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Zhao, Y.

Publications and source records attributed to Zhao, Y..

At least 685 records · Page 38Linked to original sources

DeepAIR: a deep-learning framework for effective integration of sequence and 3D structure to enable adaptive immune receptor analysis

Structural docking between the adaptive immune receptors (AIRs), including T cell receptors (TCRs) and B cell receptors (BCRs), and their cognate antigens is one of the most fundamental processes in adaptive immunity. However, current methods for predicting AIR-antigen binding largely rely on sequence-derived features of AIRs, omitting the structure features that are essential for binding affinity. In this study, we present a deep-learning framework, termed DeepAIR, for the accurate prediction of AIR-antigen binding by integrating both sequence and structure features of AIRs. DeepAIR consists of three feature encoders (a trainable-embedding-layer-based gene encoder, a transformer-based sequence encoder, and a pre-trained AlphaFold2-based structure encoder), a gating-based attention mechanism to extract important features, and a tensor fusion mechanism to integrate obtained features. We train and evaluate DeepAIR on three downstream prediction tasks, including the prediction of AIR-antigen binding affinity, the prediction of AIR-antigen binding reactivity, and the classification of the immune repertoire. On five representative datasets, DeepAIR shows outstanding prediction performance in terms of AUC (area under the ROC curve) in predicting the binding reactivity to various antigens, as well as the classification of immune repertoire for nasopharyngeal carcinoma (NPC) and inflammatory bowel disease (IBD). DeepAIR is freely available for academic purposes at https://github.com/TencentAILabHealthcare/DeepAIR. We anticipate that DeepAIR can serve as a useful tool for characterizing and profiling antigen binding AIRs, thereby informing the design of personalized immunotherapy. HighlightsO_LIIntegrating predicted AIR structures using AlphaFold2 significantly improves the prediction accuracy of the binding reactivity between AIRs and antigens. C_LIO_LIDeepAIR is featured by a novel deep learning architecture that leverages both the gating-based attention mechanism and tensor fusion mechanism to effectively extract and integrate informative features from three feature encoders, including a trainable embedding-layer-based gene encoder, a transformer-based sequence encoder, and a pre-trained AlphaFold2-based structure encoder. C_LIO_LIDeepAIR is implemented as a biologically interpretable deep learning framework that highlights the key residues in both and {beta} chains that are critical for predicting the AIR-antigen binding. C_LI

immunology↗

An Integrated Physiological, Cytology and Proteomics Reveals Network of Sugarcane Protoplasts Responses to Enzymolysis

The protoplast experimental system has been becoming a powerful tool for functional genomics and cell fusion breeding. However, the physiology and molecular mechanism during enzymolysis is not completely understood and has become a major obstacle to protoplast regeneration. Our study used physiological, cytology, iTRAQ (Isobaric Tags for Relative and Absolute Quantification) -based proteomic and RT-PCR analyses to compare the young leaves of sugarcane (ROC22) and protoplasts of more than 90% viability. We found that oxidation product MDA content increased in the protoplasts after enzymolysis and several antioxidant enzymes such as POD, CAT, APX, and O2- content significantly decreased. The cytology results showed that after enzymolysis, the cell membranes were perforated to different degrees, the nuclear activity was weakened, the nucleolus structure was not obvious, and the microtubules depolymerized and formed many short rod-like structures in protoplasts. The proteomic results showed that 1,477 differential proteins were down-regulated and 810 were up-regulated after enzymolysis of sugarcane young leaves. The GO terms, KEGG and KOG enrichment analysis revealed that differentially abundant proteins were mainly involved in bioenergetic metabolism, cellular processes, osmotic stress, and redox homeostasis of protoplasts, which would allow protein biosynthesis or / degradation. The RT-PCR analysis revealed the expression of osmotic stress resistance genes such as DREB, WRKY, MAPK4, and NAC were up-regulated. Meanwhile, the expression of key regeneration genes such as CyclinD3, CyclinA, CyclinB, Cdc2, PSK, CESA and GAUT were significantly down-regulated in the protoplasts. Hierarchical clustering, identification of redox proteins and oxidation products showed that these proteins were involved in dynamic networks in response to oxidative stress after enzymolysis. We used a variety of methods to figure out how young sugarcane leaves react to enzymes.

cell biology↗

Pathway elucidation of pharmaceutical cucurbitacin IIa in Hemsleya chinensis and high-level production of precursor cucurbitadienol in engineered Saccharomyces cerevisiae and Nicotiana benthamiana

Cucurbitacin IIa is a triterpene isolated exclusively from Hemsleya plants, which is non-steroidal anti-inflammatory drug that function as the main ingredient of Hemslecin capsules and Supplemental Tablets in China. In this study, the biosynthetic pathway of cucurbitacin IIa was elucidated by characterization of squalene epoxidases (HcSE1, HcSE2), cucurbitenol synthases (HcOSC6) and acyltransferases (HcAT1) in Hemsleya chinensis. Meanwhile, cycloartenol synthases (HcOSC1), isomultiflorenol synthases (HcOSC5) and {beta}-amyrin synthase (HcOSC2-4) involved in sterol and triterpenes biosynthesis were functionally illustrated. The high-level production of yeast the key cucurbitacin precursor, cucurbitadienol, was constructed to produce 296.37 mg/L cucurbitadienol and 722.99 mg/L total triterpenoid which is the highest yield cucurbitadienol from known engineered microbes. Moreover, production of cucurbitenol in transient expression of tobacco was employed to achieve 94.8 mg/g dry weight (dw) cucurbitenol from leaves. In this study, the key genes involved in cucurbitacin IIa biosynthesis were identified to facilitate its medical applications via biosynthetic strategy. Meanwhile, the high-level production of cucurbitadienol chassis yeast and tobacco transient expression offered a robust and sSupplemental Table substrate for pharmaceutical cucurbitacin production and screening platform for candidate genes involved in cucurbitacin biosynthesis.

synthetic biology↗

Exosome-derived lncRNA HOXA-AS3 promotes castration resistance and progression of prostate cancer via the miR-29b-3p/Mcl-1/STAT3 axis

Prostate cancer is one of the leading causes of cancer-related deaths in men. While endocrine therapy is effective in the early stage of metastasis, significantly inhibits the progression of metastatic prostate cancer, most patients eventually develop CRPC. Tumor microenvironment are involved in the progression of prostate cancer as an "accomplice", cancer cell-secreted exosomes were identified as crucial messengers can carry lncRNAs to participate in intercellular communication. we revealed PC-3-derived exosomes promote androgen resistance in LNCaP cells. HOXA-AS3 as a ceRNA of miRNA-29b-3p affects the proliferation and invasion ability of prostate cancer cells. A series of molecular experiments, cell experiments and clinical tissue verification experiments confirmed that HOXA-AS3 participates in the castration resistance and progression of prostate cancer through regulating the miR-29b-3p/Mcl-1/STAT3/Cytochrome C/caspases-9 pathway. Dysregulation of HOXA-AS3 is observed in many cancer types, and this study shows the importance of this lncRNA in controlling prostate cancer cell progression, thus highlighting it as a potential biomarker for inhibiting prostate cancer progression and a target for immunotherapy.

genomics↗

Alternative mRNA polyadenylation bridges mitochondrion-to-nucleus communication in Arabidopsis

Mitochondria produce signals besides energy and metabolites that influence plant growth and fitness. However, how mitochondrial signals are relayed to other cellular compartments is largely unknown. By applying poly(A)-site RNA-sequencing (PAS-seq) to wildtype Arabidopsis seedlings and a mutant in the histone demethylase JMJ30 treated with the mitochondrial electron transfer chain inhibitor antimycin A (AA), we identified a previously undefined mitochondrion-to-nucleus communication pathway by which mitochondrial functional state regulates co-transcriptionally alternative polyadenylation (APA) of nuclear mRNA. We observed a global shortening of 3' untranslated regions (UTRs) as a molecular signature of AA-activated mitochondrial retrograde response (MRR), which contributed in part to translational regulation of auxin response and cell wall biogenesis. JMJ30 regulated AA-induced 3' UTR shortening, resulting in more transcripts with shortened 3' UTRs upon AA treatment in a JMJ30 gain-of-function mutant and overexpression lines. We also report on the JMJ30-interacting protein CPSF30, a cleavage and polyadenylation specificity factor that recruits JMJ30 to modulate H3K27me3 status at its target loci. Our study illustrates how epigenetic modification and APA coordinate mitochondrion-to-nucleus communication to allow cells to rapidly respond to changes in mitochondrial functional state and shape plant growth and fitness. One-sentence summaryEpigenetic modification and APA coordinate mitochondrion-to-nucleus communication to allow cells to rapidly respond to changes in mitochondrial functional state and shape plant growth and fitness.

molecular biology↗

The genomes of medicinal skullcaps reveal the polyphyletic origins of clerodane diterpene biosynthesis in the family Lamiaceae.

The presence of anticancer clerodane diterpenoids is a chemotaxonomic marker for the traditional Chinese medicinal plant Scutellaria barbata, although the molecular mechanisms behind clerodane biosynthesis are unknown. Here, we report a high-quality assembly of the 414.98 Mb genome of S. barbata into thirteen pseudochromosomes. Using phylogenomic and biochemical data, we mapped the plastidial metabolism of kaurene (gibberellins), abietane and clerodane diterpenes in three species of the family Lamiaceae (Scutellaria barbata, Scutellaria baicalensis and Salvia splendens), facilitating the identification of genes involved in the biosynthesis of the clerodanes, kolavenol and isokolavenol. We show that clerodane biosynthesis evolved through recruitment and neofunctionalization of genes from gibberellin and abietane metabolism. Despite the assumed monophyletic origin of clerodane biosynthesis which is widespread in species of the Lamiaceae, our data show distinct evolutionary lineages and suggest polyphyletic origins of clerodane biosynthesis in the family Lamiaceae. Our study not only provides significant insights into the evolution of clerodane biosynthetic pathways in the mint family, Lamiaceae, but also will facilitate the elucidation of anticancer clerodanes biosynthesis and future metabolic engineering efforts to increase the production of these high-value chemicals.

plant biology↗

Genome-scale mapping of DNA damage suppressors identifies GNB1L as essential for ATM and ATR biogenesis

To maintain genome integrity, cells must avoid DNA damage by ensuring the accurate duplication of the genome and by having efficient repair and signaling systems that counteract the genome-destabilizing potential of DNA lesions. To uncover genes and pathways that suppress DNA damage in human cells, we undertook genome-scale CRISPR/Cas9 screens that monitored the levels of DNA damage in the absence or presence of DNA replication stress. We identified 160 genes in RKO cells whose mutation caused high levels of DNA damage in the absence of exogenous genotoxic treatment. This list was highly enriched in essential genes, highlighting the importance of genomic integrity for cellular fitness. Furthermore, the majority of these 160 genes are involved in a limited set of biological processes related to DNA replication and repair, nucleotide biosynthesis, RNA metabolism and iron sulfur cluster biogenesis, suggesting that genome integrity may be insulated from a wide range of cellular processes. Among the many genes identified and validated in this study, we discovered that GNB1L, a schizophrenia/autism-susceptibility gene implicated in 22q11.2 syndrome, protects cells from replication catastrophe promoted by mild DNA replication stress. We show that GNB1L is involved in the biogenesis of ATR and related phosphatidylinositol 3-kinase-related kinases (PIKKs) through its interaction with the TTT co-chaperone complex. These results implicate PIKK biogenesis as a potential root cause for the neuropsychiatric phenotypes associated with 22q11.2 syndrome. The phenotypic mapping of genes that suppress DNA damage in human cells therefore provides a powerful approach to probe genome maintenance mechanisms.

molecular biology↗

Relative Brain Age Is Associated with Socioeconomic Status and Anxiety/Depression Problems in Youth

Socioeconomic status (SES) has been linked to differences in brain structure and psychiatric risk across the lifespan. Despite many neuropsychiatric disorders emerging in childhood, few studies have examined the influence of SES on brain aging and psychopathology in youth. We re-analyzed relative brain age (RBA) data from the Healthy Brain Network to examine the influence of SES components (parent education, occupation, household income-to-needs ratio (INR), public assistance enrollment) on RBA. RBA was previously determined using covariation patterns for cortical morphology, white, and subcortical gray matter volumes without SES in predictive models. We also examined associations between RBA and psychiatric symptoms (child behavior checklist). Full case analysis included 470 youth (5-17 years; 61.3% male), self-identifying as White (55%), African American (15%), Hispanic (9%), or multiracial (17.2%). Mean household income was 3.95{+/-}2.33 (Mean{+/-}SD) times the federal poverty threshold. Multiple linear regression examined if 1) SES components associated with RBA, and 2) RBA associated with psychiatric symptoms. Models covaried for sex, scan location, and parent psychiatric diagnoses. RBA associated with public assistance (p = 0.03), parent occupation (p = 0.01), and parent psychiatric diagnosis (p = 0.01), but not with INR and parent education. Parent occupation (p = 0.02) and RBA (p = 0.04) associated with CBCL anxiety/depression scores. Components of SES associated with brain aging, underscoring the risk of omitting these factors in developmental brain research. Further, delayed brain aging was associated with low parental occupational prestige and child anxiety/depression scores, suggesting a possible biological pathway from SES to mental health risk.

neuroscience↗

Adaptive compensation of arcuate fasciculus lateralization in developmental dyslexia

Previous studies have reported anomalies in the arcuate fasciculus (AF) lateralization in developmental dyslexia (DD). Still, the relationship between AF lateralization and literacy skills in DD remains largely unknown. The purpose of our study is to investigate the relationship between the lateralization of the AF anterior segment (AFAS), AF long segment (AFLS), and AF posterior segment (AFPS) in connection to literacy skills in DD. The participants included 26 children with dyslexia and 31 age-matched children in the control group. High angular diffusion imaging, combined with spherical deconvolution tractography, was used to reconstruct the AF. Connectivity measures of hindrance-modulated oriented anisotropy (HMOA) were computed for each of the three segments of the AF: anterior segment (AFAS), long segment (AFLS), and posterior segment (AFPS). The lateralization index (LI) of each AF segment was calculated by (right HMOA - left HMOA) / (right HMOA + left HMOA). Results showed that the LIs of AFAS and AFLS were positively correlated with reading accuracy in children with dyslexia. Specifically, the LI of AFAS was positively correlated with text and nonword reading accuracy, while the LI of AFLS accounted for word reading accuracy. The results suggest adaptive compensation of arcuate fasciculus lateralization in developmental dyslexia and functional dissociation of the anterior segment and long segment in the compensation.

neuroscience↗

Steric-free bioorthogonal profiling of cellular acetylation and glycosylation via a fluorine-selenol displacement reaction (FSeDR)

Global detection and identification of protein post-translational modification (PTM) is a major bottleneck due to its dynamic property and rather low abundance. Tremendous efforts have been since made to develop antibody-based immunoaffinity enrichment or bioorthogonal chemistry-based chemical reporter approach but both suffer from inherent limitations. Following our previously reported steric-free tagging strategy, we hereby report the invention of selenol as a new generation of fluorine-displacement probe. The fluorine-selenol based displacement reaction enabled us to efficiently label and image acetylation and glycosylation at cellular level. We further pursued FSeDR in tandem with SILAC based quantitative proteomics to globally profile acetylation substrate proteins in a representative prostate cancer cell line PC3. Our results unraveled the fluorine-based toolbox for powerful chemical biology probing and allow for the future study of PTMs in a systemic manner.

cell biology↗

High-throughput TCRB enrichment sequencing of human cord blood exhibited a distinct fetal T cell repertoire in the third trimester of pregnancy

Study questionWhat are the molecular characteristics during the maturation process of the human fetal immune system in the third trimester of pregnancy? Summary answerBoth the diversity and length of complementarity determining region 3 (CDR3s) in the fetal TCRB repertoire were less than those of adult CDR3s, and the fetal CDR3 length increased with gestation weeks in late pregnancy. What is known alreadyThe adaptive immune system recognizes various pathogens based on a large repertoire of T-cell receptors (TCR repertoire), but the maturation dynamics of the fetal TCR repertoire in the third trimester are largely unknown. The CDR3is the most diversified segment in the T-cell receptor {beta} chain (TCRB) that binds and recognizes the antigen. Study design, size, and durationThis was a basic research to assess the composing characteristics of TCRBs in core blood and the dynamic pattern with fetal development in the third trimester of pregnancy. Participants/materials, setting methodsHigh-throughput TCRB-enrichment sequencing was utilized to characterize the TCRB repertoire of cord blood at 24~38 weeks of gestational age (WGA) with nonpreterm fetuses and to investigate their difference compared with that of adult peripheral blood. Main results and the role of chanceCompared to the adult control, the fetal TCRB repertoire had a 4.8-fold lower number of unique CDR3s, a comparable Shannon diversity index (p=0.7387), a lower mean top clone rate (p < 0.001) and a constrictive top 1000 unique clone rates. Although all kinds of TCRBV and TCRBJ genes present in adult CDR3s were identified in fetuses, nearly half of these fragments showed a significant difference in usage. Moreover, the fetal TCRB repertoire held a shorter CDR3 length, and the CDR3 length showed a progressive increase with fetal development. Jensen-Shannon (JS) divergences of TCRBV and TCRBJ gene usage in dizygotic twins were much lower than those in unrelated pairs. In the parental-fetal pair, JS divergence of TCRBV gene usage was not obviously different, while that of TCRBJ gene usage was only slightly lower. Limitations, reasons for cautionThe sample size is limited due to the limited accessibility to cord blood in late pregnancy with healthy nonpreterm fetuses. Wider implications of the findingsOur findings reveal the unique properties of fetal TCRB repertoires in the third trimester, fill the gap in our understanding of the maturation process of prenatal fatal immunity, and deepen our understanding of the immunologically relevant problems in neonates. Study funding/competing interest(s)This work was supported by the National Natural Science Foundation of China (82171661) and Tianjin Municipal Science and Technology Special Funds for Enterprise Development (NO. 14ZXLJSY00320). The authors declare that they have no competing interests.

genetics↗

GLKs directly regulate carotenoid biosynthesis via interacting with GBFs in nuclear condensates in plants

Carotenoids are vital photosynthetic pigments for plants and provide essential nutrients for humans. However, our knowledge of the regulatory control of carotenoid biosynthesis remains limited. Golden2-like transcription factors (GLKs) are widely recognized as essential and conserved factors for chloroplast development and the major regulators of chlorophyll biosynthesis. Yet the molecular mechanisms by which GLKs transcriptionally activate their target genes are unclear. Here, we report that GLKs directly regulate carotenoid biosynthesis in a G-box Binding Factor (GBF)-dependent manner. Both in vitro and in vivo studies reveal that GLKs physically interact with GBFs. Through the direct binding of GBFs to the G-box motif, the GLK-GBF regulatory module transcriptionally activates phytoene synthase (PSY), the gene encoding the rate-limiting enzyme for carotenoid biosynthesis. The ability of GLKs to promote carotenoid and chlorophyll biosynthesis is greatly diminished in the Arabidopsis gbf1/2/3 triple knockout mutants, showing the requirement of GBFs for GLK function. GLKs and GBFs form liquid-liquid phase separation-mediated nuclear condensates as the compartmented and concentrated transcriptional complexes. Our findings uncover a novel and conserved regulatory module for photosynthetic pigment biosynthesis through formation of GLK-GBF transcriptional complexes and nuclear biomolecular condensates in plants. One-sentence summaryGLKs transcriptionally regulate photosynthetic pigment synthesis in a GBF-dependent manner and are associated with the formation of phase separation-mediated nuclear condensates.

plant biology↗

Initial niche condition determines the aging speed and regenerative activity of quiescent cells

Quiescent cell ages with decline in both the survivability and regenerative activity. While most cellular quiescence/ageing research have focused on the survivability and from the population level, the question how the regenerative activity change with the quiescence time (i.e., chronological age) has rarely been addressed quantitatively. In this work, we systematically measured both features in ageing quiescent fission yeast cells at single cell level. We found that the regenerative activity declines linearly before survivability decline and the cellular chronological ageing speed is predetermined by the initial niche condition. Moreover, this linear ageing behavior is robust under various niche conditions and follows a common ageing trajectory in terms of gene expression. Furthermore, initial calorie restriction was found to improve not only the survivability but also the later regenerative activity. Our results reveal a continuous diverse spectrum of quiescence depth and ageing plasticity.

cell biology↗

Chemoenzymatic Measurement of Cell-surface Glycan in Single-cell Multiomics: LacNAc as an Example

Despite the rich information of a cells physiological state encoded in the dynamic changes of cell-surface glycans, methods of capturing glycosylation states at the single-cell level are quite limited. Here we report a chemoenzymatic single-cell N-acetyllactosamine (LacNAc) detection method via tagging the LacNAc with a specific DNA barcode. Compared to the lectin-based glycan detection, the chemoenzymatic labeling does not change the transcriptional status of immune cells and is more compatible with scRNA-seq. Integrated analysis of LacNAc and transcriptome of T cells at a single-cell level reveals that the quantity of cell-surface LacNAc is significantly upregulated in activated CD8+ T cells but maintained at the basal level in quiescent CD8+ T cells (i.e., naive and central memory T cells). Further analysis confirms that the LacNAc level is positively correlated to the glycolytic activity of CD8+ T cells at all statues. Taken together, our study demonstrates the feasibility of chemoenzymatic detection of cell-surface glycan in single-cell RNA sequencing-based multiomics with information of TCR sequence and cell-surface epitopes (i.e., scTCR and CITE-seq) and offers a new way to characterize the biological role of glycan in diversified physiological states.

immunology↗

CRISPR Mediated Transactivation in the Human Disease Vector Aedes aegypti

As a major insect vector of multiple arboviruses, Aedes aegypti poses a significant global health and economic burden. A number of genetic engineering tools have been exploited to understand its biology with the goal of reducing its impact. For example, current tools have focused on knocking-down RNA transcripts, inducing loss-of-function mutations or expressing exogenous DNA. However, methods for transactivating endogenous genes have not been developed. To fill this void, here we developed a CRISPR activation (CRISPRa) system in Ae. aegypti to transactivate target gene expression. Gene expression is activated through pairing a catalytically-inactive ( dead) Cas9 (dCas9) with a highly-active tripartite activator, VP64-p65-Rta (VPR) and synthetic guide RNA (sgRNA) complementary to a user defined target-gene promoter region. As a proof of concept, we demonstrate that engineered Ae. aegypti mosquitoes harboring a binary CRISPRa system can be used to effectively overexpress two developmental genes, even-skipped (eve) and hedgehog (hh), resulting in observable morphological phenotypes. We also used this system to overexpress the positive transcriptional regulator of the Toll immune pathway known as AaRel1, which resulted in a significant suppression of dengue virus serotype 2 (DENV2). This system provides a versatile tool for research pathways not previously possible in Ae. aegypti, such as programmed overexpression of endogenous genes, and may lead to the development of innovative vector control tools.

bioengineering↗

Transcriptional and clonal characterization of cytotoxic CD8+ T cells in crescentic glomerulonephritis

Crescentic glomerulonephritis (cGN), most often caused by anti-neutrophil cytoplasmic autoantibody (ANCA)-associated vasculitis, is an aggressive form of immune-mediated kidney disease and represents an important cause of end-stage renal failure. Although it is known that T cells infiltrate the kidney in cGN, their precise role in autoimmune kidney disease remains to be fully elucidated. By performing single-cell analysis, we identified activated, clonally expanded CD8+ T cells with a cytotoxic gene expression profile in the kidneys of patients with ANCA-associated cGN. Using an experimental model of cGN, we demonstrated that clonally expanded murine CD8+ T cells highly expressed the cytotoxic molecule granzyme B. Moreover, lack of CD8+ T cells or granzyme B resulted in an ameliorated course of cGN. This was associated with reduced cleaved caspase-3 induction in renal tissue cells. Our data indicate that clonally expanded cytotoxic CD8+ T cells have a previously unrecognized pathogenic function in aggravating immune-mediated kidney disease.

immunology↗

Senescent cells develop PDK4-dependent hypercatabolism and form an acidic microenvironment to drive cancer resistance

Cellular senescence is a state of stable growth arrest, usually accompanied by development of the senescence-associated secretory phenotype (SASP). Although senescent cells remain metabolically active, little is known about their metabolic landscape and in vivo pathophysiological implications. Here we show that expression of the pyruvate dehydrogenase (PDH) inhibitory enzyme, pyruvate dehydrogenase kinase 4 (PDK4), is significantly upregulated in human senescent stromal cells. Preferentially expressed upon genotoxicity-induced senescence (GIS), PDK4 is negatively correlated with posttreatment survival of cancer patients. Upon cellular senescence, PDK4 shifts glucose metabolic flux from oxidative phosphorylation to aerobic glycolysis, causing enhanced lactate production and forming an acidic microenvironment. However, distinct from the cancer cell-featured Warburg effect, senescent cells maintain an intensive use of pyruvate through the tricarboxylic acid cycle (TCA), displaying increased respiration and redox activity, indicative of a special form of metabolic reprogramming. Conditioned media from PDK4+ stromal cells change global expression and promote malignancy of recipient cancer cells in vitro and accelerate tumor progression in vivo. Pharmacologically targeting PDK4 restrains the adverse effects of PDK4 in cell-based assays, while promoting tumor regression and extending posttreatment survival in preclinical trials. Together, our study substantiates the hypercatabolic nature of senescent cells, and reveals a metabolic link between senescence-associated acidic microenvironment and age-related pathologies including but not limited to cancer.

cell biology↗

Screening cell-cell communication in spatial transcriptomics via collective optimal transport

Spatial transcriptomic technologies and spatially annotated single cell RNA-sequencing (scRNA-seq) datasets provide unprecedented opportunities to dissect cell-cell communication (CCC). How to incorporate the spatial information and complex biochemical processes in reconstructing CCC remains a major challenge. Here we present COMMOT to infer CCC in spatial transcriptomics, which accounts for the competition among different ligand and receptor species as well as spatial distances between cells. A novel collective optimal transport method is developed to handle complex molecular interactions and spatial constraints. We introduce downstream analysis tools on spatial directionality of signalings and genes regulated by such signalings using machine learning models. We apply COMMOT to simulation data and eight spatial datasets acquired with five different technologies, showing its effectiveness and robustness in identifying spatial CCC in data with varying spatial resolutions and gene coverages. Finally, COMMOT reveals new CCCs during skin morphogenesis in a case study of human epidermal development. Both the method and the computational package have broad applications in inferring cell-cell interactions within spatial genomics datasets.

bioinformatics↗