Translational Profiling Research Articles

Systemic Toxicity of Recombinant Adeno-Associated Virus Gene Therapy Vectors.

Recombinant adeno-associated virus (rAAV) vectors have emerged as a promising tool for gene therapy. However, the systemic administration of rAAV vectors is not without risks, particularly for dose levels >1 × 1014 viral genome per kilogram of body weight (vg/kg). rAAV-associated toxicities can variably manifest either acutely or in a delayed manner. Acute toxicities often present shortly after administration and can include severe immune responses, hepatotoxicity, and thrombotic microangiopathy (TMA). Delayed toxicities, on the other hand, may emerge weeks to months post-treatment, potentially involving chronic liver damage or prolonged immune activation. Thrombotic microangiopathy is often associated with complement activation and endothelial damage. The activation of the complement system can additionally trigger a cascade of inflammatory responses, exacerbating systemic toxicity. While many of these toxicities are reversible with appropriate medical intervention, there have been instances where the adverse effects were severe enough to lead to fatalities. Both human and animal studies have reported these adverse effects, highlighting the critical importance of thorough preclinical testing. However, a differential toxicity profile associated with systemic AAV administration exists between humans and nonhuman primates (NHPs), in which certain toxicities reported in humans are yet to be observed in NHPs, and vice versa. This review aims to explore the recent literature on systemic rAAV toxicities, focusing on dose levels, the role of the complement activation pathway, endothelial injury, TMA, hepatotoxicity, and the bidirectional translational safety profiles from both human and animal studies.

Cytosolic N6AMT1-dependent translation supports mitochondrial RNA processing

Mitochondrial biogenesis relies on both the nuclear and mitochondrial genomes, and imbalance in their expression can lead to inborn errors of metabolism, inflammation, and aging. Here, we investigate N6AMT1, a nucleo-cytosolic methyltransferase that exhibits genetic codependency with mitochondria. We determine transcriptional and translational profiles of N6AMT1 and report that it is required for the cytosolic translation of TRMT10C (MRPP1) and PRORP (MRPP3), two subunits of the mitochondrial RNAse P enzyme. In the absence of N6AMT1, or when its catalytic activity is abolished, RNA processing within mitochondria is impaired, leading to the accumulation of unprocessed and double-stranded RNA, thus preventing mitochondrial protein synthesis and oxidative phosphorylation, and leading to an immune response. Our work sheds light on the function of N6AMT1 in protein synthesis and highlights a cytosolic program required for proper mitochondrial biogenesis.

Translation profiling of stress-induced small proteins reveals a novel link among signaling systems.

Signaling networks allow adaptation to stressful environments by activating genes that counteract stressors. Small proteins (≤ 50 amino acids long) are a rising class of stress response regulators. Escherichia coli encodes over 150 small proteins, most of which lack phenotypes and their biological roles remain elusive. Using magnesium limitation as a stressor, we identify stress-induced small proteins using ribosome profiling, RNA sequencing, and transcriptional reporter assays. We uncover 17 small proteins with increased translation initiation, several of them transcriptionally upregulated by the PhoQ-PhoP two-component signaling system, crucial for magnesium homeostasis. Next, we describe small protein-specific deletion and overexpression phenotypes, underscoring their physiological significance in low magnesium stress. Most remarkably, we elucidate an unusual connection via a small membrane protein YoaI, between major signaling networks - PhoR-PhoB and EnvZ-OmpR in E. coli, advancing our understanding of small protein regulators in cellular signaling.

Mimicking and in vitro validating chronic inflammation in human gingival fibroblasts

ObjectiveThe aim of this study was to identify and validate in vitro conditions that may mimic the translational, cytokine and chemokine profiles observed in human inflamed gingiva in vivo. DesignPrimary human gingiva fibroblast cells (HFIB-G) were cultured under serum starvation conditions (0 – 10 %), supplemented with increasing lipopolysaccharide (LPS) concentrations (0.1, 1, or 10 µg/ml) from two bacterial strains E. coli and P. gingivalis and 0.1, 1, or 10 ng/ml recombinant interleukin 1β (IL-1β), alone or in combinations. The levels of cytokines/chemokines were measured in the cell culture medium by Luminex, and gene expression was quantified by Affymetrix microarrays at 24, 48 and 72 h. ResultsInflammation markers were not elevated after stimulation with P. gingivalis LPS, while E. coli LPS and IL-1β individually increased the secretion of interleukin 6 (IL-6) and monocyte chemoattractant protein-1 (MCP-1) to the cell culture medium. IL-1β administration also increased the secretion of several factors, including tumor necrosis factor (TNFα). However, the combination of 1 µg/ml E. coli LPS, 1 ng/ml IL-1β and serum starvation led to increased secretion of IL-6, TNFα, in addition to other factors found in inflamed tissue. Gene expression analyses revealed that this combination not only enhanced the expression interleukins/chemokines genes but also T helper cell signaling and matrix metalloproteinases. ConclusionSerum reduction in cell culture medium together with the administration of E. coli LPS and IL-1β resulted in gene expression and secreted cytokine/chemokine profiles similar to that found in vivo during chronic inflammation.

Common and divergent pathways in early stages of glutamate and tau-mediated toxicities in neurodegeneration

It has been shown that excitotoxicity and tau-mediated toxicities are major contributing factors to neuronal death in Alzheimer's disease (AD). The excitatory amino acid transporter 2 (EAAT2 or GLT-1), the major glutamate transporter in the brain that regulates glutamate levels synaptically and extrasynaptically, has been shown to be deficient in AD brains, leading to excitotoxicity and subsequent cell death. Similarly, buildup of neurofibrillary tangles, which consist of hyperphosphorylated tau protein, correlates with cognitive decline and neuronal atrophy in AD. However, common genes and pathways that are critical in the aforementioned toxicities have not been well elucidated. To investigate the impact of glutamate dyshomeostasis and tau accumulation on translational profiles of affected hippocampal neurons, we used mouse models of excitotoxicity and tau–mediated toxicities (GLT-1−/− and P301S, respectively) in conjunction with BAC-TRAP technology. Our data show that GLT-1 deficiency in CA3 pyramidal neurons leads to translational signatures characterized by dysregulation of pathways associated with synaptic plasticity and neuronal survival, while the P301S mutation induces changes in endocytic pathways and mitochondrial dysfunction. Finally, the commonly dysregulated pathways include impaired ion homeostasis and metabolic pathways. These common pathways may shed light on potential therapeutic targets for ameliorating glutamate and tau-mediated toxicities in AD.

Search and match across spatial omics samples at single-cell resolution.

Spatial omics technologies characterize tissue molecular properties with spatial information, but integrating and comparing spatial data across different technologies and modalities is challenging. A comparative analysis tool that can search, match and visualize both similarities and differences of molecular features in space across multiple samples is lacking. To address this, we introduce CAST (cross-sample alignment of spatial omics), a deep graph neural network-based method enabling spatial-to-spatial searching and matching at the single-cell level. CAST aligns tissues based on intrinsic similarities of spatial molecular features and reconstructs spatially resolved single-cell multi-omic profiles. CAST further allows spatially resolved differential analysis (∆Analysis) to pinpoint and visualize disease-associated molecular pathways and cell-cell interactions and single-cell relative translational efficiency profiling to reveal variations in translational control across cell types and regions. CAST serves as an integrative framework for seamless single-cell spatial data searching and matching across technologies, modalities and sample conditions.

The eukaryotic translation initiation factor eIF4E regulates flowering and circadian rhythm in Arabidopsis.

Translation initiation is a critical, rate-limiting step in protein synthesis. The eukaryotic translation initiation factor 4E (eIF4E) plays an essential role in this process. However, the mechanisms by which eIF4E-dependent translation initiation regulates plant growth and development remain not fully understood. In this study, we found that Arabidopsis eIF4E proteins are distributed in both the nucleus and cytoplasm, with only the cytoplasmic eIF4E being involved in the control of photoperiodic flowering. Genome-wide translation profiling using Ribo-tag sequencing reveals that eIF4E may regulate plant flowering by maintaining the homeostatic translation of components in the photoperiodic flowering pathway. eIF4E not only regulates the translation of flowering genes such as FLOWERING LOCUS T (FT) and FLOWERING LOCUS D (FLD) but also influences the translation of circadian genes like CIRCADIAN CLOCK ASSOCIATED 1 (CCA1) and PSEUDO-RESPONSE REGULATOR 9 (PRR9). Consistently, our results show that the eIF4E modulates the rhythmic oscillation of the circadian clock. Together, our study provides mechanistic insights into how the protein translation regulates multiple developmental processes in Arabidopsis, including the circadian clock and photoperiodic flowering.

An atypical form of 60S ribosomal subunit in Diamond-Blackfan anemia linked to RPL17 variants.

Diamond-Blackfan anemia syndrome (DBA) is a ribosomopathy associated with loss-of-function variants in more than 20 ribosomal protein (RP) genes. Here, we report the genetic, functional, and biochemical dissection of 2 multigenerational pedigrees with variants in RPL17, a large ribosomal subunit protein-encoding gene. Affected individuals had clinical features and erythroid proliferation defects consistent with DBA. Further, RPL17/uL22 depletion resulted in anemia and micrognathia in zebrafish larvae, and in vivo complementation studies indicated that RPL17 variants were pathogenic. Lymphoblastoid cell lines (LCLs) derived from patients displayed a ribosomal RNA maturation defect reflecting haploinsufficiency of RPL17. The proteins encoded by RPL17 variants were not incorporated into ribosomes, but 10%-20% of 60S ribosomal subunits contained a short form of 5.8S rRNA (5.8SC), a species that is marginal in normal cells. These atypical 60S subunits were actively engaged in translation. Ribosome profiling showed changes of the translational profile, but those are similar to LCLs bearing RPS19 variants. These results link an additional RP gene to DBA. They show that ribosomes can be modified substantially by RPL17 haploinsufficiency but support the paradigm that translation alterations in DBA are primarily related to insufficient ribosome production rather than to changes in ribosome structure or composition.

Translational regulation enhances distinction of cell types in the nervous system.

Multicellular organisms are composed of specialized cell types with distinct proteomes. While recent advances in single-cell transcriptome analyses have revealed differential expression of mRNAs, cellular diversity in translational profiles remains underinvestigated. By performing RNA-seq and Ribo-seq in genetically defined cells in the Drosophila brain, we here revealed substantial post-transcriptional regulations that augment the cell-type distinctions at the level of protein expression. Specifically, we found that translational efficiency of proteins fundamental to neuronal functions, such as ion channels and neurotransmitter receptors, was maintained low in glia, leading to their preferential translation in neurons. Notably, distribution of ribosome footprints on these mRNAs exhibited a remarkable bias toward the 5' leaders in glia. Using transgenic reporter strains, we provide evidence that the small upstream open-reading frames in the 5' leader confer selective translational suppression in glia. Overall, these findings underscore the profound impact of translational regulation in shaping the proteomics for cell-type distinction and provide new insights into the molecular mechanisms driving cell-type diversity.

Translational regulation enhances distinction of cell types in the nervous system

Multicellular organisms are composed of specialized cell types with distinct proteomes. While recent advances in single-cell transcriptome analyses have revealed differential expression of mRNAs, cellular diversity in translational profiles remains underinvestigated. By performing RNA-seq and Ribo-seq in genetically defined cells in the Drosophila brain, we here revealed substantial post-transcriptional regulations that augment the cell-type distinctions at the level of protein expression. Specifically, we found that translational efficiency of proteins fundamental to neuronal functions, such as ion channels and neurotransmitter receptors, was maintained low in glia, leading to their preferential translation in neurons. Notably, distribution of ribosome footprints on these mRNAs exhibited a remarkable bias toward the 5′ leaders in glia. Using transgenic reporter strains, we provide evidence that the small upstream open-reading frames in the 5’ leader confer selective translational suppression in glia. Overall, these findings underscore the profound impact of translational regulation in shaping the proteomics for cell-type distinction and provide new insights into the molecular mechanisms driving cell-type diversity.

Metabolic dialogues: regulators of chimeric antigen receptor Tcell function in the tumor microenvironment.

Tumor-infiltrating lymphocytes (TILs) and chimeric antigen receptor (CAR) Tcells have demonstrated remarkable success in the treatment of relapsed/refractory melanoma and hematological malignancies, respectively. These treatments have marked a pivotal shift in cancer management. However, as "living drugs," their effectiveness is dependent on their ability to proliferate and persist in patients. Recent studies indicate that the mechanisms regulating these crucial functions, as well as the Tcell's differentiation state, are conditioned by metabolic shifts and the distinct utilization of metabolic pathways. These metabolic shifts, conditioned by nutrient availability as well as cell surface expression of metabolite transporters, are coupled to signaling pathways and the epigenetic landscape of the cell, modulating transcriptional, translational, and post-translational profiles. In this review, we discuss the processes underlying the metabolic remodeling of activated Tcells, the impact of a tumor metabolic environment on Tcell function, and potential metabolic-based strategies to enhance Tcell immunotherapy.

Long-read Ribo-STAMP simultaneously measures transcription and translation with isoform resolution.

Transcription and translation are intertwined processes in which mRNA isoforms are crucial intermediaries. However, methodological limitations in analyzing translation at the mRNA isoform level have left gaps in our understanding of critical biological processes. To address these gaps, we developed an integrated computational and experimental framework called long-read Ribo-STAMP (LR-Ribo-STAMP) that capitalizes on advancements in long-read sequencing and RNA-base editing-mediated technologies to simultaneously profile translation and transcription at both the gene and mRNA isoform levels. We also developed the EditsC metric to quantify editing and leverage the single-molecule, full-length transcript information provided by long-read sequencing. Here, we report concordance between gene-level translation profiles obtained with long-read and short-read Ribo-STAMP. We show that LR-Ribo-STAMP successfully profiles translation of mRNA isoforms and links regulatory features, such as upstream open reading frames (uORFs), to translation measurements. We apply LR-Ribo-STAMP to discovering translational differences at both the gene and isoform levels in a triple-negative breast cancer cell line under normoxia and hypoxia and find that LR-Ribo-STAMP effectively delineates orthogonal transcriptional and translation shifts between conditions. We also discover regulatory elements that distinguish translational differences at the isoform level. We highlight GRK6, in which hypoxia is observed to increase expression and translation of a shorter mRNA isoform, giving rise to a truncated protein without the AGC Kinase domain. Overall, LR-Ribo-STAMP is an important advance in our repertoire of methods that measures mRNA translation with isoform sensitivity.

MDB-38. AN INTEGRATED MODEL FOR RESISTANCE TO BROMODOMAIN INHIBITORS IN CHILDHOOD MEDULLOBLASTOMA

Abstract BACKGROUND Bromodomain inhibitors (BETi) have emerged as a potential treatment option for children with medulloblastoma, where hyperactivation of gene transcription by the MYC and MYCN transcription factors may lead to a transcriptional dependency. Yet, drug resistance limits the utility of these agents when employed as a monotherapy. We therefore sought to identify mechanisms of BETi resistance that inform rational development of multimodal therapy options. METHODS We used CRISPR screening of D458 medulloblastoma cells that have acquired resistance to the JQ1 inhibitor. We subsequently used small molecule inhibition and knockdown experiments to validate Menin as a target. Finally, we used RNAseq, ribosome profiling, and mass spectrometry to characterize transcriptional and post-transcriptional changes in D458 cells compared to D458 with JQ1 resistance. RESULTS In the setting of BETi resistance, we observed dependency on key transcriptional actors, such as MLL (KMT2A) and the Mediator complex, which we are now validating in mini-pool experiments. We further characterized aberrant MLL complex function through knockdown, small molecule inhibition, and RNA-sequencing of Menin, a critical MLL cofactor. Next, we were surprised to observe ribosome and proteosome genes as CRISPR dependencies in our initial screening of BETi-resistant cells, suggesting post-transcriptional regulation. Indeed, MYC, whose transcription is potently blocked by BETi, remained robust at the protein level in BETi resistance. We therefore performed integrated transcriptional, translational, and proteomic profiling to characterize gene regulation in BETi-resistance. We found that the BETi-resistant state leads to an “uncoupling” of transcriptional and post-transcriptional regulation for a subset of genes, leading us to test small molecule inhibitors of post-transcriptional processes in BETi-resistant medulloblastoma. CONCLUSIONS Taken together, our data inform an integrated model of BETi resistance based on both transcriptional and post-transcriptional mechanisms, suggesting new therapeutic angles that may be effective in combination with BETi therapies.

Comprehensive translational profiling and STE AI uncover rapid control of protein biosynthesis during cell stress.

Translational control is important in all life, but it remains a challenge to accurately quantify. When ribosomes translate messenger (m)RNA into proteins, they attach to the mRNA in series, forming poly(ribo)somes, and can co-localize. Here, we computationally model new types of co-localized ribosomal complexes on mRNA and identify them using enhanced translation complex profile sequencing (eTCP-seq) based on rapid in vivo crosslinking. We detect long disome footprints outside regions of non-random elongation stalls and show these are linked to translation initiation and protein biosynthesis rates. We subject footprints of disomes and other translation complexes to artificial intelligence (AI) analysis and construct a new, accurate and self-normalized measure of translation, termed stochastic translation efficiency (STE). We then apply STE to investigate rapid changes to mRNA translation in yeast undergoing glucose depletion. Importantly, we show that, well beyond tagging elongation stalls, footprints of co-localized ribosomes provide rich insight into translational mechanisms, polysome dynamics and topology. STE AI ranks cellular mRNAs by absolute translation rates under given conditions, can assist in identifying its control elements and will facilitate the development of next-generation synthetic biology designs and mRNA-based therapeutics.

Abstract PO1-24-01: ADAR1 drives ribosomal biogenesis by regulating NOP14 and stabilizing FBL-NOP58 complex in breast cancer

Abstract Background Breast cancer (BC) has been widely accepted as a highly heterogeneous disease. Transcriptional and translational dysregulation is commonly found in BC patients. Adenosine-to-inosine (A-to-I) editing on RNA is the most abundant RNA editing form in human, mediated mainly by ADARs. Though the role of ADAR1 in RNA editing and immune response has been deeply investigated, the change of the translational profile and the biology sequalae after base editing are still unclear. In this study, we uncovered a previously unknown role of ADAR1 in the regulation of ribosome biosynthesis and translational dysregulation in BC cells. Method RNA-seq was used for gene set enrichment analysis (GSEA) and A-to-I editing analysis. Transmission electron microscopy (TEM) was conducted to visualize the nucleolar architecture. Nuclear rRNA abundances of 18S and 28S rRNAs were monitored using Qsep100. Ribosomal fractions were isolated with a Beckman SW41Ti rotor and quantified on a 2100 Bioanalyzer. 3' Untranslated region (3′UTR) reporter construction and dual-luciferase reporter assay were used to validate the correlation. In-vitro transcription, RNA pull-down assay and sanger sequencing were used to directly confirm the direct interaction and A-to-I editing status. Cell proliferation, migration assay, apoptosis assay in vitro and xenograft mouse model in vivo were performed for phenotype study. Co-immunoprecipitation (Co-IP) was used to identify the interactive protein. Immunofluorescence (IF) assay was applied to indicate the co-localization. Immunohistochemistry (IHC) staining was applied to tissue microarrays and assess of expression. Survival analysis was made by Kaplan-Meier method. RNA polymerase I inhibitor CX-5461 was used for treatment. Result Through bioinformatic analysis with RNA-seq data from cell lines and clinical samples, we found the expression of ADAR1 was correlated with signatures of ribosomes. Consistently, BC cells with overexpression of ADAR1 showed larger nucleoli and contained more 18S and 28S rRNAs. To uncover the potential ribosomal genes involved in this process, we analyzed the transcriptional profile of 88 BC samples in combination with ADAR1 editing profiles identified by comparing ADAR1-null and control cells. Nucleolar Protein 14 (NOP14), a nucleolar ribosome biogenesis gene, was found to be hyper-edited. Phenotype experiments revealed that NOP14 promotes tumor growth and invasion in vitro and in vivo. The RNA and protein level of NOP14 is regulated by ADAR1 through A-to-I editase activity. Mechanically, ADAR1 binds directly with NOP14 transcripts in the 3’UTR region through Sanger sequencing and RNA-pull down. The binding region of NOP14 with ADAR1 was also a target of miR-939-3p, while the ADAR1 mediated-editing led to less binding of miR-939-3p with NOP14 and resulted in NOP14 up-regulation. Notably, NOP14 facilitates the assembly of the box C/D small nucleolar ribonucleoprotein (snoRNP) and stabilize the interaction of fibrillarin (FBL)-nucleolar Protein 58 (NOP58) with this complex. Loss of NOP14 impaired the nucleolar distribution of FBL and the abundance of ribosomes. CX-5461, an RNA polymerase I inhibitor, suppressed the overexpression of ribosomes in ADAR1 high cells and displayed a strong inhibition efficacy on tumor growth both in vitro and in vivo. Conclusion Taken together, these results shed light on the role of ADAR1 in ribosomal biogenesis in breast cancer. The promising results also provide potential targets in BCs with high ADAR1 by suppressing translational dysregulation. Citation Format: Liren Wangxu, Hengyu Ren, Zhibo Shao, Jiong Wu, Yayun Chi. ADAR1 drives ribosomal biogenesis by regulating NOP14 and stabilizing FBL-NOP58 complex in breast cancer [abstract]. In: Proceedings of the 2023 San Antonio Breast Cancer Symposium; 2023 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2024;84(9 Suppl):Abstract nr PO1-24-01.

Effect of Adipose Biopsy Technique on Inflammatory Markers in Adipose Tissue

Objectives: The purpose of this study was to compare adipose tissue (AT) biomarkers obtained from the Bergström and Mercedes biopsy techniques in healthy, recreationally active adults. Hypotheses: There would be no difference in expression of inflammatory and adipokine genes of interest between techniques. There would be no difference in the concentration of inflammatory cytokine levels between techniques. Methods: Basal abdominal subcutaneous AT was obtained from 12 (8M, 4F; 28±4 y; 86±8 kg; BMI 26.8±2.9 kg/m2; body fat 29±8%; VO2max 3.4±0.7 L/min) healthy, recreationally active adults (i.e., regular aerobic and/or resistance exercise 3-5 days/wk) on contralateral sides of the umbilicus via Bergström and Mercedes biopsy techniques. Inflammatory and adipokine gene expression levels (IL1β, IL6, IL8, IL10, TNFα, ADIPOQ, LEPD) were measured in AT (n=8) via qPCR. Inflammatory cytokine concentrations (GM-CSF, IFNγ, IL1β, IL2, IL5, IL6, IL8, IL12p70, IL17A, IL23, TNFα, IL4, IL10, IL13) were measured in AT (n=11) via high sensitivity discovery assay. Results: There were no differences in inflammatory nor adipokine gene expression between AT biopsy techniques (P>0.05). Of the measurable cytokines (GM-CSF, IFNγ, IL8, IL17A, IL13), there were no differences between Bergström and Mercedes AT (P>0.05). Average tissue yield for the Mercedes biopsy was greater than the Bergström biopsy (1007±625 mg vs. 291±83 mg, respectively; p<0.05). Conclusions: The analyses performed in this study suggest AT collected from Bergström and Mercedes techniques provide high-quality RNA (RNA integrity numbers >7.0) and protein with comparable basal transcriptional and translational profiles. Both techniques may be utilized in the collection of AT; however, research questions may impact the technique chosen as the Mercedes biopsy technique obtains larger tissue yields whereas the Bergström technique may allow for an increased number of biopsies due to the smaller abdominal area impacted. This research was supported by the Human Bioenergetics program at Ball State University. This is the full abstract presented at the American Physiology Summit 2024 meeting and is only available in HTML format. There are no additional versions or additional content available for this abstract. Physiology was not involved in the peer review process.

Importance of the ECM-receptor interaction for adaptive response to hypoxia based on integrated transcription and translation analysis.

Low dissolved oxygen (LO) conditions represent a major environmental challenge to marine life, especially benthic animals. For these organisms, drastic declines in oxygen availability (hypoxic events) can trigger mass mortality events and thus, act as agents of selection influencing the evolution of adaptations. In sea cucumbers, one of the most successful groups of benthic invertebrates, the exposure to hypoxic conditions triggers adaptive adjustments in metabolic rates and behaviour. It is unclear, however, how these adaptive responses are regulated and the genetic mechanisms underpinning them. Here, we addressed this knowledge gap by assessing the genetic regulation (transcription and translation) of hypoxia exposure in the sea cucumber Apostichopus japonicus. Transcriptional and translational gene expression profiles under short- and long-term exposure to low oxygen conditions are tightly associated with extracellular matrix (ECM)-receptor interaction in which laminin and collagen likely have important functions. Finding revealed that genes with a high translational efficiency (TE) had a relatively short upstream open reading frame (uORF) and a high uORF normalized minimal free energy, suggesting that sea cucumbers may respond to hypoxic stress via altered TE. These results provide valuable insights into the regulatory mechanisms that confer adaptive capacity to holothurians to survive oxygen deficiency conditions and may also be used to inform the development of strategies for mitigating the harmful effects of hypoxia on other marine invertebrates facing similar challenges.

Abstract 3798: Advancements in multiplexed spatial phenotyping

Abstract Spatial omics is an expanding research area focused on integrating spatial knowledge of tissue with transcriptomics (RNA) and proteomics (protein). Understanding the complexity of the biological structure(s) is an important biological process in cancer immunotherapy research which requires accurate target classification. Translational profiling of 4+ targets on a single sample at one time can be difficult in many ways, such as, panel design, staining protocols, and data analysis. Furthermore, to design a reliable multi-target biomarker panel, there are many parts to overcome, such as protein abundance and localization, fluorophore compatibility, varying tissue types, and data characterization, to name a few. To address the needs of high target multiplex ability, labeling methods have advanced in cyclic detection enabling iterative labeling and detection using automated fluidics, however these approaches suffer from low simultaneous target throughput. Thermo Fisher Scientific can now provide a streamline process for tissue labelling; a process that enables sufficient labelling of high multiplexed panels completed within a couple of hours. We show successful detection of a wide range of various protein markers across numerous tissue organs used in various biological research applications with our uniform technique of labelling. Citation Format: Leticia Montoya, Scott Clarke, Austin Harvey, Jen Serafin, Mae Voeun. Advancements in multiplexed spatial phenotyping [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3798.

Control of poly(A)-tail length and translation in vertebrate oocytes and early embryos

During oocyte maturation and early embryogenesis, changes in mRNA poly(A)-tail lengths strongly influence translation, but how these tail-length changes are orchestrated has been unclear. Here, we performed tail-length and translational profiling of mRNA reporter libraries (each with millions of 3' UTR sequence variants) in frog oocytes and embryos and in fish embryos. Contrasting to previously proposed cytoplasmic polyadenylation elements (CPEs), we found that a shorter element, UUUUA, together with the polyadenylation signal (PAS), specify cytoplasmic polyadenylation, and we identified contextual features that modulate the activity of both elements. In maturing oocytes, this tail lengthening occurs against a backdrop of global deadenylation and the action of C-rich elements that specify tail-length-independent translational repression. In embryos, cytoplasmic polyadenylation becomes more permissive, and additional elements specify waves of stage-specific deadenylation. Together, these findings largely explain the complex tapestry of tail-length changes observed in early frog and fish development, with strong evidence of conservation in both mice and humans.

On the simulations of micromagnetorotation (MMR) effects within micropolar conducting liquids

ABSTRACT In this paper, the MMR effect on boundary layer flow characteristics within magneto-micropolar liquids is investigated. To date, magnetization was supposed to be parallel to applied magnetic field and consequently, its impact on the flow was neglected in almost all studies present in the literature. In this contribution, the theory of conducting micropolar liquids is employed to derive an initial-boundary-value problem (IBVP) with the presence of MMR effect. The obtained problem is implemented and analysed through MATLAB. It is observed that the skin-friction coefficient is reduced with the consideration of MMR effect. The relative difference in the skin-friction coefficient increases with increase in magnetization and is found approximately in the range 14.4% to 16.27%. In the absence of micro-inertia the micro-rotational and translational velocity profiles are decreased with increasing MMR effect. The obtained results evince that MMR effect, which has been neglected in earlier investigations, should be taken into account while investigating biomedical magnetized processes, polymer processing, spreading of thin films in coating and printing industry and other related industrial solutions through magnetic-micropolar framework. Moreover, it is worth mentioning that the applications of magnetic micropolar liquids in heat absorption process through solar panels has potential applications in harnessing ambient energy.