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Chen, S.

Publications and source records attributed to Chen, S..

At least 595 records · Page 33Linked to original sources

SE(3) Equivalent Graph Attention Network as an Energy-Based Model for Protein Side Chain Conformation

Protein design energy functions have been developed over decades by leveraging physical forces approximation and knowledge-derived features. However, manual feature engineering and parameter tuning might suffer from knowledge bias. Learning potential energy functions fully from crystal structure data is promising to automatically discover unknown or high-order features that contribute to the proteins energy. Here we proposed a graph attention network as an energy-based model for protein conformation, namely GraphEBM. GraphEBM is equivariant to the SE(3) group transformation, which is the important principle of modern machine learning for molecules-related tasks. GraphEBM was benchmarked on the rotamer recovery task and outperformed both Rosetta and the state-of-the-art deep learning based methods. Furthermore, GraphEBM also yielded promising results on combinatorial side chain optimization, improving 22.2%{chi} 1 rotamer recovery to the PULCHRA method on average.

bioinformatics↗

Intra-islet glucagon signalling regulates pulsatile insulin secretion and glucose homeostasis

BackgroundType 2 diabetes (T2D) is characterised by the loss of pulsatile insulin secretion. We studied mice with {beta}-cell specific loss of the glucagon receptor (Gcgr fl/fl X Ins-1Cre), to investigate the role of intra-islet glucagon receptor signalling on pan-islet calcium oscillations and insulin pulsatility. MethodsFrequently sampled intravenous glucose tolerance tests were conducted on Gcgr {beta}-cell-/- and littermate controls. Crossing with GCaMP6f (STOP flox) animals further allowed for {beta}-cell specific expression of a fluorescent calcium indicator. These islets were functionally imaged in vitro and in vivo. Wild-type mice were transplanted with islets expressing GCaMP6f in {beta}-cells into the anterior eye chamber and placed on a high fat diet. Part of the cohort received a glucagon analogue (GCG-analogue) for 40 days and the control group were fed to achieve weight matching. Calcium imaging was performed regularly during the development of hyperglycaemia and in response to GCG-analogue treatment. ResultsGcgr {beta}-cell-/- mice exhibited impaired glucose tolerance following intraperitoneal glucose challenge (control 12.7mmol/L {+/-}0.6 vs. Gcgr {beta}-cell-/- 15.4mmol/L {+/-}0.0 at 15 min, p=0.002); fasting glycaemia was not different to controls. In vitro, Gcgr {beta}-cell-/- islets showed profound loss of synchronised calcium waves in response to glucose which was only partially rescued in vivo. First-phase insulin pulsatility on peripheral blood sampling (n=5) was significantly disordered in Gcgr {beta}-cell-/- mice (burst mass Gcgr {beta}-cell-/- 0.30 {+/-}0.03 versus 0.84 {+/-}0.23 for controls p=0.04). Diet induced obesity and hyperglycaemia resulted in a loss of co-ordinated [Ca2+]I waves in transplanted islets. This was reversed with GCG-analogue treatment, independently of weight-loss (n=8). ConclusionThese data provide novel evidence for the role of intra-islet GCGR signalling in sustaining synchronised calcium oscillations and support a possible therapeutic role for glucagonergic agents to restore the insulin pulsatility lost in T2D.

physiology↗

Dissecting aneuploidy phenotypes by constructing Sc2.0 chromosome VII and SCRaMbLEing synthetic disomic yeast

Aneuploidy compromises genomic stability, often leading to embryo inviability, and is frequently associated with tumorigenesis and aging. Different aneuploid chromosome stoichiometries lead to distinct transcriptomic and phenotypic changes, making it helpful to study aneuploidy in tightly controlled genetic backgrounds. By deploying the engineered SCRaMbLE system to the newly synthesized Sc2.0 megabase chromosome VII (synVII), we constructed a synthetic disomic yeast and screened hundreds of SCRaMbLEd derivatives with diverse chromosomal rearrangements. Phenotypic characterization and multi-omics analysis revealed that fitness defects associated with aneuploidy could be restored by i) removing most of the chromosome content, or ii) modifying specific regions in the duplicated chromosome. These findings indicate that both chromosome copy number and chromosomal regions contribute to the aneuploidy-related phenotypes, and the synthetic yeast resource opens new paradigms in studying aneuploidy. In briefUse of SCRaMbLE and newly synthesized Mb-scale Sc2.0 chromosome VII enables insights into genotype/phenotype relationships associated with aneuploidy HighlightsO_LIDe novo design and synthesis of a Mb-scale synthetic yeast chromosome VII, carrying 11.8% sequence modifications and representing nearly 10% of the yeast genome. C_LIO_LIA disomic yeast (n + synVII) is constructed for dissecting the aneuploidy phenotype C_LIO_LISCRaMbLE enables systematic exploration of regions causing aneuploidy phenotypes C_LIO_LIChromosomal copy number and content both contribute to aneuploidy phenotypes C_LIO_LIA 20 Kb deletion on the right arm of synVII leads to fitness improvement linked to up-regulation of protein synthesis C_LI

synthetic biology↗

Depolarization of astrocytes in the basolateral amygdala restores WFS1 neuronal activity and rescues impaired risk-avoidance behavior in DISC1TM mice

Many mental illnesses are accompanied by abnormal risk-avoidance behavior, yet we have only a limited understanding of the neuronal regulatory mechanisms involved. We previously established an inducible DISC1-N terminal fragment transgenic mouse (DISC1-NTM) model which has exhibited risk-avoidance deficiency. Using this model, we analyzed differentially expressed genes (DEGs) using snRNA-seq and the results indicate impaired neuron-astrocyte interactions. We used optogenetic tools to modulate astrocytes in the basolateral amygdala (BLA) and found that ChR2-expressing astrocytes were able to rescue risk-avoidance impairment in DISC1-NTM mice. Using patch clamp recordings combined with signal-cell qPCR, we found impaired excitability of BLAWFS1 neurons in DISC1-NTM mice and that ChR2-expressing astrocytes can induce action potentials (APs) in WFS1 neurons, which restores WFS1 neuronal activity. WFS1 neurons are necessary for BLA astrocytes to modulate impaired risk-avoidance behavior. These finding provide new insights into mechanisms of astrocyte-neuron interactions and suggest that BLA astrocytes may be a promising target for impaired risk avoidance in mental illness. HighlightsChR2-expressing astrocytes in the BLA rescue impaired risk-avoidance behavior in DISC1-NTM mice. Astrocytes in the BLA modulate different nearby neurons to different degrees. Depolarization of BLA astrocytes restore neuronal activity in WFS1 neurons. Astrocytes in the BLA modulate WFS1 neurons via NMDARs.

neuroscience↗

Not4-dependent targeting of MMF1 mRNA to mitochondria limits its expression via ribosome pausing, Egd1 ubiquitination, Caf130, No-Go-Decay and autophagy

The Ccr4-Not complex is a conserved multi protein complex with diverse roles in the mRNA life cycle. Recently we determined that the Not1 and Not4 subunits of Ccr4-Not inversely regulate mRNA solubility and thereby impact dynamics of co-translation events. One mRNA whose solubility is limited by Not4 is MMF1 encoding a mitochondrial matrix protein. In this work we determine that Not4 promotes the co-translational docking of MMF1 mRNA to mitochondria via the mitochondrial targeting sequence of the Mmf1 nascent chain, the Egd1 chaperone, the Om14 mitochondrial outer membrane protein and the co-translational import machinery. We observe that MMF1 mRNA is translated with ribosome pausing and uncover a mechanism that depends upon its targeting to the mitochondria and limits its overexpression. We have named this mechanism Mito-ENCay. It relies on Egd1 ubiquitination by Not4, the Caf130 subunit of the Ccr4-Not complex, the mitochondrial outer membrane protein Cis1, No-Go-Decay as well as autophagy. We propose that in fermenting yeast, mRNAs whose encoded proteins depend upon co-translational folding and/or assembly are regulated by Caf130-dependent quality control mechanisms similar to Mito-ENCay.

molecular biology↗

NS5A domain I antagonises PKR to facilitate the assembly of infectious hepatitis C virus particles

Hepatitis C virus NS5A is a multifunctional phosphoprotein comprised of three domains (DI, DII and DIII). DI and DII have been shown to function in genome replication, whereas DIII has a role in virus assembly. We previously demonstrated that DI in genotype 2a (JFH1) also plays a role in virus assembly, exemplified by the P145A mutant which exhibited no defect in genome replication, but blocked infectious virus production (1). Here we extend this analysis to identify two other conserved and surface exposed residues proximal to P145 (C142 and E191) that shared the same phenotype. Further analysis revealed changes in the abundance of dsRNA, the size and distribution of lipid droplets (LD) and the co-localisation between NS5A and LDs in cells infected with these mutants, compared to wildtype. In parallel, to investigate the mechanism(s) underpinning this role of DI, we assessed the involvement of the interferon-induced double-stranded RNA-dependent protein kinase (PKR). In PKR-knockout cells, C142A and E191A exhibited levels of infectious virus production, LD size and co-localisation between NS5A and LD that were indistinguishable from wildtype. Co-immunoprecipitation and in vitro pulldown experiments confirmed that wildtype NS5A domain I (but not C142A or E191A) interacted with PKR. We further showed that the assembly phenotype of C142A and E191A was restored by ablation of interferon regulatory factor-1 (IRF1), a downstream effector of PKR. These data suggest a novel interaction between NS5A DI and PKR that functions to evade an antiviral pathway that blocks virus assembly through IRF1. Author summaryThe non-structural 5A protein (NS5A) of hepatitis C virus (HCV) plays a critical role in both virus genome replication and the assembly of infectious virus particles. NS5A is a target for potent and highly efficacious direct acting antivirals used extensively for HCV treatment. NS5A comprises 3 domains. Here, we show that the N-terminal domain I (DI) plays a role in virus assembly. Mutations in DI block both virus assembly and the perturbation of lipid droplet morphology that is a hallmark of HCV infection. Strikingly, this phenotype is abrogated by silencing of the cellular cytoplasmic double-stranded RNA sensor, PKR, a key antiviral factor. These mutations have therefore uncovered a hitherto uncharacterised antiviral pathway controlled by PKR which functions to block assembly of infectious virus particles.

microbiology↗

Deriving Schwann Cells from hPSCs Enables Disease Modeling and Drug Discovery for Diabetic Peripheral Neuropathy

Schwann cells (SCs) are the myelinating and non-myelinating glia of the peripheral nervous system (PNS) and are essential for its function. Defects in SCs are associated with many PNS disorders including diabetic peripheral neuropathy (DPN), a condition affecting millions of patients. Here we present a strategy for deriving and purifying SCs from human pluripotent stem cells (hPSCs). The scalable cultures of SCs allow basic and translational applications such as high-resolution molecular and functional characterization, developmental studies, modeling and mechanistic understanding of SC diseases and drug discovery. Our hPSC-derived SCs recapitulate the key molecular features of primary SCs and are capable of engrafting efficiently and producing myelin in injured sciatic nerves in rats. We further established an hPSC-based in vitro model of DPN that revealed the selective vulnerability of human SCs to hyperglycemia-induced cytotoxicity. We established a high-throughput screening system that identified a candidate drug that counteracts glucose-mediated cytotoxicity in SCs and normalizes glucose-induced transcriptional and metabolic abnormalities in SCs. Treatment of hyperglycemic mice with this drug candidate rescues sensory function, prevents SC death, and counteracts myelin damage in sciatic nerves suggesting considerable potential as a novel treatment for DPN.

developmental biology↗

An examination of the divergent spatiotemporal signaling of GLP-1R versus GIPR in pancreatic beta cells

The incretin receptors, glucagon-like peptide-1 receptor (GLP-1R) and glucose-dependent insulinotropic polypeptide receptor (GIPR), are class B GPCRs and prime therapeutic targets for the treatment of type 2 diabetes (T2D) and obesity. They are expressed in pancreatic beta cells where they potentiate insulin release in response to food intake. Despite GIP being the main incretin in healthy individuals, GLP-1R has been favoured versus GIPR as a therapeutic target due to GIPR responses being blunted in T2D patients and the conflicting effects of GIPR agonists and antagonists in improving glucose tolerance and preventing weight gain. There is, however, a recently renewed interest in GIPR biology following the realisation that GIPR responses can be restored after an initial period of blood glucose normalization and the recent development of dual GLP-1R-GIPR agonists with superior capacity for the control of blood glucose levels and weight. The importance of GLP-1R trafficking and subcellular signaling in the control of receptor outputs is well established, but little is known about the pattern of spatiotemporal signaling from the GIPR in beta cells. Here we have directly compared the main trafficking and signaling characteristics of both receptors in pancreatic beta cells, finding striking differences in their propensities for internalization, recycling, and degradation, as well as plasma membrane versus endosomal activity, with potential implications for receptor-specific control of beta cell function.

cell biology↗

Function and Cryo-EM structures of broadly potent bispecific antibodies against multiple SARS-CoV-2 Omicron sublineages

The SARS-CoV-2 variant, Omicron (B.1.1.529), rapidly swept the world since its emergence. Compared with previous variants, Omicron has a high number of mutations, especially those in its spike glycoprotein that drastically dampen or abolish the efficacy of currently available vaccines and therapeutic antibodies. Several major sublineages of Omicron evolved, including BA.1, BA.1.1, BA.2, BA.2.12.1, BA.3, BA.4/5, and BA.2.75, which rapidly changing the global and regional landscape of the pandemic. Although vaccines are available, therapeutic antibodies remain critical for infected and especially hospitalized patients. To address this, we have designed and generated a panel of human/humanized therapeutic bispecific antibodies against Omicron and its sub-lineage variants, with activity spectrum against other lineages. Among these, the top clone CoV2-0213 has broadly potent activities against multiple SARS-CoV-2 ancestral and Omicron lineages, including BA.1, BA.1.1, BA.2, BA.2.12.1, BA.3, BA.4/5, and BA.2.75. We have solved the cryo-EM structure of the lead bi-specific antibody CoV-0213 and its major Fab arm MB.02. Three-dimensional structural analysis shows distinct epitope of antibody - spike receptor binding domain (RBD) interactions and reveals that both Fab fragments of CoV2-0213 can simultaneously target one single spike RBD or two adjacent ones in the same spike trimer, further corroborating its mechanism of action. CoV2-0213 represents a unique and potent broad-spectrum SARS-CoV-2 neutralizing bispecific antibody (nbsAb) against the currently circulating major Omicron variants (BA.1, BA.1.1, BA.2, BA.2.12.1, BA.2.75, BA.3, and BA.4/5). CoV2-0213 is primarily human and ready for translational testing as a countermeasure against the ever-evolving pathogen.

immunology↗

Plasmodium falciparum has evolved multiple mechanisms to hijack human immunoglobulin M

Plasmodium falciparum causes the most severe malaria in humans. Immunoglobulin M (IgM) serves as the first line of humoral defense against infection and potently activates the complement pathway to facilitate P. falciparum clearance. A number of P. falciparum proteins hijack IgM, leading to immune evasion and severe disease. However, the underlying molecular mechanisms remain unknown. Here, using high-resolution cryo-electron microscopy, we delineate how P. falciparum proteins VAR2CSA, TM284VAR1, DBLMSP, and DBLMSP2 target IgM. Each protein binds IgM in a different manner, and together they present a variety of Duffy-binding-like domain-IgM interaction modes. We further show that these proteins interfere directly with IgM-mediated complement activation, with VAR2CSA exhibiting the most potent inhibitory effect. Structural analyses suggest that VAR2CSA occludes the congregation of the complement C1 complex on IgM. These results underscore the importance of IgM for the adaptation of P. falciparum to humans, and provide critical insights into the immune evasion mechanism of P. falciparum.

biochemistry↗

TSNAdb v2.0: the updated version of tumor-specific neoantigen database

Tumor neoantigens have been well-acknowledged as ideal targets for tumor immunotherapy in recent years. With the deepening of research on neoantigen-based tumor immunotherapy, comprehensive neoantigen databases are urgently needed to meet the growing demand for clinical studies. We have built the Tumor-Specific NeoAntigen Database (TSNAdb v1.0) previously, which has attracted wide attention. In this study, we provide an updated version of the Tumor-Specific NeoAntigen Database (TSNAdb v2.0) with several new features including 1) taking stricter criteria for neoantigen identification. 2) providing predicted neoantigens derived from three types of somatic mutations. 3) collecting experimentally validated neoantigens and classifying them according to the evidence. TSNAdb v2.0 is freely available at https://pgx.zju.edu.cn/tsnadb/.

bioinformatics↗

naRNA is a canonical neutrophil extracellular trap (NET) component and novel inflammation-amplifying composite DAMP

Neutrophil extracellular traps (NETs) are a key antimicrobial feature of cellular innate immunity mediated by polymorphonuclear neutrophils (PMNs), the primary human leukocyte population. NETs trap and kill microbes but have also been linked to inflammation, e.g. atherosclerosis, arthritis or psoriasis by unknown mechanisms. We here characterize naRNA (NET-associated RNA), as a new canonical, abundant, and unexplored inflammatory NET component. naRNA, upon release by NET formation, drove further NET formation in naive PMN, and induced macrophage and keratinocyte activation via TLR8 in humans and Tlr13 in mice, in vitro and in vivo. Importantly, in vivo naRNA strongly drove skin inflammation, whereas genetic ablation of RNA sensing drastically ameliorated psoriatic skin inflammation. Rather than accidentally assembling with LL37 on the NET, naRNA was intracellularly pre-associated in resting neutrophils as a composite DAMP, thus highlighting NET formation as a DAMP release process. This re-defines sterile NETs as an intentionally inflammatory agent, signaling and amplifying neutrophil activation. Moreover, in the many conditions previously linked to NETs and extracellular RNA, TLR-mediated naRNA sensing emerges as both potential cause and new intervention target. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=175 SRC="FIGDIR/small/499571v4_ufig1.gif" ALT="Figure 1"> View larger version (94K): org.highwire.dtl.DTLVardef@11b866org.highwire.dtl.DTLVardef@16139ceorg.highwire.dtl.DTLVardef@1a2905org.highwire.dtl.DTLVardef@17b0e7e_HPS_FORMAT_FIGEXP M_FIG C_FIG Created with biorender.com

immunology↗

The highly conserved RNA-binding specificity of nucleocapsid protein facilitates the identification of drugs with broad anti-coronavirus activity

The binding of SARS-CoV-2 nucleocapsid (N) protein to both the 5'- and 3'-ends of genomic RNA has different implications arising from its binding to the central region during virion assembly. However, the mechanism underlying selective binding remains unknown. Herein, we performed the high-throughput RNA-SELEX (HTR-SELEX) to determine the RNA-binding specificity of the N proteins of various SARS-CoV-2 variants as well as other {beta}-coronaviruses and showed that N proteins could bind two unrelated sequences, both of which were highly conserved across all variants and species. Interestingly, both these sequence motifs are virtually absent from the human transcriptome; however, they exhibit a highly enriched, mutually complementary distribution in the coronavirus genome, highlighting their varied functions in genome packaging. Our results provide mechanistic insights into viral genome packaging, thereby increasing the feasibility of developing drugs with broad-spectrum anti-coronavirus activity by targeting RNA binding by N proteins.

molecular biology↗

Bioinformatics analysis of immune-related prognostic genes and immunotherapy in renal clear cell carcinoma

Clear cell renal cell carcinoma (ccRCC) is an immunogenic tumor and investigating the immunorelated genes is of great significance. To investigate the immunoprognostic genes of ccRCC, we analyzed the data assimilated from a public database (The Cancer Genome Atlas (TCGA) database and the gene expression omnibus (GEO) database) using bioinformatics. Then, a immunoprognosis model was constructed to identify 4 hub genes with moderate predictive values for the prognosis of ccRCC patients. Interestingly, these 4 genes were associated with the prognosis of ccRCC patients based on Oncomine and Gena Expression Profiling Interactive Analysis (GEPIA) databases. The correlation analysis between the immune infiltrate, immune checkpoints, and immunotherapy and this immunoprognosis model showed that immune infiltrate and could predict the immunotherapy effects. We also conducted a quantitative real-time polymerase chain reaction analysis and found that the expressions of 3 hub genes were associated with tumor progression (P<0.1). In conclusion, 4 genes that may serve as potential biomarkers in ccRCC were identified with respect to prognosis.

cancer biology↗

Bivalent mRNA vaccine booster induces robust antibody immunity against Omicron subvariants BA.2, BA.2.12.1 and BA.5

As the immune protection conferred by first booster shot wanes over time and new Omicron subvariant emerges with stronger immune evasion, the need for variant-adapted COVID vaccine booster is increasingly imminent. However, the rapid replacement of dominant Omicron subvariants (from BA.1 to BA.2, then BA.2.12.1 and now BA.4/5) poses a great challenge to update COVID vaccine targeting the fast-evolving variants while maintaining potency against existing variants. It is a crucial question to ask which variant-based antigen(s) to use in the next generation COVID vaccine to elicit potent and broad response to past, present, and potential rising variants. Bivalent vaccine candidates have been under active clinical testing such as Modern mRNA-1273.214. In this study, we generate a Delta + BA.2 bivalent mRNA vaccine candidate and tested in animals. We compare the antibody response elicited by ancestral (wild type, WT), Delta, BA.2 spike based monovalent or Delta & BA.2 bivalent mRNA boosters against Omicron BA.2, BA.2.12.1 and BA.4/5 subvariants. In mice pre-immunized with two doses of WT lipid nanoparticle mRNA (LNP-mRNA), all three monovalent and one bivalent boosters elevated Omicron neutralizing antibody titers to various degree. The boosting effect of Delta and BA.2 specific monovalent or bivalent LNP-mRNAs is universally higher than that of WT LNP-mRNA, which modestly increased antibody titer in neutralization assays of Omicron BA.5, BA.2.12.1 and BA.2. The Delta & BA.2 bivalent LNP-mRNA showed better performance of titer boosting than either monovalent counterparts, which is especially evident in neutralization of Omicron BA.4 or BA.5. Interestingly compared to the neutralizing titers of BA.2 and BA.2.12.1 pseudovirus, BA.2 monovalent but not Delta & BA.2 bivalent booster suffered a significant loss of BA.4/5 neutralizing titer, indicative of broader activity of bivalent booster and strong neutralization evasion of Omicron BA.4 or BA.5 even in the BA.2 mRNA vaccinated individuals. These data provide evaluation of WT, Delta, BA.2 monovalent and bivalent boosters antibody potency against Omicron BA.2, BA.2.12.1 and BA.4/5 subvariants.

immunology↗

Study of the anti-inflammatory and anti-apoptosis effect of the traditional Mongolian Hohgardi-9 in acute lung injury

ObjectiveTo explore the main active components of Hohgardi-9 and its mechanism treating in ALI. MethodsThrough searching the TCMSP database, we obtained the main components and action targets of Hohgardi-9, and the targets related to ALI were analyzed as the possible targets of Hohgardi-9. Then, the compound target network was constructed using Cytoscape software and obtained the key compounds of Hohgardi-9 acting on ALI. The blood entering components of Hohgardi-9 were analyzed by metabonomics. Using a string database to investigate the interaction between proteins of possible targets of Hohgardi-9, Gene Ontology (GO) function annotation and Tokyo Encyclopedia of the genome (KEGG) pathway enrichment analysis were carried out at the same time to predict its mechanism. Finally, the ALI rat model verified the pharmacodynamic effects and key targets of Huhgridi-9. ResultsThe network pharmacology and blood component analysis results showed that 27 potentially active components such as quercetin, herbacetin, izoteolin, and columbinetin acetate were the major functional components in Hohgardi-9. Those might act on NF kappa B signalling pathway, toll-like receptor signalling pathway, and TNF signalling pathway through key targets such as RELA (p65), TLR4, etc. In vivo experiments showed that Hohgardi-9 significantly improved lung tissue injury and pulmonary edema in ALI rats. At the same time, the Hohgardi-9 intervention could significantly reduce the mRNA expression levels of TRL4, TNFa, IL-1 {beta}, and ICAM1 in ALI rats. ConclusionHohgardi-9 revealed ALI through the inhibiting inflammatory factor apoptosis-related gene expression.

pharmacology and toxicology↗

Dissecting the genetic basis of the heterosis of Y900, an elite super-hybrid rice

Y900 is one of the top hybrid rice varieties with a yield exceeding 15 t/hm2. To dissect the mechanism of heterosis, the male parent line R900 and female parent line Y58S were sequenced using long-read and Hi-C technology. High-quality reference genomes of sizes of 396.41 Mb and 398.24 Mb were obtained for R900 and Y58S, respectively. Genome-wide variations between the parents were systematically identified, including 1,367,758 SNPs and 299,149 Indels. No megabase level structural variations exist. >75% of genes exhibited variation between the two parents. Compared with other two-line hybrids sharing the same female parent, the Geng/japonica-type genetic components from different male parents showed an increasing trend from phase 2-4 super-hybrid rice; Transcriptome analysis revealed that additive and dominance effects are the main genetic effects that constitute the heterosis of Y900. Allele-specific expression patterns and expression regulation patterns are quite dynamic in different tissues. For young panicle tissues, cis-regulation is dominant, while trans-regulation is more popular in leaf issues. Overdominance is more likely regulated by the trans-regulation mechanism. The differential gene expression and regulation pattern are closely related to Geng/japonica introgression. Additionally, R900 contained several excellent japonica haplotypes, such as NAL1, OsSPL13, Ghd8, OsBRI1, and DTH2, which make a good complement to Y58S. The fine tune mechanism through dynamic expression or regulation pattern change, especially on some key functional genes, is the base for heterosis.

plant biology↗

Longitudinal Urine Metabolic Profiling and Gestational Age Prediction in Pregnancy

Pregnancy is a critical time that has long-term impacts on both maternal and fetal health. During pregnancy, the maternal metabolome undergoes dramatic systemic changes, although correlating longitudinal changes in maternal urine remain largely unexplored. We applied an LCMS-based untargeted metabolomics profiling approach to analyze 346 longitudinal maternal urine samples collected throughout pregnancy for 36 women from diverse ethnic backgrounds with differing clinical characteristics. We detected 20,314 metabolic peaks and annotated 875 metabolites. Altered metabolites include a broad panel of glucocorticoids, lipids, and amino acid derivatives, which revealed systematic pathway alterations during pregnancy. We also developed a machine-learning model to precisely predict gestational age (GA) at time of sampling using urine metabolites that provides a non-invasive method for pregnancy dating. This longitudinal maternal urine study demonstrates the clinical utility of using untargeted metabolomics in obstetric settings. One Sentence SummaryMachine-learning based gestational age and due date using longitudinal urine samples of pregnancy.

systems biology↗