Systems Biology
Virtually the Same? Evaluating the Effectiveness of Remote Undergraduate Research Experiences
CBE Life Sci Educ. 2023 Jun;22(2):ar25. doi: 10.1187/cbe.22-01-0001.
ABSTRACT
In-person undergraduate research experiences (UREs) promote students' integration into careers in life science research. In 2020, the COVID-19 pandemic prompted institutions hosting summer URE programs to offer them remotely, raising questions about whether undergraduates who participate in remote research can experience scientific integration and whether they might perceive doing research less favorably (i.e., not beneficial or too costly). To address these questions, we examined indicators of scientific integration and perceptions of the benefits and costs of doing research among students who participated in remote life science URE programs in Summer 2020. We found that students experienced gains in scientific self-efficacy pre- to post-URE, similar to results reported for in-person UREs. We also found that students experienced gains in scientific identity, graduate and career intentions, and perceptions of the benefits of doing research only if they started their remote UREs at lower levels on these variables. Collectively, students did not change in their perceptions of the costs of doing research despite the challenges of working remotely. Yet students who started with low cost perceptions increased in these perceptions. These findings indicate that remote UREs can support students' self-efficacy development, but may otherwise be limited in their potential to promote scientific integration.
PMID:37058442 | DOI:10.1187/cbe.22-01-0001
Mining and Validation of Novel Hemp Seed-Derived DPP-IV-Inhibiting Peptides Using a Combination of Multi-omics and Molecular Docking
J Agric Food Chem. 2023 Apr 14. doi: 10.1021/acs.jafc.3c00535. Online ahead of print.
ABSTRACT
Hemp seed-derived inhibitors of dipeptidyl peptidase IV (DPP-IV) demonstrate potential as novel therapeutics for diabetes; however, their proteome and genome remain uncharacterized. We used multi-omics technology to mine peptides capable of inhibiting DPP-IV. First, 1261 and 1184 proteins were identified in fresh and dry hemp seeds, respectively. Simulated protease cleavage of dry seed proteins yielded 185,446 peptides for virtual screening to select the potential DPP-IV-inhibiting peptides. Sixteen novel peptides were selected according to their DPP-IV-binding affinity determined via molecular docking. In vitro DPP-IV inhibition assays identified the peptides LPQNIPPL, YPYY, YPW, LPYPY, WWW, YPY, YPF, and WS with half-maximal inhibitory concentration (IC50) values lower than 0.5 mM, which were 0.08 ± 0.01, 0.18 ± 0.03, 0.18 ± 0.01, 0.20 ± 0.03, 0.22 ± 0.03, 0.29 ± 0.02, 0.42 ± 0.03, and 0.44 ± 0.09 mM, respectively. The dissociation constants (KD) of the 16 peptides ranged from 1.50 × 10-4 to 1.82 × 10-7 M. Furthermore, Caco2 and INS-1 cell assays showed that all 16 peptides could efficiently inhibit DPP-IV activity and increase insulin and glucagon-like peptide-1 concentrations. These results demonstrate a well-established and efficient method to isolate food-derived therapeutic DPP-IV-inhibiting peptides.
PMID:37058363 | DOI:10.1021/acs.jafc.3c00535
Rapid Profiling of Protein Complex Reorganization in Perturbed Systems
J Proteome Res. 2023 Apr 14. doi: 10.1021/acs.jproteome.3c00125. Online ahead of print.
ABSTRACT
Protein complexes constitute the primary functional modules of cellular activity. To respond to perturbations, complexes undergo changes in their abundance, subunit composition, or state of modification. Understanding the function of biological systems requires global strategies to capture this contextual state information. Methods based on cofractionation paired with mass spectrometry have demonstrated the capability for deep biological insight, but the scope of studies using this approach has been limited by the large measurement time per biological sample and challenges with data analysis. There has been little uptake of this strategy into the broader life science community despite its rich biological information content. We present a rapid integrated experimental and computational workflow to assess the reorganization of protein complexes across multiple cellular states. The workflow combines short gradient chromatography and DIA/SWATH mass spectrometry with a data analysis toolset to quantify changes in a complex organization. We applied the workflow to study the global protein complex rearrangements of THP-1 cells undergoing monocyte to macrophage differentiation and subsequent stimulation of macrophage cells with lipopolysaccharide. We observed substantial proteome reorganization on differentiation and less pronounced changes in macrophage stimulation. We establish our integrated differential pipeline for rapid and state-specific profiling of protein complex organization.
PMID:37058003 | DOI:10.1021/acs.jproteome.3c00125
Expanding Extender Substrate Selection for Unnatural Polyketide Biosynthesis by Acyltransferase Domain Exchange within a Modular Polyketide Synthase
J Am Chem Soc. 2023 Apr 14. doi: 10.1021/jacs.2c11027. Online ahead of print.
ABSTRACT
Modular polyketide synthases (PKSs) are polymerases that employ α-carboxyacyl-CoAs as extender substrates. This enzyme family contains several catalytic modules, where each module is responsible for a single round of polyketide chain extension. Although PKS modules typically use malonyl-CoA or methylmalonyl-CoA for chain elongation, many other malonyl-CoA analogues are used to diversify polyketide structures in nature. Previously, we developed a method to alter an extension substrate of a given module by exchanging an acyltransferase (AT) domain while maintaining protein folding. Here, we report in vitro polyketide biosynthesis by 13 PKSs (the wild-type PKS and 12 AT-exchanged PKSs with unusual ATs) and 14 extender substrates. Our ∼200 in vitro reactions resulted in 13 structurally different polyketides, including several polyketides that have not been reported. In some cases, AT-exchanged PKSs produced target polyketides by >100-fold compared to the wild-type PKS. These data also indicate that most unusual AT domains do not incorporate malonyl-CoA and methylmalonyl-CoA but incorporate various rare extender substrates that are equal to in size or slightly larger than natural substrates. We developed a computational workflow to predict the approximate AT substrate range based on active site volumes to support the selection of ATs. These results greatly enhance our understanding of rare AT domains and demonstrate the benefit of using the proposed PKS engineering strategy to produce novel chemicals in vitro.
PMID:37057992 | DOI:10.1021/jacs.2c11027
Diagnostic TR-FRET assays for detection of antibodies in patient samples
Cell Rep Methods. 2023 Feb 20;3(3):100421. doi: 10.1016/j.crmeth.2023.100421. eCollection 2023 Mar 27.
ABSTRACT
Serological assays are important diagnostic tools for surveying exposure to the pathogen, monitoring immune response post vaccination, and managing spread of the infectious agent among the population. Current serological laboratory assays are often limited because they require the use of specialized laboratory technology and/or work with a limited number of sample types. Here, we evaluate an alternative by developing time-resolved Förster resonance energy transfer (TR-FRET) homogeneous assays that exhibited exceptional versatility, scalability, and sensitivity and outperformed or matched currently used strategies in terms of sensitivity, specificity, and precision. We validated the performance of the assays measuring total immunoglobulin G (IgG) levels; antibodies against severe acute respiratory syndrome coronavirus (SARS-CoV) or Middle Eastern respiratory syndrome (MERS)-CoV spike (S) protein; and SARS-CoV-2 S and nucleocapsid (N) proteins and applied it to several large sample sets and real-world applications. We further established a TR-FRET-based ACE2-S competition assay to assess the neutralization propensity of the antibodies. Overall, these TR-FRET-based serological assays can be rapidly extended to other antigens and are compatible with commonly used plate readers.
PMID:37056371 | PMC:PMC10088089 | DOI:10.1016/j.crmeth.2023.100421
The esBAF and ISWI nucleosome remodeling complexes influence occupancy of overlapping dinucleosomes and fragile nucleosomes in murine embryonic stem cells
BMC Genomics. 2023 Apr 13;24(1):201. doi: 10.1186/s12864-023-09287-4.
ABSTRACT
BACKGROUND: Nucleosome remodeling factors regulate the occupancy and positioning of nucleosomes genome-wide through ATP-driven DNA translocation. While many nucleosomes are consistently well-positioned, some nucleosomes and alternative nucleosome structures are more sensitive to nuclease digestion or are transitory. Fragile nucleosomes are nucleosome structures that are sensitive to nuclease digestion and may be composed of either six or eight histone proteins, making these either hexasomes or octasomes. Overlapping dinucleosomes are composed of two merged nucleosomes, lacking one H2A:H2B dimer, creating a 14-mer wrapped by ~ 250 bp of DNA. In vitro studies of nucleosome remodeling suggest that the collision of adjacent nucleosomes by sliding stimulates formation of overlapping dinucleosomes.
RESULTS: To better understand how nucleosome remodeling factors regulate alternative nucleosome structures, we depleted murine embryonic stem cells of the transcripts encoding remodeler ATPases BRG1 or SNF2H, then performed MNase-seq. We used high- and low-MNase digestion to assess the effects of nucleosome remodeling factors on nuclease-sensitive or "fragile" nucleosome occupancy. In parallel we gel-extracted MNase-digested fragments to enrich for overlapping dinucleosomes. We recapitulate prior identification of fragile nucleosomes and overlapping dinucleosomes near transcription start sites, and identify enrichment of these features around gene-distal DNaseI hypersensitive sites, CTCF binding sites, and pluripotency factor binding sites. We find that BRG1 stimulates occupancy of fragile nucleosomes but restricts occupancy of overlapping dinucleosomes.
CONCLUSIONS: Overlapping dinucleosomes and fragile nucleosomes are prevalent within the ES cell genome, occurring at hotspots of gene regulation beyond their characterized existence at promoters. Although neither structure is fully dependent on either nucleosome remodeling factor, both fragile nucleosomes and overlapping dinucleosomes are affected by knockdown of BRG1, suggesting a role for the complex in creating or removing these structures.
PMID:37055726 | DOI:10.1186/s12864-023-09287-4
Babesia duncani multi-omics identifies virulence factors and drug targets
Nat Microbiol. 2023 Apr 13. doi: 10.1038/s41564-023-01360-8. Online ahead of print.
ABSTRACT
Babesiosis is a malaria-like disease in humans and animals that is caused by Babesia species, which are tick-transmitted apicomplexan pathogens. Babesia duncani causes severe to lethal infection in humans, but despite the risk that this parasite poses as an emerging pathogen, little is known about its biology, metabolic requirements or pathogenesis. Unlike other apicomplexan parasites that infect red blood cells, B. duncani can be continuously cultured in vitro in human erythrocytes and can infect mice resulting in fulminant babesiosis and death. We report comprehensive, detailed molecular, genomic, transcriptomic and epigenetic analyses to gain insights into the biology of B. duncani. We completed the assembly, 3D structure and annotation of its nuclear genome, and analysed its transcriptomic and epigenetics profiles during its asexual life cycle stages in human erythrocytes. We used RNA-seq data to produce an atlas of parasite metabolism during its intraerythrocytic life cycle. Characterization of the B. duncani genome, epigenome and transcriptome identified classes of candidate virulence factors, antigens for diagnosis of active infection and several attractive drug targets. Furthermore, metabolic reconstitutions from genome annotation and in vitro efficacy studies identified antifolates, pyrimethamine and WR-99210 as potent inhibitors of B. duncani to establish a pipeline of small molecules that could be developed as effective therapies for the treatment of human babesiosis.
PMID:37055610 | DOI:10.1038/s41564-023-01360-8
Correction to: Human papilloma virus (HPV) integration signature in Cervical Cancer: identification of MACROD2 gene as HPV hot spot integration site
Br J Cancer. 2023 Apr 13. doi: 10.1038/s41416-023-02261-7. Online ahead of print.
NO ABSTRACT
PMID:37055522 | DOI:10.1038/s41416-023-02261-7
Non-functional ubiquitin C-terminal hydrolase L1 drives podocyte injury through impairing proteasomes in autoimmune glomerulonephritis
Nat Commun. 2023 Apr 13;14(1):2114. doi: 10.1038/s41467-023-37836-8.
ABSTRACT
Little is known about the mechanistic significance of the ubiquitin proteasome system (UPS) in a kidney autoimmune environment. In membranous nephropathy (MN), autoantibodies target podocytes of the glomerular filter resulting in proteinuria. Converging biochemical, structural, mouse pathomechanistic, and clinical information we report that the deubiquitinase Ubiquitin C-terminal hydrolase L1 (UCH-L1) is induced by oxidative stress in podocytes and is directly involved in proteasome substrate accumulation. Mechanistically, this toxic gain-of-function is mediated by non-functional UCH-L1, which interacts with and thereby impairs proteasomes. In experimental MN, UCH-L1 becomes non-functional and MN patients with poor outcome exhibit autoantibodies with preferential reactivity to non-functional UCH-L1. Podocyte-specific deletion of UCH-L1 protects from experimental MN, whereas overexpression of non-functional UCH-L1 impairs podocyte proteostasis and drives injury in mice. In conclusion, the UPS is pathomechanistically linked to podocyte disease by aberrant proteasomal interactions of non-functional UCH-L1.
PMID:37055432 | DOI:10.1038/s41467-023-37836-8
Galectin-3 promotes secretion of proteases that decrease epithelium integrity in human colon cancer cells
Cell Death Dis. 2023 Apr 13;14(4):268. doi: 10.1038/s41419-023-05789-x.
ABSTRACT
Galectin-3 is a galactoside-binding protein that is commonly overexpressed in many epithelial cancers. It is increasingly recognized as a multi-functional, multi-mode promoter in cancer development, progression, and metastasis. This study reports that galectin-3 secretion by human colon cancer cells induces cancer cell secretion, in an autocrine/paracrine manner, of a number of proteases including cathepsin-B, MMP-1 and MMP-13. The secretion of these proteases causes disruption of epithelial monolayer integrity, increases its permeability and promotes tumour cell invasion. This effect of galectin-3 is shown to be mediated through induction of cellular PYK2-GSK3α/β signalling and can be prevented by the presence of galectin-3 binding inhibitors. This study thus reveals an important mechanism in galectin-3-mediated promotion of cancer progression and metastasis. It provides further evidence to the increased realization of galectin-3 as a potential therapeutic target for the treatment of cancer.
PMID:37055381 | DOI:10.1038/s41419-023-05789-x
Sphingosine Kinases Promote Ebola Virus Infection and Can Be Targeted to Inhibit Filoviruses, Coronaviruses, and Arenaviruses Using Late Endocytic Trafficking to Enter Cells
ACS Infect Dis. 2023 Apr 13. doi: 10.1021/acsinfecdis.2c00416. Online ahead of print.
ABSTRACT
Entry of enveloped viruses in host cells requires the fusion of viral and host cell membranes, a process that is facilitated by viral fusion proteins protruding from the viral envelope. These viral fusion proteins need to be triggered by host factors, and for some viruses, this event occurs inside endosomes and/or lysosomes. Consequently, these 'late-penetrating viruses' must be internalized and delivered to entry-conducive intracellular vesicles. Because endocytosis and vesicular trafficking are tightly regulated cellular processes, late-penetrating viruses also depend on specific host proteins for efficient delivery to the site of fusion, suggesting that these could be targeted for antiviral therapy. In this study, we investigated a role for sphingosine kinases (SKs) in viral entry and found that chemical inhibition of sphingosine kinase 1 (SK1) and/or SK2 and knockdown of SK1/2 inhibited entry of Ebola virus (EBOV) into host cells. Mechanistically, inhibition of SK1/2 prevented EBOV from reaching late-endosomes and lysosomes that contain the EBOV receptor, Niemann Pick C1 (NPC1). Furthermore, we present evidence that suggests that the trafficking defect caused by SK1/2 inhibition occurs independently of sphingosine-1-phosphate (S1P) signaling through cell-surface S1P receptors. Lastly, we found that chemical inhibition of SK1/2 prevents entry of other late-penetrating viruses, including arenaviruses and coronaviruses, and inhibits infection by replication-competent EBOV and SARS-CoV-2 in Huh7.5 cells. In sum, our results highlight an important role played by SK1/2 in endocytic trafficking, which can be targeted to inhibit entry of late-penetrating viruses and could serve as a starting point for the development of broad-spectrum antiviral therapeutics.
PMID:37053583 | DOI:10.1021/acsinfecdis.2c00416
Fibrosis in Pathology of Heart and Kidney: From Deep RNA-Sequencing to Novel Molecular Targets
Circ Res. 2023 Apr 14;132(8):1013-1033. doi: 10.1161/CIRCRESAHA.122.321761. Epub 2023 Apr 13.
ABSTRACT
Diseases of the heart and the kidney, including heart failure and chronic kidney disease, can dramatically impair life expectancy and the quality of life of patients. The heart and kidney form a functional axis; therefore, functional impairment of 1 organ will inevitably affect the function of the other. Fibrosis represents the common final pathway of diseases of both organs, regardless of the disease entity. Thus, inhibition of fibrosis represents a promising therapeutic approach to treat diseases of both organs and to resolve functional impairment. However, despite the growing knowledge in this field, the exact pathomechanisms that drive fibrosis remain elusive. RNA-sequencing approaches, particularly single-cell RNA-sequencing, have revolutionized the investigation of pathomechanisms at a molecular level and facilitated the discovery of disease-associated cell types and mechanisms. In this review, we give a brief overview over the evolution of RNA-sequencing techniques, summarize most recent insights into the pathogenesis of heart and kidney fibrosis, and discuss how transcriptomic data can be used, to identify new drug targets and to develop novel therapeutic strategies.
PMID:37053278 | DOI:10.1161/CIRCRESAHA.122.321761
Role of the Microbiome in Gut-Heart-Kidney Cross Talk
Circ Res. 2023 Apr 14;132(8):1064-1083. doi: 10.1161/CIRCRESAHA.123.321763. Epub 2023 Apr 13.
ABSTRACT
Homeostasis is a prerequisite for health. When homeostasis becomes disrupted, dysfunction occurs. This is especially the case for the gut microbiota, which under normal conditions lives in symbiosis with the host. As there are as many microbial cells in and on our body as human cells, it is unlikely they would not contribute to health or disease. The gut bacterial metabolism generates numerous beneficial metabolites but also uremic toxins and their precursors, which are transported into the circulation. Barrier function in the intestine, the heart, and the kidneys regulates metabolite transport and concentration and plays a role in inter-organ and inter-organism communication via small molecules. This communication is analyzed from the perspective of the remote sensing and signaling theory, which emphasizes the role of a large network of multispecific, oligospecific, and monospecific transporters and enzymes in regulating small-molecule homeostasis. The theory provides a systems biology framework for understanding organ cross talk and microbe-host communication involving metabolites, signaling molecules, nutrients, antioxidants, and uremic toxins. This remote small-molecule communication is critical for maintenance of homeostasis along the gut-heart-kidney axis and for responding to homeostatic perturbations. Chronic kidney disease is characterized by gut dysbiosis and accumulation of toxic metabolites. This slowly impacts the body, affecting the cardiovascular system and contributing to the progression of kidney dysfunction, which in its turn influences the gut microbiota. Preserving gut homeostasis and barrier functions or restoring gut dysbiosis and dysfunction could be a minimally invasive way to improve patient outcomes and quality of life in many diseases, including cardiovascular and kidney disease.
PMID:37053274 | DOI:10.1161/CIRCRESAHA.123.321763
Adaptive evolution of the Spike protein in coronaviruses
Mol Biol Evol. 2023 Apr 13:msad089. doi: 10.1093/molbev/msad089. Online ahead of print.
ABSTRACT
Coronaviruses are single-stranded, positive-sense RNA viruses that can infect many mammal and avian species. The Spike (S) protein of coronaviruses binds to a receptor on the host cell surface to promote viral entry. The interactions between the S proteins of coronaviruses and receptors of host cells are extraordinarily complex, with coronaviruses from different genera being able to recognize the same receptor and coronaviruses from the same genus able to bind distinct receptors. As the COVID-19 pandemic has developed, many changes in the S protein have been under positive selection by altering the receptor binding affinity, reducing antibody neutralization activities, or affecting T-cell responses. It is intriguing to determine whether the selection pressure on the S gene differs between SARS-CoV-2 and other coronaviruses due to the host shift from nonhuman animals to humans. Here, we show that the S gene, particularly the S1 region, has experienced positive selection in both SARS-CoV-2 and other coronaviruses. While the S1-NTD domain exhibits signals of positive selection in the pairwise comparisons in all four coronavirus genera, positive selection is primarily detected in the S1-CTD domain (the receptor-binding domain, RBD) in the ongoing evolution of SARS-CoV-2, possibly owing to the change in host settings and the widespread natural infection and SARS-CoV-2 vaccination in humans.
PMID:37052956 | DOI:10.1093/molbev/msad089
Single nucleotide variants in <em>Pseudomonas aeruginosa</em> populations from sputum correlate with baseline lung function and predict disease progression in individuals with cystic fibrosis
Microb Genom. 2023 Apr;9(4). doi: 10.1099/mgen.0.000981.
ABSTRACT
The severity and progression of lung disease are highly variable across individuals with cystic fibrosis (CF) and are imperfectly predicted by mutations in the human gene CFTR, lung microbiome variation or other clinical factors. The opportunistic pathogen Pseudomonas aeruginosa (Pa) dominates airway infections in most CF adults. Here we hypothesized that within-host genetic variation of Pa populations would be associated with lung disease severity. To quantify Pa genetic variation within CF sputum samples, we used deep amplicon sequencing (AmpliSeq) of 209 Pa genes previously associated with pathogenesis or adaptation to the CF lung. We trained machine learning models using Pa single nucleotide variants (SNVs), microbiome diversity data and clinical factors to classify lung disease severity at the time of sputum sampling, and to predict lung function decline after 5 years in a cohort of 54 adult CF patients with chronic Pa infection. Models using Pa SNVs alone classified lung disease severity with good sensitivity and specificity (area under the receiver operating characteristic curve: AUROC=0.87). Models were less predictive of lung function decline after 5 years (AUROC=0.74) but still significantly better than random. The addition of clinical data, but not sputum microbiome diversity data, yielded only modest improvements in classifying baseline lung function (AUROC=0.92) and predicting lung function decline (AUROC=0.79), suggesting that Pa AmpliSeq data account for most of the predictive value. Our work provides a proof of principle that Pa genetic variation in sputum tracks lung disease severity, moderately predicts lung function decline and could serve as a disease biomarker among CF patients with chronic Pa infections.
PMID:37052589 | DOI:10.1099/mgen.0.000981
EBD: an eye biomarker database
Bioinformatics. 2023 Apr 13:btad194. doi: 10.1093/bioinformatics/btad194. Online ahead of print.
ABSTRACT
MOTIVATION: Many ophthalmic disease biomarkers have been identified through comprehensive multi-omics profiling, and hold significant potential in advancing the diagnosis, prognosis, and management of diseases. Meanwhile, the eye itself serves as a natural biomarker for several systemic diseases including neurological, renal and cardiovascular systems. We aimed to collect and standardize these eye biomarkers information and construct the eye biomarker database (EBD) to provide ophthalmologists with a platform to search, analyse and download these eye biomarker data.
RESULTS: Data were collected from published papers, and the database was constructed based on the MySQL server. Biological network and functional analysis were conducted to analyse biomarkers in-network and pathway levels. In this study, we present the Eye Biomarker Database (EBD) <http://www.eyeseeworld.com/ebd/index.html>, a world-first online compilation comprising 889 biomarkers for 26 ocular diseases and 939 eye biomarkers for 181 systemic diseases. The EBD also includes the information of 78 "non-biomarkers"-the objects that have been proven cannot be biomarkers. Biological function and network analysis were conducted for these ocular disease biomarkers, and several hub pathways and common network topology characteristics were newly identified, which may promote future ocular disease biomarker discovery and characterizes the landscape of biomarkers for eye diseases at the pathway and network level. The EBD is expected to yield broader utility among developmental biologists and clinical scientists in and outside of the eye field by assisting in the identification of biomarkers linked to eye disorders and related systemic diseases.
AVAILABILITY: EBD is available at http://www.eyeseeworld.com/ebd/index.html.
SUPPLEMENTARY INFORMATION: Supplementary data are available at Bioinformatics online.
PMID:37052519 | DOI:10.1093/bioinformatics/btad194
Dicer-like 3a mediates intergenerational resistance against root-knot nematodes in rice via hormone responses
Plant Physiol. 2023 Apr 13:kiad215. doi: 10.1093/plphys/kiad215. Online ahead of print.
ABSTRACT
In a continuously changing and challenging environment, passing down the memory of encountered stress factors to offspring could provide an evolutionary advantage. In this study, we demonstrate the existence of 'intergenerational acquired resistance' in the progeny of rice (Oryza sativa) plants attacked by the belowground parasitic nematode Meloidogyne graminicola. Transcriptome analyses revealed that genes involved in defense pathways are generally downregulated in progeny of nematode-infected plants under uninfected conditions but show a stronger induction upon nematode infection. This phenomenon was termed "spring loading" and depends on initial downregulation by the 24nt siRNA biogenesis gene dicer-like 3a (dcl3a) involved in the RNA-directed DNA methylation pathway. Knock-down of dcl3a led to increased nematode susceptibility and abolished intergenerational acquired resistance, as well as jasmonic acid/ethylene spring loading in the offspring of infected plants. The importance of ethylene signaling in intergenerational resistance was confirmed by experiments on a knock-down line of ethylene insensitive 2 (ein2b), which lacks intergenerational acquired resistance. Taken together, these data indicate a role for DCL3a in regulating plant defense pathways during both within-generation and intergenerational resistance against nematodes in rice.
PMID:37052181 | DOI:10.1093/plphys/kiad215
A haptoglobin (HP) structural variant alters the effect of APOE alleles on Alzheimer's disease
Alzheimers Dement. 2023 Apr 12. doi: 10.1002/alz.13050. Online ahead of print.
ABSTRACT
BACKGROUND: Haptoglobin (HP) is an antioxidant of apolipoprotein E (APOE), and previous reports have shown HP binds with APOE and amyloid beta (Aβ) to aid its clearance. A common structural variant of the HP gene distinguishes it into two alleles: HP1 and HP2.
METHODS: HP genotypes were imputed in 29 cohorts from the Alzheimer's Disease Genetics Consortium (N = 20,512). Associations between the HP polymorphism and Alzheimer's disease (AD) risk and age of onset through APOE interactions were investigated using regression models.
RESULTS: The HP polymorphism significantly impacts AD risk in European-descent individuals (and in meta-analysis with African-descent individuals) by modifying both the protective effect of APOE ε2 and the detrimental effect of APOE ε4. The effect is particularly significant among APOE ε4 carriers.
DISCUSSION: The effect modification of APOE by HP suggests adjustment and/or stratification by HP genotype is warranted when APOE risk is considered. Our findings also provided directions for further investigations on potential mechanisms behind this association.
PMID:37051669 | DOI:10.1002/alz.13050
Genomic prediction and selection response for grain yield in safflower
Front Genet. 2023 Mar 27;14:1129433. doi: 10.3389/fgene.2023.1129433. eCollection 2023.
ABSTRACT
In plant breeding programs, multiple traits are recorded in each trial, and the traits are often correlated. Correlated traits can be incorporated into genomic selection models, especially for traits with low heritability, to improve prediction accuracy. In this study, we investigated the genetic correlation between important agronomic traits in safflower. We observed the moderate genetic correlations between grain yield (GY) and plant height (PH, 0.272-0.531), and low correlations between grain yield and days to flowering (DF, -0.157-0.201). A 4%-20% prediction accuracy improvement for grain yield was achieved when plant height was included in both training and validation sets with multivariate models. We further explored the selection responses for grain yield by selecting the top 20% of lines based on different selection indices. Selection responses for grain yield varied across sites. Simultaneous selection for grain yield and seed oil content (OL) showed positive gains across all sites with equal weights for both grain yield and oil content. Combining g×E interaction into genomic selection (GS) led to more balanced selection responses across sites. In conclusion, genomic selection is a valuable breeding tool for breeding high grain yield, oil content, and highly adaptable safflower varieties.
PMID:37051598 | PMC:PMC10083426 | DOI:10.3389/fgene.2023.1129433
Counteracting lineage-specific transcription factor network finely tunes lung adeno-to-squamous transdifferentiation through remodeling tumor immune microenvironment
Natl Sci Rev. 2023 Feb 14;10(4):nwad028. doi: 10.1093/nsr/nwad028. eCollection 2023 Apr.
ABSTRACT
Human lung adenosquamous cell carcinoma (LUAS), containing both adenomatous and squamous pathologies, harbors strong plasticity and is significantly associated with poor prognosis. We established an up-to-date comprehensive genomic and transcriptomic landscape of LUAS in 109 Chinese specimens and demonstrated LUAS development via adeno-to-squamous transdifferentiation. Unsupervised transcriptomic clustering and dynamic network biomarker analysis identified an inflammatory subtype as the critical transition stage during LUAS development. Dynamic dysregulation of the counteracting lineage-specific transcription factors (TFs), containing adenomatous TFs NKX2-1 and FOXA2, and squamous TFs TP63 and SOX2, finely tuned the lineage transition via promoting CXCL3/5-mediated neutrophil infiltration. Genomic clustering identified the most malignant subtype featured with STK11-inactivation, and targeting LSD1 through genetic deletion or pharmacological inhibition almost eradicated STK11-deficient lung tumors. These data collectively uncover the comprehensive molecular landscape, oncogenic driver spectrum and therapeutic vulnerability of Chinese LUAS.
PMID:37051524 | PMC:PMC10084920 | DOI:10.1093/nsr/nwad028