Biology subjects

Gao, L.

Publications and source records attributed to Gao, L..

At least 163 records · Page 9Linked to original sources

bioRxiv2020

Dextran sulfate sodium salt corrupted colonic crypts declined the smooth muscle tension in mouse large intestine

Ulcerative colitis is one kind of colonic mucosa damage, shows high number of inflammatory epithelial cells. Dextran sulfate sodium salt (DSS) induce a milder onset of colitis or a more aggressive response. It may damage the protective effects on intestinal barrier. In this study, we investigated the damaging of colon crypts, evaluated the smooth muscle tension beneath corrupted crypts in DSS exposed mice. Methodsfemale specific-pathogen-free BALB/C mice (n=16) are randomly divided as: group A: control mice (n=4); group B: DSS-mice (colitis, 5% DSS in drink water, days 1 to 7, n = 12). The DSS is replaced every 2 days. On day 8, mice colons are excised from the colon-cecal junction to the anus. The distal colon segment is longitude incision and aberrant crypt area are determined by methylene blue staining method. The smooth muscle strip is separated and prepared for passive tension tests. The rest segment is fixed with 10% formalin and embedded in paraffin. Histological scores are evaluated in hematoxylin-eosin staining section: crypt damage (none = 0, basal 1/3 damaged = 1, basal 2/3 damaged = 2, only the surface epithelium is intact = 3, and entire crypt and epithelium are lost = 4). The smooth muscle passive tension beneath the aberrant crypt area in DSS-mice are tested and compared with the preparations from control mice. ResultsIn DSS uptake mice, the inflammation in large intestine mucosa damaged crypts with architectural distortions on day 7 (n=7). In crypts damage area, the smooth muscle passive tension and relative myogenic spontaneous contraction parameters are significantly reduced under the high preload conditions. The maximum rate of change of velocity of spontaneous contraction was noticeable attenuated. ConclusionOur findings demonstrate that low dosage DSS water drink result in corrupted colonic crypts. The corrupted crypts damage the large intestinal epithelium barrier, affect the smooth muscle functions, which declined in myogenic spontaneous contraction under the preload. This further may reduce the peristalsis in large intestine.

physiology↗

bioRxiv2020

Role and Dynamics of Vacuolar pH during Cell-in-Cell mediated Death

The non-autonomous cell death by entosis was mediated by the so-called cell-in-cell structures, which were believed to kill the internalized cells by a mechanism dependent on acidified lysosomes. However, the precise values and roles of pH critical for the death of the internalized cells remained undetermined yet. We creatively employed keima, a fluorescent protein that displays different excitation spectra in responding to pH changes, to monitor the pH dynamics of the entotic vacuoles during cell-in-cell mediated death. We found that different cells varied in their basal intracellular pH, and the pH was relatively stable for entotic vacuoles containing live cells, but sharply dropped to a narrow range along with the inner cell death. In contrast, the lipidation of entotic vacuoles by LC3 displayed previously underappreciated complex patterns associated with entotic and apoptotic death, respectively. The pH decline seemed to play distinct roles in the two types of inner cell deaths, where apoptosis is preceded with moderate pH decline while a profound pH decline is likely to be determinate for entotic death. Whereas the cancer cells seemed to be lesser tolerant to acidified environments than non-cancerous cells, manipulating vacuolar pH could effectively control inner cell fates and switch the ways whereby inner cell die. Together, this study demonstrated for the first time the pH dynamics of entotic vacuoles that dictate the fates of internalized cells, providing a rationale for tuning cellular pH as a potential way to treat cell-in-cell associated diseases such as cancer.

cell biology↗

bioRxiv2020

Identification and validation of a ferroptosis-related genes based prognostic signature for prostate cancer

Ferroptosis, an iron-dependent form of selective cell death, involves in the development of many cancers. However, systematic analysis of ferroptosis related genes (FRGs) in prostate cancer (PCa) remains to be clarified. In our research, we collected the mRNA expression profiles and clinical information of PCa patients from TCGA and MSKCC databases. The univariate, LASSO and multivariate Cox regression method were performed to construct prognostic signature in TCGA cohort. Seven FRGs, AKR1C3, ALOXE3, ATP5MC3, CARS1, MT1G, PTGS2, TFRC, were included to establish the risk model, which was validated in MSKCC dataset. Subsequently, we found that high risk group was strongly correlated with copy number alteration load, tumor burden mutation, immune cell infiltration, mRNAsi, immuetherapy and bicalutamide response. Finally, it was identified that overexpression of TFRC could induce proliferation and invasion in PCa cell lines in vitro. These results demonstrated that this risk model based on recurrence free survival (RFS) could accurately predict prognosis in PCa patients, suggesting that FRGs are promising prognostic biomarkers and drug target genes for PCa patients.

cancer biology↗

bioRxiv2020

Genome sequencing sheds light on the contribution of structural variants to Brassica oleracea diversification

Brassica oleracea includes several morphologically diverse, economically important vegetable crops. Here we present high-quality chromosome-scale genome assemblies for two B. oleracea morphotypes, cauliflower and cabbage. Direct comparison of these two assemblies identifies ~120 K high-confidence structural variants (SVs). Population analysis of 271 B. oleracea accessions using these SVs clearly separates different morphotypes, suggesting the association of SVs with B. oleracea intraspecific divergence. Genes affected by SVs selected between cauliflower and cabbage are enriched with functions related to response to stress and stimulus and meristem and flower development. Furthermore, genes affected by selected SVs and involved in the switch from vegetative to generative growth that defines curd initiation, inflorescence meristem proliferation for curd formation, maintenance and enlargement, are identified, providing insights into the regulatory network of curd development. This study reveals the important roles of SVs in diversification of different morphotypes of B. oleracea, and the newly assembled genomes and the SVs provide rich resources for future research and breeding.

plant biology↗

bioRxiv2020

Integrative Analysis the characterization of peroxiredoxins in pan-cancer

Peroxiredoxins (PRDXs) are antioxidant enzymes protein family members that involves the process of several biological functions, such as differentiation, cell growth. Considerable evidence demonstrates that PRDXs play critical roles in the occurrence and development of carcinomas. However, a systematic analysis of PRDXs in cancers is deficiency. Therefore, we perform a comprehensive analysis of PRDXs in 33 cancer types including mRNA expression profiles, genetic alterations, methylation, prognostic values, potential biological pathways and target drugs. Moreover, we validated that PRDX6 could regulate cancer cell proliferation via JAK2-STAT3 pathway and involve into the process of cell cycle in bladder cancer.

cancer biology↗

bioRxiv2020

The mouse cortico-basal ganglia-thalamic network

The cortico-basal ganglia-thalamic loop is one of the fundamental network motifs in the brain. Revealing its structural and functional organization is critical to understanding cognition, sensorimotor behavior, and the natural history of many neurological and neuropsychiatric diseases. Classically, the basal ganglia is conceptualized to contain three primary information output channels: motor, limbic, and associative. However, given the roughly 65 cortical areas and two dozen thalamic nuclei that feed into the dorsal striatum, a three-channel view is overly simplistic for explaining the myriad functions of the basal ganglia. Recent works from our lab and others have subdivided the dorsal striatum into numerous functional domains based on convergent and divergent inputs from the cortex and thalamus. To complete this work, we generated a comprehensive data pool of [~]700 injections placed across the striatum, external globus pallidus (GPe), substantia nigra pars reticulata (SNr), thalamic nuclei, and cortex. We identify 14 domains of SNr, 36 in the GPe, and 6 in the parafascicular and ventromedial thalamic nuclei. Subsequently, we identify 6 parallel cortico-basal ganglia-thalamic subnetworks that sequentially transduce specific subsets of cortical information with complex patterns of convergence and divergence through every elemental node of the entire cortico-basal ganglia loop. These experiments reveal multiple important novel features of the cortico-basal ganglia network motif. The prototypical sub-network structure is characterized by a highly interconnected nature, with cortical information processing through one or more striatal nodes, which send a convergent output to the SNr and a more parallelized output to the GPe; the GPe output then converges with the SNr. A domain of the thalamus receives the nigral output, and is interconnected with both the striatal domains and the cortical areas that filter into its nigral input source. This study provides conceptual advancement of our understanding of the structural and functional organization of the classic cortico-basal ganglia network.

neuroscience↗

bioRxiv2020

Cellular Anatomy of the Mouse Primary Motor Cortex

An essential step toward understanding brain function is to establish a cellular-resolution structural framework upon which multi-scale and multi-modal information spanning molecules, cells, circuits and systems can be integrated and interpreted. Here, through a collaborative effort from the Brain Initiative Cell Census Network (BICCN), we derive a comprehensive cell type-based description of one brain structure - the primary motor cortex upper limb area (MOp-ul) of the mouse. Applying state-of-the-art labeling, imaging, computational, and neuroinformatics tools, we delineated the MOp-ul within the Mouse Brain 3D Common Coordinate Framework (CCF). We defined over two dozen MOp-ul projection neuron (PN) types by their anterograde targets; the spatial distribution of their somata defines 11 cortical sublayers, a significant refinement of the classic notion of cortical laminar organization. We further combine multiple complementary tracing methods (classic tract tracing, cell type-based anterograde, retrograde, and transsynaptic viral tracing, high-throughput BARseq, and complete single cell reconstruction) to systematically chart cell type-based MOp input-output streams. As PNs link distant brain regions at synapses as well as host cellular gene expression, our construction of a PN type resolution MOp-ul wiring diagram will facilitate an integrated analysis of motor control circuitry across the molecular, cellular, and systems levels. This work further provides a roadmap towards a cellular resolution description of mammalian brain architecture.

neuroscience↗

bioRxiv2020

Transferrin receptor (Tfr1) ablation in satellite cells impacts skeletal muscle regeneration through the activation of ferroptosis

Satellite cells (SCs) are critical to the postnatal development and skeletal muscle regeneration. Inactivation of SCs is linked with the skeletal muscle loss. Leveraging on the RNAseq screening, transferrin receptor (Tfr1) is identified to be associated with muscle/SC ageing and the declined regeneration potential. Muscle-specific deletion of Tfr1 results in the growth retardation, metabolic disorder and lethality, shedding light on the importance of Tfr1 in skeletal muscle physiology. Here, our investigation reported that conditional SC-ablation of Tfr1 leads to the SCs inactivation and skeletal muscle regeneration defects, followed by the labile iron accumulation, de novo lipogenesis via fibroadipogenic progenitors (FAPs) and Gpx4/Nrf2-mediated ROS-scavenger defects. These abnormal phenomena, such as Hmox1-mediated myoglobin degradation, Tfr1-Slc39a14 functional switch and the activation of unsaturated fatty acid biosynthesis pathway are orchestrated with the occurrence of ferroptosis in skeletal muscle. Ferroptosis may further prevent SC proliferation and skeletal muscle regeneration. Ferrostatin-1, a ferroptosis inhibitor could not rescue Tfr1-ablation induced ferroptosis. However, intramuscular administration of lentivirus expressing Tfr1 could partially reduce labile iron accumulation, decrease de novo lipogenesis and promote skeletal muscle regeneration. Most importantly, Tfr1/Slc39a14 functional switch, labile iron accumulation and fatty acid biosynthesis are recapitulated in aged skeletal muscle of rodents, indicating that ferroptosis occurs in the skeletal muscles of aged rodents. The present study also bridges the gap between pathogenesis of iron and functional defects in the skeletal muscle, providing mechanistic information to develop anti-aging strategies. One Sentence SummaryConditional ablation of Tfr1 in satellite cells (SCs) results in the SC inactivation, skeletal muscle regeneration defects, labile iron accumulation, and unsaturated fatty acid biosynthesis, leading to the activation of ferroptosis, which is recapitulated in skeletal muscles of aged rodents to be a new cell death form identified in skeletal muscle and sheds light on the development of novel anti-ageing strategies.

cell biology↗

bioRxiv2020

DNA Methylation Reprogramming during Sex Determination and Transition in Zebrafish

It is a mystery about sex determination and sexual plasticity in species without sex chromosomes. DNA methylation is a prevalent epigenetic modification in vertebrates, which has been shown to involve in the regulation of gene expression and embryo development. However, it remains unclear about how DNA methylation regulates sexual development. To elucidate it, we used zebrafish to investigate DNA methylation reprogramming during juvenile germ cell development and adult female-to-male sex transition. We revealed that primordial germ cells (PGCs) undergo significant DNA methylation reprogramming during germline development and set to an oocyte/ovary-like pattern at 9 days post fertilization (9 dpf). When blocking DNMTs activity in juveniles after 9 dpf, the zebrafish preferably develops into females. We also show that Tet3 involves in PGC development. Notably, we find that DNA methylome reprogramming during adult zebrafish sex transition is similar to the reprogramming during the sex differentiation from 9 dpf PGCs to sperm. Furthermore, inhibiting DNMTs activity can prevent the female-to-male sex transition, suggesting that methylation reprogramming is required for zebrafish sex transition. In summary, DNA methylation plays important roles in zebrafish germline development and sexual plasticity.

developmental biology↗

bioRxiv2020

1RS.1BL molecular resolution provides novel contributions to wheat improvement

Wheat-rye 1RS.1BL translocation has a significant impact on wheat yield and hence food production globally. However, the genomic basis of its contributions to wheat improvement is undetermined. Here, we generated a high-quality assembly of 1RS.1BL translocation comprising 748,715,293 bp with 4,996 predicted protein-coding genes. We found the size of 1RS is larger than 1BS with the active centromere domains shifted to the 1RS side instead of the 1BL side in Aikang58 (AK58). The gene alignment showed excellent synteny with 1BS from wheat and genes from 1RS were expressed well in wheat especially for 1RS where expression was higher than that of 1BS for the grain-20DPA stage associated with greater grain weight and negative flour quality attributes. A formin-like-domain protein FH14 (TraesAK58CH1B01G010700) was important in regulating cell division. Two PPR genes were most likely the genes for the multi fertility restoration locus Rf multi. Our data not only provide the high-resolution structure and gene complement for the 1RS.1BL translocation, but also defined targets for enhancing grain yield, biotic and abiotic stress, and fertility restoration in wheat.

genomics↗

bioRxiv2020

Ultrafast contour imaging for time-domain diffuse optical tomography

Diffuse optical tomography (DOT) is well known to be ill-posed and suffers from a poor resolution. While time domain DOT can bolster the resolution by time-gating to extract weakly scattering photons, it is often confronted by an inferior signal to noise ratio and a low measurement density. This is particularly problematic for non-contact DOT imaging of non-planar objects, which faces an inherent tradeoff between the light collection efficiency and depth of field. We present here ultrafast contour imaging, a method that enables efficient light collection over curved surfaces with a dense spatiotemporal sampling of diffused light, allowing DOT imaging in the objects native geometry with an improved resolution. We demonstrated our approach with both phantom and small animal imaging results. (C)2020 Optical Society of America

bioengineering↗

bioRxiv2020

When and why an essential popular mineral-calcium-is an effective antifungal adjuvant against the human pathogen?

In eukaryotes, calcium not only is an essential mineral nutrient but also serves as an intracellular second messenger that is necessary for many physiological processes. Here, we show that exogenous calcium is toxic when fungal cells lack functional calcineurin, a calcium-dependent protein phosphatase that acts as the central regulator of the calcium signaling pathway. By monitoring intracellular calcium, particularly by tracking vacuolar calcium dynamics in living cells through a novel procedure using modified aequorin, we found that calcineurin dysfunction perturbed calcium homeostasis in intracellular compartments including the cytosol, mitochondria, and vacuole, leading to drastic autophagy global organelle fragmentation, and even lastly resulting in cell death upon an extracellular calcium stimulus. Notably, the defective phenotypes seen with calcineurin mutants can be significantly suppressed by alleviating a cytosolic calcium overload or increasing vacuolar calcium storage capacity, suggesting toxicity of exogenous calcium to calcineurin mutants is tightly associated with abnormal cytosolic calcium accumulation and vacuolar calcium storage capacity deficiency. Our findings provide insights into how calcineurin regulates intracellular calcium homeostasis for cell survival and may have important implications for antifungal therapy and clinical drug administration.

microbiology↗

bioRxiv2020

Designed Variants of Recombinant ACE2-Fc that Decouple Anti-SARS-CoV-2 Activities from Unwanted Cardiovascular Effects

Angiotensin-converting enzyme 2 (ACE2) is the entry receptor for SARS-CoV-2, and recombinant ACE2 decoys are being evaluated as new antiviral therapies. We designed and tested an antibody-like ACE2-Fc fusion protein, which has the benefit of long pharmacological half-life and the potential to facilitate immune clearance of the virus. Out of a concern that the intrinsic catalytic activity of ACE2 may unintentionally alter the balance of its hormonal substrates and cause adverse cardiovascular effects in treatment, we performed a mutagenesis screening for inactivating the enzyme. Three mutants, R273A, H378A and E402A, completely lost their enzymatic activity for either surrogate or physiological substrates. All of them remained capable of binding SARS-CoV-2 and could suppress the transduction of a pseudotyped virus in cell culture. This study established new ACE2-Fc candidates as antiviral treatment for SARS-CoV-2 without potentially harmful side effects from ACE2s catalytic actions toward its vasoactive substrates.

biochemistry↗

bioRxiv2020

High-speed compressed-sensing fluorescence lifetime imaging microscopy of live cells

We present high-resolution, high-speed fluorescence lifetime imaging microscopy (FLIM) of live cells based on a compressed sensing scheme. By leveraging the compressibility of biological scenes in a specific domain, we simultaneously record the time-lapse fluorescence decay upon pulsed laser excitation within a large field of view. The resultant system, referred to as compressed FLIM, can acquire a widefield fluorescence lifetime image within a single camera exposure, eliminating the motion artifact and minimizing the photobleaching and phototoxicity. The imaging speed, limited only by the readout speed of the camera, is up to 100 Hz. We demonstrated the utility of compressed FLIM in imaging various transient dynamics at the microscopic scale.

bioengineering↗

bioRxiv2020

Development and validation of a six-RNA binding proteins prognostic signature and candidate drugs for prostate cancer

The dysregulation of RNA binding proteins (RBPs) play critical roles in the progression of several cancers. However, the overall functions of RBPs in prostate cancer (PCa) remain poorly understood. Therefore, we first identified 144 differentially expressed RBPs in tumors compared to normal tissues based on the TCGA dataset. Next, six RBP genes (MSI1, MBNL2, LENG9, REXO2, RNASE1, PABPC1L) were screened out as prognosis hub genes by univariate, LASSO and multivariate Cox regression and used to establish the prognostic signature. Further analysis indicated that high risk group was significantly associated with poor RFS, which was validated in the MSKCC cohort. Besides, patients in high risk group was closely associated with dysregulation of DNA damage repair pathway, copy number alteration, tumor burden mutation and low-respond to cisplatin (P < 0.001), bicalutamide (P < 0.001). Finally, three drugs (ribavirin, carmustine, carbenoxolone) were predicted using Connectivity Map. In summary, we identified a six-RBP gene signature and three candidate drugs against PCa, which may promote the individualized treatment and further improve the life quality of PCa patients.

genomics↗

bioRxiv2020

Genome of Solanum pimpinellifolium provides insights into structural variants during tomato breeding

Solanum pimpinellifolium (SP) is the wild progenitor of cultivated tomato. Because of its remarkable stress tolerance and intense flavor, SP has been used as an important germplasm donor in modern breeding of tomato. Here we present a high-quality chromosome-scale genome sequence of SP LA2093. Genome comparison identifies more than 92,000 high-confidence structural variants (SVs) between LA2093 and the modern cultivar, Heinz 1706. Genotyping these SVs in ~600 representative tomato accessions unravels alleles under selection during tomato domestication, improvement and modern breeding, and discovers numerous novel SVs underlying genes known to regulate important breeding traits such as fruit weight and lycopene content. Expression quantitative trait locus (eQTL) analysis detects hotspots harboring master regulators controlling important fruit quality traits, including cuticular wax accumulation and flavonoid biosynthesis, and novel SVs contributing to these complex regulatory networks. The LA2093 genome sequence and the identified SVs provide rich resources for future research and biodiversity-based breeding.

genomics↗

bioRxiv2020

C3: Connect separate Connected Components to form a succinct disease module

Accurate disease module is helpful in understanding the molecular mechanism of disease causation and identifying drug target. However, for the fragmentization of disease module in incomplete human interactome, how to determine connectivity pattern and detect a full neighbourhood of disease is an open problem. In this paper, a topology-based method is developed to dissect the connectivity of intermediate nodes and edges and form a succinct disease module. By applying this Connect separate Connected Components (CCC, C3) method on a large corpus of curated diseases, we find that most Separate Connected Components (SCCs) formed by Disease-Associated Proteins (DAPs) can be connected into a well-connected component as a succinct observable module. This pattern also holds for altered genes from multi-omics data such as The Cancer Genome Atlas. Overall, C3 tool can not only inspire a deeper understanding of interconnectedness of phenotypically related genes and different omics data, but also be used to detect a well-defined neighbourhood that drives complex pathological processes.

bioinformatics↗

bioRxiv2020

An exploratory rehearsal on AIE dots assisted NIR-II fluorescence non-human primates imaging

Superb reliability and biocompatibility equip aggregation-induced emission (AIE) dots with tremendous potential for fluorescence bioimaging. However, there is still a chronic lack of design instructions of excretable and bright AIE emitters. Here, we designed a kind of PEGylated AIE (OTPA-BBT) dots with strong absorption and extremely high NIR-II PLQY as 13.6%, and proposed the long-aliphatic-chain design blueprint contributing to their excretion from animal body. Assisted by the OTPA-BBT dots with bright fluorescence beyond 1100 nm and even 1500 nm (NIR-IIb), large-depth cerebral vasculature (beyond 600 m) as well as real-time blood flowing were monitored through-thinned-skull, and noninvasive NIR-IIb imaging with rich high-spatial-frequency information gave a precise presentation of gastrointestinal tract in marmosets. Importantly, after intravenous or oral administration, the definite excretion of OTPA-BBT dots from the body was demonstrated, which showed an influential evidence of bio-safety.

bioengineering↗