Biology subjects

Xiang, X.

Publications and source records attributed to Xiang, X..

At least 37 records · Page 2Linked to original sources

bioRxiv2023

Identification and functional analysis of extrachromosomal circular DNA in plasma extracellular vesicles of liver failure patients

Withdrawal statementThe authors have withdrawn their manuscript owing to having identified certain issues with the current representation of the data in the manuscript after performing further analyses of the bioinformatics data from their eccDNA sequencing results. Therefore, the authors do not wish this work to be cited as reference for the project. A revised and corrected version will be submitted in the future. If you have any questions, please contact the corresponding authors.

genomics↗

bioRxiv2023

The Multifaceted Effects of Short-Term Acute Hypoxia Stress: Insights into the tolerance mechanism of Propsilocerus akamusi (Diptera: Chironomidae)

Plenty of freshwater species, especially macroinvertebrates that are essential to the provision of numerous ecosystem functions, encountered higher mortality due to acute hypoxia. However, within the family Chironomidae, a wide range of tolerance to hypoxia/anoxia is displayed and Propsilocerus akamusi depends on this great endurance to become a dominant species in eutrophic lakes. To further understand how P. akamusi responds to acute hypoxic stress, we used multi-omics analysis in combination with histomorphological characteristics and physiological indicators. To evaluate enzyme activity, the transcriptome and metabolome, and histomorphological characteristics, we set up two groups: a control group (DO 8.4mg/L) and a hypoxic group (DO 0.39mg/L). With blue-black chromatin, cell tightness, cell membrane invagination, and the production of apoptotic vesicles, tissue cells displayed typical apoptotic features. While lactate dehydrogenase (LDH), (Alcohol dehydrogenase) ADH, catalase (CAT), and Na+/K+ -ATPase (NKA) activities were dramatically enhanced under hypoxic stress, glycogen content, and superoxide dismutase (SOD) activities were significantly reduced compared to the control group. The above results were further supported by the joint analysis of the transcriptome and metabolome, which further revealed that in addition to carbohydrates, including glycogen, the energy metabolism of the fatty acid, trehalose, and glyoxylate cycles is also included. Furthermore, we also revealed the ethanol tested in hypoxic stress should derive from symbiodinium of P akamusi. Understanding the processes which enable P. akamusi to survive lengthy periods of hypoxia in eutrophic lakes might help to design sensitive biomonitoring procedures, and this species has the potential to be used as an effective eutrophication indicator.

biophysics↗

bioRxiv2023

TREM2 promotes glioma progression and angiogenesis mediated by microglia/brain macrophages

TREM2, a myeloid cell-specific signaling molecule, controls essential functions of microglia and impacts on the pathogenesis of Alzheimers disease and other neurodegenerative disorders. TREM2 is also highly expressed in tumor-associated macrophages and plays detrimental roles in an experimental mouse sarcoma model. Here we studied whether TREM2 influences glioma progression. We found a sex- dependent effect of TREM2: the glioma volume is significantly attenuated in TREM2- deficient male but not female mice injected with GL261-EGFP glioma cells. The accumulation of glioma-associated microglia/macrophages (GAMs) and vascularization is reduced in male TREM2-deficient mice. A transcriptomic analysis of glioma tissue revealed that TREM2 deficiency suppresses angiogenic genes and MHC clusters. In an organotypic slice model devoid of functional vascularization, the tumor size was not affected by TREM2-deficiency. In human resection samples from glioblastoma, TREM2 is upregulated in GAMs. Based on the TCGA and CGGA databases, the TREM2 expression levels are negatively correlated with survival. Thus, the TREM2-dependent crosstalk between GAMs and the vasculature formation promotes glioma growth. Graphic abstractTREM2-dependent crosstalk between glioma-associated microglia/macrophages and the vasculature formation promotes glioma growth in male glioma mouse model. Created with BioRender.com O_FIG O_LINKSMALLFIG WIDTH=200 HEIGHT=137 SRC="FIGDIR/small/540621v1_ufig1.gif" ALT="Figure 1"> View larger version (39K): org.highwire.dtl.DTLVardef@65bec7org.highwire.dtl.DTLVardef@1d00961org.highwire.dtl.DTLVardef@117ee5eorg.highwire.dtl.DTLVardef@227994_HPS_FORMAT_FIGEXP M_FIG C_FIG

neuroscience↗

bioRxiv2023

Aspergillus SUMOylation mutants have normal dynein function but exhibit chromatin bridges

AbstractFunctions of protein SUMOylation remain incompletely understood in different cell types. The budding yeast SUMOylation machinery interacts with LIS1, a protein critical for dynein activation, but dynein-pathway components were not identified as SUMO-targets in the filamentous fungus Aspergillus nidulans. Via A. nidulans forward genetics, here we identified ubaBQ247*, a loss-of-function mutation in a SUMO-activation enzyme UbaB. Colonies of the ubaBQ247*, {Delta}ubaB and {Delta}sumO mutants looked similar and less healthy than the wild-type colony. In these mutants, about 10% of nuclei are connected by abnormal chromatin bridges, indicating the importance of SUMOylation in the completion of chromosome segregation. Nuclei connected by chromatin bridges are mostly in interphase, suggesting that these bridges do not prevent cell-cycle progression. UbaB-GFP localizes to interphase nuclei just like the previously studied SumO-GFP, but the nuclear signals disappear during mitosis when the nuclear pores are partially open, and the signals reappear after mitosis. The nuclear localization is consistent with many SUMO-targets being nuclear proteins, for example, topoisomerase II whose SUMOylation defect gives rise to chromatin bridges in mammalian cells. Unlike in mammalian cells, however, loss of SUMOylation in A. nidulans does not apparently affect the metaphase-to-anaphase transition, further highlighting differences in the requirements of SUMOylation in different cell types. Finally, loss of UbaB or SumO does not affect dynein-and LIS1-mediated early-endosome transport, indicating that SUMOylation is unnecessary for dynein or LIS1 function in A. nidulans.

cell biology↗

bioRxiv2023

Reconstruction of TrkB complex assemblies and localizing an-tidepressant targets using Artificial Intelligence

Since Major Depressive Disorder (MDD) represents a neurological pathology caused by inter-synaptic messaging errors, membrane receptors, the source of signal cascades, constitute appealing drugs targets. G protein-coupled receptors (GPCRs) and ion channel receptors chelated antidepressants (ADs) high-resolution architectures were reported to realize receptors physical mechanism and design prototype compounds with minimal side effects. Tyrosine kinase receptor 2 (TrkB), a receptor that directly modulates synaptic plasticity, has a finite three-dimensional chart due to its high molecular mass and intrinsically disordered regions (IDRs). Leveraging breakthroughs in deep learning, the meticulous architecture of TrkB was projected employing Alphfold 2 (AF2). Furthermore, the Alphafold Multimer algorithm (AF-M) models the coupling of intra- and extra-membrane topologies to chaperones: mBDNF, SHP2, Etc. Conjugating firmly dimeric transmembrane helix with novel compounds like 2R,6R-hydroxynorketamine (2R,6R-HNK) expands scopes of drug screening to encompass all coding sequences throughout genomes. The operational implementation of TrkB kinase-SHP2, PLC{gamma}1, and SHC1 ensembles has paved the path for machine learning in which it can forecast structural transitions in the self-assembly and self-dissociation of molecules during trillions of cellular mechanisms. In silicon, the cornerstone of the alteration will be artificial intelligence (AI), empowering signal networks to operate at the atomic level and picosecond timescales.

bioinformatics↗

bioRxiv2022

Targeting the pathological network: feasibility of network-based optimization of transcranial magnetic stimulation coil placement for treatment of psychiatric disorders

It has been recognized that the efficacy of TMS-based modulation may depend on the network profile of the stimulated regions throughout the brain. However, what profile of this stimulation network optimally benefits treatment outcomes is yet to be addressed. The answer to the question is crucial for informing network-based optimization of stimulation parameters, such as coil placement, in TMS treatments. In this study, we aimed to investigate the feasibility of taking a disease-specific network as the target of stimulation network for guiding individualized coil placement in TMS treatments. We present here a novel network-based model for TMS targeting of the pathological network. First, combining E-field modeling and resting-state functional connectivity, stimulation networks were modeled from locations and orientations of the TMS coil. Second, the spatial anti-correlation between the stimulation network and the pathological network of a given disease was hypothesized to predict the treatment outcome. The proposed model was validated to predict treatment efficacy from the position and orientation of TMS coils in two depression cohorts and one auditory verbal hallucinations cohort. We further demonstrate the utility of the proposed model in guiding individualized TMS treatment for psychiatric disorders. In this proof-of-concept study, we demonstrated the feasibility of the novel network-based targeting strategy that uses the whole-brain, system-level abnormity of a specific psychiatric disease as a target. Results based on empirical data suggest that the strategy may potentially be utilized to identify individualized coil parameters for maximal therapeutic effects. HighlightsO_LIProposed a model of targeting pathological brain networks for pre-treatment TMS coil placement planning in the treatment of psychiatric disorders; C_LIO_LIValidated the network targeting model in three cohorts of patients with depression or auditory verbal hallucinations, via prediction of individual TMS treatment efficacy from the parameters of coil placement; C_LIO_LIDemonstrated the utility of the network targeting model in guiding individualized TMS coil placement. C_LI

neuroscience↗

bioRxiv2022

Kinesin-1 autoinhibition facilitates the initiation of dynein cargo transport

Kinesin-1 undergoes autoinhibition but its functional significance has been unclear. Kinesin-1 transports multiple cargoes including cytoplasmic dynein to the microtubule plus ends. From a genetic screen for Aspergills mutants defective in dynein-mediated early endosome transport, we identified a kinesin-1 mutation kinAK895* that disrupts kinesin-1 autoinhibition. Consistent with kinAK895* making kinesin-1 constitutively active, the mutant proteins accumulate abnormally near the microtubule plus ends. Unexpectedly, our genetic data show that kinesin-1 autoinhibition is unnecessary for transporting its cargoes such as secretory vesicles. Dynein accumulates normally at the microtubule plus ends in the kinAK895* mutant. However, the frequency but not the speed of dynein-mediated early endosome transport is significantly decreased, indicating that kinesin-1 autoinhibition facilitates dynein to initiate its cargo transport. Furthermore, kinesin-1 autoinhibition promotes dynein cargo initiation in a way mechanistically distinct from LIS1-promoted dynein switching from its autoinhibited form. Thus, while dynein activation involves dynactin, cargo adapter and LIS1, this study adds kinesin-1 autoinhibition as a new regulatory factor in vivo.

cell biology↗

bioRxiv2022

Processing Stage Flexibility of the SNARC effect: Task Relevance or Magnitude Relevance?

Previous studies have shown that the processing stage of the spatial-numerical association of response codes (SNARC) effect was flexible. Two recent studies by Nan et al. (2021) and Yan et al. (2021) used the same experimental paradigm to check whether the SNARC effect occurred in the semantic-representation stage but reached contradictory conclusions, showing that the SNARC effect was influenced by a magnitude Stroop effect in a magnitude comparison task but not by a parity Stroop effect in a parity judgment task. The two studies had two distinct operational factors: the task type (magnitude comparison task or parity judgment task, with the numerical magnitude information task-relevant or task-irrelevant) and the semantic representation stage-related interference information (magnitude or parity Stroop effect, with the interference information magnitude-relevant or magnitude-irrelevant). To determine which factor influenced the SNARC effect, in the present study, the Stroop effect was switched in the two tasks based on the previous studies. The findings of four experiments consistently showed that the SNARC effect was not influenced by the parity Stroop effect in the magnitude comparison task but was influenced by the magnitude Stroop effect in the parity judgment task. Combined with the results of Nan et al. (2021) and Yan et al. (2021), the findings indicated that regardless of the task type or the task-relevance of numerical magnitude information, magnitude-relevant interference information was the primary factor to affect the SNARC effect. Furthermore, a two-stage processing model that explained the observed flexibility of the SNARC effect was proposed and discussed. Public Significance StatementPrevious studies have shown that the spatial-numerical association of response codes (SNARC) effect is flexible in the direction and processing stage. The task type and interference information might be two influential factors for the flexibility of the SNARC effect. The present study reported that magnitude-relevant interference information, regardless of task type, was a crucial role to affect the SNARC effect. Moreover, a two-stage processing model was proposed to reveal the processing pathway of the SNARC effect and provided a possible explanation for the longstanding debate about the processing stage of the SNARC effect.

animal behavior and cognition↗

bioRxiv2021

Pre-therapeutic Microglia Activation and Sex Determine Therapy Effects of Chronic Immunomodulation

Modulation of the innate immune system is emerging as a promising therapeutic strategy against Alzheimers disease (AD). However, determinants of a beneficial therapeutic effect are ill-understood. Thus, we investigated the potential of 18 kDa translocator protein positron-emission-tomography (TSPO-PET) for assessment of microglial activation in mouse brain before and during chronic immunomodulation. Serial TSPO-PET was performed during five months of chronic microglia modulation by stimulation of peroxisome proliferator-activated receptor (PPAR)-{gamma} with pioglitazone in two different mouse models of AD (PS2APP, AppNL-G-F). Using mixed statistical models on longitudinal TSPO-PET data, we tested for effects of therapy and sex on treatment response. We tested correlations of baseline with longitudinal measures of TSPO-PET, and correlations between PET results with spatial learning performance and {beta}-amyloid accumulation of individual mice. Immunohistochemistry was used to determine the molecular source of the TSPO-PET signal. Pioglitazone-treated female PS2APP and AppNL-G-F mice showed attenuation of the longitudinal increases in TSPO-PET signal when compared to vehicle controls, whereas treated male AppNL-G-F mice showed the opposite effect. Baseline TSPO-PET strongly predicted changes in microglial activation in treated mice (R=-0.874, p<0.0001) but not in vehicle controls (R=-0.356, p=0.081). Reduced TSPO-PET signal upon treatment was associated with better spatial learning and higher fibrillar {beta}-amyloid accumulation. Immunohistochemistry confirmed activated microglia to be the source of the TSPO-PET signal (R=0.952, p<0.0001). TSPO-PET represents a sensitive biomarker for monitoring of immunomodulation and closely reflects activated microglia. Pre-therapeutic assessment of baseline microglial activation and sex are strong predictors of individual immunomodulation effects and could serve for responder stratification.

neuroscience↗

bioRxiv2021

Chronic PPARγ Stimulation Shifts Amyloidosis to Higher Fibrillarity but Improves Cognition

BackgroundWe undertook longitudinal {beta}-amyloid positron emission tomography (A{beta}-PET) imaging as a translational tool for monitoring of chronic treatment with the peroxisome proliferator-activated receptor gamma (PPAR{gamma}) agonist pioglitazone in A{beta} model mice. We thus tested the hypothesis this treatment would rescue from increases of the A{beta}-PET signal while promoting spatial learning and preservation of synaptic density. MethodsPS2APP mice (N=23; baseline age: 8 months) and AppNL-G-F mice (N=37; baseline age: 5 months) were investigated longitudinally for five months using A{beta}-PET. Groups of mice were treated with pioglitazone or vehicle during the follow-up interval. We tested spatial memory performance and confirmed terminal PET findings by immunohistochemical and biochemistry analyses. ResultsSurprisingly, A{beta}-PET and immunohistochemistry revealed a shift towards higher fibrillary composition of A{beta}-plaques during upon chronic pioglitazone treatment. Nonetheless, synaptic density and spatial learning were improved in transgenic mice with pioglitazone treatment, in association with the increased plaque fibrillarity. ConclusionThese translational data suggest that a shift towards higher plaque fibrillarity protects cognitive function and brain integrity. Increases in the A{beta}-PET signal upon immunomodulatory treatments targeting A{beta} aggregation can thus be protective.

neuroscience↗

bioRxiv2021

Role of molecular polymorphism in defining tau filament structures in neurodegenerative diseases

Misfolding and aggregation of tau protein is implicated in many neurodegenerative diseases that are typified by the presence of large, filamentous tau inclusions. The aggregation of tau in human brain is disease-specific with characteristic filaments defining the neuropathology. An understanding of how identical tau isoforms aggregate into disparate filament morphologies in phenotypically distinct tau-related diseases remains elusive. Here, we determine the structure of a brain-derived twisted tau filament in progressive supranuclear palsy and compare it to a dissimilar tau fold found in corticobasal degeneration. While the tau filament core in both diseases is comprised of residues 274 to 380, molecular-level polymorphism exists. Potential origins of the molecular polymorphism, such as noncovalent cofactor binding, are identified and predicted to modulate tau filament structures in the brain.

biophysics↗

bioRxiv2021

Dynein activation in vivo is regulated by the nucleotide states of its AAA3 domain

Cytoplasmic dynein is activated by dynactin and cargo adapters in vitro, and the activation also needs LIS1 (Lissencephaly 1) in vivo. How this process is regulated remains unclear. Here we found in Aspergillus nidulans that a dynein AAA4 arginine-finger mutation bypasses the requirement of LIS1 for dynein activation driven by the early endosomal adapter HookA. As the AAA4 arginine-finger is implicated in AAA3 ATP hydrolysis, we examined AAA3 mutants defective in ATP binding and hydrolysis respectively. Astonishingly, blocking AAA3 ATP hydrolysis allows dynein activation by dynactin in the absence of LIS1 or HookA. As a consequence, dynein accumulates at microtubule minus ends while early endosomes stay near the plus ends. On the other hand, blocking AAA3 ATP binding abnormally prevents LIS1 from being dissociated from dynein upon motor activation. Thus, the AAA3 ATPase cycle regulates the coordination between dynein activation and cargo binding as well as the dynamic dynein-LIS1 interaction.

cell biology↗

bioRxiv2021

An updated assembly strategy helps parsing the cryptic mitochondrial genome evolution in plants

Although plant mitogenomes are small in size, their variations are no less than any other complex genomes. They are under rapid structure and size changes. These characters make the assembly a great challenge. This caused two intertwined problems, a slow growth of known mitogenomes and a poor knowledge of their evolution. In many species, mitogenome becomes the last genome that undeciphered. To have a better understanding of these two questions, we developed a strategy using short sequencing reads and combining current tools and manual steps to get high quality mitogenomes. This strategy allowed us to assembled 23 complete mitogenomes from 5 families in Fagales. Our large-scale comparative genomic analyses indicated the composition of mitogenomes is very mosaic that "horizontal transfers" can be from almost all taxa in seed plants. The largest mitogenome contains more homologous DNA with other Fagales, rather than unique sequences. Besides of real HGTs, sometimes mitovirus, nuclear insertions and other third-part DNA could also produce HGT-like sequences, accounting partially for the unusual evolutionary trajectories, including the cryptic size expansion in Carpinus. Mitochondrial plasmid was also found. Its lower GC content indicates that it may be only an interphase of a foreign DNA before accepting by the main chromosome. Our methods and results provide new insights into the assembly and mechanisms of mitogenome evolution.

evolutionary biology↗

bioRxiv2020

SARS-CoV-2 Quasispecies provides insight into its genetic dynamics during infection

A novel coronavirus disease (COVID-19) caused by SARS-CoV-2 has been pandemic worldwide. The genetic dynamics of quasispecies afford RNA viruses a great fitness on cell tropism and host range. However, no quasispecies data of SARS-CoV-2 have been reported yet. To explore quasispecies haplotypes and its transmission characteristics, we carried out single-molecule real-time (SMRT) sequencing of the full-length of SARS-CoV-2 spike gene within 14 RNA samples from 2 infection clusters, covering first-to third-generation infected-patients. We observed a special quasispecies structure of SARS-CoV-2 (modeled as One-King): one dominant haplotype (mean abundance ~70.15%) followed by numerous minor haplotypes (mean abundance < 0.10%). We not only discovered a novel dominant haplotype of F1040 but also realized that minor quasispecies were also worthy of attention. Notably, some minor haplotypes (like F1040 and currently pandemic one G614) could potentially reveal adaptive and converse into the dominant one. However, minor haplotypes exhibited a high transmission bottleneck (~6% could be stably transmitted), and the new adaptive/dominant haplotypes were likely originated from genetic variations within a host rather than transmission. The evolutionary rate was estimated as 2.68-3.86 x 10-3 per site per year, which was larger than the estimation at consensus genome level. The One-King model and conversion event expanded our understanding of the genetic dynamics of SARS-CoV-2, and explained the incomprehensible phenomenon at the consensus genome level, such as limited cumulative mutations and low evolutionary rate. Moreover, our findings suggested the epidemic strains may be multi-host origin and future traceability would face huge difficulties.

pathology↗

bioRxiv2020

Massively parallel quantification of CRISPR editing in cells by TRAP-seq enables better design of Cas9, ABE, CBE gRNAs of high efficiency and accuracy

The CRISPR RNA-guided endonucleases Cas9, and Cas9-derived adenine/cytosine base editors (ABE/CBE), have been used in both research and therapeutic applications. However, broader use of this gene editing toolbox is hampered by the great variability of efficiency among different target sites. Here we present TRAP-seq, a versatile and scalable approach in which the CRISPR gRNA expression cassette and the corresponding surrogate site are captured by Targeted Reporter Anchored Positional Sequencing in cells. TRAP-seq can faithfully recapitulate the CRISPR gene editing outcomes introduced to the corresponding endogenous genome site and most importantly enables massively parallel quantification of CRISPR gene editing in cells. We demonstrate the utility of this technology for high-throughput quantification of SpCas9 editing efficiency and indel outcomes for 12,000 gRNAs in human embryonic kidney cells. Using this approach, we also showed that TRAP-seq enables high throughput quantification of both ABE and CBE efficiency at 12,000 sites in cells. This rich amount of ABE/CBE outcome data enable us to reveal several novel nucleotide features (e.g. preference of flanking bases, nucleotide motifs, STOP recoding types) affecting base editing efficiency, as well as designing improved machine learning-based prediction tools for designing SpCas9, ABE and CBE gRNAs of high efficiency and accuracy (>70%). We have integrated all the 12,000 CRISPR gene editing outcomes for SpCas9, ABE and CBE into a CRISPR-centered portal: The Human CRISPR Atlas. This study extends our knowledge on CRISPR gene and base editing, and will facilitate the application and development of CRISPR in both research and therapy.

systems biology↗

bioRxiv2020

The Alzheimer's disease-associated protective Plcγ2-P522R variant promotes beneficial microglial functions

BackgroundMicroglia-specific genetic variants are enriched in several neurodegenerative diseases, including Alzheimers disease (AD), implicating a central role for alterations of the innate immune system in the disease etiology. A rare coding variant in the PLCG2 gene (rs72824905, p.P522R) selectively expressed in microglia and macrophages was recently identified and shown to reduce the risk for AD. MethodsTo assess the role of this variant in the context of immune cell functions, we generated a Plc{gamma}2-P522R knock-in (KI) mouse model using CRISPR/Cas9 gene editing. ResultsFunctional analyses of macrophages derived from homozygous KI mice and wild type (WT) littermates revealed that the P522R variant potentiates the primary function of Plc{gamma}2 as a Pip2-metabolizing enzyme. This was associated with improved survival, enhanced phagocytic activity, and increased acute inflammatory response of the KI cells. Enhanced phagocytosis was also observed in mouse BV2 microglia-like cells overexpressing human PLC{gamma}2-P522R, but not in PLC{gamma}2-WT expressing cells. Furthermore, the brain mRNA signature together with microglia-specific PET imaging indicated microglia activation in Plc{gamma}2-P522R KI mice. ConclusionThus, we have delineated cellular mechanisms of the protective Plc{gamma}2-P522R variant, which provide further support for the emerging idea that activated microglia exert protective functions in AD.

neuroscience↗

bioRxiv2019

Glucose starvation to rapid death of Nrf1, but not Nrf2, deficient hepatoma cells from its fatal defects in the redox metabolism reprogramming

Metabolic reprogramming exists in a variety of cancer cells, with the most relevance to glucose as a source of energy and carbon for survival and proliferation. Of note, Nrf1 was shown to be essential for regulating glycolysis pathway, but it is unknown whether it plays a role in cancer metabolic reprogramming, particularly in response to glucose starvation. Herein, we discover that Nrf1-/--derived hepatoma cells are sensitive to rapid death induced by glucose deprivation, such cell death appears to be rescued by Nrf2 interference, but Nrf1/2+/+ or Nrf2-/--derived cells are roughly unaffected by glucose starvation. Further evidence revealed that Nrf1-/- cell death is resulted from severe oxidative stress arising from abberrant redox metabolism. Strikingly, altered gluconeogenesis pathway was aggravated by glucose starvation of Nrf1-/- cells, as also accompanied by weakened pentose phosphate pathway, dysfunction of serine-to-glutathione synthesis, and accumulation of reactive oxygen species (ROS) and damages, such that the intracellular GSH and NADPH were exhausted. These demonstrate that glucose starvation leads to acute death of Nrf1-/-, rather than Nrf2-/-, cells resulting from its fatal defects in the redox metabolism reprogramming. This is owing to distinct requirements of Nrf1 and Nrf2 for regulating key genes involved in the redox metabolic reprogramming. Altogether, this work substantiates the preventive and therapeutic strategies against Nrf1-deficient cancer by limiting its glucose and energy demands.

cell biology↗

bioRxiv2019

Existence and functions of hypothalamic kisspeptin neuropeptide signaling system in a non-chordate deuterostome species

The kisspeptin (Kp) system is a central modulator of the hypothalamic-pituitary-gonadal axis in vertebrates. Its existence outside the vertebrate lineage remains largely unknown. Here we report the identification and characterization of Kp system in the sea cucumber Apostichopus japonicus. The gene encoding the Kp precursor, generates two mature neuropeptides, AjKiss1a and AjKiss1b. The Kp receptors, AjKissR1 and AjKissR2, are strongly activated by synthetic A. japonicus and vertebrate Kps, triggering a rapid intracellular mobilization of Ca2+, followed by receptor internalization. AjKissR1 and AjKissR2 share similar intracellular signaling pathways via Gq/PLC/PKC/MAPK cascade, when activated by C-terminal decapeptide (AjKiss1b-10). The A. japonicus Kp system functions in mutiple tissues which are closely related to reproduction and metabolism. Overall, our findings uncover for the first time, to our knowledge, the existence and function of the Kp system in a non-chordate species and provide new evidence to support the ancient origin of the hypothalamic neurosecretory system.

evolutionary biology↗