Voluntary Wheel Running an Effective Intervention in the Management of Excessive Food Usage in CD-1 Mice (Mus musculus).

Some mice demonstrate excessive food-grinding behaviors in which food pellets are broken down into crumbs (orts). This is considered abnormal behavior and is undesirable in a research environment, as it is thought to potentially be a stereotypic behavior suggestive of a negative welfare state in these animals. Further, food grinding often necessitates more frequent food and bedding changes. Research outcomes may also be affected if investigators do not exclude food losses due to grinding when measuring food consumption. We hypothesized some mice may excessively grind food in part to expend energy and access to a running wheel would contribute to a reduction in food grinding. Total daily food usage (the combined weight of food consumption and ort production) was measured for 40 d in CD-1 mice that exhibited food grinding. Median daily food usage was compared 10 d before, 20 d during, and 10 d after access to a running wheel. Additional cages of similar food-grinding mice that did not have access to a running wheel were monitored during the same period for comparison. A significant reduction in food usage was observed in 8 out of the 20 d in which mice had access to a running wheel compared with controls (P < 0.05). This reduction was significantly less than the median daily food usage before and after the running wheels were available (P < 0.01). Food usage significantly increased sharply in the 3 d following removal of the running wheel compared with controls during the same period (P < 0.05). A positive correlation between relative humidity and median daily food usage was observed (P < 0.05). Despite fluctuations in relative humidity, providing a running wheel effectively reduced excessive food-grinding behavior.

A Retrospective Analysis of Liraglutide (GLP-1 Agonist) Use in a Chinchilla (Chinchilla lanigera) Model of Auditory Blast Injury.

Chinchillas are a relatively novel research model compared with other rodent species. They require special considerations when it comes to their husbandry and daily care. Chinchillas tend to be shy animals that are well adapted to masking clinical signs of illness. These characteristics can make them a difficult species to maintain in a research setting. The authors' institution has maintained chinchillas and established standardized daily animal care procedures for them. Chinchillas are most commonly used for auditory research. They are often used to study the mechanism of different induced auditory conditions or injuries as well as exploration for potential alleviating treatments. Often, tested therapeutics have demonstrated potentially beneficial effects but have not been applied in the specific condition or injury of interest. The development of new applications for therapeutics can lead to groundbreaking discoveries, but testing of new therapeutic applications is often initially performed in an animal model without knowing how the therapeutic will behave in the species. During testing, unexpected adverse events may manifest that require more focused monitoring and supportive care. This scenario occurred when adverse effects were observed in a chinchilla blast-injury model after receiving an acylated glucagon-like peptide-1 (GLP-1) receptor agonist. The study involved evaluation of this therapeutic over an extended amount of time after inducing a controlled pressurized blast-injury followed by multiple repeated hearing tests under anesthesia. Chinchillas enrolled in the study exhibited several clinical signs including weight loss, lethargy, labored breathing, neurologic abnormalities, decreased appetite or decreased fecal output, and otitis. Five primary abnormalities were reported on pathology: aspiration pneumonia, hepatic steatosis, right ventricular dilation, pancreatitis, and tubulointerstitial nephritis. Initially abnormal clinical signs, early mortality rates, and pathology were attributed to multiple anesthetic events. However, a retrospective analysis evaluating the association of different study variable exposures in a stratified comparison demonstrated that the early mortality rates were actually associated with the therapeutic drug given for the first time in this species. In this study, we describe the detailed findings of the retrospective analysis and explore different strategies that can be incorporated to maintain good animal welfare and decrease early animal loss.

Corrigendum: Sex differences in the genetics of sarcoidosis across European and African ancestry populations.

[This corrects the article DOI: 10.3389/fmed.2023.1132799.].

TRAF7 is an essential regulator of blood vessel integrity during mouse embryonic and neonatal development.

Targeted deletion of TRAF7 revealed that it is a crucial part of shear stress-responsive MEKK3-MEK5-ERK5 signaling pathway induced in endothelial cells by blood flow. Similar to Mekk3-, Mek5- or Erk5-deficient mice, Traf7-deficient embryos died in utero around midgestation due to impaired endothelium integrity. They displayed significantly lower expression of transcription factor Klf2, an essential regulator of vascular hemodynamic forces downstream of the MEKK3-MEK-ERK5 signaling pathway. In addition, deletion of Traf7 in endothelial cells of postnatal mice was associated with severe cerebral hemorrhage. Here, we show that besides MEKK3 and MEK5, TRAF7 associates with a planar cell polarity protein SCRIB. SCRIB binds with an N-terminal region of TRAF7, while MEKK3 associates with the C-terminal WD40 domain. Downregulation of TRAF7 as well as SCRIB inhibited fluid shear stress-induced phosphorylation of ERK5 in cultured endothelial cells. These findings suggest that TRAF7 and SCRIB may comprise an upstream part of the MEKK3-MEK5-ERK5 signaling pathway.

Sex differences in the genetics of sarcoidosis across European and African ancestry populations.

Background: Sex differences in the susceptibility of sarcoidosis are unknown. The study aims to identify sex-dependent genetic variations in two clinical sarcoidosis phenotypes: Löfgren's syndrome (LS) and non-Löfgren's syndrome (non-LS). Methods: A meta-analysis of genome-wide association studies was conducted on Europeans and African Americans, totaling 10,103 individuals from three population-based cohorts, Sweden (n = 3,843), Germany (n = 3,342), and the United States (n = 2,918), followed by an SNP lookup in the UK Biobank (UKB, n = 387,945). A genome-wide association study based on Immunochip data consisting of 141,000 single nucleotide polymorphisms (SNPs) was conducted in the sex groups. The association test was based on logistic regression using the additive model in LS and non-LS sex groups independently. Additionally, gene-based analysis, gene expression, expression quantitative trait loci (eQTL) mapping, and pathway analysis were performed to discover functionally relevant mechanisms related to sarcoidosis and biological sex. Results: We identified sex-dependent genetic variations in LS and non-LS sex groups. Genetic findings in LS sex groups were explicitly located in the extended Major Histocompatibility Complex (xMHC). In non-LS, genetic differences in the sex groups were primarily located in the MHC class II subregion and ANXA11. Gene-based analysis and eQTL enrichment revealed distinct sex-specific gene expression patterns in various tissues and immune cell types. In LS sex groups, a pathway map related to antigen presentation machinery by IFN-gamma. In non-LS, pathway maps related to immune response lectin-induced complement pathway in males and related to maturation and migration of dendritic cells in skin sensitization in females were identified. Conclusion: Our findings provide new evidence for a sex bias underlying sarcoidosis genetic architecture, particularly in clinical phenotypes LS and non-LS. Biological sex likely plays a role in disease mechanisms in sarcoidosis.

Identification of Environmental Exposures Associated with Risk of Sarcoidosis in African Americans.

Rationale: Sarcoidosis is a racially disparate granulomatous disease likely caused by environmental exposures, genes, and their interactions. Despite increased risk in African Americans, few environmental risk factor studies in this susceptible population exist. Objectives: To identify environmental exposures associated with the risk of sarcoidosis in African Americans and those that differ in effect by self-identified race and genetic ancestry. Methods: The study sample comprised 2,096 African Americans (1,205 with and 891 without sarcoidosis) compiled from three component studies. Unsupervised clustering and multiple correspondence analyses were used to identify underlying clusters of environmental exposures. Mixed-effects logistic regression was used to evaluate the association of these exposure clusters and the 51 single-component exposures with risk of sarcoidosis. A comparison case-control sample of 762 European Americans (388 with and 374 without sarcoidosis) was used to assess heterogeneity in exposure risk by race. Results: Seven exposure clusters were identified, five of which were associated with risk. The exposure cluster with the strongest risk association was composed of metals (P < 0.001), and within this cluster, exposure to aluminum had the highest risk (odds ratio, 3.30; 95% confidence interval [95% CI], 2.23-4.09; P < 0.001). This effect also differed by race (P < 0.001), with European Americans having no significant association with exposure (odds ratio, 0.86; 95% CI, 0.56-1.33). Within African Americans, the increased risk was dependent on genetic African ancestry (P = 0.047). Conclusions: Our findings support African Americans having sarcoidosis environmental exposure risk profiles that differ from those of European Americans. These differences may underlie racially disparate incidence rates that are partially explained by genetic variation differing by African ancestry.

Specific gene expression signatures of low grade meningiomas.

Introduction: Meningiomas are the most common primary central nervous system (CNS) tumors in adults, representing approximately one-third of all primary adult CNS tumors. Although several recent publications have proposed alternative grading systems of meningiomas that incorporate genomic and/or epigenomic data to better predict meningioma recurrence and progression-free survival, our understanding of driving forces of meningioma development is still limited. Objective: To define gene expression signatures of the most common subtypes of meningiomas to better understand cellular processes and signaling pathways specific for each tumor genotype. Methods: We used RNA sequencing (RNA-seq) to determine whole transcriptome profiles of twenty meningiomas with genomic alterations including NF2 inactivation, loss of chr1p, and missense mutations in TRAF7, AKT1 and KLF4. Results: The analysis revealed that meningiomas with NF2 gene inactivation expressed higher levels of BCL2 and GLI1 compared with tumors harboring TRAF7 missense mutations. Moreover, NF2 meningiomas were subdivided into two distinct groups based on additional loss of chr1p. NF2 tumors with intact chr1p were characterized by the high expression of tumor suppressor PTCH2 compared to NF2 tumors with chr1p loss. Taken together with the high expression of BCL2 and GLI1, these results suggest that activation of Sonic Hedgehog pathway may contribute to NF2 meningioma development. In contrast, NF2 tumors with chr1p loss expressed high levels of transcription factor FOXD3 and its antisense RNA FOXD3-AS1. Examination of TRAF7 tumors demonstrated that TRAF7 regulates a number of biomechanically responsive genes (KRT6a, KRT16, IL1RL1, and AQP3 among others). Interestingly, AKT1 and KLF4 meningiomas expressed genes specific for PI3K/AKT signaling pathway, suggesting overlapping gene signatures between the two subtypes. In addition, KLF4 meningiomas had high expression of carcinoembryonic antigen family members CEACAM6 and CEACAM5. Conclusions: Each group of meningiomas displayed a unique gene expression signature suggesting signaling pathways potentially implicated in tumorigenesis. These findings will improve our understanding of meningioma tumorigenesis and prognosis.

Examination of eQTL Polymorphisms Associated with Increased Risk of Progressive Complicated Sarcoidosis in European and African Descent Subjects.

Background: A limited pool of SNPs are linked to the development and severity of sarcoidosis, a systemic granulomatous inflammatory disease. By integrating genome-wide association studies (GWAS) data and expression quantitative trait loci (eQTL) single nuclear polymorphisms (SNPs), we aimed to identify novel sarcoidosis SNPs potentially influencing the development of complicated sarcoidosis. Methods: A GWAS (Affymetrix 6.0) involving 209 African-American (AA) and 193 European-American (EA, 75 and 51 complicated cases respectively) and publicly-available GWAS controls (GAIN) was utilized. Annotation of multi-tissue eQTL SNPs present on the GWAS created a pool of ~46,000 eQTL SNPs examined for association with sarcoidosis risk and severity (Logistic Model, Plink). The most significant EA/AA eQTL SNPs were genotyped in a sarcoidosis validation cohort (n=1034) and cross-validated in two independent GWAS cohorts. Results: No single GWAS SNP achieved significance (p<1x10-8), however, analysis of the eQTL/GWAS SNP pool yielded 621 eQTL SNPs (p<10-4) associated with 730 genes that highlighted innate immunity, MHC Class II, and allograft rejection pathways with multiple SNPs validated in an independent sarcoidosis cohort (105 SNPs analyzed) (NOTCH4, IL27RA, BTNL2, ANXA11, HLA-DRB1). These studies confirm significant association of eQTL/GWAS SNPs in EAs and AAs with sarcoidosis risk and severity (complicated sarcoidosis) involving HLA region and innate immunity. Conclusion: Despite the challenge of deciphering the genetic basis for sarcoidosis risk/severity, these results suggest that integrated eQTL/GWAS approaches may identify novel variants/genes and support the contribution of dysregulated innate immune responses to sarcoidosis severity.

Mutated KLF4(K409Q) in meningioma binds STRs and activates FGF3 gene expression.

Krüppel-like factor 4 (KLF4) is a transcription factor that has been proven necessary for both induction and maintenance of pluripotency and self-renewal. Whole-genome sequencing defined a unique mutation in KLF4 (KLF4K409Q) in human meningiomas. However, the molecular mechanism of this tumor-specific KLF4 mutation is unknown. Using genome-wide high-throughput and focused quantitative transcriptional approaches in human cell lines, primary meningeal cells, and meningioma tumor tissue, we found that a change in the evolutionarily conserved DNA-binding domain of KLF4 alters its DNA recognition preference, resulting in a shift in downstream transcriptional activity. In the KLF4K409Q-specific targets, the normally silent fibroblast growth factor 3 (FGF3) is activated. We demonstrated a neomorphic function of KLF4K409Q in stimulating FGF3 transcription through binding to its promoter and in using short tandem repeats (STRs) located within the locus as enhancers.