ABSTRACT
Dopamine (DA) is a central monoamine neurotransmitter involved in many physiological and pathological processes. A longstanding yet largely unmet goal is to measure DA changes reliably and specifically with high spatiotemporal precision, particularly in animals executing complex behaviors. Here, we report the development of genetically encoded GPCR-activation-based-DA (GRABDA) sensors that enable these measurements. In response to extracellular DA, GRABDA sensors exhibit large fluorescence increases (ΔF/F0 â¼90%) with subcellular resolution, subsecond kinetics, nanomolar to submicromolar affinities, and excellent molecular specificity. GRABDA sensors can resolve a single-electrical-stimulus-evoked DA release in mouse brain slices and detect endogenous DA release in living flies, fish, and mice. In freely behaving mice, GRABDA sensors readily report optogenetically elicited nigrostriatal DA release and depict dynamic mesoaccumbens DA signaling during Pavlovian conditioning or during sexual behaviors. Thus, GRABDA sensors enable spatiotemporally precise measurements of DA dynamics in a variety of model organisms while exhibiting complex behaviors.
Subject(s)
Dopamine/analysis , Drosophila/metabolism , Zebrafish/metabolism , Animals , Animals, Genetically Modified/genetics , Animals, Genetically Modified/metabolism , Behavior, Animal , Dopamine/metabolism , Female , Green Fluorescent Proteins/genetics , HEK293 Cells , Humans , Male , Mice , Mice, Inbred C57BL , Microscopy, Fluorescence , Neurons/cytology , Neurons/metabolism , Optogenetics/methods , Receptors, G-Protein-Coupled/genetics , TRPV Cation Channels/genetics , Zebrafish Proteins/geneticsABSTRACT
Virus-induced drought tolerance presents a fascinating facet of biotic-abiotic interaction in plants, yet its molecular intricacies remain unclear. Our study shows that cowpea mild mottle virus (CPMMV) infection enhances drought tolerance in common bean (Phaseolus vulgaris) plants through a virus-derived small interfering RNA (vsiRNA)-activated autophagy pathway. Specifically, a 21â nt vsiRNA originating from the CPMMV Triple Gene Block1 (TGB1) gene targeted the 5' untranslated region (UTR) of the host Teosinte branched 1, Cycloidea, Proliferating Cell Factor (TCP) transcription factor gene PvTCP2, independent of the known role of TGB1 as an RNA silencing suppressor. This targeting attenuated the expression of PvTCP2, which encodes a transcriptional repressor, and in turn upregulated the core autophagy-related gene (ATG) PvATG8c, leading to activated autophagy activity surpassing the level induced by drought or CPMMV infection alone. The downstream EARLY RESPONSIVE TO DEHYDRATION (ERD) effector PvERD15 is a homologue of Arabidopsis thaliana AtERD15, which positively regulates stomatal aperture. PvERD15 was degraded in PvATG8c-mediated autophagy. Therefore, we establish a TGB1-PvTCP2-PvATG8c-PvERD15 module as a trans-kingdom fine-tuning mechanism that contributes to virus-induced drought tolerance in plant-drought-virus interactions.
Subject(s)
Autophagy , Droughts , Gene Expression Regulation, Plant , RNA, Small Interfering , Autophagy/genetics , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism , Plant Proteins/genetics , Plant Proteins/metabolism , Phaseolus/virology , Phaseolus/genetics , Phaseolus/physiology , RNA, Messenger/genetics , RNA, Messenger/metabolism , RNA, Viral/genetics , RNA, Viral/metabolism , Comovirus/physiology , Comovirus/genetics , Plant Diseases/virology , Plant Diseases/genetics , Host-Pathogen Interactions/genetics , Drought ResistanceABSTRACT
Plasma membrane rupture (PMR) is the final cataclysmic event in lytic cell death. PMR releases intracellular molecules known as damage-associated molecular patterns (DAMPs) that propagate the inflammatory response1-3. The underlying mechanism of PMR, however, is unknown. Here we show that the cell-surface NINJ1 protein4-8, which contains two transmembrane regions, has an essential role in the induction of PMR. A forward-genetic screen of randomly mutagenized mice linked NINJ1 to PMR. Ninj1-/- macrophages exhibited impaired PMR in response to diverse inducers of pyroptotic, necrotic and apoptotic cell death, and were unable to release numerous intracellular proteins including HMGB1 (a known DAMP) and LDH (a standard measure of PMR). Ninj1-/- macrophages died, but with a distinctive and persistent ballooned morphology, attributable to defective disintegration of bubble-like herniations. Ninj1-/- mice were more susceptible than wild-type mice to infection with Citrobacter rodentium, which suggests a role for PMR in anti-bacterial host defence. Mechanistically, NINJ1 used an evolutionarily conserved extracellular domain for oligomerization and subsequent PMR. The discovery of NINJ1 as a mediator of PMR overturns the long-held idea that cell death-related PMR is a passive event.
Subject(s)
Cell Adhesion Molecules, Neuronal/metabolism , Cell Death , Cell Membrane/metabolism , Nerve Growth Factors/metabolism , Animals , Apoptosis , Cell Adhesion Molecules, Neuronal/chemistry , Cell Adhesion Molecules, Neuronal/genetics , Cell Death/genetics , Female , Humans , Macrophages , Male , Mice , Mutation , Necrosis , Nerve Growth Factors/chemistry , Nerve Growth Factors/genetics , Protein Multimerization , Pyroptosis/geneticsABSTRACT
The striato-nigral (Str-SN) circuit is composed of medium spiny neuronal projections that are mainly sent from the striatum to the midbrain substantial nigra (SN), which is essential for regulating motor behaviors. Dysfunction of the Str-SN circuitry may cause a series of motor disabilities that are associated with neurodegenerative disorders, such as Huntington's disease (HD). Although the etiology of HD is known as abnormally expanded CAG repeats of the huntingtin gene, treatment of HD remains tremendously challenging. One possible reason is the lack of effective HD model that resembles Str-SN circuitry deficits for pharmacological studies. Here, we first differentiated striatum-like organoids from human pluripotent stem cells (hPSCs), containing functional medium spiny neurons (MSNs). We then generated 3D Str-SN assembloids by assembling striatum-like organoids with midbrain SN-like organoids. With AAV-hSYN-GFP-mediated viral tracing, extensive MSN projections from the striatum to the SN are established, which formed synaptic connection with GABAergic neurons in SN organoids and showed the optically evoked inhibitory postsynaptic currents and electronic field potentials by labeling the striatum-like organoids with optogenetic virus. Furthermore, these Str-SN assembloids exhibited enhanced calcium activity compared to that of individual striatal organoids. Importantly, we further demonstrated the reciprocal projection defects in HD iPSC-derived assembloids, which could be ameliorated by treatment of brain-derived neurotrophic factor. Taken together, these findings suggest that Str-SN assembloids could be used for identifying MSN projection defects and could be applied as potential drug test platforms for HD.
Subject(s)
Huntington Disease , Organoids , Humans , Huntington Disease/pathology , Huntington Disease/metabolism , Organoids/pathology , Organoids/metabolism , Substantia Nigra/pathology , Substantia Nigra/metabolism , Corpus Striatum/pathology , Corpus Striatum/metabolism , Neurons/metabolism , Neurons/pathology , Cell Differentiation , GABAergic Neurons/metabolism , GABAergic Neurons/pathology , Pluripotent Stem Cells/metabolism , OptogeneticsABSTRACT
The female reproductive lifespan is highly dependent on egg quality, especially the presence of a normal number of chromosomes in an egg, known as euploidy. Mistakes in meiosis leading to egg aneuploidy are frequent in humans. Yet, knowledge of the precise genetic landscape that causes egg aneuploidy in women is limited, as phenotypic data on the frequency of human egg aneuploidy are difficult to obtain and therefore absent in public genetic datasets. Here, we identify genetic determinants of reproductive aging via egg aneuploidy in women using a biobank of individual maternal exomes linked with maternal age and embryonic aneuploidy data. Using the exome data, we identified 404 genes bearing variants enriched in individuals with pathologically elevated egg aneuploidy rates. Analysis of the gene ontology and protein-protein interaction network implicated genes encoding the kinesin protein family in egg aneuploidy. We interrogate the causal relationship of the human variants within candidate kinesin genes via experimental perturbations and demonstrate that motor domain variants increase aneuploidy in mouse oocytes. Finally, using a knock-in mouse model, we validate that a specific variant in kinesin KIF18A accelerates reproductive aging and diminishes fertility. These findings reveal additional functional mechanisms of reproductive aging and shed light on how genetic variation underlies individual heterogeneity in the female reproductive lifespan, which might be leveraged to predict reproductive longevity. Together, these results lay the groundwork for the noninvasive biomarkers for egg quality, a first step toward personalized fertility medicine.
Subject(s)
Aneuploidy , Kinesins , Oocytes , Kinesins/genetics , Kinesins/metabolism , Female , Humans , Animals , Mice , Oocytes/metabolism , Genetic Variation , Ovum/metabolism , Maternal Age , Adult , Meiosis/geneticsABSTRACT
CD11b(+) dendritic cells (DCs) seem to be specialized for presenting antigens via major histocompatibility (MHC) class II complexes to stimulate helper T cells, but the genetic and regulatory basis for this is not established. Conditional deletion of Irf4 resulted in loss of CD11b(+) DCs, impaired formation of peptide-MHC class II complexes and defective priming of helper T cells but not of cytotoxic T lymphocyte (CTL) responses. Gene expression and chromatin immunoprecipitation followed by deep sequencing (ChIP-Seq) analyses delineated an IRF4-dependent regulatory module that programs enhanced MHC class II antigen presentation. Expression of the transcription factor IRF4 but not of IRF8 restored the ability of IRF4-deficient DCs to efficiently process and present antigen to MHC class II-restricted T cells and promote helper T cell responses. We propose that the evolutionary divergence of IRF4 and IRF8 facilitated the specialization of DC subsets for distinct modes of antigen presentation and priming of helper T cell versus CTL responses.
Subject(s)
Antigen Presentation/genetics , Dendritic Cells/immunology , Histocompatibility Antigens Class II/immunology , Interferon Regulatory Factors/metabolism , T-Lymphocytes, Cytotoxic/immunology , T-Lymphocytes, Helper-Inducer/immunology , Animals , Cell Differentiation/genetics , Cell Differentiation/immunology , Cells, Cultured , Gene Expression Profiling , Gene Expression Regulation/genetics , Gene Expression Regulation/immunology , Histocompatibility Antigens Class II/genetics , Interferon Regulatory Factors/genetics , Lymphocyte Activation/genetics , Mice , Mice, Inbred C57BL , Mice, Knockout , Protein Binding/genetics , Transgenes/geneticsABSTRACT
ABSTRACT: Venetoclax, the first-generation inhibitor of the apoptosis regulator B-cell lymphoma 2 (BCL2), disrupts the interaction between BCL2 and proapoptotic proteins, promoting the apoptosis in malignant cells. Venetoclax is the mainstay of therapy for relapsed chronic lymphocytic leukemia and is under investigation in multiple clinical trials for the treatment of various cancers. Although venetoclax treatment can result in high rates of durable remission, relapse has been widely observed, indicating the emergence of drug resistance. The G101V mutation in BCL2 is frequently observed in patients who relapsed treated with venetoclax and sufficient to confer resistance to venetoclax by interfering with compound binding. Therefore, the development of next-generation BCL2 inhibitors to overcome drug resistance is urgently needed. In this study, we discovered that sonrotoclax, a potent and selective BCL2 inhibitor, demonstrates stronger cytotoxic activity in various hematologic cancer cells and more profound tumor growth inhibition in multiple hematologic tumor models than venetoclax. Notably, sonrotoclax effectively inhibits venetoclax-resistant BCL2 variants, such as G101V. The crystal structures of wild-type BCL2/BCL2 G101V in complex with sonrotoclax revealed that sonrotoclax adopts a novel binding mode within the P2 pocket of BCL2 and could explain why sonrotoclax maintains stronger potency than venetoclax against the G101V mutant. In summary, sonrotoclax emerges as a potential second-generation BCL2 inhibitor for the treatment of hematologic malignancies with the potential to overcome BCL2 mutation-induced venetoclax resistance. Sonrotoclax is currently under investigation in multiple clinical trials.
Subject(s)
Antineoplastic Agents , Bridged Bicyclo Compounds, Heterocyclic , Drug Resistance, Neoplasm , Hematologic Neoplasms , Proto-Oncogene Proteins c-bcl-2 , Sulfonamides , Proto-Oncogene Proteins c-bcl-2/genetics , Proto-Oncogene Proteins c-bcl-2/antagonists & inhibitors , Proto-Oncogene Proteins c-bcl-2/metabolism , Sulfonamides/pharmacology , Bridged Bicyclo Compounds, Heterocyclic/pharmacology , Bridged Bicyclo Compounds, Heterocyclic/therapeutic use , Humans , Drug Resistance, Neoplasm/drug effects , Drug Resistance, Neoplasm/genetics , Animals , Hematologic Neoplasms/drug therapy , Hematologic Neoplasms/genetics , Hematologic Neoplasms/pathology , Mice , Antineoplastic Agents/pharmacology , Antineoplastic Agents/therapeutic use , Xenograft Model Antitumor Assays , Cell Line, Tumor , Mutation , Apoptosis/drug effectsABSTRACT
Lipopolysaccharide (LPS) resides in the outer membrane of Gram-negative bacteria where it is responsible for barrier function1,2. LPS can cause death as a result of septic shock, and its lipid A core is the target of polymyxin antibiotics3,4. Despite the clinical importance of polymyxins and the emergence of multidrug resistant strains5, our understanding of the bacterial factors that regulate LPS biogenesis is incomplete. Here we characterize the inner membrane protein PbgA and report that its depletion attenuates the virulence of Escherichia coli by reducing levels of LPS and outer membrane integrity. In contrast to previous claims that PbgA functions as a cardiolipin transporter6-9, our structural analyses and physiological studies identify a lipid A-binding motif along the periplasmic leaflet of the inner membrane. Synthetic PbgA-derived peptides selectively bind to LPS in vitro and inhibit the growth of diverse Gram-negative bacteria, including polymyxin-resistant strains. Proteomic, genetic and pharmacological experiments uncover a model in which direct periplasmic sensing of LPS by PbgA coordinates the biosynthesis of lipid A by regulating the stability of LpxC, a key cytoplasmic biosynthetic enzyme10-12. In summary, we find that PbgA has an unexpected but essential role in the regulation of LPS biogenesis, presents a new structural basis for the selective recognition of lipids, and provides opportunities for future antibiotic discovery.
Subject(s)
Cell Membrane/chemistry , Escherichia coli Proteins/chemistry , Escherichia coli Proteins/metabolism , Escherichia coli/chemistry , Escherichia coli/pathogenicity , Lipopolysaccharides/chemistry , Lipopolysaccharides/metabolism , Amidohydrolases/chemistry , Amidohydrolases/metabolism , Amino Acid Motifs , Bacterial Outer Membrane/chemistry , Bacterial Outer Membrane/metabolism , Binding Sites , Cell Membrane/metabolism , Enzyme Stability , Escherichia coli/cytology , Escherichia coli/drug effects , Genes, Essential , Hydrolases/chemistry , Hydrolases/metabolism , Lipid A/chemistry , Lipid A/metabolism , Lipopolysaccharides/biosynthesis , Microbial Sensitivity Tests , Microbial Viability/drug effects , Models, Molecular , Peptide Fragments/chemistry , Peptide Fragments/metabolism , Peptide Fragments/pharmacology , Periplasm/chemistry , Periplasm/metabolism , Protein Binding , VirulenceABSTRACT
Mutations in the death receptor FAS1,2 or its ligand FASL3 cause autoimmune lymphoproliferative syndrome, whereas mutations in caspase-8 or its adaptor FADD-which mediate cell death downstream of FAS and FASL-cause severe immunodeficiency in addition to autoimmune lymphoproliferative syndrome4-6. Mouse models have corroborated a role for FADD-caspase-8 in promoting inflammatory responses7-12, but the mechanisms that underlie immunodeficiency remain undefined. Here we identify NEDD4-binding protein 1 (N4BP1) as a suppressor of cytokine production that is cleaved and inactivated by caspase-8. N4BP1 deletion in mice increased the production of select cytokines upon stimulation of the Toll-like receptor (TLR)1-TLR2 heterodimer (referred to herein as TLR1/2), TLR7 or TLR9, but not upon engagement of TLR3 or TLR4. N4BP1 did not suppress TLR3 or TLR4 responses in wild-type macrophages, owing to TRIF- and caspase-8-dependent cleavage of N4BP1. Notably, the impaired production of cytokines in response to TLR3 and TLR4 stimulation of caspase-8-deficient macrophages13 was largely rescued by co-deletion of N4BP1. Thus, the persistence of intact N4BP1 in caspase-8-deficient macrophages impairs their ability to mount robust cytokine responses. Tumour necrosis factor (TNF), like TLR3 or TLR4 agonists, also induced caspase-8-dependent cleavage of N4BP1, thereby licensing TRIF-independent TLRs to produce higher levels of inflammatory cytokines. Collectively, our results identify N4BP1 as a potent suppressor of cytokine responses; reveal N4BP1 cleavage by caspase-8 as a point of signal integration during inflammation; and offer an explanation for immunodeficiency caused by mutations of FADD and caspase-8.
Subject(s)
Caspase 8/metabolism , Cytokines/immunology , Immunity, Innate/immunology , Nuclear Proteins/metabolism , RNA-Binding Proteins/metabolism , Adaptor Proteins, Vesicular Transport/metabolism , Animals , Cells, Cultured , Cytokines/antagonists & inhibitors , Humans , Inflammation/immunology , Mice , Mice, Inbred C57BL , Toll-Like Receptor 3/metabolism , Toll-Like Receptor 4/metabolism , Tumor Necrosis Factor-alpha/immunology , Tumor Necrosis Factor-alpha/metabolismABSTRACT
Cryoelectron tomography directly visualizes heterogeneous macromolecular structures in their native and complex cellular environments. However, existing computer-assisted structure sorting approaches are low throughput or inherently limited due to their dependency on available templates and manual labels. Here, we introduce a high-throughput template-and-label-free deep learning approach, Deep Iterative Subtomogram Clustering Approach (DISCA), that automatically detects subsets of homogeneous structures by learning and modeling 3D structural features and their distributions. Evaluation on five experimental cryo-ET datasets shows that an unsupervised deep learning based method can detect diverse structures with a wide range of molecular sizes. This unsupervised detection paves the way for systematic unbiased recognition of macromolecular complexes in situ.
Subject(s)
Electron Microscope Tomography , Image Processing, Computer-Assisted , Image Processing, Computer-Assisted/methods , Cluster Analysis , Molecular Structure , Electron Microscope Tomography/methods , Macromolecular Substances/chemistry , Cryoelectron Microscopy/methodsABSTRACT
The purinergic signaling molecule adenosine (Ado) modulates many physiological and pathological functions in the brain. However, the exact source of extracellular Ado remains controversial. Here, utilizing a newly optimized genetically encoded GPCR-Activation-Based Ado fluorescent sensor (GRABAdo), we discovered that the neuronal activity-induced extracellular Ado elevation is due to direct Ado release from somatodendritic compartments of neurons, rather than from the axonal terminals, in the hippocampus. Pharmacological and genetic manipulations reveal that the Ado release depends on equilibrative nucleoside transporters but not the conventional vesicular release mechanisms. Compared with the fast-vesicular glutamate release, the Ado release is slow (~40 s) and requires calcium influx through L-type calcium channels. Thus, this study reveals an activity-dependent second-to-minute local Ado release from the somatodendritic compartments of neurons, potentially serving modulatory functions as a retrograde signal.
Subject(s)
Adenosine , Neurons , Adenosine/pharmacology , Nucleoside Transport Proteins/genetics , Signal Transduction/physiology , Guanine Nucleotide Exchange Factors/metabolismABSTRACT
Plant intracellular nucleotide-binding domain, leucine-rich repeat-containing receptors (NLRs) activate a robust immune response upon detection of pathogen effectors. How NLRs induce downstream immune defense genes remains poorly understood. The Mediator complex plays a central role in transducing signals from gene-specific transcription factors to the transcription machinery for gene transcription/activation. In this study, we demonstrate that MED10b and MED7 of the Mediator complex mediate jasmonate-dependent transcription repression, and coiled-coil NLRs (CNLs) in Solanaceae modulate MED10b/MED7 to activate immunity. Using the tomato CNL Sw-5b, which confers resistance to tospovirus, as a model, we found that the CC domain of Sw-5b directly interacts with MED10b. Knockout/down of MED10b and other subunits including MED7 of the middle module of Mediator activates plant defense against tospovirus. MED10b was found to directly interact with MED7, and MED7 directly interacts with JAZ proteins, which function as transcriptional repressors of jasmonic acid (JA) signaling. MED10b-MED7-JAZ together can strongly repress the expression of JA-responsive genes. The activated Sw-5b CC interferes with the interaction between MED10b and MED7, leading to the activation of JA-dependent defense signaling against tospovirus. Furthermore, we found that CC domains of various other CNLs including helper NLR NRCs from Solanaceae modulate MED10b/MED7 to activate defense against different pathogens. Together, our findings reveal that MED10b/MED7 serve as a previously unknown repressor of jasmonate-dependent transcription repression and are modulated by diverse CNLs in Solanaceae to activate the JA-specific defense pathways.
Subject(s)
Arabidopsis Proteins , Plant Immunity , Plant Immunity/genetics , Cyclopentanes , Transcription Factors/genetics , Transcription Factors/metabolism , Mediator Complex/genetics , Mediator Complex/metabolism , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolismABSTRACT
The low CO2-inducible NDH complex (NDH-1MS) plays a crucial role in the cyanobacterial CO2-concentrating mechanism. However, the components in this complex and the regulation mechanism are still not completely understood. Using a mutant only with NDH-1MS as active Ci sequestration system, we identified a functional gene sll1736 named as cupAR (CupA Regulator). The cupAR deletion mutant, ΔcupAR, grew faster than the WT under high CO2 (HC) condition, more evidently at low pH. The activities of O2 evolution, CO2 uptakeï¼NDH-1, and the building up of a transthylakoid proton were stimulated in this mutant under HC conditions. The cupAR gene is cotranscribed with the NDH-1S operon (ndhF3-ndhD3-cupA) and encoded protein, which specifically suppresses the transcription level of this operon under HC conditions. Mutation of cupAR significantly upregulated the accumulation of CupA, the key protein of NDH-1MS, under HC condition. CupAR interacted with NdhD3 and NdhF3, the membrane components of NDH-1MS, while accumulation of CupAR was reduced in the ΔndhD3 mutant. Furthermore, CupAR was colocated with CupA in both NDH-1MS complex and NDH-1S subcomplex. On the other hand, deletion of ndhR, a negative regulator of the NDH-1S operon, increased the accumulation of CupAR, whereas deletion of cupAR significantly lowered NdhR. Based on these results, we concluded that CupAR is a novel subunit of NDH-1MS, negatively regulating the activities of CupA and CO2 uptake dependent on NDH-1MS by positive regulation of NdhR under enriched CO2 conditions.
Subject(s)
Bacterial Proteins , Gene Expression Regulation, Bacterial , Synechocystis , Synechocystis/metabolism , Synechocystis/genetics , Bacterial Proteins/metabolism , Bacterial Proteins/genetics , Operon , Carbon Dioxide/metabolism , Carbon/metabolismABSTRACT
The sophisticated regulation of state transition is required to maintain optimal photosynthetic performance under fluctuating light condition, through balancing the absorbed light energy between photosystem II and photosystem I. This exquisite process incorporates phosphorylation and dephosphorylation of light-harvesting complexes and PSII core subunits, accomplished by thylakoid membrane-localized kinases and phosphatases that have not been fully identified. In this study, one Chlamydomonas high light response gene, THYLAKOID ENRICHED FRACTION 8 (TEF8), was characterized. The Chlamydomonas tef8 mutant showed high light sensitivity and defective state transition. The enzymatic activity assays showed that TEF8 is a bona fide phosphatase localized in thylakoid membranes. Biochemical assays, including BN-PAGE, pull-down, and phosphopeptide mass spectrometry, proved that TEF8 associates with photosystem II and is involved in the dephosphorylation of D2 and CP29 subunits during state 2 to state 1 transition. Taken together, our results identified TEF8 as a thylakoid phosphatase with multiple dephosphorylation targets on photosystem II, and provide new insight into the regulatory mechanism of state transition and high light resistance in Chlamydomonas.
ABSTRACT
Recent evidence has shown that presenilin enhancer 2 (Pen2; Psenen) plays an essential role in corticogenesis by regulating the switch of apical progenitors (APs) to basal progenitors (BPs). The hippocampus is a brain structure required for advanced functions, including spatial navigation, learning and memory. However, it remains unknown whether Pen2 is important for hippocampal morphogenesis. To address this question, we generated Pen2 conditional knockout (cKO) mice, in which Pen2 is inactivated in neural progenitor cells (NPCs) in the hippocampal primordium. We showed that Pen2 cKO mice exhibited hippocampal malformation and decreased population of NPCs in the neuroepithelium of the hippocampus. We found that deletion of Pen2 neither affected the proliferative capability of APs nor the switch of APs to BPs in the hippocampus, and that it caused enhanced transition of APs to neurons. We demonstrated that expression of the Notch1 intracellular domain (N1ICD) significantly increased the population of NPCs in the Pen2 cKO hippocampus. Collectively, this study uncovers a crucial role for Pen2 in the maintenance of NPCs during hippocampal development.
Subject(s)
Hippocampus , Neurons , Animals , Hippocampus/metabolism , Mice , Mice, Inbred C57BL , Mice, Knockout , Neurogenesis/genetics , Neurons/metabolism , Presenilins/metabolismABSTRACT
MOTIVATION: Deep learning models have achieved remarkable success in a wide range of natural-world tasks, such as vision, language, and speech recognition. These accomplishments are largely attributed to the availability of open-source large-scale datasets. More importantly, pre-trained foundational modellearnings exhibit a surprising degree of transferability to downstream tasks, enabling efficient learning even with limited training examples. However, the application of such natural-domain models to the domain of tiny Cryo-Electron Tomography (Cryo-ET) images has been a relatively unexplored frontier. This research is motivated by the intuition that 3D Cryo-ET voxel data can be conceptually viewed as a sequence of progressively evolving video frames. RESULTS: Leveraging the above insight, we propose a novel approach that involves the utilization of 3D models pre-trained on large-scale video datasets to enhance Cryo-ET subtomogram classification. Our experiments, conducted on both simulated and real Cryo-ET datasets, reveal compelling results. The use of video initialization not only demonstrates improvements in classification accuracy but also substantially reduces training costs. Further analyses provide additional evidence of the value of video initialization in enhancing subtomogram feature extraction. Additionally, we observe that video initialization yields similar positive effects when applied to medical 3D classification tasks, underscoring the potential of cross-domain knowledge transfer from video-based models to advance the state-of-the-art in a wide range of biological and medical data types. AVAILABILITY AND IMPLEMENTATION: https://github.com/xulabs/aitom.
ABSTRACT
Type 2 innate lymphoid cells (ILC2 cells) participate in host defense against helminth parasites and in allergic inflammation. Given their functional relatedness to type 2 helper T cells (T(H)2 cells), we explored whether Gfi1 acts as a shared transcriptional determinant in ILC2 cells. Gfi1 promoted the development of ILC2 cells and controlled their responsiveness during infection with Nippostrongylus brasiliensis and protease allergen-induced lung inflammation. Gfi1 'preferentially' regulated the responsiveness of ILC2 cells to interleukin 33 (IL-33) by directly activating Il1rl1, which encodes the IL-33 receptor (ST2). Loss of Gfi1 in activated ILC2 cells resulted in impaired expression of the transcription factor GATA-3 and a dysregulated genome-wide effector state characterized by coexpression of IL-13 and IL-17. Our findings establish Gfi1 as a shared determinant that reciprocally regulates the type 2 and IL-17 effector states in cells of the innate and adaptive immune systems.
Subject(s)
DNA-Binding Proteins/immunology , Immunity, Innate/immunology , Th2 Cells/immunology , Transcription Factors/immunology , Transcriptome/immunology , Animals , Bronchoalveolar Lavage Fluid/chemistry , Bronchoalveolar Lavage Fluid/immunology , Cells, Cultured , DNA-Binding Proteins/genetics , DNA-Binding Proteins/metabolism , Flow Cytometry , GATA3 Transcription Factor/genetics , GATA3 Transcription Factor/immunology , GATA3 Transcription Factor/metabolism , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , Interleukin-1 Receptor-Like 1 Protein , Interleukin-13/genetics , Interleukin-13/immunology , Interleukin-13/metabolism , Interleukin-17/genetics , Interleukin-17/immunology , Interleukin-17/metabolism , Interleukin-33 , Interleukins/pharmacology , Lung/immunology , Lung/metabolism , Lymphocyte Activation/drug effects , Lymphocyte Activation/immunology , Mice , Mice, Inbred Strains , Mice, Knockout , Mice, Transgenic , Nippostrongylus/immunology , Nippostrongylus/physiology , Oligonucleotide Array Sequence Analysis , Receptors, Interleukin/genetics , Receptors, Interleukin/immunology , Receptors, Interleukin/metabolism , Reverse Transcriptase Polymerase Chain Reaction , Strongylida Infections/immunology , Strongylida Infections/parasitology , Th2 Cells/metabolism , Th2 Cells/parasitology , Transcription Factors/genetics , Transcription Factors/metabolism , Transcriptome/geneticsABSTRACT
Aluminum-activated malate transporters (ALMTs) and slow anion channels (SLACs) are important in various physiological processes in plants, including stomatal regulation, nutrient uptake, and in response to abiotic stress such as aluminum toxicity. To understand their evolutionary history and functional divergence, we conducted phylogenetic and expression analyses of ALMTs and SLACs in green plants. Our findings from phylogenetic studies indicate that ALMTs and SLACs may have originated from green algae and red algae, respectively. The ALMTs of early land plants and charophytes formed a monophyletic clade consisting of three subgroups. A single duplication event of ALMTs was identified in vascular plants and subsequent duplications into six clades occurred in angiosperms, including an identified clade, 1-1. The ALMTs experienced gene number losses in clades 1-1 and 2-1 and expansions in clades 1-2 and 2-2b. Interestingly, the expansion of clade 1-2 was also associated with higher expression levels compared to genes in clades that experienced apparent loss. SLACs first diversified in bryophytes, followed by duplication in vascular plants, giving rise to three distinct clades (I, II, and III), and clade II potentially associated with stomatal control in seed plants. SLACs show losses in clades II and III without substantial expansion in clade I. Additionally, ALMT clade 2-2 and SLAC clade III contain genes specifically expressed in reproductive organs and roots in angiosperms, lycophytes, and mosses, indicating neofunctionalization. In summary, our study demonstrates the evolutionary complexity of ALMTs and SLACs, highlighting their crucial role in the adaptation and diversification of vascular plants.
Subject(s)
Magnoliopsida , Plant Proteins , Phylogeny , Plant Proteins/genetics , Plant Proteins/metabolism , Aluminum/metabolism , Plants/genetics , Plants/metabolism , Biological Evolution , Magnoliopsida/genetics , Evolution, MolecularABSTRACT
Cold tolerance at the booting (CTB) stage is a major factor limiting rice (Oryza sativa L.) productivity and geographical distribution. A few cold-tolerance genes have been identified, but they either need to be overexpressed to result in CTB or cause yield penalties, limiting their utility for breeding. Here, we characterize the function of the cold-induced transcription factor WRKY53 in rice. The wrky53 mutant displays increased CTB, as determined by higher seed setting. Low temperature is associated with lower gibberellin (GA) contents in anthers in the wild type but not in the wrky53 mutant, which accumulates slightly more GA in its anthers. WRKY53 directly binds to the promoters of GA biosynthesis genes and transcriptionally represses them in anthers. In addition, we uncover a possible mechanism by which GA regulates male fertility: SLENDER RICE1 (SLR1) interacts with and sequesters two critical transcription factors for tapetum development, UNDEVELOPED TAPETUM1 (UDT1), and TAPETUM DEGENERATION RETARDATION (TDR), and GA alleviates the sequestration by SLR1, thus allowing UDT1 and TDR to activate transcription. Finally, knocking out WRKY53 in diverse varieties increases cold tolerance without a yield penalty, leading to a higher yield in rice subjected to cold stress. Together, these findings provide a target for improving CTB in rice.
Subject(s)
Oryza , Oryza/metabolism , Gibberellins/metabolism , Gene Expression Regulation, Plant/genetics , Plant Proteins/genetics , Plant Proteins/metabolism , Genes, Plant , Transcription Factors/genetics , Transcription Factors/metabolismABSTRACT
Regulatory T cells (Tregs) ameliorate inflammatory bowel diseases. However, their plasticity is not completely understood. In this study using a mouse colitis model, Tregs and T helper 17 (Th17)-like Tregs were detected and sorted using flow cytometry, followed by transcriptome sequencing, real-time RT-PCR, and flow cytometry to analyze the mRNA profiles of these cells. Treg plasticity was evaluated by in vitro differentiation assays. The immunosuppressive activities of Tregs and Th17-like Tregs were assessed in an adoptive transfer assay. We found Tregs-derived Th17-like Tregs in inflamed colonic lamina propria (LP). LP Th17-like Tregs expressed higher Th17-related cytokines and lower immunosuppressive cytokines compared with LP Tregs. Notably, Tregs expressed higher Yes-associated protein 1 (YAP1) but lower transcriptional coactivator with PDZbinding motif (TAZ) than Th17-like Tregs. Verteporfin-mediated inhibition of YAP1 activity enhanced Th17-like Treg generation, whereas IBS008739-induced TAZ activation did not affect Th17-like Treg generation. Besides, verteporfin enhanced while IBS008739 suppressed the differentiation of Th17-like Tregs into Th17 cells. Furthermore, YAP1 activated STAT5 signaling in Tregs, whereas YAP1 and TAZ activated STAT3 and STAT5 signaling in Th17-like Tregs. Compared with Tregs, Th17-like Tregs were less efficacious in ameliorating colitis. Therefore, YAP1 suppressed Treg differentiation into Th17-like Tregs. Both YAP1 and TAZ inhibited the differentiation of Th17-like Tregs into Th17 cells. Therefore, YAP1 and TAZ probably maintain the immunosuppressive activities of Tregs and Th17-like Tregs in colitis.