Biology subjects

Jiang, C.

Publications and source records attributed to Jiang, C..

At least 163 records · Page 9Linked to original sources

bioRxiv2020

Glycyrrhizin inhibits LPS-induced inflammatory responses in goat ruminal epithelial cells in vitro

A long-term of high concentration feeding in ruminants can bring huge economic profits, but it also impose ruminants into great threat of suffering subacute ruminal acidosis (SARA). SARA is a kind of disease which attenuate the health, feed intake and production of ruminants, and when ruminants suffer SARA, the concentration of lipopolysaccharide (LPS) increase largely. Glycyrrhizin is reported to have anti-inflammation effects, and the study was conducted to investigate effects of glycyrrhizin on LPS-induced goat ruminal epithelial cells (GRECs) to provide evidence for using glycyrrhizin as a treatment for SARA. Effects of LPS, and glycyrrhizin on cell viability of GRECs were investigated, respectively. Then GRECs were stimulated with LPS (50 mg/L) for 2 h, and glycyrrhizin were added at the concentration of 0, 50, 75, 100 and 125 mg/L for 24 h to investigate the expression of inflammatory cytokines (by Elisa kits), the mRNA expression of NF-κB and inflammatory cytokines (by qRT-PCR), the distribution of Zo-1 and Occludin (by immunofluorescence staining), the expression of Occludin (by Western blot analysis), and the morphology of GRECs. The results showed that: (1) Glycyrrhizin at the concentration of 50, 75, 100, and 125 mg/L had no cytotoxic effects on GRECs, and LPS at the concentration of 50 mg/L significantly decreased the cell viability of GRECs. (2) Glycyrrhizin attenuated the expression and relative mRNA expression of TNF-α, IL-1β, IL-6, IL-8 and IL-12 by a dose-dependent manner, and significantly attenuated the relative mRNA expression of NF-κB. (3) Immunofluorescence staining and Western blot analysis showed that the quantity of Zo-1 and Occludin, and the expression of Occludin all increased with the treatment of glycyrrhizin. (4) Glycyrrhizin attenuated LPS-induced autophagy and protected the structural integrity of GRECs. In conclusion, glycyrrhizin significantly inhibited the inflammatory response in LPS-stimulated GRECs, and it may be used as a potential agent for the treatment of SARA.View Full Text

zoology↗

bioRxiv2020

Structural basis of bile acid receptor activation and Gs coupling

G protein-coupled bile acid receptor (GPBAR) is a membrane receptor that senses bile acids to regulate diverse functions through Gs activation. Here, we report the cryo-EM structures of GPBAR-Gs complexes stabilized by either high-affinity P395 or the semisynthesized bile acid derivative INT-777 at 3-[A] resolution. These structures revealed a large oval-shaped ligand pocket with several sporadic polar groups to accommodate the amphipathic cholic core of bile acids. A fingerprint of key residues recognizing diverse bile acids in the orthosteric site, a putative second bile acid binding site with allosteric properties and structural features contributing to bias property were identified through structural analysis and mutagenesis studies. Moreover, structural comparison of GPBAR with other GPCRs uncovered an atypical mode of receptor activation and G-protein- coupling, featuring a different set of key residues connecting the ligand binding pocket to the Gs coupling site, and a specific interaction motif localized in intracellular loop 3. Overall, our study not only provides unique structural features of GPBAR in bile acid recognition, allosteric effects and biased signaling, but also suggests that distinct allosteric connecting mechanisms between the ligand binding pocket and the G protein binding site exist in the GPCR superfamily.

biochemistry↗

bioRxiv2020

Tyrosine kinase inhibitors induce mitochondrial dysfunction during cardiomyocyte differentiation through alteration of GATA4-mediated networks

Maternal drug exposure during pregnancy increases the risks of developmental cardiotoxicity, leading to congenital heart defects (CHDs). In this study, we used human stem cells as an in-vitro system to interrogate the mechanisms underlying drug-induced toxicity during cardiomyocyte differentiation, including anticancer tyrosine kinase inhibitor (TKI) drugs (imatinib, sunitinib, and vandetanib). H1-ESCs were treated with these drugs at sublethal levels during cardiomyocyte differentiation. We found that early exposure to TKIs during differentiation induced obvious toxic effects in differentiated cardiomyocytes, including disarranged sarcomere structure, interrupted Ca2+-handling, and impaired mitochondrial function. As sunitinib exposure showed the most significant developmental cardiotoxicity of all TKIs, we further examine its effect with in-vivo experiments. Maternal sunitinib exposure caused fetal death, bioaccumulation, and histopathologic changes in the neonatal mice. Integrative analysis of both transcriptomic and chromatin accessibility landscapes revealed that TKI-exposure altered GATA4-mediated regulatory network, which included key mitochondrial genes. Overexpression of GATA4 with CRISPR-activation restored morphologies, contraction, and mitochondria function in cardiomyocytes upon TKI exposure early during differentiation. Altogether, our study identified a novel crosstalk mechanism between GATA4 activity and mitochondrial function during cardiomyocyte differentiation, and revealed potential therapeutic approaches for reducing TKI-induced developmental cardiotoxicity for human health. HighlightsO_LIEarly-stage exposure to TKIs induced cardiotoxicity and mitochondrial dysfunction C_LIO_LIGATA4 transcriptional activity is inhibited by TKIs C_LIO_LINetwork analysis reveals interactions between GATA4 and mitochondrial genes C_LIO_LIGATA4-overexpression rescues cardiomyocytes and mitochondria from TKI exposure C_LI

systems biology↗

bioRxiv2020

Histone loaders CAF1 and HIRA restrict Epstein-Barr virus B-cell lytic reactivation

Epstein-Barr virus (EBV) infects 95% of adults worldwide and causes infectious mononucleosis. EBV is associated with endemic Burkitt lymphoma, Hodgkin lymphoma, post-transplant lymphomas, nasopharyngeal and gastric carcinomas. In these cancers and in most infected B-cells, EBV maintains a state of latency, where nearly 80 lytic cycle antigens are epigenetically suppressed. To gain insights into host epigenetic factors necessary for EBV latency, we recently performed a human genome-wide CRISPR screen that identified the chromatin assembly factor CAF1 as a putative Burkitt latency maintenance factor. CAF1 loads histones H3 and H4 onto newly synthesized host DNA, though its roles in EBV genome chromatin assembly are uncharacterized. Here, we identified that CAF1 depletion triggered lytic reactivation and transforming virion secretion from Burkitt cells, despite strongly also inducing interferon stimulated genes. CAF1 perturbation diminished occupancy of histones 3.1, 3.3 and repressive H3K9me3 and H3K27me3 marks at multiple viral genome lytic cycle regulatory elements. Suggestive of an early role in establishment of latency, EBV strongly upregulated CAF1 expression in newly infected primary human B-cells prior to the first mitosis, and histone 3.1 and 3.3 were loaded on the EBV genome by this timepoint. Knockout of CAF1 subunit CHAF1B impaired establishment of latency in newly EBV-infected Burkitt cells. A non-redundant latency maintenance role was also identified for the DNA synthesis-independent histone 3.3 loader HIRA. Since EBV latency also requires histone chaperones ATRX and DAXX, EBV coopts multiple host histone pathways to maintain latency, and these are potential targets for lytic induction therapeutic approaches. IMPORTANCEEpstein-Barr virus (EBV) was discovered as the first human tumor virus in endemic Burkitt lymphoma, the most common childhood cancer in sub-Saharan Africa. In Burkitt lymphoma and in 200,000 EBV-associated cancers per year, epigenetic mechanisms maintain viral latency, where lytic cycle factors are silenced. This property complicated EBVs discovery and facilitates tumor immunoevasion. DNA methylation and chromatin-based mechanisms contribute to lytic gene silencing. Here, we identify histone chaperones CAF1 and HIRA, which have key roles in host DNA replication-dependent and replication independent pathways, respectively, are each important for EBV latency. EBV strongly upregulates CAF1 in newly infected B-cells, where viral genomes acquire histone 3.1 and 3.3 variants prior to the first mitosis. Since histone chaperones ATRX and DAXX also function in maintenance of EBV latency, our results suggest that EBV coopts multiple histone pathways to reprogram viral genomes and highlights targets for lytic induction therapeutic strategies.

microbiology↗

bioRxiv2020

Mechanochemical control of epidermal stem cell divisions by B-plexins

The precise spatiotemporal control of cell proliferation is key to the morphogenesis of epithelial tissues. Epithelial cell divisions lead to tissue crowding and local changes in force distribution, which in turn suppress the rate of cell divisions. However, the molecular mechanisms underlying this mechanical feedback are largely unclear. Here, we identify a critical requirement of B-plexin transmembrane receptors in the response to crowding-induced mechanical forces during embryonic skin development. Epidermal stem cells lacking B-plexins fail to sense mechanical compression, resulting in disinhibition of the transcriptional coactivator YAP, hyperproliferation, and tissue overgrowth. Mechanistically, we show that B-plexins mediate mechanoresponses to crowding through stabilization of adhesive cell junctions and lowering of cortical stiffness. Finally, we provide evidence that the B-plexin-dependent mechanochemical feedback is also pathophysiologically relevant to limit tumor growth in basal cell carcinoma, the most common type of skin cancer. Our data uncover a central role of B-plexins in mechanosensation to couple cell density and cell division in development and disease.

cell biology↗

bioRxiv2020

Cognitive Deficits and Altered Functional Brain Network Organization in Pediatric Brain Tumor Patients

Pediatric brain tumor survivors experience significant cognitive sequelae from their diagnosis and treatment. The exact mechanisms of cognitive injury are poorly understood, and validated predictors of long-term cognitive outcome are lacking. Large-scale, distributed brain systems provide a window into brain organization and function that may yield insight into these mechanisms and outcomes. Here, we evaluated functional network architecture, cognitive performance, and brain-behavior relationships in pediatric brain tumor patients. Patients ages 4-18 years old with diagnosis of a brain tumor underwent awake resting state fMRI during regularly scheduled clinical visits and were tested with the NIH Toolbox Cognition Battery. We observed that functional network organization was significantly altered in patients compared to age- and sex-matched healthy controls, with the integrity of the dorsal attention network particularly affected. Moreover, patients demonstrated significant impairments in multiple domains of cognitive performance, including attention. Finally, a significant amount of variance of age-adjusted total composite scores from the Toolbox was explained by changes in segregation between the dorsal attention and default mode networks. Our results suggest that changes in functional network organization may provide insight into long-term changes in cognitive function in pediatric brain tumor patients.

neuroscience↗

bioRxiv2020

Tocilizumab treatment in severe COVID-19 patients attenuates the inflammatory storm incited by monocyte centric immune interactions revealed by single-cell analysis

ABSTRACTDespite the current devastation of the COVID-19 pandemic, several recent studies have suggested that the immunosuppressive drug Tocilizumab can powerfully treating inflammatory responses that occur in this disease. Here, by employing single-cell analysis of the immune cell composition of severe-stage COVID-19 patients and these same patients in post Tocilizumab-treatment remission, we have identified a monocyte subpopulation specific to severe disease that contributes to inflammatory storms in COVID-19 patients. Although Tocilizumab treatment attenuated the strong inflammatory immune response, we found that immune cells including plasma B cells and CD8+ T cells still exhibited an intense humoral and cell-mediated anti-virus immune response in COVID-19 patients after Tocilizumab treatment. Thus, in addition to providing a rich, very high-resolution data resource about the immune cell distribution at multiple stages of the COVID-19 disease, our work both helps explain Tocilizumab’s powerful therapeutic effects and defines a large number of potential new drug targets related to inflammatory storms.Competing Interest StatementJingwen Fang is the executive officer of HanGen BiotechView Full Text

genomics↗

bioRxiv2020

Retrospective identification of rare cell populations underlying drug resistance connects molecular variability with cell fate

Molecular differences between individual cells can lead to dramatic differences in cell fate, such as death versus survival of cancer cells upon drug treatment. These originating differences remain largely hidden due to difficulties in determining precisely what variable molecular features lead to which cellular fates. Thus, we developed Rewind, a methodology that combines genetic barcoding with RNA FISH to directly capture rare cells that give rise to cellular behaviors of interest. Applied to BRAFV600E melanoma, we trace drug-resistant cell fates back to single-cell gene expression differences in their drug-naive precursors (initial frequency of [~]1:1000-1:10,000 cells) and relative persistence of MAP-kinase signaling soon after drug treatment. Within this rare subpopulation, we uncover a rich substructure in which molecular differences between several distinct subpopulations predict future differences in phenotypic behavior, such as proliferative capacity of distinct resistant clones following drug treatment. Similarly, we show that treatments that modify the frequency of resistance can allow otherwise non-resistant cells in the drug-naive population to become resistant, and that these new populations are marked by the variable expression of distinct genes. Together, our results reveal the presence of hidden, rare-cell variability that can underlie a range of latent phenotypic outcomes upon drug exposure.

systems biology↗

bioRxiv2020

Parallel social information processing circuits are differentially impacted in autism

Parallel processing circuits are thought to dramatically expand the network capabilities of the nervous system. Magnocellular and parvocellular oxytocin neurons have been proposed to subserve two parallel streams of social information processing, which allow a single molecule to encode a diverse array of ethologically distinct behaviors, although to date direct evidence to support this hypothesis is lacking. Here we provide the first comprehensive characterization of magnocellular and parvocellular oxytocin neurons, validated across anatomical, projection target, electrophysiological, and transcriptional criteria. We next used novel multiple feature selection tools in Fmr1 KO mice to provide direct evidence that normal functioning of the parvocellular but not magnocellular oxytocin pathway is required for autism-relevant social reward behavior. Finally, we demonstrate that autism risk genes are uniquely enriched in parvocellular oxytocin neurons. Taken together these results provide the first evidence that oxytocin pathway specific pathogenic mechanisms account for social impairments across a broad range of autism etiologies. One Sentence SummaryPathoclisis of parvocellular oxytocin neurons plays an important role in the pathogenesis of social impairments in autism.

neuroscience↗

bioRxiv2020

DREAM: A Toolbox to Decode Rhythms of the Brain System

Rhythms of the brain are generated by neural oscillations across multiple frequencies, which can be observed with multiple modalities. Following the natural log linear law of frequency distribution, these oscillations can be decomposed into distinct frequency intervals associated with specific physiological processes. This perspective on neural oscillations has been increasingly applied to study human brain function and related behaviors. In practice, relevant signals are commonly measured as a discrete time series, and thus the sampling period and number of samples determine the number and ranges of decodable frequency intervals. However, these limits have been often ignored by researchers who instead decode measured oscillations into multiple frequency intervals using a fixed sample period and numbers of samples. One reason for such misuse is the lack of an easy-to-use toolbox to implement automatic decomposition of frequency intervals. We report on a toolbox with a graphical user interface for achieving local and remote decoding rhythms of the brain system (DREAM) which is accessible to the public via GitHub. We provide worked examples of DREAM used to investigate frequency-specific performance of both neural (spontaneous brain activity) and neurobehavioral (in-scanner head motion) oscillations. DREAM analyzed the head motion oscillations and found that younger children moved their heads more than older children across all five frequency intervals whereas boys moved more than girls in the age interval from 7 to 9 years. It is interesting that the higher frequency bands contains more head movements, and showed stronger age-motion associations but the weaker sex-motion interactions. Using the fast functional magnetic resonance imaging data from the Human Connectome Project, DREAM mapped the amplitude of these neural oscillations into multiple frequency bands and evaluated their test-retest reliability. A novel result indicated that the higher frequency bands exhibited more reliable amplitude measurements, implying more inter-individual variability of the amplitudes for the higher frequency bands. In summary, these findings demonstrated the applicability of DREAM for frequency-specific human brain mapping as well as the assessments on their measurement reliability and validity.

neuroscience↗

bioRxiv2020

A strategy for complete telomere-to-telomere assembly of ciliate macronuclear genome using ultra-high coverage Nanopore data

Ciliates contain two kinds of nuclei: the germline micronucleus (MIC) and the somatic macronucleus (MAC) in a single cell. The MAC usually have fragmented chromosomes. These fragmented chromosomes, capped with telomeres at both ends, could be gene size to several megabases in length among different ciliate species. So far, no telomere-to-telomere assembly of entire MAC genome in ciliate species is finished. Development of the third generation sequencing technologies allows to generate sequencing reads up to megabases in length that could possibly span an entire MAC chromosome. Taking advantage of ultra-long Nanopore reads, we established a simple strategy for the complete assembly of ciliate MAC genomes. Using this strategy, we assembled the complete MAC genomes of two ciliate species Tetrahymena thermophila and Tetrahymena shanghaiensis, composed of 181 and 214 chromosomes telomere-to-telomere respectively. The established strategy as well as the high-quality genome data will provide a useful approach for ciliate genome assembly, and a valuable community resource for further biological, evolutionary and population genomic studies.

genomics↗

bioRxiv2019

Boron alters carboxyl group binding capacity and Al transport pathway to relieve Al toxicity

Boron (B) is indispensable for plant growth and has been reported in the mitigation of aluminum (Al) toxicity in different plants. This study unraveled the efficacy of B in reducing the toxicity of Al to trifoliate orange seedlings in a hydroponic experiment. In the current study, B supply had a positive effect on root length and plant growth-related parameters, and attenuated Al-induced inhibition of plasma membrane H+-ATPase activity. The results of XPS and SEM-EDS revealed that B reduces the Al accumulation in root cell wall (CW), especially acts on pectin fractions (alkali-soluble pectin), accompanied by suppressing the pectin synthesis, inhibiting pectin methylesterase (PME) activity and PME expression. Furthermore, B application inhibits NRAT1 expression while increases ALS1 expression, which are responsible for restraining Al transport from external cells to the cytoplasm and accelerating Al divert to vacuoles, and the results can be further demonstrated by TEM-EDS analysis. Taken together, our results indicated that B mainly promotes the efflux of H+ by regulating the plasma membrane H+-ATPase activity, futhur reduce the demethylation of pectin to weaken Al binding ability to carboxyl. More importantly, B alleviated some of the toxic effects of Al by decreasing the deposition of Al in cytoplasm and compartmentalizes Al into vacuoles. One-sentence summaryBoron can reduce the binding amount of carboxyl group to Al in pectin, decreasing the deposition of Al in cytoplasm and compartmentalizes Al into vacuoles, thereby reduce the toxicity of Al to plants..

physiology↗

bioRxiv2019

Genetic Association Study of Childhood Aggression across raters, instruments and age

Childhood aggressive behavior (AGG) has a substantial heritability of around 50%. Here we present a genome-wide association meta-analysis (GWAMA) of childhood AGG, in which all phenotype measures across childhood ages from multiple assessors were included. We analyzed phenotype assessments for a total of 328 935 observations from 87 485 children aged between 1.5 and 18 years, while accounting for sample overlap. We also meta-analyzed within subsets of the data - i.e. within rater, instrument and age. SNP-heritability for the overall meta-analysis (AGGoverall) was 3.31% (SE=0.0038). We found no genome-wide significant SNPs for AGGoverall. The gene-based analysis returned three significant genes: ST3GAL3 (P=1.6E-06), PCDH7 (P=2.0E-06) and IPO13 (P=2.5E-06). All three genes have previously been associated with educational traits. Polygenic scores based on our GWAMA significantly predicted aggression in a holdout sample of children (variance explained = 0.44%) and in retrospectively assessed childhood aggression (variance explained = 0.20%). Genetic correlations (rg) among rater-specific assessment of AGG ranged from rg =0.46 between self- and teacher-assessment to rg =0.81 between mother- and teacher-assessment. We obtained moderate to strong rgs with selected phenotypes from multiple domains, but hardly with any of the classical biomarkers thought to be associated with AGG. Significant genetic correlations were observed with most psychiatric and psychological traits (range |rg| : 0.19 - 1.00), except for obsessive-compulsive disorder. Aggression had a negative genetic correlation (rg =~ -0.5) with cognitive traits and age at first birth. Aggression was strongly genetically correlated with smoking phenotypes (range |rg| : 0.46 - 0.60). The genetic correlations between aggression and psychiatric disorders were weaker for teacher-reported AGG than for mother- and self-reported AGG. The current GWAMA of childhood aggression provides a powerful tool to interrogate the rater-specific genetic etiology of AGG.

genomics↗

bioRxiv2019

Genomic Characterization of SiGRFs in Foxtail Millet and SiGRF1-overexpression in Arabidopsis thaliana Promotes Plant Avoidance of Salt Stress

In plants, 14-3-3 proteins are recognized as mediators of signal transduction and function in both development and stress response. However, their functions have not been reported in the C4 crop foxtail millet. Here, phylogenetic analysis categorized foxtail millet 14-3-3s (SiGRFs) into ten discrete groups (Clusters I to {square}). Transcriptome and qPCR analyses showed that all the SiGRFs responded to at least one abiotic stress. All but one SiGRF-overexpressing (OE) Arabidopsis thaliana line (SiGRF1) exhibited insensitivity to abiotic stresses during seed germination and seedling growth. Compared with the Col-0 wild-type, SiGRF1-OEs had slightly lower germination rates and smaller leaves. However, flowering time of SiGRF1-OEs occurred earlier than that of Col-0 under high-salt stress. Interaction of SiGRF1 with a foxtail millet E3 ubiquitin-protein ligase (SiRNF1/2) indicates that the proteinase system might hydrolyse SiGRF1. Further investigation showed that SiGRF1 localized in the cytoplasm, and its gene was ubiquitously expressed in various tissues throughout various developmental stages. Additionally, flowering-related genes, WRKY71, FLOWERING LOCUS T, LEAFY and FRUITFULL, in SiGRF1-OEs exhibited considerably higher expression levels than those in Col-0 under salinity-stressed conditions. Results suggest that SiGRF1 hastens flowering, thereby providing a means for foxtail millet to complete its life cycle and avoid further salt stress. HighlightSiGRFs in foxtail millet: SiGRF1 hastens flowering in transgenic Arabidopsis thaliana exposed to salt stress

genomics↗

bioRxiv2019

Reconstructing lost BOLD signal in individual participants using deep machine learning

The blood oxygen level-dependent (BOLD) signal in functional neuroimaging suffers from magnetic susceptibility artifacts and interference from metal implants. The resulting signal loss hampers functional neuroimaging studies and can lead to misinterpretation of findings. Here, we reconstructed compromised BOLD signal using deep machine learning. We trained a deep learning model to learn principles governing BOLD activity in one dataset and reconstructed artificially-compromised regions in another dataset, frame by frame. Strikingly, BOLD time series extracted from reconstructed frames were correlated with the original time series, even though the frames did not independently carry information about BOLD fluctuations through time. Moreover, reconstructed functional connectivity (FC) maps exhibited good correspondence with the original FC maps, indicating that the deep learning model recovered functional relationships among brain regions. We replicated this result in patients whose scans suffered signal loss due to intracortical electrodes. Critically, the reconstructions captured individual-specific information rather than group information learned during training. Deep machine learning thus presents a unique opportunity to reconstruct compromised BOLD signal while capturing features of an individuals own functional brain organization.

neuroscience↗

bioRxiv2019

Clinical severity in Fanconi anemia correlates with residual function of FANCB missense variants

Fanconi anemia (FA) is the most common genetic cause of bone marrow failure, and is caused by inherited pathogenic variants in any of 22 genes. Of these, only FANCB is X-linked. We describe a cohort of 19 children with FANCB variants, from 16 families of the International Fanconi Anemia Registry (IFAR). Those with FANCB deletion or truncation demonstrate earlier than average onset of bone marrow failure, and more severe congenital abnormalities compared to a large series of FA individuals in the published reports. This reflects the indispensable role of FANCB protein in the enzymatic activation of FANCD2 monoubiquitination, an essential step in the repair of DNA interstrand crosslinks. For FANCB missense variants, more variable severity is associated with the extent of residual FANCD2 monoubiquitination activity. We used transcript analysis, genetic complementation, and biochemical reconstitution of FANCD2 monoubiquitination to determine the pathogenicity of each variant. Aberrant splicing and transcript destabilization was associated with two missence variants. Individuals carrying missense variants with drastically reduced FANCD2 monoubiquitination in biochemical and/or cell-based assays showed earlier onset of hematologic disease and shorter survival. Conversely, variants with near-normal FANCD2 monoubiquitination were associated with more favorable outcome. Our study reveals a genotype-phenotype correlation within the FA-B complementation group of FA, where severity is linked to the extent of residual FANCD2 monoubiquitination.\n\nKEY POINTSO_LIX-linked FANCB pathogenic variants predominantly cause acute, early onset bone marrow failure and severe congenital abnormalities\nC_LIO_LIBiochemical and cell-based assays with patient variants reveal functional properties of FANCB that associate with clinical severity\nC_LI

molecular biology↗

bioRxiv2019

Repurposing cell growth-regulating compounds identifies kenpaullone which ameliorates pathologic pain via normalization of inhibitory neurotransmission

Inhibitory GABA-ergic neurotransmission is fundamental for the adult vertebrate central nervous system and requires low chloride ion concentration in neurons. This basic ionic-homeostatic mechanism relies on expression and function of KCC2, a neuroprotective ionic transporter that extrudes neuronal chloride. Importantly, no other transporter can rescue KCC2 deficit, and attenuated expression of KCC2 is strongly associated with circuit malfunction in chronic pain, epilepsy, neuro-degeneration, neuro-trauma, and other neuro-psychiatric illnesses. To isolate Kcc2 gene expression-enhancing compounds, we screened 1057 cell growth-regulating compounds in cultured primary cortical neurons. We identified kenpaullone (KP), which enhanced Kcc2/KCC2 expression and function in cultured rodent and human neurons by inhibiting GSK3{beta}. KP effectively reduced pathologic pain in preclinical mouse models of nerve constriction injury and bone cancer. In nerve-injury pain, KP restored Kcc2 expression and GABA-evoked chloride reversal potential in the spinal cord dorsal horn. Delta-catenin, a phosphorylation-target of GSK3{beta} in neurons, activated the Kcc2 promoter via Kaiso transcription factor. Validating this new pathway in-vivo, transient spinal over-expression of delta-catenin mimicked KP analgesia. With relevance for pathologic pain, our discoveries of a newly repurposed compound and a novel genetically-encoded mechanism that each enhance Kcc2 gene expression enable us to re-normalize disrupted inhibitory neurotransmission through genetic re-programming.

neuroscience↗

bioRxiv2019

Effects of different dietary NFC/NDF on rumen microbiomes of Karakul sheep based on Three Generations of Full-length Amplifiers sequencing

An study was was conducted to investigate the effects of dietary(non fibrous carbohydrate) NFC/(neutral detergent fiber)NDF on ruminal bacteria in Karakul sheep. Twelve Karakul sheep were assigned randomly to four dietary treatments of NFC/NDF (0.78, 1.23, 1.61 and 2.00 respectively) as group 1, 2, 3 to 4. The experiment lasted for four periods, period I (1~18 d), II (19~36 d), III (37~54 d) and IV (55~72 d). Ruminal digesta were collected consecutively for three days to measure pH and bacteria per period. The results indicated that the average ruminal pH and amounts of OTUs were decreased with the increase of dietary NFC/NDF for four periods. At phylum level, Bacteroidetes and Firmicutes were the predominant bacteria of four periods, Bacteroidetes were decreased, while the relative abundance of Firmicutes was increased with dietary NFC/NDF for four periods, but the difference wasnt significant (P>0.05). At genus level, the most relative abundance genus was unidentified-Lachnospiraceae which reached the highest in group 3 for four periods, but the difference wasnt significant (P>0.05). Conclusion: ruminal pH and bacteria were decreased with the increase of dietary NFC/NDF and the most dominant bacteria were not change with dietary NFC/NDF and periods in Karakul sheep.

microbiology↗