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1.
Cell ; 184(1): 243-256.e18, 2021 01 07.
Article in English | MEDLINE | ID: mdl-33417861

ABSTRACT

Craniosynostosis results from premature fusion of the cranial suture(s), which contain mesenchymal stem cells (MSCs) that are crucial for calvarial expansion in coordination with brain growth. Infants with craniosynostosis have skull dysmorphology, increased intracranial pressure, and complications such as neurocognitive impairment that compromise quality of life. Animal models recapitulating these phenotypes are lacking, hampering development of urgently needed innovative therapies. Here, we show that Twist1+/- mice with craniosynostosis have increased intracranial pressure and neurocognitive behavioral abnormalities, recapitulating features of human Saethre-Chotzen syndrome. Using a biodegradable material combined with MSCs, we successfully regenerated a functional cranial suture that corrects skull deformity, normalizes intracranial pressure, and rescues neurocognitive behavior deficits. The regenerated suture creates a niche into which endogenous MSCs migrated, sustaining calvarial bone homeostasis and repair. MSC-based cranial suture regeneration offers a paradigm shift in treatment to reverse skull and neurocognitive abnormalities in this devastating disease.


Subject(s)
Cognition/physiology , Cranial Sutures/physiopathology , Craniosynostoses/physiopathology , Regeneration/physiology , Skull/physiopathology , Animals , Behavior, Animal/drug effects , Cognition/drug effects , Craniosynostoses/genetics , Dura Mater/pathology , Dura Mater/physiopathology , Gelatin/pharmacology , Gene Expression Profiling , Hand Strength , Intracranial Pressure/drug effects , Intracranial Pressure/physiology , Locomotion/drug effects , Mesenchymal Stem Cells/drug effects , Methacrylates/pharmacology , Mice, Inbred C57BL , Motor Activity/drug effects , Organ Size/drug effects , Regeneration/drug effects , Skull/pathology , Twist-Related Protein 1/metabolism , Wnt Signaling Pathway/drug effects
2.
Cell ; 162(1): 198-210, 2015 Jul 02.
Article in English | MEDLINE | ID: mdl-26140597

ABSTRACT

Histidine phosphorylation (pHis) is well studied in bacteria; however, its role in mammalian signaling remains largely unexplored due to the lack of pHis-specific antibodies and the lability of the phosphoramidate (P-N) bond. Both imidazole nitrogens can be phosphorylated, forming 1-phosphohistidine (1-pHis) or 3-phosphohistidine (3-pHis). We have developed monoclonal antibodies (mAbs) that specifically recognize 1-pHis or 3-pHis; they do not cross-react with phosphotyrosine or the other pHis isomer. Assays based on the isomer-specific autophosphorylation of NME1 and phosphoglycerate mutase were used with immunoblotting and sequencing IgG variable domains to screen, select, and characterize anti-1-pHis and anti-3-pHis mAbs. Their sequence independence was determined by blotting synthetic peptide arrays, and they have been tested for immunofluorescence staining and immunoaffinity purification, leading to putative identification of pHis-containing proteins. These reagents should be broadly useful for identification of pHis substrates and functional study of pHis using a variety of immunological, proteomic, and biological assays.


Subject(s)
Antibodies, Monoclonal , Histidine/metabolism , Animals , Centrosome , Chromatography, Liquid , HeLa Cells , Humans , Models, Chemical , Peptides/analysis , Phosphorylation , Spindle Poles , Tandem Mass Spectrometry
3.
Genes Dev ; 36(17-18): 1016-1030, 2022 09 01.
Article in English | MEDLINE | ID: mdl-36302555

ABSTRACT

Deubiquitylating enzymes (DUBs) remove ubiquitin chains from proteins and regulate protein stability and function. USP7 is one of the most extensively studied DUBs, since USP7 has several well-known substrates important for cancer progression, such as MDM2, N-MYC, and PTEN. Thus, USP7 is a promising drug target. However, systematic identification of USP7 substrates has not yet been performed. In this study, we carried out proteome profiling with label-free quantification in control and single/double-KO cells of USP7and its closest homolog, USP47 Our proteome profiling for the first time revealed the proteome changes caused by USP7 and/or USP47 depletion. Combining protein profiling, transcriptome analysis, and tandem affinity purification of USP7-associated proteins, we compiled a list of 20 high-confidence USP7 substrates that includes known and novel USP7 substrates. We experimentally validated MGA and PHIP as new substrates of USP7. We further showed that MGA deletion reduced cell proliferation, similar to what was observed in cells with USP7 deletion. In conclusion, our proteome-wide analysis uncovered potential USP7 substrates, providing a resource for further functional studies.


Subject(s)
Proteomics , Ubiquitin Thiolesterase , Ubiquitin-Specific Peptidase 7/metabolism , Ubiquitin Thiolesterase/genetics , Ubiquitin Thiolesterase/metabolism , Proteome , Ubiquitin/metabolism , Ubiquitination
4.
Cell ; 152(3): 599-611, 2013 Jan 31.
Article in English | MEDLINE | ID: mdl-23374352

ABSTRACT

Tumor cells have high-energetic and anabolic needs and are known to adapt their metabolism to be able to survive and keep proliferating under conditions of nutrient stress. We show that PKCζ deficiency promotes the plasticity necessary for cancer cells to reprogram their metabolism to utilize glutamine through the serine biosynthetic pathway in the absence of glucose. PKCζ represses the expression of two key enzymes of the pathway, PHGDH and PSAT1, and phosphorylates PHGDH at key residues to inhibit its enzymatic activity. Interestingly, the loss of PKCζ in mice results in enhanced intestinal tumorigenesis and increased levels of these two metabolic enzymes, whereas patients with low levels of PKCζ have a poor prognosis. Furthermore, PKCζ and caspase-3 activities are correlated with PHGDH levels in human intestinal tumors. Taken together, this demonstrates that PKCζ is a critical metabolic tumor suppressor in mouse and human cancer.


Subject(s)
Adenocarcinoma/metabolism , Adenoma/metabolism , Colonic Neoplasms/metabolism , Protein Kinase C/metabolism , Adenomatous Polyposis Coli Protein/genetics , Adenomatous Polyposis Coli Protein/metabolism , Animals , Biosynthetic Pathways , Cell Transformation, Neoplastic , Glucose/metabolism , Humans , Mice , Serine/biosynthesis , Specific Pathogen-Free Organisms , Stress, Physiological
5.
Genes Dev ; 34(7-8): 580-597, 2020 04 01.
Article in English | MEDLINE | ID: mdl-32115408

ABSTRACT

Dysregulation of early neurodevelopment is implicated in macrocephaly/autism disorders. However, the mechanism underlying this dysregulation, particularly in human cells, remains poorly understood. Mutations in the small GTPase gene RAB39b are associated with X-linked macrocephaly, autism spectrum disorder (ASD), and intellectual disability. The in vivo roles of RAB39b in the brain remain unknown. We generated Rab39b knockout (KO) mice and found that they exhibited cortical neurogenesis impairment, macrocephaly, and hallmark ASD behaviors, which resembled patient phenotypes. We also produced mutant human cerebral organoids that were substantially enlarged due to the overproliferation and impaired differentiation of neural progenitor cells (NPCs), which resemble neurodevelopmental deficits in KO mice. Mechanistic studies reveal that RAB39b interacts with PI3K components and its deletion promotes PI3K-AKT-mTOR signaling in NPCs of mouse cortex and cerebral organoids. The mTOR activity is robustly enhanced in mutant outer radial glia cells (oRGs), a subtype of NPCs barely detectable in rodents but abundant in human brains. Inhibition of AKT signaling rescued enlarged organoid sizes and NPC overproliferation caused by RAB39b mutations. Therefore, RAB39b mutation promotes PI3K-AKT-mTOR activity and alters cortical neurogenesis, leading to macrocephaly and autistic-like behaviors. Our studies provide new insights into neurodevelopmental dysregulation and common pathways associated with ASD across species.


Subject(s)
Autistic Disorder/genetics , Cerebral Cortex/embryology , Megalencephaly/genetics , Neurogenesis/genetics , rab GTP-Binding Proteins/genetics , Animals , Autistic Disorder/physiopathology , Behavior, Animal/physiology , Cell Differentiation/genetics , Cell Proliferation/genetics , Cerebral Cortex/cytology , Gene Deletion , Humans , Megalencephaly/physiopathology , Mice , Mice, Knockout , Models, Animal , Organoids/cytology , Phosphatidylinositol 3-Kinases/metabolism , Signal Transduction/genetics , Stem Cells/cytology , TOR Serine-Threonine Kinases/metabolism , rab GTP-Binding Proteins/metabolism
6.
Development ; 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38940473

ABSTRACT

The direction of left-right visceral asymmetry is conserved in vertebrates. Deviations of the standard asymmetric pattern are rare, and the underlying mechanisms are not understood. Here we use the teleost Astyanax mexicanus, consisting of surface fish with normal left-oriented heart asymmetry and cavefish with high levels of reversed right-oriented heart asymmetry, to explore natural changes in asymmetry determination. We show that Sonic Hedgehog (Shh) signaling is increased at the posterior midline, Kupffer's Vesicle, the teleost left-right organizer, is enlarged and contains longer cilia, and the number of dorsal forerunner cells is increased in cavefish. Furthermore, Shh increase in surface fish embryos induces asymmetric changes resembling the cavefish phenotype. Asymmetric expression of the Nodal antagonist dand5 is equalized or reversed in cavefish, and Shh increase in surface fish mimics changes in cavefish dand5 asymmetry. Shh decrease reduces the level of right-oriented heart asymmetry in cavefish. Thus, naturally occurring modifications in cavefish heart asymmetry are controlled by the effects of Shh signaling on left-right organizer function.

7.
Development ; 151(2)2024 Jan 15.
Article in English | MEDLINE | ID: mdl-38108472

ABSTRACT

Nerves play important roles in organ development and tissue homeostasis. Stem/progenitor cells differentiate into different cell lineages responsible for building the craniofacial organs. The mechanism by which nerves regulate stem/progenitor cell behavior in organ morphogenesis has not yet been comprehensively explored. Here, we use tooth root development in mouse as a model to investigate how sensory nerves regulate organogenesis. We show that sensory nerve fibers are enriched in the dental papilla at the initiation of tooth root development. Through single cell RNA-sequencing analysis of the trigeminal ganglion and developing molar, we reveal several signaling pathways that connect the sensory nerve with the developing molar, of which FGF signaling appears to be one of the important regulators. Fgfr2 is expressed in the progenitor cells during tooth root development. Loss of FGF signaling leads to shortened roots with compromised proliferation and differentiation of progenitor cells. Furthermore, Hh signaling is impaired in Gli1-CreER;Fgfr2fl/fl mice. Modulation of Hh signaling rescues the tooth root defects in these mice. Collectively, our findings elucidate the nerve-progenitor crosstalk and reveal the molecular mechanism of the FGF-SHH signaling cascade during tooth root morphogenesis.


Subject(s)
Tooth , Animals , Mice , Molar , Morphogenesis/genetics , Odontogenesis/genetics , Tooth Root
8.
Semin Immunol ; 67: 101753, 2023 05.
Article in English | MEDLINE | ID: mdl-37060806

ABSTRACT

Fusarium, Aspergillus and Candida are important fungal pathogens that cause visual impairment and blindness in the USA and worldwide. This review will summarize the epidemiology and clinical features of corneal infections and discuss the immune and inflammatory responses that play an important role in clinical disease. In addition, we describe fungal virulence factors that are required for survival in infected corneas, and the activities of neutrophils in fungal killing, tissue damage and cytokine production.


Subject(s)
Fusarium , Keratitis , Humans , Fungi , Cornea/microbiology , Cornea/pathology , Keratitis/microbiology , Keratitis/pathology , Fusarium/physiology , Neutrophils
9.
Nature ; 580(7805): 653-657, 2020 04.
Article in English | MEDLINE | ID: mdl-32350464

ABSTRACT

The aboveground parts of terrestrial plants, collectively called the phyllosphere, have a key role in the global balance of atmospheric carbon dioxide and oxygen. The phyllosphere represents one of the most abundant habitats for microbiota colonization. Whether and how plants control phyllosphere microbiota to ensure plant health is not well understood. Here we show that the Arabidopsis quadruple mutant (min7 fls2 efr cerk1; hereafter, mfec)1, simultaneously defective in pattern-triggered immunity and the MIN7 vesicle-trafficking pathway, or a constitutively activated cell death1 (cad1) mutant, carrying a S205F mutation in a membrane-attack-complex/perforin (MACPF)-domain protein, harbour altered endophytic phyllosphere microbiota and display leaf-tissue damage associated with dysbiosis. The Shannon diversity index and the relative abundance of Firmicutes were markedly reduced, whereas Proteobacteria were enriched in the mfec and cad1S205F mutants, bearing cross-kingdom resemblance to some aspects of the dysbiosis that occurs in human inflammatory bowel disease. Bacterial community transplantation experiments demonstrated a causal role of a properly assembled leaf bacterial community in phyllosphere health. Pattern-triggered immune signalling, MIN7 and CAD1 are found in major land plant lineages and are probably key components of a genetic network through which terrestrial plants control the level and nurture the diversity of endophytic phyllosphere microbiota for survival and health in a microorganism-rich environment.


Subject(s)
Arabidopsis/genetics , Arabidopsis/microbiology , Gene Regulatory Networks/genetics , Plant Components, Aerial/genetics , Plant Components, Aerial/microbiology , Plant Diseases/genetics , Plant Diseases/prevention & control , Arabidopsis/immunology , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Cell Death , Environment , Firmicutes/genetics , Firmicutes/isolation & purification , Genes, Plant/genetics , Genotype , Guanine Nucleotide Exchange Factors/genetics , Guanine Nucleotide Exchange Factors/metabolism , Homeostasis , Microbiota/genetics , Microbiota/physiology , Mutation , Phenotype , Plant Diseases/immunology , Plant Diseases/microbiology , Plant Immunity/genetics , Plant Leaves/genetics , Plant Leaves/microbiology , Proteobacteria/genetics , Proteobacteria/isolation & purification
10.
Mol Biol Evol ; 41(3)2024 Mar 01.
Article in English | MEDLINE | ID: mdl-38401527

ABSTRACT

Following invasion, insects can become adapted to conditions experienced in their invasive range, but there are few studies on the speed of adaptation and its genomic basis. Here, we examine a small insect pest, Thrips palmi, following its contemporary range expansion across a sharp climate gradient from the subtropics to temperate areas. We first found a geographically associated population genetic structure and inferred a stepping-stone dispersal pattern in this pest from the open fields of southern China to greenhouse environments of northern regions, with limited gene flow after colonization. In common garden experiments, both the field and greenhouse groups exhibited clinal patterns in thermal tolerance as measured by critical thermal maximum (CTmax) closely linked with latitude and temperature variables. A selection experiment reinforced the evolutionary potential of CTmax with an estimated h2 of 6.8% for the trait. We identified 3 inversions in the genome that were closely associated with CTmax, accounting for 49.9%, 19.6%, and 8.6% of the variance in CTmax among populations. Other genomic variations in CTmax outside the inversion region were specific to certain populations but functionally conserved. These findings highlight rapid adaptation to CTmax in both open field and greenhouse populations and reiterate the importance of inversions behaving as large-effect alleles in climate adaptation.


Subject(s)
Adaptation, Physiological , Chromosome Inversion , Animals , Adaptation, Physiological/genetics , Climate , Temperature , Insecta
11.
Hum Mol Genet ; 32(8): 1252-1265, 2023 04 06.
Article in English | MEDLINE | ID: mdl-36322143

ABSTRACT

G4C2 repeat expansion in C9orf72 causes the most common familial frontotemporal dementia and amyotrophic lateral sclerosis (C9FTD/ALS). The pathogenesis includes haploinsufficiency of C9orf72, which forms a protein complex with Smcr8, as well as G4C2 repeat-induced gain of function including toxic dipeptide repeats (DPRs). The key in vivo disease-driving mechanisms and how loss- and gain-of-function interplay remain poorly understood. Here, we identified dysregulation of a lysosome-ribosome biogenesis circuit as an early and key disease mechanism using a physiologically relevant mouse model with combined loss- and gain-of-function across the aging process. C9orf72 deficiency exacerbates FTD/ALS-like pathologies and behaviors in C9ORF72 bacterial artificial chromosome (C9-BAC) mice with G4C2 repeats under endogenous regulatory elements from patients. Single nucleus RNA sequencing (snRNA-seq) and bulk RNA-seq revealed that C9orf72 depletion disrupts lysosomes in neurons and leads to transcriptional dysregulation of ribosomal protein genes, which are likely due to the proteotoxic stress response and resemble ribosomopathy defects. Importantly, ectopic expression of C9orf72 or its partner Smcr8 in C9FTD/ALS mutant mice promotes lysosomal functions and restores ribosome biogenesis gene transcription, resulting in the mitigation of DPR accumulation, neurodegeneration as well as FTD/ALS-like motor and cognitive behaviors. Therefore, we conclude that loss- and gain-of-function crosstalk in C9FTD/ALS converges on neuronal dysregulation of a lysosome-ribosome biogenesis circuit leading to proteotoxicity, neurodegeneration and behavioral defects.


Subject(s)
Amyotrophic Lateral Sclerosis , Frontotemporal Dementia , Animals , Mice , Amyotrophic Lateral Sclerosis/genetics , Frontotemporal Dementia/genetics , C9orf72 Protein/genetics , Ribosomes/metabolism , Lysosomes/metabolism , DNA Repeat Expansion , Carrier Proteins/genetics
12.
Genome Res ; 32(6): 1183-1198, 2022 06.
Article in English | MEDLINE | ID: mdl-35609992

ABSTRACT

Over a thousand different transcription factors (TFs) bind with varying occupancy across the human genome. Chromatin immunoprecipitation (ChIP) can assay occupancy genome-wide, but only one TF at a time, limiting our ability to comprehensively observe the TF occupancy landscape, let alone quantify how it changes across conditions. We developed TF occupancy profiler (TOP), a Bayesian hierarchical regression framework, to profile genome-wide quantitative occupancy of numerous TFs using data from a single chromatin accessibility experiment (DNase- or ATAC-seq). TOP is supervised, and its hierarchical structure allows it to predict the occupancy of any sequence-specific TF, even those never assayed with ChIP. We used TOP to profile the quantitative occupancy of hundreds of sequence-specific TFs at sites throughout the genome and examined how their occupancies changed in multiple contexts: in approximately 200 human cell types, through 12 h of exposure to different hormones, and across the genetic backgrounds of 70 individuals. TOP enables cost-effective exploration of quantitative changes in the landscape of TF binding.


Subject(s)
Chromatin , Transcription Factors , Bayes Theorem , Binding Sites/genetics , Chromatin/genetics , Genome, Human , Humans , Protein Binding , Transcription Factors/metabolism
14.
Immunity ; 44(2): 422-37, 2016 Feb 16.
Article in English | MEDLINE | ID: mdl-26885862

ABSTRACT

Dendritic cells (DCs) orchestrate complex membrane trafficking through an interconnected transportation network linked together by Rab GTPases. Through a tandem affinity purification strategy and mass spectrometry, we depicted an interactomic landscape of major members of the mammalian Rab GTPase family. When complemented with imaging tools, this proteomic analysis provided a global view of intracellular membrane organization. Driven by this analysis, we investigated dynamic changes to the Rab32 subnetwork in DCs induced by L. monocytogenes infection and uncovered an essential role of this subnetwork in controlling the intracellular proliferation of L. monocytogenes. Mechanistically, Rab32 formed a persistent complex with two interacting proteins, PHB and PHB2, to encompass bacteria both during early phagosome formation and after L. monocytogenes escaped the original containment vacuole. Collectively, we have provided a functional compartmentalization overview and an organizational framework of intracellular Rab-mediated vesicle trafficking that can serve as a resource for future investigations.


Subject(s)
Dendritic Cells/immunology , Listeria monocytogenes/immunology , Listeriosis/immunology , Multiprotein Complexes/metabolism , rab GTP-Binding Proteins/metabolism , Acyltransferases/metabolism , Animals , Anti-Infective Agents/therapeutic use , Cell Line , Computational Biology , Containment of Biohazards , Dendritic Cells/microbiology , Listeria monocytogenes/growth & development , Listeriosis/drug therapy , Mice , Prohibitins , Protein Transport , Repressor Proteins/metabolism , Vacuoles/metabolism
15.
Exp Cell Res ; 434(1): 113866, 2024 01 01.
Article in English | MEDLINE | ID: mdl-38042247

ABSTRACT

Endometrial carcinoma (EC) is a rising concern among gynecological malignancies. Iroquois Homeobox 2 (IRX2), a member of the Iroquois homeobox gene family, demonstrates variable effects in different cancer types, emphasizing the need for extensive exploration of its involvement in EC progression. Utilizing TCGA and GEO databases, as well as performing immunohistochemistry (IHC) analysis on clinical samples, we assessed the expression levels of IRX2 and its promoter methylation in EC. To understand the functional roles of IRX2, we conducted various assays including in vitro CCK-8 assays, colony formation assays, cell invasion assays, and cell apoptosis assays. Moreover, we utilized in vivo subcutaneous xenograft mouse models. Additionally, we performed KEGG pathway and gene set enrichment analyses to gain insights into the underlying mechanisms. To validate the regulatory relationship between IRX2 and RUVBL1, we employed chromatin immunoprecipitation and luciferase reporter assays. Our results indicate significantly reduced levels of IRX2 expression in EC, correlating with higher histological grades, advanced clinical stages, and diminished overall survival. We observed that DNA methylation of the IRX2 promoter suppresses its expression in EC, with cg26333652 and cg11793269 playing critical roles as methylated sites. In contrast, ectopic overexpression of IRX2 substantially inhibits cell proliferation and invasion, and promotes cell apoptosis. Additionally, we discovered that IRX2 exerts negative regulation on the expression of RUVBL1, which is upregulated in EC and associated with a poorer prognosis. In conclusion, our findings indicate that decreased expression of IRX2 facilitates EC cell growth through the regulation of RUVBL1 expression, thereby contributing to the development of EC. Hence, targeting the IRX2-RUVBL1 axis holds promise as a potential therapeutic strategy for EC treatment.


Subject(s)
Endometrial Neoplasms , MicroRNAs , Female , Humans , Animals , Mice , Cell Transformation, Neoplastic/genetics , Genes, Homeobox , Apoptosis/genetics , Endometrial Neoplasms/pathology , Cell Line, Tumor , Cell Proliferation/genetics , Gene Expression Regulation, Neoplastic/genetics , MicroRNAs/genetics , ATPases Associated with Diverse Cellular Activities/genetics , ATPases Associated with Diverse Cellular Activities/metabolism , Carrier Proteins/metabolism , DNA Helicases/metabolism
16.
Mol Ther ; 32(4): 1016-1032, 2024 Apr 03.
Article in English | MEDLINE | ID: mdl-38327049

ABSTRACT

Chimeric antigen receptor (CAR) T cells are activated to trigger the lytic machinery after antigen engagement, and this has been successfully applied clinically as therapy. The mechanism by which antigen binding leads to the initiation of CAR signaling remains poorly understood. Here, we used a set of short double-stranded DNA (dsDNA) tethers with mechanical forces ranging from ∼12 to ∼51 pN to manipulate the mechanical force of antigen tether and decouple the microclustering and signaling events. Our results revealed that antigen-binding-induced CAR microclustering and signaling are mechanical force dependent. Additionally, the mechanical force delivered to the antigen tether by the CAR for microclustering is generated by autonomous cell contractility. Mechanistically, the mechanical-force-induced strong adhesion and CAR diffusion confinement led to CAR microclustering. Moreover, cytotoxicity may have a lower mechanical force threshold than cytokine generation. Collectively, these results support a model of mechanical-force-induced CAR microclustering for signaling.


Subject(s)
Receptors, Chimeric Antigen , Receptors, Chimeric Antigen/genetics , Receptors, Chimeric Antigen/metabolism , Receptors, Antigen, T-Cell/metabolism , Signal Transduction , Antigens , Immunotherapy, Adoptive/methods
17.
Mol Cell ; 65(2): 296-309, 2017 Jan 19.
Article in English | MEDLINE | ID: mdl-28065600

ABSTRACT

In mammalian cells, histone deacetylase (HDAC) and Sirtuin (SIRT) are two families responsible for removing acetyl groups from acetylated proteins. Here, we describe protein deacetylation coupled with deacetylimination as a function of lysyl oxidase (LOX) family members. LOX-like 3 (Loxl3) associates with Stat3 in the nucleus to deacetylate and deacetyliminate Stat3 on multiple acetyl-lysine sites. Surprisingly, Loxl3 N-terminal scavenger receptor cysteine-rich (SRCR) repeats, rather than the C-terminal oxidase catalytic domain, represent the major deacetylase/deacetyliminase activity. Loxl3-mediated deacetylation/deacetylimination disrupts Stat3 dimerization, abolishes Stat3 transcription activity, and restricts cell proliferation. In Loxl3-/- mice, Stat3 is constitutively acetylated and naive CD4+ T cells are potentiated in Th17/Treg cell differentiation. When overexpressed, the SRCR repeats from other LOX family members can catalyze protein deacetylation/deacetylimination. Thus, our findings delineate a hitherto-unknown mechanism of protein deacetylation and deacetylimination catalyzed by lysyl oxidases.


Subject(s)
Amino Acid Oxidoreductases/metabolism , CD4-Positive T-Lymphocytes/enzymology , Colitis/enzymology , Protein Processing, Post-Translational , STAT3 Transcription Factor/metabolism , Acetylation , Amino Acid Oxidoreductases/deficiency , Amino Acid Oxidoreductases/genetics , Animals , CD4-Positive T-Lymphocytes/immunology , Catalysis , Cell Differentiation , Cell Nucleus/enzymology , Cell Proliferation , Colitis/genetics , Colitis/immunology , Disease Models, Animal , Genotype , HEK293 Cells , HeLa Cells , Humans , MCF-7 Cells , Mice, Inbred C57BL , Mice, Knockout , Phenotype , Protein Domains , Protein Multimerization , RNA Interference , STAT3 Transcription Factor/genetics , T-Lymphocytes, Regulatory/enzymology , T-Lymphocytes, Regulatory/immunology , Th17 Cells/enzymology , Th17 Cells/immunology , Transcription, Genetic , Transfection
18.
Am J Physiol Cell Physiol ; 326(5): C1423-C1436, 2024 May 01.
Article in English | MEDLINE | ID: mdl-38497113

ABSTRACT

Nicotinamide adenine dinucleotide (NAD+) is a pivotal coenzyme, essential for cellular reactions, metabolism, and mitochondrial function. Depletion of kidney NAD+ levels and reduced de novo NAD+ synthesis through the tryptophan-kynurenine pathway are linked to acute kidney injury (AKI), whereas augmenting NAD+ shows promise in reducing AKI. We investigated de novo NAD+ biosynthesis using in vitro, ex vivo, and in vivo models to understand its role in AKI. Two-dimensional (2-D) cultures of human primary renal proximal tubule epithelial cells (RPTECs) and HK-2 cells showed limited de novo NAD+ synthesis, likely due to low pathway enzyme gene expression. Using three-dimensional (3-D) spheroid culture model improved the expression of tubular-specific markers and enzymes involved in de novo NAD+ synthesis. However, de novo NAD+ synthesis remained elusive in the 3-D spheroid culture, regardless of injury conditions. Further investigation revealed that 3-D cultured cells could not metabolize tryptophan (Trp) beyond kynurenine (KYN). Intriguingly, supplementation of 3-hydroxyanthranilic acid into RPTEC spheroids was readily incorporated into NAD+. In a human precision-cut kidney slice (PCKS) ex vivo model, de novo NAD+ synthesis was limited due to substantially downregulated kynurenine 3-monooxygenase (KMO), which is responsible for KYN to 3-hydroxykynurenine conversion. KMO overexpression in RPTEC 3-D spheroids successfully reinstated de novo NAD+ synthesis from Trp. In addition, in vivo study demonstrated that de novo NAD+ synthesis is intact in the kidney of the healthy adult mice. Our findings highlight disrupted tryptophan-kynurenine NAD+ synthesis in in vitro cellular models and an ex vivo kidney model, primarily attributed to KMO downregulation.NEW & NOTEWORTHY Nicotinamide adenine dinucleotide (NAD+) is essential in regulating mitochondrial function. Reduced NAD+ synthesis through the de novo pathway is associated with acute kidney injury (AKI). Our study reveals a disruption in de novo NAD+ synthesis in proximal tubular models, but not in vivo, attributed to downregulation of enzyme kynurenine 3-monooxygenase (KMO). These findings highlight a crucial role of KMO in governing de novo NAD+ biosynthesis within the kidney, shedding light on potential AKI interventions.


Subject(s)
Epithelial Cells , Kidney Tubules, Proximal , Kynurenine 3-Monooxygenase , NAD , Tryptophan , Animals , Humans , Mice , Acute Kidney Injury/metabolism , Acute Kidney Injury/pathology , Acute Kidney Injury/enzymology , Cell Line , Cells, Cultured , Epithelial Cells/metabolism , Kidney Tubules, Proximal/metabolism , Kynurenine/metabolism , Kynurenine 3-Monooxygenase/metabolism , Kynurenine 3-Monooxygenase/genetics , Mice, Inbred C57BL , NAD/metabolism , NAD/biosynthesis , Tryptophan/metabolism
19.
Stroke ; 2024 Jun 17.
Article in English | MEDLINE | ID: mdl-38881452

ABSTRACT

BACKGROUND: Surgical risk assessment is intriguing for clinical decision-making of brainstem cavernous malformation (BSCM) treatment. While the BSCM grading scale, encompassing size, developmental venous anomaly, crossing axial midpoint, age, and timing of intervention, is increasingly utilized, the clinical relevance of neurological fluctuation and recurrent hemorrhage has not been incorporated. This study aimed to propose a supplementary grading scale with enhanced predictive efficacy. METHODS: Using a retrospective nationwide registry of consecutive patients with BSCMs undergoing surgery in China from March 2011 to May 2023, a new supplementary BSCM grading scale was developed from a derivative cohort of 260 patients and validated in an independent concurrent cohort of 67 patients. The primary outcome was unfavorable neurological function (modified Rankin Scale score >2) at the latest follow-up. The performance of the supplementary grading system was evaluated for discrimination, calibration, and clinical utility and further compared with its original counterpart. RESULTS: Over a follow-up of at least 6 months after surgery, the unfavorable outcomes were 31% in the overall cohort (101/327 patients). A preoperative motor deficit (odds ratio, 3.13; P=0.001), recurrent hemorrhage (odds ratio, 3.05; P<0.001), timing of intervention (odds ratio, 7.08; P<0.001), and crossing the axial midpoint (odds ratio, 2.57; P=0.006) were associated with the unfavorable outcomes and composed the initial Huashan grading variables. A supplementary BSCM grading system was subsequently developed by incorporating the Huashan grading variables into the original BSCM grading scale. The predictive capability of the supplementary scale was consistently superior to the original counterpart in either the derivative cohort (area under the receiver operating characteristic curve, 0.74 [95% CI, 0.68-0.80] for the supplementary versus 0.68 [95% CI, 0.61-0.74] for the original) or the validation cohort (0.75 [95% CI, 0.62-0.87] versus 0.64 [95% CI, 0.48-0.81]). CONCLUSIONS: This study highlights the neurological relevance of BSCM hemorrhage in surgical risk assessment. Via compositing preoperative motor function and recurrent hemorrhages, a supplementary grading scale may improve a dynamic risk assessment for clinical decisions in the management of BSCMs.

20.
BMC Genomics ; 25(1): 504, 2024 May 22.
Article in English | MEDLINE | ID: mdl-38778260

ABSTRACT

BACKGROUND: Skeletal muscle development plays a crucial role in yield and quality of pork; however, this process is influenced by various factors. In this study, we employed whole-genome bisulfite sequencing (WGBS) and transcriptome sequencing to comprehensively investigate the longissimus dorsi muscle (LDM), aiming to identify key genes that impact the growth and development of Duroc pigs with different average daily gains (ADGs). RESULTS: Eight pigs were selected and divided into two groups based on ADGs: H (774.89 g) group and L (658.77 g) group. Each pair of the H and L groups were half-siblings. The results of methylation sequencing revealed 2631 differentially methylated genes (DMGs) involved in metabolic processes, signalling, insulin secretion, and other biological activities. Furthermore, a joint analysis was conducted on these DMGs and the differentially expressed genes (DEGs) obtained from transcriptome sequencing of the same individual. This analysis identified 316 differentially methylated and differentially expressed genes (DMEGs), including 18 DMEGs in promoter regions and 294 DMEGs in gene body regions. Finally, LPAR1 and MEF2C were selected as candidate genes associated with muscle development. Bisulfite sequencing PCR (BSP) and quantitative real-time PCR (qRT-PCR) revealed that the promoter region of LPAR1 exhibited significantly lower methylation levels (P < 0.05) and greater expression levels (P < 0.05) in the H group than in the L group. Additionally, hypermethylation was observed in the gene body region of MEF2C, as was a low expression level, in the H group (P < 0.05). CONCLUSIONS: These results suggest that the differences in the ADGs of Duroc pigs fed the same diet may be influenced by the methylation levels and expression levels of genes related to skeletal muscle development.


Subject(s)
DNA Methylation , Muscle, Skeletal , Transcriptome , Animals , Muscle, Skeletal/metabolism , Muscle, Skeletal/growth & development , Swine/genetics , Epigenome , Muscle Development/genetics , Gene Expression Profiling
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