of the interaction between PKM2 and UBA2, facilitating the SUMOylation of PKM2 and the subsequent formation of PKM2 dimers. This process promotes the Warburg effect and facilitates the nuclear translocation of PKM2, ultimately leading to the phosphorylation of STAT3. These molecular events contribute to the promotion of ovarian cancer glycolysis and vasculogenic mimicry. Furthermore, our study revealed that Shikonin effectively inhibits the molecular interaction between ESM1 and PKM2, consequently preventing the formation of PKM2 dimers and thereby inhibiting ovarian cancer glycolysis, fatty acid synthesis and vasculogenic mimicry. CONCLUSION: Our findings demonstrated that hypoxia increases ESM1 expression through the transcriptional regulation of HIF-1α to induce dimerization via PKM2 SUMOylation, which promotes the OC Warburg effect and VM.

ANGPTL4 accelerates ovarian serous cystadenocarcinoma carcinogenesis and angiogenesis in the tumor microenvironment by activating the JAK2/STAT3 pathway and interacting with ESM1.

BACKGROUND: Ovarian cancer (OC) is a malignant neoplasm that displays increased vascularization. Angiopoietin-like 4 (ANGPTL4) is a secreted glycoprotein that functions as a regulator of cell metabolism and angiogenesis and plays a critical role in tumorigenesis. However, the precise role of ANGPTL4 in the OC microenvironment, particularly its involvement in angiogenesis, has not been fully elucidated. METHODS: The expression of ANGPTL4 was confirmed by bioinformatics and IHC in OC. The potential molecular mechanism of ANGPTL4 was measured by RNA-sequence. We used a series of molecular biological experiments to measure the ANGPTL4-JAK2-STAT3 and ANGPTL4-ESM1 axis in OC progression, including MTT, EdU, wound healing, transwell, xenograft model, oil red O staining, chick chorioallantoic membrane assay and zebrafish model. Moreover, the molecular mechanisms were confirmed by Western blot, Co-IP and molecular docking. RESULTS: Our study demonstrates a significant upregulation of ANGPTL4 in OC specimens and its strong association with unfavorable prognosis. RNA-seq analysis affirms that ANGPTL4 facilitates OC development by driving JAK2-STAT3 signaling pathway activation. The interaction between ANGPTL4 and ESM1 promotes ANGPTL4 binding to lipoprotein lipase (LPL), thereby resulting in reprogrammed lipid metabolism and the promotion of OC cell proliferation, migration, and invasion. In the OC microenvironment, ESM1 may interfere with the binding of ANGPTL4 to integrin and vascular-endothelial cadherin (VE-Cad), which leads to stabilization of vascular integrity and ultimately promotes angiogenesis. CONCLUSION: Our findings underscore that ANGPTL4 promotes OC development via JAK signaling and induces angiogenesis in the tumor microenvironment through its interaction with ESM1.

Angiopoietin4 (ANGPT4) expression and potential mechanisms in carcinogenesis: current achievements and perspectives.

Angiopoietin4(ANGPT4) which plays a significant role in endothelial cell proliferation, survival, angiogenesis and expansion in tumors and other pathological states is a significant regulator of tumor angiogenesis. ANGPT4 expression is enhanced in many cancer cells. For example, the overexpression of ANGPT4 promotes the formation, development and progress of lung adenocarcinoma, glioblastoma and ovarian cancer. Related studies show that ANGPT4 encourages the proliferation, survival and invasion of tumor cells, while promoting the expansion of the tumor vascular system and affecting the tumor immune microenvironment. ANGPT4 can also promote carcinogenesis by affecting the ERK1/2, PI3K/AKT and other signal pathways downstream of tyrosine kinase with immunoglobulin-like and EGF-like domains 2(TIE2) and TIE2. Therefore, ANGPT4 may be a potential and significant biomarker for predicting malignant tumor progression and adverse outcomes. In addition, inhibition of ANGPT4 may be a meaningful cancer treatment. This paper reviews the latest research results of ANGPT4 in preclinical research, and emphasizes its role in carcinogenesis. Additional research on the carcinogenic function of ANGPT4 could provide new insights into cancer biology and novel methods for cancer diagnosis and treatment.

Patterns and abiotic drivers of soil organic carbon in perennial tea (Camellia sinensis L.) plantation system of China.

Understanding soil organic carbon (SOC), the largest carbon (C) pool of a terrestrial ecosystem, is essential for mitigating climate change. Currently, the spatial patterns and drivers of SOC in the plantations of tea, a perennial leaf crop, remain unclear. Therefore, the present study surveyed SOC across the main tea-producing areas of China, which is the largest tea producer in the world. We analyzed the soil samples from tea plantations under different scenarios, such as provinces, regions [southwest China (SW), south China (SC), south Yangtze (SY), and north Yangtze (NY)], climatic zones (temperate, subtropical, and tropical), and cultivars [large-leaf (LL) and middle or small-leaf (ML) cultivars]. Preliminary analysis revealed that most tea-producing areas (45%) had SOC content ranging from 10 to 20 g kg-1. The highest SOC was recorded for Yunnan among the various provinces, the SW tea-producing area among the four regions, the tropical region among the different climatic zones, and the areas with LL cultivars compared to those with ML cultivars. Further Pearson correlation analysis demonstrated significant associations between SOC and soil variables and random forest modeling (RF) identified that total nitrogen (TN) and available aluminum [Ava(Al)] of soil explained the maximum differences in SOC. Besides, a large indirect effect of geography (latitude and altitude) on SOC was detected through partial least squares path modeling (PLS-PM) analysis. Thus, the study revealed a high spatial heterogeneity in SOC across the major tea-producing areas of China. The findings also serve as a basis for planning fertilization strategies and C sequestration policies for tea plantations.

Machine Learning Enables Prediction of Pyrrolysyl-tRNA Synthetase Substrate Specificity.

Knowledge about the substrate scope for a given enzyme is informative for elucidating biochemical pathways and also for expanding applications of the enzyme. However, no general methods are available to accurately predict the substrate specificity of an enzyme. Pyrrolysyl-tRNA synthetase (PylRS) is a powerful tool for incorporating various noncanonical amino acids (NCAAs) into proteins, which enabled us to probe, image, rationally engineer, and evolve protein structure and function. However, the incorporation of a new NCAA typically requires the selection of large libraries of PylRS with randomized mutations at active sites, and this process requires multiple rounds of selection for each new substrate. Therefore, a single aminoacyl-tRNA synthetase with broad substrate promiscuity is ideal to facilitate widespread applications of the genetic NCAA incorporation technique. Herein, machine learning models were developed to predict the substrate specificity of PylRS to accept novel NCAAs that could be incorporated into proteins by three PylRS mutants. The models were built from a training set of 285 unique enzyme-substrate pairs of three PylRS mutants including IFRS, BtaRS, and MFRS against 95 NCAAs. The best BaggingTree (BT) model was then used for virtually screening a NCAAs library containing 1474 phenylalanine, tyrosine, tryptophan, and alanine analogues, and 156 NCAAs were predicted to be accepted by at least one of the three PylRS mutants. Then, 27 NCAAs including 24 positive and 3 negative substrates were experimentally tested for their activities, and 20 of the 24 positive substrates showed weak or strong activity and were accepted by at least one PylRS mutant, among which 11 NCAAs were never reported to be incorporated into proteins before. Three negative substrates did not show any activity. Experimental results suggested that the BT model provides a three-class classification accuracy of 0.69 and a binary classification accuracy of 0.86. This study expanded the substrate scope of three PylRS variants and provided a framework for developing machine learning models to predict substrate specificity of other PylRS variants.

Magnesium promotes tea plant growth via enhanced glutamine synthetase-mediated nitrogen assimilation.

Acidic tea (Camellia sinensis) plantation soil usually suffers from magnesium (Mg) deficiency, and as such, application of fertilizer containing Mg can substantially increase tea quality by enhancing the accumulation of nitrogen (N)-containing chemicals such as amino acids in young tea shoots. However, the molecular mechanisms underlying the promoting effects of Mg on N assimilation in tea plants remain unclear. Here, both hydroponic and field experiments were conducted to analyze N, Mg, metabolite contents, and gene expression patterns in tea plants. We found that N and amino acids accumulated in tea plant roots under Mg deficiency, while metabolism of N was enhanced by Mg supplementation, especially under a low N fertilizer regime. 15N tracing experiments demonstrated that assimilation of N was induced in tea roots following Mg application. Furthermore, weighted gene correlation network analysis (WGCNA) analysis of RNA-seq data suggested that genes encoding glutamine synthetase isozymes (CsGSs), key enzymes regulating N assimilation, were markedly regulated by Mg treatment. Overexpression of CsGS1.1 in Arabidopsis (Arabidopsis thaliana) resulted in a more tolerant phenotype under Mg deficiency and increased N assimilation. These results validate our suggestion that Mg transcriptionally regulates CsGS1.1 during the enhanced assimilation of N in tea plant. Moreover, results of a field experiment demonstrated that high Mg and low N had positive effects on tea quality. This study deepens our understanding of the molecular mechanisms underlying the interactive effects of Mg and N in tea plants while also providing both genetic and agronomic tools for future improvement of tea production.

Rational design of enzyme activity and enantioselectivity.

The strategy of rational design to engineer enzymes is to predict the potential mutants based on the understanding of the relationships between protein structure and function, and subsequently introduce the mutations using the site-directed mutagenesis. Rational design methods are universal, relatively fast and have the potential to be developed into algorithms that can quantitatively predict the performance of the designed sequences. Compared to the protein stability, it was more challenging to design an enzyme with improved activity or selectivity, due to the complexity of enzyme molecular structure and inadequate understanding of the relationships between enzyme structures and functions. However, with the development of computational force, advanced algorithm and a deeper understanding of enzyme catalytic mechanisms, rational design could significantly simplify the process of engineering enzyme functions and the number of studies applying rational design strategy has been increasing. Here, we reviewed the recent advances of applying the rational design strategy to engineer enzyme functions including activity and enantioselectivity. Five strategies including multiple sequence alignment, strategy based on steric hindrance, strategy based on remodeling interaction network, strategy based on dynamics modification and computational protein design are discussed and the successful cases using these strategies are introduced.

Validation of ESM1 Related to Ovarian Cancer and the Biological Function and Prognostic Significance.

Background: Ovarian cancer (OC), a serious gynecological malignant disease, remains an enormous challenge in early diagnosis and medical treatment. Based on the GEO and TCGA databases in R language, endothelial cell-specific molecule 1 (ESM1) was confirmed separately with the bioinformatic analysis tool. ESM1 has been demonstrated to be upregulated in multiple cancer types, but the oncogenic mechanism by which ESM1 promotes OC is still largely unknown. Methods: In this study, we used WGCNA and random survival forest variable screening to filter out ESM1 in OC differentially expressed genes (DEGs). Next, we confirmed the mRNA and protein levels of ESM1 in OC samples via PCR and IHC. The correlation between the ESM1 level and clinical data of OC patients was further confirmed, including FIGO stage, lymph node metastasis, and recurrence. The role of ESM1 in OC development was explored by several functional experiments in vivo and in vitro. Then, the molecular mechanisms of ESM1 were further elucidated by bioinformatic end experimental analysis. Results: ESM1 was significantly upregulated in OC and was positively correlated with PFS but negatively correlated with OS. ESM1 knockdown inhibited cell proliferation, apoptosis escape, the cell cycle, angiogenesis, migration and invasion in multiple experiments. Moreover, GSVA found that ESM1 was associated with the Akt pathway, and our results supported this prediction. Conclusion: ESM1 was closely correlated with OC development and progression, and it could be considered a novel biomarker and therapeutic target for OC patients.

An evolved pyrrolysyl-tRNA synthetase with polysubstrate specificity expands the toolbox for engineering enzymes with incorporation of noncanonical amino acids.

Aminoacyl-tRNA synthetase (aaRS) is a core component for genetic code expansion (GCE), a powerful technique that enables the incorporation of noncanonical amino acids (ncAAs) into a protein. The aaRS with polyspecificity can be exploited in incorporating additional ncAAs into a protein without the evolution of new, orthogonal aaRS/tRNA pair, which hence provides a useful tool for probing the enzyme mechanism or expanding protein function. A variant (N346A/C348A) of pyrrolysyl-tRNA synthetase from Methanosarcina mazei (MmPylRS) exhibited a wide substrate scope of accepting over 40 phenylalanine derivatives. However, for most of the substrates, the incorporation efficiency was low. Here, a MbPylRS (N311A/C313A) variant was constructed that showed higher ncAA incorporation efficiency than its homologous MmPylRS (N346A/C348A). Next, N-terminal of MbPylRS (N311A/C313A) was engineered by a greedy combination of single variants identified previously, resulting in an IPE (N311A/C313A/V31I/T56P/A100E) variant with significantly improved activity against various ncAAs. Activity of IPE was then tested toward 43 novel ncAAs, and 16 of them were identified to be accepted by the variant. The variant hence could incorporate nearly 60 ncAAs in total into proteins. With the utility of this variant, eight various ncAAs were then incorporated into a lanthanide-dependent alcohol dehydrogenase PedH. Incorporation of phenyllactic acid improved the catalytic efficiency of PedH toward methanol by 1.8-fold, indicating the role of modifying protein main chain in enzyme engineering. Incorporation of O-tert-Butyl-L-tyrosine modified the enantioselectivity of PedH by influencing the interactions between substrate and protein. Enzymatic characterization and molecular dynamics simulations revealed the mechanism of ncAAs affecting PedH catalysis. This study provides a PylRS variant with high activity and substrate promiscuity, which increases the utility of GCE in enzyme mechanism illustration and engineering.

Aluminum Supplementation Mediates the Changes in Tea Plant Growth and Metabolism in Response to Calcium Stress.

Tea plants are more sensitive to variations in calcium concentration compared to other plants, whereas a moderate aluminum concentration facilitates the growth and development of tea plants. Aluminum and calcium show a competitive interaction with respect to the uptake of elements, consequently exerting physiological effects on plants. To further explore these interactions, in this study, we used the solution culture method to treat tea plants with two calcium concentrations (0.8 mM and 5.6 mM) and three aluminum concentrations (0 mM, 0.4 mM, and 1 mM). We then determined the influence of the combined treatments on root growth and quality compound accumulation in the tissues by a combination of phenotype, gene expression, and metabolite analyses. Moderate aluminum supplementation (0.4 mM) alleviated the inhibition of root growth caused by high calcium stress. High calcium stress significantly inhibited the accumulation of most amino acids (e.g., Glutamic acid, Citulline, and Arginine) and organic acids (e.g., a-ketoglutaric acid) in the roots, stems, and leaves, whereas aluminum deficiency significantly increased most amino acids in the roots and leaves (except Serine, Alanine, and Phenylalanine in the roots and Ser in the leaves), with a more than two-fold increase in Arg and Lysine. High calcium stress also induced the accumulation of secondary metabolites such as epigallocatechin gallate and procyanidin in the roots, whereas aluminum supplementation significantly reduced the contents of flavonol glycosides such as quercetin, rutin, myricitrin, and kaempferitrin, as well as caffeine, regardless of calcium concentration. Aluminum supplementation reversed some of the changes in the contents of leaf metabolites induced by calcium stress (e.g., 4-dihydroquercetin, apigenin C-pentoside, phenethylamine, and caffeine). Overall, calcium stress caused severe growth inhibition and metabolic disorders in tea plants, which could be reversed by aluminum supplementation, particularly in maintaining the root tips and the accumulation of secondary metabolites. These results provide a theoretical basis for improving calcium-aluminum nutrient management to promote tea plant growth and quality.

Effect of Interactions between Phosphorus and Light Intensity on Metabolite Compositions in Tea Cultivar Longjing43.

Light intensity influences energy production by increasing photosynthetic carbon, while phosphorus plays an important role in forming the complex nucleic acid structure for the regulation of protein synthesis. These two factors contribute to gene expression, metabolism, and plant growth regulation. In particular, shading is an effective agronomic practice and is widely used to improve the quality of green tea. Genotypic differences between tea cultivars have been observed as a metabolic response to phosphorus deficiency. However, little is known about how the phosphorus supply mediates the effect of shading on metabolites and how plant cultivar gene expression affects green tea quality. We elucidated the responses of the green tea cultivar Longjing43 under three light intensity levels and two levels of phosphorus supply based on a metabolomic analysis by GC×GC-TOF/MS (Two-dimensional Gas Chromatography coupled to Time-of-Flight Mass Spectrometry) and UPLC-Q-TOF/MS (Ultra-Performance Liquid Chromatography-Quadrupole-Time of Flight Mass Spectrometry), a targeted analysis by HPLC (High Performance Liquid Chromatography), and a gene expression analysis by qRT-PCR. In young shoots, the phosphorus concentration increased in line with the phosphate supply, and elevated light intensities were positively correlated with catechins, especially with epigallocatechin of Longjing43. Moreover, when the phosphorus concentration was sufficient, total amino acids in young shoots were enhanced by moderate shading which did not occur under phosphorus deprivation. By metabolomic analysis, phenylalanine, tyrosine, and tryptophan biosynthesis (PTT) were enriched due to light and phosphorus effects. Under shaded conditions, SPX2 (Pi transport, stress, sensing, and signaling), SWEET3 (bidirectional sugar transporter), AAP (amino acid permeases), and GSTb (glutathione S-transferase b) shared the same analogous correlations with primary and secondary metabolite pathways. Taken together, phosphorus status is a crucial factor when shading is applied to increase green tea quality.

[Status of Heavy Metal in Organic Fertilizers in Main Tea Growing Regions of China].

To provide guidance for the safe use of organic fertilizers and improve soil quality and tea safety, it is necessary to conduct systematic analyses of the heavy metal content of organic fertilizers applied in the main tea producing areas of China. In this study, we analyzed the heavy metal contents in organic fertilizer samples collected from 2017 to 2019. The risks of collected organic fertilizers from different areas and sources were calculated. The results showed that the average concentrations of ω(As), ω(Hg), ω(Pb), ω(Cd), ω(Cr), ω(Cu), ω(Zn), and ω(Ni) in the collected organic fertilizers were 4.60, 0.22, 27.1, 0.78, 27.9, 58.3, 250.1, and 16.3 mg·kg-1, respectively. According to the assessment standard in NY/T 525- 2021, the over-limit rates of As, Hg, Pb, Cd, and Cr were 6.19%, 1.33%, 4.42%, 4.42%, and 1.33%, respectively. With respect to the area, the qualified rates were 100% in Shaanxi, Jiangsu, Anhui, Fujian, and Guangxi; 80%-90% in Shandong, Zhejiang, Hubei, Sichuan, Yunnan, and Guangdong; and only 54.5% in Jiangxi. The qualified rates of sources were 100% in rapeseed cake, soybean cake, and pig manure; 95.8% in sheep manure; 91.7% in cow manure; 90.7% in chicken manure; 87.2% in manure of other animals; 82.4% in the mixture of plant and animal sources; 65.2% in other plant sources; and 63.6% in other sources. According to the recommended application rate, the accumulation rate of heavy metals in soil with pig manure, cow manure, chicken manure, and sheep manure would be much higher than that with rapeseed cake and soybean cake. The average accumulation rate of organic fertilizer from animal sources was 7-30 times higher than that from plant sources. Therefore, it is recommended to use rapeseed cake or soybean cake fertilizer in tea plantation and to increase the supervision of heavy metal accumulation in soil and tea in those high-risk areas.

Integration of Metabolomics and Transcriptomics Reveal the Mechanism Underlying Accumulation of Flavonols in Albino Tea Leaves.

Albino tea plants (Camellia sinensis) have been reported to possess highly inhibited metabolism of flavonoids compared to regular green tea leaves, which improves the quality of the tea made from these leaves. However, the mechanisms underlying the metabolism of catechins and flavonols in albino tea leaves have not been well elucidated. In this study, we analyzed a time series of leaf samples in the greening process from albino to green in a thermosensitive leaf-color tea mutant using metabolomics and transcriptomics. The total content of polyphenols dramatically decreased, while flavonols (such as rutin) were highly accumulated in albino leaves compared to in green leaves. After treatment with increasing environment temperature, total polyphenols and catechins were increased in albino mutant tea leaves; however, flavonols (especially ortho-dihydroxylated B-rings such as rutin) were decreased. Meanwhile, weighted gene co-expression network analysis of RNA-seq data suggested that the accumulation of flavonols was highly correlated with genes related to reactive oxygen species scavenging. Histochemical localization further demonstrated that this specific accumulation of flavonols might be related to their biological functions in stress tolerance. These findings suggest that the temperature-stimulated accumulation of total polyphenols and catechins in albino mutant tea leaves was highly induced by enhanced photosynthesis and accumulation of its products, while the initial accumulation and temperature inhibition of flavonols in albino mutant tea leaves were associated with metabolism related to oxidative stress. In conclusion, our results indicate that the biosynthesis of flavonoids could be driven by many different factors, including antioxidation and carbon skeleton storage, under favorable and unfavorable circumstances, respectively. This work provides new insights into the drivers of flavonoid biosynthesis in albino tea leaves, which will further help to increase tea quality by improving cultivation measures.

Dynamic Changes in the Antioxidative Defense System in the Tea Plant Reveal the Photoprotection-Mediated Temporal Accumulation of Flavonoids under Full Sunlight Exposure.

To reveal the mechanisms underlying how light affects flavonoid metabolism and the potential role of flavonoids in protecting against photooxidative stress in tea leaves, tea plants adapted to low-light conditions were exposed to full sunlight over 48 h. There was an increase in the activities of catalase (CAT) and superoxide dismutase (SOD) as well as greater accumulation of reactive oxygen species, lutein, tocopherols, ascorbate and malondialdehyde, suggestive of a time-dependent response to photooxidative stress in tea leaves. Analysis of the time dependency of each element of the antioxidant system indicated that carotenoids and tocopherols exhibited the fastest response to light stress (within 3 h), followed by SOD, CAT and catechin, which peaked at 24 h. Meanwhile, flavonols, vitamin C and glutathione showed the slowest response. Subsequent identification of the main phytochemicals involved in protecting against oxidative stress using untargeted metabolomics revealed a fast and initial accumulation of nonesterified catechins that preceded the increase in flavonol glycosides and catechin esters. Gene expression analysis suggested that the light-induced accumulation of flavonoids was highly associated with the gene encoding flavonol synthase. Ultraviolet B (UV-B) irradiation further validated the time-dependent and collaborative effects of flavonoids in photoprotection in tea plants. Intriguingly, the dynamics of the metabolic response are highly distinct from those reported for Arabidopsis, suggesting that the response to light stress is not conserved across plants. This study additionally provides new insights into the functional role of flavonoids in preventing photooxidative stress and may contribute to further improving tea quality through the control of light intensity.

Identification of key genes associated with polycystic ovary syndrome (PCOS) and ovarian cancer using an integrated bioinformatics analysis.

BACKGROUND: Accumulating evidence suggests a strong association between polycystic ovary syndrome (PCOS) and ovarian cancer (OC), but the potential molecular mechanism remains unclear. In this study, we identified previously unrecognized genes that are significantly correlated with PCOS and OC via bioinformatics. MATERIALS AND METHODS: Multiple bioinformatic analyses, such as differential expression analysis, univariate Cox analysis, functional and pathway enrichment analysis, protein-protein interaction (PPI) network construction, survival analysis, and immune infiltration analysis, were utilized. We further evaluated the effect of OGN on FSHR expression via immunofluorescence. RESULTS: TCGA-OC, GSE140082 (for OC) and GSE34526 (for PCOS) datasets were downloaded. Twelve genes, including RNF144B, LPAR3, CRISPLD2, JCHAIN, OR7E14P, IL27RA, PTPRD, STAT1, NR4A1, OGN, GALNT6 and CXCL11, were identified as signature genes. Drug sensitivity analysis showed that OGN might represent a hub gene in the progression of PCOS and OC. Experimental analysis found that OGN could increase FSHR expression, indicating that OGN could regulate the hormonal response in PCOS and OC. Furthermore, correlation analysis indicated that OGN function might be closely related to m6A and ferroptosis. CONCLUSIONS: Our study identified a 12-gene signature that might be involved in the prognostic significance of OC. Furthermore, the hub gene OGN represent a significant gene involved in OC and PCOS progression by regulating the hormonal response.

Accumulation of Amino Acids and Flavonoids in Young Tea Shoots Is Highly Correlated With Carbon and Nitrogen Metabolism in Roots and Mature Leaves.

The quality of tea product and the metabolism of quality-related compounds in young shoots are significantly affected by the nitrogen(N) supply. However, little is known of the metabolic changes that take place in tea roots and mature leaves under different supplies, which has a large effect on the accumulation of quality-related compounds in young shoots. In this study, young shoots, mature leaves, and roots under different N conditions were subjected to metabolite profiling using gas chromatography and ultraperformance liquid chromatography, coupled with quadrupole time-of-flight mass spectrometry. The contents of free amino acids (e.g., theanine and glutamate) involved in N metabolism were significantly greater under high N than under low N, while a high N supply reduced soluble sugars (e.g., glucose) in all three tissues. Organic acids (e.g., malate, fumarate, α-ketoglutatare, and succinate) involved in tricarboxylic acid cycle remarkably increased as the nitrogen supply increased, which confirms that carbon (C) allocation was restricted by increasing the nitrogen supply, especially in mature leaves. RT-PCR results indicated that gene expression related to nitrogen assimilation significantly increased in roots with increasing nitrogen supply, which had a significant positive relationship with the level of free amino acids in young shoots. In addition, the expression of most genes involved in flavonoid synthesis was significantly upregulated under conditions of low nitrogen supply relative to high nitrogen supply in young shoot and roots. These data suggest that enhanced assimilation of N in tea roots and the coordinated regulation of C (sugars, organic acids, and flavonoids) and N(amino acids) in mature leaves can lead to a high accumulation of amino acids in young shoots. Furthermore, as the N supply increased, more C was partitioned into compounds containing N in mature leaves and roots, resulting in a decrease in flavonoids in young shoots. In conclusion, the accumulation of amino acids and flavonoids in young tea shoots is highly correlated with carbon and nitrogen metabolism in roots and mature leaves.

Foliar N Application on Tea Plant at Its Dormancy Stage Increases the N Concentration of Mature Leaves and Improves the Quality and Yield of Spring Tea.

Over 30% of the Chinese tea plantation is supplied with excess fertilizer, especially nitrogen (N) fertilizer. Whether or not foliar N application on tea plants at the dormancy stage could improve the quality of spring tea and be a complementary strategy to reduce soil fertilization level remains unclear. In this study, the effects of foliar N application on tea plants were investigated by testing the types of fertilizers and their application times, and by applying foliar N under a reduced soil fertilization level using field and 15N-labeling pot experiments. Results showed that the foliar N application of amino acid liquid fertilizer two times at the winter dormancy stage was enough to significantly increase the N concentration of the mature leaves and improved the quality of spring tea. The foliar application of 2% urea or liquid amino acid fertilizer two times at the winter dormancy stage and two times at the spring dormancy stage showed the best performance in tea plants among the other foliar N fertilization methods, as it reduced the soil fertilization levels in tea plantations without decreasing the total N concentration of the mature leaves or deteriorating the quality of spring tea. Therefore, foliar N application on tea plants at its dormancy stage increases the N concentration of the mature leaves, improves the quality and yield of spring tea, and could be a complementary strategy to reduce soil fertilization levels.

Light Intensity Modulates the Effect of Phosphate Limitation on Carbohydrates, Amino Acids, and Catechins in Tea Plants (Camellia sinensis L.).

Metabolites are major contributors to the quality of tea that are regulated by various abiotic stresses. Light intensity and phosphorus (P) supply affect the metabolism of tea plants. However, how these two factors interact and mediate the metabolite levels in tea plants are not fully understood. The present study investigated the consequences of different light intensity and P regimes on the metabolism of carbohydrates, amino acids, and flavonoids in the Fengqing tea cultivar. The leaves and young shoots were subjected to untargeted metabolomics analysis by two-dimensional gas chromatography coupled to time-of-flight mass spectrometry (GC×GC-TOF/MS), ultra-performance liquid chromatography-quadrupole-TOF/MS (UPLC-Q-TOF/MS), and targeted analysis by high-performance liquid chromatography (HPLC) along with quantification of gene expression by quantitative real time-PCR (qRT-PCR). The results from young shoots showed that amino acids, pentose phosphate, and flavonol glycosides pathways were enhanced in response to decreasing light intensities and P deficiency. The expression of the genes hexokinase 1, ribose 5-phosphate isomerase A (RPIA), glutamate synthetase 1 (GS1), prolyl 4-hydroxylase (P4H), and arginase was induced by P limitation, thereafter affecting carbohydrates and amino acids metabolism, where shading modulated the responses of transcripts and corresponding metabolites caused by P deficiency. P deprivation repressed the expression of Pi transport, stress, sensing, and signaling (SPX2) and induced bidirectional sugar transporter (SWEET3) and amino acid permeases (AAP) which ultimately caused an increase in the amino acids: glutamate (Glu), proline (Pro), and arginine (Arg) under shading but decreased catechins [epicatechingallate (ECG) and Gallic acid, GA] content in young shoots.