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The hippocampus is important for social behavior and exhibits unusual structural plasticity in the form of continued production of new granule neurons throughout adulthood, but it is unclear how adult neurogenesis contributes to social interactions. In the present study, we suppressed neurogenesis using a pharmacogenetic mouse model and examined social investigation and aggression in adult male mice to investigate the role of hippocampal adult-born neurons in the expression of aggressive behavior. In simultaneous choice tests with stimulus mice placed in corrals, mice with complete suppression of adult neurogenesis in adulthood (TK mice) exhibited normal social investigation behaviors, indicating that new neurons are not required for social interest, social memory, or detection of and response to social olfactory signals. However, mice with suppressed neurogenesis displayed decreased offensive and defensive aggression in a resident-intruder paradigm, and less resistance in a social dominance test, relative to neurogenesis-intact controls, when paired with weight and strain-matched (CD-1) mice. During aggression tests, TK mice were frequently attacked by the CD-1 intruder mice, which never occurred with WTs, and normal CD-1 male mice investigated TK mice less than controls when corralled in the social investigation test. Importantly, TK mice showed normal aggression toward prey (crickets) and smaller, nonaggressive (olfactory bulbectomized) C57BL/6J intruders, suggesting that mice lacking adult neurogenesis do not avoid aggressive social interactions if they are much larger than their opponent and will clearly win. Taken together, our findings show that adult hippocampal neurogenesis plays an important role in the instigation of intermale aggression, possibly by weighting a cost-benefit analysis against confrontation in cases where the outcome of the fight is not clear., (Published 2024. This article is a U.S. Government work and is in the public domain in the USA. Hippocampus published by Wiley Periodicals LLC.)

Impaired control of the G1/S checkpoint allows initiation of DNA replication under non-permissive conditions. Unscheduled S-phase entry is associated with DNA replication stress, demanding for other checkpoints or cellular pathways to maintain proliferation. Here, we uncovered a requirement for ADARp150 to sustain proliferation of G1/S-checkpoint-defective cells under growth-restricting conditions. Besides its well-established mRNA editing function in inversely oriented short interspersed nuclear elements (SINEs), we found ADARp150 to exert a critical function in mitosis. ADARp150 depletion resulted in tetraploidization, impeding cell proliferation in mitogen-deprived conditions. Mechanistically we show that ADAR1 depletion induced aberrant expression of Cyclin B3, which was causative for mitotic failure and whole-genome duplication. Finally, we find that also in vivo ADAR1-depletion-provoked tetraploidization hampers tumor outgrowth., (© The Author(s) 2024. Published by Oxford University Press on behalf of Nucleic Acids Research.)

The selection of appropriate defensive behaviors in the face of potential threat is fundamental to survival. However, after repeated exposures to threatening stimuli that did not signal real danger, an animal must learn to adjust and optimize defensive behaviors. Despite extensive research on innate threat processing, little is known how individuals change their defensive behaviors when presented with recurrent threat exposures without evidence of a real risk. Insight into this process is critical as its dysregulation may contribute to neuropsychiatric conditions, such as anxiety disorders. Here, we used the visual looming stimulus (VLS) paradigm in mice to investigate innate threat processing and adaptive defensive learning. Repeated exposure to VLS over consecutive sessions reduced immediate freezing responses and time spent inside a sheltered area upon VLS events, leading to an increase in foraging behaviors. Fiber photometry recordings and optogenetic manipulations revealed that VLS innate adaptive defensive learning is associated with reduced recruitment of the midbrain interpeduncular nucleus (IPN), a structure associated with fear and anxiety-related behaviors. Functional circuit-mapping identified a role for select IPN projections to the laterodorsal tegmental nucleus in gating defensive learning. Finally, we uncovered a subpopulation of IPN neurons that express the neuropeptide somatostatin and encode safety- and avoidance signals in response to VLS. These results identify critical behavioral signatures of innate defensive responses and a circuit that regulates the essential features of threat processing.

Background: With advancements in CF drug development, people with cystic fibrosis (PwCF) now take a median of seven medications daily, increasing treatment complexity, risk of drug therapy problems (DTPs), and interference with treatment goals. Given that some of these DTPs can be prevented with preemptive pharmacogenetic testing, the overall goal of this study was to test the clinical utility of a multi-gene pharmacogenetics (PGx) panel in potentially reducing DTPs in PwCF., Methods: A population based retrospective study of patients with CF was conducted at the University of Utah Health Care System. The patients were genotyped for CYP450 enzymes using a pharmacogenomic assay, and their drug utilization information was obtained retrospectively. This pharmacogenomic information was combined with clinical guidelines to predict the number of actionable PGx interventions in this patient cohort., Results: A total of 52 patients were included in this study. In the patient sample, a minimum of one order of actionable PGx medication was observed in 75 % of the cases. Results revealed that 4.2 treatment modifications per 10 patients can be enabled with the help of a PGx intervention in this patient population. Additionally, our findings suggest that polymorphisms in CYP2D6 and CYP2C19 are most likely to be the primary contributors to DTP's within PwCF., Conclusion: This study provides evidence that the PGx panel has the potential to help alleviate the clinical burden of DTPs in PwCF and can assist in informing pharmacotherapy recommendations. Future research should validate these findings and evaluate which subgroups of PwCF would most benefit from pharmacogenetic testing., Competing Interests: Declaration of competing interest Anindit Chhibber reports no potential conflict of interest. Hollyann Jacobs reports no potential conflict of interest. Alexandre Hikiji Watanabe reports no potential conflict of interest. Aditi Kharat reports no potential conflict of interest. Sakil M. Syeed reports no potential conflict of interest. Catherine M. Sherwin reports no potential conflict of interest. Nathorn Chaiyakunapruk reports no potential conflict of interest. Joseph Biskupiak reports no potential conflict of interest. Venkata K. Yellepeddi reports no potential conflict of interest. Diana Brixner reports no potential conflict of interest. David C. Young reports no potential conflict of interest., (Copyright © 2024 European Cystic Fibrosis Society. Published by Elsevier B.V. All rights reserved.)

Cellulose nanofibril-silver (CNF-Ag) hybrid and ultralight silver-infused aerogel were produced using cotton gin trash (CGT), an abundant agro-waste material. This repurposing of CGT was achieved by exploiting its potential for CNF extraction and the in situ synthesis of silver nanoparticles (Ag NPs). CNFs were extracted from CGT through a mechanical shearing process. These CNFs served as a multifunctional nanotemplate for the controlled reduction of Ag ions, efficient nucleation, and stabilization of NPs, resulting in the production of a high concentration of Ag NPs (ca. 19 wt %) within the CNFs. Transmission electron microscopy images of cross-sectioned CNFs confirmed the uniform dispersion of NPs (ca. 18 nm diameter) inside the CNFs. Rietveld refinement analysis of X-ray diffraction patterns revealed that CNFs produced smaller Ag crystallites compared to CGT microparticles. The CNF-Ag hybrid was then fabricated into an aerogel using freeze-drying, with its weight being light enough to rest on a cotton flower's stamen. The infusion of Ag NPs led to approximately 20% reductions in the specific surface area and pore volume of the aerogel., Competing Interests: The authors declare no competing financial interest., (© 2024 The Authors. Published by American Chemical Society.)

Fanconi anemia (FA) is a rare hereditary disease resulting from an inactivating mutation in the FA/BRCA pathway, critical for the effective repair of DNA interstrand crosslinks (ICLs). The disease is characterized by congenital abnormalities, progressing bone marrow failure, and an increased risk of developing malignancies early in life, in particular head and neck squamous cell carcinoma (HNSCC). While ICL-inducing cisplatin combined with radiotherapy is a mainstay of HNSCC treatment, cisplatin is contra-indicated for FA-HNSCC patients. This dilemma necessitates the identification of novel treatment modalities tolerated by FA-HNSCC patients. To identify druggable targets, an siRNA-based genetic screen was previously performed in HNSCC-derived cell lines from FA and non-FA tumor origin. Here, we report that the Ribonucleotide Reductase (RNR) complex, consisting of the RRM1 and RRM2 subunits, was identified as a therapeutic target for both, FA and non-FA HNSCC. While non-FA HNSCC cells responded differentially to RNR depletion, FA-HNSCC cells were consistently found hypersensitive. This insight was confirmed pharmacologically using 2', 2'-difluoro 2'deoxycytidine (dFdC), also known as gemcitabine, a clinically used nucleotide analog that is a potent inhibitor of the RNR complex. Importantly, while cisplatin exposure displayed severe, long-lasting toxicity on the hematopoietic stem and progenitor compartments in Fancg-/- mice, gemcitabine was well tolerated and had only a mild, transient impact. Taken together, our data implicate that gemcitabine-based chemoradiotherapy could serve as an alternative HNSCC treatment in Fanconi patients, and deserves clinical testing., (© 2024. The Author(s).)

The Fanconi anemia (FA) repair pathway governs repair of highly genotoxic DNA interstrand crosslinks (ICLs) and relies on translesion synthesis (TLS). TLS is facilitated by REV1 or site-specific monoubiquitination of proliferating cell nuclear antigen (PCNA) (PCNA-Ub) at lysine 164 (K164). A Pcna K164R/K164R but not Rev1 -/- mutation renders mammals hypersensitive to ICLs. Besides the FA pathway, alternative pathways have been associated with ICL repair (1, 2), though the decision making between those remains elusive. To study the dependence and relevance of PCNA-Ub in FA repair, we intercrossed Pcna K164R/+ ; Fancg -/+ mice. A combined mutation ( Pcna K164R/K164R ; Fancg -/- ) was found embryonically lethal. RNA-seq of primary double-mutant (DM) mouse embryonic fibroblasts (MEFs) revealed elevated levels of replication stress-induced checkpoints. To exclude stress-induced confounders, we utilized a Trp53 knock-down to obtain a model to study ICL repair in depth. Regarding ICL-induced cell toxicity, cell cycle arrest, and replication fork progression, single-mutant and DM MEFs were found equally sensitive, establishing PCNA-Ub to be critical for FA-ICL repair. Immunoprecipitation and spectrometry-based analysis revealed an unknown role of PCNA-Ub in excluding mismatch recognition complex MSH2/MSH6 from being recruited to ICLs. In conclusion, our results uncovered a dual function of PCNA-Ub in ICL repair, i.e. exclude MSH2/MSH6 recruitment to channel the ICL toward canonical FA repair, in addition to its established role in coordinating TLS opposite the unhooked ICL., (© The Author(s) 2024. Published by Oxford University Press on behalf of National Academy of Sciences.)

Background: People with cystic fibrosis (PwCF) are frequently hospitalized for treatment of pulmonary exacerbation. The Cystic Fibrosis Foundation Pulmonary Guidelines support the use of intravenous aminoglycosides with therapeutic drug monitoring for the treatment of pulmonary exacerbation due to Pseudomonas aeruginosa. Serum intravenous tobramycin concentrations are commonly collected by peripheral venipuncture (PV). Discomfort associated with collection of samples by PV prompts collection via PICC, but the accuracy of intravenous tobramycin serum levels collected by PICC has not been documented in adult PwCF. The primary study objective was to evaluate the difference between intravenous tobramycin serum levels collected by PV and PICC in adult PwCF., Methods: The authors conducted a prospective case-control study of adult PwCF admitted to University of Utah Health for a pulmonary exacerbation receiving tobramycin by a single lumen PICC. The authors compared tobramycin peak and random serum levels collected by PV and PICC using a detailed flush and waste protocol., Results: The authors analyzed a total of 19 patients with peripheral and PICC samples. The mean tobramycin peak collected by PV (27.2 mcg/mL) was similar to the mean peak collected by PICC (26.9 mcg/mL) (paired samples Wilcoxon signed-rank test, p = .94). The correlation coefficient was 0.88 (95% CI = 0.85-0.91, p < .001)., Conclusion: Tobramycin serum samples collected by PICC appear to be similar in value to PV collections. Collecting aminoglycoside levels by PICC rather than PV may reduce patient discomfort and improve quality of life. Additional multicenter studies are needed to confirm these results., (© 2024 The Authors. Pediatric Pulmonology published by Wiley Periodicals LLC.)

CD4 + T cells can "help" or "license" conventional type 1 dendritic cells (cDC1s) to induce CD8 + cytotoxic T lymphocyte (CTL) anticancer responses, as proven in mouse models. We recently identified cDC1s with a transcriptomic imprint of CD4 + T-cell help, specifically in T-cell-infiltrated human cancers, and these cells were associated with a good prognosis and response to PD-1-targeting immunotherapy. Here, we delineate the mechanism of cDC1 licensing by CD4 + T cells in humans. Activated CD4 + T cells produce IFNβ via the STING pathway, which promotes MHC-I antigen (cross-)presentation by cDC1s and thereby improves their ability to induce CTL anticancer responses. In cooperation with CD40 ligand (L), IFNβ also optimizes the costimulatory and other functions of cDC1s required for CTL response induction. IFN-I-producing CD4 + T cells are present in diverse T-cell-infiltrated cancers and likely deliver "help" signals to CTLs locally, according to their transcriptomic profile and colocalization with "helped/licensed" cDCs and tumor-reactive CD8 + T cells. In agreement with this scenario, the presence of IFN-I-producing CD4 + T cells in the TME is associated with overall survival and the response to PD-1 checkpoint blockade in cancer patients., (© 2024. The Author(s).)