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Chang, Q.

Publications and source records attributed to Chang, Q..

At least 19 recordsLinked to original sources

Early development of cerebellar functional connectivity

The cerebellum makes a critical contribution to cognitive and behavioural function, extending well beyond motor control, and is recognised as an important determinant of neurodevelopmental outcome. Despite this, little is known about the foundations of cerebellar functional organisation in early life. Addressing this gap is essential for establishing typical developmental trajectories against which atypical development can be assessed. Here, we analysed fMRI data from term-born neonates (n=155) scanned between 37 and 44 weeks postmenstrual age and mapped intra-cerebellar and cerebro-cerebellar functional connectivity across multiple levels of organisation. We identified 13 intrinsic connectivity networks (ICNs) within the neonatal cerebellum that recapitulated adult subdivisions, with two ICNs showing age-related increases in coverage and strength. Analysis of cerebro-cerebellar connectivity identified 15 sensory, motor and association cerebral clusters, seven increasing connectivity with age. Functional gradient analysis identified a continuous axis from somatomotor to association regions within intra-cerebellar and cerebro-cerebellar organisation, which became more pronounced with age. Together, these findings suggest that the foundations of adult cerebellar functional organisation are present at birth but undergo rapid and regionally heterogeneous maturation over the first weeks of postnatal life. This developmental framework provides a normative reference for understanding cerebellar development and its implications for later neurodevelopmental variation.

neuroscience↗

Development of Neonatal Functional Brain Network Organisation and Its Association with Childhood Neurodevelopmental Outcomes

The human brain undergoes rapid dynamic changes in the neonatal period that are essential for later cognitive and behavioural performance. Using resting-state fMRI data from 394 neonates (325 term-born, 69 preterm-born) within the first month after birth, we characterised the early development of functional network organisation, the effects of preterm birth, and the association between neonatal functional organisation and later neurodevelopmental outcomes in infancy (18 months) and childhood (4-6 years). We found increased functional integration and segregation across a wide range of functional sub-networks and increased mean functional connectivity strength (mean FCS) within the subcortical and cerebellar regions with increasing PMA at scan. Compared with term-born neonates, preterm-born neonates showed significantly lower mean FCS, functional integration and segregation globally. We further showed that whilst neonatal functional brain network organisation was not associated with neurodevelopmental outcomes measured during infancy (18 months), it was associated with later neurodevelopmental outcomes in early childhood (4-6 years). Specifically, higher functional integration and segregation at birth were linked with lower SDQ total difficulties score at 4-6 years. Our findings suggest that neonatal functional brain organisation reflects not only transient developmental processes, but also stable individual differences that provide insight into neurodevelopmental outcomes in later childhood.

neuroscience↗

Emergence of long- and short-range functional connectivity shapes neonatal brain gradients

The emergence of macroscale brain organisation during the perinatal period represents a critical but poorly understood process. Using resting-state fMRI in 325 term-born neonates within the first month of postnatal life, we characterised the early emergence of macroscale brain organisation with functional gradients. Neonatal functional gradients showed a distinct pattern compared with the canonical adult gradients: the principal gradient in neonates, separating the primary sensorimotor and visual networks, corresponded to the secondary gradient in adults (sensorimotor-visual axis), whereas the secondary gradient in neonates, spanning from primary visual to association networks, aligned with the principal gradient in adults (sensorimotor-association axis). We identified distance-dependent functional connectivity as a key mechanism shaping perinatal functional gradients and potentially underlying the protracted development of the sensorimotor-association hierarchy in neonates. Regions with a higher proportion of short-range functional connectivity contributed more to the sensorimotor-visual gradient in neonates, while regions with a greater proportion of middle-to long-range functional connectivity drive the sensorimotor-association hierarchy. Together, these findings highlight the critical role of short- and long-range functional connectivity in shaping neonatal macroscale functional hierarchy. Disruptions to this process during the perinatal period may alter macroscale brain organisation and contribute to the early origins of neurodevelopmental conditions. Significance statementMacroscale brain organisation, characterised by functional gradients, is a fundamental feature of the adult brain and is closely linked to neurodevelopmental conditions. Characterising its emergence in early life and the underlying mechanisms is therefore critical for understanding typical and atypical brain development. Here, we showed that macroscale brain organisation is present at birth, with neonatal functional gradients showing a reversed pattern compared to adults, highlighting the early maturation of primary visual and sensorimotor networks. We further demonstrated that the perinatal development of long- and short-range functional connectivity shapes neonatal functional gradients, identifying a potential mechanism through which early disruptions in functional connectivity may contribute to later neurodevelopmental outcomes.

neuroscience↗

Periosteal and periarticular compartments house lymphatic vessels in bone

The anatomical localization of lymphatic vessels in bone remains controversial and has led to conflicting interpretations of skeletal lymphatic function. Here we assessed lymphatic identity and localization in bone using mouse genetic labeling, tissue clearance, and three-dimensional imaging. We analyzed long bones after extensive periosteum removal and identified Vegfr3+ blood vessels lacking Lyve1 expression within bone marrow, whereas Vegfr3+Lyve1+ lymphatic vessels were confined to residual periosteal regions. Genetic lineage tracing using Prox1-Cre/ER;mScarlet further confirmed that lymphatic vessels are absent from long bone marrow and restricted to periosteal compartments, particularly in fibrous but not cambial layers. Extending these analyses to the mandible, we observed Vegfr3+Lyve1+ lymphatic vessels localized to periarticular soft tissues surrounding the temporomandibular joint (TMJ), while mandibular bone marrow contained only Vegfr3+Lyve1- blood vessels and lacked Prox1 lineage-traced lymphatic vessels. Together, these findings establish that lymphatic vessels in bone are confined to periosteal and periarticular compartments and absent from bone marrow, providing a framework for interpreting lymphatic contributions to skeletal physiology and disease.

cell biology↗

ClumPyCells resolves spatial aggregation in complex tissues overcoming size biases

The spatial arrangement of cells within a tissue microenvironment shapes their interactions and cell states, which are essential for tissue development, homeostasis, and disease. Spatial -omics technologies can precisely map the location of each cell within complex tissue structures, while also profiling their protein content and transcriptional diversity. Various approaches have been developed to analyze spatial patterns of cell aggregation, repulsion, or random distribution within tissues. However, differences in cell morphology within a tissue can introduce significant bias. Cell size in particular is not accounted for and introduces challenges when quantifying the aggregation of cells or their molecular features. To overcome such limitations, we present ClumPyCells: a statistical framework that measures cell and marker aggregation within tissue while correcting for size morphology. ClumPyCells enables interpretation of cell aggregation, bypassing interfering cell types or tissue regions unrelated to the desired spatial correlation. We demonstrate the capabilities of ClumPyCells across several tumor types, including melanoma and colorectal cancer, and spatial -omics technologies such as spatial transcriptomics and proteomics, while benchmarking how cell-size differences contribute to misinterpretations. By correcting for disruptive cell types within a region of interest, ClumPyCells will determine new tissue patterns and structures without morphological interference.

bioinformatics↗

Extracellular matrix regulates lineage plasticity in prostate cancer through YAP/TEAD

Treatment-related neuroendocrine prostate cancer (NEPC) is an increasingly frequent mechanism of resistance to androgen receptor pathway inhibitor (ARPI) therapy in prostate adenocarcinoma (PRAD). This lineage transition is dependent on upregulation of the NE-specifying transcription factor ASCL1, typically in a genetic background of RB1 and TP53 loss. Here we identify extracellular matrix-integrin-YAP1/TEAD signaling as a critical brake on NEPC lineage transition. Deletion of Itgb1, the shared B1 subunit required for collagen and laminin-mediated integrin activation, is sufficient to induce ASCL1 and NE lineage gene expression, by activating LATS1/2 kinases with subsequent inactivation of YAP1/TEAD signaling. Conversely, restoration of YAP1/TEAD signaling by pharmacological LATS1/2 inhibition, or by expression of constitutively active YAP1/TAZ mutants, prevents or reverts NEPC lineage transition. NOTCH and AR cooperate with YAP/TEAD to repress ASCL1, such that combined inhibition leads to complete reprograming of PRAD into NEPC in vitro, providing a dynamic platform to dissect the molecular events responsible for lineage transition over time. We find that lineage transition is accompanied by a redistribution of FOXA1 and TEAD cistromes from PRAD to NEPC-specific enhancers and requires the pioneering activity of FOXA1. Thus, extracellular matrix/integrin signaling in the PRAD tumor microenvironment restrains NE lineage plasticity, highlighting a potential path for pharmacological inhibitors in modulating treatment-induced lineage change.

cancer biology↗

Syntactic Processing Engages the Semantic Control Network

The relationship between semantics and syntax is highly contested. Neuroimaging evidence has offered conflicting views on whether these domains are neurally separable, in part because prior work has not distinguished two key components of semantic cognition: semantic representation and semantic control. In this study, we conducted an activation likelihood estimation (ALE) meta-analysis to identify regions consistently engaged by more versus less demanding syntactic processing, and compared these directly with regions recruited by demanding versus less demanding semantic processing. Demanding syntactic processing engaged regions across the semantic control network (SCN), including the inferior frontal gyrus (IFG) and insula (particularly on the left), left posterior temporal cortex (posterior superior temporal sulcus and middle temporal gyrus), and bilateral dorsomedial prefrontal cortex. No regions outside the SCN responded significantly more to syntactic demands than semantic control. Within the SCN, there was significantly less reliable activation for syntactic than semantic control demands in some anterior (pars triangularis) and ventral (pars orbitalis) portions of the left IFG and a region in posterior fusiform and inferior temporal gyrus. Greater involvement for syntax than semantic control was identified in a small region of posterior left IFG (pars opercularis) within the SCN. Moreover, both controlled semantic and syntactic processing showed multimodal responses to auditory and visual stimuli in the left IFG and posterior temporal cortex. Together, these findings suggest that syntactic processing is distinct from semantic representation, yet demanding syntax engages portions of the SCN, reflecting a shared need to access and manipulate stored semantic knowledge for flexible, context-sensitive use.

neuroscience↗

Circulating extracellular vesicles from HIV-1 gp120-treated mice act as endogenous algogens, mediating and maintaining HIV-associated chronic pain

HIV-associated chronic pain (HIV-PAIN) remains prevalent in the post combined antiretroviral therapy era, affecting 30-60% of HIV patients worldwide. The underlying mechanism responsible for the development and maintenance of chronic pain remains unclear. gp120 is a causal factor of the HIV-PAIN and functions as an exogenous algogen. The pain experienced by human HIV-PAIN has been modeled in mice (referred to as mHIV-PAIN) using intrathecal (i.t.) injections of gp120. gp120 is a relatively short-term, static, exogenous algogen that is exhaustible in vivo. In authentic infection, HIV virions serve as the primary source of exogenous gp120, which initiates the early phase of clinical HIV-PAIN. Interestingly, while the source of replenishing gp120 decreases after antiretroviral therapy by suppressing viremia, the prevalence of chronic HIV-PAIN remains stable. To induce chronic pain in mice, gp120 needs to be repeatedly applied by the i.t. route. This raises a key question: Is an endogenous inexhaustible algogen responsible for maintaining the chronicity of HIV-PAIN? In the present study, we isolated circulating small extracellular vesicles (sEV) from mice using our mHIV-PAIN model that is i.t. injected with gp120. We refer to such sEV as gp120-sEV herein. We observed that gp120 is absent in gp120-sEV. Following transfusion of gp120-sEV intrathecally, naive recipient mice exhibit an extensive pain phenotype, including cold pain tested with we newly invented dry ice vapor cold test. RNA-sequence analysis suggests that gp120-sEVs induced expression of genes related to nociception and neuroinflammation pathways. These findings provide direct evidence that circulating sEV function as endogenous long-term "dynamic" algogens that enhance initial pain and extend the chronification of HIV-PAIN in mice, suggesting that chronic HIV-PAIN requires an exogenous algogen (gp120) paired with endogenous algogen (gp120-sEV), and that these components work synchronically to initiate and extend pain chronification. This double algogen concept provides a new insight into the pathogenesis of HIV-PAIN chronification. Our new mechanistic understanding will also assist in identifying new therapeutics to alleviate HIV-PAIN by targeting pathological gp120-sEV.

neuroscience↗

General model with biclustering for target selection in severe preeclampsia

Preeclampsia is a complex and multifactorial disease and a leading cause of death in pregnancy with no current effective treatment strategies, especially severe preeclampsia. A new general regression model with biclustering scalability is developed to quantify causal relationship from genes to gene products to clinical phenotypes among multiple datasets. It can identify those key genes and relationships between gene expression and clinical phenotype, which will be interpreted further, for molecular mechanism disclosure and effective drug development by pathway enrichment analysis. We observed pattern variation of gene expression relating to clinical phenotype among three preeclampsia datasets in parallel. Eighty-one genes are recommended as potential druggable targets for severe preeclampsia by their highly correlation between gene expression variation with preeclampsia clinical phenotypes in hypertension, HELLP (Hemolysis, Elevated Liver enzymes and Low Platelets) syndrome, proteinuria, and gestation week. Genes ENG, Flt and NEU1 and NEU2 show overexpression in severe preeclampsia in attenuating hypertension and proteinuria in multiple datasets of preeclampsia. Those genes are involved in the angiogenic factors and vascular molecular function. Treatment with either Flt or NEU1 have exciting clinical implications, and likely will transform the detection and treatment for patients with severe preeclampsia. The novel network mathematical models can quantify a causal relationship from genes to gene products to clinical phenotypes, and they can model causal influences of genes that are either monomorphic or polymorphic among heterology datasets, which is suggesting that key gene expression variation may be more likely to influence complex clinical phenotype variation in preeclampsia among multiple datasets.

bioinformatics↗

NeuroTD: A Time-Frequency Based Multimodal Learning Approach to Analyze Time Delays in Neural Activities

Studying the temporal dynamics of neural activities is essential for understanding how neurons function. These dynamics often involve temporal delays between neurons that vary over time, revealing both their functions and how they interact within circuits. Recent techniques such as Neuropixels, depth electrodes, and Patch-seq enable time-series recordings of neural activity at various scales, ranging from single neurons to large populations. However, inferring such time-varying delays remains challenging due to noise, high sampling rates, and complex temporal patterns. To address these challenges, we developed NeuroTD, a novel computational approach based on sliding windows to align time-series datasets and infer time-varying delays. Particularly, NeuroTD integrates adaptive window-size tuning to obtain optimal and robust delay estimates. We first benchmarked NeuroTD in simulation studies, demonstrating its robustness and outperformance. Then we applied it to two emerging real-world datasets: (i) intracranial multi-channel electrophysiological recordings from depth electrodes across medial temporal lobe regions in humans, showing that hippocampal signals recorded via depth electrodes exhibited consistently significantly longer time delays than other regions during working memory tasks, and (ii) Patch-seq data in the mouse motor cortex, revealing intrinsic electro-physiological time-delays of excitatory neurons correlated with gene expression and highlighting pathways related to ion transport and neuronal excitability. Finally, NeuroTD is open-source and available at https://github.com/daifengwanglab/NeuroTD for general use.

bioinformatics↗

eIF4A controls translation of estrogen receptor alpha and is a therapeutic target in advanced breast cancer

The majority of human breast cancers are dependent on hormone-stimulated estrogen receptor alpha (ER) and are sensitive to its inhibition. Treatment resistance arises in most advanced cancers due to genetic alterations that promote ligand independent activation of ER itself or ER target genes. Whereas re-targeting of the ER ligand binding domain (LBD) with newer ER antagonists can work in some cases, these drugs are largely ineffective in many genetic backgrounds including ER fusions that lose the LBD or in cancers that hyperactivate ER targets. By identifying the mechanism of ER translation, we herein present an alternative strategy to target ER and difficult to treat ER variants. We find that ER translation is cap-independent and mTOR inhibitor insensitive, but dependent on 5 UTR elements and sensitive to pharmacologic inhibition of the translation initiation factor eIF4A, an mRNA helicase. EIF4A inhibition rapidly reduces expression of ER and short-lived targets of ER such as cyclin D1 and other components of the cyclin D-CDK complex in breast cancer cells. These effects translate into suppression of growth of a variety of ligand-independent breast cancer models including those driven by ER fusion proteins that lack the ligand binding site. The efficacy of eIF4A inhibition is enhanced when it is combined with fulvestrant--an ER degrader. Concomitant inhibition of ER synthesis and induction of its degradation causes synergistic and durable inhibition of ER expression and tumor growth. The clinical importance of these findings is confirmed by results of an early clinical trial (NCT04092673) of the selective eIF4A inhibitor zotatifin in patients with estrogen receptor positive metastatic breast cancer. Multiple clinical responses have been observed on combination therapy including durable regressions. These data suggest that eIF4A inhibition could be a useful new strategy for treating advanced ER+ breast cancer.

cancer biology↗

ERK Activation by BRAFV600E suppresses mesenchymal migration and tumorigenesis by inhibiting RAC1.

BRAFV600E mutation occurs in 46% of melanomas and drives high levels of ERK activity and ERK-dependent proliferation. However, BRAFV600E is insufficient to drive melanoma in GEMM models, and 82% of human benign nevi harbor BRAFV600E mutations. We show here that BRAFV600E inhibits mesenchymal migration by causing feedback inhibition of RAC1 activity. ERK pathway inhibition induces RAC1 activation and restores migration and invasion. In cells with BRAFV600E, mutant RAC1, overexpression of PREX1, PREX2, or PTEN inactivation restore RAC1 activity and cell motility. Together, these lesions occur in 48% of BRAFV600E melanomas. Thus, although BRAFV600E activation of ERK deregulates cell proliferation, it prevents full malignant transformation by causing feedback inhibition of cell migration. Secondary mutations are, therefore, required for tumorigenesis. One mechanism underlying tumor evolution may be the selection of lesions that rescue the deleterious effects of oncogenic drivers. Statement of significanceBRAFV600E activation of ERK causes feedback inhibition of cell migration and invasion and thus blocks tumorigenesis. Secondary genetic lesions are required to rescue these processes and enable tumor development. Thus, oncogenic feedback can shape the details of tumor progression and, in doing so, selects for new mutations that may be therapeutic targets.

cancer biology↗

Synergistic activity of rhamnolipid combined with linezolid against linezolid-resistant Enterococcus faecium

Enterococci resistance is increasing sharply, which poses a serious threat to public health. Rhamnolipids are a kind of amphiphilic compound used for its bioactivities, while the combination of nontraditional drugs to restore linezolid activity is an attractive strategy to treat infections caused by these pathogens. This study aimed to investigate the activity of linezolid in combination with the rhamnolipids against Enterococcus faecium. Here, we determined that the rhamnolipids could enhance the efficacy of linezolid against enterococci infections by a checkerboard MIC assay, a time-kill assay, a combined disk test, anti-biofilm assay, molecular simulation dynamics, and mouse infection models. We identified that the combination of rhamnolipids and linezolid restored the linezolid sensitivity. Anti-biofilm experiments show that our new scheme can effectively inhibit biofilm generation. The mouse infection model demonstrated that the combination therapy significantly reduced the bacterial load in the feces, colons and kidneys following subcutaneous administration. This study showed that rhamnolipids could play a synergistic role with linezolid against Enterococcus. Our combined agents could be appealing candidates for developing new combinatorial agents to restore antibiotic efficacy in the treatment of linezolid-resistant Enterococcus infections. HighlightThe identification of a potential inhibitor of LRE, RLS could restore the antibacterial activity of LNZ. A rational mechanism of synergism between LNZ and RLS. ;;L;;RLS in combination with LNZ promote the egress of pathogenic E. faecium from the intestinal tract of mice to reduce its colonization, which has obvious synergistic effects.

microbiology↗

Multimodal analysis of neuronal maturation in the developing primate prefrontal cortex

The prefrontal cortex (PFC) is critical for myriad high-cognitive functions and is associated with several neuropsychiatric disorders. Here, using Patch-seq and single-nucleus multiomic analyses, we identified genes and regulatory networks governing the maturation of distinct neuronal populations in the PFC of rhesus macaque. We discovered that specific electrophysiological properties exhibited distinct maturational kinetics and identified key genes underlying these properties. We unveiled that RAPGEF4 is important for the maturation of resting membrane potential and inward sodium current in both macaque and human. We demonstrated that knockdown of CHD8, a high-confidence autism risk gene, in human and macaque organotypic slices led to impaired maturation, via downregulation of key genes, including RAPGEF4. Restoring the expression of RAPGEF4 rescued the proper electrophysiological maturation of CHD8-deficient neurons. Our study revealed regulators of neuronal maturation during a critical period of PFC development in primates and implicated such regulators in molecular processes underlying autism.

neuroscience↗

Circulating exosomes from Alzheimer's disease suppress VE-cadherin expression and induce barrier dysfunction in recipient brain microvascular endothelial cell

BackgroundBlood-brain barrier (BBB) breakdown is a component of the progression and pathology of Alzheimers disease (AD). BBB dysfunction is primarily caused by reduced or disorganized tight junction or adherens junction proteins of brain microvascular endothelial cell (BMEC). While there is growing evidence of tight junction disruption in BMECs in AD, the functional role of adherens junctions during BBB dysfunction in AD remains unknown. Exosomes secreted from senescent cells have unique characteristics and contribute to modulating the phenotype of recipient cells. However, it remains unknown if and how these exosomes cause BMEC dysfunction in AD. ObjectivesThis study aimed to investigate the potential roles of AD circulating exosomes and their RNA cargos in brain endothelial dysfunction in AD. MethodsWe isolated exosomes from sera of five cases of AD compared with age- and sex-matched cognitively normal controls using size-exclusion chromatography technology. We validated the qualities and particle sizes of isolated exosomes with nanoparticle tracking analysis and atomic force microscopy. We measured the biomechanical natures of the endothelial barrier of BMECs, the lateral binding forces between live BMECs, using fluidic force miscopy. We visualized the paracellular expressions of the key adherens junction protein VE-cadherin in BMEC cultures and a 3D BBB model that employs primary human BMECs and pericytes with immunostaining and evaluated them using confocal microscopy. We also examined the VE-cadherin signal in brain tissues from five cases of AD and five age- and sex-matched cognitively normal controls. ResultsWe found that circulating exosomes from AD patients suppress the paracellular expression levels of VE-cadherin and impair the barrier function of recipient BMECs. Immunostaining analysis showed that AD circulating exosomes damage VE-cadherin integrity in a 3D model of microvascular tubule formation. We found that circulating exosomes in AD weaken the BBB depending on the RNA cargos. In parallel, we observed that microvascular VE-cadherin expression is diminished in AD brains compared to normal controls. ConclusionUsing in vitro and ex vivo models, our study illustrates that circulating exosomes from AD patients play a significant role in mediating the damage effect on adherens junction of recipient BMEC of the BBB in an exosomal RNA-dependent manner. This suggests a novel mechanism of peripheral senescent exosomes for AD risk.

neuroscience↗

Integrated Cell Landscape and Dynamics in the Progression of Bone Repair

Bone homeostasis and repair is a systematic progress with spatiotemporal interaction of multiple cell types involved in skeletal and immune system. Precise spatiotemporal regulation of cell type-specific functions in bone repair contributes to further development of tissue engineering and regenerative medicine. Here, we utilized single-cell RNA sequencing to illustrate a map of cell landscape and dynamics in the progression of rodent bone self-healing and a perturbation by lymphoid cell-deficiency. We identified different functions of myeloid cell and lymphoid cell to osteogenesis and angiogenesis during bone repair and their mutual complementation under lymphoid cell-deficient condition. Additionally, we used CD34+ humanized reconstituted mice to reveal further insights into the mechanism of human bone homeostasis and repair. Our integrated cellular analysis of bone repair explores the functional diversity and complementation between myeloid cells and lymphoid cells during bone healing process and provides further therapeutic implications for the treatment of bone disease and degeneration following ageing.

cell biology↗

Identification of common sequence motifs shared exclusively among selectively packed exosomal pathogenic microRNAs during rickettsial infections

We previously reported that microRNA (miR)23a and miR30b are selectively sorted into rickettsia-infected, endothelial cell-derived exosomes (R-ECExos). Yet, the mechanism remains unknown. The number of cases of spotted fever rickettsioses has been increasing in recent years, and infections with these bacteria cause life-threatening diseases by targeting brain and lung tissues. Therefore, the aim of the present study is to continue to dissect the molecular mechanism underlying R-ECExos-induced barrier dysfunction of normal recipient microvascular endothelial cells (MECs), depending on their exosomal RNA cargos. Rickettsiae are transmitted to human hosts by the bite of an infected tick into the skin. In the present study we demonstrate that treatment with R-ECExos, which were derived from spotted fever group R parkeri infected human dermal MECs, induced disruptions of the paracellular adherens junctional protein VE-cadherin and breached the paracellular barrier function in recipient pulmonary MECs (PMECs) in an exosomal RNA-dependent manner. Similarly, we did not detect different levels of miRs in parent dermal MECs following rickettsial infections. However, we demonstrated that the microvasculopathy-relevant miR23a-27a-24 cluster and miR30b are selectively enriched in R-ECExos. Bioinformatic analysis revealed that common sequence motifs are shared exclusively among the exosomal, selectively-enriched miR23a cluster and miR30b at different levels. Taken together, these data warrant further functional identification and characterization of a single, bipartition, or tripartition among ACA, UCA, and CAG motifs that guide recognition of microvasculopathy-relevant miR23a-27a-24 and miR30b, and subsequently results in their selective enrichments in R-ECExos.

molecular biology↗

RabbitVar: ultra-fast and accurate somatic small-variant calling on multi-core architectures

The continuous development of next-generation sequencing (NGS) technology has led to extensive and frequent use of genomic analysis in cancer research. The associated production of large-scale NGS datasets establishes the need for high-precision somatic variant calling methods that are highly optimized on commonly used hardware platforms. We present RabbitVar (https://github.com/LeiHaoa/RabbitVar), a scalable variant caller that can detect small somatic variants from paired tumor/normal NGS data on modern multi-core CPUs. Our approach combines candidate-finding and machine-learning-based filtering strategies with optimized data structures and multi-threading to achieve both high accuracy and efficiency. We have compared the performance of RabbitVar to leading state-of-the-art callers (Strelka2, Mutect2, NeuSomatic, VarDict, VarScan2) on real-world HCC1395 breast cancer datasets under different sequencing conditions and contamination rates. The evaluation results demonstrate that RabbitVar achieves highly competitive F1-scores when calling SNVs. Moreover, when calling the more challenging indel variants, it consistently achieves the highest F1-scores. RabbitVar is able to process a paired tumor and normal whole human genome sequencing datasets with 80x depth in less than 20 minutes on a 48-core workstation outperforming all other tested variant callers in terms of efficiency.

bioinformatics↗