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Ma, D.

Publications and source records attributed to Ma, D..

At least 37 records · Page 2Linked to original sources

Persistent interferon signaling and clonal expansion mark early events in DNA methylation damage-induced liver cancer

N-Nitrosodimethylamine (NDMA), a probable human carcinogen, induces toxic and mutagenic O6-methylguanine lesions that are repaired by the O6-methylguanine methyltransferase (MGMT). To elucidate mechanisms of NDMA-induced liver cancer progression, we performed longitudinal analyses of phenomic, transcriptomic, and phosphoproteomic changes in wild-type and MGMT-deficient mice, observing amplified responses in the deficient genotype. Early molecular rewiring indicative of a DNA damage response was detected by phosphoproteomic and transcriptomic profiling within days post-exposure. Transcriptomic analyses identified a persistent and robust interferon response as the dominant activated pathway. This chronic interferon signaling, which remained unresolved, correlated with extensive clonal expansion, an early hallmark of oncogenesis. Spatial transcriptomics further revealed pathway alterations favoring tumorigenesis within clonally expanded cells. These findings delineate the cascade of molecular events triggered by acute early-life NDMA exposure, culminating in cancer development months later. Our study unveils potential predictive biomarkers and strategies for disease mitigation.

cancer biology↗

PHLDA2 promotes breast cancer metastasis by co-opting a developmental program for placental vascular remodeling

Identifying drivers of metastasis is essential for developing new treatments for patients with advanced disease. Here, we identify PHLDA2 as a robust driver of breast cancer metastasis. Previous work established PHLDA2 as an imprinted gene expressed by trophoblasts which are critical for vascular remodeling during placental development. We find that hypomethylation of PHLDA2 in breast tumors correlates with increased gene expression, which is associated with metastasis and poor survival in breast cancer patients. RNA-sequencing showed that PHLDA2 overexpression results in upregulation of genes that control invasion, extracellular matrix assembly, and vascular remodeling, consistent with trophoblast functions in placental development. Using an in vitro vascularized microtumor (VMT) system, we find that PHLDA2 functions through SPARC, which promotes metastasis by inducing vascular permeability and enhancing tumor dissemination. These data suggest that increased expression of PHLDA2 through hypomethylation promotes metastasis by ectopic expression of a developmental program for vascular remodeling.

cancer biology↗

DAXX governs the silencing of LINE1 during spermatogenesis in mice

The suppression of transposable elements in germline is critical for safeguarding fertility. Here we identify that the DAXX, a potent transcription repressor and an H3.3 chaperone, is indispensable for transposable elements silencing during spermatogenesis. Male mice with conditional knockout of Daxx in germ cells mediated by Ddx4-cre display delayed meiotic progression, deformed and reduced production of sperms, and an age-dependent decline in fertility. The ablation of DAXX results in activation of evolutionarily young LINE1 and ERVs subfamilies. Mechanistically, DAXX interacts with DMAP1 to maintain DNA methylation of LINE1 in meiotic cells. In summary, this study identifies DAXX as a previously unknown regulator of spermatogenesis and demonstrates that it functions as an epigenetic regulator to maintain the silencing the young LINE1 by DNA methylation.

developmental biology↗

Methicillin-Resistant Staphylococcus aureus has Phenotypic Variation in mecA Expression that Alters Antibiotic Sensitivity

Methicillin resistant Staphylococcus aureus (MRSA) sepsis has a high rate of morbidity and mortality. Multiple clinical studies have demonstrated improved outcomes when MRSA sepsis is treated with dual antibiotic therapy that includes a {beta}-lactam antibiotic such as cefazolin. This is a paradox as MRSA should be inherently resistant to this class of antibiotics. We report a serendipitous observation revealed a phenotype where MRSA became sensitive to cefazolin when cultured in a physiologic relevant media of fetal bovine serum as well as in synovial fluid. This could be observed across multiple clinical isolates. Expected resistance was maintained when cultured in Muller Hinton Broth (MHB). MRSA {beta}-lactam antibiotic resistance is mediated by PBP2a, a penicillin-binding protein encoded by mecA. We hypothesized that this phenotype of antibiotic sensitivity in physiologic medium was based, in part, on levels of PBP2a expression and post-translational modifications of peptidoglycan wall teichoic acid (WTA). We therefore conducted quantitative RT-PCR analysis and Western blotting which demonstrated limited mecA expression in the mRNA level and limited PBP2a protein level when cultured in FBS or synovial fluid as compared to the clinical microbiology standard MHB, respectively. Whole genome sequencing of loss of function mutants generated through serial passaging in FBS revealed that the clp family of proteins and rpo genes were involved in {beta}-lactam resistance. Cell wall peptidoglycan analysis suggested that WTA glycosylation was altered between {beta}-lactam resistant and sensitive MRSA phenotypes. Together, this suggests pathways for clpP, rpoB, and WTA glycosylation can be new potential targets for MRSA treatment. IMPORTANCEThis study demonstrates that MRSA has phenotypic variation in mecA expression, PBP2a protein levels, and patterns of wall teichoic acid glycosylation based on environmental conditions which can result in a phenotype of {beta}-lactam antibiotic sensitivity. The presence of an antibiotic resistance gene does not necessarily result in antibiotic resistance. This provides a possible explanation for the clinical observations of potential therapeutic benefit of {beta}-lactam antibiotics in dual therapy treatment of MRSA sepsis and suggests new therapeutic strategies to combat multidrug resistant bacteria. More importantly, identifying genes potentially responsible for this phenotype offers new potential therapeutic targets for the treatment of multidrug resistant infection.

microbiology↗

Altered auditory maturation in Fragile X syndrome and its involvement in audiogenic seizure susceptibility

BackgroundAuditory hypersensitivity is a prominent symptom in Fragile X syndrome (FXS), the most prevalent monogenic cause of autism and intellectual disability. FXS arises through the loss of the protein encoded by the FMR1 (Fragile X Messenger Ribonucleoprotein 1) gene, FMRP, required for normal neural circuit excitability. In the brainstem, FMRP is necessary for normal development of acoustic reactivity, and its loss has been implicated in audiogenic seizures (AGS) in Fmr1 knockout (KO) mice, modelling auditory hypersensitivity and seizures in FXS patients. PurposeThe present study investigated the correlation between auditory brainstem function and behavioral expression of AGS at the early (postnatal day P20, infancy) and late (P32, juvenile) stage of auditory development in Fmr1 KO mice compared with wildtype (WT) mice, and in both females and males. MethodsWe tested responsiveness to pure tones of select auditory pathway elements through auditory brainstem responses; and neural synchronization to amplitude envelopes of modulated acoustic stimuli through auditory steady-state responses. AGS behavior was categorized for severity during 5-minute exposure to loud sound. Expression of the immediate early gene cFos was quantified as a marker for neuronal activity in the inferior colliculus. ResultsDuring infancy, more severe AGS expression in Fmr1 KO mice compared with WT mice was accompanied by increased responsiveness to acoustic stimuli at the level of the superior olivary complex and inferior colliculus, and stronger neural synchronicity in subcortical auditory neurons. Fmr1 KO mice also had higher cFos positive cell counts in the inferior colliculus after exposure to loud sound. With age, both AGS susceptibility and exaggerated acoustic stimulus-evoked activity in the Fmr1 KO mice subsided. Intriguingly, Fmr1 KO mice displayed altered developmental profile in both the threshold and amplitude of auditory brainstem response. ConclusionOur findings support evidence that AGS activity relies upon hyperexcitability in the auditory system, including in the lower brainstem, possibly due to disturbed auditory maturation. Hyper-synchronization to modulated sounds in subcortical auditory neurons seemed to predict AGS severity. A better understanding of FXS-related circuit and behavioral symptoms of auditory processing across development provides the potential to identify therapeutic strategies to achieve auditory function recovery in FXS.

neuroscience↗

Structural basis of phosphate export by human XPR1

Phosphate is essential for all life forms because of its indispensable roles in energy metabolism, nucleic acid and phospholipid synthesis, cellular signaling, and the formation of bones and teeth. Its homeostasis is maintained through balanced import and export processes. In humans, XPR1 has been proposed as the sole phosphate exporter, although some controversy remains. Here, we report the closed and open structures of human XPR1, purified in the absence and presence of exogenous InsP6, respectively. The exporter forms a symmetric homodimer, with transmembrane helix (TM) 1 serving as the dimeric interface. The transmembrane domain of each protomer contains a transport module (TM5-10) and a supporting module (TM1-4). Compared to the closed XPR1, the open structure demonstrates a significant displacement of the extracellular portion of TM9 towards the periphery of the phosphate transport pathway, creating an open portal to the extracellular milieu. Additionally, a potential phosphate ion coordination site is strategically located in the middle of the transport pathway. On the intracellular side, the pathway entrance is obstructed by a cluster of residues, the C-plug, positioned on the carboxyl side of TM10. Consistently, the removal of the C-terminus significantly increases the transport activity of XPR1 in reconstituted liposomes. Our findings provide a comprehensive understanding of the export mechanism of human XPR1 and hold promise for the development of potential therapeutics for primary familial brain calcification and ovarian cancer.

biochemistry↗

UltimateSynth: MRI Physics for Pan-Contrast AI

Magnetic resonance imaging (MRI) is commonly used in healthcare for its ability to generate diverse tissue contrasts without ionizing radiation. However, this flexibility complicates downstream analysis, as computational tools are often tailored to specific types of MRI and lack generalizability across the full spectrum of scans used in healthcare. Here, we introduce a versatile framework for the development and validation of AI models that can robustly process and analyze the full spectrum of scans achievable with MRI, enabling model deployment across scanner models, scan sequences, and age groups. Core to our framework is UltimateSynth, a technology that combines tissue physiology and MR physics in synthesizing realistic images across a comprehensive range of meaningful contrasts. This pan-contrast capability bolsters the AI development life cycle through efficient data labeling, generalizable model training, and thorough performance benchmarking. We showcase the effectiveness of UltimateSynth by training an off-the-shelf U-Net to generalize anatomical segmentation across any MR contrast. The U-Net yields highly robust tissue volume estimates, with variability under 4% across 150,000 unique-contrast images, 3.8% across 2,000+ low-field 0.3T scans, and 3.5% across 8,000+ images spanning the human lifespan from ages 0 to 100.

bioinformatics↗

Sociality shapes the adaptive response of breeders to harsh thermal environments? An experiment in a burying beetle

O_LIThe rapid pace of environmental change seems to outstrip the evolutionary response rates of many species. Physiological, morphological, and behavioral plasticity alone may also not suffice to cope with environments drastic changes, potentially hindering individuals ability to adapt. Therefore, it has been proposed that social flexibility may be a powerful mechanism for fast adaptation, but empirical evidence is lacking. C_LIO_LIWe investigated the combined effects of manipulated social conditions and ambient temperature during the reproductive phase on parental care, reproductive success, and offspring performance of the burying beetle (Nicrophorus vespilloides), a facultative social breeding insect. C_LIO_LIWe conducted a mixed factorial design experiment, establishing four categories of social conditions during breeding (no-care, unifemale-care, biparenta-care, and multiple-care) alongside two thermal conditions (benign: 20{degrees}C and harsh: 23{degrees}C). Additionally, dispersed larvae produced from each of these breeding conditions were allocated to climate rooms maintained at either 20{degrees}C or 23{degrees}C for pupation. Data on brood size, brood mass, dispersed larval weight, larval development duration, body size and lifespan of newly eclosed beetles, and parental care were collected C_LIO_LIOur results showed that (1) harsh temperature and the without-care condition (i.e., no-care compared to the other three social conditions) reduced brood size, brood mass, body size of newly eclosed beetles; (2) social and ambient thermal conditions had interactive effects on dispersed larval weight, larval development duration, and newly eclosed beetles lifespan; and (3) harsh temperature reduced both individual and total parental care, whereas sociality had opposing effects: individual care decreased, but total care increased from unifemale-care to biparental-care and multiple-care conditions. C_LIO_LIOur findings shed light on the critical role of sociality in modulating the adaptive response of individuals to harsh thermal environments, one of the ecological problems exacerbated by ongoing global warming. C_LI

evolutionary biology↗

Ecological and social factors lead to variation in parental care between sexes in a burying beetle

Sexual conflict over parental care represents a divergence in the evolutionary interests between males and females, consequently leading to distinct sex roles in parental care and reproductive strategies. However, whether and how various ecological and social environments influence such sex differences remains largely unclear. In the present study, using the burying beetles Nicrophorus vespilloides, we experimentally investigated the impacts of resource availability and inter- and intra-specific competition pressure on individual parental care and reproduction in males and females. We manipulated the resource availability for the breeding pairs by providing them with either large or small mouse carcasses, and constructed the presence of intra- and inter-specific competition, by introducing an additional, small pair of beetles and blowfly maggots Calliphora, respectively. We expected that males would decrease their parental care, while females would increase theirs, in response to smaller carcass. We also expected that the presence of intra- and inter-specific competition differentially affected the cares of males and females. We found that, compared to males and females breeding on large carcasses, males did not change their care, whereas females increased their care, when breeding on small carcasses. In the presence of another pair of adults, both males and females increased their parental care, whereas in the presence of blowfly maggots they both decreased their parental care. Our results showed that males and females adjust their parental care based on resource availability and competition pressure, with sex-specific differences driven by ecological and social factors. Our study sheds light on the importance of sex-specific parental care in response to various external drivers which contributes to a better understanding of the evolution of sex conflict over parental care.

animal behavior and cognition↗

Unveiling allopolyploidization-driven genome duplications through progressive analysis of deep genome skimming data

Whole-genome duplication (WGD) events are widespread across the Web of Life (WoL). Given the prevalence of WGDs in the polyploid Prunus (Rosaceae), this economically- and agriculturally-important angiosperm lineage provides an excellent model for exploring this mode of reticulation. We used the polyploid Prunus to demonstrate a progressive strategy for analyzing Deep Genome Skimming (DGS) data in the presence of WGDs. Phylogenomic discordance analyses indicated that allopolyploidization, rather than Incomplete Lineage Sorting (ILS), played a dominant role in the origin and dynamics of polyploid Prunus. This study underscores how a progressive strategy to identify WGD events at different depths in a phylogenetic tree reveals the nuances of evolutionary mechanisms driving allopolyploidization. We inferred that the continued uplift of the Himalayas from the Middle to Late Miocene drove the rapid diversification of the Eastern Asia endemic Maddenia clade, by facilitating frequent hybridization and allopolyploidization, specifically introgression between the Himalayas-Hengduan and the Central-Eastern China clades.

systems biology↗

Four SpsP neurons are an integrating sleep regulation hub in Drosophila

Sleep is an essential and conserved behavior, yet the mechanisms underlying sleep regulation remain largely unknown. To address the neural mechanisms of sleep drive, here we carry out whole brain calcium-modulated photoactivatable ratiometric integrator (CaMPARI) imaging of Drosophila and show that the activity of the protocerebral bridge (PB), a part of the central complex, correlates with sleep drive. Through a neural activation screen followed by anatomical and functional connectivity assays, we further narrow down the key player of sleep regulation in the PB to a three-layer circuit composed of 4 SpsP neurons and their upstream and downstream synaptic partners: the 4 SpsP neurons act as an integrating hub by responding to ellipsoid body (EB) signals from EPG neurons, and by sending signals back to the EB through PEcG neurons. Moreover, sleep deprivation enriches the presynaptic active zones of SpsP neurons and strengthens the connections of the EPG-SpsP-PEcG circuit, indicating plasticity gating in the circuit in response to sleep drive change. As the SpsP neurons also receive input from the sensorimotor brain region and given their known role in navigation, these neurons potentially further integrate sleep drive with other sensorimotor cues. The data taken together indicate that the four SpsP neurons and their sleep regulatory circuit play an important and dynamic role in sleep regulation.

neuroscience↗

DeepAge: Harnessing Deep Neural Network for Epigenetic Age Estimation FromDNA Methylation Data of human blood samples

Accurate prediction of biological age from DNA methylation data is a critical endeavor in understanding the molecular mechanisms of aging and developing age-related disease interventions. Traditional epigenetic clocks rely on linear regression or basic machine learning models, which often fail to capture the complex, non-linear interactions within methylation data. This study introduces DeepAge, a novel deep learning framework utilizing Temporal Convolutional Networks (TCNs) to enhance the prediction of biological age from DNA methylation profiles using selected CpGs by a Dual-Correlation based apparoach. DeepAge leverages a sequence-based approach with dilated convolutions to effectively capture long-range dependencies between CpG sites, addressing the limitations of prior models by incorporating advanced network architectures including residual connections and dropout regularization. The dual correlation feature selection enhances our models predictive capabilities by identifying the most age-relevant CpG sites. Our model outperforms existing epigenetic clocks across multiple datasets, offering significant improvements in accuracy and providing deeper insights into the epigenetic determinants of aging. The proposed method not only sets a new standard in age estimation but also highlights the potential of deep learning in biologically relevant feature extraction and interpretation, contributing to the broader field of computational biology and precision medicine.

bioinformatics↗

Unraveling the Web of Life: Incomplete lineage sorting and hybridization as primary mechanisms over polyploidization in the evolutionary dynamics of pear species

In contrast to the traditional Tree of Life (ToL) paradigm, the Web of Life (WoL) model provides a more nuanced and precise depiction of organismal phylogeny, particularly considering the prevalent incongruence observed among gene/species trees. The lack of a generalized pipeline for teasing apart potential evolutionary mechanisms--such as Incomplete Lineage Sorting (ILS), hybridization, introgression, polyploidization, and Whole-Genome Duplication--poses significant challenges to the delineation of the WoL. The pear genus Pyrus, characterized by extensive hybridization events, serves as an excellent model for investigating the WoL. This study introduces a novel Step-by-Step Exclusion (SSE) approach to deciphering the complexities inherent in the WoL. Our findings indicate: 1) ILS, rather than polyploidization, is identified as the primary driver behind the origin of Pyrus from the arid regions of the Himalayas-Central Asia; 2) the two subgenera of Pyrus have independent evolutionary trajectories, facilitated by the geographical barriers that arose via the uplift of the Tibetan Plateau and increased aridity in Central Asia; 3) ILS and hybridization have facilitated the diversification of Oriental pears, while hybridization alone has driven the reticulate evolution of Occidental pears; 4) the establishment of the Silk Road during the Han Dynasty acted as a conduit for genetic exchange between Occidental and Oriental pears. The novel SSE approach provides a universally applicable framework for investigating evolutionary mechanisms defining the WoL paradigm.

systems biology↗

Nanoscale organization is changed in native, surface AMPARs by mouse brain region and tauopathy

The distribution of synaptic and extra-synaptic AMPA receptors (AMPARs) on neuronal plasma membranes is correlated with learning and memory. Although AMPAR organization has been extensively studied in neuronal cultures, its native cell-surface distribution in intact adult brain tissue across distinct brain regions and in neurodegenerative pathology remains poorly understood. Here, we combine a selective small-molecule labeling strategy with two-color 3D super-resolution dSTORM imaging to map native surface AMPAR organization at the nanoscale in 30 micron thick mouse brain slices. We find that wild-type mice exhibit marked regional differences in AMPAR organization, with the CA1 hippocampus containing a substantially larger extrasynaptic AMPAR pool than the nearby motor and somatosensory cortex. In the PS19 tauopathy mouse model, at an age preceding overt neurodegeneration, AMPAR organization is selectively disrupted in the hippocampus but largely preserved in the cortex. Specifically, we observe depletion of the extrasynaptic receptor pool together with reduced synaptic nanodomain organization, revealing early molecular-scale synaptic remodeling associated with tau pathology. These findings provide direct structural insight into region- and disease-dependent AMPAR organization in intact adult brain tissue and establish a broadly applicable framework for nanoscale investigation of synaptic receptor architecture in health and neurological disease.

neuroscience↗

Comparison of black soldier fly, cricket, and superworm on growth performance, nutrient utilization and fatty acid profiles of rainbow trout

Inclusion of fishmeal and fish oil in feeds for farmed fish is not sustainable and alternatives need to be evaluated. The aim of this study was to determine the effect of diets including defatted black soldier fly larvae (Hermetia illucens), adult cricket (Gryllodes sigillatus) and superworm (Zophobas morio) on the growth performance, apparent nutrient digestibility, nutrient retention, and fatty acid profiles of juvenile rainbow trout (Oncorhynchus mykiss). Triplicate tanks of fish (100.5 {+/-} 0.6 g; mean {+/-} SD) were fed one of four diets, a control diet with 20% fishmeal, and three experimental diets containing either 15% defatted black soldier fly meal, 15% full-fat adult cricket meal or 15% full-fat superworm meal, where each insect meal partially replaced fishmeal and fish oil. After 84 days of feeding, no significant differences were observed between diets for growth performance indicators or body indices. Fish fed the control and superworm diets had a higher protein content and retention in whole-body carcass compared to the cricket and black soldier fly diet groups. No significant effects between diets were found on whole-body carcass regarding fatty acid classes SFA, MUFA, PUFA n-3 and PUFA n-6, although lauric acid and myristic acid were significantly higher in fish fed black soldier fly diet and linoleic acid was higher in fish fed superworm and cricket diets. Retention of fatty acids was higher for most classes in fish fed the black soldier fly diet, yet whole carcass lipid content did not differ significantly between diets. Additionally, apparent digestibility of phosphorous was significantly improved for all insect diets compared to the control. These results indicate that insect meals can partially replace fishmeal and fish oil in diets for rainbow trout without compromising growth performance and fatty acid composition, while improving phosphorous utilization.

physiology↗

SaprotHub: Making Protein Modeling Accessible to All Biologists

Training and deploying large-scale protein language models typically requires deep machine learning expertise -- a barrier for researchers outside this field. SaprotHub overcomes this challenge by offering an intuitive platform that facilitates training and prediction as well as storage and sharing of models. We provide the ColabSaprot framework built on Google Colab which potentially powers hundreds of protein training and prediction applications, enabling researchers to collaboratively build and share customized models.

bioinformatics↗

Biological activity of a stable 6-aryl-2-benzoyl-pyridine colchicine-binding site inhibitor, 60c, in metastatic, triple-negative breast cancer

BackgroundImproving survival for patients diagnosed with metastatic disease and overcoming chemoresistance remain significant clinical challenges in treating breast cancer. Triple-negative breast cancer (TNBC) is an aggressive subtype characterized by a lack of therapeutically targetable receptors (ER/PR/HER2). TNBC therapy includes a combination of cytotoxic chemotherapies, including microtubule-targeting agents (MTAs) like paclitaxel (taxane class) or eribulin (vinca class); however, there are currently no FDA-approved MTAs that bind to the colchicine-binding site. Approximately 70% of patients who initially respond to paclitaxel will develop taxane resistance (TxR). We previously reported that an orally bioavailable colchicine-binding site inhibitor (CBSI), VERU-111, inhibits TNBC tumor growth and treats pre-established metastatic disease. To further improve the potency and metabolic stability of VERU-111, we created next-generation derivatives of its scaffold, including 60c. Results60c shows improved in vitro potency compared to VERU-111 for taxane-sensitive and TxR TNBC models, and suppress TxR primary tumor growth without gross toxicity. 60c also suppressed the expansion of axillary lymph node metastases existing prior to treatment. Comparative analysis of excised organs for metastasis between 60c and VERU-111 suggested that 60c has unique anti-metastatic tropism. 60c completely suppressed metastases to the spleen and was more potent to reduce metastatic burden in the leg bones and kidney. In contrast, VERU-111 preferentially inhibited liver metastases and lung metastasis repression was similar. Together, these results position 60c as an additional promising CBSI for TNBC therapy, particularly for patients with TxR disease.

cancer biology↗

Genome sequencing of 'Fuji' apple clonal varieties reveals evolutionary history and genetic mechanism of the spur-type morphology

Somatic variations arising during asexual reproduction can lead to the emergence of bud sports exhibiting advantageous traits, forming the basis for bud sport breeding in perennial plants. Here, we report a near-complete, fully phased genome assembly of Fuji apple, enabling comprehensive identification of somatic variants across 74 clonally propagated Fuji varieties. Phylogenetic analysis of Fuji sport varieties indicates that the emergence of spur-type and early maturation traits results from multiple independent formation events. A number of putative functional somatic variants are identified, including one spur-type specific deletion located in the promoter of the TCP transcription factor gene MdTCP11. DNA methylation level of the deletion-associated miniature inverted-repeat transposable element is lower in the spur-type varieties compared to the standard-type varieties, while the expression of MdTCP11 is significantly higher. Overexpression of MdTCP11 in apple decreases the plant height, highlighting its important role in the development of spur-type apple varieties. This study sheds light on the 80-year cloning history of Fuji and provides valuable candidate causative mutations for apple breeding.

plant biology↗