Biology subjects

Jin, P.

Publications and source records attributed to Jin, P..

36 records · Page 2Linked to original sources

bioRxiv2023

Resolving the unsolved: Comprehensive assessment of tandem repeats at scale

Tandem repeat (TR) variation is associated with gene expression changes and over 50 rare monogenic diseases. Recent advances in sequencing have enabled accurate, long reads that can characterize the full-length sequence and methylation profile of TRs. However, despite these advances in sequencing technology, computational methods to fully profile tandem repeats across the genome do not exist. To address this gap, we introduce tools for tandem repeat genotyping (TRGT), visualization and an accompanying TR database. TRGT accurately resolves the length and sequence composition of TR regions in the human genome. Assessing 937,122 TRs, TRGT showed a Mendelian concordance of 99.56%, allowing a single repeat unit difference. In six samples with known repeat expansions, TRGT detected all repeat expansions while also identifying methylation signals, mosaicism, and providing finer resolution of repeat length. Additionally, we release a database with allele sequences and methylation levels for 937,122 TRs across 100 genomes.

genomics↗

bioRxiv2023

Dysregulation of Prefrontal Oligodendrocyte Lineage Cells Across Mouse Models of Adversity and Human Major Depressive Disorder

Animal models of adversity have yielded few molecular mechanisms that translate to human stress-related diseases like major depressive disorder (MDD). We congruently analyze publicly available bulk-tissue transcriptomic data from prefrontal cortex (PFC) in multiple mouse models of adversity and in MDD. We apply strategies, to quantify cell-type specific enrichment from bulk-tissue transcriptomics, utilizing reference single cell RNA sequencing datasets. These analyses reveal conserved patterns of oligodendrocyte (OL) dysregulation across animal experiments, including susceptibility to social defeat, acute cocaine withdrawal, chronic unpredictable stress, early life stress, and adolescent social isolation. Using unbiased methodologies, we further identify a dysregulation of layer 6 neurons that associate with deficits in goal-directed behavior after social isolation. Human post-mortem brains with MDD show similar OL transcriptome changes in Brodmann Areas 8/9 in both male and female patients. This work assesses cell type involvement in an unbiased manner from differential expression analyses across animal models of adversity and human MDD and finds a common signature of OL dysfunction in the frontal cortex.

neuroscience↗

bioRxiv2023

Single nucleus multiome analysis of the prefrontal cortex from C9orf72 ALS/FTD patients illuminates pathways affected during disease progression

Repeat expansions in the C9orf72 gene are the most common genetic cause of amyotrophic lateral sclerosis and familial frontotemporal dementia (ALS/FTD). To identify molecular defects that take place in the dorsolateral frontal cortex of patients with C9orf72 ALS/FTD, we compared healthy controls with C9orf72 ALS/FTD donor samples staged based on the levels of cortical phosphorylated TAR DNA binding protein (pTDP-43), a neuropathological hallmark of disease progression. We identified distinct molecular changes in different cell types that take place during FTD development. Loss of neurosurveillance microglia and activation of the complement cascade take place early, when pTDP-43 aggregates are absent or very low, and become more pronounced in late stages, suggesting an initial involvement of microglia in disease progression. Reduction of layer 2-3 cortical projection neurons with high expression of CUX2/LAMP5 also occurs early, and the reduction becomes more pronounced as pTDP-43 accumulates. Several unique features were observed only in samples with high levels of pTDP-43, including global alteration of chromatin accessibility in oligodendrocytes, microglia, and astrocytes; higher ratios of premature oligodendrocytes; increased levels of the noncoding RNA NEAT1 in astrocytes and neurons, and higher amount of phosphorylated ribosomal protein S6. Our findings reveal previously unknown progressive functional changes in major cell types found in the frontal cortex of C9orf72 ALS/FTD patients that shed light on the mechanisms underlying the pathology of this disease.

neuroscience↗

bioRxiv2022

FMRP phosphorylation modulates neuronal translation through YTHDF1

Translation activation of local synaptic mRNAs is critical to learning and memory1-3. Despite extensive studies on how phosphorylation of ribosomal proteins and translation factors enables timely response to exogenous stimuli4, our knowledge on molecular pathways utilized by RNA binding proteins (RBPs) to control translation of specific mRNAs remains incomplete. We have previously found that YTHDF1 regulates depolarization-induced protein synthesis by promoting translation of N6-methyladenosine (m6A)-modified transcripts5. Here we report an unexpected mechanism that the stimuli-induced neuronal translation is mediated by phosphorylation of a YTHDF1-binding protein FMRP. Phosphorylation of FMRP serine 499 induced by neuronal depolarization alters the condensing behavior of prion-like protein YTHDF1. Unphosphorylated FMRP sequesters YTHDF1 away from the translation initiation complex, whereas the stimulation-induced FMRP phosphorylation releases YTHDF1 to form translational active condensates with the ribosome to activate translation of YTHDF1 target transcripts. In fragile X syndrome (FXS) models characterized by low FMRP expression, we observed YTHDF1-mediated hyperactive translation, which notably impacts FXS pathophysiology. Developmental defects in an FXS forebrain organoid model could be reversed by a selective small-molecule inhibitor of YTHDF1 which acts by suppressing its condensation in neurons. We characterized transcriptome-wide mRNA translation with inhibitor treatment in organoids and identified targets that explain alleviated FXS pathology. Our study thus reveals FMRP and its phosphorylation as an important regulator of the activity-dependent translation during neuronal development and stimulation, and identifies YTHDF1 as a potential therapeutic target for FXS in which developmental defects caused by FMRP depletion could be reversed through YTHDF1 inhibition.

molecular biology↗

bioRxiv2022

Highly synchronized cortical circuit dynamics mediate spontaneous pain

Cortical neural dynamics mediate information processing for the cerebral cortex, implicated in fundamental biological processes, such as vision and olfaction, in addition to neurological and psychiatric diseases. Spontaneous pain is a key feature of human neuropathic pain. Whether spontaneous pain pushes cortical network into an aberrant state, and if so, whether it can be brought back to a normal operating range to ameliorate pain are unknown. Using a clinically relevant mouse model of neuropathic pain with robust spontaneous pain-like behavior, we report that orofacial spontaneous pain activated a specific area within the primary somatosensory cortex (S1), displaying synchronized neural dynamics revealed by intravital two-photon calcium imaging. This synchronization was underpinned by local GABAergic interneuron hypoactivity. Pain-induced cortical synchronization could be attenuated by manipulating local S1 networks or clinically effective pain therapies. Specifically, both chemogenetic inhibition of pain-related c-Fos-expressing neurons, and selective activation of GABAergic interneurons, significantly attenuated S1 synchronization. Clinically effective pain therapies including carbamazepine and nerve root decompression could also dampen S1 synchronization. More importantly, restoring a normal range of neural dynamics, through attenuating pain-induced S1 synchronization, alleviated pain-like behavior. These results suggest spontaneous pain pushes S1 regional network into a synchronized state, whereas reversal of this synchronization alleviates pain.

neuroscience↗

bioRxiv2022

Proteomics and Functional Analysis Revealed TaGSTU6/TaCBSX3 Enhances Wheat Resistance to Powdery Mildew

Wheat stripe rust and powdery mildew are important worldwide diseases of wheat (Triticum aestivum). The wheat cultivar Xingmin318 (XM318) is resistant to both wheat stripe rust and powdery mildew, which are caused by Puccinia striiformis f. sp. tritici (Pst) and Blumeria graminis f. sp. tritici (Bgt), respectively. To explore the molecular mechanisms of wheat defenses against Pst and Bgt, quantitative proteomic analyses of XM318 inoculated with Pst and Bgt, respectively, were performed using tandem mass tags (TMT) technology. A total of 741 proteins were identified as differentially accumulated proteins (DAPs). Bioinformatics analyses indicated that some functional categories, including antioxidant activity, exhibited obvious differences between Pst and Bgt infections. Intriguingly, only 42 DAPs responded to both Pst and Bgt infections. Twelve DAPs were randomly selected for RT-qPCR analysis, and the mRNA expression levels of eleven were consistent with their protein expression. Furthermore, gene silencing using the virus-induced gene silencing system indicated that glutathione S-transferase (TaGSTU6) has an important role in resistance to Bgt but not to Pst. TaGSTU6 was shown to interact with the cystathionine beta-synthase (CBS) domain-containing protein (TaCBSX3). Knockdown of TaCBSX3 expression only reduced wheat resistance to Bgt infection. Overexpression of TaGSTU6 and TaCBSX3 in Arabidopsis (Arabidopsis thaliana) promoted plant resistance to Pseudomonas syringae pv. tomato DC3000 (Pst DC3000). Our results indicated that the TaGSTU6 interacting with TaCBSX3 only confers wheat resistance to Bgt, suggesting that wheat has different response mechanisms to Pst and Bgt stress. One-sentence summaryProteomics revealed a difference in the wheat resistance response to Pst and Bgt, and the TaGSTU6/TaCBSX3 interaction plays an important role only in wheat resistance to Bgt.

pathology↗

bioRxiv2021

LRcell: detecting the source of differential expression at the sub-cell type level from bulk RNA-seq data

Given most tissues are consist of abundant and diverse sub cell-types, an important yet unaddressed problem in bulk RNA-seq analysis is to identify at which sub cell-type(s) the differential expression occur. Single-cell RNA-sequencing (scRNA-seq) technologies can answer the question, but they are often labor-intensive and cost-prohibitive. Here, we present LRcell, a computational method aiming to identify specific sub-cell type(s) that drives the changes observed in a bulk RNA-seq experiment. In addition, LRcell provides pre-embedded marker genes computed from putative single-cell RNA-seq experiments as options to execute the analyses. Using three different real datasets, we show that LRcell successfully identifies known cell types involved in psychiatric disorders and LRcell is more sensitive than even the leading deconvolution methods.

bioinformatics↗

bioRxiv2020

Transgenerational inheritance of BPA-induced obesity correlates with transmission of new CTCF sites in the Fto gene

Transgenerational transmission of epiphenotypes is poorly understood. Here we show that exposure of pregnant mouse F0 females to BPA results in obesity in the F2 progeny due to increased food intake and leptin resistance. This epiphenotype can be transmitted up to the F6 generation and disappears in F7. Analyses of chromatin accessibility in sperm of the F1-F6 generations reveals alterations in the binding of CTCF at two enhancers of the Fto gene in obese but not control animals that correlates with transmission of obesity. Deletion of the CTCF site in Fto results in mice that fail to become obese when exposed to BPA. These Fto enhancers show increased interactions in sperm of obese mice with the Irx3 and Irx5 genes, which are involved in the differentiation of appetite controlling AgRP/NPY neurons. Single-nucleus and immunofluorescence analyses in the arcuate nucleus of the hypothalamus suggest that exposure to BPA results in expansion of the number of orexigenic AgRP neurons. This expansion correlates with increased accessibility of the Fto proximal enhancer in radial glia-like neural stem cells (RG-NSCs), which give rise to AgRP/NPY neurons, and in mature oligodendrocytes. The results provide a molecular mechanism for transgenerational inheritance in mammals and suggest that both genetic and epigenetic alterations of Fto can lead to the same phenotypic outcomes.

genomics↗

bioRxiv2020

The genomic and transcriptomic foundations of viviparous seed development in mangroves

Vivipary in plants refers to a specific seed development and reproductive strategy where seeds minimize the dormancy stage and germinate while still attached to their maternal plants. It is one of the most unique adaptive genetic features used by many mangrove species where elongated hypocotyls aid in quick root emergence to anchor the seedling in coastal intertidal wetlands. The genetic mechanisms behind mangrove vivipary, however, remain elusive. Using comparative genomic and transcriptomic technologies to investigate viviparous mangroves and their close inland relatives, we found that a full array of gene expression profiles were altered, including key plant hormone metabolic pathways, high expression of embryonic signature genes, and reduced production of proanthocyanidins and storage proteins. Along with these changes, a major gene regulating seed dormancy, Delay of Germination-1 (DOG1), is entirely missing or defunct within the entire linage of the four genera with true viviparous characteristics. These results suggest a systemic level change is required to warrant the genetic program of mangrove vivipary. Understanding of the molecular processes of vivipary could benefit the design of pregerminated propagules for forestation in harsh environments or prevent precocious germination of grain crops pre- and post-harvest.

genomics↗

bioRxiv2020

Environmental RNA interference in two-spotted spider mite, Tetranychus urticae, reveals dsRNA processing requirements for efficient RNAi response

Comprehensive understanding of pleiotropic roles of RNAi machinery highlighted the conserved chromosomal functions of RNA interference. The consequences of the evolutionary variation in the core RNAi pathway genes are mostly unknown, but may lead to the species-specific functions associated with gene silencing. The two-spotted spider mite, Tetranychus urticae, is a major polyphagous chelicerate pest capable of feeding on over 1,100 plant species and developing resistance to pesticides used for its control. A well annotated genome, susceptibility to RNAi and economic importance, make T. urticae an excellent candidate for development of an RNAi protocol that enables high-throughput genetic screens and RNAi-based pest control. Here, we show that the length of the exogenous dsRNA critically determines its processivity and ability to induce RNAi in vivo. A combination of the long dsRNAs and the use of dye to trace the ingestion of dsRNA enabled the identification of genes involved in membrane transport and 26S proteasome degradation as sensitive RNAi targets. Our data demonstrate that environmental RNAi can be an efficient reverse genetics and pest control tool in T. urticae. In addition, the species-specific properties together with the variation in the components of the RNAi machinery make T. urticae a potent experimental system to study the evolution of RNAi pathways.

molecular biology↗

bioRxiv2020

Integrated analysis of a compendium of RNA-Seq datasets for splicing factors

A vast amount of public RNA-sequencing datasets have been generated and used widely to study transcriptome mechanisms. These data offer precious opportunity for advancing biological research in transcriptome studies such as alternative splicing. We report the first large-scale integrated analysis of RNA-Seq data of splicing factors for systematically identifying key factors in diseases and biological processes. We analyzed 1,321 RNA-Seq libraries of various mouse tissues and cell lines, comprising more than 6.6 TB sequences from 75 independent studies that experimentally manipulated 56 splicing factors. Using these data, RNA splicing signatures and gene expression signatures were computed, and signature comparison analysis identified a list of key splicing factors in Rett syndrome and cold-induced thermogenesis. We show that cold-induced RNA-binding proteins rescue the neurite outgrowth defects in Rett syndrome using neuronal morphology analysis, and we also reveal that SRSF1 and PTBP1 are required for energy expenditure in adipocytes using metabolic flux analysis. Our study provides an integrated analysis for identifying key factors in diseases and biological processes and highlights the importance of public data resources for identifying hypotheses for experimental testing.

bioinformatics↗

bioRxiv2020

The generalist herbivore Tetranychus urticae (Koch) adapts to novel plant hosts through rapid evolution of metabolic resistance

Genetic adaptation, occurring over a long evolutionary time, enables host-specialized herbivores to develop novel resistance traits and to efficiently counteract the defenses of a narrow range of host plants. In contrast, physiological acclimation, leading to the suppression and/or detoxification of host defenses is hypothesized to enable broad-generalists to shift between plant hosts. However, the host adaptation mechanisms used by generalists composed of host-adapted populations are not known. Tetranychus urticae is an extreme generalist herbivore whose individual populations perform well only on a subset of potential hosts. We combined experimental evolution, Arabidopsis genetics, mite reverse genetics, and pharmacological approaches to examine mite host adaptation upon the shift of a bean-adapted population to Arabidopsis thaliana. We showed that cytochrome P450 monooxygenases are required for mite adaptation to Arabidopsis. We identified activities of two tiers of P450s: general xenobiotic-responsive P450s that have a limited contribution to mite adaptation to Arabidopsis and adaptation-associated P450s that efficiently counteract Arabidopsis defenses. In {approx}25 generations of mite selection on Arabidopsis plants, mites evolved highly efficient detoxification-based adaptation, characteristic of specialist herbivores. This demonstrates that specialization to plant resistance traits can occur within the ecological timescale, enabling the two-spotted spider mite to shift to novel plant hosts.

evolutionary biology↗

bioRxiv2020

Single-cell Analysis of ACE2 Expression in Human Kidneys and Bladders Reveals a Potential Route of 2019-nCoV Infection

Since December 2019, a novel coronavirus named 2019 coronavirus (2019-nCoV) has emerged in Wuhan of China and spread to several countries worldwide within just one month. Apart from fever and respiratory complications, acute kidney injury has been observed in some patients with 2019-nCoV. In a short period of time, angiotensin converting enzyme II (ACE2), have been proposed to serve as the receptor for the entry of 2019-nCoV, which is the same for severe acute respiratory syndrome coronavirus (SARS). To investigate the possible cause of kidney damage in 2019-nCoV patients, we used both published kidney and bladder cell atlas data and an independent unpublished kidney single cell RNA-Seq data generated in-house to evaluate ACE2 gene expressions in all cell types in healthy kidneys and bladders. Our results showed the enriched expression of all subtypes of proximal tubule cells of kidney and low but detectable levels of expression in bladder epithelial cells. These results indicated the urinary system is a potential route for 2019-nCoV infection, along with the respiratory system and digestion system. Our findings suggested the kidney abnormalities of SARS and 2019-nCoV patients may be due to proximal tubule cells damage and subsequent systematic inflammatory response induced kidney injury. Beyond that, laboratory tests of viruses and related indicators in urine may be needed in some special patients of 2019-nCoV.

genomics↗

bioRxiv2019

An All-to-All Approach to the Identification of Sequence-Specific Readers for Epigenetic DNA Modifications on Cytosine

The authors have withdrawn their manuscript whilst they perform additional experiments to test some of their conclusions further. Therefore, the authors do not wish this work to be cited as reference for the project. If you have any questions, please contact the corresponding author.Competing Interest StatementThe authors have declared no competing interest.

systems biology↗

bioRxiv2019

Manipulating patterns of dynamic deformation elicits the impression of cloth with varying stiffness

Cloth is a common material and humans can visually estimate its mechanical properties by observing how it deforms under external forces. Here we ask whether, and how, dynamic deformation can affect the perception of mechanical properties of cloth. In Experiment 1, we find that both intrinsic mechanical properties and optical properties affect stiffness perception when the stimuli are presented as images. By contrast, in videos, humans can partially discount the effect of optical appearances and exhibit higher sensitivity to stiffness. We further identified an idiosyncratic deformation pattern (i.e., movement uniformity) to differentiate stiffness, which can be reliably measured by six optical flow features. In Experiment 2, we isolate the deformation by creating dynamic dot stimuli from the 3D mesh of the cloth. We directly alter the movement pattern by manipulating the uniformity of the displacement vectors on the dot stimuli, and show that changing the pattern of dynamic deformation alone can alter the perceived stiffness of cloth in a variety of scene set-ups. Furthermore, by analyzing optical flow fields extracted from the manipulated dynamic dot stimuli, we confirmed the same six optical flow features can be diagnostic of the degree of stiffness of moving cloth across different scenes. Overall, our study demonstrates that manipulating patterns of dynamic deformation alone can elicit the impression of cloth with varying stiffness, suggesting that human visual system might rely on the idiosyncratic pattern of dynamic deformation for estimating stiffness.

neuroscience↗

bioRxiv2018

Auditory and Language Contributions to Neural Encoding of Speech Features in Noisy Environments

Recognizing speech in noisy environments is a challenging task that involves both auditory and language mechanisms. Previous studies have demonstrated noise-robust neural tracking of the speech envelope, i.e., fluctuations in sound intensity, in human auditory cortex, which provides a plausible neural basis for noise-robust speech recognition. The current study aims at teasing apart auditory and language contributions to noise-robust envelope tracking by comparing 2 groups of listeners, i.e., native listeners of the testing language and foreign listeners who do not understand the testing language. In the experiment, speech is mixed with spectrally matched stationary noise at 4 intensity levels and the neural responses are recorded using electroencephalography (EEG). When the noise intensity increases, an increase in neural response gain is observed for both groups of listeners, demonstrating auditory gain control mechanisms. Language comprehension creates no overall boost in the response gain or the envelope-tracking precision but instead modulates the spatial and temporal profiles of envelope-tracking activity. Based on the spatio-temporal dynamics of envelope-tracking activity, the 2 groups of listeners and the 4 levels of noise intensity can be jointly decoded by a linear classifier. All together, the results show that without feedback from language processing, auditory mechanisms such as gain control can lead to a noise-robust speech representation. High-level language processing, however, further modulates the spatial-temporal profiles of the neural representation of the speech envelope.

neuroscience↗

bioRxiv2018

Estimating mechanical properties of cloth from videos using dense motion trajectories: human psychophysics and machine learning

Humans can visually estimate the mechanical properties of deformable objects (e.g. cloth stiffness). While much of the recent work on material perception has focused on static image cues (e.g., textures and shape), little is known whether humans can integrate information over time to make a judgment. Here, we investigate the effect of spatiotemporal information across multiple frames (multi-frame motion) on estimating the bending stiffness of cloth. Using high-fidelity cloth animations, we first examined how the perceived bending stiffness changed as a function of the physical bending stiffness defined in the simulation model. Using maximum likelihood difference scaling methods (MLDS) we found that the perceived stiffness and the physical bending stiffness were highly correlated. A second experiment in which we scrambled the frame sequences diminished this correlation. This suggests that multi-frame motion plays an important role. To provide further evidence for this finding, we extracted dense motion trajectories from the videos across 15 consecutive frames and used the trajectory descriptors to train a machine-learning model with the measured perceptual scales. The model can predict human perceptual scales in new videos with varied winds, optical properties of cloth, and scene setups. When the correct multi-frame was removed (using either scrambled videos or 2-frame optical flow to train the model), the predictions significantly worsened. Our findings demonstrate that multi-frame motion information is important for both humans and machines to estimate the mechanical properties. In addition, we show that dense motion trajectories are effective features to build a successful automatic cloth estimation system.

neuroscience↗

bioRxiv2017

Loss of MECP2 leads to telomere dysfunction and neuronal stress

To determine the role for mutations of MECP2 in Rett Syndrome, we generated isogenic lines of human iPSCs (hiPSCs), neural progenitor cells (NPCs), and neurons from patient fibroblasts with and without MECP2 expression in an attempt to recapitulate disease phenotypes in vitro. Molecular profiling uncovered neuronal specific gene expression changes including induction of a Senescence Associated Secretory Phenotype (SASP) program. Patient derived Neurons made without MECP2 show signs of stress, including induction of p53, and senescence. The induction of p53 appeared to affect dendritic branching in Rett neurons, as p53 inhibition restored dendritic complexity. These disease-in-a-dish data suggest that loss of MECP2 can lead to dendritic defects due to an increase in aspects of neuronal aging.

developmental biology↗