Systems Biology

Total Synthesis and Biological Evaluation of the Anti-Inflammatory (13<em>R</em>,14<em>S</em>,15<em>R</em>)-13-Hydroxy-14-deoxyoxacyclododecindione

Fri, 2023-03-31 06:00

J Nat Prod. 2023 Mar 31. doi: 10.1021/acs.jnatprod.2c01145. Online ahead of print.

ABSTRACT

The first total synthesis of the natural product (13R,14S,15R)-13-hydroxy-14-deoxyoxacyclododecindione, which was isolated in 2018 as a member of the oxacyclododecindione family, is reported. A synthetic strategy through intramolecular Friedel-Crafts acylation combined with the stereoselective synthesis of a new triol key fragment allowed the preparation of the macrolactone. Due to mismatching physical data of the synthetic product, a revision of the configuration of the natural product isolated in 2018 is required. Light-induced E/Z-isomerism of the macrolactone backbone is described for the first time in the class of oxacyclododecindione-type macrolactones. The hydroxylated macrolactone prepared herein was found to show highly promising IC50 values in biological assays addressing the inhibition of inflammatory responses.

PMID:37001011 | DOI:10.1021/acs.jnatprod.2c01145

Categories: Literature Watch

PAD2: interactive exploration of transcription factor genomic colocalization using ChIP-seq data

Fri, 2023-03-31 06:00

STAR Protoc. 2023 Mar 29;4(2):102203. doi: 10.1016/j.xpro.2023.102203. Online ahead of print.

ABSTRACT

Characterizing transcription factor (TF) genomic colocalization is essential for identifying cooperative binding of TFs in controlling gene expression. Here, we introduce a protocol for using PAD2, an interactive web application that enables the investigation of colocalization of various TFs and chromatin-regulating proteins from mouse embryonic stem cells at various functional genomic regions. We describe steps for accessing and searching the PAD2 database and selecting and submitting genomic regions. We then detail protein colocalization analysis using heatmap and ranked correlation plot. For complete details on the use and execution of this protocol, please refer to Kim et al. (2022).1.

PMID:37000617 | DOI:10.1016/j.xpro.2023.102203

Categories: Literature Watch

When does the female bias arise? Insights from the sex determination cascade of a flea beetle with a strongly skewed sex ratio

Fri, 2023-03-31 06:00

Funct Integr Genomics. 2023 Mar 31;23(2):112. doi: 10.1007/s10142-023-01023-1.

ABSTRACT

Reproduction-manipulating bacteria like Wolbachia can shift sex ratios in insects towards females, but skewed sex ratios may also arise from genetic conflicts. The flea beetle Altica lythri harbors three main mtDNA strains that are coupled to three different Wolbachia infections. Depending on the mtDNA types, the females produce either offspring with a balanced sex ratio or exclusively daughters. To obtain markers that can monitor when sex bias arises in the beetle's ontogeny, we elucidated the sex determination cascade of A. lythri. We established a RT-PCR method based on length variants of dsx (doublesex) transcripts to determine the sex of morphologically indistinguishable eggs and larvae. In females of one mtDNA type (HT1/HT1*) known to produce only daughters, male offspring were already missing at the egg stage while for females of another type (HT2), the dsx splice variants revealed a balanced sex ratio among eggs and larvae. Our data suggest that the sex determination cascade in A. lythri is initiated by maternally transmitted female-specific tra (transformer) mRNA as primary signal. This tra mRNA seems to be involved in a positive feedback loop that maintains the production of the female splice variant, as known for female offspring in Tribolium castaneum. The translation of the maternally transmitted female tra mRNA must be inhibited in male offspring, but the underlying primary genetic signal remains to be identified. We discuss which differences between the mtDNA types can influence sex determination and lead to the skewed sex ratio of HT1.

PMID:37000335 | DOI:10.1007/s10142-023-01023-1

Categories: Literature Watch

Comparison Theorems for Stochastic Chemical Reaction Networks

Fri, 2023-03-31 06:00

Bull Math Biol. 2023 Mar 31;85(5):39. doi: 10.1007/s11538-023-01136-5.

ABSTRACT

Continuous-time Markov chains are frequently used as stochastic models for chemical reaction networks, especially in the growing field of systems biology. A fundamental problem for these Stochastic Chemical Reaction Networks (SCRNs) is to understand the dependence of the stochastic behavior of these systems on the chemical reaction rate parameters. Towards solving this problem, in this paper we develop theoretical tools called comparison theorems that provide stochastic ordering results for SCRNs. These theorems give sufficient conditions for monotonic dependence on parameters in these network models, which allow us to obtain, under suitable conditions, information about transient and steady-state behavior. These theorems exploit structural properties of SCRNs, beyond those of general continuous-time Markov chains. Furthermore, we derive two theorems to compare stationary distributions and mean first passage times for SCRNs with different parameter values, or with the same parameters and different initial conditions. These tools are developed for SCRNs taking values in a generic (finite or countably infinite) state space and can also be applied for non-mass-action kinetics models. When propensity functions are bounded, our method of proof gives an explicit method for coupling two comparable SCRNs, which can be used to simultaneously simulate their sample paths in a comparable manner. We illustrate our results with applications to models of enzymatic kinetics and epigenetic regulation by chromatin modifications.

PMID:37000280 | DOI:10.1007/s11538-023-01136-5

Categories: Literature Watch

The potential of integrating human and mouse discovery platforms to advance our understanding of cardiometabolic diseases

Fri, 2023-03-31 06:00

Elife. 2023 Mar 31;12:e86139. doi: 10.7554/eLife.86139.

ABSTRACT

Cardiometabolic diseases encompass a range of interrelated conditions that arise from underlying metabolic perturbations precipitated by genetic, environmental, and lifestyle factors. While obesity, dyslipidaemia, smoking, and insulin resistance are major risk factors for cardiometabolic diseases, individuals still present in the absence of such traditional risk factors, making it difficult to determine those at greatest risk of disease. Thus, it is crucial to elucidate the genetic, environmental, and molecular underpinnings to better understand, diagnose, and treat cardiometabolic diseases. Much of this information can be garnered using systems genetics, which takes population-based approaches to investigate how genetic variance contributes to complex traits. Despite the important advances made by human genome-wide association studies (GWAS) in this space, corroboration of these findings has been hampered by limitations including the inability to control environmental influence, limited access to pertinent metabolic tissues, and often, poor classification of diseases or phenotypes. A complementary approach to human GWAS is the utilisation of model systems such as genetically diverse mouse panels to study natural genetic and phenotypic variation in a controlled environment. Here, we review mouse genetic reference panels and the opportunities they provide for the study of cardiometabolic diseases and related traits. We discuss how the post-GWAS era has prompted a shift in focus from discovery of novel genetic variants to understanding gene function. Finally, we highlight key advantages and challenges of integrating complementary genetic and multi-omics data from human and mouse populations to advance biological discovery.

PMID:37000167 | DOI:10.7554/eLife.86139

Categories: Literature Watch

Mechanism of skin whitening through San-Bai decoction-induced tyrosinase inhibition and discovery of natural products targeting tyrosinase

Fri, 2023-03-31 06:00

Medicine (Baltimore). 2023 Mar 31;102(13):e33420. doi: 10.1097/MD.0000000000033420.

ABSTRACT

Melanin deposition is the main cause of skin darkening, which can lead to severe physical and psychological distress, necessitating the development of approaches for preserving skin health and fairness. Tyrosinase (TYR) is the rate-limiting enzyme in melanin synthesis, and its activity directly determines the degree of melanin accumulation in the skin, which in turn affects skin color. Currently, TYR inhibitors derived from natural products are widely used for skin whitening. San-Bai decoction (SBD) is effective for skin whitening and softening, but its mechanism of action, efficacy and high efficiency TYR inhibitors for skin whitening remain poorly understood. Here, we employed systems biology and network pharmacology to analyze the active compounds and targets of SBD, using the follow databases: TCMIP, TCMID, and BATMAN-TCM. Construct a molecular network centered on the regulation of TYR by SBD in skin whitening, using STRING database and cytoscape. Enrichment analysis using KOBAS database and ClusterProfiler. Virtual screening of candidate TYR inhibitors using Molecular Operating Environment software and Amber 18 software. SBD may act through tyrosine metabolism, melanogenesis, and other signaling pathways to regulate TYR activity and inhibit melanogenesis. We identified TYR and ESR1 as possible key targets for the whitening effect of SBD and screened out pentagalloylglucose, 1,3,6-tri-O-galloyl-beta-D-glucose, 1,2,4,6-tetragalloylglucose, and liquiritigenin 4',7-diglucoside as inhibitors of TYR, in addition to glycyrrhizic acid, pachymic acid methyl ester, nicotiflorin, gamma-sitosterol, and isoliensinine as inhibitors of ESR1. We also performed virtual drug screening of a library of natural small-molecule compounds (19,505 in total) and screened out lycopsamine, 2-phenylethyl b-D-glucopyranoside, and 6-beta-hydroxyhyoscyamine as inhibitors of TYR. We identified natural compounds with the potential for skin whitening through inhibition of TYR, thus advancing research on SBD and its applications.

PMID:37000099 | DOI:10.1097/MD.0000000000033420

Categories: Literature Watch

Identification of Key Genes in Angiogenesis of Breast and Prostate Cancers in the Context of Different Cell Types

Fri, 2023-03-31 06:00

Curr Med Chem. 2023 Mar 31. doi: 10.2174/0929867330666230331101458. Online ahead of print.

ABSTRACT

INTRODUCTION: Angiogenesis involves the development of new blood vessels. Biochemical signals start this process in the body, which is followed by migration, growth, and differentiation of endothelial cells that line the inside wall of blood vessels. This process is vital for the growth of cancer cells and tumors.

MATERIALS AND METHODS: We started our analysis by composing a list of genes that have a validated impact in humans with respect to angiogenesis-related phenotypes. Here, we have investigated the expression patterns of angiogenesis-related genes in the context of previously published single-cell RNA-Seq data from prostate and breast cancer samples.

RESULTS: Using a protein-protein interaction network, we showed how different modules of angiogenesis-related genes are overexpressed in different cell types. In our results, genes, such as ACKR1, AQP1, and EGR1, showed a strong cell type-dependent overexpression pattern in the two investigated cancer types, which can potentially be helpful in the diagnosis and follow-up of patients with prostate and breast cancer.

CONCLUSION: Our work demonstrates how different biological processes in distinct cell types contribute to the angiogenesis process, which can provide clues regarding the potential application of targeted inhibition of the angiogenesis process.

PMID:36999716 | DOI:10.2174/0929867330666230331101458

Categories: Literature Watch

RNA-seq data science: From raw data to effective interpretation

Fri, 2023-03-31 06:00

Front Genet. 2023 Mar 13;14:997383. doi: 10.3389/fgene.2023.997383. eCollection 2023.

ABSTRACT

RNA sequencing (RNA-seq) has become an exemplary technology in modern biology and clinical science. Its immense popularity is due in large part to the continuous efforts of the bioinformatics community to develop accurate and scalable computational tools to analyze the enormous amounts of transcriptomic data that it produces. RNA-seq analysis enables genes and their corresponding transcripts to be probed for a variety of purposes, such as detecting novel exons or whole transcripts, assessing expression of genes and alternative transcripts, and studying alternative splicing structure. It can be a challenge, however, to obtain meaningful biological signals from raw RNA-seq data because of the enormous scale of the data as well as the inherent limitations of different sequencing technologies, such as amplification bias or biases of library preparation. The need to overcome these technical challenges has pushed the rapid development of novel computational tools, which have evolved and diversified in accordance with technological advancements, leading to the current myriad of RNA-seq tools. These tools, combined with the diverse computational skill sets of biomedical researchers, help to unlock the full potential of RNA-seq. The purpose of this review is to explain basic concepts in the computational analysis of RNA-seq data and define discipline-specific jargon.

PMID:36999049 | PMC:PMC10043755 | DOI:10.3389/fgene.2023.997383

Categories: Literature Watch

Highlighting the potential of <em>Synechococcus elongatus</em> PCC 7942 as platform to produce α-linolenic acid through an updated genome-scale metabolic modeling

Fri, 2023-03-31 06:00

Front Microbiol. 2023 Mar 14;14:1126030. doi: 10.3389/fmicb.2023.1126030. eCollection 2023.

ABSTRACT

Cyanobacteria are prokaryotic organisms that capture energy from sunlight using oxygenic photosynthesis and transform CO2 into products of interest such as fatty acids. Synechococcus elongatus PCC 7942 is a model cyanobacterium efficiently engineered to accumulate high levels of omega-3 fatty acids. However, its exploitation as a microbial cell factory requires a better knowledge of its metabolism, which can be approached by using systems biology tools. To fulfill this objective, we worked out an updated, more comprehensive, and functional genome-scale model of this freshwater cyanobacterium, which was termed iMS837. The model includes 837 genes, 887 reactions, and 801 metabolites. When compared with previous models of S. elongatus PCC 7942, iMS837 is more complete in key physiological and biotechnologically relevant metabolic hubs, such as fatty acid biosynthesis, oxidative phosphorylation, photosynthesis, and transport, among others. iMS837 shows high accuracy when predicting growth performance and gene essentiality. The validated model was further used as a test-bed for the assessment of suitable metabolic engineering strategies, yielding superior production of non-native omega-3 fatty acids such as α-linolenic acid (ALA). As previously reported, the computational analysis demonstrated that fabF overexpression is a feasible metabolic target to increase ALA production, whereas deletion and overexpression of fabH cannot be used for this purpose. Flux scanning based on enforced objective flux, a strain-design algorithm, allowed us to identify not only previously known gene overexpression targets that improve fatty acid synthesis, such as Acetyl-CoA carboxylase and β-ketoacyl-ACP synthase I, but also novel potential targets that might lead to higher ALA yields. Systematic sampling of the metabolic space contained in iMS837 identified a set of ten additional knockout metabolic targets that resulted in higher ALA productions. In silico simulations under photomixotrophic conditions with acetate or glucose as a carbon source boosted ALA production levels, indicating that photomixotrophic nutritional regimens could be potentially exploited in vivo to improve fatty acid production in cyanobacteria. Overall, we show that iMS837 is a powerful computational platform that proposes new metabolic engineering strategies to produce biotechnologically relevant compounds, using S. elongatus PCC 7942 as non-conventional microbial cell factory.

PMID:36998399 | PMC:PMC10043229 | DOI:10.3389/fmicb.2023.1126030

Categories: Literature Watch

Bursts in biosynthetic gene cluster transcription are accompanied by surges of natural compound production in the myxobacterium Sorangium sp

Fri, 2023-03-31 06:00

Microb Biotechnol. 2023 Mar 30. doi: 10.1111/1751-7915.14246. Online ahead of print.

ABSTRACT

A better understanding of the genetic regulation of the biosynthesis of microbial compounds could accelerate the discovery of new biologically active molecules and facilitate their production. To this end, we have investigated the time course of genome-wide transcription in the myxobacterium Sorangium sp. So ce836 in relation to its production of natural compounds. Time-resolved RNA sequencing revealed that core biosynthesis genes from 48 biosynthetic gene clusters (BGCs; 92% of all BGCs encoded in the genome) were actively transcribed at specific time points in a batch culture. The majority (80%) of polyketide synthase and non-ribosomal peptide synthetase genes displayed distinct peaks of transcription during exponential bacterial growth. Strikingly, these bursts in BGC transcriptional activity were associated with surges in the net production rates of known natural compounds, indicating that their biosynthesis was critically regulated at the transcriptional level. In contrast, BGC read counts from single time points had limited predictive value about biosynthetic activity, since transcription levels varied >100-fold among BGCs with detected natural products. Taken together, our time-course data provide unique insights into the dynamics of natural compound biosynthesis and its regulation in a wild-type myxobacterium, challenging the commonly cited notion of preferential BGC expression under nutrient-limited conditions. The close association observed between BGC transcription and compound production warrants additional efforts to develop genetic engineering tools for boosting compound yields from myxobacterial producer strains.

PMID:36998231 | DOI:10.1111/1751-7915.14246

Categories: Literature Watch

A mechanistic view of the use of cold temperature in the treatment of cancer

Thu, 2023-03-30 06:00

iScience. 2023 Mar 30;26(4):106511. doi: 10.1016/j.isci.2023.106511. eCollection 2023 Apr 21.

ABSTRACT

In their latest article, Seki and colleagues investigate the potential role of cold as a therapeutical option to treat various cancer types, including even clinically untreatable cancers such as pancreatic cancers. The authors suggest that cold exposure may have a tumor-suppressive effect mediated by the activation of brown adipose tissue (BAT), in charge of dissipating heat through non-shivering thermogenesis. In this regard, circulating blood glucose is decreased, restricting the tumor glucose uptake, which is redistributed, favoring BAT uptake to fuel thermogenesis.1.

PMID:37091251 | PMC:PMC10119757 | DOI:10.1016/j.isci.2023.106511

Categories: Literature Watch

Abundance, classification and genetic potential of Thaumarchaeota in metagenomes of European agricultural soils: a meta-analysis

Thu, 2023-03-30 06:00

Environ Microbiome. 2023 Mar 30;18(1):26. doi: 10.1186/s40793-023-00479-9.

ABSTRACT

BACKGROUND: For a sustainable production of food, research on agricultural soil microbial communities is inevitable. Due to its immense complexity, soil is still some kind of black box. Soil study designs for identifying microbiome members of relevance have various scopes and focus on particular environmental factors. To identify common features of soil microbiomes, data from multiple studies should be compiled and processed. Taxonomic compositions and functional capabilities of microbial communities associated with soils and plants have been identified and characterized in the past few decades. From a fertile Loess-Chernozem-type soil located in Germany, metagenomically assembled genomes (MAGs) classified as members of the phylum Thaumarchaeota/Thermoproteota were obtained. These possibly represent keystone agricultural soil community members encoding functions of relevance for soil fertility and plant health. Their importance for the analyzed microbiomes is corroborated by the fact that they were predicted to contribute to the cycling of nitrogen, feature the genetic potential to fix carbon dioxide and possess genes with predicted functions in plant-growth-promotion (PGP). To expand the knowledge on soil community members belonging to the phylum Thaumarchaeota, we conducted a meta-analysis integrating primary studies on European agricultural soil microbiomes.

RESULTS: Taxonomic classification of the selected soil metagenomes revealed the shared agricultural soil core microbiome of European soils from 19 locations. Metadata reporting was heterogeneous between the different studies. According to the available metadata, we separated the data into 68 treatments. The phylum Thaumarchaeota is part of the core microbiome and represents a major constituent of the archaeal subcommunities in all European agricultural soils. At a higher taxonomic resolution, 2074 genera constituted the core microbiome. We observed that viral genera strongly contribute to variation in taxonomic profiles. By binning of metagenomically assembled contigs, Thaumarchaeota MAGs could be recovered from several European soil metagenomes. Notably, many of them were classified as members of the family Nitrososphaeraceae, highlighting the importance of this family for agricultural soils. The specific Loess-Chernozem Thaumarchaeota MAGs were most abundant in their original soil, but also seem to be of importance in other agricultural soil microbial communities. Metabolic reconstruction of Switzerland_1_MAG_2 revealed its genetic potential i.a. regarding carbon dioxide (CO[Formula: see text]) fixation, ammonia oxidation, exopolysaccharide production and a beneficial effect on plant growth. Similar genetic features were also present in other reconstructed MAGs. Three Nitrososphaeraceae MAGs are all most likely members of a so far unknown genus.

CONCLUSIONS: On a broad view, European agricultural soil microbiomes are similarly structured. Differences in community structure were observable, although analysis was complicated by heterogeneity in metadata recording. Our study highlights the need for standardized metadata reporting and the benefits of networking open data. Future soil sequencing studies should also consider high sequencing depths in order to enable reconstruction of genome bins. Intriguingly, the family Nitrososphaeraceae commonly seems to be of importance in agricultural microbiomes.

PMID:36998097 | DOI:10.1186/s40793-023-00479-9

Categories: Literature Watch

A complete gap-free diploid genome in Saccharum complex and the genomic footprints of evolution in the highly polyploid Saccharum genus

Thu, 2023-03-30 06:00

Nat Plants. 2023 Mar 30. doi: 10.1038/s41477-023-01378-0. Online ahead of print.

ABSTRACT

A diploid genome in the Saccharum complex facilitates our understanding of evolution in the highly polyploid Saccharum genus. Here we have generated a complete, gap-free genome assembly of Erianthus rufipilus, a diploid species within the Saccharum complex. The complete assembly revealed that centromere satellite homogenization was accompanied by the insertions of Gypsy retrotransposons, which drove centromere diversification. An overall low rate of gene transcription was observed in the palaeo-duplicated chromosome EruChr05 similar to other grasses, which might be regulated by methylation patterns mediated by homologous 24 nt small RNAs, and potentially mediating the functions of many nucleotide-binding site genes. Sequencing data for 211 accessions in the Saccharum complex indicated that Saccharum probably originated in the trans-Himalayan region from a diploid ancestor (x = 10) around 1.9-2.5 million years ago. Our study provides new insights into the origin and evolution of Saccharum and accelerates translational research in cereal genetics and genomics.

PMID:36997685 | DOI:10.1038/s41477-023-01378-0

Categories: Literature Watch

The C-terminal tail of polycystin-1 suppresses cystic disease in a mitochondrial enzyme-dependent fashion

Thu, 2023-03-30 06:00

Nat Commun. 2023 Mar 30;14(1):1790. doi: 10.1038/s41467-023-37449-1.

ABSTRACT

Autosomal dominant polycystic kidney disease (ADPKD) is the most prevalent potentially lethal monogenic disorder. Mutations in the PKD1 gene, which encodes polycystin-1 (PC1), account for approximately 78% of cases. PC1 is a large 462-kDa protein that undergoes cleavage in its N and C-terminal domains. C-terminal cleavage produces fragments that translocate to mitochondria. We show that transgenic expression of a protein corresponding to the final 200 amino acid (aa) residues of PC1 in two Pkd1-KO orthologous murine models of ADPKD suppresses cystic phenotype and preserves renal function. This suppression depends upon an interaction between the C-terminal tail of PC1 and the mitochondrial enzyme Nicotinamide Nucleotide Transhydrogenase (NNT). This interaction modulates tubular/cyst cell proliferation, the metabolic profile, mitochondrial function, and the redox state. Together, these results suggest that a short fragment of PC1 is sufficient to suppress cystic phenotype and open the door to the exploration of gene therapy strategies for ADPKD.

PMID:36997516 | DOI:10.1038/s41467-023-37449-1

Categories: Literature Watch

It is better to light a candle than to curse the darkness: single-cell transcriptomics sheds new light on pancreas biology and disease

Thu, 2023-03-30 06:00

Gut. 2023 Mar 30:gutjnl-2022-329313. doi: 10.1136/gutjnl-2022-329313. Online ahead of print.

ABSTRACT

Recent advances in single-cell RNA sequencing and bioinformatics have drastically increased our ability to interrogate the cellular composition of traditionally difficult to study organs, such as the pancreas. With the advent of these technologies and approaches, the field has grown, in just a few years, from profiling pancreas disease states to identifying molecular mechanisms of therapy resistance in pancreatic ductal adenocarcinoma, a particularly deadly cancer. Single-cell transcriptomics and related spatial approaches have identified previously undescribed epithelial and stromal cell types and states, how these populations change with disease progression, and potential mechanisms of action which will serve as the basis for designing new therapeutic strategies. Here, we review the recent literature on how single-cell transcriptomic approaches have changed our understanding of pancreas biology and disease progression.

PMID:36997301 | DOI:10.1136/gutjnl-2022-329313

Categories: Literature Watch

Structural elements promote architectural stripe formation and facilitate ultra-long-range gene regulation at a human disease locus

Thu, 2023-03-30 06:00

Mol Cell. 2023 Mar 22:S1097-2765(23)00166-1. doi: 10.1016/j.molcel.2023.03.009. Online ahead of print.

ABSTRACT

Enhancer clusters overlapping disease-associated mutations in Pierre Robin sequence (PRS) patients regulate SOX9 expression at genomic distances over 1.25 Mb. We applied optical reconstruction of chromatin architecture (ORCA) imaging to trace 3D locus topology during PRS-enhancer activation. We observed pronounced changes in locus topology between cell types. Subsequent analysis of single-chromatin fiber traces revealed that these ensemble-average differences arise through changes in the frequency of commonly sampled topologies. We further identified two CTCF-bound elements, internal to the SOX9 topologically associating domain, which promote stripe formation, are positioned near the domain's 3D geometric center, and bridge enhancer-promoter contacts in a series of chromatin loops. Ablation of these elements results in diminished SOX9 expression and altered domain-wide contacts. Polymer models with uniform loading across the domain and frequent cohesin collisions recapitulate this multi-loop, centrally clustered geometry. Together, we provide mechanistic insights into architectural stripe formation and gene regulation over ultra-long genomic ranges.

PMID:36996812 | DOI:10.1016/j.molcel.2023.03.009

Categories: Literature Watch

Lysine-Derived Charge-Altering Releasable Transporters: Targeted Delivery of mRNA and siRNA to the Lungs

Thu, 2023-03-30 06:00

Bioconjug Chem. 2023 Mar 30. doi: 10.1021/acs.bioconjchem.3c00019. Online ahead of print.

ABSTRACT

Targeted delivery of nucleic acid therapeutics to the lungs could transform treatment options for pulmonary disease. We have previously developed oligomeric charge-altering releasable transporters (CARTs) for in vivo mRNA transfection and demonstrated their efficacy for use in mRNA-based cancer vaccination and local immunomodulatory therapies against murine tumors. While our previously reported glycine-based CART-mRNA complexes (G-CARTs/mRNA) show selective protein expression in the spleen (mouse, >99%), here, we report a new lysine-derived CART-mRNA complex (K-CART/mRNA) that, without additives or targeting ligands, shows selective protein expression in the lungs (mouse, >90%) following systemic IV administration. We further show that by delivering siRNA using the K-CART, we can significantly decrease expression of a lung-localized reporter protein. Blood chemistry and organ pathology studies demonstrate that K-CARTs are safe and well-tolerated. We report on the new step economical, organocatalytic synthesis (two steps) of functionalized polyesters and oligo-carbonate-co-α-aminoester K-CARTs from simple amino acid and lipid-based monomers. The ability to direct protein expression selectively in the spleen or lungs by simple, modular changes to the CART structure opens fundamentally new opportunities in research and gene therapy.

PMID:36996808 | DOI:10.1021/acs.bioconjchem.3c00019

Categories: Literature Watch

Distinct gene dysregulation patterns herald precision medicine potentiality in systemic lupus erythematosus

Thu, 2023-03-30 06:00

J Autoimmun. 2023 Mar 28;136:103025. doi: 10.1016/j.jaut.2023.103025. Online ahead of print.

ABSTRACT

OBJECTIVES: We aimed at investigating the whole-blood transcriptome, expression quantitative trait loci (eQTLs), and levels of selected serological markers in patients with SLE versus healthy controls (HC) to gain insight into pathogenesis and identify drug targets.

METHODS: We analyzed differentially expressed genes (DEGs) and dysregulated gene modules in a cohort of 350 SLE patients and 497 HC from the European PRECISESADS project (NTC02890121), split into a discovery (60%) and a replication (40%) set. Replicated DEGs qualified for eQTL, pathway enrichment, regulatory network, and druggability analysis. For validation purposes, a separate gene module analysis was performed in an independent cohort (GSE88887).

RESULTS: Analysis of 521 replicated DEGs identified multiple enriched interferon signaling pathways through Reactome. Gene module analysis yielded 18 replicated gene modules in SLE patients, including 11 gene modules that were validated in GSE88887. Three distinct gene module clusters were defined i.e., "interferon/plasma cells", "inflammation", and "lymphocyte signaling". Predominant downregulation of the lymphocyte signaling cluster denoted renal activity. By contrast, upregulation of interferon-related genes indicated hematological activity and vasculitis. Druggability analysis revealed several potential drugs interfering with dysregulated genes within the "interferon" and "PLK1 signaling events" modules. STAT1 was identified as the chief regulator in the most enriched signaling molecule network. Drugs annotated to 15 DEGs associated with cis-eQTLs included bortezomib for its ability to modulate CTSL activity. Belimumab was annotated to TNFSF13B (BAFF) and daratumumab was annotated to CD38 among the remaining replicated DEGs.

CONCLUSIONS: Modulation of interferon, STAT1, PLK1, B and plasma cell signatures showed promise as viable approaches to treat SLE, pointing to their importance in SLE pathogenesis.

PMID:36996699 | DOI:10.1016/j.jaut.2023.103025

Categories: Literature Watch

Handyfuge Microfluidic for On-Site Antibiotic Susceptibility Testing

Thu, 2023-03-30 06:00

Anal Chem. 2023 Mar 30. doi: 10.1021/acs.analchem.3c00557. Online ahead of print.

ABSTRACT

Low-cost, rapid, and accurate acquisition of minimum inhibitory concentrations (MICs) is key to limiting the development of antimicrobial resistance (AMR). Until now, conventional antibiotic susceptibility testing (AST) methods are typically time-consuming, high-cost, and labor-intensive, making them difficult to accomplish this task. Herein, an electricity-free, portable, and robust handyfuge microfluidic chip was developed for on-site AST, termed handyfuge-AST. With simply handheld centrifugation, the bacterial-antibiotic mixtures with accurate antibiotic concentration gradients could be generated in less than 5 min. The accurate MIC values of single antibiotics (including ampicillin, kanamycin, and chloramphenicol) or their combinations against Escherichia coli could be obtained within 5 h. To further meet the growing demands of point-of-care testing, we upgraded our handyfuge-AST with a pH-based colorimetric strategy, enabling naked eye recognition or intelligent recognition with a homemade mobile app. Through a comparative study of 60 clinical data (10 clinical samples corresponding to six commonly used antibiotics), the accurate MICs by handyfuge-AST with 100% categorical agreements were achieved compared to clinical standard methods (area under curves, AUCs = 1.00). The handyfuge-AST could be used as a low-cost, portable, and robust point-of-care device to rapidly obtain accurate MIC values, which significantly limit the progress of AMR.

PMID:36996249 | DOI:10.1021/acs.analchem.3c00557

Categories: Literature Watch

Brassinosteroid gene regulatory networks at cellular resolution in the <em>Arabidopsis</em> root

Thu, 2023-03-30 06:00

Science. 2023 Mar 31;379(6639):eadf4721. doi: 10.1126/science.adf4721. Epub 2023 Mar 31.

ABSTRACT

Brassinosteroids are plant steroid hormones that regulate diverse processes, such as cell division and cell elongation, through gene regulatory networks that vary in space and time. By using time series single-cell RNA sequencing to profile brassinosteroid-responsive gene expression specific to different cell types and developmental stages of the Arabidopsis root, we identified the elongating cortex as a site where brassinosteroids trigger a shift from proliferation to elongation associated with increased expression of cell wall-related genes. Our analysis revealed HOMEOBOX FROM ARABIDOPSIS THALIANA 7 (HAT7) and GT-2-LIKE 1 (GTL1) as brassinosteroid-responsive transcription factors that regulate cortex cell elongation. These results establish the cortex as a site of brassinosteroid-mediated growth and unveil a brassinosteroid signaling network regulating the transition from proliferation to elongation, which illuminates aspects of spatiotemporal hormone responses.

PMID:36996230 | DOI:10.1126/science.adf4721

Categories: Literature Watch

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