Biology subjects

Jiang, G.

Publications and source records attributed to Jiang, G..

At least 37 records · Page 2Linked to original sources

bioRxiv2025

Spatiotemporal changes in soil properties predict plant health at continental scale

Abiotic and biotic soil properties are strong predictors of plant yield globally1-5, but they become unreliable over large areas when plant health is threatened by pathogen6-8. Here we present a novel approach to predict plant health based on spatiotemporal changes in soil chemical and biological properties. We first demonstrate that plant health and soil properties consistently respond to environmental change (organic fertilization) regardless of the soil type or geographical origin. Second, we experimentally show that trackable shifts in soil properties reliably explain soil suppressiveness to the Ralstonia solanacearum bacterial pathogen and that a scalable spatiotemporal model predicts plant health with 84% accuracy across multiple climatic zones and cropping systems. Our results suggest that this tight coupling between soil properties and plant health could facilitate the development of agricultural practices aimed at sustainably improving crop yields while safeguarding crop health.

ecology↗

bioRxiv2024

Determination of Gaussian curvature modulus and spontaneous curvature via membrane buckling

The elastic properties of membranes are typically characterized by a few phenomenological parameters, including bending and Gaussian curvature moduli measuring the membrane rigidity against its deformation and topological change, as well as spontaneous curvature arising from the asymmetry between the two leaflets in the lipid bilayers. Though tether-based and fluctuation-based experiments are commonly utilized to measure the bending modulus, measuring the Gaussian curvature modulus and the spontaneous curvature of the membrane is considered to be much more difficult. In this paper, we study the buckling process of a circular membrane with nonzero spontaneous curvature under compressive stresses. It is found that when the stress exceeds a critical value, the circular membrane will transform from a spherical cap to a buckled shape, with its buckling degree enhanced with the increase of stress until its base is constricted to almost zero. As the stress-strain relationship of the buckled membrane strongly depends on the Gaussian curvature modulus and the spontaneous curvature,we therefore propose a method to determine the Gaussian curvature modulus and the spontaneous curvature simultaneously by measuring its stress-strain relationship during a buckling process.

biophysics↗

bioRxiv2024

Substrate utilization and cross-feeding synergistically determine microbiome resistance to pathogen invasion

Understanding how microbiomes resist pathogen invasion remains a key challenge in natural ecosystems. Here, we combined genome-scale metabolic models with synthetic community experiments to unravel the mechanisms driving pathogen suppression. We developed curated genome-scale models for each strain, incorporating 48 common resource utilization profiles to fully capture their metabolic capacities. Trophic interactions inferred from models accurately predicted pathogen invasion outcomes, achieving an F1 score of 96% across 620 invasion tests involving diverse microbial communities and nutrient environments. Importantly, considering both substrate and metabolite features provided a more holistic understanding of pathogen suppression. In particular, cross-feeding metabolites within the native community emerged as crucial yet often overlooked predictors of community resistance, disproportionally favoring native species over invaders. This study lays the foundation for designing disease-resistant microbiomes, with broad implications for mitigating pathogen exposure in diverse environments.

ecology↗

bioRxiv2024

A genome wide code to define cell-type specific CTCF binding and chromatin organization

CTCF-mediated chromatin folding plays a key role in gene regulation, however the mechanisms controlling chromatin organization across cell states are not fully elucidated. Comprehensive analyses reveal that CTCF binding stability and cohesin overlap in mice and humans, are regulated by species specific differences in CTCF binding site (CBS) accessibility and enrichment of motifs corresponding to expressed TFs. By analyzing TFs, we confirm the co-operativity and competitiveness of TF/CTCF binding, which we further validate by allele specific analysis of SNPs. TF motif enrichment at CTCF bound sites is determined by cell state-specific transcriptional programs, which either stabilize or destabilize CTCF binding, as reflected by changing TF concentration. To examine CTCF binding in the context of nucleosome positioning, we performed single molecule nano-NOMe-seq. Subsetting reveals a continuum of binding states for CTCF, which are differentially represented at accessible versus inaccessible CBSs. As expected, CTCF degradation leads to a progressive loss of binding and nucleosome repositioning giving profiles similar to CTCF free CBSs. We also observe a similar time dependent effect when the cohesin subcomponent, SSC1 is degraded although CTCF remains bound, indicating that cohesin mediates CTCF-associated nucleosome repositioning. Stratified analysis of CTCF signal strength and accessibility reveals that in the presence of cohesin, CTCF strength contributes to nucleosome repositioning and chromatin insulation independent of accessibility. However, cobound TFs can uncouple the relationship between signal strength and nucleosome repositioning, without affecting the connection between repositioning and insulation. These studies identify mechanisms underlying cell state-specific CTCF profiles, linked to local and long-range chromatin organization.

genomics↗

bioRxiv2024

Chemoenzymatic Synthesis Planning Guided by Reaction Type Score

Thanks to the growing interests in computer-aided synthesis planning (CASP), a wide variety of retrosynthesis and retrobiosynthesis tools have been developed in the past decades. However, synthesis planning tools for multi-step chemoenzymatic reactions are still rare despite the widespread use of enzymatic reactions in chemical synthesis. Herein we report a reaction type score (RTscore)-guided chemoenzymatic synthesis planning (RTS-CESP) strategy. Briefly, the RTscore is trained using a text-based convolutional neural network (TextCNN) to distinguish synthesis reactions from decomposition reactions and evaluate synthesis efficiency. Once multiple chemical synthesis routes are generated by a retrosynthesis tool for a target molecule, RTscore is used to rank them and find the step(s) that can be replaced by enzymatic reactions to improve synthesis efficiency. As proof of concept, RTS-CESP was applied to 10 molecules with known chemoenzymatic synthesis routes in literature and was able to predict all of them with six being the top-ranked routes. Moreover, RTS-CESP was employed for 1000 molecules in the boutique database and was able to predict the chemoenzymatic synthesis routes for 554 molecules, outperforming ASKCOS, a state-of-the-art chemoenzymatic synthesis planning tool. Finally, RTS-CESP was used to design a new chemoenzymatic synthesis route for the FDA-approved drug Alclofenac, which was shorter than literature-reported route and have been experimentally validated.

bioinformatics↗

bioRxiv2024

Substrate tunnel regulates substrate specificity switching in hyaluronan synthase

Hyaluronic acid (HA), a ubiquitous linear polysaccharide in the extracellular matrix of vertebrates and the capsule of certain pathogenic bacteria, is characterized by its unique structure of alternating {beta}-1,3-N-acetylglucosamine and {beta}-1,4-glucuronic acid units. HA is synthesized by Class I hyaluronan synthase (HAS) in the majority of organisms, but the molecular mechanisms determining the alternating sequence of HA remain unclear. Here, we demonstrated that HA synthesized in vitro using Streptococcus equisimilis HAS maintained its alternating sequence, regardless of substrate ratios and concentrations. While the active pocket lacks intrinsic selectivity, a distal allosteric regulation from the transmembrane tunnel is revealed. The lingering HA terminals in the active pocket ensure lower binding energies for alternating substrates through Coulombic repulsion and competitive binding. Moreover, the dynamic C-terminal loop at the substrate tunnel entrance reduces transport distance for alternating substrates. Our findings indicate that HA-substrate interactions and enzyme dynamics in the substrate tunnel collectively govern the alternating substrate specificity of HAS. This study provides the first molecular insight into precise substrate specificity control within a single active pocket during template-independent polymer synthesis.

biophysics↗

bioRxiv2024

Water use efficiency of Cupressus gigantea is higher in mountain slope habitats compared to riverside habitats

Cupressus gigantea is an endemic species of the Yarlung Zangbo River in Tibet, China, and is designated as a national key protected wild plant. It is only distributed in the narrow area along Yarlung Zangbo River from Jiacha County to Danniang village Milin City in various habitats such as the waterline along the Yarlung Zangbo River, terraces, and mountain slopes. In this study, we utilized stable isotope technology ({delta}D, {delta}18O, and {delta}13C), combined with the IsoSource model, to quantitatively determined the sources of water absorption and the water use efficiency of C. gigantea in various habitats, including riverside area, terraces and mountain slopes. The results showed that the content of soil total nitrogen, soil nitrate nitrogen, soil ammonium nitrogen, and soil organic carbon are significantly higher on mountain slope than in the other two habitats, while the total carbon content, water content, and total nitrogen content of C. gigantea leaves are significantly lower on mountain slope than in the other two habitats (P<0.05). The water use efficiency (WUE) of C. gigantea in the mountain slope habitats is 107.8 mol mol-1, which is significantly higher than that of other habitats (P<0.05), with the WUE of C. gigantea in the riverside habitat being the lowest at 35.7 mol mol-1. C. gigantea distributed on the mountain slope and terrace uses soil water as the main water source. During the normal rainy season, the proportion of soil water utilization is the highest, accounting for more than 60%; in the dry season, the utilization of river water and groundwater increases, while soil water utilization decreases. C. gigantea distributed along the riverside mainly absorbs water from the Yarlung Zangbo River, about 63%. In August when the rainfall increases in the rainy season, the use of soil moisture increases, and in the dry season, river water becomes the main water source. This indicates that with the alternation of rainy and dry seasons, the water absorption sources and strategies of C.gigantea adjusted accordingly. The research results provide an important scientific basis for the protection and management measures of the C. gigantea population.

ecology↗

bioRxiv2024

Dynamic Hydrogel Crosslink Strength Controls Yielding Characteristics and Cell Viability During Injection

Yielding of dynamically crosslinked hydrogels, or transition between a solid-like and liquid-like state, allows facile injection and utility in translational biomedical applications including delivery of therapeutic cells. Unfortunately, characterizing the time-varying nature of the transition has not been attempted, nor are there design rules for understanding the effects of yielding on encapsulated cells. Here, we unveil underlying molecular mechanisms governing the yielding transition of dynamically crosslinked gels currently being researched for use in cell therapy. We demonstrate through nonlinear rheological characterization that the network dynamics of the dynamic hydrogels dictate the speed and character of their yielding transition. Rheological testing of these materials reveals unexpected elastic strain stiffening during yielding, as well as characterizing the rapidity of the yielding transition. A slower yielding speed explains enhanced protection of directly injected cells from shear forces, highlighting the importance of mechanical characterization of all phases of yield-stress biomaterials. Significance StatementMany direct-injection cell therapies suffer from poor viability of injected cells due to membrane disruption by shear stresses during injection. Injectable hydrogels with dynamic crosslinks can increase viability during injection, utilizing the ability of these materials to undergo a reversible solid-to-liquid shear-rate dependent yielding transition. Much effort has been applied to understanding the yielding transition of these materials, yet design rules for connecting the character of yielding to viability of injected cells has not been established. Here, we apply rheological testing to show that faster network dynamics result in a more gradual yielding transition, affording greater protection to cells during injection. This work introduces a new rheological protocol for the development of injectable hydrogels for cell therapy.

bioengineering↗

bioRxiv2024

Integrated Single-Cell Multiomic Profiling of Caudate Nucleus Suggests Key Mechanisms in Alcohol Use Disorder

Alcohol use disorder (AUD) induces complex transcriptional and regulatory changes across multiple brain regions including the caudate nucleus, which remains understudied. Using paired single-nucleus RNA-seq and ATAC-seq on caudate samples from 143 human postmortem brains, including 74 with AUD, we identified 17 distinct cell types. We found that a significant portion of the alcohol-induced changes in gene expression occurred through altered chromatin accessibility. Notably, we identified novel transcriptional and chromatin accessibility differences in medium spiny neurons, impacting pathways such as RNA metabolism and immune response. A small cluster of D1/D2 hybrid neurons showed distinct differences, suggesting a unique role in AUD. Microglia exhibited distinct activation states deviating from classical M1/M2 designations, and astrocytes entered a reactive state partially regulated by JUND, affecting glutamatergic synapse pathways. Oligodendrocyte dysregulation, driven in part by OLIG2, was linked to demyelination and increased TGF-{beta}1 signaling from microglia and astrocytes. We also observed increased microglia-astrocyte communication via the IL-1{beta} pathway. Leveraging our multiomic data, we performed cell type-specific expression quantitative trait loci analysis, integrating that with public genome-wide association studies to identify AUD risk genes such as ADAL and PPP2R3C, providing a direct link between genetic variants, chromatin accessibility, and gene expression in AUD. These findings not only provide new insights into the genetic and cellular mechanisms in the caudate related to AUD but also demonstrate the broader utility of large-scale multiomic studies in uncovering complex gene regulation across diverse cell types, which has implications beyond the substance use field.

neuroscience↗

bioRxiv2024

The up-regulation of TGF-beta1 by miRNA-132-3p/WT1 is involved in inducing leukemia cells to differentiate into macrophages

Although it has been shown that abnormal expression of Wilms tumor gene 1 (WT1) is associated with the occurrence of leukemia, the specific mechanism via which it induces leukemia cells to differentiate into macrophages remains poorly understood. Based on the prediction that the microRNA miRNA-132-3p is the miRNA that possibly lies upstream of the WT1 gene, we hypothesized that miRNA-132-3p may participate in the polarization process of macrophages through regulating expression of the WT1 gene. The focus of the present study was therefore to investigate the role of the miRNA-132-3p/WT1 signaling axis in the differentiation of THP-1 leukemia cells into macrophages induced by PMA. The results obtained indicated that, compared with the control group, the proliferation of THP-1 cells was clearly inhibited by PMA, and the cell cycle was arrested at G0/G1 phase, associated with an upregulation of CD11b and CD14 expression. Induced by PMA, the expression level of miRNA-132-3p was increased, WT1 expression was decreased, and the expression level of TGF-{beta}1 was increased. Following transfection with miRNA-132-3p mimics, however, the expression of WT1 in the THP-1 cells was downregulated, with upregulation of the CD11b and CD14 antigens, whereas this downregulation of WT1 mediated by miRNA-132-3p mimics could be reversed by co-transfection with WT1 vector, which was accompanied by downregulation of the CD11b and CD14 antigens. The luciferase activity of the co-transfected miRNA-132-3p mimic + WT1-wild-type (WT) group was found to be statistically significantly lower compared with that of the co-transfected miRNA-132-3p mimic + WT1-mutated (MUT) group. Furthermore, chromatin immunoprecipitation experiments showed that WT1 was able to directly target the promoter of the downstream target gene TGF-{beta}1, which led to the negative modulation of TGF-{beta}1 expression, whereas downregulation of WT1 led to an upregulation of the expression of TGF-{beta}1, which thereby promoted the differentiation of THP-1 cells into macrophages. Taken together, the present study has provided evidence, to the best of the authors knowledge for the first time, that the miRNA-132-3p/WT1/TGF-{beta}1 axis is able to regulate the committed differentiation of leukemia cells into macrophages.

immunology↗

bioRxiv2024

Brain and cancer associated binding domain mutations provide insight into CTCF's relationship with chromatin and its ability to act as a chromatin organizer

Here we used a series of CTCF mutations to explore CTCFs relationship with chromatin and its contribution to gene regulation. CTCFs impact depends on the genomic context of bound sites and the unique binding properties of WT and mutant CTCF proteins. Specifically, CTCFs signal strength is linked to changes in accessibility, and the ability to block cohesin is linked to its binding stability. Multivariate modelling reveals that both CTCF and accessibility contribute independently to cohesin binding and insulation, however CTCF signal strength has a stronger effect. CTCF and chromatin have a bidirectional relationship such that at CTCF sites, accessibility is reduced in a cohesin-dependent, mutant specific fashion. In addition, each mutant alters TF binding and accessibility in an indirect manner, changes which impart the most influence on rewiring transcriptional networks and the cells ability to differentiate. Collectively, the mutant perturbations provide a rich resource for determining CTCFs site-specific effects.

molecular biology↗

bioRxiv2023

Single nuclei chromatin accessibility and transcriptomic map of breast tissues of women of diverse genetic ancestry

Single nuclei analysis is allowing robust classification of cell types in an organ that helps to establish relationships between cell-type specific gene expression and chromatin accessibility status of gene regulatory regions. Using breast tissues of 92 healthy donors of various genetic ancestry, we have developed a comprehensive chromatin accessibility and gene expression atlas of human breast tissues. Integrated analysis revealed 10 distinct cell types in the healthy breast, which included three major epithelial cell subtypes (luminal hormone sensing, luminal adaptive secretory precursor, and basal-myoepithelial cells), two endothelial subtypes, two adipocyte subtypes, fibroblasts, T-cells, and macrophages. By integrating gene expression signatures derived from epithelial cell subtypes with spatial transcriptomics, we identify specific gene expression differences between lobular and ductal epithelial cells and age-associated changes in epithelial cell gene expression patterns and signaling networks. Among various cell types, luminal adaptive secretory cells and fibroblasts showed genetic ancestry dependent variability. A subpopulation of luminal adaptive secretory cells with alveolar progenitor (AP) cell state were enriched in Indigenous American (IA) ancestry and fibroblast populations were distinct in African ancestry. ESR1 expression pattern was distinctly different in cells from IA compared to the rest, with a high level of ESR1 expression extending to AP cells and crosstalk between growth factors and Estrogen Receptor signaling being evident in these AP cells. In general, cell subtype-specific gene expression did not uniformly correlate with cell-specific chromatin accessibility, suggesting that transcriptional regulation independent of chromatin accessibility governs cell type-specific gene expression in the breast.

cancer biology↗

bioRxiv2023

SARS-CoV-2 Omicron infection augments the magnitude and durability of systemic and mucosal immunity in triple-dose CoronaVac recipients

BackgroundThe inactivated whole-virion vaccine, CoronaVac, is one of the most widely used coronavirus disease 2019 (COVID-19) vaccines worldwide. There is a paucity of data indicating the durability of the immune response and the impact of immune imprinting induced by CoronaVac upon Omicron breakthrough infection. MethodsIn this prospective cohort study, 41 recipients of triple-dose CoronaVac and 14 unvaccinated individuals were recruited. We comprehensively profiled adaptive immune parameters in both groups, including spike-specific immunoglobulin (Ig) G and IgA titers, neutralizing activity, B cells, follicular helper T (Tfh) cells, CD4+ and CD8+ T cells, and their memory subpopulations at 12 months after the third booster dose and at 4 weeks and 20 weeks after Omicron BA.5 infection. ResultsTwelve months after the third CoronaVac vaccination, spike-specific antibody and cellular responses were detectable in most vaccinated individuals. BA.5 infection significantly augmented the magnitude, cross-reactivity and durability of serum neutralization activities, Fc-mediated phagocytosis, and nasal spike-specific IgA responses, memory B cells, activated Tfh cells memory CD4+ T cells, and memory CD8+ T cells for both the ancestral strain and Omicron subvariants, compared to unvaccinated individuals. Notably, the increase in BA.5-specific immunity after breakthrough infection was consistently higher than for the ancestral strain, suggesting no evidence of immune imprinting. Immune landscape analyses showed vaccinated individuals have better synchronization of multiple immune components than unvaccinated individuals upon heterologous SARS-CoV-2 infection. ConclusionOur data provides detailed insight into the protective role of inactivated COVID-19 vaccine in shaping humoral and cellular immune responses to heterologous Omicron infection. Trial registrationClinicalTrials.gov NCT05680896 FundingThis study was supported by the National Natural Science Foundation of China (92269118, 92269205), Nanjing Important Science & Technology Specific Projects (2021-11005), Scientific Research Project of Jiangsu Health Commission (M2022013), Clinical Trials from the Affiliated Drum Tower Hospital, Medical School of Nanjing University (2021-LCYJ-PY-9), and Jiangsu graduate practice innovation project (JX22013929).

immunology↗

bioRxiv2023

Label-Free Composition Analysis of Supramolecular Polymer - Nanoparticle Hydrogels by Reversed-Phase Liquid Chromatography Coupled with a Charged Aerosol Detector

Supramolecular hydrogels formed through polymer-nanoparticle interactions are promising biocompatible materials for translational medicines. This class of hydrogels exhibits shear-thinning behavior and rapid recovery of mechanical properties following applied stresses, providing desirable attributes for formulating sprayable and injectable therapeutics. Characterization of hydrogel composition and loading of encapsulated drugs is critical to achieving desired rheological behavior as well as tunable in vitro and in vivo payload release kinetics. However, quantitation of hydrogel compositions is challenging due to material complexity, heterogeneity, high molecular weight, and the lack of chromophores. Here, we present a label-free approach to simultaneously determine hydrogel polymeric components and encapsulated payloads by coupling a reversed phase liquid chromatographic method with a charged aerosol detector (RPLC-CAD). The hydrogel studied consists of modified hydroxypropylmethylcellulose, self-assembled PEG-b-PLA nanoparticles, and a therapeutic compound, Bimatoprost. The three components were resolved and quantitated using the RPLC-CAD method with a C4 stationary phase. The method demonstrated robust performance, applicability to alternative cargos (i.e. proteins), and was suitable for composition analysis as well as for evaluating in vitro release of cargos from the hydrogel. Moreover, this method can be used to monitor polymer degradation and material stability, which can be further elucidated by coupling the RPLC method with high resolution mass spectrometry and a Fourier-transform based deconvolution algorithm. To our knowledge, this is the first RPLC-CAD method for characterizing the critical quality attributes of supramolecular hydrogels. We envision this analytical strategy could be generalized to characterize other classes of supramolecular hydrogels, establish structure-property relationships, and provide rational design guidance in hydrogel drug product development.

biochemistry↗

bioRxiv2023

MethNet: a robust approach to identify regulatory hubs and their distal targets in cancer

Aberrations in the capacity of DNA/chromatin modifiers and transcription factors to bind non-coding regions can lead to changes in gene regulation and impact disease phenotypes. However, identifying distal regulatory elements and connecting them with their target genes remains challenging. Here, we present MethNet, a pipeline that integrates large-scale DNA methylation and gene expression data across multiple cancers, to uncover novel cis regulatory elements (CREs) in a 1Mb region around every promoter in the genome. MethNet identifies clusters of highly ranked CREs, referred to as hubs, which contribute to the regulation of multiple genes and significantly affect patient survival. Promoter-capture Hi-C confirmed that highly ranked associations involve physical interactions between CREs and their gene targets, and CRISPRi based scRNA Perturb-seq validated the functional impact of CREs. Thus, MethNet-identified CREs represent a valuable resource for unraveling complex mechanisms underlying gene expression, and for prioritizing the verification of predicted non-coding disease hotspots.

cancer biology↗

bioRxiv2023

Population genomics reveals extensive inbreeding and purging of mutational load in wild Amur tigers

The inbreeding is a big threat for the persistence of genetic diversity in small and isolated populations of endangered species. The homozygous genome could exacerbate inbreeding depression by introducing homozygous deleterious alleles in the population. However, purging of inbreeding loads as they become homozygotes in small populations could alleviate the depression. The Amur tiger (Panthera tigris altaica) is typically exists in small population living in forests in Northeast Asia and is among the most endangered animals on the planet with great symbolic significance of conservation. By comparing with captive individuals, we revealed substantially higher and more extensive inbreeding in the wild Amur tiger population (FROH=0.51) than in captive Amur tigers (FROH=0.26). We further found much less mutational loads in wild populations when compared with captive Amur tigers. However, the frequency of loss of function and deleterious nonsynonymous mutations inside ROH regions are much lower than that in non-ROH regions in both wild and captive Amur tigers, indicating the purging may had occurred in both populations but much effective in the wild population. In addition, we found the average frequency of deleterious alleles was much lower than that of neutral alleles in the wild population, indicating that the purifying selection contributed to the purging of mutational loads in the wild Amur tigers. These findings provide valuable genome-wide evidence to support the making of future conservation plans of wild Amur tigers.

genomics↗

bioRxiv2023

Enrichment and delivery of target proteins into the cell cytosol via Outer Membrane Vesicles

Advanced intracellular delivery of proteins has profound applications in both scientific investigations and therapies. However, existing strategies relying on various chemical and physical methods, have drawbacks such as the requirement of high concentration in vitro prepared target proteins and difficulty in labeling target proteins. Developing new delivery systems integrating the enveloping and labeling of target proteins would bring great advantages for efficient protein transfections. Here, we enriched a high concentration (62 mg/ml) of several target proteins into outer membrane vesicles (OMVs) of E. coli to employ the native property of OMVs to deliver proteins into the cytosol of eukaryotic cells. The results revealed a high protein transfection efficiency arranging from 90-97% for different cell lines. Moreover, the free penetration of molecules less than 600 Dalton across the membrane of OMVs allows direct labeling of target proteins within OMVs, facilitating the visualization of target proteins. Importantly, the nanobody delivered intracellularly by OMVs retains the biological activity of binding with its target, highlighting the advantages of OMVs as an emerging tool for efficient intracellular delivery of proteins.

cell biology↗

bioRxiv2022

Identifying human islet microRNAs associated with donor sex, age and body mass index

ObjectivesHuman islets are widely researched to understand pathophysiological mechanisms leading to diabetes. Sex, age, and body mass index (BMI) are key donor traits influencing insulin secretion. Islet function is also regulated by an intricate network of microRNAs. MethodsHere, we profiled 754 microRNAs and 58,190 potential targets in up to 131 different human islet donor preparations (without diabetes) and assessed their association with donor traits. We further performed mechanistical studies to observe the causal role of the age-associated key microRNAs on relative telomere length in human islets. ResultsMicroRNA discovery analyses identified miR-199a-5p and miR-214-3p associated with sex, age and BMI; miR-147b with sex and age; miR-378a-5p with sex and BMI; miR-542-3p, miR-34a-3p, miR-34a-5p, miR-497-5p and miR-99a-5p with age and BMI. There were 959 mRNA transcripts associated with sex (excluding those from sex-chromosomes), 940 with age and 418 with BMI. MicroRNA-199a-5p and miR-214-3p levels inversely associate with transcripts critical in islet function, metabolic regulation, and senescence. Our functional studies verified that inhibition of these two microRNAs (miR-199a-5p/-214-3p) slowed down telomere length shortening in human islet cells maintained in vitro and demonstrating cellular senescence. ConclusionsOur analyses identify human islet cell microRNAs influenced by donor traits. Graphical abstract O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=113 SRC="FIGDIR/small/512222v2_ufig1.gif" ALT="Figure 1"> View larger version (32K): org.highwire.dtl.DTLVardef@1666c2org.highwire.dtl.DTLVardef@b4695forg.highwire.dtl.DTLVardef@720e99org.highwire.dtl.DTLVardef@1c78ae_HPS_FORMAT_FIGEXP M_FIG C_FIG

cell biology↗