Biology subjects

Sun, J.

Publications and source records attributed to Sun, J..

At least 307 records · Page 17Linked to original sources

bioRxiv2022

The bHLH-PAS transcriptional complex Sim:Tgo plays active roles in late oogenesis to promote follicle maturation and ovulation

Across species, ovulation is a process induced by a myriad of signaling cascades that ultimately results in activation of proteolytic enzymes and degradation of the follicle wall to release encapsulated oocytes. Follicles need to first mature and gain ovulatory competency before ovulation. However, the signaling pathways regulating follicle maturation are incompletely understood in Drosophila and other species. Our previous work showed that bHLH-PAS transcription factor Single-minded (Sim) likely plays important roles for follicle maturation downstream of the NR5A-family nuclear receptor Ftz-f1 in Drosophila. Here, we explore the mechanism of Sim-regulated follicle maturation. We demonstrate that Tango (Tgo), another bHLH-PAS protein acts as a cofactor of Sim to promote follicle cell differentiation from stages 10 to 12. In addition, we discovered that re-upregulation of Sim in stage-14 follicle cells is also essential to promote ovulatory competency by upregulating octopamine receptor in mushroom body (OAMB), matrix metalloproteinase 2 (Mmp2), and NADPH oxidase (NOX), either independent of or in conjunction with the zinc-finger protein Hindsight (Hnt). All of these factors are critical for successful ovulation. Together, our work indicates that the transcriptional complex Sim:Tgo plays multiple roles in late-stage follicle cells to promote follicle maturation and ovulation.

developmental biology↗

bioRxiv2022

ZBTB20 is Essential for Cochlear Maturation and Hearing in Mice

The mammalian cochlear epithelium undergoes substantial remodeling and maturation before the onset of hearing. However, very little is known about the transcriptional network governing cochlear late-stage maturation and particularly the differentiation of its lateral non-sensory region. Here we establish ZBTB20 as an essential transcription factor required for cochlear terminal differentiation and maturation and hearing. ZBTB20 is abundantly expressed in the developing and mature cochlear non-sensory epithelial cells, with transient expression in immature hair cells and spiral ganglion neurons. Otocyst-specific deletion of Zbtb20 causes profound deafness with reduced endolymph potential in mice. The subtypes of cochlear epithelial cells are normally generated but their postnatal development is arrested in the absence of ZBTB20, as manifested by an immature appearance of the organ of Corti, malformation of tectorial membrane, a flattened spiral prominence, and a lack of identifiable Boettcher cells. Furthermore, these defects are related with a failure in the terminal differentiation of the non-sensory epithelium covering the outer border Claudius cells, outer sulcus root cells and spiral prominence epithelial cells. Transcriptome analysis shows ZBTB20 regulates genes coding for tectorial membrane proteins in the greater epithelial ridge, and those preferentially expressed in root cells and spiral prominence epithelium. Our results point to ZBTB20 as an essential regulator for postnatal cochlear maturation and particularly for the terminal differentiation of cochlear lateral non-sensory domain.

developmental biology↗

bioRxiv2022

Molecular insights into the gating mechanisms of voltage-gated calcium channel CaV2.3

High-voltage-activated R-type CaV2.3 channel plays pivotal roles in many physiological activities and is implicated in epilepsy, convulsions, and other neurodevelopmental impairments. Here, we determine the high-resolution cryo-electron microscopy (cryo-EM) structure of human CaV2.3 in complex with the 2{delta}1 and {beta}1 subunits. The VSDII is stabilized in the resting state. Electrophysiological experiments elucidate that the conformational change of VSDII in response to variation in membrane potential is not required for channel activation, whereas the other VSDs are essential for channel opening. The intracellular gate is blocked by the W-helix. A pre-W-helix adjacent to the W-helix can significantly regulate closed-state inactivation (CSI) by modulating the association and dissociation of the W-helix with the gate. Electrostatic interactions formed between the negatively charged domain on S6II, which is exclusively conserved in the CaV2 family, and nearby regions at the alpha-interacting domain (AID) and S4-S5II helix are identified. Further functional analyses indicate that these interactions are critical for the open-state inactivation (OSI) of CaV2 channels.

biophysics↗

bioRxiv2022

Phylogenomic analyses shed light on the relationships of chiton superfamilies and shell-eye evolution

Mollusca is the second-largest animal phylum with over 100,000 species among eight distinct taxonomic classes. Across 1000 living species in the class Polyplacophora, chitons have a relatively constrained morphology but with some notable deviations. Several genera possess "shell eyes", true eyes with a lens and retina that are embedded within the dorsal shells, which represent the most recent evolution of animal eyes. The phylogeny of major chiton clades is mostly well established, in a set of superfamily and higher-level taxa supported by various approaches including multiple gene markers, mitogenome-phylogeny and phylotranscritomic approaches as well as morphological studies. However, one critical lineage has remained unclear: Schizochiton was controversially suggested as a potential independent origin of chiton shell eyes. Here, with the draft genome sequencing of Schizochiton incisus (superfamily Schizochitonoidea) plus assembly of transcriptome data from other polyplacophorans, we present phylogenetic reconstructions using both mitochondrial genomes and phylogenomic approaches with multiple methods. Phylogenetic trees from mitogenomic data are inconsistent, reflecting larger scale confounding factors in molluscan mitogenomes. A consistent robust topology was generated with protein coding genes using different models and methods. Our results support Schizochitonoidea is a sister group to other Chitonoidea in Chitonina, in agreement with established classification. This suggests that the earliest origin of shell eyes is in Schizochitonoidea, which were also gained secondarily in other genera in Chitonoidea. Our results have generated a holistic review of the internal relationship within Polyplacophora, and a better understanding on the evolution of Polyplacophora.

evolutionary biology↗

bioRxiv2022

PlantServation: time-series phenotyping using machine learning revealed seasonal pigment fluctuation in diploid and polyploid Arabidopsis

Long-term field monitoring of leaf pigment content is informative for understanding plant responses to environments distinct from regulated chambers, but is impractical by conventional destructive measurements. We developed PlantServation, a method incorporating robust image-acquisition hardware and deep learning-based software to analyze field images, where the plant shape, color, and background vary over months. We estimated the anthocyanin contents of small individuals of four Arabidopsis species using color information and verified the results experimentally. We obtained >4 million plant images over three field seasons to study anthocyanin fluctuations. We found significant effects of past radiation, coldness, and precipitation on the anthocyanin content in the field. The synthetic allopolyploid A. kamchatica recapitulated the fluctuations of natural polyploids by integrating diploid responses. The data support a long-standing hypothesis stating that allopolyploids can inherit and combine the traits of progenitors. PlantServation pipeline facilitates the study of plant responses to complex environments termed "in natura."

plant biology↗

bioRxiv2022

Arabidopsis ORP2A positively regulates glucose signaling by interacting with AtRGS1 and promoting AtRGS1 degradation

Heterotrimeric GTP-binding proteins (G proteins) are a group of regulators essential for signal transmission into cells. AtRGS1 (Regulator of G protein Signaling 1) with intrinsic GTPase-accelerating protein (GAP) activity could suppress G protein and glucose signal transduction in Arabidopsis. However, how AtRGS1 activity is regulated is currently poor understood. Here we identified a knockout mutant orp2a-1 (oxysterol-binding protein (OSBP)-related protein 2A) which shows phenotypes similar to agb1-2 (arabidopsis g-protein beta 1). With overexpression of ORP2A, transgenic lines display short hypocotyl, hypersensitivity to sugar and lower intracellular AtRGS1 level than control. Consistently, ORP2A shows interaction with AtRGS1 in vitro and vivo. Tissue specificity of ORP2A with two alternative protein forms imply its functions in organ size and shape controlling. Bioinformatic data and phenotypes of orp2a-1, agb1-2 and double mutant reveal genetic interactions in the regulation of G protein signaling and sugar response between ORP2A and G{beta}. Both alternative splicing forms of ORP2A locate in the ER, PM (Plasma Membrane) and EPCS (ER-PM Contact Sites), and interact with VAP27-1 mediated by a FFAT-like motif in vivo and vitro. ORP2A also displays differential phosphatidyl phosphoinositide binding activity mediated by its PH domain in vitro. Taken together, it is suggested that Arabidopsis membrane protein ORP2A interacts with AtRGS1 and VAP27-1 to positively regulate G protein and sugar signaling by facilitating AtRGS1 degradation.

plant biology↗

bioRxiv2022

O-GlcNAcylation promotes YTHDF1 cytosolic localization and colorectal cancer tumorigenesis

O-linked N-acetylglucosamine (O-GlcNAc) is an emerging post-translation modification that couples metabolism with cellular signal transduction by crosstalking with phosphorylation and ubiquitination to orchestrate various biological processes. Herein we show that it modifies the N6-methyladenosine (m6A)-mRNA reader YTHDF1 and fine-tunes its nuclear translocation by the exportin protein Crm1. First we present evidence that YTHDF1 interacts with the sole O-GlcNAc transferase (OGT). Second, we verified the YTHDF1 O-GlcNAcylation sites to be Ser196/Ser197/Ser198, as described in previous numerous chemoproteomic studies. Then we constructed the O-GlcNAc-deficient YTHDF1-S196AS197FS198A (AFA) mutants, which significantly attentuated O-GlcNAc signals. Moreover, we revealed that YTHDF1 is a nucleocytoplasmic protein, whose nuclear export is mediated by Crm1. Furthermore, O-GlcNAcylation increases the cytosolic portion of YTHDF1 by enhancing binding with Crm1, thus upregulating the downstream target (e.g. c-Myc) expression. Molecular dynamics simulations suggest that O-GlcNAcylation at S197 might promote the binding between the nuclear export signal motif and Crm1 through increasing hydrogen bonding. Mouse xenograft assays further demonstrate that YTHDF1-AFA mutants decreased the colon cancer mass and size via decreasing c-Myc expression. In sum, we found that YTHDF1 is a nucleocytoplasmic protein, whose cytosolic localization is dependent on O-GlcNAc modification. We propose that the OGT-YTHDF1-c-Myc axis might underlie colorectal cancer tumorigenesis.

biochemistry↗

bioRxiv2022

The shadowing effect of initial expectation on learning asymmetry

Evidence for positivity and optimism bias abounds in high-level belief updates. However, no consensus has been reached regarding whether learning asymmetries exists in more elementary forms of updates such as reinforcement learning (RL). In RL, the learning asymmetry concerns the sensitivity difference in incorporating positive and negative prediction errors (PE) into value estimation, namely the asymmetry of learning rates associated with positive and negative PEs. Although RL has been established as a canonical framework in interpreting agent and environment interactions, the direction of the learning rate asymmetry remains controversial. Here, we propose that part of the controversy stems from the fact that people may have different value expectations before entering the learning environment. Such default value expectation influences how PEs are calculated and consequently biases subjects choices. We test this hypothesis in two learning experiments with stable or varying reinforcement probabilities, across monetary gains, losses and gain-loss mixtures environments. Our results consistently support the model incorporating asymmetric learning rates and initial value expectation, highlighting the role of initial expectation in value update and choice preference. Further simulation and model parameter recovery analyses confirm the unique contribution of initial value expectation in accessing learning rate asymmetry. Author SummaryWhile RL model has long been applied in modeling learning behavior, where value update stands in the core of the learning process, it remains controversial whether and how learning is biased when updating from positive and negative PEs. Here, through model comparison, simulation and recovery analyses, we show that accurate identification of learning asymmetry is contingent on taking into account of subjects default value expectation in both monetary gain and loss environments. Our results stress the importance of initial expectation specification, especially in studies investigating learning asymmetry.

neuroscience↗

bioRxiv2022

Confocal reflectance microscopy for mapping collagen fiber organization in the vitreous gel of the eye

Vitreous collagen structure plays an important role in ocular mechanics, but capturing this structure with existing vitreous imaging methods is hindered by loss of sample position and orientation, low resolution, or small field of view. The objective of this study was to evaluate confocal reflectance microscopy as a solution to these limitations. The use of intrinsic reflectance avoids staining and optical sectioning eliminates the requirement for thin sectioning, minimizing processing for optimal preservation of natural structure. We developed a sample preparation and imaging strategy using ex vivo grossly sectioned porcine eyes. Imaging revealed a network of uniform diameter crossing fibers (1.1 {+/-} 0.3 m for a typical image) with generally poor alignment (alignment coefficient = 0.40 {+/-} 0.21 for a typical image). To test the utility of our approach for detecting differences in fiber spatial distribution, we imaged eyes every 1 mm along an anterior-posterior axis originating at the limbus and quantified the number of fibers in each image. Fiber density was higher anteriorly near the vitreous base, regardless of imaging plane. These data demonstrate that confocal reflectance microscopy addresses the previously unmet need for a robust, micron-scale technique to map features of collagen networks in situ across the vitreous.

biochemistry↗

bioRxiv2022

Discovery of benzophenanthridine derivatives with potent activity against multidrug resistant Mycobacterium tuberculosis

Mycobacterium tuberculosis (Mtb), the pathogen responsible for tuberculosis (TB), is the leading cause of bacterial disease-related death worldwide. Current antibiotic regimens for the treatment of TB remain dated and suffer from long treatment times as well as the development of drug-resistance. As such, the search for novel chemical modalities that have selective or potent anti-Mtb properties remains an urgent priority, particularly against multidrug resistant (MDR) Mtb strains. Herein, we design and synthesize 35 novel benzo[c]phenanthridine derivatives (BPD). The two most potent compounds, BPD-6 and BPD-9, accumulated within the bacterial cell and exhibited strong inhibitory activity (MIC90 [~] 2-10 M) against multiple Mycobacterium strains, while remaining inactive against a range of other Gram-negative and Gram-positive bacteria. BPD-6 and BPD-9 were also effective in reducing Mtb viability within infected macrophages. The two BPD compounds displayed comparable efficacy to rifampicin, a critical frontline antibiotic used for the prevention and treatment of TB. Importantly, BPD-6 and BPD-9 inhibited the growth of multiple MDR Mtb clinical isolates, suggesting a completely novel mechanism of action compared to existing frontline TB dugs. The discovery of BPDs provides novel chemical scaffolds for anti-TB drug discovery. TOC/GRAPHICAL ABSTRACT O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=110 SRC="FIGDIR/small/515485v1_ufig1.gif" ALT="Figure 1"> View larger version (29K): org.highwire.dtl.DTLVardef@1536acaorg.highwire.dtl.DTLVardef@1881e83org.highwire.dtl.DTLVardef@18b2f58org.highwire.dtl.DTLVardef@d15f1a_HPS_FORMAT_FIGEXP M_FIG C_FIG

microbiology↗

bioRxiv2022

Antigen presentation by discrete class I molecules on brain endothelium dynamically regulates T-cell mediated neuropathology in experimental cerebral malaria

CD8 T cell engagement of brain vasculature is a putative mechanism of neuropathology in human cerebral malaria. To define contributions of brain endothelial cell MHC class I antigen-presentation to CD8 T cells in establishing this pathology, we developed novel H-2Kb LoxP and H-2Db LoxP mice crossed with Cdh5-Cre mice to achieve targeted deletion of discrete class I molecules on brain endothelium. Using the Plasmodium berghei ANKA model of experimental cerebral malaria (ECM), we observe that H-2Kb and H-2Db regulate distinct patterns of disease onset, CD8 T cell infiltration, targeted cell death, and regional blood-brain barrier (BBB) disruption. Strikingly, ablation of H-2Kb or H-2Db from brain endothelial cells resulted in reduced CD8 T cell activation, attenuated T cell interaction with brain vasculature, lessened targeted cell death, preserved BBB integrity, and prevented ECM and the death of the animal. These data demonstrate that interactions of CD8 T cells with discrete MHC class I molecules on brain endothelium regulate development of ECM neuropathology. Therefore, targeting MHC class I interactions therapeutically may hold potential for treatment of cases of severe malaria.

neuroscience↗

bioRxiv2022

The splicing switch of SLK controls tumor progression partially via different associations with occludin

RNA splicing control is a pivotal aspect of gene regulation and is closely associated with cancer development. From a pan-cancer transcriptome investigation in the splicing layer, we discovered a critical cancer-associated alternative splicing (AS) event at exon 13 of SLK which produces two isoforms, SLK-L and SLK-S. The splicing is dramatically shifted towards SLK-L across multiple prevalent cancer types. We demonstrated that SLK-L plays an essential role in cancer development, especially in metastasis both in cells and in mice, whereas splicing toward SLK-S inhibits cancer development. RNA-seq revealed the two SLK isoforms play different roles in pathways related to cell migration. Furthermore, different SLK isoforms demonstrate varying binding affinities to certain cell junction markers, in part indicating the AS of SLK contributes to cancer cell migration. In addition, the splicing factor Rbfox2 was identified to specifically inhibit the inclusion of exon 13 by binding intron 12 of SLK. Collectively, our study innovatively uncovers the biological consequences and underlying mechanisms for one of the most mis-spliced genes in cancer, highlighting its potential significance in cancer diagnosis and treatment.

cancer biology↗

bioRxiv2022

The entry of pinewood nematode is linked to programmed tracheal development of vector beetles

The transmission of some pathogens by insect vectors often requires fine-tuned biological synchronization and communication between the two parties. However, the role of tissue development in mediating this pathogen-vector coordination remains elusive. Here we investigated the association between tracheal development of Monochamus alternatus beetle and a notorious plant parasitic pine wood nematode Bursaphelenchus xylophilus, which enter and inhabit inside the tracheal system after adult beetle eclosion and then were transmitted to pine trees (Pinus spp.) by the beetle. We found that the tracheal systems of newly emerged adult beetles underwent morphological changes during the adult sclerotization, characterized by a remarkable increase of diameter of thoracic tracheal dorsal tubes. Consistently, comparative transcriptomics further revealed dramatic changes in gene expression occurring within five days after eclosion, demonstrating sequential regulation of tracheal genes. Genes controlling primary branching were up-regulated soon after eclosion, whereas those controlling terminal branching and branch fusion were up-regulaed at the later stage. Interestingly, during tracheal maturation, genes involved in biosynthesis of Juvenile Hormone (JH) and ecdysteroids were activated. Nematode loading assay further revealed that the entry of nematodes to beetle tracheae was initiated earliest after three days post eclosion, implying that nematode entry is reliant on the formation of the vectors primary tracheal branches and is perhaps stimulated by production of insect hormones or their precursors. In addition, specific regulation on secreted proteins, such as Defensin-1-like and membrane proteins, at later stages of tracheal maturation may further facilitate the entry of nematodes by improving their retention. Therefore, this study highlights vital role of programed tracheal development on nematode entry into its vector beetle, and suggests a potential roles of insect genes and metabolites in manipulation of interspecific biological developmental synchronization between parasites and their insect vectors.

ecology↗

bioRxiv2022

Chaperones Hsc70 and Hsp70 Play Distinct Roles in Bocaparvovirus Minute Virus of Canines Infection

Minute virus of canines (MVC) belongs to the genus Bocaparvovirus and reproduces rapidly in its permissive cells Walter Reed/3873D (WRD). The crosstalk between MVC and WRD is poorly characterized in terms of molecular requirements and mechanisms. Here, we identified two novel cellular proteins Hsc70 and Hsp70 that interact with both NS1 and VP2 via mass spectrometry (MS), co-immunoprecipitation (Co-IP) and confocal immunofluorescence assays (IFA). Hsp70 was upregulated upon MVC infection. Respective silencing of Hsc70 and Hsp70 led to contrasting results at nearly every stage of MVC life cycle, including virus entry, transcription, translation, replication and production. Strikingly, transfection with low and high dose of pFlag-Hsp70 contributed to opposing impacts on viral protein levels and virus production possibly through a ubiquitin-dependent manner, indicating that MVC is quite sensitive to the levels of Hsp70. Treatment with quercetin and VER155008, two Hsp70 family inhibitors, both significantly decreased viral replication and particle levels. Together, these results illustrated that both Hsc70 and Hsp70 are involved in MVC life cycle, and targeting to Hsp70 family may represent a novel anti-MVC mechanism.

molecular biology↗

bioRxiv2022

Cuproptosis is correlated with clinical status, tumor immune microenvironment and immunotherapy in colorectal cancer: a multi-omic analysis

Copper, like double-edged sword, either too little or too much can lead to cell death. Cuproptosis, a novel identified cell death form induced by copper, is characterized by aggregation of lipoylated mitochondrial enzymes and the destabilization of Fe-S cluster proteins. However, the function and potential clinical value of cuproptosis in colorectal cancer remains largely unknown. In this study, 16 cuproptosis-related molecules (CPRMs) were identified and analyzed by transcriptomics, genomics, and single-cell transcriptome profiling from multiple databases. We established two cuproptosis-related molecular phenotypes (CMP1 and 2) to distinguish CRC individuals, in which there were significantly differences in prognosis, biological function, somatic mutation frequency, immune cell infiltration in CRC individuals. A novel cuproptosis-related scoring system (CuproScore) was also constructed to predict the prognosis of CRC individuals, TME and the response to immunotherapy. Of notion, the value of CuproScore was also confirmed in our transcriptome cohort, demonstrating that CRC individuals in the high CuproScore group tended to have higher immune cell infiltrations and higher immune checkpoint expression. We also checked and analyzed the expression and clinical significance of 16 CPRMs in CRC cell lines and CRC tissues. This study indicated that cuproptosis and CPRMs played significant role in CRC progression and in modeling the TME. Inducing cuproptosis may be a useful tool for tumor therapy in the future.

cancer biology↗

bioRxiv2022

Study on the interactions between cisplatin and cadherin

Cisplatin is an important platinum drug in the chemotherapy of many malignant tumors in clinical application. It is well accepted that its main target is DNA molecule. However, recent studies have shown that platinum drugs may also act on some important functional proteins in the human body and have complicate effects on their efficacy. E-cadherin is newly discovered glycoproteins which have been regarded as the important signs of the occurrence and development of some tumors. In this study, the interactions between cisplatin and E-cadherin were explored by fluorescence spectroscopy and atomic force microscopy (AFM). The fluorescence spectroscopy results indicated that cisplatin can efficiently quench the fluorescence of E-cadherin, and the calculated binding constant Kb was 3.20x106 (25{degrees}C), 1.36 x106(31{degrees}C) and 8.22x105 L mol-1 (37{degrees}C). The thermodynamic parameters {Delta}H <0, {Delta}S <0, {Delta}G <0, reveal that the fluorescence quenching effect of cisplatin on E-cadherin is static quenching, which is dominated by hydrogen bond and van der Waals interaction. The AFM results revealed that there was a staggered interaction between the intermolecular domains of E-cadherin to form a long spherical chain structure. The addition of cisplatin could significantly affect the staggered effect of the E-cadherin molecules. All these results confirmed that there are strong interactions between cisplatin and cadherin.

biochemistry↗

bioRxiv2022

Host mixotrophy, habitat stability and recombination may all decrease geographic differentiation between symbiont populations in Western Pacific deep-sea mussels

The intra-host composition of horizontally transmitted microbial symbionts can vary across host populations due to interactive effects of host genetics, environmental and geographic factors. While adaptation to local habitat conditions can drive geographic subdivision of symbiont strains, it is unknown whether these patterns are universal and how differences in ecological characteristics among host-symbiont associations influence the genomic structure of symbiont populations. To address this question, we sequenced metagenomes of different populations of the deep-sea mussel Bathymodiolus septemdierum, which are common at Western Pacific deep-sea hydrothermal vents and show characteristic patterns of niche partitioning with sympatric gastropod symbioses. Bathymodiolus septemdierum lives in close symbiotic relationship with sulfur-oxidizing chemosynthetic bacteria but supplements its symbiotrophic diet through filter-feeding, enabling it to occupy ecological niches with less exposure to geochemical reductants. Our analyses indicate that symbiont populations associated with B. septemdierum show structuring by geographic location, but that the dominant symbiont strain is uncorrelated with vent site. These patterns are in contrast to co-occurring Alviniconcha and Ifremeria symbioses that exhibit greater symbiont nutritional dependence and occupy habitats with higher spatial variability in environmental conditions. Our results suggest that relative habitat homogeneity combined with sufficient symbiont dispersal and genomic mixing might promote persistence of similar symbiont strains across geographic locations, while mixotrophy might decrease selective pressures on the host to affiliate with locally adapted symbiont strains. Overall, these data contribute to our understanding of the potential mechanisms influencing symbiont population structure across a spectrum of marine microbial symbioses that vary in ecological niche and relative host dependency.

evolutionary biology↗

bioRxiv2022

Neuronal C-Reactive Protein Mediates Neuropathic Pain by Activating Nociceptive FcγRI-Coupled Signaling

BackgroundNeuropathic pain is difficult to treat in clinical practice, and the underlying mechanisms are insufficiently elucidated. Previous studies have demonstrated that Fc{gamma} receptor I (Fc{gamma}RI) is expressed in the neurons of the dorsal root ganglion (DRG) and may be involved in chronic pain. MethodsChronic constriction injury (CCI) was used to induce neuropathic pain in rats. Primary neuron-specific Fcgr1 conditional knockout (CKO) rats were established by crossing rats carrying a Fcgr1loxP+/+ with the PirtCRE+ line. Behavioral and molecular studies were conducted to evaluate the differences between wild-type and CKO rats after CCI. ResultsWe first revealed that CCI activated neuronal Fc{gamma}RI-related signaling in the DRG. CCI-induced neuropathic pain was alleviated in CKO rats. C-reactive protein (CRP) was increased in the DRG after nerve injury. Intraganglionic injection or overexpression of the recombinant CRP protein in the DRG evoked pain accompanied and activated neuronal Fc{gamma}RI. CRP-evoked pain was significantly reduced in CKO rats. Furthermore, microinjection of native IgG into the DRG alleviated neuropathic pain and the activation of neuronal Fc{gamma}RI-related signaling. ConclusionsOur results indicate that the activation of neuronal CRP/Fc{gamma}RI-related signaling plays an important role in the development of pain in CCI. Our findings may provide novel insights into the neuroimmune responses after peripheral nerve injury and might suggest potential therapeutic targets for neuropathic pain.

neuroscience↗