Biology subjects

Yang, R.

Publications and source records attributed to Yang, R..

At least 181 records · Page 10Linked to original sources

bioRxiv2021

Defining the KRAS-regulated kinome in KRAS-mutant pancreatic cancer

Oncogenic KRAS drives cancer growth by activating diverse signaling networks, not all of which have been fully delineated. We set out to establish a system-wide profile of the KRAS-regulated kinase signaling network (kinome) in KRAS-mutant pancreatic ductal adenocarcinoma (PDAC). We knocked down KRAS expression in a panel of six cell lines, and then applied Multiplexed Inhibitor Bead/Mass Spectrometry (MIB/MS) chemical proteomics to monitor changes in kinase activity and/or expression. We hypothesized that depletion of KRAS would result in downregulation of kinases required for KRAS-mediated transforming activities, and in upregulation of other kinases that could potentially compensate for the deleterious consequences of the loss of KRAS. We identified 15 upregulated and 13 downregulated kinases in common across the panel. In agreement with our hypothesis, all 15 of the upregulated kinases have established roles as cancer drivers (e.g., SRC, TGFBR1, ILK), and pharmacologic inhibition of the upregulated kinase, DDR1, suppressed PDAC growth. Interestingly, 11 of the 13 downregulated kinases have established driver roles in cell cycle progression, particularly in mitosis (e.g., WEE1, Aurora A, PLK1). Consistent with a crucial role for the downregulated kinases in promoting KRAS-driven proliferation, we found that pharmacologic inhibition of WEE1 also suppressed PDAC growth. The unexpected paradoxical activation of ERK upon WEE1 inhibition led us to inhibit both WEE1 and ERK concurrently, which caused further potent growth suppression and enhanced apoptotic death than WEE1 inhibition alone. We conclude that system-wide delineation of the KRAS-regulated kinome can identify potential therapeutic targets for KRAS-mutant pancreatic cancer.

cancer biology↗

bioRxiv2021

Taste Bud Connectome: Implications for Taste Information Processes

Taste buds contain 3 types of morphologically identifiable mature cells, 2 of which mediate transduction of specific taste qualities: Type III cells transduce sour while Type II cells transduce either sweet, bitter or umami. A long-standing controversy is whether the nerve fibers innervating these cells are wired specifically, in a labeled-line fashion, or non-specifically, leading to broad responsiveness across taste qualities, the so-called across-fiber system of encoding. Using serial blockface scanning electron microscopy through 5 circumvallate mouse taste buds, we reconstructed the patterns of connectivity of nerve fibers as well as the degree of potential interaction between the two types of taste transducing cells. Type II and Type III cells share few points of contact with one another, and display no morphologically identifiable synapses, suggesting limited direct interaction between these cell types. Of the 127 nerve fibers that make synaptic contacts with taste cells in the sampling volume, about 70% (n=91) synapse with only one taste cell. Of the remaining 36 fibers, 4 synapse with both Type II and Type III cells, the remainder synapsing exclusively with multiple Type II taste cells or multiple Type III cells. Since Type II and Type III cells transduce different taste qualities, the few mixed fibers do not follow a labeled-line organization according to taste quality information and show that connectional specificity in taste buds is not absolute. Significance StatementTaste buds, the sensory end organs for the sense of taste, contain multiple types of sensory cells, with each responding to one of the primary tastes: salt, sweet, sour, bitter and umami. A long-standing question is whether each type of taste cell is wired specifically to a unique set of nerve fibers conveying a "labeled-line" message to the brain. Using serial sections, we determined the neural connectivity in mouse circumvallate taste buds. The majority of individual nerve fibers connect to a single type of taste cell, but 3.1% of the fibers branch to receive input from taste cells known to have different specificities. Thus taste cannot entirely be carried along nerve fibers dedicated to single taste qualities.

neuroscience↗

bioRxiv2021

Assessing the origins of the European Plagues following the Black Death: a synthesis of genomic, historical and ecological information

The Second Plague Pandemic started in Europe with the Black Death in 1346 and lasted until the 19th century. Based on ancient DNA studies, there is a scientific disagreement over whether the bacterium, Yersinia pestis, came into Europe once (Hypothesis 1), or repeatedly over the following four centuries (Hypothesis 2). Here we synthesize the most updated phylogeny together with historical, archeological, evolutionary and ecological information. On the basis of this holistic view, we conclude that Hypothesis 2 is the most plausible. We also suggest that Y. pestis lineages might have developed attenuated virulence during transmission, which can explain the convergent evolutionary signals, including pla-decay, that appeared at the end of the pandemics. Significance StatementOver the last few years there has been a great deal of scientific debate regarding whether the plague bacterium, Yersinia pestis, spread from a Western European reservoir during the Second Plague Pandemic, or if it repeatedly came to Europe from Asia. Here we make a synthesis of the available evidence, including genomes of ancient DNA, historical, archeological and ecological information. We conclude that the bacterium most likely came to Europe from Asia several times during the Second Plague Pandemic.

evolutionary biology↗

bioRxiv2021

Deep neural network analysis employing diffusion basis spectrum imaging metrics as classifiers improves prostate cancer detection and grading

Structural and cellular complexity of prostatic histopathology limits the accuracy of noninvasive detection and grading of prostate cancer (PCa). We addressed this limitation by employing a novel diffusion basis spectrum imaging (DBSI) to derive structurally-specific diffusion fingerprints reflecting various underlying prostatic structural and cellular components. We further developed diffusion histology imaging (DHI) by combining DBSI-derived structural fingerprints with a deep neural network (DNN) algorithm to more accurately classify different histopathological features and predict tumor grade in PCa. We examined 243 patients suspected with PCa using in vivo DBSI. The in vivo DBSI-derived diffusion metrics detected coexisting prostatic pathologies distinguishing inflammation, PCa, and benign prostatic hyperplasia. DHI distinguished PCa from benign peripheral and transition zone tissues with over 95% sensitivity and specificity. DHI also demonstrated over 90% sensitivity and specificity for Gleason score noninvasively. We present DHI as a novel diagnostic tool capable of noninvasive detection and grading of PCa. One sentence summaryDiffusion histology imaging noninvasively and accurately detects and grades prostate cancer.

bioinformatics↗

bioRxiv2021

GRAMMAR-Lambda: An Extreme Simplification for Genome-wide Mixed Model Association Analysis

A highly efficient genome-wide association method, GRAMMAR-Lambda is proposed to make simple genomic control for the test statistics deflated by GRAMMAR, producing statistical power as high as exact mixed model association method. Using the simulated and real phenotypes, we show that at a moderate or above genomic heritability, polygenic effects can be estimated using a small number of randomly selected markers, which extremely simplify genome-wide association analysis with an approximate computational complexity to naive method in large-scale complex population. Upon a test at once, joint association analysis offers significant increase in statistical power over existing methods.

bioinformatics↗

bioRxiv2021

Generalized Hierarchical Mixed Model Association Analysis

In genome-wide association analysis (GWAS) for binary traits, we stratified the genomic generalized linear mixed model (GLMM) into two hierarchies--the GLMM regarding genomic breeding values (GBVs) and a generalized linear regression of the normally distributed GBVs to the tested marker effects. In the first hierarchy, the GBVs were predicted by solving for the genomic best linear unbiased prediction for GLMM with the estimated variance components or genomic heritability in advance, and in the second hierarchy, association tests were performed using the generalized least square (GLS) method for the GBVs. Like the Hi-LMM for regular quantitative traits, the so-called Hi-GLMM method exhibited higher statistical power to detect quantitative trait nucleotides (QTNs) with better genomic control for complex population structure than existing methods, especially when the GBVs were estimated precisely and using joint association analysis for QTN candidates obtained from a test at once. Application of the Hi-GLMM to re-analyze maize kernel colors and six human diseases illustrated its advantage over existing GLMM-based association methods in terms of computing efficiency and statistical power.

bioinformatics↗

bioRxiv2021

Efficient Genomic Control for Mixed Model Associationsin Large-scale Population

Among linear mixed model-based association methods, GRAMMAR has the lowest computing complexity for association tests, but it produces a high false-negative rate due to the deflation of test statistics for complex population structure. Here, we present an optimized GRAMMAR method by efficient genomic control, Optim-GRAMMAR, that estimates the phenotype residuals by regulating downward genomic heritability in the genomic best linear unbiased prediction. Even though using the fewer sampling markers to evaluate genomic relationship matrices and genomic controls, Optim-GRAMMAR retains a similar statistical power to the exact mixed model association analysis, which infers an extremely efficient approach to handle large-scale data. Moreover, joint association analysis significantly improved statistical power over existing methods.

bioinformatics↗

bioRxiv2021

Dependency of LKB1-inactivated lung cancer on aberrant CRTC-CREB activation

Lung cancer with loss-of-function of the LKB1 tumor suppressor is a common aggressive subgroup with no effective therapies. LKB1-deficiency induces constitutive activation of cAMP/CREB-mediated transcription by a family of three CREB-regulated transcription coactivators (CRTC1-3). However, the significance and mechanism of CRTC activation in promoting the aggressive phenotype of LKB1-null cancer remain poorly characterized. Here we observed overlapping CRTC expression patterns and mild growth phenotypes of individual CRTC-knockouts in lung cancer, suggesting functional redundancy of CRTC1-3. We consequently designed a dominant-negative mutant (dnCRTC) to block all three CRTCs to bind and co-activate CREB. Expression of dnCRTC efficiently inhibited the aberrantly activated cAMP/CREB-mediated oncogenic transcriptional program induced by LKB1-deficiency, and specifically blocked the growth of LKB1-inactivated lung cancer. Collectively, this study provides direct proof for an essential role of the CRTC-CREB activation in promoting the malignant phenotypes of LKB1-null lung cancer and proposes the CRTC-CREB interaction interface as a novel therapeutic target.

cancer biology↗

bioRxiv2020

Human Polyomavirus-Encoded Circular RNAs

Circular RNAs (circRNAs) are a conserved class of RNAs with diverse functions. A subset of circRNAs are translated into peptides. Here we describe circular RNAs encoded by human polyomaviruses (HPyVs), including circular forms of RNAs encoding variants of the previously described alternative large T antigen open reading frame (ALTO) gene. Circular ALTO RNAs (circALTOs) can be detected in virus positive Merkel cell carcinoma (VP-MCC) cell lines and tumor samples. CircALTOs are stable, predominantly located in the cytoplasm, and N6-methyladenosine (m6A) modified. MCPyV circALTOs produce ALTO protein in cultured cells. MCPyV ALTO promotes the transcription of co-transfected reporter genes. MCPyV circALTOs are enriched in exosomes derived from VP-MCC lines and circALTO-transfected 293T cells, and purified exosomes can mediate ALTO expression and transcriptional activation. The related trichodysplasia spinulosa polyomavirus (TSPyV) also expresses a circALTO that can be detected in infected tissues and produces ALTO protein in cultured cells. Thus, human polyomavirus circRNAs are expressed in human tumors and tissues, encode for proteins, and may contribute to the infectious and tumorigenic properties of these viruses.

molecular biology↗

bioRxiv2020

Longest Order Conserved Exemplar Subsequences

We propose a new problem whose input data are two linear genomes together with two indexed gene subsequences of them, which asks to find a longest common exemplar subsequence of the two given genomes with a subsequence identical to the given indexed gene subsequences. We present an algorithm for this problem such that the algorithm is allowed to take diminishing time and space to solve the problem by setting the indexed genes with an incremental number. Although an incremental number of indexed genes were selected, the algorithm was verified definite to reach a solution whose length insistently comes very close to a real longest common exemplar subsequence of the two given genomes. Aiming at 23 human/gorilla chromosome pairs, the algorithm was examined for use in questing for longest common exemplar subsequences whose basic units are annotated genes as well as pseudo genes, namely consecutive DNA subsequences. By contrasting the pseudo gene common exemplar subsequences the algorithm had reached for the human chromosomes 7 and 16 and their gorilla homologues with those annotated genes in the human and gorilla chromosomes, we found more than 1 000 and 500 pseudo genes in the human chromosomes 7 and 16 that occur in the same order as they are in the gorilla chromosomes 7 and 16 and, do not overlap with any annotated gene. Author summaryThere is a benefit of the algorithm: It can reach a long enough common exemplar subsequence of two linear genomes in as fast a speed as one requires even if the given genomes would be equipped with too many duplicated genes, which can be done by setting incremental number of indexed genes. We developed a Java software based on the algorithm, that has been available for download on https://github.com/ShuZhang-sdu/LCES. Only in need to set the indexed gene sequences as null, was it verified successful for our algorithm to obtain the longest common exemplar subsequences of the annotated gene summary pairs extracted from 23 human/gorilla chromosome pairs. In convenience for researchers to find new motifs or conserved genes, we devoted for the algorithm to quest pseudo gene (i.e. consecutive DNA subsequences) summary pairs of the 23 human/gorilla chromosome pairs for solutions. There are 20 pseudo gene summary pairs whose longest common exemplar subsequences have been found by the algorithm with null indexed gene sequences. The other 3 pseudo gene summary pairs were verified solvable for the algorithm to reach their longest common exemplar subsequences that have to admit subsequences identical to given indexed gene subsequences. There were informed to exist 2 353 and 1 148 pseudo genes in the gorilla chromosome 7 and 16 that occur in the same order as they are in the human chromosome 7 and 16 and, do not overlap with any annotated gene. These pseudo genes should be significant for annotating the human or gorilla genome.

bioinformatics↗

bioRxiv2020

Cryo-EM structures of outer-arm dynein array bound to microtubule doublet reveal a mechanism for motor coordination

Thousands of outer-arm dyneins (OADs) are arrayed in the axoneme to drive a rhythmic ciliary beat. Coordination among multiple OADs is essential for generating mechanical forces to bend microtubule doublets (MTDs). Using electron microscopy, we determined high-resolution structures of OAD arrays bound to MTD in two different states. OAD preferentially binds to MTD protofilaments with a pattern resembling the native tracks for its distinct microtubule-binding domains. Upon MTD binding, free OADs are induced to adopt a stable parallel conformation, primed for array formation. Extensive tail-to-head (TTH) interactions between OADs are observed, which need to be broken for ATP turnover by the dynein motor. We propose that OADs in an array sequentially hydrolyze ATP to slide MTDs. ATP-hydrolysis in turn relaxes the TTH interfaces to effectuate free nucleotide cycles of downstream OADs. These findings lead to a model explaining how conformational changes in the axoneme produce coordinated action of dyneins.

biophysics↗

bioRxiv2020

Identification of mutations that cooperate with defects in B cell transcription factors to initiate leukemia

The transcription factors EBF1 and PAX5 are frequently mutated in B cell acute lymphoblastic leukemia (B-ALL). We demonstrate that Pax5+/- x Ebf1+/- compound heterozygous mice develop highly penetrant leukemia. Similar results were seen in Pax5+/- x Ikzf1+/- and Ebf1+/- x Ikzf1+/- mice for B-ALL, or in Tcf7+/- x Ikzf1+/- mice for T cell leukemia. To identify genetic defects that cooperate with Pax5 and Ebf1 compound heterozygosity to initiate leukemia, we performed a Sleeping Beauty (SB) transposon screen that identified cooperating partners including gain-of-function mutations in Stat5 ([~]65%) and Jak1([~]68%), or loss-of-function mutations in Cblb (61%) and Myb (32%). These findings underscore the role of JAK/STAT5 signaling in B cell transformation and demonstrate unexpected roles for loss-of-function mutations in Cblb and Myb in leukemic transformation. RNA-Seq studies demonstrated upregulation of a PDK1>SGK3>MYC pathway; treatment of Pax5+/- x Ebf1+/- leukemia cells with PDK1 inhibitors blocked proliferation in vitro. Finally, we identified conserved transcriptional variation in a subset of genes between human leukemias and our mouse B-ALL models. Thus, compound haploinsufficiency for B cell transcription factors likely plays a critical role in transformation of human B cells and suggest that PDK1 inhibitors may be effective for treating patients with such defects.

cancer biology↗

bioRxiv2020

Modularity and neural coding from a brainstem synaptic wiring diagram

How much can connectomes with synaptic resolution help us understand brain function? An optimistic view is that a connectome is a major determinant of brain function and a key substrate for simulating a brain. Here we investigate the explanatory power of connectomics using a wiring diagram reconstructed from a larval zebrafish brainstem. We identify modules of strongly connected neurons that turn out to be specialized for different behavioral functions, the control of eye and body movements. We then build a neural network model using a synaptic weight matrix based on the reconstructed wiring diagram. This leads to predictions that statistically match the neural coding of eye position as observed by calcium imaging. Our work shows the promise of connectome-based brain modeling to yield experimentally testable predictions of neural activity and behavior, as well as mechanistic explanations of low-dimensional neural dynamics, a widely observed phenomenon in nervous systems.

neuroscience↗

bioRxiv2020

Multiscale and multimodal reconstruction of cortical structure and function

We present a semi-automated reconstruction of L2/3 mouse primary visual cortex from 3 million cubic microns of electron microscopic images, including pyramidal and inhibitory neurons, astrocytes, microglia, oligodendrocytes and precursors, pericytes, vasculature, mitochondria, and synapses. Visual responses of a subset of pyramidal cells are included. The data are being made publicly available, along with tools for programmatic and 3D interactive access. The density of synaptic inputs onto inhibitory neurons varies across cell classes and compartments. We uncover a compartment-specific correlation between mitochondrial coverage and synapse density. Frequencies of connectivity motifs in the graph of pyramidal cells are predicted quite accurately from node degrees using the configuration model of random graphs. Cells receiving more connections from nearby cells exhibit stronger and more reliable visual responses. These example findings illustrate the resources utility for relating structure and function of cortical circuits as well as for neuronal cell biology.

neuroscience↗

bioRxiv2020

Application of EGCG modified EDC/NHS cross-linked extracellular matrix to promote macrophage adhesion

Though chemically cross-linked by EDC/NHS endows collagen membrane with promising mechanical properties, it is not conducive to modulation of foreign body reaction (FBR) after implantation or guidance of osteogenesis. In our previous research, we have found that macrophages have a strong regulatory effect on tissue and bone regeneration during FBR, and EGCG modified membranes could adjust the recruitment and phenotypes of macrophages. Accordingly, we develop the EGCG-EDC/NHS membranes, prepared with physically immersion, while the surface morphology of the membrane was observed by SEM, the biological activity of collagen was determined by FTIR, the activity and adhesion of cell culture in vitro, angiogenesis and monocyte/macrophage recruitment after subcutaneous implantation, etc. are characterized. It could be concluded that EGCG-EDC/NHS collagen membrane is hopeful to be used in implant dentistry for it not only retains the advantages of the collagen membrane itself, but also improves cell viability, adhesion and vascularization tendency. However, the mechanism that lies in the regenerative advantages of such membrane needs further exploration, but it is certain that the differences in surface morphology can have a significant impact on the reaction between the host and the implant, not to mention macrophage in bone regeneration.

immunology↗

bioRxiv2020

PD-L1 lncRNA splice promotes lung adenocarcinoma progression via enhancing c-Myc activity

Although blockade of programmed death-ligand 1 (PD-L1) to enhance T cell immune responses shows great promise in tumor immunotherapy, the efficacy of such immune-checkpoint inhibition strategy is limited for patients with solid tumors. The mechanism underlying the limited efficacy of PD-L1 inhibitors remains unclear. Here, we show that human lung adenocarcinoma, regardless of PD-L1 protein positive or negative, all produce a long non-coding RNA isoform of PD-L1 (PD-L1-lnc) via alternative splicing, which promotes lung adenocarcinoma proliferation and metastasis. PD-L1-lnc in various lung adenocarcinoma cells is significantly upregulated by IFN{gamma} in a manner similar to PD-L1 mRNA. Both in vitro and in vivo studies demonstrate that PD-L1-lnc increases proliferation and invasion but decreases apoptosis of lung adenocarcinoma cells. Mechanistically, PD-L1-lnc directly binds to c-Myc and enhances c-Myc transcriptional activity downstream in lung adenocarcinoma cells. Our results provide targeting PD-L1-lnc-c-Myc axis as a novel strategy for lung cancer therapy.

cancer biology↗

bioRxiv2020

Human T-bet governs innate and innate-like adaptive IFN-γ immunity against mycobacteria

Inborn errors of human IFN-{gamma} immunity underlie mycobacterial disease. We report a patient with mycobacterial disease due to an inherited deficiency of the transcription factor T-bet. This deficiency abolishes the expression of T-bet target genes, including IFNG, by altering chromatin accessibility and DNA methylation in CD4+ T cells. The patient has profoundly diminished counts of mycobacterial-reactive circulating NK, invariant NKT (iNKT), mucosal-associated invariant T (MAIT), and V{delta}2+ {gamma}{delta} T lymphocytes, and of non-mycobacterial-reactive classic TH1 lymphocytes, the remainders of which also produce abnormally low amounts of IFN-{gamma}. Other IFN-{gamma}-producing lymphocyte subsets however develop normally, but with low levels of IFN-{gamma} production, with exception of V{delta}2- {gamma}{delta} T lymphocytes, which produce normal amounts of IFN-{gamma} in response to non-mycobacterial stimulation, and non-classic TH1 (TH1*) lymphocytes, which produce IFN-{gamma} normally in response to mycobacterial antigens. Human T-bet deficiency thus underlies mycobacterial disease by preventing the development of, and IFN-{gamma} production by, innate (NK) and innate-like adaptive lymphocytes (iNKT, MAIT, and V{delta}2+ {gamma}{delta} T cells), with mycobacterial-specific, IFN-{gamma}-producing, purely adaptive {beta} TH1* cells unable to compensate for this deficit.

immunology↗

bioRxiv2020

Multi-batch cytometry data integration for optimal immunophenotyping

We describe the integration of multi-batch cytometry datasets (iMUBAC), a flexible, robust, and scalable computational framework for unsupervised cell-type identification across multiple batches of high-dimensional cytometry datasets. After overlaying cells from healthy controls across multiple batches, iMUBAC learns batch-specific cell-type classification boundaries and identifies aberrant immunophenotypes in patient samples. We illustrate unbiased and streamlined immunophenotyping, using both in-house and public mass and flow cytometry datasets.

bioinformatics↗