bioRxiv Science⌕ Search

Biology subjects

Zhu, F.

Publications and source records attributed to Zhu, F..

At least 91 records · Page 5Linked to original sources

Hello darkness, my old friend: 3-Ketoacyl-Coenzyme A Synthase4 is a branch point in the regulation of triacylglycerol synthesis in Arabidopsis by re-channeling fatty acids under carbon starvation

Due to their sessile lifestyle, plants have evolved unique mechanisms to deal with environmental challenges. Under stress, plant lipids are important as alternative sources of carbon and energy when sugars or starch are limited. Here, we applied combined heat and darkness and extended darkness to a panel of [~] 300 Arabidopsis accessions to study lipid remodeling under carbon starvation. Natural allelic variation at 3-KETOACYL-COENZYME A SYNTHASE4 (KCS4), a gene encoding for an enzyme involved in very long chain fatty-acid (VLCFA) synthesis, underlies a differential accumulation of polyunsaturated triacylglycerols (puTAGs) under stress. Ectopic expression in yeast and plants proved that KCS4 is a functional enzyme localized in the ER with specificity for C22 and C24 saturated acyl-CoA. Allelic mutants and transient overexpression in planta revealed the differential role of KCS4 alleles in VLCFA synthesis and wax coverage, puTAG accumulation and biomass. Moreover, the region harboring KCS4 is under high selective pressure and allelic variation at KCS4 correlated with environmental parameters from the locales of Arabidopsis accessions. Our results provide evidence that KCS4 plays a decisive role in the subsequent fate of fatty acids released from chloroplast-membrane lipids under carbon starvation. This work sheds light on both plant response mechanisms and the evolutionary events shaping the lipidome under carbon starvation. One sentence summaryNatural variation at KCS4 underlies a differential accumulation of polyunsaturated triacylglycerols under carbon starvation, by acting as a regulatory branch point in the fate of fatty acids.

genetics↗

Association of gut microbiota with cerebral cortex and cerebrovascular abnormality in human mild traumatic brain injury

Key roles of the gut-brain axis in brain injury development have been suggested in various mouse models; however, little is known about its functional significance in human mild traumatic brain injury (TBI). Here, we decipher this axis by profiling the gut microbiota in 98 acute mild TBI patients and 62 matched controls, and subgroup of them also measured circulating mediators and applied neuroimaging. Mild TBI patients had increased -diversity and different overall microbial compositions compared with controls. 25-microbial genus classifiers distinguish patients from controls with an area under the receiver operating characteristic curve (AUC) of 0.889, while adding serum mediators and neuroimaging features further improved performance even in a small sample size (AUC = 0.969). Numerous correlations existed between gut bacteria, aberrant cortical thickness and cerebrovascular injury. Co-occurrence network analysis revealed two unique gut-brain axes in patients: 1) altered intestinal Lachnospiraceae_NK4A136_group and Eubacterium_ruminantium_group-increased serum GDNF-subcallosal hypertrophy and cerebrovascular injury; 2) decreased intestinal Eubacterium_xylanophilum_group-upregulated IL-6-thinned anterior insula. Our findings provide a new integrated mechanistic understanding and diagnostic model of mild TBI.

microbiology↗

SeedExtractor: an open-source GUI for seed image analysis

ABSTRACTAccurate measurement of seed size parameters is essential for both: breeding efforts□aimed at□enhancing yields and basic research□focused on discovering genetic components that regulate seed size. To address this need, we have developed an open-source graphical user interface (GUI) software, SeedExtractor that□determines seed size and shape (including area, perimeter, length, width, circularity, and centroid), and seed color with capability to process a large number of images in a time-efficient manner. In this context, our application takes ∼2 seconds for analyzing an image, i.e. significantly less compared to the other tools. As this software is open-source, it can be modified by users□to serve more specific needs. The adaptability of SeedExtractor was demonstrated by analyzing scanned seeds from multiple crops. We further validated the utility of this application by analyzing mature-rice seeds from 231 accessions in Rice Diversity Panel 1. The derived seed-size traits, such as seed length, width, were subjected to genome-wide association analysis. We identified well-known loci for regulating seed length (GS3) and width (qSW5/GW5) in rice, which demonstrated the accuracy of this application to extract seed phenotypes and accelerate trait discovery. In summary, we present a publicly available application that can be used to determine key yield-related traits in crops.HIGHLIGHT SeedExtractor is an open-source application designed to accurately measure seed size and seed color in a time-efficient manner for a wide variety of plant species.Competing Interest StatementThe authors have declared no competing interest.View Full Text

plant biology↗

Redox proteomics of stomatal immunity reveals role of a lipid transfer protein in plant defense

Redox-based post-translational modifications (PTMs) involving protein cysteine residues as redox sensors are important to various physiological processes. However, little is known about redox-sensitive proteins in guard cells and their functions in stomatal immunity. In this study, we applied an integrative protein labeling method cysTMTRAQ and identified guard cell proteins that were altered by thiol redox PTMs in response to a bacterial flagellin peptide flg22. In total, eight, seven and 20 potential redox-responsive proteins were identified in guard cells treated with flg22 for 15, 30 and 60 min, respectively. The proteins fall into several functional groups including photosynthesis, lipid binding, oxidation-reduction, and defense. Among the proteins, a lipid transfer protein (LTP)-II was confirmed to be redox-responsive and involved in plant resistance to Pseudomonas syringe pv. tomato DC3000. This study not only creates an inventory of potential redox-sensitive proteins in flg22 signal transduction in guard cells, but also highlights the relevance of the lipid transfer protein in plant defense against the bacterial pathogens. Sentence summaryThiol-redox proteomics identified potential redox sensors important in stomatal immunity, and a lipid transfer protein was characterized to function as a redox sensor in plant immune response.

plant biology↗

Role of short-chain fatty acids in the gut-brain axis in schizophrenia: contribution to immune activation and pathophysiology in humans and mice

ObjectiveGut microbiota dysbiosis and aberrant gut-brain functional modules including short-chain fatty acid (SCFA) production and long-lasting immune activation (IA) are presented in schizophrenia. Given the key roles of gut microbiota and SCFA in shaping immunity, we propose that dysbiosis-induced SCFA upregulation could contribute to IA and behavioral symptoms in schizophrenia. DesignGut microbiota, SCFA, and IA biomarkers were compared between schizophrenic patients and healthy controls. The roles of SCFA in schizophrenia-related IA were analyzed in cultured peripheral blood mononuclear cells (PBMCs) and a mouse model of schizophrenia. The effects of SCFAs on schizophrenia-related phenotypes were analyzed in both human and mouse. ResultsBoth microbial-derived SCFA and SCFA-producing bacteria were elevated in the guts of schizophrenic patients, and this increased SCFA production in gut was associated with IA in schizophrenia. The microbiome signature underpinning schizophrenia-related IA includes increased diversity and increased SCFA-producing bacteria and inflammation-associated bacteria. The impact of SCFAs on immune responses of cultured PBMC depend on the diagnosis and IA status of donors. Small-molecule serum filtrates from immune-activated schizophrenic patients increased the inflammatory response of PBMCs from healthy volunteers, which can be enhanced and attenuated by SCFAs supplementation and inhibition of SCFA signaling, respectively. Chronically elevated SCFAs in adolescence induced neuroinflammation and schizophrenia-like behaviors in adult mice. Moreover, chronically elevated SCFAs in adult mice prenatally exposed to IA potentiated their expression of schizophrenia-like behaviors. Conclusionmicrobiota-derived SCFAs are important mediators of dysregulated gut-brain axis and participant in pathogenesis via enhance IA in schizophrenia. SummaryO_ST_ABSSignificance of this studyC_ST_ABSO_LIWhat is already known about this subject? [tpltrtarr]Schizophrenia pathogenesis goes beyond the brain since increasing peripheral abnormalities are revealed including gut microbiota dysbiosis, GI dysfunction, and systemic immune activation (IA). [tpltrtarr]Systemic IA/inflammation contributes to the neuroinflammation and brain impairment underlying schizophrenia, and adjunctive immunotherapy can improve psychotic symptoms. [tpltrtarr]Short-chain fatty acids (SCFA) mediate the microbiota-gut-brain communication and modulate several pathways involved in schizophrenia, including pathways of immunity and neurotransmitters. C_LIO_LIWhat are the new findings? [tpltrtarr]Patients with schizophrenia displayed increased rates of IA and increased SCFA production compared with healthy controls, and increased SCFA is associated with IA in patients. [tpltrtarr]A unique microbiota signature including enriched SCFA-producing bacterial species can distinguish patients with IA from other patients and controls. [tpltrtarr]Small molecules in the serum of immune-activated patients with schizophrenia enhance LPS-induced immune response of cultured peripheral blood mononuclear cell (PBMCs), which is partially mediated by SCFA signaling. [tpltrtarr]SCFA intake upregulates both peripheral and brain inflammation and potentiates the expression of schizophrenia-like behaviors in mice prenatally exposed to IA. C_LIO_LIHow might it impact on clinical practice in the foreseeable future? [tpltrtarr]Interference of SCFA signaling or targeted destruction of SCFA-producing bacteria may provide a new approach for the prevention and treatment of schizophrenia. [tpltrtarr]Immune activation status of patients should be an important condition considered when selecting immunotherapy for future precision psychiatric therapy. C_LI

neuroscience↗

HTCC as a highly effective polymeric inhibitor of SARS-CoV-2 and MERS-CoV

The beginning of 2020 brought us information about the novel coronavirus emerging in China. Rapid research resulted in the characterization of the pathogen, which appeared to be a member of the SARS-like cluster, commonly seen in bats. Despite the global and local efforts, the virus escaped the healthcare measures and rapidly spread in China and later globally, officially causing a pandemic and global crisis in March 2020. At present, different scenarios are being written to contain the virus, but the development of novel anticoronavirals for all highly pathogenic coronaviruses remains the major challenge. Here, we describe the antiviral activity of previously developed by us HTCC compound (N-(2-hydroxypropyl)-3-trimethylammonium chitosan chloride), which may be used as potential inhibitor of currently circulating highly pathogenic coronaviruses - SARS-CoV-2 and MERS-CoV.

microbiology↗

ZmCLA4 regulates leaf angle through multiple plant hormone-mediated signal pathways in maize

Leaf angle in cereals is an important agronomic trait contributing to plant architecture and grain yield by determining the plant compactness. Although ZmCLA4 was identified to shape plant architecture by affecting leaf angle, the detailed regulatory mechanism of ZmCLA4 in maize remains unclear. ZmCLA4 was identified as a transcriptional repressor using the Gal4-LexA/UAS system and transactivation analysis in yeast. The DNA affinity purification (DAP)-seq assay showed that ZmCLA4 not only acts as a repressor containing the EAR motif (CACCGGAC), but was also found to have two new motifs, CCGARGS and CDTCNTC. On analyzing the ZmCLA4-bound targeted genes, we found that ZmCLA4, as a cross node of multiple plant hormone-mediated pathways, directly bound to ARF22 and IAA26 to regulate auxin transport and mediated brassinosteroid signaling by directly binding to BZR3 and 14-3-3. ZmCLA4 bound two WRKY genes involved with abscisic acid, two genes (CYP75B1, CYP93D1) involved with jasmonic acid, B3 involved in the response to ethylene, and thereby negatively regulated leaf angle formation. We built a new regulatory network for the ZmCLA4 gene controlling leaf angle in maize, which contributed to the understanding of ZmCLA4s regulatory mechanism and will improve grain yields by facilitating optimization of plant architecture.

molecular biology↗

A data-driven drug repositioning framework discovered a potential therapeutic agent targeting COVID-19

The global spread of SARS-CoV-2 requires an urgent need to find effective therapeutics for the treatment of COVID-19. We developed a data-driven drug repositioning framework, which applies both machine learning and statistical analysis approaches to systematically integrate and mine large-scale knowledge graph, literature and transcriptome data to discover the potential drug candidates against SARS-CoV-2. The retrospective study using the past SARS-CoV and MERS-CoV data demonstrated that our machine learning based method can successfully predict effective drug candidates against a specific coronavirus. Our in silico screening followed by wet-lab validation indicated that a poly-ADP-ribose polymerase 1 (PARP1) inhibitor, CVL218, currently in Phase I clinical trial, may be repurposed to treat COVID-19. Our in vitro assays revealed that CVL218 can exhibit effective inhibitory activity against SARS-CoV-2 replication without obvious cytopathic effect. In addition, we showed that CVL218 is able to suppress the CpG-induced IL-6 production in peripheral blood mononuclear cells, suggesting that it may also have anti-inflammatory effect that is highly relevant to the prevention immunopathology induced by SARS-CoV-2 infection. Further pharmacokinetic and toxicokinetic evaluation in rats and monkeys showed a high concentration of CVL218 in lung and observed no apparent signs of toxicity, indicating the appealing potential of this drug for the treatment of the pneumonia caused by SARS-CoV-2 infection. Moreover, molecular docking simulation suggested that CVL218 may bind to the N-terminal domain of nucleocapsid (N) protein of SARS-CoV-2, providing a possible model to explain its antiviral action. We also proposed several possible mechanisms to explain the antiviral activities of PARP1 inhibitors against SARS-CoV-2, based on the data present in this study and previous evidences reported in the literature. In summary, the PARP1 inhibitor CVL218 discovered by our data-driven drug repositioning framework can serve as a potential therapeutic agent for the treatment of COVID-19.

systems biology↗

Discovery of a 382-nt deletion during the early evolution of SARS-CoV-2

To date, the SARS-CoV-2 genome has been considered genetically more stable than SARS-CoV or MERS-CoV. Here we report a 382-nt deletion covering almost the entire open reading frame 8 (ORF8) of SARS-CoV-2 obtained from eight hospitalized patients in Singapore. The deletion also removes the ORF8 transcription-regulatory sequence (TRS), which in turn enhances the downstream transcription of the N gene. We also found that viruses with the deletion have been circulating for at least four weeks. During the SARS-CoV outbreak in 2003, a number of genetic variants were observed in the human population [1], and similar variation has since been observed across SARS-related CoVs in humans and bats. Overwhelmingly these viruses had mutations or deletions in ORF8, that have been associated with reduced replicative fitness of the virus [2]. This is also consistent with the observation that towards the end of the outbreak sequences obtained from human SARS cases possessed an ORF8 deletion that may be associated with host adaptation [1]. We therefore hypothesise that the major deletion revealed in this study may lead to an attenuated phenotype of SARS-CoV-2.

microbiology↗

Estimation of the number of synapses in the hippocampus and brain-wide by volume electron microscopy and genetic labeling

Determining the number of synapses that are present in different brain regions is crucial to understand brain connectivity as a whole. Membrane-associated guanylate kinases (MAGUKs) are a family of scaffolding proteins that are expressed in excitatory glutamatergic synapses. We used genetic labeling of two of these proteins (PSD95 and SAP102), and Spinning Disc confocal Microscopy (SDM), to estimate the number of fluorescent puncta in the CA1 area of the hippocampus. We also used FIB-SEM, a three-dimensional electron microscopy technique, to calculate the actual numbers of synapses in the same area. We then estimated the ratio between the three-dimensional densities obtained with FIB-SEM (synapses/m3) and the bi-dimensional densities obtained with SDM (puncta/100 m2). Given that it is impractical to use FIB-SEM brain-wide, we used previously available SDM data from other brain regions and we applied this ratio as a conversion factor to estimate the minimum density of synapses in those regions. We found the highest densities of synapses in the isocortex, olfactory areas, hippocampal formation and cortical subplate. Low densities were found in the pallidum, hypothalamus, brainstem and cerebellum. Finally, the striatum and thalamus showed a wide range of synapse densities.

neuroscience↗

The Pathogenicity of 2019 Novel Coronavirus in hACE2 Transgenic Mice

Severe acute respiratory syndrome CoV-2 (SARS-CoV-2) caused the Corona Virus Disease 2019 (COVID-19) cases in China has become a public health emergency of international concern (PHEIC). Based on angiotensin converting enzyme 2 (ACE2) as cell entry receptor of SARS-CoV, we used the hACE2 transgenic mice infected with SARS-CoV-2 to study the pathogenicity of the virus. Weight loss and virus replication in lung were observed in hACE2 mice infected with SARS-CoV-2. The typical histopathology was interstitial pneumonia with infiltration of significant lymphocytes and monocytes in alveolar interstitium, and accumulation of macrophages in alveolar cavities. Viral antigens were observed in the bronchial epithelial cells, alveolar macrophages and alveolar epithelia. The phenomenon was not found in wild type mice with SARS-CoV-2 infection. The pathogenicity of SARS-CoV-2 in hACE2 mice was clarified and the Kochs postulates were fulfilled as well, and the mouse model may facilitate the development of therapeutics and vaccines against SARS-CoV-2.

microbiology↗

Disease associated protein-protein interaction network reconstruction based on comprehensive influence analysis

Proteins and their interactions are fundamental to biological system. With the scientific paradigm shifting to systems biology, functional study of proteins from a network viewpoint to get a deep understanding of their roles in human life and diseases being increasingly essential. Although several methods already existed for protein-protein interaction (PPI) network building, the precise reconstruction of disease associated PPI network remains a challenge. In this paper we introduce a novel concept of comprehensive influence of proteins in network, in which direct and indirect connections are adopted for the calculation of influential effects of a protein with different weights. With the optimized weights, we calculate and select the important proteins and their interactions to reconstruct the PPI network for further validation and confirmation. To evaluate the performance of the method, we compared our model with the six existed ones by using five standard data sets. The results indicated that our method outperforms the existed ones. We then applied our model to prostate cancer and Parkinsons disease to predict novel disease associated proteins for the future experimental validation. Author SummaryThe diverse protein-protein interaction networks have dramatic effects on biological system. The disease associated PPI networks are generally reconstructed from experimental data with computational models but with limited accuracy. We developed a novel concept of comprehensive influence of proteins in network for reconstructing the PPI network. Our model outperforms the state-of-the-art ones and we then applied our model to identify novel interactions for further validation.

bioinformatics↗

PI-Plat: A high-resolution image-based 3D reconstruction method to estimate growth dynamics of rice inflorescence traits

BackgroundRecent advances in image-based plant phenotyping have improved our capability to study vegetative stage growth dynamics. However, more complex agronomic traits such as inflorescence architecture (IA), which predominantly contributes to grain crop yield are more challenging to quantify and hence are relatively less explored. Previous efforts to estimate inflorescence-related traits using image-based phenotyping have been limited to destructive end-point measurements. Development of non-destructive inflorescence phenotyping platforms could accelerate the discovery of the phenotypic variation with respect to inflorescence dynamics and mapping of the underlying genes regulating critical yield components. ResultsThe major objective of this study is to evaluate post-fertilization development and growth dynamics of inflorescence at high spatial and temporal resolution in rice. For this, we developed the Panicle Imaging Platform (PI-Plat) to comprehend multi-dimensional features of IA in a non-destructive manner. We used 11 rice genotypes to capture multi-view images of primary panicle on weekly basis after the fertilization. These images were used to reconstruct a 3D point cloud of the panicle, which enabled us to extract digital traits such as voxel count and color intensity. We found that the voxel count of developing panicles is positively correlated with seed number and weight at maturity. The voxel count from developing panicles projected overall volumes that increased during the grain filling phase, wherein quantification of color intensity estimated the rate of panicle maturation. Our 3D based phenotyping solution showed superior performance compared to conventional 2D based approaches. ConclusionsFor harnessing the potential of the existing genetic resources, we need a comprehensive understanding of the genotype-to-phenotype relationship. Relatively low-cost sequencing platforms have facilitated high-throughput genotyping, while phenotyping, especially for complex traits, has posed major challenges for crop improvement. PI-Plat offers a low cost and high-resolution platform to phenotype inflorescence-related traits using 3D reconstruction-based approach. Further, the non-destructive nature of the platform facilitates analyses of the same panicle at multiple developmental time points, which can be utilized to explore the genetic variation for dynamic inflorescence traits in cereals.

plant biology↗

Application of Optogenetic Amyloid-β Distinguishes Between Metabolic and Physical Damage in Neurodegeneration

The brains of Alzheimers Disease patients show a decrease in brain mass and a preponderance of extracellular Amyloid-{beta} plaques. These plaques are formed by aggregation of polypeptides that are derived from Amyloid Precursor Protein (APP). Amyloid-{beta} plaques are thought to play either a direct or an indirect role in disease progression, however the exact role of aggregation and plaque formation in the ethology of Alzheimers Disease is subject to debate, not least because the biological effects of soluble and aggregated Amyloid-{beta} peptides are difficult to separate in vivo. To investigate the consequences of formation of Amyloid-{beta} oligomers in living tissues, we developed a fluorescently tagged, optogenetic Amyloid-{beta} peptide that oligomerizes rapidly in the presence of blue light. We applied this system to the crucial question of how intracellular Amyloid-{beta} oligomers underlie the pathologies of Alzheimers Disease. We show that, although both expression and induced oligomerization of Amyloid-{beta} were detrimental to lifespan and healthspan, we were able to separate the metabolic and physical damage caused by light-induced Amyloid-{beta} oligomerization from Amyloid-{beta} expression alone. The physical damage caused by Amyloid-{beta} oligomers also recapitulated the catastrophic tissue loss that is a hallmark of late AD. We show that the lifespan deficit induced by Amyloid-{beta} oligomers was reduced with Li+ treatment. Our results present the first model to separate different aspects of disease progression.

developmental biology↗

RNA interference of NADPH-Cytochrome P450 reductase increases susceptibilities to multiple acaricides in Tetranychus urticae

The two-spotted spider mite, Tetranychus urticae, is a polyphagous pest feeding on over 1,100 plant species, including numerous highly valued economic crops. The control of T. urticae largely depends on the use of acaricides, which leads to pervasive development of acaricide resistance. Cytochrome P450-mediated metabolic detoxification is one of the major mechanisms of acaricide resistance in T. urticae. NADPH-cytochrome P450 reductase (CPR) plays as a crucial co-factor protein that donates electron(s) to microsomal cytochrome P450s to complete their catalytic cycle. This study seeks to understand the involvement of CPR in acaricide resistance in urticae. The full-length cDNA sequence of T. urticaes CPR (TuCPR) was cloned and characterized. TuCPR was ubiquitously transcribed in different life stages of T. urticae and the highest transcription was observed in the nymph and adult stages. TuCPR was constitutively over-expressed in six acaricide resistant populations compared to a susceptible one. TuCPR transcriptional expression was also induced by multiple acaricides in a time-dependent manner. Down-regulation of TuCPR via RNA interference (RNAi) in T. urticae led to reduced enzymatic activities of TuCPR and cytochrome P450s, as well as a significant reduction of resistance to multiple acaricides, abamectin, bifenthrin, and fenpyroximate. The outcome of this study highlights CPR as a potential novel target for eco-friendly control of T. urticae and other related plant-feeding pests.\n\nHighlightsO_LIPipernoyl butoxide significantly reduced abamectin, bifenthrin, and fenpyroximate resistance in T. urticae populations\nC_LIO_LIT. urticaes cytochrome P450 reductase (TuCPR) was cloned, sequenced and phylogenetically analyzed\nC_LIO_LIAbamectin, bifenthrin and fenpyroximate treatment induced TuCPR gene expression\nC_LIO_LISilencing of TuCPR in T. urticae caused a reduction in acaricide resistance\nC_LI

pharmacology and toxicology↗

Identification of gut microbiome markers for schizophrenia delineates a potential role of Streptococcus

Emerging evidence has linked the gut microbiota to schizophrenia. However, the functional changes in the gut microbiota and the biological role of individual bacterial species in schizophrenia have not been explored systematically. Here, we characterized the gut microbiota in schizophrenia using shotgun metagenomic sequencing of feces from a discovery cohort of 90 drug-free patients and 81 controls, as well as a validation cohort of 45 patients taking antipsychotics and 45 controls. We screened 83 schizophrenia-associated bacterial species and constructed a classifier comprising 26 microbial biomarkers that distinguished patients from controls with a 0.896 area under the receiver operating characteristics curve (AUC) in the discovery cohort and 0.765 AUC in the validation cohort. Our analysis of fecal metagenomes revealed that schizophrenia-associated gut-brain modules included short-chain fatty acids synthesis, tryptophan metabolism, and synthesis/degradation of neurotransmitters including glutamate, {gamma}-aminobutyric acid, and nitric oxide. The schizophrenia-enriched gut bacterial species include several oral cavity-resident microbes, such as Streptococcus vestibularis. We transplanted Streptococcus vestibularis into the gut of the mice with antibiotic-induced microbiota depletion to explore its functional role. We observed that this microbe transiently inhabited the mouse gut and this was followed by hyperactivity and deficit in social behaviors, accompanied with altered neurotransmitter levels in peripheral tissues. In conclusion, our study identified 26 schizophrenia-associated bacterial species representing potential microbial targets for future treatment, as well as gut-brain modules, some of which may give rise to new microbial metabolites involved in the development of schizophrenia.

microbiology↗

CXCR4 allows T cell acute lymphoblastic leukemia to escape from JAK1/2 and BCL2 inhibition through CNS infiltration

Targeting the JAK/STAT and BCL2 pathways in patients with relapsed/refractory T cell acute lymphoblastic leukemia (T-ALL) may provide an alternative approach to achieve clinical remissions. Ruxolitinib and venetoclax show a dose-dependent effect on T-ALL individually, but combination treatment reduces survival and proliferation of T-ALL in vitro. Using a xenograft model, the combination treatment fails to improve survival, with death from hind limb paralysis. Despite on-target inhibition by the drugs, histopathology demonstrates increased leukemic infiltration into the central nervous system (CNS) as compared to liver or bone marrow. Liquid chromatography-tandem mass spectroscopy shows that ruxolitinib and venetoclax insufficiently cross into the CNS. The addition of the CXCR4 inhibitor plerixafor with ruxolitinib and venetoclax reduces clinical scores and enhances survival. While combination therapy with ruxolitinib and venetoclax shows promise for treating T-ALL, additional inhibition of the CXCR4-CXCL12 axis may be needed to maximize the possibility of complete remission.

cancer biology↗

Comparative genetic architectures of schizophrenia in East Asian and European populations

Author summarySchizophrenia is a severe psychiatric disorder with a lifetime risk of about 1% world-wide. Most large schizophrenia genetic studies have studied people of primarily European ancestry, potentially missing important biological insights. Here we present a study of East Asian participants (22,778 schizophrenia cases and 35,362 controls), identifying 21 genome-wide significant schizophrenia associations in 19 genetic loci. Over the genome, the common genetic variants that confer risk for schizophrenia have highly similar effects in those of East Asian and European ancestry (rg=0.98), indicating for the first time that the genetic basis of schizophrenia and its biology are broadly shared across these world populations. A fixed-effect meta-analysis including individuals from East Asian and European ancestries revealed 208 genome-wide significant schizophrenia associations in 176 genetic loci (53 novel). Trans-ancestry fine-mapping more precisely isolated schizophrenia causal alleles in 70% of these loci. Despite consistent genetic effects across populations, polygenic risk models trained in one population have reduced performance in the other, highlighting the importance of including all major ancestral groups with sufficient sample size to ensure the findings have maximum relevance for all populations.

genetics↗