Search Results (104)

Background: The reproducibility of research findings continues to be a challenge in many fields, including neurosciences. It is now required that biological variables such as sex and age be considered in preclinical and clinical research. Rodents are frequently used to model clinical conditions; however, litter information is rarely presented. Some studies utilize entire litters with each animal treated as an independent sample, while others equally assign animals from each litter to different groups/treatments, and others use averaged data. These methods can yield different results. Methods: This study used different analysis methods to evaluate embryo and placenta weights from E17.5 acid-sensing ion channel 2a (ASIC2a) mice with or without seizure exposure. Results: When each embryo was treated as an individual sample, fetal and placental weight significantly differed following seizures in the ASIC2a heterozygous (+/−) and homozygous (−/−) groups. Differences in fetal weight were driven by females in the ASIC2a+/− group and both sexes in the ASIC2a−/− group. These differences were lost when an average per sex/genotype/litter was used. There was no difference in placental weight when treated individually; however, female ASIC2a−/− placentas weighed less following seizures. This difference was lost with averaged data. ASIC2a−/− fetuses from −/− dams had reduced weights post-seizure exposure. Position on the uterine horn influenced embryo and placental weight. Conclusions: Our results indicate that using full litters analyzed as individual data points should be avoided, as it can lead to Type I errors. Furthermore, studies should account for litter effects and be transparent in their methods and results. Full article

The largest Eurasian rodent, the Eurasian beaver Castor fiber, is known for its amphibious lifestyle that allows it to adapt its environment to its needs. Due to its lifestyle and evolutionary history, the beaver is characterized by a distinct, unique parasitofauna. In this context, the occurrence of mites from the Demodecidae family in the Eurasian beaver was investigated. The topography of the Demodex castoris was analyzed: it was previously known from a single record from a single skin location of this host. The mite was found in large numbers in various locations in the hairy skin, including the head, trunk, and limbs. In addition, a new species associated with hairless skin, mainly around the mouth, was discovered and described: Demodex ovaportans sp. nov. The females of this species carry the egg on the dorsal side of the podosoma, which may be a form of care and a previously unknown reproductive strategy in Demodecidae. Our findings confirm that a host-specific demodecid mite species associated with the hairy skin of the entire body is a universal model in mammals. They also emphasize the uniqueness of the beaver parasitofauna, as evidenced by the host specificity and the different biology of the demodecids described in it. Full article

Background: Diabetic cardiomyopathy (DCM) is characterized by progressive cardiac dysfunction, metabolic dysregulation, myocardial fibrosis, and mitochondrial impairment. Existing animal models, such as streptozotocin (STZ)-induced models, suffer from high mortality and fail to replicate chronic metabolic dysregulation induced by high-fat diets (HFD), whereas HFD or HFD/STZ-combined rodent models require high maintenance costs. This study aimed to establish a zebrafish HFD-DCM model to facilitate mechanistic exploration and drug discovery. Methods: Eighty wild-type female zebrafish were divided into normal diet (N, 6% fat) and HFD (H, 24% fat) groups and fed the diet for 8 weeks. Metabolic phenotypes were evaluated using intraperitoneal glucose tolerance tests and insulin level analysis. Cardiac function was assessed by using echocardiography (ejection fraction, E peak). Structural, metabolic, and oxidative stress alterations were analyzed by histopathology (H&E, Masson, and Oil Red O staining), molecular assays (RT-qPCR, Western blotting), and mitochondrial structure/function evaluations (respiratory chain activity, transmission electron microscopy, and DHE staining). Results: HFD-fed zebrafish developed obesity, insulin resistance, and impaired glucose tolerance. Echocardiography revealed cardiac hypertrophy, reduced ejection fraction, and diastolic dysfunction. Excessive lipid accumulation, upregulated fibrosis/inflammatory markers, impaired mitochondrial respiration, elevated reactive oxygen species levels, and a disrupted redox balance were observed. Conclusions: We established a female zebrafish HFD model that recapitulates human DCM features, including hypertrophy, metabolic dysregulation, fibrosis, inflammation, and mitochondrial dysfunction. This model offers novel insights into DCM pathogenesis and serves as a valuable platform for mechanistic studies and targeted drug screening. Full article

Mammary tumors occur in female and male guinea pigs. However, published data on their histology and sex predispositions are limited. Histologically, we examined proliferative mammary lesions of 69 female and 48 male pet guinea pigs. Lobular hyperplasia was observed only in females (n = 50). Benign tumors included simple adenomas (n = 20), adenolipomas (n = 3) and intraductal papillary adenomas (n = 5). All except two intraductal papillary adenomas occurred in females. Most malignancies were tubulopapillary and solid carcinomas (n = 54), and intraductal papillary carcinomas (n = 13). These were diagnosed more frequently in male (n = 41) than in female (n = 26) guinea pigs. The carcinomas of males had higher mitotic counts than those of females (p = 0.05). Three carcinosarcomas developed in adenolipoma, and one arose in adenoma. Results show that the mammary tumor classification of dogs and cats can be applied to guinea pigs. However, some tumors (adenolipoma, metaplastic carcinoma) are unique to guinea pigs and shared with laboratory rodents and humans, respectively. Benign tumors may undergo malignant progression. Male guinea pigs appear predisposed to ductal-associated and malignant tumors. Data suggest that male guinea pigs represent an animal model for human male breast cancer. Full article

Background: Preeclampsia is a leading cause of maternal and fetal morbidity and mortality, with obesity recognised as a significant risk factor. However, the direct contribution of obesity to the pathophysiology underpinning preeclampsia remains unclear. Objectives: This study aimed to develop and characterise a diet-induced obese mouse model with superimposed preeclampsia to better understand the impact of obesity on disease pathogenesis. Methods: Female mice were fed either standard rodent chow or a high-fat diet from weaning. At 8 weeks of age, mice were mated. Pregnant mice were treated with L-N^G-Nitro arginine methyl ester (L-NAME; to block nitric oxide production) from gestational day (D)7.5 to D17.5 to induce a preeclampsia-like phenotype. Blood pressure was measured on D14.5 and D17.5, followed by the collection of maternal and fetal tissues for histological, biochemical, and molecular analyses. Results: Obese dams exhibited significantly increased body, fat pad, and liver weights compared to lean controls. While L-NAME induced hypertension in the control mice, contrary to expectations, the L-NAME-induced hypertension was partially attenuated in obese dams, with significantly lower systolic and diastolic blood pressures at D14.5 and reduced systolic pressure at D17.5. Fetal weights were comparable between groups, however, placentas were significantly heavier with obesity. Endothelial function, inflammatory markers, and renal gene expression patterns suggested distinct physiological adaptations in obese preeclamptic-like mice. Conclusions: These findings challenge the prevailing assumption that obesity drives hypertension, endothelial dysfunction, and inflammatory markers. The differential vascular and physiological responses observed in the obese dams highlight the complexity of obesity–preeclampsia interactions and underscore the need for refined preclinical models to disentangle mechanistic contributions. This work has implications for personalised management strategies and targeted therapeutic interventions in obese pregnancies at risk of preeclampsia. Full article

Early-onset heart failure is a major treat to healthy aging individuals with HIV-1 infection. Women with HIV-1 infection (WLWH) are especially vulnerable and develop heart failure with preserved ejection fraction (HFpEF), of which left ventricular diastolic dysfunction, vascular deficits, myocardial infarction, and fibrosis are major components. HIV-infected rodent models that exhibit these pathophysiological features remain under-reported, and this has left a void in our understanding of their molecular causes and therapeutic strategies to blunt its development. Here, we show that female NOD.Cg-Prkdc^scidIl2rgt^m1Wjl/SzJ humanized mice (Hu-mice) infected with HIV-1_ADA and treated for 13 weeks with dolutegravir (DTG)/tenofovir disoproxil fumarate (TDF)/emtricitabine (FTC) develop progressive diastolic dysfunction with preserved ejection fraction (E:A ratio, E:e′, IVRT, left atrial volume and global longitudinal strain increased by 32.1 ± 5.1%, 28.2 ± 5.6%, 100.2 ± 12.6%, 26.6 ± 4.2% and 32.5 ± 4.3%, respectively). In vivo photoacoustic imaging revealed a 30.4 ± 6.8% reduction in saturated oxygenated hemoglobin in the anterior wall of the heart. The ex vivo analysis of hearts showed a reduction in density of perfused microvessels/ischemia (30.6 ± 6.2%) with fibrosis (20.2 ± 1.2%). The HIF-1α level was increased 2.6 ± 0.5-fold, while inflammation-induced serum semicarbazide amine oxidase and glycolysis byproduct methylglyoxal increased 2-fold and 2.1-fold, respectively. Treating H9C2 cardiac myocytes with DTG, FTC and TDF dose-dependently increased expression of HIF-1α. These data show that HIV-infected Hu-mice treated with DTG/TDF/FTC for thirteen weeks develop cardiac diastolic dysfunction, with vascular deficits, ischemia, and fibrosis like those reported in women living with HIV-1 infection (WLWH). They also show that DTG, TDF, and FTC treatment can increase total HIF-1α in H9C2 cells. Full article

Many neurobehavioral tests are used for the assessment of human-like behaviors in animals. Most of them were developed in rodents and are used for the assessment of animal models that mimic human neurodevelopmental and neuropsychiatric disorders (NDDs). We have described tests for assessing social behavior, social interaction, and social communication; tests for restricted and repetitive behaviors; tests for cognitive impairment, for sensory stimuli, for anxiety like behavior, and for motor coordination deviations. These tests are used to demonstrate autistic-like behavior as well as other NDDs. We described possible general pitfalls in the performance of such studies, as well as probable individual errors for each group of tests assessing specific behavior. The mentioned pitfalls may induce crucial errors in the interpretation of the results, minimizing the reliability of specific models of defined human NDD. It is imperative to minimize these pitfalls and use sufficient and reliable tests that can demonstrate as many of the traits of the human disorder, grade the severity of the specific deviations and the severity of the tested NDD by using a scoring system. Due to possible gender differences in the clinical presentations of NDD, it is important to carry out studies on males and females. Full article

$\beta$-hydroxy-$\beta$-methylbutyrate (HMB) has been shown to enhance muscle function and strength in older humans and rodents after periods of consumption extending for several weeks. We investigated the feasibility of utilizing Drosophila as a model organism to study the biological effects of HMB on aging muscle when consumed throughout adult life. Using flight ability as an index of flight muscle function, we found that HMB attenuates the age-dependent decline in flight ability. Male and female flies fed a diet supplemented with 10 mg/mL HMB had significantly higher flight scores from median age until the onset of flight senescence than control flies fed a standard diet. HMB supplementation also resulted in improved flight scores in males before median age and delayed the onset of flight senescence in females. Notably, the consumption of HMB throughout adult life increased the rate of survival and extended lifespan. The effect on lifespan did not result from changes in food consumption or body weight. Old flies on the HMB-supplemented diet retained a higher proportion of flight muscle mitochondria whose morphology resembled that of young flies than the control diet group. Together, these results suggest that HMB attenuates the age-dependent decline in flight ability and prolongs lifespan by enhancing muscle health. Full article

Deoxynivalenol (DON) is a mycotoxin commonly found worldwide and is implicated in various health effects. We recently demonstrated that subacute oral exposure to DON significantly exacerbates symptoms of type 2 helper T-cell-mediated allergic diseases in a model. We aim to investigate the role of oral DON exposure in type 17 helper T-cell-mediated immunoreactive diseases using a mouse psoriasis model. Psoriasis was induced by the dermal administration of 5% imiquimod in female BALB/c mice. A standard rodent diet was supplemented with DON to achieve a final concentration of 0.3 ppm (1.5 μg/kg bw/day), which was administered daily for 14 days. Skin thickness, scratching behavior, and transepidermal water loss (TEWL) were continuously measured during imiquimod administration. Mice exposed to DON exhibited significant increases in skin thickness, TEWL, and scratching behavior. Histological evaluations revealed aggravated hyperplasia, neutrophil infiltration, and inflammatory cell accumulation in the dermis. Furthermore, DON exposure significantly increased the number of CD4+ helper T cells and CD11c+ MHC class II+ dendritic cells in the auricular lymph nodes, along with elevated TNF-α and IL-17 levels in stimulated T cells. The gene expression of IL-17 in skin tissue was also significantly up-regulated in DON-treated mice. Collectively, these findings suggest that oral exposure to DON aggravates symptoms in a mouse psoriasis model. Full article

Background/Objectives: Both hyperandrogenism (HA) and vitamin D deficiency (VDD) can separately lead to impaired vascular reactivity and ovulatory dysfunction in fertile females. The aim was to examine the early interactions of these states in a rat model of PCOS. Methods: Four-week-old adolescent female rats were divided into four groups: vitamin D (VD)-supplemented (n = 12); VD-supplemented and testosterone-treated (n = 12); VDD- (n = 11) and VDD-and-testosterone-treated (n = 11). Animals underwent transdermal testosterone treatment for 8 weeks. Target VD levels were achieved with oral VD supplementation and a VD-free diet. Estrous cycles were followed by vaginal smear, and quantitative histomorphometric measurements of the ovaries were also taken. In the 8th week, testosterone- and estrogen-induced relaxation of coronary arterioles was examined with pressure angiography. Estrogen receptor (ER) density and oxidative and nitrative stress parameters (Poly-(ADP-Ribose)-Polymerase and 3-nitrotyrosine) in the vessel wall were investigated with immunohistochemistry. Results: VDD caused impaired estrous cycles, and testosterone caused anovulatory cycles (the cycles were stopped at the diestrous phase). VDD combined with testosterone treatment resulted in reduced testosterone and estrogen vasorelaxation, lower ER density, and higher oxidative and nitrative stress in the vessel wall. Conclusions: PCOS with vitamin D deficiency may be associated with increased oxidative–nitrative stress in coronary arterioles. This oxidative and nitrative stress, potentially caused by hyperandrogenism and/or vitamin D deficiency, could impair estrogen-induced relaxation of the coronary arterioles, possibly by decreasing NO bioavailability and disrupting the estrogen-induced relaxation pathway. Full article

Background/Objectives: Rodents provide a useful translational model of fear- and anxiety-related behaviors. Previously stressed animals exhibit physiological and behavioral stress responses that parallel those observed in anxious humans. Patients diagnosed with post-traumatic stress disorder (PTSD) present with a spectrum of debilitating anxiety symptoms that result from exposure to one or more traumatic events, with individuals exposed to early adverse experiences and women having increased vulnerability for diagnoses; however, the mechanisms of this increased vulnerability remain unknown. PTSD involves a complex network of highly interconnected brain regions, including the bed nucleus of the stria terminalis (BNST). Serotonin (5-HT) release into the BNST yields an increased expression of both fear and anxiety, specifically through 5-HT_2C receptor signaling. The present experiment addressed whether 5-HT_2C receptor signaling in the BNST is necessary for the acquisition of early-life stress (ELS)-induced enhancements in adult contextual fear learning. Methods: Rats received 0 or 15 footshocks on postnatal day 17, an established model of acute ELS (aELS) that yields enhanced adult fear learning. In adulthood, rats received bilateral infusions of a vehicle, a 5-HT_2C receptor antagonist (RS-102221), or a 5-HT_2C receptor agonist (MK-212) into the BNST 15 min prior to one-footshock contextual fear conditioning in a novel context. The next day, rats were returned to the fear-conditioning context to assess their fear memory (freezing). Results: Females demonstrated aELS-induced enhancement in contextual fear learning, while males did not. BNST infusions of RS-102221 reduced contextual fear conditioning, independent of aELS condition and sex. Infusions of MK-212 had no effect. Conclusions: Taken together, these data suggest that serotonergic signaling through 5-HT_2C receptors in the BNST contributes to contextual fear conditioning, but not aELS-induced stress-enhanced fear learning (SEFL). Full article

Thyroid hormones (THs) require iodine for biosynthesis and play critical roles in brain development. Perchlorate is an environmental contaminant that reduces serum THs by blocking the uptake of iodine from the blood to the thyroid gland. Using a pregnant rodent model, we examined the impact of maternal exposure to perchlorate under conditions of dietary iodine deficiency (ID) on the brain and behavior of offspring. We observed modest reductions in thyroxine (T4) in the serum of dams and no effect on T4 in pup serum in response to maternal exposure to 300 ppm of perchlorate in the drinking water. Likewise, serum T4 was reduced in ID dams, but, as with perchlorate, no effects were evident in the pup. However, when ID was coupled with perchlorate, reductions in pup serum THs and transcriptional alterations in the thyroid gland and pup brain were detected. These observations were accompanied by reductions in the number of cortical inhibitory interneurons containing the calcium-binding protein parvalbumin (Pvalb). Alterations in Pvalb expression in the neonatal brain were associated with deficits in the prepulse inhibition of acoustic startle in adult male offspring and enhanced fear conditioning in females. These findings support and extend structural defects in the brain previously reported in this model. Further, they underscore the critical need to consider additional non-chemical stressors in the determination of hazards and risks posed by environmental contaminants that affect the thyroid system. Full article

Background: Although estrogenic compounds promise therapeutic potential in treating various conditions, concerns regarding their endocrine-disrupting effects have been raised. Current methodologies for screening estrogenicity in rodent models are limited to the female-specific uterotrophic bioassay. Studies have reported enlargement of the seminal vesicles in orchiectomized males treated with estrogens. However, identifying estrogenicity strictly through changes in wet weights is uninformative regarding the molecular mechanisms of these agents. Therefore, protein-based biomarkers can complement and improve the sensitivity of weight-based assessments. To this end, we present a discovery-driven proteomic analysis of 17β-estradiol’s effects on the seminal vesicles. Methods: We treated orchidectomized mice with the hormone for five days and used the vehicle-treated group as a control. Seminal vesicles were analyzed by shotgun approach using data-dependent nanoflow liquid chromatography–tandem mass spectrometry and label-free quantification. Proteins found to be differentially expressed between the two groups were processed through a bioinformatics pipeline focusing on pathway analyses and assembly of protein interaction networks. Results: Out of 668 identified proteins that passed rigorous validation criteria, 133 were regulated significantly by 17β-estradiol. Ingenuity Pathway Analysis^® linked them to several hormone-affected pathways, including those associated with immune function such as neutrophil degranulation. The altered protein interaction networks were also related to functions including endocrine disruption, abnormal metabolism, and therapeutic effects. Conclusions: We identified several potential biomarkers for estrogenicity in mouse seminal vesicles, many of them not previously linked with exogenous 17β-estradiol exposure. Full article

Recent studies have indicated that hindbrain [fourth ventricle (4V)] administration of the neurohypophyseal hormone, oxytocin (OT), reduces body weight, energy intake and stimulates interscapular brown adipose tissue temperature (T_IBAT) in male diet-induced obese (DIO) rats. What remains unclear is whether chronic hindbrain (4V) OT can impact body weight in female high fat diet-fed (HFD) rodents and whether this involves activation of brown adipose tissue (BAT). We hypothesized that OT-elicited stimulation of sympathetic nervous system (SNS) activation of interscapular brown adipose tissue (IBAT) contributes to its ability to activate BAT and reduce body weight in female high HFD-fed rats. To test this hypothesis, we determined the effect of disrupting SNS activation of IBAT on OT-elicited stimulation of T_IBAT and reduction of body weight in DIO rats. We first measured the impact of bilateral surgical SNS denervation to IBAT on the ability of acute 4V OT (0.5, 1, and 5 µg ≈ 0.5, 0.99, and 4.96 nmol) to stimulate T_IBAT in female HFD-fed rats. We found that the high dose of 4V OT (5 µg ≈ 4.96 nmol) stimulated T_IBAT similarly between sham rats and denervated rats (p = NS). We subsequently measured the effect of bilateral surgical denervation of IBAT on the effect of chronic 4V OT (16 nmol/day ≈ 16.1 μg/day) or vehicle infusion to reduce body weight, adiposity and energy intake in female HFD-fed rats (N = 7–8/group). Chronic 4V OT reduced body weight gain (sham: −18.0 ± 4.9 g; denervation: −15.9 ± 3.7 g) and adiposity (sham: −13.9 ± 3.7 g; denervation: −13.6 ± 2.4 g) relative to vehicle treatment (p < 0.05) and these effects were similar between groups (p = NS). These effects were attributed, in part, to reduced energy intake evident during weeks 2 (p < 0.05) and 3 (p < 0.05). To test whether these results translate to other female rodent species, we also examined the effect of chronic 4V infusion of OT on body weight and adiposity in two strains of female HFD-fed mice. Similar to what we found in the HFD-fed rat model, we also found that chronic 4V OT (16 nmol/day) infusion resulted in reduced body weight gain, adiposity and energy intake in female DIO C57BL/6J and DBA/2J mice (p < 0.05 vs. vehicle). Together, these findings suggest that (1) sympathetic innervation of IBAT is not necessary for OT-elicited increases in BAT thermogenesis and weight loss in female HFD-fed rats and (2) the effects of OT to reduce weight gain and adiposity translate to other female mouse models of diet-induced obesity (DIO). Full article

Pain is the primary clinical indication of osteoarthritis (OA), and behavioral assessments in rodent pain models are widely used to understand pain patterns. These preclinical pain assessments can also help us to understand the effectiveness of emerging therapeutics for prolonged OA pain management. Along with evoked methods like mechanical allodynia and thermal hyperalgesia, non-evoked methods such as dynamic weight bearing (DWB) analysis are valuable tools for behavioral assessments of pain. Both these methods were utilized to study pain-induced behavioral changes in a monoiodoacetate (MIA)-induced osteoarthritic pain model, which is a well-established preclinical OA pain model. However, the utility of DWB analysis as an indicator of long-term pain sensitivity (more than 4 weeks) remains largely unexplored. Understanding the long-term sensitivity of DWB is valuable to study the effectiveness of novel prolonged pain-relieving therapeutics. Here, we studied the dynamic behavioral changes in MIA-induced OA rats over a period of 16 weeks using DWB measurements. Female Sprague Dawley rats were injected in the right knee joint with MIA (3 mg) using X-ray guidance. Multiple dynamic postural evaluations such as ipsilateral weight percentage, paw area, contralateral/ipsilateral weight ratio and area ratio were assessed to understand the behavioral changes. The data showed that the ipsilateral weight bearing percentage alone is not sufficient to assess pain-related behavior beyond 6 weeks. This study shows the advantages and limitations of dynamic weight bearing as an assessment tool for the long-term progression of pain behavior in MIA-induced OA rats. Full article