Systems Biology
miR-9-5p deficiency contributes to schizophrenia
Schizophr Res. 2023 Nov 21;262:168-174. doi: 10.1016/j.schres.2023.11.006. Online ahead of print.
ABSTRACT
MicroRNA-9-5p (miR-9-5p) is highly expressed in the brain and has been implicated in the risk of schizophrenia. We compared the expression levels of miR-9-5p in schizophrenia cases and healthy controls and evaluated whether regulatory targets of miR-9-5p are enriched in schizophrenia genome-wide risk genes. Literature-based analysis was conducted to construct molecular pathways connecting miR-9-5p and schizophrenia. We found that the expression levels of miR-9-5p were down-regulated in the peripheral blood of schizophrenia patients compared with those in healthy controls. miR-9-5p can regulate 24 out of the 1136 genome-wide risk genes of schizophrenia, which was higher than by chance (hypergeometric test P = 4.09E-06). The literature-based analysis showed that quantitative genetic changes driven by miR-9 exert more inhibitory (the IL1B, ABCB1, FGFR1 genes) than promoting (the INS gene) effects on schizophrenia, suggesting that miR-9 may protect against schizophrenia. Our results suggest that miR-9-5p deficiency may contribute to the development of schizophrenia.
PMID:37992560 | DOI:10.1016/j.schres.2023.11.006
Molecular Coping Mechanisms: Reprogramming tRNAs To Regulate Codon-Biased Translation of Stress Response Proteins
Acc Chem Res. 2023 Nov 22. doi: 10.1021/acs.accounts.3c00572. Online ahead of print.
ABSTRACT
ConspectusAs part of the classic central dogma of molecular biology, transfer RNAs (tRNAs) are integral to protein translation as the adaptor molecules that link the genetic code in messenger RNA (mRNA) to the amino acids in the growing peptide chain. tRNA function is complicated by the existence of 61 codons to specify 20 amino acids, with most amino acids coded by two or more synonymous codons. Further, there are often fewer tRNAs with unique anticodons than there are synonymous codons for an amino acid, with a single anticodon able to decode several codons by "wobbling" of the base pairs arising between the third base of the codon and the first position on the anticodon. The complications introduced by synonymous codons and wobble base pairing began to resolve in the 1960s with the discovery of dozens of chemical modifications of the ribonucleotides in tRNA, which, by analogy to the epigenome, are now collectively referred to as the epitranscriptome for not changing the genetic code inherent to all RNA sequences. tRNA modifications were found to stabilize codon-anticodon interactions, prevent misinitiation of translation, and promote translational fidelity, among other functions, with modification deficiencies causing pathological phenotypes. This led to hypotheses that modification-dependent tRNA decoding efficiencies might play regulatory roles in cells. However, it was only with the advent of systems biology and convergent "omic" technologies that the higher level function of synonymous codons and tRNA modifications began to emerge.Here, we describe our laboratories' discovery of tRNA reprogramming and codon-biased translation as a mechanism linking tRNA modifications and synonymous codon usage to regulation of gene expression at the level of translation. Taking a historical approach, we recount how we discovered that the 8-10 modifications in each tRNA molecule undergo unique reprogramming in response to cellular stresses to promote translation of mRNA transcripts with unique codon usage patterns. These modification tunable transcripts (MoTTs) are enriched with specific codons that are differentially decoded by modified tRNAs and that fall into functional families of genes encoding proteins necessary to survive the specific stress. By developing and applying systems-level technologies, we showed that cells lacking specific tRNA modifications are sensitized to certain cellular stresses by mistranslation of proteins, disruption of mitochondrial function, and failure to translate critical stress response proteins. In essence, tRNA reprogramming serves as a cellular coping strategy, enabling rapid translation of proteins required for stress-specific cell response programs. Notably, this phenomenon has now been characterized in all organisms from viruses to humans and in response to all types of environmental changes. We also elaborate on recent findings that cancer cells hijack this mechanism to promote their own growth, metastasis, and chemotherapeutic resistance. We close by discussing how understanding of codon-biased translation in various systems can be exploited to develop new therapeutics and biomanufacturing processes.
PMID:37992267 | DOI:10.1021/acs.accounts.3c00572
MATLAB-Based Algorithm and Software for Analysis of Wavy Collagen Fibers
Microsc Microanal. 2023 Nov 22:ozad117. doi: 10.1093/micmic/ozad117. Online ahead of print.
ABSTRACT
Knowledge of soft tissue fiber structure is necessary for accurate characterization and modeling of their mechanical response. Fiber configuration and structure informs both our understanding of healthy tissue physiology and of pathological processes resulting from diseased states. This study develops an automatic algorithm to simultaneously estimate fiber global orientation, abundance, and waviness in an investigated image. To our best knowledge, this is the first validated algorithm which can reliably separate fiber waviness from its global orientation for considerably wavy fibers. This is much needed feature for biological tissue characterization. The algorithm is based on incremental movement of local regions of interest (ROI) and analyzes two-dimensional images. Pixels belonging to the fiber are identified in the ROI, and ROI movement is determined according to local orientation of fiber within the ROI. The algorithm is validated with artificial images and ten images of porcine trachea containing wavy fibers. In each image, 80-120 fibers were tracked manually to serve as verification. The coefficient of determination R2 between curve lengths and histograms documenting the fiber waviness and global orientation were used as metrics for analysis. Verification-confirmed results were independent of image rotation and degree of fiber waviness, with curve length accuracy demonstrated to be below 1% of fiber curved length. Validation-confirmed median and interquartile range of R2, respectively, were 0.90 and 0.05 for curved length, 0.92 and 0.07 for waviness, and 0.96 and 0.04 for global orientation histograms. Software constructed from the proposed algorithm was able to track one fiber in about 1.1 s using a typical office computer. The proposed algorithm can reliably and accurately estimate fiber waviness, curve length, and global orientation simultaneously, moving beyond the limitations of prior methods.
PMID:37992253 | DOI:10.1093/micmic/ozad117
Tree architecture: A strigolactone-deficient mutant reveals a connection between branching order and auxin gradient along the tree stem
Proc Natl Acad Sci U S A. 2023 Nov 28;120(48):e2308587120. doi: 10.1073/pnas.2308587120. Epub 2023 Nov 22.
ABSTRACT
Due to their long lifespan, trees and bushes develop higher order of branches in a perennial manner. In contrast to a tall tree, with a clearly defined main stem and branching order, a bush is shorter and has a less apparent main stem and branching pattern. To address the developmental basis of these two forms, we studied several naturally occurring architectural variants in silver birch (Betula pendula). Using a candidate gene approach, we identified a bushy kanttarelli variant with a loss-of-function mutation in the BpMAX1 gene required for strigolactone (SL) biosynthesis. While kanttarelli is shorter than the wild type (WT), it has the same number of primary branches, whereas the number of secondary branches is increased, contributing to its bush-like phenotype. To confirm that the identified mutation was responsible for the phenotype, we phenocopied kanttarelli in transgenic BpMAX1::RNAi birch lines. SL profiling confirmed that both kanttarelli and the transgenic lines produced very limited amounts of SL. Interestingly, the auxin (IAA) distribution along the main stem differed between WT and BpMAX1::RNAi. In the WT, the auxin concentration formed a gradient, being higher in the uppermost internodes and decreasing toward the basal part of the stem, whereas in the transgenic line, this gradient was not observed. Through modeling, we showed that the different IAA distribution patterns may result from the difference in the number of higher-order branches and plant height. Future studies will determine whether the IAA gradient itself regulates aspects of plant architecture.
PMID:37991945 | DOI:10.1073/pnas.2308587120
Correction: Radiomics-based prediction of FIGO grade for placenta accreta spectrum
Eur Radiol Exp. 2023 Nov 22;7(1):73. doi: 10.1186/s41747-023-00397-y.
NO ABSTRACT
PMID:37991638 | DOI:10.1186/s41747-023-00397-y
Multicellular factor analysis of single-cell data for a tissue-centric understanding of disease
Elife. 2023 Nov 22;12:e93161. doi: 10.7554/eLife.93161. Online ahead of print.
ABSTRACT
Biomedical single-cell atlases describe disease at the cellular level. However, analysis of this data commonly focuses on cell-type centric pairwise cross-condition comparisons, disregarding the multicellular nature of disease processes. Here we propose multicellular factor analysis for the unsupervised analysis of samples from cross-condition single-cell atlases and the identification of multicellular programs associated with disease. Our strategy, which repurposes group factor analysis as implemented in multi-omics factor analysis, incorporates the variation of patient samples across cell-types or other tissue-centric features, such as cell compositions or spatial relationships, and enables the joint analysis of multiple patient cohorts, facilitating the integration of atlases. We applied our framework to a collection of acute and chronic human heart failure atlases and described multicellular processes of cardiac remodeling, independent to cellular compositions and their local organization, that were conserved in independent spatial and bulk transcriptomics datasets. In sum, our framework serves as an exploratory tool for unsupervised analysis of cross-condition single-cell atlases and allows for the integration of the measurements of patient cohorts across distinct data modalities.
PMID:37991480 | DOI:10.7554/eLife.93161
REC protein family expansion by the emergence of a new signaling pathway
mBio. 2023 Nov 22:e0262223. doi: 10.1128/mbio.02622-23. Online ahead of print.
ABSTRACT
We explore when and why large classes of proteins expand into new sequence space. We used an unsupervised machine learning approach to observe the sequence landscape of REC domains of bacterial response regulator proteins. We find that within-gene recombination can switch effector domains and, consequently, change the regulatory context of the duplicated protein.
PMID:37991384 | DOI:10.1128/mbio.02622-23
Shared sequence characteristics identified in non-canonical rearrangements of HSV-1 genomes
J Virol. 2023 Nov 22:e0095523. doi: 10.1128/jvi.00955-23. Online ahead of print.
ABSTRACT
Mutations and genetic rearrangements are the primary driving forces of evolution. Viruses provide valuable model systems for investigating these mechanisms due to their rapid evolutionary rates and vast genetic variability. To investigate genetic rearrangements in the double-stranded DNA genome of herpes simplex virus type 1, the viral population was serially passaged in various cell types. The serial passaging led to formation of defective genomes, resulted from cell-specific non-canonical rearrangements (NCRs). Interestingly, we discovered shared sequence characteristics underlying the formation of these NCRs across all cell types. Moreover, most NCRs identified in clinical samples shared these characteristics. Based on our findings, we propose a model elucidating the formation of NCRs during viral replication within the nucleus of eukaryotic cells.
PMID:37991369 | DOI:10.1128/jvi.00955-23
Mitochondria-sequestered Aβ renders synaptic mitochondria vulnerable in the elderly with a risk of Alzheimer disease
JCI Insight. 2023 Nov 22;8(22):e174290. doi: 10.1172/jci.insight.174290.
ABSTRACT
Mitochondria are critical for neurophysiology, and mitochondrial dysfunction constitutes a characteristic pathology in both brain aging and Alzheimer disease (AD). Whether mitochondrial deficiency in brain aging and AD is mechanistically linked, however, remains controversial. We report a correlation between intrasynaptosomal amyloid β 42 (Aβ42) and synaptic mitochondrial bioenergetics inefficiency in both aging and amnestic mild cognitive impairment, a transitional stage between normal aging and AD. Experiments using a mouse model expressing nonmutant humanized Aβ (humanized Aβ-knockin [hAβ-KI] mice) confirmed the association of increased intramitochondrial sequestration of Aβ42 with exacerbated synaptic mitochondrial dysfunction in an aging factor- and AD risk-bearing context. Also, in comparison with global cerebral Aβ, intramitochondrial Aβ was relatively preserved from activated microglial phagocytosis in aged hAβ-KI mice. The most parsimonious interpretation of our results is that aging-related mitochondrial Aβ sequestration renders synaptic mitochondrial dysfunction in the transitional stage between normal aging and AD. Mitochondrial dysfunction in both brain aging and the prodromal stage of AD may follow a continuous transition in response to escalated intraneuronal, especially intramitochondrial Aβ, accumulation. Moreover, our findings further implicate a pivotal role of mitochondria in harboring early amyloidosis during the conversion from normal to pathological aging.
PMID:37991017 | DOI:10.1172/jci.insight.174290
How to maximize power for differential expression analysis in discovery omics through experimental design
Expert Rev Proteomics. 2023 Nov 22. doi: 10.1080/14789450.2023.2287054. Online ahead of print.
NO ABSTRACT
PMID:37990821 | DOI:10.1080/14789450.2023.2287054
Mitochondrial and immune response dysregulation in melanoma recurrence
Clin Transl Med. 2023 Nov;13(11):e1495. doi: 10.1002/ctm2.1495.
NO ABSTRACT
PMID:37990633 | DOI:10.1002/ctm2.1495
Increased Diversity of Citrus Tristeza Virus in Europe
Plant Dis. 2023 Nov 21. doi: 10.1094/PDIS-09-23-1718-RE. Online ahead of print.
ABSTRACT
This study investigated the genetic diversity of citrus tristeza virus (CTV) isolates from Montenegro and Croatia, European countries with the northernmost citrus growing regions situated on the Eastern Adriatic coast. Fifteen complete or nearly complete CTV genomes were reconstructed from high-throughput sequencing of samples collected in distinct municipalities in Montenegro and Opuzen municipality in Croatia. Phylogenetic analyses assigned some of the sequences to VT and T30 strains, previously recorded in Europe, while remarkably other isolates were placed in S1 and RB groups, which have not been reported in Europe so far. In addition, a new phylogenetic lineage including only isolates from Montenegro was delineated and tentatively proposed as the MNE cluster. Recombination analysis revealed evidence of 11 recombination events in the sequences obtained in this study, between isolates of related strains, within isolates of the same strain, and between distant strains. These findings show that CTV diversity in Europe is higher than reported before and calls for the re-evaluation of management strategies.
PMID:37990525 | DOI:10.1094/PDIS-09-23-1718-RE
Proceedings of the inaugural Dark Genome Symposium: November 2022
Mob DNA. 2023 Nov 21;14(1):18. doi: 10.1186/s13100-023-00306-5.
ABSTRACT
In November 2022 the first Dark Genome Symposium was held in Boston, USA. The meeting was hosted by Rome Therapeutics and Enara Bio, two biotechnology companies working on translating our growing understanding of this vast genetic landscape into therapies for human disease. The spirit and ambition of the meeting was one of shared knowledge, looking to strengthen the network of researchers engaged in the field. The meeting opened with a welcome from Rosana Kapeller and Kevin Pojasek followed by a first session of field defining talks from key academics in the space. A series of panels, bringing together academia and industry views, were then convened covering a wide range of pertinent topics. Finally, Richard Young and David Ting gave their views on the future direction and promise for patient impact inherent in the growing understanding of the Dark Genome.
PMID:37990347 | DOI:10.1186/s13100-023-00306-5
Correction: The esBAF and ISWI nucleosome remodeling complexes influence occupancy of overlapping dinucleosomes and fragile nucleosomes in murine embryonic stem cells
BMC Genomics. 2023 Nov 21;24(1):699. doi: 10.1186/s12864-023-09806-3.
NO ABSTRACT
PMID:37990151 | DOI:10.1186/s12864-023-09806-3
Isolation may select for earlier and higher peak viral load but shorter duration in SARS-CoV-2 evolution
Nat Commun. 2023 Nov 21;14(1):7395. doi: 10.1038/s41467-023-43043-2.
ABSTRACT
During the COVID-19 pandemic, human behavior change as a result of nonpharmaceutical interventions such as isolation may have induced directional selection for viral evolution. By combining previously published empirical clinical data analysis and multi-level mathematical modeling, we find that the SARS-CoV-2 variants selected for as the virus evolved from the pre-Alpha to the Delta variant had earlier and higher peak in viral load dynamics but a shorter duration of infection. Selection for increased transmissibility shapes the viral load dynamics, and the isolation measure is likely to be a driver of these evolutionary transitions. In addition, we show that a decreased incubation period and an increased proportion of asymptomatic infection are also positively selected for as SARS-CoV-2 mutated to adapt to human behavior (i.e., Omicron variants). The quantitative information and predictions we present here can guide future responses in the potential arms race between pandemic interventions and viral evolution.
PMID:37989736 | DOI:10.1038/s41467-023-43043-2
Responses to pattern-violating visual stimuli evolve differently over days in somata and distal apical dendrites
J Neurosci. 2023 Nov 21:JN-RM-1009-23. doi: 10.1523/JNEUROSCI.1009-23.2023. Online ahead of print.
ABSTRACT
Scientists have long conjectured that the neocortex learns patterns in sensory data to generate top-down predictions of upcoming stimuli. In line with this conjecture, different responses to pattern-matching vs pattern-violating visual stimuli have been observed in both spiking and somatic calcium imaging data. However, it remains unknown whether these pattern-violation signals are different between the distal apical dendrites, which are heavily targeted by top-down signals, and the somata, where bottom-up information is primarily integrated. Furthermore, it is unknown how responses to pattern-violating stimuli evolve over time as an animal gains more experience with them. Here, we address these unanswered questions by analyzing responses of individual somata and dendritic branches of layer 2/3 and layer 5 pyramidal neurons tracked over multiple days in primary visual cortex of awake, behaving female and male mice. We use sequences of Gabor patches with patterns in their orientations to create pattern-matching and pattern-violating stimuli, and two-photon calcium imaging to record neuronal responses. Many neurons in both layers show large differences between their responses to pattern-matching and pattern-violating stimuli. Interestingly, these responses evolve in opposite directions in the somata and distal apical dendrites, with somata becoming less sensitive to pattern-violating stimuli and distal apical dendrites more sensitive. These differences between the somata and distal apical dendrites may be important for hierarchical computation of sensory predictions and learning, since these two compartments tend to receive bottom-up and top-down information, respectively.Significance Statement Hierarchical predictive computation is believed to be a major function of the neocortex. However, it is unknown whether stimuli that violate previously-experienced sensory patterns induce different responses in the compartments of neurons where bottom-up and top-down signals are predominantly integrated. Here, we track the responses of different compartments of neurons in mouse visual cortex as we present animals with pattern-violating and pattern-matching visual stimuli. In the neuronal compartments that receive bottom-up and top-down signals, we find that the responses to pattern-violating compared to pattern-matching stimuli evolve differently over time. This may provide critical insight into hierarchical sensory computation and predictive learning in the brain.
PMID:37989593 | DOI:10.1523/JNEUROSCI.1009-23.2023
Enhancer-driven 3D chromatin domain folding modulates transcription in human mammary tumor cells
Life Sci Alliance. 2023 Nov 21;7(2):e202302154. doi: 10.26508/lsa.202302154. Print 2024 Feb.
ABSTRACT
The genome is organized in functional compartments and structural domains at the sub-megabase scale. How within these domains interactions between numerous cis-acting enhancers and promoters regulate transcription remains an open question. Here, we determined chromatin folding and composition over several hundred kb around estrogen-responsive genes in human breast cancer cell lines after hormone stimulation. Modeling of 5C data at 1.8 kb resolution was combined with quantitative 3D analysis of multicolor FISH measurements at 100 nm resolution and integrated with ChIP-seq data on transcription factor binding and histone modifications. We found that rapid estradiol induction of the progesterone gene expression occurs in the context of preexisting, cell type-specific chromosomal architectures encompassing the 90 kb progesterone gene coding region and an enhancer-spiked 5' 300 kb upstream genomic region. In response to estradiol, interactions between estrogen receptor α (ERα) bound regulatory elements are reinforced. Whereas initial enhancer-gene contacts coincide with RNA Pol 2 binding and transcription initiation, sustained hormone stimulation promotes ERα accumulation creating a regulatory hub stimulating transcript synthesis. In addition to implications for estrogen receptor signaling, we uncover that preestablished chromatin architectures efficiently regulate gene expression upon stimulation without the need for de novo extensive rewiring of long-range chromatin interactions.
PMID:37989525 | DOI:10.26508/lsa.202302154
Fractionation of neural reward processing into independent components by novel decoding principle
Neuroimage. 2023 Nov 19:120463. doi: 10.1016/j.neuroimage.2023.120463. Online ahead of print.
ABSTRACT
How to retrieve latent neurobehavioural processes from complex neurobiological signals is an important yet unresolved challenge. Here, we develop a novel approach, orthogonal-Decoding multi-Cognitive Processes (DeCoP), to reveal underlying latent neurobehavioural processing and show that its performance is superior to traditional non-orthogonal decoding in terms of both false inference and robustness. Processing value and salience information are two fundamental but mutually confounded pathways of reward reinforcement essential for decision making. During reward/punishment anticipation, we applied DeCoP to decode brain-wide responses into spatially overlapping, yet functionally independent, evaluation and readiness processes, which are modulated differentially by meso-limbic vs nigro-striatal dopamine systems. Using DeCoP, we further demonstrated that most brain regions only encoded abstract information but not the exact input, except for dorsal anterior cingulate cortex and insula. Furthermore, we anticipate our novel analytical principle to be applied generally in decoding multiple latent neurobehavioral processes and thus advance both the design and hypothesis testing for cognitive tasks.
PMID:37989457 | DOI:10.1016/j.neuroimage.2023.120463
Toward Systems-Level Metabolic Analysis in Endocrine Disorders and Cancer
Endocrinol Metab (Seoul). 2023 Nov 21. doi: 10.3803/EnM.2023.1814. Online ahead of print.
ABSTRACT
Metabolism is a dynamic network of biochemical reactions that support systemic homeostasis amidst changing nutritional, environmental, and physical activity factors. The circulatory system facilitates metabolite exchange among organs, while the endocrine system finely tunes metabolism through hormone release. Endocrine disorders like obesity, diabetes, and Cushing's syndrome disrupt this balance, contributing to systemic inflammation and global health burdens. They accompany metabolic changes on multiple levels from molecular interactions to individual organs to the whole body. Understanding how metabolic fluxes relate to endocrine disorders illuminates the underlying dysregulation. Cancer is increasingly considered a systemic disorder because it not only affects cells in localized tumors but also the whole body, especially in metastasis. In tumorigenesis, cancer-specific mutations and nutrient availability in the tumor microenvironment reprogram cellular metabolism to meet increased energy and biosynthesis needs. Cancer cachexia results in metabolic changes to other organs like muscle, adipose tissue, and liver. This review explores the interplay between the endocrine system and systems-level metabolism in health and disease. We highlight metabolic fluxes in conditions like obesity, diabetes, Cushing's syndrome, and cancers. Recent advances in metabolomics, fluxomics, and systems biology promise new insights into dynamic metabolism, offering potential biomarkers, therapeutic targets, and personalized medicine.
PMID:37989266 | DOI:10.3803/EnM.2023.1814
scCURE identifies cell types responding to immunotherapy and enables outcome prediction
Cell Rep Methods. 2023 Nov 20;3(11):100643. doi: 10.1016/j.crmeth.2023.100643.
ABSTRACT
A deep understanding of immunotherapy response/resistance mechanisms and a highly reliable therapy response prediction are vital for cancer treatment. Here, we developed scCURE (single-cell RNA sequencing [scRNA-seq] data-based Changed and Unchanged cell Recognition during immunotherapy). Based on Gaussian mixture modeling, Kullback-Leibler (KL) divergence, and mutual nearest-neighbors criteria, scCURE can faithfully discriminate between cells affected or unaffected by immunotherapy intervention. By conducting scCURE analyses in melanoma and breast cancer immunotherapy scRNA-seq data, we found that the baseline profiles of specific CD8+ T and macrophage cells (identified by scCURE) can determine the way in which tumor microenvironment immune cells respond to immunotherapy, e.g., antitumor immunity activation or de-activation; therefore, these cells could be predictive factors for treatment response. In this work, we demonstrated that the immunotherapy-associated cell-cell heterogeneities revealed by scCURE can be utilized to integrate the therapy response mechanism study and prediction model construction.
PMID:37989083 | DOI:10.1016/j.crmeth.2023.100643