Biology subjects

Lan, C.

Publications and source records attributed to Lan, C..

At least 19 recordsLinked to original sources

bioRxiv2026

LARP4 is a B cell-specific metabolic checkpoint for plasma cell differentiation and a therapeutic target in systemic lupus erythematosus

RNA-binding protein LARP4 plays an important role in T cell activation and differentiation, but its role in B cell biology and the pathogenesis of systemic lupus erythematosus (SLE) remains unclear. This study found that LARP4 was specifically highly expressed in B cells of SLE patients and was positively correlated with disease activity. By constructing T cell-specific and B cell-specific conditional knockout mice, we found that deletion of LARP4 in B cells, but not in T cells, significantly alleviated pristane-induced and Bm12-induced lupus nephritis. Further analysis showed that LARP4 deletion selectively inhibited B cell differentiation into plasma cells, but did not affect germinal center B cell formation. Integrated transcriptomic and metabolomics analyses revealed that this effect is due to reduced phosphatidic acid synthesis and decreased mTORC1 activity caused by mitochondrial oxidative phosphorylation dysfunction. Furthermore, we used LIPEP, a LARP4 inhibitory peptide that effectively mimicked the therapeutic effects of LARP4 gene knockout in the MRL/lpr spontaneous lupus model and outperformed cyclophosphamide in reducing glomerular immune complex deposition and improving extrarenal dermatitis. These results indicates that LARP4 is a key metabolic checkpoint regulating B cell differentiation into Plasma cells and suggest that it may be a potential therapeutic target for SLE.

immunology↗

bioRxiv2026

Long-lived mammals contain more phosphorylation sites in the SIRT6 C-terminus that enhance PARP1 interaction and resistance to oxidative stress

Sirtuin 6 (SIRT6) is a protein deacetylase and ribosyltransferase that is a vital hub for maintaining epigenetic homeostasis, regulating the transcriptome, and repairing DNA double stranded breaks (DSBs). Comprehensive proteomic profiling of the SIRT6 post-translational landscape, however, remains elusive. The SIRT6 C-terminal domain contains multiple phosphorylation sites. We find that the presence and use of these sites is strongly correlated with maximum lifespan across mammals. Subsequent biochemical and in silico analyses revealed that SIRT6 hyperphosphorylation enhances its interaction with PARP1. Mutating the T294 phosphorylation site in human fibroblasts led to decreased survival after oxidative stress in the phospho-null T294A and improved oxidative stress resistance in the phospho-mimetic T294E. Together, these results suggest SIRT6 C-terminal phosphorylation increases stress resistance through interaction with PARP1, and that this effect has been enhanced by evolution in long-lived species.

molecular biology↗

bioRxiv2026

Microencapsulation of a novel Bacteroides thetaiotaomicron strain: a promising strategy to fortify intestinal barrier fortification in weaned pig model

Porcine Bacteroides thetaiotaomicron LYH5 demonstrated in vitro antimicrobial activity, suggesting probiotic potential. Due to poor gastric juice tolerance, LYH5 was encapsulated via extrusion using sodium alginate (SA) and gellan gum. Box-Behnken design optimization yielded optimal parameters: SA 1.5%, gellan gum 0.4%, CaCl2 0.9%, bacteria:glue ratio 1:4, achieving an encapsulation rate of 84.22{+/-}0.17%. Its effect on weaned piglet intestinal health was evaluated using 78 piglets (7.69{+/-}0.52 kg) randomly assigned to 4 groups for 40 days: CON (control), T (basal diet + LYH5 live bacteria, 1x10{superscript 1} CFU/mL), TJ (basal diet + LYH5 microcapsules, 1x10{superscript 1} CFU/mL, J (basal diet + empty capsules). The results of this experiment showed that compared with the control group, LYH5 microcapsule can improve the intestinal barrier function without affecting the growth performance of piglets, and provide ideas and references for the development of human next-generation probiotics (NGP). IMPORTANCEThis study addresses the key bottleneck of poor gastric acid tolerance of probiotics via microencapsulation and provides a practical reference for the development of human next-generation probiotics.

microbiology↗

bioRxiv2026

Genetic analysis and mapping of adult plant stripe rust resistance loci in CIMMYT wheat 'Kijil under Mexican and Chinese field environments

Stripe rust, caused by Puccinia striiformis f. sp. tritici, can cause severe yield losses in wheat (Triticum aestivum L.) during epidemics. Breeding resistant wheat varieties remains the most cost-effective approach to manage this disease; and the identification of new resistance loci is essential for maintaining genetic diversity. The CIMMYT-derived wheat line Kijil was highly resistant to stripe rust in both Mexican and Chinese environments. A population of 153 F recombinant inbred lines (RILs) was derived from a cross between Kijil and the susceptible parent Apav#1. The population was phenotyped for stripe rust resistance across seven environments in two countries and genotyped using a genotyping-by-sequencing (GBS) platform. Inclusive composite interval mapping (ICIM) was uesd to construct a genetic map and identify significant resistance quantitative trait loci (QTLs) using 5,468 polymorphic markers. Mapping revealed the known resistance loci Yr29, Yr30 and QYr.hzau-3AS, along with two novel loci, QYr.hzau-2BS and QYr.hzau-5DL, across both Chinese and Mexican rust environments. Among these, QYr.hzau-2BS accounted for 11.75% to 19.19% of the phenotypic variance. A corresponding KASP marker, KASP_2BS, was developed to facilitate maker-assisted selection. Based on the mapping interval, four candidate genes underlying this locus were predicted. Further analysis revealed that Yr29 showed significant additive effects with other stripe rust resistance genes/loci, and the combination of Yr29, Yr30, and QYr.hzau-2BS reduced disease severity by up to 67.8%. Our findings suggest that Kijil and RILs carrying Yr29, Yr30, and QYr.hzau-2BS can serve as valuable donors for breeding wheat varieties with improved stripe rust resistance. Author summaryStripe rust is an important disease that seriously threatens the yield and quality of wheat. It is crucial to explore new resistant resources and cultivate durable resistant varieties in the current breeding programme. In this study, we analysed the genetic basis of resistance to stripe rust in the wheat line "Kijil", which has broad-spectrum resistance to stripe rust. Through genetic mapping, we identified five quantitative trait loci for stripe rust, including two new resistance loci. A closely linked KASP marker, KASP_2BS, was developed for the QYr.hzau-2BS, which can be used for rapid and accurate screening of resistant plants in early breeding populations. Meanwhile, within this QTL region, we screened four candidate genes based on expression analysis. In addition, it was found that polymerization of QYr.hzau-2BS with known resistance genes, Yr29 and Yr30, significantly enhanced resistance and reduced disease severity to low levels and near immunity. In conclusion, this study provides new genetic resources, practical molecular markers and effective gene polymerization strategies for breeding wheat for stripe rust resistance. Kijil and the lines containing resistance loci have important breeding utilization value.

plant biology↗

bioRxiv2025

Pantetheinamides that inhibit the growth of intracellular Salmonella Typhimurium

The metabolic adaptability of intracellular pathogens, such as the Gram-negative Salmonella enterica serovar Typhimurium (STm), enables their survival in nutrient-restricted host environments, while also presenting an opportunity for selective antimicrobial targeting. Herein, we report the synthesis and screening of a small pantetheinamide library aimed at inhibiting the proliferation of STm within macrophages. Two lead compounds exhibited selective activity against intracellular STm and reduced bacterial burden in a murine colitis model. Mechanistic studies suggest their primary mode of action to be the inhibition of coenzyme A (CoA) biosynthesis via the PanD-PanZ regulatory complex, which is absent in host cells. Importantly, resistance pressure to our compound was shown to be significantly stronger in nutrient-limited media compared to nutrient-rich media, supporting the targeting of nutrient stress as a strategy to delay resistance. This work highlights the value of inhibiting pathogen-specific metabolic vulnerabilities in combination with host defence mechanisms to develop novel antimicrobials.

microbiology↗

bioRxiv2024

Single-cell analysis reveals multi-faceted features of B cell development together with age-associated B cell subpopulations

The development and maturation of B lymphocytes involve intricate orchestrated processes, where dedicated gene regulations (GR) take place within specific microenvironments shaped by both extracellular matrix and neighboring cells. Despite extensive investigations aimed at deepening our comprehension of these mechanisms, there remains a dearth of high-dimensional and integrated analysis concerning B cell heterogeneity, gene regulation, and external factors implicated in B cell development. In this study, we scrutinized single-cell transcriptomic data and B cell receptor (BCR) sequencing data obtained from B cells and their surrounding counterparts in the bone marrow, tonsil, and peripheral blood. A full picture of the GR dynamics, the heterogeneity of conventional B cells and cell-cell interactions (CCIs) along B cell development axis was depicted. We found immature B cells represent the most quiescent stage characterized by the least number of expressed genes and low RNA velocity. The homeostatic proliferation and activation of naive B cells is niche-confined and individualized, respectively. Two development models for memory B cell subpopulations seem not mutually exclusive and warrant in-depth investigation. Moreover, CCI analysis reveals a pivotal role of myeloid cells and two dominant and stage-dependent CCI categories, TNF and adhesion signaling, in B cell development. Besides, we unexpectedly identified two age-associated B cell subpopulations that respectively express S100A8/S100A9 and C1q and experimentally confirmed the secretion of S100A8/A9 from human B cells in vitro, suggesting a senescence-associated secretion phenotype. Our integrated analysis provides valuable insights into GR dynamics, the evolution of B cells, and potential intercellular communication networks involved in B cell development and revealed novel phenotypes of age-associated B cell aberrance. This study serves as a valuable resource for in-depth exploration of the intricacies of B cell biology.

cell biology↗

bioRxiv2024

Integration of the DD-genome reshapes gene transcription, chromatin architecture and metabolome of allohexaploid wheat leading to enhanced adaptability

The integration, through hybridization, of the DD genome into domesticated tetraploid wheat gave rise to allohexaploid wheat, the most cultivated wheat globally growing across diverse environmental conditions. However, the regulatory basis of this integration on increased environmental adaptability in allohexaploid remains largely unexplored. Here, we investigated the change of transcriptome, epigenome as well as the chromatin interactome, and metabolome in three independent polyploidization events representing DD genome integration. Our findings reveal that polyploidization events induce the activation of defense-related genes through comprehensive reorganization of epigenome and chromatin architecture. DD integration not only brings an additional gene copy but also activates the homoeologs existing in the A and B subgenomes through chromatin interactions. Furthermore, secondary metabolites represented by alkaloids and flavonoids that are crucial for environmental adaptation, are significantly enriched following polyploidization. Thus, hexaploid wheat exhibits enhanced tolerance to alkalinity, UV-B light stress and high salt conditions was observed. These results highlight the indispensable role of DD genome integration in the adaptability of allohexaploid wheat during its evolution.

plant biology↗

bioRxiv2024

Signatures of social pain empathy: general and process-specific brain-wide representations of social exclusion and separation

Empathy can be elicited by physiological pain, as well as in social contexts. Although physiological and different social contexts induce a strong subjective experience of empathy, the general and context-specific neural representations remain elusive. Here, we combine fMRI with multivariate pattern analysis to establish neurofunctional models for pain empathy triggered by social exclusion and separation. Our findings revealed both overlapping and distinct neural representations for social exclusion and separation empathy across cortical and subcortical regions. This study established an evolutionary model that traces the progression from social pain to physiological pain empathy. In conclusion, this study establishes neural decoding models for pain empathy evoked by social exclusion and social separation, revealing their neural foundations and interconnectedness of empathy induced by social and physiological stimuli. These findings deepen our understanding of the neurobiological mechanisms underlying social pain empathy and provide robust neuromarkers to precisely evaluate empathy across physiological and social domains.

neuroscience↗

bioRxiv2024

Distinct neural computations scale the violation of expected reward and emotion in social transgressions

Traditional decision-making models conceptualize humans as optimal learners aiming to maximize outcomes by leveraging reward prediction errors (PE). While violated emotional expectations (emotional PEs) have recently been formalized, the underlying neurofunctional basis and whether it differs from reward PEs remain unclear. Using a modified fMRI Ultimatum Game on n=43 participants we modelled reward and emotional PEs in response to unfair offers and subsequent punishment decisions. Computational modelling revealed distinct contributions of reward and emotional PEs to punishment decisions, with reward PE exerting a stronger impact. This process was neurofunctionally dissociable such that (1) reward engaged the dorsomedial prefrontal cortex while emotional experience recruited the anterior insula, (2) multivariate decoding accurately separated reward and emotional PEs. Predictive neural expressions of reward but not emotional PEs in fronto-insular systems predicted neurofunctional and behavioral punishment decisions. Overall, these findings suggest distinct neurocomputational processes underlie reward and emotional PEs which uniquely impact social decisions.

neuroscience↗

bioRxiv2024

Decoding the spatiotemporal dynamic neural representation of repetitive facial expression imitation

Imitating facial emotion expressions can facilitate social interactions, although the behavioral and neural spatiotemporal dynamics is unclear. Here participants (N=100) imitated facial emotions repeatedly over one month (16 times in total) with neural activity measured on three occasions using functional near-infrared spectroscopy. Additionally, the transfer effect of repeated imitation on emotional face and scene perception was assessed by fMRI with multivariate pattern analysis. Valence specific imitation performance was facilitated by the alterations in the similarity of spatiotemporal patterns evoked in the mirror neuron system (MNS) with information flow moving progressively towards the inferior frontal gyrus as the as the number of times of imitation increase. Furthermore, MNS representation predictive patterns of processing emotional faces, but not scenes, were enhanced. Overall, these findings provide a neural changes of information flow within MNS and advance our understanding of the spatiotemporal dynamics from novice to proficient of facial emotion imitation.

neuroscience↗

bioRxiv2023

Single-molecule FRET and tracking of transfected biomolecules: multi-dimensional protein dynamics in living cells

Proteins and DNA in cells exhibit different conformational states, which are influenced by dynamic interactions with other biomolecules. All these interactions are affected by the molecules localization within the cell, i.e., their compartmentalization. Such, in cellula, compartment-specific dynamics is difficult to measure, because of limitations in instrumentation, autofluorescence of cells, and the necessity to track diffusing molecules. Here, we present a bottom-up engineering approach, which allows us to track transfected proteins in cellula and to analyze time-resolved single-molecule FRET efficiencies. This has been achieved by alternating laser excitation (ALEX) based three-channel (donor, acceptor and FRET) tracking with a live-cell HILO microscope. We validate our strategy by characterizing long-term static-FRET traces of customized DNA with known dye positions. We utilize two different transfection strategies, namely a biological (Streptolysin-O toxin protein) and a physical one (Microinjection). By comparing in vitro and in cellula measurements we show that the cellular environment in this case changes the FRET efficiency by about 25%. In addition, we evaluate single-molecule FRET traces for the heat shock protein Hsp90 in cellula. The obtained FRET efficiency distribution is largely consistent with known Hsp90 structures and in vitro distributions, but also shows some clear differences. Altogether, we show that FRET-TTB (Forster Resonance Energy Transfer-Tracking of Transfected Biomolecules) opens the path to study protein state changes of transfected biomolecules in cellula, including time-resolved cellular localization. SignificanceInside cells, proteins and DNA can change shape depending on their environment and their interactions. Studying these changes for single biomolecules is challenging because they move around in the cell and the cell environment makes it hard to see them clearly. Here, we demonstrate a new technique called FRET-TTB that enables us to track individual proteins inside living cells over time using single-molecule fluorescence microscopy. We validate the approach with custom DNA and apply it to study the heat shock protein Hsp90. Our results show that this method can reveal changes in protein conformation and location within living cells.

biophysics↗

bioRxiv2022

ExposomeX: Integrative Exposomic Platform Expediates Discovery of "Exposure-Biology-Disease" Nexus

Exposome has become the hotspot of next-generation health studies. To date, there is no available effective platform to standardize the analysis of exposomic data. In this study, we aim to propose one new framework of exposomic analysis and build up one novel integrated platform "ExposomeX" to expediate the discovery of the "Exposure-Biology-Disease" nexus. We have developed 13 standardized modules to accomplish six major functions including statistical learning (E-STAT), exposome database search (E-DB), mass spectrometry data processing (E-MS), meta-analysis (E-META), biological link via pathway integration and protein-protein interaction (E-BIO) and data visualization (E-VIZ). Using ExposomeX, we can effectively analyze the multiple-dimensional exposomics data and investigate the "Exposure-Biology-Disease" nexus by exploring mediation and interaction effects, understanding statistical and biological mechanisms, strengthening prediction performance, and automatically conducting meta-analysis based on well-established literature databases. The performance of ExposomeX has been well validated by re-analyzing two previous multi-omics studies. Additionally, ExposomeX can efficiently help discover new associations, as well as relevant in-depth biological pathways via protein-protein interaction and gene ontology network analysis. In sum, we have proposed a novel framework for standardized exposomic analysis, which can be accessed using both R and online interactive platform (http://www.exposomex.cn/).

bioinformatics↗

bioRxiv2022

Quantitative real-time in-cell imaging reveals heterogeneous clusters of proteins prior to condensation

The formation of biomolecular condensates underpins many cellular processes; however, our current understanding of condensate formation within cells is largely based on observing the final near-equilibrium condensate state. It is less clear how proteins behave before condensates form or at concentrations at which condensation does not occur in cells. Here, we use a combination of fluorescence microscopy and photobleaching analysis to quantify phase separation of negative elongation factor (NELF) in living and stressed cells. We use the recently reported system of stress-induced condensation of NELF in human nuclei as a model to study the behaviour of proteins before condensation. We find that pre-condensate heterogeneous clusters both grow and shrink and are not freely diffusing. Unexpectedly, we also find such small dynamic clusters in unstressed cells in which condensates do not form. We provide a categorisation of small and large clusters based on their dynamics and their response to p38 kinase inhibition. Overall, our data are best explained as non-classical nucleation with a flat free-energy landscape for clusters of a range of sizes and an inhibition of condensation.

biophysics↗

bioRxiv2022

Boosting transformation in wheat by BBM-WUS

Agrobacterium-mediated transformation is a cost-effective and convenient way to introduce foreign genetic elements to plants. However, only limited protocols successfully generates transgenic plants with fielder, a spring wheat variety. Wheat transformation method with higher efficiency and without genotype restriction is heavily demanded. Here, a heat-shock protocol, independent of Japan Tobacco had been established. Transgenic plants can be obtained from immature embryo within only 60 days by this protocol. Morphogenic regulators Baby boom and Wuschel (BBM-WUS) was proved to promote transformation efficiency for five to six times in wheat when co-infiltrated with agrobacterium containing target construct. Notably, half of the transformants are BBM-WUS free and moreover, the BBM-WUS containing plants could be picked by florescent marker that was co-expressed with BBM-WUS. In conclusion, we managed to establish a new wheat transformation protocol with shorter duration than published protocol.

plant biology↗

bioRxiv2021

Oxytocinergic modulation of stress-associated amygdala-hippocampus pathways in humans is specially mediated by serotonergic mechanisms

BackgroundThe hypothalamic neuropeptide oxytocin (OXT) may exert anxiolytic and stress-reducing actions via modulatory effects on amygdala circuits. Animal models and initial findings in humans suggest that some of these effects are mediated by interactions with other neurotransmitter systems, in particular the serotonin (5-HT) system. Against this background, the present pharmacological resting state fMRI study aimed at determining whether effects of OXT on stress-associated amygdala intrinsic networks are mediated by 5-HT. MethodsWe employed a randomized placebo-controlled double-blind parallel-group pharmacological fMRI resting state experiment during which n = 112 healthy male participants underwent a transient decrease in 5-HT signaling via acute tryptophan depletion (ATD) or the corresponding placebo-control protocols (ATDc) before the administration of intranasal OXT or placebo intranasal spray, respectively. ResultsOXT and 5-HT modulation exerted interactive effects on the coupling of the left amygdala with the ipsilateral hippocampus and adjacent midbrain. OXT increased intrinsic coupling in this pathway, while this effect of OXT was significantly attenuated during transiently decreased central serotonergic signaling induced via ATD. In the absence of OXT or 5-HT modulation this pathway showed a trend for an association with self-reported stress perception in everyday life. No interactive effects were observed for the right amygdala. ConclusionsTogether, the findings provide first evidence that effects of OXT on stress-associated amygdala-hippocampal-midbrain pathways are critically mediated by the 5-HT system in men.

neuroscience↗

bioRxiv2021

Knowledge-based antibody repertoire simulation, a novel allele detection tool evaluation and application

Detailed knowledge of the diverse immunoglobulin germline genes is critical for the study of humoral immunity. Hundreds of alleles have been discovered by analyzing antibody repertoire sequencing (Rep-seq or Ig-seq) data via multiple novel allele detection tools (NADTs). However, the performance of these NADTs through antibody sequences with intrinsic somatic hypermutations (SHMs) is unclear. Here, we developed a tool to simulate repertoires by integrating the full spectrum features of an antibody repertoire such as germline gene usage, junctional modification, position-specific SHM and clonal expansion based on 2152 high-quality datasets. We then systematically evaluated these NADTs using both simulated and genuine Ig-seq datasets. Finally, we applied these NADTs to 687 Ig-seq datasets and identified 43 novel alleles using defined criteria. Twenty-five alleles were validated through findings of other sources. In addition to the novel alleles detected, our simulation tool, the results of our comparison, and the streamline of this process may benefit further humoral immunity studies via Ig-seq.

bioinformatics↗

bioRxiv2021

Spray-induced gene silencing for disease control is dependent on the efficiency of pathogen RNA uptake

Recent discoveries show that fungi can take up environmental RNA, which can then silence fungal genes through environmental RNA interference. This discovery prompted the development of Spray-Induced Gene Silencing (SIGS) for plant disease management. In this study, we aimed to determine the efficacy of SIGS across a variety of eukaryotic microbes. We first examined the efficiency of RNA uptake in multiple pathogenic and non-pathogenic fungi, and an oomycete pathogen. We observed efficient double-stranded RNA (dsRNA) uptake in the fungal plant pathogens Botrytis cinerea, Sclerotinia sclerotiorum, Rhizoctonia solani, Aspergillus niger, and Verticillium dahliae, but no uptake in Colletotrichum gloeosporioides, and weak uptake in a beneficial fungus, Trichoderma virens. For the oomycete plant pathogen, Phytophthora infestans, RNA uptake was limited, and varied across different cell types and developmental stages. Topical application of dsRNA targeting virulence-related genes in the pathogens with high RNA uptake efficiency significantly inhibited plant disease symptoms, whereas the application of dsRNA in pathogens with low RNA uptake efficiency did not suppress infection. Our results have revealed that dsRNA uptake efficiencies vary across eukaryotic microbe species and cell types. The success of SIGS for plant disease management can largely be determined by the pathogen RNA uptake efficiency.

microbiology↗

bioRxiv2020

Gut microbiome couples gut and brain during calorie restriction in treating obesity

Calorie restriction (CR) has been widely recognized for its effect in reducing body weight and alleviating diabetes in humans, as well as prolonging life span in animal studies. Gut microbiome shifts contribute to part of the effects of CR, but little is known regarding their influences except on metabolism and immunity. Here we monitored gut microbiome using metagenomics and metatranscriptomics in obese individuals undergoing CR, and revealed microbial determinants that could contribute to successful weight loss. Microbiome changes are linked to changes in blood metabolome and hormones, which eventually correlate to brain functional changes as studied using functional magnetic resonance imaging (fMRI). Brain functional shifts indicate response of central neural system (CNS) to CR, and microbiome constitutes the keystone of gut-brain axis. Animal experiment further reaffirms the gut microbiome changes, metabolic and hormonal shifts of CR, while proteomic analysis of brain tissues suggest that epigenetic modifications of key proteins could explain responses of CNS to CR. Our study establishes linkage between CR, gut microbiome, metabolome/ hormones and CNS function, and demonstrates that CR has multi-facet, coordinated effects on the host, of which many could contribute to weight loss and other beneficial effects.

microbiology↗