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Epstein-Barr virus nuclear antigen 1 (EBNA1) contains two arginine-glycine (RG) repeats that contain symmetric/asymmetric dimethylarginine (SDMA/ADMA) and monomethylarginine (MMA) residues. We generated mouse monoclonal antibodies directed against a monomethylated GRGRGG-containing repeat located between amino acids 328 and 377 of EBNA1. In addition to detecting MMA-modified EBNA1, we also had the goal of identifying cellular proteins that bind to MMA-modified EBNA1 in EBV-positive Raji cells. Furthermore, we hypothesized that antibodies against MMA-modified EBNA1 might also recognize cell factors that use an MMA-modified surface structure similar to that of EBNA1 to bind to their common targets. Using a combination of immunoprecipitation and mass spectrometry, we identified a number of such cellular proteins, including SNRPD1-3, ALY/REF, RPS15, DIDO1, LSM12, LSM14A, DAP3, and CPSF1. An NACA complex protein that was shown previously to bind to the glycine-alanine repeat of EBNA1 was also identified. The proteins identified in this study are involved in splicing, tumorigenesis, transcriptional activation, DNA stability, and RNA processing or export., (© 2024. The Author(s).)

Imaging plays a crucial role in the immediate evaluation of the trauma patient, particularly using multi-detector computed tomography (CT), and especially in moderately to severely injured trauma patients. There are specific areas of relative consensus, while other aspects of whole-body computed tomography (WB-CT) use remain controversial and are subject to opinion/debate based on the current literature. Even a few hours of a delayed diagnosis may result in a detrimental outcome for the patient. One must utilize all the tools available to enhance the interpretation of images. It is also important to recognize imaging pitfalls and artifacts to avoid unnecessary intervention., Competing Interests: Disclosure All authors certify they have no competing interests to declare relevant to this manuscript's content., (Copyright © 2024 Elsevier Inc. All rights reserved.)

The alpha7 nicotinic acetylcholine receptor (α7 nAChR; CHRNA7) is expressed in the nervous system and in non-neuronal tissues. Within the central nervous system, it is involved in various cognitive and sensory processes such as learning, attention, and memory. It is also expressed in the cerebellum, where its roles are; however, not as well understood as in the other brain regions. To investigate the consequences of absence of CHRNA7 on the cerebellum proteome, we performed a quantitative nano-LC-MS/MS analysis of samples from CHRNA7 knockout (KO) mice and corresponding wild type (WT) controls. Liver, an organ which does not express this receptor, was analyzed, in comparison. While the liver proteome remained relatively unaltered (three proteins more abundant in KOs), 90 more and 20 less abundant proteins were detected in the cerebellum proteome of the KO mice. The gene ontology analysis of the differentially abundant proteins indicates that the absence of CHRNA7 leads to alterations in the glutamatergic system and myelin sheath in the cerebellum. In conclusion, our dataset provides new insights in the role of CHRNA7 in the cerebellum, which may serve as a basis for future in depth-investigations., (© 2024 The Authors. PROTEOMICS published by Wiley‐VCH GmbH.)

Reactive aldehydes are abundant endogenous metabolites that challenge homeostasis by crosslinking cellular macromolecules. Aldehyde-induced DNA damage requires repair to prevent cancer and premature aging, but it is unknown whether cells also possess mechanisms that resolve aldehyde-induced RNA lesions. Here, we establish photoactivatable ribonucleoside-enhanced crosslinking (PAR-CL) as a model system to study RNA crosslinking damage in the absence of confounding DNA damage in human cells. We find that such RNA damage causes translation stress by stalling elongating ribosomes, which leads to collisions with trailing ribosomes and activation of multiple stress response pathways. Moreover, we discovered a translation-coupled quality control mechanism that resolves covalent RNA-protein crosslinks. Collisions between translating ribosomes and crosslinked mRNA-binding proteins trigger their modification with atypical K6- and K48-linked ubiquitin chains. Ubiquitylation requires the E3 ligase RNF14 and leads to proteasomal degradation of the protein adduct. Our findings identify RNA lesion-induced translational stress as a central component of crosslinking damage., Competing Interests: Declaration of interests R.G. is a member of the scientific advisory board at the journal Molecular Cell., (Copyright © 2023 The Author(s). Published by Elsevier Inc. All rights reserved.)

The cation channel 'transient receptor potential vanilloid 2' (TRPV2) is activated by a broad spectrum of stimuli, including mechanical stretch, endogenous and exogenous chemical compounds, hormones, growth factors, reactive oxygen species, and cannabinoids. TRPV2 is known to be involved in inflammatory and immunological processes, which are also of relevance in the ovary. Yet, neither the presence nor possible roles of TRPV2 in the ovary have been investigated. Data mining indicated expression, for example, in granulosa cells (GCs) of the human ovary in situ, which was retained in cultured GCs derived from patients undergoing medical reproductive procedures. We performed immunohistochemistry of human and rhesus monkey ovarian sections and then cellular studies in cultured GCs, employing the preferential TRPV2 agonist cannabidiol (CBD). Immunohistochemistry showed TRPV2 staining in GCs of large antral follicles and corpus luteum but also in theca, endothelial, and stromal cells. TRPV2 transcript and protein levels increased upon administration of hCG or forskolin. Acutely, application of the agonist CBD elicited transient Ca2+ fluxes, which was followed by the production and secretion of several inflammatory factors, especially COX2, IL6, IL8, and PTX3, in a time- and dose-dependent manner. CBD interfered with progesterone synthesis and altered both the proteome and secretome, as revealed by a proteomic study. While studies are somewhat hampered by the lack of highly specific TRPV2 agonist or antagonists, the results pinpoint TRPV2 as a modulator of inflammation with possible roles in human ovarian (patho-)physiology. Finally, as TRPV2 is activated by cannabinoids, their possible ovarian actions should be further evaluated., (© The Author(s) 2023. Published by Oxford University Press on behalf of European Society of Human Reproduction and Embryology. All rights reserved. For permissions, please email: journals.permissions@oup.com.)

In Brief: Nicotinic acetylcholine receptor alpha 7 (nAChRa7), encoded by Chrna7, is expressed by various murine ovarian cells. Morphological and molecular investigations, including a proteomic study of adult Chrna7 knockout (KO) mouse ovaries, reveal the roles of these receptors in the local regulation of the ovary., Abstract: Nicotinic acetylcholine receptor alpha 7 (nAChRa7), encoded by Chrna7, is involved in cellular functions ranging from synaptic transmission in neurons to regulation of inflammation, cell growth and metabolism to cell death in other cells. Our qPCR results and other studies indicated that nAChRa7 is expressed in the adult mouse ovary, while in situ hybridization and single-cell sequencing data suggested this expression may be shared by several ovarian cells, including fibroblast-like and steroidogenic stroma cells, macrophages and oocytes of small follicles. To explore a possible involvement of nAChRa7 in ovarian functions, we evaluated ovarian morphology of Chrna7-null mutant adult mice (KO) and wildtype mice (WT; 3 months, metestrus) by performing immunohistochemistry, qPCR studies, measurements of serum progesterone and proteomic analyses. The evaluation of serial sections indicated fewer primordial follicles but similar numbers of primary, secondary and tertiary follicles, as well as corpora lutea in KO and WT mice. Atresia was unchanged. Serum progesterone and mRNA levels of proliferation and most apoptosis markers were not changed, yet two typical macrophage markers were elevated. Furthermore, the proteomes of KO ovaries were significantly altered with 96 proteins increased and 32 decreased in abundance in KOs compared to WTs. Among the elevated proteins were markers for stroma cells. Hence, the lack of nAChRa7 causes changes in small follicle counts and alterations of the ovarian stroma cells. The ovarian phenotype of Chrna7 mutant mice links this channel protein to the local regulation of ovarian cells, including stroma cells.

Background: As microRNA-142 (miR-142) is the only human microRNA gene where mutations have consistently been found in about 20% of all cases of diffuse large B-cell lymphoma (DLBCL), we wanted to determine the impact of miR-142 inactivation on protein expression of DLBCL cell lines., Methods: miR-142 was deleted by CRISPR/Cas9 knockout in cell lines from DLBCL., Results: By proteome analyses, miR-142 knockout resulted in a consistent up-regulation of 52 but also down-regulation of 41 proteins in GC-DLBCL lines BJAB and SUDHL4. Various mitochondrial ribosomal proteins were up-regulated in line with their pro-tumorigenic properties, while proteins necessary for MHC-I presentation were down-regulated in accordance with the finding that miR-142 knockout mice have a defective immune response. CFL2, CLIC4, STAU1, and TWF1 are known targets of miR-142, and we could additionally confirm AKT1S1, CCNB1, LIMA1, and TFRC as new targets of miR-142-3p or -5p., Conclusions: Seed-sequence mutants of miR-142 confirmed potential targets and novel targets of miRNAs can be identified in miRNA knockout cell lines. Due to the complex contribution of miRNAs within cellular regulatory networks, in particular when miRNAs highly present in RISC complexes are replaced by other miRNAs, primary effects on gene expression may be covered by secondary layers of regulation.

Penetrating injuries account for a large percentage of visits to emergency departments and trauma centers worldwide. Emergency laparotomy is the accepted standard of care in patients with a penetrating torso injury who are not hemodynamically stable and have a clinical indication for exploratory laparotomy, such as evisceration or gastrointestinal bleeding. Continuous advances in technology have made computed tomography (CT) an indispensable tool in the evaluation of many patients who are hemodynamically stable, have no clinical indication for exploratory laparotomy, and are candidates for conservative treatment. Multidetector CT may depict the trajectory of a penetrating injury and help determine what type of intervention is necessary on the basis of findings such as active arterial extravasation and major vascular, hollow viscus, or diaphragmatic injuries. Because multidetector CT plays an increasing role in the evaluation of patients with penetrating wounds to the torso, the radiologists who interpret these studies should be familiar with the CT findings that mandate intervention.