Systems Biology
Whole genome sequencing of human Borrelia burgdorferi isolates reveals linked blocks of accessory genome elements located on plasmids and associated with human dissemination
PLoS Pathog. 2023 Aug 31;19(8):e1011243. doi: 10.1371/journal.ppat.1011243. eCollection 2023 Aug.
ABSTRACT
Lyme disease is the most common vector-borne disease in North America and Europe. The clinical manifestations of Lyme disease vary based on the genospecies of the infecting Borrelia burgdorferi spirochete, but the microbial genetic elements underlying these associations are not known. Here, we report the whole genome sequence (WGS) and analysis of 299 B. burgdorferi (Bb) isolates derived from patients in the Eastern and Midwestern US and Central Europe. We develop a WGS-based classification of Bb isolates, confirm and extend the findings of previous single- and multi-locus typing systems, define the plasmid profiles of human-infectious Bb isolates, annotate the core and strain-variable surface lipoproteome, and identify loci associated with disseminated infection. A core genome consisting of ~900 open reading frames and a core set of plasmids consisting of lp17, lp25, lp36, lp28-3, lp28-4, lp54, and cp26 are found in nearly all isolates. Strain-variable (accessory) plasmids and genes correlate strongly with phylogeny. Using genetic association study methods, we identify an accessory genome signature associated with dissemination in humans and define the individual plasmids and genes that make up this signature. Strains within the RST1/WGS A subgroup, particularly a subset marked by the OspC type A genotype, have increased rates of dissemination in humans. OspC type A strains possess a unique set of strongly linked genetic elements including the presence of lp56 and lp28-1 plasmids and a cluster of genes that may contribute to their enhanced virulence compared to other genotypes. These features of OspC type A strains reflect a broader paradigm across Bb isolates, in which near-clonal genotypes are defined by strain-specific clusters of linked genetic elements, particularly those encoding surface-exposed lipoproteins. These clusters of genes are maintained by strain-specific patterns of plasmid occupancy and are associated with the probability of invasive infection.
PMID:37651316 | DOI:10.1371/journal.ppat.1011243
Genetic analysis of low-grade adenosquamous carcinoma of the breast progressing to high-grade metaplastic carcinoma
Breast Cancer Res Treat. 2023 Aug 31. doi: 10.1007/s10549-023-07078-9. Online ahead of print.
ABSTRACT
PURPOSE: Low-grade adenosquamous carcinoma (LGASC) is a rare type of metaplastic carcinoma of the breast (MBC) with an indolent clinical course. A few LGASC cases with high-grade transformation have been reported; however, the genetics underlying malignant progression of LGASC remain unclear.
METHODS: We performed whole-genome sequencing analysis on five MBCs from four patients, including one case with matching primary LGASC and a lymph node metastatic tumor consisting of high-grade MBC with a predominant metaplastic squamous cell carcinoma component (MSC) that progressed from LGASC and three cases of independent de novo MSC.
RESULTS: Unlike de novo MSC, LGASC and its associated MSC showed no TP53 mutation and tended to contain fewer structural variants than de novo MSC. Both LGASC and its associated MSC harbored the common GNAS c.C2530T:p.Arg844Cys mutation, which was more frequently detected in the cancer cell fraction of MSC. MSC associated with LGASC showed additional pathogenic deletions of multiple tumor-suppressor genes, such as KMT2D and BTG1. Copy number analysis revealed potential 18q loss of heterozygosity in both LGASC and associated MSC. The frequency of SMAD4::DCC fusion due to deletions increased with progression to MSC; however, chimeric proteins were not detected. SMAD4 protein expression was already decreased at the LGASC stage due to unknown mechanisms.
CONCLUSION: Not only LGASC but also its associated high-grade MBC may be genetically different from de novo high-grade MBC. Progression from LGASC to high-grade MBC may involve the concentration of driver mutations caused by clonal selection and inactivation of tumor-suppressor genes.
PMID:37650999 | DOI:10.1007/s10549-023-07078-9
Targeted delivery of a short antimicrobial peptide (CM11) against Helicobacter pylori gastric infection using concanavalin A-coated chitosan nanoparticles
J Mater Sci Mater Med. 2023 Aug 31;34(9):44. doi: 10.1007/s10856-023-06748-w.
ABSTRACT
Helicobacter pylori is the cause of most cases of stomach ulcers and also causes some digestive cancers. The emergence and spread of antibiotic-resistant strains of H. pylori is one of the most important challenges in the treatment of its infections. The present study aims to develop a concanavalin A (ConA) coated chitosan (CS) nanocarrier-based drug delivery for the targeted release of peptides to the site of H. pylori infection. Accordingly, chitosan was used as an encapsulating agent for CM11 peptide delivery by applying ionotropic gelation method. Con-A was used for coating CS nanoparticles to target H. pylori. The CS NPs and ConA-CS NPs were characterized by FTIR, dynamic light scattering (DLS), and scanning electron microscopy (SEM). The MIC of CM11-loaded ConA-CS NPs against H. pylori SS1 strain was analyzed in vitro. In order to evaluate the treatment efficiency in vivo, a gastric infection model of H. pylori SS1 strain was established in mice and histopathological studies and IL-1β cytokine assay were performed. Based on the results, the size frequency for CS NPs and ConA-CS NPs was about 200 and 350 nm, respectively. The prepared CM11-loaded ConA-CS NPs exhibited antibacterial activity against H. pylori SS1 strain with a concentration of 32 µg/ml. The highest healing process was observed in synthesized CM11-loaded ConA-CS NPs treatments and a significant decrease in IL-1β was observed. Our findings highlight the potential of chitosan nanoparticles as a drug delivery vehicle in the treatment of gastric infection model of H. pylori SS1 strain.
PMID:37650975 | DOI:10.1007/s10856-023-06748-w
Exploration of glycosyltransferases mutation status in cervical cancer reveals PARP14 as a potential prognostic marker
Glycoconj J. 2023 Aug 31. doi: 10.1007/s10719-023-10134-7. Online ahead of print.
ABSTRACT
This study investigates the potential role of Glycosyltransferases (GTs) in the glycosylation process and their association with malignant tumors. Specifically, the study focuses on PARP14, a member of GTs, and its potential as a target for tumors in the diagnosis and treatment of cervical cancer. To gather data, the study used somatic mutation data, gene expression data and clinical information from TCGA-CESE dataset as well as tissue samples from cervical cancer patients. Further verification was conducted through RT-qPCR and immunohistochemistry staining on cervical cancer tissues to confirm the expression of PARP14. The study utilized Kaplan-Meier for survival analysis of cervical cancer patient and found significant mutational abnormalities in GTs. The high frequency mutated gene was identified as PARP14. RT-qPCR revealed significantly higher mRNA expression of PARP14 compared to precancerous tissue. Using IHC combined with Kaplan-Meier,patients in the PARP14 high expression group had a better prognosis than the low expression group. The study identified PARP14 as a frequently mutated gene in cervical cancer and proposed its potential role in diagnosis and treatment.
PMID:37650946 | DOI:10.1007/s10719-023-10134-7
Bacillus subtilis NrnB is expressed during sporulation and acts as a unique 3'-5' exonuclease
Nucleic Acids Res. 2023 Aug 31:gkad662. doi: 10.1093/nar/gkad662. Online ahead of print.
ABSTRACT
All cells employ a combination of endo- and exoribonucleases to degrade long RNA polymers to fragments 2-5 nucleotides in length. These short RNA fragments are processed to monoribonucleotides by nanoRNases. Genetic depletion of nanoRNases has been shown to increase abundance of short RNAs. This deleteriously affects viability, virulence, and fitness, indicating that short RNAs are a metabolic burden. Previously, we provided evidence that NrnA is the housekeeping nanoRNase for Bacillus subtilis. Herein, we investigate the biological and biochemical functions of the evolutionarily related protein, B. subtilis NrnB (NrnBBs). These experiments show that NrnB is surprisingly different from NrnA. While NrnA acts at the 5' terminus of RNA substrates, NrnB acts at the 3' terminus. Additionally, NrnA is expressed constitutively under standard growth conditions, yet NrnB is selectively expressed during endospore formation. Furthermore, NrnA processes only short RNAs, while NrnB unexpectedly processes both short RNAs and longer RNAs. Indeed, inducible expression of NrnB can even complement the loss of the known global 3'-5' exoribonucleases, indicating that it acts as a general exonuclease. Together, these data demonstrate that NrnB proteins, which are widely found in Firmicutes, Epsilonproteobacteria and Archaea, are fundamentally different than NrnA proteins and may be used for specialized purposes.
PMID:37650646 | DOI:10.1093/nar/gkad662
Widespread effects of DNA methylation and intra-motif dependencies revealed by novel transcription factor binding models
Nucleic Acids Res. 2023 Aug 31:gkad693. doi: 10.1093/nar/gkad693. Online ahead of print.
ABSTRACT
Several studies suggested that transcription factor (TF) binding to DNA may be impaired or enhanced by DNA methylation. We present MeDeMo, a toolbox for TF motif analysis that combines information about DNA methylation with models capturing intra-motif dependencies. In a large-scale study using ChIP-seq data for 335 TFs, we identify novel TFs that show a binding behaviour associated with DNA methylation. Overall, we find that the presence of CpG methylation decreases the likelihood of binding for the majority of methylation-associated TFs. For a considerable subset of TFs, we show that intra-motif dependencies are pivotal for accurately modelling the impact of DNA methylation on TF binding. We illustrate that the novel methylation-aware TF binding models allow to predict differential ChIP-seq peaks and improve the genome-wide analysis of TF binding. Our work indicates that simplistic models that neglect the effect of DNA methylation on DNA binding may lead to systematic underperformance for methylation-associated TFs.
PMID:37650641 | DOI:10.1093/nar/gkad693
Optimisation of TP53 reporters by systematic dissection of synthetic TP53 response elements
Nucleic Acids Res. 2023 Aug 31:gkad718. doi: 10.1093/nar/gkad718. Online ahead of print.
ABSTRACT
TP53 is a transcription factor that controls multiple cellular processes, including cell cycle arrest, DNA repair and apoptosis. The relation between TP53 binding site architecture and transcriptional output is still not fully understood. Here, we systematically examined in three different cell lines the effects of binding site affinity and copy number on TP53-dependent transcriptional output, and also probed the impact of spacer length and sequence between adjacent binding sites, and of core promoter identity. Paradoxically, we found that high-affinity TP53 binding sites are less potent than medium-affinity sites. TP53 achieves supra-additive transcriptional activation through optimally spaced adjacent binding sites, suggesting a cooperative mechanism. Optimally spaced adjacent binding sites have a ∼10-bp periodicity, suggesting a role for spatial orientation along the DNA double helix. We leveraged these insights to construct a log-linear model that explains activity from sequence features, and to identify new highly active and sensitive TP53 reporters.
PMID:37650627 | DOI:10.1093/nar/gkad718
A Survey of Cancer Risk Behaviors, Beliefs, and Social Drivers of Health in New Hampshire and Vermont
Cancer Res Commun. 2023 Aug 29;3(8):1678-1687. doi: 10.1158/2767-9764.CRC-23-0267. eCollection 2023 Aug.
ABSTRACT
Compared with urban areas, rural areas have higher cancer mortality and have experienced substantially smaller declines in cancer incidence in recent years. In a New Hampshire (NH) and Vermont (VT) survey, we explored the roles of rurality and educational attainment on cancer risk behaviors, beliefs, and other social drivers of health. In February-March 2022, two survey panels in NH and VT were sent an online questionnaire. Responses were analyzed by rurality and educational attainment. Respondents (N = 1,717, 22%) mostly lived in rural areas (55%); 45% of rural and 25% of urban residents had high school education or less and this difference was statistically significant. After adjustment for rurality, lower educational attainment was associated with smoking, difficulty paying for basic necessities, greater financial difficulty during the COVID-19 pandemic, struggling to pay for gas (P < 0.01), fatalistic attitudes toward cancer prevention, and susceptibility to information overload about cancer prevention. Among the 33% of respondents who delayed getting medical care in the past year, this was more often due to lack of transportation in those with lower educational attainment (21% vs. 3%, P = 0.02 adjusted for rurality) and more often due to concerns about catching COVID-19 among urban than rural residents (52% vs. 21%; P < 0.001 adjusted for education). In conclusion, in NH/VT, smoking, financial hardship, and beliefs about cancer prevention are independently associated with lower educational attainment but not rural residence. These findings have implications for the design of interventions to address cancer risk in rural areas.
SIGNIFICANCE: In NH and VT, the finding that some associations between cancer risk factors and rural residence are more closely tied to educational attainment than rurality suggest that the design of interventions to address cancer risk should take educational attainment into account.
PMID:37649812 | PMC:PMC10464638 | DOI:10.1158/2767-9764.CRC-23-0267
Non-contact microfluidic analysis of the stiffness of single large extracellular vesicles from IDH1-mutated glioblastoma cells
Adv Mater Technol. 2023 Apr 6;8(7):2201412. doi: 10.1002/admt.202201412. Epub 2023 Jan 29.
ABSTRACT
In preparation for leveraging extracellular vesicles (EVs) for disease diagnostics and therapeutics, fundamental research is being done to understand EV biological, chemical, and physical properties. Most published studies have investigated nanoscale EVs and focused on EV biochemical content. There is much less understanding of large microscale EV characteristics and EV mechanical properties. We recently introduced a non-contact microfluidic technique that measures the stiffness of large EVs (>1 μm diameter). This pilot study probes the robustness of the microfluidic technique to distinguish between EV populations by comparing stiffness distributions of large EVs derived from glioblastoma cell lines. EVs derived from cells expressing the IDH1 mutation, a common glioblastoma mutation known to disrupt lipid metabolism, were stiffer than those expressed from wild-type cells in a statistical comparison of sample medians. A supporting lipidomics analysis showed that the IDH1 mutation increased the amount of saturated lipids in EVs. Taken together, these data encourage further investigation into the potential of high-throughput microfluidics to distinguish between large EV populations that differ in biomolecular composition. These findings contribute to the understanding of EV biomechanics, in particular for the less studied microscale EVs.
PMID:37649709 | PMC:PMC10465107 | DOI:10.1002/admt.202201412
Molecular and clonal evolution <em>in vivo</em> reveal a common pathway of distant relapse gliomas
iScience. 2023 Aug 2;26(9):107528. doi: 10.1016/j.isci.2023.107528. eCollection 2023 Sep 15.
ABSTRACT
The evolutionary trajectories of genomic alterations underlying distant recurrence in glioma remain largely unknown. To elucidate glioma evolution, we analyzed the evolutionary trajectories of matched pairs of primary tumors and relapse tumors or tumor in situ fluid (TISF) based on deep whole-genome sequencing data (ctDNA). We found that MMR gene mutations occurred in the late stage in IDH-mutant glioma during gene evolution, which activates multiple signaling pathways and significantly increases distant recurrence potential. The proneural subtype characterized by PDGFRA amplification was likely prone to hypermutation and distant recurrence following treatment. The classical and mesenchymal subtypes tended to progress locally through subclonal reconstruction, trunk genes transformation, and convergence evolution. EGFR and NOTCH signaling pathways and CDNK2A mutation play an important role in promoting tumor local progression. Glioma subtypes displayed distinct preferred evolutionary patterns. ClinicalTrials.gov, NCT05512325.
PMID:37649695 | PMC:PMC10462858 | DOI:10.1016/j.isci.2023.107528
Comparative and population genomics of buckwheat species reveal key determinants of flavor and fertility
Mol Plant. 2023 Aug 29:S1674-2052(23)00248-4. doi: 10.1016/j.molp.2023.08.013. Online ahead of print.
ABSTRACT
Common buckwheat (Fagopyrum esculentum Moench) is an ancient crop with a world-wide distribution. Due to its excellent nutritional quality and high economic and ecological value, common buckwheat is becoming increasingly important throughout the world. The availability of a high-quality reference genome sequence and population genomic data will accelerate the breeding of common buckwheat, but the high heterozygosity due to the outcrossing nature has greatly hindered the genome assembly. Here we constructed a chromosome-scale high-quality reference genome of F. esculentum var. homotropicum, a homozygous self-pollinating variant of common buckwheat. Comparative genomics revealed that two cultivated buckwheat species, common buckwheat (F. esculentum) and Tartary buckwheat (F. tataricum), underwent metabolomic divergence and ecotype differentiation. The expansion of several gene families in common buckwheat, including FhFAR genes, is associated with its wider distribution than Tartary buckwheat. Copy number variation of genes involved in the metabolism of flavonoids is associated with the difference of rutin content between common and Tartary buckwheat. We also present a comprehensive atlas of genomic variation based on whole-genome resequencing of 572 accessions of common buckwheat. Population and evolutionary genomics reveal genetic variation associated with environmental adaptability and floral development between Chinese and non-Chinese cultivated groups. Genome-wide association of multi-year agronomic traits and the content of flavonoids were carried out and revealed Fh05G014970 is a potential major regulator of flowering period, a key agronomic trait controlling the yield of outcrossing crops, and Fh06G015130 is a crucial gene underlying flavor-associated flavonoids. Moreover, the gene translocation and sequence variation of FhS-ELF3 contribute to the homomorphic self-compatibility of common buckwheat. Our results elucidate the genetic basis of speciation, ecological adaptation, fertility and unique flavor of common buckwheat, and provide new resource for future genomics-assisted breeding of this economically important crop.
PMID:37649255 | DOI:10.1016/j.molp.2023.08.013
MYB24 orchestrates terpene and flavonol metabolism as light responses to anthocyanin depletion in variegated grape berries
Plant Cell. 2023 Aug 30:koad228. doi: 10.1093/plcell/koad228. Online ahead of print.
ABSTRACT
Variegation is a rare type of mosaicism not fully studied in plants, especially fruits. We examined red and white sections of grape (Vitis vinifera cv. 'Béquignol') variegated berries and found that accumulation of products from branches of the phenylpropanoid and isoprenoid pathways showed an opposite tendency. Light-responsive flavonol and monoterpene levels increased in anthocyanin-depleted areas in correlation with increasing MYB24 expression. Cistrome analysis suggested that MYB24 binds to the promoters of 22 terpene synthase (TPS) genes, as well as 32 photosynthesis/light-related genes, including carotenoid pathway members, the flavonol-regulator HY5 HOMOLOGUE (HYH), and other radiation response genes. Indeed, TPS35, TPS09, the carotenoid isomerase gene CRTISO2 and HYH were activated in the presence of MYB24 and MYC2. We suggest that MYB24 modulates ultraviolet and high-intensity visible light stress responses that include terpene and flavonol synthesis and potentially affect carotenoids. The MYB24 regulatory network is developmentally triggered after the onset of berry ripening, while the absence of anthocyanin sunscreens accelerates its activation, likely in a dose-dependent manner due to increased radiation exposure. Anthocyanins and flavonols in variegated berry skins act as effective sunscreens but for different wavelength ranges. The expression patterns of stress marker genes in red and white sections of 'Béquignol' berries strongly suggest that MYB24 promotes light-stress amelioration but only partly succeeds during late ripening.
PMID:37648264 | DOI:10.1093/plcell/koad228
Publisher Correction: Scientific discovery in the age of artificial intelligence
Nature. 2023 Aug 30. doi: 10.1038/s41586-023-06559-7. Online ahead of print.
NO ABSTRACT
PMID:37648871 | DOI:10.1038/s41586-023-06559-7
A pentameric TRPV3 channel with a dilated pore
Nature. 2023 Aug 30. doi: 10.1038/s41586-023-06470-1. Online ahead of print.
ABSTRACT
Transient receptor potential (TRP) channels are a large, eukaryotic ion channel superfamily that control diverse physiological functions, and therefore are attractive drug targets1-5. More than 210 structures from more than 20 different TRP channels have been determined, and all are tetramers4. Despite this wealth of structures, many aspects concerning TRPV channels remain poorly understood, including the pore-dilation phenomenon, whereby prolonged activation leads to increased conductance, permeability to large ions and loss of rectification6,7. Here, we used high-speed atomic force microscopy (HS-AFM) to analyse membrane-embedded TRPV3 at the single-molecule level and discovered a pentameric state. HS-AFM dynamic imaging revealed transience and reversibility of the pentamer in dynamic equilibrium with the canonical tetramer through membrane diffusive protomer exchange. The pentamer population increased upon diphenylboronic anhydride (DPBA) addition, an agonist that has been shown to induce TRPV3 pore dilation. On the basis of these findings, we designed a protein production and data analysis pipeline that resulted in a cryogenic-electron microscopy structure of the TRPV3 pentamer, showing an enlarged pore compared to the tetramer. The slow kinetics to enter and exit the pentameric state, the increased pentamer formation upon DPBA addition and the enlarged pore indicate that the pentamer represents the structural correlate of pore dilation. We thus show membrane diffusive protomer exchange as an additional mechanism for structural changes and conformational variability. Overall, we provide structural evidence for a non-canonical pentameric TRP-channel assembly, laying the foundation for new directions in TRP channel research.
PMID:37648856 | DOI:10.1038/s41586-023-06470-1
The effects of pathogenic variants for inherited hemostasis disorders in 140,214 UK Biobank participants
Blood. 2023 Aug 30:blood.2023020118. doi: 10.1182/blood.2023020118. Online ahead of print.
ABSTRACT
Rare genetic diseases affect millions, and identifying causal DNA variants is essential for patient care. Therefore, it is imperative to estimate the effect of each independent variant and improve their pathogenicity classification. Our study of 140,214 unrelated UK Biobank (UKB) participants found each carries a median of 7 variants previously reported as pathogenic or likely pathogenic. We focused on 967 diagnostic-grade genes (DGGs) variants for rare bleeding, thrombotic, and platelet disorders (BTPDs) observed in 12,367 UKB participants. By association analysis, for a subset of these variants, we estimated effect sizes for platelet count and volume, and odds ratios for bleeding and thrombosis. Variants causal of some autosomal recessive platelet disorders revealed phenotypic consequences in carriers. Loss-of-function variants in MPL, which cause chronic amegakaryocytic thrombocytopenia if biallelic, were unexpectedly associated with increased platelet counts in carriers. We also demonstrated that common variants identified by genome-wide association studies (GWAS) for platelet count or thrombosis risk may influence the penetrance of rare variants in BTPD DGGs on their associated hemostasis disorders. Network-propagation analysis applied to an interactome of 18,410 nodes and 571,917 edges showed that GWAS variants with large effect sizes are enriched in DGGs and their first-order interactors. Finally, we illustrate the modifying effect of polygenic scores for platelet count and thrombosis risk on disease severity in participants carrying rare variants in TUBB1, or PROC and PROS1, respectively. Our findings demonstrate the power of association analyses using large population datasets in improving pathogenicity classifications of rare variants.
PMID:37647632 | DOI:10.1182/blood.2023020118
A systems approach reveals species differences in hepatic stress response capacity
Toxicol Sci. 2023 Aug 30:kfad085. doi: 10.1093/toxsci/kfad085. Online ahead of print.
ABSTRACT
To minimize the occurrence of unexpected toxicities in early phase preclinical studies of new drugs, it is vital to understand fundamental similarities and differences between preclinical species and humans. Species differences in sensitivity to acetaminophen (APAP) liver injury have been related to differences in the fraction of the drug that is bioactivated to the reactive metabolite N-acetyl-p-benzoquinoneimine (NAPQI). We have used physiologically-based pharmacokinetic modeling to identify oral doses of APAP (300 and 1000 mg/kg in mice and rats, respectively) yielding similar hepatic burdens of NAPQI to enable the comparison of temporal liver tissue responses under conditions of equivalent chemical insult. Despite pharmacokinetic and biochemical verification of the equivalent NAPQI insult, serum biomarker and tissue histopathology analyses revealed that mice still exhibited a greater degree of liver injury than rats. Transcriptomic and proteomic analyses highlighted the stronger activation of stress response pathways (including the Nrf2 oxidative stress response and autophagy) in the livers of rats, indicative of a more robust transcriptional adaptation to the equivalent insult. Components of these pathways were also found to be expressed at a higher basal level in the livers of rats compared with both mice and humans. Our findings exemplify a systems approach to understanding differential species sensitivity to hepatotoxicity. Multi-omics analysis indicated that rats possess a greater basal and adaptive capacity for hepatic stress responses than mice and humans, with important implications for species selection and human translation in the safety testing of new drug candidates associated with reactive metabolite formation.
PMID:37647630 | DOI:10.1093/toxsci/kfad085
Structures of wild-type and selected CMT1X mutant connexin 32 gap junction channels and hemichannels
Sci Adv. 2023 Sep;9(35):eadh4890. doi: 10.1126/sciadv.adh4890. Epub 2023 Aug 30.
ABSTRACT
In myelinating Schwann cells, connection between myelin layers is mediated by gap junction channels (GJCs) formed by docked connexin 32 (Cx32) hemichannels (HCs). Mutations in Cx32 cause the X-linked Charcot-Marie-Tooth disease (CMT1X), a degenerative neuropathy without a cure. A molecular link between Cx32 dysfunction and CMT1X pathogenesis is still missing. Here, we describe the high-resolution cryo-electron cryo-myography (cryo-EM) structures of the Cx32 GJC and HC, along with two CMT1X-linked mutants, W3S and R22G. While the structures of wild-type and mutant GJCs are virtually identical, the HCs show a major difference: In the W3S and R22G mutant HCs, the amino-terminal gating helix partially occludes the pore, consistent with a diminished HC activity. Our results suggest that HC dysfunction may be involved in the pathogenesis of CMT1X.
PMID:37647412 | DOI:10.1126/sciadv.adh4890
Leaf metabolic traits reveal hidden dimensions of plant form and function
Sci Adv. 2023 Sep;9(35):eadi4029. doi: 10.1126/sciadv.adi4029. Epub 2023 Aug 30.
ABSTRACT
The metabolome is the biochemical basis of plant form and function, but we know little about its macroecological variation across the plant kingdom. Here, we used the plant functional trait concept to interpret leaf metabolome variation among 457 tropical and 339 temperate plant species. Distilling metabolite chemistry into five metabolic functional traits reveals that plants vary on two major axes of leaf metabolic specialization-a leaf chemical defense spectrum and an expression of leaf longevity. Axes are similar for tropical and temperate species, with many trait combinations being viable. However, metabolic traits vary orthogonally to life-history strategies described by widely used functional traits. The metabolome thus expands the functional trait concept by providing additional axes of metabolic specialization for examining plant form and function.
PMID:37647404 | DOI:10.1126/sciadv.adi4029
Biochemical, Serological and Immunological Tests for Diagnosis of Coronavirus Disease 2019 (COVID-19) Patients: A Comprehensive Systematic Review and Meta-analysis
Infect Disord Drug Targets. 2023;23(7):42-65. doi: 10.2174/1871526523666230228144910.
ABSTRACT
BACKGROUND: Recent studies have suggested the role of primary laboratory tests in addition to clinical symptoms for patients suspected to have coronavirus disease 2019 (COVID-19), which play a significant role in the diagnosis of COVID-19. However, the results of these studies are contradictory. The present study was conducted to evaluate biochemical, serological, and immunological tests for the diagnosis of COVID-19 patients.
METHODS: This study was presented in accordance with the PRISMA protocol. This protocol is registered with the code CRD42019145410 in PROSPERO. We conducted a comprehensive literature search in databases, including Web of Science, PubMed/Medline, CINAHL Scopus, Cochrane Library, EMBASE, Science Direct, and EBSCO to find citations from the beginning of January 2019 until the beginning of April 2020 without any restrictions.
RESULTS: Finally, 51 studies, including 5,490 COVID-19 patients, were included in the present metaanalysis. The prevalence of different factors observed in laboratory findings was as follows: the prevalence of lymphopenia in patients with COVID-19 accounted for 51.6% (95% CI: 44.0-59.1), elevated C-reactive protein (CRP) was 63.6% (95% CI: 57.0-69.8), elevated erythrocyte sedimentation rate (ESR) was 62.5% (95% CI: 50.1-73.5), elevated tumor necrosis factor alpha (TNFα) was 28.7% (95% CI: 9.0-62.1), elevated serum amyloid-A level was 74.7% (95% CI: 50.0-89.7), elevated procalcitonin level was 72.6% (95% CI: 58.1-83.5), elevated interleukin-6 level was 59.9% (95% CI: 48.2-70.5), reduced CD3 level was 68.3% (95% CI: 50.1-82.2), reduced CD4 level was 62.0% (95% CI: 51.1- 71.6), elevated lactate dehydrogenase (LDH) level accounted for 53.1% (95% CI: 43.6-62.4), elevated brain natriuretic peptide (BNP) accounted for 48.9% (95% CI: 30.4-67.7), reduced albumin and reduced pre-albumin levels in patients with COVID-19 were estimated to be 54.7% (95% CI: 38.1-70.2) and 49.0% (95% CI: 26.6-71.8), and D-dimer level was 44.9% (95% CI: 31.0-59.6).
CONCLUSION: The results show lymphopenia, elevated ESR level, elevated CRP level, elevated serum amyloid-A, elevated TNFα, elevated procalcitonin level, elevated interleukin-6 level, reduced CD3, reduced CD4, elevated BNP, elevated LDH, reduced albumin, reduced pre-albumin, and elevated Ddimer levels as the most common findings at the time of admission.
PMID:37646320 | DOI:10.2174/1871526523666230228144910
A stepwise and digital pattern of RSK phosphorylation determines the outcome of thymic selection
iScience. 2023 Aug 9;26(9):107552. doi: 10.1016/j.isci.2023.107552. eCollection 2023 Sep 15.
ABSTRACT
Developing CD4+CD8+ double-positive (DP) thymocytes with randomly generated T cell receptors (TCRs) undergo positive (maturation) or negative (apoptosis) selection on the basis of the strength of TCR stimulation. Selection fate is determined by engagement of TCR ligands with a subtle difference in affinity, but the molecular details of TCR signaling leading to the different selection outcomes have remained unclear. We performed phosphoproteome analysis of DP thymocytes and found that p90 ribosomal protein kinase (RSK) phosphorylation at Thr562 was induced specifically by high-affinity peptide ligands. Such phosphorylation of RSK triggered its translocation to the nucleus, where it phosphorylated the nuclear receptor Nur77 and thereby promoted its mitochondrial translocation for apoptosis induction. Inhibition of RSK activity protected DP thymocytes from antigen-induced cell death. We propose that RSK phosphorylation constitutes a mechanism by which DP thymocytes generate a stepwise and binary signal in response to exposure to TCR ligands with a graded affinity.
PMID:37646020 | PMC:PMC10460994 | DOI:10.1016/j.isci.2023.107552