Biology subjects

Jiang, P.

Publications and source records attributed to Jiang, P..

At least 73 records · Page 4Linked to original sources

bioRxiv2023

Decoupling the correlation between cytotoxic and exhausted T lymphocyte transcriptomic signatures enhances melanoma immunotherapy response prediction

BackgroundCytotoxic T lymphocytes (CTL) play a crucial role in anti-cancer immunity. Progression of CTL to terminal exhausted T lymphocytes (ETL) that overexpress inhibitory receptors can substantially decrease effector cytokines production and diminish cytolytic activity and terminal exhausted T cell cannot be reprogrammed by ICIs in tumor microenvironment (TME). However, while the activity levels of CTL and ETL are considered important determinants of immune checkpoint inhibitors (ICIs) response, it has been repeatedly observed that their predictive power of the latter is quite limited. Studying this conundrum on a large scale across the TCGA cohort, we find that ETL and CTL activity (estimated based on conventional gene signatures in the bulk tumor expression) is strongly positively correlated in most cancer types. We hypothesized that the limited predictive power of CTL activity might result from the high concordance of CTL and ETL activities, which mutually cancels out their individual antagonistic effects on ICI response. MethodsConsequently, we have set out to identify a set of genes whose expression identifies a subset of patients where the CTL and ETL correlation is diminished, such that the association between these CD8+ T cell states and ICIs response is enhanced. Resultsnalyzing TCGA melanoma bulk gene expression, we identified a set of genes whose over-expression markedly diminishes the CTL and ETL correlation, termed a decoupling signature (DS). Reassuringly, we first find that the correlation between ETL and CTL activities is indeed markedly lower across high scoring DS patients than that observed across low scoring DS patients in numerous independent melanoma ICIs cohorts. Second, indeed, this successful decoupling increases the power of CTL activity in predicting ICIs response in high DS scoring patients. We show that the resulting prediction accuracy is superior to other state-of-art ICI predictive transcriptomic signatures. ConclusionThe new decoupling score boosts the power of CTL activity in predicting ICIs response in melanoma from the tumor bulk expression. Its use enables a two-step stratification approach, where the response of high scoring DS patient can be predicted more accurately that with extant transcriptomic signatures. What is already known on this topicThe predictive power of CTL activity based on bulk tumor transcriptomics, despite being a widely studied important determinant of ICI treatment, is very limited. What this study addsThe efficacy of CTL activity in predicting ICI therapy response is significantly higher among patients with decoupled CTL and ETL activities. How this study might affect research, practice or policyWe identified a set of genes as the decoupling signature, whose upregulation markedly diminishes the correlation between CTL and ETL activities. Our decoupling signature enhances the power of CTL in predicting ICI treatment response, outperforming other extant expression-based signatures.

bioinformatics↗

bioRxiv2023

Dietary Restriction Impacts Peripheral Circadian Clock Output Important for Longevity in Drosophila

Circadian clocks may mediate lifespan extension by caloric or dietary restriction (DR). We find that the core clock transcription factor Clock is crucial for a robust longevity and fecundity response to DR in Drosophila. To identify clock-controlled mediators, we performed RNA-sequencing from abdominal fat bodies across the 24 h day after just 5 days under control or DR diets. In contrast to more chronic DR regimens, we did not detect significant changes in the rhythmic expression of core clock genes. Yet we discovered that DR induced de novo rhythmicity or increased expression of rhythmic clock output genes. Network analysis revealed that DR increased network connectivity in one module comprised of genes encoding proteasome subunits. Adult, fat body specific RNAi knockdown demonstrated that proteasome subunits contribute to DR-mediated lifespan extension. Thus, clock control of output links DR-mediated changes in rhythmic transcription to lifespan extension.

genetics↗

bioRxiv2022

The E2 SUMO-conjugating enzyme UBE2I coordinates the oocyte and zygotic transcriptional programs

In mammals, meiotically competent oocytes develop cyclically during ovarian folliculogenesis. During folliculogenesis, prophase I arrested oocytes are transcriptionally active, producing and storing transcripts required for their growth and for early stages of embryogenesis prior to the maternal to zygotic transition. Defective oocyte development during folliculogenesis leads to meiotic defects, aneuploidy, follicular atresia, or non-viable embryos. Here we generated a novel oocyte-specific knockout of the SUMO E2 ligase, Ube2i, using Zp3-cre to test its function during folliculogenesis. Ube2i Zp3-cre+ female mice are sterile with oocytes that arrest in meiosis I with defective spindles and chromosome alignment. Fully grown mutant oocytes abnormally maintain transcription but downregulate maternal effect genes and prematurely activate the zygotic transcriptional program. Thus, this work uncovers UBE2i as a novel orchestrator of chromatin and transcriptional regulation in mouse oocytes. TeaserOocyte-specific deletion of Ube2i causes loss of transcriptional repression and premature activation of the zygotic genome.

cell biology↗

bioRxiv2022

A quantitative model for the transcriptional landscape of the bacterial cell cycle

Organisms determine the transcription rates of thousands of genes through a few modes of regulation that recur across the genome. These modes interact with a changing cellular environment to yield highly dynamic expression patterns. In bacteria, the relationship between a genes regulatory architecture and its expression is well understood for individual model gene circuits. However, a broader perspective of these dynamics at the genome-scale is lacking, in part because bacterial transcriptomics have hitherto captured only a static snapshot of expression averaged across millions of cells. As a result, the full diversity of gene expression dynamics and their relation to regulatory architecture remains unknown. Here we present a novel genome-wide classification of regulatory modes based on each genes transcriptional response to its own replication, which we term the Transcription-Replication Interaction Profile (TRIP). We found that the response to the universal perturbation of chromosomal replication integrates biological regulatory factors with biophysical molecular events on the chromosome to reveal a genes local regulatory context. While the TRIPs of many genes conform to a gene dosage-dependent pattern, others diverge in distinct ways, including altered timing or amplitude of expression, and this is shaped by factors such as intra-operon position, repression state, or presence on mobile genetic elements. Our transcriptome analysis also simultaneously captures global properties, such as the rates of replication and transcription, as well as the nestedness of replication patterns. This work challenges previous notions of the drivers of expression heterogeneity within a population of cells, and unearths a previously unseen world of gene transcription dynamics.

systems biology↗

bioRxiv2022

Optical Biopsy using a neural network to predict functional state from photos of wounds

BackgroundThe clinical characterization of the functional status of active wounds remains a considerable challenge that at present, requires excision of a tissue biopsy. In this pilot study, we use a convolutional Siamese neural network architecture to predict the functional state of a wound using digital photographs of wounds in a canine model of volumetric muscle loss (VML). Materials and MethodsImages of volumetric muscle loss injuries and tissue biopsies were obtained in a canine model of VML. Gene expression profiles for each image were obtained using RNAseq. These profiles were then converted to functional profiles using a manual review of validated gene ontology databases. A Siamese neural network was trained to regress functional profile expression values as a function of the data contained in an extracted image segment showing the surface of a small tissue biopsy. Network performance was assessed in a test set of images using Mean Absolute Percentage Error (MAPE). ResultsThe network was able to predict the functional expression of a range of functions based with a MAPE ranging from [~]5% to [~]50%, with functions that are most closely associated with the early-state of wound healing to be those best-predicted. ConclusionsThese initial results suggest promise for further research regarding this novel use of ML regression on medical images. The regression of functional profiles, as opposed to specific genes, both addresses the challenge of genetic redundancy and gives a deeper insight into the mechanistic configuration of a region of tissue in wounds. As this preliminary study focuses on the first 14 days of wound healing, future work will focus on extending the training data to include longer time periods which would result in additional functions, such as tissue remodeling, having a larger presence in the training data.

bioinformatics↗

bioRxiv2022

An in situ cut-and-paste genome editing platform mediated by CRISPR/Cas9 or Cas12a

Recombinant DNA technology mediated by restriction enzymes and ligases allows in vitro manipulation of a DNA segment isolated from the genome. Short overhangs generated by restriction enzymes facilitate efficient pasting together a DNA sequence and a vector. We adopted this recombinant DNA strategy to develop an in vivo recombinant-genome genome editing approach. Using the programmable endonuclease Cas9 or Cas12a as a restriction enzyme, we devised an in situ cut-and-paste (iCAP) genome editing method that was tested in both mouse germline and human cell line platforms. Mouse gene loci Slc35f2 and Slc35f6 were each edited with in-frame insertion of a large APEX2-Cre cassette and concurrent FRT3 insertion at a second location providing proof of principle for the iCAP method. Further, a de nova single nucleotide mutation associated with MED13L syndrome was efficiently corrected in patient cells. Altogether, the iCAP method provides a single genome editing platform with flexibility and multiutility enabling versatile and precise sequence alterations, such as insertion, substitution, and deletion, at single or multiple locations within a genomic segment in mammalian genomes.

molecular biology↗

bioRxiv2022

Effect of GDF15 on acetaminophen (APAP)-induced liver injury in mice

Acetaminophen (APAP)-induced liver injury (AILI) has been recognized as a pivotal contributor to drug-induced liver failure in western countries, but its molecular mechanism remains poorly understood. After data mining using the Gene Expression Omnibus (GEO) database, we found that the gene expression of growth differentiation factor 15 (GDF15) increased significantly after APAP-induced hepatotoxicity in mouse liver. However, the precise role of GDF15 in AILI has yet to be clarified. To deal with this question, we first examined the temporal gene expression pattern of GDF15 after APAP treatment. Next, overexpression of hepatic GDF15 using adeno-associated virus serotype 8 (AAV8) was employed to investigate the role of GDF15 in AILI. In addition, therapeutic administration of recombinant human GDF15 (rhGDF15) was conducted to probe its curative effect after APAP overdose. We observed that protein expression of GDF15 was significantly increased after APAP overdose. However, there were no significant differences in AILI-related outcomes after overexpression or supplementation of GDF15. The contents of serum alanine aminotransferase (ALT) and aspartate aminotransferase (AST), morphological feature of liver, the level of reduced form of glutathione (GSH), the activation of c-Jun-N-terminal kinase (JNK), the expression of genes relevant to oxidative stress and cell proliferation were not remarkably changed between AAV8-GFP and AAV8-Gdf15 groups. Although the liver injury was not improved by rhGDF15 administration, the gene expression levels of glutamate-cysteine ligase modifier subunit (Gclm) and glutamate-cysteine ligase catalytic subunit (Gclc) which function downstream of Nrf2 signaling pathway were significantly increased. Altogether, despite a noticeable elevated expression after APAP overdose, GDF15 overexpression or supplementation exerted no significant ameliorative effect on AILI. Further mechanism and consequence of Gclm and Gclc elevation by GDF15 remains to be elucidated.

pharmacology and toxicology↗

bioRxiv2022

CRSP: Comparative RNA-seq pipeline for species lacking both of sequenced genomes and reference transcripts

RNA sequencing (RNA-seq) has been a widely used high-throughput method to characterize transcriptomic dynamics spatiotemporally. However, typical RNA-seq data analysis pipelines depend on either a sequenced genome or corresponding reference transcripts or them both. This restriction makes the use of RNA-seq for species lacking both of sequenced genomes and corresponding reference transcripts challenging. Nile grass rat (Arvicanthis niloticus) is a diurnal rodent species with several unique characteristics making it as a useful model to study diet-induced type 2 diabetes and other physiological or behavioral processes due to its diurnal nature. However, there is neither a high-quality annotated Nile grass rat genome nor a reference transcript sets available so far, making it technically challenging to perform large-scale RNA-seq based transcriptomic studies. Although we are working on the first draft of Nile grass rat genome, a well annotated genome typically requires several rounds of manually reviewing curated transcripts and can take years to achieve. To solve this problem, we developed a Comparative RNA-Seq Pipeline (CRSP), integrating a comparative species strategy but not depending on a specific sequenced genome or species-matched reference transcripts. Benchmarking suggests the CRSP tool can achieve high accuracy to quantify gene expression levels. In this study, we generated the first ultra-deep (2.3 billion x 2 paired-end) Nile grass rat RNA-seq data from 59 biopsy samples representing 22 major organs, providing a unique resource and spatial gene expression reference for using Nile grass rat as a model to study human diseases. To facilitate a general use of CRSP, we also characterized the number of RNA-seq reads required for accurate estimation via simulation studies. CRSP and documents are available at: https://github.com/pjiang1105/CRSP. HighlightsO_LICRSP is a novel software tool which can quantify gene expression levels from RNA-seq data for species lacking both a sequenced genome and corresponding reference transcripts. C_LIO_LINile grass rat is a unique diurnal rodent species (day active but not night active) with several unique characteristics making it as a useful model to study diet-induced type 2 diabetes and other physiological or behavioral processes due to its diurnal nature. C_LIO_LIWe generated the first ultra-deep (2.3 billion x 2 paired-end reads) Nile grass rat RNA-seq data from 59 biopsy samples representing 22 major organs, providing a unique resource and spatial transcriptomic reference (e.g., tissue gene expression baseline) for using Nile grass rat as a model to study human diseases. C_LI

bioinformatics↗

bioRxiv2022

The bladder microbiome, metabolome, cytokines, and phenotypes in patients with systemic lupus erythematosus

Background and aimsEmerging studies reveal a unique bacterial community in the human bladder, with alteration of composition associated to disease states. Systemic lupus erythematosus (SLE) is a complex autoimmune disease that is characterized by frequent impairment of the kidney. Here, we explored the bladder microbiome, metabolome, and cytokine profiles in SLE patients, as well as correlations between microbiome and metabolome, cytokines, and disease profiles. Methods and materialsWe recruited a cohort of 50 SLE patients and 50 individually matched asymptomatic controls. We used transurethral catheterization to collect urine samples, 16S rRNA gene sequencing to profile bladder microbiomes, and LC-MS/MS to perform untargeted metabolomic profiling. ResultsCompared to controls, SLE patients possessed a unique bladder microbial community and increased alpha diversity. These differences were accompanied by differences in urinary metabolomes, cytokines, and patients disease profiles. The SLE-enriched genera, including Bacteroides, were positively correlated with several SLE-enriched metabolites, including olopatadine. The SLE-depleted genera, such as Pseudomonas, were negatively correlated to SLE-depleted cytokines, including IL-8. Alteration of the bladder microbiome was associated with disease profile. For example, the genera Megamonas and Phocaeicola were negatively correlated with serum complement C3, and Streptococcus was positively correlated with IgG. ConclusionsOur present study reveals associations between the bladder microbiome and the urinary metabolome, cytokines, and disease phenotypes. Our results could help identify biomarkers for SLE.

microbiology↗

bioRxiv2022

Predicting patient treatment response and resistance via single-cell transcriptomics of their tumors

Tailoring the best treatments to cancer patients is an important open challenge. Here, we build a precision oncology data science and software framework for PERsonalized single-Cell Expression-based Planning for Treatments In Oncology (PERCEPTION). Our approach capitalizes on recently published matched bulk and single-cell transcriptome profiles of large-scale cell-line drug screens to build treatment response models from patients single-cell (SC) tumor transcriptomics. First, we show that PERCEPTION successfully predicts the response to monotherapy and combination treatments in screens performed in cancer and patient-tumor-derived primary cells based on SC-expression profiles. Second, it successfully stratifies responders to combination therapy based on the patients tumors SC-expression in two very recent multiple myeloma and breast cancer clinical trials. Thirdly, it captures the development of clinical resistance to five standard tyrosine kinase inhibitors using tumor SC-expression profiles obtained during treatment in a lung cancer patients cohort. Notably, PERCEPTION outperforms state-of-the-art bulk expression-based predictors in all three clinical cohorts. In sum, this study provides a first-of-its-kind conceptual and computational method that is predictive of response to therapy in patients, based on the clonal SC gene expression of their tumors.

bioinformatics↗

bioRxiv2021

Type I Interferon Signaling Drives Microglial Dysfunction and Senescence in Human iPSC Models of Down Syndrome and Alzheimers Disease

Microglia are critical for brain development and play a central role in Alzheimers disease (AD) etiology. Down syndrome (DS), also known as trisomy 21, is the most common genetic origin of intellectual disability and the most common risk factor for AD. Surprisingly, little information is available on the impact of trisomy of human chromosome 21 (Hsa21) on microglia in DS brain development and AD in DS (DSAD). Using our new induced pluripotent stem cell (iPSC)-based human microglia-containing cerebral organoid and chimeric mouse brain models, here we report that DS microglia exhibit enhanced synaptic pruning function during brain development. Consequently, electrophysiological recordings demonstrate that DS microglial mouse chimeras show impaired synaptic functions, as compared to control microglial chimeras. Upon being exposed to human brain tissue-derived soluble pathological tau, DS microglia display dystrophic phenotypes in chimeric mouse brains, recapitulating microglial responses seen in human AD and DSAD brain tissues. Further flow cytometry, single-cell RNA- sequencing, and immunohistological analyses of chimeric mouse brains demonstrate that DS microglia undergo cellular senescence and exhibit elevated type I interferon signaling after being challenged by pathological tau. Mechanistically, we find that shRNA-mediated knockdown of Hsa21encoded type I interferon receptor genes, IFNARs, rescues the defective DS microglial phenotypes both during brain development and in response to pathological tau. Our findings provide first in vivo evidence supporting a paradigm shifting theory that human microglia respond to pathological tau by exhibiting accelerated senescence and dystrophic phenotypes. Our results further suggest that targeting IFNARs may improve microglial functions during DS brain development and prevent human microglial senescence in DS individuals with AD.

neuroscience↗

bioRxiv2021

A haplotype-resolved genome assembly of the Nile rat facilitates exploration of the genetic basis of diabetes

The Nile rat (Avicanthis niloticus) is an important animal model for biomedical research, including the study of diurnal rhythms and type 2 diabetes. Here, we report a 2.5 Gb, chromosome-level reference genome assembly with fully resolved parental haplotypes, generated with the Vertebrate Genomes Project (VGP). The assembly is highly contiguous, with contig N50 of 11.1 Mb, scaffold N50 of 83 Mb, and 95.2% of the sequence assigned to chromosomes. We used a novel workflow to identify 3,613 segmental duplications and quantify duplicated genes. Comparative analyses revealed unique genomic features of the Nile rat, including those that affect genes associated with type 2 diabetes and metabolic dysfunctions. These include 14 genes that are heterozygous in the Nile rat or highly diverged from the house mouse. Our findings reflect the exceptional level of genomic detail present in this assembly, which will greatly expand the potential of the Nile rat as a model organism for genetic studies.

genomics↗

bioRxiv2021

Analyses of the Autism-associated Neuroligin-3 R451C Mutation in Human Neurons Reveals a Gain-of-Function Synaptic Mechanism

Mutations in many synaptic genes are associated with autism spectrum disorders (ASDs), suggesting that synaptic dysfunction is a key driver of ASD pathogenesis. Among these mutations, the R451C-substitution in the NLGN3 gene that encodes the postsynaptic adhesion molecule Neuroligin-3 is noteworthy because it was the first specific mutation linked to ASDs. In mice, the corresponding Nlgn3 R451C-knockin mutation recapitulates social interaction deficits of ASD patients and produces synaptic abnormalities, but the impact of the NLGN3 R451C-mutation on human neurons has not been investigated. Here, we generated human knock-in neurons with the NLGN3 R451C-mutation. Strikingly, analyses of NLGN3 R451C-mutant neurons revealed that the R451C-mutation decreased NLGN3 protein levels but enhanced the strength of excitatory synapses without affecting inhibitory synapses. No significant cell death and endoplasmic reticulum stress were detected. Importantly, the augmentation of excitatory transmission was confirmed in vivo with human neurons transplanted into mouse forebrain. Using single-cell RNA-seq experiments with co-cultured excitatory and inhibitory NLGN3 R451C-mutant neurons, we identified differentially expressed genes in relatively mature human neurons that corresponded to synaptic gene expression networks. Moreover, gene ontology and enrichment analyses revealed convergent gene networks associated with ASDs and other mental disorders. Our findings suggest that the NLGN3 R451C-mutation induces a gain-of-function enhancement in excitatory synaptic transmission that may contribute to the pathophysiology of ASDs.

neuroscience↗

bioRxiv2021

Salmonella enterica serovar Typhimurium chitinases modulate the intestinal glycome and promote small intestinal invasion.

Salmonella enterica serovar Typhimurium (Salmonella) is one of the leading causes of food-borne illnesses worldwide. To colonize the gastrointestinal tract, Salmonella produces multiple virulence factors that facilitate cellular invasion. Chitinases have been recently emerging as virulence factors for various pathogenic bacterial species and the Salmonella genome contains two annotated chitinases: STM0018 (chiA) and STM0233. However, the role of these chitinases during Salmonella pathogenesis is unknown. The putative chitinase STM0233 has not been studied previously and only limited data exists on ChiA. Chitinases typically hydrolyze chitin polymers, which are absent in vertebrates. However, chiA expression was detected in infection models and purified ChiA cleaved carbohydrate subunits present on mammalian surface glycoproteins, indicating a role during pathogenesis. Here, we demonstrate that expression of chiA and STM0233 is upregulated in the mouse gut and that both chitinases facilitate epithelial cell adhesion and invasion. Salmonella lacking both chitinases showed a 70% reduction in invasion of small intestinal epithelial cells in vitro. In a gastroenteritis mouse model, chitinase-deficient Salmonella strains were also significantly attenuated in the invasion of small intestinal tissue. This reduced invasion resulted in significantly delayed Salmonella dissemination to the spleen and the liver, but chitinases were not required for systemic survival. The invasion defect of the chitinase-deficient strain was rescued by the presence of wild-type Salmonella, suggesting that chitinases are secreted. By analyzing N-linked glycans of small intestinal cells, we identified specific N-acetylglucosamine-containing glycans as potential extracellular targets of Salmonella chitinases. This analysis also revealed differential abundance of Lewis X-containing glycans that is likely a result of host cell modulation due to the detection of Salmonella chitinases. Similar glycomic changes elicited by chitinase deficient strains indicate functional redundancy of the chitinases. Overall, our results demonstrate that Salmonella chitinases contribute to intestinal adhesion and invasion through modulation of the host glycome. Author SummarySalmonella Typhimurium infection is one of the leading causes of food-borne illnesses worldwide. In order for Salmonella to effectively cause disease, it has to invade the epithelial cells lining the intestinal tract. This invasion step allows Salmonella to replicate efficiently, causing further tissue damage and inflammation. In susceptible patients, Salmonella can spread past the intestines and infect peripheral organs. It is essential to fully understand the invasion mechanism used by Salmonella to design better treatments for infection. Here, we demonstrate that the two chitinases produced by Salmonella are involved in this invasion process. We show that Salmonella chitinases interact with surface glycans of intestinal epithelial cells and promote adhesion and invasion. Using a mouse infection model, we show that Salmonella chitinases are required for the invasion of the small intestine and enhance the dissemination of Salmonella to other organs. This study reveals an additional mechanism by which Salmonella invades and causes infection.

microbiology↗

bioRxiv2021

Genome-wide analysis of DNA methylation reveals selection signatures of the grass carp during domestication

With the rapid development of aquaculture, more and more fish species from wild environments are artificially domesticated and cultured. In the process of domestication, the fish develop some adaptations and phenotypic traits, namely selection signatures. However, it is still unclear about the biological process underlying these selection signatures. Here, we used grass carp (Ctenopharyngodon idellus), an aquaculture fish with the largest production worldwide, to detect its selection signatures and investigate the roles of DNA methylation in the emergence of selection signatures during domestication based on whole-genome bisulfite sequencing technology. Our results showed that domesticated grass carp demonstrated four selection signatures, including growth and metabolism, immunity, foraging and learning behaviors, and 38 candidate genes were associated with these traits. 16 of candidate genes, such as IGF-1, GK, GYS1, etc., were found to play major roles in the growth and metabolism. Immunity signature was related to 11 of candidate genes, including MHCI, MHCII, C1QA, etc. The GRM1, TAS1R1 and TAS1R3 genes were essential for the adaptation of domesticated grass carp to commercial feed in artificial rearing condition. The C-FOS, POMC and CBP genes might be responsible for the acquisition of novel feeding habits and contribute to faster growth indirectly by enhancing food intake. These findings would provide new insights to expand our understanding on the role of DNA methylation in shaping physiological phenotypes in fish, and also contribute to efficient breeding of aquaculture stocks and restocking programs.

genetics↗

bioRxiv2021

Targeting circPTPN12/1 miR-21-5p/ΔNp63α pathway as a therapeutic strategy for human endometrial fibrosis

Emerging evidence demonstrates the important role of circular RNAs (circRNAs) in regulating pathological processes in various diseases including organ fibrosis. Endometrium fibrosis is the leading cause of uterine infertility, but the role of circRNAs in its pathogenesis is largely unknown. Here, we provide the evidence that upregulation of circPTPN12 in endometrial epithelial cells (EECs) of fibrotic endometrium functions as endogenous sponge of miR-21-5p to inhibit miR-21-5p expression and activity, which in turn results in upregulation of {Delta}Np63 to induce the epithelial mesenchymal transition (EMT) of EECs (EEC-EMT). In a mouse model of endometrium fibrosis, circPTPN12 appears to be a cofactor of driving EEC-EMT. Our findings reveal the novel mechanism in the pathogenesis of endometrium fibrosis and the potential therapeutic strategy for endometrium fibrosis via targeting circPTPN12/miR-21-5p/{Delta}Np63 pathway.

molecular biology↗

bioRxiv2021

Human immunodeficiency reveals GIMAP5 as lymphocyte-specific regulator of senescence

Elucidating the molecular basis of immunodeficiency diseases is a powerful approach to discovering new immunoregulatory pathways in humans. Here we report 10 affected individuals from 4 families with a new immunodeficiency disease comprising of severe progressive lymphopenia, autoimmunity, immunodeficiency, and liver disease due to recessive loss of function variants in "GTPase of immunity-associated proteins" protein 5 (GIMAP5). We show that the disease involves the progressive loss of naive T lymphocytes and a corresponding increase in antigen-experienced, but poorly functional and replicatively senescent T cells. In vivo treatment of Gimap5-deficient mice with rapamycin (an inhibitor of mTORC1) significantly restores the fraction of naive T lymphocytes. Furthermore, a GIMAP5-deficient human patient who was treated with rapamycin (sirolimus) showed a remarkable reduction in spleen/lymph node size. Together, these observations reveal that GIMAP5 plays a critical role in lymphocyte metabolism which is essential for senescence prevention and immune competence, suggesting that an inhibitor of mTORC1 could be a valuable clinical intervention in treating patients deficient for GIMAP5.

immunology↗

bioRxiv2021

A modified fluctuation assay reveals a natural mutator phenotype that drives mutation spectrum variation within Saccharomyces cerevisiae

Although studies of Saccharomyces cerevisiae have provided many insights into mutagenesis and DNA repair, most of this work has focused on a few laboratory strains. Much less is known about the phenotypic effects of natural variation within S. cerevisiaes DNA repair pathways. Here, we use natural polymorphisms to detect historical mutation spectrum differences among several wild and domesticated S. cerevisiae strains. To determine whether these differences are likely caused by genetic mutation rate modifiers, we use a modified fluctuation assay with a CAN1 reporter to measure de novo mutation rates and spectra in 16 of the analyzed strains. We measure a 10-fold range of mutation rates and identify two strains with distinctive mutation spectra. These strains, known as AEQ and AAR, come from the panels "Mosaic beer" clade and share an enrichment for C>A mutations that is also observed in rare variation segregating throughout the genomes of several Mosaic beer and Mixed origin strains. Both AEQ and AAR are haploid derivatives of the diploid natural isolate CBS 1782, whose rare polymorphisms are enriched for C>A as well, suggesting that the underlying mutator allele is likely active in nature. We use a plasmid complementation test to show that AAR and AEQ share a mutator allele in the DNA repair gene OGG1, which excises 8-oxoguanine lesions that can cause C>A mutations if left unrepaired.

evolutionary biology↗