Naringenin protects against septic cardiomyopathy in mice by targeting HIF-1α

Myocardial dysfunction is a prevalent complication of sepsis (septic cardiomyopathy) with a high mortality rate and limited therapeutic options. Naringenin, a natural flavonoid compound with anti-inflammatory and antioxidant properties, holds promise as a potential treatment for sepsis-induced myocardial dysfunction. This study investigated the pharmacological effects of naringenin on septic cardiomyopathy. In vivo and in vitro experiments demonstrated that naringenin improved cardiomyocyte damage. Network pharmacology and database analysis revealed that HIF-1α is a key target protein of naringenin. Elevated expression of HIF-1α was observed in damaged cardiomyocytes, and the HIF-1α inhibitor effectively protected against LPS-induced cardiomyocyte damage. Molecular docking studies confirmed the direct binding between naringenin and HIF-1α protein. Importantly, our findings demonstrated that naringenin did not provide additional attenuation of cardiomyocyte injury on the biases of HIF-1α inhibitor treatment. In conclusion, this study proves that naringenin protects against septic cardiomyopathy through HIF-1α signaling. Naringenin is a promising therapeutic candidate for treating septic cardiomyopathy.

Integrated network toxicology, molecular docking, and in vivo experiments to elucidate molecular mechanism of aflatoxin B1 hepatotoxicity

Due to the rise in temperature and sea level caused by climate change, the detection rate of aflatoxin B1 (AFB1) in food crops has increased dramatically, and the frequency and severity of aflatoxicosis in humans and animals are also increasing. AFB1 has strong hepatotoxicity, causing severe liver damage and even cancer. However, the mechanism of AFB1 hepatotoxicity remains unclear. By integrating network toxicology, molecular docking and in vivo experiments, this research was designed to explore the potential hepatotoxicity mechanisms of AFB1. Thirty-three intersection targets for AFB1-induced liver damage were identified using online databases. PI3K/AKT1, MAPK, FOXO1 signaling pathways, and apoptosis were significantly enriched. In addition, the proteins of ALB, AKT1, PIK3CG, MAPK8, HSP90AA1, PPARA, MAPK1, EGFR, FOXO1, and IGF1 exhibited good affinity with AFB1. In vivo experiments, significant pathological changes occurred in the liver of mice. AFB1 induction increased the expression levels of EGFR, ERK, and FOXO1, and decreased the expression levsls of PI3K and AKT1. Moreover, AFB1 treatment caused an increase in Caspase3 expression, and a decrease in Bcl2/Bax ratio. By combining network toxicology with in vivo experiments, this study confirms for the first time that AFB1 promotes the FOXO1 signaling pathway by inactivating PI3K/AKT1 and activating EGFR/ERK signaling pathways, hence aggravating hepatocyte apoptosis. This research provides new strategies for studying the toxicity of environmental pollutants and new possible targets for the development of hepatoprotective drugs.

Polystyrene nanoplastics and cadmium co-exposure aggravated cardiomyocyte damage in mice by regulating PANoptosis pathway

Micro/nanoplastics (M/NPs) are the novel contaminants ubiquitous in the environment. Cadmium (Cd), a kind of heavy metal pollutant widely distributed, could potentially co-exist with PS-NPs in the environment. However, their combined effects on cardiomyocyte and its molecular mechanism in mammals remained ambiguous. Here, we examined whether PANoptosis, an emerging and complicated kind of programmed cell death, was involved in PS-NPs and Cd co-exposure-elicited cardiac injury. In this study, 60 male mice were orally subjected to environmentally relevant concentrations of PS-NPs (1 mg/kg) and/or CdCl2 (1.5 mg/kg) for 35 days. As we speculated, PS-NPs and Cd co-exposure affected the expression of pyroptosis(Caspase-1, Cleaved-Caspase-1, GSDMD, N-GSDMD, AIM2, Pyrin, NLRP3, IL-18, IL-1β)-, apoptosis(Caspase-3, Cleaved-Caspase-3, Caspase-8, Cleaved-Caspase-8, Caspase-7, BAX)- and necroptosis (t-RIPK3, p-RIPK3, t-RIPK1, p-RIPK1, t-MLKL, p-MLKL, ZBP1)-related genes and protein, resulting in growth restriction and damaged myocardial microstructure in mice. Notably, the combined effects on Cd and PS-NPs even predominantly aggravated the toxic damage. Intriguingly, we fortuitously discovered PS-NPs and/or Cd exposure facilitated linear ubiquitination of certain proteins in mice myocardium. In summation, this study shed light toward the effects of Cd and PS-NPs on cardiotoxicity, advanced the understanding of myocardial PANoptosis and provided a scientific foundation for further exploration of the combined toxicological effects of PS-NPs and heavy metals.

Evaluation of curcumin-based ophthalmic nano-emulsion on atropine-induced dry eye in mice

Background

One of the most efficient treatments for dry eye syndrome (DES) is to use nanocarriers as a potential delivery system. We aim to evaluate curcumin in a nano emulsion formulation.

Methods

A new formulation containing 5.5% curcuminoid was used. DLS, Zeta potential, TEM, and HPLC tests were performed to determine the size and morphology. First, 30 mice were selected as atropine-induced dry eye models. Next, 25 mice in 5 groups were treated with the nano emulsion at different doses, and corneal tissues were separated for evaluation.

Results

The DLS test results were indicative of the particles' stability. Nano curcumin appeared to be thoroughly effective in all groups, with the highest dose showing the most similarity to the healthy control group.

Conclusions

Curcumin-based nano emulsion eye drop is a promising candidate for DES management. However, further investigation is required to evaluate the possible risks in humans.

Line- and sex-dependent effects of juvenile stress on contextual fear- and anxiety-related behavior in high- and low-alcohol-preferring mouse lines

Juvenile stress (JS) is a known risk factor for the development of alcohol use disorder (AUD) and post-traumatic stress disorder (PTSD), both of which are frequently co-morbid. Data suggest there may be common, genetically-influenced biological responses to stress that contribute to the development of both AUD and PTSD. The present study investigated the impact of JS on contextual fear learning and extinction, as well as corticosterone (CORT) responses before and after JS, before and after contextual fear conditioning (CFC), and after fear extinction in male and female high-alcohol-preferring (HAP2) and low-alcohol-preferring (LAP2) mouse lines. We also measured unconditioned anxiety-related behavior in the light-dark-transition test before CFC. HAP2 and LAP2 mice did not differ in fear acquisition, but HAP2 mice showed faster fear extinction compared to LAP2 mice. No effects of JS were seen in HAP2 mice, whereas in LAP2 mice, JS reduced fear acquisition in males and facilitated fear extinction in females. Females showed greater fear-related behavior relative to males, regardless of subgroup. HAP2 males demonstrated more anxiolytic-like responses than LAP2 males and LAP2 females demonstrated more anxiolytic-like responses than LAP2 males in the light-dark transition test. HAP2 and LAP2 mice did not differ in CORT during the juvenile stage; however, adult LAP2 mice showed greater CORT levels than HAP2 mice at baseline and after CFC and extinction testing. These findings build upon prior work in these unique mouse lines that differ in genetic propensity toward alcohol preference and provide new information regarding contextual fear learning and extinction mechanisms theorized to contribute to co-morbid AUD and PTSD.

Role of p57KIP2 in Stem and Progenitor Leydig Cells of Mouse Testes

PURPOSE

Precise control of proliferation and differentiation of Leydig cells is important for gonadal androgenesis and spermatogenesis. Though cyclin-dependent kinase inhibitors are crucial for cell proliferation and differentiation, their role in the development of early adult Leydig cells (ALCs) remained unanswered. To understand mechanism for ALC development, functional expression of p57KIP2 (cdkn1c) was investigated in the stem Leydig cells (SLCs) and progenitor Leydig cells (PLCs) in mice.

MATERIALS AND METHODS

The roles of p57KIP2 in the proliferation, differentiation, apoptosis, and steroidogenesis in SLCs and PLCs were investigated by antibodies and bromodeoxyuridine (BrdU) labeling in the early neonatal testes and p57kip2 siRNA in the isolated SLCs and PLCs. Steroidogenic differentiation of PLCs was examined by progesterone and testosterone production in cell culture.

RESULTS

From postnatal day (PND) 1 to 14, p57KIP2(+) spindle-shaped cells in the testis interstitium were α-smooth muscle actin (αSMA)(-), a peritubular myoid cells marker, suggesting that they are SLCs and PLCs. Besides, p57KIP2 was also expressed in HSD3β(+) fetal Leydig cells. From PND1 to 14, BrdU(+)/αSMA(-), Ki67(+)/p57KIP2(+), and BrdU(+)/p57KIP2(+) spindle-shaped cells were gradually decreased. From PND1 to 14, p57KIP in the αSMA(-)/p57KIP2(+) cells was peaked at PND7 and decreased thereafter. In THY1(+) isolated SLCs, p57kip2 siRNA significantly increased ki67 and pcna mRNA and pdgfrα mRNA, a differentiation marker and decreased nestin mRNA, a SLC marker. No significant difference in apoptosis related genes mRNA was found after p57kip2 siRNA treatment. In HSD3β(+) PLCs, p57kip2 siRNA increased proapoptotic genes mRNA, annexin V(+) early-apoptotic cells. Importantly, p57kip2 siRNA significantly decreased hsd3β6 and cyp17a1 mRNA and progesterone production.

CONCLUSIONS

p57KIP2 may suppress proliferation and support stemness of SLCs. In PLCs, p57KIP2 may suppress apoptosis and potentiate the steroidogenic differentiation.

Establishment of stellate ganglion block in mice

BACKGROUND

There have been no reports on the successful implementation of stellate ganglion block (SGB) in mice.

OBJECTIVES

This study aims to investigate a new method for implementing SGB in mice by placing them in a supine position with abducted upper limbs and touching the trachea and sternoclavicular joint with the hand.

METHODS

Fifty BABL/C mice, 8-10 weeks, were selected and randomly divided into four groups: control group (n = 5); SGB-R group (n = 15); SGB-L group (n = 15); and SGB-L + R (group n = 15). SGB was administered with 0.15% ropivacaine solution in a volume of 0.1 mL. The control group received equal volumes of saline. Horner's syndrome, heart rate, and complications such as brachial plexus block, vascular injury, pneumothorax, local anesthetic toxicity, and death were observed.

RESULTS

Horner's syndrome developed in 100% of SGB surviving mice; no difference was seen in the time to onset (100.4 ± 13.4 vs 96.7 ± 12.4, mean ± SD, seconds) and duration (264.1 ± 40.5 vs 296.3 ± 48.0, mean ± SD, min) of Horner's syndrome in the left and right SGB (P > 0.05). Compared with the control group (722 [708-726], median [IQR], bpm), the heart rate was significantly slowed down in the right SGB (475 [451.5-491], median [IQR], bpm) (P < 0.05). While the heart rate was slowed down after performing the left SGB, the difference was not statistically significant (P > 0.05). The overall complication rate was 18.4%, with a brachial plexus block rate of 12.3%, a vascular injury rate of 4.6%, and a mortality rate of 1.5%, as well as no local anesthetic toxicity (includes bilateral implementation of SGB) or pneumothorax manifestations were found.

CONCLUSIONS

This method allows for the successful implementation of SGB in a mouse model.

Neuroligin-2 shapes individual slow waves during slow-wave sleep and the response to sleep deprivation in mice

BACKGROUND

Sleep disturbances are a common comorbidity to most neurodevelopmental disorders and tend to worsen disease symptomatology. It is thus crucial to understand mechanisms underlying sleep disturbances to improve patients' quality of life. Neuroligin-2 (NLGN2) is a synaptic adhesion protein regulating GABAergic transmission. It has been linked to autism spectrum disorders and schizophrenia in humans, and deregulations of its expression were shown to cause epileptic-like hypersynchronized cerebral activity in rodents. Importantly, the absence of Nlgn2 (knockout: KO) was previously shown to alter sleep-wake duration and quality in mice, notably increasing slow-wave sleep (SWS) delta activity (1-4 Hz) and altering its 24-h dynamics. This type of brain oscillation is involved in memory consolidation, and is also a marker of homeostatic sleep pressure. Sleep deprivation (SD) is notably known to impair cognition and the physiological response to sleep loss involves GABAergic transmission.

METHODS

Using electrocorticographic (ECoG) recordings, we here first aimed to verify how individual slow wave (SW; 0.5-4 Hz) density and properties (e.g., amplitude, slope, frequency) contribute to the higher SWS delta activity and altered 24-h dynamics observed in Nlgn2 KO mice. We further investigated the response of these animals to SD. Finally, we tested whether sleep loss affects the gene expression of Nlgn2 and related GABAergic transcripts in the cerebral cortex of wild-type mice using RNA sequencing.

RESULTS

Our results show that Nlgn2 KO mice have both greater SW amplitude and density, and that SW density is the main property contributing to the altered 24-h dynamics. We also found the absence of Nlgn2 to accelerate paradoxical sleep recovery following SD, together with profound alterations in ECoG activity across vigilance states. Sleep loss, however, did not modify the 24-h distribution of the hypersynchronized ECoG events observed in these mice. Finally, RNA sequencing confirmed an overall decrease in cortical expression of Nlgn2 and related GABAergic transcripts following SD in wild-type mice.

CONCLUSIONS

This work brings further insight into potential mechanisms of sleep duration and quality deregulation in neurodevelopmental disorders, notably involving NLGN2 and GABAergic neurotransmission.

Anethole as a promising antidepressant for maternal separation stress in mice by modulating oxidative stress and nitrite imbalance

The occurrence of major depressive disorder is widespread and can be observed in individuals belonging to all societies. It has been suggested that changes in the NO pathway and heightened oxidative stress may play a role in developing this condition. Anethole is a diterpene aromatic compound found in the Umbelliferae, Apiaceae, and Schisandraceae families. It has potential pharmacological effects like antioxidant, anxiolytic, analgesic, anti-inflammatory, antidiabetic, gastroprotective, anticancer, estrogenic, and antimicrobial activities. This study aimed to investigate the potential antidepressant properties of Anethole in a mouse model experiencing maternal separation stress while also examining its impact on oxidative stress and nitrite levels. The research involved the participation of 40 male NMRI mice, separated into five distinct groups to conduct the study. The control group was administered 1 ml/kg of normal saline, while the MS groups were given normal saline and Anethole at 10, 50, and 100 mg/kg doses. The study comprised various behavioural tests, including the open field test (OFT), forced swimming test (FST), and splash test, to assess the effects of Anethole on the mice. In addition to the behavioural tests, measurements were taken to evaluate the total antioxidant capacity (TAC), malondialdehyde (MDA), and nitrite levels in the hippocampus of the mice. According to the findings, maternal separation stress (MS) led to depressive-like conduct in mice, including a rise in immobility duration during the FST and a reduction in the duration of grooming behaviour in the splash test. Additionally, the results indicated that MS correlated with an increase in the levels of MDA and nitrite and a reduction in the TAC in the hippocampus. However, the administration of Anethole resulted in an increase in grooming activity time during the splash test and a decrease in immobility time during the FST. Anethole also exhibited antioxidant characteristics, as demonstrated by its ability to lower MDA and nitrite levels while increasing the TAC in the hippocampus. The results suggest that Anethole may have an antidepressant-like impact on mice separated from their mothers, likely partly due to its antioxidant properties in the hippocampus.

Possible role of apelin on the ovarian steroidogenesis and uterine apoptosis of infantile mice: An in vitro study

The expression of adipokines is well-known in the ovary and uterus. Recently we have shown that apelin and its receptor, APJ are developmentally regulated in the ovary and uterus of mice with elevation at postnatal day 14 (PND14). However, its role in the ovary and uterus of PND14 has not been investigated. Thus, we aimed to unravel the role of the apelin system (by APJ antagonist, ML221) on ovarian steroid secretion, proliferation, and apoptosis along with its role in uterine apoptosis in PND14 mice by in vitro approaches. The treatment of ML221 decreased estrogen, testosterone, and androstenedione secretion while increasing the progesterone secretion from the infantile ovary. These results suggest that apelin signaling would be important for ovarian estrogen synthesis in infantile mice (PND14). The abundance of 3β-HSD, 17β-HSD, aromatase, and active caspase3 increased in the infantile ovary after ML221 treatment. The expression of ERs and BCL2 were also down-regulated by ML221 treatment. The decreased BCL2 and increased active caspase3 by ML221 suggest the suppressive role of apelin on ovarian apoptosis. The APJ antagonist treatment also down-regulated the ER expression in the uterus along with increased active caspase3 and decreased BCL2 expression. In conclusion, apelin signaling inhibits the ovarian and uterine apoptosis via estrogen signaling in the ovary and uterus.

Synergistic antidepressant-like effect of citicoline and CB 1 agonist in male mice

BACKGROUND

The endocannabinoid system plays a key role in the control of many emotional-correlated reactions such as stress, depressed mood, and anxiety. Moreover, citicoline has neuroprotective properties and indicates beneficial effects in the treatment of depressive problems. Acute restraint stress (ARS) is an experimental model used for the induction of rodent models of depression.

OBJECTIVE

This research was designed to assess the effects of intracerebroventricular (i.c.v.) injection of cannabinoid CB1 receptor agents on citicoline-induced response to depression-like behaviors in the non-acute restraint stress (NARS) and ARS mice.

METHODS

For i.c.v. microinjection, a guide cannula was implanted in the left lateral ventricle of male mice. The ARS model was carried out by movement restraint for 4 h. Depression-related behaviors were assessed by forced swimming test (FST), tail suspension test (TST), and splash test.

RESULTS

The results exhibited that the ARS mice showed depressive-like responses. I.c.v. infusion of ACPA (1 μg/mouse) induced an antidepressant-like effect in the NARS and ARS mice by reduction of immobility time in the FST and TST as well as enhancement of grooming activity time in the splash test. On the other hand, i.c.v. microinjection of AM251 dose-dependently (0.5 and 1 μg/mouse) induced a depressant-like effect in the NARS mice. I.p. injection of citicoline (80 mg/kg) induced an antidepressant-like response in the NARS and ARS mice. Furthermore, ACPA (0.25 μg/mouse, i.c.v.) potentiated the antidepressant-like response induced by citicoline (20 mg/kg, i.p.) in the NARS and ARS mice. However, AM251 (0.25 μg/mouse, i.c.v.) reversed the antidepressant-like effect produced by the citicoline (80 mg/kg, i.p.) in the NARS and ARS mice. Interestingly, our results indicated a synergistic effect between citicoline and ACPA based on the induction of an antidepressant-like effect in the NARS and ARS mice.

CONCLUSIONS

These results suggested an interaction between citicoline and cannabinoid CB1 receptors on the modulation of depression-like behaviors in the NARS and ARS mice.

Interaction of tetracycline and copper co-intake in inducing antibiotic resistance genes and potential pathogens in mouse gut

The widespread use of copper and tetracycline as growth promoters in the breeding industry poses a potential threat to environmental health. Nevertheless, to the best of our knowledge, the potential adverse effects of copper and tetracycline on the gut microbiota remain unknown. Herein, mice were fed different concentrations of copper and/or tetracycline for 6 weeks to simulate real life-like exposure in the breeding industry. Following the exposure, antibiotic resistance genes (ARGs), potential pathogens, and other pathogenic factors were analyzed in mouse feces. The co-exposure of copper with tetracycline significantly increased the abundance of ARGs and enriched more potential pathogens in the gut of the co-treated mice. Copper and/or tetracycline exposure increased the abundance of bacteria carrying either ARGs, metal resistance genes, or virulence factors, contributing to the widespread dissemination of potentially harmful genes posing a severe risk to public health. Our study provides insights into the effects of copper and tetracycline exposure on the gut resistome and potential pathogens, and our findings can help reduce the risks associated with antibiotic resistance under the One Health framework.

Additive anxiolytic-like effect of citicoline and ACPA in the non-acute restraint stress (NARS) and acute restraint stress (ARS) mice

The cannabinoid system plays a key role in stress-related emotional symptoms such as anxiety. Citicoline is a supplemental substance with neuroprotective properties that alleviates anxiety-related behaviors. There is a relation between the actions of cannabinoids and cholinergic systems. So, we decided to evaluate the effects of intracerebroventricular (i.c.v.) infusion of cannabinoid CB1 receptor agents on citicoline-produced response to anxiety-like behaviors in the non-acute restraint stress (NARS) and acute restraint stress (ARS) mice. For i.c.v. microinjection of drugs, a guide cannula was inserted in the left lateral ventricle. ARS was induced by movement restraint for 4 h. Anxiety-related behaviors were assessed using an elevated plus maze (EPM). The results showed that induction of ARS for 4 h decreased the percentage of time spent in the open arms (%OAT) and the percentage of entries to the open arms (%OAE) without affecting locomotor activity, showing anxiogenic-like behaviors. i.c.v. infusion of ACPA (1 µg/mouse) induced an anxiolytic-like effect due to the enhancement of %OAT in the NARS and ARS mice. Nonetheless, i.c.v. microinjection of AM251 (1 µg/mouse) decreased %OAT in the NARS and ARS mice which suggested an anxiogenic-like response. Intraperitoneal (i.p.) administration of citicoline (80 mg/kg) induced an anxiolytic-like effect by the augmentation of %OAT in the ARS mice. Furthermore, when ACPA and citicoline were co-administrated, ACPA potentiated the anxiolytic-like effect induced by citicoline in the NARS and ARS mice. On the other hand, when AM251 and the citicoline were co-injected, AM251 reversed the anxiolytic-like response induced by the citicoline in the NARS and ARS mice. The results of this research exhibited an additive effect between citicoline and ACPA on the induction of anxiolytic-like response in the NARS and ARS mice. Our results indicated an interaction between citicoline and cannabinoid CB1 receptor drugs on the control of anxiety-like behaviors in the NARS and ARS mice.

Impact of caloric restriction on oxidative stress and key glycolytic enzymes in the cerebral cortex, liver and kidney of old and middle-aged mice

Caloric restriction (CR) is proposed as a strategy to prevent age-related alterations like impaired glucose metabolism and intensification of oxidative stress. In this study, we examined effects of aging and CR on the activities of glycolytic enzymes and parameters of oxidative stress in the cerebral cortex, liver, and kidney of middle-aged (9 months old) and old (18 months old) C57BL6/N mice. Control middle-aged and old mice were fed ad libitum (AL groups), whereas age-matched CR groups were subjected to CR (70% of individual ad libitum food intake) for 6 and 12 months, respectively. There were no significant differences in the activities of key glycolytic and antioxidant enzymes and oxidative stress indices between the cortices of middle-aged and old AL mice. The livers and kidneys of old AL mice showed higher activity of glucose-6-phosphate dehydrogenase, an enzyme that produces NADPH in the pentose phosphate pathway, compared to those of middle-aged mice. CR regimen modulated some biochemical parameters in middle-aged but not in old mice. In particular, CR decreased oxidative stress intensity in the liver and kidney but had no effects on those parameters in the cerebral cortex. In the liver, CR led to lower activities of glycolytic enzymes, whereas its effect was the opposite in the kidney. The results suggest that during physiological aging there is no significant intensification of oxidative stress and glycolysis decline in mouse tissues during the transition from middle to old age. The CR regimen has tissue-specific effects and improves the metabolic state of middle-aged mice. This article is part of the Special Issue on "Ukrainian Neuroscience".

Sildenafil delays bone remodeling of fractured femora in aged mice by reducing the number and activity of osteoclasts within the callus tissue

The elderly exhibit a reduced healing capacity after fracture, which is often associated with delayed or failed bone healing. This is due to a plethora of factors, such as an impaired bone vascular system and delayed angiogenesis. The phosphodiesterase-5 (PDE-5) inhibitor sildenafil exerts pro-angiogenic and pro-osteogenic effects. Hence, we herein investigated in aged mice whether sildenafil can improve fracture healing. For this purpose, 40 aged CD-1 mice (16-18 months) were daily treated with 5 mg/kg body weight sildenafil (n = 20) or vehicle (control, n = 20) by oral gavage. The callus tissue of their femora was analyzed at 2 and 5 weeks after fracture by X-ray, biomechanics, micro-computed tomography (µCT), histology, immunohistochemistry as well as Western blotting. These analyses revealed a significantly increased bone volume and higher ratio of callus to femoral bone diameter in sildenafil-treated mice at 5 weeks after fracture when compared to controls. This was associated with a reduced number and activity of osteoclasts at 2 weeks after fracture, most likely caused by an increased expression of osteoprotegerin (OPG). Taken together, these findings indicate that sildenafil does not improve fracture healing in the elderly but delays the process of bone remodeling most likely by reducing the number and activity of osteoclasts within the callus tissue.

The cellular senescence response and neuroinflammation in juvenile mice following controlled cortical impact and repetitive mild traumatic brain injury

Traumatic brain injury (TBI) is a leading cause of disability and increases the risk of developing neurodegenerative diseases. The mechanisms linking TBI to neurodegeneration remain to be defined. It has been proposed that the induction of cellular senescence after injury could amplify neuroinflammation and induce long-term tissue changes. The induction of a senescence response post-injury in the immature brain has yet to be characterised. We carried out two types of brain injury in juvenile CD1 mice: invasive TBI using controlled cortical impact (CCI) and repetitive mild TBI (rmTBI) using weight drop injury. The analysis of senescence-related signals showed an increase in γH2AX-53BP1 nuclear foci, p53, p19ARF, and p16INK4a expression in the CCI group, 5 days post-injury (dpi). At 35 days, the difference was no longer statistically significant. Gene expression showed the activation of different senescence pathways in the ipsilateral and contralateral hemispheres in the injured mice. CCI-injured mice showed a neuroinflammatory early phase after injury (increased Iba1 and GFAP expression), which persisted for GFAP. After CCI, there was an increase at 5 days in p16INK4, whereas in rmTBI, a significant increase was seen at 35 dpi. Both injuries caused a decrease in p21 at 35 dpi. In rmTBI, other markers showed no significant change. The PCR array data predicted the activation of pathways connected to senescence after rmTBI. These results indicate the induction of a complex cellular senescence and glial reaction in the immature mouse brain, with clear differences between an invasive brain injury and a repetitive mild injury.

Triphenyl phosphate induces cardiotoxicity through myocardial fibrosis mediated by apoptosis and mitophagy of cardiomyocyte in mice

Triphenyl phosphate (TPHP) is an organophosphorus flame retardant, but its cardiac toxicity has not been adequately investigated. Therefore, in the current study, the effect of TPHP on the heart and the underlying mechanism involved was evaluated. C57BL/6 J mice were administered TPHP (0, 5, and 50 mg/kg/day) for 30 days. In addition, H9c2 cells were treated with three various concentrations (0, 50, and 150 μM) of TPHP, with and without the reactive oxygen species (ROS) scavenger N-acetyl-L-cysteine or the mitochondrial fusion promoter M1. TPHP caused cardiac fibrosis and increased the levels of CK-MB and LDH in the serum. TPHP increased the levels of ROS, malondialdehyde (MDA), and decreased the level of superoxide dismutase (SOD) and Glutathione peroxidase (GSH-Px). Furthermore, TPHP caused mitochondrial damage, and induced fusion and fission disorders that contributed to mitophagy in both the heart of C57BL/6 J mice and H9c2 cells. Transcriptome analysis showed that TPHP induced up- or down-regulated expression of various genes in myocardial tissue and revealed enriched apoptosis pathways. It was also found that TPHP could remarkably increase the expression levels of Bax, cleaved Caspase-9, cleaved Caspase-3, and decreased Bcl-2, thereby causing apoptosis in H9c2 cells. Taken together, the results suggested that TPHP promoted mitophagy through mitochondria fusion dysfunction resulting from oxidative stress, leading to fibrosis by inducing myocardial apoptosis.

Intracellular iron accumulation facilitates mycobacterial infection in old mouse macrophages

Aging has a significant impact on the immune system, leading to a gradual decline in immune function and changes in the body's ability to respond to bacterial infections. Non-tuberculous mycobacteria (NTM), also known as atypical mycobacteria or environmental mycobacteria, are commonly found in soil, water, and various environmental sources. While many NTM species are considered opportunistic pathogens, some can cause significant infections, particularly in individuals with compromised immune systems, such as older individuals. When mycobacteria enter the body, macrophages are among the first immune cells to encounter them and attempt to engulf mycobacteria through a process called phagocytosis. Some NTM species, including Mycobacterium avium (M. avium) can survive and replicate within macrophages. However, little is known about the interaction between NTM and macrophages in older individuals. In this study, we investigated the response of bone marrow-derived macrophage (BMMs) isolated from young (5 months) and old (25 months) mice to M. avium serotype 4, one of the main NTM species in patients with pulmonary NTM diseases. Our results demonstrated that BMMs from old mice have an increased level of intracellular iron and are more susceptible to M. avium serotype 4 infection compared to BMMs from young mice. The whole-cell proteomic analysis indicated a dysregulated expression of iron homeostasis-associated proteins in old BMMs regardless of mycobacterial infection. Deferoxamine, an iron chelator, significantly rescued mycobacterial killing and phagolysosome maturation in BMMs from old mice. Therefore, our data for the first time indicate that an intracellular iron accumulation improves NTM survival within macrophages from old mice and suggest a potential application of iron-chelating drugs as a host-directed therapy for pulmonary NTM infection in older individuals.

Developing garlic polysaccharide-Fe (III) complexes using garlic pomace to provide enhanced iron-supplementing activity in vivo

This study investigated the potential of garlic polysaccharides (GPs) from garlic pomace as iron carriers. The obtained GP-Fe (III) complexes had a higher molecular weight (5646 Da) and more fructose (90.46 %) than the GPs did and contained 9.7 % Fe (III). GPs were mainly composed of → 2)-β-d-Fruf (1 → and → 2)-β-d-Fruf (6 → residues, and their interactions with Fe (III) reduced the crystallinity, increased the thermal stability, and altered the morphological features through targeting the OH stretching vibrations of the hydroxyl groups and affecting the COC and OCO structures. The GP-Fe (III) complexes had high stability under simulated gastrointestinal digestion system and showed better therapeutic effects on iron deficiency anemia in mice than FeSO4 did, evidenced by improved hematological parameters, restored iron levels, and attenuated oxidative damage. Thus, GP-Fe (III) complexes are promising as novel Fe (III) supplements for Fe-deficient individuals, and promote the high-value utilization of garlic pomace.

A novel inducible von Willebrand Factor Cre recombinase mouse strain to study microvascular endothelial cell-specific biological processes in vivo

Mouse models are invaluable to understanding fundamental mechanisms in vascular biology during development, in health and different disease states. Several constitutive or inducible models that selectively knockout or knock in genes in vascular endothelial cells exist; however, functional and phenotypic differences exist between microvascular and macrovascular endothelial cells in different organs. In order to study microvascular endothelial cell-specific biological processes, we developed a Tamoxifen-inducible von Willebrand Factor (vWF) Cre recombinase mouse in the SJL background. The transgene consists of the human vWF promoter with the microvascular endothelial cell-selective 734 base pair sequence to drive Cre recombinase fused to a mutant estrogen ligand-binding domain [ERT2] that requires Tamoxifen for activity (CreERT2) followed by a polyadenylation (polyA) signal. We initially observed Tamoxifen-inducible restricted bone marrow megakaryocyte and sciatic nerve microvascular endothelial cell Cre recombinase expression in offspring of a mixed strain hemizygous C57BL/6-SJL founder mouse bred with mT/mG mice, with >90% bone marrow megakaryocyte expression efficiency. Founder mouse offspring were backcrossed to the SJL background by speed congenics, and intercrossed for >10 generations to develop hemizygous Tamoxifen-inducible vWF Cre recombinase (vWF-iCre/+) SJL mice with stable transgene insertion in chromosome 1. Microvascular endothelial cell-specific Cre recombinase expression occurred in the sciatic nerves, brains, spleens, kidneys and gastrocnemius muscles of adult vWF-iCre/+ SJL mice bred with Ai14 mice, with retained low level bone marrow and splenic megakaryocyte expression. This novel mouse strain would support hypothesis-driven mechanistic studies to decipher the role(s) of specific genes transcribed by microvascular endothelial cells during development, as well as in physiologic and pathophysiologic states in an organ- and time-dependent manner.

Immature carob pods extract and its fractions prevent lipid metabolism disorders and lipoprotein-rich plasma oxidation in mice: A phytochemical and pharmacological study

ETHNOPHARMACOLOGICAL RELEVANCE

In Morocco carob fruits are used traditionally to treat hypercholesterolemia, diabetes and related diseases.

AIMS

This study was designed to evaluate the hypolipidemic activity of Ceratonia siliqua green pods extract and its fractions in Triton WR-1339 and high fat/cholesterol diet (HFCD) induced hyperlipidemia mice, as well as their ability to prevent lipoproteins oxidation in vitro.

MATERIALS AND METHODS

High performance liquid chromatography (HPLC) analysis was used to determine the phenolic composition of the immature carob pods extract (HWCE). Antioxidant activities were evaluated using the DPPH radical scavenging test as well as MDA measurement in oxidized lipoprotein rich plasma. Plasma lipids, glucose and biliary total cholesterol, as well as lipids level in liver and feces, were analyzed. The acute oral toxicity was performed in mice single dosed with the HWCE at 2000 and 5000 mg/kg body weight.

RESULTS

HPLC analysis shows that gallic acid is the main phenolic compound in the HWCE. The acute oral toxicity assessment revealed that the HWCE is not toxic (LD50 is greater than 5000 mg/kg body weight). In the acute hypolipidemic study, mice treated with the HWCE and its fractions exhibited a significant (P < 0.001) reduction in plasma total cholesterol (TC), triglycerides (TG) and low density lipoprotein-cholesterol (LDL-C) levels. Importantly, immature carob aqueous extract was more effective in lowering mice hypercholesterolemia than its fractions. Indeed, mice fed the HFCD for 12 weeks showed a significant raise in plasma TC, TG and LDL-C, as well as in hepatic and fecal TC and TG levels. The HWCE at 100 and 200 mg/kg body weight significantly (P < 0.001) reversed the plasmatic levels of these lipid parameters, increased plasma HDL-C level, reduced hepatic lipids accumulation, but increased cholesterol level in the bile and fecal lipids excretion. The HWCE decreased also the atherogenic index, the LDL-C/HDL-C ratio and plasma glucose level after 12 weeks' experiment. On the other hand, the HWCE was more effective in preventing mice lipoprotein-rich plasma oxidation than its fractions, with a concentration-dependent manner.

CONCLUSION

C. siliqua green fruits extract could be effective in preventing atherosclerosis and related cardiovascular complications through the inhibition of lipoprotein oxidation and cholesterol clearance.

Potential therapeutic role of spermine via Rac1 in osteoporosis: Insights from zebrafish and mice

Osteoporosis is a prevalent metabolic bone disease. While drug therapy is essential to prevent bone loss in osteoporotic patients, current treatments are limited by side effects and high costs, necessitating the development of more effective and safer targeted therapies. Utilizing a zebrafish ( Danio rerio) larval model of osteoporosis, we explored the influence of the metabolite spermine on bone homeostasis. Results showed that spermine exhibited dual activity in osteoporotic zebrafish larvae by increasing bone formation and decreasing bone resorption. Spermine not only demonstrated excellent biosafety but also mitigated prednisolone-induced embryonic neurotoxicity and cardiotoxicity. Notably, spermine showcased protective attributes in the nervous systems of both zebrafish embryos and larvae. At the molecular level, Rac1 was identified as playing a pivotal role in mediating the anti-osteoporotic effects of spermine, with P53 potentially acting downstream of Rac1. These findings were confirmed using mouse ( Mus musculus) models, in which spermine not only ameliorated osteoporosis but also promoted bone formation and mineralization under healthy conditions, suggesting strong potential as a bone-strengthening agent. This study underscores the beneficial role of spermine in osteoporotic bone homeostasis and skeletal system development, highlighting pivotal molecular mediators. Given their efficacy and safety, human endogenous metabolites like spermine are promising candidates for new anti-osteoporotic drug development and daily bone-fortifying agents.

Anti-sepsis effect of Xiaochaihu decoction based on the TLR4/MyD88/NF-κB signalling pathway

The aims of this study were to explore the protective effect of Xiaochaihu decoction in mice with sepsis induced by intraperitoneal injection; to explore its anti-inflammatory effect on the TLR4-MyD88-NF-κB signalling pathway; and to explore the main material basis of the anti-inflammatory effect of Xiaochaihu decoction, with the aim of supplementing and expanding the associated research and providing a scientific foundation for the clinical use of the decoction. The effects of Xiaochaihu decoction on septic mice were analysed by measurements of white blood cells (WBC) and Platelets (PLT); Nitric Oxide (NO) level in serum; IL-6, IL-1β and TNF-α levels in serum; RT-PCR; Haematoxylin-Eosin (HE) immunohistochemistry; western blotting (WB). The results showed the excellent in vivo anti-inflammatory effects of Xiaochaihu decoction in LPS-induced septic mice, through down regulation of the gene and protein expression of TLR4, MYD88, TRAF6, IKK, IKBα and p65 and the subsequent reduction in the release of inflammatory mediators IL-6, IL-1β, TNF-α and NO. Moreover, significant anti-septic effect was observed from high and medium doses of Xiaochaihu decoction, but not from the low dose.

Program freezing of diapausing embryos in the mouse

Embryonal diapause is a characteristic feature of about 130 mammalian species. However, very few studies have addressed cryopreservation of diapausing embryos. This work is aimed to apply program freezing to blastocysts obtained from CD1 mice, which were at diapause state after ovariectomy and the subsequent hormonal therapy. Blastocysts collected from non-operated mice of the same strain served as controls. Some diapausing as well as non-diapausing frozen-thawed blastocysts demonstrated blastocoel re-expansion after 24 h of in vitro culture (IVC) indicating their viability after cryopreservation. Raman spectroscopy assessment of phenylalanine accumulation revealed that the fraction of new synthesized proteins was lower for non-frozen as well as for frozen-thawed diapausing blastocysts compared to non-diapausing ones. Although protein metabolism was reduced in diapausing embryos, most of the protein synthesis remained active. Cell number increased after 24 h of IVC in non-frozen as well as in the frozen-thawed blastocysts of the control but not of the diapause group. However, cell numbers were increased in frozen-thawed diapausing blastocysts after 47 h of IVC in a medium supplemented with putrescine. This indicates viability of frozen-thawed diapausing embryos after cryopreservation. Besides, protein metabolism was not affected by cryopreservation in diapausing and non-diapausing murine embryos indicating their viability. Our results demonstrated the possibility of successful cryopreservation of diapausing murine embryos.

Sex differences in the anticompulsive-like effect of memantine: Involvement of nitric oxide pathway but not AMPA receptors

Memantine, an N-Methyl-D-Aspartate (NMDA) antagonist, has been examined as a potential treatment for Obsessive-Compulsive Disorder (OCD). Yet, there is limited knowledge regarding how it works to reduce compulsive behaviour and whether it has different effects on individuals based on their sex. Herein, we investigated if there are sex differences in the anticompulsive-like effect of memantine in adult Swiss mice. Additionally, we explored whether the nitric oxide (NO) pathway and α-amino-3-hydroxy-5-methyl-4-isoazolepropionic acid (AMPA) receptors play a role in memantine's effects. To start, we assessed the impact of a single intraperitoneal dose of memantine (at 3, 5, and 10 mg/kg) on behaviours exhibited in the open field test (OFT) and the marble-burying test (MBT), the latter being a predictive test for anticompulsive effects. All doses of memantine reduced marble-burying behaviour in both male and female mice without affecting their locomotor activity in the OFT. This anticompulsive-like effect was also confirmed in another predictive test, the nest-building test, with the highest memantine dose (10 mg/kg) reducing nest-building behaviour without significant differences between male and female mice. We observed that pre-treatment with L-arginine, a NO precursor, mitigated the anticompulsive-like effect of memantine in male mice but had no effect in female mice in the MBT. Finally, NBQX, an AMPA receptor antagonist, did not block the anticompulsive-like effect of memantine. In summary, our study suggests that the anticompulsive-like effect of memantine does not appear to be sex-specific, does not depend on AMPA receptors, and involves the NO pathway primarily in male mice.

Ameliorative effect of Ononis natrix against chronic lead poisoning in mice: neurobehavioral, biochemical, and histological study

Lead (Pb) is one of the most common heavy metals with toxicological effects on many tissues in humans as well as animals. In order to counteract the toxic effects of this metal, the administration of synthetic or natural antioxidants is thus required. The aim of this study was to examine the beneficial effect of the aqueous extract of Ononis natrix (AEON) against lead acetate-induced damage from a behavioral, biochemical, and histological point of view. Forty-eight male mice were divided into four equal groups: Ctr (control); Pb (lead acetate 1g/l); Pb + On 100 mg/kg (lead acetate 1 g/l + AEON 100 mg/kg); Pb + On 500 mg/kg (lead acetate 1 g/l + AEON 500 mg/kg). AEON was administered orally from day 21 after the start of lead exposure up to the end of the experiment. The results revealed that lead induced behavioral disorders, increased serum levels of liver markers (AST, ALT, and bilirubin), as well as kidney markers (urea and creatinine). At the same time, levels of thiobarbituric acid reactive substances (TBARS) and glutathione peroxidase (GPx) increased significantly. Moreover, Pb caused structural changes in the liver and kidneys of Pb-exposed mice. However, AEON administration significantly improved all lead-induced brain, liver, and kidney dysfunctions. Our results suggest that AEON could be a source of molecules with therapeutic potential against brain, liver, and kidney abnormalities caused by lead exposure.

Impact of enriched environment on motor performance and learning in mice

Neuroscience heavily relies on animal welfare in laboratory rodents as it can significantly affect brain development, cognitive function and memory formation. Unfortunately, laboratory animals are often raised in artificial environments devoid of physical and social stimuli, potentially leading to biased outcomes in behavioural assays. To assess this effect, we examined the impact of social and physical cage enrichment on various forms of motor coordination. Our findings indicate that while enriched-housed animals did not exhibit faster learning in eyeblink conditioning, the peak timing of their conditioned responses was slightly, but significantly, improved. Additionally, enriched-housed animals outperformed animals that were housed in standard conditions in the accelerating rotarod and ErasmusLadder test. In contrast, we found no significant effect of enrichment on the balance beam and grip strength test. Overall, our data suggest that an enriched environment can improve motor performance and motor learning under challenging and/or novel circumstances, possibly reflecting an altered state of anxiety.

Correlation of IVIM/DKI Parameters with Hypoxia Biomarkers in Fibrosarcoma Murine Models: Direct Control of MRI and Pathological Sections

RATIONALE AND OBJECTIVES

To investigate whether intravoxel incoherent motion (IVIM) and diffusion kurtosis imaging (DKI) parameters correlate with hypoxia biomarkers, namely hypoxia inducible factor-1ɑ (HIF-1ɑ), carbonic anhydrase IX (CAIX), and pimonidazole (PIMO), in fibrosarcoma (FS) murine models.

MATERIALS AND METHODS

A model of 30 FS nude mice was established. All mice underwent magnetic resonance imaging (MRI) scans after which the IVIM (standard apparent diffusion coefficient [standard ADC], pure diffusion coefficient [D], pseudo-diffusion coefficient [D*], and perfusion fraction [f]) and DKI parameters (mean diffusion [MD], mean kurtosis [MK]) were obtained. Based on an MRI-pathology controlled method, correlations between each MRI parameter and hypoxia biomarkers were assessed by Pearson or Spearman tests. An independent sample t-test or Wilcoxon's rank sum test, and receiver operating characteristic curves were used to identify whether MRI parameters could differentiate between high and low expressions of hypoxia biomarkers.

RESULTS

The IVIM/DKI parameters showed varying degrees of correlation with HIF-1α, CAIX, and PIMO expression. Among them, the D, f, and MK values could confirm HIF-1α expression, while D, f, and MK values could assess CAIX expression. Finally, standard D and MK values could evaluate PIMO expression levels.

CONCLUSION

IVIM and DKI parameters can be used to reflect hypoxic biomarkers of FS and have the potential to detect tumor hypoxia.

Prime editing in mice with an engineered pegRNA

CRISPR editing involves double-strand breaks in DNA with attending insertions/deletions (indels) that may result in embryonic lethality in mice. The prime editing (PE) platform uses a prime editing guide RNA (pegRNA) and a Cas9 nickase fused to a modified reverse transcriptase to precisely introduce nucleotide substitutions or small indels without the unintended editing associated with DNA double-strand breaks. Recently, engineered pegRNAs (epegRNAs), with a 3'-extension that shields the primer-binding site of the pegRNA from nucleolytic attack, demonstrated superior activity over conventional pegRNAs in cultured cells. Here, we show the inability of three-component CRISPR or conventional PE to incorporate a nonsynonymous substitution in the Capn2 gene, expected to disrupt a phosphorylation site (S50A) in CAPN2. In contrast, an epegRNA with the same protospacer correctly installed the desired edit in two founder mice, as evidenced by robust genotyping assays for the detection of subtle nucleotide substitutions. Long-read sequencing demonstrated sequence fidelity around the edited site as well as top-ranked distal off-target sites. Western blotting and histological analysis of lipopolysaccharide-treated lung tissue revealed a decrease in phosphorylation of CAPN2 and notable alleviation of inflammation, respectively. These results demonstrate the first successful use of an epegRNA for germline transmission in an animal model and provide a solution to targeting essential developmental genes that otherwise may be challenging to edit.

Prevention of high-fat-diet-induced obesity in mice by soluble dietary fiber from fermented and unfermented millet bran

Obesity-related diabetes, cardiovascular disease, and hypertension pose many risks to human health. Thus, mice on a high-fat diet were gavaged with millet bran (unfermented/fermented) soluble dietary fiber (RSDF/FSDF, 500 mg·kg-1) for 10 weeks in current research, and then evaluated the various biological indicators. These findings revealed that RSDF and FSDF supplements could prevent fat synthesis by inhibiting sterol regulatory element-binding protein-1c gene expression. The RSDF supplements can also accelerate fat catabolism through enhanced the mRNA expression levels of adipose triglyceride lipase and peroxisome proliferator-activated receptor α. FSDF supplements can prevent obesity by decreasing 3-hydroxy-3-methyl-glutaryl-CoA reductase expression and increasing cholesterol 7α-hydroxylase expression. Moreover, FSDF also controls obesity development by lowering total cholesterol and low-density lipoprotein cholesterol levels in the blood, triglyceride, total cholesterol, and bile acid levels in the liver. Notably, FSDF supplements can promote Bacteroides and Prevotella propagation; excretive propionic acid binds to free fatty acid receptor 2/3 and then stimulates intestinal epithelial cells to generate glucagon-like-peptide-1 and peptide YY, which can reduce food and energy intake and ultimately prevent obesity. All evidence suggests that FSDF supplements play a crucial role in preventing obesity.

Effects of acute- and long-term aerobic exercises at different intensities on bone in mice

INTRODUCTION

Exercise intensity determines the benefits of aerobic exercise. Our objectives were, in aerobic exercise at different intensities, to determine (1) changes in bone metabolism-related genes after acute exercise and (2) changes in bone mass, strength, remodeling, and bone formation-related proteins after long-term exercise.

MATERIALS AND METHODS

Total 36 male C57BL/6J mice were divided into a control group and exercise groups at 3 different intensities: low, moderate, or high group. Each exercise group was assigned to acute- or long-term exercise groups. Tibias after acute exercise were evaluated by real-time PCR analysis. Furthermore, hindlimbs of long-term exercise were assessed by micro-CT, biomechanical, histological, and immunohistochemical analyses.

RESULTS

Acute moderate-intensity exercise decreased RANKL level as bone resorption marker, whereas low- and high-intensity exercise did not alter it. Additionally, only long-term exercise at moderate intensity increased bone mass and strength. Moderate-intensity exercise promoted osteoblast activity and suppressed osteoclast activity. After low- and high-intensity exercise, osteoblast and osteoclast activity were unchanged. An increase in the number of β-catenin-positive cells and a decrease in sclerostin-positive cells were observed in the only moderate group.

CONCLUSION

These results showed that moderate-intensity exercise can inhibit bone resorption earlier, and long-term exercise can increase bone mass and strength through promoted bone formation via the Wnt/β-catenin activation. High-intensity exercise, traditionally considered better for bone, may fail to stimulate bone remodeling, leading to no change in bone mass and strength. Our findings suggest that moderate-intensity exercise, neither too low nor high, can maintain bone health.

Carcinogenic effect of low doses of polycyclic and heterocyclic aromatic hydrocarbons and amines and lack of protection by inulin supplementation

Evidence suggests that meat processing and heat treatment may increase cancer risk through exposure to potentially carcinogenic compounds, polycyclic aromatic hydrocarbons (PAHs), and heterocyclic aromatic amines (HAAs). This study aims to investigate the effect of low concentrations of PAHs and HAAs (from 1 to 100 μmol/L/24h and 48h) in colorectal tumor cells (HT-29, HCT116, and LS174T) and to evaluate the effect of PAHs in the presence of inulin in mice. In vitro, the 4-PAHs have no effect on healthy colon cells but decreased the viability of the colorectal tumor cells and activated the mRNA and protein expressions of CYP1A1 and CYP1B1. In vivo, in mice with colitis induced by 3% DSS, the 4-PAHs (equimolar mix at 50,100, 150 mg/kg.bw, orally 3 times a week for 3 weeks) induced a loss of body weight and tumor formation. Inulin (10 g/L) had no effect on colon length and tumor formation. A significant decrease in the loss of b.w was observed in inulin group as compared to the fiber free group. These results underscore the importance of considering the biological association between low-dose exposure to 4-HAPs and diet-related colon tumors.

A comprehensive assessment of palmatine as anticonvulsant agent - In vivo and in silico studies

Previously, we demonstrated that palmatine (PALM) - an isoquinoline alkaloid from Berberis sibrica radix, exerted antiseizure activity in the pentylenetetrazole (PTZ)-induced seizure assay in larval zebrafish. The aim of the present study was to more precisely characterize PALM as a potential anticonvulsant drug candidate. A range of zebrafish and mouse seizure/epilepsy models were applied in the investigation. Immunostaining analysis was conducted to assess the changes in mouse brains, while in silico molecular modelling was performed to determine potential targets for PALM. Accordingly, PALM had anticonvulsant effect in ethyl 2-ketopent-4-enoate (EKP)-induced seizure assay in zebrafish larvae as well as in the 6 Hz-induced psychomotor seizure threshold and timed infusion PTZ tests in mice. The protective effect in the EKP-induced seizure assay was confirmed in the local field potential recordings. PALM did not affect seizures in the gabra1a knockout line of zebrafish larvae. In the scn1Lab-/- zebrafish line, pretreatment with PALM potentiated seizure-like behaviour of larvae. Repetitive treatment with PALM, however, did not reduce development of PTZ-induced seizure activity nor prevent the loss of parvalbumin-interneurons in the hippocampus of the PTZ kindled mice. In silico molecular modelling revealed that the noted anticonvulsant effect of PALM in EKP-induced seizure assay might result from its interactions with glutamic acid decarboxylase and/or via AMPA receptor non-competitive antagonism. Our study has demonstrated the anticonvulsant activity of PALM in some experimental models of seizures, including a model of pharmacoresistant seizures induced by EKP. These results indicate that PALM might be a suitable new drug candidate but the precise mechanism of its anticonvulsant activity has to be determined.

Effects of Nostoc commune extract on the cerebral oxidative and neuroinflammatory status in a mice model of schizophrenia

Cyanobacterium Nostoc commune has long been used to alleviate various diseases. This research examines the effects of Nostoc commune extract (NCE) against behavioral disorders, cerebral oxidative stress, and inflammatory damage in the ketamine-induced schizophrenia model. Oral NCE administration (70 and 150 mg/kg/d) is performed after intraperitoneal ketamine injection (20 mg/kg) for 14 consecutive days. The forced swimming and open field tests are used to assess schizophrenia-like behaviors. After the behavioral test, dopamine (DA) level, oxidative stress markers, as well as the interleukin-6 (IL-6) and tumor necrosis factor-α (TNF-α) expression are measured in the cerebral cortex. The results show that NCE treatment ameliorates KET-induced anxiety and depressive-like behaviors in OFT and FST, respectively. NCE considerably decreases the malondialdehyde (MDA) and DA levels and IL-6 and TNF-α expressions in mice with schizophrenia-like symptoms. Also, a significant increase is observed in the glutathione (GSH) level and catalase (CAT), superoxide dismutase (SOD), and glutathione reductase (GRx) activity in cerebral tissue. The present study shows that NCE treatment effectively improves KET-induced schizophrenia-like behaviors and oxidative and inflammatory damage. Therefore, NCE, via its bioactive constituents, could have strong neuroprotective effects in the schizophrenia-like model.

Results from omic approaches in rat or mouse models exposed to inhaled crystalline silica: a systematic review

BACKGROUND

Crystalline silica (cSiO2) is a mineral found in rocks; workers from the construction or denim industries are particularly exposed to cSiO2 through inhalation. cSiO2 inhalation increases the risk of silicosis and systemic autoimmune diseases. Inhaled cSiO2 microparticles can reach the alveoli where they induce inflammation, cell death, auto-immunity and fibrosis but the specific molecular pathways involved in these cSiO2 effects remain unclear. This systematic review aims to provide a comprehensive state of the art on omic approaches and exposure models used to study the effects of inhaled cSiO2 in mice and rats and to highlight key results from omic data in rodents also validated in human.

METHODS

The protocol of systematic review follows PRISMA (Preferred Reporting Items for Systematic Reviews and Meta-Analyses) guidelines. Eligible articles were identified in PubMed, Embase and Web of Science. The search strategy included original articles published after 1990 and written in English which included mouse or rat models exposed to cSiO2 and utilized omic approaches to identify pathways modulated by cSiO2. Data were extracted and quality assessment was based on the SYRCLE's Risk of Bias tool for animal studies.

RESULTS

Rats and male rodents were the more used models while female rodents and autoimmune prone models were less studied. Exposure of animals were both acute and chronic and the timing of outcome measurement through omics approaches were homogeneously distributed. Transcriptomic techniques were more commonly performed while proteomic, metabolomic and single-cell omic methods were less utilized. Immunity and inflammation were the main domains modified by cSiO2 exposure in lungs of mice and rats. Less than 20% of the results obtained in rodents were finally verified in humans.

CONCLUSION

Omic technics offer new insights on the effects of cSiO2 exposure in mice and rats although the majority of data still need to be validated in humans. Autoimmune prone model should be better characterised and systemic effects of cSiO2 need to be further studied to better understand cSiO2-induced autoimmunity. Single-cell omics should be performed to inform on pathological processes induced by cSiO2 exposure.

The disruption of circadian rhythmicity of gene expression in the hippocampus and associated structures in Gria2R/R mice; a comparison with C57BL/6J and Adar2-/- mice strains

Adar2-/- mice are a widely used model for studying the physiological consequences of reduced RNA editing. These mice are viable only when the Q/R editing site of the Gria2 subunit of the AMPA receptor is constitutively mutated to the codon for arginine, and Gria2R/R mice often serve as the sole control for Adar2-/- mice. Our study aimed to investigate whether ADAR2 inactivity and the Gria2R/R phenotype affect the rhythmicity of the circadian clock gene pattern and the expression of Gria1 and Gria2 subunits in the suprachiasmatic nucleus (SCN), hippocampus, parietal cortex and liver. Our data show that Gria2R/R mice completely lost circadian rhythmicity in the hippocampus compared to Adar2-/- mice. Compared to C57BL/6J mice, the expression profiles in the hippocampus and parietal cortex of Gria2R/R mice differ to the same extent as in Adar2-/-. No alterations were detected in the circadian profiles in the livers. These data suggest that the natural gradual postnatal increase in the editing of the Q/R site of the Gria2 subunit may be important for the development of circadian clockwork in some brain structures, and the use of Gria2R/R mice as the only control to Adar2-/- mice in the experiments dependent on the hippocampus and parietal cortex should therefore be considered.

Pharmacological diacylglycerol lipase inhibition impairs contextual fear extinction in mice

Acquisition and extinction of associative fear memories are critical for guiding adaptive behavioral responses to environmental threats, and dysregulation of these processes is thought to represent important neurobehavioral substrates of trauma and stress-related disorders including posttraumatic stress disorder (PTSD). Endogenous cannabinoid (eCB) signaling has been heavily implicated in the extinction of aversive fear memories and we have recently shown that pharmacological inhibition of 2-arachidonoylglycerol (2-AG) synthesis, a major eCB regulating synaptic suppression, impairs fear extinction in an auditory cue conditioning paradigm. Despite these data, the role of 2-AG signaling in contextual fear conditioning is not well understood. Here, we show that systemic pharmacological blockade of diacylglycerol lipase, the rate-limiting enzyme catalyzing in the synthesis of 2-AG, enhances contextual fear learning and impairs within-session extinction. In sham-conditioned mice, 2-AG synthesis inhibition causes a small increase in unconditioned freezing behavior. No effects of 2-AG synthesis inhibition were noted in the Elevated Plus Maze in mice tested after fear extinction. These data provide support for 2-AG signaling in the suppression of contextual fear learning and the expression of within-session extinction of contextual fear memories.

Prolonged stress response induced by chronic stress and corticosterone exposure causes adult neurogenesis inhibition and astrocyte loss in mouse hippocampus

Chronic stress is a pervasive and complex issue that contributes significantly to various mental and physical health disorders. Using the previously established chronic unpredictable stress (CUS) model, which simulates human stress situations, it has been shown that chronic stress induces major depressive disorder (MDD) and memory deficiency. However, this established model is associated with several drawbacks, such as limited research reproducibility and the inability to sustain stress response. To resolve these issues, we developed a new CUS model (CUS+C) that included exogenous corticosterone exposure to induce continuous stress response. Thereafter, we evaluated the effect of this new model on brain health. Thus, we observed that the use of the CUS+C model decreased body and brain weight gain and induced an uncontrolled coat state as well as depressive-like behavior in adult mice. It also impaired learning memory function and cognitive abilities, reduced adult hippocampal neurogenesis as well as the number of hippocampal astrocytes, and downregulated glial fibrillary acidic protein expression in the brains of adult mice. These findings can promote the utilization and validity of the animal stress model and provide new information for the treatment of chronic stress-induced depressive and memory disorders.

Rapamycin attenuates reconsolidation of a backwards-conditioned aversive stimuli in female mice

RATIONALE

The mammalian target of rapamycin (mTOR) kinase is known to mediate consolidation and reconsolidation of aversive memories. Most studies in this area use a forward conditioning paradigm in which the conditioned stimulus (CS) precedes the unconditioned stimulus (US). Little is known, however, about the neurobiological underpinnings of backwards (BW) conditioning paradigms, particularly in female mice. In BW conditioning, the CS does not become directly associated with the US; it instead evokes conditioned fear by reactivating a memory of the conditioning context and indirectly retrieving a memory of the aversive US.

OBJECTIVES

We sought to examine BW conditioned fear memory processes in female mice. First, we examined whether freezing to a BW CS is mediated by fear to the conditioning context. Second, we tested whether blocking consolidation of a BW CS attenuated memory of the CS and conditioning context. Finally, we tested whether blocking reconsolidation of a BW CS attenuated memory of the conditioning context.

RESULTS

We show that conditioned freezing to a BW CS is mediated by fear to the conditioning context. Furthermore, rapamycin-an mTOR inhibitor, when given immediately following BW conditioning, impairs consolidation of both cued and contextual fear memory. Similarly, rapamycin given following retrieval of a BW CS blocks context recall. Rapamycin is acting on reconsolidation as CS retrieval is necessary to see the effects of rapamycin on context memory recall.

CONCLUSIONS

Our study provides novel evidence that indirect retrieval cues are sensitive to rapamycin in female mice. The capacity to indirectly reactivate memories and render them susceptible to disruption is critical in the translation of reconsolidation-based approaches to the clinic.

Oxidized/unmodified-polyethylene microplastics neurotoxicity in mice: Perspective from microbiota-gut-brain axis

Microplastics (MPs) are inevitably oxidized in the environment, and their potential toxicity to organisms has attracted wide attention. However, the neurotoxicity and mechanism of oxidized polyethylene (Ox-PE) MPs to organisms remain unclear. Herein, we prepared oxidized low-density polyethylene (Ox-LDPE) and established a model of MPs exposure by continuously orally gavage of C57BL/6 J mice with LDPE-MPs/Ox-LDPE-MPs for 28 days with or without oral administration of Lactobacillus plantarum DP189 and galactooligosaccharides (DP189&GOS). The experimental results indicated that LDPE-MPs or Ox-LDPE-MPs caused several adverse effects in mice, mainly manifested by behavioral changes, disruption of the intestinal and blood-brain barrier (BBB), and simultaneous oxidative stress, inflammatory reactions, and pathological damage in the brain and intestines. Brain transcriptomic analysis revealed that the cholinergic synaptic signaling pathways, which affect cognitive function, were significantly disrupted after exposure to LDPE-MPs or Ox-LDPE-MPs. Real-time quantitative polymerase chain reaction and Western Blotting results further demonstrated that the critical genes (Slc5a7, Chat and Slc18a3) and proteins (Chat and Slc18a3) in the cholinergic synaptic signaling pathway were significantly down-regulated after exposure to LDPE-MPs or Ox-LDPE-MPs. These alterations lead to reduced acetylcholine concentration, which causes cognitive dysfunction in mice. Importantly, the DP189&GOS interventions effectively mitigated the MPs-induced cognitive dysfunction and intestinal microbiota alteration, improved intestinal and BBB integrity, attenuated the oxidative stress and inflammatory response, and also saw a rebound in the release of acetylcholine. These results indicated that LDPE-MPs and Ox-LDPE-MPs exert neurotoxic effects on mice by inducing oxidative stress, inflammatory responses, and dysregulation of cholinergic signaling pathways in the mouse brain. That probiotic supplementation is effective in attenuating MPs-induced neurotoxicity in mice. Overall, this study reveals the potential mechanisms of neurotoxicity of LDPE-MPs and Ox-LDPE-MPs on mice and their improvement measures, necessary to assess the potential risks of plastic contaminants to human health.

Interaction between citalopram and omega-3 fatty acids on anxiety and depression behaviors and maintaining the stability of brain pyramidal neurons in mice

This research was done to examine the combination of citalopram, an antidepressant drug, and omega-3 in a mice model of depression. Mice received citalopram (1 and 2 mg/kg) or omega-3 (10 and 20 mg/kg) daily over 30 days. Then, they were exposed to acute and chronic restraint stress to assess the possible increasing effect of omega-3 on the antidepressant and anxiolytic effects of citalopram. Elevated plus-maze (EPM) and forced swimming test (FST) were used to assess anxiety and depression symptoms in non-restraint stress (NRS), acute restraint stress (ARS), and chronic restraint stress (CRS) mice. The results indicated that induction of acute and chronic restraint stress reduced %OAT (Open arm time) and %OAE (Open arm entrance) in the EPM test but enhanced immobility time in the FST, showing anxiogenic- and depressive-like effects. These stresses reduced the stability of pyramidal neurons in the prefrontal cortex (PFC) and hippocampus. Aone and combination administration with citalopram and omega-3 induced anxiolytic- and antidepressant-like effects in NRS, ARS, and CRS mice. This combination usage increased the stability of pyramidal neurons in the PFC and hippocampus. These results suggested an interaction between citalopram and omega-3 upon the induction of anxiolytic- and antidepressant-like effects as well as augmentation of the ratio of pyramidal live to dark neurons in the PFC and hippocampus of the ARS and CRS mice.

Unlocking the role of dorsal hippocampal α4β2 nicotinic acetylcholine receptors in Ethanol-Induced conditioned place preference in mice

Alcohol Use Disorder (AUD) presents a significant and challenging public health concern, marked by a dearth of effective pharmacological treatments. Understanding the neurobiological underpinnings of AUD is of paramount importance for the development of efficacious interventions. The process of addiction entails the acquisition of associative behaviors, prominently engaging the dorsal region of the hippocampus for encoding these associative memories. Nicotinic receptor systems have been implicated in mediating the rewarding effects of ethanol, as well as memory and learning processes. In our current investigation, we delved into the role of α4β2 nicotinic acetylcholine receptors (nAChRs) within the dorsal hippocampus in the context of ethanol-induced conditioned place preference (CPP), a robust model for scrutinizing the rewarding properties and drug-associated behaviors. To establish CPP, ethanol (2 g/kg) was administered intraperitoneally during a 8-day conditioning phase. Fos immunohistochemistry was employed to assess the involvement of discrete subregions within the dorsal hippocampus in ethanol-induced CPP. Additionally, we probed the influence of α4β2 nAChRs on CPP via microinjections of a selective nAChR antagonist, dihydro-β-erythroidine (DHBE, at dosages of 6, 12, and 18 µg/0.5 µL per hemisphere) within the hippocampus. Our results unveiled that ethanol-induced CPP was associated with an increase Fos -positive cells in various subregions of the dorsal hippocampus, including CA1, CA2, CA3, and the dentate gyrus. Intrahippocampal administration of DHBE (at doses of 6 and 18 µg/0.50 µL per hemisphere) effectively blocked ethanol-induced CPP, while leaving locomotor activity unaffected. These findings underscore the critical involvement of the dorsal hippocampus and α4β2 nAChRs in the acquisition of ethanol-associated learning and reward.

Chemoprotective and immunomodulatory potential of Lactobacillus reuteri against cadmium chloride-induced breast cancer in mice

INTRODUCTION

The current study aimed to investigate the role of probiotic Lactobacillus reuteri for the treatment and prevention of breast cancer.

MATERIALS AND METHODS

Breast cancer was induced by using Cadmium Chloride (Cd) (2 mg/kg) in group II. Tamoxifen was administered to group III. Group IV was treated with Lactobacillus reuteri. Group V was treated with Cd for one month and divided into three subgroups including VA, VB, and VC which were treated with tamoxifen, Lactobacillus reuteri, and tamoxifen + Lactobacillus reuteri, respectively.

RESULTS

Significantly higher levels of TNF-α (40.9 ± 4.2 pg/mL), IL-6 (28.0 ± 1.5 pg/mL), IL-10 (60.2 ± 2.0 pg/mL), IFN-γ (60.2 ± 2.0 pg/mL), ALAT (167.2 ± 6.2 U/l), ASAT (451.6 ± 13.9 U/l), and MDA (553.8 ± 19.6 U/l) was observed in Cd group. In comparison, significantly lower levels of TNF-α (18.0 ± 1.1 pg/mL), IL-6 (9.4 ± 0.4 pg/mL), IL-10 (20.8 ± 1.1 pg/mL), IFN-γ (20.8 ± 1.1 pg/mL), ALAT (85.2 ± 3.6 U/l), ASAT (185 ± 6.9 U/l), and MDA (246.0 ± 7.5 U/l) were observed in group Cd + Tam + LR. Liver histopathology of the Cd group showed hemorrhage and ductal aberrations. However, mild inflammation and healthier branched ducts were observed in treatment groups. Furthermore, the renal control group showed normal glomerular tufts, chronic inflammation from the Cd group, and relatively healthier glomerulus with mild inflammation in treatment groups.

CONCLUSION

Hence, the preventive and anticancerous role of probiotic Lactobacillus reuteri is endorsed by the findings of the current study.

Differential pulmonary toxicity and autoantibody formation in genetically distinct mouse strains following combined exposure to silica and diesel exhaust particles

BACKGROUND

Inhalation of airborne particulate matter, such as silica and diesel exhaust particles, poses serious long-term respiratory and systemic health risks. Silica exposure can lead to silicosis and systemic autoimmune diseases, while DEP exposure is linked to asthma and cancer. Combined exposure to silica and DEP, common in mining, may have more severe effects. This study investigates the separate and combined effects of occupational-level silica and ambient-level DEP on lung injury, inflammation, and autoantibody formation in two genetically distinct mouse strains, thereby aiming at understanding the interplay between genetic susceptibility, particulate exposure, and disease outcomes. Silica and diesel exhaust particles were administered to mice via oropharyngeal aspiration. Assessments of lung injury and host response included in vivo lung micro-computed tomography, lung function tests, bronchoalveolar lavage fluid analysis including inflammatory cytokines and antinuclear antibodies, and histopathology with particle colocalization.

RESULTS

The findings highlight the distinct effects of silica and diesel exhaust particles (DEP) on lung injury, inflammation, and autoantibody formation in C57BL/6J and NOD/ShiLtJ mice. Silica exposure elicited a well-established inflammatory response marked by inflammatory infiltrates, release of cytokines, and chemokines, alongside mild fibrosis, indicated by collagen deposition in the lungs of both C57BL/6J and NOD/ShilLtJ mice. Notably, these strains exhibited divergent responses in terms of respiratory function and lung volumes, as assessed through micro-computed tomography. Additionally, silica exposure induced airway hyperreactivity and elevated antinuclear antibody levels in bronchoalveolar lavage fluid, particularly prominent in NOD/ShiLtJ mice. Moreover, antinuclear antibodies correlated with extent of lung inflammation in NOD/ShiLTJ mice. Lung tissue analysis revealed DEP loaded macrophages and co-localization of silica and DEP particles. However, aside from contributing to airway hyperreactivity specifically in NOD/ShiLtJ mice, the ambient-level DEP did not significantly amplify the effects induced by silica. There was no evidence of synergistic or additive interaction between these specific doses of silica and DEP in inducing lung damage or inflammation in either of the mouse strains.

CONCLUSION

Mouse strain variations exerted a substantial influence on the development of silica induced lung alterations. Furthermore, the additional impact of ambient-level DEP on these silica-induced effects was minimal.

Continuous high-frequency repetitive transcranial magnetic stimulation at extremely low intensity affects exploratory behavior and spatial cognition in mice

High-frequency repetitive transcranial magnetic stimulation (HF-rTMS) has been shown to be effective for cognitive intervention. However, whether HF-rTMS with extremely low intensity could influence cognitive functions is still under investigation. The present study systematically investigated the effects of continuous 40 Hz and 10 Hz rTMS on cognition in young adult mice at extremely low intensity (10 mT and 1 mT) for 11 days (30 min/day). Cognitive functions were assessed using diverse behavioral tasks, including the open field, Y-maze, and Barnes maze paradigms. We found that 40 Hz rTMS significantly impaired exploratory behavior and spatial memory in both 10 mT and 1 mT conditions. In addition, 40 Hz rTMS induced remarkably different effects on exploratory behavior between 10 mT and 1mT, compared to 10 Hz stimulation. Our results indicate that extremely low intensity rTMS can significantly alter cognitive performance depending on intensity and frequency, shedding light on the understanding of the mechanism of rTMS effects.

Sanguinarine: an alkaloid with promising in vitro and in vivo antiparasitic activity against different developmental stages of Schistosoma mansoni and in silico pharmacokinetic properties (ADMET)

The objective of the study was to evaluate the in vitro and in vivo schistosomicidal activity of sanguinarine (SA) on Schistosoma mansoni and its in silico pharmacokinetic parameters. ADMET parameters and oral bioavailability were evaluated using the PkCSM and SwissADME platforms, respectively. The activity of SA in vitro, at the concentrations of 1.0-25 µM, was analyzed through the parameters of motility, mortality, and cell viability of the worms at intervals of 3-24 h. Mice were infected with cercariae and treated by gavage with SA (5 mg/kg/day, in a single dose or two doses of 2.5 mg/kg every 12 h for 5 consecutive days) on the 1st (skin schistosomula), 14th (pulmonary schistosomula), 28th (young worms), and 45th (adult worms) days after infection. In vitro and in vivo praziquantel was the control. In vitro, SA showed schistosomicidal activity against schistosomula, young worms, and couples; with total mortality and reduced cell viability at low concentrations and incubation time. In a single dose of 5 mg/kg/day, SA reduces the total worm load by 47.6%, 54%, 55.2%, and 27.1%, and female worms at 52.0%, 39.1%, 52.7%, and 20.2%, respectively, results which are similar to the 2.5 mg/kg/day dose. SA reduced the load of eggs in the liver, and in histopathological and histomorphometric analyses, there was a reduction in the number and volume of hepatic granulomas, which exhibited less inflammatory infiltrate. SA has promising in vitro and in vivo schistosomicidal activity against different developmental stages of S. mansoni, in addition to reducing granulomatous liver lesions. Furthermore, in silico, SA showed good predictive pharmacokinetic ADMET profiles.

Correlation analysis between the in vivo bioavailability and in vitro bioaccessibility of nitro PAHs in soil: Application of simplified FOREhST in vitro methods based on the Chinese pharmacopoeia

In this study, the relative bioavailability (RBA) of nitrated polycyclic aromatic hydrocarbons (NPAHs) in soil samples (n = 30) was assessed using an in vivo mouse model. Based on the correlation between the bioaccessibility data obtained from the Tenax improved traditional Fed ORganic Estimation human Simulation Test (FOREhST) in vitro method (TITF) and the bioavailability data obtained from in vivo experiments, the TITF method was further optimized and simplified by referring to the "Pharmacopoeia of the People's Republic of China: Volume IV, 2020" to adjust the formulation and parameters of the gastrointestinal fluid (GIF) in order to establish a simpler and lower cost in vitro method for the determination of the bioaccessibilities of NPAHs. The dose-accumulation relationship of the in vivo experiment showed that the linear dose-response was better in adipose tissue (R2 = 0.77-0.93), and the accumulation of NPAHs in adipose tissue was higher than that in kidney or liver tissue. Depending on the mouse adipose model, the NPAHs-RBA ranged from 1.88 % to 73.92 %, and a strongly significant negative relationship (R2 = 0.94, p < 0.05) was found between the NPAHs-RBA and Log Kow. The simplified experiment of the TITF showed that the composition of the GIF medium had a significant effect on the bioaccessibilities of NPAHs. The NPAH bioaccessibilities measured by the Tenax improved simplified FOREhST method (TISF) (9.0-36.5 %) were higher than that of the traditional FOREhST method (6.8-22.8 %) but significantly lower than that of the TITF method (16.8-55.2 %). With an increase in the bile concentration in the GIF (from 6 to 10 g/L), the bioaccessibilities of NPAHs increased from 9.0 to 36.5 % to 12.9-42.4 %. The accuracies of the four in vitro methods for predicting the bioavailabilities of NPAHs was in the following order: Tenax improved simplified FOREhST method with increased bile concentration (TITF-IB) (R2 = 0.54-0.87) ≈ TITF (R2 = 0.55-0.85) > TISF (R2 = 0.41-0.77) > FOREhST (R2 = 0.02-0.68). These results indicated that the simple in vitro method could also effectively predict the bioavailabilities of NPAHs.

Serotonergic agonism and pharmacologically-induced adolescent stress cause operant-based learning deficits in mice

BACKGROUND

The interplay between environmental stress and genetic factors is thought to play an important role in the pathogenesis and maintenance of obsessive-compulsive disorder (OCD). However, the relative contribution of these causative antecedents in the manifestation of cognitive inflexibility-a phenotype often seen in obsessive-compulsive (OC)- spectrum disorders-is not fully understood.

METHOD

In this study, we treated mice with 50 mg/L corticosterone (CORT, a glucocorticoid stress hormone) in their drinking water during adolescence. In adulthood, we assessed anxiety-like behaviour and locomotor activity; along with operant-based discrimination and reversal learning. RU-24969, a selective serotonin receptor 5-HT1A/1B receptor agonist, was used as an acute pharmacological model of OC-like behaviour. RU-24969 (5 mg/kg) was administered prior to each reversal learning testing session.

RESULTS

We found that acute treatment with 5 mg/kg RU-24969 induced stereotyped hyperlocomotion in vehicle- and CORT-treated mice. Furthermore, pre-treatment with CORT in adolescence produced subtle anxiety-like behaviour in adult mice, and also resulted in an impairment to late-stage discrimination learning and alterations to reversal learning. Finally, acute treatment with 5 mg/kg RU-24969 caused an impairment to early-stage reversal learning.

CONCLUSION

Whilst we revealed dissociable detrimental effects of adolescent CORT treatment and acute 5-HT1A/1B receptor agonism on discrimination and reversal learning, respectively, we did not find evidence of additive deleterious effects of these two treatments. We therefore suggest that while disrupted serotonergic signalling is likely to be involved in the cognitive phenotype of OC-spectrum disorders, distinct neuropathological pathways may be at play in mediating the role of stress as an antecedent in OCD and related illnesses.

Effect of nanocurcumin on fertility in murine model of polycystic ovary syndrome

The precise pathophysiology of polycystic ovary syndrome (PCOS) is not well-founded. In an attempt to fill this gap, the current study was executed to probe the effect of nanocurcumin (NCC) on ovarian tissue, in vitro fertilization (IVF) and pre-implantation embryo development in a mouse model of PCOS. Fifty adult female mice were randomly categorized into five equal groups including non-treated control and PCOS (receiving 0.20 mg estradiol valerate (EV) intra-peritoneally once a day for 21 days) as well as NCC12.50 + PCOS, NCC25 + PCOS and NCC50 + PCOS (receiving respectively 12.50, 25.00 and 50.00 mg kg-1 NCC daily along with EV injection through oral gavages for 21 days) groups. Subsequently, ovarian histo-architecture and total anti-oxidant capacity, and malonaldehyde and catalase levels as well as in vitro fertilizing potential, early embryonic development and serum testosterone concentration were analyzed. Results showed that NCC in a dose-dependent manner improved ovarian cyto-architectural organization and oxidant/anti-oxidant balance along with IVF rate and pre-implantation embryo development in PCOS mice. These findings revealed that NCC at the doses of 25.00 and 50.00 mg kg-1 could alleviate PCOS-linked reproductive disruptions in female mice.

A novel model of urosepsis in mice developed by ureteral ligation and injection of Escherichia coli into the renal pelvis

Despite extensive investigations, urosepsis remains a life-threatening and high-mortality illness. The absence of widely acknowledged animal models for urosepsis prompted this investigation with the objective of formulating a replicable murine model. Eighty-four adult male C57BL/6J mice were arbitrarily distributed into three cohorts based on the concentration of the Escherichia coli (E. coli) solution administered into the renal pelvis: Sham, Low-grade sepsis (1.0 × 108 cfu/mL), and High-grade sepsis (1.0 × 109 cfu/mL). By fabricating a glass needle with a 100 μm outer diameter, bacterial leakage during renal pelvic injection was minimized. After the ureteral ligation, the mice were injected with this needle into the right renal pelvis (normal saline or E. coli solution, 1 ml/kg). Ten days post after E. coli injection, the mortality rates for the Low-grade sepsis and High-grade sepsis groups stood at 30 % and 100 %, respectively. Post-successful modeling, mice in the urosepsis cohort exhibited a noteworthy reduction in activity, body temperature, and white blood cell count within a 2-h timeframe. At the 24-h mark post-modeling, mice afflicted with urosepsis displayed compromised coagulation functionality. Concurrently, multiple organ dysfunction was confirmed as evidenced by markedly elevated levels of inflammatory factors (IL-6 and TNF-α) in four distinct organs (heart, lung, liver, and kidney). This study confirmed the feasibility of establishing a standardized mouse model of urosepsis by ureteral ligation and E. coli injection into the renal pelvis. A primary drawback of this model resides in the mice's diminished blood volume, rendering continuous blood extraction at multiple intervals challenging.