Your browser doesn't support javascript.
loading
Show: 20 | 50 | 100
Results 1 - 20 de 4.519
Filter
Add more filters

Publication year range
1.
Cell ; 181(2): 442-459.e29, 2020 04 16.
Article in English | MEDLINE | ID: mdl-32302573

ABSTRACT

Single-cell RNA sequencing (scRNA-seq) is a powerful tool for defining cellular diversity in tumors, but its application toward dissecting mechanisms underlying immune-modulating therapies is scarce. We performed scRNA-seq analyses on immune and stromal populations from colorectal cancer patients, identifying specific macrophage and conventional dendritic cell (cDC) subsets as key mediators of cellular cross-talk in the tumor microenvironment. Defining comparable myeloid populations in mouse tumors enabled characterization of their response to myeloid-targeted immunotherapy. Treatment with anti-CSF1R preferentially depleted macrophages with an inflammatory signature but spared macrophage populations that in mouse and human expresses pro-angiogenic/tumorigenic genes. Treatment with a CD40 agonist antibody preferentially activated a cDC population and increased Bhlhe40+ Th1-like cells and CD8+ memory T cells. Our comprehensive analysis of key myeloid subsets in human and mouse identifies critical cellular interactions regulating tumor immunity and defines mechanisms underlying myeloid-targeted immunotherapies currently undergoing clinical testing.


Subject(s)
Colonic Neoplasms/pathology , Myeloid Cells/metabolism , Single-Cell Analysis/methods , Adult , Aged , Aged, 80 and over , Animals , Base Sequence/genetics , CD8-Positive T-Lymphocytes/immunology , China , Colonic Neoplasms/therapy , Colorectal Neoplasms/pathology , Dendritic Cells/immunology , Female , Humans , Immunotherapy , Macrophages/immunology , Male , Mice , Middle Aged , Sequence Analysis, RNA/methods , Tumor Microenvironment/genetics , Tumor Microenvironment/immunology
2.
Mol Cell ; 84(12): 2304-2319.e8, 2024 Jun 20.
Article in English | MEDLINE | ID: mdl-38838666

ABSTRACT

Circular RNAs (circRNAs) are upregulated during neurogenesis. Where and how circRNAs are localized and what roles they play during this process have remained elusive. Comparing the nuclear and cytoplasmic circRNAs between H9 cells and H9-derived forebrain (FB) neurons, we identify that a subset of adenosine (A)-rich circRNAs are restricted in H9 nuclei but exported to cytosols upon differentiation. Such a subcellular relocation of circRNAs is modulated by the poly(A)-binding protein PABPC1. In the H9 nucleus, newly produced (A)-rich circRNAs are bound by PABPC1 and trapped by the nuclear basket protein TPR to prevent their export. Modulating (A)-rich motifs in circRNAs alters their subcellular localization, and introducing (A)-rich circRNAs in H9 cytosols results in mRNA translation suppression. Moreover, decreased nuclear PABPC1 upon neuronal differentiation enables the export of (A)-rich circRNAs, including circRTN4(2,3), which is required for neurite outgrowth. These findings uncover subcellular localization features of circRNAs, linking their processing and function during neurogenesis.


Subject(s)
Active Transport, Cell Nucleus , Adenosine , Cell Nucleus , Neurogenesis , Neurons , Poly(A)-Binding Protein I , RNA, Circular , RNA , RNA, Circular/metabolism , RNA, Circular/genetics , Neurons/metabolism , Adenosine/metabolism , Cell Nucleus/metabolism , Humans , Poly(A)-Binding Protein I/metabolism , Poly(A)-Binding Protein I/genetics , Animals , RNA/metabolism , RNA/genetics , Cell Line , Cell Differentiation , Cytoplasm/metabolism , Prosencephalon/metabolism
3.
Mol Cell ; 83(10): 1588-1604.e5, 2023 05 18.
Article in English | MEDLINE | ID: mdl-37080207

ABSTRACT

Gene expression in metazoans is controlled by promoter-proximal pausing of RNA polymerase II, which can undergo productive elongation or promoter-proximal termination. Integrator-PP2A (INTAC) plays a crucial role in determining the fate of paused polymerases, but the underlying mechanisms remain unclear. Here, we establish a rapid degradation system to dissect the functions of INTAC RNA endonuclease and phosphatase modules. We find that both catalytic modules function at most if not all active promoters and enhancers, yet differentially affect polymerase fate. The endonuclease module induces promoter-proximal termination, with its disruption leading to accumulation of elongation-incompetent polymerases and downregulation of highly expressed genes, while elongation-competent polymerases accumulate at lowly expressed genes and non-coding elements, leading to their upregulation. The phosphatase module primarily prevents the release of paused polymerases and limits transcriptional activation, especially for highly paused genes. Thus, both INTAC catalytic modules have unexpectedly general yet distinct roles in dynamic transcriptional control.


Subject(s)
Phosphoric Monoester Hydrolases , RNA Polymerase II , RNA Polymerase II/genetics , RNA Polymerase II/metabolism , Phosphoric Monoester Hydrolases/metabolism , Gene Expression Regulation , Transcriptional Activation , Up-Regulation , Transcription, Genetic
4.
Nat Methods ; 2024 Jul 04.
Article in English | MEDLINE | ID: mdl-38965442

ABSTRACT

Dynamic imaging of genomic loci is key for understanding gene regulation, but methods for imaging genomes, in particular non-repetitive DNAs, are limited. We developed CRISPRdelight, a DNA-labeling system based on endonuclease-deficient CRISPR-Cas12a (dCas12a), with an engineered CRISPR array to track DNA location and motion. CRISPRdelight enables robust imaging of all examined 12 non-repetitive genomic loci in different cell lines. We revealed the confined movement of the CCAT1 locus (chr8q24) at the nuclear periphery for repressed expression and active motion in the interior nucleus for transcription. We uncovered the selective repositioning of HSP gene loci to nuclear speckles, including a remarkable relocation of HSPH1 (chr13q12) for elevated transcription during stresses. Combining CRISPR-dCas12a and RNA aptamers allowed multiplex imaging of four types of satellite DNA loci with a single array, revealing their spatial proximity to the nucleolus-associated domain. CRISPRdelight is a user-friendly and robust system for imaging and tracking genomic dynamics and regulation.

5.
Proc Natl Acad Sci U S A ; 121(34): e2407285121, 2024 Aug 20.
Article in English | MEDLINE | ID: mdl-39133859

ABSTRACT

Discovering and engineering herbicide-resistant genes is a crucial challenge in crop breeding. This study focuses on the 4-hydroxyphenylpyruvate dioxygenase Inhibitor Sensitive 1-Like (HSL) protein, prevalent in higher plants and exhibiting weak catalytic activity against many ß-triketone herbicides (ß-THs). The crystal structures of maize HSL1A complexed with ß-THs were elucidated, identifying four essential herbicide-binding residues and explaining the weak activity of HSL1A against the herbicides. Utilizing an artificial evolution approach, we developed a series of rice HSL1 mutants targeting the four residues. Then, these mutants were systematically evaluated, identifying the M10 variant as the most effective in modifying ß-THs. The initial active conformation of substrate binding in HSL1 was also revealed from these mutants. Furthermore, overexpression of M10 in rice significantly enhanced resistance to ß-THs, resulting in a notable 32-fold increase in resistance to methyl-benquitrione. In conclusion, the artificially evolved M10 gene shows great potential for the development of herbicide-resistant crops.


Subject(s)
Herbicide Resistance , Herbicides , Oryza , Plant Proteins , Oryza/genetics , Oryza/metabolism , Herbicide Resistance/genetics , Herbicides/pharmacology , Plant Proteins/genetics , Plant Proteins/metabolism , Plant Breeding/methods , Plants, Genetically Modified/genetics , Mutation
6.
Proc Natl Acad Sci U S A ; 121(35): e2406787121, 2024 Aug 27.
Article in English | MEDLINE | ID: mdl-39163337

ABSTRACT

Muscle stem cells (MuSCs) are specialized cells that reside in adult skeletal muscle poised to repair muscle tissue. The ability of MuSCs to regenerate damaged tissues declines markedly with aging and in diseases such as Duchenne muscular dystrophy, but the underlying causes of MuSC dysfunction remain poorly understood. Both aging and disease result in dramatic increases in the stiffness of the muscle tissue microenvironment from fibrosis. MuSCs are known to lose their regenerative potential if cultured on stiff plastic substrates. We sought to determine whether MuSCs harbor a memory of their past microenvironment and if it can be overcome. We tested MuSCs in situ using dynamic hydrogel biomaterials that soften or stiffen on demand in response to light and found that freshly isolated MuSCs develop a persistent memory of substrate stiffness characterized by loss of proliferative progenitors within the first three days of culture on stiff substrates. MuSCs cultured on soft hydrogels had altered cytoskeletal organization and activity of Rho and Rac guanosine triphosphate hydrolase (GTPase) and Yes-associated protein mechanotransduction pathways compared to those on stiff hydrogels. Pharmacologic inhibition identified RhoA activation as responsible for the mechanical memory phenotype, and single-cell RNA sequencing revealed a molecular signature of the mechanical memory. These studies highlight that microenvironmental stiffness regulates MuSC fate and leads to MuSC dysfunction that is not readily reversed by changing stiffness. Our results suggest that stiffness can be circumvented by targeting downstream signaling pathways to overcome stem cell dysfunction in aged and disease states with aberrant fibrotic tissue mechanics.


Subject(s)
Biocompatible Materials , Hydrogels , Muscle, Skeletal , Animals , Hydrogels/chemistry , Biocompatible Materials/chemistry , Muscle, Skeletal/metabolism , Mice , Mechanotransduction, Cellular , Stem Cells/metabolism , Stem Cells/cytology , rhoA GTP-Binding Protein/metabolism , Cells, Cultured
7.
Nat Methods ; 20(7): 1070-1081, 2023 07.
Article in English | MEDLINE | ID: mdl-37291262

ABSTRACT

The development of transgenic mouse models that express genes of interest in specific cell types has transformed our understanding of basic biology and disease. However, generating these models is time- and resource-intensive. Here we describe a model system, SELective Expression and Controlled Transduction In Vivo (SELECTIV), that enables efficient and specific expression of transgenes by coupling adeno-associated virus (AAV) vectors with Cre-inducible overexpression of the multi-serotype AAV receptor, AAVR. We demonstrate that transgenic AAVR overexpression greatly increases the efficiency of transduction of many diverse cell types, including muscle stem cells, which are normally refractory to AAV transduction. Superior specificity is achieved by combining Cre-mediated AAVR overexpression with whole-body knockout of endogenous Aavr, which is demonstrated in heart cardiomyocytes, liver hepatocytes and cholinergic neurons. The enhanced efficacy and exquisite specificity of SELECTIV has broad utility in development of new mouse model systems and expands the use of AAV for gene delivery in vivo.


Subject(s)
Gene Transfer Techniques , Genetic Vectors , Mice , Animals , Genetic Vectors/genetics , Mice, Transgenic , Genetic Therapy , Transgenes , Dependovirus/genetics , Transduction, Genetic
8.
Proc Natl Acad Sci U S A ; 120(24): e2302854120, 2023 06 13.
Article in English | MEDLINE | ID: mdl-37276396

ABSTRACT

Stomata are pores found in the epidermis of stems or leaves that modulate both plant gas exchange and water/nutrient uptake. The development and function of plant stomata are regulated by a diverse range of environmental cues. However, how carbohydrate status in preexisting leaves might determine systemic stomatal formation within newly developing leaves has remained obscure. The glucose (Glc) sensor HEXOKINASE1 (HXK1) has been reported to decrease the stability of an ethylene/Glc signaling transcriptional regulator, EIN3 (ETHYLENE INSENSITIVE3). EIN3 in turn directly represses the expression of SUC2 (sucrose transporter 2), encoding a master transporter of sucrose (Suc). Further, KIN10, a nuclear regulator involved in energy homeostasis, has been reported to repress the transcription factor SPCH (SPEECHLESS), a master regulator of stomatal development. Here, we demonstrate that the Glc status of preexisting leaves determines systemic stomatal development within newly developing leaves by the HXK1-¦EIN3-¦SUC2 module. Further, increasing Glc levels in preexisting leaves results in a HXK1-dependent decrease of EIN3 and increase of SUC2, triggering the perception, amplification and relay of HXK1-dependent Glc signaling and thereby triggering Suc transport from mature to newly developing leaves. The HXK1-¦EIN3-¦SUC2 molecular module thereby drives systemic Suc transport from preexisting leaves to newly developing leaves. Subsequently, increasing Suc levels within newly developing leaves promotes stomatal formation through the established KIN10⟶ SPCH module. Our findings thus show how a carbohydrate signal in preexisting leaves is sensed, amplified and relayed to determine the extent of systemic stomatal development within newly developing leaves.


Subject(s)
Arabidopsis Proteins , Arabidopsis , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Arabidopsis/genetics , Arabidopsis/metabolism , Sugars/metabolism , Plant Leaves/metabolism , Ethylenes/metabolism , Sucrose/metabolism , Gene Expression Regulation, Plant , Basic Helix-Loop-Helix Transcription Factors/metabolism
9.
J Biol Chem ; 300(6): 107394, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38768813

ABSTRACT

Periprosthetic osteolysis and subsequent aseptic loosening are the primary causes of failure following total joint arthroplasty. Wear particle-induced osteogenic impairment is recognized as an important contributing factor in the development of osteolysis, with endoplasmic reticulum (ER) stress emerging as a pivotal underlying mechanism. Hence, searching for potential therapeutic targets and agents capable of modulating ER stress in osteoblasts is crucial for preventing aseptic loosening. Kaempferol (KAE), a natural flavonol compound, has shown promising osteoprotective effects and anti-ER stress properties in diverse diseases. However, the influence of KAE on ER stress-mediated osteogenic impairment induced by wear particles remains unclear. In this study, we observed that KAE effectively relieved TiAl6V4 particles-induced osteolysis by improving osteogenesis in a mouse calvarial model. Furthermore, we demonstrated that KAE could attenuate ER stress-mediated apoptosis in osteoblasts exposed to TiAl6V4 particles, both in vitro and in vivo. Mechanistically, our results revealed that KAE mitigated ER stress-mediated apoptosis by upregulating the IRE1α-XBP1s pathway while concurrently partially inhibiting the IRE1α-regulated RIDD and JNK activation. Collectively, our findings suggest that KAE is a prospective therapeutic agent for treating wear particle-induced osteolysis and highlight the IRE1α-XBP1s pathway as a potential therapeutic target for preventing aseptic loosening.


Subject(s)
Endoplasmic Reticulum Stress , Endoribonucleases , Kaempferols , Osteoblasts , Osteogenesis , Osteolysis , Protein Serine-Threonine Kinases , X-Box Binding Protein 1 , Animals , Endoplasmic Reticulum Stress/drug effects , Kaempferols/pharmacology , Protein Serine-Threonine Kinases/metabolism , X-Box Binding Protein 1/metabolism , X-Box Binding Protein 1/genetics , Mice , Osteogenesis/drug effects , Endoribonucleases/metabolism , Endoribonucleases/genetics , Osteoblasts/metabolism , Osteoblasts/drug effects , Osteolysis/metabolism , Osteolysis/chemically induced , Osteolysis/pathology , Osteolysis/drug therapy , Apoptosis/drug effects , Signal Transduction/drug effects , Male , Humans , Mice, Inbred C57BL
10.
Plant Physiol ; 195(3): 2309-2322, 2024 Jun 28.
Article in English | MEDLINE | ID: mdl-38466216

ABSTRACT

Soil (or plant) water deficit accelerates plant reproduction. However, the underpinning molecular mechanisms remain unknown. By modulating cell division/number, ABSCISIC ACID-INSENSITIVE 5 (ABI5), a key bZIP (basic (region) leucine zippers) transcription factor, regulates both seed development and abiotic stress responses. The KIP-RELATED PROTEIN (KRP) cyclin-dependent kinases (CDKs) play an essential role in controlling cell division, and SHOOT MERISTEMLESS (STM) plays a key role in the specification of flower meristem identity. Here, our findings show that abscisic acid (ABA) signaling and/or metabolism in adjust reproductive outputs (such as rosette leaf number and open flower number) under water-deficient conditions in Arabidopsis (Arabidopsis thaliana) plants. Reproductive outputs increased under water-sufficient conditions but decreased under water-deficient conditions in the ABA signaling/metabolism mutants abscisic acid2-1 (aba2-1), aba2-11, abscisic acid insensitive3-1 (abi3-1), abi4-1, abi5-7, and abi5-8. Further, under water-deficient conditions, ABA induced-ABI5 directly bound to the promoter of KRP1, which encodes a CDK that plays an essential role in controlling cell division, and this binding subsequently activated KRP1 expression. In turn, KRP1 physically interacted with STM, which functions in the specification of flower meristem identity, promoting STM degradation. We further demonstrate that reproductive outputs are adjusted by the ABI5-KRP1-STM molecular module under water-deficient conditions. Together, our findings reveal the molecular mechanism by which ABA signaling and/or metabolism regulate reproductive development under water-deficient conditions. These findings provide insights that may help guide crop yield improvement under water deficiency.


Subject(s)
Abscisic Acid , Arabidopsis Proteins , Arabidopsis , Flowers , Gene Expression Regulation, Plant , Arabidopsis/genetics , Arabidopsis/growth & development , Arabidopsis/metabolism , Arabidopsis/physiology , Arabidopsis Proteins/metabolism , Arabidopsis Proteins/genetics , Abscisic Acid/metabolism , Flowers/genetics , Flowers/growth & development , Flowers/physiology , Basic-Leucine Zipper Transcription Factors/metabolism , Basic-Leucine Zipper Transcription Factors/genetics , Signal Transduction , Meristem/genetics , Meristem/growth & development , Meristem/metabolism , Reproduction , Mutation/genetics , Cyclin-Dependent Kinases/metabolism , Cyclin-Dependent Kinases/genetics , Homeodomain Proteins
11.
Blood ; 141(2): 156-167, 2023 01 12.
Article in English | MEDLINE | ID: mdl-35714312

ABSTRACT

This open-label, randomized, phase 3 trial (NCT02577406) compared enasidenib, an oral IDH2 (isocitrate dehydrogenase 2) inhibitor, with conventional care regimens (CCRs) in patients aged ≥60 years with late-stage, mutant-IDH2 acute myeloid leukemia (AML) relapsed/refractory (R/R) to 2 or 3 prior AML-directed therapies. Patients were first preselected to a CCR (azacitidine, intermediate-dose cytarabine, low-dose cytarabine, or supportive care) and then randomized (1:1) to enasidenib 100 mg per day or CCR. The primary endpoint was overall survival (OS). Secondary endpoints included event-free survival (EFS), time to treatment failure (TTF), overall response rate (ORR), hematologic improvement (HI), and transfusion independence (TI). Overall, 319 patients were randomized to enasidenib (n = 158) or CCR (n = 161). The median age was 71 years, median (range) enasidenib exposure was 142 days (3 to 1270), and CCR was 36 days (1 to 1166). One enasidenib (0.6%) and 20 CCR (12%) patients received no randomized treatment, and 30% and 43%, respectively, received subsequent AML-directed therapies during follow-up. The median OS with enasidenib vs CCR was 6.5 vs 6.2 months (HR [hazard ratio], 0.86; P = .23); 1-year survival was 37.5% vs 26.1%. Enasidenib meaningfully improved EFS (median, 4.9 vs 2.6 months with CCR; HR, 0.68; P = .008), TTF (median, 4.9 vs 1.9 months; HR, 0.53; P < .001), ORR (40.5% vs 9.9%; P <.001), HI (42.4% vs 11.2%), and red blood cell (RBC)-TI (31.7% vs 9.3%). Enasidenib safety was consistent with prior reports. The primary study endpoint was not met, but OS was confounded by early dropout and subsequent AML-directed therapies. Enasidenib provided meaningful benefits in EFS, TTF, ORR, HI, and RBC-TI in this heavily pretreated older mutant-IDH2 R/R AML population.


Subject(s)
Isocitrate Dehydrogenase , Leukemia, Myeloid, Acute , Aged , Humans , Cytarabine/therapeutic use , Isocitrate Dehydrogenase/genetics , Leukemia, Myeloid, Acute/drug therapy , Leukemia, Myeloid, Acute/genetics , Mutation
12.
Plant Cell ; 34(10): 3665-3684, 2022 09 27.
Article in English | MEDLINE | ID: mdl-35897146

ABSTRACT

The endoplasmic reticulum-localized DnaJ family 3B (ERdj3B), is a component of the stromal cell-derived factor 2 (SDF2)-ERdj3B-binding immunoglobulin protein (BiP) chaperone complex, which functions in protein folding, translocation, and quality control. We found that ERdj3B mutations affected integument development in the Ler ecotype but not in the Col-0 ecotype of Arabidopsis (Arabidopsis thaliana). Map-based cloning identified the ERECTA (ER) gene as a natural modifier of ERdj3B. The double mutation of ERdj3B and ER caused a major defect in the inner integument under heat stress. Additional mutation of the ER paralog ERECTA-LIKE 1 (ERL1) or ERL2 to the erdj3b er double mutant exacerbated the defective integument phenotype. The double mutation of ER and SDF2, the other component of the SDF2-ERdj3B-BiP complex, resulted in similar defects in the inner integument. Furthermore, both the protein abundance and plasma membrane partitioning of ER, ERL1, and ERL2 were markedly reduced in erdj3b plants, indicating that the SDF2-ERdj3B-BiP chaperone complex might control the translocation of ERECTA-family proteins from the endoplasmic reticulum to the plasma membrane. Our results suggest that the SDF2-ERdj3B-BiP complex functions in ovule development and the heat stress response in coordination with ERECTA-family receptor kinases.


Subject(s)
Arabidopsis Proteins , Arabidopsis , Arabidopsis/metabolism , Arabidopsis Proteins/genetics , Arabidopsis Proteins/metabolism , Carrier Proteins/metabolism , HSP40 Heat-Shock Proteins/metabolism , Heat-Shock Response , Ovule/metabolism , Protein Serine-Threonine Kinases
13.
FASEB J ; 38(4): e23469, 2024 Feb 29.
Article in English | MEDLINE | ID: mdl-38358361

ABSTRACT

The adenopituitary secretes follicle-stimulating hormone (FSH), which plays a crucial role in regulating the growth, development, and reproductive functions of organisms. Investigating the process of FSH synthesis and secretion can offer valuable insights into potential areas of focus for reproductive research. Epidermal growth factor (EGF) is a significant paracrine/autocrine factor within the body, and studies have demonstrated its ability to stimulate FSH secretion in animals. However, the precise mechanisms that regulate this action are still poorly understood. In this research, in vivo and in vitro experiments showed that the activation of epidermal growth factor receptor (EGFR) by EGF induces the upregulation of miR-27b-3p and that miR-27b-3p targets and inhibits Foxo1 mRNA expression, resulting in increased FSH synthesis and secretion. In summary, this study elucidates the precise molecular mechanism through which EGF governs the synthesis and secretion of FSH via the EGFR/miR-27b-3p/FOXO1 pathway.


Subject(s)
Epidermal Growth Factor , MicroRNAs , Animals , Rats , Biological Transport , ErbB Receptors/genetics , Follicle Stimulating Hormone , MicroRNAs/genetics
14.
PLoS Biol ; 20(12): e3001951, 2022 Dec.
Article in English | MEDLINE | ID: mdl-36577117

ABSTRACT

[This corrects the article DOI: 10.1371/journal.pbio.3000923.].

15.
Cereb Cortex ; 34(2)2024 01 31.
Article in English | MEDLINE | ID: mdl-38212284

ABSTRACT

Functional MRI measures the blood-oxygen-level dependent signals, which provide an indirect measure of neural activity mediated by neurovascular responses. Cerebrovascular reactivity affects both task-induced and resting-state blood-oxygen-level dependent activity and may confound inter-individual effects, such as those related to aging and biological sex. We examined a large dataset containing breath-holding, checkerboard, and resting-state tasks. We used the breath-holding task to measure cerebrovascular reactivity, used the checkerboard task to obtain task-based activations, and quantified resting-state activity with amplitude of low-frequency fluctuations and regional homogeneity. We hypothesized that cerebrovascular reactivity would be correlated with blood-oxygen-level dependent measures and that accounting for these correlations would result in better estimates of age and sex effects. We found that cerebrovascular reactivity was correlated with checkerboard task activations in the visual cortex and with amplitude of low-frequency fluctuations and regional homogeneity in widespread fronto-parietal regions, as well as regions with large vessels. We also found significant age and sex effects in cerebrovascular reactivity, some of which overlapped with those observed in amplitude of low-frequency fluctuations and regional homogeneity. However, correcting for the effects of cerebrovascular reactivity had very limited influence on the estimates of age and sex. Our results highlight the limitations of accounting for cerebrovascular reactivity with the current breath-holding task.


Subject(s)
Brain Mapping , Brain , Brain/diagnostic imaging , Brain/physiology , Brain Mapping/methods , Cerebrovascular Circulation/physiology , Magnetic Resonance Imaging/methods , Oxygen
16.
Cereb Cortex ; 34(1)2024 01 14.
Article in English | MEDLINE | ID: mdl-38100332

ABSTRACT

Functional magnetic resonance imaging faces inherent challenges when applied to deep-brain areas in rodents, e.g. entorhinal cortex, due to the signal loss near the ear cavities induced by susceptibility artifacts and reduced sensitivity induced by the long distance from the surface array coil. Given the pivotal roles of deep brain regions in various diseases, optimized imaging techniques are needed. To mitigate susceptibility-induced signal losses, we introduced baby cream into the middle ear. To enhance the detection sensitivity of deep brain regions, we implemented inductively coupled ear-bars, resulting in approximately a 2-fold increase in sensitivity in entorhinal cortex. Notably, the inductively coupled ear-bar can be seamlessly integrated as an add-on device, without necessitating modifications to the scanner interface. To underscore the versatility of inductively coupled ear-bars, we conducted echo-planner imaging-based task functional magnetic resonance imaging in rats modeling Alzheimer's disease. As a proof of concept, we also demonstrated resting-state-functional magnetic resonance imaging connectivity maps originating from the left entorhinal cortex-a central hub for memory and navigation networks-to amygdala hippocampal area, Insular Cortex, Prelimbic Systems, Cingulate Cortex, Secondary Visual Cortex, and Motor Cortex. This work demonstrates an optimized procedure for acquiring large-scale networks emanating from a previously challenging seed region by conventional magnetic resonance imaging detectors, thereby facilitating improved observation of functional magnetic resonance imaging outcomes.


Subject(s)
Alzheimer Disease , Magnetic Resonance Imaging , Rats , Animals , Magnetic Resonance Imaging/methods , Brain Mapping/methods , Brain , Gyrus Cinguli
17.
Proc Natl Acad Sci U S A ; 119(26): e2204289119, 2022 06 28.
Article in English | MEDLINE | ID: mdl-35727985

ABSTRACT

Behçet's disease (BD) is a chronic vasculitis characterized by systemic immune aberrations. However, a comprehensive understanding of immune disturbances in BD and how they contribute to BD pathogenesis is lacking. Here, we performed single-cell and bulk RNA sequencing to profile peripheral blood mononuclear cells (PBMCs) and isolated monocytes from BD patients and healthy donors. We observed prominent expansion and transcriptional changes in monocytes in PBMCs from BD patients. Deciphering the monocyte heterogeneity revealed the accumulation of C1q-high (C1qhi) monocytes in BD. Pseudotime inference indicated that BD monocytes markedly shifted their differentiation toward inflammation-accompanied and C1qhi monocyte-ended trajectory. Further experiments showed that C1qhi monocytes enhanced phagocytosis and proinflammatory cytokine secretion, and multiplatform analyses revealed the significant clinical relevance of this subtype. Mechanistically, C1qhi monocytes were induced by activated interferon-γ (IFN-γ) signaling in BD patients and were decreased by tofacitinib treatment. Our study illustrates the BD immune landscape and the unrecognized contribution of C1qhi monocytes to BD hyperinflammation, showing their potential as therapeutic targets and clinical assessment indexes.


Subject(s)
Behcet Syndrome , Complement C1q , Monocytes , Behcet Syndrome/genetics , Behcet Syndrome/immunology , Complement C1q/genetics , Complement C1q/immunology , Humans , Monocytes/immunology , RNA-Seq , Single-Cell Analysis
18.
Proc Natl Acad Sci U S A ; 119(22): e2202913119, 2022 05 31.
Article in English | MEDLINE | ID: mdl-35605116

ABSTRACT

SignificanceHydrogen peroxide is a highly competitive ready-to-use product for solar energy transformation. Nevertheless, the contemporary photosynthetic systems are not efficient enough, due to severe charge recombination caused by high activation energy and binding energy of the exciton. Herein, we achieve spontaneous exciton dissociation at room temperature. Moreover, the photosynthesis of H2O2 reaches between 9,366 and 12,324 µmol·g-1 from 9 AM to 4 PM in ambient conditions, that is, sunlight irradiation, real water including fresh water and seawater, room temperature, and open air. The ultrahigh photocatalytic efficiency in ambient conditions allows the solar-to-chemical conversion in a real cost-effective and sustainable way, which represents an important step toward real applications.

19.
BMC Biol ; 22(1): 104, 2024 May 03.
Article in English | MEDLINE | ID: mdl-38702712

ABSTRACT

BACKGROUND: Gonadotropin precisely controls mammalian reproductive activities. Systematic analysis of the mechanisms by which epigenetic modifications regulate the synthesis and secretion of gonadotropin can be useful for more precise regulation of the animal reproductive process. Previous studies have identified many differential m6A modifications in the GnRH-treated adenohypophysis. However, the molecular mechanism by which m6A modification regulates gonadotropin synthesis and secretion remains unclear. RESULTS: Herein, it was found that GnRH can promote gonadotropin synthesis and secretion by promoting the expression of FTO. Highly expressed FTO binds to Foxp2 mRNA in the nucleus, exerting a demethylation function and reducing m6A modification. After Foxp2 mRNA exits the nucleus, the lack of m6A modification prevents YTHDF3 from binding to it, resulting in increased stability and upregulation of Foxp2 mRNA expression, which activates the cAMP/PKA signaling pathway to promote gonadotropin synthesis and secretion. CONCLUSIONS: Overall, the study reveals the molecular mechanism of GnRH regulating the gonadotropin synthesis and secretion through FTO-mediated m6A modification. The results of this study allow systematic interpretation of the regulatory mechanism of gonadotropin synthesis and secretion in the pituitary at the epigenetic level and provide a theoretical basis for the application of reproductive hormones in the regulation of animal artificial reproduction.


Subject(s)
Alpha-Ketoglutarate-Dependent Dioxygenase FTO , Gonadotropin-Releasing Hormone , Animals , Alpha-Ketoglutarate-Dependent Dioxygenase FTO/metabolism , Alpha-Ketoglutarate-Dependent Dioxygenase FTO/genetics , Gonadotropin-Releasing Hormone/metabolism , Gonadotropin-Releasing Hormone/genetics , Gonadotropins/metabolism , RNA Methylation , RNA, Messenger/metabolism , RNA, Messenger/genetics , Rats
20.
J Neurosci ; 43(7): 1256-1266, 2023 02 15.
Article in English | MEDLINE | ID: mdl-36609454

ABSTRACT

Effective rehabilitation in Parkinson's disease (PD) is related to brain reorganization with restoration of cortico-subcortical networks and compensation of frontoparietal networks; however, further neural rehabilitation evidence from a multidimensional perspective is needed. To investigate how multidisciplinary intensive rehabilitation treatment affects neurovascular coupling, 31 PD patients (20 female) before and after treatment and 30 healthy controls (17 female) underwent blood oxygenation level-dependent functional magnetic resonance imaging and arterial spin labeling scans. Cerebral blood flow (CBF) was used to measure perfusion, and fractional amplitude of low-frequency fluctuation (fALFF) was used to measure neural activity. The global CBF-fALFF correlation and regional CBF/fALFF ratio were calculated as neurovascular coupling. Dynamic causal modeling (DCM) was used to evaluate treatment-related alterations in the strength and directionality of information flow. Treatment reduced CBF-fALFF correlations. The altered CBF/fALFF exhibited increases in the left angular gyrus and the right inferior parietal gyrus and decreases in the bilateral thalamus and the right superior frontal gyrus. The CBF/fALFF alteration in right superior frontal gyrus showed correlations with motor improvement. Further, DCM indicated increases in connectivity from the superior frontal gyrus and decreases from the thalamus to the inferior parietal gyrus. The benefits of rehabilitation were reflected in the dual mechanism, with restoration of executive control occurring in the initial phase of motor learning and compensation of information integration occurring in the latter phase. These findings may yield multimodal insights into the role of rehabilitation in disease modification and identify the dorsolateral superior frontal gyrus as a potential target for noninvasive neuromodulation in PD.SIGNIFICANCE STATEMENT Although rehabilitation has been proposed as a promising supplemental treatment for PD as it results in brain reorganization, restoring cortico-subcortical networks and eliciting compensatory activation of frontoparietal networks, further multimodal evidence of the neural mechanisms underlying rehabilitation is needed. We measured the ratio of perfusion and neural activity derived from arterial spin labeling and blood oxygenation level-dependent fMRI data and found that benefits of rehabilitation seem to be related to the dual mechanism, restoring executive control in the initial phase of motor learning and compensating for information integration in the latter phase. We also identified the dorsolateral superior frontal gyrus as a potential target for noninvasive neuromodulation in PD patients.


Subject(s)
Neurovascular Coupling , Parkinson Disease , Humans , Female , Neurovascular Coupling/physiology , Brain/diagnostic imaging , Brain/pathology , Prefrontal Cortex , Magnetic Resonance Imaging/methods , Spin Labels
SELECTION OF CITATIONS
SEARCH DETAIL