ABSTRACT
The future of healthcare for cardiovascular diseases holds immense promise, not only based in new discoveries in cardiac metabolism but also in translating them to solutions for critical challenges faced by society. Here, ten scientists share their insights, shedding light on the future that lies ahead for this field.
Subject(s)
Cardiovascular Diseases , Humans , Cardiovascular Diseases/metabolism , Cardiovascular Diseases/therapy , Translational Research, Biomedical , AnimalsABSTRACT
During development, melanopsin-expressing intrinsically photosensitive retinal ganglion cells (ipRGCs) become light sensitive much earlier than rods and cones. IpRGCs project to many subcortical areas, whereas physiological functions of these projections are yet to be fully elucidated. Here, we found that ipRGC-mediated light sensation promotes synaptogenesis of pyramidal neurons in various cortices and the hippocampus. This phenomenon depends on activation of ipRGCs and is mediated by the release of oxytocin from the supraoptic nucleus (SON) and the paraventricular nucleus (PVN) into cerebral-spinal fluid. We further characterized a direct connection between ipRGCs and oxytocin neurons in the SON and mutual projections between oxytocin neurons in the SON and PVN. Moreover, we showed that the lack of ipRGC-mediated, light-promoted early cortical synaptogenesis compromised learning ability in adult mice. Our results highlight the importance of light sensation early in life on the development of learning ability and therefore call attention to suitable light environment for infant care.
Subject(s)
Oxytocin , Retinal Ganglion Cells , Animals , Brain/metabolism , Humans , Mice , Retinal Ganglion Cells/physiology , Rod Opsins/metabolismABSTRACT
The stem cells that maintain and repair the postnatal skeleton remain undefined. One model suggests that perisinusoidal mesenchymal stem cells (MSCs) give rise to osteoblasts, chondrocytes, marrow stromal cells, and adipocytes, although the existence of these cells has not been proven through fate-mapping experiments. We demonstrate here that expression of the bone morphogenetic protein (BMP) antagonist gremlin 1 defines a population of osteochondroreticular (OCR) stem cells in the bone marrow. OCR stem cells self-renew and generate osteoblasts, chondrocytes, and reticular marrow stromal cells, but not adipocytes. OCR stem cells are concentrated within the metaphysis of long bones not in the perisinusoidal space and are needed for bone development, bone remodeling, and fracture repair. Grem1 expression also identifies intestinal reticular stem cells (iRSCs) that are cells of origin for the periepithelial intestinal mesenchymal sheath. Grem1 expression identifies distinct connective tissue stem cells in both the bone (OCR stem cells) and the intestine (iRSCs).
Subject(s)
Bone and Bones/cytology , Intercellular Signaling Peptides and Proteins/metabolism , Intestine, Small/cytology , Mesenchymal Stem Cells/cytology , Animals , Cartilage/metabolism , Intestine, Small/metabolism , Mesenchymal Stem Cells/metabolism , Mice , Mice, Inbred C57BLABSTRACT
A compact protein with a size of <1,000 amino acids, the CRISPR-associated protein CasX is a fundamentally distinct RNA-guided nuclease when compared to Cas9 and Cas12a. Although it can induce RNA-guided genome editing in mammalian cells, the activity of CasX is less robust than that of the widely used S. pyogenes Cas9. Here, we show that structural features of two CasX homologs and their guide RNAs affect the R-loop complex assembly and DNA cleavage activity. Cryo-EM-based structural engineering of either the CasX protein or the guide RNA produced two new CasX genome editors (DpbCasX-R3-v2 and PlmCasX-R1-v2) with significantly improved DNA manipulation efficacy. These results advance both the mechanistic understanding of CasX and its application as a genome-editing tool.
Subject(s)
Gene Editing , RNA, Guide, Kinetoplastida , Animals , CRISPR-Cas Systems/genetics , Endonucleases/genetics , Endonucleases/metabolism , Gene Editing/methods , Mammals/metabolism , RNA/genetics , RNA, Guide, Kinetoplastida/genetics , RNA, Guide, Kinetoplastida/metabolismABSTRACT
Proteins carrying a signal peptide and/or a transmembrane domain enter the intracellular secretory pathway at the endoplasmic reticulum (ER) and are transported to the Golgi apparatus via COPII vesicles or tubules. SAR1 initiates COPII coat assembly by recruiting other coat proteins to the ER membrane. Mammalian genomes encode two SAR1 paralogs, SAR1A and SAR1B. While these paralogs exhibit ~90% amino acid sequence identity, it is unknown whether they perform distinct or overlapping functions in vivo. We now report that genetic inactivation of Sar1a in mice results in lethality during midembryogenesis. We also confirm previous reports that complete deficiency of murine Sar1b results in perinatal lethality. In contrast, we demonstrate that deletion of Sar1b restricted to hepatocytes is compatible with survival, though resulting in hypocholesterolemia that can be rescued by adenovirus-mediated overexpression of either SAR1A or SAR1B. To further examine the in vivo function of these two paralogs, we genetically engineered mice with the Sar1a coding sequence replacing that of Sar1b at the endogenous Sar1b locus. Mice homozygous for this allele survive to adulthood and are phenotypically normal, demonstrating complete or near-complete overlap in function between the two SAR1 protein paralogs in mice. These data also suggest upregulation of SAR1A gene expression as a potential approach for the treatment of SAR1B deficiency (chylomicron retention disease) in humans.
Subject(s)
Monomeric GTP-Binding Proteins , Animals , Humans , Mice , COP-Coated Vesicles/metabolism , COP-Coated Vesicles/genetics , Endoplasmic Reticulum/metabolism , Hepatocytes/metabolism , Mice, Knockout , Monomeric GTP-Binding Proteins/metabolism , Monomeric GTP-Binding Proteins/geneticsABSTRACT
EfpA, the first major facilitator superfamily (MFS) protein identified in Mycobacterium tuberculosis (Mtb), is an essential efflux pump implicated in resistance to multiple drugs. EfpA-inhibitors have been developed to kill drug-tolerant Mtb. However, the biological function of EfpA has not yet been elucidated. Here, we present the cryo-EM structures of EfpA complexed with lipids or the inhibitor BRD-8000.3 at resolutions of 2.9 Å and 3.4 Å, respectively. Unexpectedly, EfpA forms an antiparallel dimer. Functional studies reveal that EfpA is a lipid transporter and BRD-8000.3 inhibits its lipid transport activity. Intriguingly, the mutation V319F, known to confer resistance to BRD-8000.3, alters the expression level and oligomeric state of EfpA. Based on our results and the observation of other antiparallel dimers in the MFS family, we propose an antiparallel-function model of EfpA. Collectively, our work provides structural and functional insights into EfpA's role in lipid transport and drug resistance, which would accelerate the development of antibiotics against this promising drug target.
Subject(s)
Bacterial Proteins , Cryoelectron Microscopy , Mycobacterium tuberculosis , Mycobacterium tuberculosis/metabolism , Bacterial Proteins/metabolism , Bacterial Proteins/chemistry , Bacterial Proteins/genetics , Membrane Transport Proteins/metabolism , Membrane Transport Proteins/chemistry , Membrane Transport Proteins/genetics , Models, Molecular , Biological TransportABSTRACT
Gene expression can be post-transcriptionally regulated via dynamic and reversible RNA modifications. N1-methyladenosine (m1A) is a recently identified mRNA modification; however, little is known about its precise location and biogenesis. Here, we develop a base-resolution m1A profiling method, based on m1A-induced misincorporation during reverse transcription, and report distinct classes of m1A methylome in the human transcriptome. m1A in 5' UTR, particularly those at the mRNA cap, associate with increased translation efficiency. A different, small subset of m1A exhibit a GUUCRA tRNA-like motif, are evenly distributed in the transcriptome, and are dependent on the methyltransferase TRMT6/61A. Additionally, we show that m1A is prevalent in the mitochondrial-encoded transcripts. Manipulation of m1A level via TRMT61B, a mitochondria-localizing m1A methyltransferase, demonstrates that m1A in mitochondrial mRNA interferes with translation. Collectively, our approaches reveal distinct classes of m1A methylome and provide a resource for functional studies of m1A-mediated epitranscriptomic regulation.
Subject(s)
Adenosine/analogs & derivatives , Cell Nucleus/metabolism , Mitochondria/metabolism , RNA Processing, Post-Transcriptional , RNA, Messenger/metabolism , RNA, Transfer/metabolism , Single Molecule Imaging/methods , 5' Untranslated Regions , Adenosine/metabolism , HEK293 Cells , Humans , Mitochondrial Proteins/biosynthesis , Mitochondrial Proteins/genetics , Nuclear Proteins/biosynthesis , Nuclear Proteins/genetics , Protein Biosynthesis , RNA Caps , RNA Interference , RNA, Messenger/genetics , RNA, Transfer/genetics , Transfection , tRNA Methyltransferases/genetics , tRNA Methyltransferases/metabolismABSTRACT
This meta-analysis summarizes evidence from 44 neuroimaging experiments and characterizes the general linguistic network in early deaf individuals. Meta-analytic comparisons with hearing individuals found that a specific set of regions (in particular the left inferior frontal gyrus and posterior middle temporal gyrus) participates in supramodal language processing. In addition to previously described modality-specific differences, the present study showed that the left calcarine gyrus and the right caudate were additionally recruited in deaf compared with hearing individuals. In addition, this study showed that the bilateral posterior superior temporal gyrus is shaped by cross-modal plasticity, whereas the left frontotemporal areas are shaped by early language experience. Although an overall left-lateralized pattern for language processing was observed in the early deaf individuals, regional lateralization was altered in the inferior frontal gyrus and anterior temporal lobe. These findings indicate that the core language network functions in a modality-independent manner, and provide a foundation for determining the contributions of sensory and linguistic experiences in shaping the neural bases of language processing.
Subject(s)
Deafness , Humans , Brain/diagnostic imaging , Brain Mapping/methods , Deafness/diagnostic imaging , Deafness/physiopathology , Language , Linguistics , Nerve Net/diagnostic imaging , Neuroimaging/methodsABSTRACT
As an efficient and clean energy carrier, hydrogen is expected to play a key role in future energy systems. However, hydrogen-storage technology must be safe with a high hydrogen-storage density, which is difficult to achieve. MgH2 is a promising solid-state hydrogen-storage material owing to its large hydrogen-storage capacity (7.6 wt %) and excellent reversibility, but its large-scale utilization is restricted by slow hydrogen-desorption kinetics. Although catalysts can improve the hydrogen-storage kinetics of MgH2, they reduce the hydrogen-storage capacity. Single-atom catalysts maximize the atom utilization ratio and the number of interfacial sites to boost the catalytic activity, while easy aggregation at high temperatures limits further application. Herein, we designed a single-atom Ni-loaded TiO2 catalyst with superior thermal stability and catalytic activity. The optimized 15wt%-Ni0.034@TiO2 catalyst reduced the onset dehydrogenation temperature of MgH2 to 200 °C. At 300 °C, the H2 released and absorbed 4.6 wt % within 5 min and 6.53 wt % within 10 s, respectively. The apparent activation energies of MgH2 dehydrogenation and hydrogenation were reduced to 64.35 and 35.17 kJ/mol of H2, respectively. Even after 100 cycles of hydrogenation and dehydrogenation, there was still a capacity retention rate of 97.26%. The superior catalytic effect is attributed to the highly synergistic catalytic activity of single-atom Ni, numerous oxygen vacancies, and multivalent Tix+ in the TiO2 support, in which the single-atom Ni plays the dominant role, accelerating electron transfer between Mg2+ and H- and weakening the Mg-H bonds. This work paves the way for superior hydrogen-storage materials for practical unitization and also extends the application of single-atom catalysis in high-temperature solid-state reactions.
ABSTRACT
We report a case of Spiroplasma bloodstream infection in a patient in China who developed pulmonary infection, acute respiratory distress syndrome, sepsis, and septic shock after emergency surgery for type A aortic dissection. One organism closely related to Spiroplasma eriocheiris was isolated from blood culture and identified by whole-genome sequencing.
Subject(s)
Sepsis , Spiroplasma , Humans , Spiroplasma/genetics , China/epidemiology , Sepsis/diagnosis , Sepsis/etiologyABSTRACT
The p6 domain of the Gag precursors (Gag p6) in human immunodeficiency virus type 1 (HIV-1) plays multifunctional roles in the viral life cycle. It utilizes the endosomal sorting complex required for transport (ESCRT) system to facilitate viral budding and release from the plasma membrane through the interactions with the ESCRT-I component tumor susceptibility gene 101 (TSG101) and with the ALG-2 interacting protein X (ALIX). Moreover, Gag p6 contributes to viral replication by a range of posttranslational modifications such as SUMOylation, ubiquitination and phosphorylation. Additionally, Gag p6 also mediates the incorporation of the accessory protein Vpr into virions, thereby promoting Vpr-induced viral replication. However, less attention is focused on Gag p6 as therapeutic intervention. This review focuses on the structures and diverse functions of Gag p6 in viral replication, host cells, and pathogenesis. Additionally, several challenges were also discussed in studying the structure of Gag p6 and its interactions with partners. Consequently, it concludes that the Gag p6 represents an attractive target for the development of antiretroviral drugs, and efforts to develop p6-targeted antiretrovirals are expected to undergo significant growth in the forthcoming years.
Subject(s)
HIV-1 , Humans , Anti-Retroviral Agents , Biological Transport , Cell Membrane , Endosomal Sorting Complexes Required for TransportABSTRACT
OBJECTIVE: Erythropoietin (EPO) known as an erythrocyte-stimulating factor is increased in patients with rheumatoid arthritis (RA). Nevertheless, the function of EPO in the process of RA and relative mechanism needs to be further clarified. METHODS: The level of EPO in serum and synovial fluid from patients with RA and healthy controls was determined by . Collagen-induced arthritis (CIA) mice were constructed to confirm the role of EPO on RA pathogenesis. Differentially expressed genes (DEGs) of EPO-treated fibroblast-like synoviocyte (FLS) were screened by transcriptome sequencing. The transcription factor of neuraminidase 3 (NEU3) of DEGs was verified by double luciferase reporting experiment, DNA pulldown, electrophoretic mobility shift assay and chromatin immunoprecipitation-quantitative PCR (qPCR) assay. RESULTS: The overexpression of EPO was confirmed in patients with RA, which was positively associated with Disease Activity Score 28-joint count. Additionally, EPO intervention could significantly aggravate the joint destruction in CIA models. The upregulation of NEU3 was screened and verified by transcriptome sequencing and qPCR in EPO-treated FLS, and signal transducer and activator of transcription 5 was screened and verified to be the specific transcription factor of NEU3. EPO upregulates NEU3 expression via activating the Janus kinase 2 (JAK2)-STAT5 signalling pathway through its receptor EPOR, thereby to promote the desialylation through enhancing the migration and invasion ability of FLS, which is verified by JAK2 inhibitor and NEU3 inhibitor. CONCLUSION: EPO, as a proinflammatory factor, accelerates the process of RA through transcriptional upregulation of the expression of NEU3 by JAK2/STAT5 pathway.
Subject(s)
Arthritis, Experimental , Arthritis, Rheumatoid , Erythropoietin , Neuraminidase , Synoviocytes , Animals , Humans , Mice , Arthritis, Experimental/genetics , Arthritis, Experimental/metabolism , Arthritis, Rheumatoid/genetics , Arthritis, Rheumatoid/metabolism , Cell Proliferation , Cells, Cultured , Erythropoietin/metabolism , Fibroblasts/metabolism , Neuraminidase/metabolism , STAT5 Transcription Factor/metabolism , Synovial Membrane/metabolism , Synoviocytes/metabolismABSTRACT
OBJECTIVES: Epstein-Barr Virus (EBV) is a widespread virus implicated in various diseases, including Systemic Lupus Erythematosus (SLE). However, the specific genes and pathways altered in SLE patients with EBV infection remain unclear. We aimed to identify key genes and immune cells in SLE patients with EBV infection. METHODS: The datasets of SLE (GSE50772 and GSE81622) or EBV infection (GSE85599 and GSE45918) were obtained from the Gene Expression Omnibus (GEO) database. Next, differential gene expression (DEGs) analysis were conducted to identify overlapping DEGs and then enrichment analysis was performed. Machine learning was applied to identify key genes. Validation was conducted using ROC curve analysis and expression level verification in test datasets and single-cell RNA sequencing. Immune cell infiltration patterns were analyzed using CIBERSORTx, and clinical data were reviewed for SLE patients. RESULTS: We identified 58 overlapping DEGs enriched in interferon-related pathways. Five overlapping DEGs (IFI27, TXK, RAPGEF6, PIK3IP1, PSENEN) were selected as key genes by machine learning algorithms, with IFI27 showing the highest diagnostic performance. The expression level of IFI27 was found higher in CD4 CTL, CD8 naïve and various B cell subsets of SLE patients with EBV infection. IFI27 showed significant correlation with B intermediate and CD4 CT. Clinical data showed lower CD4 T cell proportions in SLE patients with EBV infection. CONCLUSION: This study identifies IFI27 as a key gene for SLE patients with EBV infection, influencing CD4 CTL and B cell subtypes. These findings enhance the understanding of the molecular mechanisms linking SLE and EBV infection, providing potential targets for diagnostic and therapeutic strategies.
ABSTRACT
INTRODUCTION: Various left atrial (LA) anatomical structures are correlated with postablative recurrence for atrial fibrillation (AF) patients. Comprehensively integrating anatomical structures, digitizing them, and implementing in-depth analysis, which may supply new insights, are needed. Thus, we aim to establish an interpretable model to identify AF patients' phenotypes according to LA anatomical morphology, using machine learning techniques. METHODS AND RESULTS: Five hundred and nine AF patients underwent first ablation treatment in three centers were included and were followed-up for postablative recurrent atrial arrhythmias. Data from 369 patients were regarded as training set, while data from another 140 patients, collected from different centers, were used as validation set. We manually measured 57 morphological parameters on enhanced computed tomography with three-dimensional reconstruction technique and implemented unsupervised learning accordingly. Three morphological groups were identified, with distinct prognosis according to Kaplan-Meier estimator (p < .001). Multivariable Cox model revealed that morphological grouping were independent predictors of 1-year recurrence (Group 1: HR = 3.00, 95% CI: 1.51-5.95, p = .002; Group 2: HR = 4.68, 95% CI: 2.40-9.11, p < .001; Group 3 as reference). Furthermore, external validation consistently demonstrated our findings. CONCLUSIONS: Our study illustrated the feasibility of employing unsupervised learning for the classification of LA morphology. By utilizing morphological grouping, we can effectively identify individuals at different risks of postablative recurrence and thereby assist in clinical decision-making.
Subject(s)
Atrial Appendage , Atrial Fibrillation , Catheter Ablation , Humans , Atrial Fibrillation/diagnostic imaging , Atrial Fibrillation/surgery , Treatment Outcome , Heart Atria/diagnostic imaging , Heart Atria/surgery , Catheter Ablation/adverse effects , Catheter Ablation/methods , RecurrenceABSTRACT
STUDY QUESTION: How does ovarian stimulation (OS), which is used to mature multiple oocytes for ART procedures, impact the principal cellular compartments and transcriptome of the human endometrium in the periovulatory and mid-secretory phases? SUMMARY ANSWER: During the mid-secretory window of implantation, OS alters the abundance of endometrial immune cells, whereas during the periovulatory period, OS substantially changes the endometrial transcriptome and impacts both endometrial glandular and immune cells. WHAT IS KNOWN ALREADY: Pregnancies conceived in an OS cycle are at risk of complications reflective of abnormal placentation and placental function. OS can alter endometrial gene expression and immune cell populations. How OS impacts the glandular, stromal, immune, and vascular compartments of the endometrium, in the periovulatory period as compared to the window of implantation, is unknown. STUDY DESIGN, SIZE, DURATION: This prospective cohort study carried out between 2020 and 2022 included 25 subjects undergoing OS and 25 subjects in natural menstrual cycles. Endometrial biopsies were performed in the proliferative, periovulatory, and mid-secretory phases. PARTICIPANTS/MATERIALS, SETTING, METHODS: Blood samples were processed to determine serum estradiol and progesterone levels. Both the endometrial transcriptome and the principal cellular compartments of the endometrium, including glands, stroma, immune, and vasculature, were evaluated by examining endometrial dating, differential gene expression, protein expression, cell populations, and the three-dimensional structure in endometrial tissue. Mann-Whitney U tests, unpaired t-tests or one-way ANOVA and pairwise multiple comparison tests were used to statistically evaluate differences. MAIN RESULTS AND THE ROLE OF CHANCE: In the periovulatory period, OS induced high levels of differential gene expression, glandular-stromal dyssynchrony, and an increase in both glandular epithelial volume and the frequency of endometrial monocytes/macrophages. In the window of implantation during the mid-secretory phase, OS induced changes in endometrial immune cells, with a greater frequency of B cells and a lower frequency of CD4 effector T cells. LARGE SCALE DATA: The data underlying this article have been uploaded to the Genome Expression Omnibus/National Center for Biotechnology Information with accession number GSE220044. LIMITATIONS, REASONS FOR CAUTION: A limited number of subjects were included in this study, although the subjects within each group, natural cycle or OS, were homogenous in their clinical characteristics. The number of subjects utilized was sufficient to identify significant differences; however, with a larger number of subjects and additional power, we may detect additional differences. Another limitation of the study is that proliferative phase biopsies were collected in natural cycles, but not in OS cycles. Given that the OS cycle subjects did not have known endometrial factor infertility, and the comparisons involved subjects who had a similar and robust response to stimulation, the findings are generalizable to women with a normal response to OS. WIDER IMPLICATIONS OF THE FINDINGS: OS substantially altered the periovulatory phase endometrium, with fewer transcriptomic and cell type-specific changes in the mid-secretory phase. Our findings show that after OS, the endometrial microenvironment in the window of implantation possesses many more similarities to that of a natural cycle than does the periovulatory endometrium. Further investigation of the immune compartment and the functional significance of this cellular compartment under OS conditions is warranted. STUDY FUNDING/COMPETING INTERESTS: Research reported in this publication was supported by the National Institute of Allergy and Infectious Diseases (R01AI148695 to A.M.B. and N.C.D.), Eunice Kennedy Shriver National Institute of Child Health and Human Development (R01HD109152 to R.A.), and the March of Dimes (5-FY20-209 to R.A.). The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or March of Dimes. All authors declare no conflict of interest.
Subject(s)
Endometrium , Ovulation Induction , Transcriptome , Humans , Female , Endometrium/metabolism , Adult , Cellular Microenvironment , Prospective Studies , Estradiol/blood , Embryo Implantation/physiology , Progesterone/blood , Progesterone/metabolism , Pregnancy , Menstrual CycleABSTRACT
Ecological networks experiencing persistent biological invasions may exhibit distinct topological properties, complicating the understanding of how network topology affects disease transmission during invasion-driven community assembly. We developed a trait-based network model to assess the impact of network topology on disease transmission, measured as community- and species-level disease prevalence. We found that trait-based feeding interactions between host species determine the frequency distribution of the niche of co-occurring species in steady-state communities, being either bimodal or multimodal. The width of the growth kernel influences the degree-biomass relationship of species, being either weakly positive or strongly negative. When this relationship is weakly positive, species-level disease prevalence is primarily correlated with biomass. However, when the degree-biomass relationship is strongly negative, species-level disease prevalence is determined by the difference between a host species' in-degree and out-degree closeness centrality. At the community level, disease prevalence is generally amplified by increasing host richness, community biomass, and the standard deviation of interaction generality, while it is diluted by higher network connectance. Our framework verifies the amplification effects of host richness during invasion-driven community assembly and offers valuable insights for estimating disease prevalence based on host network topology.
ABSTRACT
A number of different receptors are distributed in glutamatergic neurons of the lateral habenula (LHb). These glutamatergic neurons are involved in different neural pathways, which may identify how the LHb regulates various physiological functions. However, the role of dopamine D1 receptor (D1R)-expressing habenular neurons projecting to the ventral tegmental area (VTA) (LHbD1R-VTA) remains not well understood. In the current study, to determine the activity of D1R-expressing neurons in LHb, D1R-Cre mice were used to establish the chronic restraint stress (CRS) depression model. Adeno-associated virus was injected into bilateral LHb in D1R-Cre mice to examine whether optogenetic activation of the LHb D1R-expressing neurons and their projections could induce depression-like behavior. Optical fibers were implanted in the LHb and VTA, respectively. To investigate whether optogenetic inhibition of the LHbD1R-VTA circuit could produce antidepressant-like effects, the adeno-associated virus was injected into the bilateral LHb in the D1R-Cre CRS model, and optical fibers were implanted in the bilateral VTA. The D1R-expressing neuronal activity in the LHb was increased in the CRS depression model. Optogenetic activation of the D1R-expressing neurons in LHb induced behavioral despair and anhedonia, which could also be induced by activation of the LHbD1R-VTA axons. Conversely, optogenetic inhibition of the LHbD1R-VTA circuit improved behavioral despair and anhedonia in the CRS depression model. D1R-expressing glutamatergic neurons in the LHb and their projections to the VTA are involved in the occurrence and regulation of depressive-like behavior.
Subject(s)
Depression , Disease Models, Animal , Habenula , Neural Pathways , Optogenetics , Receptors, Dopamine D1 , Ventral Tegmental Area , Animals , Ventral Tegmental Area/physiopathology , Ventral Tegmental Area/physiology , Habenula/physiology , Mice , Male , Receptors, Dopamine D1/metabolism , Depression/physiopathology , Depression/etiology , Neural Pathways/physiopathology , Mice, Transgenic , Stress, Psychological/physiopathology , Mice, Inbred C57BL , Restraint, Physical , Neurons/physiologyABSTRACT
Mitochondria are essential for maintaining skeletal muscle metabolic homeostasis during adaptive response to a myriad of physiologic or pathophysiological stresses. The mechanisms by which mitochondrial function and contractile fiber type are concordantly regulated to ensure muscle function remain poorly understood. Evidence is emerging that the Folliculin interacting protein 1 (Fnip1) is involved in skeletal muscle fiber type specification, function, and disease. In this study, Fnip1 was specifically expressed in skeletal muscle in Fnip1-transgenic (Fnip1Tg) mice. Fnip1Tg mice were crossed with Fnip1-knockout (Fnip1KO) mice to generate Fnip1TgKO mice expressing Fnip1 only in skeletal muscle but not in other tissues. Our results indicate that, in addition to the known role in type I fiber program, FNIP1 exerts control upon muscle mitochondrial oxidative program through AMPK signaling. Indeed, basal levels of FNIP1 are sufficient to inhibit AMPK but not mTORC1 activity in skeletal muscle cells. Gain-of-function and loss-of-function strategies in mice, together with assessment of primary muscle cells, demonstrated that skeletal muscle mitochondrial program is suppressed via the inhibitory actions of FNIP1 on AMPK. Surprisingly, the FNIP1 actions on type I fiber program is independent of AMPK and its downstream PGC-1α. These studies provide a vital framework for understanding the intrinsic role of FNIP1 as a crucial factor in the concerted regulation of mitochondrial function and muscle fiber type that determine muscle fitness.
Subject(s)
AMP-Activated Protein Kinases/metabolism , Carrier Proteins/genetics , Carrier Proteins/metabolism , Mitochondria, Muscle/metabolism , Muscle Fibers, Skeletal/metabolism , Animals , Female , Gene Expression Profiling , Male , Mice , Mice, Transgenic , Mitochondria, Muscle/ultrastructure , Muscle Fibers, Skeletal/ultrastructure , Organ Specificity , Oxidation-Reduction , Oxidative StressABSTRACT
Ultrasonic hearing and vocalization are the physiological mechanisms controlling echolocation used in hunting and navigation by microbats and bottleneck dolphins and for social communication by mice and rats. The molecular and cellular basis for ultrasonic hearing is as yet unknown. Here, we show that knockout of the mechanosensitive ion channel PIEZO2 in cochlea disrupts ultrasonic- but not low-frequency hearing in mice, as shown by audiometry and acoustically associative freezing behavior. Deletion of Piezo2 in outer hair cells (OHCs) specifically abolishes associative learning in mice during hearing exposure at ultrasonic frequencies. Ex vivo cochlear Ca2+ imaging has revealed that ultrasonic transduction requires both PIEZO2 and the hair-cell mechanotransduction channel. The present study demonstrates that OHCs serve as effector cells, combining with PIEZO2 as an essential molecule for ultrasonic hearing in mice.
Subject(s)
Hair Cells, Auditory, Outer/metabolism , Hearing/physiology , Ion Channels/metabolism , Ultrasonics , Animals , Calcium/metabolism , Freezing Reaction, Cataleptic , Gene Deletion , HEK293 Cells , Humans , Mechanotransduction, Cellular , Mice, KnockoutABSTRACT
OBJECTIVE: This study aimed to establish a permanent middle cerebral artery occlusion (pMCAO) model in rats to simulate the pathological process of stroke patients with no reperfusion. And screen highly sensitive items that could be used to detect long-term behavioral abilities in rat of intraluminal suture models. METHOD: Established the pMCAO model then tested the rats for the bilateral asymmetry, modified neurological severity score, grid-walking, cylinder, rotating, and water maze test from week 1 to week 16. RESULTS: The infarct volume of the model rats was stable (26.72% ±1.86%). The sensorimotor test of bilateral asymmetry, grid-walking, cylinder, and mNSS test showed significant differences from week 1 to week 16 after injury. The water maze test at week 16 showed significant differences in spatial exploration and learning ability between the two groups. We confirmed that there was no significant difference between MRI and TTC staining in detecting the degree of brain injury, which facilitated the diversity of subsequent detection methods. We also confirmed that at multiple time points, grid, cylinder and water maze test were significantly positively correlated with rat brain infarct volume. CONCLUSION: They are suitable for the long-term observation of behaviors in the sequela stage of stroke in rat.